顶管法在灌渠改线工程中的应用

水利工程布置与已建建筑物的交叉,一定要慎重地选择方案,既要考虑工期又要考虑施工对周边带来的影响。文章介绍的顶管法是一种现代化的管道敷设方法,介绍了该案提出的缘由及工程设计要点,以供类似工程参考。     

求实创新 真抓实干──全省各地贯彻总队工作会议情况综述

全省消防工作会议结束后，各支队及时召开党委会、办公会，结合实际情况，研究贯彻措施，拿出具体意见，向地方党委、政府、公安处（局）领导汇报，召开支队工作会议。党委、政府和公安处（局）对贯彻全省消防工作会议非常重视，不少市地的书记、市长（专员）、公安处（局）长、政委都亲自出席会议，作重要指示。部分地市还以政府名义召开消防工作会议，主管安全工作的县、市（区）长参加了会议，规模之大，规格之高，都是前所未确的。从各地贯彻总队会议情况看主要有以干几个特点：一、指导思想明确，工作思路清楚。按照总队的总体要求，各…     

重庆北部新区EBD园区发展过程研析

从EBD园区实际开发建设角度出发,着重回答EBD园区发展的指导思想,发展的特点和原因,发展过程中阶段性问题,以及发生机制,找出转型的客观需求,最后对可持续发展过程中经验、教训、规律和方法进行总结。     

考虑安装误差的减变速一体化齿轮齿面接触分析

减变速一体化齿轮是一种圆与非圆相匹配、可以实现减速与变速集成传动的新型齿轮机构。基于齿轮啮合理论,推导了减变速一体化齿轮的齿面方程,建立了考虑轴交角、轴交错、轴向偏移3种安装误差的齿面接触模型,分析了齿面接触轨迹的分布特征,得到节曲线参数和安装误差对齿面点接触轨迹的影响规律。分析结果表明,非圆面齿轮每个轮齿上接触迹线的倾斜度随传动比变化率增大而增大,安装误差使接触轨迹向外径或内径处偏移,移动方向由误差方向而定。     

Interactions between multiple filaments and bacterial biofilms on the surface of an apple

In this paper, the interactions between two dielectric barrier discharge(DBD) filaments and three bacterial biofilms are simulated. The modeling of a DBD streamer is studied by means of 2D finite element calculation. The model is described by the proper governing equations of air DBD at atmospheric pressure and room temperature. The electric field in the computing domain and the self-consistent transportation of reactive species between a cathode and biofilms on the surface of an apple are realized by solving a Poisson equation and continuity equations. The electron temperature is solved by the electron energy conservation equation. The conductivity and permittivity of bacterial biofilms are considered, and the shapes of the bacterial biofilms are irregular in the uncertainty and randomness of colony growth. The distribution of the electrons suggests that two plasma channels divide into three plasma channels when the streamer are 1 mm from the biofilms. The toe-shapes of the biofilms and the simultaneous effect of two streamer heads result in a high electric field around the biofilms, therefore the stronger ionization facilitates the major part of two streamers combined into one streamer and three streamers arise.The distribution of the reactive oxygen species and the reactive nitrogen species captured by time fluences are non-uniform due to the toe-shaped bacterial biofilms. However, the plasma can intrude into the cavities in the adjacent biofilms due to the μm-scale mean free path. The two streamers case has a larger treatment area and realizes the simultaneous treatment of three biofilms compared with one streamer case.     

川东北裂缝性碳酸盐岩气层钻井完井保护技术

为实现高酸性裂缝性碳酸盐岩气藏的安全钻井和气层的及时发现,以四川盆地川东北探区碳酸盐岩储层为研究对象,开展了钻井完井随钻暂堵堵漏及储层保护技术的研究.现场资料、X衍射及SEM分析表明,研究区H2S与CO2体积分数高,敏感矿物发育,井漏等钻井安全事故频发,储层损害十分严重,影响了探区天然气勘探开发的进程.针对储层及钻井安...     

浪鲸卫浴郑州推出董事长签售活动

本刊讯9月10日，浪鲸卫浴在郑州推出董事长签售活动。浪鲸卫浴董事长携带比平时进货价更低的厂家直通价，直飞郑州亲自签售。     

北京市房地产建设项目雨洪利用模式及评价研究

根据北京降雨特征与水土流失特点,分析阐述了北京市房地产建设项目普遍采用的雨水集蓄利用的集雨池、下凹式绿地、透水砖以及渗水沟、渗水井等多种方式,对不同模式的特点进行分析研究,提出不同模式的适用方式,探讨北京市生产建设项目雨洪集蓄利用的适宜模式。