Polymorphism of Amino Acid‐Based Dendrons: From Organogels to Microcrystals

There is a delicate balance for a low‐weight molecule to behave as a gelator or crystal. The synthesis of two novel amino acid‐based naphthalene‐dendrons, Nap ‐ G1 and Nap ‐ G2 is described. Both dendrons display polymorphic properties in organic solvents. Nap ‐ G1 developed a fibrous network with β‐sheet architecture in cyclohexane but exhibited a spherulitic network in mixed solvents (chloroform/petroleum ether 1:5, v/v). On the other hand, Nap ‐ G2 acted as an efficient organogelator in chloroform but formed crystalline fibers in relatively high polarity solvents (such as acetone and methanol). Combinations of characterizations have been employed to study the polymorphism.     

Experimental study on generation of high energy few cycle pulses with hollow fiber filled with neon

25 fs pulses with energy up to 0.8 mJ from a multi-pass amplifier system have been spectrally broadened from 460 nm to 950 nm due to strong self-phase modulation (SPM) effect in a gas filled hollow fiber. Using a set of chirped mirrors, the ultra-broadband dispersion compensation was achieved, and the compressed pulses reached their transform limit. Under optimized conditions we achieved pulses with duration of 5.1 fs and with energy of 400 μJ, corresponding to the peak power up to 80 GW. Supported by the National Natural Science Foundation of China (Grant Nos. 60608003, 60490280, 60225005 and 60621063)     

First structural characterization of core modified 10,15-meso aryl azuliporphyrins: observation of C-H...pi interaction between pyrrole beta-CH and mesityl ring

First successful syntheses and structural characterization of new core modified meso aryl azuliporphyrins by a simple [3 + 1] methodology are reported.     

香兰素对甲苯胺希夫碱稀土配合物的红外光声光谱

研究了香兰素对甲苯胺希夫碱及其金属配合物在３８００－２００ ｃｍ＾－１范围的傅里叶变换红外光谱光谱，对主要谱带进行了经验归属。     

光学介质表面波度的计算机模型

任一光学介质表面波度对光散射具有不可忽视的影响.本文对用激光轮廓仪所测物体表面曲线进行研究,运用傅里叶级数和最小二乘法拟合光学介质表面波形形态分布,建立了光学介质表面波度的计算机一维模型.     

A separated-electron pair study of the electronic structure of the Li2O molecule

A separated pair calculation of the electronic structure of the Li₂O molecule is described. Rather extensive calculations were made of the potential surface for symmetric configurations of Li₂O using a double zeta Slater orbital basis. A linear configuration with LiO bond length of 1.71 Å is found to be most stable. The electron distribution and correlation effects are discussed.     

Gasdynamic characteristics of toroidal shock and detonation wave converging

Shock wave focusing is a fundamental problem in the shock wave research and the instantaneous impulse of high temperature and pressure generated at the focal points has been applied recently in industrial and medical researches[1]. There are several methods to create shock wave focusing, among which the more commonly-used one is to make a planar shock wave reflect from a concave surface, such as the elliptical or parabolic re- flector. Toroidal shock wave focusing has been proposed and investi…     

Convergence Analysis of an Infeasible Interior Point Algorithm Based on a Regularized Central Path for Linear Complementarity Problems

Most existing interior-point methods for a linear complementarity problem (LCP) require the existence of a strictly feasible point to guarantee that the iterates are bounded. Based on a regularized central path, we present an infeasible interior-point algorithm for LCPs without requiring the strict feasibility condition. The iterates generated by the algorithm are bounded when the problem is a P _* LCP and has a solution. Moreover, when the problem is a monotone LCP and has a solution, we prove that the convergence rate is globally linear and it achieves `-feasibility and `-complementarity in at most O(n ² ln(1/`)) iterations with a properly chosen starting point.