频域自适应陷波器抑制罗兰C中窄带干扰技术

目前罗兰C接收机采用固定频率点的模拟陷波器抑制窄带干扰,针对固定频率点的模拟陷波器在抑制窄带干扰方面的缺陷,提出将频域自适应陷波器应用于罗兰C窄带干扰的抑制,克服了时域自适应陷波器收敛慢等缺点.通过仿真,此陷波器具有较好的抑制窄带干扰的能力.     

既有铁路客运站次生环境影响分析

通过现场调研、测试，研究既有铁路客运站周边地区的环境质量状况，主要剖析区域噪声、大气温度水平等。结合站点周边区域的土地利用情况、人口分布状况、机动车流量等相关因素，分析不同规模铁路车站周边区域环境质量的次生影响。     

基于PWS-1409的便携式测控系统

本文介绍了基于PWS-1409的便携式测控系统的原理、特点、硬件构成和软件设计。该系统采用研华公司的PCI-1710、PCLD-885板和ActiveDAQ软件构成。试验证明该系统具有较高的通用性、灵活性和稳定性。     

条码解码系统DSS的硬件设计

给出了具有语音功能的条码解码系统ＤＳＳ的硬件设计。该条码解码系统具有良好的人机界面。     

建设世界城市给北京市交通管理工作带来的机遇与挑战

北京建设世界城市目标的提出,为交通管理工作搭建了全新平台。世界城市具有国际金融中心、决策控制中心、国际活动聚集地、信息发布中心和高端人才聚集中心等显著特征,这些特征的达成为交通管理工作提出了更高要求,为一些长期存在的交通难点提供了破解契机。从机遇与挑战两个方面加以分析,具体提出了一些应对策略,以期对世界城市交通管理发展战略研究有所裨益。     

浅谈国有大中型施工企业的人力资源管理

研究目的:在建筑市场竞争日趋激烈的情况下,为满足市场变化的需要,增强企业核心竞争力,提高人力资源管理水平,结合国有施工企业的现状,从组成、布局、策划、劳务等多方面对人力资源管理现状进行分析。研究方法:从战略规划、人才选择、绩效管理、薪酬管理、培训与发展等方面找问题,查原因,认为目前国有大中型施工企业人力资源管理关键缺乏战略性规划与牵引,缺乏标准制定,缺乏整体性设计与执行,缺乏职业化管理者。研究结果:根据企业实际情况,提出了整体改进思路,从优化人才结构、提升人才素质、实现人才价值、开发人才高地、创新人才机制、优化人才环境等环节详细论述,并提出了切实可行的解决途径。研究结论:国有施工企业必须加强人才结构调整,以开发存量资源、提高现有人才素质为主,完善选拔机制、激励机制。     

A comparative analysis of the European and North-American approaches to dealing with major oil spills

Background  

The question of what should be the right level of preparedness to react to a major oil spill (i.e. the EXXON VALDEZ spill, the ERIKA spill, and the PRESTIGE spill) is highly debated, especially in the aftermath of such spills. Little research, however, has been conducted with the aim to identify and compare governments’ best practices not only to fund preparedness measures but also to assess the countries’ ability to respond effectively to catastrophic oil spills. It is the author’s belief that important lessons can be learnt from a comparative analysis of countries’ best practices.     

浅谈如何搞好班组管理

简述了班组管理对企业发展的重要性,认为提高班组管理水平必须做好挑选合格班组长、搞好班组制度建设、巧用团队力量、规范有效措施、及时了解员工思想动态等方面的工作。     

Numerical analysis of crack under compression by 3D displacement discontinuity method

A 3D displacement discontinuity method is applied to solve the fracture mechanics problems of the mixed mode crack under compression. Friction between the surface of the closed crack is considered by establishing a simple and efficient iterative algorithm based on method of contact resistance mitigation. On the surfaces of the closed crack, the Mohr-coulomb rule is satisfied by iteration when the crack is in condition of sliding. The stress intensity factors are obtained using displacement fitting method. It is shown that the numerical results agree with the experimental results well and that friction plays an important role in resisting crack propagation.     

Experimental study on the liquid slug of cryogenic slug flow in inclined tubes

An experimental study was carried out to understand the phenomena of the boiling flow of liquid nitrogen in inclined tubes with closed bottom by using a high speed motion analyzer.The experimental tubes are 0.018 and 0.014 m inner diameter(ID) and 1.0 m in length.The range of the inclination angle is 45°-90° from the horizontal.The experimental observation on the liquid slug was carried out along the tubes.Statistical method was employed to analyze the experimental data.The experiment analyzed the influences of the inclination angle and the tube diameter on the liquid slug length and velocity.The results show the liquid slug propagation velocity increases with the decrease of inclination angle θ.For all cases,the maximum values of the mean liquid slug lengths were obtained at θ = 60°.The mean liquid slug lengths were greater for large tube at higher tube position.These conclusions provide a basis for further study liquid slug of cryogenic two-phase undeveloped slug flow.