Preparation, characterization and gas sensing properties of lead tetra-(tert-butyl)-5,10,1 5,20-tetraazaporphyrin spin-coating films

A spin-coated film of lead tetra-(tert-butyl)-5,10,15,20-tetraazaporphyrin complex (PbTAP(t-Bu)(4)) was obtained and characterized by IR spectra, absorption spectra and atomic force microscopy. The response and recovery characteristics of the film to NH3, NO2 and C2H5OH vapor were investigated at room temperature. In addition, the reversibility and stability of the film to NH3 were also studied. The results indicate that the PbTAP(t-Bu)(4) derivative can be exploited as an NH3 sensor at room temperature. (c) 2007 Elsevier B.V. All rights reserved.

Growth of (10(1)over-bar(3)over-bar) semipolar GaN on m-plane sapphire by hydride vapor phase epitaxy

The crystalline, surface, and optical properties of the (10 (1) over bar(3) over bar) semipolar GaN directly grown on m-plane sapphire substrates by hydride vapor phase epitaxy (HVPE) were investigated. It was found that the increase of V/III ratio led to high quality (10 (1) over bar(3) over bar) oriented GaN epilayers with a morphology that may have been produced by step-flow growth and with minor evidence of anisotropic crystalline structure. After etching in the mixed acids, the inclined pyramids dominated the GaN surface with a density of 2 X 10(5) cm(-2), revealing the N-polarity characteristic. In the low-temperature PL spectra, weak BSF-related emission at 3.44eV could be observed as a shoulder of donor-bound exciton lines for the epilayer at high V/III ratio, which was indicative of obvious reduction of BSFs density. In comparison with other defect related emissions, a different quenching behavior was found for the 3.29 eV emission, characterized by the temperature-dependent PL measurement. (C) 2009 Elsevier B.V. All rights reserved.

Hydride Vapor Phase Epitaxy Growth of Semipolar, 10(1)over-bar(3)over-barGaN on Patterned m-Plane Sapphire

We have investigated the hydride vapor-phase epitaxy growth of (10 (1) over bar(3) over bar)-oriented GaN thick films on patterned sapphire substrates (PSSs) (10 (1) over bar0). From characterization by atomic force microscopy, scanning electron microscopy, double-crystal X-ray diffraction, and photoluminescence (PL), it is determined that the crystalline and optical qualities of (10 (1) over bar(3) over bar) GaN epilayers grown on the cylindrical PSS are better than those on the flat sapphire. However, two main crystalline orientations (10 (1) over bar(3) over bar) and (11 (2) over bar2) dominate the GaN epilayers grown on the pyramidal PSS, demonstrating poor quality. After etching in the mixed acids, these (10 (1) over bar(3) over bar) GaN films are dotted with oblique pyramids, concurrently lining along the < 30 (3) over bar2 > direction, indicative of a typical N-polarity characteristic. Defect-related optical transitions of the (10 (1) over bar(3) over bar) GaN epilayers are identified and detailedly discussed in virtue of the temperature-dependent PL. In particular, an anomalous blueshift-redshift transition appears with an increase in temperature for the broad blue luminescence due to the thermal activation of the shallow level.

铕铽柠檬酸-1,10-菲咯啉配合物的合成及荧光性质研究

分别合成了稀土(Eu3+和Tb3+)与柠檬酸、1,10 菲咯啉配位的稀土配合物。通过元素分析和红外分析确定了配合物的组成。通过荧光光谱与荧光寿命的测试,研究了它们的荧光性质。结果表明当铽掺入配合物后,铽能极大地增强铕的特征荧光,而铽的荧光被严重猝灭,其荧光强度以指数形式衰减。铕的荧光在铽荧光猝灭最严重时,被增强的效果最好,铕的荧光强度是荧光增强效果和铕的含量共同作用的结果,当铕与铽的浓度比为6∶4时能得到相应的铕的荧光最强的配合物。

四氯合锌酸1,10-癸二铵配合物的晶体结构

合成了[NH_3(CH_2)_(10)NH_3]ZnCl_4配合物(简称DDAZn),用X射线衍射法研究了它的晶体结构,晶体属三斜晶系,空间群为P1,晶胞参数为:α=0.7296(1),b=1.0110(3),c=1.2814(4)nm;α=90.84(2),β=101.17(2),γ=92.52(2)°;Z=2.该配合物为层型结构.由单个四面体阴离子ZnCl_4~(2-)构成的阴离子层被夹在烷基铵阳离子层之间,形成“夹心面包”型体系.在层之间的烷基铵链在垂直于层的方向上倾斜排列.

STRUCTURE OF CIS-DIAQUABIS(1,10-PHENANTHROLINE)ZINC SULFATE HEXAHYDRATE

[Zn(C12H8N2)2(H2O)2]SO4.6H2O, M(r) = 665.98, triclinic, P1BAR, a = 10.070 (4), b = 12.280 (3), c = 13.358 (2) angstrom, alpha = 109.12 (2), beta = 92.58 (2), gamma = 110.85 (2)-degrees, V = 1433.9 (7) angstrom 3, Z = 2, D(x) = 1.54 g cm-3, lambda(Mo K-alpha) = 0.71069 angstrom, mu = 10.1 cm-1, F(000) = 692, T = 293 K, R = 0.044 for 3985 observed reflections. The Zn atom is coordinated in a distorted octahedral geometry by four N atoms from two 1,10-phenanthroline (phen) ligands and two water molecules. The intermolecular ring-stacking interactions between the phen ligands occur in two forms: infinite chains and discrete dimers. Hydrogen bonds further stabilize the structure.

硬粒小麦-节节麦人工合成种HMW-GS组成及1.5＋10亚基的遗传分析

对CIMMYT的99份硬粒小麦-节节麦人工合成种（简称合成种）的HMW-GS组成分析发现，Glu-B1和Glu-D1位点的变异类型比普通小麦丰富，分别有9种和12种亚基类型；筛选出含有比5＋10亚基更优质的1．5＋10和5＋12亚基的合成种分别有8份和1份；含有优质亚基1．5＋10的合成种与普通小麦杂交结实正常；对2个合成种与2个普通小麦品种的8个止反交组合F1种子电泳发现，优质亚基1．5＋10在F1代能正常表达，双亲所有亚基任F1代都得到表达，表现共显性遗传。本研究为优质亚基1．5＋10和5＋12转育到普通小麦中奠定了基础。

DG-10数显光栅测微仪

<正> 由中国科学院力学研究所研制的DG-10数显光栅测微仪,经中国计量科学研究院检定,其主要技术指标: 1.量程0-10mm;2.分度值0.001mm;3.示值误差在全量程内为±0.001mm;4.回程误差0.001mm;5.测杆受径向力作用时示值变化0.001mm。

Monolithic integration of electroabsorption modulator and DFB laser for 10-Gb/s transmission

A strained InGaAsP-InP multiple-quantum-well DFB laser monolithically integrated with electroabsorption modulator by ultra-low-pressure (22 mbar) selective-area-growth is presented. The integrated chip exhibits superior characteristics, such as low threshold current of 19 mA, single-mode operation around 1550 nm range with side-mode suppression ratio over 40 dB, and larger than 16 dB extinction ratio when coupled into a single-mode fiber. More than 10 GHz modulation bandwidth is also achieved. After packaged in a compact module, the device successfully performs 10-Gb/s NRZ transmission experiments through 53.3 km of standard fiber with 8.7 dB dynamic extinction ratio. A receiver sensitivity of -18.9 dBm at bit-error-rate of 10(-1)0 is confirmed. (c) 2005 Elsevier B.V. All rights reserved.

铬系催化剂聚合1,3-双烯烃的研究

铬系催化剂是合成1,2-聚丁二烯和3,4-聚异戊二烯的一种主要催化剂体系，1,2-聚丁二烯和3,4-聚异戊二烯是制造高性能轮胎的重要原料。本论文研究了以含氮化合物和含磷化合物为配体的铬催化剂合成1,2-聚丁二烯和3,4-聚异戊二烯的反应规律。 1. 以邻菲咯啉为配体的铬催化剂在己烷中50℃下可获得1,2-结构、顺-1,4-结构和反-1,4-结构单元含量分别约为50%、30%和20%，分子量呈双峰分布的聚丁二烯。改变聚合温度，可有效控制聚合物的1,2-结构含量和分子量及分布。催化剂通过预陈化方式，可有效抑制低聚物的生成。 2. 以亚磷酸二烷基酯为配体的铬催化剂是合成1,2-聚丁二烯的高效催化剂，所得聚合物具有高的1,2-结构含量（> 78%）。改变烷基铝和亚磷酸二烷基酯的结构，可以得到高熔点或低熔点间同1,2-聚丁二烯和无规1,2-聚丁二烯。催化剂以现配方式的活性最高。 3. 以磷酸三苯酯为配体的铬催化剂可获得间同1,2-聚丁二烯，而聚合物中含有低聚物。催化剂以现配方式的活性最高。聚合物的熔点，低聚物的含量与磷酸三苯酯的结构有一定的关系。 4. 以邻菲咯啉为配体的铬催化剂在50℃下聚合异戊二烯，具有高的催化活性，可获得3,4-结构含量约67%的高分子量无规3,4-聚异戊二烯。催化剂的组成对聚合物的微观结构无明显影响。改变聚合温度，可有效控制聚合物的3,4-结构含量和分子量及分布。

中国部分地区未经治疗HIV-1 感染者耐药基因研究

高效抗逆转录病毒治疗(HAART)的应用，极大的降低了AIDS发病率和死亡 率，延长了HIV感染者的生命。但HIV耐药在很大程度上影响了HAART的疗效， 耐药株的产生成为影响抗病毒治疗效果的主要因素。欧洲、美国的耐药监测技术 规范均推荐在新感染未经抗病毒药物治疗的患者中进行原发耐药检测。我国政府 于2003年底出台了艾滋病治疗的“四免一关怀”政策，陆续在全国范围内开展了大 规模的免费抗病毒治疗，监测我国未经抗病毒药物治疗HIV-1感染者中的耐药情 况可以为制定合理的用药方案和减少耐药毒株出现提供科学依据。 根据世界卫生组织(WHO)的“HIV 耐药监测指南”，无偿献血者中的HIV-1 感染者，可以认定为HIV 新诊断未治疗人群。分析了云南无偿献血者的血浆和 外周血单核细胞(PBMC)，研究云南无偿献血人群的耐药状况。 已有实验室血清学方法识别HIV-1 新近感染和长期感染，用BED-CEIA 方 法，在河南、安徽、山西自愿咨询检测(VCT)人群中检出新近感染人群，进行耐 药基因研究, 对照研究了部分长期感染人群。 样品提取核酸后，巢式聚合酶链反应(nested-PCR)扩增pol 基因区(含蛋白酶 区1～99 氨基酸全长和逆转录酶区1～242 氨基酸)。PCR 产物双脱氧法测序，所 得序列与洛斯阿拉莫斯HIV 核酸序列库(Los Alamos HIV Database)标准株构建系 统进化树分析亚型；用斯坦福大学耐药数据库(Standford HIV Drug Resistance Database)分析耐药。 研究发现，云南省2005～2006 年无偿献血者中，有52 例为HIV-1 阳性，其 中49 例血浆和相应的PBMC 样品病毒基因扩增成功。序列分析表明，HIV 病毒 的亚型分布为CRF08_BC (51.0%), CRF07_BC (24.5%), CRF01_AE (20.4%)和B (4.1%)；所有样品均未发现蛋白酶抑制剂（PI）耐药基因位点主要突变，只在6 例(11.7%)样品中发现7 例次PI 次要耐药位点突变；另外，在9 例(18.4%)样品中发现10 例次核苷类逆转录酶抑制剂(NRTI) 耐药突变，1 例(2.0%)发生非核苷类 逆转录酶抑制剂(NNRTI) 耐药突变；针对具体药物PI/NRTI/NNRTI 均只有1 例 有潜在的低度耐药，临床仍对药物敏感。PBMC 和血浆的病毒耐药没有显著差异。 从河南、安徽、山西27 个VCT 检测点2006～2007 年采集的10310 例样品 中，通过WB 和BED-CEIA 检测出新近感染人群63 例，分析成功50 例血浆样 品；河南VCT 长期感染样品中随机抽样，分析成功19 例样品。分析成功的69 例VCT 样品中，HIV 病毒株的亚型分布分别为B’ (95.7%)，CRF01_AE(2.9%)和 C(1.4%)。上诉样品均未检出PI 主要耐药相关突变，只在26 例(37.7%)样品中存 在27 例次PI 次要耐药相关突变；3 例(4.3%)样品出现6 例次NRTI 耐药相关突 变，7 例(10.1%)样品出现8 例次NNRTI 耐药相关突变。通过与斯坦福大学耐药 数据库比对，没有发现针对PI 类药物的临床耐药；但有2 例(2.8%)针对NRTI 类 药物耐药，1 例有M184V 突变导致对拉米夫定(3TC)和氟代拉米夫定(FTC)高度 耐药；1 例样品存在T215Y、M41L、L210W 三重突变位点，对阿巴卡韦(ABC)、 去羟肌苷(ddI)和坦那夫韦(TDF)中度耐药，对齐多夫定(AZT)和司他夫定(d4T)高 度耐药；针对NNRTI 类药物，有3 例(4.3%)毒株有耐药，1 例有K103N 突变导 致对奈韦拉平(NVP)、地拉韦啶(DLV)和依菲韦伦(EFV)的高度耐药；1 例有Y188L 突变导致对NVP 和EFV 的高度耐药；1 例存在K101E 和G190A 双重突变，导 致对NVP 的高度耐药，对DLV、EFV 和依曲韦林(ETR)中度耐药。 比较长期感染和新近感染者之间的亚型和耐药，未发现显著差异。 研究结果表明，云南、河南和安徽未经治疗HIV-1 感染者中耐药处于低流行 状态。亚型分布云南无偿献血者以CRF_BC 为主，河南、安徽VCT 人群以B’ 为主。应持续在未经治疗人群中进行耐药监测。

Narrow-beam divergence 1.55μm laser diodes with integrated self-aligned spotsize conVerter

This paper describes the high performance of narrow-beam divergence spot size converter (SSC) integrated separately confined heterostructure (SCH) LD. The upper optical confinement layer (OCL) and the butt-coupled tapered thickness waveguide were regrown simultaneously, which not only offered the separated optimization of the active region and the integrated spotsize converter, but also reduced the difficulty of the butt-joint selective regrowth. The threshold current was as low as 5.4 mA, the output power at 55 mA was 10.1 mW, the vertical and horizontal far field divergence angles were as low as 9°and 15°, and the 1-dB misalignment tolerances were 3.6 and 3.4μm, respectively.

MBE[（GaAs）l（Ga（1-x）AlxAs）m]n/GaAs（001）一维超晶格的X射线双晶...

于2010-11-23批量导入

1.23GeV Fe离子在C_(60)薄膜中形成潜径迹的Raman谱分析

用能量为1.23GeV的快Fe离子辐照了多层堆叠的C60薄膜。用Raman散射技术分析了快Fe离子在C60薄膜中由强电子激发引起的效应,主要包括辐照引起C60分子的聚合及其高温、高压相(HTHP)的形成,和在髙电子能损下C60晶体点阵位置上的C60分子向非晶碳的转变。由此演绎出了快Fe离子在C60薄膜中的损伤截面或潜径迹截面σ和潜径迹的半径Re,及其随沉积在电子系统中的能量密度的变化而变化的规律。

超声波法提取土壤样品中1,2,4-三氯苯和GC测定

本方法采用超声波振荡提取，用10％的丙酮正已烷混合溶液作为提取剂，对易挥发的1，2，4－三氯苯的分析具有简单、快速、灵敏、可靠、节省试剂的特点，也适用于土壤环境样品氯苯类化合物的测定。