The Boundedness and the Global Mittag-Leffler Synchronization of Fractional-Order Inertial Cohen–Grossberg Neural Networks with Time Delays

Neural Processing Letters - The boundedness and the global Mittag-Leffler synchronization (GMLS) of fractional-order inertial Cohen–Grossberg neural networks (CGNNS) with time delays are...     

Effect of nanoparticles orientation on morphology of polymeric nanocomposite foams: preparation of foamed nanocomposite fibers by supercritical carbon dioxide

ABSTRACT

Polymeric foams have received increasing attention in both academic and industrial communities. Using of nanoparticles as heterogeneous nucleation agent has been verified as one of the most valid means to enhance cell nucleation and improve cell morphology. However, few researches have been conducted to investigate the effect of the nanoparticles’ spatial orientation on their nucleation efficiency. In this work, to study the influence of the orientation of nanoparticles on their performance in improving morphology of polymeric foam, thermoplastic polyurethane (TPU) composite fibers with different nanoparticles (carbon nanotubes, graphene and SiO₂) were prepared by using different traction speeds. The different traction speeds lead to different orientation state of the nanoparticles which then resulted different nucleation effect. It was found that carbon nanotubes (CNTs) were easily oriented and aligned along the fiber length direction under the high traction speed, while graphene and SiO₂ nanoparticles did not show orientation under the traction speed in this study. As a result, the foam of TPU/CNTs composite fibers from high traction speed exhibited a much smaller cell size and higher cell density compared to the foams of the fibers from low traction speeds, while TPU/graphene, and TPU/SiO₂ composite fibers with different traction speeds showed almost similar cell size and size density after foaming, indicating that the orientated nanoparticles possessed higher heterogeneous nucleation efficiency. To our best knowledge, this work, for the first time, demonstrated the high nucleation effect of the aligned nanoparticles, which hopefully open a new path for improving the cell morphology of polymeric foam materials.     

急性炎性疾病患者乳酸林格氏液液体动力学

目的:探索炎性疾病患者的乳酸林格氏液（Ringer's lactate,RL）液体动力学特征以及炎性生物标记物是否可以作为协变量影响RL分布和排泄。方法:本研究为前瞻性队列研究。选择40例美国麻醉医师分级（ASA）I-II级，腹腔镜下择期胆囊切除术（胆囊炎组，n=20）或者腹腔镜下急诊阑尾切除术（阑尾炎组，n=20）。所有患者麻醉诱导前开始输注RL，按15 mL/kg，35 min内输毕。采用酶联免疫（enzyme-linked immunosorbent assay,ELISA）方法测定血浆炎症（TNF-α,IL-10和CRP）或者内皮损伤生物标记物（syndecan-1,SDC-1）；利用血红蛋白（Hb）稀释-时间曲线和尿量，使用Phoenix软件，采用非线性混合效应模型分析计算RL液体动力学参数和协变量的影响。结果:与胆囊炎组相比，阑尾炎组RL从组织间隙到血浆的转运速率常数（k21）显著降低（14×10-3min-1 versus 35×10-3min-1;P=0.012）。阑尾炎组C反应蛋白（CRP）升高［中位数38.1(1.8-143.6) μg/mL versus 1.3(0.1-159.0) μg/mL;P<0.001］；与清醒状态相比，麻醉期间（输液开始后30～45 min），液体从中央室中到外周室的转运速率常数（k12）显著增加（57×10-3min-1 versus 32×10-3min-1；P<0.01）。清除速率常数（k10）降低90%（0.6×10-3min-1 versus 5.3×10-3min-1;P<0.001）。无论在清醒状态还是麻醉状态下低血压均能降低液体清除；炎症或者内膜损伤的生物标记物不能作为显著影响RL液体动力学参数的协变量。结论:阑尾炎或者胆囊炎患者术前输入液体后“炎症反应的生物标记物”不是RL的液体动力学的协变量，但是两组患者中，全身麻醉期间输入液体的清除率下降。     

A new decomposition based evolutionary algorithm with uniform designs for many-objective optimization

For many-objective optimization problems, how to get a set of solutions with good convergence and diversity is a difficult and challenging work. In this paper, a new decomposition based evolutionary algorithm with uniform designs is proposed to achieve the goal. The proposed algorithm adopts the uniform design method to set the weight vectors which are uniformly distributed over the design space, and the size of the weight vectors neither increases nonlinearly with the number of objectives nor considers a formulaic setting. A crossover operator based on the uniform design method is constructed to enhance the search capacity of the proposed algorithm. Moreover, in order to improve the convergence performance of the algorithm, a sub-population strategy is used to optimize each sub-problem. Comparing with some efficient state-of-the-art algorithms, e.g., NSGAII-CE, MOEA/D and HypE, on six benchmark functions, the proposed algorithm is able to find a set of solutions with better diversity and convergence.     

我国突发性水资源污染事故应急机制的若干问题评述

基于突发性水资源污染事故应急处理现状的分析,对目前我国突发性水资源污染事故防范和应急机制的建立进行探讨,指出当前工作中的三大缺陷,并有针对性地提出如何加快防范突发性水资源污染事故以及建立相关应急机制的进程的若干措施,包括突发污染事故的隐患调查、脆弱性评价、水质预报、动态监测以及应急组织机构等方面,以期能为我国减少突发性水资源污染事故及其损失提供一定的理论分析依据。     

负离子功能针织物在直接蒸发冷却式空调中的应用

在分析负离子净化空气的原理及环境状况与空气中负离子浓度的关系基础上,应用负离子功能粘胶长丝和涤纶短纤混纺纱针织物作为空调滤材,利用空调出风(冷风)使针织物滤材试样飘动,相互拍击摩擦,使空调出风中的氧气分子和水分发生有效电离,从而产生大量空气负离子。实验结果表明,负离子功能粘胶长丝和涤纶短纤混纺纱针织物都有释放空气负离子的功能;而且在同规格纱线的平针组织、双罗纹组织、蜂巢组织和畦编组织针织物中,畦编组织针织物释放的负离子量最大;空气相对湿度对功能材料释放负离子数量有明显影响,当相对湿度在65%~70%时释放的负离子量趋于最大。     

基于双CPU结构的电能质量监测系统设计

电能质量的监测管理和电力污染的治理工作越来越重要。介绍以DSP TMS320F28335为数据处理核心和单片机C8051F340为调度控制核心的双CPU模式的电能质量监测系统的设计,实现对电网电能质量的实时监测和参数分析,为电能质量的监测管理和电力污染的治理提供可靠依据,与国内外同类产品相比,该系统具有较好的性价比。测试结果表明:该系统测量准确,符合国家关于电能质量的监测标准,可以广泛应用于各电力部门和大中型用电企业。     

基于.NET Remoting口令系统的设计

由于B/S模式下客户机对服务器的验证困难,提出了使用Remoting程序对网站的真伪进行验证。方案实现了客户端和服务器端的相互认证、服务器端敏感信息的安全存储和每次认证产生不同的会话密钥,安全分析表明,所提的方案能有效防范钓鱼网站等的常见攻击,增加了系统的安全性。方案使用.NET进行实现,证明是可行的。     

中、后期雨水收集分流优化

为提高传统雨水收集方法中的雨水调蓄能力,提出一种基于SWMM(Storm Water Management Model)的雨水分流优化方法。该方法在传统的初期雨水弃流工艺基础之上,依据分离器中水位与出口流量之间的关系,调节分离器中的雨水蓄留池出口和市政雨水管道出口之间的高差h来调整分流器的雨水削峰作用。依据分流器原理构建了优化方法的目标函数,并运用PSO(Particle Swarm Optimization)与SWMM相结合对目标函数进行求解进而获得不同降雨情景下的最优高差h,使得分离器在不同降雨情景下针对中、后期的降雨过程具有最佳的雨水削峰作用。研究结果表明:优化方法充分利用了雨水蓄留池的调蓄空间,将削峰作用最大化,与传统雨水收集方法相比,优化方法具有较好的雨水削峰效果,特别是在高重现期降雨下(20 a、50 a、100 a)的雨水峰值分别削减了44.76%、42.03%和40.77%。研究结果可以为城市雨水收集相关研究提供参考依据。     

含预制双裂纹试样岩桥贯通模式的数值研究

当双裂纹岩体破坏时,不同裂纹之间的应力场会相互作用,岩桥区域会发生贯通。将应变强度准则嵌入到二次开发的扩展离散元UDEC中,模拟了含预制双裂纹试样的拉伸裂纹及剪切裂纹的扩展。数值模拟结果发现双裂纹试样在单轴压缩过程中会出现4种岩桥基本贯通模式:（1）伴随着2条预制裂纹尖端的翼裂纹独立逐渐扩展,但岩桥区域不发生贯通的不贯通模式;（2）在岩桥区域内,主应力场及切应力场集中,产生剪切裂纹贯通岩桥,切应力对贯通起主导作用的剪切贯通模式;（3）在岩桥区域内,主应力场高度集中,岩桥贯通具有瞬时性,拉伸裂纹贯通岩桥的拉伸贯通模式;（4）在拉力与剪力共同作用下,试样达到强度最高峰值后产生的拉剪混合贯通模式。通过与室内试验对比,将应变强度准则运用到数值模拟分析中可以更准确描述细观破坏时应力应变及岩桥贯通的变化,丰富了多裂纹岩样在细观力学中的贯通机理,为研究岩体细观破坏提供数值模拟参考。