308nm准分子激光对C60薄膜的刻蚀特性研究

测量在空气和真空中３０８ｎｍ准分子激光对Ｃ６０薄膜的刻蚀速率和刻蚀阈值，讨论了环境中氧气对刻蚀特性的影响。     

Darboux Transformation and Variable Separation Approach： the Nizhnik-Novikov-Veselov Equation

Darboux transformation (DT) is developed to systematically find variable separation solutions for the Nizhnik-Novikov-Veselov equation. Starting from a seed solution with some arbitrary functions, the one-step DT yields the variable separable solutions, which can be obtained from the truncated Painleve analysis, and the two-step DT leads to some new variable separable solutions, which are the generalization of the known results obtained by using a guess ansatz to solve the generalized trilinear equation.     

Symmetries and Strong Symmetries of the （3＋1）-Dimensional Burgers Equatio

The strong symmetries (recursion operators) and the inverse strong symmetries of a (3 1)-dimensional Burgers equation are given explicitly.Infinitely many symmetries of the considered model are obtained by acting the strong symmetries and the inverse strong symmetries on some seeds.An infinite-dimensional full Lie point symmetry algebra is also given.     

苯基取代的环戊二烯基锆化合物的合成及催化乙烯聚合

一系列苯基取代的环戊二烯配体在甲苯中相继与丁基锂及ZrCl4作用，生成相 应的苯基取代的茂金属化合物，通过^1H NMR，MS和元素分析表征了化合物的分子 结构，并研究了在MAO（甲基铝氧烷的助催化下，化合物对乙烯聚合的催化性能， 结果发现单苯基取代茂金属化合物的催化活性和产物聚乙聚的分子量都随聚合温度 的升高而增大。     

用高效液相色谱测定食物中维生素B_1、B_2含量

本文着重介绍使用高效液相色谱荧光测定天然食品中维生素B_1、B_2含量。在测试维生素B_1时,使用键合C_(18)分析柱,流动相为CH_3OH-0.01M KH_2PO_4 45/55,流速1.5ml/min,Ex:390nm,EM:470nm,柱温45℃;测维生素B_2时用强阳离子交换柱,流动相CH_3OH/0.01M KH_2PO_4,CH_3OH由30～70分钟梯度淋洗,流速1.5ml/min,柱温45℃,Ex:449nm,EM:530nm。在上述条件下所测部分食物中维生素B_1的回收率是92.51～101.85%,变异系数2.14～6.57%;维生素B_2的回收率为89.91～95.18%,变异系数0.19～6.19%。部分食物样品的测试结果令人满意。     

正确认识和对待"核心期刊"的价值和作用

近年来,一种学术现象———对“核心期刊”的遴选及其作用的泛化、异化———在我国大地上蔓延。“核心期刊”遴选体系越来越多,所谓的“核心期刊”数量也越来越大;“核心期刊”早已不局限于文献计量学的范畴,仅为图书情报界了解和订购期刊提供参考,而被毫无节制地应用到现实的     

新型含氟姜黄素类似物的合成、晶体结构及抗肿瘤活性

采用活性基团拼接法将含氟苯甲醛与酮反应, 合成了5个含氟单羰基姜黄素类似物, 结构经IR, ¹H NMR及ESI-MS确认. 对所合成的化合物进行了抗肿瘤活性测试(MTT法), 结果表明, 部分化合物对肿瘤细胞有较强的选择性抑制活性, 其中2,6-二(4-氟亚苯基)环己酮(3a)和2,6-二(2-氟亚苯基)环己酮(3b)的抗肿瘤谱广, 活性较好, 就此对化合物3b作了单晶培养, 并就晶体结构进行了X衍射分析. 结构表明化合物3b属三斜晶系, 空间群 P-1. 晶胞参数 a＝0.9222(2) nm, b＝0.9732(2) nm, c＝1.0127(2) nm, α＝88.920(4)°, β＝75.672(3)°, γ＝62.404(3)°, V＝0.7755(3) nm³, Z＝2, D_c＝1.329 Mg•m^－3, μ＝0.097 mm^－1, F(000)＝324, 最终偏离因子R＝0.0590, wR＝0.1841.     

SUSPENSION-SWELLING GRAFT COPOLYMERIZATION——SYNTHESIS OF ACS RESINS*

Acrylonitrile (AN)-chlorinated polyethylene (CPE)-styrene (St) (ACS) terpolymer was synthesized by suspension-swelling graft copolymerization method, in which two key factors such as dispersing system and time were studied. Highly effective comples dispersing system was chosen and determined, and two-layer protection model was put forward to clarify the stable effect mechanism Varying the swelling time of CPE in AN and St monomer mixture, some results such as grafting effect, particle characteristics, rubber particle morphology and its size distribution, and properties of ACS resins were investigated , thus the optimum swelling time was proposed.     

金属有机化学与不对称合成

一、前言手性因素在化学、生物学及其它多种学科和技术领域中起了极其重要的作用。随着自然演变、生命的产生和发展,在生物体内的手征性成为普遍现象。自然界往往对一种手性有偏爱。自然界存在的糖为D-构型,氨基酸为L-构型,而核酸的螺旋构象则全为左旋的。分子的手性是四面体碳原子构成的有机化学中的重要概念。