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   1021篇
  免费   52篇
  国内免费   14篇
电工技术   17篇
综合类   2篇
化学工业   239篇
金属工艺   23篇
机械仪表   28篇
建筑科学   50篇
矿业工程   1篇
能源动力   75篇
轻工业   113篇
水利工程   9篇
石油天然气   8篇
无线电   117篇
一般工业技术   165篇
冶金工业   82篇
原子能技术   9篇
自动化技术   149篇
  2024年   6篇
  2023年   17篇
  2022年   35篇
  2021年   40篇
  2020年   45篇
  2019年   45篇
  2018年   44篇
  2017年   65篇
  2016年   51篇
  2015年   32篇
  2014年   36篇
  2013年   97篇
  2012年   48篇
  2011年   47篇
  2010年   43篇
  2009年   41篇
  2008年   43篇
  2007年   24篇
  2006年   27篇
  2005年   22篇
  2004年   16篇
  2003年   12篇
  2002年   6篇
  2001年   7篇
  2000年   12篇
  1999年   7篇
  1998年   32篇
  1997年   18篇
  1996年   17篇
  1995年   17篇
  1994年   11篇
  1993年   13篇
  1992年   11篇
  1991年   6篇
  1990年   6篇
  1989年   10篇
  1988年   9篇
  1987年   6篇
  1986年   3篇
  1985年   10篇
  1984年   11篇
  1983年   7篇
  1982年   9篇
  1981年   4篇
  1980年   3篇
  1977年   2篇
  1976年   3篇
  1974年   2篇
  1973年   3篇
  1966年   1篇
排序方式: 共有1087条查询结果,搜索用时 9 毫秒
61.
The effect of a rigid filler on the elastic properties of starch‐based composites is investigated. Thermomolding of the targeted composite is conducted using a starch matrix with varying silicone carbide content. Mechanical testing reveals that the composite's Young modulus cannot be rationalized using two‐phase analytical models. The effect of a weak interphase region is highlighted using a finite‐element model that assumes the generation of virtual microstructures. Numerical results are discussed by describing the influence of the structural and interphase parameters on the composite's elastic modulus. Identification of optimal interphase parameters quantitatively demonstrates the weak adhesion between intrinsic phases for all studied filler fractions.

  相似文献   

62.
63.
Newly developed inulin powders were prepared from roots of Asparagus falcatus (AF) and Taraxacum javanicum (TJ) plants grown in Sri Lanka. Inulin content, analyzed by enzymatic spectrophotometric as well as high‐performance liquid chromatographic methods, showed that AF and TJ inulin powders contain 65.5% and 45.4% (dry wt) inulin, respectively, compared with 72% dry wt in the commercially available chicory inulin. Treating the AF and TJ inulin powders using ion exchange techniques significantly (P < 0.05) reduced their contents of micro (Zn, Cu, Mn, Fe) and macro (Na, K, Ca, Mg) elements. Enzymatic hydrolysis of inulin into fructose and glucose by fructanase, and FT‐IR analyses proved that the developed AF and TJ inulins have characteristic molecular composition similar to commercial inulin. TJ inulin contained significantly (P < 0.05) greater amounts of total phenolics (4.37 mg GAE/g), total flavonoids (2.79 mg QE/g), and antioxidant capacity (833.11 mM TE/g) than AF inulin, which contained 1.33 mg GAE/g of total phenolics, 0.43 mg QE/g of total flavonoids, and 406.26 mM TE/g antioxidant capacity. The current study suggests that the newly developed inulin from AF and TJ roots could be used as an alternative commercial source of inulin for the food industry.  相似文献   
64.
A completely solar-powered greenhouse complex has been designed for climate controlled food production in hot, humid environments. The concept uses passive design features to provide irrigation water from saline water sources. This paper discusses the overall system concept and the solar still subsystem which has been designed to provide a continuous fresh water supply. While incorporating many innovative features, the use of proven technologies and passive design results in a system that should compete economically with current, more traditional designs.  相似文献   
65.
A lumped element circuit model for the operation of a junction mixing scanning tunneling microscope (JM-STM) is presented. Fits from this model show excellent agreement with experimental results in the picosecond time regime. The tip sample capacitance employed in the model was calculated to be 33 fF, using the method of images. By varying the capacitance, various tip/sample geometries can be investigated. Testing the response of the model tunnel junction, for faster electrical pulses, suggests how the JM-STM can be pushed into the femtosecond time regime  相似文献   
66.
Multimedia Tools and Applications - One of the most critical aspects of this technologically progressive era is the propagation of information through an unsecured communication channel. The...  相似文献   
67.
In this study, grape pomace (GP), a by-product consisting of grape skins and seeds rich in dietary fibres and polyphenols, was used in wafer sheets at different concentrations [5.00 (GP5), 10.0 (GP10), and 15.0 g 100 g−1 (GP15)] for the partial replacement of wheat flour (WF) and improve the functionality of wafer sheets. The GP inclusion at concentrations higher than 5.00 g 100 g−1 significantly affected the texture of sheets as well as the flow behaviour of batters, resulting in softer sheets and more viscous batters (P < 0.05). Moisture contents did not significantly change after GP addition (P > 0.05). After the addition of GP, the L* values decreased and the a* values increased, making the wafers darker (P < 0.05). Moreover, under simulated in vitro digestion conditions, the bioaccessibility of total phenolic compounds in saliva, gastric juice, and intestinal juice was significantly higher than control even at the lowest GP concentration (P < 0.05). Regarding sensory properties, only smoothness and crispness were significantly affected by GP addition, and samples were found to be crisper with higher concentrations of GP. In conclusion, it is possible to partially replace the WF in wafers with GP at a concentration of 5.00 g 100 g−1 to develop a product with higher functionality and nutrient content.  相似文献   
68.
In this study, grape pomace (mixture of grape seeds and skins) powder (GPP), obtained from grape processing, was used at different concentrations [10.0 (GPP10), 20.0 (GPP10) and 30.0 (GPP10) g/100 g] in white chocolate formulation for the partial replacement of sucrose. The results indicated that GPP addition at a higher concentration (>10.0 g/100 g) significantly affected the particle size, moisture content, texture and flow behaviour of white chocolate samples (P < 0.05). However, using GPP at a concentration of 10.0 g/100 g had advantages for physicochemical and flow properties. As expected, under simulated in vitro digestion conditions, the bioaccessibility of total phenolic compounds in saliva, gastric juice and intestinal juice for GPP10 samples was significantly higher than the control (P < 0.05). In conclusion, results of the study showed that it was possible to partially replace the sucrose with GPP at a concentration of 10.0 g/100 g in white chocolate formulations.  相似文献   
69.
70.
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