把它们"就地正法"

听刘老师的课越久,同学们也越来越相信,刘老师掌握着许多神秘好玩的学习方法,谁要是能把它们都学到手,那么数学考试一定能得高分。不过大家也都变得有点儿怕他,担心自己的学习不能让他满意,这点好像和以前的江老师不一样呢。就像今天,刘老师眉头紧锁地走进教室,他一句话都还没说呢,就先叹了一口气,这下大家紧张了。刘老师转过身,在黑板上写下了一行     

冲击法测螺线管磁场实验的改进

冲击法测螺线管磁场实验的改进韩字璞，师善雨（河北师范学院物理系石家庄０５００９１）影响冲击法测螺线管轴向磁感应强度实验精度的因素很多，其主要。素。脉冲电。作用时间的长短，其次是电路中各线圈位置的摆放及其他等．如何减小和消除这些因素的影响，提高测量准确...     

Syntheses of Chiral Calix [4] arene Derivatives Bearing Amino Acid Residue

The syntheses of chirai calix[4]arene derivatives bearing amino acid residue at the lower rim or upper rim by three different methods were reported.     

固有手性杯芳烃的研究

固有手性杯芳烃是指在杯芳烃三维骨架上引入数个非手性基团使之不再具有对称面或反转中心而呈现出整体手性。本文综述了固有手性杯芳烃的合成、光学拆分及其在手性识别和不对称催化领域的应用。     

N－甲基丙烯酰－N＇－嘧啶哌嗪与过硫酸钾引发体系引发的丙烯酰胺聚合

Ｎ－甲基丙烯酰－Ｎ＇－嘧啶哌嗪与过硫酸钾引发体系引发的丙烯酰胺聚合高青雨，张福莲，杨更须，张举贤（河南大学化学化工系，开封，４７５００１）李福绵（北京大学化学系，北京，１０００８７１）关键词Ｎ－甲基丙烯酰－Ｎ＇－嘧啶哌嗪，可聚合芳香叔胺，氧化还原引发...     

固相自引发基团置换反应制备LiNi1/3Co1/3Mn1/3O2正极材料

自从2001年Ohzuku T和Makimura Y报导LiNi1/3Co1／3Mn1/3O2正极材料以来，其一直被认为是最有可能取代LiCoO2的新型锂离子二次电池正极材料之一。氢氧化物共沉淀法是最常用的一种合成LiNi1/3Co1／3Mn1/3O2材料的方法，通过混合氢氧化物共沉淀法可以获得有着均一分布且具有很高的振实密度的球形LiNi1/3Co1/3Mn1/3O2。     

N-甲基丙烯酰-N′-嘧啶基哌嗪及其聚合物敏化的丙烯腈光聚合

The photopolymerization of acrylonitrile (AN) sensitized by N-methacrylyl-N'-pyrimidi-nopiperazine (MPMP) and its polymer, P(MPMP) was studied kinetically. It was found that the photopolymerization rate of AN sensitized by monomeric MPMP is proportional to 0.35th power of MPMP concentration and 0.85th power of AN concentration, respectively. In the case sensitized by Polymeric MPMP, P(MPMP) is proportional to 0.30th power of P(MP-MP) concentration and 1.0 power of AN concentration, respectively. The overall activation energies for photopolymerization sensitized with MPMP and P(MPMP) were determined to be 4.71Kcal/mol and 4.58Kcal/mol,respectively.From the fluorescence analysis for P(AN) senstitized by either MPMP or P(MPMP),it was confirmed that MPMP and P(MPMP) not only sensitized the photopolymerization of AN but also entered into the P(AN) chains.     

N-甲基-N-(2-甲基丙烯酰氧乙基)苯胺敏化的丙烯腈光聚合

The photopolymerization of acrylonitrile sensitized by N-methyl-N-(2-methacryloyloxye-thyl)aniline (MEMA) was studied kinetically. The photopolymerization rate of AN in DMF by using MEMA as sensitizer is proportional to 0.32 th power of MEMA concentration and 1.20 th power of AN concentration. The overall activation energy for the polymerization was found to be 4.82 Kcal/Mol. From the fluorescence analysis of obtained polyacrylonitrile sensitized by MEMA, it was confirmed that MEMA not only joined the inition but also entered into the polyacrylonitrile chains. The initiation mechanism was proposed tentatively.     

N-甲基丙烯酰-N′-嘧啶基哌嗪及其聚合物的荧光光谱研究

A novel acrylic monomer bearing pyrimidino-moiety, N-methacrylyl-N'-pyrimidinopipe-razine (MPMP) was synthesized by the reaction of N-pyrimidinopiperazine and methacrylyl chloride in the presence of triethylamine. Both absorption and fluorescence spectum for the monomer and its polymer were recorded. It was observed that the fluorescence intensity of monomeric MPMP was slightly lower than that of its polymer. The monomer did not dramatically appear its structural self-quenching effect as we have reported previously. The fluores-cence of the polymer,P(MPMP) culd be quenched by electron-deficient quenchers such as methacrylonitrile,acrylonitrile,fumaronitrile; methyl acrylate and methyl methacrylate. The Stern-Volmer constants of those quenchers for P(MPMP) were determined.