2－（1，3－亚丙二硫基）亚甲基环己酮的晶体结构

报导了标题化合物Ｃ_（１０）Ｈ_（１４）ＯＳ_２（Ｍ_ｒ＝２１４．３５）的晶体结构，该晶体属正交晶系，空间群为Ｐ２_１２_１２_１，晶胞参数为ａ＝６．４４３（３），ｂ＝８．９８０（４），ｃ＝１８．２１３（７）；Ｖ＝１０５３．８（６）３；Ｚ＝４，Ｄ_ｘ＝１．３５ｇ／ｃｍ~３，Ｆ（０００）＝４５５，μ＝４．５ｃｍ~（－１）（ＭｏＫａ）。最终偏离因子Ｒ＝０．０３３，Ｒ_ｗ＝０．０３４。分子中的两支Ｃ_（ｓｐ）２－Ｓ键键长近于相等，分别为１．７６１（３）和１．７６９（３），Ｃ（１）－Ｃ（５）键长为１．３６１（４）。

Unprecedented 5,5-connected (4(7)center dot 6(3)) (4(8)center dot 6(2)) structural topology: A lead biphosphonate with double layered structure

A new lead(II) phosphonate, Pb[(PO3)(2)C(OH)CH3]center dot H2O (1) was hydrothermally synthesized and characterized by IR, elemental analysis, UV, TGA, SEM, and single crystal X-ray diffraction analysis. X-ray crystallographic study showed that complex 1 has a two-dimensional double layered hybrid structure containing interconnected 4- and 12-membered rings and shows an unusual (5,5)-connected (4(7) . 6(3)) (4(8) .6(2)) topology. (C) 2008 Elsevier B.V. All rights reserved.

Detection of carbohydrates using new labeling reagent 1-(2-naphthyl)-3-methyl-5-pyrazolone by capillary zone electrophoresis with absorbance (UV)

A novel labeling reagent 1-(2-naphthyl)-3-methyl-5-pyrazolone (NMP) coupled with capillary electrophoresis (CE) with DAD detection for the determination of carbohydrates has been developed. The chromophore in the 1-phenyl-3-methyl-5-pyrazolone (PMP) reagent is replaced by naphthyl functional group, which results in a reagent with very high molar absorptivity (epsilon(251nm) = 5.58 x 10(4) L mol(-1) cm(-1)). This pen-nits NMP-labeled carbohydrates to be detected with UV absorbance in standard 50-mu m-i.d. fused silica capillaries by zone electrophoresis. in this mode, nanomolar concentrations of detection limits are obtained. The method for the derivatization. of carbohydrates with NMP is simplified. The derivatization reaction is rapid and mild in the presence of ammonia catalyst without further transfer steps. Nine monosaccharide derivatives such as mannose, galacturonic acid, glucuronic acid, rhamnose, glucose, galactose, xylose, arabinose and fucose can successfully be detected in CE mode. Good reproducibility can be obtained with relative standard deviation (R.S.D.) values of the migration times and peak area, respectively, from 0.44 to 0.48 and from 3.2 to 4.8. Furthermore, the developed method has been successfully applied to the analysis of carbohydrates in the hydrolyzed rape bee pollen samples. (C) 2008 Published by Elsevier B.V.

Infrared (1.2-1.6 mu m) luminescence in Yb, Cr : YAG with 940 nm diode pumping

Infrared (1.2-1.6 mum) luminescence in a yttrium aluminium garnet (YAG) crystal, co-doped with Yb (10 at.%) and Cr (0.05 at.%) ions, was investigated under CW laser diode pumping (lambda = 940 nm). The Cr4+ emission band was observed with its peak at 1.35 mum and measured to be about 6% with respect to Yb3+ IR luminescence (lambda = 1.03 mum). Analysis of the crystal absorption and luminescence spectra allows one to conclude that Yb3+-Cr4+ energy transfer is a mechanism responsible for the B-3(2)(T-3(2))-B-3(1)((3)A(2)) emission of Cr4+ ions. This crystal is promising as an efficient source of the near infrared emission. (C) 2004 Elsevier B.V. All rights reserved.

Infrared (1.2-1.6 mu m) luminescence in Cr4+: Yb3Al5O12 single crystal with 940 nm diode pumping

Infrared (1.2-1.6 mu m) luminescence in a ytterbium aluminium garnet (YbAG) crystal, doped with Cr (0.05 at.%) ions, was investigated under CW laser diode pumping (lambda = 940 nm). The Cr4+ emission band was observed with its peak at 1.34 mu m and measured to be about 1.3 times with respect to Yb3+ IR luminescence (lambda = 1.03 mu m). We demonstrate that for the excitation wavelength of 940 nm Yb3+ ions act as sensitizers of the B-3(2)(T-3(2))-B-3(1)((3)A(2)) emission of Cr4+ ions. This crystal is promising as a high-efficient system for tunable laser (1.2-1.6 mu m) output. (c) 2004 Elsevier B.V. All rights reserved.

Growth and characterization of high-quality LiAlO2 single crystal

g-LiAlO2 single crystal is a promising substrate for GaN heteroepitaxy. In this paper, we present the growth of large-sized LiAlO2 crystal by modified Czochralski method. The crystal quality was characterized by high-resolution X-ray diffraction and chemical etching. The results show that the as-grown crystal has perfect quality with the full width at half maximum (FWHM) of 17.7-22.6 arcsec and etch pits density of (0.3-2.2) x 10(4) cm(-2) throughout the crystal boule. The bottom of the crystal boule shows the best quality. The optical transmission spectra from UV to IR exhibits that the crystal is transparent from 0.2 to 5.5 mu m and becomes completely absorbing around 6.7 mu m wavelength. The optical absorption edge in near UV region is about 191 nm.

2μm波段激光薄膜的研制

概述了国内外关于～2μ波段发光的掺Tm^3＋，THo^3＋和Er^3＋等激光晶体镀膜的使用情况，结合我们实验室已有的工作基础，对其设计原理和制备工艺进行了详细分析，制备出了较高性能2．94μm的激光薄膜。

乙醛脱氢酶2( ALDH2) 基因研究进展及其与饮酒行为的关系

:亚洲人群中普遍存在突变型的乙醛脱氢酶2 ( ALDH2 3 2) 。此酶突变后活性缺失,导致乙醛在肝脏内大量 累积使突变携带者在喝酒后会有脸红等不适反应,因此这可能影响他们的饮酒行为。由于ALDH2 3 2 等位基因 与饮酒行为相关,它也可能与酒精引起的肝脏损伤及某些癌症密切相关,而且,它在不同的亚洲人群中有不同的频 率分布。近年来对ALDH2 3 2 等位基因的序列结构、表达及其重要功能等有了更深入的了解,对ALDH2 的多态 性在研究方法、研究群体分布范围等都有很大进展。同时还讨论了不同地理分布、不同年龄结构、性别差异条件 下,中国人群中ALDH2 基因型频率与饮酒行为的关系。

猕猴属3个种的肱骨远端关节面的比较研究

对猕猴(Macaca mulatta)、 藏酋猴(M.thibetana)和熊猴(M.assamensis)肱 骨远端关节面Ⅱ项变量的分析表明, 关节面宽、鹰嘴窝宽、内上髁宽和滑车长 是区别3种猴类标本的主要变量。与其他灵长类相应变量的比较和主分量分析表 明: 与猕猴相比, 藏酋猴和熊猴的肱骨远端关节更为相似, 而猕猴则相似于暗色 叶猴、长臂猿和豚尾猴的关节面。 图2表2参17

利用3对引物鉴定产毒和非产毒微囊藻

根据微囊藻毒素合成酶基因簇序列 ,合成了 3对引物epF/mb1R ,mcF/teR ,mcF/umR ,通过全细胞PCR的方法检测了 19种不同来源微囊藻产毒的情况。 3种引物对 15株产毒微囊藻中均可扩增到预期大小的片段 ,测序结果证明这些片段是微囊藻毒素合成酶基因片段。PCR反应结果与HPLC分析所得到的结果有良好的对应性。在此基础上 ,初步确定了 3对引物检测产毒微囊藻对细胞浓度要求的下限。与其它引物相比 ,3对引物的特异性强 ,扩增条带大小适中 ,便于观察

在患病鳜鱼组织中观察到3种病毒

在患暴发性流行病的鳜鱼组织中观察到 3种不同形态的病毒 ,它们分别是直径约为2 80nm的球形病毒、大小约为 2 5 0nm× 1 2 0nm的弹状病毒和大小约为 2 0 0nm× 1 0 0nm的杆状病毒 .这种现象表明 ,单一病毒疫苗难以达到预防鳜鱼暴发性流行病的原因可能是由于鳜鱼受到多种病毒病原的侵染 ,提示鳜鱼病毒病的防治不要忽视病毒病原的复杂性 .

湖泊水体中土霉味化合物2-甲基异莰醇的合成与测定

利用甲基格氏试剂和天然樟脑反应，合成土霉味化合物２－甲基异莰醇（ＭＩＢ），并用色谱、质谱和红外光谱对其进行鉴定，然后以合成ＭＩＢ作标样，测定ＭＩＢ的气相色谱保留值及其在东湖水体中浓度随季节变化规律。研究结果表明，东湖水体产生土霉味的主要成份为ＭＩＢ，在１９９５～１９９６年期间，１月、４月和９月为武汉东湖水体中ＭＩＢ浓度的高峰期，经测定东湖水中ＭＩＢ的ＧＣ保留值与合成的ＭＩＢ的ＧＣ保留值完全一致。

~(59)Co~(2+)对~1H与~(35)Cl的NMR影响

<正> 在前文的基础上,用~(59)CO~2+Cl_2·6H_2O加D_2O作为样品,在200MHz谱仪上观察~1H,在400MHz谱仪上观察~(35)Cl,研究强顺磁离子~(59)Co~2+(s=3/2,I=7/2)在外加直流磁场H_0作用下,它对~1H与~(35)Cl的NMR影响。因为强顺磁离子~(59)Co~(2+)的电子自旋(s=3/2)是围绕着核旋转的,因此可以统计平均计算,

聚丙烯酸钠对3种土壤持水能力及作物产量的影响

在离心机模拟不同水吸力条件下,研究了聚丙烯酸钠(sodium polyacrylate记作SP)5种使用浓度(占干土质量0,0.01%,0.08%,0.2%与1%)对3种土壤(砂土、壤土、黏土)持水能力的影响;采用大田试验研究了地表撒施2 g/m2SP对冬小麦与下季玉米产量及WUE影响。结果表明:3种土壤在0.01 MPa至1.5 MPa水吸力下的持水能力随着SP用量的增加而增加,砂土的作用效果较壤土、黏土更显著;3种土壤适宜浓度为0.08%~0.2%,最佳用量为0.2%,此用量条件下砂土、壤土、黏土的最大毛管持水量分别较对照增加了138.61%,7.22%,62.70%;不灌水条件下,SP处理较不施用SP冬小麦增产4%,WUE增加5.7%,灌浆期灌水28.5 mm条件下SP处理较不施用SP增产1%,WUE降低1%;SP处理的玉米产量较对照降低0.5%,WUE提高3%,效果明显低于对冬小麦效果。