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   44591篇
  免费   2742篇
  国内免费   44篇
工业技术   47377篇
  2023年   368篇
  2022年   412篇
  2021年   1193篇
  2020年   932篇
  2019年   1084篇
  2018年   1801篇
  2017年   1743篇
  2016年   1835篇
  2015年   1369篇
  2014年   1703篇
  2013年   3344篇
  2012年   2655篇
  2011年   2637篇
  2010年   2072篇
  2009年   1942篇
  2008年   1826篇
  2007年   1712篇
  2006年   1216篇
  2005年   1060篇
  2004年   936篇
  2003年   821篇
  2002年   799篇
  2001年   581篇
  2000年   540篇
  1999年   567篇
  1998年   2886篇
  1997年   1950篇
  1996年   1245篇
  1995年   777篇
  1994年   601篇
  1993年   677篇
  1992年   259篇
  1991年   270篇
  1990年   194篇
  1989年   200篇
  1988年   196篇
  1987年   176篇
  1986年   156篇
  1985年   179篇
  1984年   152篇
  1983年   125篇
  1982年   159篇
  1981年   183篇
  1980年   183篇
  1979年   90篇
  1978年   94篇
  1977年   306篇
  1976年   668篇
  1975年   66篇
  1973年   80篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Journal of Materials Science: Materials in Electronics - Non-volatile organic memory devices were fabricated using polystyrene sulfonate (PSS)?+?nitrogen-doped multi-walled carbon...  相似文献   
2.
Brito  Claúdia  Esteves  Marisa  Peixoto  Hugo  Abelha  António  Machado  José 《Wireless Networks》2022,28(3):1269-1277
Wireless Networks - Continuous ambulatory peritoneal dialysis (CAPD) is a treatment used by patients in the end-stage of chronic kidney diseases. Those patients need to be monitored using blood...  相似文献   
3.
4.
International Journal of Fracture - The development of high-performance automotive steels involves increasingly complex chemistries and heat treating sequences, to produce stronger and lighter...  相似文献   
5.
6.
7.
8.
The study was conducted to evaluate the effect of non-traditional and highly available and nutrient-dense ingredients in the production of value-added crackers. The crackers were prepared by combining partially defatted chia flour, wheat germ, quinoa, and oat. The antioxidant activity and the polyphenol content were 7.0–8.4 times higher in crackers produced with non-traditional ingredients compared to the control snack. The hydroperoxide value indicated a low oxidative deterioration of the oil. The sample with 10% of partially defatted chia flour was selected for shelf-life test under storage conditions and sensory evaluation. Modified atmosphere exerted a protective effect on the lipid stability regardless of the incorporation of BHT to the formulation. All the evaluated attributes scored highly during consumer acceptance. The formulated cracker presented a relevant content of protein, dietary fibre and omega-3 and -6 fatty acids. Based on these results, the crackers containing non-traditional ingredients resulted in a product with a good potential for both consumer acceptance and outstanding nutritional benefits.  相似文献   
9.
Journal of Porous Materials - The present study reports a systematic analysis of morphology and hydrogen sorption capacity of mesoporous organic-inorganic silica prepared by varying the silica...  相似文献   
10.
Recent advancements in isolation and stacking of layered van der Waals materials have created an unprecedented paradigm for demonstrating varieties of 2D quantum materials. Rationally designed van der Waals heterostructures composed of monolayer transition-metal dichalcogenides (TMDs) and few-layer hBN show several unique optoelectronic features driven by correlations. However, entangled superradiant excitonic species in such systems have not been observed before. In this report, it is demonstrated that strong suppression of phonon population at low temperature results in a formation of a coherent excitonic-dipoles ensemble in the heterostructure, and the collective oscillation of those dipoles stimulates a robust phase synchronized ultra-narrow band superradiant emission even at extremely low pumping intensity. Such emitters are in high demand for a multitude of applications, including fundamental research on many-body correlations and other state-of-the-art technologies. This timely demonstration paves the way for further exploration of ultralow-threshold quantum-emitting devices with unmatched design freedom and spectral tunability.  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