以交联聚乙烯醇为载体的离子交换剂对蛋白质的分离性能

本文对阴离子交换剂ＤＥＡ—ＰＶＴ常压液相离子交换色谱分离蛋白质的性能、分离条件进行了探讨。结果表明其对蛋白质的分离性能良好，容易洗脱。与载体交联聚乙烯醇相比，ＤＥＡ—ＰＶＴ对蛋白质的非特异性吸附明显降低。     

硫化态K—Mo合成低碳醇催化剂的制备条件和载体效应研究

用浸渍法制备以KCl为助剂的ZrO_2、γ-Al_2O_3和SiO_2负载硫化态钼基催化剂,研究了钼和助剂钾两种组分浸渍顺序、助剂含量、载体差别以及浸渍溶液的酸碱性对催化剂上CO加氢合成低碳混合醇性能的影响。ZrO_2按先钼后钾、γ-Al_2O_3和SiO_2则按相反的顺序浸渍两种组分、且K/Mo原子比分别为0.5,0.8和1.0制备催化剂,其合成醇活性最佳。由于载体性质的差异,K-Mo/SiO_2、特别是K-Mo/ZrO_2的合成醇活性强烈依赖于钾助剂含量。而K-Mo/SiO_2在较宽的钾含量范围内,其活性差别不明显。适当选择较高碱性的浸渍溶液制备K-Mo/γ-Al_2O_3催化剂,有利于醇活性的提高。     

手性胺醇稀土配合物的合成、荧光性质及其催化芳香酮的不对称氢化反应

合成了三种新的含C₂-对称轴的手性胺醇(PhOHCHCH₂)₂NCH₂C₆H₄R (R＝OCH₃, L₁; R＝CH₃, L₂; R＝Cl, L₃), 将其与无水氯化稀土LnCl₃•4THF (Ln＝La, Sm, Gd)反应生成了九个新的胺醇类稀土配合物LLnCl•2THF (L＝L₁, L₂, L₃; Ln＝La, Sm, Gd). 用元素分析、热重分析、红外和紫外光谱等手段对它们进行了表征. 荧光光谱显示一些配合物具有荧光性能. 原位催化芳香酮的不对称氢化反应表明: L₁/SmCl₃•4THF体系催化苯乙酮不对称氢化反应的转化率达71%, 相应的对映体过量值达32%.     

硒化合物对不饱和脂肪酸过氧自由基的作用

本文用电子自旋共振谱技术研究了硒代二乙酸和硒代二丙酸对不饱和脂肪酸过氧自由基的作用。结果表明,硒化合物清除不饱和度为2和2以上的脂肪酸的过氧自由基,但促进仅含一个双键的不饱和脂肪酸的过氧自由基的生成。     

γ－芳基取代烯丙醇菊酯的合成及杀虫活性

γ－芳基取代烯丙醇菊酯的合成及杀虫活性陈亚娟，黄润秋，马军安（南开大学元素有机化学研究所，天津，３０００７１）关键词γ－芳基取代烯丙醇，拟除虫菊酯，杀虫活性第一个人工合成除虫菊酯烯丙菊酯保留了天然除虫菊酯醇部分的环戊烯醇酮结构，至今仍广泛用作卫生杀虫...     

Refining adsorption parameters of n-butyl alcohol at the interface of mercury electrode with aqueous NaF and Na2SO4 solutions by correcting the adsorbate concentration

As an adjunct to the regression analysis of differential capacitance curves, which allows refining the adsorption parameters, a program, which takes into account possible errors in volume concentrations of organic substances, is developed. Using this procedure, the earlier data on the differential capacitance of a mercury electrode in aqueous solutions of normal butanol (1-BuOH) containing either 0.1 M NaF or 0.05 and 0.5 M Na₂SO₄ as the supporting electrolyte are analyzed. This allows obtaining the most accurate values of adsorption parameters for the systems mentioned above within the framework of the model of two parallel capacitors and the Frumkin isotherm. It is shown that, when a linear dependence of the intermolecular interaction parameter on the electrode potential is taken into account, the standard deviation of experimental capacitance values from those calculated using the mentioned model is 6.8–8.8%, which points to very high accuracy of this phenomenological model.     

HMS和NaY固载酒石酸钛配合物的研究

利用化学键合和“瓶中造船”方法,成功地将酒石酸钛配合物接枝到HMS(heragonal mesoporous silicas)上或包络合于微孔NaY内.FT-IR表征表明酒石酸钛在HMS上是通过与载体表面羟基发生交换作用而被固载的;在NaY载体上则是通过包络合被封装在载体的超笼内.UV-Vis可见漫反射表征表明两类固载型催化剂有着相似的钛配位环境.在催化肉桂醇环氧化反应中,HMS键合型催化剂的反应转化率比NaY包络型催化剂的高;但后者在环氧化选择性上要高于前者.回收样品的重复使用实验结果表明,两类固载型催化剂在重复使用过程中均存在不同程度的失活.     

Integrated production of ethanol fuel and protein from Coastal Bermudagrass

The herbaceous crops that may provide fermentable carbohydrates for production of fuels and chemicals also contain 10–20% protein. Protein coproduction with biomass-derived fuels and chemicals has important advantages: (1) food and fuel production can be integrated, and (2) protein is a high-value product that may significantly improve overall process economics. We report the results of an integrated approach to producing protein and fermentable sugars from one herbaceous species, Coastal Bermudagrass (CBG). The ammonia fiber explosion (AFEX) process makes possible over 90% conversion of cellulose and hemicellulose to simple sugars (about 650 mg reducing sugars/g dry CBG) at 5 IU cellulase/g vs < 20% conversion for untreated CBG. The AFEX treatment also improves protein extraction from CBG; over 80% protein recovery is possible from AFEX-treated CBG vs about 30% recovery from untreated CBG.     

High-performances membranes for pervaporation I. Poly(vinyl alcohol)–poly(N-vinyl pyrrolidone) blends

Dense membranes were prepared from poly(vinyl alcohol)–poly(N-vinyl pyrrolidone) (PVA–PVP) blends of different compositions and studied in swelling and dehydration by pervaporation of three organic solvents contaminated by 5 wt% water. The swelling generally increases with the PVP content. No extraction occurs in water–tetrahydrofuran (THF) and water–methyl ethyl ketone (MEK) mixtures. In ethanol containing 10 wt% of water, there is no extraction for blends containing less than 40 wt% PVP and an increasing extraction beyond this PVP content. The pervaporation flux of the water–ethanol mixture increases drastically at the same threshold whereas the water permselectivity falls to a low level. The values of the diffusion and permeability coefficients determined from transient permeation of the test water–ethanol mixture exhibit a similar sudden increase at the same PVP content threshold. This singular behavior of the blend membranes is interpreted by a strong affinity of the PVP component to ethanol, combined with a disappearance of crystallites in the blend at this threshold. Consequently the amorphous membrane can swell freely according to the affinity of the PVP component, leading to the observed behavior.     

不饱和链烃沸点的拓扑研究

基于邻接矩阵与边价 (fi)定义边价连接性指数 ( mF) ,其中的0 F ,1 F与 2 94种不饱和链烃 (包括烯烃、炔烃及烯炔烃 )的沸点 (Tb)关联 ,得到良好的数学模型 :ln( 70 0 -Tb) =6 5 2 3 3 1-0 0 0 4880 F2 -0 3 46771 F0 5(n =2 94,R =0 9979,R2 =0 995 8,F =3 490 4,S =5 12 ) ,该回归模型经Jackknife法检验具有总体稳健性 .可以预示 ,该指数将在定量构效关系研究中成为重要参数 .