Adsorption of organic molecules on a melamine-modified porous polymer

Inverse gas chromatography in the infinite dilution regime was used to study the adsorp-tion of organic molecules on a micromesoporous styrene-divinylbenzene copolymer modified with melamine deposited onto its surface in amounts of 10^–6, 10^–5, 10^–4, 10^–3, 10^–2, and 5?10^–2 weight parts. Contributions of different intermolecular interactions and polarity of the samples to adsorption energy values were calculated using LFER and by Dong method. Contributions of methyl group to Helmholtz adsorption energy and to its dispersion compo-nent were determined. The polarity of the modified samples showed a non-linear dependence on the amount of the deposited modifier (pC): at 4 < pC < 6, it increases as the modifier concentration grows, abruptly falls at pC = 3, and does not change with the further decrease in pC. This is probably caused by the formation of melamine intermolecular associates at higher modifier concentrations.     

表面磁极化子的回旋共振性质

在磁场中有不少的极性晶体,电子和体纵光学声子的耦合弱,而与表面光学声子的耦合强。本文讨论电子和体纵光学声子耦合弱,与表面光学声子耦合强时对表面磁极化子的性质的影响。采用改进了的线性组合算符法导出了磁场中表面极化子的回旋共振频率和回旋共振质量,对AgCl晶体进行了数值计算。结果表明,磁场中表面极化子的回旋共振频率和回旋共振质量随磁场的增加而增加。     

High-energy 4(10)-2-fluoro-2,2-dinitroethyl and 4(10)-2,2-dinitropropyl derivatives of polynitrohexaazaisowurtzitanes

Russian Chemical Bulletin - Methods for the syntheses of a series of high-energy 4(10)-2-fluoro-2,2-dinitroethyl and 4(10)-2,2-dinitroethyl derivatives of polynitrohexaazaisowurtzitanes were...     

WLAN性能测试的价值

通信世界对无线局域网络（WLAN）的依赖性越来越强。基于802.11标准的新应用在迅速地延伸到企业、家庭住宅、无线因特网服务提供商，以及热点应用中。和所有新技术一样，最初的新奇最终将逝去。由此，了解产品如何在其预定应用环境中响应和表现变得越来越重要。随着该技术变成主流，对其产生了更全面更精确的测试要求。