摘要：Broadband sound sink/absorber via a structure with deep sub-wavelength thickness is of great and continuing interest in physics and engineering *** intuitive technique extensively used is to combine components(resonators)with quasi-perfect absorption to piece together a broad absorbing band,but the requirement of quasi-perfect absorption substantially places a very strict restriction on the impedance and thickness of the ***,we theoretically and experimentally demonstrate that a compact broadband acoustic sink that quasi-perfectly absorbs broadband arriving sound waves can be achieved with coherently coupled‘‘weak resonances"(resonant sound absorbing systems with low absorption peaks).Although each component exhibits rather low absorption peak alone,via manipulating the coherent coupling effect among the components,they collectively provide a remarkably improved performance over a wide frequency range with a significantly compressed *** illustrate the design principle,a hybrid metasurface utilizing the coaction of parallel and cascade couplings is presented,which possesses an average absorption coefficient of 0.957 in the quasi-perfect band(a>0:9)from 870 to 3224 Hz with a thickness of only 3.9 *** results open new avenues for the development of novel and highly efficient acoustic absorbers against low frequency noise,and more essentially,suggest an efficient approach towards on-demand acoustic impedance engineering in broadband.

摘要：在无线传感器网络路由协议的设计中,传感器节点的监测数据要以多跳中继的方式向sink汇聚节点进行传输。在sink汇聚节点固定网络,临近sink汇聚节点的传感器节点需要中转其他节点的监测数据,从而耗费大量的电池能量,很容易造成过早地死亡,使网络的连通度下降,甚至会造成网络的分割,缩短了网络寿命。为了解决这一问题,从sink汇聚节点的角度,提出了一个基于sink汇聚节点移动的能量均衡的路由协议——SERP路由协议,通过sink汇聚节点的移动,使其附近的传感器节点不断地发生变化也就是网络内的"热点"不断地发生变化,从而促使传感器节点间的负载得到均衡,达到延长网络寿命的目的。在协议中,首先将无线传感器网络的监测区域分成有限个虚拟单元格,然后以每个单元格的中心作为sink汇聚节点的移动位置,最后通过线性规划确定sink汇聚节点在每个位置的停留时间。针对上述路由协议,对它进行了仿真分析,结果显示网络内节点的能量消耗比较高效均衡,有效地延长了网络寿命。

摘要：WSN和Adhoc统称为自组织网络,但WSN有不同于Ad hoc的技术要求和特征。WSN的最关键问题在于能量高度受限以及网络中节点的失效频繁等问题,这使得设计一个有效的路由算法协议成为近年研究无线传感器网络相关问题的热点。本文介绍了无线传感器网络的特点及路由设计中的关键因素。总结了层次结构划分下地几种路由算法,并给出了相应的改进。

摘要：在近日举行的“泰克公司HDMI设计和验证研讨会”上，泰克公司专家在现场为工程师演示了HDMI标准从sink端、Source端到cable和视频内容分析及验证的全系列测试解决方案。同时泰克还携手全球IT测试和验证咨询机构百佳泰（Allion ***），为从事领先串行数据测试的工程师分析并介绍了HDMI认证测试与流程。