首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   138篇
  免费   0篇
  国内免费   1篇
电工技术   1篇
综合类   7篇
化学工业   30篇
金属工艺   6篇
机械仪表   12篇
建筑科学   9篇
矿业工程   2篇
能源动力   3篇
轻工业   1篇
水利工程   1篇
石油天然气   3篇
武器工业   1篇
无线电   1篇
一般工业技术   8篇
冶金工业   44篇
原子能技术   1篇
自动化技术   9篇
  2023年   1篇
  2021年   1篇
  2020年   2篇
  2018年   1篇
  2017年   2篇
  2015年   2篇
  2014年   3篇
  2013年   3篇
  2012年   3篇
  2011年   11篇
  2010年   13篇
  2009年   5篇
  2008年   8篇
  2007年   7篇
  2006年   14篇
  2005年   8篇
  2004年   10篇
  2003年   9篇
  2002年   11篇
  2001年   2篇
  2000年   5篇
  1999年   2篇
  1998年   2篇
  1997年   2篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1989年   1篇
  1988年   1篇
  1986年   1篇
  1985年   1篇
  1982年   1篇
排序方式: 共有139条查询结果,搜索用时 15 毫秒
1.
油气输送管线冰堵定位检测技术的开发与应用   总被引:4,自引:0,他引:4  
马秋宁  蔡有军  王学军 《当代化工》2003,32(3):137-139,168
冬季油气输送管线的冰堵时刻威胁着高寒地区石油化工装置的安全运行,带式传感器动态应变定位检测技术的研制与开发解决了这一难题,它能迅速而准确地查找冰堵点,从而保证炼化装置的冬季正常运行。  相似文献   
2.
八面河油田水平井水平井段长、储层非均质性严重,在酸化处理中,井段均匀布酸困难,酸化效果不佳。根据在全井段均匀分配酸化液的原则,对水平井均匀酸化管柱进行优化,采用"大酸量、大排量、及时返排"的工艺措施,可有效解除水平井段地层污染堵塞,沟通地层裂缝,使水平井的酸化处理效果得到明显改善和提高。  相似文献   
3.
玻璃钢管具有质量轻、承受压力高、耐腐蚀、不易结垢、施工简便、使用寿命长的优点。从2000年起,江汉油田将高压玻璃钢管线广泛应用于注水系统和污水处理系统,收到了良好的效果。在生产过程中,由于受外部损伤、施工质量、玻璃性能等因素的影响,漏失现象时有发生。针对这种情况,可采取切割造锥,利用钢制转换接头连接、管沟回填等措施进行解决,以规范施工工艺,保证质量和安全生产。  相似文献   
4.
邹左英  杜菊 《辽宁化工》1997,26(3):147-149
烷基苯的磺化是制造阴离子表面活性剂的关键工序之一。本文重点介绍了采用国内消化吸收的意胡利Ballestra公司多管膜多磺化法生产烷基苯碘酸的技术,该技术工艺流程合理,设备结构简单,能耗低,产品质量好,不但适应于烷基苯的磺化,还可用于脂肪醇,脂肪醇聚氧乙烯醚等多种原料的磺化。  相似文献   
5.
In order to prevent traffic accidents on snow-covered bridge decks, the writers developed a new pipe heating system that uses only groundwater stored in a large underground tank. The underground tank provides geothermal energy, i.e., groundwater of constant temperature, through heating pipes embedded in concrete pavements with no electric heater or fuel boiler. The pipe heating system was constructed at approximately 50% of the cost of comparable systems. In addition, there is a reduction of 10% in operating costs compared with the previous system. The present paper outlines its design and construction and provides fundamental data for the developed system. The piped heating system has kept the road conditions safe during the winter season by always removing the snow and ice from the heated road and bridge sections earlier than the surrounding roads. According to long-term temperature measurements, this system has prevented the road temperature from decreasing below 0°C, even through nighttime and morning periods. This report presents the system as an economical and effective solution for snow thawing and ice prevention.  相似文献   
6.
Scaling often leads to a series of technical and economical problems in industrial plants and equipments by blocking water flow in pipes or limiting heat transfer in heat exchangers. While most contemporary studies are focusing on crystallization at heat‐exchanger surfaces and scaling on nanofilters in desalination plants, very little work has been done investigating scale formation on pipe and vessel walls. A comprehensive investigation of the effects of various process parameters in controlling the formation of calcium sulfate scale in pipes was undertaken. Supersaturation ratio, run time, and operational hydrodynamics were altered systematically to determine their influence on the scale growth rate. The results confirmed that the deposition of gypsum on pipe walls was significantly affected by these process parameters.  相似文献   
7.
Organic contaminants may permeate through plastic pipes in water distribution systems and adversely affect the quality of drinking water. In this study, we developed a microscopic visualization technique to investigate the permeation of common organic contaminants (benzene, toluene, ethylbenzene, xylene, and trichloroethene) through polyvinyl chloride (PVC) pipes. By observing the propagation of organic moving fronts in the pipe materials with a light microscope, the technique was able to predict the permeation breakthrough times through PVC pipes that were determined in the pipe-bottle test. The advance of an organic moving front was found to be linearly dependent on the square-root of time and the propagation rate increased with an increase in the external organic chemical activity. Permeation of organic mixtures into PVC pipes was found to be additive in proportion to the permeation rates and volume percents of each component. In combination with a 2-year pipe-bottle test for PVC pipes exposed to premium gasoline, mathematical extrapolations based on the microscopic visualization tests predicted that PVC pipe are likely to resist permeation by commercial gasoline for the service life of the pipe.  相似文献   
8.
本文通过试验研究,找出了碱液蒸发缶换热管腐蚀的原因,并指出其防护途径和具体措施。  相似文献   
9.
An accurate, simple, and efficient approximation to the Vardy–Brown unsteady friction equation is derived and shown to be easily implemented within a one-dimensional characteristics solution for unsteady pipe flow. For comparison, the exact Vardy–Brown unsteady friction equation is used to model shear stresses in transient turbulent pipe flows and the resulting waterhammer equations are solved by the method of characteristics. The approximate Vardy–Brown model is more computationally efficient (i.e., requires one-sixth the execution time and much less memory storage) than the exact Vardy–Brown model. Both models are compared with measured data from different research groups and with numerical data produced by a two-dimensional turbulence waterhammer model. The results show that the exact Vardy–Brown model and the approximate Vardy–Brown model are in good agreement with both laboratory and numerical experiments over a wide range of Reynolds number and wave frequencies. The proposed approximate model only requires the storage of flow variables from a single time step while the exact Vardy–Brown model requires the storage of flow variables at all previous time steps and the two-dimensional model requires the storage of flow variables at all radial nodes.  相似文献   
10.
The nonsteady‐state gas‐particle flows in pipelines are considered. Chaotically moving particles are described as granular gas characterized by granular temperature. This temperature dissipates because of partially inelastic particle collisions with the wall, with each other and also because of the particle viscous friction with gas. The energy losses on a microscale are translated into the pressure losses on a macroscale. The model developed is validated for both steady‐state and nonsteady‐state regimes by comparing calculated pressure losses with experimental data. A detailed numerical study of the nonsteady‐state flows shows that the pipe wall roughness is a major parameter affecting the pressure drop. Flow regimes for different particle elastic properties, particle sizes, and solids loading are studied.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号