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61.
Jin Zhu Ning Ma Shuo Li Liang Zhang Xiaoling Tong Yanyan Shao Chao Shen Yeye Wen Muqiang Jian Yuanlong Shao Jin Zhang 《Advanced functional materials》2023,33(14):2213644
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. 相似文献
62.
63.
Zhendong Shao Yeh R.K. 《IEEE transactions on circuits and systems. I, Regular papers》2005,52(3):668-671
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). 相似文献
64.
65.
Shao‐I Chu Wei‐Cheng Lin Hung‐Peng Lee Hsin‐Chiu Chang 《Wireless Communications and Mobile Computing》2013,13(16):1464-1481
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. 相似文献
66.
基于蛙跳算法的模糊图像复原 总被引:1,自引:0,他引:1
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。 相似文献
67.
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... 相似文献
68.
69.
Hanyong Shao 《Circuits, Systems, and Signal Processing》2010,29(4):637-647
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. 相似文献
70.
较详细阐述了有线电视双向网络光节点的设置,电缆干线网、用户分配网的设计等问题,最后介绍了回传调试的有关操作事宜。 相似文献