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   212篇
  免费   8篇
电工技术   4篇
化学工业   54篇
金属工艺   2篇
机械仪表   1篇
建筑科学   8篇
矿业工程   2篇
能源动力   5篇
轻工业   13篇
无线电   17篇
一般工业技术   35篇
冶金工业   30篇
原子能技术   3篇
自动化技术   46篇
  2022年   4篇
  2021年   2篇
  2020年   1篇
  2019年   2篇
  2018年   3篇
  2016年   2篇
  2015年   3篇
  2014年   7篇
  2013年   8篇
  2012年   18篇
  2011年   13篇
  2010年   7篇
  2009年   5篇
  2008年   9篇
  2007年   7篇
  2006年   11篇
  2005年   9篇
  2004年   4篇
  2003年   13篇
  2002年   7篇
  2001年   6篇
  2000年   1篇
  1999年   2篇
  1998年   5篇
  1997年   2篇
  1996年   2篇
  1995年   2篇
  1994年   3篇
  1993年   4篇
  1992年   3篇
  1991年   1篇
  1990年   7篇
  1989年   8篇
  1988年   1篇
  1987年   2篇
  1985年   4篇
  1984年   3篇
  1983年   6篇
  1982年   3篇
  1981年   5篇
  1980年   2篇
  1979年   3篇
  1978年   5篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1973年   1篇
  1970年   1篇
排序方式: 共有220条查询结果,搜索用时 15 毫秒
11.
There are basically three fundamental organizations that can be established in an engineering department to carry out a major product development program. These organizational approaches are: 1. Project Teams 2. Functional Groups 3. Matrix Organization Each approach has its inherent strengths and weaknesses. This paper describes the three approaches, with concentration on the matrix organization. Is it a cure-all (panacea) or wild confusion and disorder (pandemonium)?  相似文献   
12.
This paper considers the phase equilibria of alkali metal oxides and their combinations with other oxides relevant to nuclear fuels, fission products, and structural materials. The other oxides include those of the lanthanides, the actinides, iron, nickel, aluminum, silicon, as well as those of periodic table groups IIA, IVB, VB, VIB, and VIA. The alkali metal halides, chalcogenides, and hydroxides are also included. Techniques are developed to permit calculation of phase equilibria and Ellingham diagrams in ternary and higher-order systems. These techniques include estimation of previously unknown 298.15 K values of the enthalpies of formation and the entropies of many compounds.  相似文献   
13.
Here the interaction between a laminar two-phase, non-pre-mixed counterflow flame and a vortex is examined. Special emphasis is given to the influence of different flame and vortex parameters on the extinction behavior of the flame. Simultaneous planar laser-induced fluorescence of the CH radical layer produced by the flame and particle-image velocimetry measurements of the flowfield are used to characterize the flame-vortex interaction. These simultaneous diagnostics are used for the first time in this configuration. The extinction processes occurring during the flame-vortex interaction can be analyzed by this method, especially the influence of strain at the flame surface. The influence of the droplets on the extinction behavior appears clearly compared with a fully gaseous flame. The spray flame is weaker and extinguishes earlier than does a gaseous flame. In the measurements an additional broadband signal in the vicinity of the CH layer is probably due to the induced fluorescence of polycyclic aromatic hydrocarbons, excited at the same wavelength.  相似文献   
14.
15.
X-ray computed tomography (CT) is used to explore the differences in gas dispersion in a stirred-tank reactor (STR) for different operating conditions by varying the impeller speed and gas flow rate. X-ray imaging has been carried out in a 0.21 m ID acrylic STR equipped with a nylon Rushton-type impeller. From the CT images, major differences in local gas holdup are observed for different operating conditions. Completely dispersed conditions have a relatively uniform holdup profile while flooded conditions show a high gas holdup near the impeller shaft. The high resolution of the X-ray system allowed fine details such as recirculation regions behind the baffles to be visualized.  相似文献   
16.
Experiments were performed to determine the formulation and manufacturing feasibility of three model solid capsule formulations using a spray-on liquid drug carrier. Methylparaben was used as a model low-dose drug in the liquid drug carrier. Formulations containing different amounts of liquid drug carrier were successfully encapsulated on the H&K 400 capsule filling machine. The formulations contained varying ratios of liquid (methylparaben-propylene carbonate solution) to solid (compressible sugar, NF), which ranged from 10.0 - 20.0 μL/450 mg. Physical characteristics (i.e. weight variation, dissolution, etc.) of the filled capsules were evaluated. The 20.0 μL liquid/450 mg solid ratio was found to be the best hard gelatin capsule formulation based upon its rapid dissolution profile and was equivalent to all other formulations tested with respect to weight variation and content uniformity.  相似文献   
17.
A training-needs assessment was conducted at California School of Professional Psychology, Berkeley/Alameda, on students' beliefs about clinical competence, past training in HIV issues, and future training needs at the school. They perceived themselves to be somewhat competent in providing clinical services to HIV patients and members of groups at high risk for HIV. A modest correlation was found between the students' total HIV training and perceived competence, but none was found between the multicultural emphasis in HIV education and their perceived competence. These findings suggest an ethical dilemma surrounding inadequately trained psychologists providing services to multicultural populations. Ethical issues concerning training standards and criteria for clinical competency are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
18.
19.
Nitric oxide planar laser-induced fluorescence (NO PLIF) imaging at repetition rates as high as 1 MHz is demonstrated in the NASA Langley 31 in. Mach 10 hypersonic wind tunnel. Approximately 200 time-correlated image sequences of between 10 and 20 individual frames were obtained over eight days of wind tunnel testing spanning two entries in March and September of 2009. The image sequences presented were obtained from the boundary layer of a 20° flat plate model, in which transition was induced using a variety of different shaped protuberances, including a cylinder and a triangle. The high-speed image sequences captured a variety of laminar and transitional flow phenomena, ranging from mostly laminar flow, typically at a lower Reynolds number and/or in the near wall region of the model, to highly transitional flow in which the temporal evolution and progression of characteristic streak instabilities and/or corkscrew-shaped vortices could be clearly identified.  相似文献   
20.
建造是建筑设计的原点、创意源泉和重要内容。欧美和我国建筑院校的建造设计是将设计拉回到我们的双手、双眼对材料、连接、表现的基本体验和把握中,强调从建造到设计、从做到学的工匠式的感悟和创造。清华大学建筑学院的建造设计教学正是基于这一理念的实验探索。  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