Stereoselective Synthesis of Piperamide Alkaloids by Modified Ramberg-Bcklund Reaction

A convenient and rapid approach for the synthesis of piperamide alkaloids la ~ h by the recently developed one-flask Ramberg-Backlund reaction was described. The synthesis of 1e was reported for the first time.     

Synthesis of quinazolin-4(3H)-ones and 1,2-dihydroquinazolin-4(3H)-ones with the aid of a low-valent titanium reagent

A short and facile synthesis of a series of quinazolin-4(3H)-ones and 1,2-dihydroquinazolin-4(3H)-ones was accomplished in good yields via the novel reductive cyclization of o-nitrobenzamides and triethyl orthoformate, aldehydes or ketones promoted by TiCl₄/Zn.     

利用天然斜发沸石从高离子强度的强碱性溶液中吸附和洗脱K+和Rb+的研究

在80℃下，用间歇法研究了NH4^ 型天然斜发沸石对某厂高离子 强碱性循环液中的K^ 和Rb^ 的吸附，得到不同粒度天然斜发沸石对K^ 和Rb^ 的交换吸附量，用不同浓度的NH4HCO3溶液对沸石进行洗脱再生，是到洗脱速率随着洗脱液浓度增大而增大。本文对沸石与钾含量很高的高离子强度强碱性溶液中碱金属的交换吸附和洗脱过程进行了初步探讨。     

三磷酸胞苷在Duolite A-30树脂上的交换过程研究

根据CTP在离子交换树脂上的吸附容量和分离因数的大小,确定Duolite A-30树脂适合CTP与CDP,CMP之间的分离.对CTP在Duolite A-30树脂上的吸附动力学和热力学研究表明,在283.15K~303.15K之间,CTP的质量浓度在7.5g/L以上时,Duolite A-30树脂对CTP的吸附主要受颗粒扩散的控制,其有效扩散系数为D=3.47×10-7cm2/s,溶液的质量浓度≤1.0g/L时,CTP与Duolite A-30树脂之间的交换速率主要受液膜控制,其液膜扩散系数为Kf =4.112×10-4/s.同时测定了不同条件下三磷酸胞苷溶液在Duolite A-30树脂固定床离子交换柱中的穿透曲线,研究了进口浓度、进口流速、原料液温度、原料液的pH值及柱高对穿透曲线的影响.用二阶动力学推动力模型描述固定床动态过程,考察了轴向返混对穿透曲线的影响,并从穿透曲线回归得到总传质系数,模型计算值与实验数据符合良好.     

苯丙水溶胶的合成与性能研究(I) 聚合工艺和反应组分对聚合稳定性和胶体性能的影响

用一次投料法、半连续滴加法和单体预乳化法三种聚合工艺，合成了苯丙乳液聚合物，并加氨微细化，转化成水溶胶，考察了聚合工艺和反应组分（乳化剂，功能单体等）对苯丙乳液及其水溶胶反应稳定性和粒子大小及分布等胶体性能的影响。     

First Synthesis of 2a-Thiol Ether Analog of Docetaxel

The chemistry of anticancer drug paclitaxel (=Taxol, 1a) has been extensively explored in recent years. A variety of its analogs with modified taxane frame work or substitutions to its core structure, as well as C-13 substituted isoserine side chains have been synthesized and biologically evaluated1. The marketing of docetaxel (=Taxotere, 1b) is one of the fruitful results from these research efforts. The beginning of clinical trial for analog 2 developed by Indena is the new example. Ba…     

牛血清白蛋白在NVP/HEMA无规共聚物水凝胶上的吸附研究

合成了不同含水量的N-乙烯吡咯烷酮(NVP)／甲基丙烯酸-β-羟乙酯(HEMA)共聚物水凝胶．研究了温度、pH值，蛋白质初浓度及离子强度等因素对牛血清白蛋白吸附性能的影响．采用紫外分光光度法测定BSA的吸附量．结果表明，蛋白质初浓度越高．温度越高，离子强度越大；蛋白质内部更多的疏水性氧基酸残基暴露于外部．吸附量增加：在等电点pH=4．7附近蛋白质沉积量最大．     

Exact Fixed-node Quantum Monte Carlo： Self-optimizing Procedure

In this paper, a novel exact fixed-node quantum Monte Carlo (EFNQMC) algorithm was proposed, which is a self-optimizing and self-improving procedure. In contrast to the previous EFN-QMC method, the importance function of this method is optimized synchronistically in the diffusion procedure, but not be-fore beginning the EFNQMC computation. In order to optimize the importance function, the improved steepest descent tech-nique is used, in which the step size is automatically adjustable.The procedure is quasi-Newton type and converges super linear-ly. The present method also uses a novel trial function, which has correct electron-electron and electron-nucleus cusp condi-tious. The novel EFNQMC algorithm and the novel trial func-tion are employed to calculate the energies of 1 ^1A1 state of CH2, ^1Ag state of Cs and the ground-states of H2, LiH, Li2 and H2O.     

紫杉醇的合成进展

紫杉醇是一种重要的抗癌药物,它具有复杂新颖的化学结构,为三环二萜类化合物.本文综述了紫杉醇的半合成和紫杉烷环的各种合成方法.     

JEE—4x型真空镀膜仪功能扩展

报道了对ＪＥＥ－４ｘ型真空镀膜仪蒸发装置的改进以及建立蒸发材料回收装置的具体方法，并介绍了改进后该仪器在高分辨扫描电镜样品制备上的应用实例．实验证明，上述改进不但扩展了ＪＥＥ—４ｘ型真空镀膜仪的制样功能又节省了蒸发材料，集中了离子溅射法及常规高真空镀膜法的优点，完全满足ＳＥＭ样品的分析要求，该方法简单易操作．