Prediction of superconductivity of Ta2AlC: in situ Raman spectrometry and density functional investigations

In this paper, in situ Raman spectra of Ta₂AlC are measured in the temperature range of 80–500 K at ambient pressure. The frequencies of the Raman modes decrease with increasing temperature, which have been explained by the anharmonic and thermal expansion effects. The line‐width of E_2g (ω₃) mode increases at elevated temperatures, which is found to be due to the anharmonic phonon–phonon scatterings. On the other hand, the line‐widths of E_2g (ω₁) and A_1g (ω₄) modes decrease continuously with increasing temperature, which is explained by the electron–phonon couplings of these two phonon modes with the Ta 5d electrons. The electron–phonon coupling strengths are obtained both in experiments and density functional calculations. Finally, Ta₂AlC is predicted to be a new superconductive MAX phase. Copyright © 2014 John Wiley & Sons, Ltd.     

光谱法研究核壳量子点CdTe/CdS与牛血清白蛋白的相互作用

应用荧光光谱、圆二色光谱和紫外吸收光谱等技术研究核壳量子点CdTe/CdS与牛血清白蛋白(BSA)相互作用的结果表明,CdTe/CdS对BSA的荧光猝灭机理为静态猝灭。根据不同温度下量子点对BSA的荧光猝灭作用计算了结合常数、热力学参数,证明了量子点与BSA相互作用力主要是范德华力或氢键作用力。探讨了量子点对BSA构象的影响。     

计算智能与力学反问题中的若干问题

计算智能是生物智能的计算模拟,包括人工神经网络、模糊系统和进化计算三个主要部分．参考国内外有关计算智能与力学反问题研究中的某些问题,并结合作者的研究工作,介绍了有关课题的研究状况以及目前的研究进展．     

氮氧自由基TEMPO：选择氧化醇的高效有机小分子催化剂*

醇被氧化为相应的醛或酮是有机合成中重要的官能团转换反应之一。自从Anelli法（TEMPO/NaBr/NaOCl）发现以来,由于所具有的醇被氧化为相应的醛或酮是有机合成中重要的官能团转换反应之一。自从Anelli法（TEMPO/NaBr/NaOCl）发现以来,由于所具有的高活性和高选择性, 有机小分子催化剂2,2,6,6-四甲基哌啶-1-氧自由基(TEMPO)催化醇的氧化反应成为温和条件下醇选择氧化的一个重要方法,并在实验室和工业生产中广泛应用。最近有关TEMPO催化醇氧化反应的研究,主要集中在开发用于分子氧对醇绿色氧化的催化体系和目的在于实现催化剂回收再用的TEMPO固载化研究两个领域上。本文以此为重点,综述了TEMPO催化醇氧化反应的发展和最近研究进展。     

Ni nanoparticles encapsulated within H-type ZSM-5 crystals for upgrading palmitic acid to diesel-like fuels

Meso-Ni@HZSM-5 bi-functional catalysts were successfully post-encapsulated with about 3–7 nm Ni nanoparticles within HZSM-5 crystals,which exhibited significantly efficient conversion activity (67.4g[palmitic acid]g[Ni]^-1h^-1) of palmitic acid and 100%selectivity of hydrocarbons with the outstanding stability during recycling application,compared to the impregnated Ni/HZSM-5 catalyst (14.0 g[palmitic acid]g[Ni]^-1h^-1).     

Solvent Induced Sphere Development in Symmetric Diblock Copolymer Thin Films

Summary: We follow the time development of the microdomain structure in symmetric polystyrene‐block‐poly(methyl methacrylate) (PS‐b‐PMMA) diblock copolymer thin films during acetone vapor treatment. Besides the highly ordered nanoscopic spheres or stripes as reported previously, a novel so‐called flower‐like pattern, which comprises six PS spheres and each PS sphere belongs to three “flowers” is formed. This finding is very helpful to discuss the highly ordered nanoscopic sphere formation process.

Transition from flower‐like structure to well‐ordered arrays of spheres, in which the flower‐like pattern, the transitional morphology, and the ordered spheres are in the portion A, B, and C, respectively.     

Fabrication of a Metal Particle Array Based on a Self‐Assembled Template from a Two‐Armed Polymer

A two‐armed polymer with a crown ether core self‐assembles to produce macroporous films with pores perpendicularly reaching through the film down to the substrate. A possible assembling mechanism is discussed. The pore size can be conveniently adjusted by changing the solution concentration. These through‐hole macroporous films provide a template for fabricating an array of Cu nanoparticle aggregates.

     

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??A single distribution-free (nonparametric) Phase II exponentially weighted moving average (EWMA) chart based on the Cucconi statistic, referred to as the EWMA-Cucconi (EC) chart, is considered here for simultaneously monitoring shifts in the unknown location and scale parameters of a univariate continuous process. A comparison with some other existing nonparametric EWMA charts is presented in terms of the average, the standard deviation and some percentiles of the run length distribution. Numerical results based on Monte Carlo analysis show that the EC chart provides quite a satisfactory performance. The effect of the Phase I (reference) sample size on the IC performance of the EC chart is studied in detail. The application of the EC chart is illustrated by two real data examples.     

To inhibit coffee ring effect in inkjet printing of light-emitting polymer films by decreasing capillary force

Coffee ring effects of inkjet printed poly(spirobifluorene) films were restrained by decreasing the capillary force due to volatility/viscosity match.     

SiCw/6061 Al复合材料中界面相的研究

利用电子显微镜分析研究了ＳｉＣ２／６０６１Ａｌ复合材料的界面相。电子衍射分析表明，ＳｉＣｗ／６０６１Ａｌ面相 体心立方结构，点阵常数为１．２８ｎｍ用Ｘ－射线能谱仪测定了界面相的化学成分。