热处理对非掺杂半绝缘LEC GaAs电特性的影响

对非掺杂（ＮＤ）半绝缘（ＳＩ）液封直拉（ＬＥＣ）ＧａＡｓ单晶在 ９５０℃下进行了不同 Ａｓ压的热处理,研究了热处理对材料电特性的影响．发现在９５０℃温度和低Ａｓ压条件下 进行１４ｈ热处理,可在样品中引入本征受主缺陷,并导致体霍尔迁移率大幅下降和体电阻 率明显增加．这些受主缺陷的产生是由于高温和低 ＡＳ压条件下 ＧａＡｓ晶体中发生 Ａｓ间隙 原子的外扩散．提高热处理过程中的Ａｓ气压,可抑制这些受主缺陷的产生和电参数的变化．     

影响电沉积镉负极活性的主要因素

改变生产工艺条件制得电沉积镉负极,观察其显微结构并用恒电流法测试其比容量。结果表明：在电沉积过程中,酸度,镉离子浓度,温度,电流密度是主要影响因素。优化工艺条件,比容量最高可达３７２ｍＡ·ｈ·ｇ＾－１,最优工艺条件：反应温度２０℃,Ｈ２ＳＯ４浓度３５ｍｏｌ／Ｌ,镉离子浓度０．２ｍｏｌ／Ｌ,电流密度０．５２Ａ／ｃｍ＾２。     

非掺杂半绝缘LFCGaAs中深施工主缺陷对注入硅激活率的影响

通过测量ＧａＡｓ金属半导体场效应晶体管的饱和漏－源电流分布研究了深施工主缺陷ＥＬ２对半绝缘（ＳＩ）ＬＥＣＧａＡｓ中注入硅激活率的影响,发现激活率随ＥＬ２浓度的增加而增加,讨论了ＥＬ２影响硅注入激活率的机理。     

一种平衡树的研究之三

本是「２」的续篇,在「２」Ｓｅａｒｃｈ（ｆ,ｒ,ａ）函数基础上对平衡树的插入算法Ｉｎｓｅａｒｔ（ｒ,ａ）进行了深入的研究。在Ｉｎｓｅａｒｔ（ｒ,ａ）算法中,构造了ＩＮＳＥＡＲＴＡＳＬＥＡＦ（ｆ,ａ）过程,对该过程中的ＩＮＳＥＡＲＴＡＳＬＥＡＦ３１（ｆ,ａ）算法进行了详细论述,最后给出了Ｉｎｓｅａｒｔ（ｒ,ａ）时间复杂度的证明。     

A THEORY FOR WAVE EQUATION INVERSE

ＡＴＨＥＯＲＹＦＯＲＷＡＶＥＥＱＵＡＴＩＯＮＩＮＶＥＲＳＥＰＲＯＢＬＥＭ：ＴＨＥＵＮＩＯＮＭＥＴＨＯＤＦＯＲＳＣＡＴＴＥＲＥＤＷＡＶＥＥＸＴＲＡＰＯＬＡＴＩＯＮＡＮＤＶＥＬＯＣＩＴＹＩＭＡＧＩＮＧＳｏｎｇＳｈｏｕｇｅｎＨｅＪｉｓｈａｎＱｕＣｈａｏｓｈ...     

GEOTHERMALEVOLUTIONOFDONGPUDEPRESSI

ＧＥＯＴＨＥＲＭＡＬＥＶＯＬＵＴＩＯＮＯＦＤＯＮＧＰＵＤＥＰＲＥＳＳＩＯＮＢＹＦＩＳＳＩＯＮＴＲＡＣＫＡＮＡＬＹＳＩＳＷａｎｇＬｕ（ＥｄｉｔｏｒｉａｌＤｅｐａｒｔｍｅｎｔｏｆＪｏｕｒｎａｌｏｆＣｅｎｔｒａｌＳｏｕｔｈＵｎｉｖｅｒｓｉｔｙｏｆＴｅｃｈ...     

LDPE悬浮聚合接枝PS及其表征

研究了ＬＤＰＥ悬浮接枝ＰＳ合成ＬＤＰＥ－ｇ－ＰＳ接枝共聚物的工艺，此接枝共聚物可作为某此聚合物共混的相容剂。讨论了苯乙烯溶胀ＬＤＰＥ时间、引发剂浓度和ＬＤＰＥ与苯乙烯投料比对接枝率的影响，发现溶胀时间为４ｈ、反应时间为８ｈ、引发剂浓度为１％时、ＬＤＰＥ与苯乙烯投料比为１：１时，其接枝共聚物接枝率最大可达３８．５％。并对ＬＤＰＥｇ－ＰＳ接枝共聚物进行了ＤＳＣ、ＩＲ及接枝率测定的表征。     

A3钢表面有机磷合钼聚多酸盐转化膜的研究

由Ｎａ２ＭｏＯ４·２Ｈ２Ｏ和Ｎａ２ＨＥＤＰ·５Ｈ２Ｏ合成了有机膦合钼聚多酸盐Ｎａ８［（ＨＥＤＰ）２Ｍｏ５Ｏ２１］·５Ｈ２Ｏ。用Ｎａ８［（ＨＥＤＰ）２Ｍｏ５Ｏ２１］·５Ｈ２Ｏ的溶液处理Ａ３钢，获得了具有一定耐蚀性的黄色转化膜，适宜的工艺条件为：浓度１６ｇ·Ｌ＾－１，ｐＨ３．５，温度５０℃，时间８０ｓ。本文还报告了膜层的ＸＰＳ和ＡＥＳ分析结果。     

INVESTIGATION ON THE MORPHOLOGY OF MARTENSITE IN CARBON STEELS

ＩＮＶＥＳＴＩＧＡＴＩＯＮＯＮＴＨＥＭＯＲＰＨＯＬＯＧＹＯＦＭＡＲＴＥＮＳＩＴＥＩＮＣＡＲＢＯＮＳＴＥＥＬＳＨｅＹｕｅｈｕｉ（ＰｏｗｄｅｒＭｅｔａｌｕｒｇｙＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅ，ＣｅｎｔｒａｌＳｏｕｔｈＵｎｉｖｅｒｓｉｔｙｏｆＴｅｃｈ...     

FHA BIOCERAMIC COMPOSITE MATERIALS ENHANCED BY ZrO_2

ＦＨＡＢＩＯＣＥＲＡＭＩＣＣＯＭＰＯＳＩＴＥＭＡＴＥＲＩＡＬＳＥＮＨＡＮＣＥＤＢＹＺｒＯ＿２ＦＨＡＢＩＯＣＥＲＡＭＩＣＣＯＭＰＯＳＩＴＥＭＡＴＥＲＩＡＬＳＥＮＨＡＮＣＥＤＢＹＺｒＯ＿２￥ＲｕａｎＪｉａｎｍｉｎ；ＨｕａｎｇＢａｉｙｕｎ（ＰｏｗｄｅｒＭｅ...     

Effects of different CdCl_2 annealing methods on the performance of CdS/Cd Te polycrystalline thin film solar cells

In this paper, the effects of different Cd Cl2 annealing methods, including vapor annealing and dip-coating annealing, on the performance of Cd S/Cd Te polycrystalline thin-film solar cells are studied. After annealing, the samples are lightly etched with 1% bromine in methanol to remove surface oxides. Both annealing methods give Cd Te polycrystalline thin films with good crystallinity and complete structure. For solar cells containing the annealed Cd Te films, cell efficiency first increases and then decreases as the concentration of Cd Cl2 solution used for dip-coating annealing increases, and the optimized Cd Cl2 concentration is 12%. The uniformity of the performance of all cells is analyzed by calculating the relative standard deviation for each parameter. The uniformity of cell performance can be improved dramatically by dip-coating annealing instead of vapor annealing. Most notably, an appropriate concentration of Cd Cl2(12%) acts as a protective layer that is conducive to realizing uniform high-performance Cd S/Cd Te solar cells. According to the location of depletion regions, the Cd Te films treated by dip-coating annealing show a relatively low doping concentration, except for the sample treated with a Cd Cl2 concentration of 6%, which is consistent with the changes of short-circuit current density of the cells. It is believed that these results can be applied to the large-scale production of Cd Te polycrystalline thin-film solar cells.     

Effects of different CdCl<Subscript>2</Subscript> annealing methods on the performance of CdS/CdTe polycrystalline thin film solar cells

In this paper, the effects of different CdCl₂ annealing methods, including vapor annealing and dip-coating annealing, on the performance of CdS/CdTe polycrystalline thin-film solar cells are studied. After annealing, the samples are lightly etched with 1% bromine in methanol to remove surface oxides. Both annealing methods give CdTe polycrystalline thin films with good crystallinity and complete structure. For solar cells containing the annealed CdTe films, cell efficiency first increases and then decreases as the concentration of CdCl₂ solution used for dip-coating annealing increases, and the optimized CdCl₂ concentration is 12%. The uniformity of the performance of all cells is analyzed by calculating the relative standard deviation for each parameter. The uniformity of cell performance can be improved dramatically by dip-coating annealing instead of vapor annealing. Most notably, an appropriate concentration of CdCl₂ (12%) acts as a protective layer that is conducive to realizing uniform high-performance CdS/CdTe solar cells. According to the location of depletion regions, the CdTe films treated by dip-coating annealing show a relatively low doping concentration, except for the sample treated with a CdCl₂ concentration of 6%, which is consistent with the changes of short-circuit current density of the cells. It is believed that these results can be applied to the large-scale production of CdTe polycrystalline thin-film solar cells.     

La~（3＋）/Ce~（4＋）掺杂对TiO_2光催化活性的影响

以钛酸四丁酯为前驱体,采用溶胶-凝胶法制备纯的及掺杂稀土的TiO2,重点考察了退火温度对纳米颗粒晶相转变的影响。通过光催化降解实验,探讨了退火温度、退火时间、稀土离子掺杂浓度等因素对TiO2光催化活性的影响。结果表明,TiO2粉末在400℃下为锐钛矿型,具有很高的光催化活性;掺杂的TiO2纳米样品在短时间内降解均较未掺杂TiO2纳米样品的催化活性高;掺La3＋最佳摩尔分数为0.05,掺Ce4＋最佳摩尔分数为0.20,最佳退火温度为400℃,退火时间为9 h。掺La3＋量相对较少时催化活性高,而掺Ce4＋的纳米粉体在相对较高的浓度下可达到完全降解。     

GaAs近红外吸收特性和主要深电子陷阱浓度的测量

本文研究液封直拉(LEC)未掺杂半绝缘GaAs室温和低温近红外吸收特性,对主要深电子陷阱(EL2)引起红外吸收的机理进行了探讨。利用低温高分辩率技术,发现样品中EL2内部跃迁特征谱及由零声子线和五个声子耦合峰组成的精细结构。零声子线与近红外吸收带具有相同的光淬灭效应,其强度与EL2浓度具有良好的线性关系,由此阐述了一种测定EL2浓度的新方法。     

Reduction of deep level defects in unintentionally doped 4H-SiC homo-epilayers by ion implantation

In order to reduce deep level defects, the theory and process design of 4H-SiC homoepitaxial layer implanted by carbon ion are studied. With the Monte Carlo simulator TRIM, the ion implantation range, location of peak concentration and longitudinal straggling of carbon are calculated. The process for improving deep energy level in undoped 4H-SiC homoepitaxial layer by three times carbon ion-implantation is proposed, including implantation energy, dose, the SiO2 resist mask, annealing temperature, annealing time and annealing protection. The deep energy level in 4H-SiC material can be significantly improved by implantation of carbon atoms into a shallow surface layer. The damage of crystal lattice can be repaired well, and the carbon ions are effectively activated after 1 600 ℃ annealing, meanwhile, deep level defects are decreased.     

电解充氢及退火热处理与ZL114合金的力学性能

充氢后的铝合金试样在空气中放置一段时间后，其力学性能与充氢前比不降反升.由此想到，若将充氢试样进行退火热处理，可望获得更佳的效果.以ZL114为试验合金，对比测定了在空气中放置和退火后的试样与原来的充氢试样的力学性能，观察了它们的断口形貌.为缩短试验周期、突出试验结果，便于对比，采用了浓度为1?mol/L的HCl溶液.结果表明，退火热处理明显改善了充氢试样的延伸率和缩面率，断口中出现韧窝状凹坑.因此，可用此法快速析出试样中的氢，减轻及消除氢对其力学性能的影响.     

退火处理对Ti-Zr-Cu-Be块体非晶合金力学性能的影响

采用铜模铸造法制备了直径为2mm的Ti55-xZr10+xBe27.5Cu7.5(x=0,10,20)块体非晶合金,并对其进行等温退火处理.利用X射线衍射(XRD)、扫描电镜(SEM)、差氏扫描量热仪(DSC)及压缩试验等方法研究了非晶合金的相结构、显微组织和热稳定性,以及退火处理对其力学性能的影响.结果表明:该系列合金在553 K及583 K下保温长达5 h时间内依然表现为非晶态.退火处理后,Ti35Zr30Be27.5Cu7.5合金屈服强度、断裂强度均提到了提高,其中在583 K下保温1 h后屈服强度、断裂强度分别达到了1 921、2 169 MPa;其塑性由处理前的3.47%提高到了6.57%.Ti45Zr20Be27.5Cu7.5合金在退火后其力学性能变化不明显.Ti55Zr10Be27.5Cu7.5合金随着退火温度及保温时间的增加其屈服强度、断裂强度及塑性均明显降低.     

Eu掺杂TiO_2纳米晶光致发光影响因素

为了寻找Ti O2∶Eu3+纳米晶的最佳制备工艺条件,采用溶胶-凝胶法制备了Ti O2∶Eu3+纳米晶,研究了Eu3+掺杂浓度、退火温度、Al3+的掺入等工艺参数对Ti O2∶Eu3+纳米晶发射光谱的影响.利用PL、PLE对样品进行了表征.结果表明用468 nm激发光源激发Ti O2∶Eu3+纳米晶时,样品显示出强红光发射,对应于Eu3+粒子的5D0→7F2超灵敏跃迁;且荧光强度随着Eu3+掺杂浓度和退火温度的升高先增强后减弱;700℃退火的样品红光发射强度达到最强,Eu3+的最佳掺杂浓度为0.8%mol;Al3+的掺入可以提高Eu3+的红光发射强度,采用钛酸正四丁脂∶异丙醇∶冰乙酸∶水=1∶4∶4∶2制备出的Ti O2:Eu3+纳米晶的红光发射光谱最强.     

基于溶胶凝胶法ITO薄膜材料的制备与表征

基于溶胶凝胶法制备了掺铟二氧化锡（ITO）薄膜,探讨聚乙二醇（PEG）、退火温度、退火过程氧气浓度等因素对ITO薄膜性能的影响。实验结果表明：在相同实验条件下,添加PEG能够降低ITO薄膜表面粗糙度,退火温度会改变ITO薄膜的结晶度,提高含锡量和氧浓度会增加ITO薄膜的电阻率。本研究为ITO埋栅结构气敏传感器制备提供了实验基础。     

GCr15钢的快速球化退火工艺

根据“离异共析”原理,对GCr15钢采用低温奥氏体化和快速球化退火新工艺,该工艺使得球化退火的奥氏体化保温时间和等温转变时间总和缩短到2h以内,与传统退火工艺相比节约能源50％以上。