Solvent‐Controlled Bifurcated Cascade Process for the Selective Preparation of Dihydrocarbazoles or Dihydropyridoindoles

A solvent‐controlled cascade process has been identified for the dual purpose of the preparation of either dihydrocarbazoles or dihydropyridoindoles from identical N‐aryl‐α,β‐unsaturated nitrones and electron‐deficient allene starting materials. These reactions proceed smoothly under mild metal‐free conditions affording a range of two types of skeletally distinct indole‐based heterocycles in high yield and diastereoselectivity. These transformations demonstrate the use of a bifurcated cascade process that hinges on the ring‐opening event of a benzazepine intermediate for the synthesis of skeletally diverse heterocyclic products and rapid access to biologically‐significant, indole‐based structures.     

基于LabVIEW机器视觉的迈克耳孙干涉仪实验

基于机器视觉设计了迈克耳孙干涉仪实验,采用机器视觉技术替代人眼对目标(干涉圆环)进行分析与测量,可有效避免因视觉疲劳而造成的测量错误.     

福建省首届大学生化学实验邀请赛无机及分析化学实验试题解析

介绍了福建省首届大学生化学实验邀请赛无机及分析化学实验的命题思路、试题原题及评分规则,并对实验中存在的问题及成绩进行了总结分析。     

Interbasis expansions for isotropic harmonic oscillator

The exact solutions of the isotropic harmonic oscillator are reviewed in Cartesian, cylindrical polar and spherical coordinates. The problem of interbasis expansions of the eigenfunctions is solved completely. The explicit expansion coefficients of the basis for given coordinates in terms of other two coordinates are presented for lower excited states. Such a property is occurred only for those degenerated states for given principal quantum number n.     

Solvent replacement to thermo‐responsive nanoparticles from long‐subchain hyperbranched PSt grafted with PNIPAM for encapsulation

Long‐subchain hyperbranched polystyrene (lsc‐hp PSt) with uniform subchain length was obtained through copper‐catalyzed azide‐alkyne cycloaddition click chemistry from seesaw macromonomer of PSt having one alkynyl group anchored at the chain centre and two azido group attached to both chain ends [alkynyl‐(PSt‐N₃)₂]. After precipitation fraction, different portions of lsc‐hp PSt having narrow overall molecular weight distribution were obtained for further grafting with alkynyl‐capped poly(N‐isopropylacrylamide) (alkynyl‐PNIPAM), which was obtained via single‐electron transfer living radical polymerization of NIPAM with propargyl 2‐bromoisobutyrate as the initiator and grafted onto the peripheral azido groups of lsc‐hp PSt via click chemistry. Thus, amphiphilic lsc‐hp PSt grafted with PNIPAM chains (lsc‐hp PSt‐g‐PNIPAM) was obtained and would have star‐like conformation in tetrahydrofuran (THF). By replacing THF with water, lsc‐hp PSt‐g‐PNIPAM was dissolved at molecular level in aqueous solution due to the hydrophilicity of PNIPAM and exhibited thermal induced shrinkage of PNIPAM arms. The water‐insoluble lsc‐hp PSt would collapse densely and could be served as a reservoir to absorb hydrophobic chemicals in aqueous solution. The influence of overall molecular weight of lsc‐hp PSt on the absorption of pyrene was studied. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

加强电力技术监督管理 提高生产安全水平

在电力生产过程中,各个环节联系紧密,任何一环出了问题,将产生由点及面,甚至到片的故障,将给企业、工农业生产带来相当严重的影响。所以,加强对电力技术监督管理,加强对电力安全生产环节的有效监督,显得尤其重要。文中从安全生产工作现状、电力技术监督管理意义及措施等方面展开了分析。     

Cerium (IV) ammonium nitrate (CAN)-mediated regioselective synthesis and anticancer activity of 6-substituted 5,8-dimethoxy-1,4-naphthoquinone

6-Substituted 5,8-O-dimethyl-1,4-naphthoquinones (6-DMNQ), the promising anticancer scaffolds, were selectively generated by oxidative demethylation of 2-substituted 1,4,5,8-tetramethoxynaphthalenes with CAN in EtOAc/H₂O in comparatively high yields. An interesting finding was that apart from the reported electron-withdrawing effects of substituents on position 2 of naphthalene ring, regioselective synthesis of 6-DMNQ was largely dependent on the steric effects in CAN-mediated oxidation. The selective cytotoxicities of 6-DMNQ from the in vitro cell-based assays were exhibited between the cancer cells and normal cells. Moreover, most of sulfur-containing 6-DMNQ derivatives displayed better anticancer activities than the corresponding oxygen-containing ones, which could provide an available strategy for the design of 6-DMNQ derivatives as potential anticancer agents.