首页 | 官方网站   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   7513篇
  免费   787篇
  国内免费   303篇
工业技术   8603篇
  2024年   21篇
  2023年   94篇
  2022年   167篇
  2021年   218篇
  2020年   202篇
  2019年   178篇
  2018年   179篇
  2017年   198篇
  2016年   245篇
  2015年   231篇
  2014年   482篇
  2013年   420篇
  2012年   479篇
  2011年   532篇
  2010年   455篇
  2009年   423篇
  2008年   408篇
  2007年   476篇
  2006年   454篇
  2005年   385篇
  2004年   325篇
  2003年   294篇
  2002年   266篇
  2001年   239篇
  2000年   216篇
  1999年   175篇
  1998年   137篇
  1997年   140篇
  1996年   77篇
  1995年   80篇
  1994年   79篇
  1993年   61篇
  1992年   66篇
  1991年   32篇
  1990年   28篇
  1989年   36篇
  1988年   27篇
  1987年   17篇
  1986年   16篇
  1985年   11篇
  1984年   9篇
  1983年   4篇
  1982年   5篇
  1980年   3篇
  1979年   1篇
  1978年   2篇
  1976年   1篇
  1975年   1篇
  1951年   8篇
排序方式: 共有8603条查询结果,搜索用时 15 毫秒
11.
介绍了内蒙古海吉氯碱化工股份有限公司6万t/a离子膜烧碱装置一次盐水设备的运行情况和运行过程中存在的问题及相应的技改措施.  相似文献   
12.
The miscibility and phase behavior of ternary blends containing dimethylpolycarbonate (DMPC), tetramethylpolycarbonate (TMPC) and poly[styrene‐co‐(methyl methacrylate)] copolymer (SMMA) have been explored. Ternary blends containing polystyrene (PS) instead of SMMA were also examined. Blends of DMPC with SMMA copolymers (or PS) did not form miscible blends regardless of methyl methacrylate (MMA) content in copolymers. However, DMPC blends with SMMA (or PS) blends become miscible by adding TMPC. The miscible region of ternary blends is compared with the previously determined miscibility region of binary blends having the same chemical components and compositions. The region where the ternary blends are miscible is much narrower than that of binary blends. Based on lattice fluid theory, the observed phase behavior of ternary blends was analyzed. Even though the term representing the Gibbs free energy change of mixing for certain ternary blends had a negative value, blends were immiscible. It was revealed that a negative value of the Gibbs free energy change of mixing was not a sufficient condition for miscible ternary blends because of the asymmetry in the binary interactions involved in ternary blends. Copyright © 2004 Society of Chemical Industry  相似文献   
13.
The main objective of the present work is to modify the traditional mapping method for the simulation of distributive mixing of multiphase flows in geometries involving moving parts such as, internal mixers or twin-screw extruders without a limitation on their geometrical periodicity. The periodicity condition, limits the results of traditional mapping method to tracking mapping mesh between specific discrete time intervals or distances for that geometry is repeated, hence, result is only for fixed orientation of rotors. Imaginary domain method is introduced to track mapping mesh from one state to the next free of geometrical periodicity limitations. In this work the method is introduced and its applicability and accuracy is discussed in details. A two-dimensional (2D) simulation of mixing of two Newtonian fluids with different viscosities in an intermeshing internal mixer is used as a test case study. In this example the key issues of ability to predict mixing state in details for all orientations of rotors is presented. To reduce diffusion errors of mapping method in the boundaries of the rotors, mapping mesh refinement technique that relies upon one single reference mesh is also presented.  相似文献   
14.
This paper investigates the effects of processing and equipment parameters of a ribbon blender (i.e. loading method of lubricant, fill level, blade speed and blade design) on magnesium stearate homogeneity. A core sampling technique is used to obtain at least one hundred samples per sampling event, which are extracted throughout the blender and yield a thorough characterization of the entire bed. The results presented here can be used as a guideline to develop appropriate blending processes and characterization protocols for ribbon blenders.  相似文献   
15.
边坡支护中多种技术措施的综合应用   总被引:1,自引:0,他引:1  
原艳 《山西建筑》2007,33(5):120-121
通过工程实例,介绍了锚杆喷射混凝土支护技术与高压喷射混凝土搅拌桩支护技术在工程中的综合利用,同时也验证了该技术的可行性及经济性。  相似文献   
16.
Here, we describe the development of a reacting flow multi-species/combustion methodology, implemented as an extension to the differential reduced ejector analysis (DREA) computer program [Mathematical and computer modeling, vol. 31, 2000, p. 21; Appl. Math. Model. 25 (2001) 427; Comput. Math. Appl. 43(10–11); NASA Contractor Report, 1998]. Use of the single fluid IVP solver framework that was developed for the original DREA model has been directly coupled into the combustion formulation. With these modifications, the analysis has an elementary single step reaction Fuel+Oxidizer→Product combustion capability. Though approximate in nature, the simplicity and efficiency of the DREA formulation make it suitable for its original niche, namely design and preliminary design environments where more complex and expensive models may be inappropriate.  相似文献   
17.
介绍画中画插入播出器的工作原理及设计思想,并给出了实际的电原理图。  相似文献   
18.
Turbulence represents an essential aspect in atmospheric and oceanic circulations.In particu-lar,it is a preponderant factor in the dispersion of pollutants of artificial or natural origin.Thevertical turbulent jets,plumes and buoyant jets discharging into static environment is one of themost important and basic flow patterns related with the environment pollution.These flows havenumerous important applications,for example,thrust augmentors,waste disposal plumes fromstacks and combustion systems,and significant problems of turbulent diffusion.  相似文献   
19.
对直径280mm、扩大直径500mm、外循环管直径65mm、总高2900mm的外循环型鼓泡式反应器,在气体空塔线速Ug为0.04-0.55m/s时,用静压差法和脉冲示踪法测定了不同部位的气含率Eg,Epg和循环液速率u1,并获得了它们的关联式:对反应段,Eg=0.4556U^0.3198g〔Ug/(Ug+U1)〕^0.7396;对反应器扩大段,Eug=0.9389U^0.4431ug;对循环管,E  相似文献   
20.
基于(I)报根据pVT和Tμp图形的相似性和Patel-Teja状态方程建立的预测纯流体气、液相粘度的统一模型,通过引入常规的状态方程参数的混合规则,将其应用于二元轻烃混合物共计1894个数据点及模拟天然气高压粘度的预测,平均相对误差分别为13.78%和16.75%;应用于油藏原油和天然气高压粘度的预测,结果优于现有的有关油气藏流体粘度模型.  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-23

京公网安备 11010802026262号