Studies of substrate specificities of lipases from different sources

Although lipases are widely applied in a wide variety of reactions, available information on the factors that are responsible for the substrate specificities of lipases from different sources is scarce. In this paper, nine lipase‐producing microorganism strains were isolated from oil‐containing samples. The properties of these enzymes, including pH optima, temperature optima, thermal stability, and pH stability, vary significantly with the different sources from which these lipases were isolated. The substrate specificities of the nine lipases, including fatty acid and positional specificities, were also studied. The fatty acid specificities of the nine lipases were observably different toward 15 substrates with different carbon chain lengths, different saturation degrees and different side chains. The lipases from S₃ Penicillium citrinum (PCL), MJ₁ Aspergillus niger (ANL), MJ₂ Aspergillus oryzae (AOL), YM Bacillus coughing (BCL), S₉ Geotrichum candidum (GCL), and S₁₁ Candida lypolytica (CLL) showed the strongest specificities to short‐chain esters, and the other lipases showed strong selectivity for medium‐ or long‐chain and branched esters. The positional specificities were examined by analyzing the hydrolytic products of triolein catalyzed by the nine lipases, using TLC. The lipases can be mainly classified into two groups by their specificities for the ester bond at position 2 of triglycerides; one group can selectively hydrolyze the ester bond at position 2 of the triglycerides, the other group cannot. All these nine lipases were divided into four groups by hierarchical clustering analysis on the basis of the results of fatty acid and positional specificities.     

不同品种甜菜类型甜菜光合特性的研究

水文研究了甜菜生育期中不同品种类型甜菜的光合特性，结果表明在生育前期，高糖型品种的叶绿素含量高，而生育中前期以丰产型高，标准型介于二者之间，ＲｕＢＰ竣化酶活性的动态变化亦显这种趋势；在叶丛形成期和块根增长期，丰产型品种光合速度最高，在糖分积累期则以高糖型品种光合速度高；不同品种不同叶位的叶绿素含量与光合速率中呈正相关。     

2—叠氮—1萘醌—5—磺酸生产工艺优化

研究以L-酸为原料,对合成用于制作PS版的2-叠氮1-萘醌-5-磺酸的亚硝化、还原及重氮化三步生产工艺进行最佳配比选优试验。结果表明对L-酸的总收率可达73-75％.获得了较高的收率。     

流延热释电厚膜陶瓷制备单元红外探测器

本文报道采用流延法制备的热释电厚膜陶瓷材料直接装配的单元红外探测器，该方法大大简化了目前探测器的制备工艺，极大地提高了材料的利用率，器件的性能也达到了目前探测器的水平。     

Robust control of nonlinear uncertain systems without generalizedmatching conditions

A novel procedure, called recursive-interlacing procedure, is proposed for designing globally stabilizing robust control. The procedure introduces new interlacing steps and combines them with the existing recursive or backstepping design. It is shown by examining all possible third-order vector systems that the procedure is applicable to systems not satisfying any of the existing structural conditions, that is, to systems in which uncertainties are potentially anywhere and of any bounding function. By its nature, the procedure is not limited to systems of any specific order; it either produces stabilizing control or reveals certain measure of unstabilizability, and it includes recursive design as a special case     

漳泽水库最优兴利调度研究

漳泽水库供水能力下降。优化调度方式是提高水库效益的最有效途径。通过采用随机动态规划方法与模拟模型交互运算得到现行控制水位的水库优化调度图。采用同样方法对不同控制水位的水库运行方式进行优化调度，选出的规划水库最优控制水位为汛限水位９０４ ．５ ｍ ，正常高水位９０５ ．５ ｍ 。优化的控制水位方案在保障水库防洪安全的前提下可供给城市生活和工业用水６ ３００ 万ｍ３ ，较现行控制水位下的供水量提高１ ２５５ 万ｍ３ 。但农业用水仍然不足，应采取一定措施给予解决，如对灌区工程进行改造，因地制宜采取不同节水措施和污水回用等。     

Synthesis of Iron-Based Laves Phase Containing Praseodymium Magnetostrictive Materials

The synthesis and magnetostriction of PrxTb1-x.Fe2, PrxTb1-x Fe2BO2 and PrxTb1-x（Fe0.6Co0.4）2 alloys were investigated in this study. The addition of boron or cobalt atom in PrxTb1-xFe2 could effectively prevent the formation of non-cubic phases, and Pr concentration limit was successfully increased from 0.2 to 0.4. X-ray step scanning for the PrxTb1-xFe2BO2 and PrxTb1-x（Fe0.6Co0.4）2 alloys showed that PrFe2 possessed a large spontaneous magnetostriction λ1111.     

天然高分子吸附剂研究Ⅱ．镍离子模板壳聚糖树脂的合成及特性

以镍离子为模板剂，合成了乙醇双环氧丙基醚交联的壳聚糖树脂，研究了其对Ｃｕ（Ⅱ）、Ｎｉ（Ⅱ）、Ｃｏ（Ⅱ）离子的吸附性能。结果表明，该法合成的树脂对Ｎｉ（Ⅱ）离子具有较强的“记忆”和“识别”能力，其对Ｃｕ（Ⅱ）、Ｎｉ（Ⅱ）、Ｃｏ（Ⅱ）的吸附量分别达２．２１、２．１３、１．４０ｍｍｏｌ／ｇ树脂。     

激光光束质量因子的研究进展

本文详细分析了各种光场下光束质量M2因子。在不同的场中,A.E.Siegman当初所定义的M2因子,已经有了很大的变化,因而M2因子的特性也与当初不同,不仅M2因子可以大于等于1,而且可以小于1,甚至小于0。其反映的物理意义,也从经典场中的衍射极限倍数,变化为非经典场中的准直性量度以及对空间相干性的某些反映。此外还列举并分析了几种特殊的光束质量因子,最后讨论了M2因子应用的问题并指出了其局限性。