Measurement of Neutral and Charged Current Cross Sections in Electron-Proton Collisions

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SECONDARY ION MASS SPECTROMETRY (SIMS)

SECONDARY ION MASS SPECTROMETRY (SIMS)BackgroundThe origins of SIMS may be traced all the way back to the discovery of secondary particle emission by J.J. Thomson in 1910. Subsequently, Arnot and Milligan studied secondary ion emission under positive ion bombardment and Woodcork observed the first known negative ion spectrum from NaF and CaF 2 in 1931. However, the development of modern SIMS instrumentation suitable for analysis purposes was largely through the efforts of Herzog and Viehböck from 1949. In fact, Herzog and his co-workers built the first commercial SIMS instrument under a NASA contract to study the extraterrestrial material brought back to earth from early space exploration. Since then, SIMS has played an important role in the characterization and analysis of semiconductor materials.Principle of the TechniqueSecondary ion mass spectrometry (SIMS) is a surface analysis technique which basically involves the mass spectrometry of secondary ions. Bombardment of a sample surface by an energetic primary ion beam (~1 – 20 keV) leads to the emission of both neutral and charged particles. The emitted secondary ions are extracted via an electrical potential and analyzed using a mass spectrometer. Ion Beam SputteringInteraction of the primary beam with the sample results in the ejection of secondary ions and neutrals, including molecular fragments and clusters. Ion beam induced atomic mixing as well as implantation of the primary ions giveSample Implanted Primary ion beamInstrumentationPrimary SourcesPrimary sources can be reactive or inert. Reactive sources like oxygen and caesium are used to enhance positive and negative secondary ion yields respectively, while inert sources like argon are produced with electron impact sources. Liquid metal ion guns like gallium produce the smallest primary beam spot size and the best lateral imaging resolution.Mass AnalyzersThe three main types of mass analyzers are quadrupole, double focusing magnetic sector and time-of-flight. Each has its own advantages and disadvantages in terms of cost, switching speed, mass resolution, transmission efficiency and mass range detectable.DetectorsElectron multipliers or Faraday cup detectors are commonly used. Dual-channel plates or resistive anodes are used for image detection.SpecificationsSIMS can detect all elements from H through U with a detection sensitivity of ppm (parts per million) or even ppb (parts per billion) level. It can also distinguish between isotopes of the same element. Detection limits vary with both element and instrumental parameters and can range from 1013 at/cm 3Primaryoptics Double Focusing MagneticSector Mass SpectrometerSchematic of a Double Focusing Magnetic Sector SIMS Instrumentto 1017 at/cm3 for common impurities in semiconductors. A typical depthresolution of ~ 10 nm is achievable for routine samples. Some insulatorsmay be analyzed with the use of electron charge compensation. An approximate quantification of the elemental composition can be achievedusing standard reference materials and relative sensitivity factors (RSFs).Disadvantages•Mass interferences are often present•Secondary ion yields are often highly dependent on the matrix •Secondary ion yields vary by more than six orders of magnitude across the elements•Destructive•Well-characterized reference standards that are as close as possible to the matrix of the samples of interest are needed for quantification •Element of interest should be in the dilute concentration regime (<1%) to exclude matrix effectsPoints to Note•Sample must be compatible with ultra-high vacuum•Samples must generally be flat for magnetic sector instruments •Presence of surface transients requires caution when quantifying top ~50 nm of surface•Surface roughness effects•Sputter-induced atomic mixing and topography can degrade depth resolution•Quantification from multilayer structures is complex, as ion yields vary from matrix to matrix and also at the interface between layersOperation ModesAlthough mass spectra and ion images are achievable, depth profiles are by far the most common application of dynamic SIMS.ApplicationsSIMS is widely used for ion implant characterization, thin film analysis and trace contamination analysis in microelectronics industries. It is a major analytical tool in the areas of quality control, failure analysis and process development. The instrument at IME, the CAMECA IMS 6f, is a magnetic sector SIMS with high mass resolution and is optimized for obtaining dopant depth profiles in semiconductors with excellent dynamic range.ExamplesFigure 1: B-implanted waferFigure 2: Trace metal contamination in SiO2Figure 3: Depth profile of multilayer SiGe/SiC sampleFigure 1: Depth profile of a boron implantFigure 2: Trace metal contamination in SiO2Figure 3: Depth profile of a SiGe/Si1-x C x multilayer film stack。

抗病毒药物达菲

Aquatic Toxicology 96 (2010) 194–202Contents lists available at ScienceDirectAquaticToxicologyj 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 /a q u a t oxMixture toxicity of the antiviral drug Tamiﬂu ®(oseltamivir ethylester)and its active metabolite oseltamivir acidBeate I.Escher a ,b ,∗,Nadine Bramaz b ,Judit Lienert b ,Judith Neuwoehner b ,Jürg Oliver Straub caThe University of Queensland,National Research Centre for Environmental Toxicology (Entox),39Kessels Rd,Brisbane,Qld 4108,Australia bEawag,Swiss Federal Institute of Aquatic Science and Technology,8600Dübendorf,Switzerland cF.Hoffmann-La Roche Ltd,Corporate Safety,Health and Environmental Protection,4070Basel,Switzerlanda r t i c l e i n f o Article history:Received 29August 2009Received in revised form 20October 2009Accepted 23October 2009Keywords:Environmental risk assessment Pharmaceuticals AlgaeMetabolite Mixture Tamiﬂu ®a b s t r a c tTamiﬂu ®(oseltamivir ethylester)is an antiviral agent for the treatment of inﬂuenza A and B.The pro-drug Tamiﬂu ®is converted in the human body to the pharmacologically active metabolite,oseltamivir acid,with a yield of 75%.Oseltamivir acid is indirectly photodegradable and slowly biodegradable in sewage works and sediment/water systems.A previous environmental risk assessment has concluded that there is no bioaccumulation potential of either of the compounds.However,little was known about the ecotoxicity of the metabolite.Ester hydrolysis typically reduces the hydrophobicity and thus the toxicity of a compound.In this case,a zwitterionic,but overall neutral species is formed from the charged parent compound.If the speciation and predicted partitioning into biological membranes is considered,the metabolite may have a relevant contribution to the overall toxicity.These theoretical considerations triggered a study to investigate the toxicity of oseltamivir acid (OA),alone and in binary mixtures with its parent compound oseltamivir ethylester (OE).OE and OA were found to be baseline toxicants in the bioluminescence inhibition test with Vibrio ﬁscheri .Their mixture effect lay between predictions for concentration addition and independent action for the mixture ratio excreted in urine and nine additional mixture ratios of OE and OA.In contrast,OE was an order of magnitude more toxic than OA towards algae,with a more pronounced effect when the direct inhibition of photosystem II was used as toxicity endpoint opposed to the 24h growth rate endpoint.The binary mixtures in this assay yielded experimental mixture effects that agreed with predictions for independent action.This is consistent with the ﬁnding that OE exhibits slightly enhanced toxicity,while OA acts as baseline toxicant.Therefore,with respect to mixture classiﬁcation,the two compounds can be considered as acting according to different modes of toxic action,although there are indications that the difference is a toxicokinetic effect,not a true difference of mechanism of toxicity.The general mixture results illustrate the need to consider the role of metabolites in the risk assessment of pharmaceuticals.However,in the concentration ratio of parent to metabolite excreted by humans,the experimental results conﬁrm that the active metabolite does not signiﬁcantly contribute to the risk quotient of the mixture.© 2009 Elsevier B.V. All rights reserved.1.IntroductionOseltamivir ethylester phosphate is used under the trade name of Tamiﬂu ®as an antiviral agent for the treatment and prophylaxis of inﬂuenza A and B.Its mechanism of action is related to the inhi-bition of the inﬂuenza virus neuraminidase (Roche,2006).With the appearance of the bird ﬂu in humans in 2007,and the H1N1pan-demic in 2009,the sales and use of this compound have increased tremendously.Most countries also keep a stock of Tamiﬂu ®to treat∗Corresponding author at:The University of Queensland,National Research Centre for Environmental Toxicology (Entox),39Kessels Rd,Brisbane,Qld 4108,Australia.Tel.:+61732749180;fax:+61732749003.E-mail address:b.escher@.au (B.I.Escher).up to 50%of their population in case of an emergency (Singer et al.,2008).In June 2006,a new “Guideline on the Environmental Risk Assessment of Medicinal Products for Human Use”(EMEA,2006)was released in the European Union,which requires an environmental risk assessment for all marketing authorization applications.It is also of interest to investigate whether compounds that are already on the market pose a hazard to the environ-ment,particularly those with growing market shares like Tamiﬂu ®.A large number of different pharmaceuticals have been detected in surface waters (Ternes,1998;Kolpin et al.,2002).The parent compound of Tamiﬂu ®has not been detected in surface waters yet.However,its active metabolite oseltamivir acid (also called oseltamivir carboxylate)was detected in low ng/L concentrations during the ﬂu season in Japan (Ghosh et al.,2009;Söederströem0166-445X/$–see front matter © 2009 Elsevier B.V. All rights reserved.doi:10.1016/j.aquatox.2009.10.020B.I.Escher et al./Aquatic Toxicology96 (2010) 194–202195et al.,2009).Oseltamivir acid is relatively persistent,showing only indirect photodegradation(Bartels and von Tumpling,2008),slow degradation in surface waters,but increased(microbial)degrada-tion in sediment/water systems(Accinelli et al.,2007;Sacca et al., 2009).Tamiﬂu®manufacturer Roche performed a prospective environ-mental risk assessment according to the EMEA guideline with a few modiﬁcations to account for pandemic use conditions(Straub, 2009).This study concluded that Tamiﬂu®does not pose an envi-ronmental risk.The risk quotient remains below one even under inﬂuenza pandemic conditions,despite very high predicted envi-ronmental concentrations in surface waters,due to its relatively low aquatic ecotoxicity(Straub,2009).Hutchinson et al.(2009) complemented this study by assessing the risk and PBT characteris-tics of oseltamivir acid for the marine environment according to the Technical Guidance document of the EU(European Commission, 2003).They found no environmental risk for the use of Tamiﬂu®in a pandemic situation.According to the EMEA guideline,risk assessment needs to be performed not only on the parent compound but also on the human metabolites,provided they exceed10%of the parent or the parent is a pro-drug(EMEA,2006).Oseltamivir ethylester(OE)is a pro-drug that lacks antiviral activity(Goodman and Gilman,2006).Approx-imately80%of OE is bioavailable after oral administration(He et al.,1999).OE is hydrolyzed by esterases in the liver to oseltamivir acid(OA)under the release of ethanol with a yield of75%and is the active antiviral agent(DrugBank,2006;Goodman and Gilman, 2006;Roche,2006;Straub,2009).No further metabolism occurs and elimination is primarily via urine with60–70%of an oral dose appearing in the urine as the active metabolite(He et al.,1999).The environmental risk assessment of Tamiﬂu®accounted for the metabolite formation by performing toxicity tests both with OE and with a mixture of OE and OA in the ratio of1:4,which cor-responds to the ratio excreted in urine(Straub,2009).The chronic toxicity assays with algae,daphnia andﬁsh performed with this mixture resulted in“No Observed Effect Concentrations”(NOEC) of10,>1,and>1mg/L,respectively(Straub,2009).The PNEC(pre-dicted no effect concentration)of0.1mg/L was derived from the ﬁsh early life stage test with Danio rerio using an assessment factor of10.Even for worst-case exposure under pandemic conditions, the risk analysis indicated no signiﬁcant risk to surface water or sewage works(Straub,2009).A more thorough investigation of the mixture toxicity of OE and OA would be helpful to support the conclusions of this environmen-tal risk assessment because the mixture expected to be excreted to wastewater was used in the risk assessment without resolving the constituents of the mixture.A predictive model of the mixture toxicity of pharmaceuticals and their transformation products had indicated that OA does not signiﬁcantly inﬂuence the overall toxic potential(Lienert et al.,2007).However,the newly published eco-toxicity data(Straub,2009)and a more thorough analysis as well as an improved prediction of the physicochemical parameters of OE and OA for the present study gave rise to the assumption that OA may contribute substantially to the overall mixture toxicity. Therefore it was the aim of this study to perform binary mix-ture experiments with OE and OA with a focus on learning more about their mixture effect and how a parent compound interacts in mixtures with its metabolite but also to substantiate the risk assessment of Tamiﬂu®.It is relatively laborious to perform systematic mixture toxic-ity experiments with chronic tests and given that the NOECs were relatively high,no clear answers would be expected.Mixture toxic-ity experiments were performed using an acute algal toxicity assay because algae proved to be a more sensitive aquatic species than daphnids orﬁsh(Straub,2009).The algal toxicity test was com-plemented by a non-speciﬁc standard bacterial toxicity screening assay,the bioluminescence inhibition test with the marine bac-terium Vibrioﬁscheri(Escher et al.,2008a),which yields information about baseline toxicity and the inhibition of energy transduction.A sound mixture toxicity analysis requires some information on the modes of toxic action of the mixture pounds that have the same target site and act according to the same mode of action are likely to follow the mixture toxicity concept of concentra-tion addition,while compounds that have different target sites act according to independent action(Altenburger et al.,2003).There-fore,prior to studying the mixtures,a mode of action analysis was performed with the single compounds to set up the appropriate hypotheses for the mixture toxicity experiments.The paper is concluded with considerations on the inclusion of metabolites into the risk assessment of pharmaceuticals highlight-ing the example of Tamiﬂu®and the results of the mixture study are related to the recently published environmental risk assessment for Tamiﬂu®(Straub,2009).2.Materials and methods2.1.ChemicalsOseltamivir ethylester phosphate(CAS204255–11–8for phos-phate salt,CAS196618–13–0for free base)and d-tartrate salt of oseltamivir carboxylate(CAS187227–45–8for the OA zwitterion) were kindly provided by F.Hoffmann-La Roche Ltd,Basel,Switzer-land.To avoid any ambiguity related to the molecular weight of the salt and the speciation in solution,all data are reported in molar units.For comparison with literature data,the molecular weights are410.4g/mol for OE phosphate salt and357g/mol for OA tartrate salt.For structures and physicochemical properties refer to Table1.2.2.Chemical analysisThe concentrations of OE in the bioassays were quantiﬁed with HPLC(Summit HPLC System;Dionex,Olten,Switzerland) and UV detection at220nm(UVD340-U,Dionex,Olten,Switzer-land).A reversed-phase C18column(125/4Nucleodur Gravity5m. Macherey-Nagel,Oensingen,Switzerland)was used for separation. The eluent was composed of buffer(10mM ortho-phosphoric acid at pH7)and acetonitrile(70:30).2.3.Bioluminescence inhibition in V.ﬁscheriThe30-min bioluminescence inhibition test with the marine bacterium V.ﬁscheri was used for assessing baseline toxicity and speciﬁc interference with the energy metabolism.It was performed according to ISO guideline11348–3(International Organization for Standardization,1998)with modiﬁcations as described in (Escher et al.,2005b)using freeze-dried bacteria(nge,Düs-seldorf,Germany).The mixture experiments were performed in96-well microtiter plate format after it was conﬁrmed that measured concentrations were equal to nominal concentrations (Escher et al.,2008a).The luminescence output of the bacteria was measured prior to addition of the sample and after30-min incubation(MicroLumatPlus,Berthold Technologies,Regensdorf, Switzerland).The inhibition of bioluminescence was calculated as described in ISO guideline11348–3.The effect concentrations EC50were derived from log-logistic concentration response curves (Escher et al.,2005a,2008b).Full concentration–effect curves were determined for all binary mixture ratios(exact ratios given in Table3).Mixture experiments were performed in a minimum of triplicates and alongside sin-gle compounds.The reported data relate to the bestﬁt of a single concentration–effect curve over all accumulated data(3–10repli-cates).196 B.I.Escher et al./Aquatic Toxicology96 (2010) 194–202Table1Structures and physicochemical properties of oseltamivir ethylester and its human metabolite oseltamivir acid.log K ow a log K lipw b p K a(base)c p K a(acid)c f neutral d log D lipw(pH7)e OE(Oseltamivir ethylester) 1.21 1.617.60–0.201 1.06OA(Oseltamivir acid)0.0060.527.81 3.780.8650.46a Octanol–water partition coefﬁcient,average of various QSARs as cited in Straub(2009).b Liposome–water partition coefﬁcient calculated with Eq.(1).c Acidity constant,estimated using SPARC(Hilal et al.,2005).d Fraction of neutral species at pH7(Schwarzenbach et al.,2003).e Liposome–water distribution ratio at pH7calculated with Eq.(2).2.4.Algal toxicityDirect and indirect effects on photosynthesis were evaluatedwith the24h chlorophyllﬂuorescence test with the green algaeDesmodesmus subspicatus using the chlorophyllﬂuorometer ToxY-PAM according to Escher et al.(2005a).Mixture experimentswere performed with Pseudokirchneriella subcapitata in96-wellmicrotiter plate format(Escher et al.,2008a)after conﬁrmationthat measured concentrations equaled nominal concentrations.Two different algal species were used to ensure consistency withthe baseline toxicity quantitative structure activity relationship(QSAR).Growth conditions were identical for each of the twostrains and both were used in the exponential growth phase.AMaxi-Imaging-PAM(IPAM)(Walz GmbH,Effeltrich,Germany)wasused to determine the yield of photosynthesis Y after2and24h,and optical density(Spectramax®Plus384,Molecular Devices Cor-poration,Sunnyvale,USA)was measured to derive the growthrate during24h.The EC50values for the inhibition of the photo-synthetic yield after2h(EC502h IPAM)or after24h(EC5024h IPAM)and the growth rate inhibition(EC5024h growth)were derived fromlog-logistic concentration–effect curves as described previously(Escher et al.,2008a).The mixture experiments were performedanalogously to those described above,however different concen-tration ratios were used(see Table5).2.5.Speciation and hydrophobicity indicatorsThe liposome–water distribution ratio at pH7,D lipw(pH7),is abetter descriptor for bioaccumulation and hydrophobicity of ioniz-able compounds than the commonly used octanol–water partitioncoefﬁcient K ow(Escher and Hermens,2002)and was therefore usedfor the QSARs.Speciation has to be accounted for when estimat-ing the liposome–water distribution(Schwarzenbach et al.,2003).The liposome–water partition coefﬁcient of the neutral speciesK lipw,neutral was calculated from the estimated octanol–water par-tition coefﬁcient log K ow with Eq.(1),which is valid for polarcompounds(Vaes et al.,1997;Escher et al.,2006).log K lipw,neutral=0.904log K ow+0.515(1)The corresponding K lipw,charged for charged species(charged=anionic or cationic)was assumed to be approximatelyone order of magnitude lower than that of the correspondingneutral species,i.e.log K lipw,charged=log K lipw,neutral−1(Escher andSigg,2004).The D lipw(pH7)was computed with Eq.(2),wheref neutral refers to the fraction of neutral species.log D lipw(pH7)=f neutral log K lipw,neutral+1−f neutral log K lipw,charged(2)2.6.Baseline toxicity versus speciﬁc mode of toxic actionThe toxic ratio TR(Eq.(3))is a measure of the speciﬁcity of amode of toxic action and is deﬁned as the quotient of the predictedbaseline effect concentration EC50baseline toxicity of a given com-pound to its experimentally determined EC50experimental(Verhaaret al.,1992).TR<10corresponds to baseline toxicity,and TR≥10to a speciﬁc mode of toxic action(Verhaar et al.,1992).The higherthe TR,the higher the intrinsic potency of a chemical,i.e.the morepronounced is a speciﬁc mode of toxic action.TR=EC50baseline toxicityEC50experimental(3)The EC50baseline toxicity values were predicted with QSARs takenfrom the literature(European Commission,2003;Escher et al.,2005a).Published QSARs are typically based on the K ow ashydrophobicity descriptor.As discussed above,the K ow is not a suit-able hydrophobicity descriptor for ionized species.However,wehave earlier demonstrated(Escher et al.,2002)that QSARs basedon the D lipw(pH7)are valid for the whole spectrum of neutral,pos-itively and negatively charged molecules,provided that the modeof toxic action is baseline toxicity.Therefore K ow-based literatureQSARs can be rescaled to the liposome–water distribution ratio ofall species at pH7,log D lipw(pH7),as the hydrophobicity descrip-tor by inserting equation1in each QSAR equation(Escher andSchwarzenbach,2002).The resulting QSARs based on log D lipw(pH7)as hydrophobicity descriptor are listed in Table2.The QSAR for the bioluminescence inhibition test in microtiterplate format was experimentally determined for a set of baselineB.I.Escher et al./Aquatic Toxicology96 (2010) 194–202197Table2Measured and modeled EC50values of the parent compound OE for various aquatic endpoints.Organism Endpoint EC50experimental(mM)QSAR equation EC50,parent,baseline QSAR(mM)TR eBacteria Vibroﬁscheri30-minbioluminescenceinhibition 10a log(1/EC50baseline toxicity(M))=0.7log D lipw(pH7)+1.54c4.50.4Algae Selenastrum capricornutum(exp.)or Chlorella vulgaris(QSAR)72h growthinhibition1.1b log(1/EC50baseline toxicity(M))=0.91log D lipw(pH7)+0.63d27.725Algae Desmodesmus subspicatu s PSII inhibition after24h 15.5a log(1/EC50baseline toxicity(M))=0.91log D lipw(pH7)+1.10c9.40.6Waterﬂea Daphnia magna48himmobilization 0.08b log(1/EC50baseline toxicity(M))=0.77log D lipw(pH7)+1.89d2.126Fish Cyprinus carpio(exp.)or Pimephales promelas(QSAR)96h lethality0.24b log(1/LC50baseline toxicity(M))=0.83log D lipw(pH7)+1.46d4.920a Data from this study,performed in vials with experimental veriﬁcation of exposure concentration by HPLC.b Data from Straub(2009).c QSAR from Escher et al.(2005a).d Baseline toxicity QSAR rescaled from K ow-based QSARs from the Technical Guidance Document(TGD)of the EU(European Commission,2003).e Toxic ratio(TR)calculated with Eq.(3).toxicants in ref.(Escher et al.,2008a)(Eq.(4)).log(1/EC50baseline toxicity,Vibrio fischeri(M))=0.84log D lipw(pH7)+1.69(4)The EC50baseline toxicity for the combined algae test is given in equa-tion5for the endpoint24h growth rate and in equation6for the endpoint24h IPAM(Escher et al.,2008a).log(1/EC50baseline toxicity,24h growth(M))=0.95log D lipw(pH7)+1.16(5) log(1/EC50baseline toxicity,24h IPAM(M))=0.84log D lipw(pH7)+1.07(6) 2.7.Mixture toxicity evaluationThe mixture experiments were evaluated with the isobolo-gram method described by Altenburger and Boedeker(1990).Here the experimental EC50value that refers to total molar concen-tration of both components of the binary mixture for a given mixture ratio was multiplied with the fraction of each mixture component.The two axes of the isobologram were constructed from EC50times fraction of OA and EC50times fraction of OE, respectively.The line connecting the two axis intercepts in this isobologram is then equivalent to the model of concentration addi-tion(Altenburger and Boedeker,1990).Although it is not common practice,it is also possible to plot the prediction for independent action into an isobologram,in order to differentiate between inde-pendent action and true antagonism.In this case,for each mixture ratio,a prediction of EC50was performed independently with the equations described in Backhaus et al.(2000).The fractions of OE and OA were multiplied with this predicted value and the result was plotted in the isobologram along with the experimental results.3.Results and discussion3.1.Toxicity of the parent compound OE in the bioluminescence inhibition test in V.ﬁscheriThe30-min EC50values in the30-min bioluminescence inhi-bition test with the marine bacterium V.ﬁscheri of the parent compound oseltamivir ethylester phosphate(OE)were10.5mM (95%conﬁdence interval:7.9–11.2mM)for the test performed according to ISO11348–3(Table2)and10.3mM(95%conﬁdence interval:9.9–10.7mM)using the microtiter plate format(Table3). These values correspond to an EC50value of4.3(4.0–4.6)g/L of OE.According to ISO11348–3,all tested concentrations were con-ﬁrmed by HPLC and refer to aqueous concentrations in the bioassay. The good agreement between the two test setups and between measured and nominal concentrations allowed us to perform all further metabolite and mixture experiments in the microtiter plate format reporting nominal concentrations.3.2.Toxicity of the parent compound OE in the algal toxicity testIn the chlorophyllﬂuorescence test with the green algae D. subspicatus,measuring photosynthesis inhibition after24h using the ToxY-PAM,the EC50was15.5mM(95%conﬁdence interval 14.9–16.2mM),which corresponds to6.4(6.1–6.7)g/L(Table2).P. subcapitata was more sensitive with an EC5024h growth of0.51mM (95%conﬁdence interval0.48–0.55mM)corresponding to210mg/L phosphate salt and an EC5024h IPAM of0.78mM(95%conﬁdence interval0.76–0.81mM)corresponding to319mg/L phosphate salt (Table4).These EC50values are very high,but consistent with the low hydrophobicity of the compound.The values are in the same range as the EC50growth of463mg/L(1.1mM)in the72h algal growth inhibition test with P.subcapitata(Straub,2009).3.3.Toxicity of the metabolite OAThe metabolite oseltamivir acid(OA)was almost equipotent to the parent oseltamivir ethylester phosphate(OE)with an EC50 of6.64mM(95%conﬁdence interval:6.55–6.70mM)for V.ﬁs-cheri,which corresponds to2.4g/L for the used tartrate salt of OA (Table3).In contrast,in the algal toxicity assay,the EC5024h growth of8.3(7.7–8.8)mM and the EC5024h IPAM of19.3(18.2–20.4)mM of OA are16and25times less toxic,respectively,than the corre-sponding EC50values for the parent OE(Table4).The slope of the concentration–effect curve of OA was much steeper than that of OE.The onset of toxicity for OE was relatively fast withﬁrst signs of photosynthesis inhibition after2h.In contrast,the metabolite OA showed<20%of PSII inhibition after2h exposure at concen-trations that lead to100%inhibition of photosynthesis and growth rate after24h(data not shown).This is an observation that could not be rationalized with any mechanistic explanation but will be relevant for the mixture toxicity experiments discussed below.198 B.I.Escher et al./Aquatic Toxicology 96 (2010) 194–202Table 3Descriptors of the log-logistic concentration–effect curves (Escher et al.,2005a )and toxic ratio (TR)analysis for the parent OE and the metabolite OA and their binary mixtures in the bioluminescence inhibition test with Vibrio ﬁscheri using the 96-well plate format.Mixture OE:OA OE fraction (%)log (1/EC50experimental (M))Slope of log-logistic ﬁt EC50experimental (mM)(95%conﬁdence intervals)log (1/EC50baseline )(M)a TR OE100% 1.99±0.01 2.2±0.110.3(10.1–10.5) 2.570.26Mixture 1:0.283% 1.94±0.01 2.5±0.211.6(11.2–12.0)Mixture 1:0.471% 1.91±0.01 3.7±0.312.3(11.9–12.7)Mixture 1:0.663% 1.90±0.01 6.3±0.712.5(12.2–12.8)Mixture 1:0.856% 1.93±0.018.3±1.011.9(11.7–12.1)Mixture 1:150% 1.94±0.01 6.9±0.511.5(11.4–11.6)Mixture 0.8:144% 2.00±0.017.4±0.910.1(9.9–10.3)Mixture 0.6:138% 2.02±0.019.1±1.39.5(9.3–9.7)Mixture 0.4:129% 2.04±0.01 4.4±0.69.0(8.7–9.4)Mixture 0.3:125% 2.06±0.0136.8±2258.6(6.9–10.7)Mixture 0.2:117% 2.10±0.0111.9±2.57.9(7.7–8.0)OA0%2.18±0.0125.5±3.96.6(6.5–6.7)2.08 1.27aQSAR Eq.(4).Table 4Concentration–effect curves and toxic ratio (TR)analysis for the parent OE and the metabolite OA in the algal toxicity test with Pseudokirchneriella subcapitata using the 96-well plate format.EC50experimental (mM)(95%conﬁdence intervals)Slope of log-logistic ﬁt EC50experimental (g/L)b EC50baseline (mM)a TREndpoint 24h growth rate OE 0.51(0.48–0.55) 2.70.21(0.20–0.26)7.013.7OA 8.27(7.75–8.82) 2.5 2.95(2.76–3.15)25.4 3.1Endpoint 24h IPAM OE 0.78(0.76–0.81) 3.10.32(0.31–0.34)10.814.0OA 19.28(18.22–20.39)1.86.88(6.51–7.27)34.41.8a QSAR Eqs.(5)and (6).bBased on phosphate salt for OE and tartrate salt for OA.3.4.Speciation and hydrophobicity indicatorsThe liposome–water partition coefﬁcient of the neutral species K lipw,neutral was calculated from the estimated octanol–water par-tition coefﬁcient log K ow of 1.21for the parent OE and 0.006for the metabolite OA (Straub,2009)using Eq.(1).Note,however,that the limit of applicability of such an equation might be reached consid-ering that OE and OA both have a K ow that is outside the test set domain of the QSAR equation.The predicted log K lipw,neutral is 1.61for OE and 0.46for OA (Table 1).OE is a weak ammonium base and is therefore positively charged at ambient pH.With an estimated acidity constant of 7.6(OE)and7.81(OA)for the basic amino group (estimated with SPARC (Hilal et al.,2005)),the fraction of neutralspecies at pH 7is 20%for OE.16%of OE is in its cationic form,result-ing in a log D lipw (pH 7)of 1.06(Eq.(2)).OA with its acidity constant of the carboxylic acid of 3.78and its retained aliphatic amine func-tion is a zwitterion and overall neutral at pH 7.The log D lipw (pH 7)of OA can therefore be assumed to be equal to log K lipw,neutral .3.5.Toxic ratio analysisAnalysis of the literature data for the parent compound OE revealed that the toxic ratio (TR)varies from 0.4to 26for the different test species (Table 2).In principle,TR >10would be the cut-off value for speciﬁc toxicity.However,for the three species with TR 20–26,there are differences between the tested species andFig.1.Toxic ratio (TR)analysis for (A)the bioluminescence inhibition test with Vibrio ﬁscheri and (B)the 24h growth rate endpoint in the algal toxicity assay with Pseu-dokirchneriella subcapitata .The experimental data of the parent OE and the metabolite OA are depicted with black diamonds.The line corresponds to the baseline toxicity QSAR for the given endpoint,derived from the experimental data of the baseline toxicants depicted with empty circles (Escher et al.,2008a ).(Drawn line:baseline toxicity,TR =1;broken line:speciﬁc mode of toxic action TR ≥10).B.I.Escher et al./Aquatic Toxicology96 (2010) 194–202199Fig.2.(A)Isobologram for the binary mixtures of the parent OE and the metabolite OA in the bioluminescence inhibition test with Vibrioﬁscheri.The drawn line corresponds to the prediction for concentration addition,the broken line to the prediction for independent action.(B)Deviation of the experimental data from the predictions for concentration addition(deviation=(EC50experimental−EC50CA prediction)/EC50experimental,empty circles)and independent action(deviation=(EC50experimental−EC50IA prediction)/EC50experimental,ﬁlled circles).the baseline QSARs that are rescaled from K ow-based QSARs,all of which adds to the uncertainty of the resulting TR value.Therefore no clear conclusions can be drawn.In contrast,the TR remained below10(Fig.1)in all endpoints from literature where the baseline QSAR was established with the same experimental setup,and was deﬁned with experimental D lipw (pH7)values as hydrophobicity descriptors.The calculated toxic ratios(TR)of OE and OA in the30-min bio-luminescence inhibition test with the marine bacterium V.ﬁscheri were0.27and1.27,respectively,indicating that both are baseline toxicants towards V.ﬁscheri(Table3,Fig.1A).Note that OE and OA are at the lower end of hydrophobicity in the baseline toxicity QSAR indicating an overall low toxicity.While the TR values of OA for both24h endpoints in the algal toxicity assay were still in the range to be classiﬁed as baseline tox-icant,the TR of OE were about10times higher than that of OA in both24h endpoints,thus marginally but signiﬁcantly exceeding the threshold value of TR=10(Table4,Fig.1B).This indicates clear differences in the mode of action between OE and OA or a signiﬁ-cant error in the estimation of D lipw(pH7)of OE.The latter is rather unlikely because if D lipw(pH7)of OE was underestimated the TR in V.ﬁscheri would be<0.1,which is an unrealistic value.The differ-ence in the time to effect discussed above supports the conclusion that there is a difference in mode of toxic action.3.6.Mixture toxicityTen different mixture experiments with binary mixtures and varying ratios of OE/OA were performed with the bioluminescence inhibition test of V.ﬁscheri.The resulting EC50values are listed in Table3.When plotting the data in form of an isobologram (Fig.2A)it is evident that the mixture experiments yield higher EC50than the prediction for concentration addition(CA),which corresponds to the straight line connecting the EC50of the two mixture components(Altenburger and Boedeker,1990).This com-bination effect is termed subadditivity(Altenburger and Boedeker, 1990).However,the experimental mixture toxicities are still higher than predictions for independent action(IA).The predictions for IA were performed independently from the isobologram analysis according to Backhaus et al.(2000)and a mixture EC50derived from the prediction for IA was also plotted in the isobologram(as indicated by the broken line in Fig.2A).The deviation of the exper-imental data from the predictions of concentration addition(ﬁlled circles)and independent action(empty circles)is approximately symmetric with a maximum of20–30%deviation from the model (Fig.2B).The TR analysis had clearly indicated that both,parent OE and metabolite OA,act as baseline toxicants.Therefore,the expected mixture toxicity model is concentration addition(Escher et al., 2002),which was not congruent with the experimental observa-tions.A major difference between OE and OA is the gradient of their concentration–effect curves(Fig.3).While OE has a slope typical for a baseline toxicant,the slope of OA is unusually steep(Table3). The mixtures vary in slope depending on the composition.Mix-tures with a higher OA content have a correspondingly higher slope (Table3).For typical binary mixtures,the predictions for concentra-tion addition and independent action are overlapping.Exceptions are binary mixtures of components with largely different slopes as it is observed here.Nevertheless,CA overpredicts the toxicity of the mixture by no more than25%.Cedergreen et al.(2008)recently compared CA and IA as models for mixtures of chemicals with dif-ferent molecular target sites and found that neither of the models was more accurate(Table5).In contrast,in the algal toxicity assay the isobologram for the endpoint24h growth rate clearly shows subadditivity with the experimental data perfectly overlapping with the prediction of independent action(Fig.4A).For the endpoint24h IPAM intheFig.3.Concentration–effect curves for the parent OE,the metabolite OA,and the equimolar mixture in the bioluminescence inhibition test with Vibrioﬁscheri.。

库仑阵列电化学高效液相色谱法测定大鼠脑组织中单胺类神经递质及代谢产物

图 1 N E、D O PA C、D A 、HO M V 标准色谱图; 图 2 5 HT 、5 H IA A 标准色谱图; 图 3 大鼠脑组织样本 N E、DO PA C、D A、H O M V 色谱图;
图 4 大鼠脑组织样本 5 HT 、5 H IA A 色谱图
2. 2 标准曲线由于脑组织标本中均存在以上生 0. 1397, r 2= 0. 9998; NE: Y= 0. 113X+ 0. 5664, r 2=
ZH A N G X iang hui , LI U J un , S U L in y an ( Mental H ealth I nstitute , Xiangy a 2nd H osp ital , Centr al South Univers ity , Changsha, 410011 China )
溶液配制成不同浓度的混合标准液。用 0. 2 mo l/ L 高氯酸将内标 DH BA 储备液稀释成含 DH BA 20
g/ L ( 并含焦亚硫酸钠 0. 04% 和乙二胺四乙酸二钠 0. 04% ) 的溶液做为蛋白沉淀剂的工作液[ 1] 。 1. 5 组织样本制备 90~ 100 g WKY 种雄性大鼠, 断头后迅速取脑皮质立即置液氮中深冻, 固化后精确称重, 每 100 m g 脑组织加 1 m l 预冷的工作内标液, 于冰浴下快速玻璃匀浆, 4 & 条件下 14 000 ∀ g 低温离心 15 m in, 取上清液用 0. 22 m 针头过滤器过滤, 滤液作为待测样品进样。 1. 6 伏安曲线取以下待测物质每种含 100 g/ L 的标准液, 设置电势为: 0、50、100、150、250、300、 350、400、450、550、600 mv, 进样 20 l, 记录峰面积。峰面积为 Y 轴, 电势为 X 轴, 作连线图。根据伏安曲线设置 4 道电势为: - 50、100、300、500 mv。 1. 7 统计学处理以 M illenium32 软件采集并处理原始数据, 以 Ex cel 软件做统计学数据处理。

半导体制造工艺讲义第七章离子体概念

Hong Xiao, Ph. D.
/HongXiao/Book.htm
18
Plasma Enhanced CVD
• PECVD with SiH4 and NO2 (laughing gas) e− + SiH4 → SiH2 + 2H + e− e− + N2O → N2 + O + e− SiH2 + 3O → SiO2 + H2O • Plasma enhanced chemical reaction • PECVD can achieve high deposition rate at relatively lower temperature
Hong Xiao, Ph. D.
/HongXiao/Book.htm
14
Relaxation
h: Planck Constant hν ν: Frequency of Light Excited State hν
Ground State
Hong Xiao, Ph. D. /HongXiao/Book.htm 15
Hong Xiao, Ph. D. /HongXiao/Book.htm 21
Hong Xiao, Ph. D. /HongXiao/Book.htm 19
Q&A
• Why are dissociation not important in the aluminum and copper PVD processes? • Aluminum and copper sputtering processes only use argon. Argon is a noble gas, which exist in the form of atoms instead of molecules. Thus there is no dissociation process in argon plasma

半导体制造技术

Semiconductor Manufacturing Technology半导体制造技术Instructor’s ManualMichael QuirkJulian SerdaCopyright Prentice HallTable of Contents目录OverviewI. Chapter1. Semiconductor industry overview2. Semiconductor materials3. Device technologies—IC families4. Silicon and wafer preparation5. Chemicals in the industry6. Contamination control7. Process metrology8. Process gas controls9. IC fabrication overview10. Oxidation11. Deposition12. Metallization13. Photoresist14. Exposure15. Develop16. Etch17. Ion implant18. Polish19. Test20. Assembly and packagingII. Answers to End-of-Chapter Review QuestionsIII. Test Bank (supplied on diskette)IV. Chapter illustrations, tables, bulleted lists and major topics (supplied on CD-ROM)Notes to Instructors:1)The chapter overview provides a concise summary of the main topics in each chapter.2)The correct answer for each test bank question is highlighted in bold. Test bankquestions are based on the end-of-chapter questions. If a student studies the end-of-chapter questions (which are linked to the italicized words in each chapter), then they will be successful on the test bank questions.2Chapter 1Introduction to the Semiconductor Industry Die:管芯 defective:有缺陷的Development of an Industry•The roots of the electronic industry are based on the vacuum tube and early use of silicon for signal transmission prior to World War II. The first electronic computer, the ENIAC, wasdeveloped at the University of Pennsylvania during World War II.•William Shockley, John Bardeen and Walter Brattain invented the solid-state transistor at Bell Telephone Laboratories on December 16, 1947. The semiconductor industry grew rapidly in the 1950s to commercialize the new transistor technology, with many early pioneers working inSilicon Valley in Northern California.Circuit Integration•The first integrated circuit, or IC, was independently co-invented by Jack Kilby at Texas Instruments and Robert Noyce at Fairchild Semiconductor in 1959. An IC integrates multiple electronic components on one substrate of silicon.•Circuit integration eras are: small scale integration (SSI) with 2 - 50 components, medium scale integration (MSI) with 50 – 5k components, large scale integration (LSI) with 5k to 100kcomponents, very large scale integration (VLSI) with 100k to 1M components, and ultra large scale integration (ULSI) with > 1M components.1IC Fabrication•Chips (or die) are fabricated on a thin slice of silicon, known as a wafer (or substrate). Wafers are fabricated in a facility known as a wafer fab, or simply fab.•The five stages of IC fabrication are:Wafer preparation: silicon is purified and prepared into wafers.Wafer fabrication: microchips are fabricated in a wafer fab by either a merchant chip supplier, captive chip producer, fabless company or foundry.Wafer test: Each individual die is probed and electrically tested to sort for good or bad chips.Assembly and packaging: Each individual die is assembled into its electronic package.Final test: Each packaged IC undergoes final electrical test.•Key semiconductor trends are:Increase in chip performance through reduced critical dimensions (CD), more components per chip (Moore’s law, which predicts the doubling of components every 18-24 months) andreduced power consumption.Increase in chip reliability during usage.Reduction in chip price, with an estimated price reduction of 100 million times for the 50 years prior to 1996.The Electronic Era•The 1950s saw the development of many different types of transistor technology, and lead to the development of the silicon age.•The 1960s were an era of process development to begin the integration of ICs, with many new chip-manufacturing companies.•The 1970s were the era of medium-scale integration and saw increased competition in the industry, the development of the microprocessor and the development of equipment technology. •The 1980s introduced automation into the wafer fab and improvements in manufacturing efficiency and product quality.•The 1990s were the ULSI integration era with the volume production of a wide range of ICs with sub-micron geometries.Career paths•There are a wide range of career paths in semiconductor manufacturing, including technician, engineer and management.2Chapter 2 Characteristics of Semiconductor MaterialsAtomic Structure•The atomic model has three types of particles: neutral neutrons（不带电的中子）, positively charged protons（带正电的质子）in the nucleus and negatively charged electrons（带负电的核外电子） that orbit the nucleus. Outermost electrons are in the valence shell, and influence the chemical and physical properties of the atom. Ions form when an atom gains or loses one or more electrons.The Periodic Table•The periodic table lists all known elements. The group number of the periodic table represents the number of valence shell electrons of the element. We are primarily concerned with group numbers IA through VIIIA.•Ionic bonds are formed when valence shell electrons are transferred from the atoms of one element to another. Unstable atoms (e.g., group VIIIA atoms because they lack one electron) easily form ionic bonds.•Covalent bonds have atoms of different elements that share valence shell electrons.3Classifying Materials•There are three difference classes of materials:ConductorsInsulatorsSemiconductors•Conductor materials have low resistance to current flow, such as copper. Insulators have high resistance to current flow. Capacitance is the storage of electrical charge on two conductive plates separated by a dielectric material. The quality of the insulation material between the plates is the dielectric constant. Semiconductor materials can function as either a conductor or insulator.Silicon•Silicon is an elemental semiconductor material because of four valence shell electrons. It occurs in nature as silica and is refined and purified to make wafers.•Pure silicon is intrinsic silicon. The silicon atoms bond together in covalent bonds, which defines many of silicon’s properties. Silicon atoms bond together in set, repeatable patterns, referred to asa crystal.•Germanium was the first semiconductor material used to make chips, but it was soon replaced by silicon. The reasons for this change are:Abundance of siliconHigher melting temperature for wider processing rangeWide temperature range during semiconductor usageNatural growth of silicon dioxide•Silicon dioxide (SiO2) is a high quality, stable electrical insulator material that also serves as a good chemical barrier to protect silicon from external contaminants. The ability to grow stable, thin SiO2 is fundamental to the fabrication of Metal-Oxide-Semiconductor (MOS) devices. •Doping increases silicon conductivity by adding small amounts of other elements. Common dopant elements are from trivalent, p-type Group IIIA (boron) and pentavalent, n-type Group VA (phosphorus, arsenic and antimony).•It is the junction between the n-type and p-type doped regions (referred to as a pn junction) that permit silicon to function as a semiconductor.4Alternative Semiconductor Materials•The alternative semiconductor materials are primarily the compound semiconductors. They are formed from Group IIIA and Group VA (referred to as III-V compounds). An example is gallium arsenide (GaAs).•Some alternative semiconductors come from Group IIA and VIA, referred to as II-VI compounds. •GaAs is the most common III-V compound semiconductor material. GaAs ICs have greater electron mobility, and therefore are faster than ICs made with silicon. GaAs ICs also have higher radiation hardness than silicon, which is better for space and military applications. The primary disadvantage of GaAs is the lack of a natural oxide.5Chapter 3Device TechnologiesCircuit Types•There are two basic types of circuits: analog and digital. Analog circuits have electrical data that varies continuously over a range of voltage, current and power values. Digital circuits have operating signals that vary about two distinct voltage levels – a high and a low.Passive Component Structures•Passive components such as resistors and capacitors conduct electrical current regardless of how the component is connected. IC resistors are a passive component. They can have unwanted resistance known as parasitic resistance. IC capacitor structures can also have unintentional capacitanceActive Component Structures•Active components, such as diodes and transistors can be used to control the direction of current flow. PN junction diodes are formed when there is a region of n-type semiconductor adjacent to a region of p-type semiconductor. A difference in charge at the pn junction creates a depletion region that results in a barrier voltage that must be overcome before a diode can be operated. A bias voltage can be configured to have a reverse bias, with little or no conduction through the diode, or with a forward bias, which permits current flow.•The bipolar junction transistor (BJT) has three electrodes and two pn junctions. A BJT is configured as an npn or pnp transistor and biased for conduction mode. It is a current-amplifying device.6• A schottky diode is formed when metal is brought in contact with a lightly doped n-type semiconductor material. This diode is used in faster and more power efficient BJT circuits.•The field-effect transistor (FET), a voltage-amplifying device, is more compact and power efficient than BJT devices. A thin gate oxide located between the other two electrodes of the transistor insulates the gate on the MOSFET. There are two categories of MOSFETs, nMOS (n-channel) and pMOS (p-channel), each which is defined by its majority current carriers. There is a biasing scheme for operating each type of MOSFET in conduction mode.•For many years, nMOS transistors have been the choice of most IC manufacturers. CMOS, with both nMOS and pMOS transistors in the same IC, has been the most popular device technology since the early 1980s.•BiCMOS technology makes use of the best features of both CMOS and bipolar technology in the same IC device.•Another way to categorize FETs is in terms of enhancement mode and depletion mode. The major different is in the way the channels are doped: enhancement-mode channels are doped opposite in polarity to the source and drain regions, whereas depletion mode channels are doped the same as their respective source and drain regions.Latchup in CMOS Devices•Parasitic transistors can create a latchup condition(???????) in CMOS ICs that causes transistors to unintentionally（无心的） turn on. To control latchup, an epitaxial layer is grown on the wafer surface and an isolation barrier（隔离阻障）is placed between the transistors. An isolation layer can also be buried deep below the transistors.Integrated Circuit Productsz There are a wide range of semiconductor ICs found in electrical and electronic products. This includes the linear IC family, which operates primarily with anal3og circuit applications, and the digital IC family, which includes devices that operate with binary bits of data signals.7Chapter 4Silicon and Wafer Preparation8z Semiconductor-Grade Silicon•The highly refined silicon used for wafer fabrication is termed semiconductor-grade silicon (SGS), and sometimes referred to as electronic-grade silicon. The ultra-high purity of semiconductor-grade silicon is obtained from a multi-step process referred to as the Siemens process.Crystal Structure• A crystal is a solid material with an ordered, 3-dimensional pattern over a long range. This is different from an amorphous material that lacks a repetitive structure.•The unit cell is the most fundamental entity for the long-range order found in crystals. The silicon unit cell is a face-centered cubic diamond structure. Unit cells can be organized in a non-regular arrangement, known as a polycrystal. A monocrystal are neatly arranged unit cells.Crystal Orientation•The orientation of unit cells in a crystal is described by a set of numbers known as Miller indices.The most common crystal planes on a wafer are (100), (110), and (111). Wafers with a (100) crystal plane orientation are most common for MOS devices, whereas (111) is most common for bipolar devices.Monocrystal Silicon Growth•Silicon monocrystal ingots are grown with the Czochralski (CZ) method to achieve the correct crystal orientation and doping. A CZ crystal puller is used to grow the silicon ingots. Chunks of silicon are heated in a crucible in the furnace of the puller, while a perfect silicon crystal seed is used to start the new crystal structure.• A pull process serves to precisely replicate the seed structure. The main parameters during the ingot growth are pull rate and crystal rotation. More homogeneous crystals are achieved with a magnetic field around the silicon melt, known as magnetic CZ.•Dopant material is added to the melt to dope the silicon ingot to the desired electrical resistivity.Impurities are controlled during ingot growth. A float-zone crystal growth method is used toachieve high-purity silicon with lower oxygen content.•Large-diameter ingots are grown today, with a transition underway to produce 300-mm ingot diameters. There are cost benefits for larger diameter wafers, including more die produced on a single wafer.Crystal Defects in Silicon•Crystal defects are interruptions in the repetitive nature of the unit cell. Defect density is the number of defects per square centimeter of wafer surface.•Three general types of crystal defects are: 1) point defects, 2) dislocations, and 3) gross defects.Point defects are vacancies (or voids), interstitial (an atom located in a void) and Frenkel defects, where an atom leaves its lattice site and positions itself in a void. A form of dislocation is astacking fault, which is due to layer stacking errors. Oxygen-induced stacking faults are induced following thermal oxidation. Gross defects are related to the crystal structure (often occurring during crystal growth).Wafer Preparation•The cylindrical, single-crystal ingot undergoes a series of process steps to create wafers, including machining operations, chemical operations, surface polishing and quality checks.•The first wafer preparation steps are the shaping operations: end removal, diameter grinding, and wafer flat or notch. Once these are complete, the ingot undergoes wafer slicing, followed by wafer lapping to remove mechanical damage and an edge contour. Wafer etching is done to chemically remove damage and contamination, followed by polishing. The final steps are cleaning, wafer evaluation and packaging.Quality Measures•Wafer suppliers must produce wafers to stringent quality requirements, including: Physical dimensions: actual dimensions of the wafer (e.g., thickness, etc.).Flatness: linear thickness variation across the wafer.Microroughness: peaks and valleys found on the wafer surface.Oxygen content: excessive oxygen can affect mechanical and electrical properties.Crystal defects: must be minimized for optimum wafer quality.Particles: controlled to minimize yield loss during wafer fabrication.Bulk resistivity(电阻系数): uniform resistivity from doping during crystal growth is critical. Epitaxial Layer•An epitaxial layer (or epi layer) is grown on the wafer surface to achieve the same single crystal structure of the wafer with control over doping type of the epi layer. Epitaxy minimizes latch-up problems as device geometries continue to shrink.Chapter 5Chemicals in Semiconductor FabricationEquipment Service Chase Production BayChemical Supply Room Chemical Distribution Center Holding tank Chemical drumsProcess equipmentControl unit Pump Filter Raised and perforated floorElectronic control cablesSupply air ductDual-wall piping for leak confinement PumpFilterChemical control and leak detection Valve boxes for leak containment Exhaust air ductStates of Matter• Matter in the universe exists in 3 basic states (宇宙万物存在着三种基本形态): solid, liquid andgas. A fourth state is plasma.Properties of Materials• Material properties are the physical and chemical characteristics that describe its unique identity.• Different properties for chemicals in semiconductor manufacturing are: temperature, pressure andvacuum, condensation, vapor pressure, sublimation and deposition, density, surface tension, thermal expansion and stress.Temperature is a measure of how hot or cold a substance is relative to another substance. Pressure is the force exerted per unit area. Vacuum is the removal of gas molecules.Condensation is the process of changing a gas into a liquid. Vaporization is changing a liquidinto a gas.Vapor pressure is the pressure exerted by a vapor in a closed container at equilibrium.Sublimation is the process of changing a solid directly into a gas. Deposition is changing a gas into a solid.Density is the mass of a substance divided by its volume.Surface tension of a liquid is the energy required to increase the surface area of contact.Thermal expansion is the increase in an object’s dimension due to heating.Stress occurs when an object is exposed to a force.Process Chemicals•Semiconductor manufacturing requires extensive chemicals.• A chemical solution is a chemical mixture. The solvent is the component of the solution present in larger amount. The dissolved substances are the solutes.•Acids are solutions that contain hydrogen and dissociate in water to yield hydronium ions. A base is a substance that contains the OH chemical group and dissociates in water to yield the hydroxide ion, OH-.•The pH scale is used to assess the strength of a solution as an acid or base. The pH scale varies from 0 to 14, with 7 being the neutral point. Acids have pH below 7 and bases have pH values above 7.• A solvent is a substance capable of dissolving another substance to form a solution.• A bulk chemical distribution (BCD) system is often used to deliver liquid chemicals to the process tools. Some chemicals are not suitable for BCD and instead use point-of-use (POU) delivery, which means they are stored and used at the process station.•Gases are generally categorized as bulk gases or specialty gases. Bulk gases are the relatively simple gases to manufacture and are traditionally oxygen, nitrogen, hydrogen, helium and argon.The specialty gases, or process gases, are other important gases used in a wafer fab, and usually supplied in low volume.•Specialty gases are usually transported to the fab in metal cylinders.•The local gas distribution system requires a gas purge to flush out undesirable residual gas. Gas delivery systems have special piping and connections systems. A gas stick controls the incoming gas at the process tool.•Specialty gases may be classified as hydrides, fluorinated compounds or acid gases.Chapter 6Contamination Control in Wafer FabsIntroduction•Modern semiconductor manufacturing is performed in a cleanroom, isolated from the outside environment and contaminants.Types of contamination•Cleanroom contamination has five categories: particles, metallic impurities, organic contamination, native oxides and electrostatic discharge. Killer defects are those causes of failure where the chip fails during electrical test.Particles: objects that adhere to a wafer surface and cause yield loss. A particle is a killer defect if it is greater than one-half the minimum device feature size.Metallic impurities: the alkali metals found in common chemicals. Metallic ions are highly mobile and referred to as mobile ionic contaminants (MICs).Organic contamination: contains carbon, such as lubricants and bacteria.Native oxides: thin layer of oxide growth on the wafer surface due to exposure to air.Electrostatic discharge (ESD): uncontrolled transfer of static charge that can damage the microchip.Sources and Control of Contamination•The sources of contamination in a wafer fab are: air, humans, facility, water, process chemicals, process gases and production equipment.Air: class number designates the air quality inside a cleanroom by defining the particle size and density.Humans: a human is a particle generator. Humans wear a cleanroom garment and follow cleanroom protocol to minimize contamination.Facility: the layout is generally done as a ballroom (open space) or bay and chase design.Laminar airflow with air filtering is used to minimize particles. Electrostatic discharge iscontrolled by static-dissipative materials, grounding and air ionization.Ultrapure deiniozed (DI) water: Unacceptable contaminants are removed from DI water through filtration to maintain a resistivity of 18 megohm-cm. The zeta potential represents a charge on fine particles in water, which are trapped by a special filter. UV lamps are used for bacterial sterilization.Process chemicals: filtered to be free of contamination, either by particle filtration, microfiltration (membrane filter), ultrafiltration and reverse osmosis (or hyperfiltration).Process gases: filtered to achieve ultraclean gas.Production equipment: a significant source of particles in a fab.Workstation design: a common layout is bulkhead equipment, where the major equipment is located behind the production bay in the service chase. Wafer handling is done with robotic wafer handlers. A minienvironment is a localized environment where wafers are transferred on a pod and isolated from contamination.Wafer Wet Cleaning•The predominant wafer surface cleaning process is with wet chemistry. The industry standard wet-clean process is the RCA clean, consisting of standard clean 1 (SC-1) and standard clean 2 (SC-2).•SC-1 is a mixture of ammonium hydroxide, hydrogen peroxide and DI water and capable of removing particles and organic materials. For particles, removal is primarily through oxidation of the particle or electric repulsion.•SC-2 is a mixture of hydrochloric acid, hydrogen peroxide and DI water and used to remove metals from the wafer surface.•RCA clean has been modified with diluted cleaning chemistries. The piranha cleaning mixture combines sulfuric acid and hydrogen peroxide to remove organic and metallic impurities. Many cleaning steps include an HF last step to remove native oxide.•Megasonics(兆声清洗) is widely used for wet cleaning. It has ultrasonic energy with frequencies near 1 MHz. Spray cleaning will spray wet-cleaning chemicals onto the wafer. Scrubbing is an effective method for removing particles from the wafer surface.•Wafer rinse is done with overflow rinse, dump rinse and spray rinse. Wafer drying is done with spin dryer or IPA(异丙醇) vapor dry (isopropyl alcohol).•Some alternatives to RCA clean are dry cleaning, such as with plasma-based cleaning, ozone and cryogenic aerosol cleaning.Chapter 7Metrology and Defect InspectionIC Metrology•In a wafer fab, metrology refers to the techniques and procedures for determining physical and electrical properties of the wafer.•In-process data has traditionally been collected on monitor wafers. Measurement equipment is either stand-alone or integrated.•Yield is the percent of good parts produced out of the total group of parts started. It is an indicator of the health of the fabrication process.Quality Measures•Semiconductor quality measures define the requirements for specific aspects of wafer fabrication to ensure acceptable device performance.•Film thickness is generally divided into the measurement of opaque film or transparent film. Sheet resistance measured with a four-point probe is a common method of measuring opaque films (e.g., metal film). A contour map shows sheet resistance deviations across the wafer surface.•Ellipsometry is a nondestructive, noncontact measurement technique for transparent films. It works based on linearly polarized light that reflects off the sample and is elliptically polarized.•Reflectometry is used to measure a film thickness based on how light reflects off the top and bottom surface of the film layer. X-ray and photoacoustic technology are also used to measure film thickness.•Film stress is measured by analyzing changes in the radius of curvature of the wafer. Variations in the refractive index are used to highlight contamination in the film.•Dopant concentration is traditionally measured with a four-point probe. The latest technology is the thermal-wave system, which measures the lattice damage in the implanted wafer after ion implantation. Another method for measuring dopant concentration is spreading resistance probe. •Brightfield detection is the traditional light source for microscope equipment. An optical microscope uses light reflection to detect surface defects. Darkfield detection examines light scattered off defects on the wafer surface. Light scattering uses darkfield detection to detectsurface particles by illuminating the surface with laser light and then using optical imaging.•Critical dimensions (CDs) are measured to achieve precise control over feature size dimensions.The scanning electron microscope is often used to measure CDs.•Conformal step coverage is measured with a surface profiler that has a stylus tip.•Overlay registration measures the ability to accurately print photoresist patterns over a previously etched pattern.•Capacitance-voltage (C-V) test is used to verify acceptable charge conditions and cleanliness at the gate structure in a MOS device.Analytical Equipment•The secondary-ion mass spectrometry (SIMS) is a method of eroding a wafer surface with accelerated ions in a magnetic field to analyze the surface material composition.•The atomic force microscope (AFM) is a surface profiler that scans a small, counterbalanced tip probe over the wafer to create a 3-D surface map.•Auger electron spectroscopy (AES) measures composition on the wafer surface by measuring the energy of the auger electrons. It identifies elements to a depth of about 2 nm. Another instrument used to identify surface chemical species is X-ray photoelectron spectroscopy (XPS).•Transmission electron microscopy (TEM) uses a beam of electrons that is transmitted through a thin slice of the wafer. It is capable of quantifying very small features on a wafer, such as silicon crystal point defects.•Energy-dispersive spectrometer (EDX) is a widely used X-ray detection method for identifying elements. It is often used in conjunction with the SEM.• A focused ion beam (FIB) system is a destructive technique that focuses a beam of ions on the wafer to carve a thin cross section from any wafer area. This permits analysis of the wafermaterial.Chapter 8Gas Control in Process ChambersEtch process chambers••The process chamber is a controlled vacuum environment where intended chemical reactions take place under controlled conditions. Process chambers are often configured as a cluster tool. Vacuum•Vacuum ranges are low (rough) vacuum, medium vacuum, high vacuum and ultrahigh vacuum (UHV). When pressure is lowered in a vacuum, the mean free path(平均自由行程) increases, which is important for how gases flow through the system and for creating a plasma.Vacuum Pumps•Roughing pumps are used to achieve a low to medium vacuum and to exhaust a high vacuum pump. High vacuum pumps achieve a high to ultrahigh vacuum.•Roughing pumps are dry mechanical pumps or a blower pump (also referred to as a booster). Two common high vacuum pumps are a turbomolecular (turbo) pump and cryopump. The turbo pump is a reliable, clean pump that works on the principle of mechanical compression. The cryopump isa capture pump that removes gases from the process chamber by freezing them.。

天麻酸奶中天麻素和天麻苷元含量的测定

武汉轻工大学学报Journai of Wuhan Polytechnio University V c S.38Nr.5Oct.2019第38卷第5期2019年10月文章编号：2095N386(2019)05-0006-06DOI：10.3969/j.issn.2095N386.2019.05.002天麻酸奶中天麻素和天麻＜元含量的测定黄先敏，甘会廷,韩立乾,孙建美（昭通学院农学与生命科学学院，云南昭通657000）摘要:以实验所做出的天麻酸奶为试验材料，对其中的天麻素和天麻昔元的含量进行测定分析，为天麻酸奶的生产利用和推广提供理论依据。

实验结果显示天麻与乳酸菌共同发酵后，发酵物中仍含有天麻素和天麻昔元。

关键词:天麻酸奶;天麻素;天麻昔元;含量;反相高效液相色谱法中图分类号:TS201.2文献标识码：AMeasurement of gastrodin and gastrodigenin in Gastrodia elata Bl yoghurt HUANG Xian-min.,GAN Hui-ting,HAN Li-qian,SUN Jian-mei(College of Agriculturo and Life Science,Zhaotong University,Zhaotong,657000,China)Abstract：The Gastrodia elata BI yoghurt made in laboratoro was used as the experimentai materiai,O s mecsure the content of gastrodin and gastrodioenin in Gastrodia elata BI yoghui powdco,which provided a theoreticoi basis fof the production,utilization and promotion of Gastrodia elata BI yorhuri.AOs the co-femientation of Gastrodia elata BI and lactic acid bacteaa,tar femientation product stili contains gastrodin and gastrodiaenia.Key words:Gastrodia elata BI%gastrodin%gastrodiaenin%content%reversed phass high perfomianco liquia chroma-iogoaphy1引言天麻（Gastuodia elatr BI）是我国传统名贵中药［1］，已有千年的药用历史，被誉为“治风之神药”&2-'（天麻中含有天麻素⑷、天麻昔元［5］、巴利森昔&6'、对k基苯甲醛切、对k基苯甲酸［8'及天麻多糖［9］等多种活性物质，其中主要的活性物质为天麻素和天麻昔元&10N1'。

TASI 2002 lectures on neutrinos

1
I.
INTRODUCTION
The success of the Standard Model (SM) can be seen as a proof that it is an eﬀective low energy description of Nature. We are therefore interested in probing the more fundamental theory. One way to go is to search for new particles that can be produced in yet unreached energies. Another way to look for new physics is to search for indirect eﬀects of heavy unknown particles. In this set of lectures we explain how neutrino physics is used to probe such indirect signals of physics beyond the SM. In the SM the neutrinos are exactly massless. This prediction, however, is rather speciﬁc to the SM. In almost all of the SM extensions the neutrinos are massive and they mix. The search for neutrino ﬂavor oscillation, a phenomenon which is possible only for massive neutrinos, is a search for new physics beyond the SM. The recent experimental indications for neutrino oscillations are indirect evidences for new physics, most likely, at distances much shorter than the weak scale. In the ﬁrst lecture the basic mechanisms for generating neutrino masses are described and the ingredients of the SM that ensure massless neutrinos are explained. Then, the neutrino oscillation formalism is developed. In the second lecture the current experimental situation is summarized. In particular, we describe the oscillation signals observed by solar neutrino experiments, atmospheric neutrino experiments and long baseline terrestrial neutrino experiments. Each of these results separately can be accounted for by a rather simple modiﬁcation to the SM. Trying to accommodate all of them simultaneously, however, is not trivial. In the third lecture we explain what are the theoretical challenges in trying to combine all the experimental indications for neutrino masses, and give several examples of models that cope with some of these challenges. These lecture notes are aimed to provide an introduction to the topic of neutrino physics. They are not meant to be a review. Therefore, many details are not given and many references are omitted. There are many textbooks [1] and reviews [2–4] about neutrinos. There is also a lot of information about neutrinos on the web [5, 6]. All these sources provide more detailed discussions with complete set of references on the topics covered in these lectures. Moreover, they also cover many subjects that are not mentioned here. In preparing the lectures I used mainly the recent review by Gonzalez-Garcia and Nir [4]. This review is a very good starting point to anyone who wants to learn more about neutrino physics.

铅酸蓄电池常用专业词汇

A mixture of lead monoxide and free lead powder used in making battery pastes - variously known as Grey
High rate of charge for a short period (usually less than an hour) intended to restore sufficient ampere hour capacity of the battery for completing the day's work or replacing losses due to storage. The volume of electrolyte solution immediately adjacent to the electrode surface in which concentration changes occur due to the effects of the electrode process (also see HOURLY RATE) Discharge or charge current, in amperes, expressed in multiples of the rated capacity. For example, the C/20 discharge current for a battery rated at the 5-h discharge rate is: C5/20(Ah) = current (A). As a cell's capacity is not the same at all discharge rates and usually increases with decreasing rate, a discharge at the C5/20 rate will run longer than 20 h. A stick of cadmium covered by a porous sheet and kept immersed in sulfuric acid of the same strength as used in the battery, for use as a reference electrode. EMF of the cell formed between the positive or negative plate group and the cadmium reference electrode A reference electrode of mercury in contract with a paste of mercury and mercurous chloride in potassium, chloride solution of specified concentration. The actual number of ampere hours a battery can deliver at a specified current to a specified end voltage The stated number of ampere hours or watt-hours that can be obtained from the battery at a specified current, to some specified final voltage. The fraction of the full capacity available from a battery under specified conditions of discharge after it has been stored for a period of time. The comparative ability of a metal to fill a mould of intricate shape reproducing the fine contours of a battery grid. Method of obtaining the desired shape of a metal (or alloy) by solidifying the molten metal (or alloy) in a suitable mould Particle, in the electrolyte, carrying a positive charge and moving toward the cathode during operation of the cell. The basic electrochemical unit used to generate or store electrical energy A cone shaped porous ceramic device fixed to the top of the battery, which allows escape of gases evolved during charging, but presents flashback. (Safety vent/flash arrestor) Process of sending current through the cell during which electrical energy is converted to chemical energy and the active materials of the plates are restored.

Accomodating Solar and Atmospheric Neutrino Deficits, Hot Dark Matter, and a Double Beta De

UCSB–HEP–94-03 UMD-PP-94-90 February,1994 Accommodating solar and atmospheric neutrino deﬁcits, hot dark matter, and a double beta decay signal
arXiv:hep-ph/9402231v2 9 Feb 1994
−6 2 2 −3 a)Small − angle MSW, ∆m2 ei ∼ 6 × 10 eV , sin 2θei ∼ 7 × 10 ,
2
−6 2 2 b)Large − angle MSW, ∆m2 ei ∼ 9 × 10 eV , sin 2θei ∼ 0.6, −10 eV2 , sin2 2θ ∼ 0.9. c)Vacuum oscillation, ∆m2 ei ei ∼ 10
(1)
Of these, (a) is favored over (b) by the ﬁts to the solar neutrino data [9], and both (b) and (c) are disfavored by information from the neutrino burst from supernova 1987A [11]. B. Atmospheric Neutrino Deﬁcit The second set of experiments indicating non-zero neutrino masses and mixings has to do with atmospheric νµ ’s and νe ’s arising from the decays of π ’s and K ’s and the subsequent decays of secondary muons produced in the ﬁnal states of the π and K decays. In the underground experiments the νµ and ν ¯µ produce muons and the νe and ν ¯e lead to e± . Observations of µ± and e± indicate a far lower value for νµ and ν ¯µ than suggested by na¨ ıve counting arguments which imply that N (νµ + ν ¯µ ) = 2N (νe + ν ¯e ). More precisely, the ratio of µ events to e-events can be normalized to the ratio of calculated ﬂuxes to reduce ﬂux uncertainties, giving [3] R(µ/e) = 0.60 ± 0.07 ± 0.05 (Kamiokande), = 0.54 ± 0.05 ± 0.12 (IMB), = 0.69 ± 0.19 ± 0.09 (Soudan II). Combining these results with observations of upward going muons by Kamiokande [3], IMB [3], and Baksan [12] and the negative Fr´ ejus [13] and NUSEX [14] results leads to the conclusion [15] that neutrino oscillations can give an explanation of these results, provided

Status of the Standard Model

a rXiv:h ep-ph/948349v223Aug1994STATUS OF THE STANDARD MODEL JONATHAN L.ROSNER Enrico Fermi Institute and Department of Physics,University of Chicago 5640S.Ellis Ave.,Chicago,IL 60637,USA EFI 94-38hep-ph/9408349August 1994Presented at DPF 94Meeting Albuquerque,NM,Aug.2–6,1994Proceedings to be published by World Scientiﬁc ABSTRACT The standard model of electroweak interactions is reviewed,stressing the top quark’s impact on precision tests and on determination of parameters of the Cabibbo-Kobayashi-Maskawa (CKM)matrix.Some opportunities for the study of CP violation in the decays of b -ﬂavored mesons are mentioned,and the possi-bility of a new “standard model”sector involving neutrino masses is discussed.1.Introduction Precision tests of the electroweak theory 1have reached a mature stage since their beginnings more than twenty years ago.We can now successfully combine weak and electromagnetic interactions in a description which also parametrizes CP violation through phases in the Cabibbo-Kobayashi-Maskawa (CKM)2,3matrix.The mass quoted recently by the CDF Collaboration 4for the top quark is one with which this whole structure is quite comfortable.Since this is the ﬁrst DPF Meeting at which we can celebrate the existence of more than a dozen top quark candidates rather than just one or two,it is appropriate to review the impact of the top quark’s observation in the context of a wide range of other phenomena.While the evidence for the top quark could certainly beneﬁt from a factor of four greater statistics,it seems safe to say that the top is here to stay.Looking beyond it for the next aspects of “standard model physics,”we shall propose that the study of neutrinos is a key element in this program.We begin in Section 2with a brief review of aspects of the top quark,covered more fully in Mel Shochet’s plenary talk 5and in parallel sessions.6–8Section 3is devoted to electroweak physics,while Section 4describes the present status of information aboutthe CKM matrix.Some aspects of the study of CP violation in B decays are mentioned in Section 5.We devote Section 6to a brief overview of neutrino masses and Section 7to an even briefer treatment of electroweak symmetry breaking.Section 8concludes.2.The top quark2.1.Cross section and massThe CDF Collaboration 4–6has reported m t =174±10+13−12GeV/c 2.The production cross section σ(¯p p →t ¯t +...)=13.9+6.1−4.8pb at √Fig.1.Masses of quarks and leptons on a logarithmic scale.Widths of bars denote uncer-tainties in quark masses.section in excess of QCD predictions could be a signature for new strongly interacting behavior in the electroweak symmetry breaking sector9,10or for the production of new quarks.11As we shall see,the mass quoted by CDF is justﬁne to account for loop eﬀects in electroweak processes(through W and Z self-energies)and in giving rise to B0−K0mixing.2.2.Family structure.The top quark is the last quark toﬁt into a set of three families of quarks and leptons,whose masses are shown in Fig.1:u d ; c s ; t b ;(1)νe e ; νµµ ; νττ .(2)Only theντhas not yet been directly observed.If there are any more quarks and leptons,the pattern must change,since the width of the Z implies there are only three light neutrinos.12The question everyone asks,for which we have no answer is:“Why is the top so heavy?”In Section6we shall return to this question in another form suggested byFig.1,namely:“Why are the neutrinos so light?”Althought the top quark is by far the heaviest,its separation from the charmed quark(on a logarithmic scale)is no more than the c−u separation.(Amusing exercises on systematics of quark mass ratios have been performed.13,14)The fractional errors on the masses of the heavy quarks t,b,c are actually smaller than those on the masses of the light quarks s,d,u.3.Electroweak physics3.1.Electroweak uniﬁcationIn contrast to the electromagnetic interaction(involving photon exchange),the four-fermion form of the weak interaction is unsuitable for incorporation into a theory which makes sense to higher orders in perturbation theory.Already in the mid-1930’s, Yukawa proposed a particle-exchange model of the weak interactions.At momentum transfers small compared with the mass M W of the exchanged particle,one identiﬁesG F 2=g2√8M2Z.(4) The electric charge is related to g and g′bye=g sinθ=g′/cosθ,(5) whereθis the angle describing the mixtures of the neutral SU(2)boson and U(1)boson in the physical photon and Z0.These relations can be rearranged to yieldM2W=πα2G F sin2θ;(6)M2Z=πα2G F sin2θcos2θ.(7)Using the Z mass measured at LEP12and a value of the electromagneticﬁne structure constantα(M2Z)≃1/128evaluated at the appropriate momentum scale, one obtains a value ofθand a consequent prediction for the W mass of about80GeV/c2,which is not too bad.However,one must be careful to deﬁneαproperly(in one convention it is more like1/128.9)and to take all vertex and self-energy corrections into account.Crucial contributions are provided by top quarks in W and Z self-energy diagrams.15Eq.(4)becomesG F 2ˆρ=g2+g′28π2√√16πsin2θ m2t−(175GeV)28πcos2θln M Hresult presented at this conference23and earlier measurements at CERN by the CDHS and CHARM Collaborations24,25imply M W=80.27±0.26GeV/c2.A number of properties of the Z,as measured at LEP26and SLC,27are relevant to precise electroweak tests.Globalﬁts to these data have been presented by Steve Olsen at this conference.12For our discussion we use the following:M Z=91.1888±0.0044GeV/c2,(12)ΓZ=2.4974±0.0038GeV,(13)σ0h=41.49±0.12nb(hadron production cross section),(14)Rℓ≡Γhadrons/Γleptons=20.795±0.040,(15) which may be combined to obtain the Z leptonic widthΓℓℓ(Z)=83.96±0.18MeV. Leptonic asymmetries include the forward-backward asymmetry parameter AℓF B= 0.0170±0.0016,leading to a valuesin2θℓ≡sin2θeﬀ=0.23107±0.0090,(16) and independent determinations of sin2θeﬀ=(1/4)(1−[gℓV/gℓA]from the parametersAτ→sin2θ=0.2320±0.0013,(17)A e→sin2θ=0.2330±0.0014.(18) The last three values may be combined to yieldsin2θ=0.2317±0.0007.(19) We do not use values of sin2θfrom forward-backward asymmetries in quark pair pro-duction,preferring to discuss them separately.There have been suggestions that the behavior of Z→b¯b may be anomalous,28,29while the asymmetries in charmed pair production still have little statistical weight and those in light-quark pair production are subject to some model-dependence.The result of Eq.(19)may be compared with that based on the left-right asym-metry A LR measured with polarized electrons at SLC27:sin2θ=0.2294±0.0010.(20) The results are in conﬂict with one another at about the level of two standard devia-tions.This is not a signiﬁcant discrepancy but we shall use the diﬀerence to illustrate the danger of drawing premature conclusions about the impact of electroweak mea-surements on the Higgs boson sector.3.4.Dependence of M W on m tWe shall illustrate the impact of various electroweak measurements by plotting contours in the M W vs.m t plane.30A more general language31is better for visualizing deviations from the standard model,but space and time limitations prevent its use here.As mentioned,QCD corrections to Eq.(9)are neglected.The measurements of M W via direct observation and via deep inelastic neutrino scattering,together with the CDF top quark mass,are shown as the plotted points in Fig.2.The results are not yet accurate enough to tell us about the Higgs boson mass, but certainly are consistent with theory.We next ask what information other types of measurements can provide.The dependence of sin2θeﬀon m t and M H leads to the contours of sin2ˆθ≈sin2θeﬀ−0.0003shown in Fig.3.Here sin2ˆθis a quantity deﬁned32in theFig.2.Dependence of W mass on top quark mass for various values of Higgs boson mass. Curves,from left to right:M H=50,100,200,500,1000GeV/c2.Horizontal error bars on plotted points correspond to CDF measurement of m t=174±17GeV/c2.Square:average of direct measurements of W mass;cross:average of determinations based on ratio of neutral-current to charged-current deep inelastic scattering cross sections.Fig.3.Dependence of W mass on top quark mass for various values of Higgs boson mass, together with contours of values of sin2ˆθ≈sin2θeﬀ−0.0003predicted by electroweak theory (dot-dashed lines)and measured by LEP(lower region bounded by dashed lines:1σlimits) and SLD(upper region).Fig.4.Dependence of W mass on top quark mass for various values of Higgs boson mass, together with contours of values of weak charge Q W for cesium as discussed in text.Table1.Electroweak observables described inﬁtQ W(Cs)−71.0±1.8a)−73.2b)0.970±0.025 M W(GeV/c2)80.24±0.15c)80.320d)0.999±0.002Γℓℓ(Z)(MeV)83.96±0.18e)83.90f)1.001±0.002 sin2θeﬀ0.2317±0.0007f)0.2320g)0.999±0.003 sin2θeﬀ0.2294±0.0010h)0.2320g)0.989±0.004elsewhere at this conference,12,28,29we shall be brief.If one allows Rb and the corresponding quantity for charm,Rc ≡Γ(Z →c ¯c )/Γ(Z →hadrons),to be free parameters in a combined ﬁt,the results are 38R b =0.2202±0.0020;R c =0.1583±0.0098,(21)to be compared with the standard model predictions Rb =0.2156±0.000639andR c ≈0.171.38If one constrainsR c to the standard model prediction,one ﬁnds insteadR b =0.2192±0.0018.The discrepancy is at a level of about 2σ.Predictions for R b in the standard model and in two diﬀerent two-Higgs-doublet models 39are shown in Fig.6.With appropriate choices of masses for neutral and charged Higgs bosons,it is possible to reduce the discrepancy between theory and experiment without violating other constraints on the Higgs sector.A curious item was reported 40in one of the parallel sessions ofthis conference.The forward-backward asymmetries in heavy-quark production,A 0,b F B and A 0,cF B ,havebeen measured both on the Z peak and 2GeV above and below it.All quantities arein accord with standard model expectations except for A 0,cF B at M Z −2GeV.Oﬀ-peakasymmetries can be a hint of extra Z ’s.414.The CKM Matrix4.1.Deﬁnitions and magnitudesThe CKM matrix for three families of quarks and leptons will have four indepen-dent parameters no matter how it is represented.In a parametrization 42in which the rows of the CKM matrix are labelled by u,c,t and the columns by d,s,b ,we may writeV = V ud V us V ub V cd V cs V cbV td V ts V tb ≈ 1−λ2/2λAλ3(ρ−iη)−λ1−λ2/2Aλ2Aλ3(1−ρ−iη)−Aλ21.(22)Note the phases in the elements V ub and V td .These phases allow the standard V −Ainteraction to generate CP violation as a higher-order weak eﬀect.The four parameters are measured as follows:1.The parameter λis measured by a comparison of strange particle decays with muon decay and nuclear beta decay,leading to λ≈sin θ≈0.22,where θis the Cabibbo 2angle.2.The dominant decays of b -ﬂavored hadrons occur via the element Vcb =Aλ2.Thelifetimes of these hadrons and their semileptonic branching ratios then lead to an estimate A =0.79±0.06.3.The decays of b -ﬂavored hadrons to charmless ﬁnal states allow one to measure the magnitude of the element V ub and thus to conclude that √Fig.6.Dependence of R b≡Γ(Z→b¯b)/Γ(Z→hadrons)on top quark mass.Solid curves:pre-dictions of Minimal Standard Model(MSM)for R b and R d≡Γ(Z→d¯d)/Γ(Z→hadrons). Dashed curves:two-Higgs models described in text with tanβ=70(upper)and1(lower). Data point:recent LEP and CDF measurements of R b and m top.4.The least certain quantity is the phase of V ub:Arg(V∗ub)=arctan(η/ρ).We shallmention ways in which information on this quantity may be improved,in part by indirect information associated with contributions of higher-order diagrams involving the top quark.The unitarity of V and the fact that V ud and V tb are very close to1allows us to write V∗ub+V td≃Aλ3,or,dividing by a common factor of Aλ3,ρ+iη+(1−ρ−iη)=1.(23) The point(ρ,η)thus describes in the complex plane one vertex of a triangle whose other two vertices are(0,0)and(0,1).4.2.Indirect informationBox diagrams involving the quarks with charge2/3are responsible for B0−K0mixing in the standard model.Since the top quark provides the dominant contribution,one obtains mainly information on the phase and magnitude of V td.The evidence for B0−K0mixing arises from an imaginary part in the mass matrix which is dominated by top quark contributions in the loop,with small corrections from charm.In the limit of complete top dominance one would have Im M∼f2K Im(V2td)∼η(1−ρ),so thatǫ=(2.26±0.02)×10−3would specify a hyperbola in the(ρ,η)plane with focus(1,0).The eﬀect of charm is to shift the focus to about(1.4,0).4.3.Constraints onρandηWhen one combines the indirect information from mixing with the constraint on (ρ2+η2)1/2arising from|V ub/V cb|,one obtains the allowed region shown in Fig.7.Here, in addition to parameters mentioned earlier,we have taken|V cb|=0.038±0.003,the vacuum-saturation factor B K=0.8±0.2,andηB B B=0.6±0.1,whereηB refers to a QCD correction.Standard QCD correction factors are taken in the kaon system.44We have also assumed f B=180±30MeV,for reasons to be described presently.The center of the allowed region is near(ρ,η)=(0,0.35),with values ofρbetween −0.3and0.3and values ofηbetween0.2and0.45permitted at the1σlevel.The main error on the constraint from(∆m/Γ)B arises from uncertainty in f B,while the main error on the hyperbolae associated withǫcomes from uncertainty in the parameter A, which was derived from V cb.Other sources of error have been tabulated by Stone at this conference.45Fig.7.Region in the(ρ,η)plane allowed by various constraints.Dotted semicircles denote central value and±1σlimits implied by|V ub/V cb|=0.08±0.02.Circular arcs with centers at(ρ,η)=(1,0)denote constraints from B−K mixing.4.4.Improved testsWe can look forward to a number of sources of improved information about CKM matrix elements.464.4.1Decay constant information on f B aﬀects the determination of|V td|(and henceρ)via B0−basis of the value taken above,where we inﬂated the error arbitrarily.]We also obtainf B s=(225±15)MeV from the ratio based on the quark model.4.4.2Rates and ratios can constrain|V ub|and possibly|V td|.The partial width Γ(B→ℓν)is proportional to f2B|V ub|2.The expected branching ratios are about (1/2)×10−4forτνand2×10−7forµν.Another interesting ratio58isΓ(B→ργ)/Γ(B→K∗γ),which,aside from phase space corrections,should be|V td/V ts|2≃1/20.At this conference,however,Soni59has argued that there are likely to be long-distance correc-tions to this relation.4.4.3The K+→π+ν¯νrate is governed by loop diagrams involving the cooper-ation of charmed and top quark contributions,and lead to constraints which involve circles in the(ρ,η)plane with centers at approximately(1.4,0).60The favored branch-ing ratio is slightly above10−10,give or take a factor of2.A low value within this range signiﬁesρ>0,while a high value signiﬁesρ<0.The present upper limit60is B(K+→π+ν¯ν)<3×10−9(90%c.l.).4.4.4The decays K L→π0e+e−and K L→π0µ+µ−are expected to be dominated by CP-violating contributions.Two types of CP-violating contributions are expected:“indirect,”via the CP-positive component K1component of K L=K1+ǫK2,and “direct,”whose presence would be a detailed veriﬁcation of the CKM theory of CP violation.These are expected to be of comparable magnitude in most61,62but not all63calculations,leading to overall branching ratios of order10−11.The“direct”CP-violating contribution to K L→π0ν¯νis expected to be dominant,making this process an experimentally challenging but theoretically clean source of information on the parameterη.614.4.5The ratioǫ′/ǫfor kaons has long been viewed as one of the most promising ways to disprove a“superweak”theory of CP violation in neutral kaon decays.61,64The latest estimates65are equivalent(for a top mass of about170GeV/c2)to[ǫ′/ǫ]|kaons= (6±3)×10−4η,with an additional factor of2uncertainty associated with hadronic matrix elements.The Fermilab E731Collaboration66measuresǫ′/ǫ=(7.4±6)×10−4, consistent withηin the range(0.2to0.45)we have already speciﬁed.The CERN NA31Collaboration67ﬁndsǫ′/ǫ=(23.0±6.5)×10−4,which is higher than theoretical expectations.Both groups are preparing new experiments,for which results should be available around1996.4.4.6B s−B s mixing?”The ratio of squares of decay constants for strange and nonstrange B mesons is expectedTable2.Dependence of mixing parameter x s on top quark mass and B s decay constant.f B s(MeV)1507.68.910.220013.515.818.225021.124.728.4=(1.19±0.10) V ts∆m dB0→J/ψK S,whose rate asymmetry is sensitive to sin[Arg(V2td)]≡sin(2β).It is necessary to know whether the decaying neutral B me-son was a B0or aFig.8.P-wave nonstrange resonances of a c quark and a light(¯u or¯d)antiquark.Check marks with or without parentheses denote observation of some or all predicted states.5.2.π−B correlationsThe correlation of a neutral B meson with a charged pion is easily visualized with the help of quark diagrams.By convention(the same as for kaons),a neutral B meson containing an initially produced¯b is a B0.It also contains a d quark.The next charged pion down the fragmentation chain must contain a¯d,and hence must be aπ+. Similarly,a¯B0will be correlated with aπ−.The same conclusion can be drawn by noting that a B0can resonate with a positive pion to form an excited B+,which we shall call B∗∗+(to distinguish it from the B∗,lying less than50MeV/c2above the B).Similarly,a¯B0can resonate with a negative pion to form a B∗∗−.The combinations B0π−and¯B0π+are exotic,i.e., they cannot be formed as quark-antiquark states.No evidence for exotic resonances exists.Resonant behavior in theπ−B(∗)system,if discovered,would be very helpful in reducing the combinatorial backgrounds associated with this method.The lightest states which can decay to Bπand/or B∗πare P-wave resonances of a b quark and a¯u or¯d.The expectations for masses of these states may be based on ex-trapolation from the known D∗∗resonances,for which present data74and predictions75 are summarized in Fig.8.The1S(singlet and triplet)charmed mesons have all been observed,while CLEO74 has presented at this conference evidence for all six(nonstrange and strange)1P states in which the light quarks’spins combine with the orbital angular momentum to form a total light-quark angular momentum j=3/2.These states have J=1and J=2. They are expected to be narrow in the limit of heavy quark symmetry.The strange1P states are about110MeV heavier than the nonstrange ones.In addition,there areexpected to be much broader(and probably lower)j=1/2D∗∗resonances with J=0 and J=1.For the corresponding B∗∗states,one should add about3.32GeV(the diﬀerence between b and c quark masses minus a small correction for binding).One then predicts75 nonstrange B∗∗states with J=(1,2)at(5755,5767)MeV.It is surprising that so much progess has been made in identifying D∗∗’s without a corresponding glimmer of hope for the B∗∗’s,especially since we know where to look.5.3.Decays to pairs of light pseudoscalarsThe decays B→(ππ,πK,K¯K)are a rich source of information on both weak (CKM)and strong phases,if we are willing to useﬂavor SU(3)symmetry.The decays B→ππare governed by transitions b→dq¯q(q=u,d,...)with∆I= 1/2and∆I=3/2,leading respectively toﬁnal states with I=0and I=2.Since there is a single amplitude for eachﬁnal isospin but three diﬀerent charge states in the decays,√2A(π+π0).The the amplitudes obey a triangle relation:A(π+π−)−triangle may be compared with that for the charge-conjugate processes and combined with information on time-dependent B→π+π−decays to obtain information on weak phases.76The decays B→πK are governed by transitions b→sq¯q(q=u,d,...)with ∆I=0and∆I=1.The I=1/2ﬁnal state can be reached by both∆I=0and∆I=1 transitions,while only∆I=1contributes to the I=3/2ﬁnal state.Consequently,there are three independent amplitudes for four decays,and one quadrangle relation √2A(π0K0).As in theππcase,this relation A(π+K0)+may be compared with the charge-conjugate one and the time-dependence of decays to CP eigenstates(in this caseπ0K S)studied to obtain CKM phase information.77 We re-examined72SU(3)analyses78of the decays B→P P(P=light pseu-doscalar).They imply a number of useful relations amongππ,πK,and K¯K decays, among which is one relating B+amplitudes alone:√2A(π+π0).(27) A(π+K0)+Here˜r u≡(f K/fπ)|V us/V ud|.This expression relates one side of theππamplitude triangle to one of the diagonals of theπK amplitude quadrangle,and thus reduces the quadrangle eﬀectively to two triangles,simplifying previous analyses.77Moreover, since one expects theπ+K0amplitude to be dominated by a penguin diagram(with expected weak phaseπ)and theπ+π0amplitude to have the phaseγ=Arg V∗ub,the comparison of this last relation and the corresponding one for charge-conjugate decays can provide information on the weak phaseγ.We have estimated44that in order to measureγto10◦one needs a sample including about100events in the channelsπ0K±.Further relations can be obtained72by comparing the amplitude triangles involv-ing both charged and neutral B decays toπK.By looking at the amplitude triangles for these decays and their charge conjugates,one can sort out a number of weak and strong phases.Some combination of the decays B0→π+π−and B0→π−K+has already been observed,80and updated analyses in these and other channels have been presented at this conference.816.Neutrino masses and new mass scales6.1.Expected ranges of parametersReferring back to Fig.1in which quark and lepton masses were displayed,we see that the neutrino masses are at least as anomalous as the top quark mass.Thereare suggestions that the known(direct)upper limits are far above the actual masses, enhancing the puzzle.Why are the neutrinos so light?A possible answer82is that light neutrinos acquire Majorana masses of orderm M=m2D/M M,where m D is a typical Dirac mass and M M is a large Majorana mass acquired by right-handed neutrinos.One explanation83of the apparent deﬁcit of solarneutrinos as observed in various terrestrial experiments invokes matter-inducedνe→νµoscillations in the Sun84with a muon neutrino mass of a few times10−3eV.With aDirac mass of about0.1to1GeV characterizing the second quark and lepton family, this would correspond to a right-handed Majorana mass M M=109−1012GeV.As stressed by Georgi in his summary talk,85nobody really knows what Dirac mass to use for such a calculation,which only enhances the value of experimental information on neutrino masses.However,using the above estimate,and taking a Dirac mass for the third neutrino characteristic of the third quark and lepton family(in the range of2to 200GeV),one is led by the ratios in Fig.1to expect theντto be at least a couple of hundred times as heavy as theνµ,and hence to be heavier than1eV or so.This begins to be a mass which the cosmologists could use to explain at least part of the missing matter in the Universe.86Ifνµ↔ντmixing is related to ratios of masses,one might expect the mixing angle to be at least mµ/mτ,and hence sin22θto exceed10−2.6.2.Present limits and hintsSome limits on neutrino masses and mixings have been summarized at a recentSnowmass workshop.87The E531Collaboration88has set limits forνµ→ντoscillations corresponding to∆m2<1eV2for largeθand sin22θ<(a few)×10−3for large∆m2. The recent measurement of the zenith-angle dependence of the apparent deﬁcit in the ratio of atmosphericνµtoνe–induced events in the Kamioka detector89,90can be interpreted in terms of neutrino oscillations(eitherνµ→νe orνµ→ντ),with∆m2 of order10−2eV2.In either case maximal mixing,withθ=45◦,is the most highly favored.We know of at least one other case(the neutral kaon system)where(nearly) maximal mixing occurs;perhaps this will serve as a hint to the pattern not only of neutrino masses but other fermion masses as well.However,it is not possible toﬁt the Kamioka atmospheric neutrino eﬀect,the apparent solar-neutrino deﬁcit,and a cosmologically signiﬁcantντusing naive guesses for Dirac masses and a single see-saw scale.Various schemes have been proposed involving near-degeneracies of two or more neutrinos or employing multiple see-saw scales.6.3.Present and proposed experimentsOpportunities exist and are starting to be realized forﬁlling in a substantial portion of the parameter space for neutrino oscillations.New short-baseline experiments are already in progress at CERN91,92and approved at Fermilab.93These are capable ofpushing theνµ↔ντmixing limits lower for mass diﬀerences∆m2of at least1eV2.New long-baseline experiments94would be sensitive in the same mass range as the Kamioka result to smaller mixing angles.At this conference we have heard a preliminary result from a search for¯νµ→¯νe oscillations using¯νµproduced in muon decays.95An excess of events is seen which,if interpreted in terms of oscillations,would correspond to∆m2 of several eV2.(No evidence for oscillations was claimed.)A further look at the solar neutrino problem will be provided by the Sudbury Neutrino Observatory.96 We will not understand the pattern of fermion masses until we understand what is going on with the neutrinos.Fortunately this area stands to beneﬁt from much experimental eﬀort in the next few years.6.4.Electroweak-strong uniﬁcationAnother potential window on an intermediate mass scale is provided by the pat-tern of electroweak-strong uniﬁcation.If the strong and electroweak coupling constants are evolved to high mass scales in accord with the predictions of the renormaliza-tion group,97as shown in Fig.9(a),they approach one another in the simplest SU(5) model,98but do not really cross at the same point.This“astigmatism”can be cured by invoking supersymmetry,99as illustrated in Fig.9(b).Here the cure is eﬀected not just by the contributions of superpartners,but by the richer Higgs structure in supersym-metric theories.The theory predicts many superpartners below the TeV mass scale, some of which ought to be observable in the next few years.Alternatively,one can embed SU(5)in an SO(10)model,100in which each family of quarks and leptons(together with a right-handed neutrino for each family)ﬁts into a16-dimensional spinor representation.Fig.9(c)illustrates one scenario for breaking of SO(10)at two diﬀerent scales,the lower of which is a comfortable scale for the breaking of left-right symmetry and the generation of right-handed neutrino Majorana masses.6.5.BaryogenesisThe ratio of baryons to photons in our Universe is a few parts in109.In1967 Sakharov101proposed three ingredients of any theory which sought to explain the preponderance of baryons over antibaryons in our Universe:(1)violation of C and CP;(2)violation of baryon number,and(3)a period in which the Universe was out of thermal equilibrium.Thus our very existence may owe itself to CP violation.However, no consensus exists on a speciﬁc implementation of Sakharov’s suggestion.A toy model illustrating Sakharov’s idea can be constructed within an SU(5) grand uniﬁed theory.The gauge group SU(5)contains“X”bosons which can decay both to uu and to e+¯d.By CPT,the total decay rates of X and¯X must be equal,but CP-violating rate diﬀerencesΓ(X→uu)=Γ(¯X→¯u¯u)andΓ(X→e+¯d)=Γ(¯X→e−d)are permitted.This example conserves B−L,whereB is baryon number(1/3 for quarks)and L is lepton number(1for electrons).It was pointed out by’t Hooft102that the electroweak theory contains an anomaly as a result of nonperturbative eﬀects which conserve B−L but violate B+L.If a theory leads to B−L=0but B+L=0at some primordial temperature T,the anomaly can wipe out any B+L as T sinks below the electroweak scale.103Thus,the toy model mentioned above and many others are unsuitable in practice.。

Concentrationmeasurement：

Concentration MeasurementBackground:It’s very important to be able to measure the concentration of various substances in a solution. If we use a certain amount of a solution in a reaction, we would really like to know the number of molecules we used, not just the volume we poured in. If we made the solution ourselves, and did it carefully, then we know the concentration, but if we use a solution that someone else made… we have to trust them, or measure it ourselves. If we use a solution that has been sitting around for a long time… the concentration MIGHT still be what is marked on the label, but it might also have changed, if reactions have occurred in the interim.Measuring the concentration of a solution is tricky, since there are no “concentration meters.” We must calculate the concentration from other measurements.We can often measure the concentration of a solution by comparing the properties of the solution to other solutions, where we know the concentrations.•If the solute absorbs visible light, a concentrated solution will have a deeper coloration than a more dilute solution. Two solutions of the same compound that absorb the same amount of light have the same concentration.•Some compounds break into ions (positively and negatively charged bits) in water. A solution of that compound will conduct electricity. The conductivity of the solution will depend upon the number of movable ions. Two solutions of the same compound that conduct equally well have the same concentration.I will give you detailed directions for Part 1 of this lab, but you are going to generate your own procedures for Part 2.Part 1: Finding Concentration using a Colorimeter (Absorbance) Probe: Preparing the solutionsMake five standard NiCl2 solutions. Nickel chloride crystals have water moleculestrapped within them. The mass of water must be considered, or the moles of nickelchloride will be incorrect. The symbol NiCl2•6H2O means that there are six watermolecules for every nickel chloride, so the molecular mass should include those eighteen atoms. You will need to perform the appropriate calculations before you come to class. If you have not done the calculations you will be unable to start the experiment. Check your work with your lab partner.Prepare 50.0 ml of a 0.260M solution of NiCl2• 6H2O.How many grams of the solid do you need to mass out?From that solution (solution 1) prepare 50.0 ml of a 0.200M solution.What volume of solution 1 do you need to use, to make solution 2?You will still have some leftover 0.260M solution for the tests.Put the extra into a test tube labeled #1.From solution 2, prepare 50.0 ml of a 0.160M solution.What volume of solution 2 do you need to use, to make solution 3?You will still have some leftover 0.200M solution for the tests.Put the extra into a test tube labeled #2.From solution 3, prepare 50.0 ml of a 0.120M solution.What volume of solution 3 do you need to use, to make solution 4?You will still have some leftover 0.160M solution for the tests.Put the extra into a test tube labeled #3.From solution 4, prepare 50.0 ml of a 0.100M solution.What volume of solution 4 do you need to use, to make solution 5?You will still have some leftover 0.120M solution for the tests.Put the extra into a test tube labeled #4.Put solution 5 into a test tube labeled #5. (If there is extra, leave it in the flask.) Preparing the Absorbance samples:Fill a cuvette (small container used in the colorimeter device) with each solution. Keep them in order, and put numbered lids on the cuvettes.The cuvettes each contain about 4 ml of liquid.Carefully, blot dry the outside of each cuvette. Try not to scratch the surfaces. Do not touch the smooth sides with your hands.Recording Absorbance data:The colorimeter is used to measure how much light of a given wavelength is absorbed by a sample. If the sample is more concentrated, it absorbs more light. As long as ALL ofthe light is not absorbed, the relationship can be determined. For NiCl2 we will set thecolorimeter to 635nm (red light, well absorbed by the green solution). Before putting any samples in the colorimeter, use the left & right arrows to select 635nm, put a cuvette filled with water into the compartment (see below for directions), and then push CAL to calibrate the device. If you are using one of the older colorimeters I will show you how to calibrate it during lab.To insert a cuvette, hold it by the ridged sides, not the clear sides, and insert it into the square well underneath the cover. The clear sides should be pointing front and back, the ridged sides, left and right. Close the cover.Using the “events with entry” mode on the LabQuest, measure the absorbance of each solution. The “value” to enter is the concentration of the solution. Inspect the data. If there is a definite pattern your solutions were well made. Record your data.Using a sixth cuvette, filled with the solution of unknown concentration, measure its absorbance. Comparing the absorbance measured with the graph you will plot, determine the concentration of the unknown solution.-----------------------------------------------------------------------------------------------------------It’s pretty cool that we can use the colorimeter to find the concentrations of solutions that are colored. But, if a solution is NOT colored, the colorimeter will not be helpful. Fortunately there are other devices that we can use.Part 2: Finding Concentration using a Conductivity Probe:You will need to come up with your own procedures for this part.We would like to find the concentration of salt in seawater. However, since we don’t want to deal with plankton and that sort of thing, we’re going to use a sample of water from a salt-water aquarium instead. As mentioned above, we want to make comparisons to solutions of known concentrations. We have plenty of solid NaCl in our lab. Consider Part 1 of this lab as you plan your Part 2 experiments. What calculations will you need to do?Our conductivity meter will not measure accurately for NaCl solutions with a concentration greater than 0.200M.What do you want to do first?What decisions do you need to make before moving on?How will you know if your data is meaningful?Comparing the conductivity measured with the graph you will plot, determine the concentration of the unknown solution.Recording conductivity data:The conductivity probe is used to measure how conductive the solution is.Select the 0 –20,000 µS setting on the probe box.To measure conductivity, the probe simply needs to be placed in a test tube containing the solution. The opening at the bottom must be fully immersed.Using the “events with entry” mode on the LabQuest, measure the conductivity of all solutions (of known and unknown concentration). Rinse and dry the conductivity probe before each measurement. Record your data.Analysis (and later discussion.)Plot a graph (in your lab notebook) of the absorbance data. It should be at least one-half page in size. What is your independent variable (x-axis)? What is your dependent variable (y-axis)? The scales you use for each variable should be evenly spaced, although your data points will not be. The origin of your graph should be (0,0). Do not offset your graph. Draw a “best-fit” line or curve (as appropriate) to your data.Plot a graph of the conductivity data. Consider the graphing tips above.unknown?What was the concentration of the NiCl2What was the concentration of salt in seawater?Analysis should include a discussion of the sources of systematic error in the experiments.How do these two methods compare? Which method was easier? Which method was more accurate? Which method was more interesting?When do scientists use each of these methods? Do you ever use these methods yourself? (Albeit without the devices) Make lab-to-world connections.Write a clear conclusion paragraph, detailing (but not repeating the entire analysis) what was learned from these experiments.。

宏欧威测试仪 macroevtest说明书

More than safe, sure.N E WT ester for checks on electriccar recharging stations andverification of domestic andindustrial electric systemsMor e than safe,sure.MACRO EV TESTMA CROEVTEST , HT's new product for verification and checks on recharging stations for electric cars (EVSE) in compliance with standards IEC/EN 61851-1 and IEC/EN60364-7-722, and for safety tests in private and industrial environmentsRecharging stations: a new way to use electric energy .BUILT-IN CABLETOUCH SCREEN SYSTEMTYPE 2* PLUG * other plugs available on demandWIFICONNECTIONCHECKS ON RECHARGING ST A TIONS FOR ELECTRIC CARSConnection is simple.MacroEVtest is connected through the provided C100EV cable to EV-Test100, which is connected, through an in-built cable provided with type2 plug, to a recharging station.SIMPLIFIESEV-Test100 can simulate the presence of a car beingrecharged and, at the same time, dialogues with MacroEVtest thanks to the new display with touch screen system , peculiar to HT's latest generation devices.SIMULATESTo correctly perform all tests, all you need to do is following the GUIDED PROCEDURE created by HT for this innovative instrument.GUIDESBefore each test, MacroEVtest indicates how the cables must precisely be connected and, at the end of measurement, further to the detected values, it provides evaluations of the tests' outcomes , if compatible or not for the recharging station's safety , indicated by a green or red thumb symbol.CONNECTS› CONTINUITY test of the recharging station's protection conductor › INSULATION test of the recharging station› Verification of the STATUSES of the recharging station › Measurement of OVERALL EARTH RESISTANCE› Verification of the RCD's tripping (test of RCDs type A, B and type B 6ma)› Vehicle not present› Vehicle present but not being charged › Vehicle present and being charged› Events and anomalies which can be detected during the recharging phase › Simulation of a fault on the protection conductor› Indication of the presence of voltages on the EVSE output connector through LED› Verification of the mechanical lock in the connection to the station: it is possible to check that the station, during the recharging phase, blocks the cable release (if the station is provided with this function)TESTSSTANDARDSVERIFICA TION TESTS ANDSIMULA TIONSSAFETY CHECKS ON PRIV A TE AND INDUSTRIAL SYSTEMSThe TFT colour display with touch-screen allows for a new and more versatile use of the instrument.MacroEVtest offers on its display all possible alternatives for the performance of a perfect measurement.The new system adopted by HT allows optimally preparing the instrument, before performing a test, by suggesting the most suitable connections to certify correct and reliable tests .The AUTO function, in the system menu, allows performing the tests very quickly .At the end of each test, further to the measured value,MacroEVtest provides an evaluation of the result , indicating whether it complies or not with standards.All tests can be saved and, in order to create a printablereport , data can be transferred via WiFi to a PC , smart phone or tablet .MEASURESPREPARESVALIDATESIEC/EN 60364STANDARDSTESTS› T est of RCDs type A, type AC also up to 1000 mA and type B. By using the accessory RCDX10, provided with the instrument, it is also possible to test RCDs with external jaws up to 10 A.› Insulation tests up to 1000V › Continuity tests› T ests of overall earth resistance and voltammetric resistance (further than with the provided rods, this latter test can also be performed by means of the optional clamp T2100).› With the appropriate programming guided by the touch-screen system, this device can test theinterruption power, tripping currents, I2t relevant to magneto-thermal switches (MCB) with curves B, C, D, K and fuses type gG and aM› Loop/Line impedance measurements and calculation of the assumed short-circuit current with high resolution (0.1mOhm) in TN systems with the use of the optional accessory IMP57HT ITALIA S.R.L.Via della Boaria, 40 48018 Faenza (RA) ItalyM AD EIT AL YINAccuracy is indicated as ± (% readings + no. of digits*resolution) at 23°C ± 5°C, <80%RHTest current: > 200mA DC for R≤5Ω (calibration included) ; Resolution for DC current :1mA Open-circuit voltage: 4V ≤ V0≤ 12VShort circuit current: <6.0mA at 500V test voltageNominal test current: >1mA if load= 1kΩ*Vnom (Vnom=50V, 100V, 250V, 500V, 1000V)Safety protection: the display shows an error message for input voltage >10VMaximum test current: 5.81A (at 265V); 10.10A (at 457V)Test voltage ranges: 100÷265V (Line-Neutral) / 100÷460V (Line-Line); 50/60Hz ± 5%Protection type: MCB (B, C, D, K), Fuse (gG, aM)RCD type:AC (), A (), B() – General (G), Selective (S) and Delayed () Rated tripping currents (I ∆N):: 6mA, 10mA, 30mA, 100mA, 300mA, 500mA, 650mA, 1000mA Line-PE, Line-N voltage: 100V ÷265V RCD type AC and A, 190V ÷265V RCD type B Frequency:50/60Hz ± 5%RCD Molded type tripping time range [ms] (TT/TN system)x 1/2 x 1 x 2 x 5 AUTOAUTO+\G S G S G SGS GS G SGS6mAAC 999 999 999 999 999 999 160 210 50 150 ✓ ✓ 310 ✓ A 999 999 999 999 999 999 160 210 50 150 ✓ ✓ 310 ✓ B 999 999 999 999 999 999 310 10mAAC 999 999 999 999 999 999 160 210 50 150 ✓ ✓ 310 ✓ A 999 999 999 999 999 999 160 210 50 150 ✓ ✓ 310 ✓ B 999 999 999 999 999 999 310 30mAAC 999 999 999 999 999 999 160 210 50 150 ✓ ✓ 310 ✓ A 999 999 999 999 999 999 160 210 50 150 ✓ ✓ 310 ✓ B 999 999 999 999 999 999 310 100mAAC 999 999 999 999 999 999 160 210 50 150 ✓ ✓ 310 A 999 999 999 999 999 999 160 210 50 150 ✓ ✓ 310 B 999 999 999 999 999 999 310 300mA AC 999 999 999 999 999 999 160 210 50 150 ✓ ✓ 310 A 999 999 999 999 999 999 160 210 50 150 ✓ ✓ 310 B 999 999 999 999 999 999 310 500mA 650mAAC 999 999 999 999 999 999 160 210 50 150 ✓ ✓ 310 A 999 999 999 999 999 999 160 210 310 B1000mAAC 999 999 999 999 999 999 160 210A 999 999 999 999 999 999 BResolution: 1ms, Accuracy: ±(2.0%rdg + 2dgt)RCD Molded type tripping time range [ms] (IT system)x 1/2 x 1 x 2x 5AUTOAUTO+ \GSG S GS G S G S G S G S6mA10mA 30mA AC 999 999 999 999 999 999 160 210 50 150✓ ✓ 310 ✓ A B 100mA 300mA 500mA 650mA AC 999 999 999 999 999 999 160 21050 150 ✓ ✓ 310 AB1000mA AC 999 999 999 999 999 999 160 210ABResolution: 1ms, Accuracy: ±(2.0%rdg + 2dgt)RCD type:AC (), A (), B() – General (G), Selective (S) and Delayed () Rated tripping currents (I ∆N):: 0.3A ÷ 10ALine-PE, Line-N voltage: 100V ÷265V RCD type AC and A, 190V ÷265V RCD type BEarth leakage delay tester RCDs trip out time range [ms] (TT/TN system)x 1/2 x 1 x 2 x 5 AUTO\G S G S GS GSG SG S0.3A ÷ 1.0A AC 999 999 999 999 999 999 200 250 50 150 ✓ ✓ 310 A 999 999 999 999 999 999 200 250 50 150 ✓ ✓ 310 B 999 999 999 999 999 999 310 1.1A ÷ 3.0A AC 999 999 999 999 999 999 200 250 50 150 ✓ ✓ 310 A 999 999 999 999 999 999 200 250 50 150 ✓ ✓ 310 B 999 999 999 999 999 999 3.1A ÷ 6.5A AC 999 999 999 999 999 999 200 250 50 150 ✓ ✓ 310 A 999 999 999 999 999 999 200 250 50 150 ✓ ✓ 310 B 9999999999999999996.6A ÷ 10.0AAC 999 999 999 999 999 999 200 250 A 999 999 999 999 999 999 BResolution: 1ms, Accuracy: ±(2.0%rdg + 2dgt)Earth leakage delay tester RCDs trip out time range [ms] (IT system)x 1/2x 1 x 2x 5 AUTO\ G SG SG S G S G SG S 0.3A ÷ 3.0A AC 999 999 999 999 999 999 200 250 50 150 ✓ ✓310 A B 3.1A ÷ 6.5A AC 999 999 999 999 999 999 200 250 50 150 ✓ ✓ 310 A B 6.6A ÷ 10.0AAC 999 999 999 999 999 999 200 250 A BResolution: 1ms, Accuracy: ±(2.0%rdg + 2dgt)NoTripTest – Non-trip earth loop impedanceN N N N N N N N N N(*) Add 5% to the accuracy if the probe resistances (Rs or Rh) > 100 x RmeasTest current: <10mA – 77.5Hz, Open-circuit voltage: < 20VrmsAllowed crest factor ≤ 3; Frequency: 42.5 ÷ 69.0 HzDISPLAY AND MEMORY:Features: Touch screen, color graphic LCD, 320x240mm Memory: 999 locations, 3 marker levelsCommunication: Optical-USB and built-in WiFiPOWER SUPPLY:Batteries: 6 x 1.2V(rechargeable) type AA or 6 x 1.5V type AA Battery life: > 500 test for each funtionsAuto Power OFF: after 5 min of idleness (disabled)MECHANICAL FEATURES:Dimensions (L x W x H): 225 x 165 x 75mmWeight (included batteries): 1.2kgWORKING ENVIRONMENTAL CONDITIONS:Reference temperature: 23°C ± 5°CWorking temperature: 0°C ÷ 40°CAllowed relative humidity: <80%RHStorage temperature: -10°C ÷ 60°CStorage humidity: <80%RHTEST VERIFIES REFERENCE STANDARDS:Continuity test with 200mA: IEC/EN61557-4Insulation resistance: IEC/EN61557-2Earth resistance: IEC/EN61557-5Fault loop impedance: IEC/EN61557-3RCD test: IEC/EN61557-6Phase sequence: IEC/EN61557-7Multifunction: IEC/EN61557-10Prospective short circuit current: EN60909-0Earth resistance on TN systems: EN61936-1 + EN50522Test on EVSE devices: IEC/EN61851-1, IEC/EN60364-7-722 (with EV-TEST100) GENERAL REFERENCE STANDARDS:Safety of measuring instruments: IEC/EN61010-1, IEC/EN61010-031, IEC/EN61010-2-032 Product type standard: IEC/EN61557-1Technical documentation : IEC/EN61187Insulation: double insulationPollution degree: 2Encapsulation : IP40Overvoltage category: CAT IV 300V~ (to ground), max 415V between inputs Max height of use: 2000m。

MATTER, ENERGY AND LIFE

Chapter 3 MATTER, ENERGY AND LIFEEvery organism uses matter and energy from its environment and transforms them into structures and processes that make life possible.The physical and chemical principles that govern the universe also govern the composition and metabolic processes of living organisms.Organisms are made of inorganic compounds and organic compounds.MATTER AND FUNDAMENTAL PARTICLESMatter is anything that has mass and takes up space.Weight is a measurement of the pull of the Earth's gravity on an object.•Weight changes with distance.•Mass of an object is constant regardless of distance.Matter is transformed and recombined but it doesn’t disappear. This is the principle of conservation of matter.Elements are the simplest substances. They cannot be broken down into simpler substance by chemical reactions.An atom is the simplest portion of an element that retains its chemical properties.Each element has its own characteristic atom represented by a chemical symbol.Subatomic particles: protons, neutrons and electrons.The number of protons, atomic number, identifies the atom.Protons carry a positive electrical charge; neutrons are electrically neutral, and electrons are negative.The number of protons and neutrons determines the mass of the atom, atomic mass.The mass of the electron is 1/1800 of the mass of a proton or neutron, and it is disregarded in calculating the atomic mass of an atom.Isotopes of an element are atoms that have the same number of protons and different number of neutrons.Some isotopes are radioactive and are called radioisotopes.CHEMICAL BONDSAtoms may combine chemically, bond, to form molecules.Molecules of an element have atoms of the same kind, e.g. H2, N2.A chemical compound is made of different type atoms, e.g. H2O, Ca(OH)2.Molecular formulas describe the atomic composition of one molecule of the compound.The forces that hold atoms together are called chemical bonds.Each bond contains certain amount of energy called chemical energy. This energy can be released in certain chemical reactions.Bonds vary in stability. Some are stable and form strong bonds that require a lot of energy to break apart. Others are weak and break with very little energy.Atoms share electrons when they form covalent bonds.The carbon atom can form four covalent bonds making it possible to make the many complex molecules found in living organisms.Atoms with equal number of protons and neutrons are electrically neutral.IONS, ACIDS AND BASESAtoms can loose or gain electrons and become electrically charged in the process. These electrically charged atoms or molecules are called ions.•Atoms that gain an electron become negative, 1- charge, and are called negative ions.We say this atom is reduced.•Atoms that loose an electron become positive, 1+ charge, and are called positive ions.We say this atom is oxidized.Example: HCl can split into H+ and Cl-.Here the hydrogen atom gave up one electron to the chlorine atom and became positive, which is 1+ or H+; the chlorine atom gained one electron and its negative charges went up by one. It is now 1- or Cl-.Compounds that release hydrogen ions are called acids and those that combine readily with hydrogen ions are called bases.The pH scale describes the number of free hydrogen ions in a solution.• A pH of 7 is neutral; a pH less than 7 is acidic and above 7 is basic.•The scale is logarithmic, which means that a pH6 represent ten times more hydrogen ions in solution than pH7.Some ions like those of Na+ and Cl- can attract each other and form ionic bonds. These bonds could be very strong like those formed by sodium chloride, table salt.Water molecules form hydrogen bonds. These bonds give water some of its important chemical and physical characteristics.Substances that release hydrogen ions (H+) in water are called acids.Substances that readily bond with hydrogen ions (H+) are called bases or alkaline substances. The pH scale measures the concentration of hydrogen ions (protons) in a solution.It is based on the negative logarithm of its concentration of H+.Example: 10-6 concentration of H+ has a pH of 6; a concentration of 10-5 has a pH of 5, which is ten times stronger than pH 6.Notice that the concentration of H+ increases as pH declines.A pH of 10 has an acid concentration of 10-10 and a hydroxide concentration of 10-4. This is a basic or alkaline solution.7 is neutral. Below 7 is acid and above 7 is basic or alkaline.ORGANIC COMPOUNDSOrganic compounds are so named because they were thought to be produced only by living organisms.Organic compounds contain carbon.There are simple carbon compounds that are considered inorganic especially if they do not contain hydrogen, e.g. CO, CO2.Carbon atoms form chains and rings that form different organic molecules found in the body of plants and animals. These are called biomolecules.Lipids, proteins, carbohydrates and nucleic acids are the principal biomolecules.•Lipids (fats and oils) are important components of cell membranes.•Carbohydrates are sources of energy and also form part of supporting structures, e.g.cellulose forms the cell wall of plants.•Proteins are involved in the structure and function of cells, e.g. structure of cell membrane; enzymes are proteins.•Nucleic acids are very complex molecules. They store genetic information and direct the life processes.CELLS1. Cells are the basic unit of structure and function of all living things.2. All cells come from preexisting cells.All cells have a similar organization:•semipermeable plasma membrane that surrounds the cell•internal structures called organelles.•DNA that contains the genetic material..Organisms may be unicellular or multicellular.A membrane, the plasma membrane, surrounds cells.The plasma membrane is made of lipids, proteins and a few carbohydrates.The plasma membrane regulates what enters and leaves the cell.Inside the cells there are "organelles" that perform different functions and permit the cell to operate.Enzymes are proteins that act as catalysts. These catalysts are specialized and permit life functions to take place.Metabolism is the sum of all the enzymatic reactions taking place in the body of an organism. ENERGYBasic conceptsEnergy is the capacity to do work.•Energy is measured in joules. One joule can move one kilogram one meter.• 1 kg = 2.2.pounds.Work is any change in the state or motion of an object.Energy can change form.Kinetic energy is the energy of motion.Potential energy is stored energy. It depends on the location and structure of matter.•Chemical energy stored is food (e.g. sugars) is a form of potential energy.Heat is the energy that can be transferred between objects of different temperature. It is the total amount of kinetic energy in a substance that its bulk is not moving.Temperature is the measure of the energy of motion of molecules.• A substance can have high heat content and low temperature!•Low average molecular speed.•Large mass with many moving molecules and atoms.ThermodynamicsThermodynamics regulates energy transfer.Matter is recycled. It changes forms but it is neither created nor destroyed.1. First law of thermodynamics.•Energy of the universe is constant.•Energy-mass cannot be created nor destroyed.•Energy may be transformed, e.g. from a energy in a chemical bond to heat energy.2. Second law of thermodynamics.When energy is converted from one form to another, some of the usable energy is converted to heat and is dispersed in the surroundings.At every step of energy transformation there is a loss of energy capable to do work.No one process that requires energy conversion is 100% efficient.All natural systems then to go from a state of order to toward a state of increasing disorder. Entropy or amount of disorder increases reflecting the loss of energy.There is less energy available at the end of a process than at the beginning.APPLICATION TO ORGANISMS:Organisms are highly organized both structurally and functionally.Constant maintenance is required to keep this organization and a constant supply of energy is required to maintain these processes.Energy is used by the cell to do work.If the energy supply is depleted the cell will die.ENERGY FOR LIFEThe sun is the ultimate source of energy for living organisms.A few ecosystems are based on energy derived from inorganic substances and the earth molten interior.ExtremophilesExtremophiles are organisms that live in severe conditions.Deep-sea hydrothermal vents provide energy to an ecosystem that lives in total darkness and under tremendous pressure.The energy source for this ecosystem is provided by inorganic molecules like hydrogen sulfide and hydrogen gas through a process called chemosynthesis.Most of these extremophiles are single celled organisms called archaea.Archaea are considered to be very primitive organisms and the conditions under which they live are thought to be similar to those in which life first evolved.Green plants get energy from the sunThe sun produces warmth and light, both of which are needed for living organisms.•Most organisms live within a narrow temperature range.•Light is composed of particles of energy that travel as waves.•Light is part of the electromagnetic spectrum, the entire range of electromagnetic radiation.Of the solar radiation that reaches the earth’s surface, 45% is visible light, 45% is infrared radiation and 10% is ultraviolet radiation.•30% is reflected back into space.•20% is absorbed by the atmosphere.•50% is absorbed by ground, water and vegetation.Less than 1% of the absorbed energy is used in photosynthesis. This small percentage is the energy base for all life on the biosphere.HOW PHOTOSYNTHESIS CAPTURES ENERGYPhotosynthesis converts radiant energy into useful, high quality chemical energy in the bonds that hold together organic molecules (food!).Photosynthesis can use mostly red and blue light. Green is reflected.Every point of the earth is illuminated for six months of the year:•Continuously during 6 months the polar summers.•Alternating 12 hours of darkness with 12 hours light in the tropics.Sunrays strike the earth obliquely in the higher latitudes.Sunlight is responsible for the flow of wind, ocean currents, weather patterns and the hydrological cycle.Photosynthesis is the conversion of light energy into chemical bond energy. It takes place in organelles called chloroplasts.6CO2 + 6 H2O + solar energy → C6H12O6 + 6O2Chlorophyll molecules in the chloroplasts trap light energy and start a series of chemical reactions that begin the process of photosynthesis.Photosynthesis begins with the split of water molecules, H2O, which releases oxygen into the atmosphere. This process happens only when light is present, from there comes the name light reactions of photosynthesis.The light-dependent reactions make high-energy molecules of ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate). These two types of molecules provide the energy for the next process, the light-independent reactions.Another set of reactions occurs independently of light. These are called the light-independent reactions.In these reactions, carbon dioxide is incorporated into small sugar molecules to make glucose, a high-energy sugar.Cellular respiration releases chemical energy found in substances.The energy released is used by the cell to make biomolecules, e.g. proteins, lipids, etc., and to do cellular work, e.g. movement.C6H12O6 + 6O2→ 6CO2 + 6 H2O + energy released Photosynthesis captures energy; respiration releases energy.LEVELS OF ORGANIZATION:Atoms → molecules → macromolecules → cells → tissues → organs → organ systems →organismsFROM SPECIES TO ECOSYSTEMSA population consists of all the members of a species living in a given area tat the same time. An ecological or biological community is a system made of species populations living and interacting in the same area.•Different species populations.•In the same area.•Interacting in spatial and trophic (feeding) relationships.Characteristics of the community are species composition, diversity, stratification and food chains.An ecosystem is a community of organisms and the physical environment interacting as a unit.ENERGY TRANSFER: FOOD CHAINS, FOOD WEBS AND TROPHIC LEVELS Photosynthesis is the base of the energy dynamics of an ecosystem, how organisms share food resources..Biomass refers to the amount of biological material produced in an ecosystem.The productivity of an ecosystem is measured by the amount of biomass produced.•The primary productivity of an ecosystem is the biomass produced by photosynthesis.•The secondary productivity of an ecosystem is the biomass produced by organisms that eat plants or other organisms.Energy is passed from organisms that carry on photosynthesis (plants, algae, bacteria) to organisms that feed on them, and which in turn are eaten by other organisms thus forming a linked feeding series, a food chain.Food chain refers to the sequence of organisms in a community on successive trophic levels and through which energy is transferred. It is a feeding series.In a community there are many food chainsThese chains interconnect to form a food web.Food webs are usually very complex involving hundreds of species.Trophic level is the position of an organism in the food chain.Producers or autotrophs make food from simple organic matter.•The largest group in a community.Consumers or heterotrophs obtain their food by eating other organisms.•Primary consumers or herbivores eat plants.•Secondary and tertiary consumers or carnivores eat other animals.•Omnivores eat both plant and animal materials.•Parasites, scavengers, detritivores and decomposers feed at all levels.•Decomposers or saprobes feed on dead organisms and wastes.Material available to saprobes include:•Dead animals (carrion): scavengers.•Feces and excreted organic compounds (detritus): detritivores.•Dead plants: logs, stumps, fallen leaves, dead roots: detritivores.•Overripe fruit.Fragments of these materials form detritus.The line between scavengers and predators is not always clear.•Many predators will eat carrion readily.•Switch from predation to scavenging and vice versa is common.Fungi and bacteria are decomposers and completer the final breakdown and recycling of organic materials.Without these decomposers, fungi and bacteria, matter would remain locked up in the bodies of dead plants and animals rather than being made available to successive generations of organisms.An ecological pyramid is formed when organisms in a community are arranged according to numbers.•Producers are the most numerous and are placed at the base of the pyramid.•The successive trophic levels decrease gradually. There are fewer deer than shrubs;less wolves than deer, etc.Primary consumers are next; secondary consumers follow; then tertiary consumers follow the secondary, etc.Remember that energy transfer is never 100% efficient. Some is always lost before and during the transfer.BIOGEOCHEMICAL CYCLESThere is a constant recycling of materials (matter) between the biotic and the abiotic components of ecosystems.HYDROLOGIC CYCLEThis is the movement of water between ocean, atmosphere and land. It constantly purifies and redistributes fresh water.Physical processes that make it possible are…•Evaporation: liquid is changed to gas (vapor).•Sublimation: change from solid to gas.•Condensation: gas changes to liquid.•Precipitation: falling of water in any of its phases upon the surface of the earth.Air can support so much water vapor at a given temperature.The Carbon cycle•There are two parts to the carbon cycle, the atmosphere and the water cycles.The Nitrogen cycle•Proteins require nitrogen.•Plants take it the form of ammonia and nitrate.•The nitrogen cycle involves the atmosphere and the soil.The Phosphorus cycle•Phosphorus is a component of phospholipids, nucleic acids and other macromolecules.•Soil solution contains about 3 x 10-6 % phosphorus but plants contain about 3% phosphorus.•There are a biotic (living) and abiotic (nonliving) portions of the cycle.•Most forms of phosphate are insoluble.The Sulfur cycle•Sulfur is a component of proteins, enzymes and other compounds.•It is rarely a limiting nutrient and is usually absorbed as sulfate.。

电气工程及其自动化专业英语第一章课文翻译

第一章第一篇sectiongTwo variables u(t) and i(t) are the most basic concepts in an electric circuit, they characterize the various relationships in an electric circuitu(t)和i(t)这两个变量是电路中最基本的两个变量，它们刻划了电路的各种关系。

Charge and CurrentThe concept of electric charge is the underlying principle for explaining all electrical phenomena. Also, the most basic quantity in an electric circuit is the electric charge. Charge is an electrical property of the atomic particles of which matter consists, measured in coulombs (C). 电荷和电流电荷的概念是用来解释所有电气现象的基本概念。

也即，电路中最基本的量是电荷。

电荷是构成物质的原子微粒的电气属性，它是以库仑为单位来度量的。

We know from elementary physics that all matter is made of fundamental building blocks known as atoms and that each atom consists of electrons, protons, and neutrons. We also know that the charge e on an electron is negative and equal in magnitude to 1.60210×1019C, while a proton carries a positive charge of the same magnitude as theelectron. The presence of equal numbers of protons and electrons leaves an atom neutrally charged. 我们从基础物理得知一切物质是由被称为原子的基本构造部分组成的，并且每个原子是由电子，质子和中子组成的。

Instruction manual.pdf_1693225695.0476854说明书

I. M EASUREMENT OF DC AND AC VOLTAGE AND CURRENT , MEASUREMENTUNCERTAINTY AND ERRORS.M ESUREMENT OF THE PARAMETERS OF DIODES ANDTRANSISTORSTheory:Theory of errors and uncertainty in the measurement. Uncertainty of type A ,type B and C. Definitions of the instrument precision by the producers. Principle of multimeters. Measurement of DC and AC voltage and current. Connection of the multimeter to the tested circuit. Measurement of the effective value of the voltage and current- definitions & principles. Measurement of the effective value alternating voltage/current with or without superimposed direct voltage/current. Shape coefficient, crest factor. Testing of diodes and transistors using the multimeter Principle of the digital frequency measurement. Exercises:1) Get acquainted with Agilent 33220A waveform generator. Set the appropriate load value according tothe resistor used (Utility > Output Setup> Load> 50Ω). ATTENTION: The generator output must be matched to the load impedance for all laboratory tasks.2) Set the generator for harmonic signal output of 2Vpp amplitude and 100 Hz frequency (setting of thegenerator, not measured value on the voltmeter). Connect the rectifier to loaded output according to the schematic. Measure the rectified voltage by available multimeters (using DC mode). Read at least10 measured values. Estimate measurement uncertainty of type A. Estimate the measurementuncertainty of type B based by parameters from datasheets. Determine overall uncertainty of your measurements (type).3) Generate a harmonic, rectangular, triangular, saw tooth and at least one of embedded arbitrarysignals with arbitrary amplitude from the range 1-5 V and frequency from the range 50-300 Hz with the offset equal to zero. Measure voltages for all shapes using both a TRMS voltmeter and simple multimeter with diode rectifier. Explain why the multimeter readings differ for every waveform and amplitude. Use a multimeter also for frequency measurement of every waveform.4) Repeat task 3 for harmonic, rectangular, triangular, saw-tooth waveform with DC offset set to 1V.Measure the output voltage of the generator by TRMS voltmeter in both AC and DC mode. What is the total dissipated power on the resistor load and what is the effective value of the voltage? Hint -Parceval´s theorem.5) Generate a harmonic signal with amplitude 1V and frequency of 5Hz. What is measured by themultimeter? Gradually adjust the frequency 10, 50, 200, 1k, 10k, 25k, 100k, 500kHz and 1MHz. What is measured by the multimeter? Try to explain the multimeter behavior.6) Set the generator for rectangular pulses of 100 Hz repeating frequency and pulse width of 100 s. Setthe low voltage level to 0V. The high level (pulse amplitude) set gradually to 0.02V, 0.2V, 2V. How does the measured rms value change for different peak values of the signal? What voltage value is shown by the multimeter? Is its variation consistent with the changes of the pulse amplitude?Compare your measurement results acquired with other types of multimeters.7) Repeat task 4 for AC and DC current through the load. How can you calculate total power dissipatedon the resistor load from the measured current and resistor’s value? Compare results with those of the task 4.8) Test available diodes using a multimeter and assess whether they passed. What does thismeasurement tell us about the measured diode? Measure also the Graetz bridge9) Measure PN junctions and h21E of available transistors in the active and inverse mode. Comparemeasured results with datasheet values.10) Switch the multimeter to frequency measurement mode. Set the generator to an arbitrary harmonicwaveform of frequency within kHz range. Gradually rise the amplitude from minimum up to 5V.Observe the measured frequency and determine an amplitude threshold, where multimeter starts to measure correctly. Try to explain the results and behavior of the multimerter in frequency measurement mode.Instruments‘ manuals:Multimeter UT 803Multimeter Agilent 34410AMultimeter Agilent 34405AMultimeter Metex 3640Multimeter METEX 3850DGenerator Agilent 33220AStudy materials:Agilent multimeter simulation installation filesWebsite simulating the function of selected instruments - meas-lab.fei.tuke.sk。

核子中奇异夸克分布不对称性与轻味夸克碎裂效应

29 10 2005 10HIGH ENERGY PHYSICS AND NUCLEAR PHYSICSVol.29,No.10Oct.,2005*( 100871)– , . , .D ..1, –[1—3]. ,. ,, –(DIS) (global analysis)[4,5], ,(intrinsic sea theory) ,µ CCFR NuTeV,[6,7]. ,. ,[4,8—12]NuTeVWeinberg [13,14],.. ,Fν2 F¯ν2,:Fν2−F¯ν2=2x[s(x)−¯s(x)]. ,,. c.CCFR NuTeV µ [6,15,16].νµs→µ−c νµd→µ−c,Cabibbo ,c ;, ¯c.CCFR NuTeV µµ+(µ−) c(¯c) ,c→H(c¯q)→µ+X. µ,µ ,. ,CCFR νµ(¯νµ) ,c(¯c) µ+(µ−) ¯B c(¯B¯c):¯Bc−¯B¯c0.1147∼0−20%[6]., ,µ . ,CCFR NuTeV µ,.( c ¯c10 965dξd y =G2s2|V cd|2].(1)s=2MEν ,r2≡(1+Q2/M2W)2.ξ . , c ,ξ Bjorken:ξ≈x(1+m2c /Q2). (1)f c≡1−m2c/2MEνξ c, [18]., ¯cd2σ¯νµN→µ+¯c Xπr2f c•ξ[¯s(ξ)|V cs|2+¯d(ξ)+¯u(ξ)dξd y−d2σ¯νµN→µ+¯c Xπr2f c•ξ (s(ξ)−¯s(ξ))|V cs|2+d v(ξ)+u v(ξ)2ξ[d v(ξ)+u v(ξ)] ,|V cs|2≃0.95 |V cd|2≃0.05[19] .12S−|V cs|2+Q V|V cd|2,(4)S−≡ ξ[s(ξ)−¯s(ξ)]dξ,Q V≡ ξ[d v(ξ)+u v(ξ)]dξ., NuTeV.[9—12],NuTeV ., (4) ,c ¯c P SA( 1).1 NuTeV c ¯c P SADing-Ma[9]Q2030%—80%0.007—0.01812%—26% Alwall-Ingelman[10]20GeV230%0.00915% Ding-Xu-Ma[11]Q2060%—100%0.014—0.02221%—29% Wakamatsu[12]16GeV270%—110%0.022—0.03530%—40%966 (HEP&NP) 29 2S+|V cs|2+(Q V+2Q S)|V cd|2.(5)S+≡ ξ[s(ξ)+¯s(ξ)]dξ,Q S≡ ξ[¯u(ξ)+¯d(ξ)]dξ.CTEQ5 Q2=16GeV2 S+,Q V,Q S, |V cs|2=0.95,|V cd|2=0.05,1 2S−/Q V 0.007(0.022), R 20%(25%). ,c ¯c, c¯c.3 µ, , c,( µ) ( ) . cH+d3σνµN→µ−H+Xdξd y D H+q(z),(6)D H+q(z) q H+ ,z H+ q . H+ c D+(c¯d) D0(c¯u) ,H− D−(¯c d) ¯D0(¯c u).c H+ H+ . , Lund , q¯qexp(−bm2q)[20], s¯s λ∼0.3[21,22], c¯c 10−5., . µ [17]. . , e+e− . , , c ¯c , D , c , , , c(¯c) , µ . , c ¯c D(c¯q) ¯D(¯c q). , , , :u→cu),d→D−(dξd y d z=G2s2|V cd|2]+δ dσνN→µ−µ+Xdξd y d z LQF=G2s2|V ud|2(1−y)2,(8)D q(z)≡D Dq(z)+D D∗q(z), D Dq(z)≡D¯D0u(z)=D D0¯u(z)=D D−d(z)=D D+¯d(z),D D∗q(z)≡D¯D∗0u(z)=D D∗0¯u(z)=D D∗−d(z)=D D∗+¯d(z). , D q(z) q , . (8) ,¯BD(∗)+=1dξd y d z=G2s2|V cd|2]+δ dσ¯νN→µ+µ−Xdξd y d z LQF=G2s2•|V ud|2(1−y)2.(10)10 967(σνN→µ−µ+X−σ¯νN→µ+µ−X)total≈−1Q V|V cd|2+2S−|V cs|2•D q¯BD(∗)+¯f c ¯Bc.D q¯BD(∗)+d x d y d z=G2s2|V ud|2D q(z)B¯D0,(12),B¯D0 ¯D0 µ− , ¯D∗0¯D0 , B¯D0 .,µ+µ+d3σ¯νN→µ+µ+Xπr2x¯u(x)+¯d(x)σµ−µ+≈Q ud|V ud|2¯fc¯Bc,(14)Q ud≡1¯fc¯Bc,D qσµ−µ+.(15)CDHSW[26] ( )µ µ σµ−µ−/σµ−µ+(σµ+µ+/σµ+µ−). 2E vis 100—200GeV ,3 .2 , , σµ−µ−/σµ−µ+σµ−µ−/σµ− ,, σµ−µ−/σµ−µ+, ,.2CDHSW 100<E vis<200GeV µ [26]pµ>6GeV(3.5±1.6)%(1.6±0.74)×10−4(4.5±2.0)%(2.2±1.0)×10−4 pµ>9GeV(2.9±1.2)%(1.05±0.43)×10−4(4.4±1.8)%(1.7±0.7)×10−4 pµ>15GeV(2.3±1.0)%(0.52±0.22)×10−4(4.1±2.3)%(0.8±0.45)×10−4968 (HEP&NP) 29dξd y d z −d3σ¯νµN→µ+H−Xπr2f cξ[(s(ξ)−¯s(ξ))|V cs|2+ d v(ξ)+u v(ξ)πr2xd v(x)+u v(x)πr2xd v(x)+u v(x)10 969(References)1Brodsky S J,MA B-Q.Phys.Lett.,1996,B381:3172Signal A I,Thomas A W.Phys.Lett.,1987,B191:2053Burkardt M,Warr B J.Phys.Rev.,1992,D45:9584Olness F et al.hep-ph/03123235Barone V et al.Eur.Phys.J.,2000,C12:2436Bazarko A O et al(CCFR Collaboration).Z.Phys.,1995, C65:1897Mason D(NuTeV Collaboration).hep-ex/04050378Kretzer S et al.Phys.Rev.Lett.,2004,93:0418029DING Y,MA B-Q.Phys.Lett.,2004,B590:216;DING Yong,L¨U Zhun,MA Bo-Qiang.HEP&NP,2004,28(9): 947(in Chinese)( , , . ,2004,28(9):947) 10Alwall J,Ingelman G.Phys.Rev.,2004,D70:111505.11DING Y,XU R-G,MA B-Q.Phys.Lett.,2005,B607:101 12Wakamatsu M.hep-ph/041120313Zeller G P et al.Phys.Rev.Lett.,2002,88:09180214Zeller G P et al.Phys.Rev.,2002,D65:11110315Rabinowitz S A et al.Phys.Rev.Lett.,1993,70:13416Goncharov M et al.Phys.Rev.,2001,D64:11200617Godbole R M,Roy D P.Z.Phys.,1984,C22:39;Z.Phys., 1989,C42:21918Astier P et al(NOMAD Collaboration).Phys.Lett.,2000, B486:3519Eidelman S et al(Particle Data Group).Phys.Lett.,2004, B592:120Andersson B et al.Nucl.Phys.,1981,B178:24221Laﬀerty G D.Phys.Lett.,1995,B353:54122Abe K et al(SLD Collaboration).Phys.Rev.Lett.,1997, 78:334123Smith J,Valenzuela G.Phys.Rev.,1983,D28:107124Aitala E M et al(Fermilab E791Collaboration).Phys.Lett.,1996,B371:15725Dias de Deus J,Dur˜a es F.Eur.Phys.J.,2000,C13:647 26Burkhardt H et al.Z.Phys.,1986,C31:3927Sandler P H et al.Z.Phys.,1993,C57:1,and References Therein.28Jonker M et al.Phys.Lett.,1981,B107:24129de Lellis G et al.Phys.Rep.,2004,399:22730Kayis-Topaksu A et al(CHORUS Collaboration).Phys.Lett.,2002,B549:4831¨Oneng¨u t G et al(CHORUS Collaboration).Phys.Lett., 2004,B604:145Nucleon Strange Asymmetry and the Light QuarkFragmentation Eﬀect*GAO Pu-Ze MA Bo-Qiang(School of Physics,Peking University,Beijing100871,China)Abstract Nucleon strange asymmetry is an important non-perturbative eﬀect in the study of nucleon structure,but it has not been checked by experiments yet.For eﬀectively measuring the nucleon strange asymmetry,we investigate the light quark fragmentation eﬀect that may aﬀect the measurement of the strange asymmetry.We suggest an inclusive measurement of charged and neutral charmed hadrons by using an emulsion target in the neutrino and antineutrino in-duced charged current deep inelastic scattering,in which the strange asymmetry eﬀect and the light quark fragmentation eﬀect can be separated.Key words strange asymmetry,light quark fragmentation,charged current deep inelastic scattering。

First Results from the Sudbury Neutrino Observatory

a r X i v :n u c l -e x /0205006v 1 14 M a y 2002FIRST RESULTS FROM THE SUDBURY NEUTRINO OBSER V ATORYG.A.McGREGOR aDepartment of Physics,Denys Wilkinson Building,Keble Road,Oxford OX13RH,U.K.The Sudbury Neutrino Observatory (SNO)is a water imaging ˇCerenkov detector.Utilisinga 1kilotonne ultra-pure D 2O target,it is the ﬁrst experiment to have equal sensitivity to all ﬂavours of active neutrinos.This allows a solar-model independent test of the neutrino oscillation hypothesis to be made.Solar neutrinos from the decay of 8B have been detected at SNO by the charged-current (CC)interaction on the deuteron and by the elastic scattering (ES)of electrons.While the CC interaction is sensitive exclusively to νe ,the ES interaction has a small sensitivity to νµand ντ.In this paper,the recent solar neutrino results from the SNO experiment are presented.The measured ES interaction rate is found to be consistent with the high precision ES measurement from the Super-Kamiokande experiment.The νe ﬂux deduced from the CC interaction rate in SNO diﬀers from the Super-Kamiokande ES measurement by 3.3σ.This is evidence of an active neutrino component,in addition to νe ,in the solar neutrino ﬂux.These results also allow the ﬁrst experimental determination of the active 8B neutrino ﬂux from the Sun,and this is found to be in good agreement with solar model predictions.1IntroductionOver the past 30years,solar neutrino experiments 1,2,3,4,5,6have measured fewer neutrinos than are predicted by models of the Sun.7,8A comparison of the predicted and observed solar neutrino ﬂuxes for these experiments are shown in table 1.These observations can be explained if the solar models are incomplete or neutrinos undergo a ﬂavour changing process while in transit toTable1:Summary of solar neutrino observations at diﬀerent solar neutrino detectors. Experiment SSM Flux72.56±0.16(stat.)±0.16(sys.)SNUSAGE2128+9−7SNU77.5±6.2(stat.)+4.3−4.7(sys.)SNU65.8+10.2−9.6(stat.)+3.4−3.6(sys.)SNUKamiokande5 5.05(1+0.20−0.16)×106cm−2s−1Super-Kamiokande6 5.05(1+0.20−0.16)×106cm−2s−1the Earth,the most accepted of which is neutrino oscillations.This puzzle is known as the solar neutrino problem.2The Sudbury Neutrino Observatory2.1The SNO DetectorSNO9is an imaging waterˇCerenkov detector located at a depth of2092m(6010m of water equivalent)in the INCO,Ltd.Creighton mine near Sudbury,Ontario.The detector,shown in ﬁgure1,is situated in a large barrel shaped cavity22m in diameter and34m in height.The 1kilotonne ultra-pure D2O target is contained within a transparent acrylic vessel(AV)12m in diameter and5.5cm thick.A17.8m diameter geodesic sphere(PSUP-photomultiplier support structure)surrounds the AV and supports9456inward looking and91outward looking20cm photomultiplier tubes(PMTs).The PSUP is supported by steel ropes attached to the deck.The remaining volume isﬁlled with ultra-pure H2O which acts as a cosmic ray veto and as a shield from naturally occurring radioactivity in both the construction materials and the surrounding rock.The light water also supports the D2O and AV with the remaining weight supported by 10Vectran rope loops.A physics event trigger is generated in the detector when18or more PMTs exceed a threshold of∼0.25photo-electrons within a coincidence time window of93ns.The trigger reaches100% eﬃciency when the PMT multiplicity is≥23.The instantaneous trigger rate is about15-20Hz, of which6-8Hz are physics triggers and the rest are diagnostic triggers.2.2Neutrino Interactions in SNOBy utilising a D2O target,the SNO detector is capable of simultaneously measuring theﬂux of electron type neutrinos and the totalﬂux of all active neutrinos from8B decay in the Sun through the following interactions:νe+d→p+p+e−(CC)νx+d→νx+p+n(NC)νx+e−→νx+e−(ES)The charged-current(CC)interaction on the deuteron is sensitive exclusively toνe,and the neutral-current(NC)interaction has equal sensitivity to all active neutrinoﬂavours(νx,x=e,µ,τ). Elastic scattering(ES)on the electron is also sensitive to all activeﬂavours,but has enhanced sensitivity toνe.Figure1:A cross-sectional view of the SNO detector.3Results from SNOThe results presented here are the recent results from the SNO collaboration.10Full details of the analysis will not be presented here;readers are encouraged to consult the original paper. The results are from data recorded between Nov.2,1999and Jan.15,2001,corresponding to 240.95days of live time.The neutrinoﬂuxes deduced from the CC and ES interactions at SNO are:ΦCC SNO =1.75±0.07(stat.)+0.12−0.11(sys.)±0.05(theor.)×106cm−2s−1ΦES SNO=2.39±0.34(stat.)+0.16−0.14(sys.)×106cm−2s−1where the theoretical uncertainty is the CC cross section uncertainty.11The diﬀerence betweenΦCC SNO andΦES SNO is0.64±0.40×106cm−2s−1,or1.6σ.The ratio ofΦCCSNOto the predicted8Bsolar neutrinoﬂux given by the BPB01solar model7is0.347±0.029where all the uncertainties are added in quadrature.The Super-Kamiokande6experiment has made a high precision measurement of the8B solar neutrinoﬂux deduced from the ES interaction:ΦES SK=2.32±0.03(stat.)+0.08−0.07(sys.)×106cm−2s−1The measurementsΦES SNO andΦES SK are consistent.Assuming that the systematic errors areTable2:Systematic uncertainties onﬂuxes.Error source ES error(per cent)-5.2,+6.1±0.5±0.5±3.1±0.7±0.5-0.8,+0.0-0.2,+0.0-0.2,+0.00.0±0.1-0.6,+0.7±0.10.0 Experimental uncertainty-5.7,+6.83.0Solar Model-16,+20normally distributed,the diﬀerence betweenΦCCSNO andΦES SK is0.57±0.17×106cm−2s−1,or3.3σ.The probability thatΦCCSNOis a≥3.3σdownwardﬂuctuation is0.04%.The CC energy spectrum was also extracted from the data and no evidence for spectral distortions was found.3.1Systematic UncertaintiesThe systematic uncertainties in the SNO results are shown in table2.The dominant uncer-tainties are the energy scale and the reconstruction accuracy.The reconstruction accuracy was determined using a triggered16N6.13MeVγ-ray source.12Figure2shows some of the results of such a study.When the source was operated at low rate,the reconstruction accuracy was observed to become worse.This was found to be because the PMT calibration characteristics were dependent on the readout history of the PMT,compounded in non-central16N calibration runs by a readout rate gradient across the detector.This was addressed by the HCA calibra-tion13which allowed the reconstruction accuracy of neutrino events to be correctly estimated at∼3%(rather than∼10%).3.2Total Active8B Neutrino FluxRemembering that SNO’s CC measurement is only sensitive to electron neutrinos,whereas Super-Kamiokande’s ES measurement has a weak sensitivity to all activeﬂavours,one can deduce the total8B solar neutrinoﬂux.Stated explicitly,the experimental sensitivities to neutrinoﬂavours are:ΦCCSNO=Φe;ΦES SK=ǫΦµτwhereΦµτis the combinedνµandντﬂux andǫ=1/6.481.These equations can be solved forΦe andΦµτ.This is shown graphically inﬁgure3.−800−600−400−2000200400600800Source z−Position (cm)−20−15−10−505101520M e a n S h i f t (f i t −s r c ) i n z −P o s i t i o n (c m )Figure 2:The shift in the reconstructed position of the 16N source as a function of source position.The HCA calibration corrects the inward shift seen in the low rate 16N data.SNOMAN is the SNO Monte Carlo package.φ(νe ) (106cm -2s -1)φ(νµτ) (106c m -2s -1)φ(νe ) (relative to BPB01)φ(νµτ) (r e l a t i v e t o B P B 01)1Figure 3:The ﬂux of 8B solar neutrinos which are µor τﬂavour vs.the ﬂux of electron neutrinos as deduced from the SNO and Super-Kamiokande results.The diagonal bands show the total 8B ﬂux as predicted by the BPB01(dashed lines)and that derived from the SNO and Super-Kamiokande results (solid lines).The interceptsof these bands with the axes represent the ±1σerrors.Figure4:Left:Comparison of the data and Monte Carlo NHITS distributions.The sharply falling component at lower NHITS is from24Na decays,and the higher NHIT bump is from neutron capture on35Cl.Right:Thedecay of the activated24Na in the D2O.The preferred value of the total active neutrino8Bﬂux is:ΦTOTSNO+SK=5.44±0.99×106cm−2s−1which is in good agreement with the standard solar model prediction:ΦTOT BPB01=5.05+1.01−0.81×106cm−2s−1This is theﬁrst determination of the total activeﬂux of8B neutrinos generated by the Sun.4The NaCl Phase of the SNO ExperimentThe deployment of NaCl to enhance the NC capability of the SNO detector began on May28, 2001.The presence of NaCl in the D2O causes the free neutron,produced by the NC interaction, to be captured by35Cl.This produces an excited state of36Cl which decays to its ground state via a cascade ofγ-rays with a total energy of∼8.6MeV.The neutron detection eﬃciency is signiﬁcantly enhanced,and the high multiplicity of theγ-ray cascade allows statistical separation from CC events based on the PMT hit pattern.4.1The24Na Calibration SourceThe addition of NaCl to the D2O presented the opportunity to deploy24Na as a containerless source.This is desirable for two reasons:24Naβγdecays are similar to theβγdecays of208Tl and214Bi;and a containerless source avoids the diﬃculties in modeling complex sources.Activating23Na in the D2O was achieved by using the‘super-hot’thorium source,which produces2.0×107±5%2.614MeVγ-rays per minute(producing neutrons from deuteron pho-todisintegration).Figure4shows the results of such a paring the detector response from the24Na calibration source to Monte Carlo predictions gives conﬁdence in,and allows systematic uncertainties to be assigned to,techniques designed to monitor the208Tl and 214Bi levels within the D2O.5Summary and OutlookTwo signiﬁcant results are reported in this paper.The data from SNO represents theﬁrst direct evidence that there is an active non-electronﬂavour neutrino component in the solar neutrino ﬂux.This is also theﬁrst experimental determination of the totalﬂux of active8B neutrinos, which is in good agreement with the solar model predictions.The SNO Collaboration is now analysing the data from the pure D2O phase with a lowered energy threshold.Eﬀorts are devoted to understanding the low energyβγdecays of208Tl and 214Bi and the photodisintegration contribution they make to the NC measurement. AcknowledgmentsThis research was supported by the Natural Sciences and Engineering Research Council of Canada,Industry Canada,National Research Council of Canada,Northern Ontario Heritage Fund Corporation and the Province of Ontario,the United States Department of Energy,and in the United Kingdom by the Science and Engineering Research Council and the Particle Physics and Astronomy Research Council.Further support was provided by INCO,Ltd.,Atomic Energy of Canada Limited(AECL),Agra-Monenco,Canatom,Canadian Microelectronics Corporation, AT&T Microelectronics,Northern Telecom and British Nuclear Fuels,Ltd.The heavy water was loaned by AECL with the cooperation of Ontario Power Generation.References1.B.T.Cleveland et al.,Astrophys.J.496,505(1998).2.J.N.Abdurashitov et al.,Phys.Rev.C60,055801(1999).3.W.Hampel et al.,Phys.Lett.B447,127(1999).4.M.Altmann et al.,Phys.Lett.B490,16(2000).5.K.S.Hirata et al.,Phys.Rev.Lett.65,1297(1990);K.S.Hirata et al.,Phys.Rev.D44,2241(1991),452170E(1992);Y.Fukuda et al.,Phys.Rev.Lett.77,1683(1996).6.S.Fukuda et al.,Phys.Rev.Lett.86,5651(2001).7.J.N.Bahcall,M.H.Pinsonneault,and S.Basu,astro-ph/0010346v2.8.A.S.Brun,S.Turck-Chi`e ze,and J.P.Zahn,Astrophys.J.525,1032(1999);S.Turck-Chi`e ze et al.,Ap.J.Lett.,v.555July1,2001.9.The SNO Collaboration,Nucl.Instr.and Meth.A449,172(2000).10.The SNO Collaboration,Phys.Rev.Lett.87,071301(2001).11.S.Nakamura,T.Sato,V.Gudkov,and K.Kubodera,Phys.Rev.C63,034617(2001);M.Butler,J.-W.Chen,and X.Kong,Phys.Rev.C63,035501(2001);G.’t Hooft,Phys.Lett.37B195(1971).12.M.R.Dragowsky et al.,Nucl.Instr.and Meth.A481,284(2002).13.G.A.McGregor,The Measurement of the Neutral Current Interaction at the Sudbury Neu-trino Observatory,D.Phil.thesis,University of Oxford(2002).。

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To be to Eur. Phys. J. C
C. Adloff¿¿, V. Andreev¾ , B. Andrieu¾ , T. Anthonis , V. Arkadov¿ , A. Astvatsatourov¿ , I. Ayyaz¾ , A. Babaev¾¿, J. B¨ ahr¿ , P. Baranov¾ , E. Barrelet¾ , W. Bartel½¼, U. Bassler¾ , ¾½ ¿ P. Bate , A. Beglarian , O. Behnke½¿, C. Beier½ , A. Belousov¾ , T. Benisch½¼ , Ch. Berger½ , G. Bernardi¾ , T. Berndt½ , J.C. Bizot¾ , V. Boudry¾ , W. Braunschweig½ , V. Brisson¾ , H.uckner½¾, P. Bruel¾ , D. Bruncko½ , J. B¨ urger½¼, F.W. B¨ usser½½ , B. Br¨ oker¾, D.P. Brown½½, W. Br¨ A. Bunyatyan½¾ ¿ , H. Burkhardt½ , A. Burrage½ , G. Buschhorn¾ , A.J. Campbell½¼, J. Cao¾ , T. Carli¾ , S. Caron½ , E. Chabert¾¾, D. Clarke , B. Clerbaux , C. Collard , J.G. Contreras ½, Y.R. Coppens¿ , J.A. Coughlan , M.-C. Cousinou¾¾, B.E. Cox¾½, G. Cozzika , J. Cvach¾ , J.B. Dainton½ , W.D. Dau½ , K. Daum¿¿ ¿ , M. Davidsson¾¼ , B. Delcourt¾ , N. Delerue¾¾, R. Demirchyan¿ , A. De Roeck½¼ ¿, E.A. De Wolf , C. Diaconu¾¾, P. Dixon½ , V. Dodonov½¾, J.D. Dowell¿ , A. Droutskoi¾¿, A. Dubak¾ , C. Duprel¾ , G. Eckerlin½¼, D. Eckstein¿ , V. Efremenko¾¿, S. Egli¿¾ , R. Eichler¿ , F. Eisele½¿ , E. Eisenhandler½ , M. Ellerbrock½¿, E. Elsen½¼ , M. Erdmann½¼ ¼ , W. Erdmann¿ , P.J.W. Faulkner¿, L. Favart , A. Fedotov¾¿, R. Felst½¼, J. Ferencei½¼, S. Ferron¾ , M. Fleischer½¼, Y.H. Fleming¿, G. Fl¨ ugge¾, A. Fomenko¾ , I. Foresti¿ , J. Form´ anek¿¼, J.M. Foster¾½, ½¼ ½ ¿¾ ¿ ¿¾ G. Franke , E. Gabathuler , K. Gabathuler , J. Garvey , J. Gassner , J. Gayler½¼, R. Gerhards½¼, assler¾ , S. Ghazaryan¿ , L. Goerlich , N. Gogitidze¾ , M. Goldberg¾ , C. Goodwin¿, C. Grab¿ , H. Gr¨ T. Greenshaw½ , G. Grindhammer¾ , T. Hadig½¿, D. Haidt½¼, L. Hajduk , W.J. Haynes , B. Heinemann½ , G. Heinzelmann½½, R.C.W. Henderson½ , S. Hengstmann¿ , H. Henschel¿ , R. Heremans , G. Herrera ½, I. Herynek¾ , M. Hildebrandt¿ , M. Hilgers¿ , K.H. Hiller¿ , J. Hladk´ y¾ , P. H¨ oting¾, D. Hoffmann½¼, R. Horisberger¿¾, S. Hurling½¼, M. Ibbotson¾½, C ¸.˙ Is ¸sever , M. Jacquet¾ , M. Jaffre¾ , L. Janauschek¾ , ½¾ ½½ D.M. Jansen , X. Janssen , V. Jemanov , L. J¨ onsson¾¼ , D.P. Johnson , M.A.S. Jones½ , H. Jung½¼, H.K. K¨ astli¿ , D. Kant½ , M. Kapichine , M. Karlsson¾¼, O. Karschnick½½, F. Keil½ , N. Keller¿ , J. Kennedy½ , I.R. Kenyon¿ , S. Kermiche¾¾, C. Kiesling¾ , P. Kjellberg¾¼, M. Klein¿ , C. Kleinwort½¼, G. Knies½¼ , B. Koblitz¾ , S.D. Kolya¾½, V. Korbel½¼, P. Kostka¿ , S.K. Kotelnikov¾ , R. Koutouev½¾, A. Koutov , M.W. Krasny¾ , H. Krehbiel½¼, J. Kroseberg¿ , K. Kr¨ uger½¼, A. Ku ¨ pper¿¿, T. Kuhr½½, ¿ ½ ½¼ ¿ ½ ¿ T. Kurˇ ca , R. Lahmann , D. Lamb , M.P.J. Landon , W. Lange , T. Laˇ stoviˇ cka¿¼ , P. Laycock½ , E. Lebailly¾ , A. Lebedev¾ , B. Leißner½, R. Lemrani½¼, V. Lendermann , S. Levonian½¼, M. Lindstroem¾¼, B. List¿ , E. Lobodzinska½¼ , B. Lobodzinski ½¼, A. Loginov¾¿ , N. Loktionova¾ , V. Lubimov¾¿, S. L¨ uders¿ , D. L¨ uke ½¼, L. Lytkin½¾ , N. Magnussen¿¿ , H. Mahlke-Kr¨ uger½¼, N. Malden¾½ , E. Malinovski¾ , I. Malinovski¾ , R. Maraˇ cek¾ , P. Marage , J. Marks½¿ , R. Marshall¾½ , H.½ ½ U. Martyn , J. Martyniak , S.J. Maxﬁeld , A. Mehta½ , K. Meier½ , P. Merkel½¼, A.B. Meyer½½ , H. Meyer¿¿ , J. Meyer½¼ , P.-O. Meyer¾ , S. Mikocki , D. Milstead½ , T. Mkrtchyan¿ , R. Mohr¾ , S. Mohrdieck½½, M.N. Mondragon , F. Moreau¾ , A. Morozov , J.V. Morris , K. M¨ uller¿ , ½ ¾ ¾¿ ½½ ¿ ¾ P. Mur´ ın , V. Nagovizin , B. Naroska , J. Naumann , Th. Naumann , G. Nellen , P.R. Newman¿ , T.C. Nicholls , F. Niebergall½½, C. Niebuhr½¼, O. Nix½ , G. Nowak , T. Nunnemann½¾, J.E. Olsson½¼ , D. Ozerov¾¿, V. Panassik , C. Pascaud¾ , G.D. Patel½ , E. Perez , J.P. Phillips½ , D. Pitzl½¼, R. P¨ oschl , I. Potachnikova½¾, B. Povh½¾, K. Rabbertz½ , G. R¨ adel½ , J. Rauschenberger½½, P. Reimer¾ , B. Reisert¾ , D. Reyna½¼ , S. Riess½½ , C. Risler¾ , E. Rizvi¿, P. Robmann¿ , R. Roosen , A. Rostovtsev¾¿ , C. Royon , S. Rusakov¾ , K. Rybicki , D.P.C. Sankey , J. Scheins½, F.-P. Schilling½¿, P. Schleper½¼, D. Schmidt¿¿, D. Schmidt½¼, S. Schmitt½¼, L. Schoeffel , A. Sch¨ oning¿ , T. Sch¨ orner¾ , V. Schr¨ oder½¼, ½¼ ¾ ¿ ¾ H.-C. Schultz-Coulon , C. Schwanenberger , K. Sedl´ ak , F. Sefkow , V. Shekelyan , I. Sheviakov¾ , L.N. Shtarkov¾ , P. Sievers½¿, Y. Sirois¾ , T. Sloan½ , P. Smirnov¾ , V. Solochenko¾¿ Ý, Y. Soloviev¾ , V. Spaskov , A. Specka¾ , H. Spitzer½½, R. Stamen , J. Steinhart½½, B. Stella¿½, A. Stellberger½ , J. Stiewe½ , U. Straumann¿ , W. Struczinski¾, M. Swart½ , M. Taˇ sevsk´ y¾ , V. Tchernyshov¾¿ , S. Tchetchelnitski¾¿ , G. Thompson½ , P.D. Thompson¿, N. Tobien½¼, D. Traynor½ , P. Tru¨ ol ¿ , ½¼ ¿ ¿ ½ ¾ ¾ G. Tsipolitis , I. Tsurin , J. Turnau , J.E. Turney , E. Tzamariudaki , S. Udluft , A. Usik¾ , 1