n型GaSb,InGaAsSb的MBE生长和特性研究

本文报导了非故意掺杂ＩｎＧａＡｓＳｂ本底浓度的降低和掺Ｔｅｎ型ＧａＳｂ和ＩｎＧａＡｓＳｂ的ＭＢＥ生长与特性的研究结果。结果表明，通过生长工艺的优化，ＧａＳｂ和ＩｎＧａＡｓＳｂ的背景空穴浓度可分别降至１．１×１０~（１６）ｃｍ~（－３）和４×１０~（１６）ｃｍ~（－３），室温空穴迁移率分别为９４０ｃｍ２／ｖ．ｓ和２６０ｃｍ~２／ｖ．ｓ。用Ｔｅ作ｎ型掺杂剂，可获得载流子浓度在１０~（１６）～１０~（１８）ｃｍ~（－３）的优质ＧａＳｂ和ＩｎＧａＡｓＳｂ外延层，所研制的材料已成功地制备出Ｄ_λ~＊＝４×１０~（１０）ｃｍＨｚ~（１／２）／Ｗ的室温ＩｎＧａＡｓＳｂ红外探测器和室温脉冲ＡｌＧａＡｓＳｂ／ＩｎＧａＡｓＳｂ双异质结激光器。     

AlGaAsSb/InGaAsSb多量子阱结构的光致发光谱

用固态源ＭＢＥ技术生长了ＡｌＧａＡｓＳｂ／ＩｎＧａＡｓＳｂ多量子阱材料,研究了通过改变多量子阱ＡｌＧａＡｓＳｂ／ＩｎＧａＡｓＳｂ中的结构参数,如多量子阱中ＩｎＧａＡｓＳｂ的阱宽,ＡｌＧａＡｓＳｂ的垒宽及垒层中Ａｌ组分和阱层中的Ｉｎ组分,多量子阱中的阱数等,来提高ＡｌＧａＡｓＳｂ／ＩｎＧａＡｓＳｂ多量子阱的ＰＬ强度。     

GaInAsSb共振腔增强光电探测器设计

本文用一插值和介电常数的计算模型,得到了ＧａＩｎＡｓＳｂ四元系２．４μｍ探测器材料的 份及其折射率。将传统的Ｐ－ｉ－ｎ－ＧａＩｎＡｓＳｂ探测器结构置于两组ＡｌＡｓＳｂ／ＧａＳＢ Ｂｒａｇｇ反射镜之间,可以得到接近１的量子效率。本文用传递矩阵方法（ＴＭＭ）计算了ＡｌＡｓＳｂ／ＧａＳｂ Ｂｒａｇｇ反射镜的反射率与波长及反射镜个数的关系,并对探测器的结构进行了设计,讨论了吸收系数与波长的函数对探测器量子     

连续输出20WAlGaAs／GaAs量子阱激光二极管线列阵

采用ＭＯＣＶＤ实现了ＡｌＧａＡｓ／ＧａＡｓ量子阱结构，获得了连续输出２０Ｗ激光二极管线列阵，线列阵长度１．０ｃｍ，激射波长８０８±４ｎｍ。     

p~＋－GaInAsSb／p－GaInAsSb／n－GaSb异质结红外控测器

ＧａＩｎＡｓＳｂ是红外探测器中重要的半导体材料之一。我们用水平常压金属氧化物化学气相淀积（ＭＯＣＶＤ）技术在ｎ型ＧａＳｂ衬底上成功地生长了ＧａＩｎＡｓＳｂ外延层，用ＰＬ谱、红外吸收谱、Ｘ射线衍射和扫描电子超声显微镜（ＳｃａｎｎｉｎｇＥｌｅｃｔｒｏｎＡｃｏｕｓｔｉｃＭｉｃｒｏｓｃｏｐｙ，ＳＥＡＭ）等实验手段对ＧａＩｎＡｓＳｂ外延层进行了表征。用ＧａＩｎＡｓＳｂ材料制作的红外探测器的光谱响应的截止波长达２．４μｍ，室温探测率Ｄ＊达１×１０９ｃｍＨｚ（１／２）／Ｗ，２．２５μｍ波长时的量子效率为３０％。本文首次给出了ＧａＩｎＡｓＳｂ外延层的扫描电子超声显微镜像（ＳＥＡＭ像），为扫描电子超声显微镜在半导体材料方面的应用开辟了一个新的领域。     

K_2NbOF_5－MF_3系玻璃的结构及电性质

研制了Ｋ＿２ＮｂＯＦ＿５－ＭＦ＿３（Ｍ＝Ａｌ、Ｇａ）新体系氟化物玻璃，测定了玻璃的特征温度、Ｒａｍａｎ光谱和电导率，玻璃中Ｎｂ￣（５＋）、Ａｌ￣（３＋）、Ｇａ￣（５＋）分别以ＮｂＯＦ、ＡＩＦ、ＧａＦ八面体形式存在，玻璃的电导率随ＡｌＦ＿３含量的增加而增加，ＡｌＦ＿３含量达到３０ｍｏｌ％时，Ａｌ￣（３＋）除ＡＩＦ八面体外，还有ＡｌＦ四面体结构出现，同时电导率降低，Ｆ￣－阴离子是主要的导电离子，７５Ｋ＿２ＮｂＯＦ＿５·２５ＡｌＦ＿３玻璃的电导率在１９６℃时，σ＝１．０２×１０￣（－２）Ｓ·ｃｍ￣（－１）。     

气态源分子束外延InGaP／GaAs结构及其在异质结双极晶体管中的应用

本文研究了ＩｎＧａＰ／ＧａＡｓ异质结构的气态源分子束外延（ＧＳＭＢＥ）生长，所得样品晶格失配率△α／α＜８．９５×１０￣（－５），本底载流子浓度为１０￣（１５）ｃｍ￣（－３）数量级，掺硅ｎ型样品的载流子浓度控制范围可达２×１０￣（１５）～４×１０￣（１８）ｃｍ￣（－３）。研究了Ｐ＿２和Ａｓ＿２气氛的切换条件对ＩｎＧａＰ／ＧａＡｓ异质结构界面特性的影响，并成功地生长了ＩｎＧａＰ／ＧａＡｓ异质结双极晶体管（ＨＢＴ）结构材料，用此材料在国内首次制成的ＨＢＴ器件ｆｒ＝２５ＧＨｚ，ｆ＿（ｍａｘ）＝４６ＧＨｚ，电流增益β＝４０，最高可达β＝１５０。     

InAlAs／InGaAs MSM光电探测器

采用ＧＳＭＢＥ方法及典型的器件工艺制成了用ＩｎＡｌＡｓ作为肖特基势垒增强材料的高性能ＩｎＡｌＡｓ／ＩｎＧａＡｓ／ＩｎＰ ＭＳＭ光电探测器。用自制的测试系统对器件的直流和瞬态特性进行了测试，测试结果表明，器件的击穿电压大于３０Ｖ，在１０Ｖ偏压下暗电流小于２０ｎＡ，对应的暗电流密度为３ｐａ／μｍ＾２，优于已有文献的报导。     

二价离子替代的Nasicon及其应用研究

含二价阳离子的Ｎａｓｉｃｏｎ，Ｍ￣（２＋）Ｎａｓｉｃｏｎ（Ｍ＝Ｍｇ、Ｃａ、Ｓｒ、Ｚｎ）可由母体Ｎａ＿３Ｚｒ＿２Ｓｉ＿２ＰＯ＿（１２）（Ｎａｓｉｃｏｎ）为起始原料与相应的二价离子的盐浓液或熔盐进行离子交换而制得。Ｘ射线衍射分析结果表明离子交换后的产物Ｍ￣（２＋）－Ｎａｓｉｃｏｎ大多保持原母体的Ｃ＿（２／ｃ）结构。交流阻抗技术测定的电导率数据显示含不同的二价替代离子的Ｎａｓｉｃｏｎ的电导率相差甚大。其中最好的是Ｍｇ￣（２＋）－Ｎａｓｉｃｏｎ，其电导率在４００℃时可达到１．４８×１０￣（－２）Ｓ／ｃｍ。Ｍｇ￣（２＋）－Ｎａｓｉｃｏｎ用作微功率固态电池Ｍｇ／ＣｕＣｌ的电解质，该电池的开路电压为２．０７Ｖ，短路电流为１ｍＡ。平均放电电压为１．６Ｖ，电池的放电容量是３．４ｍＡＨ。     

用于掺铒光纤放大器泵浦源的高性能980nm InGaAs应变量子阱激光器

利用分子束外延方法研制出了高质量的ＩｎＧａＡｓ／ＡｌＧａＡｓ庆变量子阱激光器外延材料，其最低的阈值电流密度可达到１２０Ａ／ｃｍ＾２，激光波长在９８０ｎｍ左右。获得了高性能的适合于掺铒光纤放大器用的９８０ｎｍ量子阱激光器泵浦源，其典型的阈值电流为１５ｍＡ，外微分量子效率的典型值和最好值分别为０．８ｍＷ／ｍＡ和１．０ｍＷ／ｍＡ，线性输出功率大于１２０ｍＷ，在２０℃－５０℃的特征温度Ｔ０为１２５Ｋ。器件     

微波消解-ICP-AES法测定茶叶中钾、钠、磷、硫、铁、锰、铜、锌、钙、镁方法研究

通过优化微波消解条件,并根据不同元素性质,调谐ICP-AES工作条件至最佳,实现了茶叶中K、Na、P、S以及Fe、Mn、Cu、Zn、Ca、Mg 10种元素的同时测定。10种元素测定结果 RSD%为0.67(Cu)～5.57(Na),回收率为84.0%(Na)～101.5%(Fe),检出限为0.001(Mn)～0.029(S)μg·g-1,表明该方法准确可靠,能够满足茶叶中K、Na、P、S、Fe、Mn、Cu、Zn、Ca、Mg分析要求。     

p,V, T and derived thermodynamic data for toluene,trichloromethane, dichloromethane,acetonitrile, aniline,and n-dodecane

Experimentally determined p,V,T data are reported for toluene, trichloromethane, dichloromethane, acetonitrile, aniline, and n-dodecane at 278, 288, 298, 313, and 323 K, except for dichloromethane, for which the highest temperature was 298 K. At each temperature, measurements were done at pressures up to about 280 MPa or (for aniline and n-dodecane) at a lower pressure slightly below the freezing pressure at the temperature of measurement. Values of the isobaric expansivity isothermal compressibility and (for toluene, trichloromethane, dichloromethane, and acetonitrile) internal pressure, derived from the p,V,T data, are presented.     

Optical properties of the metals Al, Co, Cu, Au, Fe, Pb, Ni, Pd, Pt, Ag, Ti, and W in the infrared and far infrared

Infrared optical constants collected from the literature are tabulated. The data for the noble metals and Al, Pb, and W can be reasonably fit using the Drude model. It is shown that -epsilon1(omega) = epsilon2(omega) approximately omega(2)(p)/(2omega(2)(tau)) at the damping frequency omega = omega(tau). Also -epsilon1(omega(tau)) approximately - (1/2) epsilon1(0), where the plasma frequency is omega(p).     

抓管理重服务求可靠要效益--记广西计量测试研究所国家实验室认可工作

我所2001年9月份顺利地通过了中国实验室认可委紧张而严格的评审,得到了权威机构认可,成为西南地区较早通过国家实验室认可的省级计量校准机构.在建立质量体系、运行质量体系走过了艰辛之路,我们将全所职工的艰辛之路介绍给大家,希望能给将要申请认可的实验室得以参考.     

Dry Autoclaving for the Nanofabrication of Sulfides,Selenides, Borides,Phosphides, Nitrides,Carbides, and Oxides

This review compiles various nanostructures fabricated by a distinct “dry autoclaving” approach, where the chemical reactions are carried out without solvents; above the dissociation temperature of the chemical precursor(s) at elevated temperature in a closed reactor. The diversity to fabricate carbides (SiC, Mo₂C, WC), oxides (VOx‐C, ZnO, Eu₂O₃, Fe₃O₄, MoO₂), hexaborides (LaB₆, CeB₆, NdB₆, SmB₆, EuB₆, GdB₆), nitrides (TiN, NbN, TaN), phosphides (PtP₂, WP), sulfides (ZnS, FeS/C, SnS/C, WS₂, WS₂/C), and selenides (Zn_1‐xMn_xSe/C, Cd_1‐xMn_xSe/C), with various shapes and sizes is accounted with plausible applications. This unique single‐step, solvent‐free synthetic process opens up a new route in the growing nanomaterials science; owing to its considerable advantages on the existing approaches.     

标准·质量·认证·会议(英文)

Standards IGRS:First Complete International Standards System in 3C Collaboration Field After ISO and IEC released three international standards of Intelligent Grouping and Resource Sharing (IGRS) including Core Protocol,File Communication Framework and Device Validation,four standards of IGRS,Application Framework,Basic Application,Service Types and Devices Types,got approved with high passing rate in the voting of Final Draft International Standard (FDIS) and will be officially issued soon around the world. It symbolizes that all     

Elastic, structural, bonding, and defect properties of zinc-blende BN, AlN, GaN, InN and their alloys

Simple tight-binding simulations, incorporating only the Herman–Skillman atomic term values, are shown to provide valuable information about the bonding, elastic and structural properties of zinc-blende group III-nitrides. Our calculated values of the elastic parameters (viz., bulk modulus, elastic stiffness constants, Kleinman's internal displacement parameter, Keating force constants, etc.) for BN, AlN, GaN, and InN are shown to exist well within the range of values derived from more sophisticated methods. Despite the crude approximations used, the tight-binding method has clearly provided the meaningful trends to the local distortions around isoelectronic impurities and has described reasonably well the bond length variations as a function of composition in ternary alloys.