激光金等离子体谱中3d-5f、3p-5s跃迁子阵计算

 激光等离子体M带0.346～0.372nm范围内精细结构谱,是金等离子体的类Co、类Ni、类Cu、类Zn离子的3d-5f、3p-5s跃迁子阵形成的。在自旋轨道劈裂阵模型下, 对平均波长在该范围内的各子阵的主要特征参数如平均波长、半高宽和总跃迁强度进行详细计算,得到与实验测量基本一致的结果,可用于等离子体的精确诊断。     

柔性变焦镜的理论计算和设计

 设计了由压电陶瓷施压的柔性变焦镜的结构。根据弹性力学建立了相应的数学模型,采用有限元法计算了镜面受力的挠变形值。当柔性变焦镜最大挠度为9μm时,镜面的曲率半径从610mm变至590mm,此时采用环形筋条结构的反射镜镜面和理想球面的面形偏差PV值仅为1μm,面形相对偏差为0.3%。     

STUDIES ON HETEROLOGOUS EXPRESSION OF Rhizobium meliloti nifA GENE AND OXYGEN SENSITIVITY OF ITS PRODUCT

When the R. meliloti (Rm) nifA'-lacZ fusion-carrying plasmids were introduced intothe strains of Agrobacterium tumefaciens, R. trifolii and R. astragalus, β-galactosidaseactivity was demonstrated. However, activity was not induced by microaerobiosis. Further-more, R. meliloti nifA'-lacZ fusion was also not expressed in the nodule bacteroids ofR. trifolii and R. astragalus. We speculate that some factor(s) important for the inductionof Rm nifA presumed to be the fixLJ regulatory system would not be operative in thesebacteria. Experiments using R. meliloti nifH'-lacZ/ K. Pneumoniae nifH'-lacZ fusion and theconstitutive Rm nifA system to test the nifA-dependent expression of nifH'-lacZ underaerobic and microaerobic conditions in E. coli were performed. The inhibition of the RmnifA activation of nifH'-lacZ expression in the bacteria grown in the aerobic conditionwas shown. Assays on the Rm nifA-m RNA produced by the constitutive Rm nifA in E.coli under aerobic and microaerobic conditions with the cloned ni     

二氧化氯催化氧化处理含酚废水的研究

以3种模拟的高浓度含酚废水为处理对象，在室温常压下，以二氧化氯为催化剂，在自制催化剂的作用下进行催化氧化分解酚类物质的研究，考察了PH，ClO2废水（体积比），反应时间，反应温度等对CODCr去除率的影响。实验表明该法能有效地降低含酸废水的CODCr，去除率达90％以上，是一种行之有效的含酚废水处理方法。     

用离子交换树脂脱除氨基酸与盐混合液中的盐

在用蛋白质酸性水解备氨基酸时,因中和残留的酸会使水解液中带入大量的盐。在进一步用离子交换色谱法分离混合氨基酸时,首先需脱掉其中的盐。本文用苯乙烯系强酸性阳离子交换树脂的盐型柱,根据氨基酸与苯乙烯系强酸性阳离子交换树脂之间既存在离子间的静电作用,又存在疏水作用,且二者之间存在协同作用,而盐在盐型苯乙烯系强酸性阳离子交换树脂柱上不保留的原理,用水作为洗脱剂,使盐和氨基酸（配制的盐和氨基酸混合液及含盐的毛发水解液）得到分离,本方法脱除氨基酸中的盐简单易行,用水作为洗脱剂即廉价由不造成污染,盐型树脂不用再生即可用于下次运行,研究了各种条件对分离性能的影响。     

Conformation and dynamics of polyoxyethylene lauryl ether (Brij-35) chains in aqueous micellar solution studied by 2D NOESY and 1H NMR relaxation

Spin-lattice relaxation time, spin-spin relaxation time and two-dimensional nuclear Overhauser enhancement spectroscopy (2D NOESY) experiments of polyoxyethylene lauryl ether (Brij-35) micelles in aqueous solutions at a concentration of 100 times the critical micellar concentration (cmc) give direct evidence that the hydrophilic polyoxyethylene chains, staying in the exterior of the micellar core, are coiled, bent and aligned around the micellar core with a certain number of water molecules included. This hydrophilic layer is in contact with the solvent, water, keeping the micellar solution stable. 1H NMR relaxation time measurements show that the first oxyethylene group next to the alkyl chain participates in the formation of the surface area of the micellar core. The motion of the hydrophilic polyoxyethylene chains is less restricted as compared with the hy-drophobic alkyl chains.     

苯醚甲环唑在芹菜及其土壤中的残留测定和消解动态研究

采用气相色谱-电子捕获检测, 对芹菜及其土壤中的苯醚甲环唑消解动态和最终残留量进行了研究, 评价了苯醚甲环唑在芹菜上使用后的残留行为和环境安全性. 苯醚甲环唑在芹菜及土壤中的残留消解动态均符合一级动力学方程, 苯醚甲环唑在芹菜上消解快; 苯醚甲环唑最终残留量与施药的剂量、施药次数及采样的间隔时间有关; 水解研究表明, 苯醚甲环唑是稳定的农药, 在不同温度和不同pH的研究条件下水解半衰期均大于166 d, 碱性条件更有利于苯醚甲环唑的降解.     

Ru/ZrO2·xH2O催化剂催化肉桂醛选择性加氢制肉桂醇

采用共沉淀法制备了7.5%Ru/ZrO2·xH2O催化剂,运用N2物理吸附-脱附法、X射线衍射、X射线光电子能谱和高分辨透射电子显微镜等技术对催化剂进行了表征,并用于催化肉桂醛选择加氢制肉桂醇反应中,考察了温度、H2压力和溶剂对肉桂醛转化率和肉桂醇选择性的影响.结果表明,肉桂醛转化率随着温度或H2压力的升高而升高,而肉...     

基于碳点荧光恢复法测定生物巯基化合物

碳点(CDots)是一种新型荧光纳米材料,Cu2+可以有效猝灭其荧光;而当有生物巯基化合物存在时,碳点-Cu2+体系的荧光可以恢复.基于此原理,我们成功地构建了检测生物体内总巯基化合物的新方法.该方法具有很好的选择性,常见氨基酸和金属离子对谷胱甘肽(GSH)、半胱氨酸(Cys)和高半胱氨酸(Hcy)的检测无影响.最佳实验条件下,谷胱甘肽、半胱氨酸、高半胱氨酸的浓度在6.0×10-6mol/L～1.0×10-4mol/L与相对荧光强度呈线性,R>0.996,检出限为2.0×10-6mol/L.该体系成功用于血清样品中总巯基化合物的检测.