共查询到20条相似文献,搜索用时 15 毫秒
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建立Ⅲ-Ⅴ族三元化合物半导体材料的分子束外延生长热力学模型。该模型与实验材料InGaP/GaAs,InGaAs/InP及已发表的GaAsP/GaAs,InAsP/InP的数据吻合得很好。将晶格应变能△G及脱附对温度敏感这两个因素同时纳入热力学模型中,束流和生长温度直接影响合金组分,晶格应变能是合金组分的函数。热力学模型计算结果反映了束流和生长温度是生长过程中最主要的影响因素。讨论和分析了四元半导体材料InGaAsP/GaAs的热力学生长模型。 相似文献
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1IntroductionTheGaSbsinglecrystalsareoftenusedasthesubstratematerialsforpreparingepilayersoflightemitingandlightdetectingd... 相似文献
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针对酸浸液钒铁分离的难题,绘制298 K时V(Ⅴ)-Fe(Ⅲ)-S(Ⅵ)-H2O系中存在的各种离子随pH以及浓度变化的热力学平衡图,全面分析钒、铁物种随pH和钒、铁、硫浓度的变化规律,在此基础上提出相应的钒铁分离方法并进行理论分析。结果表明:强酸条件(?1相似文献
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《稀有金属(英文版)》1990,(2)
The processing of InP, GaAs and related compounds doped with rare earth metals, such as Er, Nd and Gd, grown by LPE isdescribed. The inhomogeneity of rare earth heavily doped epi-layers is studied by SIMS, SEM and X-ray diffraction techniques. 相似文献
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1IntroductionThebiologicaleffectsofvanadiuminvolvenormalizationofsugarlevels,particularlyinvariousenzymesystemsasaninhibitorand/oracofactor[1].Vanadiumisalsoanessentialmicroamountelementforhumanandanimals,anditspresenceintherange20~150ng/mlindrinkingwaterha… 相似文献
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This paper studied the dispersion of Detonation Nano-diamond(DND)in acid medium,then well dispersed DND suspension with different concentrations were added to the trivalent chromium electrolyte.The chromium and chromium-nanodiamond composite coatings were prepared by composite plating process.Scanning electron microscopy(SEM) confirmed the presence of composite coatings and Energy Dispersive X-ray Analysis(EDX)revealed the composition,the effect of coating time on microhardness of chromium coatings and chromium-nanodiamond coatings were disscussd.It is found that the addition of nanodiamond increases the microhardness of the coatings.When the concentration of DND in electrolyte is 2.0-3.0 g/L,the plating time is about 15-20 min,the maximum hardness is obtained. 相似文献
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Nano-TiO2 was employed for the adsorption of gallium from aqueous solution in batch equilibrium experiments to investigate its adsorption properties. It was found that the adsorption efficiency of Ga(Ⅲ) was more than 96% at pH 3.0. The adsorption capacities and rates of Ga(Ⅲ) onto nano-TiO2 were evaluated as a function of solution concentration and temperature. The results were analyzed using the Langmuir adsorption isotherms. Adsorption isothermal data could be well interpreted by the Langmuir model. The mean energy of adsorption, 15.81 kJ·mol-1, was calculated from the D-R adsorption isotherm. The kinetic experimental data properly correlate with the pseudo-second-order kinetic model. The thermodynamic parameters for the process of adsorption have been estimated. The △ H Οand △ GΟvalues of gallium(Ⅲ) adsorption on nano-TiO2 showed an endothermic and spontaneous nature of adsorption. 相似文献
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ElectroreductionofYb(Ⅲ)onCoCathodeinMoltenChloride①LiuGuankun,TongYexiang,YangQiqin,HongHuichanandChenShengyang(刘冠昆)(童叶翔)(杨绮琴... 相似文献
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WANG Jun LIU Zhenrong ZHANG Xiangdong JIA Weiguo and ZHANG YangDepartment of Chemistry Liaoning University Shenyang China 《稀有金属(英文版)》2003,22(4)
The crystal and molecular structures of the K[TbⅢ(edta)(H2O)3]-5H2O (edta = ethylenediaminetetraacetic acid) and K4[TbⅢ2(Httha)2]+14H2O (ttha = triethylenetetraminehexaacetic acid) complexes have been determined by sin-gle-crystal X-ray diffraction analyses. The crystal of the K[TbⅢ(edta)(H2O)3]·5H2O complex belongs to orthorhombic crys-tal system and Fdd2 space group. The crystal data are as follows: a = 1.9373(5) nm, b = 3.5429(10) nm, c = 1.2114(3) nm, V = 8.315(4) nm3, Z= 16, M = 630.35, Dc = 2.014 g cn-3, m = 3.683 mm-1 and F(000) = 5024. The final R and wR values are 0.0224 and 0.0557 for 3189 [I> 2.0o(I)] unique reflections, and 0.0245 and 0.0567 for all 8206 reflections, respectively. The [TbⅢ(edta)(H2O)3]- complex anion has a nine-coordinated pseudo-monocapped square antiprismatic structure in which the nine coordinate atoms, two N and seven O come from one edta ligand and three water molecules. The crystal of the K4[TbⅢ2(Httha)2]·14H2O complex belongs to monoclinic system and P2(1)/n sp 相似文献
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采用比应变能判据和权函数法对相变增韧陶瓷Ⅰ-Ⅲ混合型裂纹的增韧结果进行了理论计算.分别给出了静止裂纹和定常扩展裂纹相变增韧的理论表达式.结果表明综合相变对静止裂纹有微小的负屏蔽效应,对扩展裂纹的增韧结果与材料的剪切模量、相变尾区高度和相应体积分数成正比,并且增韧值随着KⅢ/KⅠ比值的增大而减小,表明相变对Ⅰ型裂纹的增韧作用比对Ⅲ型裂纹的增韧作用更为显著. 相似文献
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1IntroductionManyanalyticalmethodsforthequantitativedeterminationofLa(Ⅲ)havebeenreported[1,2],inwhichrelatedCLanalysishasneverbeeninvolved.Inthispaper,anewmethodofflowinjectionCLapplicationforthedeterminationofLa(Ⅲ)ionispresented.Itisbasedontheinh… 相似文献
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The special strUcture and iflteresting luminescent character of Eu(lll) complex made it veryimportant in applied researches as well as in theoretical Studies. The cryStal stricture and luminescence spectrum of europium p-methylbenzoate complex with l, 10-penanthroline were reported [l]. Its non-isothermal kinetics and thermal decomposition mechanism, however, hasrarely been studied. In the paped, the thermal decomposition behavior of europium p-methylbenzoate complex with l, 10-penanthroline… 相似文献
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LIU Junshen HE Zhengguang CAIJun CAI Chunguang ZHOU Baoxue and CAI Weimin) Department of Environmental Science Engineering Harbin Institute of Technology Harbin China) School of Environmental Science Engineering Shanghai Jiaotong University Shanghai China 《稀有金属(英文版)》2003,(4)
A kind of Levextrel resin separation process was developed for separation of indium (Ⅲ), gallium (Ⅲ), and zinc (Ⅱ) from aqueous sulfate solution with Levextrel resin containing di(2-ethylhexyl) phosphoric acid (CL-P204). The aim of the research is to collect preliminary results for a pilot-scale production. Properties of adsorbing indium (Ⅲ), gallium (Ⅲ), and zinc (Ⅱ) from sulfate solution with the Levextrel resin were first studied by batch operation and column operation. The optimum pH, adsorption capacities and concentrations of stripping agents for indium (Ⅲ), gallium (Ⅲ) were tested. The separation order of indium (Ⅲ), gallium (Ⅲ), and zinc (Ⅱ) from sulfate solution with CL-P204 Levextrel resin was found that indium (Ⅲ) could be first separated by adsorbing at the acidity of 1.0 mol/L whereas gallium (Ⅲ) and zinc (Ⅱ) could not, and they were adsorbed together by adsorbing at pH = 2.8, then separated from each other by stripping with 0.1 and 0.5 mol/L hydrochloric acid, respectively. T 相似文献
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The cyclic voltammetry, current-time curve at potential step and potential-time curve of galvanostatic method were used to investigate the electrochemical behavior of Er(Ⅲ) in ErCl3-LiClO4-DMF(N, N-dimethylformamide) system on Pt and Cu electrodes. Results indicate that the electroreducation of Er(Ⅲ) to Er(0) is irreversible on Pt and Cu electrodes, the diffusion coefficient and electron transfer coefficient of Er(Ⅲ) in 0.01mol/L ErCl3-0.1mol/L LiClO4-DMF system at 303K are 1.96×10-6 cm2*s-1 and 0.081 respectively. The Er metal film was prepared by galvanostatic electrolysis on Cu electrode in ErCl3-LiClO4-DMF system at 40A*m-2(current density). The deposites composed of Er over 95%(mass fraction) were obtained. 相似文献
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ElectroreductionofCo(Ⅱ)andLa(Ⅲ)inUreaMeltYangQqin,QiuKairongandPanShijian(杨绮琴)(丘开容)(潘仕健)DepartmentofChemistry,ZhongshanUnicue... 相似文献
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Synthesis and Structural Determination of Nine-coordinate K_2[Y~Ⅲ(dtpa)(H_2O)]·7H_2O 总被引:1,自引:0,他引:1
1 IntroductionThecompoundsoftheradioactiveele ment90 Yhaveoftenbeenusedforthetreat mentofeverykindofcancer[1]becausetheycanemitpureandhigh energy β rayandpossesstheappropriatehalf life (t1/ 2 =64 0h)andmoderateenergy(Emax=2 .2 7MeV) .However,theradioactiveraysofthe90 Yi… 相似文献