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   20787篇
  免费   898篇
  国内免费   312篇
工业技术   21997篇
  2023年   92篇
  2022年   142篇
  2021年   464篇
  2020年   265篇
  2019年   332篇
  2018年   382篇
  2017年   362篇
  2016年   401篇
  2015年   352篇
  2014年   529篇
  2013年   1028篇
  2012年   802篇
  2011年   988篇
  2010年   755篇
  2009年   819篇
  2008年   817篇
  2007年   843篇
  2006年   721篇
  2005年   618篇
  2004年   684篇
  2003年   914篇
  2002年   1193篇
  2001年   1021篇
  2000年   592篇
  1999年   542篇
  1998年   1357篇
  1997年   871篇
  1996年   641篇
  1995年   429篇
  1994年   319篇
  1993年   356篇
  1992年   195篇
  1991年   158篇
  1990年   148篇
  1989年   137篇
  1988年   134篇
  1987年   111篇
  1986年   115篇
  1985年   150篇
  1984年   87篇
  1983年   92篇
  1982年   83篇
  1981年   103篇
  1980年   103篇
  1979年   62篇
  1978年   49篇
  1977年   101篇
  1976年   196篇
  1975年   52篇
  1973年   51篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
Load testing of applications is an important and costly activity for software provider companies. Classical solutions are very difficult to set up statically, and their cost is prohibitive in terms of both human and hardware resources. Virtualized cloud computing platforms provide new opportunities for stressing an application's scalability, by providing a large range of flexible and less expensive (pay‐per‐use model) computation units. On the basis of these advantages, load testing solutions could be provided on demand in the cloud. This paper describes a Benchmark‐as‐a‐Service solution that automatically scales the load injection platform and facilitates its setup according to load profiles. Our approach is based on: (i) virtualization of the benchmarking platform to create self‐scaling injectors; (ii) online calibration to characterize the injector's capacity and impact on the benched application; and (iii) a provisioning solution to appropriately scale the load injection platform ahead of time. We also report experiments on a benchmark illustrating the benefits of this system in terms of cost and resource reductions. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
12.
Protection of Metals and Physical Chemistry of Surfaces - In this work, phthalic acid is investigated for its corrosion inhibition properties (for aluminum in solutions of HCl and H2SO4) through...  相似文献   
13.
Excessive energy intake may evoke complex biochemical processes characterized by inflammation, oxidative stress, and impairment of mitochondrial function that represent the main factors underlying noncommunicable diseases. Because cow milk is widely used for human nutrition and in food industry processing, the nutritional quality of milk is of special interest with respect to human health. In our study, we analyzed milk produced by dairy cows fed a diet characterized by a high forage:concentrate ratio (high forage milk, HFM). In view of the low n-6:n-3 ratio and high content of conjugated linoleic acid of HFM, we studied the effects of this milk on lipid metabolism, inflammation, mitochondrial function, and oxidative stress in a rat model. To this end, we supplemented for 4 wk the diet of male Wistar rats with HFM and with an isocaloric amount (82 kJ, 22 mL/d) of milk obtained from cows fed a diet with low forage:concentrate ratio, and analyzed the metabolic parameters of the animals. Our results indicate that HFM may positively affect lipid metabolism, leptin:adiponectin ratio, inflammation, mitochondrial function, and oxidative stress, providing the first evidence of the beneficial effects of HFM on rat metabolism.  相似文献   
14.
Lysophosphatidic acid (lysoPtdOH) levels have previously been reported to decrease in rodents with short-term fasting. We investigated whether a 16 h fast would change expression of autotaxin, the predominant phospholipase D responsible for adipose-derived lysoPtdOH synthesis, or any of the lysophosphatidic acid receptors (1–6) in four white adipose tissue (WAT) depots and interscapular brown adipose tissue (BAT) in male C57Bl/6J mice fed ad libitum, or fasted for 16 h. Aside from small inductions of Lpar1 in epididymal WAT and Lpar2 in epididymal and inguinal WAT, no significant changes were observed in expression of the Lpar family members, or autotaxin in perirenal, retroperitoneal, epididymal, or inguinal WAT or BAT with fasting. Comparison of the relative expression of Lpar1-6 in various depots showed that Lpar6 was the predominant Lpar in both WAT and BAT, and suggests that further work on the adipose-specific role of Lpar6 is warranted.  相似文献   
15.
16.
为降低老石旦洗煤厂的粗精煤灰分,在对粗煤泥性质分析的基础上,采用MC脉冲粗煤泥分选机对其进行分选。介绍了该分选机的结构、工作原理、技术特点、技术参数,并分析了其在老石旦洗煤厂的应用情况。生产实践表明:MC脉冲粗煤泥分选机不但可降低粗精煤灰分,而且可提高其产率。该分选机投入使用后粗精煤灰分下降3个百分点,总精煤产率提高0.5个百分点,达到了降灰的目的。  相似文献   
17.
18.
19.
20.
Microsystem Technologies - This paper represents low power and high speed design issues of Hamming code generation and error detection circuit using complementary metal oxide semiconductor (CMOS)...  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