超分子化合物[H3N(CH2)3NH3]•[Pb2(SIP)2]•6H2O的水热合成与表征

在水热条件下, 用NaH2SIP与Pb(Ⅱ)盐, 以1,3-丙二胺(1,3-PDA)作为结构导向剂进行反应, 得到化合物[H3N(CH2)3NH3]•[Pb2(SIP)2]•6H2O(1). 同时采用单晶X射线衍射、X射线粉末衍射、元素分析、红外光谱和荧光光谱对化合物1进行了表征.     

常温预辐射聚合法物理包埋葡萄糖氧化酶的研究

多数生物活性分子,如酶,抗体及药物在室温下接受辐射能后其生物活性和药力会受到不同程度的损伤。低温(-78℃)辐射对酶的辐射失活有不同程度的保护作用。为此,嘉悦憅等人曾发展了一种低温辐射包埋技术。另外,有一些酶(如过氧化氢酶、辣根过氧化物酶等)还具有辐射后失活效应,即受辐照酶样品取出辐射场后其活性仍随存放时间而不断下降。低温可以减缓后失活速率但难以完全排除。为避免低温操作的麻烦和辐射失活与后失活的损失,作者曾使用一种室温预辐射包埋技术。这一技术是将包埋过程分为两步:先使单体溶液在不断通氧下室温预辐照,然后在辐射场外与适当酶混合,通氮使其聚合,达到物理包埋的效果。     

光引发N-乙烯基吡咯烷酮在嵌段聚醚聚氨酯膜上接枝聚合的研究

本文研究了在碱性介质中,氮气氛下 N-乙烯基吡咯烷酮(N-VP)在嵌段聚醚聚氨酯(SPEU)膜上的接枝聚合。测定了接枝率与接枝液中 N-VP单体浓度、光照时间、催化剂浓度等条件的关系。测定了接枝后 SPEU 膜的吸水性,并用扫描电镜对膜表面进行了观察。对碱性介质中的接枝机理进行了初步探讨。     

Synthesis of 1,2,3,4-tetrasubstituted pyrrole derivatives via the palladium-catalyzed reaction of 1,3-diketones with methyleneaziridines

The palladium-catalyzed reaction of 1,3-diketones 2 with methyleneaziridines 1 produced the corresponding 1,2,3,4-tetrasubstituted pyrroles 3 in good to high yields.     

比色法测定蒙药铜灰体系中产生的*OH自由基

根据细胞色素C的氧化特性,采用比色法测定蒙药铜灰体系中产生的·OH自由基。实验证明,以盐酸羟胺为还原剂,在磷酸二氢钾缓冲溶液中测定,效果较好。该体系不受β-胡萝卜素的抑制,仅受硫脲的抑制,说明蒙药铜灰可作为筛选抗·OH自由基的消除剂,并具有“燥脓、清肺、肝之热”等功能。     

松香产品中重质松节油成分的气相色谱/质谱法分析

利用水汽蒸馏提取法富集了松香产品中残留的重质松节油,经气相色谱／质谱联机分析,发现其主要由１９种单萜和倍半萜化合物组成,全部为香味物质（未知物除外）。为提高松香产品的品质和开发利用松香重质松节油提供了依据。     

布里渊放大器中Stokes光的高增益放大

微小Stokes信号光在布里渊放大器中得到放大,当Stokes信号光强度为015mj时,增益系数达到67。Stokes光增益决定于Stokes信号光强度及放大池中泵光与Stokes光的耦合程度,小信号Stokes光将得到较大的增益,并能得到较好的相位共轭效果     

Identification of wheat varieties using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and an artificial neural network

A novel tool for variety identification of wheat (Triticum aestivum L.) has been developed: an artificial neural network (ANN) is used to classify the gliadin fraction analysed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS). The robustness of this novel method with respect to various experimental parameters has been tested. The results can be summarised: (i) With this approach 97% of the wheat varieties can be classified correctly with a corresponding correlation coefficient of 1.0, (ii) The method is fast since the time of extracting gliadins from flour can be reduced to 20 min without significant decrease in overall performance, (iii) The storage of flour or extracts under standard conditions does not influence the classification ability (i. e. the generalisation ability) of the method, and (iv) The classification obtained is not influenced by the identity of the operator making the analysis. This study demonstrates that a combination of an ANN and MALDI-TOFMS analysis of the gliadin fraction provides a fast and reliable tool for the variety identification of wheat. Copyright 1999 John Wiley & Sons, Ltd.     

A SEMI-MICROSCOPIC MODEL FOR ACOUSTICAL ACTIVITY

In this paper we suggest a semi-microscopic model to describe the phenomenon of acoustical activity and to extend the point group symmetry consideration first given by Portigal and Burstein[1].