功能性超薄有序分子沉积膜的制备及其结构研究

1991年G.Decher等首次探讨了阴阳离子与聚电解质交替沉积制备有机超薄膜的方法。我们在完善成膜技术和发展成膜基质的基础上,详细研究了其成膜过程与膜的结构,并定义这种新的自组装超薄有序膜为分子沉积膜——MD膜。MD膜是利用阴阳离子的静电吸附反应特性,通过相反离子体系的交替分子沉积制备的层状有序自组装多层超薄膜。需要指出的是,分子沉积既是有机超薄膜的制备技术,本身又是一种自组装超薄有序膜。MD膜制备工艺简单,热稳定性和长期稳定性好,不受基体形状与面积限制。     

一般工商业零售电价套餐适应性评估与优化方法

在电力体制改革的大背景下,合理评估零售电价套餐适应性,对控制电网经营风险和推进售电侧改革有重要意义。针对我国电力市场以及一般工商业的特点,首先从竞争、用户以及市场环境角度出发建立了一般工商业零售电价套餐评估指标体系;其次将层次分析法和改进的灰色白化权函数相结合,对电价套餐进行适应性评估;最后针对该评估方法建立了基于蚁群算法的优化模型,以最小成本得到提高电价套餐适应性等级的优化方案,并验证了该方法具有良好的鲁棒性,具有一定的参考意义。     

Synthesis and Expression of a Gene From Kringle-2 Domain of Tissue Plasminogen Activator in E. coli

The DNA fragment corresponding to the tissue plasminogen activator (tPA) sequence 174-262 (Kringle-2 domain) has been synthesized by using the solid phase phosphotriester method. The Kringle-2 domain of human tPA was expressed in Escherichia colt by secretion into the periplasmic space using the Lpp-Lac promoter and PIN-Ⅲ OmpA2 signal sequence. About two thirds of the expression product was secreted into the periplasmic space , and purified with ammonium sulfate fractionation, affinity chro-matography on Lysine-Sepharose, and FPLC-Mono Q exchange chromatography. The amino acid composition observed from the Kringle-2 purified from E. coli is identical with that expected for the 174-262 fragment of human tPA. Radio binding assay shows that the recombinant Kringle-2 domain possesses the activity of fibrin binding.     

蛋白质的结构预测和分子设计

蛋白质的结构预测及分子设计是适应基因工程的需要发展起来的对蛋白质的空间结构进行研究并在此基础上提供蛋白质改造方案的方法。通过对已知的蛋白质结构数据进行总结、分析,结合分子力学、分子动力学等计算方法可以进行某些种类的结构预测。在对蛋白质的结构与功能研究的基础上可以提出改造方案,从而进行有目的的分子设计。     

十六烷基三甲基溴化铵水溶液热致相变的红外光谱研究

在280～320K的温度范围内考察了30％十六烷基三甲基溴化铵水溶液的红外光谱随温度的变化。结果表明该体系的凝聚胶-液晶相转变温度为300K。在300K以下的凝聚胶相,分子的极性头部基团处于高度“固定”的状态,分子的碳氢链以有序的相互平行方式排列,极性头与碳氢链之间有一定的倾斜角。在300K以上的液晶相,极性头内部CH_3-(N~+)基团以及整个极性头与碳氢链之间发生了旋转,碳氢链变为以六方亚晶胞填充形式存在,旦扭曲式构象异构体数量显著增多,极性头与碳氢链之间已不存在倾斜角,分子的亲水极性头和疏水碳氢链部分都处于“融化”状态。     

废弃线路板化学分析采样、制样及检测方法

介绍废弃线路板中有回收价值元素和有害物质分析的采样、制样及检测技术。样品经过分类采样、剪切破碎和高温灰化制样,采用样品全分析或副批混合样分析。通过提高称样量、多次测定求平均值的办法,火试金富集-重量法测定贵金属金、银。湿法王水溶解样品,碘量法测定主体元素铜。电感耦合等离子体发射光谱(ICP-AES)法测定其它杂质元素,被测元素质量浓度在0~10μg/mL范围内与光谱强度呈良好线性关系,相关系数均大于0.9998。测定结果的相对标准偏差小于10%(n=5),加标回收率为97.0%~102.5%。该方法简单、快速,有效地解决了线路板样品不均匀而难采样,以及硬度、韧性强制样难,金属易包裹难分解的技术瓶颈,测定结果准确,具有代表性。该方法适用于废弃线路板化学成分分析,其它废弃电子产品检测可参考此方法。     

THE STRUCTURAL BASIS OF THE POOR FIBRIN SPECIFICITY OF UROKINASE(Ⅰ)——KNOWLEDGE-BASED PREDICTION OF KRINGLE STRUCTURES OF UROKINASE AND ITS RELATED PROTEINS

The Kringle-1 structure of plasminogen (PGK-1), the Kringle-2 structure of tissue plasminogen activator (PAK-2) and the Kringle structure of prourokinase (UKK) has been modeled on the basis of the three-dimensional structure of Kringle-1 of prothrombin (PTK-1) at 2.8 resolution. The predicted three-dimensional structure of these Kringles shows that the binding site of PGK-1 is characterized by an apparent dipolar site, the polar parts of which are separated by a hydrophobic region. PAK-2 possesses the anionic center but has not a cationic binding center which might be provided by a guanidinium group from Arg-69 located adjacent to the Arg-71 position. UKK possesses neither the anionic binding center nor the cationic center which are probably the main reason for the poor fibrin specificity of urokinase.     

Physical and chemical properties of a durably efficacious ammonium bicarbonate as a fertilizer and its yield-increasing mechanism

A new fertilizer of cocrystal type,known as durably efficacious ammonium bicarbonate (DEAB),has been developed by adding a certain amount of dicyandiamide (DCD) as an ammonia-stabilizing agent to ammonium bearbenate(AB)during the process of its production.As compared with AB,DEAB was found to have a reduction of direct volatilization loss by 53%,a fertilizer availability period prolonged from 35-45 to 90-110 d,and an increase in the rate of nitrogen in fertilizer being utilized by 5.9%-10.2%,and a saving of the amount of fertilizer to be ap-phed by 20%-30% for the same level of yield,or an increase of the crop yield by over 10% for the same level of ni-tregen fertilization;in addition,it was found to show usually a function of promoting the crop to early mature.It can be apptied as basal dressing all in one time to soil and thus also used as a labour-saving and crop yield-increasing fertil-izer for is non-mtertillage,plastics film covering and water-saving agriculture     

抗活化血小板单克隆抗体与尿激酶杂合分子的纤溶作用

用双功能团试剂将尿激酶(UK)B链和抗人活化血小板α-颗粒膜蛋白GMP-140单克隆抗体(SZ-51)的Fab片段共价偶联。偶联的杂合分子UK-SZ-51保留了原抗体的结合专一性,它在体外的溶栓效率较尿激酶提高约5倍,其溶栓作用对血浆中纤维蛋白原的含量无影响。     

甲醇气相羰基化制备乙酸的钴催化剂(YSCo)的研究

甲醇气相羰基化制备乙酸的钴催化剂（ＹＳＣｏ）的研究潘平来，柳忠阳，黄茂开，袁国卿（中国科学院化学研究所，北京１０００８０）关键词甲醇，羰基化，乙酸，钴催化剂通过甲醇羰基化制备乙酸是目前乙酸工业最先进的技术路线．该法与乙烯和乙醇氧化法相比较，无论从原料...