Scope and regioselectivity of the 1,3-dipolar cycloaddition of azides with methyl 2-perfluoroalkynoates for an easy,metal-free route to perfluoroalkylated 1,2,3-triazoles

1,3-Dipolar cycloadditions of methyl 2-perfluoroalkynoates with various azides have been examined, leading to a simple metal-free synthetic protocol for the synthesis of perfluoroalkylated 1,2,3-triazoles. The regiochemical results demonstrated that the cycloaddition was controlled by FMO (the frontier molecular obitals) interaction and steric hindrance in transition states.     

Biological evaluation of novel selenazole‐based compounds as potential thioredoxin reductase inhibitors

Recently, thioredoxin reductase as a target for treatment of tumors has attracted the attention of scientists. 1,2‐[Bis(1,2‐benzisoselenazolone‐3(2 H)‐ketone)]ethane (ethaselen, BBSKE, PCT: CN02/00412), designed and synthesized previously, is an effective thioredoxin reductase inhibitor; presently it is in phase II clinical trials, targeting gastric cancer, lung cancer and colon cancer. To seek more novel and effective anticancer drugs, we have developed many selenazole‐based compounds. Evaluation of the thioredoxin reductase inhibitory effect and investigation of the mechanism of anticancer drugs require abundant thioredoxin reductase, but since commercial thioredoxin reductase is expensive its use is often limited. Therefore, the preparation of thioredoxin reductase is necessary. Base on the above investigation, in this work we have prepared thioredoxin reductase and evaluated selenazole‐based compounds, and found that 44 compounds have high inhibitory effect on thioredoxin reductase with IC₅₀ < 10 µ m , of which 16 compounds have IC₅₀ values below 1 µ m . This is helpful in investigating and elucidating the mechanism of this kind of compound. Copyright © 2012 John Wiley & Sons, Ltd.     

Correlated scale-free network with community: modeling and transportation dynamics

Many transport processes on network depend crucially on the underlying network topology. In this paper, we propose a model to generate correlated scale free transportation networks with community structure by considering the mechanisms of dynamical network evolution and rewiring links. With the introduction of congestion effects, we investigate the performance and carrying capacity of this network. The results show that congestion in the uncorrelated network is more serious than the assortative or disassortative ones. Therefore, the correlated network with communities can bear much more traffic flow. In addition, the networks with lager modularity can enhance the transportation efficiently.     

256色模式下调色板的匹配

在计算机屏幕上同时显示两幅颜色相差较大、调色板各异的图像，需要匹配两幅图像的调色板．本文引入了两种匹配算法：颜色中和算法和颜色分类算法，并分别详述这两种算法的基本原理和在２５６色模式下的实现方法．     

大视角彩虹全息新设计

用光纤制成的光束变换元件代替大孔径透镜和狭缝拍摄彩虹全息图,大大提高了全息图的视角,而且方法简单.本文介绍了用光纤光束变换器的摄大视角彩虹全息图的原理、方法,并进行了实验验证,收到了较为满意的效果.     

集中荷载下叠合梁抗剪强度

本文对低叠合面钢筋破简支在合梁二阶段受力的斜截面抗剪性能进行了试验研究，并运用非线性有限元分析和试验实测数据，得出了一个适合于集中荷载下高低叠合面叠合梁的抗剪强度计算公式．     

用光谱学方法研究不同放电等离子体粒子约束

本文用光谱学方法研究在ＨＬ－１装置上ＬＨＣＤ及ＥＣＲＨ等离子体，弹丸注入等离子体，偏压电极与偏压孔栏等离子体粒子约束特性。结果表明：在弹丸注入使用正向偏压电极与偏压孔栏期间，等离子体粒子约束行到改善，较低密度下（＾ｎｅ＜２．０×１０＾１＾３ｃｍ＾－＾３），ＬＨＣＤ脉冲期间粒子约束得到改善；而当密度＾－ｎｅ大于２．０×１０＾１＾３ｃｍ＾－＾３时，等离子体约束变坏。ＥＣＲＨ脉冲期间粒子约束得不到改善。     

Amplification of spontaneous emission in Nd~(3 )-doped fiber pumped by Ti: Al_2O_3 tunable laser

Amplification of spontaneous emission(ASE) in 4m Nd~(3 )-doped fiber pumped by Ti : Al~2O_3 tunable laser is studied theoretically and experimentally. The output of 2.64mW from ASE source pumped at 833 nm is obtained and the experimental results of ASE source are compared with that of Nd~(3 )-doped fiber ring laser.     

环戊烯分子内价轨道1a′的电子动量谱学研究

报道了环戊烯（C₅H₈）分子1a′轨道的电子动量谱，并且给出了价 轨道的电离能谱信息 .实验在非共面对称几何条件下用能量多道型电子动量谱仪完成，入射电子的能量为1200 eV 加结合能.通过Hartree-Fock 和密度泛函方法计算得到了C₅H₈分子 1a′轨道的动量谱. 对1a′轨道的电子动量谱的实验值和理论计算进行了比较，得到了该轨道的极强度（pole s trength）的信息.