Regulating the Water Molecular in the Solvation Structure for Stable Zinc Metal Batteries

Rechargeable aqueous zinc batteries are promising energy storage devices because of their low cost, high safety, and high energy density. However, their performance is plagued by the unsatisfied cyclability due to the dendrite growth and hydrogen evolution reaction (HER) at the Zn anode. Herein, it is demonstrated that the concentrated hybrid aqueous/non-aqueous ZnCl₂ electrolytes constitute a peculiar chemical environment for not only the Zn-ions but also water molecules. The high concentration of chloride ions substitutes the H₂O molecular in the solvation structure of Zn²⁺, while the acetonitrile further interacts with H₂O to decrease its activity. The hybrid electrolytes both inhibit the dendrite formation and HER, enabling an ultrahigh average Coulombic efficiency of 99.9% in the Zn||Cu half-cell and a highly reversible Zn plating/stripping with a low overpotential of 21 mV. Using this hybrid electrolyte, the Zn||polytriphenylamine (PTPAn) full cell deliveres a high discharge capacity of 110 mAh g⁻¹, a high power density of 9200 W kg⁻¹ at 100 °C and maintains 85% of the capacity for over 6000 cycles at 10 °C. This study provides a deep understanding between the solvation structure and columbic efficiency of Zn anode, thus inspiring the development for stable Zn batteries.     

管道生产信息网络拓扑分析及改进

随着数字管道的建设和发展,信息网络是实现生产管理智能化、事务处理自动化、数据共享远程化不可或缺的纽带和基础设施。针对某管道储运企业的网络建设情况,通过网络拓扑结构可靠性分析,从连通性和结合度的角度,对网络可靠性进行探讨,查找影响网络可靠运行的链路连通问题。在综合考虑投资与效益等因素,提出了基于原有拓扑结构,适当增加链路冗余,配置路由策略等改进措施,停机断网次数减少,有效地控制网络碎片产生,取得了明显的效果。     

基于多业务QoS服务的拓扑控制算法研究

随着无线网络技术的不断发展,无线Ad hoc网络中,快速变化的网络拓扑影响着网络的性能。因此,在实现网络能量优化的前提下,如何提供有效的QoS服务来满足多业务要求是无线Ad hoc网络所必须面对的问题。针对此问题,提出了一种基于多业务需求的拓扑控制的方法,该方法考虑业务QoS指标的同时引入跨层的设计思想,实现了跨层的功率控制,减少了网络中节点的能量消耗,延长了网络的生命周期。     

New algorithm for hub-and-spoke topological virtual networks embedding problem

The virtual network embedding/mapping problem is a core issue of the network virtualization.It's mainly concerned with how to map virtual network requests to the substrate network efficiently.Previous ...     

Throughput Scalability of Wireless Hybrid Networks over a Random Geometric Graph

In this paper, we consider the transport capacity of ad hoc networks with a random flat topology under the present support of an infinite capacity infrastructure network. Such a network architecture allows ad hoc nodes to communicate with each other by purely using the remaining ad hoc nodes as their relays. In addition, ad hoc nodes can also utilize the existing infrastructure fully or partially by reaching any access point (or gateway) of the infrastructure network in a single or multi-hop fashion. Using the same tools as in [9], we show that the per source node capacity of Θ(W/log(N)) can be achieved in a random network scenario with the following assumptions: (i) The number of ad hoc nodes per access point is bounded above, (ii) each wireless node, including the access points, is able to transmit at W bits/sec using a fixed transmission range, and (iii) N ad hoc nodes, excluding the access points, constitute a connected topology graph. This is a significant improvement over the capacity of random ad hoc networks with no infrastructure support which is found as in [9]. We also show that even when less stringent requirements are imposed on topology connectivity, a per source node capacity figure that is arbitrarily close to Θ(1) cannot be obtained. Nevertheless, under these weak conditions, we can further improve per node throughput significantly. We also provide a limited extension on our results when the number of ad hoc nodes per access point is not bounded.Ulaş C. Kozat was born in 1975, in Adana, Turkey. He received his B.Sc. degree in Electrical and Electronics Engineering from Bilkent University, Ankara, Turkey and his M.Sc. in Electrical Engineering from The George Washington University, Washington D.C. in 1997 and 1999 respectively. He has received his Ph.D. degree in May 2004 from the Department of Electrical and Computer Engineering at University of Maryland, College Park. He has conducted research under the Institute for Systems Research (ISR) and Center for Hybrid and Satellite Networks (CSHCN) at the same university. He worked at HRL Laboratories and Telcordia Technologies Applied Research as a research intern. His current research interests primarily focus on wireless and hybrid networks that span multiple communication layers and networking technologies. Mathematical modelling, resource discovery and allocation, vertical integration of wireless systems and communication layers, performance analysis, architecture and protocol development are the main emphasis of his work. E-mail: kozat@isr.umd.eduLeandros Tassiulas (S′89, M′91) was born in 1965, in Katerini, Greece. He obtained the Diploma in Electrical Engineering from the Aristotelian University of Thessaloniki, Thessaloniki, Greece in 1987, and the M.S. and Ph.D. degrees in Electrical Engineering from the University of Maryland, College Park in 1989 and 1991 respectively.He is Professor in the Dept. of Computer and Telecommunications Engineering, University of Thessaly, Greece and Research Professor in the Dept. of Electrical and Computer Eng and the Institute for Systems Research, University of Maryland College Park since 2001. He has held positions as Assistant Professor at Polytechnic University New York (1991–95), Assistant and Associate Professor University of Maryland College Park (1995–2001) and Professor University of Ioannina Greece (1999–2001).His research interests are in the field of computer and communication networks with emphasis on fundamental mathematical models, architectures and protocols of wireless systems, sensor networks, high-speed internet and satellite communications.Dr. Tassiulas received a National Science Foundation (NSF) Research Initiation Award in 1992, an NSF CAREER Award in 1995 an Office of Naval Research, Young Investigator Award in 1997 and a Bodosaki Foundation award in 1999 and the INFOCOM′94 best paper award. E-mail: leandros@isr.umd.edu     

基于拓扑序列法的灰色航迹关联方法

为了解决组网雷达存在系统偏差情况下的航迹关联问题,提出了基于拓扑序列法的灰色航迹关联方法。首先,采用灰色理论生成当前时刻目标拓扑序列的灰色关联矩阵,并建立航迹间的相关度量;然后,运用全局最优化方法对相关度量矩阵进行最优化分配获得航迹关联对。该算法采用全局最优化方法避免了门限选择不当对正确关联概率带来的影响,有效地利用了航迹的空间分布信息和状态信息。仿真结果表明,该算法可以有效地实现系统偏差情况下的航迹关联。     

传感器网络节点定位精度的几何稀释分析

通过分析时间到达(Time of Arrival,TOA)算法的定位原理,利用定位精度的几何稀释(Geometrical Dilution ofPrecision,GDOP),描述定位误差与锚节点群几何布局关系,并给出基于测距的算法中GDOP的计算方法。采用蒙特卡罗仿真方法,仿真次数100,设定锚节点的测距误差相同,取锚节点数为3、5,对基于锚节点群内点、外点的未知节点定位误差的归一化GDOP值和GDOP均值求解,结合质心算法原理,验证了自身节点定位精度与确定该节点位置的锚节点的几何关系密切相关,得到锚节点群内点定位精度高的结论。     

Ad hoc网络安全与攻击探讨

介绍了Ad hoc网络的体系结构和特点,分析了其存在的网络安全问题,总结了对Ad hoc网络的多种攻击方法,并提出了几种改善Ad hoc网络安全的策略。     

中国IP级网络拓扑测量与分析

以建立中国IP级网络拓扑图景为目标，首先评价了传统的目标抽样法，提出了3项改进技术，并测量了中国网络，然后运用复杂网络研究方法提取并比较分析了拓扑特征，最后采用IP2AS技术统计了自治域规模。结果表明，传统目标抽样法将丢失大量信息，改进技术在保持完整性的同时降低约一半负载。获得新的中国拓扑规模5倍于CAIDA的skitter。新拓扑与skitter拓扑相比，呈现更显著的非相称性、更弱的聚集、更短的距离、更不均衡的节点流量分布。发现了中国自治域规模的重尾分布。     

一种厚膜混合集成结构的温度控制电路

为了实现小体积、高可靠性的温度控制,设计了一种厚膜混合集成的温度控制电路,它通过控制热电致冷器（TEC）电流的方向和大小,将激光器管芯的温度控制在一个恒定的值上,实现了稳定激光器波长、控制波长精度、提高光纤陀螺的精确度和稳定度的目的。电路采用厚膜工艺制造,全裸芯片和表面贴装元件组装,缩小了体积,提高了可靠性。经实际应用,该电路不仅安全可靠地实现了温度控制功能,而且能在恶劣的使用环境下安全工作,适合军、民两用;