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   2435篇
  免费   261篇
  国内免费   4篇
电工技术   36篇
综合类   1篇
化学工业   655篇
金属工艺   84篇
机械仪表   156篇
建筑科学   21篇
能源动力   129篇
轻工业   159篇
水利工程   6篇
无线电   487篇
一般工业技术   600篇
冶金工业   80篇
原子能技术   45篇
自动化技术   241篇
  2023年   42篇
  2022年   23篇
  2021年   67篇
  2020年   69篇
  2019年   92篇
  2018年   93篇
  2017年   93篇
  2016年   118篇
  2015年   88篇
  2014年   122篇
  2013年   199篇
  2012年   173篇
  2011年   215篇
  2010年   141篇
  2009年   159篇
  2008年   141篇
  2007年   109篇
  2006年   114篇
  2005年   79篇
  2004年   67篇
  2003年   81篇
  2002年   70篇
  2001年   51篇
  2000年   48篇
  1999年   40篇
  1998年   45篇
  1997年   31篇
  1996年   23篇
  1995年   24篇
  1994年   11篇
  1993年   15篇
  1992年   8篇
  1991年   10篇
  1990年   7篇
  1989年   9篇
  1988年   5篇
  1987年   3篇
  1986年   2篇
  1985年   4篇
  1984年   2篇
  1983年   2篇
  1982年   1篇
  1980年   3篇
  1974年   1篇
排序方式: 共有2700条查询结果,搜索用时 15 毫秒
1.
Park  Se-Ho  Lee  Mi-Ra  Yang  Su Young  Lee  Ju Yeon  Lee  Hyun Ha  Seong  Yeong-Je  Kim  Bohye  Kim  Hee-Jun  Jin  Hui  Johnston  Tony V.  Ku  Seockmo  Park  Myeong Soo 《Food science and biotechnology》2022,31(13):1703-1715
Food Science and Biotechnology - In this work, the in vivo functionalities of milk fermented with Weissella confusa VP30 (VP30-EPS) and purified exopolysaccharide (pEPS) from the milk fermented...  相似文献   
2.
Wireless Personal Communications - The dependence on broadband to enhance the economy and environment sustainability is imposing immense urgency to provide ubiquitous wireless broadband access...  相似文献   
3.
Chrysanthemum flower is among one of the highly sought after and widely planted flower crops, in particular for cultural and religious ceremonies. However, the chrysanthemum stem and stalk have little value and usually discard as by‐product waste from floristry. The objective of this research is to investigate the potential value of utilizing chrysanthemum stem and stalk as reinforcing fillers for thermoplastic composites. In this study, 2‐mm thick composite sheet containing predefined formulations of polylactic acid (PLA), chrysanthemum waste filler (CWF) ranging from 15 to 60 phr, and maleated polyethylene (MAPE) coupling agent up to 5 phr were prepared with the aid of Haake internal mixer and compression molding. The effect of MAPE loading on tensile, thermal, and morphological properties of PLA/CWF composites was investigated. The findings revealed that PLA/CWF composite attained improved tensile modulus compared to the neat PLA, and the tensile modulus increases with higher concentration of CWF. However, both tensile strength and elongation at break reduces with increase loading of CWF. Overall, PLA/CWF composites with MAPE shows better performance compared to those without MAPE, where an optimum strength of 21.8 MPa can be achieved with 60 phr CW and 3 phr MAPE. The measured tensile strength is comparable to alternatives natural fiber thermoplastic composites demonstrating its potential to be used in non‐structurally demanding application. J. VINYL ADDIT. TECHNOL., 26:10–16, 2020. © 2019 Society of Plastics Engineers  相似文献   
4.
This work demonstrates a means of automatic transformation from planar electronic devices to desirable 3D forms. The method uses a spatially designed thermoplastic framework created via extrusion shear printing of acrylonitrile–butadiene–styrene (ABS) on a stress‐free ABS film, which can be laminated to a membrane‐type electronic device layer. Thermal annealing above the glass transition temperature allows stress relaxation in the printed polymer chains, resulting in an overall shape transformation of the framework. In addition, the significant reduction in the Young's modulus and the ability of the polymer chains to reflow in the rubbery state release the stress concentration in the electronic device layer, which can be positioned outside the neutral mechanical plane. Electrical analyses and mechanical simulations of a membrane‐type Au electrode and indium gallium zinc oxide transistor arrays before and after transformation confirm the versatility of this method for developing 3D electronic devices based on planar forms.  相似文献   
5.
Abstract

T-shaped ambulatory piezoelectric actuator which can be used for various purposes such as lifesaving and environmental monitoring was proposed. The actuator consists of eight piezoelectric benders, t-shaped stator, and four legs, and it is very simple in structure and has the advantages of being easily manufactured and downsizing. It is also driven by four legs and can be moved forward and backward. The piezoelectric bender was composed of a carbon body and a ceramic plate. Vibration motions of the piezoelectric benders in x and z axes were transfer to the legs and the elliptical displacements at the ends of the legs were obtained by combination of the phase difference of 90 degrees. Characteristics of the actuators were simulated by finite element analysis, and the optimized prototype actuator was fabricated and experimented.  相似文献   
6.
7.
8.
Thermal tempering is an industrial process widely used to make soda lime silica (SLS) glass panels stronger and tougher. During the tempering process, the upper and bottom sides of the glass may experience different cooling rates, and thus, their properties could be different. This study characterized changes in surface composition and subsurface glass network structures as well as indentation and wear resistance properties of the air- and tin-sides of 6-mm-thick SLS window panels faced toward the upper and sliding roller sides during thermal tempering. The results showed that although the chemical and structural differences detected with X-ray photoelectron spectroscopy and specular reflection infrared spectroscopy are subtle, there are large differences in nanoindentation behaviors and mechanochemical wear properties of the SLS glass surface. The findings of this study provide further insights into the performance difference between the air- and tin-sides of the SLS glass panel treated with thermal tempering.  相似文献   
9.
Functional materials exhibiting magnetic and luminescent properties have been recognized as an emerging class of materials with great potential in advanced applications. Herein, properties of multifunctional ceramic composites consisting of two garnets, luminescent cerium-doped Y3Al5O12 (Ce:YAG) and magnetic Y3Fe5O12 (YIG), are reported. On increasing the sintering temperature, both the photoluminescence and saturation magnetization of the Ce:YAG-YIG composites decreased gradually because of the interdiffusion of trivalent ions such as Al3+ and Fe3+. At a constant sintering temperature of 1100?°C, the YIG contents in the composites increased, thereby causing their luminescent properties to degrade and the saturation magnetizations to increase. For application to electronics, Ce:YAG-YIG composite thin films were integrated on quartz substrates by sputtering the ceramic target. The composite thin films exhibited both magnetic and luminescent properties after annealing. These techniques facilitate the incorporation of multifunctional nanocomposites into various devices.  相似文献   
10.
Journal of Mechanical Science and Technology - Confocal fringe patterns of evaporating sessile drops have provided initial evidence of the presence of a sub-micron thin liquid film emanating from...  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