G-型分次对偶模的同调维数

文章主要研究Gr-凝聚环中每个f.g .半自反分次模的分次对偶模的平坦维数和分次投射维数之间的关系 ,以及与分次环的gr.w .gl.dim关系 ,所得的结果包含了非分次的情形。     

由“铝土矿冶炼金属铝”分析铝及其重要化合物之间的转化关系

铝是高中化学需要掌握的重要金属之一,主要内容有铝、氧化铝、氢氧化铝。高考化学中铝的考点主要集中在铝及其化合物的两性,即既可以与酸反应,也可以与碱反应的特性。其中对铝土矿冶炼金属铝的过程涉及较多,利用教材典型案例分析铝及其重要化合物之间的转化关系,可达到巩固基础、突破难点的教学目的。     

Synthetic and biological studies on a cyclopolypeptide of plant origin

Objective: A natural cyclic peptide previously isolated from Citrus medica was synthesized by coupling oftetrapep-tide units Boc-Leu-Pro-Trp-Leu-Ome and Boc-Ile-Ala-Ala-Gly-Ome after proper deprotection at carboxyl and amino terminals followed by cyclization of linear octapeptide segment.Methods: Solution phase technique was adopted for the synthesis of cyclooctapeptide--sarcodactylamide.Required tetrapeptide units were prepared by coupling of Boc-protected dipeptides viz.Boc-Leu-Pro-OH and Boc-Ile-Ala-OH with respective dipeptide methyl esters Trp-Leu-Ome and Ala-Gly-Ome.Cyclization of linear octapeptide unit was done by p-nitrophenyl ester method.The structure of synthesized cyclopolypeptide was elucidated by FTIR,1H NMR,13C NMR,FABMS spectral data and elemental analysis.The newly synthesized peptide was evaluated for dif-ferent pharmacological activities including antimicrobial,anthelmintic and cytotoxic activities.Results: Synthesis of sarcodac-tylamide was accomplished with >78% yield utilizing dicyclohexylcarbodiimide (DCC) as coupling agent.Newly synthesized peptide possessed potent cytotoxic activity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines,in addition to moderate anthelmintic activity against earthworms Megascoplex konkanensis,Pontoscotex corethruses and Eudrilus sp.Moreover,cyclopolypeptide displayed good antimicrobial activity against pathogenic fungi Candida albicans and Gram-negative bacteria Pseudomonas aeruginosa,in comparison to standard drugs griseofulvin and ciprofloxacin.Conclusion: Solution phase technique employing DCC and triethylamine (TEA) as base proved to be effective for the synthesis of natural cyclooctapeptide.N-methyl morpholine (NMM) was found to be a better base for the cyclization of linear octapeptide unit in comparison to TEA and pyridine.     

双苯并咪唑烷基胺类化合物的合成

本报道二乙醇胺与1-溴代烷反应，与亚硫酰氯反应，再与2-苯并咪唑硫醇钾合成N，N-双（？-苯并咪唑-2-硫-乙基）取代胺桥联化合物。这些化合物增色被1HNMR、IR和元素分析证实。     

大湖名城战略与环巢湖体育圈的构建

"大湖名城、创新高地"的发展战略为构建环巢湖体育圈提供了契机。环巢湖体育圈融要主动融入大湖名城战略规划之中,做好统筹规划,实现科学布局;立足自身条件,寻求特色创新;利用大湖优势,注重生态发展;着眼长远利益,重视人才培育,打造以城乡休闲体育健身为鲜明特色的品牌。     

二碘化钐引起的分子内还原偶联反应

本文综述了二碘化钐引起的分子内还原偶联反应,包括分子内酮一烯还原偶联、酮一炔还原偶联、频哪醇偶联和其它有关还原偶联反应。     

数据库加密体制

利用多项式环上的孙子定理建立了一数据库加密体制，其特点是速度快、易实现。     

牛顿环干涉实验方法的研究与改进

本文分析了牛顿环干涉实验中常见的问题,提出了具体的解决办法,并应用现代传感技术改进测量方法,使其具有良好的示教和演示效果.     

离子的极化作用及对化合物性质的影响

本文介绍了离子的极化作用，离子极化作用和变形性的某些规律，离子极化对化舍物性质的影响，如溶解性，热稳定性，导电率和金属性等。     

面对"3+综合"调整复习策略--以《卤素》为例初探元素化合物复习思路

新一轮高考改革中备受关注的文理“综合科目”终于于2000年7月在江苏、浙江等省揭下了神秘的“面纱”。“理科综合”所展现的“突出基础、重视能力、体现综合”的特点，无疑对原有的教学观念、教学方式及教学策略带来了很大的冲击。面对这一现状，在高三复习中对复习策略作相应的调整，该是每一位化学教师首先应该考虑的问题。