Hemostatic efficacy and tissue reaction of oxidized regenerated cellulose hemostats

Oxidized regenerated cellulose (ORC) has been used as an absorbable hemostat since World War II. In the present study, hemostasis time was determined in a spleen incision model in swine. The effect of mass on absorbable hemostat efficacy and hemostasis time was evaluated by standardizing the ORC materials on a mass basis. The median hemostasis time for a single layer of the new nonwoven ORC was as much as 51 % shorter than woven ORC (P < 0.001). The mean hemostasis time for nonwoven ORC was not affected by the mass of hemostat applied to the wound. The hemostatic efficacy of woven ORC increased with the mass (layers) of hemostat applied to the wound. Nonwoven ORC is significantly faster in achieving hemostasis than woven ORC, and its hemostatic efficacy is not influenced by the mass of material applied. Tissue reaction was minimal and the material was fully absorbed by 14 days.     

室内环境中脑控轮椅的路径跟踪控制

为了实现室内环境中脑控轮椅的自主导航,提出了一种简单有效的路径跟踪控制方法。给定的路径通常被表示为一系列离散点,根据这一特点,提出了分段直线路径跟踪方法,即依次跟踪由前后两个路径点构成的直线路径到达目标点。基于预瞄点技术并结合模糊算法和传统的PID控制方法设计控制器,完成各分段直线路径的跟踪,并给出了有效的切换条件。实验结果表明,本文提出的路径跟踪控制方法能够使脑控轮椅在室内环境中精确地跟踪给定路径。     

基于无线传感器网络的飞行器测控通信系统测量方案设计

随着航天技术的发展,飞行器测控通信系统需要测量的参数种类和数量不断增加,但同时要求系统在进行方案搭建时满足更高的可靠性、更小的体积和更小的设备质量。为解决这类问题,提出了基于无线传感器网络的飞行器测量方案,方案重点从节点配置、时间同步、网络拓扑、能源供应等方面对方案进行阐述,最后给出了应解决的关键技术攻关方向。     

一种新型多功能信号源系统的设计

为适应航天领域遥测外系统的快速发展,提出了一种新型多功能信号源系统的设计。系统以FPGA为逻辑控制单元,采用PCI总线接口实现了与上位机的通信,同时结合AD5628、AQY210及RS422接口芯片稳定地输出了多路模拟信号、开关信号及一路PCM信号。重点阐述了信号源系统硬件及软件设计中的关键技术。试验结果表明,该系统能够提供多种高精度、高可靠性的信号,且工作性能稳定,抗干扰能力强,数据传输速率达到40Mbps,PCM码率高达983.04kbps,满足了系统设计的要求。     

具有奇性与真空粘性依赖于密度的非牛顿流局部强解的存在唯一性

研究一维有界区间上粘性依赖于密度且具有奇性、初始允许真空的可压缩非牛顿流.通过正则化奇性项以及逐步迭代构造初边值问题的逼近解,对逼近解取极限得到其局部强解的存在唯一性,进一步推广了相关文献中关于非牛顿流解的存在性结果.     

Interactions of delta shock waves for the relativistic Chaplygin Euler equations with split delta functions

In this article, we are concerned with the interactions of delta shock waves with contact discontinuities for the relativistic Euler equations for Chaplygin gas by using split delta functions method. The solutions are obtained constructively and globally when the initial data consists of three piecewise constant states. The global structure and large time‐asymptotic behaviors of the solutions are analyzed case by case. During the process of the interaction, the strengths of delta shock waves are computed completely. Moreover, it can be found that the Riemann solutions are stable for such small perturbations with special initial data by letting perturbed parameter ε tends to zero. Copyright © 2014 John Wiley & Sons, Ltd.     

Infinitely many homoclinic orbits for a class of second‐order damped differential equations

We investigate the existence and multiplicity of homoclinic orbits for the second‐order damped differential equations For Equation 1 where L(t) and W(t,u) are neither autonomous nor periodic in t. Under certain assumptions on g, L, and W, we get infinitely many homoclinic orbits for superquadratic, subquadratic and concave–convex nonlinearities cases by using fountain theorem and dual fountain theorem in critical point theory. These results generalize and improve some existing results in the literature. Copyright © 2015 JohnWiley & Sons, Ltd.     

Periodic solutions for fourth-order nonlinear functional difference equations

By using the critical point method, some new criteria are obtained for the existence and multiplicity of periodic solutions for fourth-order nonlinear functional difference equations. The proof is based on the linking theorem in combination with variational technique. Recent results in the literature are generalized and significantly improved. Copyright © 2013 John Wiley & Sons, Ltd.     

Palladium‐Catalyzed C(sp3)?H Activation: A Facile Method for the Synthesis of 3,4‐Dihydroquinolinone Derivatives

3,4‐Dihydroquinolinones were synthesized by the palladium‐catalyzed, oxidative‐addition‐initiated activation and arylation of inert C(sp³) H bonds. Pd(OAc)₂ and P(o‐tol)₃ were used as the catalyst and ligand, respectively, to improve the efficiency of the reaction. A further advantage of this reaction is that it could be performed in air. A relatively rare seven‐membered palladacycle was proposed as a key intermediate of the catalytic cycle.     

Copper‐Based Ternary and Quaternary Semiconductor Nanoplates: Templated Synthesis,Characterization, and Photoelectrochemical Properties

Two‐dimensional (2D) copper‐based ternary and quaternary semiconductors are promising building blocks for the construction of efficient solution‐processed photovoltaic devices at low cost. However, the facile synthesis of such 2D nanoplates with well‐defined shape and uniform size remains a challenge. Reported herein is a universal template‐mediated method for preparing copper‐based ternary and quaternary chalcogenide nanoplates, that is, CuInS₂, CuIn_xGa_1−xS₂, and Cu₂ZnSnS₄, by using a pre‐synthesized CuS nanoplate as the starting template. The various synthesized nanoplates are monophasic with uniform thickness and lateral size. As a proof of concept, the Cu₂ZnSnS₄ nanoplates were immobilized on a Mo/glass substrate and used as semiconductor photoelectrode, thus showing stable photoelectrochemical response. The method is general and provides future opportunities for fabrication of cost‐effective photovoltaic devices based on 2D semiconductors.