Reinforced Wool Keratin Fibers via Dithiol Chain Re-bonding

Regenerated wool keratin fibers (RWKFs) have heretofore attracted tremendous interest according to environmental friendliness, ample resource, and intrinsic biocompatibility for broad applications. In this realm, both uncontrollable keratin fibril assembly procedure and resultant insufficient mechanical strength, have greatly hindered their large-scale manufacture and commercial viability. Herein, a continuous wet-spinning strategy is put forward to rebuild wool keratin into compact regenerated bio-fibers with improved strength via disulfide re-bonding. Dithiothreitol (DTT) has been introduced to renovate disulfide linkage inside keratin polypeptide chains, and bridge keratin fibrils via covalent thiol bonding to form a continuous backbone as mechanical support. A thus-derived RWKF manifests a tensile strength of 186.1 ± 7.0 MPa and Young's modulus of 7.4 ± 0.2 GPa, which exceeds those of natural wool, feathers, and regenerated wool or feather keratin fibers. The detailed wet-spinning technical parameters, such as coagulation, oxidation, and post-treatment, have been systematically optimized to guarantee the continuous preparation of high-strength regenerated keratin fibers. This work offers insight into solving the concurrent challenges for continuous manufacture of regenerated protein fibers and sustainability concerns about biomass waste.     

编队电子战信息融合仿真系统设计

根据编队电子战系统信息融合的特点,构造信息融合仿真系统结构,阐述了编队电子战系统多源信息融合方法和策略．提出了信息融合评估的数学模型以及编队电子战系统信息融合需重点解决的问题。     

The L(2,1)-labeling and operations of graphs

Motivated by a variation of the channel assignment problem, a graph labeling analogous to the graph vertex coloring has been presented and is called an L(2,1)-labeling. More precisely, an L(2,1)-labeling of a graph G is a function f from the vertex set V(G) to the set of all nonnegative integers such that |f(x)-f(y)| /spl ges/ 2 if d(x,y)=1 and |f(x)-f(y)| /spl ges/ 1 if d(x,y) = 2. The L(2,1)-labeling number /spl lambda/(G) of G is the smallest number k such that G has an L(2,1)-labeling with max{f(v):v/spl isin/V(G)}=k. A conjecture states that /spl lambda/(G) /spl les/ /spl Delta//sup 2/ for any simple graph with the maximum degree /spl Delta//spl ges/2. This paper considers the graphs formed by the Cartesian product and the composition of two graphs. The new graph satisfies the conjecture above in both cases(with minor exceptions).     

掺杂位置对基于马赫-曾德尔干涉的硅光调制器的消光比的影响

在基于马赫-曾德尔干涉的硅光调制器中,载流子吸收会极大的影响器件的消光比。并且,不同的掺杂位置会引起注入的载流子的分布不一样,从而导致不同的消光比。从实验上研究了这一现象,实验中的器件采用0.18 μm CMOS工艺制作在SOI材料上。实验表明,掺杂位置离脊波导的边沿0.5 μm左右时,器件会获得最佳的消光比。     

Performance analysis and power allocation for decode‐and‐forward cooperative communications over Rician fading channel

This paper derives the asymptotic symbol error rate (SER) and outage probability of decode‐and‐forward (DF) cooperative communications over Rician fading channels. How to optimally allocate the total power is also addressed when the performance metric in terms of SER or outage probability is taken into consideration. Analysis reveals the insights that Rician factor has a great impact on the system performance as compared with the channel variance, and the relay–destination channel quality is of importance. In addition, the source–relay channel condition is irrelevant to the optimal power allocation design. Simulation and numerical evaluation substantiate the tightness of the asymptotic expressions in the high‐SNR regions and demonstrate the accuracy of our theoretical analysis. Copyright © 2011 John Wiley & Sons, Ltd.     

基于蛙跳算法的模糊图像复原

为了提高模糊图像复原后的清晰度,提出蛙跳算法。将蛙群体分成若干个族群,每个族群包含若干只青蛙,每次进化只更新最差青蛙的位置。为防止解空间收缩,对最优个体进行高斯变异算子操作,同时设定阈值策略对蛙跳各维变量进行指导性更新。建立模糊图像复原模型,用蛙跳算法非线性映射特性建立模糊图像与复原的函数关系,使模糊图像复原的解最终收敛于泊松统计的最大似然解。建立了复原评价指标。仿真实验结果表明,与其他算法相比,蛙跳算法复原较清晰,改善百分比最大,同时耗时最少。     

提高声表面波传感器检测精度的方法

在利用声表面波(SAW)进行检测的系统中,回波相位解调的相位模糊严重影响检测精度。针对延迟线型声表面波温度传感器,理论分析表明,结合时延测量和相位测量的解调方法可唯一确定待测量;实验证明,在温度变化较大的范围内,该方法能解决相位模糊问题,检测精度可达0.5℃。     

A low jitter, low spur multiphase phase-locked loop for an IR-UWB receiver

A low jitter,low spur multiphase phase-locked loop(PLL) for an impulse radio ultra-wideband(IR-UWB) receiver is presented.The PLL is based on a ring oscillator in order to simultaneously meet the jitter requirement, low power consumption and multiphase clock output.In this design,a noise and matching improved voltage-controlled oscillator(VCO) is devised to enhance the timing accuracy and phase noise performance of multiphase clocks.By good matching achieved in the charge pump and careful choice of the l...     

一种基于SystemC的D触发器验证平台研究

当今复杂电子系统更倾向于在更高抽象级进行建模一种基于C/C＋＋的硬件描述语言,SystemC语言变得非常重要,在此介绍了SystemC语言的验证库,以及验证库的顶层设计,接口设计。文章在最后的阶段对D触发器进行了基于SystemC的验证平台搭建,进而展现了SystemC在验证上的优势。     

Novel Delay-Dependent Stability Results for Neural Networks with Time-Varying Delays

This paper is concerned with the stability of static neural networks with time-varying delays. With the construction of a new Lyapunov functional and advanced techniques for calculating its derivative, a delay-dependent stability criterion is obtained that is less conservative than existing ones. A delay-independent criterion is also given that, together with the delay-dependent one, can be checked using recently developed algorithms. Examples are provided to illustrate the effectiveness and the reduced conservatism of the proposed results.