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Optimizing matrix and ﬁber/matrix interface to achieve combination of strength,ductility and toughness in carbon nanotube-reinforced carbon/carbon compositesLei Feng,Kezhi Li ⁎,Bei Xue,Qiangang Fu,Leilei Zhang ⁎State Key Laboratory of Solidi ﬁcation Processing,Carbon/Carbon Composites Research Center,Northwestern Polytechnical University,Xi'an,710072,ChinaH I G H L I G H T S•Both matrix and ﬁber/matrix interface of carbon/carbon composites were opti-mized.•Radial carbon nanotube (CNT)was grown on carbon ﬁbers (CF)to strength-en matrix.•Pyrocarbon layer was introduced be-tween CF and CNT/matrix to optimize interface.•Optimal designs endowed composite with improved strength,ductility and toughness.G R A P H I C A L A B S T R A CTa b s t r a c ta r t i c l e i n f o Article history:Received 2July 2016Received in revised form 2October 2016Accepted 3October 2016Available online 5October 2016The direct attachment of carbon nanotubes (CNTs)on carbon ﬁbers (CFs)always leads to a decrease of ﬁber-dominated properties (e.g.,ﬂexural strength)and a brittle fracture behavior of C/Cs,although the matrix-domi-nated properties (e.g.,compressive strength and interlaminar shear strength (ILSS))exhibit an obvious enhance-ment.To achieve the combination of mechanical strength,ductility and toughness in C/Cs,in this work,efforts were spent on simultaneously optimizing the matrix and ﬁber/matrix (F/M)Ts with radial orienta-tion were grown onto the CFs by double-injection chemical vapor deposition to modify the microstructure of ma-trix.Pyrocarbon was deposited on the surface of CFs before CNT growth to protect CFs and to weaken interfacial strength between CFs and CNT/matrix.These optimal designs create strengthening and toughness mechanisms such as crack de ﬂection and long pullout of CFs in the failure process of composites,which endow C/Cs with im-proved ﬂexural strength of 31.5%,ﬂexural ductility of 118%,compressive strength of 81.5%and ILSS of 82%,ac-companied by a clear change from brittle fracture to pseudo-plastic fracture during ﬂexural test.This work may provide a meaningful way to not only enhance both the ﬁber-and matrix-dominated strength but to sub-stantially improve the ductility and toughness of C/Cs.©2016Elsevier Ltd.All rights reserved.Keywords:Carbon nanotubesCarbon/carbon composites Interface Strength Toughness1.IntroductionDesign of high-performance structural engineering carbon/carbon composites (C/Cs)is driven by optimizing combinations of mechanicalMaterials and Design 113(2017)9–16⁎Corresponding authors.E-mail addresses:likezhi@ (K.Li),zhangleilei@ (L.Zhang)./10.1016/j.matdes.2016.10.0060264-1275/©2016Elsevier Ltd.All rightsreserved.Contents lists available at ScienceDirectMaterials and Designj o u r n a l h o me p a g e :ww w.e l s e v i e r.c o m /l o c a t e /m a t d e sproperties such as strength,ductility,toughness and requirements for stability and non-catastrophic failure during service[1,2].C/Cs exhibits high speciﬁc strength and modulus,however,they have weak compres-sion and interlaminar properties,lack ductility and toughness,and al-ways fail in an apparently brittle manner in unconstrained loading geometries[3–5].Recently,the huge interest in incorporating carbon nanotubes (CNTs)into structural composites have been stimulated by virtue of their extraordinary intrinsic properties,such as ultrahigh strength,ex-cellent electrical and thermal conductivities[6,7].These outstanding mechanical and physical properties,in combination with their unique 1D nanostructures with high speciﬁc surface areas,allow for efﬁcient tailoring of both matrix microstructure andﬁber/matrix(F/M)interface state[8,9].For the incorporation of CNTs into composite structures,the general trend has been focused on in situ-growth of CNTs[10–12]or attaching CNTs to the carbonﬁbers(CFs)[13–15].Unlike attracting CNTs which trend to lie in the plane ofﬁber surface and thus only pro-vide one-side reinforcement to the C/Cs(just at F/M interface area), growing CNTs on the surface of CFs by catalytic chemical vapor deposi-tion(CVD)has many advantages in terms of controllability of size and orientation of CNTs,particularly a radial orientation that allows for si-multaneous reinforcements to the matrix and F/M interface[16].Excit-ing increases in matrix-dominated properties(e.g.,compressive strength and interlaminar shear strength)of C/Cs have been observed by growing CNTs onto carbonﬁbers[17–19].Nevertheless,there still exit some critical issues regarding the C/Cs reinforced with CVD-grown CNTs.Firstly,due to the potential damage(dissolution of metal catalysts into carbon,local oxidation and gasiﬁcation)of the CFs during the growth reaction[20,21],and the difﬁculty of controlling the orienta-tion and uniformity of the grafted CNTs on CFs[16,22,23],the studies on the enhancements both inﬁber-and matrix-dominated strengths of C/ Cs have rarely been reported.Secondly and more importantly,the direct attachment of CNTs onto CF surface always result in strong F/M interfa-cial bonding and thus obstructs the crack deﬂection along the axis of CFs [17,23–25],which leads to the failure ofﬁber pullout as an effective strengthening and toughening mechanism.There will be little or no property enhancement in the ductility and toughness expected in such a mode of composite failure[26,27].If CNT-reinforced C/Cs is to re-place C/Cs in industries,it is necessary to achieve the combination of global strength,ductility and toughness in C/Cs.Over the past few de-cades,however,few efforts have been spent on this issue.To improve the comprehensive mechanical performance of CNT-re-inforced C/Cs,the substantial problem and great challenge are how to moderate the F/M interfacial bonding so that it is neither too strong nor too weak and how to supply effective reinforcements to the carbon matrix without degrading theﬁber strength.In this work,a thin pyrocarbon(PyC)interface layer was deposited on the surface of CFs by chemical vapor inﬁltration(CVI)technique to optimize the F/M in-terfacial bonding,whilst preventing the dissolution of metal catalysts into CFs occurred during the subsequent growth of CNTs.Afterwards, double-injection CVD(DICVD)technique was developed to grow radial-ly-aligned CNTs on PyC-coated CFs.The schematic of this manufacturing process is depicted in Fig.1.The hybridﬁber preforms were then desiﬁned by CVI technique to obtain theﬁnal CNT-reinforced C/Cs. Three-point bending,compression and interlaminar shearing tests were applied to examine the effect of these optimal designs on the me-chanical properties of C/Cs.2.Experimental2.1.Raw materialsCarbon felts(bulk density0.2g/cm3,ﬁber diameters6–8μm,Yixing Tianniao Co.Ltd.,China)used in this work were fabricated by alterna-tively overlapping layers of randomly oriented shortﬁber bundles with needle-punching step-by-step.2.2.Deposition of PyC interface layer on CFs and the growth of CNTsCarbon felts wereﬁrstly deposited with an interface layer of PyC by isothermal CVI technology,which was carried out at1080°C using ﬂowing mixture of CH4(40L/h)and N2(160L/h)under the ambient pressure.The growth of CNTs in carbon felts was conducted by DICVD technique using FeSO4·6H2O as catalyst precursor.Incipient wetness technique was applied to introduce catalysts into felts using distilled water as solvent.Afterwards,they were placed in a CVD reactor and heated to750°C under Arﬂowing.At the growth temperature,xylene as the hydrocarbon source was injected into the reactor through a thin tube via a syringe.Ethylenediamine as the growth promoter wasﬁlled in another syringe and was injected separately from the same side for the xylene injection.The ratio of injection rates of xylene and ethylenediamine was8:1.The Ar/H2(2/1)gas mixture was used as the carrier gas with aﬂow rate of600sccm.The growth time was2h. The direct growth of CNTs in carbon felts without PyC interface layer was also performed by DICVD technique under identical growth condi-tions.The volume fractions of CNTs in carbon felts with and without PyC interface layer were approximately1.3%.posite preparation and mechanical property testsThe densiﬁcation was carried out by isothermal CVI technique for 150h under the conditions described in section2.2.The C/Cs containing both the PyC interface layer and CNTs were denoted as CNT-PyC-C/Cs, while the C/Cs containing only CNTs were denoted as CNT-C/Cs.The Fig.1.Schematic of depositing PyC interface layer on CFs and followed by growth of radial CNTs by DICVD to maintainﬁber strength,optimize F/M interface and strengthen matrix of C/Cs. 10L.Feng et al./Materials and Design113(2017)9–16densities of pure C/Cs,CNT-C/Cs and CNT-PyC-C/Cs were measured in the range of 1.64–1.67g/cm 3.The sizes of samples for bending tests were machined into 50mm ×8mm ×4mm.The support span for bend-ing tests was 40mm.To study the quasi-ductile fracture behavior of the composites,a ductility factor was introduced.It was calculated from the ratio of the secant modulus (the slope of the line from the origin to the stress at failure in the ﬂexural stress-strain curve)to the elastic modulus [28].The samples used for compression test and interlaminar shearing test were machined into the sizes of 5mm ×5mm ×4mm.The numbers of samples for bending,compression and shearing tests were not less than 5.All the tests were carried out on a universal testing machine (CMT5304)at a constant speed of 0.5mm/min.2.4.CharacterizationThe morphologies and microstructures of grafted CNTs were exam-ined by scanning electrical microscopy (SEM,JSM-6700)operated at 15kV and transmission electrical microscopy (TEM,Tecnai F30G 2)op-erated at 200kV,respectively.Microstructure of the matrix PyC was in-vestigated using polarized light microscopy (PLM,Leica DMLP).The Raman spectrum was recorded on a Renishaw Invia RM200using aninVia micro-Raman spectrometer with an Ar ion laser of 514.5nm wavelength at room temperature.3.Results and discussion3.1.Radially-aligned CNTs grafted on CFs with and without PyC coating Fig.2a shows the surface SEM image of the CFs coated with a homog-enous PyC interface layer with a thickness of about 200nm (Fig.2b).After the growth process by DICVD,the CFs without (Fig.2c)and with (Fig.2d)PyC interface layer are uniformly covered with CNTs.The CNTs exhibit radial grafting morphologies,indicating that the DICVD technique has good repeatability for growing radial CNTs on different carbonaceous substrates.These radial nanotubes extend into the space among ﬁbers capability of providing ef ﬁcient reinforcements both to the interlaminar and intralaminar matrix [29].Observation of the cross-section of hybrid ﬁbers presents the detailed information about the CNT length ranging from 4to 7μm (Fig.2e).TEM investigation (Fig.2f)reveals that the products are hollow nanotubes with smooth walls and a typical outer diameter of about 300nm.And the inner diam-eter and tube-wall thickness are about 200nm and 50nm,respectively.Fig.2.SEM images:(a)surface and (b)cross-section of PyC-coated CFs;(c)surface of radially-aligned CNTs grafted on CFs;(d)surface and (e)cross-section of radially-aligned CNTs grafted on PyC-coated CFs.(f)TEM image of an individual CNT and its high resolution TEM image (inset of f).11L.Feng et al./Materials and Design 113(2017)9–16High resolution TEM image (Fig.2f inset)presents that the CNTs have multi-walled structures and the graphitic sheets are parallel to the axial direction,exhibiting a good crystallinity.3.2.Microstructure of compositesThe polished transverse section of the C/Cs,CNT-C/Cs and CNT-PyC-C/Cs viewed by polarized light microscopy is shown in Fig.3.For C/Cs (Fig.3a),the PyC around CFs is in the shape of circular shell and has large grain size,long boundaries between interference colors and pro-nounced homocentric annular cracks.By contrast,PyC in CNT-PyC-C/Cs (Fig.3b)and CNT-C/Cs (Fig.3b inset)demonstrates a different mor-phology.As for the CFs grafted with radial CNTs,the PyC will deposit around the nanotubes rather than directly on the surface of CFs (here,CNTs provide direct reinforcement to the matrix within the reach of nanotubes).Besides,it has been demonstrated in our previous work [30],where the CNTs can also affect the PyC out of the reach of nano-tubes by inducing the formation of spherical or cone-shaped PyC and then restricting their growing up (here,it can be called as “indirect rein-forcement ”).As a result,the consequent PyC is clearly different in mor-phology from that in pure C/Cs.As seen,the PyC in C/Cs containing CNTs exhibits small grain size,short boundaries between interference colors and no annular cracks.In addition,it is interesting to note that CFs in CNT-PyC-C/Cs present white outlines (labeled by arrows in Fig.3b)at-tributed to the presence of PyC interface layers.Fig.3c and d presents the Raman results of C/Cs and CNT-PyC-C/Cs (same with CNT-C/Cs),respectively.Intensity ratio of disorder-inducedD-peak and tangential G-peak is inversely proportional to the level of crystalline order and crystal size L a (in nm)[31].As stated in Table 1,the D:G intensity ratio,I D /I G ,is about 1.85for C/Cs and falls to approxi-mately 1.52for CNT-PyC-C/Cs,suggesting that PyC has a signi ﬁcant im-provement in crystallinity and meanwhile a big increase in L a after introducing radial CNTs.Axisymmetric peak broadening represents for large interplanar spacing d 002of carbon materials [32].As seen,both G-peak and D-peak of interlayer become sharper and more de ﬁned after introducing radial CNTs,which indicates that,the d 002value of PyC in CNT-PyC-C/Cs has a distinct decrease compared with that in C/Cs.As the crystalline order improves and crystal size increases,the bond density within the interlayer increases [33].High bond densities and few defects could lead to a signi ﬁcant increase in mechanical strength of PyC matrix.3.3.Mechanical properties of compositesFig.4presents the stress-strain curves of the three composites re-corded during bending test,compression test and shearing test.The de-tailed results of mechanical tests of three composites are listed in Table pared with C/Cs,CNT-PyC-C/Cs shows obvious improve-ment in ﬂexural strength,ﬂexural ductility,compressive strength and interlaminar shear strength (ILSS):31.5%in ﬂexural strength,118%in ﬂexural ductility,81.5%in compressive strength and 82%in ILSS.How-ever,the ﬂexural strength and ﬂexural ductility of CNT-C/Cs are de-creased by 14.5%and 73%,although the compressive strength and ILSS are increased by 67%and 115%,respectively.From the ﬂexuralstress-Fig.3.PLM images (a,b and inset)and Raman spectra (c,d)of the three composites:(a and c)C/Cs;(inset of b)CNT-C/Cs;(b and d)CNT-PyC-C/Cs (note:red points marked in a and b are the Raman detection positions).Table 1Raman testing data of C/Cs,and CNT-PyC-C/Cs (±values represent standard deviation).Composite FWHM of G-peak (cm −1)FWHM of D-peak (cm −1)I D /I GC/Cs84.41±0.21116.54±0.30 1.85±0.01CNT-PyC-C/Cs78.76±1.8288.62±1.341.52±0.0712L.Feng et al./Materials and Design 113(2017)9–16strain curves (Fig.4a),we can get the information regarding the fracture behavior of the three composites.For C/Cs and CNT-C/Cs,the ﬂexural stress-strain curves can be divided in two segments:linear rise and lin-ear decrease of stress.The stress suddenly drops leading to the cata-strophic failure of the samples as stress goes up to the peak value,which designates brittle fracture occurs in the two composites.By con-trast,CNT-PyC-C/Cs shows pronounced pseudo-plastic fracture behav-ior since the load decreases in a step-style rather than perpendicularly after the peak value.The stress-stain curve can be divided into three segments:linear rise of load,non-linear rise of load and stepped de-crease of load.The different segments correspond to three stages:ma-trix elastic deformation,appearing and propagating of destructive cracks among matrix,interfacial debonding and ﬁber pullout,respec-tively [34,35].It means that CNT-PyC-C/Cs does not rupture completely but only fractures partly,avoiding the catastrophic failure as the loading stress reaches to the maximum value,which indicates a signi ﬁcant im-provement in the fracture toughness [36,37].The observation from the compressive and shear stress-strain curves (Fig.4b and c)is that the compressive strength and ILSS of C/Cs can be signi ﬁcantly increased by grafting radial CNTs onto CFs,no matter whether the PyC interface layer is presented or not.From these results it is suggested that if we want to improve the global mechanical strength,ductility and tough-ness of C/Cs,it is necessary to simultaneously optimize both the matrix and F/M interface.When the ﬂexural stress is loaded on the composite samples,the strength of the composites is mainly depended on the strength of CFs.Fig.5shows the SEM images of ﬂexural fracture surfaces of the three composites.In Fig.5a,the fracture surface of C/Cs shows plenty of step-wise fractured PyC and very limited ﬁber pullout.These fracture steps result from the annular cracks that supply the paths for the spreading and link up of destructive cracks and then lead to the formation of step-wise PyC panels.Besides,the F/M interfacial bonding of C/Cs is loose with obvious gaps between CFs and PyC (Fig.5a inset).According to the observations from Fig.5a,the fracture process in C/Cs during bend-ing test can be described as follows:when the bending stress is loaded on the composite samples,destructive cracks will appear somewhere in matrix at the most critical ﬂaws,and then propagate along the annu-lar cracks leading to the delaminating of PyC;it is hard for the weak ma-trix and poor F/M interface to induce the de ﬂection of destructive cracks to propagate along ﬁber surface,which leads to the early failure of CFs since the CFs is dif ﬁcult to be hold on by matrix [38];as the stress further increases,these destructive cracks link up with each other and then the failure of composites occurs.The strength of CFs cannot be fully re ﬂected and thus the C/Cs exhibits brittle fracture with low fracture strength.As for CNT-C/Cs,the fracture surface is ﬂat and with nearly ab-sent of ﬁber pullout (Fig.5b).This fracture surface can be attributed to the strongly-enhanced cohesion in matrix and also the powerful me-chanical interlocking at F/M interface,which lead the destructive cracks to extend into and through the CFs without interfacial debonding (Fig.5b inset).Additionally,the degradation of tensile strength of CFs caused during the CNT growth process is also responsible for the degra-dation of ﬂexural strength of CNT-C/Cs [39].In contrast,CNT-PyC-C/Cs shows a stepwise fracture surface with abundant ﬁber pullouts (Fig.5c).Enlarged SEM image (Fig.5d)illustrates that the destructive cracks spread along the nano/μ-scale grain boundaries (labeled by red dotted lines).When the destructive cracks extend to the CFs,PyC inter-face layer plays a role in changing their direction and facilitates them spreading along the direction parallel to the ﬁber axis as much as possi-ble (as shown in Fig.5e,where exposed PyC interface layer on the pulled-out CFs can be clearly observed).The PyC interface layer protects CFs effectively and weakens the interfacial strength between CFs and CNT/PyC,leading to the long pull-out of CFs compared with brittle frac-ture of CFs without PyC interface layer.Therefore,the stress can be ef ﬁ-ciently transferred from the matrix to the CFs through the strengthened matrix and optimized F/M interface.Crack de ﬂection and ﬁber pullout require a great amount of fractured energy consumption during the fail-ure process [26,27,30,40],which in turn increase the ﬂexural strength and ductility of CNT-PyC-C/Cs and also make the ﬂexural stress release gently,resulting in the sliding region occurred in the ﬂexural stress-strain curve which corresponds to an improved fracture toughness.When the compressive stress is loaded on the composite samples,the compressive strength is mainly depended on the matrix cohesion.Fig.6presents the SEM images of compressive fracture surfaces of the three composites.The fracture surface of C/Cs shows ﬂat and no CFs exist on the surface (Fig.6a),implying that fracture primarily occurs as a typical delamination failure without crack de ﬂection during com-pression test (corresponding failure model is depicted in Fig.6a inset).High degree of matrix delaminating is the dominant mechanism for the delamination failure (Fig.6b).Enlarged SEM image (Fig.6c)clearly shows existing annular cracks provide main channels for the long-dis-tance extending of destructive cracks and then opening the plies.As for CNT-C/Cs (Fig.6d),the strongly-enhanced matrix ef ﬁciently im-pedes the propagation of destructive cracks in the interlaminar region (corresponding failure mode is shown in Fig.6d inset).The de ﬂected destructive cracks then turn to the intralaminar regions (Fig.6e)and di-rectly pass through the CFs by virtue of strong F/M interfacialbonding,Fig.4.Stress-strain curves of the three composites recorded during different mechanical tests:(a)ﬂexural test;(b)compression test;(c)Shearing test.Table 2Mechanical properties of C/Cs,CNT-C/Cs and CNT-PyC-C/Cs (±values represent standard deviation).Composite Flexural strength (MPa)Flexural ductility Compressive strength (MPa)Shear strength (MPa)C/Cs54±60.11±0.03195±1133±5CNT-C/Cs46±70.03±0.01326±1371±8CNT-PyC-C/Cs71±100.24±0.06354±1660±613L.Feng et al./Materials and Design 113(2017)9–16forming many ﬂat fractured surfaces (Fig.6f).But comparatively,CNT-PyC-C/Cs shows a rugged fracture surface with many exposed CFs (Fig.6g),indicating that the propagation direction of destructive cracks also changes mangy times during compression test (corresponding fail-ure mode is shown in Fig.6g inset).The optimized F/M interface induces the long-distance propagation of destructive cracks along the ﬁber sur-face rather than directly pass through the CFs occurred in CNT-C/Cs (Fig.6h and i).More energies are dissipated during this course,which in turn could explain the more pronounced increment in the compressive strength for CNT-PyC-C/Cs (that is 81.5%)than that of CNT-C/Cs (that is 67%).When the interlaminar shear stress is loaded on the composite sam-ples,the shear strength is mainly depended on both the matrix cohesion and F/M interfacial bonding strength.Fig.7presents the shearing frac-ture surface of three composites.As seen in Fig.8a,the smooth PyC shearing fracture surface suggests a serious matrix delaminating in C/Cs,which is similar to the failure mode observed in compression test.It can be thus said that for C/Cs the matrix cohesion is lowerthanFig.5.SEM images of the ﬂexural fracture surfaces of the three composites:(a and inset)C/Cs;(b and inset)CNT-C/Cs;(c –e)CNT-PyC-C/Cs.Fig.6.SEM images of the compressive fracture surfaces of the three composites:(a –c)C/Cs;(d –f)CNT-C/Cs;(g –i)CNT-PyC-C/Cs (insets are the failure modes of the composites during compression tests).14L.Feng et al./Materials and Design 113(2017)9–16F/M interfacial bonding strength.As for the CNT-C/Cs (Fig.8b),matrix delaminating is inhibited and abundant damaged CFs can be clearly ob-served in the shearing fracture surface,indicating that the interfacial strength between CFs and CNT/PyC is strong enough to generate a crack de ﬂection from CNT/PyC to CFs and thus leading to the cleaving of CFs.However,for the CNT-C/Cs (Fig.8c),the F/M interfacial bonding seems to be relatively weak compared with the strongly-enhanced ma-trix,according to the long-distance spreading of destructive cracks along CF surface.This observation provides direct evidence that the PyC interface layer weakens the interfacial bonding strength between CFs and CNT/PyC (Fig.8c inset).It also explains the reason why the in-crement in ILSS of CNT-PyC-C/Cs (that is 82%)is lower than that of CNT-C/Cs (that is 115%).In addition,CNT pullout has rarely been found in all the fracture surfaces of composite samples.Therefore,it can be said that the contribution of our CNTs to the high mechanical strengths of composites is mainly re ﬂected in strengthening the matrix.From the above analysis,the schematic modeling of the failure mecha-nisms of the three composites during loading process has been established,as shown in Fig.8.4.ConclusionsPyC deposited on the CF surface following the radial CNT growth en-ables F/M interface optimizing,matrix strengthening and minimum degradation to the ﬁber strength.SEM morphologies of fracture surfaces of failure composites reveal that the synergistic effects of strongly-en-hanced matrix and optimized F/M interface not only ef ﬁciently de ﬂects the propagation direction of destructive cracks,but also induces the long-distance spreading of destructive cracks along the surfaces of CFs,which signi ﬁcantly increase the ﬂexural strength,ﬂexural ductility,frac-ture toughness,compressive strength and ILSS of C/Cs.However,the speci ﬁc interfacial bonding strength between CFs and CNT/PyC as well as the effect of thickness of PyC interface layer on the mechanical perfor-mance of CNT-reinforced C/Cs are still unclear.Still and all,this work might open up a possibility to produce CNT-reinforced C/Cs with excel-lent mechanical strength,ductility and toughness to replace traditional C/Cs in industries.AcknowledgementsThis work has been supported by the Fundamental Research Funds for the Central universities under Grant No.3102014JCQ01030and “111”Project of China (B08040),and the Natural Science Foundation of China (Grant Nos.51521061and51502242).Fig.7.SEM images of the shearing fracture surfaces of the three composites:(a)C/Cs;(b)CNT-C/Cs;(c and inset)CNT-PyC-C/Cs.Fig.8.The failure mechanisms of the three composites during loading process (red lines 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无冬之夜2背叛者的面具完全图文攻略(一)

0LH-游戏攻略资料集2008年2月上海开始游戏--------------------------------------------------启动游戏程序，进入开始画面。

选择开始新游戏或载入游戏存档继续游戏。

1在无冬的2夜里，我带领着我的伙伴们，终于消灭了邪恶的阴影之王，但随之而来的大坍塌，使我没能回到我的故乡，还有美丽平安了的无冬城，失去了战友、伙伴，也顿时失去了知觉……我将开始新的历程。

如果你从资料片重新开始游戏，需要建立一个新角色。

先选择人物性别、外观、职业和技能点数分配。

完成人物基本设定后，游戏自动转入一间装潢不错的厅屋里。

厅是你能根据自己喜好选择塑造主人公的一个安全的地方。

游戏将会给你165000经验点,也可以手动或自动达到18级人物。

游戏也会给你一些基本3个装备，但是你在大厅没开始游戏之前，将不会看到它。

最后完成的，以后实际在游戏画面中的战士形象：2完成后出门。

厅的出口门位于东南3于东南方（下面厅俯视全景图中的左上角）的角落角落。

4序章5古墓下层1-出发点这是你游戏开始点。

你将会很快地发现嵌在你体内心脏旁的银剑碎片已经被取走，而且你现在变成从内而发出的黑暗饥饿感，需要吞噬什么东西。

然后,一个塞恩Thay的红袍巫师萨菲雅Safiya飘然而至,身边还带着一个宠物精灵卡吉Kaji，而且她将会加入你的队伍。

如果你在这里碰周围符文石柱runestone中之一，那么你将会有男孩、一个女人和一面墙壁的幻影视觉记忆，而且你将会赚得250经验点。

幻影视觉记忆将会渐渐消失。

你也可能在附近注意一个骨骼。

它也稍后将会给你较多的感觉。

在最底层古墓进入古墓下层前，你应该检查你的详细信息栏、物品栏和你的法术栏及快捷设定等。

这时你将没有任何武器或者黄金，你的斗蓬需要装备上，而且你可能不记住任何的符咒魔法。

让你在开始的地方休息是安全的。

注意:你也要检查萨菲雅Safiya的栏目。

她有坚固的魔法技能,还有比较实用的魔法卷轴，意谓你能将她的卷轴移进自己的物品栏，再设定在快捷栏内使用,这可以在24个小时里使用。

10.1007_s00253-010-2443-4

BIOTECHNOLOGICAL PRODUCTS AND PROCESS ENGINEERINGEffects of biotic and abiotic elicitors on cell growth and tanshinone accumulation in Salvia miltiorrhiza cell culturesJiang-Lin Zhao &Li-Gang Zhou &Jian-Yong WuReceived:7September 2009/Revised:6January 2010/Accepted:6January 2010/Published online:2March 2010#Springer-Verlag 2010Abstract This study examined the effects of biotic and abiotic elicitors on the production of diterpenoid tanshi-nones in Salvia miltiorrhiza cell culture.Four classes of elicitors were tested,heavy metal ions (Co 2+,Ag +,Cd 2+),polysaccharides (yeast extract and chitosan),plant response-signaling compounds (salicylic acid and methyl jasmonate),and hyperosmotic stress (with sorbitol).Of these,Ag (silver nitrate),Cd (cadmium chloride),and polysaccharide from yeast extract (YE)were most effective to stimulate the tanshinone production,increasing the total tanshinone content of cell by more than ten-fold (2.3mg g -1versus 0.2mg g -1in control).The stimulating effect was concentration-dependent,most significant at 25μM of Ag and Cd and 100mg l -1(carbohydrate content)of YE.Of the three tanshinones detected,cryptotanshinone was stimulat-ed most dramatically by about 30-fold and tanshinones I and IIA by no more than 5-fold.Meanwhile,most of the elicitors suppressed cell growth,decreasing the biomass yield by about 50%(5.1–5.5g l -1versus 8.9g l -1in control).The elicitors also stimulated the phenylalanine ammonia lyase activity of cells and transient increases in the medium pH and conductivity.The results suggest that the elicitor-stimulated tanshinone accumulation was a stress response of the cells.Keywords Salvia miltiorrhiza .Cell culture .Tanshinones .Elicitors .Stress responseIntroductionSalvia miltiorrhiza Bunge (Lamiaceae),called Danshen in Chinese,is a well-known and important medicinal plant because its root is an effective herb for treatment of menstrual disorders and cardiovascular diseases and for the prevention of inflammation (Tang and Eisenbrand 1992).As its Chinese name refers,Danshen root is characterized by the abundance of red pigments which are mainly ascribed to numerous diterpene quinones generally known as tanshinones,e.g.,tanshinone I (T-I),tanshinone-IIA (T-IIA),and T-IIB,isotanshinone I and II,and cryptotanshinone (CT).Tanshinones constitute a major class of bioactive compounds in S .miltiorrhiza roots with proven therapeutic effects and pharmacological activities (Wang et al.2007).Danshen in combination with a few other Chinese herbs is an effective medicine widely used for the treatment of cardiovascular diseases and used as an emergency remedy for coronary artery disease and acute ischemic stroke.According to WHO statistics,cardiovas-cular diseases are and will continue to be the number one cause of death in the world (www.who.int/cardiovascular_diseases ).It is of significance to develop more efficient means for the production of Danshen and its active constituents.Although field cultivation is currently the major produc-tion means for Danshen and most other plant herbs,plant tissue cultures provide more well-controlled and sustainable systems for efficient production of desired bioactive compounds of the herb.Plant tissue cultures are the most useful and convenient experimental systems for examiningJ.-L.Zhao :L.-G.Zhou (*)Department of Plant Pathology,China Agricultural University,Beijing 100193,China email:lgzhou@J.-Y .Wu (*)Department of Applied Biology and Chemical Technology,The Hong Kong Polytechnic University,Hung Hom,Kowloon,Hong Kong email:bcjywu@.hkAppl Microbiol Biotechnol (2010)87:137–144DOI 10.1007/s00253-010-2443-4various factors on the biosynthesis of desired products and for exploring effective measures to enhance their produc-tion.The importance of Danshen for traditional and modern medicines has promoted the long-lasting research interest in the development of tiorrhiza tissue cultures for production of bioactive compounds for more than two decades.In an early study,Nakanishi et al.(1983)induced several cell lines from plant seedlings and screened out a cell line capable of producing significant amounts of CT and another diterpene,ferruginol.In later studies,the group performed a fuller evaluation and optimization of the medium for cell growth and CT production and,eventually,derived an effective production medium with a simpler composition(ten components)than the original Murashige and Skoog(MS) medium(about20components),achieving a high CT yield of 110mg l-1(Miyasaka et al.1987).Many recent studies have been focused on hairy root cultures of tiorrhiza transformed by Agrobacterium rhizogenes(Hu and Alfermann1993;Chen et al.2001)and by our group (Zhang et al.2004;Ge and Wu2005;Shi et al.2007).Most of the bioactive compounds in medicinal plants belong to secondary metabolites which are usually less abundant than primary metabolites in the plants.Since the accumulation of secondary metabolites in plants is a common response of plants to biotic and abiotic stresses, their accumulation can be stimulated by biotic and abiotic elicitors.Therefore,elicitation,treatment of plant tissue cultures with elicitors,is one of the most effective strategies for improving secondary metabolite production in plant tissue cultures(Chong et al.2005;Smetanska2008).The most common and effective elicitors used in previous studies include the components of microbial cells especially poly-and oligosaccharides(biotic)and heavy metal ions, hyperosmotic stress,and UV radiation(abiotic),and the signaling compounds in plant defense responses such as salicylic acid(SA)and methyl jasmonate(MJ;Zhou and Wu2006;Smetanska2008).Some of these elicitors,yeast extract(mainly the polysaccharide fraction),silver ion Ag+, and hyperosmotic stress(by an osmoticum)have also been applied and shown effective to enhance the production of tanshinones in tiorrhiza hairy root cultures(Chen et al.2001;Zhang et al.2004;Shi et al.2007).To the best of our knowledge,only a few studies have been documented on the effects of elicitors,YE,SA,and MJ,on the secondary metabolite production in Agro-bacterium tumefaciens transformed tiorrhiza cell cultures from one research group(Chen and Chen1999, 2000)but not any study in normal cell cultures.The present study focuses on the effects of common biotic and abiotic elicitors including polysaccharides,heavy metal ions, SA and MJ,and osmotic stress(with sorbitol)on the growth and accumulation of three major tanshinones T-I, T-IIA,and CT in suspension culture of normal tior-rhiza cells.In addition to the effects of various elicitors on the total tanshinone content of cells,the study will examine the effects on different tanshinone species and the potential relationship to plant stress response.Material and methodsCallus induction and cell suspension cultureYoung stem explants of tiorrhiza Bunge were collected from the botanical garden at the Institute of Medicinal Plant Development,Chinese Academy of Med-ical Sciences,Beijing,China,in May2005.The fresh explants were washed with tap water,surface-sterilized with 75%ethanol for1min,and then soaked in0.1%mercuric chloride for10min and rinsed thoroughly with sterilized water.The clean and sterilized explants were cut into∼0.5-cm segments and placed on solid MS medium(Murashige and Skoog1962)supplemented with sucrose(30g l-1),2,4-D(2mg l-1)and6-BA(2mg l-1)to induce callus formation. The callus culture of tiorrhiza was maintained on a solid,hormone-free MS medium with8g l-1agar and 30g l-1sucrose at25°C in the dark and subcultured every 4weeks.The culture was deposited in Lab Y1210at The Hong Kong Polytechnic University with a collection number of Danshen cell-1.All experiments in this study were performed in suspension culture of tiorrhiza cells in a liquid medium of the same composition as for the solid culture but excluding agar.The cell suspension culture was maintained in shake-flasks,i.e.,125-ml Erlenmeyer flasks on an orbital shaker operated at110–120rpm,at 25°C in the dark.Each of the flasks was filled with25ml medium and inoculated with0.3g fresh cells from18–21-day-old shake–flask culture.Elicitor preparation and administrationEight elicitors were tested,each at three concentrations,in the initial elicitation experiments(Table1).These are representative of the four major classes of elicitors for the induction of plant responses and the stimulation of secondary metabolite production in plant tissue cultures (Zhou and Wu2006;Smetanska2008).All elicitors except MJ were prepared as a concentrated stock solution in water and autoclaved at121°C for15min,and stored at4°C in a refrigerator prior to use.Yeast elicitor(YE)was the polysaccharide fraction of yeast extract(Y4250,Sigma, St.Louis,MO,USA)prepared by ethanol precipitation as described previously(Hahn and Albersheim1978;Ge and Wu2005).In brief,yeast extract was dissolved in distilled water(20g/100ml)and then mixed with400ml of ethanol and allowed to precipitate for4days at4°C in arefrigerator.The precipitate was redissolved in100ml of distilled water and subjected to another round of ethanol precipitation.The final gummy precipitate was dissolved in 50ml of distilled water and stored at4°C before use.The concentration of YE was represented by total carbohydrate content which was determined by the Anthrone test using sucrose as a reference.Chitosan solution was prepared by dissolving0.5g crab shell chitosan(C3646,Sigma)in1ml glacial acetic acid at55–60°C for15min,and then the final volume was adjusted to50ml with distilled water and the pH adjusted to5.8with NaOH(Prakash and Srivastava 2008).MJ(Cat.39,270-7,Sigma-Aldrich)was dissolved in 95%ethanol and sterilized by filtering through a microfilter (0.2µm).SA(10,591-0,Sigma-Aldrich),sorbitol(S3755, Sigma),and the salts of heavy metals including cobalt chloride(C8661,Sigma-Aldrich),silver nitrate(S7276, Sigma-Aldrich),and cadmium chloride(C5081,Sigma-Aldrich)were dissolved in distilled water to the desired concentrations and adjusted to pH5.8.Elicitor treatment was administered to the shake–flask culture of tiorrhiza cell on day18,which was about 2–3days before reaching the stationary phase.This time point is usually favorable for elicitation when the biomass concentration is high(compared with earlier days of growth),and the cell metabolism is still active(compared with that during or after stationary phase;Buitelaar et al. 1992;Cheng et al.2006).Each of the elicitor solutions was added into the culture medium with a micropipette at the desired concentration.After the elicitor addition,the shake–flask culture of cells was maintained for another7days and then harvested for analysis.All treatments were performed in triplicate,and the results were averaged.After the initial experiments on the eight elicitors,the three most effective ones,Ag(25µM),Cd(25µM),and YE(100mg l-1)were applied in the following experiments on the time courses of elicitor-treated cell growth and tanshinone accumulation in the tiorrhiza cell culture.Measurement of cell weight,sucrose concentration, medium pH,and conductivityThe cells were separated from the liquid medium by filtration.The cell mass on the filter paper was rinsed thoroughly with water and filtered again,and blotted dry by paper towels and then dried at50°C in an oven to attain the dry weight.Sucrose concentration in the liquid medium was determined by the Anthrone test using sucrose as a reference(Ebell1969),and the medium pH and conduc-tivity were measured with the respective electrodes on an Orion720A+pH meter(Thermo Fisher Scientific,Inc., Beverly,MA,USA)and a CD-4303conductivity meter (Lutron,Taiwan),respectively.Measurement of PAL activityPhenylalanine ammonia lyase(PAL)was extracted from fresh tiorrhiza cells with borate buffer(pH8.8).The cells were ground in the buffer(0.15g ml-1)for2min with a pestle and mortar on ice,and then centrifuged at10,000rpm and4°C for20min to obtain a solid-free extract.The PAL activity was determined based on the conversion of L-phenylalanine to cinnamic acid as described by Wu and Lin(2002).Analysis of tanshinone contentsThe cell mass from culture was dried and ground into powder and extracted with methanol/dichloromethane(4:1, v/v,10mg ml-1)under sonication for60min.After removal of the solid,the liquid extract was evaporated to dryness and redissolved in methanol/dichloromethane(9:1,v/v). Tanshinone content was determined by high performance liquid chromatography(HPLC)on a HP1100system using C18column,acetonitrile/water(55:45,v/v)as the mobile phase,and UV detection at275nm as described previously (Shi et al.2007).Three tanshinone species CT,T-I,and T-IIA were detected and quantified with authentic standards obtained from the Institute for Identification of Pharmaceu-tical and Biological Products(Beijing,China).Total tanshinone content is the total content of the three tanshinones in the cells.Tanshinone content in the culture medium was negligible and not determined.ResultsCell growth and tanshinone accumulation in tiorrhiza cell cultureThe time course of tiorrhiza cell growth exhibited a lag phase or slow growth period in the first3–6days, a rapid,linear growth period between day9–18,and aTable1Elicitors and concentrations tested in the initial experiments Elicitors Unit ConcentrationC1C2C3Cobalt chloride(Co)µM 5.02550 Silver nitrate(Ag)µM 5.02550 Cadmium chloride(Cd)µM 5.02550 Salicylic acid(SA)µM1050100 Methyl jasmonate(MJ)µM1050100 Yeast elicitor(YE)mg l-150100200 Chitosan(CH)mg l-150100200 Sorbitol(SO)g l-152550stationary or declining phase in the later days,reaching the maximum biomass concentration (8.1g l -1)around day 21.The total tanshinone content of cells remained at a very low level from days 1–12and then increased steadily from days 12–27to a maximum of 0.16mg g -1.A significant portion (65%)of the tanshinone accumulation or content increase occurred during the stationary phase from days 21–27(Fig.1a ),which is characteristic of secondary metabolite production in a batch culture process.The time course of sugar (sucrose)concentration (Fig.1b )was nearly sym-metrical to that of cell growth,indicating a direct correlation of the cell growth (or biomass production)to sugar consumption.As the major carbon source,sugar was required for the S .miltiorrhiza cell growth,and when it was depleted (around day 21),the cell growth stopped,and the biomass concentration began to drop.As seen from Fig.1b ,the medium pH showed a notable drop in the first 3days (due to consumption of NH 4+and release of protons)and a gradual increase after day 6(due to consumption of nitrate NO 3-)(Morard et al.1998).Effects of various elicitors on cell growth and tanshinone productionFigure 2shows the effects of elicitor treatments on the cell growth and tanshinone accumulation in S .miltiorrhiza cell cultures,which were dependent both on the elicitor species and elicitor dose.As seen from Fig.2a ,most of the elicitor treatments except Co 2+and sorbitol at lower concentrations suppressed the cell growth to a lower biomass concentra-tion than that of the untreated control culture,and the growth suppression was more severe at a high elicitor dose.On the other hand,most of the elicitor treatments except Co 2+,sorbitol,SA,and MJ at lower concentrations increased the total tanshinone content of cell to a higher level than in the control (Fig.2b ).Overall the results indicated that the enhancement of tanshinone accumulation by an elicitor treatment concurred with a notable suppres-sion of cell growth or biomass production.Nevertheless,some of the elicitors had a much stronger stimulating effect on the tanshinone accumulation than the suppressing effect on the cell growth.In particular,Ag and Cd both at 25μM,and YE at 100mg l -1increased the total tanshinone content to 2.30mg g -1,about 11.5-fold versus that of the control (0.20mg g -1),but decreased the biomass production by no more than 50%(5.1–5.5g l -1versus 8.9g l -1).Another three elicitors,SA,MJ (both at 50μM),and sorbitol (50g l -1)increased the total tanshinone content by 2–3-fold but decreased the biomass by 30–45%compared with the control.The stimulating effect of chitosan on tanshinone accumulation (about 6-fold)was stronger than SA,MJ,and sorbitol but much weaker than Ag,Cd,and YE,while its suppressing effect on the cell growth was as severe as Ag,Cd,and YE.In summary,the results indicate that Ag,Cd,YE are the most favorable elicitors for the tanshinone production in S .miltiorrhiza cell culture and were used in the following experiments.Figure 3shows the time courses of cell growth and tanshinone production after treatment with the three most effective elicitors Ag (25μM),Cd (25μM),and YE (100mg l -1)and the control culture.All three elicitor treatments caused a steady decline of biomass concentration from initially 8.5g l -1to 5.3g l -1on day 6while biomass in00.040.080.120.160.20246810TT content (mg g -1)C e l l b i o m a s s (g d w l -1)dw TTa4.85.1 5.45.76.001020304036912151821242730p HS u c r o s e (g l -1)Culture time (d)bSucrosepHFig.1Time courses of biomass and total tanshinone content (a ),residue sugar (sucrose)and medium pH (b )in S .miltiorrhiza cell cultures (error bars for standard deviations,n =3)246810C e l l b i o m a s s (g l -1)0.00.51.01.52.02.5Control AgCdSAMJYECH SOT T c o n t e n t (m g g -1)Elicitor treatmentCo Fig.2Effects of various elicitors on biomass growth (a )andtanshinone production (b )in S .miltiorrhiza cell cultures (elicitors added to cultures on day 18at three concentrations C1,C2,and C3as shown in Table 1,and cultures harvested on day 25;error bars for standard deviations,n =3)the control culture was increased during this period (Fig.3a ).In the meantime,the tanshinone content of cells in the three elicitor-treated cultures increased sharply and most rapidly by Ag (from 0.14to 1.98mg g -1),while that of control increased slightly (from 0.14to 0.21mg g -1;Fig.3b ).The volumetric total tanshinone yields (the products of total tanshinone content and cell dry weight)were 1.9mg l -1in the control,and 9.2mg l -1,10.7mg l -1and 11.7mg l -1in cultures treated with 100mg l -1YE,25μM Cd,and Ag,respectively (on day 6).Another test was performed on the effects of two and three elicitors in combinations in the S .miltiorrhiza cell culture.As shown in Fig.4,the tanshinone content was increased about 20%with either two elicitors and about 40%with all three elicitors in combination compared with that with a single elicitor.The results suggest an additive or synergistic effect of these elicitors on the tanshinone accumulation in the cells.However,the combined use of two or three elicitors also suppressed the cell growth (biomass)more severely than with a single elicitor.Effects of elicitor treatments on different tanshinone species Of the three tanshinone species detected,CT was stimulated most significantly by all elicitors without exception;T-IIA was stimulated by most elicitors,and T-I was stimulated significantly only by chitosan but slightly stimulated or suppressed by other elicitors (Table 2).The highest CT content was about 2mg g -1(1,854–2,011μg g -1)in cellcultures treated with 25μM Ag and Cd,and 100mg l -1YE,about 31–34fold of the control level (60μg g -1),the highest T-I content 0.27mg g -1with 100mg l -1chitosan (3.4-fold of the control 80μg g -1)and the highest T-IIA content 0.37mg g -1with 25μM Cd (6-fold of the control 60μg g -1).As seen from the HPLC chromatograms (Fig.5),the cultures treated with the three different elicitors exhibited a similar profile with virtually identical major peaks.The experimental results do not suggest any specificity of particular tanshinone species to the type of elicitors,YE and chitosan as biotic polysaccharides,Cd and Ag as abiotic heavy metals,or SA and MJ as plant stress signaling pared with that of control,the HPLC profiles of elicitor-treated cultures also had three new unknown peaks appearing before the CT peak,between 10.0–11.5min and a high peak at 11.1min,which0.00.51.01.52.02.5123456T T c o n t e n t (m g g -1)Time after treatment (d)b4681012C e l l b i o m a s s (g l -1)Control Ag 25Cd 25YE 100aFig.3Time courses of biomass (a )and total tanshinone content (b )in S .miltiorrhiza cell cultures after treatment with Ag (25µM),Cd (25µM),and YE (100mg l -1;error bars for standard deviations,n =3)24681012345Cell dry weight (g l -1)T T c o n t e n t (m g g -1)Elicitor treatmentTTdwFig.4Effects of single and combined elicitors on S .miltiorrhiza cell growth and tanshinone accumulation (elicitors added to cell cultures on day 18at the same concentrations as in Fig.3,and cultures harvested on day 25;error bars for standard deviations,n =3)Table 2Effects of various elicitors on the accumulation of three tanshinones in S .miltiorrhiza cells Treatment aContent,μg/g (fold of content control)CTT-IT-IIA Control 59.9(1)81.6(1)57.6(1)Co-50263.7(4.4)67.5(0.83)55.5(0.96)Ag-251,817.5(30)71.0(0.87)225.8(3.9)Cd-251,854.0(31)80.3(0.98)369.0(6.4)SA-100390.0(6.5)78.5(0.96)72.8(1.3)MJ-100299.8(5.0)109.5(1.3)82.6(1.4)YE-1002,011.4(34)90.3(1.1)190.3(3.3)CH-100597.2(10)276.0(3.4)98.8(1.7)SO-50584.6(9.8)56.9(0.70)83.0(1.4)CT cryptotanshinone,T-I tanshinone I,T-IIA tanshinone-IIAaNumber after each elicitor symbol represents the elicitor concentra-tion as shown in Table 1may be ascribed to tanshinone relatives of higher polarity than CT induced by the elicitors.PAL activity,pH,and conductivity changes induced by elicitorsFigure 6shows the changes of intracellular PAL activity and medium pH and conductivity in the S .miltiorrhiza cell culture after the treatment by Ag (25μM),Cd (25μM),and YE (100mg l -1).The PAL activity of cells was stimulated by all three elicitors to the similar level,from 1.4-to 1.9-fold of the control level over 6days (Fig.6a ).PAL is a key enzyme at the entrance step in the phenylpropanoid pathway in plants,and its activity increase stimulated by the elicitors is suggestive of an enhanced secondary metabolism in the plant cells (Taiz and Zeiger 2006).The pH and conductivity of culture medium were also increased (to higher levels than those of the control)by all three elicitors but more significantly by YE (Fig.6b,c ).Most significant increases (differences from the control level)in the medium pH and conductivity were shown in the very early period from day 0–1.The increase in medium conductivity in the early period was most probably attributed to the release of potassium K +ion from the cells or K +efflux across the cell membrane (Zhang et al.2004).Transient medium pH increase (alkalinization)and K +efflux across the cell membrane are early and important events in the elicitation of plant responses and phytoalexin production (Ebel and Mithöer 1994;Roos et al.1998).The conductivity decline in the later period after day 1of Ag +and Cd 2+-treated cultures and the control cultures can be attributed to the consumption of inorganic and mineral nutrients in the culture medium (Kinooka et al.1991).Overall,the results here provide further evidence forthe01234R e l a t i v e P A L a c t i v i t yControl Ag CdYEa5.05.45.86.26.6M e d i u m p H b2.03.04.05.06.00246M e d i u m c o n d u c t i v i t y (m S )Time after treatment (d)cFig.6Time courses of PAL activity (a ),medium pH (b ),and conductivity (c )of S .miltiorrhiza cell cultures after elicitor treatments in comparison with the control (error bars for standard deviation,n =3)elicitor activities of Ag,Cd,and YE in stimulating the stress responses and secondary metabolism of the S. miltiorrhiza cells.DiscussionThe effects of various elicitors on tanshinone accumulation found here in the normal tiorrhiza cell cultures are in general agreement with those found in transformed cell and hairy root cultures of tiorrhiza.In transformed cell cultures(Chen and Chen1999),the CT accumulation was also stimulated significantly by YE but not by SA or MJ alone,and YE also inhibited the cell growth.The tanshinone(mainly CT)production in hairy root cultures was also enhanced significantly(3–4fold)by Ag(Zhang et al.2004)and YE(Shi et al.2007).In all these culture systems,CT was the major tanshinone species stimulated by various elicitor treatments.CT has been identified as a phytoalexin in tiorrhiza plant which plays a defense role against pathogen invasion of the plant(Chen and Chen 2000).In this connection,the stimulated CT accumulation by the elicitors may be a defense or stress response of the cells.CT was also the major diterpenoid produced by a normal tiorrhiza cell line which was initially grown in the MS medium and then transferred to a production medium containing only about half of the nutrient compo-nents of the MS medium(Miyasaka et al.1987).It is very possible that the improvement of CT yield in this production medium was also attributed,at least partially, to the stress imposed by the nutrient deficiency which suppressed growth but stimulated secondary metabolite accumulation.MJ or its relative jasmonic acid has been shown effective for stimulating a variety of secondary metab-olites in plant tissue cultures such as hypericin in Hypericum perforatum L.(St.John’s Wort)cell cultures (Walker et al.2002),paclitaxol(diterpenoid)and related taxanes in various Taxus spp.and ginsenosides in Panax spp.(Zhong and Yue2005),and bilobalide and ginkgo-lides in Ginkgo biloba cell cultures(Kang et al.2006). However,MJ showed only a moderate or insignificant stimulating effect on tanshinone accumulation in normal and transformed tiorrhiza cell cultures.The discrep-ancy suggests that the effects of various elicitors on secondary metabolite production in plant tissue cultures are dependent on the specific secondary metabolites.This argument is also supported by the much stronger stimu-lation of CT than T-I and T-IIA by most elicitors found in our tiorrhiza cell cultures.In addition,the hairy roots appeared more tolerant to the elicitor stress,and the growth was less inhibited by the elicitors or even enhanced in some cases,e.g.,by YE(Chen et al.2001)and sorbitol(Shi et al.2007).Moreover,sorbitol as an osmotic agent significantly stimulated the tanshinone accumulation(3–4folds)in tiorrhiza hairy root cultures,but not so significantly in the cell cultures.This shows that the elicitor activities for the same metabolites can vary with the tissue culture systems.In conclusion,the polysaccharide fraction of yeast extract and two heavy metal ions Ag+and Cd2+were potent elicitors for stimulating the tanshinone production in tiorrhiza cell culture.The stimulated tanshinone production by most elicitors was associated with notable growth suppression.CT was more responsive to the elicitors and enhanced more dramatically than another two tanshinones,T-I and IIA.The results from this study in the tiorrhiza cell cultures and from previous studies in hairy root cultures suggest that the cell and hairy root cultures may be effective systems for CT production, provided with the elicitors.As most of the elicitor chemicals are commercially available or can be readily prepared in the laboratory and easily administered to the cell and root cultures,they are suitable for practical applications in the laboratory or large-scale production. Acknowledgements This work was supported by grants from The Hong Kong Polytechnic University(G-U502and1-BB80)and the China Hi-Tech Research and Development Program(2006AA10A209).ReferencesBuitelaar RM,Cesário MT,Tramper J(1992)Elicitation of thiophene production by hairy roots of Tagetes patula.Enzyme Microb Technol14:2–7Chen H,Chen F(1999)Effects of methyl jasmonate and salicylic acid on cell growth and cryptotanshinone formation in Ti transformed Salvia miltiorrhiza cell suspension cultures.Biotechnol Lett 21:803–807Chen H,Chen F(2000)Effect of yeast elicitor on the secondary metabolism of Ti-transformed Salvia miltiorrhiza cell suspension cultures.Plant Cell Rep19:710–717Chen H,Chen F,Chiu FCK,Lo CMY(2001)The effect of yeast elicitor on the growth and secondary metabolism of hairy root cultures of Salvia miltiorrhiza.Enzyme Microb Technol28:100–105Cheng XY,Zhou HY,Cui X,Ni W,Liu CZ(2006)Improvement of phenylethanoid glycosides biosynthesis in Cistanche deserticola cell suspension cultures by chitosan elicitor.J Biotechnol 121:253–260Chong TM,Abdullah MA,Lai QM,Nor’Aini FM,Lajis NH(2005) Effective elicitation factors in Morinda elliptica cell suspension culture.Process Biochem40:3397–3405Ebel J,Mithöer A(1994)Early events in the elicitation of plant defence.Planta206:335–348Ebell LF(1969)Variation in total soluble sugars of conifer tissues with method of analysis.Phytochemistry8:227–233Ge XC,Wu JY(2005)Tanshinone production and isoprenoid pathways in Salvia miltiorrhiza hairy roots induced by Ag+and yeast elicitor.Plant Sci168:487–491。

2015_-_Jian_Geng_-_Thestabilityofboundchloridesincementpastewithsulfa[retrieved_2015-09-23]

The stability of bound chlorides in cement paste with sulfate attackJian Geng a ,b ,⁎,Dave Easterbrook b ,Long-yuan Li b ,Li-wei Mo aa Research Center of Green Building Materials and Waste Resources Reuse,Ningbo Institute of Technology,Zhejiang University,China bSchool of Marine Science and Engineering,University of Plymouth,UKa b s t r a c ta r t i c l e i n f o Article history:Received 10July 2014Accepted 25November 2014Available online 27December 2014Keywords:Sulfate attack (C)Bound chlorides (D)Stability (C)Fly ash (D)Ground granulated blast-furnace slag (D)This paper presents an experimental investigation on the stability of bound chlorides in chloride-contaminated cement pastes with and without FA/GGBS when subjected to Na 2SO 4and MgSO 4attack.It is shown that bound chlorides were released in the chloride-contaminated pastes when exposed to Na 2SO 4or MgSO 4solution.This is mainly attributed to the decomposition of Friedel's salt (FS),where Cl −bound in FS is replaced by SO 42−.How-ever there were fewer released chlorides found in the pastes exposed to MgSO 4solution than in those exposed to Na 2SO 4solution.This is partly due to the low pH in the pore solution and partly due to the blocking effect of brucite on ionic transport caused by MgSO 4.The inclusion of FA/GGBS in concrete can increase the decomposition of FS and thus the release of bound chlorides.However,it also resists the penetration of Na 2SO 4and thus reduces the attack of Na 2SO 4.©2014Elsevier Ltd.All rights reserved.1.IntroductionThe corrosion of reinforcing steel in concrete structures,due to chlo-ride ion contamination,is one of the main reasons for the deterioration of concrete structures.There are two forms of chloride ions in concrete.One is free chlorides and the other is bound chlorides.It is well-known that the corrosion of reinforcing steel is mainly induced by the free chlo-rides,so reducing free chlorides by increasing bound chlorides will be bene ﬁcial to the durability of concrete structures.According to the bind-ing mechanism,chloride ions can be bound through chemical reactions and physical absorption.In the former,chloride ions are mainly bound in Friedel's salt (FS)(3CaO·Al 2O 3·CaCl 2·10H 2O)through hydration reactions between chloride ions,tricalcium aluminate (C 3A)and its hydration products.In the latter,chloride ions are mainly absorbed by calcium silicate hydrate (C –S –H gel).It was reported that the formation of bound chlorides could be affected by a multitude of factors such as the quantity of C 3A in cement,supplementary cementitious materials (SCM),alkalinity of pore solution,Ca/Si and Ca/Al of hydration products,chloride salt type,and service condition of concrete structures [1–5].In summary,the chloride binding capacity of concrete can be improved by using SCM or cement with high C 3A content.However,many researchers have identi ﬁed that the stability of bound chlorides,espe-cially of FS,can be affected by pH,carbonation,and chemical erosion [6–9].Sulfate attack is another problem for the durability of concrete struc-tures.The attack of sodium sulfate (Na 2SO 4)and magnesium sulfate (MgSO 4)on concrete is a common phenomenon.The mechanisms of Na 2SO 4and MgSO 4attack on concrete are different,mainly due to the solubility of phases formed with sodium and magnesium ions [10–12].With regard to Na 2SO 4attack,the deterioration of concrete is attributed to the formation of expansion products such as gypsum (CaSO 4·2H 2O)and secondary ettringite (AFt)(3CaO·Al 2O 3·3CaSO 4·32H 2O)according to the following equations:Ca ðOH Þ2þNa 2SO 4þ2H 2O →CaSO 4·2H 2O þ2NaOHð1Þ3ðCaSO 4·2H 2O Þþ3CaO ·Al 2O 3þ26H 2O →3CaO ·Al 2O 3·3CaSO 4·32H 2Oð2Þ2ðCaSO 4·2H 2O Þþ3CaO ·Al 2O 3·CaSO 4·12H 2O þ16H 2O →3CaO ·Al 2O 3·3CaSO 4·32H 2O :ð3ÞWhereas for MgSO 4attack,the transformation of the cementitious C –S –H gel to the non-cementitious magnesium silicate hydrate mush (M –S –H),which has very little strength,is the main reason for the dete-rioration of concrete,although gypsum and secondary AFt are also formed during the attack.In addition,brucite,i.e.Mg(OH)2,will form when magnesium is present in the pore solution,which has low solubil-ity and could densify the pore system and thus affect the transport ofCement and Concrete Research 68(2015)211–222⁎Corresponding author.E-mail address:gengjian@ (J.Geng)./10.1016/j.cemconres.2014.11.0100008-8846/©2014Elsevier Ltd.All rightsreserved.Contents lists available at ScienceDirectCement and Concrete Researchj o u rn a l h o m e p a g e :h t tp ://e e s.e l s e v i e r.c o m /C EM C O N /d e f a u l t.a s pions in the cement paste.The mechanism of MgSO4attack occurs according to the following equations:CaðOHÞ2þMgSO4þ2H2O→CaSO4·2H2OþMgðOHÞ2ð4Þx CaO·y SiO2·z H2Oþx MgSO4þð3xþ0:5y−zÞH2O→xðCaSO4·2H2OÞþx MgðOHÞ2þ0:5yð2SiO2·H2OÞð5Þ4MgðOHÞ2þSiO2·nH2O→4MgO·SiO2·8:5H2Oþðn−4:5ÞH2O:ð6ÞIn fact,sulfate attack and chloride contamination are often found to coexist in concrete structures which are exposed to marine and saline environments.The effects of the sulfate and chloride on a concrete structure's durability are multifaceted.On the one hand,the existence of sulfate,especially of Na2SO4,inhibits the formation of FS and reduces the quantity of bound chlorides[13–15].On the other hand,the exis-tence of chloride ions is beneﬁcial for the resistance of concrete to Na2SO4and MgSO4attack[15–18].However,Baghabra argued that the effect of chloride ions on MgSO4attack was slight because the trans-formation of cementitious C–S–H gel to non-cementitious M–S–H was not affected by chloride ions[19].Despite the work on the interaction of sulfate and chloride in con-crete mentioned above,there is very little work on the effect of sulfate attack on the stability of bound chlorides in concrete.Brown and Badger investigated the distributions of bound sulfates and chlorides inﬁeld concrete cores exposed to mixed NaCl,Na2SO4and MgSO4attack. They found that there was extensive AFt in the absence of a gypsum zone for some concrete cores[20].Xu et al.obtained similar results, i.e.that sulfate attack could lead to the release of bound chlorides[21]. Both studies suggested the transformation of FS to AFt due to sulfate attack,but the mechanism of FS transform to AFt and the stability of bound chlorides absorbed by C–S–H gel under sulfate attack were not discussed in depth.It is well known that the use ofﬂy ash(FA)and ground granulated blast-furnace slag(GGBS)in concrete can not only improve the chloride binding capacity of concrete,but also the resistance of concrete to sulfate attack[22,23].Hence,it would be interesting to know how they affect the stability of bound chlorides when the concrete is under sulfate attack.The purpose of this paper is to report the experimental in-vestigation on the stability of bound chlorides in cement paste under Na2SO4and MgSO4attack,and the corresponding inﬂuence of FA and GGBS on the stability of bound chlorides.The stability of bound chlorides in cement paste was examined by analyzing the change of a dimensionless index,R cl,which represents the mass ratio of bound chlo-rides to initial total chlorides in the sample after it was exposed to a5% Na2SO4solution or a5%MgSO4solution for28,56or90days.The mech-anisms of the release of bound chlorides are discussed based on the results of X-ray diffraction(XRD),Fourier transform infrared(FT-IR) and differential thermo-gravimetric analysis(DTG).2.Experiment2.1.MaterialsThe materials used in the experiments were Type42.5Ordinary Portland Cement(OPC),grade II FA and GGBS.The chemical composi-tions of OPC,FA and GGBS are listed in Table1.The potential phase com-positions of OPC,calculated from chemical analysis by Bogue,are given in Table2.All other chemical reagents used in the experiments,but not listed in the tables,are analytically pure.2.2.MethodsIn order to reduce the experimental running time but still able to achieve good and representative results,chloride binding was achieved by using0.5mol/L NaCl solution as the mixing water for the casting of samples.The mass ratio of the mixing water to the binder(cement and SCM)was0.5,which was the same for all samples.The inﬂuence of single and combined use of FA and GGBS on the stability of bound chlorides was also investigated.The replacement of cement with SCM was30%by weight,and the proportions of FA to GGBS in the combined samples were either1:1or7:3.The detailed mix proportions of the samples tested are listed in Table3.A total of106samples were tested.All samples were of a size of 40mm×40mm×160mm.There were three groups of samples.The ﬁrst group(2×5×7samples)were cured at a standard curing condi-tion(20±2°C and95%RH)for periods of1,3,7,14,28,56and90days for the investigation of the effect of curing time and SCM on the evolu-tion of bound chlorides in the cement paste.The second group(2×5×3 samples)were examined for the effect of Na2SO4attack on the stability of bound chlorides.In this group,all samples,after the56days standard curing,were dried at a room temperature(20±2°C and60%RH)for 1day.Then,for each sample itsﬁve surfaces were sealed by parafﬁn wax and one40mm×40mm surface was left untouched.After then, all samples were immersed in a covered plastic container(575mm ×400mm×275mm)of5%Na2SO4solution for28,56and90days at the standard curing condition(20±2°C and95%RH).The third group(2×1×3samples)were for the samples only with OPC,which were cured as the same as those done in the second group.The only dif-ference is that they were immersed in a similar covered container of5% MgSO4solution for28,56and90days at the standard curing condition (20±2°C and95%RH)for the examination of the effect of MgSO4at-tack on the stability of bound chlorides.The volume of the sulfate solu-tions used in the immersion tests was25L and the storage solutions were not renewed during the immersed tests.In the second and third groups,when the attack time reached28,56, and90days,the samples were dried at room temperature for1day,and then were sliced into four pieces parallel to the exposed surface (starting from the exposed surface)and each piece is one cm thick. Afterwards,each piece was broken into small blocks,which were then immersed in anhydrous ethanol for7days to terminate hydration. These small blocks were ground intoﬁne powder by passing through a sieve of0.15mm mesh aperture size,which was then stored in a des-iccator with silica gel and soda lime at11%RH to minimize carbonation before it was used in the tests for chloride content titration and other material characterization analyses.The initial total chloride content(C t)of the sample cured at the stan-dard curing condition can be calculated based on the mixing water of Table1Chemical composition of main materials(data presented by mass%).SiO2CaO MgO Fe2O3Al2O3SO3Ignition loss OPC19.6760.43 4.56 4.20 5.70 2.30 2.54FA43.10 6.300.247.2638.200.70 2.04GGBS23.5052.80 6.500.7011.80 1.650.78Table2Potential phase composition of OPC(data presented by mass%).Potential phase composition OPCC3S51.58C2S17.77C3A8.01C4AF12.773.91212J.Geng et al./Cement and Concrete Research68(2015)211–2220.5mol/L NaCl solution,which is 8.863mg ·g −1.The free chloride content (C f )was measured using the traditional leaching method according to the standard of Test Code for Hydraulic Concrete (SL352-2006)and the total chloride content (C t )was measured using the acid-soluble method (SL352-2006).In order to analyze the stability of bound chlorides in concrete,the dimensionless index (R cl )was exam-ined,which is de ﬁned as follows,R cl ¼C t −C f %ð7Þwhere 8.863mg.g −1is the initial total chloride content in the sample.X-ray diffraction (XRD)/reference intensity ratio (RIR)analysis and DTG can be used to approximately determine the quantity of FS,AFt and calcium hydroxide (CH)in the samples.XRD/RIR can determine the relative mass relations among different minerals in a sample,which is calculated according to the following equations [24,25]:W i ¼I i =RIR iX i ¼1I i=RIR i ðÞð8ÞW 1þW 2þW 3þ⋯þW l ¼1ð9Þwhere W i is the relative mass of mineral i ,RIR i is the reference intensityratio of mineral i ,which can be collected from the PDF card of the Inter-national Centre for Diffraction Data (ICDD),I i is the integral intensity of the highest peak of mineral i ,which is calculated using X'Pert HighScore Plus ™software,and N is the number of minerals in the sample.XRD/RIR is usually used to determine the quantity of substances in metals because of simple compositions [25].For cement based materials,it is rather complicated to accurately determine the kinds of hydration products,which increases the dif ﬁculty of the quantitative analysis.However,if the quantity of one of the minerals can be determinedusing other methods,the calculation process of XRD/RIR becomes pared with the FS and AFt,the quantity of CH can be accurately determined using DTG.Therefore,the quantities of the FS and AFt can be calculated by solving the following algebraic equations,m FS :m AFt ¼T 1ð10Þm FSFS þm AFt þm CH ¼T 2ð11Þm AFtm FS þm AFt þm CH ¼T 3ð12Þm CHm FS þm AFt þm CH¼T 4ð13Þwhere m FS ,m AFt and m CH are masses of FS,AFt and CH,respectively,T 1,T 2,T 3and T 4are the mass ratios,which can be calculated from Eqs.(8)and (9).Note that,m CH can be determined by DTG and thus m FS and m AFt can be determined by Eq.(10)plus any one taken from Eqs.(11)–(13).XRD was carried out using the D8Advance instrument of Bruker AXS with a Cu K αradiation generated with 40kV and 30mA.The diffraction spectra were collected in the range of 5–60°(2θ)scale,with a step sizeTable 3Mix proportions (data presented by mass %).Samples OPC FA GGBS w/b a NoteCN 100000.5Exposed to 5%Na 2SO 4solutionCF 703000.5CG 700300.5CF1G17015150.5CF7G3702190.5CM1000.5Exposed to 5%MgSO 4solutionaw/b represents the mass ratio of mixing water (i.e.0.5mol/L NaCl solution)to binder (cement +SCM).Fig.1.Variation of R cl with standard curing time in samples of differentmixes.Fig.2.Values of R cl in the surface layer of the sample at various different sulfate attack times (CM was exposed to MgSO 4,while all the others were exposed to Na 2SO 4).Fig.3.Values of R cl in different layers of the sample after 90days sulfate attack (1st layer is next to the surface and 4th layer is away from the surface.CM was exposed to MgSO 4,while all the others were exposed to Na 2SO 4).213J.Geng et al./Cement and Concrete Research 68(2015)211–222of 0.02°/s.FT-IR was performed for the samples on a Nicolet Nexus 470spectrometer using the KBr pellet technique in the range of 400–4000cm −1.DTG was carried out in a Netzsch TG-209F1thermal an-alyzer,using a heating rate of 20°C/min at the range of 25–1000°C,in N 2atmosphere.3.Stability of bound chlorides 3.1.Standard curing conditionThe variation of R cl during the standard curing time is shown in Fig.1.It can be seen from the ﬁgure that R cl in the samples with SCM is higher than that in the sample only with OPC when they have the same curing time,which is more obvious after the curing time exceeds 14days.Up to 28days,the combined use of FA and GGBS results in higher values of R cl in CF1G1and CF7G3than in the samples with only either FA (CF)or GGBS (CG).However,after the 28days standard curing,the R cl value of the samples has an order of CF ≈CF7G3N CF1G1N CG,which increases with the increased proportion of FA to GGBS.The latereffect of FA on chloride binding is mainly due to its slow pozzolanic re-action.The results shown in Fig.1indicate that the inclusion of SCM in concrete can increase the chloride binding capacity and the effect of FA on chloride binding is more signi ﬁcant than that of GGBS.Furthermore,they also show that the R cl values of all samples increase very obviously before 28days but after that there is less change,suggesting that the equilibrium between free and bound chlorides has been reached.3.2.Sulfate attack conditionFig.2shows the expected decrease in R cl of the surface layer of all samples with the sulfate attack,but the rate of the decrease is higher than that was reported [21].The R cl value in the surface layer of sample CN exposed to Na 2SO 4solution,for example,decreases from 59.8%to 4.3%after only 28days.After that,R cl continuously decreases with the attack time but with a slow reduction rate,from 4.3%at 28days to 1.9%at 90days.The results for locations other than the surface layer at 90days are shown in Fig.3.It can be seen from the ﬁgure that,although the 4th layer of sample CN is far away from theexposedFig.4.XRD patterns of samples CN(CM),CF and CG at standard curing condition for (A)28and (B)56days (E:ettringite (AFt),F:Friedel's salt (FS),CH:calcium hydroxide,M:mono-sulfoaluminate,V:Vaterite,CSH:C –S –H gel,C:calcite).214J.Geng et al./Cement and Concrete Research 68(2015)211–222surface,there is still a notable decrease in the R cl value from59.8%at the beginning of the Na2SO4attack to16.6%after90days of attack.This demonstrates that the stability of bound chlorides in concrete is very susceptible to Na2SO4attack.Note that the data plotted in Fig.2show that there is also a decrease in the R cl values of the samples with SCM after Na2SO4attack for28days, but the R cl values are still higher than that of the sample CN only with OPC.This suggests that the use of SCM can alleviate the effect of Na2SO4attack on the stability of bound chlorides.This is partly because the effect of SCM on the diffusion of ions,since the ionic diffusion coef-ﬁcient in cement paste with SCM is normally lower than that in OPC paste,and partly because the cement paste with SCM has more bound chlorides[26].Additionally,in contrast with the results obtained under the standard curing condition,the R cl values of the samples with SCM increase with the decreased proportion of FA to GGBS,and also the R cl value of the surface layer of sample CF is the lowest of all samples containing SCM,following the Na2SO4attack.This suggests that Na2SO4attack can also alter the effect of SCM on the stability of bound chlorides.This appears to be consistent with what is reported in literature[21].The stability of bound chlorides in concrete under MgSO4attack is also shown in Figs.2and3.When the MgSO4attack time extends from0to28days,the R cl value of the surface layer of sample CM decreases from59.8%to26.3%,which is slower than that of sample CN exposed to Na2SO4solution.When the attack time reaches90days, the R cl value of sample CM's surface layer decreases to7.5%,which is still almost four times as high as that of sample CN.This indicates that the stability of bound chlorides is less susceptible to MgSO4attack when compared with Na2SO4attack.Again,thisﬁnding is consistent with what is reported in other experiments[21,27].The different reductions of R cl in samples CM and CN reﬂect the different effects of MgSO4and Na2SO4on bound chlorides.During the immersion process free chloride ions will diffuse out and sulfate ions will diffuse into the specimen.The former may decrease the bound chlo-ride level in the sample owing to the equilibrium between the free and bound chlorides.The latter can transform FS into AFt,which not only can reduce the bound chlorides but also can change the pore system and thus affect the diffusion rate of ions.In addition,when magnesium is present,brucite will be formed,which can also change the pore sys-tem and thus affect the transport of ions and the R cl value.The slower reduction of R cl found in sample CM shown in Figs.2and3indicates that the magnesium ions must have some inﬂuence on the sulfate attack to the bound chlorides.This inﬂuence could be physical and/or chemi-cal.The former is mainly due to the forming of brucite in the surface layer,which reduces the inward diffusion of sulfate ions and the out-ward diffusion of chloride ions.Indeed,the measured free chloride con-centration after the90days immersion was found to be higher in sample CM than in sample CN and have the ratios of about1:0.72for the surface layer and1:0.81for the4th layer.An accurate analysis for the diffusion effect on the bound chlorides requires having more data on thinner layers and knowing the binding isotherms.Nevertheless, the above results did indicate that the diffusion of chloride ions was affected by magnesium ions.The chemical effect of magnesium ions on bound chlorides will be discussed in the next section.Note that the ionic diffusion coefﬁcient in concrete with SCM is nor-mally smaller than that in concrete only with OPC.Thus,the inclusion of SCM in cement paste can provide additional resistance to the ingress of sulfate ions,which in turn can affect the stability of bound chlorides. More discussion on this will be provided in the next section.4.Material characterization analyses4.1.X-ray diffractionThe XRD patterns of samples CN,CF and CG cured at the standard curing condition for28and56days are shown in Fig.4.From the XRD patterns one can identify the FS with a very obvious diffraction peak at around11°2θ.Fig.5shows the relative masses of AFt,FS and CH in samples CN,CF and CG after they were cured in the standard condition for56days.It can be seen from theﬁgure that the use of FA and GGBS is beneﬁcial to forming more FS.This result can be attributed to two rea-sons.First,the forming process of FS in concrete has been associated with the quantity of aluminate in cementious materials.The higher the quantity of aluminate,the more FS is formed.According to the chemical composition shown in Table1,there is a larger quantity of alu-minate in GGBS and FA than in OPC,which can be released due to the latent hydraulic property of GGBS and the pozzolanic property of FA, which is beneﬁcial to the formation of FS.Secondly,the formation of FS would be hindered because SO42−can react with aluminate prior to Cl−to form mono-sulfoaluminate(AFm)and AFt[13–15].In addition, C–A–H and C–S–H gel,formed due to the hydration reactions induced by FA and GGBS,are also beneﬁcial to chloride binding.As shown in Fig.5,although the quantity of aluminate in FA is higher than that in GGBS,the quantity of FS in sample CF is still lower than that in sample CG after standard curing for56days.It was believed that only reactive alumina Al2O3r−in SCM could react with Cl−to form FS[5].The quantity of CaO in FA used in this study is6.3%,which is low calciumﬂy ash according to Chinese speciﬁcation GB/T15696-2005,and where Mullite is the main form of Al2O3,so it is adverse to the formation of FS.Nevertheless,a notable decrease in the intensity of diffraction peak (IDP)of CH can be found in the XRD patterns of sample CF over the curing time from28to56days,which is induced due to the pozzolanic reaction between CH and FA.As a result,more C–S–H gel and C–A–H are formed,which could increase the bound chlorides in sample CF.It should be noticed that the IDP change at around30°(2θ)shown in Fig.4correlates with both C–S–H gel and calcite(CaCO3),because of the overlap of the two strongest diffraction peaks at29.25°(2θ)and 29.40°2θ,respectively[8,28].The XRD patterns of sample CN under Na2SO4attack are shown in Fig.6.It can be observed from Fig.6A that the IDP of FS in the surface layer of sample CN becomes very weak after Na2SO4attack for28 days,which indicates that FS has been decomposed due to the Na2SO4 attack.A quantitative analysis of FS,AFt and CH of sample CN after the Na2SO4attack for28and90days is shown in Fig.7.It can be seen from theﬁgure that the relative mass of FS in the sample decreases very quickly from2.04to0.45after the28days attack.This suggests that the stability of FS is very susceptible to Na2SO4attack,which may also explain why the decrease of R cl is quick as is shown in Fig.2.How-ever,when the attack time is extended from28to90days,the change in the quantity of FS is slight,which indicates that a large quantity of FShasFig.5.Analysis of ettringite(AFt),Friedel's salt(FS)and calcium hydroxide(CH)in sam-ples CN/CM,CF and CG after they had56days standard curing(wt.%represents the mass percentage of AFt/FS/CH in sample).215J.Geng et al./Cement and Concrete Research68(2015)211–222been decomposed following 28days of the Na 2SO 4attack.Moreover,it can be seen from Fig.7that the quantity of FS gradually decreases from the inside to the surface,which correlates with the change of the R cl value shown in Fig.3.In addition,one can see from Fig.6B that AFt with a diffraction peak at around 9°(2θ)can be detected in every layer of sample CN after the Na 2SO 4attack for 90days.The data shown in Fig.7for AFt indicate that the quantity of AFt in the fourth layer of sam-ple CN is higher than its initial value,which con ﬁrms that the attack of Na 2SO 4has reached the fourth layer of the sample.Fig.7also shows the expected opposite changes of FS and AFt with time.The XRD patterns of samples CF and CG after the Na 2SO 4attack for 90days are shown in Fig.8.Similar to the sample CN,the diffraction peaks of FS in the samples with SCM,especially in sample CF,become very weak.Similar to the analysis of the sample CN,Fig.9shows the relative mass of FS,AFt and CH of samples CF and CG after the Na 2SO 4attack for 90days.It seems that the quantities of FS in samples CF and CG are as high as that in sample CN after the Na 2SO 4attack.However,considering the higher quantity of FS in samples CF and CG before the Na 2SO 4attack as shown in Fig.5,the decrease of the quantity of FS in them is quicker than that in sample CN.Therefore,it can be concluded that the stability of FS in the samples with FA or GGBS is susceptible to Na 2SO 4attack when compared to the sample CN.The XRD patterns of samples CN and CM attacked by Na 2SO 4and MgSO 4for 90days are shown in Fig.10.An interesting ﬁnding is that there is still an obvious diffraction peak of FS in the sample CM,which is different from the sample CN attacked by Na 2SO 4.The analysis results shown in Fig.11demonstrate that there is more FS in sample CM than in sample CN.Therefore,it can be concluded that the Na 2SO 4attack has more effect on the decomposition of FS in hardened cement paste than the MgSO 4attack.In addition,the IDP of AFt in sample CM is lower than that in sample CN due to the different erosion mechanisms.However,there is still an obvious increase in AFt for sample CM from 0to 90days as demonstrated in Figs.5and 11,which indicates that MgSO 4attack can also lead to the formation of secondary AFt.NoteFig.6.XRD patterns of samples CN with Na 2SO 4attack.(A)1st layer at different days and (B)different layers at 90days (E:ettringite (AFt),F:Friedel's salt (FS),CH:calcium hydroxide,M:mono-sulfoaluminate,V:Vaterite,CSH:C –S –H gel,C:calcite).216J.Geng et al./Cement and Concrete Research 68(2015)211–222that,when magnesium is included in the exposure solution,brucite is formed at the expense of calcium hydroxide,which can affect not only the leaching of chloride from the specimen but also the inward trans-port of sulfate from the exposed solution and thus provide the in ﬂuence on the decomposition of FS and the formation of AFt.However,our XRD result did not reveal a signi ﬁcant amount of brucite and/or gypsum in the surface layer.This is probably due to the specimen layer used in the tests being too thick.Both Skaropoulou and Sotiriadis reported their test results in which brucite was detected in XRD patterns,but the IDP of it was very weak when compared to other phases [11,17].However,in other similar experiments brucite was not detected in XRD patterns [27,29,30].This is probably attributed to the consumption of brucite due to the formation of M –S –H as shown in Eqs.(4)–(6)[19].4.2.Fourier transform infrared (FT-IR)Fig.12shows the FT-IR spectra of sample CN after the Na 2SO 4attack for 28and 90days,respectively.The band at around 3640cm −1is due to the stretching vibration of \OH in Ca(OH)2[30],which is very weak in all samples due to Na 2SO 4attack.The presence of carbonate bands at around 1430and 870cm −1indicates that the samples have already absorbed CO 2molecules from the air before they were immersed into sulfate solution [31].The band at around 1110cm −1comes from asym-metric stretching vibration of S –O in SO 42−,which is identi ﬁed as the ﬁngerprint peak of AFt [32,33].As is shown in Fig.12,owing to more secondary AFt being formed,this band becomes stronger from the in-side to the surface over the attack time.The changes in the bands at around 3440and 1650cm −1are due to the stretching vibration of \OH in structural water of hydration products and the bending vibra-tion of \OH in the interlayer water of hydration products [30].The two bands are also related to the formation of secondary AFt,which be-come strong with the increased quantity of secondary AFt.In addition,the band at around 970cm −1comes from asymmetric stretching vibra-tion of Si –O in C –S –H gel [31,34].It can be observed from Fig.12that there is no obvious change in this band over the attack time,which sug-gests that the stability of C –S –H gel is independent of Na 2SO 4attack.With regard to FS,because chloride ions are not absorbed in the range 400–4000cm −1,the bands at around 730,530and 460cm −1,which are due to Al –O vibrations of [Al(OH)6]3−,can be identi ﬁed as the ﬁn-gerprint peaks of FS [35,36].Owing to the decomposition of FS under Na 2SO 4attack,the strength of these bands appears very weak.Fig.13shows the FT-IR spectra of samples CF and CG after the Na 2SO 4attack.There is no obvious band at around 3640cm −1in thespectra due to the consumption of CH induced by hydration reactions of FA and GGBS and sulfate attack.It can be observed from Fig.13that there is an increase in the strength of the band of C –S –H gel at 976cm −1in sample CF over the attack time from 56to 90days.Guerre-ro et al.attributed this to the further activating action on FA due to the increase in alkalinity induced by Na 2SO 4attack [15].Moreover,this re-sult also indicates that the stability of C –S –H gel is independent of Na 2SO 4attack.The difference of the bands at 714,535and 458cm −1be-tween samples CF and CG is slight.Fig.14shows the FT-IR spectra of samples CN and CM after Na 2SO 4and MgSO 4attack for 90days,respectively.It is observed from Fig.14that the strength of the band at around 710cm −1in sample CM is much stronger than that in sample CN.Also there is more FS in sample CM than in sample CN,which agrees with the results shown in Figs.10and 11.Moreover,it can be seen clearly from Fig.14that the strength of the band at around 970cm −1in sample CM is lower than that in sample CN.This is likely attributed to the decomposition of C –S –H gel induced by MgSO 4attack.As a result of that,the bound chlorides absorbed by C –S –H gel are released.A weak band at around 1110cm −1in sample CM due to the attack of MgSO 4can induce the formation of secondary AFt.4.3.Derivative thermo-gravimetric analysis (DTG)The DTG curves of sample CN attacked by Na 2SO 4are shown in Fig.15.There are some notable endothermic peaks in the DTG curves.The peak near 100°C is mainly attributed to the dehydration of C –S –H gel and AFt,which are dif ﬁcult to distinguish because of the overlap of dehydration temperature from 85to 130°C [23].The peak near 160°C is attributed to AFm [23].Besides these,the peaks near 340,450and 710°C are attributed to the dehydration of FS,CH and the decomposi-tion of calcite.The absence of the peak for FS in the DTG curve after the Na 2SO 4attack for 28days shown in Fig.15further demonstrates that the stability of FS is susceptible to Na 2SO 4attack.The change in the peak of AFm,which plays an important role in the formation of sec-ondary AFt during the Na 2SO 4attack,is also consistent with the change of FS.Fig.16shows the DTG curves of samples CF and CG after the Na 2SO 4attack for pared to sample CG,sample CF has a weak strength of the peak for FS,which is consistent with the analysis result shown in Fig.9and the R cl data shown in Fig.2.Fig.17shows similar DTG results of samples CN and CM after Na 2SO 4and MgSO 4attack for 90days.It is noticed from the ﬁgure that the strength of the peak for C –S –H gel and AFt in sample CM is far lower than that in sample CN.Ac-cording to the FT-IR results shown in Fig.14,this result further indicates that MgSO 4attack will lead to the decomposition of C –S –H gel,resulting in the release of bound chlorides.5.Discussion5.1.Stability of Friedel's saltSuryavanshi and Swamy reported that a drop in alkalinity of pore so-lution due to carbonation could induce the decomposition of FS [8].Con-versely,Na 2SO 4attack can increase the alkalinity of the pore solution,which has a negative effect on chloride binding [23,27,37].The question now is how Na 2SO 4attack affects the stability of FS.The exchange be-tween Cl −and SO 42−is the main mechanism in the formation of FS,which can be explained by the following reaction [27]:3CaO ·Al 2O 3·CaSO 4·12H 2O ðAFm Þþ2Cl −→3CaO ·Al 2O 3·CaCl 2·10H 2O ðFS ÞþSO 2−4þ2H 2O :ð14ÞEssentially,FS belongs to a phase of the AFm family,which has a complex chemical and structural constitution.A general formula for AFm phase is [Ca 2(Al,Fe)(OH)6]+X·m H 2O,where the bracketsindicateFig.7.Analysis of ettringite (AFt),Friedel's salt (FS)and calcium hydroxide (CH)in sample CN after Na 2SO 4attack for 0,28and 90days (wt.%represents the mass percentage of AFt/FS/CH in sample).217J.Geng et al./Cement and Concrete Research 68(2015)211–222。

1-s2.0-S0263436814001590-main

Effect of rare earth elements on the consolidation behavior and microstructure of tungsten alloysMingyue Zhao a ,Zhangjian Zhou a ,⁎,Qingming Ding a ,Ming Zhong a ,Kameel Arshad ba School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China bSchool of Physics and Nuclear Energy Engineering,Beihang University,Beijing 100191,Chinaa b s t r a c ta r t i c l e i n f o Article history:Received 11February 2014Available online 23July 2014Keywords:Rare earth element Tungsten alloyConsolidation behavior MicrostructureThe effects of rare earth elements (Y 2O 3,Y and La)on the consolidation behavior,microstructure and mechanical properties of tungsten alloys were investigated in this work.The starting powders were mechanical alloyed (MA)and then consolidated by spark plasma sintering (SPS).It was found that Y doping was bene ﬁcial to obtain fully dense tungsten alloys with more re ﬁned grains as compared to any other rare earth elements.The maximum values of Vickers microhardness and bending strength obtained from W –0.5wt.%Y alloy reached up to 614.4HV 0.2and 701.0MPa,respectively.©2014Elsevier Ltd.All rights reserved.IntroductionTungsten is a promising candidate material for high temperature applications due to its attractive properties,such as high melting point,high conductivity,low thermal expansion coef ﬁcients and low sputtering yield [1].However,a major limitation of its use is the inherently high ductile –brittle transition temperature (DBTT)and low recrystallization temperature.Fine grained tungsten materials have shown improved properties in terms of reduced brittleness and improved toughness and strength [1,2].However,the improved mechanical properties will be deteriorated when exposed to high temperatures for long time and when the service temperature is higher than the recrystallization temperature of pure tungsten.Recent studies suggested that the dispersion of high temperature oxide nanoparticles,such as La 2O 3and Y 2O 3,will not only inhibit the grain growth of W during the consolidation but also stabilize the microstructure when exposed to higher temperature [3,4].It is well known that,the impurities,especially for oxygen,have det-rimental in ﬂuence on the sinterability of tungsten powders and make tungsten materials embrittlement.Thus adding rare earth elements in the metallic state instead of the oxidic state should be better for fabrica-tion of high performance tungsten alloys,due to the high af ﬁnity of rare earth elements with oxygen.A recent research conducted by L.Veleva et al.[5]found that the relative density of W –(0.3–2)wt.%Y appeared higher than that of W –(0.3–2)wt.%Y 2O 3,however,the microhardnessappeared always lower than that of W –(0.3–2)wt.%Y 2O 3.From the viewpoint of oxygen absorption,it is suggested that La will be better than Y when used as alloying element for fabrication of W [6].However there are almost no reports on W –La alloy and their comparison with W –Y alloy.It will be interesting and important to investigate the effects of different rare earth elements on the densi ﬁcation of W and their mechanical properties.This is the motivation of this work.In this study the effect of rare earth elements,including Y 2O 3,Y and La on the consolidation behavior of W under the same sintering condi-tion was investigated.The microstructural evolution and mechanical properties of different rare earth tungsten materials were examined and compared.Experimental proceduresPowders of commercial pure W (with an average particle size of 2.0μm and a purity of 99.9%),rare earth element of Y or La (with an av-erage particle size of 48μm and a purity of 99.9%),and rare earth oxide of Y 2O 3(with an average particle size of 30nm and a purity of 99.9%)were used as starting materials.The mixture powders of W –0.5wt.%Y 2O 3(named as WYO),W –0.5wt.%Y (named as WY)or W –0.5wt.%La (named as WL)were mechanical alloyed (MA)in a planetary ball mill,respectively.The MA parameters can be found in our previous work [7,8].Then,the MA treated powders were placed into graphite tool in glove box and sintered by spark plasma sintering (SPS)in vacuum.Fig.1shows the temperature and pressure pro ﬁle of SPS as a function of time.In order to get fully dense bulk materials by suppress-ing the pore-boundary separation,the samples were ﬁrst sintered at 1373K for 2min and then sintered at 1873K according to [9].Int.Journal of Refractory Metals and Hard Materials 48(2015)19–23⁎Corresponding author at:Laboratory of Special Ceramics and Powder Metallurgy,School of Materials Science and Engineering,University of Science &Technology Beijing,Beijing 100083,PR China.Tel./fax:+861062334951.E-mail address:zhouzhj@ (Z.Zhou)./10.1016/j.ijrmhm.2014.07.0140263-4368/©2014Elsevier Ltd.All rightsreserved.Contents lists available at ScienceDirectInt.Journal of Refractory Metals and Hard Materialsj o u r n a l h o m e p a g e :w w w.e l s e v i e r.c o m/l o c a t e /I J R M H MThe shrinkage of the specimens was continuously monitored by the displacement of the punch rod.The density of the compacts was measured by Archimedes method.A ﬁeld emission scanning electron microscope (FE-SEM)equipped with Energy-dispersive X-ray Spectros-copy (EDS)and Scanning electron microscope (SEM)were employed to investigate the microstructural features,i.e.,the element distribution,and the size and morphology of the grains and the pores of the samples.Moreover,XRD was used to determine the phase and X-ray diffraction analysis was made by the Rietveld method using the Full prof program [10].The average crystallite size as well as the internal stress of the MA treated powders were determined from the diffraction peak widths taking into account the diffractometer resolution function.Vickers mi-crohardness was measured at room temperature by applying a load of 1.96N for 15s.Three point bending tests were conducted on specimens with dimensions of 2mm ×3mm ×18mm with a span of 13.1mm and a crosshead speed of 0.5mm/min.The thermal behavior of the MA treated powders in the range 373–1723K was investigated by differen-tial scanning calorimetry (DSC)at a heating rate of 10K/min in ﬂowing pure Ar.Results and discussion Consolidation behaviorFig.2compares the consolidation behavior of all tungsten alloys as a function of temperature.It can be clearly seen that the displacement of WY alloy is similar with that of WL alloy,and shows quite different ten-dency from that of WYO alloy,especially at the sintering temperature of 1373K.For WY and WL alloys,the displacement decreased by 0.6mm between 993K and 1373K due to the thermal expansion of graphite punch rods and the matrix overweighing the contribution of pre-compaction,and continued to decrease at the sintering temperature of 1373K.For WYO alloy,the displacement experiences a slower down-ward trend between 993K and 1373K and a weak upward trend at 1373K.After that,the displacement of WY sees a similar trend with that of WYO.It was found that the WY alloy experienced a substantial decrease in the displacement while the WYO alloy experienced a slight increase at the temperature of 1373K.This result is likely to arise from the formation of a higher volume of Y 2O 3due to the oxidation of Y ele-ment in the WY system.Chemical analysis of the consolidated compacts was performed by the HORIBA EMIA-820V and LECO TCH600devices to measure the C and O contents,respectively.It shows that the C contents were about 240ppm for various tungsten materials fabricated under the same conditions.The amount of oxygen content which existed in MA treated WY powders was 0.4808wt.%,which is enough for the reactionwith added Y particles to form Y 2O 3.Fig.3shows the DSC curve of the MA treated WY powders in the range 373–1723K.A weak exothermic peak at 1500K with an onset temperature of 1400K is found.It probably corresponds to the oxidation of the metallic Y with the residual oxygen in a hermetically sealed pan,which also illustrates that the remaining Y particles are likely to start to react with oxygen around 1373K during SPS.Moreover,a sharp strong and a small exothermic peak can be clear-ly seen at 1003K and 1173K,respectively.According to [11,12],these peaks indicate that the strain relief took place during the heating of MA treated powders.Similar results on the oxygen analysis and the thermal behavior are also found for MA treated WL powders.Fig.4shows the milling and sintering effect on the XRD patterns of the investigated samples.It is obvious that the diffraction peaks are broadened after milling,which was caused by the re ﬁnement of powder particles and a high level of internal strain in the W grains fabricated by the MA process.After sintering,the diffraction peaks become narrow again due to the grain growth and strain relief.The quantitative data on such grain growth and strain relief can be obtained by the compari-son of lattice parameters after each stage of the powder processing (Table 1).It should be noted that the XRD patterns for all samples after milling exhibit a single BCC phase,suggesting that the rare earth elements were dissolved into the W lattice.This solid solutionduringFig.1.The temperature and pressure pro ﬁle as a function of time for the sintering experiments of rare earth tungstenalloys.Fig.2.The real time sintering curves of all samples without removing the contribution of the thermal expansion of the graphite tool andmatrix.Fig.3.DSC curve of the MA treated WY powder.The peak temperatures of thermally induced transformation of the powders are indicated by arrows.20M.Zhao et al./Int.Journal of Refractory Metals and Hard Materials 48(2015)19–23the MA process can be further demonstrated by the lattice parameter increase of the MA treated powders compared with that of the starting pure tungsten powder (Table 1).Microstructure observationMicrostructure of the fracture surfacesThe fracture surfaces of WY,WYO and WL samples are presented in Fig.5.It can be clearly seen that the rare earth elements in ﬂuence the grain re ﬁnement signi ﬁcantly.Fig.6shows the grain size distribution which was determined from the SEM micrographs of fracture surfaces.For each image,about 130grains were chosen randomly to eliminate the bias of grain counting.The grain size distributions of WL and WYO alloys are in the range from 1.6to 8.0μm and from 0.8to 4.4μm,respec-tively,and their average grain sizes are 2.46μm and 4.62μm,respective-ly;while,the average grain size of WY alloy is only 1.10μm,which is much smaller than that of WL and WYO alloys.The grain size distribu-tion of WY alloy is in the range from 0.3to 2.0μm,which is much nar-row as compared with that of WL and WYO alloys.Moreover,it is worth noting that the average grain size acquired from the SEM images of fracture surfaces has a remarkable consistency with those calculated by the Rietveld method using the Full prof program,as shown in Table 1.More careful analysis of Fig.6reveals that the WY alloy is denser than WYO and WL alloys.Many big worm-like pores (indicated by yel-low arrows)and small pores (indicated by white dot circles)can be found for WYO and WL alloys on the surface of individual tungstengrains and in the triple junctions.It is easy to learn that the tungsten grains with different additions grew up in a different speed (WL N WYO N WY)according to the average grain size of each stage of powder processing.Besides,the grain growth of pure tungsten or ODS W-based materials sintered by SPS starts between 1373K and 1773K according to literature [9,13].Under a certain pressure between 1773K and 1873K in our present work,the smaller the grain size,the easier the re-arrangement and plastic deformation,and thus higher shrinkage can be achieved.During the holding time at sintering temperature (1873K),grain growth took place simultaneously with further densi ﬁcation,which was achieved dominantly by more homogeneous interfacial atomic diffusion but with minimized involvement of surface diffusion according to [9].Meanwhile,the worm-like pores could be formed if the holding time at sintering temperature of 1873K was not enough for W –0.5La alloy having a large grain size.The microstructure of chemically etched surfacesThe microstructures of chemically etched surface are illustrated in Fig.7.EDS analysis indicated that the black phases which existed in WYO,WY and WL alloys are rare earth oxides (indicated by blue ar-rows)and the dark gray phases are pores (indicated by red arrows).For WY alloy (Fig.7b),pores can hardly be found,which is consistent with the microstructure observation of the fracture surface.Besides,ﬁne Y 2O 3particles are distributed uniformly along grain boundaries of WY alloy;while for WYO and WL alloys (Fig.7a and c),many micro-scale pores are found in triple junctions and tungsten grain boundaries,especially for WL alloy.Moreover,the FESEM images shown in Fig.7a and c reveal that the oxide particles are irregular and not distributed uniformly.In the XRD measurements performed on the WL alloy (Fig.4and Table 1),a weak diffraction peak of La 2O 3phase and lattice parameter decrease of sintered WL alloy are observed,which also suggest that the La particles separate from tungsten grains and become micro-scale La 2O 3during sintering.The densi ﬁcation analysisTable 2shows the relative density of the rare earth tungsten alloys.The relative density of WY reaches 99.4%,which is much higherthanFig.4.Effect of milling and SPS sintering on the XRD patterns of rare earth tungsten alloys.(a)MA treated powders,and (b)sintered compacts.Table 1Lattice parameters after each stage of the powder processing and the average grain size ac-quired from the SEM images of fracture surfaces.SamplePowder Sintered compact Crystallite size (nm)lattice strain (%)a (W:nm)Grain size (nm)Lattice strain (%)Grain size (nm)—SEM WY 8050.3510.31646215220.0701100WL 4100.3010.31659956650.0414620WYO 6200.3860.31653424820.0342460W11740.0450.31604021M.Zhao et al./Int.Journal of Refractory Metals and Hard Materials 48(2015)19–23the WYO (92.1%)and WL (88.3%).This result is agreeable with the mi-crostructure observation.Owing to the grain boundary cleaning effect and sintering enhancing effect of Y particles during SPS,Y doping is ben-e ﬁcial to achieve fully dense tungsten alloys than Y 2O 3doping.On the other hand,the well-distributed ﬁne Y 2O 3dispersions which existed in WY alloy play a prominent role in the re ﬁnement of tungsten grains,thus dense ﬁne grained sample can be obtained under the present sintering process.Kim et al.[14]reported that the second phases can act as obstacles in inhibiting the grain growth only in solid phase sintering.Owing to the formation of metallic La liquid phase at 1193Kaccording to the phase diagram Mo –La and then the formation of micro-scale and non-uniformly distributed La 2O 3dispersions as a result of oxidation,the grain growth speed of WL alloy is much higher than that of WYO and WY alloys.Thereby,the relative density of WL alloy is lower than that of WYO alloy and WY alloy even though La particles can exert cleaning effect on the tungsten grain boundaries.Besides,in accordance with literatures [4,15,16],the internal energy originating from the signi ﬁcant strain of the particles could serve as a part of sintering driving force.As shown in Table 1,the lattice strain of WL alloy is 0.301%,lower than that of WYO (0.386%)and WY (0.351%),which is another reason for the lower relative density of WL alloy.The basic mechanical propertiesVickers microhardness and bending strength of the rare earth tung-sten alloys were also listed in Table 2.Of all the three kinds of tungsten materials,the hardness of WY sample is 614.4HV 0.2,much higher than that of WYO (445.2HV 0.2)and WL (303HV 0.2).The lower hardness of WYO and WL alloys originates from the lower relative density and coarse grain size,as shown in Figs.5and 6.Moreover,WY exhibits the highest bending strength (701MPa)among these tungsten alloys,which is 11%and 88%higher than that of WYO and WL alloys.As shown in Fig.5,the remaining pores,including worm-like pores and small pores,reduce the contact area of tungsten grains,thus the bending strength of WYO and WL to some extent decreases.Besides,the coarse grain size (Fig.6)and inhomogeneous dispersions of oxide particles (Fig.7)of WYO and WL alloys are also the reason for their low bending strength.ConclusionsTungsten alloys were successfully fabricated by adding different rare earth elements to W matrix.The effect of dispersing rare earthelementsFig.5.SEM micrographs of fracture surfaces for:(a)WYO,(b)WY,and (c)WL;the yellow arrows denote worm-like pores existed on the surface of individual grains,and the white dot circles denote pores located in the triplejunctions.Fig.6.Histograms of the grain size distributions for WYO,WY and WL alloys.22M.Zhao et al./Int.Journal of Refractory Metals and Hard Materials 48(2015)19–23on the microstructure evolution and mechanical properties of the tung-sten alloys can be concluded as follows:(1).The relative density of WY,WYO and WL alloy reached 99.4%,92.1%and 88.3%,respectively.The Y doping was bene ﬁcial toobtain fully dense tungsten alloys as compared with Y 2O 3doping and La doping because the ﬁnely distributed second phase parti-cles suppressed the tungsten grain growth and thus ensured the suf ﬁcient grain boundary volume available for densi ﬁcation by grain boundary diffusion.The analysis of consolidation behavior and thermal behavior of MA treated WY or WL powders revealed that the added Y or La particles were likely to start to react with oxygen around 1373K during SPS.(2).The average grain sizes of WY,WYO and WL alloys were 1.10μm,2.46μm and 4.62μm,respectively.The Y doping was bene ﬁcial to obtain tungsten alloys with more re ﬁned tungsten grains as com-pared with Y 2O 3doping and La doping.(3).Of all the three kinds of rare earth tungsten alloys,WY alloy ex-hibited the highest mechanical properties at room temperature.The maximum values of Vickers microhardness and bending strength reached up to 614.4HV 0.2and 701.0MPa,respectively.AcknowledgmentsThe authors would like to express their thanks for the ﬁnancial support of the National Natural Science Foundation of China under grant No.50634060.References[1]Zhang Y,Ganeev AV,Wang JT,Liu JQ,Alexandrov IV.Observations on the ductile-to-brittle transition in ultra ﬁne-grained tungsten of commercial purity.Mater Sci Eng A 2009;503:37–40.[2]Kitsunai Y,Kurishita H,Kayano H,Hiraoka Y,Igarashi T,Takida T.Microstructure andimpact properties of ultra-ﬁne grained tungsten alloys dispersed with TiC.J Nucl Mater 1999;271–272:423–8.[3]Kim Y,Lee KH,Kim E,Cheong D,Hong SH.Fabrication of high temperature oxidesdispersion strengthened tungsten composites by spark plasma sintering process.J Refract Met Hard Mater 2009;5:842–6.[4]Wang HT,Fang ZZ,Hwang KS,Zhang HB,Siddle D.Sinter-ability of nanocrystallinetungsten powder.Int J Refract Met Hard Mater 2010;28:312–6.[5]Veleva L,Oksiuta Z,Vogt U,Baluc N.Sintering and characterization of W –Y andW –Y 2O 3materials.Fusion Eng Des 2009;84:1920–4.[6]Brown PH,Rathjen AH,Graham RD,Tribe DE.Chapter 92rare earth elements inbiological systems.Handbook on the physics and chemistry of rare earths;1990.p.423–52.[7]Zhou ZJ,Tan J,Qu DD,Pintsuk G,Rödig M,Linke J.Basic characterization of oxidedispersion strengthened ﬁne-grained tungsten based materials fabricated by me-chanical alloying and spark plasma sintering.J Nucl Mater 2012;431:202–5.[8]Tan J,Zhou ZJ,Zhu XP,Guo SQ,Qu DD,Lei MK,et al.Evaluation of ultra-ﬁne grainedtungsten under transient high heat ﬂux by high-intensity pulsed ion beam.Trans Nonferrous Metals Soc China 2012;22:1081–5.[9]Ma J,Zhang JZ,Liu W,Shen ZJ.Suppressing pore-boundary separation during sparkplasma sintering of tungsten.J Nucl Mater 2013;438:199–203.[10]Rodríguez-Carvajal J.Recent advances in magnetic structure determination byneutron powder diffraction +FullProf.Physica B 1993;192:55–6.[11]Muñoz A,Monge MA,Savoini B,Rabanal ME,Garces G,Pareja 2O 3-reinforced Wand W –V alloys produced by hot isostatic pressing.J Nucl Mater 2011;417:508–11.[12]Maweja K,Phasha MJ,Choenyane LJ.Thermal stability and magnetic saturation ofannealed nickel –tungsten and tungsten milled powders.J Refract Met Hard Mater 2012;30:78–84.[13]Yar MA,Wahlberg S,Bergqvist H,Salem HG,Johnsson M,Muhammed M.Spark plas-ma sintering of tungsten –yttrium oxide composites from chemically synthesized nanopowders and microstructural characterization.J Nucl Mater 2011;412:227–32.[14]Kim Y,Hong MH,Lee SH,Kim EP,Lee S,Noh JW.The effect of yttrium oxide on thesintering behavior and hardness of tungsten.Met Mater Int 2006;12:245–8.[15]Han Y,Fan JL,Liu T,Cheng HC,Tian JM.The effects of ball-milling treatment on thedensi ﬁcation behavior of ultra-ﬁne tungsten powder.Int J Refract Met Hard Mater 2011;29:743–50.[16]Prabhu G,Chakraborty A,Sarma B.Microwave sintering of tungsten.Int J Refract MetHard Mater 2009;27:545–8.Fig.7.FESEM micrographs of chemically etched surface of:(a)WYO,(b)WY,and (c)WL.Table 2The relative density and basic mechanical properties of rare earth tungsten alloys.Sample Relative density (%)Microhardness (HV 0.2)Bending strength (MPa)WYO 92.1445.2631WY 99.4614.4701WL88.3303372.123M.Zhao et al./Int.Journal of Refractory Metals and Hard Materials 48(2015)19–23。

Raritan Paragon II 使用指南 Release 4.1 版

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V2G-Cal-2001

Vehicle-to-Grid Power: Battery, Hybrid, and Fuel Cell Vehicles as Resources for Distributed Electric Power in California
Willett Kempton (Principal Investigator) and Jasna Tomic ´ , University of Delaware Steven Letendre, Green Mountain College Alec Brooks, AC Propulsion, Inc. Timothy Lipman, University of California, Berkeley and Davis
Disclaimer:
The statements and conclusions in this report are those of the contractor and not necessarily those of the California Air Resources Board. The mention of commercial products, their use in connection with material reported herein is not to be construed as actual or implied endorsement of such products.
i
Executive Summary
Electric-drive vehicles can become an important resource for the California electric utility system, with consequent air pollution, system reliability, and economic benefits. We refer to electric power resources from vehicles as "Vehicle to Grid" power (V2G). The economic value of some forms of V2G appear high, more than enough to offset the initially higher costs of electric-drive vehicles, thus having the potential to accelerate their introduction. To realize this potential, some coordination of vehicle and infrastructure planning will be needed. This study calculates three parameters of electric drive vehicles (EDVs) which are important for their use by the electric system: resource size, availability, and economic potential. Economic potential was calculated for three power markets: peak power, spinning reserves, and regulation services. Vehicles were not found to be competitive for baseload power. The analysis uses California electricity market prices for three years—1998, 1999, and 2000—as well as historical electric utility experience. This three-year comparison insures that recent disruptions, and historically atypical prices, in the 2000 California electricity market do not bias the results. In addition to electricity markets, "customer side of the meter" strategies are analyzed, in which vehicle power offsets time-of-use charges, demand charges, and interruptible rates. These multiple calculations of the value of EDV power make the conclusions about its economic viability more robust. This report analyzes V2G power from three types of EDVs—battery, hybrid, and fuel cell. Battery EDVs can store electricity, charging during low demand times and discharging when power is scarce and prices are high. Fuel cell and hybrid EDVs are sources of new power generation. For economic reasons they would sell power only when prices are high. Battery and plug-in hybrid EDVs can also sell regulation services, which involves little or no net battery discharge. In the terminology of the California Air Resources Board (CARB), battery and fuel cell EDVs are considered Zero Emission Vehicles (ZEV), hybrids are considered Advanced Technology Partial ZEV (AT-PZEV), and battery EDVs are often referred to simply as EVs. The report begins by describing the technical requirements needed to realize the most value from vehicle power. These include on-board power electronics, plug-tovehicle connections, and communications facilities ("telematics"). The required technologies are all in production or in prototype vehicles, although they have not been put together in the ways we propose. We also discuss bridge strategies; for example, the conductive charging stations now being installed for recharging battery vehicles will later be valuable for carrying power from hybrid and fuel cell vehicles to the grid. Implications for current industry directions are also discussed; for example, existing onboard conductive chargers can be used for V2G whereas, current inductive chargers cannot. Formulas are derived to calculate the power capacity of each vehicle type. Calculated capacity depends on the charger capacity, residential and commercial electrical service capacity, fuel or electricity needed for the next trip, whether a continuous piped gaseous fuel source is connected to the vehicle, and other factors. The battery vehicles have power capacity on the order of 10 kW and fuel cell vehicles have up

ProAc Response D2R书架箱

HOT 57UFFI r 品橱窗Gryphon EthosCD 播放器产品代理：威达公司Arcam CDS50SACD/CD 串流播放器Gryphon 推出建厂至今首台提供数码及USB 输入的旗舰CD 播放器，它的名字叫Ethos 思潮。

Ethos 采用破旧立新的前卫三角造型，贯彻约束层阻尼化缓震技术的机身，以银色拉丝铝合金和厚重的黑色亚加力板组合而成，所有边位与角位全数经过细心处理，突显Gryphon 产品无可匹敌的细致工艺。

Ethos 的下半部分，装有三组以两前一后方式设置的自家 Atlas 避震钉脚。

Stream Unlimited CD-Pro 8 S 重量级激光拾讯机芯配上Gryphon 工程团队精心研发，经过多番人手打磨、抛光及镀金处理的专用碟镇，保证讯号完美拾取。

Ethos 配备了经过电气隔离处理的同轴BNC,平衡AES/EBU 及最高支持32bit/384kHz 及DSD512规格的USB-B 型输入接口，另加一组平衡AES/EBU 数码输出。

至于全平衡设计的模拟放大及输出线路，亦同时提供RCA 及XLR 插座。

Gryphon 工程团队一向非常重视供电环节的制作，Ethos 贵为一体化旗舰CD 播放器的代表当然不会例外，左右声道模拟放大线路，数码核心和转盘/显示屏幕，合共使用4枚秘制供电变压器，加上独立整流器和阵容鼎盛的电解电容作为能量备储，有效防止各环产品代理：威达公司Arcam HDA 系列最新成员CDS50,它采用全金属机箱，配备高稳定度激光拾讯机芯，可播放传统CD 、CD-R/RW.单层及双层SACD 光盘，而机内所使用的解码芯片亦从CDS-27沿用之Tl/Burr Brown PCM1794升格为炙手可热的发烧级ESS903&接口方面，CDS50的模拟部分同样提供RCA 及平衡XLR 输岀，数字接口亦齐备同轴S/PDIF 、光纤、Wi-Fi 、USB 及以太网 Ethernet 接口。

外源钙与丛枝菌根真菌协同对连作花生产量和品质的影响

㊀山东农业科学㊀２０２３ꎬ５５(１１):１４４~１５０ＳｈａｎｄｏｎｇＡｇｒｉｃｕｌｔｕｒａｌＳｃｉｅｎｃｅｓ㊀ＤＯＩ:１０.１４０８３/ｊ.ｉｓｓｎ.１００１－４９４２.２０２３.１１.０２１收稿日期:２０２３－０２－０７基金项目:国家花生产业技术体系项目(ＣＡＲＳ－１３)ꎻ泰山学者工程项目ꎻ山东省自然科学基金青年基金项目(ＺＲ２０２１ＱＣ１６３)ꎻ山东省自然科学基金面上项目(ＺＲ２０２０ＭＣ０９４)ꎻ山东省农业科学院农业科技创新工程项目(ＣＸＧＣ２０２３Ｃ０４)作者简介:衣婷婷(１９９９ )ꎬ女ꎬ山东烟台人ꎬ硕士研究生ꎬ主要从事花生栽培与生理生态研究ꎮＥ－ｍａｉｌ:１０８３７４７５２９＠ｑｑ.ｃｏｍ通信作者:崔利(１９８１ )ꎬ女ꎬ安徽泗县人ꎬ副研究员ꎬ主要从事花生连作障碍机理研究ꎮＥ－ｍａｉｌ:ｃｕｉｌｉ０５５７＠１６３.ｃｏｍ万书波(１９６２ )ꎬ男ꎬ山东栖霞人ꎬ研究员ꎬ主要从事花生栽培与生理生态研究ꎮＥ－ｍａｉｌ:ｗａｎｓｈｕｂｏ２０１６＠１６３.ｃｏｍ外源钙与丛枝菌根真菌协同对连作花生产量和品质的影响衣婷婷１ꎬ唐朝辉２ꎬ王建国２ꎬ张佳蕾２ꎬ郭峰２ꎬ崔利２ꎬ万书波２(１.青岛农业大学农学院ꎬ山东青岛㊀２６６１０９ꎻ２.山东省农业科学院农作物种质资源研究所ꎬ山东济南㊀２５０１００)㊀㊀摘要:连作严重影响花生植株生长ꎬ导致花生产量和品质下降ꎮ另外ꎬ长期连作还导致土壤酸化ꎬ土壤中交换性钙缺失ꎬ造成花生荚果发育受阻ꎮ补充外源钙可显著提高荚果与籽仁产量ꎮ为探明丛枝菌根真菌和外源钙对连作花生生长发育的协同作用ꎬ本试验以花育２２为材料ꎬ研究摩西斗管囊霉(Ｆｕｎｎｅｌｉｆｏｒｍｉｓｍｏｓｓｅａｅ)协同外源钙施用对连作花生植株性状㊁干物质积累㊁矿物质元素含量及产量和品质的影响ꎮ结果表明ꎬ二者协同能显著增加连作花生的株高和分枝数ꎬ促进植株干物质积累和对矿物质元素的吸收ꎬ从而提高花生产量和品质ꎮ综上ꎬ摩西斗管囊霉结合外源钙能提高连作花生的产量和品质ꎮ该结论可为增加连作花生产量提供实践和理论依据ꎮ关键词:外源钙ꎻ丛枝菌根真菌ꎻ连作花生ꎻ产量ꎻ品质中图分类号:Ｓ５６５.２:Ｓ１５４.３㊀㊀文献标识号:Ａ㊀㊀文章编号:１００１－４９４２(２０２３)１１－０１４４－０７ＳｙｎｅｒｇｉｓｔｉｃＥｆｆｅｃｔｓｏｆＥｘｏｇｅｎｏｕｓＣａｌｃｉｕｍａｎｄＡｒｂｕｓｃｕｌａｒＭｙｃｏｒｒｈｉｚａｌＦｕｎｇｉｏｎＹｉｅｌｄａｎｄＱｕａｌｉｔｙｏｆＣｏｎｔｉｎｕｏｕｓＣｒｏｐｐｉｎｇＰｅａｎｕｔＹｉＴｉｎｇｔｉｎｇ１ꎬＴａｎｇＺｈａｏｈｕｉ２ꎬＷａｎｇＪｉａｎｇｕｏ２ꎬＺｈａｎｇＪｉａｌｅｉ２ꎬＧｕｏＦｅｎｇ２ꎬＣｕｉＬｉ２ꎬＷａｎＳｈｕｂｏ２(１.ＣｏｌｌｅｇｅｏｆＡｇｒｏｎｏｍｙꎬＱｉｎｇｄａｏＡｇｒｉｃｕｌｔｕｒａｌＵｎｉｖｅｒｓｉｔｙꎬＱｉｎｇｄａｏ２６６１０９ꎬＣｈｉｎａꎻ２.ＩｎｓｔｉｔｕｔｅｏｆＣｒｏｐＧｅｒｍｐｌａｓｍＲｅｓｏｕｒｃｅｓꎬＳｈａｎｄｏｎｇＡｃａｄｅｍｙｏｆＡｇｒｉｃｕｌｔｕｒａｌＳｃｉｅｎｃｅｓꎬＪｉｎａｎ２５０１００ꎬＣｈｉｎａ)Ａｂｓｔｒａｃｔ㊀Ｃｏｎｔｉｎｕｏｕｓｃｒｏｐｐｉｎｇｓｅｒｉｏｕｓｌｙａｆｆｅｃｔｓｔｈｅｇｒｏｗｔｈｏｆｐｌａｎｔｓꎬｒｅｓｕｌｔｉｎｇｉｎｄｅｃｒｅａｓｅｄｙｉｅｌｄａｎｄｑｕａｌｉｔｙｏｆｐｅａｎｕｔ.Ｉｎａｄｄｉｔｉｏｎꎬｌｏｎｇ￣ｔｅｒｍｃｏｎｔｉｎｕｏｕｓｃｒｏｐｐｉｎｇａｌｓｏｌｅａｄｓｔｏｓｏｉｌａｃｉｄｉｆｉｃａｔｉｏｎａｎｄｌｏｓｓｏｆｅｘ￣ｃｈａｎｇｅａｂｌｅｃａｌｃｉｕｍｉｎｓｏｉｌꎬｒｅｓｕｌｔｉｎｇｉｎｈｉｎｄｅｒｅｄｄｅｖｅｌｏｐｍｅｎｔｏｆｐｅａｎｕｔｐｏｄ.Ｓｕｐｐｌｅｍｅｎｔｉｎｇｅｘｏｇｅｎｏｕｓｃａｌｃｉ￣ｕｍｃｏｕｌｄｓｉｇｎｉｆｉｃａｎｔｌｙｉｍｐｒｏｖｅｐｏｄａｎｄｓｅｅｄｙｉｅｌｄｓ.ＩｎｏｒｄｅｒｔｏｉｎｖｅｓｔｉｇａｔｅｔｈｅｓｙｎｅｒｇｉｓｔｉｃｅｆｆｅｃｔｏｆａｒｂｕｓｃｕｌａｒｍｙｃｏｒｒｈｉｚａｌｆｕｎｇｉａｎｄｅｘｏｇｅｎｏｕｓｃａｌｃｉｕｍｏｎｔｈｅｇｒｏｗｔｈａｎｄｄｅｖｅｌｏｐｍｅｎｔｏｆｃｏｎｔｉｎｕｏｕｓｃｒｏｐｐｉｎｇｐｅａｎｕｔꎬＨｕａ￣ｙｕ２２ｗａｓｕｓｅｄａｓｔｈｅｔｅｓｔｍａｔｅｒｉａｌｔｏｓｔｕｄｙｔｈｅｅｆｆｅｃｔｓｏｆＦｕｎｎｅｌｉｆｏｒｍｉｓｍｏｓｓｅａｅｓｙｎｅｒｇｉｚｉｎｇｗｉｔｈｅｘｏｇｅｎｏｕｓｃａｌ￣ｃｉｕｍｏｎｔｈｅｐｌａｎｔｔｒａｉｔｓꎬｄｒｙｍａｔｔｅｒａｃｃｕｍｕｌａｔｉｏｎꎬｍｉｎｅｒａｌｅｌｅｍｅｎｔｃｏｎｔｅｎｔꎬｙｉｅｌｄａｎｄｑｕａｌｉｔｙｏｆｃｏｎｔｉｎｕｏｕｓｃｒｏｐｐｉｎｇｐｅａｎｕｔ.ＴｈｅｒｅｓｕｌｔｓｓｈｏｗｅｄｔｈａｔｔｈｅｓｙｎｅｒｇｉｓｔｉｃｅｆｆｅｃｔｏｆＦ.ｍｏｓｓｅａｅａｎｄｅｘｏｇｅｎｏｕｓｃａｌｃｉｕｍｃｏｕｌｄｓｉｇ￣ｎｉｆｉｃａｎｔｌｙｉｎｃｒｅａｓｅｔｈｅｐｌａｎｔｈｅｉｇｈｔａｎｄｂｒａｎｃｈｎｕｍｂｅｒｏｆｃｏｎｔｉｎｕｏｕｓｃｒｏｐｐｉｎｇｐｅａｎｕｔꎬｐｒｏｍｏｔｅｔｈｅａｃｃｕｍｕｌａ￣ｔｉｏｎｏｆｄｒｙｍａｔｔｅｒａｎｄｔｈｅａｂｓｏｒｐｔｉｏｎｏｆｍｉｎｅｒａｌｅｌｅｍｅｎｔｓꎬａｎｄｔｈｕｓｉｍｐｒｏｖｅｔｈｅｙｉｅｌｄａｎｄｑｕａｌｉｔｙｏｆｐｅａｎｕｔ.ＩｎｃｏｎｃｌｕｓｉｏｎꎬｔｈｅｃｏｍｂｉｎａｔｉｏｎｏｆＦ.ｍｏｓｓｅａｅａｎｄｅｘｏｇｅｎｏｕｓｃａｌｃｉｕｍｃｏｕｌｄｉｍｐｒｏｖｅｔｈｅｙｉｅｌｄａｎｄｑｕａｌｉｔｙｏｆｃｏｎ￣ｔｉｎｕｏｕｓｃｒｏｐｐｉｎｇｐｅａｎｕｔꎬｗｈｉｃｈｃｏｕｌｄｐｒｏｖｉｄｅｐｒａｃｔｉｃａｌａｎｄｔｈｅｏｒｅｔｉｃａｌｂａｓｅｓｆｏｒｉｎｃｒｅａｓｉｎｇｔｈｅｙｉｅｌｄｏｆｃｏｎｔｉｎ￣ｕｏｕｓｃｒｏｐｐｉｎｇｐｅａｎｕｔ.Ｋｅｙｗｏｒｄｓ㊀ＥｘｏｇｅｎｏｕｓｃａｌｃｉｕｍꎻＡｒｂｕｓｃｕｌａｒｍｙｃｏｒｒｈｉｚａｌｆｕｎｇｉꎻＣｏｎｔｉｎｕｏｕｓｃｒｏｐｐｉｎｇｐｅａｎｕｔꎻＹｉｅｌｄꎻＱｕａｌｉｔｙ㊀㊀花生是我国主要的油料作物和经济作物ꎬ在保障我国食用油安全㊁提高国民身体素质等方面具有举足轻重的作用ꎮ近年来ꎬ花生需求量增加ꎬ然而种植面积有限ꎬ很多花生主产区为追求经济利益常常大规模连续种植花生数年ꎬ连作现象十分严重[１]ꎬ严重影响花生植株的生长发育ꎬ导致产量和品质下降ꎮ丛枝菌根真菌(ａｒｂｕｓｃｕｌａｒｍｙｃｏｒｒｈｉｚａｌｆｕｎｇｉꎬＡＭＦ)是陆地生态系统中分布最广的一类共生真菌ꎬ能够与约８０％的陆生植物形成互惠共生体ꎮＡＭＦ与根系形成的菌根共生体通过吸收和转运土壤中的矿物营养物质为寄主植物提供养分[２]ꎮ目前ꎬＡＭＦ在农业生产上的应用已被广泛报道ꎬＡＭＦ通过根外菌丝吸收氮㊁磷㊁钾㊁钙等矿物质营养ꎬ并将其转移到植物根系内部ꎬ显著增加作物营养元素含量[３]ꎮ近年来ꎬ大量研究结果表明ꎬＡＭＦ能有效促进逆境环境中宿主植物的碳同化产物积累ꎬ并最终促进植株生长[４－６]ꎮ另外ꎬＡＭＦ能够增加寄主植物产量ꎬ提高果实品质ꎬ缓解连作障碍对植株产生的影响等[７]ꎮ有研究表明ꎬＡＭＦ能够改善连作花生土壤的理化性质ꎬ从而促进花生生长和产量增加[８－９]ꎮ另外ꎬ钙是影响花生荚果发育的重要营养元素ꎬ钙素对于花生荚果形成和产量具有重要作用ꎮ花生是需钙较多的作物ꎬ每形成１００ｋｇ荚果需要吸收的钙高达２.０~２.５ｋｇ[１０]ꎮ长期连作花生的土壤容易酸化ꎬ从而缺乏植物能够吸收的有效性钙ꎬ导致花生荚果发育受阻ꎬ造成花生产量和质量下降[１１]ꎮ缺钙会造成花生荚果小㊁仁秕㊁空壳㊁果实腐烂等ꎬ甚至出现黑胚芽等现象ꎬ严重影响产量和品质[１２]ꎮ钙离子作为植物体内第二信使广泛参与植物响应的各种生物和非生物胁迫的信号转导ꎮ目前ꎬ关于外源钙对花生生长发育的研究主要集中在以下几个方面:外源钙通过缓解光合系统中ＰＳⅡ光抑制来提高花生对高温强光胁迫的抗性[１３－１４]ꎻ提高花生植株体内保护酶活性ꎬ增加花生产量和品质[１５]ꎻ通过对细胞膜的保护来提高花生对干旱和盐胁迫的抗性等[１４]ꎮ但是ꎬＡＭＦ与钙元素协同作用对连作花生整个生长过程中生理指标及产量和品质的影响还未见报道ꎮ本试验前期相关研究证明ꎬ２０ｍｍｏｌ/Ｌ外源钙离子协同ＡＭＦ能够促进连作花生苗期的生长[８]ꎮ摩西斗管囊霉(Ｆｕｎｎｅｌｉｆｏｒｍｉｓｍｏｓｓｅａｅ)是ＡＭＦ的一种ꎮ为了研究二者协同作用对连作花生整个生育期生理指标及产量和品质的影响ꎬ本研究进一步开展试验ꎬ分析摩西斗管囊霉协同外源钙对连作花生植株生长指标㊁干物质积累㊁矿物质元素吸收及产量和品质的影响ꎬ以期找到解决或缓解花生连作障碍的方法ꎬ为促进连作花生生长发育和提高其产量品质提供实践和理论依据ꎮ１㊀材料与方法１.１㊀试验概况取花生连作５年的０~２０ｃｍ耕层土壤ꎬ经钴６０辐照灭菌后室温放置５ｄ备用ꎮ采用盆栽试验ꎬ盆口直径３９ｃｍꎬ高３０ｃｍꎬ每盆装土１８ｋｇꎮ花生品种为花育２２ꎬ种子经消毒后放入黑暗培养箱ꎬ待根长至３~５ｃｍ时移入装有灭菌土的盆中ꎮ采用穴播ꎬ每盆３穴ꎬ每穴两粒ꎮ出苗后每穴保留１株ꎬ每盆保留长势一致的健康苗３株ꎮ每处理１２盆ꎬ重复３次ꎮ为减少外界环境影响ꎬ盆栽试验在山东省农业科学院饮马泉试验基地旱棚内进行ꎮ１.２㊀试验设计丛枝菌根真菌来自北京农林科学院植物营养与资源研究所ꎬ编号为ＢＧＣＨＬＪ０２ꎬ种名摩西斗管囊霉(Ｆｕｎｎｅｌｉｆｏｒｍｉｓｍｏｓｓｅａｅ)ꎮ共设４个处理ꎬ分别为:对照组(既不加菌也不加钙ꎬＣＫ)㊁加菌组(只加菌不加钙ꎬＡＭＦ)㊁加钙组[只加２０ｍｍｏｌ/ＬＣａ(ＮＯ３)２４Ｈ２ＯꎬＣａ２０]㊁加菌加钙组[加菌和２０ｍｍｏｌ/ＬＣａ(ＮＯ３)２４Ｈ２ＯꎬＡＭＦ＋Ｃａ２０]ꎮ摩西斗管囊霉按每穴４００个孢子(１０ｇ含有摩西斗管囊霉孢子及菌丝的沙土)在播种时撒入种子周围的土壤中ꎮ分别于花生苗期(播种后３５ｄ)㊁花针期(播种后５０ｄ)和荚果膨大期(播种后７５ｄ)施入外源钙ꎮ每盆浇灌１Ｌ浓度为２０ｍｍｏｌ/Ｌ的５４１㊀第１１期㊀㊀㊀㊀衣婷婷ꎬ等:外源钙与丛枝菌根真菌协同对连作花生产量和品质的影响Ｃａ(ＮＯ３)２４Ｈ２Ｏ溶液ꎮ为平衡硝酸根离子对花生植株生长的影响ꎬ未添加Ｃａ(ＮＯ３)２处理添加２０ｍｍｏｌ/Ｌ的ＮＨ４ＮＯ３ꎮ１.３㊀测定项目及方法１.３.１㊀植株性状㊀每个处理分别于花针期㊁结荚期和成熟期选取１２株花生植株取样ꎬ室内考察主茎高㊁侧枝长㊁分枝数ꎮ同时ꎬ将各个时期花生植株的根㊁茎㊁叶分离ꎬ１０５ħ杀青３０ｍｉｎꎬ８０ħ烘干至恒重ꎬ计算各个时期花生不同器官的干物质量ꎮ１.３.２㊀植株养分㊀将花针期和成熟期的花生根系和叶片干样分别粉碎ꎬ采用凯氏定氮法测定全氮含量[１６]ꎬ采用酸溶－钼锑抗比色法测定全磷含量[１６]ꎬ采用氢氧化钠熔融－火焰分光光度计法测定全钾含量[１６]ꎬ采用原子吸收分光光度计法测定全钙含量[１７]ꎮ１.３.３㊀单株产量构成㊀成熟期各处理分别选取２０盆(６０株)ꎬ考察单株荚果数㊁饱果数㊁荚果重㊁饱果重ꎮ１.３.４㊀荚果品质㊀利用多功能谷物近红外分析仪(ＤＡ７２５０ＰｅｒｔｅｎꎬＨäｇｅｒｓｔｅｎꎬＳｗｅｄｅｎ)对各处理花生籽仁的蛋白质㊁脂肪酸㊁总氨基酸㊁油酸㊁亚油酸进行测定ꎬ计算油酸和亚油酸比值(Ｏ/Ｌ)ꎮ１.４㊀数据处理与分析采用ＭｉｃｒｏｓｏｆｔＥｘｃｅｌ对试验数据进行整理和绘图ꎬ采用ＤＰＳ软件进行统计分析及显著性差异分析(Ｐ<０.０５)ꎮ２㊀结果与分析２.１㊀外源钙与ＡＭＦ协同对连作花生植株性状的影响由表１可以看出ꎬ与对照相比ꎬ钙与ＡＭＦ相关处理对连作花生花针期和结荚期的主茎高都无显著影响ꎻ成熟期ꎬＡＭＦ㊁Ｃａ２０和ＡＭＦ＋Ｃａ２０处理的主茎高均显著增加ꎮ钙与ＡＭＦ相关处理对侧枝长的影响与主茎高相同ꎬ不同处理成熟期的侧枝长均显著高于对照ꎮ对于分枝数而言ꎬＡＭＦ＋Ｃａ２０处理花针期和成熟期的分枝数显著高于对照ꎬ分别增加６.１％㊁１０.６％ꎻ而不同时期ＡＭＦ和Ｃａ２０处理的分枝数与对照均无显著差异ꎮ㊀㊀表１㊀外源钙与ＡＭＦ协同对连作花生株高、侧枝长和分枝数的影响处理主茎高/ｃｍ花针期结荚期成熟期侧枝长/ｃｍ花针期结荚期成熟期分枝数花针期结荚期成熟期ＣＫ１６.７８ａ２４.６８ａ２９.３０ｂ１８.９７ａ２７.１７ａ３２.５３ｂ９.５０ｂ１０.８３ａ１０.６７ｂＡＭＦ１７.１１ａ２６.２１ａ３２.７０ａ１９.１５ａ２９.４９ａ３７.６７ａ９.６７ｂ１１.００ａ１１.００ａｂＣａ２０１６.３４ａ２６.０５ａ３１.９１ａ１８.４０ａ３０.３３ａ３５.８８ａ９.４２ｂ１０.７５ａ１１.３３ａｂＡＭＦ＋Ｃａ２０１７.３３ａ２７.６３ａ３２.０６ａ９.１３ａ２９.５９ａ３６.３１ａ１０.０８ａ１１.４２ａ１１.８０ａ㊀㊀注:同列数据后不同小写字母表示处理间差异显著(Ｐ<０.０５)ꎬ下同ꎮ２.２㊀外源钙与ＡＭＦ协同对连作花生干物质积累量的影响从表２中可以看出ꎬ不同处理下连作花生单株干物质积累量有显著差异ꎮ花针期ꎬＡＭＦ㊁Ｃａ２０处理的根干重与对照无显著差异ꎬＡＭＦ＋Ｃａ２０处理则显著高于对照ꎬ增加４２.６％ꎻ结荚期ꎬＡＭＦ㊁Ｃａ２０处理的根干重与对照差异不显著ꎬＡＭＦ＋Ｃａ２０处理则显著高于对照ꎬ且ＡＭＦ＋Ｃａ２０处理显著高于Ｃａ２０处理ꎻ成熟期ꎬ各处理下根干重的变化趋势与结荚期一致ꎬ也表现为ＡＭＦ＋Ｃａ２０处理的根干重最大ꎮ不同处理下花生茎㊁叶干重变化与根干重变化相似ꎬ都表现为ＡＭＦ＋Ｃａ２０处理显著高于对照ꎮ㊀㊀表２㊀外源钙与ＡＭＦ协同对连作花生单株干物质积累量的影响处理根干重/ｇ花针期结荚期成熟期茎干重/ｇ花针期结荚期成熟期叶干重/ｇ花针期结荚期成熟期ＣＫ０.４７ｂ０.６２ｃ２.６１ｃ４.２９ｂ８.４２ｃ１３.７８ｂ５.５８ｂ８.７２ｂ１３.７０ｂＡＭＦ０.５４ｂ０.７３ｂｃ２.６９ｂｃ４.９２ｂ８.２９ｂｃ１３.８８ｂ６.３５ａｂ９.１３ｂ１３.８１ｂＣａ２００.５２ｂ０.７２ｂｃ２.９０ｂ４.９６ｂ９.２６ｂ１４.５９ｂ５.６６ａｂ９.７０ｂ１４.３１ｂＡＭＦ＋Ｃａ２００.６７ａ０.９６ａ３.１９ａ５.９３ａ１２.２３ａ１７.６９ａ６.６９ａ１２.４２ａ１７.９１ａ６４１㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀山东农业科学㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀第５５卷㊀２.３㊀外源钙与ＡＭＦ协同对连作花生养分吸收的影响由图１Ａ可知ꎬ与对照相比ꎬＡＭＦ处理显著提高连作花生花针期和成熟期的根系全氮含量ꎬ分别增加１７.０％㊁１０.７％ꎻＡＭＦ＋Ｃａ２０处理仅显著提高成熟期花生根系全氮含量ꎬ提高了４３.４％ꎮ由图１Ｂ可知ꎬ与对照相比ꎬＡＭＦ＋Ｃａ２０处理显著提高花针期花生叶片全氮含量ꎻＡＭＦ㊁Ｃａ２０㊁ＡＭＦ＋Ｃａ２０处理均显著提高成熟期花生叶片全氮含量ꎬ分别提高１３.４％㊁５.９％㊁９.５％ꎮ由图１Ｃ㊁Ｄ可知ꎬ与对照相比ꎬＡＭＦ＋Ｃａ２０处理显著提高成熟期花生根系和叶片全磷含量ꎬ分别提高６５.７％㊁２５.４％ꎻ显著提高花针期花生根系全磷含量ꎬ提高３１.０％ꎮＡＭＦ处理显著提高花针期花生根系和叶片全磷含量ꎬ分别提高９.８％㊁２３.１％ꎻ显著提高成熟期叶片全磷含量ꎬ提高１９.２％ꎮ综上ꎬＡＭＦ＋Ｃａ２０处理显著提高连作花生根系和叶片全磷含量ꎮ同时期柱上不同小写字母表示处理间差异显著(Ｐ<０.０５)ꎮ图１㊀外源钙与ＡＭＦ协同对连作花生养分吸收的影响７４１㊀第１１期㊀㊀㊀㊀衣婷婷ꎬ等:外源钙与丛枝菌根真菌协同对连作花生产量和品质的影响㊀㊀由图１Ｅ㊁Ｆ可知ꎬ与对照相比ꎬＣａ２０㊁ＡＭＦ＋Ｃａ２０处理显著提高花针期和成熟期花生根系和叶片全钾含量ꎬＣａ２０处理花针期㊁成熟期的根系㊁叶片全钾含量分别较对照提高３８.５％㊁１９.４％和７９.７％㊁３８.９％ꎬＡＭＦ＋Ｃａ２０分别提高５０.４％㊁３１.７％和１１２.２％㊁５８.３％ꎻＡＭＦ处理显著提高成熟期花生叶片㊁根系和花针期叶片的全钾含量ꎬ分别提高２４.３％㊁５１.０％和１７.３％ꎮ综上ꎬＡＭＦ＋Ｃａ２０处理能够显著提高花针期㊁成熟期花生根㊁叶的全钾含量ꎮ由图１Ｇ㊁Ｈ可知ꎬ与对照相比ꎬＡＭＦ和Ｃａ２０处理显著提高成熟期花生根系和花针期花生叶片全钙含量ꎬＡＭＦ处理成熟期花生根系㊁花针期花生叶片的全钙含量较对照分别显著提高了３１.４％㊁２８.１％ꎬＣａ２０处理分别显著提高了３０.３％㊁１８.５％ꎬＡＭＦ与Ｃａ２０处理间无显著差异ꎻＡＭＦ＋Ｃａ２０处理不同生育时期的根㊁叶全钙含量均最高ꎬ不同时期根系中的含量显著高于其他处理ꎬ叶片的全钙含量ꎬ花针期显著高于ＣＫ㊁Ｃａ２０处理ꎬ成熟期显著高于ＣＫ㊁ＡＭＦ处理ꎮ说明ＡＭＦ＋Ｃａ２０处理能够显著促进连作花生吸收钙的能力ꎮ２.４㊀外源钙与ＡＭＦ协同对连作花生产量和品质的影响从表３中可以看出ꎬ不同处理下连作花生荚果产量性状存在差异ꎮＡＭＦ＋Ｃａ２０处理的荚果数量最高ꎬ显著高于其他处理ꎬ较对照提高３３.９％ꎻＣａ２０处理的荚果数量也显著高于对照ꎬ但与ＡＭＦ处理差异不显著ꎮ饱果率的变化趋势与荚果数量一致ꎬ亦表现为Ｃａ２０＋ＡＭＦ处理表现最优ꎬ显著高于其他处理ꎮ荚果重和饱果重的变化趋势一致ꎬＡＭＦ＋Ｃａ２０处理显著高于其他处理ꎬ而ＡＭＦ㊁Ｃａ２０㊁ＣＫ间无显著差异ꎮ㊀㊀表３㊀外源钙与ＡＭＦ协同对连作花生产量性状的影响处理荚果数量/(个/株)饱果率/％荚果重/(ｇ/株)饱果重/(ｇ/株)ＣＫ２４.８ｃ５５.６ｃ３６.００ｂ２８.００ｂＡＭＦ２５.１ｂｃ５８.０ｃ３６.６７ｂ２９.８９ｂＣａ２０２５.９ｂ６４.５ｂ３７.７８ｂ３１.３３ｂＡＭＦ＋Ｃａ２０３３.２ａ７２.５ａ４８.６７ａ３９.３３ａ㊀㊀由表４看出ꎬ不同处理下连作花生的籽仁品质存在差异ꎮ与对照相比ꎬＣａ２０㊁ＡＭＦ＋Ｃａ２０处理显著增加花生籽仁蛋白质㊁总氨基酸含量ꎬ且二者差异显著ꎬＡＭＦ＋Ｃａ２０较Ｃａ２０处理提高８.７％㊁１６.５％ꎻＡＭＦ处理的籽仁脂肪酸含量较对照显著增加７.３％ꎬ但油酸和亚油酸含量无显著变化ꎻＡＭＦ＋Ｃａ２０处理籽仁脂肪酸㊁油酸含量显著提高ꎬ较对照都提高９.４％ꎬ亚油酸含量较对照显著降低ꎬ达１２.９％ꎻ不同处理的油酸/亚油酸值均显著高于对照ꎬ且ＡＭＦ＋Ｃａ２０处理最高ꎬ较对照显著增长２５.４％ꎮ㊀㊀表４㊀外源钙与ＡＭＦ协同对连作花生品质的影响处理蛋白质/％脂肪酸/％总氨基酸/％油酸/％亚油酸/％油酸/亚油酸值ＣＫ１８.２７ｃ５２.４６ｃ１６.２０ｃ５２.４６ｂ２７.２０ａ１.９３ｃＡＭＦ１９.１０ｃ５６.２８ａｂ１７.８３ｂｃ５４.６２ｂ２６.１１ａｂ２.０９ｂＣａ２０２０.１３ｂ５３.７７ｂｃ１８.２９ｂ５３.７７ｂ２４.７９ｂｃ２.１７ｂＡＭＦ＋Ｃａ２０２１.８９ａ５７.３８ａ２１.３０ａ５７.３８ａ２３.６８ｃ２.４２ａ３㊀讨论与结论长期连作严重影响花生植株的正常生长发育ꎬ叶片中抗氧化物酶活性下降ꎬ光合作用减弱ꎬ从而导致生物量和产量降低[１８]ꎮＡＭＦ不仅能提高植物对营养元素的吸收ꎬ而且能提高寄主植株对逆境胁迫的抗性ꎬ增加寄主抵抗病原菌侵染的能力[１９]ꎮ同时ꎬ外源钙不仅作为营养物质促进植物生长发育ꎬ也能作为信号物质提高植物对环境胁迫的抗性[２０]ꎮ研究发现ꎬＡＭＦ协同外源钙能够促进连作花生的生长发育和干物质积累ꎬ这可能是因为二者协同作用增加了连作花生对矿物质元素的吸收ꎬ从而积累更多干物质[２１]ꎮ本研究结果表明ꎬＡＭＦ协同外源钙显著提高连作花生植株对氮素的吸收能力ꎬ这与黄志[２２]的研究结果一致ꎬ１５Ｎ的标记示踪试验发现ꎬＡＭＦ菌丝能够从寄主根系以外几厘米到十几厘米的地方吸收ＮＨ＋４转运到寄主体内ꎬ增加寄主氮的含量ꎮ本研究发现ＡＭＦ协同外源钙促进连作花生吸收磷元素ꎬ这可能是因为丛枝菌根真菌改变植物根际土壤的酸碱度ꎬ活化土壤中的难溶性磷酸盐[２３－２４]ꎬ增加了根系吸收的磷酸盐转运到植物体内的量ꎬ从而提高植物对磷素的吸收与利用能力[２５]ꎮ另外ꎬ本研究结果表明ꎬＡＭＦ侵染的连作花生植株体内的钾离子含量较高ꎬ在玉米根系[２６]㊁莴苣叶片[２７]㊁小麦茎秆[２８]中都有类似发８４１㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀山东农业科学㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀第５５卷㊀现ꎮＳｃｈｅｌｏｓｋｅ等[２９]利用Ｘ射线评估ＡＭＦ侵染的寄主根系ꎬ发现与未被侵染的根系相比ꎬ受ＡＭＦ侵染的根系中含有较高的钾离子ꎮ另外ꎬＡＭＦ协同外源钙进一步提高植株体内钙离子的含量ꎮ本研究结果得出ꎬＡＭＦ协同外源钙对连作花生干物质积累和营养元素吸收的促进作用更大ꎮ这可能是因为ꎬＤＥＬＬＡ(丛枝菌根形成的关键调控因子)蛋白在丛枝菌根共生体激活的不同信号传导途径中起着核心连接作用ꎬ并且在菌根共生体形成中起到正调控作用[３０]ꎻ在丛枝菌根共生体建立过程中ꎬ外源钙离子的应用上调了编码ＤＥＬＬＡ蛋白基因的转录本ꎬ表明钙离子的应用可能促进丛枝菌根共生体中各种信号的连接ꎬ有利于菌根共生体的建立和功能的发挥ꎬ从而更好地提高菌根共生体吸收营养元素的能力[８]ꎮ因此ꎬ适当的外源钙能提高菌根共生体对植物生长的促进作用ꎮＡＭＦ能够提高蔬菜作物的产量和品质[６]ꎮ本研究发现ꎬＡＭＦ与外源钙离子结合(ＡＭＦ＋Ｃａ２０)可以更好地提高连作花生的产量和品质ꎬ这可能与二者协同引起植物次生代谢物的改变有关[３１]ꎮ综上ꎬＡＭＦ与外源钙协同能够提高连作花生根㊁叶矿物质元素含量ꎬ促进干物质积累ꎬ从而增加连作花生的产量和品质ꎮ本研究结果可为缓解花生连作障碍提供实践参考和理论依据ꎮ参㊀考㊀文㊀献:[１]㊀李孝刚ꎬ张桃林ꎬ王兴祥.花生连作土壤障碍机制研究进展[Ｊ].土壤ꎬ２０１５ꎬ４７(２):２６６－２７１.[２]㊀ＳｍｉｔｈＳＥꎬＲｅａｄＤ.Ｍｙｃｏｒｒｈｉｚａｓｉｎａｇｒｉｃｕｌｔｕｒｅꎬｈｏｒｔｉｃｕｌｔｕｒｅａｎｄｆｏｒｅｓｔｒｙ[Ｊ].ＭｙｃｏｒｒｈｉｚａｌＳｙｍｂｉｏｓｉｓ(ＴｈｉｒｄＥｄｉｔｉｏｎ)ꎬ２００８:６１１－６１８.[３]㊀陈保冬ꎬ于萌ꎬ郝志鹏ꎬ等.丛枝菌根真菌应用技术研究进展[Ｊ].应用生态学报ꎬ２０１９ꎬ３０(３):１０３５－１０４６. [４]㊀Ｒｕｉｚ￣ＬｏｚａｎｏＪＭꎬＡｒｏｃａＲꎬＺａｍａｒｒｅñｏÁＭꎬｅｔａｌ.Ａｒｂｕｓｃｕｌａｒｍｙｃｏｒｒｈｉｚａｌｓｙｍｂｉｏｓｉｓｉｎｄｕｃｅｓｓｔｒｉｇｏｌａｃｔｏｎｅｂｉｏｓｙｎｔｈｅｓｉｓｕｎｄｅｒｄｒｏｕｇｈｔａｎｄｉｍｐｒｏｖｅｓｄｒｏｕｇｈｔｔｏｌｅｒａｎｃｅｉｎｌｅｔｔｕｃｅａｎｄｔｏｍａｔｏ[Ｊ].ＰｌａｎｔＣｅｌｌ＆Ｅｎｖｉｒｏｎｍｅｎｔꎬ２０１６ꎬ３９(２):４４１－４５２. [５]㊀Ｓáｎｃｈｅｚ￣ＲｏｍｅｒａＢꎬＲｕｉｚ￣ＬｏｚａｎｏＪＭꎬＺａｍａｒｒｅñｏÁＭꎬｅｔａｌ.Ａｒｂｕｓｃｕｌａｒｍｙｃｏｒｒｈｉｚａｌｓｙｍｂｉｏｓｉｓａｎｄｍｅｔｈｙｌｊａｓｍｏｎａｔｅａｖｏｉｄｔｈｅｉｎｈｉｂｉｔｉｏｎｏｆｒｏｏｔｈｙｄｒａｕｌｉｃｃｏｎｄｕｃｔｉｖｉｔｙｃａｕｓｅｄｂｙｄｒｏｕｇｈｔ[Ｊ].Ｍｙｃｏｒｒｈｉｚａꎬ２０１６ꎬ２６(２):１１１－１２２.[６]㊀韩冰ꎬ贺超兴ꎬ郭世荣ꎬ等.丛枝菌根真菌对盐胁迫下黄瓜幼苗渗透调节物质含量和抗氧化酶活性的影响[Ｊ].西北植物学报ꎬ２０１１ꎬ３１(１２):２４９２－２４９７.[７]㊀杨环宇.丛枝菌根真菌对连作土壤中桃实生苗生长的影响[Ｄ].武汉:华中农业大学ꎬ２０１４.[８]㊀ＣｕｉＬꎬＧｕｏＦꎬＺｈａｎｇＪＬꎬｅｔａｌ.Ａｒｂｕｓｃｕｌａｒｍｙｃｏｒｒｈｉｚａｌｆｕｎｇｉｃｏｍｂｉｎｅｄｗｉｔｈｅｘｏｇｅｎｏｕｓｃａｌｃｉｕｍｉｍｐｒｏｖｅｓｔｈｅｇｒｏｗｔｈｏｆｐｅａ￣ｎｕｔ(ＡｒａｃｈｉｓｈｙｐｏｇａｅａＬ.)ｓｅｅｄｌｉｎｇｓｕｎｄｅｒｃｏｎｔｉｎｕｏｕｓｃｒｏｐｐｉｎｇ[Ｊ].ＪｏｕｒｎａｌｏｆＩｎｔｅｇｒａｔｉｖｅＡｇｒｉｃｕｌｔｕｒｅꎬ２０１９ꎬ１８(２):４０７－４１６.[９]㊀崔利ꎬ郭峰ꎬ张佳蕾ꎬ等.摩西斗管囊霉改善连作花生根际土壤的微环境[Ｊ].植物生态学报ꎬ２０１９ꎬ４３(８):７１８－７２８. [１０]吴旭银ꎬ吴贺平ꎬ李彦生ꎬ等.地膜覆盖花生对钙㊁镁㊁硫吸收特性的研究[Ｊ].植物营养与肥料学报ꎬ２００７ꎬ１３(１):１７１－１７４.[１１]张佳蕾ꎬ郭峰ꎬ孟静静ꎬ等.酸性土施用钙肥对花生产量和品质及相关代谢酶活性的影响[Ｊ].植物生态学报ꎬ２０１５ꎬ３９(１１):１１０１－１１０９.[１２]万书波ꎬ郭峰ꎬ曾英松ꎬ等.花生防空壳高产栽培技术[Ｊ].花生学报ꎬ２０１２ꎬ４１(４):３４－３６.[１３]ＹａｎｇＳꎬＷａｎｇＦꎬＧｕｏＦꎬｅｔａｌ.ＥｘｏｇｅｎｏｕｓｃａｌｃｉｕｍａｌｌｅｖｉａｔｅｓｐｈｏｔｏｉｎｈｉｂｉｔｉｏｎｏｆＰＳⅡｂｙｉｍｐｒｏｖｉｎｇｔｈｅｘａｎｔｈｏｐｈｙｌｌｃｙｃｌｅｉｎｐｅａｎｕｔ(Ａｒａｃｈｉｓｈｙｐｏｇａｅａ)ｌｅａｖｅｓｄｕｒｉｎｇｈｅａｔｓｔｒｅｓｓｕｎｄｅｒｈｉｇｈｉｒｒａｄｉａｎｃｅ[Ｊ].ＰＬｏＳＯＮＥꎬ２０１３ꎬ８(８):ｅ７１２１４.[１４]王芳ꎬ杨莎ꎬ郭峰ꎬ等.钙对花生幼苗生长㊁活性氧积累和光抑制程度的影响[Ｊ].生态学报ꎬ２０１５ꎬ３５(５):１４９６－１５０４. [１５]周录英ꎬ李向东ꎬ王丽丽ꎬ等.钙肥不同用量对花生生理特性及产量和品质的影响[Ｊ].作物学报ꎬ２００８ꎬ３４(５):８７９－８８５.[１６]鲍士旦.土壤农化分析[Ｍ].第三版.北京:中国农业出版社ꎬ１９９９:４２－５６ꎬ７１－８０ꎬ１００－１０８.[１７]中华人民共和国水利部.铅㊁镉㊁钒㊁磷等３４种元素的测定电感耦合等离子体原子发射光谱法(ＩＣＰ－ＡＥＳ):ＳＬ３９４.１－２００７[Ｓ].北京:中国标准出版社ꎬ２００７.[１８]ＬｉｕＷＸꎬＷａｎｇＱＬꎬＷａｎｇＢＺꎬｅｔａｌ.Ｃｈａｎｇｅｓｉｎｔｈｅａｂｕｎ￣ｄａｎｃｅａｎｄｓｔｒｕｃｔｕｒｅｏｆｂａｃｔｅｒｉａｌｃｏｍｍｕｎｉｔｉｅｓｕｎｄｅｒｌｏｎｇ￣ｔｅｒｍｆｅｒｔｉｌｉｚａｔｉｏｎｔｒｅａｔｍｅｎｔｓｉｎａｐｅａｎｕｔｍｏｎｏｃｒｏｐｐｉｎｇｓｙｓｔｅｍ[Ｊ].ＰｌａｎｔａｎｄＳｏｉｌꎬ２０１５ꎬ３９５(１/２):４１５－４２７.[１９]ＮａｄｅｅｍＳＭꎬＡｈｍａｄＭꎬＺａｈｉｒＺＡꎬｅｔａｌ.Ｔｈｅｒｏｌｅｏｆｍｙｃｏｒ￣ｒｈｉｚａｅａｎｄｐｌａｎｔｇｒｏｗｔｈｐｒｏｍｏｔｉｎｇｒｈｉｚｏｂａｃｔｅｒｉａ(ＰＧＰＲ)ｉｎｉｍ￣ｐｒｏｖｉｎｇｃｒｏｐｐｒｏｄｕｃｔｉｖｉｔｙｕｎｄｅｒｓｔｒｅｓｓｆｕｌｅｎｖｉｒｏｎｍｅｎｔｓ[Ｊ].Ｂｉｏ￣ｔｅｃｈｎｏｌｏｇｙＡｄｖａｎｃｅｓꎬ２０１４ꎬ３２(２):４２９－４４８.[２０]ＹｉｎＹＱꎬＹａｎｇＲＱꎬＨａｎＹＢꎬｅｔａｌ.Ｃｏｍｐａｒａｔｉｖｅｐｒｏｔｅｏｍｉｃａｎｄｐｈｙｓｉｏｌｏｇｉｃａｌａｎａｌｙｓｅｓｒｅｖｅａｌｔｈｅｐｒｏｔｅｃｔｉｖｅｅｆｆｅｃｔｏｆｅｘｏｇｅ￣ｎｏｕｓｃａｌｃｉｕｍｏｎｔｈｅｇｅｒｍｉｎａｔｉｎｇｓｏｙｂｅａｎｒｅｓｐｏｎｓｅｔｏｓａｌｔｓｔｒｅｓｓ[Ｊ].ＪｏｕｒｎａｌｏｆＰｒｏｔｅｏｍｉｃｓꎬ２０１５ꎬ１１３:１１０－１２６.[２１]ＣｕｉＬꎬＧｕｏＦꎬＺｈａｎｇＪＬꎬｅｔａｌ.Ａｒｂｕｓｃｕｌａｒｍｙｃｏｒｒｈｉｚａｌｆｕｎｇｉｃｏｍｂｉｎｅｄｗｉｔｈｅｘｏｇｅｎｏｕｓｃａｌｃｉｕｍｉｍｐｒｏｖｅｓｔｈｅｇｒｏｗｔｈｏｆｐｅａ￣ｎｕｔ(ＡｒａｃｈｉｓｈｙｐｏｇａｅａＬ.)ｓｅｅｄｌｉｎｇｓｕｎｄｅｒｃｏｎｔｉｎｕｏｕｓｃｒｏｐｐｉｎｇ[Ｊ].ＪｏｕｒｎａｌｏｆＩｎｔｅｇｒａｔｉｖｅＡｇｒｉｃｕｌｔｕｒｅꎬ２０１９ꎬ１８:４０７－４１６. [２２]黄志.丛枝菌根真菌对甜瓜抗旱性的生理效应及分子机制的研究[Ｄ].杨凌:西北农林科技大学ꎬ２０１０.[２３]李芳ꎬ郝志鹏ꎬ陈保冬.菌根植物适应低磷胁迫的分子机制９４１㊀第１１期㊀㊀㊀㊀衣婷婷ꎬ等:外源钙与丛枝菌根真菌协同对连作花生产量和品质的影响[Ｊ].植物营养与肥料学报ꎬ２０１９ꎬ２５(１１):１９８９－１９９７. [２４]ＨｉｎｓｉｎｇｅｒＰꎬＰｌａｓｓａｒｄＣꎬＪａｉｌｌａｒｄＢ.Ｒｈｉｚｏｓｐｈｅｒｅ:Ａｎｅｗｆｒｏｎ￣ｔｉｅｒｆｏｒｓｏｉｌｂｉｏｇｅｏｃｈｅｍｉｓｔｒｙ[Ｊ].Ｃｈｅｍｉｎｆｏｒｍꎬ２００６ꎬ８８(１):２１０－２１３.[２５]ＳｃｈｅｌｏｓｋｅＳꎬＭａｅｔｚＭꎬＳｃｈｎｅｉｄｅｒＴꎬｅｔａｌ.ＥｌｅｍｅｎｔｄｉｓｔｒｉｂｕｔｉｏｎｉｎｍｙｃｏｒｒｈｉｚａｌａｎｄｎｏｎｍｙｃｏｒｒｈｉｚａｌｒｏｏｔｓｏｆｔｈｅｈａｌｏｐｈｙｔｅＡｓｔｅｒｔｒｉｐｏｌｉｕｍｄｅｔｅｒｍｉｎｅｄｂｙｐｒｏｔｏｎｉｎｄｕｃｅｄＸ￣ｒａｙｅｍｉｓｓｉｏｎ[Ｊ].Ｐｒｏｔｏｐｌａｓｍａꎬ２００４ꎬ２２３:１８３－１８９.[２６]ＫａｌｄｏｒｆＭꎬＫｕｈｎＡＪꎬＳｃｈｒöｄｅｒＷＨꎬｅｔａｌ.Ｓｅｌｅｃｔｉｖｅｅｌｅｍｅｎｔｄｅｐｏｓｉｔｓｉｎｍａｉｚｅｃｏｌｏｎｉｚｅｄｂｙａｈｅａｖｙｍｅｔａｌｔｏｌｅｒａｎｃｅｃｏｎｆｅｒ￣ｒｉｎｇａｒｂｕｓｃｕｌａｒｍｙｃｏｒｒｈｉｚａｌｆｕｎｇｕｓ[Ｊ].ＪｏｕｒｎａｌｏｆＰｌａｎｔＰｈｙｓｉ￣ｏｌｏｇｙꎬ１９９９ꎬ１５４(５/６):７１８－７２８.[２７]ＢａｓｌａｍＭꎬＧａｒｍｅｎｄｉａＩꎬＧｏｉｃｏｅｃｈｅａＮ.Ｔｈｅａｒｂｕｓｃｕｌａｒｍｙｃｏｒ￣ｒｈｉｚａｌｓｙｍｂｉｏｓｉｓｃａｎｏｖｅｒｃｏｍｅｒｅｄｕｃｔｉｏｎｓｉｎｙｉｅｌｄａｎｄｎｕｔｒｉｔｉｏｎ￣ａｌｑｕａｌｉｔｙｉｎｇｒｅｅｎｈｏｕｓｅ￣ｌｅｔｔｕｃｅｓｃｕｌｔｉｖａｔｅｄａｔｉｎａｐｐｒｏｐｒｉａｔｅｇｒｏｗｉｎｇｓｅａｓｏｎｓ[Ｊ].ＳｃｉｅｎｔｉａＨｏｒｔｉｃｕｌｔｕｒａｅꎬ２０１３ꎬ１６４:１４５－１５４.[２８]ＯｌｉｖｅｉｒａＲＳꎬＲｏｃｈａＩꎬＭａＹꎬｅｔａｌ.Ｓｅｅｄｃｏａｔｉｎｇｗｉｔｈａｒｂｕｓ￣ｃｕｌａｒｍｙｃｏｒｒｈｉｚａｌｆｕｎｇｉａｓａｎｅｃｏｔｅｃｈｎｏｌｏｇｉｃａｌａｐｐｒｏａｃｈｆｏｒｓｕｓ￣ｔａｉｎａｂｌｅａｇｒｉｃｕｌｔｕｒａｌｐｒｏｄｕｃｔｉｏｎｏｆｃｏｍｍｏｎｗｈｅａｔ(ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｍＬ.)[Ｊ].ＪｏｕｒｎａｌｏｆＴｏｘｉｃｏｌｌｏｇｙａｎｄＥｎｖｉｒｏｎｍｅｎｔａｌＨｅａｌｔｈ(ＰａｒｔＡ)ꎬ２０１６ꎬ７９(７):３２９－３３７.[２９]宋勇春ꎬ冯固ꎬ李晓林.接种不同ＶＡ菌根真菌对红三叶草利用不同磷源的影响[Ｊ].生态学报ꎬ２００１ꎬ２１(９):１５０６－１５１１.[３０]ＰｉｍｐｒｉｋａｒＰꎬＣａｒｂｏｎｎｅｌＳꎬＰａｒｉｅｓＭꎬｅｔａｌ.ＡＣＣａＭＫ￣ＣＹ￣ＣＬＯＰＳ￣ＤＥＬＬＡｃｏｍｐｌｅｘａｃｔｉｖａｔｅｓｔｒａｎｓｃｒｉｐｔｉｏｎｏｆＲＡＭ１ｔｏｒｅｇ￣ｕｌａｔｅａｒｂｕｓｃｕｌｅｂｒａｎｃｈｉｎｇ[Ｊ].ＣｕｒｒｅｎｔＢｉｏｌｏｇｙꎬ２０１６ꎬ２６(８):９８７－９９８.[３１]ＳｂｒａｎａＣꎬＡｖｉｏＬꎬＧｉｏｖａｎｎｅｔｔｉＭ.Ｂｅｎｅｆｉｃｉａｌｍｙｃｏｒｒｈｉｚａｌｓｙｍ￣ｂｉｏｎｔｓａｆｆｅｃｔｉｎｇｔｈｅｐｒｏｄｕｃｔｉｏｎｏｆｈｅａｌｔｈ￣ｐｒｏｍｏｔｉｎｇｐｈｙｔｏｃｈｅｍｉ￣ｃａｌｓ[Ｊ].Ｅｌｅｃｔｒｏｐｈｏｒｅｓｉｓꎬ２０１４ꎬ３５(１１):１５３５－１５４６.０５１㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀山东农业科学㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀第５５卷㊀。

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冰霜傀儡狩猎刀透明的瓶子体力药水
火焰傀儡大容量的瓶子纯净水体力药水
剧毒傀儡煮药的罐子干净的雨水体力药水

Image Registration fot remote sensing

Spatial and Spectral Characteristics of Some Operational Sensors (Ch. 14-22
What is Image Registration …
• Definition
“Exact pixel-to-pixel matching of two different images or matching of one image to a map”
Misregistration
• (Towsnhend et al, 1992) and (Dai & Khorram, 1998): small error in registration may have a large impact on global change measurements accuracy • e.g., 1 pixel misregistration error => 50% error in Vegetation Index (NDVI) computation (using 250m MODIS data)
Experiments … Datasets (1) • Synthetic Data Experiments
Experiments (1) … Analysis Samples • Various Features; Convergence as a function of noise and radiometric variations
Image Registration for Remote Sensing
Jacqueline Le Moigne Nathan S. Netanyahu Roger D. Eastman

2025高考英语步步高大一轮复习讲义人教版选择性必修第二册 Unit 3 Food and 含答案

2025高考英语步步高大一轮复习讲义人教版选择性必修第二册Unit 3Food and Culture含答案Ⅰ.阅读单词——会意1．cuisine n．菜肴；风味；烹饪2．pepper n．甜椒；灯笼椒；胡椒粉3．recipe n．烹饪法；食谱4．chef n．厨师；主厨5．peppercorn n．胡椒粒6．vinegar n．醋7．onion n．洋葱；葱头8．lamb n．羊羔肉；羔羊9．lamb kebab烤羊肉串10．dim sum n．点心(中国食品)11．vegetarian n．素食者12．junk n．无用的东西13．junk food(＝junk)垃圾食品14．garlic n．蒜15．bacon n．熏猪肉；咸肉16．ham n．火腿17．sausage n．香肠；腊肠18．cabbage n．甘蓝；卷心菜；洋白菜19．bean curd n．(＝tofu)豆腐20．brand n．品牌21．olive n．油橄榄；橄榄树22．fig n．无花果23．ingredient n．(尤指烹饪)材料；成分24．dough n．生面团25．haggis n．(苏格兰)羊杂碎肚26．cafeteria n．自助餐厅；自助食堂27．bun n．圆面包；小圆甜饼28．chilli n．(NAmE＝chili)[pl.-es]辣椒29．pork n．猪肉30．red braised pork红烧肉31．pearl n．珍珠32．vitamin n．维生素33．dairy adj.奶制的；乳品(业)的n．乳制品；乳品店；牛奶厂34．moderation n．适度；合理35．chew v i.& v t.咀嚼；嚼碎n．咀嚼Ⅱ.重点单词——记形1．bold adj.大胆自信的；敢于冒险的2．stuff v t.填满；把……塞进n．东西；物品3．slice n．(切下的食物)薄片v t.把……切成薄片4．elegant adj.精美的；讲究的；文雅的5．exceptional adj.特别的；罕见的；杰出的6．minimum adj.最低(限度)的；最小的n．最小值；最少量7．temper n．脾气；火气8．dessert n．(饭后)甜点9．canteen n．食堂；餐厅10．somewhat ad v.有点；稍微11．madam n．夫人；女士12．calorie n．卡路里(热量单位)13．regardless ad v.不顾；不加理会14．category n．类别；种类15．fibre(especially US fiber)n.纤维；纤维制品16．quantity n．数量；数额17．ideal adj.完美的；理想的；想象的n．理想；完美的人(或事物) 18．fundamental adj.根本的；基础的；基本的n．基本规律；根本法则19．modest adj.些许的；谦虚的；朴素的20．overall ad v.总体上；大致上adj.全面的；综合的Ⅲ.拓展单词——悉变1．prior adj.先前的；优先的→priority n．优先事项；优先权2．consist v i.由……组成(或构成)；在于→consistent adj.一致的；连续的3．consume v t.吃；喝；饮；消耗→consumer n．消费者；用户；客户→consumption n．消费；消耗(量)4．stable adj.稳定的；稳重的→stability n．稳定(性)；稳固(性)5．association n．协会；关联→associate v t.联想；联系v i.交往adj.副的；联合的→associated adj.有关联的；相关的6．trick n．诀窍；计谋；把戏v t.欺骗→tricky adj.棘手的；难对付的1．solidarity /ˌsɒl I'dærəti/n．团结；相互支持2．be glued to全神贯注看着某物；像用胶固定3．overlook /ˌəʊvə'lʊk/v t.忽略；未注意到；俯视4．worship /'wɜːʃI p/v i.& v t.信奉(神)；崇拜；敬仰5．evolve /i'vɒlv/v i.& v t.逐步形成；进化6．renowned /r I'naʊnd/adj.有声望的；著名的7．solo /'səʊləʊ/adj.独自的；单独的8．merge /mɜːdʒ/v i.& v t.融合；合并9．accumulate /ə'kjuːmjəle I t/v t.& v i.积累；积聚10．pave /pe I v/v t.铺路；(用砖石)铺(地)pave the way to为……铺平道路，创造条件Ⅳ.背核心短语1．prior to在……之前的2．consist of由……组成(或构成)3．slice...off切下4．regardless of不管；不顾5．relate...to...把……与……联系起来6．in many ways在许多方面7．on the other hand另一方面8．make up组成；构成；化妆9．in other words换言之10．be up to sb 由某人决定Ⅴ.悟经典句式1．Prior to coming to China，my only experience with Chinese cooking was in America，with Chinese food that had been changed to suit American tastes.(had been done)来中国之前，我只在美国接触过中式烹饪，那里的中国食物已被改变，以适应美国人的口味。

d2常见缩写

LZ-----------楼主
JR-----------贱人,奸人, 一般指BBS上的好人,名人, 禁止对MM使用
B4-----------鄙视
LJ------------垃圾
JP------------极品
JS------------奸商
QR-----------穷人
TH-----------土豪,有很多好装备的人
atk : attack 攻击，有时也指攻击力
asn/ass : Assassin 刺客
au : Angel Union 天使联盟(战队)
a(X) : Act(X) 第X关
B----------------------------------------
b : baal, act5 boss
FCR——Fast cast rate 快速施法率
（加快施法速度,用以计算魔法型角色释放魔法的速度,fcr越高,释放魔法速度越快）
Fr/w——Fast run/walk 快速奔跑/行走
FHR——Fast hit recover 快速打击恢复
（快速打击恢复, 人物在受到攻击时,当怪物造成的伤害比较大时,可能会出现一个向后仰的动作。要从这个动作中恢复过来,需要一定的时间,这个时间就由fhr的值决定, fhr越高,恢复越快）
剑类的缩写。
DOOM--冠军之剑，暗金剑。
GF--祖父，最好的暗金剑。
CCB，CCBQ--兰色的剑，这个我就不详细说了，反正最好的剑就是极品CCBQ。
其他的WT--一种MF（寻宝）的鞋子，50%就是极品。
TITAN--太坦，亚麻逊杀牛用的标枪。
GAZE--物免头盔。
WM--一般就是代表物免的意思，比如说WMJ，就是物免甲的意思。

花生(peanut)分析

（2）分枝
➢ 种子发芽出土后3～5天，主茎上有一片真叶展开时，着生在两片子叶叶腋内的两个侧芽发育，长成第一、第二两条呈对生状态的分枝，称为第一对侧枝。
➢ 当出苗后15～20天，主茎第5、6片真叶展开时，从第1、 2片真叶叶腋里分别长出第3、4条分枝，由于主茎第1、 2片真叶互生,节很短，第3、4条分枝分化后就象对生的一样，因此习惯称为第二对侧枝。
1）氧气：根瘤菌为好氧性细菌，因此需结构疏松的土壤，深耕整地、中耕松土。
2）温度：18-28℃。 3）水分：60%。 4）PH：5.5-7.2。 5）营养元素：根瘤生长和固氮需多种元素。N过多，尤
其硝态N过多，对根瘤固氮有抑制作用，但在花生生长初期，适量供N肥，可促进幼苗生长健壮，对后期固氮有促进作用。
连续开花型
交替开花型
（三）花生亚种和变种的生物学特点
1．亚种间的差异
➢➢ 分生枝理性特性密：枝交亚替种开二花级亚枝种多品，种能的发成生熟三种级子以休上眠分性枝较，强单；株连分续枝开数花量亚较种多的，种疏子枝休亚眠种期二很级短分或枝无数；少交，替一开般花无亚三种对级结枝果，层单土株壤分缺枝钙数和量干较旱少敏。感，易出现缺钙症状，而连续
出苗—始花20—25天, 始花—终花50—60天； • 普通型中熟品种花期较长，出苗—始花25—30天，始花—终花80—90天。
2、果针
①果针的形成和伸长受精后，子房基部的一部分细胞开始分裂、伸长，大约
在开花后4—6天，即形成明显可见的子房柄。子房柄连同位于其先端的子房合称果针。
② 特性
单产：
美国平均约3000 kg／hm2居第 1位，中国平均约 2380kg/hm2，居第2位，阿根廷 2350kg／hm2，居第3位。

花生(peanut)课件

用途
花生主要用于榨取花生油，同时也是食品、饲料和工业原料。
花生生长环境
土壤
花生适应多种土壤类型，但以排水良好、富含有机质的砂质壤土
为佳。
气候
花生喜温暖湿润的气候，生长适宜温度为25-30℃，需水量较大。
地区
花生主要生长在中国、印度、美国和其他一些热带和亚热带地区。
花生种植历史
起源
花生起源于南美洲的秘鲁和智利沿海地区。
取出轻轻一搓，花生皮即可脱落。
热水去皮法
02
将花生放入开水中浸泡约2分钟，然后迅速捞出放入冷水中，待
冷却后用手搓掉花生皮。
烤箱去皮法
03
将花生放入预热至200度的烤箱中烤5-10分钟，取出后趁热用
手搓掉花生皮。
花生过敏怎么办？
避免接触过敏源
对于已知对花生过敏的人，应避免食用花生及其制品，同时也要注意避免接触含有花生成分的食品和化妆品。
制作花生酱和糖果
总结词：风味独特
详细描述：将花生制作成花生酱或糖果，可以增添独特的口感和风味。花生酱可以用于烘焙或作为调味品，而花生糖果则是甜点或零食的不错选择。
04
CATALOGUE
花生健康益处
控制体重
花生中的蛋白质和纤维有助于增加饱腹感，减少过度饮食和暴饮
暴食的情况。
适量食用花生可以作为健康零食选择，满足口腹之欲的同时控制
03
CATALOGUE
花生食用方法
生吃
总结词：原味享受
详细描述：直接食用花生，可以品尝到其原汁原味的口感和香味，是较为常见的食用方法。
煮食
总结词：营养丰富
详细描述：将花生煮至软糯，可以更好地保留其营养成分，同时口感更加细腻。可以加入粥或炖汤中一同食用。

alphafold2算法

alphafold2算法
AlphaFold2是DeepMind开发的一种深度学习算法，用于预测蛋白质的三维结构。

蛋白质的结构对于理解其功能和作用机制至关重要，但通过实验方法确定蛋白质结构的成本和时间非常高昂。

AlphaFold2利用神经网络和深度学习技术，通过分析蛋白质的序列信息来预测其三维结构。

AlphaFold2的算法基于残基-残基接触预测和立体构象采样。

它首先使用一个类似于Transformer的深度学习网络，通过分析蛋白质的氨基酸序列，预测残基之间的接触概率。

然后，基于这些接触概率，使用一种Monte Carlo搜索算法来寻找最可能的蛋白质结构。

最后，通过使用经验能量函数来对结构进行优化和评估，以得到更准确的结构预测结果。

AlphaFold2在2020年进行的CASP（Critical Assessment of Structure Prediction）比赛中取得了惊人的成绩，准确预测了大量蛋白质结构，赢得了比赛。

其结构预测的准确性和速度使其成为一个非常有前景的工具，有助于加速蛋白质研究和药物设计等领域的进展。

尽管AlphaFold2的性能和成果非常令人印象深刻，但它仍然是一个预测算法，预测结果可能存在一定的误差。

因此，在实际应用中，仍需要结合实验数据和其他验证方法来进行验证和确认。

人教版高一生物必修二第一章第一节孟德尔的豌豆杂交试验(一) 课件

A.光桃
B.毛桃
C.光桃的概率为1/3 D.毛桃的概率为1/3
1.桃果实表面光滑对有毛为显性，现对毛桃的雌蕊授
以纯合光桃的花粉，该雌蕊发育成的果实应是 ( B )
A.光桃
B.毛桃
C.光桃的概率为1/3 D.毛桃的概率为1/3
2.将上题中发育成的果实中的种子取出，将其种下，
等它长大、雌蕊成熟后又授以纯合毛桃花粉，则这次
【花粉=植物的雄配子，相当于人类的精子。这个实验属于直接证明分离定律，叫做花粉鉴定法】；
练习4：能巧识陷阱
取纯种高茎豌豆与纯种矮茎豌豆杂交，所得F1让它自交得到F2，从F2中取出高茎后代，去与矮茎豌豆杂交，理论上讲，它们的后代中矮茎豌豆将占多少比例？
____1_/_3____
练习5：学会化繁为简(导学案P5上面第3题)
演绎推理
实验结果与推理结果相符实验检验实验结果与推理结果不相符
得出结论
七、区分概念(导学案P4表格)
(1)杂交: 基因型不同的个体之间交配(如AA×Aa)
(2)自交: 基因型相同的个体之间交配(如Aa×Aa)
(3)测交: (显性)待测个体与隐性纯合子交配 (如D_×dd,常用于检测待测个体是否纯合)
二、豌豆是严格的自花传粉，自然情况下根本不可能跟其他豌豆杂交，孟德尔是怎么做到的?
去雄套袋传粉套袋
三、一对相对性状的杂交实验
符号 P F1 F2 × ×○ ♀ 含义亲本子一代子二代杂交自交母本父本
性状分离：高茎 →○× 高茎、矮茎白猫× 白猫→白猫、黑猫、黄猫
四、对分离现象的解释:
)2]aa
Fn 杂合子纯合子显性纯合子隐性纯合子显性性状个体隐性性状个体

QuantaPhi-2 PLQY 积分球体商品说明书

/quantaphi-2QuantaPhi-2PLQY Integrating SphereThis sample tray accessory includes an all-reflectivesphere into which a sample is placed. The measurementof the sample, and of a non-fluorescent blank, allows forthe direct measurement of the quantum yield of a solid,powder or solution sample.Combined with our highest sensitivity and flexiblespectrofluorometers, and their simple-to-use, dedicatedQY and colorimetry software, the QuantaPhi-2 provides ahigh quality, simple and absolute PLQY solution.The quantum yield of a molecule or material is defined asthe number of photons emitted as a fraction of the numberof photons absorbed. This characteristic property of afluorophore or fluorescent molecule, is very important forunderstanding molecular behavior and optimization formany key materials.QuantaPhi-2 Integrating Sphereshown with top mounting cuvette holder3 Materials and Applications for which PLQY are Important Parameters• Photovoltaics (PV) and solar cells• Novel nanomaterials• Nanoparticles• Quantum dots• Graphene/single walled carbon nanotubes• New fluorescent probes• Biomarkers and biosensors• Lighting and display materials (OLED, LED and phosphors)• Thin films and coatings• Light emitting devices• Cured/doped polymers, gels, hydrogels• Paints, coatings,• Rare earth materialsA Better PLQY DesignQuantaPhi-2 features a large, 121 mm internaldiameter Spectralon® integrating sphere with excellentreflectivity from 250 to 2500 nm. This is an internal slide-in, tray-mountedintegrating sphere with two excitation, and two emission ports.Each port has a Spectralon plug with sphere-matching curvature for when openings are not in use.The QuantaPhi-2 features a unique bottom loading sample tray for solids or powders, ensuringthat any sample spills are limited to the small, replaceable Spectralon cup.The sample cup is 1 cm in diameter and 3 mm in depth, with a quartz coverslip for powdercontainment. This bottom loading tray can save a tremendous amount of time and money, asthe prevention of sphere contamination is the number one priority when using an integrating sphere.The QuantaPhi-2 also includes a center-mounted 10 mm cuvette sample holder for PLQY studiesof samples in solution.Upconversion PLQY andLaser-excited PLQYThis PLQY sample tray accessory also allows for direct mounting ofDPSS lasers on the front of the sample tray for upconversion PLQY orlaser-excited PLQY. Contact HORIBA for a list of available DPSS lasers.QuantaPhi-2 shown withbottom loading sample trayfor powders and solidsReplacementSpectralon samplecup and coverslipCuvette Holder980 nm DPSS laser mounted to the front ofthe Fluorolog-QM PLQY sample trayCharacterize Light-emitting Devices Electroluminescent quantum yield (ELQY) measurements of light-emitting devices, such as LEDs, OLEDs, and other luminescent sources, are fully accommodated by the QuantaPhi-2. Electrical connections to the device are facilitated by a dedicated wiring port in the bottom loading drawer, allowing a customer to feed wires to their custom modified sample cup holder. Shown below are the CIE values and total luminous intensity plots of asimple LED measured using the QuantaPhi-2.HORIBA FluorEssence software interface for the Fluoromax and Nanolog spectrofluorometers.Software That Makes PLQY Simple and AccurateThe QuantaPhi-2 integrating sphere accessory is compatible with a number of HORIBA fluorescence spectrometers, and all of these systems have a PLQY App, that simplifies the process of acquiring an accurateQY value for an unknown sample.FelixFL software on the Fluorolog-QM modular researchspectrofluorometer incorporates a quantum yield calculator which, when coupled with an integrating sphere, allows you to calculate the quantum yield with ease.QuantaPhi-2 Hardware SpecificationsQuantaPhi-2 Performance Specifications* Spectralon is a registered trademark of Labsphere, Inc.*******************/quantaphi-2USA: +1 732 494 8660 France: +33 (0)1 69 74 72 00 Germany: +49 (0) 6251 8475 0UK: +44 (0)1604 542 500 Italy: +39 06 51 59 22 1 Japan: +81(75)313-8121 China: +86 (0)21 6289 6060 India: +91 80 41273637 S i ngapore: +65 (0)6 745 8300Taiwan: +886 3 5600606Brazil: +55 (0)11 2923 5400 Other: +33 (0)1 69 74 72 00。

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