6,7,8,9-Tetrahydro-5H-pyrido[2,3-b]azepine-5,8-dione: a hydrogen-bonded dimer structure

In the title compound, C9H8N2O2, two crystallographically independent molecules form a dimer structure, in which two N-H center dot center dot center dot N hydrogen bonds generate an intermolecular R-2(2)( 8) ring.

SJ-5号卫星空间流体实验系统——开展遥科学实践

本文详细介绍了SJ-5号科学卫星微重力流体实验的用户系统的体系与配置及其对空间科学实验的支持。该系统在SJ-5号空间流体8天的实验过程中,取得约12000幅流场图象和30余小时全程多路温控温测数据,实现了两层流体在两个液池内的不同物理模型的实验,并通过姿控模式的改变实现在两种微重力水平下的对比实验。这是我国科学家首次以实验图象为判据的天地可交互方式完成的空间微重力流体科学实验研究。

Elevated levels of urinary 8-hydroxy-2'-deoxyguanosine in male electrical and electronic equipment dismantling workers exposed to high concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans, polybrominated diphenyl ethers, and polychlorinated biphenyls

To investigate the occupational exposure levels to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs), indoor dust (n = 3) in workshops and hair samples from male workers (n = 64) were collected at two electrical and electronic equipment waste (E-waste) dismantling factories located in the LQ area in east China in July 11-13, 2006. Pre- and postworkshift urines (64 of each) were also collected from the workers to study oxidative damage to DNA using 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a biomarker. The concentrations of PCDD/Fs, PCDD/F-WHO-TEQs, PBDEs, PCBs and PCB-WHO-TEQs were (50.0 +/- 8.1) x 10(3), 724.1 +/- 249.6, (27.5 +/- 5.8) x 10(6), (1.6 +/- 0.4) x 10(9), (26.2 +/- 3.0) x 10(3) pg/g dry weight (dw) in dust, and (2.6 +/- 0.6) x 10(3), 42.4 +/- 9.3, (870.8 +/- 205.4) x 10(3), (1.6 +/- 0.2) x 10(6), 41.5 +/- 5.5 pg/g dw in hair, respectively. The homologue and congener profiles in the samples demonstrated that high concentrations of PCDD/Fs, PBDEs, and PCBs were originated from open burning of E-waste. The 8-OHdG levels were detected at 6.40 +/- 1.64 mu mol/mol creatinine in preworkshift urines. However, the levels significantly increased to 24.55 +/- 5.96 mu mol/mol creatinine in postworkshift urines (p < 0.05). Then, it is concluded that there is a high cancer risk originated from oxidative stress indicated by the elevated 8-OHdG levels in the E-waste dismantling workers exposed to high concentrations of PCDD/Fs, PBDEs, and PCBs.

含8－羟基喹啉和噁二唑发光材料的合成与表征

本论文以提高有机／聚合物电致发光材料的发光效率为目的，通过改善发光材料分子的载流子传输平衡、增大分子体积为手段来减小荧光淬灭，设计并合成了一系列新型结构的络合物和聚合物。发现了一种合成五配位8-轻基喳琳铝络合物和双核铝8-轻基喳琳络合物的新方法，在分子中引入了电子和空穴传输基团改善了分子的载流子传输平衡，设计并合成了新型大体积的分子，提高了材料的发光效率，并系统地研究了分子结构与发光波长和发光效率的关系。主要工作如下：1发现了一种合成五配位8-经基喳琳铝络合物和双核铝8-经基喳琳络合物的新方法，克服了没有2一甲基的空间位阻作用很难形成五配位8-轻基喳琳铝络合物的困难。2合成了五配位2-甲基-8-轻基喳琳铝络合物并引入了具有不同空穴传输能力的第二配体。结果表明，与A 1 q;,相比，2-甲基-8-经基喳琳的引入导致了五配位络合物发光的蓝移，同时具有空穴传输能力的三苯胺基团的引入使电致发光器件的效率降低。3设计并合成了五配位8-轻基喳琳铝络合物，同时与Alq做了对比研究。研究发现，这一系列五配位络合物发射绿色荧光，五配位8-轻基喳琳铝络合物的发光波长主要由第一配体决定。4以五配位2-甲基-8-轻基喳琳铝和五配位8-轻基喳琳铝络合物为发光层制备了双层器件。结果表明，五配位8-经基喳琳铝络合物的电致发光波长主要由第一配体决定，第二配体只起到微弱的调节作用；第一配体对器件的发光效率起决定性的作用，第二配体的结构对络合物器件发光效率的影响在同一系列络合物中表现得非常明显。5从增加分子体积能够减小分子之间聚集，增强荧光效率这一观点出发，合成了具有双核铝的8一TTA-基喳琳络合物Me-DAlqz和PPv-DAlq3,用Me-DAlq,作发光层制备了双层器件，并与Alq_3i和AIMq_3作了对比研究。结果表明，DA 1 q,双层器件中的发光效率比Alq_3器件的性能稍高一些，证明了大体积分子能够增加荧光效率的观点。6合成了含有空穴传输性能的三苯胺基团的嗯二吟配体，并用其合 成了金属络合物。这些络合物发射蓝色的荧光，与不带三苯胺的德二哇金属络合物在溶液中发基本相同波长的荧光。但在薄膜和单层电致发光器件中，络合物的荧光发生了不同程度的红移。含三苯胺络合物的单层器件发光效率高于不含三苯胺络合物的单层器件的效率，证实了三苯胺的引入改进了载流子的传输平衡。7合成了系列嗯二哇基团两侧带有蔡环的金属络合物并以这些络合物为发光层制备了双层有机电致发光器件。结果表明，蔡环的引入导致了嗯二哇金属络合物在薄膜状态和电致发光器件中的发光波长比在溶液中的发光波长有了很大的红移。8设计并合成了既具有空穴传输性能又具有电子传输性能的蓝色发光聚合物。用电化学方法证明了它们具有两极性质，表明嗯二哇的引入增加了聚合物的电子传输能力。

不同降水量处理时5种蒿属植物瘦果粘液溶出

用粘沙法对科尔沁沙地西部5种蒿属植物冷蒿(Artemisiafrigida)、差巴嘎蒿(A.halodendron)、大籽蒿(A.sieversiana)、黄蒿(A.scoparia)、乌丹蒿(A.wudanica)进行了瘦果粘液溶出及粘沙量的比较。主要模拟埋深5mm、降水量为1、2、4、8mm时瘦果的粘液溶出。5种供试植物均有粘液瘦果。在降水量1mm时,供试植物的粘液瘦果就能溶出粘液。当降水量达到2～4mm时,典型的沙生植物乌丹蒿和差巴嘎蒿的粘液瘦果粘沙量平均值分别达到7.31～13.56mg、0.63～2.55mg。除冷蒿外,其它4种植物均有随降水增多、粘液溶出量加大的趋势。粘液瘦果比例从大到小的排序是冷蒿>乌丹蒿>差巴嘎蒿>大籽蒿>黄蒿。在各种处理时,粘沙瘦果百粒瘦果粘沙量由大到小的顺序是乌丹蒿>差巴嘎蒿>大籽蒿>冷蒿>黄蒿。溶出粘液粘沙后,冷蒿瘦果所形成沙团重量达到瘦果重量的5～7倍,差巴嘎蒿2～9倍,大籽蒿3～5倍,黄蒿5～8倍,乌丹蒿5～29倍。流沙先锋植物乌丹蒿和差巴嘎蒿百粒瘦果粘沙量较其它植物大、在较低降水量时这两种植物粘液瘦果粘沙量较大表明瘦果溶出粘液粘沙是植物针对沙地流动性的进化适应之一。

Water resistant sulfonated polyimides based on 4,4'-binaphthyl-1,1',8,8'-tetracarboxylic dianhydride (BNTDA) for proton exchange membranes

A series of sulfonated polyimides (SPIs) were synthesized in in-cresol from 4,4'-binaphthyl- 1,11,8,8'-tetracarboxylic dianhydride (BNTDA), 4.4'-diaminodiphenylether-2,2-disulfonicacid (ODADS), and 4.4'-diamino-diphenyl ether (ODA) in the presence of triethylamine and benzoic acid. The resulted polyimides showed much better water resistance than the corresponding sulfonated polyimides from 1,4,5,8-naphthatenetetracarboxylic dianhydride (NTDA) and ODADS, which is contributed to the higher electron density in the carbonyl carbon atoms of BNTDA. Copolyimides S-75 and S-50 maintained their mechanical properties and proton conductivities after aging in water at 100 degrees C for 800 h. The proton conductivity of these SPIs was 0.0250-0.3565 S/cm at 20 degrees C and 100% relative humidity (RH), and increased to 0.11490.9470 S/cm at 80 degrees C and 100% RH. The methanol permeability values of these SPIs were in the range of 0.99-2.36 x 10(-7) cm(2)/S, which are much lower than that of Nafion 117 (2 x 10(-6) cm(2)/s).

Synthesis, crystal structure and properties of H-8[P4W14O58Na4 (H2O)(20)] center dot 16H(2)O

A novel heteropoly tungstophosphates, H-8[P4W14O58Na4(H2O)(20)] . 16H(2)O, was synthesized by hydrothermal method and characterized by elemental analysis, IR spectrum and single-crystal X-ray structure analysis. The thermal stability of the compound was investigated by using TG-DTA. The crystal is triclinic system with space group P (1) over bar, a = 1. 137 9(2) nm, b=1. 363 2(3) nm, c=1. 627 1(3) nm; alpha=78. 20(3)degrees, beta=71, 20(3)degrees, gamma= 71. 62(3)degrees; V = 2. 252 5(8) nm(3), Z=1, M-r= 4 374. 38, D-c = 3. 225 mg/cm(3), mu = 18. 007 mm(-1), F(000)=1 972, R=0. 074 2, R-w=0. 200 4. The result of structure analysis shows that the anion of the compound consists of two PW7O29Na2(H2O)(10) subunits and two linked phosphorous atoms. A kind of microporous with size of 0. 661 4 nm X 0. 318 9 nm was formed in the crystal structure.

SARS流行预测分析

表面上突如其来的SARS本质上却有极规律的内在发展演化机制,遵从初始缓慢增长、加速、减速和稳定终止四个阶段总体道路,自然和社会生活领域众多事件演化都符合这一规律,因而可以运用广义的Logistic生长模型进行描述.基于先期流行的广东SARS感染病例数据,以及尚未结束的北京、全国2003年SARS流行统计数据,借助于最优化分析技术,运用广义的Logistic生长模型对该事件演化特征参量进行了辨识;在此基础上,又借助于广义生长模型的特例--Gompertz函数进行了演化过程的预测,并与其他生长模型结果进行了比较.研究表明,生长模型模拟结果均与实际数据有很好的一致性,可以用来预测事件的发生演化过程,此次SARS事件堪称生长模型的经典实例.

固井工程中的流动问题

同井是油气在建过程中的重要工程，一般分下套管和注水泥两个过程．本文结合作者近年来的研究，着重阐述了钻井液、前置液、水泥浆在环形空间中流动的流体力学问题，包括：高温高压下的水泥浆流变性、偏心环形空间中浆液的流动特性、钻井液-前置液和前置液-水泥浆界面的稳定性等，介绍了国内外学者对这些问题的研究进展，提出了今后应深入研究的问题.

超燃冲压模型发动机实验设备与实验技术

超燃冲压发动机是高超声速飞行器的先进的动力系统，在基础研究和工程应用方面都具有重大意义。其实验设备的建设与实验技术的积累是一个国家在航空航天领域综合实力的体现。本文综述了国外超燃冲压发动机地面实验设备的发展情况，介绍了我国用于超燃冲压模型发动机；实验的高超声速推进实验装置及其关键组成部分的设计思想、研制方法和调试结果。马赫数5.8，总压5MPa，总温2000K，总流量4.5kg/s的设备运行参数为超燃冲压模型发动机的研究提供了必要的实验条件。

Experimental investigation on the cavity-based scramjet model

The present work focused on improving the engine performance with different fuel equivalence ratios and fuel injections. A scramjet model with strut/cavity integrated configurations was tested under Mach 5.8 flows. The results showed that the strut may sreve as an effective tool in a kerosene-fueled scramjet. The integration of strut/cavities also had great effect on stablizing the combustion in a wide range of fuel equivalence ratio. The one-sdimensional analysis method was used to analyze the main characteristics of the model. The two-stage fuel injection should have better performance in increasing the chemical reaction rate in the first cavity region.

冶炼钨钼复合铁合金的新工艺

简单介绍了钨钼在合金钢中的使用情况,阐述了用三相交流工频等离子技术冶炼钨钼复合铁合金的机理及使用由钨精矿和钼精矿组成混合炉料直接制取钨钼复合铁合金的扩大量试验和分析结果。钨钼复合铁合金的Mo／W质量比为0．05～0．50，钨和钼的直收率高于90％，能满足冶炼合金钢的要求，为钨钼共生矿资源的利用，探索了新的冶炼工艺。