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   142篇
  免费   3篇
  国内免费   2篇
电工技术   2篇
综合类   1篇
化学工业   18篇
金属工艺   2篇
机械仪表   7篇
建筑科学   3篇
轻工业   43篇
无线电   5篇
一般工业技术   36篇
冶金工业   8篇
自动化技术   22篇
  2023年   1篇
  2022年   2篇
  2019年   1篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2014年   1篇
  2013年   50篇
  2012年   5篇
  2011年   4篇
  2010年   1篇
  2009年   2篇
  2008年   3篇
  2007年   1篇
  2006年   3篇
  2005年   2篇
  2004年   4篇
  2003年   3篇
  2002年   2篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1998年   1篇
  1997年   5篇
  1996年   2篇
  1995年   4篇
  1994年   6篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1989年   2篇
  1987年   1篇
  1986年   4篇
  1985年   2篇
  1984年   4篇
  1983年   2篇
  1982年   1篇
  1981年   4篇
  1980年   1篇
  1978年   2篇
  1977年   1篇
  1976年   1篇
  1973年   2篇
  1971年   2篇
  1970年   1篇
  1969年   1篇
  1968年   2篇
排序方式: 共有147条查询结果,搜索用时 0 毫秒
1.
A large variety of porous fluorescent glasses were prepared and the concentration of different elements in these glasses was analyzed. The start porous glasses were soaked in a solution containing soluble salts and then heated at 650 ℃ for 3 h to decompose the salts in the pores into oxides. Fluorescent agents, such as UO3, Eu203, were impregnated into the porous glasses to prepare the fluorescent glasses. The results show that soaking is a feasible method to prepare the glass sphere with compositions distinguishable from each other and easy to be located in a complicated background. Six or more components can be impregnated together into one glass sample and the concentration of them can be analyzed accurately. UO3 and Eu203 can be impregnated into porous glass to make the glass strongly fluorescent. Higher concentration of Eu203 produces stronger fluorescence while higher concentration of UO3 reduces the fluorescence intensity because of the concentration quenching effect.  相似文献   
2.
Conflict situations do not only arise from misunderstandings, erroneous perceptions, partial knowledge, false beliefs, etc., but also from differences in “opinions” and in the different agents' value systems. It is not always possible, and maybe not even desirable, to “solve” this kind of conflict, as the sources are subjective. The communicating agents can, however, use knowledge of the opponent's preferences, to try and convince the partner of a point of view which they wish to promote. To deal with these situations requires an argumentative capacity, able to handle not only “demonstrative” arguments but also “dialectic” ones, which may not necessarily be based on rationality and valid premises. This paper presents a formalization of a theory of informal argumentation, focused on techniques to change attitudes of the interlocutor, in the domain of health promotion.  相似文献   
3.
4.
The leaching of a real multimetal bulk concentrate cannot often be adequately understood on the basis of published literature on simpler and often ideal systems because the process is far too complex, Moreover, the data can become ambiguous in the absence of adequate information on raw materials. Thus any process development work requires a thorough knowledge of the raw material characteristics. This paper describes the use of an interdisciplinary study for a better understanding of ammonia leaching of multimetal sulphides. The techniques employed comprise of X-ray diffraction, thermal analysis, chemical analysis and microscopy.  相似文献   
5.
Iron ore fines and coal fines can be made to react to produce direct reduced iron (DRI) fines. There are three ways to achieve the reactions, namely, (a) using homogeneous mixtures, (b) arranging the ore and coal fines in separate but adjacent layers and (c) by fluidizing a mixture of iron ore fines and coal fines by air. This paper mainly discusses the work done by the author and his coworkers on the kinetic aspects of reactions in such systems.  相似文献   
6.
Abstract

Using LANDSAT-1 data for an area around Esfahan, central Iran, the effect which an hierarchical cascaded clustering algorithm has upon terrain cover classification is examined.  相似文献   
7.
AMIT A DESHMUKH  K P RAY 《Sadhana》2017,42(10):1671-1684
Broadband microstrip antenna using variations of U-slot has been widely reported. However, in most of the reported work, an in-depth explanation about the mode introduced by U-slot and procedure to design U-slot cut antennas at any given frequency is not explained. In this paper, first an extensive analysis to study the broadband response in symmetrical and a new configuration of asymmetrical U-slot cut rectangular microstrip antennas is presented. The U-slot tunes higher-order orthogonal mode resonance frequency of the patch with respect to fundamental mode to realise wider bandwidth. Further formulation in resonant length at modified patch modes in symmetrical U-slot cut antenna is proposed. Frequencies calculated using these formulations show closer agreement with simulated and measured results. Using proposed formulations, a procedure to design U-slot cut antenna at different frequencies over 800–4000 MHz range which shows broadband response is explained. Thus, the proposed work gives an insight into the functioning of widely used U-slot cut antennas and the formulations will be helpful for designing at any given frequency.  相似文献   
8.
The phase diagram for the system ZrO2-Y2O3 was redetermined. The extent of the fluorite-type ZrO2-YzO3 solid solution field was determined with a high-temperature X-ray furnace, precise lattice parameter measurements, and a hydrothermal technique. Long range ordering occurred at 40 mol% Y2O3 and the corresponding ordered phase was Zr3Y4OL12. The compound has rhombohedra1 symmetry (space group R 3), is isostructural with UY6Ol2 and decomposes above 1250±50°C. The results indicate that the eutectoid may occur at a temperature <400°C at a composition between 20 and 30 mol% Y2O3 Determination of the liquidus line indicated a eutectic at 83± 1 mol% Y2O3 and a peritectic at 76 ± 1 mol% Y2O3.  相似文献   
9.
10.
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