Detection of the spectra of multicharged ions with time resolution and the determination of the parameters of the hot component of the plasma in the case of the magnetic implosion of multiwire arrays

The dynamics of the hot component of the plasma of imploding multiwire arrays has been analyzed using the time behavior of the X-ray spectral lines of multicharge ions. The spectra of H- and He-like aluminum ions with nanosecond time resolution have been detected using electron-optical chronography in experiments on the implosion of multiwire arrays by mega-ampere currents. The simultaneous appearance of the resonance lines of H- and He-like ions implies that the hot plasma whose electron temperature is higher than 0.5 keV has existed on the axis before the implosion of the main mass of the liner. The further dynamics of the intensity of the lines is primarily attributed to an increase in the mass of the emitting plasma.     

钯系催化剂的氨中毒研究

 考察了CO常压气相偶联合成草酸酯反应体系中在不同氨含量下Prnd系催化剂活性随反应时间的变化．结果表明,随着氨含量的增加,催rn化剂活性降低的速率加快,氨含量不超过0．54％时,仅引起催化剂活rn性下降,但不会造成催化剂完全失活;当氨含量达1．16％时,催化剂rn活性随反应时间迅速下降,直至完全失活．同时,观测了催化剂氨中毒rn的不可逆性．利用XPS和TEM表征手段探讨了Pd系催化剂氨中毒机理,并rn分析了在工业生产条件下催化剂氨中毒不可逆性的原因．     

不对称催化合成中手性膦配体的研究进展(Ⅰ)(待续)

对近十多年来不对称催化合成领域中出现的手性膦配体进行了综述,按其不对称中心以及结构上的特征加以分类,并对其催化性能进行总结。     

Chiral bifunctional squaramide catalyzed asymmetric Michael addition of ethyl α-nitroacetate to β,γ-unsaturated α-ketoesters

We have developed an efficient bifunctional squaramide catalyst for the asymmetric Michael addition of ethyl α-nitroacetate to β,γ-unsaturated α-ketoesters. This organocatalytic asymmetric reaction provides convenient and valuable access to highly functionalized 2-nitro-5-oxo-3-arylhexanedioates in excellent yields with uniformly high levels of enantioselectivity (up to >99% ee) albeit with no diastereoselectivity. The resulting products could be conveniently transformed into 5-nitro-2-oxo-4-arylpentanoic acids without loss of enantiomeric excess via basic hydrolysis and the subsequent decarboxylation. This represents an example of in-direct, but efficient asymmetric conjugate addition of pyruvic acid to nitroolefins.     

Synthesis of Cellulose Long-Chain Esters in 1-Butyl-3-methylimidazolium Acetate: Structure-Property Relations

In this study, we prepared cellulose long-chain esters homogeneously in 1-butyl-3-methylimidazolium acetate, using cotton linter as the raw material, long-chain fatty acid as the esterification agent and paratoluensulfonyl chloride as the co-reactant. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction were used to characterize the product. The maximum degree of substitution was found to be 1.53 when the molar ratio of cellulose, lauric acid and paratoluensulfonyl chloride was 1 : 6 : 6, provided that the reaction temperature was 60°C and the reaction time was 24 h. The mechanical property of the free-film made of cellulose laurate was also tested. It was found that the toughness of cellulose laurate was much better than that of cellulose acetate.     

铝丝阵等离子体K壳层辐射区域测量

采用球面云母晶体,在特定的几何布局下,通过选择适当的设计参数,在1.3 MA脉冲功率装置上获得了Ly线表征的Z箍缩铝丝阵等离子体K壳层辐射时间积分2维分布。与通常采用的带滤片卡域的时间积分针孔成像相比,避免了由于无法将测量能段准确设定在K壳层辐射谱线所在能区,而造成测量结果偏离真实的K壳层辐射分布的缺点,为模拟计算Z箍缩等离子体辐射输运程序提供了更为精确的校验参数。     

烧伤病人血浆和痂下组织中头孢噻甲羧肟的高效液相色谱测定及其药代动力学研究

烧伤病人血浆和痂下组织中头孢噻甲羧肟的高效液相色谱测定及其药代动力学研究尤忠义，雷政宏，宗光全（第三军医大学烧伤研究所重庆６３００３８）１前言感染是烧伤病人的重要死亡原因之一￣［１］．而创面则是烧伤感染的重要来源￣［２］，抗生素是防治烧伤感染的常用药...     

Z扫描测量中的热致非线性效应

从热传导方程出发，研究了用脉冲激光进行了Ｚ扫描测量时因样品线性吸收引起热效应而产生的折射率变化，所得结论同以前实验结果相符合。