Syntheses,crystal structures and magnetic properties of two new cyano-bridged bimetallic complexes

Transition Metal Chemistry - Two complexes [Fe(1,10-phen)2Ni(CN)4]n (1), {[Fe2(1,10-phen)4(CN)4Co2(1,10-phen)2Fe(CN)6]·2H2O}n (2) were prepared in the reaction of K3[Fe(CN)6] as cyanometalate...     

Broad-bandwidth shot-noise-limited class-A operation of a monomode semiconductor fiber-based ring laser

We demonstrate the operation of a monomode semiconductor laser with a relative intensity noise limited by the shot-noise floor, -156 dB/Hz for a typical detected photocurrent of 1 mA, over a large frequency range from 50 MHz to 18 GHz. We achieve direct control of photon lifetime to turn an initially class-B laser into a relaxation-oscillation-free class-A one while preserving strict single-mode operation. Finally, we confirm experimentally that the laser operation in the desired class-A regime allows a dramatic filtering out of the relative intensity noise.     

Carbazole-based bi-functional photorefractive polyphosphazene for correcting the laser wavefront distortion

Carbazole-based polyphosphazene containing nitro azo chromophore moieties was synthesized first. The photorefractive polyphosphazene was prepared to optical qualitative films and used to correct the laser wavefront distortion under the room temperature without external electric field, pre-poling and addition agent. The results indicate that the photorefractive polyphosphazene film can correct both the diffraction distortion and phase distortion of the laser wavefront. At the same time the high-resolution laser wavefront distortion correction can be achieved. Further, as the result of the effectively correction of the diffraction distortion, the polymer film may be applied in microscale direct image.     

Optimal filtering of piecewise deterministic processes for source detection and separation in electric load monitoring

We wish to compute in discrete real time the best estimate for the composition of the total active power recorded at a customer's house, without any intrusion. A new solution for online characterization of the electric load is proposed. The solution is based on issues from the applied stochastic analysis of Markov processes. We specifically suggest that optimal filtering of a hybrid stochastic differential system covers entirely the detection and separation subproblems underlying the main problem.     

Observation of slow light in the noise spectrum of a vertical external cavity surface-emitting laser

The role of coherent population oscillations is evidenced in the noise spectrum of an ultralow noise laser. This effect is isolated in the intensity noise spectrum of an optimized single-frequency vertical external cavity surface-emitting laser. The coherent population oscillations induced by the lasing mode manifest themselves through their associated dispersion that leads to slow light effects probed by the spontaneous emission present in the nonlasing side modes.     

Solid phase synthesis of combinatorial libraries using anhydrides as templates

A simple and general approach to the synthesis of chemical libraries based on a universal anhydride template allows the preparation of large number of compounds. Various cyclic/acyclic amines, primary/secondary amines, differentially protected bifunctional amines were used as nucleophiles to react with anhydrides. The free carboxylic acid generated was then coupled with solid-bound amines. The facile and rapid generation of compounds through this multi-component assembly can be accomplished in a combinatorial parallel synthesis. This revised version was published online in August 2006 with corrections to the Cover Date.     

Optimal scheduling and power allocation in wireless networks with heavy traffic

This paper addresses the problem of joint transmit power allocation and time slot scheduling in a wireless communication system with time varying traffic. The system is handled by a single base station transmitting over time varying channels. This may be the case in practice of a hybrid TDMA-CDMA (Time Division Multiple Access-Code Division Multiple Access) system. The operating time horizon is divided into time slots; a fixed amount of power is available at each time slot. The users share each time slot and the power available at this time slot with the objective of minimizing the expected total queue length. The problem is reformulated, via a heavy traffic approximation, as the optimal control of a reflected diffusion in the positive orthant. We establish a closed form solution for the obtained control problem. The main feature that makes it possible is an astute choice of some auxiliary weighting matrices in the cost rate. The proposed solution relies also on the knowledge of the covariance matrix of the non-standard multi-dimensional Wiener process which is the driving process in the reflected diffusion. We then compute this covariance matrix given the stationary distribution of the multi-dimensional channel process. Further stochastic analysis is provided: the cost variance, and the Fokker–Planck equation for the distribution density of the queue length.     

New Type of Food Processing Material: The Crystal Structure and Functional Properties of Waxy and Non-Waxy Proso Millet Resistant Starches

Resistant starch (RS) is widely used in the food industry because of its ability to regulate and protect the small intestine, but their distinct effects on the structural and functional properties of waxy and non-waxy proso millet starches are not completely understood. The crystalline structure and physicochemical properties of waxy and non-waxy proso millets’ starch samples were analyzed after heat-moisture treatment (HMT). The analysis revealed significant differences between the RS of waxy and non-waxy proso millets. The crystal type of proso millets’ starch changed from type A to type B + V. The relative crystallinity of the RS of waxy proso millet was better than that of non-waxy proso millet. The gelatinization temperature and thermal stability of RS significantly increased, and the pasting temperature (PTM) of the RS of waxy proso millet was the highest. The water solubility and swelling power of the RS in proso millet decreased, and the viscoelasticity improved. The correlation between the short-range ordered structure of RS and ΔH, and gelatinization properties has a stronger correlation. This study provides practical information for improving the nutritional benefits of waxy and non-waxy proso millet in food applications.     

基于混合自组装单分子层的可控分子整流

基于自组装单分子层(SAM)的分子器件的性能取决于分子层的超分子结构. 而混合自组装单分子层是一种简便易行的调控单分子层组成和结构的方法. 将具有整流特性的11-二茂铁基-1-十一烷基硫醇(FUT)和惰性1-十一烷硫醇(C11-SH)通过溶液共混制备了混合单分子层, 并用液态EGaIn作为顶电极研究了SAM器件的性质. C11-SH与FUT分子的比例可以调节器件的整流性能: 随着惰性C11-SH分子比例增高, SAM器件的整流比逐渐降低. 有趣的是, 当惰性C11-SH的比例小于20%时, 器件的整流性能反而随C11-SH的加入而得到了提升. 这是由于少量C11-SH分子减弱了由二茂铁分子的排列缺陷引起的漏电流, 改善了分子器件的稳定性和重现性, 为单分子层器件的性能调控提供了一种简便有效的方法.