移动通信机房基站绿色节能减排方法探讨

从2/3G共站建设、BBU+RRU分布式基站建设、替换机房G2 BSC、双密度载频应用、提高基站设备覆盖效率、DPS技术、AMR技术应用、移动网络IP化等方面入手,探讨通过网规网优实现移动通信机房基站节能减排的方法。     

三种小波及其在图象压缩中的比较

介绍了小波家族中张量积小波、非张量积小波以及向量小波的发展及其特点，并根据小波的特点设计了测试图象，使其更好的体现小波的特征，对它们在测试图象中的分解特点进行了比较，从而对这三种小波有一个全面的认识。『     

Structural and phase transformation behaviour of electroless Ni-W-Cr-P alloy coatings on stainless steel

Ni-W-Cr-P alloy coatings were prepared by electroless deposition on stainless steel. The effects of heat-treatment on the structure and phase transformation behavior, microhardness of the Ni-W-Cr-P alloy coatings were mainly investigated. XRD analysis shows that as-deposited Ni-W-Cr-P coatings were microcrystalline; the precipitation of Ni₃P was observed at the annealing temperature of 400°C; after heat-treatment at 500°C the crystallization of Ni₃P and Ni was near completion; at 600°C new phase Cr_1.12Ni_2.88 was observed and Ni₃P began to decompose. Cr_1.07Fe_18.93 and Ni₁₇W₃ were formed when heated at 700°C, and Ni₃P was not found. With increasing temperature to 800°C, FeNi₂P and Cr₄Ni₁₅W were the only two dominant phases. The experimental results reveal that with an increase in the annealing temperature, micro-hardness of the Ni-W-Cr-P alloy coatings increased, reached the maximum value at 700°C, and then decreased slightly. Annealing temperature dependence of the microhardness and corrosion resistance of the coatings was also observed. The related strengthening mechanism in the electroless deposited Ni-W-Cr-P alloy coatings is also discussed.     

基于润滑油光谱数据的发动机磨损部位识别

在分析发射光谱原始数据的基础上,提出了基于模糊聚类分析方法和灰色关联分析理论的发动机磨损部位识别方法,并通过一实例阐述了磨损部位识别的具体应用步骤。结果表明,用模糊聚类和灰色关联度分析方法进行基于润滑油光谱数据的故障部位识别能达到较高的准确率。     

浅析民用建筑机械防排烟系统问题及对策

探讨民用建筑机械防排烟系统设计、施工以及管理中存在的问题,提出了加强机械防排烟系统工程质量的对策,从而使防排烟设施发挥应有的作用,确保国家和人民的生命财产安全。     

Sliding mode control for a class of uncertain nonlinear system based on disturbance observer

In this paper, a sliding mode control (SMC) scheme is proposed for a class of nonlinear systems based on disturbance observers. For a nonlinear system, the disturbance that cannot be directly measured is estimated using a nonlinear disturbance observer. By choosing an appropriate nonlinear gain function, the disturbance observer can well approximate the unknown disturbance. Based on the output of the disturbance observer, an SMC scheme is presented for the nonlinear system, and the stability of the closed‐loop system is established using Lyapunov method. Finally, two simulation examples are presented to illustrate the features and the effectiveness of the proposed disturbance‐observer‐based SMC scheme. Copyright © 2009 John Wiley & Sons, Ltd.     

一种基于以太网的双单片机的应用实例

介绍一种采用AT89C52及SX52BD的双单片家用智能报警器。包含电话及语音报警、远程控制、图像及声音监控等诸多功能。该方案采用模块化设计，可方便地增减功能模块，具有易用性、高可靠性和优势的功能扩展性。     

确定性光学加工中抑制边缘效应的一种方法(英文)

在确定性光学抛光过程中,当加工到工件边缘时由于工艺条件发生变化会产生边缘效应,导致加工效率降低和面形误差增大.针对这种情况,提出了一种可修正边缘现象的球形工具抛光技术,其去除函数稳定性较好,形状趋于高斯分布且束径也较小,对修正边缘现象以及局部面形误差具有较好的效果.同时规划了其抛光路径,采用一种伪ρ-θ光栅扫描运动方式的加工路径,简化了球形抛光工具的结构,并且由于使加工纹路有了变化,可使加工后的表面纹理呈现无序性和均匀性特征,相应可提高加工后工件的表面质量.最后通过对一块微晶球面镜的加工(面形误差峰谷值PV由加工前1.607λ(λ=632.8 nm)收敛到加工后0.365λ,均方根值RMS由0.195λ收敛到0.024λ),验证了球形抛光工具具有修正边缘翘边现象的能力.     

铝合金覆盖件快速超塑成形技术的研究

快速超塑成形技术是将热冲压与超塑气胀相结合的一种技术,它利用热冲压的快速性和超塑性的良好成形性来解决铝合金冲压难成形和超塑成形慢的难题.在5083铝合金性能研究的基础上,采用该工艺对某车型引擎罩的成形进行了实验.结果表明,该工艺切实可行,并且生产效率较高.     

丰龙北翼风井井筒基岩段硬岩炮掘揭槽的改进

1 工程概况 丰龙北翼风井井筒由武汉设计院设计,由中煤河北煤炭建设第四工程处承建.井筒净直径Φ5.5 m,设计深度890.5m.按设计要求,丰龙北翼风井施工分为表土层冻结法施工、基岩段机械化施工方法进行施工. 基岩段深度785.5 m(标高:-64.5 m～-850 m),标高-247.5 m以上砼强度为C35,以下为C40.