基于小波变换的超声电机启动和关断特性的测试与分析

叙述了本研究中心研发的超声电机瞬态测试系统及其测试方法。由于噪声的影响，启动、关断响应曲线常常不太光滑，以往采用平滑技术和数字滤波等处理办法，获得启动和关断响应特性精度较差。本文利用小波变换对原始启动、关断响应数据进行分析，去除噪声，从而较准确地获得了超声电机启动和关断的响应时间。实验结果表明，超声电机确实具有毫秒级的响应时间。     

薄板坯连铸连轧技术在我国的确大有可为

对我国薄板坯连铸连轧技术2002年以后的发展进行了分析，认为今后将有更大的发展前景，并提出开发新一代薄板坯连铸连轧生产线的设想。     

浅谈仿生传感器

仿生学就是利用现有的科学技术把生物体或人的行为和思维进行部分模拟的行为。科学家和工程技术人员对人的种种行为如视觉、听觉、感觉、嗅觉和思维等进行模拟,研制了自动捕获信息、处理信息、模仿人类的行为装置——仿生传感器。本文就常见的仿生传感器的应用现状及前景作了较为全面的定性介绍。     

具有(k,r)-正交的(g,f)-因子分解的子图

研究了图的正交因子分解，通过构造函数p(x)和q(x)，证明了(mg k，mf-k)-图具有子图，该图有(g，f)-因子分解与kr-星(k，r)-正交，从而推广了原晋江教授的关于(mg m-1，mf-m 1)-图，存在(g，f)-因子分解与星(m，r)-正交的结论．     

Investigation of the copper concentration on photocurrent collection of CuInSe2 solar cells

In this study, CuInSe₂ (CISe) thin films were prepared from thermally evaporated Cu/In precursors, having various Cu/In atomic ratio, under the same selenization conditions. The precursors were converted into CISe absorber by annealing in a quartz tube furnace in the selenium vapours at substrate temperature of 500 °C. We developed four CISe films with Cu/In atomic ratio of 0.81–1.19, denoted as Cu‐very rich, Cu‐rich, Cu‐poor, and Cu‐very poor CISe thin films respectively. The effects of Cu/In atomic ratio on grain size, surface morphology, micro‐structure and defect formation of the resulting CISe films were examined. It has been found that the photovoltaic properties were strongly related to Cu concentration, as well as carrier transport mechanism. Defects at the surface and in the bulk of CISe thin films were observed using X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy, Raman spectroscopy, energy dispersive X‐ray spectroscopy and scanning electron microscopy. Moreover, XRD revealed that the CISe film surface had a preferred orientation along the (112) plane. The XRD intensity and full width at half maximum of the (112) plane of CISe varied according to the Cu/In atomic ratio. Our experimental results show that the Cu‐rich solar cell achieves conversion efficiency of 4.55% and exhibits an exceptional high short‐circuit current density. Copyright © 2016 John Wiley & Sons, Ltd.     

FDTD simulations on radar cross sections of metal cone and plasma covered metal cone

Electromagnetic wave interaction with a plasma covered metal surface has been studied using the Radar Cross Section (RCS) changes of a 10 cm diameter and 30 cm height metal cone with and without plasma coverage. A Finite-Difference-Time-Difference (FDTD) method was use to calculate the case of a cone with and without a covering of a 1 cm thick sheet plasma for both S Band (2,3, and 4 GHz) and X Band (8, 10, and 12 GHz) frequencies. The characteristic plasma frequency ω_pe was set at 10 GHz, and electron-neutral collision frequency ν_en chosen to be 20 GHz. The results indicate that the metal cone has very small RCS at head-on direction, and a large RCS looking from the back end. A Plasma covered metal cone was shown to achieve head-on direction monostatic RCS changes between −0.47 and −7.2 dBm² from 2 to 4 GHz, and −11 to −3.2 dBm² RCS changes from 8 to 12 GHz, but at the back end the RCS increases between 2.2 and 2.6 dBm² from 2 to 4 GHz, and varies between −0.9 and 0 dBm² from 8 to 12 GHz. In the two frequency bands investigated, maximum RCS reduction of −15 dBm² occurs at 8 GHz at the same direction as the incident electromagnetic wave polarization. Plasma stealth offers advantages like frequency tunability, but the challenge is establishing an adaptive feedback mechanism that can main a constant plasma density and thus a constant RCS by adjusting the power supplied to plasma generator while monitoring the changes in air speed, altitude, and humidity.     

某原煤预均化堆场基础不均匀沉降分析及处理

<正>1工程场地概况工程位于白银市白银区王岘街道东涧沟下游北岸,厂址地处陇西旋卷构造体系与河西构造体系交汇地带,属于北祁连优地槽褶皱带。区域褶皱、断裂走向以北西西向为主,其次为北北东向。主要断裂:西湾—苏家湾断裂,自西南距评估区约800 m的洪沟穿过,断层长约30km,走向300°左右,断层面倾向东北,倾角40°~85°,清楚可见奥陶系地层斜冲于三叠系地层之上,断层泥宽1~3 m,为压扭性断裂;东     

市政道路综合改造设计思路及要点综述

近年来,随着我国经济快速增长和城市化进程加快,城市人口和车辆也不断增加,我国城市交通面临着越来越艰巨的任务,城市交通拥堵、交通安全和环境污染问题日益受到人们的重视。特别是一些位于老城区内的市政道路,经过较长年代的运营,道路运行状况出现了种种问题,因此这些市政道路综合改造就被提上议程。本文依托衢州市市政道路综合改造项目建设实践,阐述了道路综合改造设计中的设计思路及要点。     

Morphology‐dependent electrochemical performance of nitrogen‐doped carbon dots@polyaniline hybrids for supercapacitors

In this work, the binary N‐CDs@PANI hybrids were fabricated by introducing zero‐dimensional nitrogen‐doped carbon dots (N‐CDs) into reticulated PANI. Firstly, N‐CDs were prepared by one‐pot microwave method, and then, the N‐CDs were introduced into in situ oxidative polymerization of aniline (ANI) monomer. The N‐CDs with abundant functional groups and high electronic cloud density played a significant role in guiding the polyaniline‐ordered growth into intriguing morphologies. Moreover, morphology‐dependent electrochemical performances of N‐CDs@PANI hybrids were investigated and N‐CDs improve static interaction and enhance the special capacitances in the N‐CDs@PANI hybrids. Especially, the specific capacitance of PC4 hybrid can reach 785 F g^?1, which exceed that of pure PANI (274 F g^?1) at current density of 0.5 A g^?1 according to three‐electrode measurement. And the capacitance retention of the PC4 hybrid still keeps 70% after 2000 cycles of charge and discharge. The N‐CDs@PANI hybrids can have potential applications in electrode materials, supercapacitors, nonlinear optics, and microwave absorption.     

A fast IP lookup scheme for high speed routers

Abstract

One of the key design issues for the next generation of IP routers is the IP lookup mechanism. IP lookup is an important action in a router, that is, to find the next hop for each incoming packet with a longest‐prefix‐match address in the routing table. In this paper, we propose an IP lookup mechanism with the number of memory accesses for an IP lookup being one in the best case and being four in the worst case. The forwarding table needed by our mechanism is small enough to fit in the SRAM. For example, a large routing table with 40000 routing entries can be compacted to a forwarding table of 260KBytes in our scheme.