Ⅲ-Ⅴ族三元化合物半导体材料分子束外延的生长热力学

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。     

Properties of GaSb Substrate Wafers for MOCVD Ⅲ-Ⅴ Antimonids

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＧａＳｂｓｉｎｇｌｅｃｒｙｓｔａｌｓａｒｅｏｆｔｅｎｕｓｅｄａｓｔｈｅｓｕｂｓｔｒａｔｅｍａｔｅｒｉａｌｓｆｏｒｐｒｅｐａｒｉｎｇｅｐｉｌａｙｅｒｓｏｆｌｉｇｈｔｅｍｉｔｉｎｇａｎｄｌｉｇｈｔｄｅｔｅｃｔｉｎｇｄ...     

MOCVD法制备碳-氧化铝太阳能选择吸收涂层的研究

目前,普遍采用射频溅射制备以氧化铝为介质基体的太阳能选择吸收涂层,但射频溅射成本高、效率低.以乙酰丙酮铝为前驱体,采用金属有机化合物化学气相沉积(MOCVD)方法,在不锈钢基体上制备碳一氧化铝太阳能选择吸收涂层,大大降低了涂层成本.研究了栽气成分、沉积时间对膜层成分和吸收率的影响.结果表明:在沉积温度为600℃、载气氧含量为3%、沉积时间4h时获得了吸收率α为0.91的涂层.     

V(Ⅴ)-Fe(Ⅲ)-S(Ⅵ)-H2O系热力学研究与钒铁分离方法理论

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   

Inhomogeneity of Rare Earth Doped Ⅲ-Ⅴ Compounds Grown by LPE

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.     

Spectrophotometric Determination of Trace Amounts of Vanadium(Ⅴ) by Means of Its Catalytic Effect on Oxidation of Azomethine-H by Bromate

1ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｂｉｏｌｏｇｉｃａｌｅｆｆｅｃｔｓｏｆｖａｎａｄｉｕｍｉｎｖｏｌｖｅｎｏｒｍａｌｉｚａｔｉｏｎｏｆｓｕｇａｒｌｅｖｅｌｓ,ｐａｒｔｉｃｕｌａｒｌｙｉｎｖａｒｉｏｕｓｅｎｚｙｍｅｓｙｓｔｅｍｓａｓａｎｉｎｈｉｂｉｔｏｒａｎｄ/ｏｒａｃｏｆａｃｔｏｒ[1].Ｖａｎａｄｉｕｍｉｓａｌｓｏａｎｅｓｓｅｎｔｉａｌｍｉｃｒｏａｍｏｕｎｔｅｌｅｍｅｎｔｆｏｒｈｕｍａｎａｎｄａｎｉｍａｌｓ,ａｎｄｉｔｓｐｒｅｓｅｎｃｅｉｎｔｈｅｒａｎｇｅ20～150ｎｇ/ｍｌｉｎｄｒｉｎｋｉｎｇｗａｔｅｒｈａ…     

Codepositon of Nanodiamonds with Chromium(Ⅲ)

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.     

Kinetic and thermodynamic studies of adsorption of gallium(Ⅲ) on nano-TiO_2

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.     

Electroreduction of Yb(Ⅲ) on Co Cathode in Molten Chloride

ＥｌｅｃｔｒｏｒｅｄｕｃｔｉｏｎｏｆＹｂ（Ⅲ）ｏｎＣｏＣａｔｈｏｄｅｉｎＭｏｌｔｅｎＣｈｌｏｒｉｄｅ①ＬｉｕＧｕａｎｋｕｎ，ＴｏｎｇＹｅｘｉａｎｇ，ＹａｎｇＱｉｑｉｎ，ＨｏｎｇＨｕｉｃｈａｎａｎｄＣｈｅｎＳｈｅｎｇｙａｎｇ（刘冠昆）（童叶翔）（杨绮琴...     

Study on syntheses and structures of nine-coordinated mononuclear K[TbⅢ(edta)(H2O)3]·5H2O and binuclear K4[TbⅢ2(Httha)2]·14H2O complexes

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     

动态应变时效处理中SA508-Ⅲ钢的组织演变

在不同应变速率和不同应变量下对SA508-III钢进行动态应变时效处理,探讨应变量和应变速率对SA508-III钢组织的影响规律。结果表明,SA508-III钢经动态应变时效处理后,显微硬度、位错密度以及析出相密度均明显提高,且随着应变量和应变速率的提高呈上升趋势。     

Ⅰ-Ⅲ混合型裂纹比应变能判据相变增韧分析

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.     

Determination of Lanthanu m in Lu minol- H_2 O_2- Cr( Ⅲ) Syste m by Flow Injection Chemilu minescence

１ＩｎｔｒｏｄｕｃｔｉｏｎＭａｎｙａｎａｌｙｔｉｃａｌｍｅｔｈｏｄｓｆｏｒｔｈｅｑｕａｎｔｉｔａｔｉｖｅｄｅｔｅｒｍｉｎａｔｉｏｎｏｆＬａ（Ⅲ）ｈａｖｅｂｅｅｎｒｅｐｏｒｔｅｄ［１，２］，ｉｎｗｈｉｃｈｒｅｌａｔｅｄＣＬａｎａｌｙｓｉｓｈａｓｎｅｖｅｒｂｅｅｎｉｎｖｏｌｖｅｄ．Ｉｎｔｈｉｓｐａｐｅｒ，ａｎｅｗｍｅｔｈｏｄｏｆｆｌｏｗｉｎｊｅｃｔｉｏｎＣＬａｐｐｌｉｃａｔｉｏｎｆｏｒｔｈｅｄｅｔｅｒｍｉｎａｔｉｏｎｏｆＬａ（Ⅲ）ｉｏｎｉｓｐｒｅｓｅｎｔｅｄ．Ｉｔｉｓｂａｓｅｄｏｎｔｈｅｉｎｈ…     

Kinetics Study on the Thermal Decomposition of Europium p-methyl-benzoate Complex with 1,10-penanthroline under Non-isothermal Con-ditions

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…     

Separation of indium (Ⅲ), gallium (Ⅲ), and zinc (Ⅱ) with Levextrel resin containing di(2-ethylhexyl) phosphoric acid (CL-P204): Part I. Selection of separation conditions

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     

Electrochemical Behavior of Er(Ⅲ）In N,N-dimethylformamide

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 0.01mol/L ErCl3-0.1mol/L LiClO4-DMF system at 303K 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 40A*m-2(current density). The deposites composed of Er over 95%(mass fraction) were obtained.     

Electroreduction of Co(Ⅱ) and La(Ⅲ)in UreaMelt

ＥｌｅｃｔｒｏｒｅｄｕｃｔｉｏｎｏｆＣｏ（Ⅱ）ａｎｄＬａ（Ⅲ）ｉｎＵｒｅａＭｅｌｔＹａｎｇＱｑｉｎ，ＱｉｕＫａｉｒｏｎｇａｎｄＰａｎＳｈｉｊｉａｎ（杨绮琴）（丘开容）（潘仕健）ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＺｈｏｎｇｓｈａｎＵｎｉｃｕｅ...     

Synthesis and Structural Determination of Nine-coordinate K_2[Y~Ⅲ(dtpa)(H_2O)]·7H_2O

1 ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｃｏｍｐｏｕｎｄｓｏｆｔｈｅｒａｄｉｏａｃｔｉｖｅｅｌｅ ｍｅｎｔ90 Ｙｈａｖｅｏｆｔｅｎｂｅｅｎｕｓｅｄｆｏｒｔｈｅｔｒｅａｔ ｍｅｎｔｏｆｅｖｅｒｙｋｉｎｄｏｆｃａｎｃｅｒ[1]ｂｅｃａｕｓｅｔｈｅｙｃａｎｅｍｉｔｐｕｒｅａｎｄｈｉｇｈ ｅｎｅｒｇｙ β ｒａｙａｎｄｐｏｓｓｅｓｓｔｈｅａｐｐｒｏｐｒｉａｔｅｈａｌｆ ｌｉｆｅ (ｔ1/ 2 =64 0ｈ)ａｎｄｍｏｄｅｒａｔｅｅｎｅｒｇｙ(Ｅｍａｘ=2 .2 7ＭｅＶ) .Ｈｏｗｅｖｅｒ,ｔｈｅｒａｄｉｏａｃｔｉｖｅｒａｙｓｏｆｔｈｅ90 Ｙｉ…