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   226篇
  免费   9篇
电工技术   23篇
化学工业   48篇
金属工艺   4篇
机械仪表   17篇
建筑科学   9篇
能源动力   2篇
轻工业   27篇
无线电   11篇
一般工业技术   37篇
冶金工业   24篇
原子能技术   19篇
自动化技术   14篇
  2022年   3篇
  2021年   8篇
  2020年   6篇
  2019年   7篇
  2018年   3篇
  2017年   4篇
  2016年   5篇
  2015年   9篇
  2014年   8篇
  2013年   17篇
  2012年   9篇
  2011年   14篇
  2010年   7篇
  2009年   13篇
  2008年   13篇
  2007年   13篇
  2006年   9篇
  2005年   14篇
  2004年   2篇
  2003年   3篇
  2002年   5篇
  2001年   1篇
  2000年   5篇
  1999年   7篇
  1998年   6篇
  1997年   6篇
  1996年   6篇
  1995年   4篇
  1994年   4篇
  1993年   6篇
  1992年   3篇
  1991年   2篇
  1990年   2篇
  1989年   2篇
  1986年   1篇
  1984年   1篇
  1983年   2篇
  1980年   2篇
  1976年   2篇
  1974年   1篇
排序方式: 共有235条查询结果,搜索用时 15 毫秒
181.
This article demonstrates that the interaction of cyclodextrins (CDs) with side chains of water soluble polymers is useful not only as simple models for biological molecular recognition but also as building blocks in nanotechnological applications. In the interaction of CDs with polymer side chains, the selectivity of CDs was enhanced by the steric effect of the polymer main chain and by interaction at multi-sites (i.e., collectivity). Utilizing the interaction of CDs with polymer side chains, stimuli-responsive systems were constructed from simple components.  相似文献   
182.
High-speed injection die casting is an efficient manufacturing technology for upgrading aluminum die-cast products. However, deficiencies (such as die damage in early period) due to larger load on the molding die compared with conventional technology have brought new challenges. In this study, the cause of damage generated in super high-speed injection was investigated by the combination of experimental observation of the dies and CAE simulation (e.g. die temperature analysis, flow analysis and thermal stress analysis). The potential countermeasures to solve the above problems were also proposed.  相似文献   
183.
MCrAlY alloy bond coat is widely used in thermal barrier coating (TBC) systems to protect substrates from high-temperature oxidizing environments. However, failure of the ceramic topcoat can occur due to a thermally grown oxide (TGO) that grows at the interface between the bond coat and the topcoat. In this study, the effect of chromate treatment was investigated. Prior to topcoat deposition, a thin film of Cr2O3 was formed on the bond coat surface. High-temperature oxidation tests were carried out, and the oxidation rates were determined by inspection of cross sections. Similar oxidation tests were carried out using MCrAlY powder material assumed to be unmelted particles. As a result, the chromate-treated bond coat showed outstanding oxidation resistance. Calculations that take into account the oxidation of particles in the topcoat indicated the generation of internal stress to cause local fracture of the topcoat.  相似文献   
184.
Interposed fibrous tissue at bone–implant interfaces was quantitatively measured in the presence or absence of polyethylene (PE) or alumina particles. Three different conditions of the interface were designed by implanting a pre-polymerized polymethylmethacrylate (PMMA) plug (plug group), a doughy PMMA (injection group) and a hydroxyapatite (HA) plug (HA group) in the hole drilled at the intercondylar notch of rabbit knees. PE (170±18 m) or alumina particles (88±26 m) were repeatedly administered into the knee joints at one month intervals (six times). All animals were sacrificed seven months after the implantation. The bone–implant interface was histomorphometrically examined using undecalcified ground sections. In the plug group, the PE particles significantly increased the extent of the interposed fibrous tissue (p < 0.05), while the alumina particles showed no effect. In contrast, both particles showed no significant effects in the injection and the HA groups. These results indicate that both particle characteristics and conditions of the bone–implant interface affected particle-induced fibrous tissue interposition. The loose PMMA plug with PE particles induced the greatest amount of fibrous tissue interposition. ©2000 Kluwer Academic Publishers  相似文献   
185.
An introduction to the special issue on the multilevel measurement model (MMM) is provided. The two- and three-level multilevel models for continuous outcomes are reviewed. The extension to the hierarchical generalized linear model and its use as a multilevel measurement model for dichotomous measurement indicators is demonstrated. The six articles in the special issue are described.  相似文献   
186.
Serratia marcescens has emerged in the last few years as an important nosocomial pathogen. Many methods for typing this organism have been described. In this study the random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was shown to be a convenient typing method for S. marcescens. Different combinations of primers previously used for typing other gram-negative bacilli were assessed. The combination of primer HLWL-74 and 1254 gave distinguishable patterns for different serotypes and proved to be the most satisfactory. By applying this combination to 175 isolates of S. marcescens, which could be classified into 38 groups on the basis of serotyping and phage typing, 73 different RAPD patterns with good reproducibility were obtained. This is, to our knowledge, the first application of the method to a large collection of S. marcescens representing a wide range of serotypes.  相似文献   
187.
This study among 426 Japanese couples working in different occupational sectors tested the hypothesis that perspective taking moderates the crossover of work engagement. More specifically, we predicted that husbands' work engagement would cross over to their wives, particularly when wives scored high on perspective taking (the spontaneous tendency to adopt the psychological perspective of other people). A similar effect was predicted from wives to husbands. In addition, we hypothesized that the crossover effect would be most pronounced when both partners were high in perspective taking (i.e., a 3-way interaction effect). The results of moderated structural equation modeling analyses confirmed the moderating role of perspective taking, but only for women; women who took the perspective of their partner scored higher on engagement with increasing partner engagement. Moreover, the results showed that engagement crossover was strongest when both men and women were high (vs. low) in perspective taking. This 3-way interaction effect was found from husbands to wives, and vice versa. These findings expand the crossover literature by shedding light on the crossover process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
188.
The effect of deaerated water on the swelling of cellulose and amylose and on the application in cotton desizing with enzyme that contains necessarily these swelling processes were studied. The total volume changes of the swelling of cellulose and amylose were measured by dilatometry. The total volume changes of cellulose and amylose were more negative in deaerated water. In deaerated water, the total volume changes are 142 ± 6% for cellulose and 229 ± 2% for amylose to those in air‐present water. The rates of cotton desizing with two kinds of enzymes were studied by measuring the concentration of generated sugars by using HPLC. Higher efficiency of 140–150% was obtained in deaerated water than in water containing dissolved gases of air, oxygen, or nitrogen. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1693–1700, 1999  相似文献   
189.
190.
Abstract— An advanced screen for use with LCD/LCoS/DMD rear‐projection TV has been developed. A lenticular lens having a pitch of 64 μm has been developed without loss in any other optical property. A 70% black‐stripe ratio was obtained by optimizing the patterning process, which maintains high contrast. As described in this paper, the FC‐Screen manufacturing technology has been further developed.  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