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   2225篇
  免费   22篇
  国内免费   1篇
电工技术   14篇
化学工业   131篇
金属工艺   29篇
机械仪表   22篇
建筑科学   23篇
矿业工程   2篇
能源动力   20篇
轻工业   127篇
水利工程   5篇
石油天然气   2篇
无线电   92篇
一般工业技术   157篇
冶金工业   1484篇
原子能技术   37篇
自动化技术   103篇
  2021年   7篇
  2019年   10篇
  2018年   11篇
  2017年   11篇
  2016年   6篇
  2015年   8篇
  2014年   11篇
  2013年   44篇
  2012年   25篇
  2011年   40篇
  2010年   36篇
  2009年   30篇
  2008年   35篇
  2007年   23篇
  2006年   22篇
  2005年   28篇
  2004年   27篇
  2003年   25篇
  2002年   29篇
  2001年   32篇
  2000年   29篇
  1999年   63篇
  1998年   417篇
  1997年   217篇
  1996年   146篇
  1995年   107篇
  1994年   104篇
  1993年   90篇
  1992年   33篇
  1991年   37篇
  1990年   38篇
  1989年   48篇
  1988年   45篇
  1987年   32篇
  1986年   36篇
  1985年   39篇
  1984年   9篇
  1983年   21篇
  1982年   18篇
  1981年   18篇
  1980年   20篇
  1979年   18篇
  1978年   17篇
  1977年   35篇
  1976年   69篇
  1975年   10篇
  1974年   6篇
  1972年   7篇
  1971年   8篇
  1965年   5篇
排序方式: 共有2248条查询结果,搜索用时 0 毫秒
61.
As the Internet has changed communication, commerce, and the distribution of information, so too it is changing psychological research. Psychologists can observe new or rare phenomena online and can do research on traditional psychological topics more efficiently, enabling them to expand the scale and scope of their research. Yet these opportunities entail risk both to research quality and to human subjects. Internet research is inherently no more risky than traditional observational, survey, or experimental methods. Yet the risks and safeguards against them will differ from those characterizing traditional research and will themselves change over time. This article describes some benefits and challenges of conducting psychological research via the Internet and offers recommendations to both researchers and institutional review boards for dealing with them. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
62.
Wheat allergies are potentially life-threatening because of the high risk of anaphylaxis. Wheats belong to four genotypes represented in thousands of lines and varieties. Monitoring changes to wheat allergens is critical to prevent inadvertent ntroduction of hyper-allergenic varieties via breeding. However, validated methods for this purpose are unavailable at present. As a proof-of-concept study, we tested the hypothesis that salt-soluble wheat allergens in our mouse model will be identical to those reported for humans. Groups of Balb/cJ mice were rendered allergic to durum wheat salt-soluble protein extract (SSPE). Using blood from allergic mice, a mini hyper-IgE plasma bank was created and used in optimizing an IgE Western blotting (IEWB) to identify IgE binding allergens. The LC-MS/MS was used to sequence the allergenic bands. An ancient Aegilops tauschii wheat was grown in our greenhouse and extracted SSPE. Using the optimized IEWB method followed by sequencing, the cross-reacting allergens in A. tauschii wheat were identified. Database analysis showed all but 2 of the durum wheat allergens and all A. tauschii wheat allergens identified in this model had been reported as human allergens. Thus, this model may be used to identify and monitor potential changes to salt-soluble wheat allergens caused by breeding.  相似文献   
63.
64.
65.
66.
Electrochemical impedance spectroscopic characterization of the low modulus Ti–35.5Nb–7.3Zr–5.7Ta alloy has been performed in phosphate buffer saline solution at 37 °C. Measurements were performed at various immersion intervals up to 720 h at OCP and also at various anodic potentials up to 2 V. The alloy exhibits a two time constant impedance response at the OCP and a one-time constant response at anodic potentials in the passive region. The thickness of the oxide film formed has been evaluated and the electrochemical interpretation of the results has been reported. Cyclic potentiodynamic profile of the alloy displays valve metal characteristics and the presence of a wide passive region that extends up to the maximum potential value of 2 V studied.  相似文献   
67.
68.
69.
70.
Dietary cis‐9,trans‐11 (c9t11) conjugated linoleic acid (CLA) fed at 0.5 % w/w was previously shown to attenuate inflammation in the murine collagen‐induced (CA) arthritis model, and growing evidence implicates c9t11‐CLA as a major anti‐inflammatory component of dairy fat. To understand c9t11‐CLA's contribution to dairy fat's anti‐inflammatory action, the minimum amount of dietary c9t11‐CLA needed to reduce inflammation must be determined. This study had two objectives: (1) determine the minimum dietary anti‐inflammatory c9t11‐CLA intake level in the CA model, and (2) compare this to anti‐inflammatory effects of dairy fat (non‐enriched, naturally c9t11‐CLA‐enriched, or c9t11‐CLA‐supplemented). Mice received the following dietary fat treatments (w/w) post arthritis onset: corn oil (6 % CO), 0.125, 0.25, 0.375, and 0.5 % c9t11‐CLA, control butter (6 % CB), c9t11‐enriched butter (6 % EB), or c9t11‐CLA‐supplemented butter (6 % SB, containing 0.2 % c9t11‐CLA). Paw arthritic severity and pad swelling were scored and measured, respectively, over an 84‐day study period. All c9t11‐CLA and butter diets decreased the arthritic score (25–51 %, P < 0.01) and paw swelling (8–11 %, P < 0.01). Throughout the study, plasma tumor necrosis factor (TNFα) was elevated in CO‐fed arthritic mice compared to non‐arthritic (NA) mice but was reduced in 0.5 % c9t11‐CLA‐ and EB‐fed mice. Interleukin‐1β and IL‐6 were increased in arthritic CO‐fed mice compared to NA mice but were reduced in 0.5 % c9t11‐CLA‐ and EB‐fed mice through day 42. In conclusion, 0.125 % c9t11‐CLA reduced clinical arthritis as effectively as higher doses, and decreased arthritis in CB‐fed mice suggested that the minimal anti‐inflammatory levels of c9t11‐CLA might be below 0.125 %.  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