ChemInform Abstract: Predicted Lithium—Boron Compounds under High Pressure.

The existence of Li₃B₂, Li₂B, Li₄B, and Li₆B that might be experimentally synthesizable over a wide range of pressures is predicted by an unbiased structure search method based on particle‐swarm optimization algorithms in combination with DFT calculations.     

Modern trends in the development of position sensitive neutron detectors for condensed matter research

Different types of neutron scattering experiment for the study of condensed matter properties pose specific and often contradictory requirements for detector characteristics. There is no single type of detector which satisfies all the criteria. Therefore, compromise is inevitable and some of the characteristics are trade off in favour of others. Present report gives an overview of detector systems presently operating at the leading neutron scattering facilities as well as some development work around the globe.      

Sensitive Electrochemical Quantification of Proanthocyanidins in Grapevine (Vitis vinifera) by Utilizing Disposable Screen-printed Carbon Electrodes

This work presents quantification of proanthocyanidins (PAs) isolated from grapevine using disposable screen-printed carbon electrodes (SPCE). Procyanidin B2 (B2) used as a model to investigate the electrochemical characteristics of complicated PAs structures in Britton Robinson buffer solution using cyclic voltammetry and square wave voltammetry. B2 exhibits a well-defined reversible redox wave at +0.49 V vs. Ag/AgCl. Significantly, the B2 was determined over a linear concentration range of 3.45–34.6 μM with a detection limit of 2.07 μM. The SPCE was used to analyze PAs in grapevine samples, and the results were consistent with those obtained using Folin-Ciocalteu standard method.     

Photo-and thermochromic spiranes 30*. Comparative study by X-ray structural analysis of the structure of spiropyrans of the indoline series containing a condensed furan fragment

The structure of an indoline spiropyran of molecular formula C₂₉H₃₃NO₂ has been studied by X-ray crystallographic analysis. Structural parameters have been determined for this spiropyran, containing a condensed furan fragment with a tert-butyl group, in comparison with the structure of other spiropyrans of this series. The observation in the absorption spectrum of a photoinduced cis-cis isomer is linked with its stabilization by the steric effect of the bulky tert-butyl group and the strength of barriers at 77 K. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 221–228, February, 2008.     

Linear regression model of DNA sequences and its application

We constructed six new models to analyze the DNA sequences. First, we regarded a DNA primary sequence as a random process in t and gave three ways to define nucleotides' random distribution functions. We extracted some parameters from the linear model and analyzed the changes of the nucleotides' distributions. In order to facilitate the comparison of DNA sequences, we proposed two ways to measure their similarities. Finally, we compared the six models by analyzing the similarities of the DNA primary sequences presented in Table 1 and selected the optimal one.     

THE APPLICATION OF HIGH RESOLUTION SOLID STATE NMR IN ADSORPTION SYSTEMS

High resolution solid state NMR techniques(such as MAS,CP/MAS andCRAMPS)were employed to study the nature of organic molecules adsorbed onporous solids. A magic angle spinning system was achieved for sealed samples with a spinning speed from 2KHz to 4.2KHz.Using this technique,high resolution ~1HMAS spectra of organic molecules and H_2S adsorbed on charcoal were obtained.EXperimental results suggest that for high coverage of adsorbed organic molecules,the spectral lines were resolved very well.But for low coverage,the spectrallines could not be separated completely.As the organic molecules condensed in     

凝聚态物理学中的基本概念

本文首先根据物质世界的层次化来说明凝聚态物理学在当今物理学中所处的地位,并阐述了复杂与简单的辨证关系,来说明为何这一学科至今仍然富有生命力;进而对这一学科的范围进行了讨论,强调了位形空间和动量空间中都存在多种类型的凝聚现象,而相应的凝聚体构成了这一学科的研究对象;还探讨了处理凝聚态理论问题的量子物理与经典物理方法有效领域的界限与分野;最终对此学科的发展历史进行回顾,并追溯和剖析了其概念全系的演变,