Discovery of Extremely Embedded X-ray Sources in the R Coronae Australis Star Forming Core

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Discovery of a Superconducting High-Entropy Alloy

Discovery of a Superconducting High-Entropy AlloyP.Koželj,1S.Vrtnik,1A.Jelen,1S.Jazbec,1Z.Jagličić,2S.Maiti,3M.Feuerbacher,4W.Steurer,3and J.Dolinšek1,* 1Faculty of Mathematics and Physics,J.Stefan Institute and University of Ljubljana,Jamova39,SI-1000Ljubljana,Slovenia 2Faculty of Civil and Geodetic Engineering,Institute of Mathematics,Physics and Mechanicsand University of Ljubljana,Jadranska19,SI-1000Ljubljana,Slovenia3Department of Materials,Laboratory of Crystallography,ETH Zürich,Vladimir-Prelog-Weg5,CH-8093Zürich,Switzerland 4Institut für Mikrostrukturforschung,Forschungszentrum Jülich,D-52425Jülich,Germany(Received13April2014;published2September2014)High-entropy alloys(HEAs)are multicomponent mixtures of elements in similar concentrations,wherethe high entropy of mixing can stabilize disordered solid-solution phases with simple structures like a body-centered cubic or a face-centered cubic,in competition with ordered crystalline intermetallic phases.Wehave synthesized an HEA with the composition Ta34Nb33Hf8Zr14Ti11(in at.%),which possesses anaverage body-centered cubic structure of lattice parameter a¼3.36Å.The measurements of the electricalresistivity,the magnetization and magnetic susceptibility,and the specific heat revealed that theTa34Nb33Hf8Zr14Ti11HEA is a type II superconductor with a transition temperature T c≈7.3K,anupper critical fieldμ0H c2≈8.2T,a lower critical fieldμ0H c1≈32mT,and an energy gap in the electronicdensity of states(DOS)at the Fermi level of2Δ≈2.2meV.The investigated HEA is close to a BCS-typephonon-mediated superconductor in the weak electron-phonon coupling limit,classifying it as a“dirty”superconductor.We show that the lattice degrees of freedom obey Vegard’s rule of mixtures,indicatingcompletely random mixing of the elements on the HEA lattice,whereas the electronic degrees of freedomdo not obey this rule even approximately so that the electronic properties of a HEA are not a“cocktail”ofproperties of the constituent elements.The formation of a superconducting gap contributes to the electronicstabilization of the HEA state at low temperatures,where the entropic stabilization is ineffective,but theelectronic energy gain due to the superconducting transition is too small for the global stabilization of thedisordered state,which remains metastable.DOI:10.1103/PhysRevLett.113.107001PACS numbers:74.70.Dd,61.43.-jWithin the past several years,a new approach to metallic alloy design with multiple principal elements in equimolar or near-equimolar ratios,termed high-entropy alloys (HEAs),has been proposed[1,2].According to this concept,the high entropy of mixing can stabilize disor-dered solid solution phases with simple structures like a body-centered cubic(bcc)or a face-centered cubic(fcc),in competition with ordered crystalline intermetallic phases that often contain structurally complex giant unit cells [3,4].The HEA structure is characterized by a topologically ordered lattice with an exceedingly high chemical(substitu-tional)disorder so that an HEA can be conveniently termed as a“metallic glass on an ordered lattice.”In order to achieve a high entropy of mixing,the alloys must be composed typically of five or more(up to13)major elements in similar concentrations,ranging from5to35 at.%for each element,but do not contain any element whose concentration exceeds50at.%.This is in contrast to traditional metallic alloy systems,which contain one principal chemical element as the matrix,even though a substantial amount of other elements is incorporated for property/processing enhancement.In a thermodynamic equilibrium,a system will minimize its Gibbs free energy G¼H−TS,where H is the enthalpy and S is the entropy.For a multicomponent system,mixing of the elements yields a contributionΔG mix¼ΔH mix−TΔS mix.Following Boltzmann’s hypothesis,the mixing configurational entropy of an r-element ideal gas(also valid for certain liquid or solid solutions,where intermolecular forces between every pair of molecular kinds are similar,so that the mixing is completely random)is given byΔS mix¼−nRPri¼1x i ln x i,where n is the total number of moles, x i¼n i=n is the mole fraction of component i,and R is the gas constant[5].For equimolar concentrations of elements, x i¼1=r,the entropy of mixing reaches its maximum value ΔS mix¼nR ln r.For example,for a five-component mix-ture(r¼5)with equimolar ratios of the elements,the mixing entropy per mole amountsΔS mix¼R ln5¼13.4J=mol K,which yields at a high temperature such as T¼2000K the entropy term TΔS mix¼26.8kJ=mol. The energy gain of a few10kJ=mol is sufficient for the entropic stabilization of a disordered solid solution phase, in competition with ordered crystalline intermetallic phases.At lower temperatures,the importance of the entropy term for the phase stabilization is reduced. However,unfavorable kinetics with sluggish atomic dif-fusion hinders phase transformations so that the simple high-temperature structure of a disordered solid solution isretained down to low temperatures as a quenched meta-stable state,whereas ultrafine crystallites of intermetallic phases may precipitate at the nanometric scale within the simple matrices.The low-temperature physical properties of such an out-of-equilibrium state are difficult to predict.It is not clear whether the physical properties of an HEA are just a compositional average of properties of constituent elemental phases (i.e.,a “cocktail ”effect)or whether they depend on a particular distribution of chemical elements on the HEA lattice.A related question is whether the mixing of elements on a HEA lattice is completely random or some preferential chemical environments form on the scale of nearest neighbor atoms that consequently govern the physical properties.The number of possible HEAs is virtually unlimited.Examples are HEAs derived within the systems Al-Si-Co-Cr-Cu-Fe-Mn-Ni-Ti [1,2],W-Nb-Mo-Ta-V [6],and Ta-Nb-Hf-Zr-Ti [7].Most existing studies are focused on the relationship between phase,microstructure,and mechani-cal properties [1,2,6–11].A highly disordered lattice scatters electron and lattice waves,which results in reduced electrical and thermal transport similar to bulk metallic glasses [8].HEAs that contain magnetic transition elementsalso show rather standard paramagnetism or ferromagnet-ism [12,13].In this paper,we report that a five-component HEA derived within the Ta-Nb-Hf-Zr-Ti system shows a spectacular property of type II superconductivity,not observed before in any of the investigated HEAs.In the investigation of the Ta-Nb-Hf-Zr-Ti system,structural and mechanical properties of a HEA with equimolar ratio of the elements,Ta 20Nb 20Hf 20Zr 20Ti 20,were presented before [7].Our HEA had quite different composition and was produced from high-purity raw materials,which were arc molten and cast into a cylindrical copper mold.The so produced rod was recast in a zone-melting setup at a feed rate of 5mm =h at about 2300°C under 400-mbar Ar atmosphere.The final ingot consisted of a single phase with grain sizes of 200–300μm.The x-ray diffraction (XRD)pattern obtained with Cu K α1radiation is shown in Fig.1,where all diffraction peaks have been identified to belong to a bcc phase.The XRD peaks are quite broad,revealing a distorted lattice with an average bcc structure.This distortion originates from different atomic radii of the constituent elements (Table 1),where the atomic radius mismatch between the largest (Zr)and the smallest (Ti)element amounts to 2ðr Zr −r Ti Þ=ðr Zr þr Ti Þ¼9%.This is below the glass-forming criterion,where it is considered that atomic radius mismatch Δr=r greater that 12%between elements of a multicomponent mixture leads to lattice distortions large enough that the energy for retaining the crystalline con-figuration is too high and the amorphous disorder is energetically preferred [14].The lattice parameter was determined to be a ¼3.36ð2ÞÅ.Energy-dispersive spec-trometer analysis yielded an average composition of Ta 34Nb 33Hf 8Zr 14Ti 11(in at.%),and there was some small compositional variation on the μm scale within Æ1at.%for each element.The theoretical lattice parameter of a HEA can be calculated by assuming validity of Vegard ’s rule of mixtures [15],a mix ¼Pi c i a i ,valid for completely random mixing of the elements.Here c i and a i are the atomic fraction and the lattice parameter of the element i .All five elements in our HEA possess a bcc structure just below their melting temperatures,which is preserved down to room temperature (RT)for Ta and Nb,whereas Hf,Zr,andFIG.1(color online).X-ray diffraction pattern of the Ta 34Nb 33Hf 8Zr 14Ti 11HEA.The peaks are indexed to a bcc crystal lattice.TABLE I.Atomic fractions c i ,the RT bcc lattice parameters a ,atomic radii r ¼a ﬃﬃﬃ3p =4[7],the Debye temperatures θD [16],the SC transition temperatures T c [17],and the linear specific heat coefficients γ[16]of the elements in the investigated Ta 34Nb 33Hf 8Zr 14Ti 11HEA.The theoretical parameter values (Theor.)for the HEA were calculated by the rule of mixtures and are compared to the experimental (Exp.)values.TaNb Hf Zr Ti Theor.Exp.c i 0.340.330.080.140.11a ðÅÞ 3.303 3.301 3.559 3.582 3.276 3.359 3.36r ðÅÞ 1.430 1.429 1.541 1.551 1.418θD (K)246276252290420282243T c (K)4.479.250.1280.610.40 4.717.27γðmJ =mol K 2Þ5.877.82.152.773.365.58.3Ti undergo a transformation to a hexagonal close packed (hcp)structure.The bcc lattice parameters of the elements at RT [7],obtained by extrapolating the high-temperature bcc parameters using the reported thermal expansion coefficients,are given in Table 1,yielding the theoretical value a mix ¼3.359Å.This is in excellent agreement with the experimental value of 3.36Å,indicating random mixing of the elements.The zero-field electrical resistivity ρis shown in Fig.2.ρðT Þexhibits a weak positive temperature coefficient with a RT value of ρ300K ¼46Æ1μΩcm.Below 8K,a sharp drop to a zero-resistivity superconducting (SC)state is observed,whereas the extrapolated normal-state residual resistivity amounts to ρT →0¼36Æ1μΩcm.The magnetic-field dependence of the resistivity in the region of the SC transition in fields up to 9T is shown in the inset of Fig.2.The SC transition temperature is systematically shifted to lower temperatures in increasing fields.The low-temperature magnetic susceptibility χðT Þin a field of 5mT,measured under zero-field-cooling (zfc)conditions,is shown in Fig.3.Below about 8K,a strong diamagnetic response is observed due to Meissner effect and the susceptibility corrected for the demagnetization factor assumes almost the ideal diamagnetic value χ¼−1intrinsic to a superconductor.The isothermal magnetization M ðH Þcurves between 2and 8K in the low-field range up to H ¼50kA =m are shown in the inset of Fig.3.Close to the origin,the M ðH Þrelation is linear with the slope −1,whereas at higher fields,the M ðH Þcurves show minimum and then approach the weakly paramagnetic value of the normal state.This behavior is typical of type II super-conductors.The field value in the minimum was taken as a measure of the lower critical field H c 1.At 2K,the lower critical field amounts to μ0H c 1≈32mT.The specific heat C was measured between RT and 350mK in magnetic fields between 0and 9T.Thelow-temperature C ðT Þbelow 9K for selected fields is shown in Fig.4(a).In zero field,a sharp discontinuous jump of ΔC ðT c Þ¼98Æ2mJ =mol K is observed at the SC transition temperature T c ¼7.27Æ0.07K.Since the lat-tice specific heat does not change at T c ,this difference equals to the change of the electronic specific heat between the SC and the normal states,ΔC ¼C es −C en .The specific heat can be used to determine the volume fraction of the SC phase.In cases when a vortex state or a mixture of the normal and SC states coexist,the presence of normal regions is reflected in a linear term in the specific heat.Assuming that the normal-state low-temperature specific heat is written as C ¼γT þαT 3,where γand αare the electronic and lattice specific heat coefficients,we present specific heats in zero field and 9T in a C=T versus T 2plot in Fig.4(b).The analysis of the normal-state specific heat (in 9T field)below 4.5K with the expression C=T ¼γþαT 2(solid line)has yielded the intercept γ¼8.3Æ0.1mJ =mol K 2and the slope α¼0.14Æ0.01mJ =mol K 4.In contrast,the zero-field specific heat intercepts the vertical axis at C=T ≈0,demonstrating that there is no linear term in the specific heat and that the superconduc-tivity is a bulk effect,where the entire specimen becomes SC below T c .By considering the nature of the SC state of our HEA (e.g.,BCS type or unconventional),the quantity of interest is the ratio ΔC ðT c Þ=γT c ,which assumes a value 1.43within the BCS theory valid for phonon-mediated superconductivity in the weak electron-phonon coupling limit [18].We obtain ΔC ðT c Þ=γT c ¼1.63Æ0.06,which is in reasonable agreement with the BCS prediction,indicat-ing that the investigated HEA is close to a BCS type.The low-temperature zero-field specific heat can be used to check for the presence of an energy gap of width 2Δin the electronic DOS at the Fermi level εF .Within the BCS theory [18],the formation of Cooper pairs leads to a temperature-dependent energy gap 2ΔðT Þ,FIG.2(color online).Electrical resistivity in zero magnetic field between 300and 2K.Magnetic-field dependence of the resistivity in the region of the SC transition for fields up to 9T is shown in theinset.FIG.3(color online).The zfc magnetic susceptibility χ¼M=H in a 5mT field in the region of the SC transition.The inset shows isothermal magnetization M ðH Þin the low-field range at temperatures between 2and 8K.The arrow denotes the lower critical field H c 1at T ¼2K.which is related to the transition temperature T c through 2Δð0Þ=k B T c ¼3.52.The energy required to break up a Cooper pair is about 2Δð0Þ,and hence,the number of pairs broken up is proportional to exp ð−2Δð0Þ=k B T Þ,which leads to an exponential temperature dependence of the specific heat at sufficiently low temperatures.The form predicted by the BCS theory is C es =γT c ¼A exp ð−BT c =T Þ[16],where A and B are two constants whose values depend on the temperature interval used.For the interval 2.5<T c =T <6,they are A ¼8.5and B ¼1.44.The graph ln ðC es =γT c Þversus T c =T should thus be a straight line.The zero-field electronic specific heat C es ¼C −αT 3is shown in this type of graph in the inset of Fig.4(a)for the temperature range 2<T c =T <5.A straight line is indeed observed and the fit yielded the parameter values A ¼7.9Æ0.1and B ¼1.54Æ0.05,which are close to the BCS prediction.The electronic DOS thus contains an energy gap at εF of approximate width 2Δð0Þ≈2.2meV.In an applied magnetic field,the jump in C is system-atically shifted to lower temperatures in higher fields.Using the peak in C as a measure of T c ,we mapped the temperature dependence of the upper critical field H c 2[inset in Fig.4(b)].H c 2ð0Þwas determined from a fit with the empirical formula H c 2ðT Þ¼H c 2ð0Þð1−ðT=T c ÞβÞ,yielding μ0H c 2ð0Þ¼8.15Æ0.05T and β¼1.51.The μ0H c 2ð0Þvalue is far below the Pauli-paramagnetic limit for weak electron-phonon coupling,μ0H c 2¼1.86T c ≈13.5T [19],and supports phonon-mediated superconduc-tivity in our HEA.The lattice specific heat coefficient αyielded the Debye temperature θD ¼ð12π4R=5αÞ1=3¼243Æ5K.The investigated Ta 34Nb 33Hf 8Zr 14Ti 11HEA is thus a type II superconductor with a transition temperature T c ≈7.3K,an upper critical field μ0H c 2≈8.3T,a lower critical field μ0H c 1≈32mT,and an energy gap in the electronic DOS at εF of 2Δ≈2.2meV.Evaluation of different criteria using parameters of the SC state indicates that the investigated HEA is close to a BCS-type phonon-mediated superconductor in the weak electron-phonon coupling limit.The XRD spectrum reveals a distorted bcc lattice with a high degree of chemical (substitutional)disorder so that our HEA classifies as a “dirty ”super-conductor describable by the theory of Anderson [20].Since the lattice parameter a ideally obeys the rule of mixtures,suggesting completely random mixing of the five chemical elements on the bcc lattice,it is interesting to check whether other physical properties obey this rule as well,i.e.,whether a given physical property of the “mixture ”Y mix is a compositional average of the properties Y i of constituent elements,Y mix ¼P i c i Y i .To see that,we evaluate the departure of the experimental values Y exp from the theoretical values Y mix using the expression ðY exp −Y mix Þ=Y mix ¼ΔY=Y mix .The Debye temperature θD is a measure of the lattice dynamics.Taking the literature-reported θD data of the elements [16](Table 1),we obtain ΔθD =θmix D ¼−14%.Since θD is not a precisely defined quantity,this mismatch can be consid-ered small,and the rule of mixtures applies reasonably well to the phonon dynamics of the HEA.In view of the high lattice distortion and large degree of chemical disorder,where elements with largely different masses (181Ta,93Nb,180Hf,90Zr,and 48Ti)are randomly positioned on the bcc lattice,this apparently simple phononic picture of the HEA lattice dynamics is surprising.Considering the electronic degrees of freedom (Table 1),we obtain for the normal-state electronic specific heat coefficient Δγ=γmix ¼51%and the SC transition temperature (recall that all five elements are SC)ΔT c =T mix c¼54%.The mismatch in γand T c is so large that the rule of mixtures is not obeyed even approximately,and the electronic properties are not a “cocktail ”of properties of the constituent elements.Theoretical description of the electronic properties of a HEA is thus a highly complex problem,aggravated by a random local distortion of the lattice and random distri-bution of five or more electronically inequivalentchemicalFIG.4(color online).(a)Low-temperature specific heat C ðT Þfor selected magnetic fields.The inset shows a semilog graph of C es =γT c against T c =T and solid line is the fit C es =γT c ¼7.9exp ð−1.54T=T c Þ.(b)Specific heat in zero field and 9T in a C=T versus T 2plot.The inset shows the upper critical field μ0H c 2ðT Þ.elements on the otherwise simple average lattice.The formation of a SC gap in the electronic DOS at εF contributes to the electronic stabilization of the HEA state at low temperatures,where the entropic stabilization is ineffective,but the electronic energy gain due to the SC transition of the order ðk B T c Þ2=εF ≈10−5meV per electron (for εF of several eV)is too small for the global stabilization of the disordered state,which remainsmetastable.*Corresponding author.jani.dolinsek@ijs.si[1]J.W.Yeh,S.K.Chen,S.J.Lin,J.Y .Gan,T.S.Chin,T.T.Shun,C.H.Tsau,and S.Y .Chang,Adv.Eng.Mater.6,299(2004).[2]J.W.Yeh,Ann.Chim.Sci.Mat.31,633(2006).[3]K.Urban and M.Feuerbacher,J.Non-Cryst.Solids 334–335,143(2004).[4]M.Conrad, B.Harbrecht,T.Weber, D.Y .Jung,and W.Steurer,Acta Crystallogr.Sect.B 65,318(2009).[5]R.A.Alberty and R.J.Silbey,Physical Chemistry (John Wiley &Sons,New York,1992),p.92.[6]O.N.Senkov,G.B.Wilks,D.B.Miracle,C.P.Chuang,and P.K.Liaw,Intermetallics 18,1758(2010).[7]O.N.Senkov,J.M.Scott,S.V .Senkova,D.B.Miracle,and C.F.Woodward,J.Alloys Compd.509,6043(2011).[8]Y .J.Zhou,Y .Zhang,Y .L.Wang,and G.L.Chen,Appl.Phys.Lett.90,181904(2007).[9]L.H.Wen,H.C.Kou,J.S.Li,H.Chang,X.Y .Xue,andL.Zhou,Intermetallics 17,266(2009).[10]M.H.Chuang,M.H.Tsai,W.R.Wang,S.J.Lin,andJ.W.Yeh,Acta Mater.59,6308(2011).[11]C.Y .Hsu,C.C.Juan,W.R.Wang,T.S.Sheu,J.W.Yeh,and S.K.Chen,Mater.Sci.Eng.A 528,3581(2011).[12]M.H.Tsai,Entropy 15,5338(2013),and references therein.[13]L.Liu,J.B.Zhu,J.C.Li,and Q.Jiang,Adv.Eng.Mater.14,919(2012).[14]M.Telford,The case for bulk metallic glasses,in MaterialsToday (Elsevier,Kidlington,UK,2004),p.36.[15]L.Vegard,Z.Phys.5,17(1921).[16]A.Tari,The Specific Heat of Matter at Low Temperatures(Imperial College Press,London,2003),p.37.[17]See,e.g.,N.W.Ashcroft and N.D.Mermin,Solid StatePhysics (Saunders,Philadelphia,1976),p.729.[18]M.Tinkham,Introduction to Superconductivity (McGraw-Hill,New York,1996),p.63.[19]B.S.Chandrasekhar,Appl.Phys.Lett.1,7(1962).[20]P.W.Anderson,J.Phys.Chem.Solids 11,26(1959).。

从锌置换渣中分段浸出锌、铅、镓和锗

Trans. Nonferrous Met. Soc. China 31(2021) 555−564Hydrometallurgical process for recovery ofZn, Pb, Ga and Ge from Zn refinery residuesShuai RAO1,2,3, Zhi-qiang LIU1,2,3, Dong-xing WANG1,2,3,Hong-yang CAO1,2,3, Wei ZHU1,2,3, Kui-fang ZHANG1,2,3, Jin-zhang TAO1,2,31. Research Institute of Rare Metals, Guangdong Academy of Sciences, Guangzhou 510650, China;2. State Key Laboratory of Separation and Comprehensive Utilization of Rare Metals,Guangdong Academy of Sciences, Guangzhou 510650, China;3. Guangdong Province Key Laboratory of Rare Earth Development and Application,Guangdong Academy of Sciences, Guangzhou 510650, ChinaReceived 3 March 2020; accepted 28 October 2020Abstract: Zn, Pb, Ga and Ge were separated and recovered from zinc refinery residues by stepwise leaching. In the first stage, by leaching with H2SO4 media, more than 90% of Zn and 99% of Ga were dissolved, leaving 92% of Ge in the leaching residue. In the second stage, by leaching with HCl media, approximately 99% of Pb and less than 2% of Ge were selectively dissolved. Finally, the remaining 90% of Ge was extracted in 1 mol/L NaOH solution by destroying the correlation between SiO2 and Ge. XRD pattern of the leaching residue demonstrated that ZnSO4·H2O, PbSO4 and SiO2 were removed sequentially through the stepwise leaching. The proposed process achieved high recoveries of Zn, Pb, Ga and Ge, thus presenting a potential industrial application.Key words: zinc refinery residues; gallium; germanium; stepwise leaching1 IntroductionGermanium (Ge) and gallium (Ga) areconsidered as strategic metals in many countriesowing to their wide applications in high-tech fieldssuch as semiconductors, optical fibers and solarcells [1−4]. However, geological and mineralogicalstudies have shown that it is difficult to findindependent deposits enriched with Ga and Ge [5,6].Currently, Ga and Ge are mainly extracted fromnon-ferrous metal residues [7−10] or secondaryresources [11,12]. The ZnS ores located inGuangdong province contain relatively highcontents of Ga and Ge [13,14]. Based on theproperties of the raw material, pressure leaching isapplied to treating the minerals for recovering Zn,Ga and Ge. During pressure leaching, almost allZn, Ga and Ge are dissolved in the leachingsolution. Zinc powder is then used as thereducing agent to remove Pb and Fe during thesubsequent purification procedure. Ga and Ge(0.1−0.5 wt.%) are also enriched in Zn refineryresidues, which usually contain large amounts of Pband Fe [15,16].Currently, Ga and Ge are extracted from zincplant residues by hydrometallurgical methodsowing to high economic benefits and lowenvironment pollution [17−19]. However, since Gaand Ge are closely correlated with Fe and Si, therecoveries of Ga and Ge are relatively low. Duringsulfuric acid leaching, the formation of silica gelresults in a deteriorating filtration performanceand significant loss of Ga and Ge [20]. To avoid theCorresponding author:Zhi-qiangLIU;Tel:+86-20-61086372;E-mail:*****************DOI:10.1016/S1003-6326(21)65517-61003-6326/© 2021 The Nonferrous Metals Society of China. Published by Elsevier Ltd & Science PressShuai RAO, et al/Trans. Nonferrous Met. Soc. China 31(2021) 555−564 556problem, hydrofluoric acid has been supplemented to sulfuric acid solutions to enhance the leaching rates of Ga and Ge [21]. However, the subsequent defluorination procedure constrains its commercial applications. Alkaline leaching has also been proposed to recover Ga and Ge [22]. Although a relatively high recovery of Ga and Ge is obtained, a large amount of sodium hydroxide is consumed owing to the dissolution of Pb and Si [23]. Organic weak acids provide milder leaching conditions than mineral acids; therefore, they exhibit a high selectivity [24]. LIU et al [25] researched the recovery of Ga and Ge from Zn refinery residues using an oxalic acid solution after selectively removing Cu and Zn in a sulfuric acid solution. Although this method can achieve high leaching rates of Ga and Ge, it is difficult to regenerate the leaching agent, resulting in a high production cost. In general, considering environmental conservation and process efficiency, there is no appropriate technology for the comprehensive recovery of valuable metals, including Zn, Pb, Ga and Ge, from Zn refinery residues.In this study, based on the properties of Zn refinery residues, stepwise leaching is proposed for the comprehensive recovery of Zn, Pb, Ga and Ge from Zn refinery residues. Firstly, Zn and Ga are dissolved in a sulfuric acid solution through controlled suitable leaching conditions, leaving behind Ge and Pb in the leaching residue. The resulting leaching solution can be further processed by adjusting the pH of the leaching solution to a weak acid environment for an effective separation of Zn and Ga. Secondly, Pb is selectively removed in a hydrochloric acid solution based on the complexation between Pb2+and Cl−. Moreover, a PbCl2product can be obtained through cooling crystallization. Finally, Ge is effectively extracted in a sodium hydroxide solution by destroying the embedded correlation between Ge and silica. The stepwise leaching method is a novel technology for the effective recovery of valuable metals from Zn refinery residues, with the potential to be applied on an industrial scale.2 Experimental2.1 MaterialsThe Zn refinery residue was obtained from a Zn metallurgy enterprise located in Shaoguan city, Guangdong province, China. Before conducting leaching, the material was dried, grounded and sieved to a particle size below 100 μm. The main elemental content of the residue was determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Table 1 shows that the residue mainly contains Zn, Pb, Fe and Si. The contents of Ga and Ge are 0.15 wt.% and 0.47 wt.%, respectively.Table 1 Main elemental contents of Zn refinery residue (wt.%)Zn Pb Fe Si Ga Ge 5.93 4.18 6.30 12.6 0.15 0.47The main phases of the Zn refinery residue were determined by X-ray diffraction (XRD). As shown in Fig. 1, the main diffraction peaks were related to some obvious phases, including SiO2, ZnSO4·H2O, PbSO4and ZnFe2O4. No other characteristic peaks corresponding to Ga or Ge phases were detected, owing to their low contents.Fig. 1 XRD pattern of Zn refinery residueFigure 2 shows the SEM image and elemental surface scanning images of the Zn refinery residue. The residue was mainly composed of many tiny dark particles representing SiO2. Some large blocky-shaped particles suggesting various phases were also observed. The brightest particle can be viewed as PbSO4, owing to the enrichment of Pb. Similarly, Fe and Zn were concentrated in some gray particles, confirming the presence of ZnFe2O4. The distributions for Ga and Ge were very sparse due to their low contents.Shuai RAO, et al/Trans. Nonferrous Met. Soc. China 31(2021) 555−564 5572.2 Experimental procedureBased on the properties of Zn refinery residue, an environmentally friendly and economical process was proposed for the efficient recovery of Zn, Pb, Ga and Ge. The integrated process flow comprises three procedures, as shown in Fig. 3, namely, Zn and Ga leaching in a H 2SO 4 solution, Pb recovery in a HCl solution, and Ge extraction in a NaOH solution. After Zn and Ga leaching, the pH of the leaching solution was adjusted to weak acid for the separation of Zn and Ga by adding ZnO.During Pb recovery, soluble 24PbClcomplex was transformed into PbCl 2 precipitate through dilution and cooling crystallization. The crystalline mothersolution was regenerated by adding CaCl 2. The pHof the leaching solution obtained from Ge extraction was adjusted to a weak alkaline condition for the separation of Ge and Si by adding HCl. All leaching experiments were performed in a beaker immersed in a water bath with a thermostat, equipped with a magnetic stirrer. All chemical reagents used were analytical grade.Fig. 2 SEM image and main elemental surface scanning images of Zn refinery residueFig. 3 Principal flow sheet for recovering valuable metals from Zn refinery residueShuai RAO, et al/Trans. Nonferrous Met. Soc. China 31(2021) 555−564 5582.3 Analytical methodsThe phases of the material and leaching residue were determined using a Rigaku TTRAX-3 X-ray diffraction instrument (40 kV, 30 mA, 10 (°)/min). The contents of the main elements, including Zn, Pb, Fe, Ga, Ge and Si, were determined using an inductively coupled plasma- atomic emission spectrometer (Thermo Electron IRIS Intrepid II XSP). The morphology and chemical composition of the samples were analyzed through SEM−EDS (SEM, JEOL, Ltd., JSM−6360LV).3 Results and discussion3.1 Zn and Ga leaching in H2SO4 solutionOwing to the formation of Ge−silica gel and PbSO4 precipitate in a H2SO4 solution, sulfuric acid leaching mainly focuses on the leaching efficiency of Zn and Ga. Moreover, the separation of Zn and Ga should also be considered after the leaching is completed. The φ–pH diagram for a Zn−Ga−Fe−H2O system has been depicted using the HSC 6.0. As illustrated in Fig. 4, Zn2+, Ga3+and Fe3+ were predominant under the acidic conditions, suggesting that sulfuric acid was an effective leaching agent to extract Zn and Ga. However, Zn, Ga and Fe each presented a different pH of hydrolysis precipitation. The precipitation of Ga3+and Fe3+in the form of Fe(OH)3and Ga(OH)3could occur at a pH above 3.0, while soluble Zn2+ existed in the solution at a pH below 6.0. Therefore, an effective separation of Zn and Ga could be obtained by adjusting the pH of the leaching solution to be 3.0−6.0.Fig. 4φ–pH diagram for Zn−Ga−Fe−H2O system at 25 °C (α(Zn2+)=1, α(Fe3+)=1, α(Ga3+)=0.01)Based on the above analyses, the effect of sulfuric acid concentration on the leaching process was investigated in detail. The other leaching conditions included a liquid solid ratio of 10 mL/g, reaction temperature of 80 °C, and leaching time of 2 h. As shown in Fig. 5, increasing the sulfuric acid concentration to 2 mol/L improved the leaching rate of Ga significantly. The Ga leaching rate approached 100% in a 2 mol/L H2SO4solution. Moreover, large amounts of Zn and Fe dissolved in the leaching solution, whereas the Ge leaching rate was relatively low due to the formation of Ge−silica gel. Therefore, a suitable sulfuric acid concentration of 2 mol/L should be selected for optimal leaching of Zn and Ga.Fig. 5 Effect of H2SO4 concentration on leaching rates of Zn, Fe, Ga and GeTable 2 lists the main elemental content of the leaching residue obtained in a 2 mol/L H2SO4 solution. It can be seen that Zn, Fe and Ga decreased significantly, whereas Pb, Si and Ge increased in the H2SO4 leaching residue. The XRD pattern of the H2SO4 leaching residue is shown in Fig. 6. Compared with the results in Fig. 1, the characteristic peaks of ZnSO4·H2O disappeared and the remaining phases contained ZnFe2O4, SiO2 and PbSO4. Figure 7 presents the SEM image of the H2SO4 leaching residue. Based on the results of the EDS analyses from Table 3, the blocky-shaped particles given by Spots 1 and 2 were confirmed as PbSO4and ZnFe2O4, respectively. These tiny dark particles (Spots 3, 4, and 5) were viewed as an enriching Si phase. More importantly, these enriching Si particles exhibited a high Ge content.Shuai RAO, et al/Trans. Nonferrous Met. Soc. China 31(2021) 555−564 559Table 2Main elemental contents of leaching residue obtained in 2 mol/L H2SO4 solution (wt.%)Zn Pb Fe Si Ga Ge 1.49 9.64 1.52 26.1 0.01 1.03Fig. 6 XRD pattern of H2SO4 leaching residueFig. 7 SEM image of H2SO4 leaching residueTable 3 Chemical composition of selected particles shown in Fig. 7 (wt.%)Element Spot 1 Spot 2 Spot 3 Spot 4 Spot 5 O 20.17 27.54 50.98 45.47 45.01S 9.87 − 3.51 − 4.06Zn −27.01 0.6 0.84 2.29Pb 69.69 −−10.87 10.09Fe −41.44 1.82 0.9 2.11Si −0.84 37.15 36.51 30.08Ga −−−−−Ge −0.01 2.02 2.18 2Once the leaching was completed, Ga and Fe were deposited as Ga(OH)3and Fe(OH)3 by adjusting the pH of the leaching solution to 4.0. The resulting ZnSO4 solution could be returned to the Zn recovery procedure, while the precipitate was further treated to extract Ga. The precipitate obtained in this study exhibited an amorphous phase structure, as shown in Fig. 8. The contents of Fe and Ga in the precipitate were 30.08 and 1.00 wt.%, respectively, suggesting that Ga in the precipitate was over five times higher than that in the material.Fig. 8 XRD pattern of precipitate obtained from H2SO4 leaching solution3.2 Pb recovery in HCl solutionAfter selective dissolution of Zn, Ga and Fe, the leaching residue was mainly composed of Pb, Ge and Si. Due to the formation of soluble 24Pb(OH)-complex in an alkaline solution, it was necessary to remove Pb before extracting Ge. Based on the complexation between Pb2+and Cl−, HCl was selected as a suitable leaching agent. The distribution curves of the Pb species with different Cl−concentrations were constructed using the Medusa software. As shown in Fig. 9, PbCl2 precipitate predominated under a relatively low Cl−concentration condition, while an increased Cl−concentration was beneficial for the formation ofsoluble 24PbCl-complex. This suggests that Pb recovery should be conducted under larger leaching agent concentration and higher liquid-to-solid ratio conditions. Therefore, the leaching process was performed with a liquid-to-solid ratio of 20 mL/g at 90 °C for 2 h. Figure 10 shows the effect of HCl concentration on the leaching rates of Pb and Ge. The leaching rate of Pb enhanced with an increasing HCl concentration from 0.5 to 2 mol/L. Almost all of the PbSO4 dissolved in a 2 mol/L HCl solution, with the Ge leaching rate below 2%.Shuai RAO, et al/Trans. Nonferrous Met. Soc. China 31(2021) 555−564 560Fig. 9Distribution of Pb species at different pH for Pb2+−Cl−−H2O system at 25 °CTable 4 lists the main elemental contents of the leaching residue. It can be seen that Ge increased to above 1.37 wt.% in the leaching residue, whereas the content of Pb reduced to below 0.1 wt.%. The main phases of the leaching residue were SiO2 and ZnFe2O4, as shown in Fig. 11. Compared with Fig. 7, Fig. 12 shows that the brightest particles representing the PbSO4 phase were seldom observed. Moreover, there was a close correlation between Ge and Si based on the Ge−Si surface distribution diagram.Fig. 10 Effect of HCl concentration on leaching rates of Pb and GeFig. 11 XRD pattern of HCl leaching residueTable 4 Main elemental contents of leaching residue obtained in 2 mol/L HCl solution (wt.%)Zn Pb Fe Si Ga Ge 1.29 0.078 1.31 30 0.007 1.37Fig. 12 SEM image and Ge−Si surface distribution of leaching residue obtained in 2 mol/L HCl solutionShuai RAO, et al/Trans. Nonferrous Met. Soc. China 31(2021) 555−564 561After completion of the Pb leaching, it is necessary to recover Pb from the leaching solution.A 24PbCl -complex can be transformed into PbCl 2 precipitate by decreasing the reaction temperature and Cl − concentration [26]. Therefore, the leaching solution was processed by dilution and cooling. Then, the PbCl 2 product was obtained by liquid −solid separation. The Pb content in the solution lowered from 4.78 to 1.79 g/L, suggesting that approximately 37.4% of Pb remained in the leaching solution. More than 60% of Pb was recovered in the form of PbCl 2, as shown in Fig. 13. The PbCl 2 product containing 74.3 wt.% Pb exhibited a high purity without any additional characteristic peaks. As shown in Fig. 14, after cooling crystallization, the resultingsolution wasregenerated by adding CaCl 2to remove 24SO -byprecipitation reaction between 24SO - and Ca 2+, allowing for the regenerated solution to be used in the subsequent lead removing procedure.Fig. 13 XRD pattern of PbCl 2 product from HCl leaching solutionFig. 14 XRD pattern of precipitate obtained from regeneration of leaching agent3.3 Extraction of Ge in NaOH solutionTo remove silica −germanium gel, NaOH is used as the leaching agent to effectively extract Ge. Leaching experiments were conducted at 80 °C with a liquid solid ratio of 20 mL/g for 2 h. Figure 15 shows the effect of NaOH concentration on the leaching rates of Ge and Si. An increased NaOH concentration significantly improved the dissolution efficiency of Ge and Si. More than 99% of Ge and 90% of Si were dissolved in 1 mol/L NaOH solution. Table 5 lists the main elemental contents of the NaOH leaching residue. Fe and Zn increased inthe leaching residue, whereas Gedecreased to 0.06%. The XRD pattern, shown in Fig. 16, indicates the main phases of the leaching residue to be SiO 2, ZnS and ZnFe 2O 4. ComparedFig. 15 Effect of NaOH concentration on leaching rates of Si and GeFig. 16 XRD pattern of NaOH leaching residueTable 5 Main elemental contents of leaching residue obtained in 1 mol/L NaOH solution (wt.%) Zn Fe Pb Si Ga Ge 6.817.10.117.690.010.06Shuai RAO, et al/Trans. Nonferrous Met. Soc. China 31(2021) 555−564562 with Fig. 8, new characteristic peaks of ZnS were observed owing to an increased Zn content in the leaching residue. Figure 17 shows the SEM image and main elemental surface distribution of the alkaline leaching residue. The tiny silica − germanium gel particles dissolved entirely, and the remaining particles, including ZnS, ZnFe 2O 4 and SiO 2, were large, preventing adequate dissolution through atmospheric leaching.Fig. 17 SEM image and main elemental surface scanning maps of leaching residueAfter Ge leaching, it is necessary to separate Ge and Si from the leaching solution owing to the dissolution of SiO 2. According to the φ−pH diagram for the Ge −Si −H 2O system in Fig. 18, Ge −silica gel can be destroyed by promoting the formation ofsoluble 3HGeO - and 3SiO(OH)-in an alkaline solution. After the leaching is complete, the precipitation of Si in the form of amorphous silicon dioxide can occur by adjusting the pH to be 6.0−12.0, allowing for an effective separation of Geand Si. Therefore, in this study, the pH of the alkaline leaching solution was adjusted to be 9.0 by adding 2 mol/L HCl. The Si content in the leaching solution lowered to less than 0.3 g/L, as shown in Table 6, allowing for an excellent Ge −Si separation efficiency. Moreover, Zn, Pb and Fe were also adequately removed. The leaching solution could then be used to recover Ge through precipitation or solvent extraction. The white precipitate obtained from the Ge −Si separation procedure was amorphous silicon dioxide and, therefore, no obvious characteristic peaks were observed, as shown in Fig. 19.Fig. 18 φ−pH diagram for Ge −Si −H 2O system at 25 °C (α(Si 4+)=1, α(Ge 4+)=0.01)Table 6 Main elemental contents of leaching solution adjusted to pH 9.0 (mg/L) Zn Pb Fe Si Ga Ge <0.5 <0.5<0.5268.1<0.5254.1Fig. 19 XRD pattern of white precipitate obtained during Ge and Si separationShuai RAO, et al/Trans. Nonferrous Met. Soc. China 31(2021) 555−564 5634 Conclusions(1) More than 90% of Zn and 99% of Ga were leached in a 2 mol/L H2SO4 solution with a liquid–solid ratio of 10 mL/g at 80 °C after 2 h, leaving approximately 92% of Ge in the leaching residue. The content of Ga in the precipitate was over 5 times higher than in the raw material.(2) About 99% of Pb and less than 2% of Ge were dissolved in a 2 mol/L HCl solution with a liquid-to-solid ratio of 20 mL/g at 90 °C for 2 h. A PbCl2 byproduct with a high purity was obtained by cooling crystallization.(3) During alkaline leaching, the remaining 90% of the Ge was extracted in a 1 mol/L NaOH solution with a liquid-to-solid ratio of 20 mL/g at 80 °C for 2 h. An effective Ge−Si separation was conducted by adjusting the pH of the leaching solution to 9.0.AcknowledgmentsThe authors are grateful for the financial supports from the National Natural Science Foundation of China (51804083, 51704081), the National Key Research and Development Project (2018YFC1903104), the Natural Science Foundation of Guangdong Province, China (2019A1515011628), the Science and Technology Planning Project of Guangzhou (201904010106) of China, and Guangdong Academy of Science Doctor Special Program of China (2020GDASYL-0104027, 2019GDASYL-0105079, 2019GDASYL-0302011, 2019GDASYL-0402003).References[1]FTHENAKIS V, WANG Wen-ming, KIM H C. Life cycleinventory analysis of the production of metals used inphotovoltaics [J]. Renewable and Sustainable EnergyReviews, 2009, 13(3): 493−517.[2]CAROLAN D. Recent advances in germanium nanocrystals:Synthesis, optical properties and applications [J]. Progress inMaterials Science, 2017, 90: 128−158.[3]FRENZEL M, MIKOLAJCZAK C, REUTER M A,GUTZMER J. Quantifying the relative availability ofhigh-tech by-product metals−The cases of gallium,germanium and indium [J]. Resources Policy, 2017, 52:327−335.[4]SIONTAS S, LI D, WANG H, A. V. P. S A, ZASLAVSKYA, PACIFICI D. High-performance germanium quantum dotphotodetectors in the visible and near infrared [J]. MaterialsScience in Semiconductor Processing, 2019, 92: 19−27. [5]LU Fang-hai, XIAO Tang-fu, LIN Jian, NING Zeng-ping,LONG Qiong, XIAO Li-hua, HUANG Fang, WANG Wan-kun, XIAO Qing-xiang, LAN Xiao-long, CHEN Hai-yan. Resources and extraction of gallium: A review [J].Hydrometallurgy, 2017, 174: 105−115.[6]MOSKALYK R R. Review of germanium processingworldwide [J]. Minerals Engineering, 2004, 17(3): 393−402.[7]FRENZEL M, HIRSCH T, GUTZMER J. Gallium,germanium, indium, and other trace and minor elements in sphalerite as a function of deposit type: A meta-analysis [J].Ore Geology Reviews, 2016, 76: 52−78.[8]LU Fang-hai, XIAO Tang-fu, LIN Jian, LI An-jing, LONGQiong, HUANG Fang, XIAO Li-hua, LI Xiang, WANG Jia-wei, XIAO Qing-xiang, CHEN Hai-yan. Recovery of gallium from Bayer red mud through acidic leaching-ion exchange process under normal atmospheric pressure [J].Hydrometallurgy, 2018, 175: 124−132.[9]KUL M, TOPKAYA Y. Recovery of germanium and othervaluable metals from zinc plant residues [J].Hydrometallurgy, 2008, 92(3): 87−94.[10]MACÍAS-MACÍAS K Y, CENICEROS-GÓMEZ A E,GUTIÉRREZ-RUIZ M E, GONZÁLEZ-CHÁVEZ J L, MARTÍNEZ-JARDINES L G. Extraction and recovery of the strategic element gallium from an iron mine tailing [J].Journal of Environmental Chemical Engineering, 2019, 7(2): 102964.[11]ZHOU Jia-zhi, ZHU Neng-wu, LIU Huang-rui, WUPing-xiao, ZHANG Xiao-ping, ZHONG Zu-qi. Recovery of gallium from waste light emitting diodes by oxalic acidic leaching [J]. Resources, Conservation and Recycling, 2019, 146: 366−372.[12]CHEN Wei-Sheng, CHANG Bi-Cheng, CHIU Kai-Lun.Recovery of germanium from waste optical fibers by hydrometallurgical method [J]. Journal of Environmental Chemical Engineering, 2017, 5(5): 5215−5221.[13]LIU Fu-peng, LIU Zhi-hong, LI Yu-hu, LIU Zhi-yong, LIQi-hou, WEN Da-min. Sulfuric leaching process of zinc powder replacement residue containing gallium and germanium [J]. The Chinese Journal of Nonferrous Metals, 2016, 26(4): 908−918. (in Chinese)[14]LIU Fu-peng, LIU Zhi-hong, LI Yu-hu, LIU Zhi-yong, LIQi-hou. Leaching mechanism of zinc powder replacement residue containing gallium and germanium by high pressure acid leaching [J]. The Chinese Journal of Nonferrous Metals, 2014, 24(4): 1091−1098. (in Chinese)[15]LIU Fu-peng, LIU Zhi-hong, LI Yu-hu, LIU Zhi-yong, LIQi-hou, ZENG Li. Extraction of gallium and germanium from zinc refinery residues by pressure acid leaching [J].Hydrometallurgy, 2016, 164: 313−320.[16]LIU Fu-peng, LIU Zhi-hong, LI Yu-hu, WILSON B P,LUNDSTRÖM M. Recovery and separation of gallium (III) and germanium (IV) from zinc refinery residues: Part I: Leaching and iron (III) removal [J]. Hydrometallurgy, 2017, 169: 564−570.[17]WU Xue-lan, WU Shun-ke, QIN Wen-qing, MA Xi-hong,NIU Yin-jian, LAI Shao-shi, YANG Cong-ren, JIAO Fen, REN Liu-yi. Reductive leaching of gallium from zinc residue [J]. Hydrometallurgy, 2012, 113−114: 195−199.[18]LIANG Duo-qiang, WANG Ji-kun, WANG Yun-hua.Shuai RAO, et al/Trans. Nonferrous Met. Soc. China 31(2021) 555−564 564Difference in dissolution between germanium and zinc during the oxidative pressure leaching of sphalerite [J].Hydrometallurgy, 2009, 95(1): 5−7.[19]ZHANG Li-bo, GUO Wen-qian, PENG Jin-hui, LI Jing, LINGuo, YU Xia. Comparison of ultrasonic-assisted and regular leaching of germanium from by-product of zinc metallurgy [J]. Ultrasonics Sonochemistry, 2016, 31: 143−149.[20]HARBUCK D D. Optimization of gallium and germaniumextraction from hydrometallurgical zinc residue [J]. Light Metals, 1989: 984−989.[21]HARBUCK D D. Increasing germanium extraction fromhydrometallurgical zinc residues [J]. Mining, Metallurgy & Exploration, 1993, 10(1): 1−4.[22]TORMA A E. Method of extracting gallium and germanium[J]. Mineral Processing and Extractive Metallurgy Review, 1991, 3: 235−258.[23]RAO Shuai, WANG Dong-xing, LIU Zhi-qiang, ZHANGKui-fang, CAO Hong-yang, TAO Jin-zhang. Selective extraction of zinc, gallium, and germanium from zinc refinery residue using two stage acid and alkaline leaching [J]. Hydrometallurgy, 2019, 183: 38−44.[24]HURŞIT M, LAÇIN O, SARAÇ H. Dissolution kinetics ofsmithsonite ore as an alternative zinc source with an organic leach reagent [J]. Journal of the Taiwan Institute of Chemical Engineers, 2009, 40(1): 6−12.[25]LIU Fu-peng, LIU Zhi-hong, LI Yu-hu, WILSON B P,LUNDSTRÖM M. Extraction of Ga and Ge from zinc refinery residues in H2C2O4solutions containing H2O2 [J].International Journal of Mineral Processing, 2017, 163: 14−23.[26]DING Yun-ji, ZHANG Shen-gen, LIU Bo, LI Bin. Integratedprocess for recycling copper anode slime from electronic waste smelting [J]. Journal of Cleaner Production, 2017, 165: 48−56.从锌置换渣中分段浸出锌、铅、镓和锗饶帅1,2,3，刘志强1,2,3，王东兴1,2,3，曹洪杨1,2,3，朱薇1,2,3，张魁芳1,2,3，陶进长1,2,31. 广东省科学院稀有金属研究所，广州510650；2. 广东省科学院稀有金属分离与综合利用国家重点实验室，广州510650；3. 广东省科学院广东省稀土开发及应用研究重点实验室，广州510650摘要：采用分段浸出方法从锌置换渣中选择性提取锌、铅、镓和锗。

scanning exercises

Reading skills for academic study: Scanning forspecific information.Exercise 1Read the following text quickly and fill in the table. What do the numbers given in the table refer to?Spoon-fed feel lost at the cutting edgeBefore arriving at university students will have been powerfully influenced by their school’s approach to learning particular subjects. Yet this is only rarely taken into account by teachers in higher education, according to new research carried out at Nottingham University, which could explain why so many students experience problems making the transition.Historian Alan Booth says there is a growing feeling on both sides of the Atlantic that the shift from school to university-style learning could be vastly improved. But little consensus exists about who or what is at fault when the students cannot cope. “School teachers commonly blame the poor quality of university teaching, citing factors such as large first-year lectures, the widespread use of inexperienced postgraduate tutors and the general lack of concern for students in an environment where research is dominant in career progression,” Dr Booth said.Many university tutors on the other hand claim that the school system is failing to prepare students for what will be expected of them at university. A-level history in particular is seen to be teacher-dominated, creating a passive dependency culture.But while both sides are bent on attacking each other, little is heard during such exchanges from the students themselves, according to Dr Booth, who has devised a questionnaire to test the views of more than 200 first-year history students at Nottingham over a three-year period. The students were asked about their experience of how history is taught at the outset of their degree programme. It quickly became clear that teaching methods in school were pretty staid.About 30 per cent of respondents claimed to have made significant use of primary sources (few felt very confident in handling them) and this had mostly been in connection with project work. Only 16 per cent had used video/audio; 2 per cent had experienced field trips and less than 1 per cent had engaged in role-play.Dr Booth found students and teachers were frequently restricted by the assessment style which remains dominated by exams. These put obstacles in the way of more adventurous teaching and active learning, he said. Of the students in the survey just 13 per cent felt their A-level course had prepared them very well for work at university. Three-quarters felt it had prepared them fairly well.One typical comment sums up the contrasting approach: “At A-level we tended to be spoon-fed with dictated notes and if we were told to do any background reading (which was rare) we were told exactly which pages to read out of the book”.To test this further the students were asked how well they were prepared in specific skills central to degree level history study. The answers reveal that the students felt most confident at taking notes from lectures and organising their notes. They were least able to give an oral presentation and there was no great confidence in contributing to seminars, knowing how much to read, using primary sources and searching for texts. Even reading and taking notes from a book were often problematic. Just 6 per cent of the sample said they felt competent at writing essays, the staple A level assessment activity.The personal influence of the teacher was paramount. In fact individual teachers were the cent re of students’ learning at A level with some 86 per cent of respondents reporting that their teachers had been more influential in their development as historians than the students’ own reading and thinking.The ideal teacher turned out to be someone who was enthusiastic about the subject; a good clear communicator who encouraged discussion. The ideal teacher was able to develop students involvement and independence. He or she was approachable and willing to help. The bad teacher, according to the survey, dictates notes and allows no room for discussion. He or she makes students learn strings of facts; appears uninterested in the subject and fails to listen to other points of view.No matter how poor the students judged their preparedness for degree-level study, however, there was a fairly widespread optimism that the experiencewould change them significantly, particularly in terms of their open mindedness and ability to cope with people.But it was clear, Dr Booth said, that the importance attached by many departments to third-year teaching could be misplaced. “Very often tutors regard the third year as the crucial time, allowing postgraduates to do a lot of the earlier teaching. But I am coming to the conclusion that the first year at university is the critical point of intervention”.Alison Utley, Times Higher Education Supplement. February 6th, 1998.Reading skills for academic study: Scanning forspecific information.Exercise 1 - AnswersRead the following text quickly and fill in the table. What do the numbers given in the table refer to?Reading skills for academic study: Scanning forspecific information.Exercise 2Read the following text quickly and answer the questions.1. W hen were X-rays discovered?2. W ho discovered them?3. W hat are the four characteristics of X-rays?The Discovery of X-raysExcept for a brief description of the Compton effect, and a few other remarks, we have postponed the discussion of X-rays until the present chapter because it is particularly convenient to treat X-ray spectra after treating optical spectra. Although this ordering may have given the reader a distorted impression of the historical importance of X-rays, this impression will be corrected shortly as we describe the crucial role played by X-rays in the development of modern physics.X-rays were discovered in 1895 by Roentgen while studying the phenomena of gaseous discharge. Using a cathode ray tube with a high voltage of several tens of kilovolts, he noticed that salts of barium would fluoresce when brought near the tube, although nothing visible was emitted by the tube. This effect persisted when the tube was wrapped with a layer of black cardboard. Roentgen soon established that the agency responsible for the fluorescence originated at the point at which the stream of energetic electrons struck the glass wall of the tube. Because of its unknown nature, he gave this agency the name X-rays. He found that X-rays could manifest themselves by darkening wrapped photographic plates, discharging charged electroscopes, as well as by causing fluorescence in a number of different substances. He also found that X-rays can penetrate considerable thicknesses of materials of low atomic number, whereas substances of high atomic number are relatively opaque. Roentgen took thefirst steps in identifying the nature of X-rays by using a system of slits to show that (1) they travel in straight lines, and that (2) they are uncharged, because they are not deflected by electric or magnetic fields.The discovery of X-rays aroused the interest of all physicists, and many joined in the investigation of their properties. In 1899 Haga and Wind performed a single slit diffraction experiment with X-rays which showed that (3) X-rays are a wave motion phenomenon, and, from the size of the diffraction pattern, their wavelength could be estimated to be 10-8 cm. In 1906 Barkla proved that (4) the waves are transverse by showing that they can be polarized by scattering from many materials.There is, of course, no longer anything unknown about the nature of X-rays. They are electromagnetic radiation of exactly the same nature as visible light, except that their wavelength is several orders of magnitude shorter. This conclusion follows from comparing properties 1 through 4 with the similarproperties of visible light, but it was actually postulated by Thomson several years before all these properties were known. Thomson argued that X-rays are electromagnetic radiation because such radiation would be expected to be emitted from the point at which the electrons strike the wall of a cathode ray tube. At this point, the electrons suffer very violent accelerations in coming to a stop and, according to classical electromagnetic theory, all accelerated charged particles emit electromagnetic radiations. We shall see later that this explanation of the production of X-rays is at least partially correct.In common with other electromagnetic radiations, X-rays exhibit particle-like aspects as well as wave-like aspects. The reader will recall that the Compton effect, which is one of the most convincing demonstrations of the existence of quanta, was originally observed with electromagnetic radiation in the X-ray region of wavelengths.Reading skills for academic study: Scanning forspecific information.Exercise 2 - AnswersRead the following text quickly and answer the questions.1. W hen were X-rays discovered?2. W ho discovered them?3. W hat are the four characteristics of X-rays?1. 18952. R oentgen3. 1. they travel in straight lines2. they are uncharged3. they are a wave motion phenomenon4. the waves are transverse。

激光熔覆马氏体

第27卷第2期粉末冶金材料科学与工程2022年4月V ol.27 No.2 Materials Science and Engineering of Powder Metallurgy Apr. 2022DOI:10.19976/ki.43-1448/TF.2021090激光熔覆马氏体/铁素体涂层的组织与抗磨耐蚀性能张磊1, 2，陈小明1, 2，霍嘉翔1，张凯1, 2，曹文菁1, 2，程新闯3(1. 水利部产品质量标准研究所浙江省水利水电装备表面工程技术研究重点实验室，杭州 310012；2. 水利部杭州机械设计研究所水利机械及其再制造技术浙江省工程实验室，杭州 310012；3. 绍兴市曹娥江大闸管理局，绍兴 312000)摘要：为提高液压活塞杆的耐腐蚀和抗磨损性能，在45号钢表面采用激光熔覆技术在不同激光功率下制备具有马氏体/铁素体组织的Fe基合金熔覆层。

利用X射线衍射仪、扫描电镜、X射线能谱仪等手段表征涂层的物相组成、微观形貌和元素分布，采用维氏硬度计和干滑动摩擦试验机对涂层的显微硬度和抗磨损性能进行测试，并通过电化学工作站研究熔覆层的耐腐蚀性能。

结果表明：Fe基合金熔覆层的主要物相为α-Fe、Ni-Cr-Fe、γ-(Fe,C)和Fe9.7Mo0.3等，主要组织为马氏体、铁素体和少量残余奥氏体。

熔覆层的枝晶态组织均匀致密，无裂纹和孔隙缺陷，涂层与基体呈冶金结合。

涂层的硬度与耐磨性能随激光功率增大而提高，当功率为2.4 kW时，涂层的平均显微硬度(HV)为647.64，耐磨性能为45号钢的9.37倍，磨损机制为磨粒磨损。

随激光功率提高，Fe基合金熔覆层的耐腐蚀性能先升高后降低，当激光功率为2.0 kW时涂层具有最佳耐腐蚀性能，显著高于活塞杆常用碳钢、不锈钢以及电镀硬铬等材料，可在相关领域替代电镀铬。

关键词：激光熔覆；Fe基合金；组织；磨损；腐蚀；活塞杆中图分类号：TG174.44文献标志码：A 文章编号：1673-0224(2022)02-196-09All Rights Reserved.Microstructure and wear-corrosion resistance performance oflaser cladding martensite/ferrite coatingZHANG Lei1, 2, CHEN Xiaoming1, 2, HUO Jiaxiang1, ZHANG Kai1, 2, CAO Wenjing1, 2, CHENG Xinchuang3(1. Key Laboratory of Surface Engineering of Equipment for Hydraulic Engineering of Zhejiang Province, Standard &Quality Control Research Institute, Ministry of Water Resources, Hangzhou 310012, China;2. Water Machinery and Remanufacturing Technology Engineering Laboratory of Zhejiang Province, HangzhouMechanical Research Institute, Ministry of Water Resources, Hangzhou 310012, China;3. Shaoxing Municipal Cao’e River Floodgate Construction Administration Committee, Shaoxing 312000, China)Abstract: To improve the corrosion resistance and wear resistance of piston rod, Fe-based coatings with martensite andferrite structure were prepared on 45# steel by laser cladding. The phase compositions, microstructure and elementsdistribution of the coatings were characterized by X-ray diffractometer, scanning electron microscope and X-ray energydispersive spectrometer. The microhardness and wear resistance of the coatings were tested by Vickers hardness testerand dry sliding friction wear tester. Furthermore, the corrosion resistance of laser cladding Fe-based coatings was studiedby electrochemical workstation. The results show that the phase of laser cladding Fe-based alloy coating is mainlycomposed of α-Fe, Ni-Cr-Fe, γ-(Fe,C), Fe9.7Mo0.3. The main microstructure is martensite, ferrite and a small amount ofresidual austenite. The dendritic structure of coating is uniform, compact, without cracks or pores. The coating and thesubstrate are bonded metallurgically. The hardness and wear resistance of the coatings increase with increasing基金项目：浙江省“一带一路”国际科技合作项目(2019C04019)；浙江省公益性技术应用研究计划资助项目(GC22E017317，LGC19E090001，2018C37029)收稿日期：2021−11−02；修订日期：2021−12−23通信作者：张磊，工程师，硕士。

portable x-ray tec

X-ray Technology and Applications UpdateThe invention of the x-ray by Roentgen in 1895 created an amazing step forward in the history of medicine. Today we see X-ray technology used in many different fields as a non-invasive inspection tool and not least in the field of security where x-rays are used for baggage scanning at airports, mailscanning in postrooms, vehicle scanning at border controls and more recently through body x-ray scanners for identifying contraband, weapons and IEDs concealed on a person. For field use, specially adapted portable systems have been developed to meet the different investigative needs of military theatres and national military and civil search.X-ray technology today uses the same basic principles in that x-rays are passed through an object and a latent shadow image is captured on an imaging panel placed behind it. Different materials will absorb different numbers of photons so that the relative densities of the object can be seen as differences in grey scales when viewed on a screen.Pre 9/11 many field based x-ray systems were still operating manual Polaroid film technology where an x-ray source was placed in front of the object requiring scanning and a cassette placed behind. The x-ray generator was manually fired by the operator and then the target area would be reapproached for the film to be retrieved for chemical processing.Although the resulting image was fairly good, it could be quite a time consuming process as the processing itself could take up to 2 minutes and if the development was not carried out in the correct conditions, several attempts were often needed before getting a picture of sufficiently good resolution. Each attempt meant another sheet of Polaroid film which involve significant weight and cost factors when carrying out multiple x-rays of a large target.In addition film had dead areas where edges of cassettes were joined or unexposed and where potentially an IED could go unseen. If dead areas are found additional x-rays need to be taken which increases time on target for EOD personnel.The range of portable x-ray equipment available in the security market is growing. Conventional Polaroid film systems are gradually being replaced by “real time” systems where images are displayed in digital form on a laptop or other portable device.Fundamentally there are 2 primary technologies available off the shelf to upgrade older Polaroid film systems to a digital platform whilst operating the same safe, tried and tested x-ray generators.The first is DR – Direct (Digital) Radiography which use either a rugged CCD X-ray Imager or a very high resolution amorphous silicon (aSi) flat panel imager to capture x-rayimages before sending them directly back to a laptop and the second is known as CR –Computed Radiography which utilises very flexible reusable digital film and an image plate processor that scans the x-ray image onto the laptop via a USB data connection.Each has its own benefits dependent on the requirements of the job but all of the imaging panels described in this article are lightweight and can be handled easily even by someone wearing heavy body armour.If we look first at the picture in overseas theatres such as Iraq and Afghanistan, their needs will be quite different from the requirements of a postal inspector needing to check a suspect package or a special projects team carrying out a room search.The homemade IED is the extremist’s deadliest weapon and our troops' biggest challenge. In 2003 there were 81 recorded IEDs in Afghanistan. In 2009 there were over 8,000. Half of all soldiers killed in Iraq were killed by IEDs and currently in Afghanistan it is two thirds.Early detection (or better, prevention) of IEDs is mission critical which is why current Counter IED methodology is focused on Defeat the Device (finding the weapon and protecting against its effects) Attack the Network (identify what an IED cell looks like so that the networks can be identified and attacked) and Train the Force.Detection of IEDS is a daunting challenge. IEDS are being concealed in everyday items such as drinks cans, toy cars, key rings and mobile phones and can be very easily disguised in rubbish, potholes and craters and a high percentage are frequently spotted by soldiers noticing something doesn’t look right. In this instance x-ray equipment may be deployed as a confirmatory tool or to remotely diagnose the insides of an object without picking it up.In such instances where the equipment is going to be used regularly by someone often operating on foot, for Special Forces a highly portable lightweight system that can be carried in a backpack would be the key requirement. A CCD imaging system also represents a very cost effective solution.A real time CCD x-ray system is combination of camera and x-ray source at the target and laptop or other viewing console at the control point. CCD systems produce a latent x-ray image on photoluminescent screen. A camera sends the image back to the laptop directly down a cable or by wireless transmission and multiple exposures can be made to gain the best possible image without having to return to the target.The most compact and portable solution on the market and one which represents some of the latest improvements in cameras and processing is the Scanwedge system which has a unique flat panel CCD X-ray imager The entire system weighs less than 10kgs in a backpack comprises only 3 components (x-ray generator, image panel and a smallhandheld tablet pc), x-ray investigation of an item can be carried out quickly and rapidly in even the most difficult to access areas. Unlike other CCD systems it does not use a mirror and is extremely rugged and flat.Many CCD systems, including Scanwedge, can be fully integrated onto EOD robots allowing the EOD team to move the x-ray equipment into place as well as controlling the x-ray system over the robot communications link or over wireless communication where applicable.In order to attack the IED network, our military teams need detailed information on the construction and composition of IEDs. Following discovery or activation of an IED every fragment is essential to the forensic team to understand both its makeup and its likely provenance. These teams gather evidence from blasts and each device is reconstructed, replicated and tested.X-ray investigation enables forensic teams to recognise a signature and also to identify patterns in bomb making that may identify a change in tactics or identify components from a common source. Recent investigation of wires, charges and other explosive components used in a series of bombs have indicated materials are being sourced from specific areas which means strategies to block these trade routes can be put into place.Forensic procedures and post blast analysis associated with IEDs do not need to be carried out where the device is found. Therefore ruggedness and portability are less of an issue and image resolution becomes the determining factor.Computed Radiography (CR) systems really come into their own for this type of task.Modern computed radiography, using storage phosphor imaging plates, can be tracedto 1973, when George Luckey, a research scientist at Eastman Kodak Company, filed a patent application titled Apparatus and Method for Producing Images Corresponding to Patterns of High Energy Radia tion. His abstract states, “A temporary storage medium, such as an infrared-stimulable phosphor or thermoluminescent material, is exposed to an incident pattern of high energy radiation.With phosphor imaging plates, you can shoot one image instead of the five or more you may need to shoot on film. That’s because a phosphor imaging plate has ten times the dynamic range of film.Unlike DR systems where the x-ray image transmits directly to the laptop, CR imaging plates need to be manually retrieved and fed through an image plate processor before the image can be viewed. For post blast investigation this time factor is less of a concern. In all types of EOD tasks, in theatre or otherwise there will be the requirement to identify the type of IED/UXO in question and discern the makeup and location of thecomponent parts within the device in order to carry out a render safe procedure. For this application a CR system is also ideal. Where an IED/EOD team has a vehicle, the resolution provided by a CR or aSi x-ray system is often of greater relevance than the cost, weight or rugged factor of a CCD system.The real benefit of a CR system is that the imaging plates are extremely flat and flexible and can be taped onto any flat surface. In addition, multiple imaging plates can be taped together to x-ray a larger object in a single x-ray exposure. More importantly CR x-ray systems can produce extremely high resolution images with pixel sizes down to 50 microns and capable of seeing 10 line pairs which is critical for the forensic analysis and for render safe procedures. In addition, Extra clarity makes detection much faster, easier and leads to a real reduction in false alarmsThe national terrorist threat has evolved rapidly since the events of 9/11 and the emphasis on traditional targets such as military bases has shifted. Any public area, building or event where large numbers of people congregate is now considered a viable target.More typically, IEDs are placed inside a building and secreted in places with relatively easy access including toilet facilities, reception areas, hallways and stairwellsThe primary use of portable x-ray equipment in these scenarios is to help military, police or specialist forces examine inside suspect packages. A suspect package could be a parcel left in a reception area, a suitcase left unattended at airport, a sports bag left by the side of the road or any object that is unexpected or looks out of place in its surroundings. Early identification of bags that do not represent a threat and eliminating those false alarms is essential.The deployment of large numbers of military teams in Iraq and Afghanistan means that traditional EOD resources in some countries are vastly overstretched, so that the responsibility for the search and detection of suspicious bags and packages is often passed to the police and to individual premises managers. Of the Quarter of a million suspect packages found on the railway system in the UK less than 1% will need attendance by bomb disposal squads, which again demonstrates the importance of x-ray screening by police and civil security teams.Context, location and deployment all come into the equation when selecting the correct x-ray system for operation.In the USA, Postal inspectors are trained to screen suspicious mail for IEDS. They are performing regular confirmatory actions and carry conventional realtime CCD based x-ray systems on their vehicles which mean they can usually resolve incidents without tying up valuable first responder resources.For fast deployment on foot to perform a simple confirmation of a package or bag’s contents a lightweight CCD x-ray system is normally the most applicable.For a vehicle, building and room search requiring more indepth information a CR system may be more suited to the job. The image plates used with CR x-ray system are able to flex around corners. They can be taped onto walls, or be placed in overhead plane luggage bays, for example, come in a range of sizes, and can be combined on a freestanding mount for checking large items such as suitcases. The dynamic range is such that even a tiny wire hidden inside a wall or ceiling cavity would be visible.Unlike Polaroid film, digital x-ray plates have a 100% active area so a complete and accurate picture of the entire contents can be taken. and can be mounted in multiple configurations to cover a large area. Flexible plates can be wrapped around pipes or bent over an aircraft wing.Image plates are scanned in individually and the software seamlessly stitches them together into a single large format image so that single large items such as a suitcase or a wall area can be checked in a single scan.Where there is a risk of chemical, biological, radiological, or nuclear (CBRN) material being present in an IED additional precautions are required and in these instances an Amorphous Silicon or aSi flat panel system would be the most applicable tool for this job.Large area aSi imaging systems have a dynamic range so high it allows penetration and details previously unavailable. Their high resolution 143 micron pixel size will capture the finest detail of wiring or circuitry with a fast readout times of 1 second. Such systems can be backpacked for lightscale operations.To provide information on organics which are helpful to CBRNE responders, Asi panels can be used with Dual energy modules fitted onto a pulsed x-ray source. Dual energy allows x-rays to be measured in two different energies, which the x-ray separates into different colours to enable bomb responders to identify and differentiate organic and inorganic materials.The image processing software used to control, view and manipulate digital x-ray images is just as important as the imaging panels them. Today’s powerful image visualization software lets you focus on suspect areas and draw out details. With fewer images to examine and the ability to adjust them, a more thorough analysis is possible. Some x-ray systems are provided with imaging software proprietory to the imaging panel so that security teams operating more than 1 type of x-ray equipment often have to learn different software programs. Other software platforms such as Scanview from Scanna will operate across the entire range of x-ray imaging panels (CCD, CR and aSi) so that training requirements are greatly reduced.Scanview software is so intuitive that you can quickly master it. The X-ray image is saved within an incident record. The image file encompasses other key information such a User Name, Date, Time, Place, Type of X-ray source used, KV, Exposure time, Description, etc. The image is saved in the System Database which can be queried and sorted for fast image retrieval using any of the parameters. As the images are digital files they are easily stored & transferred to colleagues by email, CD, memory stick or even across the internet.The x-ray image data is used in a number of ways including the analysis of X-ray data for identification of explosives/initiators/booby traps, to produce technical reports on findings and develop device profiles and to maintain and document chain of custody of x-ray data.It is clear that x-ray technology available today is a quantum leap from the very first x-ray Roentgen took over a century ago and that there are many considerations to make when selecting a system. What is also clear that whatever the demands of the job, whether you need a lightweight system, a system with flexible plates, a high performance system with a wide dynamic range, a system that will operate off vehicle power or an x-ray product capable of dealing with CBRNE requirements, there are systems available off the shelf to meet those needs.。

211050371_正负压一体式无空气X_射线光电子能谱原位转移仓的开发及研制

第 29 卷第 1 期分析测试技术与仪器Volume 29 Number 1 2023年3月ANALYSIS AND TESTING TECHNOLOGY AND INSTRUMENTS Mar. 2023大型仪器功能开发(30 ~ 36)正负压一体式无空气X射线光电子能谱原位转移仓的开发及研制章小余，赵志娟，袁　震，刘　芬（中国科学院化学研究所，北京　100190）摘要：针对空气敏感材料的表面分析，为了获得更加真实的表面组成与结构信息，需要提供一个可以保护样品从制备完成到分析表征过程中不接触大气环境的装置. 通过使用O圈密封和单向密封柱，提出一种简便且有效的设计概念，自主研制了正负压一体式无空气X射线光电子能谱（XPS）原位转移仓，用于空气敏感材料的XPS测试，利用单向密封柱实现不同工作需求下正负压两种模式的任意切换. 通过对空气敏感的金属Li片和CuCl粉末进行XPS分析表明，采用XPS原位转移仓正压和负压模式均可有效避免样品表面接触空气，保证测试结果准确可靠，而且采用正压密封方式转移样品可以提供更长的密封时效性. 研制的原位转移仓具有设计小巧、操作简便、成本低、密封效果好的特点，适合给有需求的用户开放使用.关键词：空气敏感；X射线光电子能谱；原位转移；正负压一体式中图分类号：O657; O641; TH842 文献标志码：B 文章编号：1006-3757（2023）01-0030-07 DOI：10.16495/j.1006-3757.2023.01.005Development and Research of Inert-Gas/Vacuum Sealing Air-Free In-Situ Transfer Module of X-Ray Photoelectron SpectroscopyZHANG Xiaoyu， ZHAO Zhijuan， YUAN Zhen， LIU Fen（Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China）Abstract：For the surface analysis of air sensitive materials, and from the sample preparation to characterization, it is necessary to provide a device that can protect samples from exposing to the atmosphere environment so as to obtain accurate and impactful data of the surface chemistry. Through the use of O-ring and one-way sealing, a simple and effective design concept has been demonstrated, and an inert-gas/vacuum sealing air-free X-ray photoelectron spectroscopic (XPS) in-situ transfer module has been developed to realize the XPS analysis of air sensitive materials. The design of one-way sealing was achieved conveniently by switching between inert-gas and vacuum sealing modes in face of different working requirements. The XPS analysis of air-sensitive metal Li sheets and CuCl powders showed that both the sealing modes (an inert-gas/vacuum sealing) of the XPS in-situ transfer module can effectively avoid air contact on the sample surface, and consequently, can ensure the accuracy and reliability of XPS data. Furthmore, the inert gas sealing mode can keep the sample air-free for a longer time. The homemade XPS in-situ transfer module in this work is characterized by a compact design, convenient operation, low cost and effective sealing, which is suitable for the open access to the users who need it.收稿日期：2022−12−07；　修订日期：2023−01−17.基金项目：中国科学院化学研究所仪器孵化项目[Instrument and Device Functional Developing Project of Institute of Chemistry Chinese Academy of Sciences]作者简介：章小余（1986−），女，硕士，工程师，主要研究方向为电子能谱技术及材料表面分析，E-mail：xyiuzhang@ .Key words：air-sensitive；X-ray photoelectron spectroscopy；in-situ transfer；inert-gas/vacuum sealingX射线光电子能谱（XPS）是一种表面灵敏的分析技术，通常用于固体材料表面元素组成和化学态分析[1]. 作为表面分析领域中最有效的方法之一，XPS广泛应用于纳米科学、微电子学、吸附与催化、环境科学、半导体、冶金和材料科学、能源电池及生物医学等诸多领域[2-3]. 其中在催化和能源电池材料分析中，有一些样品比较特殊，比如碱金属电池[4-6]、负载型纳米金属催化剂[7-8]和钙钛矿材料[9]对空气非常敏感，其表面形态和化学组成接触空气后会迅速发生改变，直接影响采集数据的准确性和有效性，因此这类样品的表面分析测试具有一定难度. 目前，常规的光电子能谱仪制样转移过程通常是在大气环境中，将样品固定在标准样品台上，随后放入仪器进样室内抽真空至1×10−6 Pa，再转入分析室内进行测试. 这种制备和进样方式无法避免样品接触大气环境，对于空气敏感材料，其表面很容易与水、氧发生化学反应，导致无法获得材料表面真实的结构信息.为了保证样品表面状态在转移至能谱仪内的过程中不受大气环境影响，研究人员采用了各种技术来保持样品转移过程中隔绝空气. 比如前处理及反应装置与电子能谱仪腔室间真空传输[10-12]、外接手套箱 [13-14]、商用转移仓[15-16]、真空蒸镀惰性金属比如Al层（1.5~6 nm）[17]等. 尽管上述技术手段有效，但也存在一些缺点，例如配套装置体积巨大、试验过程不易操作、投入成本高等，这都不利于在普通实验室内广泛应用. 而一些电子能谱仪器制造商根据自身仪器的特点也研发出了相应配套的商用真空传递仓，例如Thermofisher公司研发的一种XPS 真空转移仓，转移过程中样品处于微正压密封状态，但其价格昂贵，体积较大，转移过程必须通过手套箱大过渡舱辅助，导致传递效率低，单次需消耗至少10 L高纯氩气，因此购置使用者较少，利用率低.另外有一些国内公司也研发了类似的商品化气体保护原位传递仓，采用微正压方式密封转移样品，但需要在能谱仪器进样室舱门的法兰上外接磁耦合机械旋转推拉杆，其操作复杂且放置样品的有效区域小，单次仅可放置尺寸为3 mm×3 mm的样品3～4个，进样和测试效率较低. 因此，从2016年起本实验团队开始自主研制XPS原位样品转移装置[18]，经过结构与性能的迭代优化[19]，最终研制出一种正负压一体式无空气XPS原位转移仓[20]（本文简称XPS原位转移仓），具有结构小巧、操作便捷、成本低、密封效果好、正压和负压密封两种模式转移样品的特点. 为验证装置的密封时效性能，本工作选取两种典型的空气敏感材料进行测试，一种是金属Li材料，其化学性质非常活泼，遇空气后表面迅速与空气中的O2、N2、S等反应导致表面化学状态改变. 另一种是无水CuCl粉末，其在空气中放置短时间内易发生水解和氧化. 试验结果表明，该XPS 原位转移仓对不同类型的空气敏感样品的无空气转移均可以提供更便捷有效的密封保护. 目前，XPS原位转移仓已在多个科研单位的实验室推广使用，支撑应用涉及吸附与催化、能源环境等研究领域.1　试验部分1.1　XPS原位转移仓的研制基于本实验室ESCALAB 250Xi型多功能光电子能谱仪器（Thermofisher 公司）的特点，研究人员设计了XPS原位转移仓. 为兼顾各个部件强度、精度与轻量化的要求，所有部件均采用钛合金材料.该装置从整体结构上分为样品台、密封罩和紧固挡板三个部件，如图1（a）~（c）所示. 在密封罩内部通过单向密封设计[图1（e）]使得XPS原位转移仓实现正负压一体，实际操作中可通过调节密封罩上的螺帽完成两种模式任意切换. 同时，从图1（e）中可以直观看到，密封罩与样品台之间通过O圈密封，利用带有螺钉的紧固挡板将二者紧密固定. 此外，为确保样品台与密封罩对接方位正确，本设计使用定向槽定位样品台与密封罩位置，保证XPS原位转移仓顺利传接到仪器进样室.XPS原位转移仓使用的具体流程：在手套箱中将空气敏感样品粘贴至样品台上，利用紧固挡板使样品台和密封罩固定在一起，通过调节密封罩上的螺帽将样品所在区域密封为正压惰性气氛（压强为300 Pa、环境气氛与手套箱内相同）或者负压真空状态，其整体装配实物图如图1（d）所示. 该转移仓结构小巧，整体尺寸仅52 mm×58 mm×60 mm，可直接放入手套箱小过渡舱传递. 由于转移仓尺寸小，其第 1 期章小余，等：正负压一体式无空气X射线光电子能谱原位转移仓的开发及研制31原料成本大大缩减，整体造价不高. 转移仓送至能谱仪进样室后，配合样品停放台与进样杆的同时双向对接，将转移仓整体固定在进样室内，如图1（f ）所示. 此时关闭进样室舱门开始抽真空，当样品台与密封罩内外压强平衡后密封罩自动解除真空密封，但仍然处于O 圈密闭状态. 等待进样室真空抽至1×10−4Pa 后，使用能谱仪进样室的样品停放台摘除脱离的密封罩[如图1（g ）所示]，待真空抽至1×10−6Pa ，即可将样品送入分析室进行XPS 测试.整个试验过程操作便捷，实现了样品从手套箱转移至能谱仪内不接触大气环境.1.2　试验过程1.2.1　样品准备及转移试验所用手套箱是布劳恩惰性气体系统（上海）有限公司生产，型号为MB200MOD （1500/780）NAC ；金属Li 片购自中能锂业，纯度99.9%；CuCl 购自ALFA 公司，纯度99.999%.金属Li 片的制备及转移：将XPS 原位转移仓整体通过手套箱过渡舱送入手套箱中，剪取金属Li 片用双面胶带固定于样品台上，分别采用正压、负压两种密封模式将XPS 原位转移仓整体从手套箱中取出，分别在空气中放置0、2、4、8、18、24、48、72 h 后送入能谱仪内，进行XPS 测试.CuCl 粉末的制备及转移：在手套箱中将CuCl 粉末压片[21]，使用上述同样的制备方法，将XPS 原位转移仓整体在空气中分别放置0、7、24、72 h 后送入能谱仪内，进行XPS 测试.1.2.2　样品转移方式介绍样品在手套箱中粘贴完成后，分别采用三种方式将其送入能谱仪. 第一种方式是在手套箱内使用标准样品台粘贴样品，将其装入自封袋密封，待能谱仪进样室舱门打开后，即刻打开封口袋送入仪器中开始抽真空等待测试，整个转移过程中样品暴露空气约15 s. 第二种方式是使用XPS 原位转移仓负压密封模式转移样品，具体操作步骤：利用紧固挡板将样品台和密封罩固定在一起，逆时针（OPEN ）旋动螺帽至顶部，放入手套箱过渡舱并将其抽为真空，此过程中样品所在区域也抽至负压. 取出整体装置后再顺时针（CLOSE ）旋动螺帽至底部，将样品所在区域进一步锁死密封. 样品在负压环境中转移至XPS 实验室，拆卸掉紧固挡板，随即送入能谱仪进样室内. 第三种方式是使用XPS 原位转移仓正压密封模式转移样品，具体操作步骤：利用紧固挡板将样品台和密封罩固定在一起，顺时针（CLOSE ）旋螺帽抽气管限位板单向密封柱密封罩主体O 圈样品台紧固挡板(e) 密封罩对接停放台机械手样品台对接进样杆(a)(b)(c)(d)(g)图1　正负压一体式无空气XPS 原位转移仓系统装置（a ）样品台，（b ）密封罩，（c ）紧固挡板，（d ）整体装配实物图，（e ）整体装置分解示意图，（f ）样品台与密封罩在进样室内对接完成，（g ）样品台与密封罩在进样室内分离Fig. 1　System device of inert-gas/vacuum sealing air-free XPS in-situ transfer module32分析测试技术与仪器第 29 卷动螺帽至底部，此时样品所在区域密封为正压惰性气氛. 直至样品转移至XPS 实验室，再使用配套真空抽气系统（如图2所示），通过抽气管将样品所在区域迅速抽为负压，拆卸掉紧固挡板，随即送入能谱仪进样室内.图2　能谱仪实验室内配套真空抽气系统Fig. 2　Vacuum pumping system in XPSlaboratory1.2.3　XPS 分析测试试验所用仪器为Thermo Fisher Scientific 公司的ESCALAB 250Xi 型多功能X 射线光电子能谱仪，仪器分析室基础真空为1×10−7Pa ，X 射线激发源为单色化Al 靶（Alk α，1 486.6 eV ），功率150 W ，高分辨谱图在30 eV 的通能及0.05 eV 的步长等测试条件下获得，并以烃类碳C 1s 为284.8 eV 的结合能为能量标准进行荷电校正.2　结果与讨论2.1　测试结果分析为了验证XPS 原位转移仓的密封性能，本文做了一系列的对照试验，选取空气敏感的金属Li 片和CuCl 粉末样品进行XPS 测试，分别采用上述三种方式转移样品，并考察了XPS 原位转移仓密封状态下在空气中放置不同时间后对样品测试结果的影响.2.1.1　负压密封模式下XPS 原位转移仓对金属Li片的密封时效性验证将金属Li 片通过两种（标准和负压密封）方式转移并在空气中放置不同时间，对这一系列样品进行XPS 测试，Li 1s 和C 1s 高分辨谱图结果如图3（a ）（b ）所示，试验所测得的Li 1s 半峰宽值如表1所列. 根据XPS 结果分析，金属Li 片采用标准样品台进样（封口袋密封），短暂暴露空气约15 s ，此时Li 1s 的半峰宽为1.62 eV. 而采用XPS 原位转移仓负压密封模式转移样品时，装置整体放置空气18 h 内，Li 1s 的半峰宽基本保持为（1.35±0.03） eV. 放置空气24 h 后，Li 1s 的半峰宽增加到与暴露空气15 s 的金属Li 片一样，说明此时原位转移仓的密封性能衰减，金属Li 片与渗入内部的空气发生反应生成新物质导致Li 1s 半峰宽变宽. 由图3（b ）中C 1s 高分辨谱图分析，结合能位于284.82 eV 的峰归属为C-C/污染C ，位于286.23 eV 的峰归属为C-OH/C-O-CBinding energy/eVI n t e n s i t y /a .u .Li 1s半峰宽增大暴露 15 s密封放置 24 h 密封放置 18 h 密封放置 8 h 密封放置 4 h 密封放置 0 h6058565452Binding energy/eVI n t e n s i t y /a .u .C 1s(a)(b)暴露 1 min 暴露 15 s 密封放置 24 h 密封放置 18 h 密封放置 0 h292290288284282286280图3　金属Li 片通过两种（标准和负压密封）方式转移并在空气中放置不同时间的（a ）Li 1s 和（b ）C 1s 高分辨谱图Fig. 3　High-resolution spectra of (a) Li 1s and (b) C 1s of Li sheet samples transferred by two methods (standard andvacuum sealings) and placed in air for different times第 1 期章小余，等：正负压一体式无空气X 射线光电子能谱原位转移仓的开发及研制33键，位于288.61~289.72 eV的峰归属为HCO3−/CO32−中的C[22]. 我们从C 1s的XPS谱图可以直观的看到，与空气短暂接触后，样品表面瞬间生成新的结构，随着暴露时间增加到1 min，副反应产物大量增加（HCO3−/CO32−）. 而XPS原位转移仓负压密封模式下在空气中放置18 h内，C结构基本不变，在空气中放置24 h后，C结构只有微小变化. 因此根据试验结果分析，对于空气极其敏感的材料，在负压密封模式下，建议XPS原位转移仓在空气中放置时间不要超过18 h. 这种模式适合对空气极其敏感样品的短距离转移.表 1 通过两种（标准和负压密封）方式转移并在空气中放置不同时间的Li 1s的半峰宽Table 1　Full width at half maxima (FWHM) of Li 1stransferred by two methods (standard and vacuum sealings) and placed in air for different times样品说明进样方式半峰宽/eV密封放置0 h XPS原位转移仓负压密封模式转移1.38密封放置2 h同上 1.39密封放置4 h同上 1.36密封放置8 h同上 1.32密封放置18 h同上 1.32密封放置24 h同上 1.62暴露15 s标准样品台进样（封口袋密封）1.622.1.2　正压密封模式下原位转移仓对金属Li片的密封时效性验证将金属Li片通过两种（标准和正压密封）方式转移并在空气中放置不同时间，对这一系列样品进行XPS测试，Li 1s高分辨谱图结果如图4所示，所测得的Li 1s半峰宽值如表2所列. 根据XPS结果分析，XPS原位转移仓正压密封后，在空气中放置72 h内，Li 1s半峰宽基本保持为（1.38±0.04） eV，说明有明显的密封效果，金属Li片仍然保持原有化学状态. 所以对于空气极其敏感的材料，在正压密封模式下，可至少在72 h内保持样品表面不发生化学态变化. 这种模式适合长时间远距离（可全国范围内）转移空气敏感样品.2.1.3　负压密封模式下XPS原位转移仓对空气敏感样品CuCl的密封时效性验证除了金属Li片样品，本文还继续考察XPS原位转移仓对空气敏感样品CuCl的密封时效性. 图5为CuCl粉末通过两种（标准和负压密封）方式转移并在空气中放置不同时间的Cu 2p高分辨谱图. XPS谱图中结合能[22]位于932.32 eV的峰归属为Cu+的Cu 2p3/2，位于935.25 eV的峰归属为Cu2+的Cu 2p3/2，此外，XPS谱图中位于940.00~947.50 eV 处的峰为Cu2+的震激伴峰，这些震激伴峰被认为是表 2 通过两种（标准和正压密封）方式转移并在空气中放置不同时间的Li 1s的半峰宽Table 2　FWHM of Li 1s transferred by two methods(standard and inert gas sealings) and placed in air fordifferent times样品说明进样方式半峰宽/eV 密封放置0 h XPS原位转移仓正压密封模式转移1.42密封放置2 h同上 1.35密封放置4 h同上 1.35密封放置8 h同上 1.34密封放置18 h同上 1.38密封放置24 h同上 1.39密封放置48 h同上 1.42密封放置72 h同上 1.38暴露15 s标准样品台进样（封口袋密封）1.62Binding energy/eVIntensity/a.u.Li 1s半峰宽比正压密封的宽半峰宽=1.62 eV半峰宽=1.38 eV暴露 15 s密封放置 72 h密封放置 48 h密封放置 24 h密封放置 18 h密封放置 0 h605856545250图4　金属Li片通过两种（标准和正压密封）方式转移并在空气中放置不同时间的Li 1s高分辨谱图Fig. 4　High-resolution spectra of Li 1s on Li sheet samples transferred by two methods (standard and inert gas sealings) and placed in air for different times34分析测试技术与仪器第 29 卷价壳层电子向激发态跃迁的终态效应所产生[23]，而在Cu +和Cu 0中则观察不到.根据XPS 结果分析，CuCl 在XPS 原位转移仓保护（负压密封）下，即使放置空气中72 h ，测得的Cu 2p 高分辨能谱图显示只有Cu +存在，说明CuCl 并未被氧化. 若无XPS 原位转移仓保护，CuCl 粉末放置空气中3 min 就发生了比较明显的氧化，从测得的Cu 2p 高分辨能谱图能够直观的看到Cu 2+及其震激伴峰的存在，并且随着放置时间增加到40 min ，其氧化程度也大大增加. 因此，对于空气敏感的无机材料、纳米催化剂和钙钛矿材料等，采用负压密封模式转移就可至少在72 h 内保持样品表面不发生化学态变化.3　结论本工作中自主研制的正负压一体式无空气XPS原位转移仓在空气敏感样品转移过程中可以有效隔绝空气，从而获得样品最真实的表面化学结构.试验者可根据样品情况和实验室条件选择转移模式，并在密封有效时间内将样品从实验室转移至能谱仪中完成测试. 综上所述，该XPS 原位转移仓是一种设计小巧、操作简便、密封性能优异、成本较低的样品无水无氧转移装置，因此非常适合广泛开放给有需求的试验者使用. 在原位和准原位表征技术被广泛用于助力新材料发展的现阶段，希望该设计理念能对仪器功能的开发和更多准原位表征测试的扩展提供一些启示.参考文献：黄惠忠. 论表面分析及其在材料研究中的应用[M ].北京: 科学技术文献出版社, 2002: 16-18.［ 1 ］杨文超, 刘殿方, 高欣, 等. X 射线光电子能谱应用综述[J ]. 中国口岸科学技术，2022，4（2）：30-37.[YANG Wenchao, LIU Dianfang, GAO Xin, et al.TheapplicationofX -rayphotoelectronspectroscopy [J ]. China Port Science and Technology ，2022，4 （2）：30-37.]［ 2 ］郭沁林. X 射线光电子能谱[J ]. 物理，2007，36（5）：405-410. [GUO Qinlin. X -ray photoelectron spectro-scopy [J ]. Physics ，2007，36 （5）：405-410.]［ 3 ］Malmgren S, Ciosek K, Lindblad R, et al. Con-sequences of air exposure on the lithiated graphite SEI [J ]. Electrochimica Acta ，2013，105 ：83-91.［ 4 ］Zhang Y H, Chen S M, Chen Y, et al. Functional poly-ethylene glycol-based solid electrolytes with enhanced interfacial compatibility for room-temperature lithium metal batteries [J ]. Materials Chemistry Frontiers ，2021，5 （9）：3681-3691.［ 5 ］周逸凡, 杨慕紫, 佘峰权, 等. X 射线光电子能谱在固态锂离子电池界面研究中的应用[J ]. 物理学报，2021，70（17）：178801. [ZHOU Yifan, YANG Muzi,SHE Fengquan, et al. Application of X -ray photoelec-tron spectroscopy to study interfaces for solid-state lithium ion battery [J ]. Acta Physica Sinica ，2021，70（17）：178801.]［ 6 ］Huang J J, Song Y Y, Ma D D, et al. The effect of thesupport on the surface composition of PtCu alloy nanocatalysts: in situ XPS and HS-LEIS studies [J ].Chinese Journal of Catalysis ，2017，38 （7）：1229-1236.［ 7 ］Koley P, Shit S C, Sabri Y M, et al. Looking into moreeyes combining in situ spectroscopy in catalytic bio-fuel upgradation with composition-graded Ag-Co core-shell nanoalloys [J ]. ACS Sustainable Chemistry &Engineering ，2021，9 （10）：3750-3767.［ 8 ］Opitz A K, Nenning A, Rameshan C, et al. Enhancingelectrochemical water-splitting kinetics by polarization-driven formation of near-surface iron(0): an in situ XPS study on perovskite-type electrodes [J ]. Ange-wandte Chemie (International Ed in English)，2015，54（9）：2628-2632.［ 9 ］Czekaj I, Loviat F, Raimondi F, et al. Characterization［ 10 ］Binding energy/eVI n t e n s i t y /a .u .Cu 2pCu +Cu 2+暴露 3 min暴露 40 min 密封放置 7 h 密封放置 72 h 密封放置 24 h密封放置 0 h960950945935925955940930920图5　CuCl 粉末通过两种（标准和负压密封）方式转移并在空气中放置不同时间的Cu 2p 高分辨谱图Fig. 5　High-resolution spectra of Cu 2p on CuCl powder samples transferred by two methods (standard and vacuumsealings) and placed in air for different times第 1 期章小余，等：正负压一体式无空气X 射线光电子能谱原位转移仓的开发及研制35of surface processes at the Ni-based catalyst during the methanation of biomass-derived synthesis gas: X -ray photoelectron spectroscopy (XPS)[J ]. Applied Cata-lysis A:General ，2007，329 ：68-78.Rutkowski M M, McNicholas K M, Zeng Z Q, et al.Design of an ultrahigh vacuum transfer mechanism to interconnect an oxide molecular beam epitaxy growth chamber and an X -ray photoemission spectroscopy analysis system [J ]. Review of Scientific Instruments ，2013，84 （6）：065105.［ 11 ］伊晓东, 郭建平, 孙海珍, 等. X 射线光电子能谱仪样品前处理装置的设计及应用[J ]. 分析仪器，2008（5）：8-11. [YI Xiaodong, GUO Jianping, SUN Haizhen, et al. Design of a sample pretreatment device for X -ray photoelectron spectrometer [J ]. Analytical Instrumentation ，2008 （5）：8-11.]［ 12 ］Aurbach D, Weissman I, Schechter A, et al. X -ray pho-toelectron spectroscopy studies of lithium surfaces pre-pared in several important electrolyte solutions. A comparison with previous studies by Fourier trans-form infrared spectroscopy [J ]. Langmuir ，1996，12（16）：3991-4007.［ 13 ］Światowska-Mrowiecka J, Maurice V, Zanna S, et al.XPS study of Li ion intercalation in V 2O 5 thin films prepared by thermal oxidation of vanadium metal [J ].Electrochimica Acta ，2007，52 （18）：5644-5653.［ 14 ］Weingarth D, Foelske-Schmitz A, Wokaun A, et al. Insitu electrochemical XPS study of the Pt/[BF 4]system [J ]. Electrochemistry Communications ，2011，13 （6）：619-622.［ 15 ］Schneider J D, Agocs D B, Prieto A L. Design of asample transfer holder to enable air-free X -ray photo-electron spectroscopy [J ]. Chemistry of Materials ，2020，32 （19）：8091-8096.［ 16 ］Karamurzov B S, Kochur A G, Misakova L B, et al.Calculation of the pure surface composition of the bin-ary alloy according to XPS data obtained after the al-loy surface contact with air [J ]. Journal of Structural Chemistry ，2015，56 （3）：576-581.［ 17 ］章小余, 赵志娟. 一种半原位XPS 样品转移装置: 中国, 201620925237.5[P ]. 2017-02-15.［ 18 ］章小余, 袁震, 赵志娟. 一种半原位X 射线光电子能谱分析仪的样品转移装置: 中国, 201720056623.X [P ]. 2017-12-08.［ 19 ］袁震, 章小余, 赵志娟. 一种样品转移装置及转移方法: 中国, 2011203822.1[P ]. 2022-03-01.［ 20 ］刘芬, 赵志娟, 邱丽美, 等. XPS 分析固体粉末时的样品制备法研究[J ]. 分析测试技术与仪器，2007，13（2）：107-109. [LIU Fen, ZHAO Zhijuan, QIU Limei, et al. Study of sample preparation method for XPS analysis of powdered samples [J ]. Analysis and Testing Technology and Instruments ，2007，13 （2）：107-109.]［ 21 ］Wagner C D, Riggs W M, Davis L E, et al. Handbookof X -ray photoelectron spectroscopy [M ]. Eden Prair-ie, Minnesota, 1978.［ 22 ］Watts J F, Wolstenholme J. 表面分析(XPS 和AES)引论[M ]. 吴正龙, 译. 上海: 华东理工大学出版社,2008.［ 23 ］36分析测试技术与仪器第 29 卷。

OE

曹老师，魏来：我看了意见，修改后是可能接受的。

修改主要是引言部分加入更多文献和说明，以及魏来设计的公式（7）-（9）的说明。

其它按照意见改好就可。

魏来按照审稿意见先改起来吧。

第二条意见中“OSA aperture” 我不明白。

要不要我问下编辑？除了审稿意见，编辑部的格式要求等意见，包括只能一个作者的邮件列出；出版费。

你们商量下。

如果列曹老师的邮件，下次投稿就直接由你们投出，以避免编辑部误解或再返到我这里。

我把意见和投稿地址等全部转发给你。

祝好！王晓方-----Original E-mail-----From: opex@Sent Time: 2011-8-18 2:20:46To: wang1@Cc:Subject: [SPAM] Decision for Optics Express Manuscript 150301Manuscript ID: 150301 Type: RegularTitle: Annulus-sector-element coded Gabor zone plate at the x-ray wavelengthAuthor: Xiaofang Wang;Dear Dr. Wang:Before making a decision on your manuscript, I would like to give you an opportunity to address the reviewer concerns. The reviews are appended below.It is the policy of Optics Express to allow only one manuscript revision. Thus it is important to respond to all of the reviewer points carefully and to make it evident that you have done so. For this reason, please note any changes that have been made to the manuscript and indicate their locations. You may type your response directly into the designated comment text box provided online. You can also update your statement asa separate file. Of course, you may not agree with the reviewers on every point; in this case, your responses and reasoning should be clearly presented. Your manuscript might be sent for re-review upon resubmission. If your paper is accepted, you will not have another opportunity to submit additional content revisions. OSA cannot make any changes to your manuscript once it appears on the Forthcoming web site.In addition to the reviewer comments, it is important that you address the production editor's notes included below, which contain format changes required to ensure that it adheres to the style guidelines of Optics Express.Please submit your revised manuscript via the Optics Express online system at/90510b07-f16d-4b50-a8ed-d53e87f6f419/oe/asBe sure to upload the native file, such as Word with embedded figures, or tar gzipped TeX with .eps figures. You will have 10 days to complete the resubmission with content and style changes. Please carefully proofread your paper before resubmission. Optics Express articles are not copyedited.Thank you for your contribution to Optics Express. If you have any questions, please contact the journal assistant at opex@.Sincerely,David PaganinAssociate Editor, Optics Express---------------------------Reviewer comments appear here:Report on manuscript: 150301 titled: "Annulus-sector-element coded Gabor zone plate at the x-ray wavelength".The paper could be of some interest for the readers of Optic Express even if the proposed optical element doesn’t show par ticular new interesting features compared to well known classical Fresnel zone plates.Nevethless let me be more specific regarding the paper.1) The introduction is too superficial because the statement regarding foci orders regards only binary zone plates. When a multilevel zone plateis considered, or more in general a blazed zone plate, the efficiency of the first order becomes dominant, and in the case of a 4 level zone plate, the first order has a theoretical efficiency of 82%.The third order is suppressed and the first active order is the fifth, whose efficiency is 1/25 smaller that the first order.In case of ideal blazed zone plate the first order has an efficiency of almost 100%.2) Even limiting the comparison to binary zone plate, in case of pure phase shift zone plate, the first order has an efficiency of 40% (neglecting the absorption) that is about a factor 4 higher that the proposed ASZP in the paper, even if, in case of binary zone plate, in order to remove the background of the third order it is needed an OSA aperture.The authors should include historical references on “conventional” zone plate and their use. Such as:a) David Attwood nature photonics | VOL 4 |, pag. 840, DECEMBER 2010 | /naturephotonicsb) Di Fabrizio, E., Romanato, F., Gentill, M., Cabrini, S., Kaulich, B., Susini, J., Barrett, R. “High-efficiency multilevel zone plates for keV X-rays”(1999) Nature, 401 (6756), pp. 895-898c) Di Fabrizio, E., Cojoc, D., Cabrini, S., Kaulich, B., Susini, J., Facci, P., Wilhein, T.Diffractive optical elements for differential interference contrastx-ray microscopy(2003) Optics Express, 11 (19), pp. 2278-2288.3) In page 2 row 7 from bottom, “annuals” should be changed by “annular”Formula (7), is obtained for zone index n>>1 (valid for outermost zone) instead in the formula n= or >1.Formula (8) need a wider explanation of its meaning and use.ri is not defined. In the same page4) Comments on figure 2. It is true that state of art fabrication can reach 13 nm and, I would say even better, but the zone rings are circular and smooth. If in the fabrication the zone are fragmentized as for ASZP or BGZP, the fabrication,especially for the medium and outermost zone becomes almost impossible, for sure figure 2a is not less difficult than figure 2b.As a final comment, I’m not against the publication of this paper, but the introduction has to be written more accurately, and contradiction or limitation in the formulas 7, 8, 9 has to mandatory be corrected or explicitly stated and not simply referring to previous literature.----------------------------STYLE CORRECTIONSOnly one author email can be listed and must be at the end of the author listing.The commas following the article titles should be inside the quotation marks.In the section and sub-section headings, use an initial capital letter followed by lowercase, except for proper names, abbreviations, etc.Authors must use one image file per figure. Please use one image file for the figures with more than one part (ie: incorporate part a and b into one image file instead of two). Also, please add the letter label (a, b, c ect.) into the image file. This will help us prepare your manuscript for publication producing full-text XML.[x] Please ensure that all references, figures, and tables are called out in the text.Your content and style corrections are due August 27th. If you have any questions, please contact us.***If this paper is accepted finally, the invoice will be addressed to you. Please let us know when you submit your revisions (by emailing opex@) if there is any reason it should be addressed differently.。

X-ray

Nick Veasey: Exposing the invisibleSo, 120 years ago, Dr. Röntgen X-rayed his wife's hand. Quite why he had to pin her fingers to the floor with her brooch, I'm not sure. It seems a bit extreme to me. That image was the start of the X-ray technology. And I'm still fundamentally using the same principles today. I'm interpreting it in a more contemporary manner.The first shot I ever did was of a soda can, which was to promote a brand that we all know, so I'm not going to do them any favors by showing you it. But the second shot I did was my shoes I was wearing on the day. And I do really like this shot, because it shows all the detritus that's sort of embedded in the sole of the sneakers. It was just one of those pot-luck things where you get it right first time.Moving on to something a bit larger, this is an X-ray of a bus. And the bus is full of people. It's actually the same person. It's just one skeleton. And back in the '60s, they used to teach student radiographers to take X-rays, thankfully not on you and I, but on dead people. So, I've still got access to one of these dead people called Frieda; she's falling apart, I'm afraid, because she's very old and fragile. But everyone on that bus is Frieda. And the bus is taken with a cargo-scanning X-ray, which is the sort of machine you have on borders, which checks for contraband and drugs and bombs and things.Fairly obvious what that is. So, using large-scale objects does sort of create drama because you just don't see X-rays of big things that often. Technology is moving ahead, and these large cargo scanner X-rays that work with the digital system are getting better and better and better. Again though, to make it come alive you need, somehow, to add the human element. And I think the reason this image works, again, is because Frieda is driving the bulldozer. (Laughter)Quite a difficult brief, make a pair of men's pants look beautiful. But I think the process, in itself, shows how exquisite they are. Fashion -- now, I'm sort of anti-fashion because I don't show the surface, I show what's within. So, the fashionistas don't really like me because it doesn't matter if Kate Moss is wearing it or if I'm wearing it, it looks the same. (Laughter) We all look the same inside, believe me. The creases in the material and the sort of nuances. And I show things for really what they are, what they're made of. I peel back the layers and expose it. And if it's well made I show it, if it's badly made I show it.And I'm sure Ross can associate that with design. The design comes from within. It's not just Topshop, I get some strange looks when I go out getting my props. Here I was fumbling around in the ladies' underwear department of a department store, almost got escorted from the premises. I live opposite a farm. And this was the runt of the litter, a piglet that died. And what's really interesting is, if you look at the legs, you'll notice that the bones haven't fused. And should that pig have grown, unfortunately it was dead, it would have certainly been dead after I X-rayed it, with the amount of radiation I used anyway. (Laughter) But once the bones had fused together it would have been healthy.So, that's an empty parka jacket. But I quite love the way it's posed. Nature is my greatest inspiration. And to carry on with a theme that we've already touched with is how nature is related to architecture. If you look at the roof of the Eden Project, or the British library, it's all this honeycomb structure. And I'm sure those architects are inspired, as I am, by what surrounds us, by nature. This, in fact, is a Victoria water lily leaf that floats on the top of a pond. An amaryllis flower looking really three-dimensional. Seaweed, ebbing in the tide. Now, how do I do this, and where do I do this, and all of that sort of thing.This is my new, purpose-built, X-ray shed. And the door to my X-ray room is made of lead and steel. It weighs 1,250 kilograms and the only exercise I get is opening and closing it. (Laughter) The walls are 700 millimeters thick of solid dense concrete. So, I'm using quite a lot of radiation.A lot more than you'd get in a hospital or a vet's. And there I am. This is a quite high-powered X-ray machine. What's interesting really about X-ray really is, if you think about it, is that that technology is used for looking for cancer or looking for drugs, or looking for contraband or whatever. And I use that sort of technology to create things that are quite beautiful.So, still working with film, I'm afraid. Technology in X-ray where it's life-size processed, apart from these large cargo-scanning machines, hasn't moved on enough for the quality of the image and the resolution to be good enough for what I want to do with it, which is show my pictures big. So, I have to use a 1980s drum scanner, which was designed in the days when everyone shot photographs on film. They scan each individual X-ray. And this shows how I do my process of same-size X-rays. So, this is, again, my daughter's dress. Still has the tag in it from me buying it, so I can take it back to the shop if she didn't like it. But there are four X-ray plates. You can see them overlapping.So, when you move forward from something fairly small, a dress which is this size, onto something like that which is done in exactly the same process, you can see that that is a lot of work. In fact, that is three months solid X-raying. There is over 500 separate components. Boeing sent me a 747 in containers. And I sent them back an X-ray. (Laughter) I kid you not.Okay, so Frieda is my dead skeleton. This, unfortunately, is basically two pictures. One on the extreme right is a photograph of an American footballer. The one on the left is an x-ray. But this time I had to use a real body. Because I needed all the skin tissue to make it look real, to make it look like it was a real athlete. So, here I had to use a recently deceased body. And getting a hold of that was extremely difficult and laborious. But people do donate their bodies to art and science. And when they do, I'm in the queue. So, I like to use them. (Laughter)The coloring, so coloring adds another level to the X-rays. It makes it more organic, more natural. It's whatever takes my fancy, really. It's not accurately colored to how it is in real life. That flower doesn't come in bright orange, I don't think. But I just like it in bright orange. And also with something technical, like these are DJ decks, it sort of adds another level. It makes a two dimensional image look more three dimensional.The most difficult things to X-ray, the most technically challenging things to X-ray are the lightestthings, the most delicate things. To get the detail in a feather, believe me, if there is anyone out here who knows anything about X-rays, that's quite a challenge. I'm now going to show you a short film, I'll step to the side.Video: (Music) The thing in there is very dangerous. If you touch that, you could possibly die through radiation poisoning. In my career I've had two exposures to radiation, which is two too many, because it stays with you for life. It's cumulative.(Music) It has human connotations. The fact that it's a child's toy that we all recognize, but also it looks like it's a robot, and it comes from a sci-fi genus. It's a surprise that it has humanity, but also man-made, future, alien associations. And it's just a bit spooky.(Music) The bus was done with a cargo-scanning X-ray machine, which is used on the borders between countries, looking for contraband and illegal immigrants. The lorry goes in front of it. And it takes slices of X-rays through the lorry. And that's how this was done. It's actually slice, slice. It's a bit like a CT scanner in a hospital. Slices. And then if you look carefully, there is all little things. He's got headphones on, reading the newspaper, got a hat on, glasses, got a bag. So, these little details help to make it work, make it real.(Music) The problem with using living people is that to take an X-ray, if I X-ray you, you get exposed to radiation. So, to avoid that -- I have to avoid it somehow -- is I use dead people. Now, that's a variety of things, from recently deceased bodies, to a skeleton that was used by student radiographers to train in taking X-rays of the human body, at different densities.(Music) I have very high-tech equipment of gloves, scissors and a bucket.(Music) I will show how the capillary action works, how it feeds, I'll be able to get all the cells inside that stem. Because it transfers food from its roots to its leaves. Look at this monster.(Music) It's so basic. It just grows wild. That's what I really like about it, the fact that I haven't got to go and buy it, and it hasn't been genetically modified at all. It's just happening. And the X-ray shows how beautiful nature can be. Not that that is particularly beautiful when you look at it with the human eye, the way the leaves form. They're curling back on each other. So the X-ray will show the overlaps in these little corners. The thicker the object, the more radiation it needs, and the more time it needs. The lighter the object, the less radiation. Sometimes you keep the time up, because the time gives you detail. The longer the exposure goes on for, the more detail you get.(Music) If you look at this, just the tube, it is quite bright. But I could get a bit darker in the tube, but everything else would suffer. So, these leaves at the edge would start to disappear. What I like is how hard the edges are, how sharp. Yeah, I'm quite pleased with it.(Music) I travel beyond the surface and show something for what it's worth, for what it's really made of, how it really works. But also I find that I've got the benefit of taking away all the surface, which is things that people are used to seeing.And that's the sort of thing I've been doing. I've got the opportunity now to show you what I'm going to be doing in the future. This is a commercial application of my most recent work. And what's good about this, I think, is that it's like a moment in time, like you've turned around, you've got X-ray vision and you've taken a picture with the X-ray camera. Unfortunately I haven't got X-ray vision. I do dream in X-ray. I see my projects in my sleep. And I know what they're going to look like in X-ray and I'm not far off.So, what am I doing in the future? Well, this year is the 50th anniversary of Issigonis's Mini, which is one of my favorite cars. So, I've taken it apart, component by component, months and months and months of work. And with this image, I'm going to be displaying it in the Victoria and Albert Museum as a light box, which is actually attached to the car. So, I've got to saw the car in half, down the middle, not an easy task, in itself. And then, so you can get in the driver's side, sit down, and up against you is a wall. And if you get out and walk around to the other side of the car, you see a life-sized light box of the car showing you how it works.And I'm going to take that idea and apply it to other sort of iconic things from my life. Like, my first computer was a big movement in my life. And I had a Mac Classic. And it's a little box. And I think that would look quite neat as an X-ray. I'm also looking to take my work from the two-dimensional form to a more three-dimensional form. And this is quite a good way of doing it. I'm also working now with X-ray video. So, if you can imagine, some of these flowers, and they're actually moving and growing and you can film that in X-ray, should be quite stunning. But that's it. I'm done. Thank you very much. (Applause)。

07铁电开关(x射线)

Progress in switching studies: to 50 µm ‘play’ device: switching speed limited to ~10nsec Smaller devices allow faster switching Need for microbeam capabilities
What are ferroelectrics?
Spontaneous permanent electric polarization. Unit cell of crystal is non-centrosymmetric (charges separated) A macroscopic sample with net zero polarization
STO SRO
hf
SrTiO3 SrRuO3 PMN-PT
θ θ
detector
1.58
1.58
L
1.56
1.56
PMN7PT3 PMN Scattering shown for epitaxial films (thickness~250nm) of PMN and PMN-PT
1.54 -0.02 0.0 1.54 0.02 -0.02 0.0 0.02
The study of ferroelectric switching using x-ray synchrotron radiation
Carol Thompson
Science with Microbeams APS Scientific Advisory Cross-cut Review January 21, 2004
11
C. Thompson, et al.

X射线的种类及应用

X射线的种类及应用摘要：Like many imperishable discoveries,X-rays’s invention or discovery was accidental. 1895 at Wurzburg, Wilhelm Rontgen discovered X-rays (Rontgen rays). After all these years, the technology of the X-rays has not only got extensivedevelopment in industry, also play a more and more important role in medical science. It is mainly used for the human body perspective and check injury. While scientists explore the essence of，they found the phenomenon of diffraction of X-rays and opened the gate of the crystal structure. With the widely use of x-ray both in micro fields and macro fields, it have brought great gospel to human.引言：自1895年X射线被发现，X射线已被广泛应用到医疗卫生、军事、科学及工农业各方面，为人类社会的发展做出了巨大贡献。

在X射线自从发现以来，医学就成为其主要应用，经过近百年的发展，X射线技术已广泛的应用于医学影像诊断，成为医学临床和科研不可或缺的因素。

本文就X射线的分类以及X射线的主要运用展开论述。

具体内容如下：内容X射线是一种波长很短的电磁辐射，其波长约为（20～0.06）×10-8厘米之间，又称伦琴射线。

XGT-9000 XRF分析微观显微镜说明书

XGT-9000XRF Analytical MicroscopeScreen, Check, Map and MeasureThe combination of elemental images and transmission images allows one to detect hidden defects.Large working distance and coaxial vertical optics provide a clear transmission image without the shadow effect in undulating electronic boards.with elemental image only)and identifiedLine profile of blue part What is the XGT-9000?Screen, check, map and measureThe XGT-9000 is an X-ray Fluorescence Analytical Microscope, which provides non-destructive elemental analysis of materials.Incident X-ray beam is guided towards thesample placed on the mapping stage.X-ray fluorescence spectrum and transmission X-ray intensity are recorded at each point.Information available: Qualitative & quantitative elemental analysis/Mapping/Hyperspectral imaging.123Optical image Elemental imagesTransmission image Elemental imagesTransmission imageTransmission imageFull spectrum at each pixelfil f blXYThe XGT-9000 can detect anddetermine the composition of foreign particles, and therefore track the source of contamination.X-ray Fluorescence photons can be partially absorbed by theencapsulated material and will not show in the spectrum. The X-ray transmission image provides a complete picture.XGT-9000 with a wide range of applicationsOptical imageTiCrFeX-ray backscatter imageX-ray transmission imageAu thicknessOptical imageMapping areaLayered imageAu patternThe combination of microbeam and thickness measurement capability makes the XGT-9000 a useful tool for the QC of semiconductors,which feature thin and narrow patterns. Thickness sensitivity depends on elements traced, but can be at the Angstrom level.Biological samples contain water or gas, and will be heavily modified or damaged if measured in a vacuum. The unique partial vacuum mode of the XGT-9000 keeps the sample in ambient conditions while the detection is in a vacuum for optimum light elements measurement.Archeological artifacts are valuable materials and can only be analyzed by non-destructive methods.Dragonfly eye: XGT-9000 measurement has helped to ascertain the Dragonfly eye found in China actually originated Egypt/Middle East during the 2nd century B.C.Sample: Foreign matter in thecapsuleSample: Fly5 c mAlCaCu ComImage processing for mappingStandard GUI RoHS mode GUI Raw imageFloating viewQueue functionMultiple measurements including mapping /multi pointsResult list viewOptical imageParticle detectionFe image Particle detectionEdited GUIProcessed imageThe user interface offers a flexible way to measure multiple samples or areas in unattended mode (queue function),display the analytical results, present the data, and edit reports. Advanced treatments include image processing, particle finder, colocalization measurement and multivariate analysis (refer to "Combination of XRF and Raman Spectroscopies").XGT-9000 Software SuiteThe particle finding function is available from all the 3 images in the XGT-9000 (Optical, Fluorescence X-ray and Transmission). The particle finding function automatically detects particles and marks their position for multi-point measurement, classification and analysis.Coordinates of detected particles are automatically stored and transferred to the multi-point analysis modeViewbaTeh t s ak c a t S dn a p x ELabSpec linkCombination of XRF9 samples For 2”/4” wafersLow backgroundXGT-9000SLThe XGT-9000SL provides a non-destructive analysis of your most valuable pieces, which may be large or fragile.MESA-50 seriesElemental analysis and RoHS characterizationSLFA seriesThe reference instrument for sulfur-in-oil analysisIn/On-line solutionsReal time analysis forthickness and compositionDo more with your HORIBA XRFHORIBA XRF family* The sample chamber of the XGT-9000SL complies with the radiation safety requirement. The sample is measured in ambient conditions, while the detector operates at ambient or vacuum modes.XRF and Raman spectroscopies are complementary techniques.XRF provides information about elemental composition of the material, whereas Raman spectroscopy offers molecular information.Co-localized measurements between the XGT-9000 and HORIBA Raman spectrometers provide more information about the sample.Transfer of the XGT-9000 data to the advanced LabSpec Suite software using LabSpec link.Various sample holders areprovided to fit different shapes and types of samples.Fast and easy change between holders with HORIBA's modularstage design.Customization examplesTransfer vessel:Measurement of samples isolatedfrom airDimensionsXGT-9000SLXGT-9000(Unit: mm)(134)(476)(38)(9)(50)(1500)(2640)(1090)(1837)(1616)(74)(12)(16)(159)(769)74(2400)1800)003()003()A E R A E C N A N E T N A M()A E R A E C N A N E T N A M((3)(MANTENANCEAREA)DOOR OPENED914.5Bulletin:HRE-3764Ba Printed in Japan 2002SK62 The specifications, appearance or other aspects of products in this catalog are subject to change without notice.Please contact us with enquiries concerning further details on the products in this catalog.The color of the actual products may differ from the color pictured in this catalog due to printing limitations.It is strictly forbidden to copy the content of this catalog in part or in full.The screen displays shown on products in this catalog have been inserted into the photographs through compositing.All brand names, product names and service names in this catalog are trademarks or registered trademarks of their respective companies.3 Changi Business Park Vista #01-01, Akzonobel House,Singapore 486051Phone: 65 (6) 745-8300 Fax: 65 (6) 745-8155Unit D, 1F, Building A, Synnex International Park, 1068 WestTianshan Road, 200335, Shanghai, ChinaPhone: 86 (21) 6289-6060 Fax: 86 (21) 6289-5553Beijing Branch12F, Metropolis Tower, No.2, Haidian Dong 3 Street, Beijing,100080, ChinaPhone: 86 (10) 8567-9966 Fax: 86 (10) 8567-9066Guangzhou BranchRoom 1611 / 1612, Goldlion Digital Network Center,138 Tiyu Road East, Guangzhou, 510620, ChinaPhone: 86 (20) 3878-1883 Fax: 86 (20) 3878-1810Head Office2 Miyanohigashi-cho, Kisshoin, Minami-ku, Kyoto, 601-8510, JapanPhone: 81 (75) 313-8121 Fax: 81 (75) 321-5725HORIBA, Ltd.HORIBA Instruments (Singapore) Pte Ltd.HORIBA (China) Trading Co., Ltd.JapanSingaporeChina HORIBA India Private LimitedHORIBA (Thailand) LimitedIndiaTaiwanThailandPT HORIBA Indonesia Indonesia9755 Research Drive, Irvine, CA 92618, U.S.A.Phone: 1 (949) 250-4811 Fax: 1 (949) 250-0924HORIBA New Jersey Optical Spectroscopy Center20 Knightsbridge Rd, Piscataway, NJ 08854, U.S.A.Phone: 1 (732) 494-8660 Fax: 1 (732) 549-5125Via Luca Gaurico 209-00143, ROMAPhone: 39 (6) 51-59-22-1 Fax: 39 (6) 51-96-43-34Neuhofstrasse 9, D_64625, BensheimPhone: 49 (0) 62-51-84-750 Fax: 49 (0) 62-51-84-752016-18, rue du Canal, 91165, Longjumeau Cedex, FrancePhone: 33 (1) 69-74-72-00 Fax: 33 (1) 69-09-07-21HORIBA FRANCE SASGermanyFranceHORIBA Jobin Yvon GmbHItalyHORIBA ITALIA SrlHORIBA Instruments Incorporated USA246, Okhla Industrial Estate, Phase 3 New Delhi-110020, IndiaPhone: 91 (11) 4646-5000 Fax: 91 (11) 4646-5020Bangalore OfficeNo.55, 12th Main, Behind BDA Complex, 6th sector, HSR Layout,Bangalore South, Bangalore-560102, IndiaPhone: 91 (80) 4127-3637393, 395, 397, 399, 401, 403 Latya Road, Somdetchaopraya,Klongsan, Bangkok 10600, ThailandPhone: 66 (0) 2-861-5995 ext.123 Fax: 66 (0) 2-861-5200East Office850 / 7 Soi Lat Krabang 30 / 5, Lat Krabang Road, Lat Krabang,Bangkok 10520, ThailandPhone: 66 (0) 2-734-4434 Fax: 66 (0) 2-734-4438Jl. Jalur Sutera Blok 20A, No.16-17, Kel. Kunciran, Kec. PinangTangerang-15144, IndonesiaPhone: 62 (21) 3044-8525 Fax: 62 (21) 3044-852125, 94-Gil, Iljik-Ro, Manan-Gu, Anyang-Si, Gyeonggi-Do,13901, KoreaPhone: 82 (31) 296-7911 Fax: 82 (31) 296-7913HORIBA KOREA Ltd.KoreaRua Presbitero Plinio Alves de Souza, 645, LoteamentoMultivias, Jardim Ermida II - Jundiai Sao Paulo - CEP13.212-181 BrazilPhone: 55 (11) 2923-5400 Fax: 55 (11) 2923-5490HORIBA Instruments Brasil, Ltda.BrazilKyoto Close Moulton Park Northampton NN3 6FL UKPhone: 44 (0) 1604 542500 Fax: 44 (0) 1604 542699HORIBA UK Limited UK8F.-8, No.38, Taiyuan St. Zhubei City, Hsinchu County 30265,Taiwan (R.O.C.)Phone: 886 (3) 560-0606 Fax: 886 (3) 560-0550HORIBA Taiwan, Inc.Lot 3 and 4, 16 Floor, Detech Tower II, No.107 Nguyen Phong SacStreet, Dich Vong Hau Ward, Cau Giay District, Hanoi, VietnamPhone: 84 (24) 3795-8552 Fax: 84 (24) 3795-8553HORIBA Vietnam Company Limited Vietnam。

同步辐射X-射线衍射技术在材料化学教学中的引入探索

大学化学Univ. Chem. 2024, 39 (3), 29收稿：2023-08-17；录用：2023-09-28；网络发表：2023-11-10*通讯作者，Email:****************.cn基金资助：南开大学“魅力材料”教育教学改革项目•专题• doi: 10.3866/PKU.DXHX202308060 同步辐射X-射线衍射技术在材料化学教学中的引入探索李伟1,*，冯国强2，常泽11南开大学材料科学与工程学院，天津 3003502湖北第二师范学院物理与机电工程学院，武汉 430205摘要：X-射线衍射是表征材料结构的一类重要技术，在材料化学教学中具有举足轻重的地位。

随着新型材料的不断发现，相应的先进X-射线衍射技术也应运而生。

本文基于当前材料化学学科前沿，对高压同步辐射X-射线衍射技术、微焦斑X-射线衍射技术和同步辐射X-射线对分布函数三种先进技术进行介绍，旨在加深学生理解X-射线衍射相关基础知识的同时，能够拓宽科研视野，并提高解决问题的能力。

关键词：X-射线衍射；高压；微焦斑；对分布函数中图分类号：G64；O6Teaching Reform of X-ray Diffraction Using Synchrotron Radiation in Materials ChemistryWei Li 1,*, Guoqiang Feng 2, Ze Chang 11 School of Materials Science and Engineering, Nankai University, Tianjin 300350, China.2 Department of Physics and Mechanical & Electrical Engineering, Hubei University of Education, Wuhan 430205, China.Abstract: X-ray diffraction is a pivotal technique for material structure analysis, playing a fundamental role in materials chemistry. In light of the continuous discovery of novel materials, advanced X-ray diffraction methods have emerged at the forefront of materials chemistry. This paper introduces a teaching reform incorporating three advanced X-ray techniques into materials chemistry instruction: high-pressure synchrotron X-ray diffraction, micro-focus X-ray diffraction, and X-ray pair distribution function analysis. We anticipate that such a teaching reform will empower students to deepen their grasp of X-ray diffraction techniques, broaden their academic horizons, and refine their problem-solving skills.Key Words: X-ray diffraction; High-pressure; Micro-focus; Pair distribution function1 引言X-射线衍射(XRD)技术作为一种重要的结构表征手段，在材料化学研究中得到了非常广泛的应用。

New Perspectives on the Structure of Graphitic Carbons

Critical Reviews in Solid State and Materials Sciences,30:235–253,2005 Copyright c Taylor and Francis Inc.ISSN:1040-8436printDOI:10.1080/10408430500406265New Perspectives on the Structure of Graphitic CarbonsPeter J.F.Harris∗Centre for Advanced Microscopy,University of Reading,Whiteknights,Reading,RG66AF,UKGraphitic forms of carbon are important in a wide variety of applications,ranging from pollutioncontrol to composite materials,yet the structure of these carbons at the molecular level ispoorly understood.The discovery of fullerenes and fullerene-related structures such as carbonnanotubes has given a new perspective on the structure of solid carbon.This review aims toshow how the new knowledge gained as a result of research on fullerene-related carbons canbe applied to well-known forms of carbon such as microporous carbon,glassy carbon,carbonﬁbers,and carbon black.Keywords fullerenes,carbon nanotubes,carbon nanoparticles,non-graphitizing carbons,microporous carbon,glassy carbon,carbon black,carbonﬁbers.Table of Contents INTRODUCTION (235)FULLERENES,CARBON NANOTUBES,AND CARBON NANOPARTICLES (236)MICROPOROUS(NON-GRAPHITIZING)CARBONS (239)Background (239)Early Models (241)Evidence for Fullerene-Like Structures in Microporous Carbons (242)New Models for the Structure of Microporous Carbons (242)Carbonization and the Structural Evolution of Microporous Carbon (243)GLASSY CARBON (244)CARBON FIBERS (245)CARBON BLACK (248)Background (248)Structure of Carbon Black Particles (249)Effect of High-Temperature Heat Treatment on Carbon Black Structure (250)CONCLUSIONS (250)ACKNOWLEDGMENTS (251)REFERENCES (251)INTRODUCTIONUntil quite recently we knew for certain of just two allotropes of carbon:diamond and graphite.The vast range of carbon ma-∗E-mail:p.j.f.harris@ terials,both natural and synthetic,which have more disordered structures have traditionally been considered as variants of one or other of these two allotropes.Because the great majority of these materials contain sp2carbon rather than sp3carbon,their struc-tures have been thought of as being made up from tiny fragments235236P.J.F.HARRISFI G.1.(a)Model of PAN-derived carbon ﬁbres from the work of Crawford and Johnson,1(b)model of a non-graphitizing carbon by Ban and colleagues.2of crystalline graphite.Examples of models for the structures of carbons in which the basic elements are graphitic are reproduced in Figure 1.The structure shown in Figure 1(a)is a model for the structure of carbon ﬁbers suggested by Crawford and Johnson in 1971,1whereas 1(b)shows a model for non-graphitizing car-bon given by Ban and colleagues in 1975.2Both structures are constructed from bent or curved sheets of graphite,containing exclusively hexagonal rings.Although these models probably provide a good ﬁrst approximation of the structures of these car-bons,in many cases they fail to explain fully the properties of the materials.Consider the example of non-graphitizing carbons.As the name suggests,these cannot be transformed into crystalline graphite even at temperatures of 3000◦C and above.I nstead,high temperature heat treatments transform them into structures with a high degree of porosity but no long-range crystalline order.I n the model proposed by Ban et al.(Figure 1(b)),the structure is made up of ribbon-like sheets enclosing randomly shaped voids.It is most unlikely that such a structure could retain its poros-ity when subjected to high temperature heat treatment—surface energy would force the voids to collapse.The shortcomings of this and other “conventional”models are discussed more fully later in the article.The discovery of the fullerenes 3−5and subsequently of re-lated structures such as carbon nanotubes,6−8nanohorns,9,10and nanoparticles,11has given us a new paradigm for solid car-bon structures.We now know that carbons containing pentago-nal rings,as well as other non-six-membered rings,among the hexagonal sp 2carbon network,can be highly stable.This new perspective has prompted a number of groups to take a fresh look at well-known forms of carbon,to see whether any evidence can be found for the presence of fullerene-like structures.12−14The aim of this article is to review this new work on the structure of graphitic carbons,to assess whether models that incorporate fullerene-like elements could provide a better basis for under-standing these materials than the conventional models,and to point out areas where further work is needed.The carbon ma-terials considered include non-graphitizing carbon,glassy car-bon,carbon ﬁbers,and carbon black.The article begins with an outline of the main structural features of fullerenes,carbon nanotubes,and carbon nanoparticles,together with a brief dis-cussion of their stability.FULLERENES,CARBON NANOTUBES,AND CARBON NANOPARTICLESThe structure of C 60,the archetypal fullerene,is shown in Figure 2(a).The structure consists of twelve pentagonal rings and twenty hexagons in an icosahedral arrangement.I t will be noted that all the pentagons are isolated from each other.This is important,because adjacent pentagonal rings form an unstable bonding arrangement.All other closed-cage isomers of C 60,and all smaller fullerenes,are less stable than buck-minsterfullerene because they have adjacent pentagons.For higher fullerenes,the number of structures with isolated pen-tagonal rings increases rapidly with size.For example,C 100has 450isolated-pentagon isomers.16Most of these higher fullerenes have low symmetry;only a very small number of them have the icosahedral symmetry of C 60.An example of a giant fullerene that can have icosahedral symmetry is C 540,as shown in Figure 2(b).There have been many studies of the stability of fullerenes as a function of size (e.g.,Refs.17,18).These show that,in general,stability increases with size.Experimentally,there is evidence that C 60is unstable with respect to large,multiwalled fullerenes.This was demonstrated by Mochida and colleagues,who heated C 60and C 70in a sublimation-limiting furnace.19They showed that the cage structure broke down at 900◦C–1000◦C,although at 2400◦C fullerene-like “hollow spheres”with diameters in the range 10–20nm were formed.We now consider fullerene-related carbon nanotubes,which were discovered by Iijima in 1991.6These consist of cylinders of graphite,closed at each end with caps that contain precisely six pentagonal rings.We can illustrate their structure by considering the two “archetypal”carbon nanotubes that can be formed by cutting a C 60molecule in half and placing a graphene cylinder between the two halves.Dividing C 60parallel to one of the three-fold axes results in the zig-zag nanotube shown in Figure 3(a),whereas bisecting C 60along one of the ﬁvefold axes produces the armchair nanotube shown in Figure 3(b).The terms “zig-zag”and “armchair”refer to the arrangement of hexagons around the circumference.There is a third class of structure in which the hexagons are arranged helically around the tube axis.Ex-perimentally,the tubes are generally much less perfect than the idealized versions shown in Figure 3,and may be eitherNEW PERSPECTIVES ON GRAPHITIC CARBONS STRUCTURE237FI G.2.The structure of (a)C 60,(b)icosahedral C 540.15multilayered or single-layered.Figure 4shows a high resolu-tion TEM image of multilayered nanotubes.The multilayered tubes range in length from a few tens of nm to several microns,and in outer diameter from about 2.5nm to 30nm.The end-caps of the tubes are sometimes symmetrical in shape,but more often asymmetric.Conical structures of the kind shown in Fig-ure 5(a)are commonly observed.This type of structure is be-lieved to result from the presence of a single pentagon at the position indicated by the arrow,with ﬁve further pentagons at the apex of the cone.Also quite common are complex cap struc-tures displaying a “bill-like”morphology such as thatshownFI G.3.Drawings of the two nanotubes that can be capped by one half of a C 60molecule.(a)Zig-zag (9,0)structure,(b)armchair (5,5)structure.20in Figure 5(b).21This structure results from the presence of a single pentagon at point “X”and a heptagon at point “Y .”The heptagon results in a saddle-point,or region of negative curvature.The nanotubes ﬁrst reported by Iijima were prepared by va-porizing graphite in a carbon arc under an atmosphere of helium.Nanotubes produced in this way are invariably accompanied by other material,notably carbon nanoparticles.These can be thought of as giant,multilayered fullerenes,and range in size from ∼5nm to ∼15nm.A high-resolution image of a nanopar-ticle attached to a nanotube is shown in Figure 6(a).22In this238P.J.F.HARRISFI G.4.TEM image of multiwalled nanotubes.case,the particle consists of three concentric fullerene shells.A more typical nanoparticle,with many more layers,is shown in Figure 6(b).These larger particles are probably relatively im-perfect instructure.FI G.5.I mages of typical multiwalled nanotube caps.(a)cap with asymmetric cone structure,(b)cap with bill-like structure.21Single-walled nanotubes were ﬁrst prepared in 1993using a variant of the arc-evaporation technique.23,24These are quite different from multilayered nanotubes in that they generally have very small diameters (typically ∼1nm),and tend to be curledNEW PERSPECTIVES ON GRAPHITIC CARBONS STRUCTURE239FI G.6.I mages of carbon nanoparticles.(a)small nanoparticle with three concentric layers on nanotube surface,22(b)larger multilayered nanoparticle.and looped rather than straight.They will not be considered further here because they have no parallel among well-known forms of carbon discussed in this article.The stability of multilayered carbon nanotubes and nanopar-ticles has not been studied in detail experimentally.However,we know that they are formed at the center of graphite electrodes during arcing,where temperatures probably approach 3000◦C.I t is reasonable to assume,therefore,that nanotubes and nanopar-ticles could withstand being re-heated to such temperatures (in an inert atmosphere)without signiﬁcant change.MICROPOROUS (NON-GRAPHITIZING)CARBONS BackgroundIt was demonstrated many years ago by Franklin 25,26that carbons produced by the solid-phase pyrolysis of organic ma-terials fall into two distinct classes.The so-called graphitizing carbons tend to be soft and non-porous,with relatively high den-sities,and can be readily transformed into crystalline graphite by heating at temperatures in the range 2200◦C–3000◦C.I n con-trast,“non-graphitizing”carbons are hard,low-densitymateri-FI G.7.(a)High resolution TEM image of carbon prepared by pyrolysis of sucrose in nitrogen at 1000◦C,(b)carbon prepared bypyrolysis of anthracene at 1000◦C.I nsets show selected area diffraction patterns.30als that cannot be transformed into crystalline graphite even at temperatures of 3000◦C and above.The low density of non-graphitizing carbons is a consequence of a microporous struc-ture,which gives these materials an exceptionally high internal surface area.This high surface area can be enhanced further by activation,that is,mild oxidation with a gas or chemical pro-cessing,and the resulting “activated carbons”are of enormous commercial importance,primarily as adsorbents.27−29The distinction between graphitizing and non-graphitizing carbons can be illustrated most clearly using transmission elec-tron microscopy (TEM).Figure 7(a)shows a TEM image of a typical non-graphitizing carbon prepared by the pyrolysis of sucrose in an inert atmosphere at 1000◦C.30The inset shows a diffraction pattern recorded from an area approximately 0.25µm in diameter.The image shows the structure to be disordered and isotropic,consisting of tightly curled single carbon layers,with no obvious graphitization.The diffraction pattern shows symmetrical rings,conﬁrming the isotropic structure.The ap-pearance of graphitizing carbons,on the other hand,approxi-mates much more closely to that of graphite.This can be seen in the TEM micrograph of a carbon prepared from anthracene,240P.J.F.HARRI Swhich is shown in Figure 7(b).Here,the structure contains small,approximately ﬂat carbon layers,packed tightly together with a high degree of alignment.The fragments can be considered as rather imperfect graphene sheets.The diffraction pattern for the graphitizing carbon consists of arcs rather than symmetrical rings,conﬁrming that the layers are preferentially aligned along a particular direction.The bright,narrow arcs in this pattern correspond to the interlayer {0002}spacings,whereas the other reﬂections appear as broader,less intense arcs.Transmission electron micrographs showing the effect of high-temperature heat treatments on the structure of non-graphitizing and graphitizing carbons are shown in Figure 8(note that the magniﬁcation here is much lower than for Figure 7).I n the case of the non-graphitizing carbon,heating at 2300◦C in an inert atmosphere produces the disordered,porous material shown in Figure 8(a).This structure is made up of curved and faceted graphitic layer planes,typically 1–2nm thick and 5–15nm in length,enclosing randomly shaped pores.A few somewhat larger graphite crystallites are present,but there is no macroscopic graphitization.n contrast,heat treatment of the anthracene-derived carbon produces large crystals of highly or-dered graphite,as shown in Figure 8(b).Other physical measurements also demonstrate sharp dif-ferences between graphitizing and non-graphitizing carbons.Table 1shows the effect of preparation temperature on the sur-face areas and densities of a typical graphitizing carbon prepared from polyvinyl chloride,and a non-graphitizing carbon prepared from cellulose.31It can be seen that the graphitizing carbon pre-pared at 700◦C has a very low surface area,which changes lit-tle for carbons prepared at higher temperatures,up to 3000◦C.The density of the carbons increases steadily as thepreparationFI G.8.Micrographs of (a)sucrose carbon and (b)anthracene carbon following heat treatment at 2300◦C.TABLE 1Effect of temperature on surface areas and densities of carbonsprepared from polyvinyl chloride and cellulose 31(a)Surface areas Speciﬁc surface area (m 2/g)for carbons prepared at:Starting material 700◦C 1500◦C 2000◦C 2700◦C 3000◦C PVC 0.580.210.210.710.56Cellulose 4081.601.172.232.25(b)Densities Helium density (g/cm 3)for carbons prepared at:Starting material 700◦C 1500◦C 2000◦C 2700◦C 3000◦C PVC 1.85 2.09 2.14 2.21 2.26Cellulose1.901.471.431.561.70temperature is increased,reaching a value of 2.26g/cm 3,which is the density of pure graphite,at 3000◦C.The effect of prepara-tion temperature on the non-graphitizing carbon is very different.A high surface area is observed for the carbon prepared at 700◦C (408m 2/g),which falls rapidly as the preparation temperature is increased.Despite this reduction in surface area,however,the density of the non-graphitizing carbon actually falls when the temperature of preparation is increased.This indicates that a high proportion of “closed porosity”is present in the heat-treated carbon.NEW PERSPECTIVES ON GRAPHITIC CARBONS STRUCTURE241FI G.9.Franklin’s representations of(a)non-graphitizing and(b)graphitizing carbons.25Early ModelsTheﬁrst attempt to develop structural models of graphitizingand non-graphitizing carbons was made by Franklin in her1951paper.25In these models,the basic units are small graphitic crys-tallites containing a few layer planes,which are joined togetherby crosslinks.The precise nature of the crosslinks is not speci-ﬁed.An illustration of Franklin’s models is shown in Figure9.Using these models,she put forward an explanation of whynon-graphitizing carbons cannot be converted by heat treatmentinto graphite,and this will now be summarized.During car-bonization the incipient stacking of the graphene sheets in thenon-graphitizing carbon is largely prevented.At this stage thepresence of crosslinks,internal hydrogen,and the viscosity ofthe material is crucial.The resulting structure of the carbon(at ∼1000◦C)consists of randomly ordered crystallites,held to-gether by residual crosslinks and van der Waals forces,as inFigure9(a).During high-temperature treatment,even thoughthese crosslinks may be broken,the activation energy for themotion of entire crystallites,required for achieving the struc-ture of graphite,is too high and graphite is not formed.Onthe other hand,the structural units in a graphitizing carbon areapproximately parallel to each other,as in Figure9(b),and thetransformation of such a structure into crystalline graphite wouldbe expected to be relatively facile.Although Franklin’s ideason graphitizing and non-graphitizing carbons may be broadlycorrect,they are in some regards incomplete.For example,thenature of the crosslinks between the graphitic fragments is notspeciﬁed,so the reasons for the sharply differing properties ofgraphitizing and non-graphitizing carbons is not explained.The advent of high-resolution transmission electron mi-croscopy in the early1970s enabled the structure of non-graphitizing carbons to be imaged directly.n a typical study,Ban,Crawford,and Marsh2examined carbons prepared frompolyvinylidene chloride(PVDC)following heat treatments attemperatures in the range530◦C–2700◦C.I mages of these car-bons apparently showed the presence of curved and twistedgraphite sheets,typically two or three layer planes thick,enclos-ing voids.These images led Ban et al.to suggest that heat-treatednon-graphitizing carbons have a ribbon-like structure,as shownin Figure1(b).This structure corresponds to a PVDC carbonheat treated at1950◦C.This ribbon-like model is rather similar to an earlier model of glassy carbon proposed by Jenkins andKawamura.32However,models of this kind,which are intendedto represent the structure of non-graphitizing carbons follow-ing high-temperature heat treatment,have serious weaknesses,as noted earlier.Such models consist of curved and twistedgraphene sheets enclosing irregularly shaped pores.However,graphene sheets are known to be highlyﬂexible,and wouldtherefore be expected to become ever more closely folded to-gether at high temperatures,in order to reduce surface energy.Indeed,tightly folded graphene sheets are quite frequently seenin carbons that have been exposed to extreme conditions.33Thus,structures like the one shown in Figure1(b)would be unlikelyto be stable at very high temperatures.It has also been pointed out by Oberlin34,35that the modelsput forward by Jenkins,Ban,and their colleagues were basedon a questionable interpretation of the electron micrographs.In most micrographs of partially graphitized carbons,only the {0002}fringes are resolved,and these are only visible when they are approximately parallel to the electron beam.Therefore,such images tend to have a ribbon-like appearance.However,because only a part of the structure is being imaged,this appear-ance can be misleading,and the true three-dimensional structuremay be more cagelike than ribbon-like.This is a very importantpoint,and must always be borne in mind when analyzing imagesof graphitic carbons.Oberlin herself believes that all graphiticcarbons are built up from basic structural units,which comprisesmall groups of planar aromatic structures,35but does not appearto have given a detailed explanation for the non-graphitizabilityof certain carbons.The models of non-graphitizing carbons described so farhave assumed that the carbon atoms are exclusively sp2and arebonded in hexagonal rings.Some authors have suggested thatsp3-bonded atoms may be present in these carbons(e.g.,Refs.36,37),basing their arguments on an analysis of X-ray diffrac-tion patterns.The presence of diamond-like domains would beconsistent with the hardness of non-graphitizing carbons,andmight also explain their extreme resistance to graphitization.Aserious problem with these models is that sp3carbon is unsta-ble at high temperatures.Diamond is converted to graphite at1700◦C,whereas tetrahedrally bonded carbon atoms in amor-phousﬁlms are unstable above about700◦C.Therefore,the242P.J.F.HARRI Spresence of sp 3atoms in a carbon cannot explain the resistance of the carbon to graphitization at high temperatures.I t should also be noted that more recent diffraction studies of non-graphitizing carbons have suggested that sp 3-bonded atoms are not present,as discussed further in what follows.Evidence for Fullerene-Like Structures in Microporous CarbonsThe evidence that microporous carbons might have fullerene-related structures has come mainly from high-resolution TEM studies.The present author and colleagues initiated a series of studies of typical non-graphitizing microporous carbons using this technique in the mid 1990s.30,38,39The ﬁrst such study in-volved examining carbons prepared from PVDC and sucrose,after heat treatments at temperatures in the range 2100◦C–2600◦C.38The carbons subjected to very high temperatures had rather disordered structures similar to that shown in Figure 8(a).Careful examination of the heated carbons showed that they often contained closed nanoparticles;examples can be seen in Figure 10.The particles were usually faceted,and often hexagonal or pentagonal in shape.Sometimes,faceted layer planes enclosed two or more of the nanoparticles,as shown in Figure 10(b).Here,the arrows indicate two saddle-points,similar to that shown in Figure 5(b).The closed nature of the nanoparticles,their hexagonal or pentagonal shapes,and other features such as the saddle-points strongly suggest that the parti-cles have fullerene-like structures.I ndeed,in many cases the par-ticles resemble those produced by arc-evaporation in a fullerene generator (see Figure 6)although in the latter case the particles usually contain many more layers.The observation of fullerene-related nanoparticles in the heat treated carbons suggested that the original,freshly prepared car-bons may also have had fullerene-related structures (see next section).However,obtaining direct evidence for this is difﬁ-cult.High resolution electron micrographs of freshly prepared carbons,such as that shown in Figure 7(a),are usuallyratherFI G.10.(a)Micrograph showing closed structure in PVDC-derived carbon heated at 2600◦C,(b)another micrograph of same sample,with arrows showing regions of negative curvature.38featureless,and do not reveal the detailed structure.Occasion-ally,however,very small closed particles can be found in the carbons.30The presence of such particles provides circumstan-tial evidence that the surrounding carbon may have a fullerene-related structure.Direct imaging of pentagonal rings by HRTEM has not yet been achieved,but recent developments in TEM imaging techniques suggest that this may soon be possible,as discussed in the Conclusions.As well as high-resolution TEM,diffraction methods have been widely applied to microporous and activated carbons (e.g.,Refs.40–44).However,the interpretation of diffraction data from these highly disordered materials is not straightforward.As already mentioned,some early X-ray diffraction studies were interpreted as providing evidence for the presence of sp 3-bonded atoms.More recent neutron diffraction studies have suggested that non-graphitizing carbons consist entirely of sp 2atoms.40It is less clear whether diffraction methods can establish whether the atoms are bonded in pentagonal or hexagonal rings.Both Petkov et al .42and Zetterstrom and colleagues 43have interpreted neutron diffraction data from nanoporous carbons in terms of a structure containing non-hexagonal rings,but other interpreta-tions may also be possible.Raman spectroscopy is another valuable technique for the study of carbons.45Burian and Dore have used this method to analyze carbons prepared from sucrose,heat treated at tem-peratures from 1000◦C–2300◦C.46The Raman spectra showed clear evidence for the presence of fullerene-and nanotube-like elements in the carbons.There was also some evidence for fullerene-like structures in graphitizing carbons prepared from anthracene,but these formed at higher temperatures and in much lower proportions than in the non-graphitizing carbons.New Models for the Structure of Microporous Carbons Prompted by the observations described in the previous section,the present author and colleagues proposed a model for the structure of non-graphitizing carbons that consists ofNEW PERSPECTIVES ON GRAPHITIC CARBONS STRUCTURE243FI G.11.Schematic illustration of a model for the structure of non-graphitizing carbons based on fullerene-like elements.discrete fragments of curved carbon sheets,in which pentagons and heptagons are dispersed randomly throughout networks of hexagons,as illustrated in Figure11.38,39The size of the micropores in this model would be of the order of0.5–1.0nm, which is similar to the pore sizes observed in typical microp-orous carbons.The structure has some similarities to the“ran-dom schwarzite”network put forward by Townsend and col-leagues in1992,47although this was not proposed as a model for non-graphitizing carbons.I f the model we have proposed for non-graphitizing carbons is correct it suggests that these carbons are very similar in structure to fullerene soot,the low-density, disordered material that forms on walls of the arc-evaporation vessel and from which C60and other fullerenes may be ex-tracted.Fullerene soot is known to be microporous,with a sur-face area,after activation with carbon dioxide,of approximately 700m2g−1,48and detailed analysis of high resolution TEM mi-crographs of fullerene soot has shown that these are consis-tent with a structure in which pentagons and heptagons are dis-tributed randomly throughout a network of hexagons.49,50It is signiﬁcant that high-temperature heat treatments can transform fullerene soot into nanoparticles very similar to those observed in heated microporous carbon.51,52Carbonization and the Structural Evolutionof Microporous CarbonThe process whereby organic materials are transformed into carbon by heat treatment is not well understood at the atomic level.53,54In particular,the very basic question of why some organic materials produce graphitizing carbons and others yield non-graphitizing carbons has not been satisfactorily answered. It is known,however,that both the chemistry and physical prop-erties of the precursors are important in determining the class of carbon formed.Thus,non-graphitizing carbons are formed, in general,from substances containing less hydrogen and more oxygen than graphitizing carbons.As far as physical properties are concerned,materials that yield graphitizing carbons usu-ally form a liquid on heating to temperatures around400◦C–500◦C,whereas those that yield non-graphitizing carbons gen-erally form solid chars without melting.The liquid phase pro-duced on heating graphitizing carbons is believed to provide the mobility necessary to form oriented regions.However,this may not be a complete explanation,because some precursors form non-graphitizing carbons despite passing through a liquid phase.The idea that non-graphitizing carbons contain pentagons and other non-six-membered rings,whereas graphitizing car-bons consist entirely of hexagonal rings may help in understand-ing more fully the mechanism of carbonization.Recently Kumar et al.have used Monte Carlo(MC)simulations to model the evo-lution of a polymer structure into a microporous carbon structure containing non-hexagonal rings.55They chose polyfurfuryl al-cohol,a well-known precursor for non-graphitizing carbon,as the starting material.The polymer was represented as a cubic lattice decorated with the repeat units,as shown in Figure12(a). All the non-carbon atoms(i.e.,hydrogen and oxygen)were then removed from the polymer and this network was used in the。

X-ray Crystallography(X射线晶体衍射)

Image from Biomolecular Crystallography by Bernhard Rupp
X-ray crystallography
Most widely used method for determining 3D structures of macromolecules
• Typically: single-crystal, single X-ray wavelength • Multiple crystals = powder diffraction; multiple-wavelength = Laue diffraction
See a com pl ete l i st ofw i nners at i ucr. org/ peopl e/ nobel -pri ze
Li nus Paul i ng
Al pha-hel i cal structure of protei ns,nature of chem i calbonds
Difference between this...
Nuclear RNA export factor 2 is believed to interact with NTF2-related export protein
...and this.
PDB code: 3nv0 1.84 Å resolution
Electron Microscopy Size limitations > 120 kDa, signal/noise (improvements) Nuclear Magnetic Resonance Size limitations < 25 kDa, protein labeling X-ray crystallography Requires crystals

X-RAY MICROSCOPE

专利名称：X-RAY MICROSCOPE发明人：KUMAKHOV, MURADIN ABUBEKIROVICH 申请号：EP02736310申请日：20020305公开号：EP1482520A4公开日：20071107专利内容由知识产权出版社提供摘要：X-ray microscope comprise extended X-ray source, as well as means for placement of test object 3 and recording means, and located between them X-ray capillary lens. Channels of the latter are diverging towards recording means. Means for placement of the test object is located between extended X-ray source and lesser end side of the X-ray capillary lens. The device is characterized in that the walls of the channels (14, 16) for radiation transmission have a coating or are made of material absorbing or scattering X-ray radiation, and have lateral surface shape of truncated cone or pyramid, or that of cylinder or prism. With specified choice of the material, phenomenon of total external reflection is excluded, while rectilinearity of longitudinal axes of the channels ensures their functioning as collimators. Therefore, channels capture radiation only from the fragments of the test object 3 situated exactly opposite their entrances. As compared with known device, possibility is excluded of radiation capture entering channel 18 at angles from zero to critical angle θc of total external reflection. Due to this, resolution is fully determined by technological possibilities of decreasing dimension of the channel entrance. The ability of using extended X-ray source allows to reduce substantially time of exposure with simultaneous decrease in the X-ray tube power.申请人：KUMAKHOV, MURADIN ABUBEKIROVICH 更多信息请下载全文后查看。

新型循环式预埋连墙件

6g坊Sichuan Building Materials 第47卷第1期2021年1月Vol.47,No.lJanuary,2021新型循环式预埋连墙件龙宏远，石仁君(重庆科技学院，重庆400000)摘要:传统的连墙件大多为钢管预埋式连墙件，在建筑施工中会留下预留洞口而导致建筑结构后期有极高的渗漏现象，同时在割除连墙件时易造成火灾，且割除下的连墙件无法循环使用。

通过分析传统连墙件的不足，设想了一种新型循环式预埋连墙件。

该连墙件分为预埋件和延伸件，之间用螺栓连接,预埋件预埋在主体中，延伸件与小横杆固定。

对于预埋件，又分为①号和②号，①号在施工完成后直接弯折，②号则进行二次防腐防锈处理，挂设钢绞圈，作为缓降逃生绳的外设固定端。

关键词：可循环利用；螺栓连接;预埋式；可分离中图分类号:TU731.2文献标志码:A文章编号:1672-4011(2021)01-0104-02DOI：10.3969/j.issn.1672-4011.2021.01.051New circulating embedded connecting wall pieceLONG Hongyuan,SHI Renjun(Chongqing University of Science and Technology,Chongqing400000,China)Abstract:Most of the traditional connecting wall parts are steel pipe embedded connecting wall parts,which will leave reserved holes in the construction process,resulting in extremely high leakage in the later stage of the building structure,and at the same time,it is easy to cause fire when cutting off the connecting wall parts The cut off wall pieces cannot be recycled.By analyzing the shortcomings of traditional connecting wall parts,a new type of circulating embedded connecting wall parts is envisaged. The connecting wall part is divided into a embedded part and an extension part,which are connected by bolts,the embedded part is embedded in the main body,and the extension part is fixed with the small cross bar.For embedded parts,it is divided into No.①and No.②，No.①is directly bent after the construction is completed,No.(2)is subjected to secondary anti-corrosion and anti-rust treatment,and a steel strand is hung to fix the peripheral equipment of the descending escape rope end.Key words:recyclable；bolted；embedded；separable1新型循环式预埋连墙件设想新型连墙件采用刚性连接方式,分为预埋件和延伸件，预埋件和延伸件通过螺栓连接,在工程结束后,延伸件被拆解下来后可循环使用。

X射线检测技术在食品安全中的应用说明书

repaPetihWContents1 Why Submit Foods to X-ray Inspection?2 How Does an X-ray System Catch Contaminants?3 Factors Affecting the Sensitivity of X-ray Inspection2W h i t e P a p e rFood manufacturers are under increasing consumer and legislative pressure to provide safe food. One of the tools that helps to maintain food safety is x-ray inspection.This white paper looks at the use of x-ray inspection systems to eliminate physical contaminants on pumped food lines. It begins with a short introduction to x-ray inspection and why it’s used in the food-processing industry. It goes on to consider the factors that affect the sensitivity of x-ray inspection, the effectiveness of x-ray inspection at different points on the production line, and the ease with which the technology can be applied to production lines based on pumped product.After reviewing the factors that production line managers should take into account when considering installing an x-ray inspection system, the white paper suggests typical applications, and then looks at points to consider when using x-ray inspection for processed meat and poultry lines and for lines involving slurries, semi-solids, and fluids.Contamination Detection in Pumped Foods1. Why Submit Foods to X-ray Inspection?X-ray inspection systems keep foods safe by offering unsurpassed detection of physical contaminants. No other technology detects such a wide range ofcontaminants such as stone, metal, glass, bone, and high-density plastic and rubber.Incorporating x-ray inspection systems into a company-wide product-safety program helpsmanufacturers comply with national and international regulations - such as HACCP (Hazard Analysis Critical Control Point) - as well as standards set by retailers.Typical contaminants2. How Does an X-ray System Catch Contaminants?An x-ray system is essentially a scanning device. When a product passes through the x-ray system, the internal sensors capture a grey-scale image of the product. The software within the x-ray system analyzes the image and compares it to a predetermined acceptance standard.On the basis of the comparison, it accepts or rejects the image. In the case of a rejection, the software sends a signal to an automatic reject system/valve which removes the product from the production line.X-ray image of processed chickenWhite PaperMETTLER TOLEDO3Fig 1: X-ray image of a ready meal - lots of varities of greys make it more difficult to detect a contaminantFig 2: X-ray image of pumped caramel - it is easier to detect a contaminant in a homogenous product4. Establishing Critical Control Point for an X-ray System on a Production LineTo be fully effective, x-ray inspection should be part of a company-wide approach to product safety and part of a product inspection program. Implementing x-ray inspection into such a program helps foodmanufacturers to achieve compliance with standards such as HACCP .HACCP consists of seven steps known as principles.1. Conduct a hazard analysis2. Identify critical control point (CCP)3. Establish critical limits for each CCP4. Establish CCP monitoring requirements5. Establish corrective actions6. Establish record-keeping procedures7. Establish procedures to verify the system is workingas intended The second of those principles – identifying the critical control point (CCP) – helps to choose the best location to apply x-ray inspection on a production line. A CCP is a step or process that’s essential to product safety. It’s the point at which control must be applied to reduce the risk of contamination to acceptable levels.To find out more about selecting CCP, please read the white paper “How to select CCP for x-ray systems” (/usxray-ccp).White PaperMETTLER TOLEDO3. Factors Affecting the Sensitivity of X-ray InspectionThe ease with which food contaminants can be identified by x-ray inspection depends on various factors such as product density, product thickness, and product homogeneity.Product DensityProduct density determines the depth of grey in the grey-scale image. The denser the product, the darker the grey.To be detectable to x-ray inspection, a contaminant has to be denser than the product in which it’s embedded. That means it will absorb more x-rays than thesurrounding product, and show up on the grey-scale image as an area that’s darker than its surroundings. In other words, any contaminant with a density similar to, or less than, that of the product in which it’s embedded is incapable of being detected by x-ray inspection.Product ThicknessAs the product thickness in the path of the x-ray beam increases, so does its overall level of absorption. That makes detection more difficult. A contaminant in ashallow layer of product flowing through a pipe is easier to detect than a contaminant hidden inside a finished sealed pack. In general, the shallower the depth of product, the better the sensitivity of x-ray inspection.Product HomogeneityThe texture and consistency of a food product has an effect on x-ray sensitivity. A product with components of varying density, such as a ready meal, shows up in a greyscale image as a variety of greys (Fig 1). The more components there are, the wider the range of greys. Analyzing the image for contaminants is harder because the software has to pick out the tell-tale dark speck of a contaminant from an image containing numerous shades of grey. The more homogeneous the product, such as liquid caramel, the easier it is to spot contaminants (Fig 2).Many other factors can affect the sensitivity of an x-ray system. To find out more about the factors limiting the sensitivity of detection, please read “The X-ray Inspection Guide” (/usxray-guide).44.2 X-ray Inspection of Processed FoodWhen installed during or after the food processing or before the filling process, x-ray inspection of pumped products is ideal as they tend to be homogeneous - their texture and density are much more uniform. And since the product is already flowing through a pipe, it can easily be presented for inspection in shallow depths by narrowing the gauge or altering the cross-section of the pipe.X-ray systems for pumped products can be used at different stages on a production line depending on the identified CCPs.5. Applying X-ray Inspection to Pumped Food ProductsPumped products typically include meat and poultry as well as slurries, semi-solids and fluids at any stage prior to final packaging.Connecting x-ray inspection equipment to an existing piped production line isn’t complicated. Standard fittings are used to attach the pipe through which the pumped products passes to the manifold of the x-ray machine. The manifold typically tapers the round production-line pipe to a rectangular-shaped inspection window with an equivalent throughput volume. The rectangular section is where the x-ray beam scans the flowing product. The depth of product at this point is typically between 35mm to 50mm. When the software detects a contaminant, it diverts the product from the pipe via a reject diverter valve.A typical x-ray pipeline systemW h i t e P a p e rOnce the CCPs on a production line are identified, other factors such as practicality and cost-effectiveness need to be taken into account to select the ideal location for an x-ray system. There are occasions where it would be necessary to install more than just one x-ray system on the production line and that’s why there is no single solution that’s right for every production line.For this white paper, we will only focus on the inspection of pumped food products.4.1 X-ray Inspection at the Beginning of the Production LineDetection levels are typically better in the early stages of the production process where unprocessed pumped product can be presented in a shallower depth and with a more uniform texture. As the line progresses, thenature of contaminants can change too. Each processing step can introduce new contaminants, or break existing contaminants down into smaller, less detectable pieces.X-ray inspection of ground meatAt each stage of the production process, the value of the product increases. For that reason, food manufacturers find it more cost-effective to reject contaminated product before it’s been processed or sealed in its final packaging.Catching contaminants early is not just more efficient in reducing product waste and costs, it also helps prevent damage to processing equipment caused by big contaminants, which could in turn introduce more contaminants. Additionally, when installed early in the production process it can serve as a check on suppliers’ quality control.White PaperMETTLER TOLEDO6. Factors to Consider When Installing X-rayInspectionProduct passing through a pipe performs slightly differently to product travelling on a conveyor. To make the most of x-ray inspection, you need to take the following factors into account:Air BubblesAir bubbles in a pumped product are tiny voids – zones containing no product. Voids absorb fewer x-rays so they appear as lighter areas on grey-scale x-ray images. The contrast at the edges of these lighter areas can trigger the x-ray software into thinking that it detected a contaminant, causing false rejects. Since air bubbles reduce the depth of grey, they could lighten the color of any contaminants directly behind or in front. That makes the contaminants harder to detect.Air bubbles are common in pumped meat and poultry appications but are not difficult to eliminate with the right x-ray system design. A vacuum filler pump, for example, generates a constant, homogeneous flow with minimal air bubbles.Slurries and other viscous products do not normally contain air bubbles when pumped through a pipe. Speed VariationsA well-designed x-ray system will automatically adapt to changes in the flow rate of the customer product. It adjusts the scan speed and the associated reject timing in accordance with a speed signal from the production-line pump.Location on the Production LineAs mentioned previously, x-ray inspection can be applied anywhere on a production line containing pumped products. But the earlier you apply it, the better. The value of rejected product is lower, plus you may be able to recover the product and feed it back into the line after removal of the contaminants.A very common location is at the start of the production process when product value is low and the risk of contaminants from incoming raw product is at its highest. Using x-ray inspection at this stage also lets you monitor suppliers’ quality control.7. Typical ApplicationsA huge range of processed food products pass through pipelines. Typical applications could be:Meat andPoultrywhole muscle, minced meats forsausages, pies, pâtésBakery jams, syrups, cake mix and fillings Dairy butter, ice cream, yogurt, cottagecheeseFruit andVegetablespurées, mousses, juices,smoothies, chopped fruit andvegetablesFish andSeafoodfish spread, processed fish forready-mealsConfectionery melted chocolate, nougats, toffees Ready-Meals sauces, soups, pie fillingsWe can divide these food products into two broad classes: (1) meat and poultry, (2) slurries, semi-solids, and fluids. We’ll look at them separately.7.1 Meat and Poultry ApplicationsTypical pumped meat and poultry products include ground meat, sausage meat, and poultry trims such as breast fillets and thigh meat. Bone contaminants are by far the most common ones, although lead or steel shot (buck shot), needles, and teeth are also common. Depending on the pumped meat or poultry application, x-ray inspection can detect metal down to 0.8mm, and calcified bone and tooth down to 2mm. The maximum pipe diameter for meat applications is 75mm (3 inches) because narrower pipes make it easier to identify fragments of bone.White PaperMETTLER TOLEDO56W h i t e P a p e rSince chicken bones are less dense than red meat bones, they’re harder to detect. The density of chicken bone tends to be closer to that of the chicken meat in which it lies. On a grey-scale image, the difference between the grey of the meat and the grey of the bone is less obvious.Let’s look at some important points to consider when using x-ray inspection for pumped meat and poultry applications:• High volume throughput of up to 10 tons an hour • Contaminants will be removed before adding further value to the product through processing• Rejected product could be reworked and reused (depending on the application)•Reject portion sizes are larger than for aconveyorized x-ray system because the pipeline reject mechanism can’t isolate a single item such as a chicken breast fillet•Faster flows increase reject portion sizes – up to 2lb to 3lb of rejected product when running at 10 tons an hour through a 76mm (3-inch) pipe •High rejection rate due to frequency of bone contaminants in meat and poultry products – an acceptable reject level needs to be defined7.2 Slurries, Semi-solids and FluidsX-ray inspection is especially useful for products that cannot be sieved. These are products such as textured fruit purées and yogurts containing fruit chunks. Sieving removes physical contaminants by catching anything that’s too big to fit through the sieve mesh and is used mainly for liquid applications like milk. X-ray inspection of pumped products is a good alternative for catching physical contaminants where sieving can’t be used.The contaminants within slurries, semi-solids, and fluids are varied. Depending on the application, x-rayinspection can detect metal down to 0.8mm, glass and stone down to 2mm, and dense plastic down to 4mm. The maximum pipe diameter for these more fluid applications is 100mm (4 inches).Contaminated slurries, semi-solids, and fluids are typically rejected from the pipe through a diverter ball valve. The ball valve automatically removescontaminated product without creating a back pressure in the system.The sanitary design of an x-ray system inspecting slurries, semi-solids, and fluids is very important. For more efficient cleaning, aseptic x-ray inspection systems are available. An aseptic design incorporates steam-cleaning ports for destruction of pathogenic bacteria growth. For dairy applications, there are x-ray inspection systems that are certified to AMI and 3-A Sanitary Standards.Let’s look at some important points to consider when using x-ray inspection for slurries, semi-solids and fluids:•High volume throughput of up to 20 tons an hour – larger than for meat and poultry because pipeline diameters are typically greater and fluids can travel faster through pipes• Contaminants will be removed before adding further value to the product through processing• Rejected product can be reworked and reused (depending on the application)•Faster flows increase reject portion sizes – up to 5kg or more of product when running at 20 tons an hour through a 100mm (4-inch) pipeWhite PaperMETTLER TOLEDO8. ConclusionFor many years, x-ray inspection has proven itseffectiveness at eliminating contaminants fromprocessed and packaged food products. Theeffectiveness of x-ray inspection systems dependson the product density, thickness and homogeneityof the inspected product.Since pumped products tend to be more homogeneous,it’s easy to adjust their depth by altering the size orshape of the pipe through which they flow. That makespumped products an ideal application for x-rayinspection, offering food manufacturers excellentlevels of contaminant detection.Pumped products on a food processing line tendto occur early in the production process before amanufacturer has added further value to the productthrough processing and packaging. Since product valueis lower at this point, this location is very common forx-ray inspection system for removing contaminants.Early removal of contaminants has two otheradvantages: it protects valuable processing equipmentfrom damage further downstream, and it serves asa check on suppliers’ quality control.Installing x-ray inspection equipment on a pumpedproduction line is a simple process. A pressure vacuumpump will eliminate air bubbles especially in meat andpoultry applications. A well-designed x-ray inspectionsystem can also automatically change the scanningspeed and the reject timings to match the customer’sflow rate.X-ray inspection is a versatile technology that’s suitablefor the inspection of a wide range of pumped foodproducts at CCPs on a food processing line. It helpsmaintain product safety and brand reputation, andcan protect valuable equipment from damage.7White PaperMETTLER TOLEDOFor more informationMettler Toledo Safeline 6005 Benjamin Road Tampa FL 33634 USATel. 813-889-9500Toll Free 800-447-4439Fax. 813-881-0840Email:*********************Subject to technical changes©05/2011 Mettler-Toledo Safeline Printed in the US/safelineusOn-Demand X-ray Webinars 24/7Our on-demand webinars give you the opportunity to learn more about x-ray inspection - at your own convenience!To view all our on-demand webinars please visit:/pi-ondemandFurther Information about X-ray InspectionFREE Technical Guide Make an informed decisionMETTLER TOLEDO has published an authoritative product inspection guide for x-ray inspection systems.The 73 page guide enables you to select the right x-ray inspection system for your production line. It supports you to install an all-encompassing product inspection program and to achieve compliance with standards, regulations and legislation.Register today for your FREE copy:/pius-guidesFREE White PapersHow Safe is X-ray Inspection of Food?Some of the most popular misconceptions about x-ray inspection of food are tackled in this White Paper. It is an indispensable white paper for food manufacturers who consider x-ray inspection to comply with food-safety regulations and legislations.Register today for your Free copy: /xrayus-safetyX-ray Inspection: More Than Just Contamination DetectionX-ray inspection can detect numerous quality shortfalls that lie hidden within product packaging or deep within the product itself. This white paper explains that x-ray inspection is no longer just a technique for catching contaminants; its become a wide-ranging tool for defending brand values and keeping customers happy.Register today for your Free copy:/xrayus-integrity。

DLM4000八通道混合信号波形显示器说明书

For today’s challenging power electronics, Only one scope will do – the world's only Two USB Terminals onFront Panel four-direction selection buttonJog shuttle androtary knobEight Analog Input Channels (Yokogawa Probe Interface Compliant)Additional 16-bits of Input Logic,for a total of 24-bits (Optional)6.6kgModest 178 mm Depth Half of the former model DL7480Channel 8 is Convertible to8-Bit Logic Input (Standard Feature)The portable eight-channel DLM4000 isthe daily instrument of choice.12.1” LCD enables eight waveforms to be easily observed.Portable178mm355mmThis combination with the optionalPBDH0150 High-Voltage Differential Probe,creates a compact andmulti-channel oating voltage and current measuring system.Numerous I/O analog, digital, and serial-bus waveforms surrounding the Electronic Control Unit (ECU) must be measured. The DLM4000 offers ample channel-count and architecture to monitor eight analog channels and up to 24-bits of logic input while simultaneously performing protocol analysis such as UART, I2C, SPI, CAN, LIN and FlexRay. The DLM4000 can speed up the the R&D process. Four channels are not enough.Example: Start-up sequence test of multi-output power supply or ConverterPrimary /secondary voltage/current and power supply control signalExample: Troubleshooting of infrequent problems Comprehensive stability test of the whole system8ch8ch8chCAN / LIN / FlexRay UART / I C /SPIformer model DL7480Product IntroductionFunctions & FeaturesOptions & AccessoriesOperability & SoftwareSpeci cations0302Reliable capture, from fast-short pulses to long recordingsFeatures, Functionality, and Operability Extra Deep Memory (125 Mega-Points) Enables Long-Duration MeasurementDual-window zooming enables two separate areas to be displayed.In addition to basic trigger functions such as Edge, State, and Pulse Width – Advanced trigger types are provided, including Edge OR Edge Edge OR Edge (quali ed)State Enhanced triggersEdge trigger For fast-short waveformsthe comprehensive trigger suite captures the waveforms you need!Use the DLM4000 like an eight-channel memory recorder or select faster sampling rates up to 1.25 GS/s across all channels!Portrait, compact bodyDLM2000 Mixed signal oscilloscope seriesProduct IntroductionFunctions & FeaturesOptions & AccessoriesOperability & SoftwareSpeci cations0504F-V conversion of frequency pulse (/G2 option)PBC100(701928) / PBC050(701929)DC to 100 MHz / DC to 50 MHz 701936Deskew correction signal sourceSCL SDASCL SDACAN_H CAN_LPower supply analysis function (/G4)assures exible probing options.Analyzing High-speed Differential Signals−PBDH1000 Differential Probe−Intelligent serial-bus auto-setup feature enables quick and easy setup. The bit-rate and voltage Many systems contain multiple serial buses. The DLM4000 analyzes four different serial-bus types simultaneously. A combination trigger of two Expansion of FFT CalculationIn addition to power spectrum, advanced FFT functions such as coherence and transfer function calculations Power AnalysisPower MeasurementThe built-in algorithm ne tunes Power Loss calculations.User-speci ed parameters include device such as IGBTs and MOSFETs.Automated measurement of power parameters such as active power, apparent power, power factor etc. (Calculation of three-phase power is also possible)By dividing the long memory into segments, the SOA (safe operating area) can be analysed and, peak voltages between switching cycles can be compared by overlaying or one-by-one replay.It is also possible to display a list of the switching loss of each cycle and save the results. By clicking a value in the list, the correspondingwaveform will be directly displayed.Example: Switching Loss AnalysisThe High Voltage Differential Probe range includes models such as the compact PBDH0150(1400Vpeak) as well as the 701926 (7kVpeak).Easy Probing for Floating Signals −High-Voltage Differential Probe−The PBC100 and PBC050 high-bandwidth current probes measure DC to 100MHz and 50MHz at up to 30Arms. The 701931 is available for higher currents up to 500Arms. The current probe range covers a wide range of applications.Wide Range of Current Measurement−Current probe−When measuring very fast switching devices,probe delay time correction (de-skew) is crucial.The 701936 signal source and auto de-skew feature makes de-skewing quick and and simple.Enables Precise Power Measurement −Deskew correction signal source−The DLM4000 offers advanced serial-bus analysis – saving precious development time of ECUs and Embedded Systems. Eight analog input channels means that multiple analog, serial-bus, and logic waveforms can be easily and simultaneously observed whilst preserving their relative timing.Up to four serial-buses can be analysed at the same time.Eight analog input channels enables four pairs of voltage and currentmeasurements, thereby supporting today’s high-speed and sophisticated power electronics circuit development. Optional analysis functions and accessories support the comprehensive measurement of power electronic devices.-Switching Loss -Safe Operating Area-Harmonic Analysis -Joule IntegralFor power device circuit voltage/current measurementCAN, LIN, I 2C, SPI, & UART(RS232) … Protocol AnalysisOptions and Accessories Product IntroductionFunctions & FeaturesOperability & SoftwareSpeci cations0706Advanced User-InterfaceFlexible and Powerful FeaturesBroad Connectivity and Easier Controlmouse keyboads/ea/products/oscilloscopes/oscilloscopes-application-software/Standard:1.8 GB Optional: 7.2 GBGP-IB connection terminal (optional)Control from a PCUSB 2.0 peripheral connection terminal x2Supports USB storage, USB mouse and keyboards.Probe power terminal x8 (optional)External trigger inputRGB video signal output terminalGO/NO-GO Output terminal USB-PC Connection terminalEthernet (1000BASE-T)Trigger output For current and differential probes that don't support the Yokogawa probe interface.Connection to an external monitorControl from a PC.Mount to PC as External storage.Monitor & Control from a work Data Transfer & Email.The push function for each knob enables fine adjustments to be made or puts the setting back to the default.Speed-sensitive knob behavior creates a natural response.The scope intelligently responds to the operator.Dedicated knobs assure analog-like, intuitive operationMulti-color LED for clarityBy pushing the knob,trigger level is set to the center of the waveform automatically.The "?" button gets the operator fast and friendly online help. No more need to consult the user's manual.Thumbnail can be viewed full-sizeSelect from 9 languages.Built-in user guidanceGraphical online helpThumbnail can be viewed full-sizeMultiple LanguagesAdvanced Waveform Parameter Measurement FunctionsVariety of Display FormatsComfortable OperationThumbnails of waveform data, waveform image data, and Wave-Zone les can be displayed. The image and le names are shown so that you can view screen image contents while copying or deleting les.Product IntroductionFunctions & FeaturesOptions & AccessoriesOperability & SoftwareSpeci cations0908Speciﬁcation DLM 4000 SeriesModelsBasic SpeciﬁcationsAnalog Signal inputInput channels CH1 to CH8(CH1 to CH7 when using logic input)Input coupling setting AC, DC, DC50 Ω, GNDInput impedance 1 MΩ ±1.0%, approximately 20 pF50 Ω ±1.0% (VSWR 1.4 or less, DC to 500MHz) Voltage axis sensitivity 1 MΩ 2 mV/div to 10 V/div (steps of 1-2-5)setting range 50 Ω 2 mV/div to 500 mV/div (steps of 1-2-5)Max. input voltage 1 MΩ 150 Vrms50 Ω Must not exceed 5 Vrms or 10 VpeakMax. DC offset 1 MΩ ±1V (2 mV/div to 50 mV/div)setting range ±10V (100 mV/div to 500 mV/div)±100V (1 V/div to 10 V/div)50 Ω ±1V (2 mV/div to 50 mV/div)±5V (100 mV/div to 500 mV/div)DC accuracy*±(1.5% of 8 div + offset voltage accuracy) Offset voltage accuracy* 2 mV to 50mV/div ±(1% of setting +0.2 mV)100 mV to 500 mV/div ±(1% of setting + 2 mV)1 V to 10 V/div ±(1% of setting + 20 mV)Frequency characteristics (-3 dB attenuation when inputting a sinewave of amplitude ±3div)**DLM4038 DLM40581 MΩ(when using passive probe)100 mV to 100 V/div DC to 350 MHz DC to 500 MHz20 mV to 50 mV/div DC to 300 MHz DC to 400 MHz50 Ω10 mV to 500 mV/div DC to 350 MHz DC to 500 MHz2 mV to 5 mV/div DC to 300 MHz DC to 400 MHzIsolation between channels -34 dB@ analog bandwidth (typical value) Residual noise level*The larger of 0.4 mV rms or 0.05 div rms(typical value)A/D resolution 8bit (25LSB/div)Max. 12 bit (in High Resolution mode) Bandwidth limit FULL, 200 MHz, 100MHz, 20 MHz, 10 MHz,5 MHz, 2 MHz, 1 MHz, 500 kHz, 250 kHz,125 kHz, 62.5 kHz, 32 kHz, 16 kHz, 8 kHz(can be set for each channel)AB triggers A Delay B 10 ns to 10 s (Edge, EdgeQuali ed, State, Serial Bus)A to B(N) 1 to 10 (Edge, Edge Quali ed,State, Serial Bus)Dual Bus Serial bus onlyForce trigger Force a trigger manuallyTrigger level setting range CH1 to CH8 ±4 div from center of screenTrigger level setting resolution CH1 to CH8 0.01 div (TV trigger: 0.1 div)Trigger level accuracy*CH1 to CH8 ±(0.2 div + 10% of trigger level)Window Comparator Center/Width can be set on individual Channelsfrom CH1 to CH8DisplayDisplay 12.1-inch TFT color liquid crystal display1024 × 768 (XGA)FunctionsWaveform acquisition modes Normal, Envelope, AverageHigh Resolution mode Max. 12 bit (the resolution of the A/D convertercan be improved equivalently by placing abandwidth limit on the input signal.)Sampling modes Real time, interpolation, repetitive samplingAccumulation Select OFF, Intensity (waveform frequency bybrightness), or Color (waveform frequency bycolor)Accumulation time 100 ms to 100 s, In niteRoll mode Enabled at 100 ms/div to 500 s/div (depending onthe record length setting)Zoom function T wo zooming windows can be set independently(Zoom1, Zoom2)Zoom factor ×2 to 2.5 points/10div (in zoom area)Scroll Auto ScrollSearch functions Edge, Edge Quali ed, State, Pulse Width, StateWidthI C (option), SPI (option), UART (option),CAN (option), LIN (option), FlexRay (option)History memory Max. data 2,500 (record length 1.25 kPoints, with standard)10,000 (record length 1.25 kPoints, with /M1 option)20,000 (record length 1.25 kPoints, with /M2 option)History search Select Rect, WAVE, Polygon, or Parameter modeReplay function Automatically displays the history waveformssequentiallyDisplay Speci ed or average waveformsCursor T ypes ∆T, ∆V, ∆T & ∆V, Marker, DegreeSnapshot Currently displayed waveform can be retained on screenComputation & Analysis FunctionsPower Measurement Automated measurement of power parameters forup to four pairs of voltage and current waveformsValues can be statistically processed and calculatedMeasurement Urms, Unm, Udc, Urmn, Uac, U+pk, U-pk, Up-pparameters Irms, Imn, Idc, Irmn, Iac, I+pk, I-pk, Ip-pP, S, Q, Z, λ, Wp, Wp+, Wp-, Abs.Wp, q, q+, q-,Abs.qI C Bus Signal Analysis Functions (/F2 & /F3 Options)Applicable bus I C bus Bus transfer rate: 3.4 Mbit/s max.Address mode: 7 bit/10 bitSM bus Complies with System Management BusI C Trigger modes Every Start, Address & Data, Non-Ack, GeneralCall, Start Byte, HS ModeAnalyzable signals All analog, logic and Math channelsAnalysis results displays Analysis no., time from trigger position (Time(ms)),1st byte address, 2nd byte address, R/W,Data, Presence/absence of ACK, informationAuto setup function Auto setting of threshold value, time axis scale,voltage axis scale, and display of analysis resultsAnalyzable no. of data 300,000 bytes max.Search function Searches data that matches speci ed addresspattern, data pattern, and acknowledge bitconditionAnalysis results save function Analysis list data can be saved to CSV-format lesSPI Bus Signal Analysis Functions (/F2 & /F3 Options)Trigger types 3 wire/4 wireAfter assertion of CS, compares data afterarbitrary byte count and triggers.Analyzable signals All analog, logic and Math channelsAnalysis results displays Analysis no., time from trigger position (Time(ms)),1st byte address, 2nd byte address, R/W,Data, Presence/absence of ACK, informationByte order MSB/LSBAuto setup function Auto setting of threshold value, time axis scale,voltage axis scale, and display of analysis resultsAnalyzable no. of data 300,000 bytes max.Decode bit length Specify data interval (1 to 32 bits), decode startpoint, and data lengthAnalysis results displays Analysis no., time from trigger position (Time(ms)), Data 1, Data 2Auxiliary analysis functions Data search functionAnalysis result save function Analysis list data can be saved to CSV-format lesUART Bus Signal Analysis Functions (/F1 & /F3 Options)Auxiliary analysis functions Data search and eld jump functionsAnalysis result save function Analysis list data can be saved to CSV-format lesFlexRay Bus Signal Analysis Functions (/F5 & /F6 Options)Applicable bus FlexRay Protocol Version2.1Analyzable signals All analog and Math channelsBit rate 10Mbps, 5Mbps, 2.5MbpsFlexRay bus Trigger modes Frame Start, Error, ID/Data, ID ORAuto setup function Auto setting of bit rate, threshold value, time axisscale,voltage axis scale, and display of analysisresultsAnalyzable no. of frames 5,000Analysis results displays Analysis no., time from trigger position (Time(ms)),Segment (Static or Dynamic),Indicator, FrameID,PayLoad length, Cycle count, Data, InformationAuxiliary analysis function Data searchAnalysis result save function Analysis list data can be saved to CSV-format lesGP-IB (/C1 Option)Electromechanical speci cations Conforms to IEEE std. 488-1978 (JIS C 1901-1987)Protocol Conforms to IEEE std. 488.2-1992Auxiliary InputRear panel I/O signal External trigger input, external trigger output,GO-NOGO output, video outputProbe interface terminal (front panel) 8 terminalsProbe power terminal (side panel) 8 terminals (/P8 option)Internal StorageCapacity Standard model: Approx. 1.8 GB/C8 option: Approx. 7.2 GBBuilt-in Printer (/B5 Option)Built-in printer 112 mm wide, monochrome, thermalUSB Peripheral Connection T erminalConnector USB type A connector × 2 (front panel)Electromechanical speci cations USB 2.0 compliantSupported transfer standards Low Speed, Full Speed, High SpeedSupported devices USB Mass Storage Class Ver. 1.1 compliant massstorage devicesUSB HID Class Ver.1.1 compliant mouse,keyboadUSB-PC Connection T erminalConnector USB type B connector × 1Electromechanical speci cations USB 2.0 compliantSupported transfer standards High Speed, Full SpeedModel Frequency bandwidth Input channelsDLM4038 DLM4058350 MHz500 MHz(standard) 8 analog channels or 7 analog channels + 8bit logic(/L16 option)8 analog channels + 16bit logic or7 analog channels + 24bit logicProduct IntroductionFunctions & FeaturesOptions & AccessoriesOperability & SoftwareSpeci cationsis included.*2: Start guide as the printerd material, and User's manuals as CD-ROM are included.*1: As the accessories for 701939 probe, various adapters are available. Please refer to DL Series Accessories brochure. *2: Current probes' maximum input current may be imited by the number of the probes used at a time.[ DLM is a registered trademark of Yokogawa Electric Corporation.]Any company's names and product names appearing in this document are the registered trademarks or trademarks of their respective companies.Accessories (sold separately)*1: Logic probes are not included. Please order the accessory logic probe 701988/701989 sold separately.*2: Only one of these can be selected at a time.*3: Specify this option when using current probes or differential probes that don't support probe interface.*4: Only one of these can be selected at a time.*5: Only one of these can be selected at a time.*6: Only one of these can be selected at a time.*7: Only one of these can be selected at a time.*8: The 701939 probes are not included when this option is speciﬁed.Logic probesRepresented by:YOKOGAWA CORPORATION OF AMERICA 2 Dart Road, Newnan, GA. 30265-1094 U.S.A.Phone: +1-770-253-7000 Facsimile: +1-770-254-0928YOKOGAWA EUROPE B. V.Euroweg 2 3825 HD Amersfoort, THE NETHERLANDS Phone: +31-88-4641000 Facsimile: +31-88-4641111YOKOGAWA ENGINEERING ASIA PTE. LTD.5 Bedok South Road, Singapore 469270 SINGAPORE Phone: +65-6241-9933 Facsimile: +65-6241-2606YOKOGAWA AMERICA DO SUL LTDA.Praca Acapulco, 31-Santo Amaro, Sao Paulo/SP, BRAZIL CEP-04675-190Phone: +55-11-5681-2400Facsimile: +55-11-5681-4434YOKOGAWA ELECTRIC KOREA CO., LTD.C&M Sales Seoul Ofﬁce1301-1305, 13rd ﬂoor, Kolon digital tower, 106-1,Yangpyongdong-5Ga, Yeongdeungpo-Gu, Seoul, 150-105, KoreaPhone: +82-2-2628-3810 Facsimile: +82-2-2628-3899YOKOGAWA AUSTRALIA PTY. LTD.Tower A/112-118 Talavera Road Macquarie Park, NSW 2113 AustraliaPhone: +61-2-8870-1100 Facsimile: +61-2-8870-1111YOKOGAWA INDIA LTD.Plot No. 96. Electronic City Complex, Hosur Road, Bangalore 560100, INDIA Phone: +91-80-4158-6000 Facsimile: +91-80-2852-1442YOKOGAWA SHANGHAI TRADING CO., LTD.4F Tower D, Cartelo Crocodile Building, No.568 West Tianshan Road, Shanghai, CHINAPhone: +86-21-6239-6363 Facsimile: +86-21-6880-4987YOKOGAWA MIDDLE EAST B. S. C.(C)P.O.BOX 10070, Manama, Building 577, Road 2516,Busaiteen 225, Muharraq, BAHRAINPhone: +973-17-358100 Facsimile: +973-17-336100YOKOGAWA ELECTRIC CIS LTD.Grokholskiy per. 13, Build. 2, 4th Floor, 129090, Moscow RUSSIAN FEDERATIONPhone: +7-495-737-7868 Facsimile: +7-495-737-7869Tachihi Bld. No.2, 6-1-3 Sakaecho, Tachikawa-shi, Tokyo, 190-8586 Japan Phone: +81-42-534-1413 Facsimile: +81-42-534-1426YOKOGAWA METERS & INSTRUMENTS CORPORATION Global Sales Dept.Subject to change without notice.[Ed : 02/b] Printed in Japan, 305(KP)All Rights Reserved, Copyright© 2012, Yokogawa Meters & Instruments Corporation.。

ABB 真空切断器说明说明书

Vacuum interruptersOver 30 years of experience in vacuum technology Worldwide more then 5 million ABB vacuum interruptersin serviceLatest technologies for high quality mass-production Process management according to Shop Floor Control (SFC) Compact and robust designHigh reliability and electrical life time1Stem / Terminal 2Twist protection 3Metal bellows 4Interrupter lid 5Shield6Ceramic insulator 7Shield 8Contacts 9Stem / Terminal 10Interrupter lidPrinciple structure12345678910Manufacturing proceduresFully automatic cleaning operation of assembly partsAutomatic transport of assembly parts directly into the clean roomEnvironmental friendly process water treatment systemManufacturing of switching contacts by dry machineVacuum furnaceBatching of pre-assembled vacuum interruptersClean room conditions to US standard class 1000Vacuum furnaces –evacuate and seals the vacuum interrupter in a single operationMonitoring of all important process parametersPressure < 10-8 hPa(mbar)Temperatures > 800°C / 1472°FQuality ControlEssential part of vacuum interrupter manufacturing processAll data is collected and storedAutomatic high voltage conditioning to achieve and prove dielectric strengthDouble internal pressure measurement for the vacuum interrupters (magnetron method)Quarantine storage in pressure chambers filled with inert gasAutomatic X-Ray examination of complete vacuum interruptersVacuum interrupter family VG and VSfor circuit-breaker application –low / mid dutyVG5VGE4VG4VGE4-S VG4-S12 kV12 kV12 kV12 kV12 kV…1250 A…1250 A…2500 A…2500 A…2500 A…20 kA…25 kA…25 kA…31,5 kA…31,5 kA17,5 kV 1)17,5 kV 1)17,5 kV 1)17,5 kV 1)17,5 kV 1)…1250 A…1250 A…2500 A…2500 A…2500 A…20 kA…25 kA…25 kA…31,5 kA…31,5 kA24 kV 1)24 kV 1)24 kV 1)…1250 A…2500 A…2500 A…16 kA…20 kA…25 kA …125/50 kV 1) 2)…95/42 kV 1) 2)…125/50 kV 1) 2)…95/42 kV 1) 2)…125/50 kV 1) 2)30.000 3)30.000 3)30.000 3)30.000 3)30.000 3)for circuit-breaker application –high dutyVG10VGE6VG6VG6-S 4)VG8VG8-S 36/40.5 kV 1)12/17.5 kV12/17.5 kV36/40,5 kV 1)36/40.5 kV1)36/40.5 kV1)…2000 A…3150 A…3150 A…3150 A…3150 A…3150 A …20 kA…40 kA…40 kA…31.5 kA…31.5 kA…40 kA24 kV 1)…3150 A…31.5 kA36/40,5 kV 1)…3150 A…31.5 kA…185/95 kV 1) 2)…95/42 kV 1) 2)…185/95 kV 1) 2)…185/95 kV 1) 2)…200/95 kV 1) 2)…200/95 kV 1) 2) 30,000 3)30,000 3)30,000 3)30,000 3)30,000 3)30,000 3)for circuit-breaker application –high duty VG7VG11VGHC212/17.5 kV12/17.5 kV 1.2 kV…3150 A…3150 A…3200 A…50 kA…63 kA…65 kA…95/42 kV2)…95/42 kV2)30,000 3)10,0003)100,0003)in silicone embedding techniqueWith Silicone embeddingBy embedding in silicone, VIs are suitable for the application in air with higher rated voltage levelsExample (in air):VG412 kV…2500 A…25 kA…30,000 COCeramic diameter: 90 mmVG4 silicone24 kV…2500 A…20 kA…30,000 COSilicone diameter: 100 mmin silicone embedding techniqueVG5 Silicone VGE4 Silicone VG4 Silicone VGE4-S Silicone VG4-S Silicone24 kV17.5 kV24 kV17.5 kV24 kV…1250 A…1250 A…2500 A…2500 A…2500 A…16 kA…25 kA…20 kA…31.5 kA…25 kA …30,000 CO3)…30,000 CO 3)…30,000 CO 3)…30,000 CO 3)…30,000 CO 3)in silicone embedding techniqueVG10 Silicone VG6 Silicone VG6-S Silicone 4)VG8 Silicone VG8-S Silicone 36/40.5 kV36/40.5 kV36/40.5 kV36/40.5 kV36/40.5 kV …2500 A…3150 A…3150 A…3150 A…3150 A…20 kA…31.5 kA…31.5 kA…31.5 kA…40 kA …30,000 CO 3)…30,000 CO 3)…30,000 CO 3)…30,000 CO 3)…30,000 CO 3)for switch applicationVAC1VS2VAS2VS4VS5 1)VG5-L7.2 kV12 kV12 kV24 kV2)27 kV2)27 kV2)…400 A…400 A…800 A…630 A…800 A…1250A …4 kA…4 kA(4 kA)(4 kA)(4 kA)(4 kA)…60/20 kV3)…75/42 kV3)…85/48 kV3)…125/50 kV2) 3)…150/70 kV2) 3)…150/60 kV2) 3)…1,000,000 CO 4)…1,000,000 CO 4)…10,000 CO 4)…30,000 CO 4)…30,000 CO 4)…30,000 CO 4)ConclusionCompact and robust design for highest demandsLatest production processes for high reliability and long life Silicone casting for out-standing external dielectric properties High quality management according to DIN EN ISO 9001 Worldwide dominant switching technology in the medium voltage rangeEnvironmental friendly and maintenance-free for lifeOur values for the customerVacuum Interrupters and Embedded Poles from ABB –Individual customer solutions and support(e.g. short leadtimes)–Full access to technical competence and test labs (e.g. type testsupport)–Dedicated customer support for day-to-day issues–Latest production and extended quality methods with high degree of automation (e.g. series X-ray check)–Benefit from the large production volume (global supplier base withfull risk management)–Proven in all ABB vacuum products –Innovations on ABB components give competitive advantages for ourpartners–Full in-house contact production and material control (z.B. batch-wisereal-life making/breaking tests)–Full access to latest embedding technologies Quality & Support Reliability & Performance Innovation The right core component for your apparatus。

烯丙孕素的合成及其晶体结构

烯丙孕素的合成及其晶体结构崔志刚，甄盼盼，杨雪，于小婷，张永赞，张磊，姜淋洁，赵健*（天津市中升挑战生物科技有限公司天津300380）过更换反应试剂对烯丙孕素的合成进行了工艺优化，使整个反应过程更适合放大生产，且安全环保、成本更低廉。

该合成方法以3-缩酮为原料，经过格氏化反应，水解反应，氧化反应得到烯丙孕素；并首次获得烯丙孕素单晶，X-射线衍射单晶结构测定表明，其结构为斜方晶系，P212121空间群，具有手性，晶胞参数：a=7.2501（15）Å，b=10.452（2）Å，c=22.252（5）Å，α=90°，β=90°，γ=90°，V=1686.2（6）Å3，Z=4，Dc=1.223mg/m 3，m=0.077mm -1，F （000）=672.0，GOF=1.034，Rint=0.0455，R1a,wR2b[I>2σ（I ）]=0.0456（0.1017），Residuals=0.0520（0.1063e Å-3）。

该晶体被剑桥晶体数据中心收录（申请人：崔志刚；晶体号：CCDC1914181）。

烯丙孕素晶型的确定为后续研究烯丙孕素制剂新剂型等方面提供选择。

孕素；合成；晶体结构烯丙孕素（又称四烯雌酮，Altrenogest ），为淡黄色至黄色结晶性粉末；无臭无味，对光敏感，无引湿性；CAS 号：850-52-2。

结构上与兽用药类固醇群勃龙有关，是一种合成的trienic C21甾类孕激素，属于19-去甲睾丸素类。

它是具有口服活性的促孕激素。

与所有类固醇一样，烯丙孕素可通过自身脂溶性渗透入靶细胞中，然后与特定受体结合来发挥作用，类似于天然孕酮的作用模式来抑制促性腺激素的释放，可作为家畜同期发情的药物。

烯丙孕素及其口服液在欧洲使用得非常广泛，欧盟（EMEA ）和美国（FDA ）已经批准上市使用，主要用于调控母猪和母马的同期发情。