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   1564篇
  免费   85篇
  国内免费   3篇
电工技术   22篇
综合类   2篇
化学工业   295篇
金属工艺   29篇
机械仪表   28篇
建筑科学   86篇
矿业工程   2篇
能源动力   45篇
轻工业   127篇
水利工程   15篇
石油天然气   2篇
无线电   85篇
一般工业技术   426篇
冶金工业   216篇
原子能技术   12篇
自动化技术   260篇
  2023年   10篇
  2022年   21篇
  2021年   43篇
  2020年   23篇
  2019年   28篇
  2018年   38篇
  2017年   34篇
  2016年   39篇
  2015年   48篇
  2014年   70篇
  2013年   95篇
  2012年   94篇
  2011年   136篇
  2010年   90篇
  2009年   82篇
  2008年   103篇
  2007年   116篇
  2006年   90篇
  2005年   87篇
  2004年   55篇
  2003年   48篇
  2002年   39篇
  2001年   30篇
  2000年   18篇
  1999年   18篇
  1998年   19篇
  1997年   19篇
  1996年   11篇
  1995年   11篇
  1994年   8篇
  1993年   11篇
  1992年   8篇
  1991年   3篇
  1990年   14篇
  1989年   9篇
  1988年   10篇
  1987年   8篇
  1985年   2篇
  1984年   5篇
  1983年   6篇
  1982年   8篇
  1981年   5篇
  1979年   3篇
  1978年   4篇
  1977年   4篇
  1976年   4篇
  1975年   3篇
  1974年   2篇
  1967年   2篇
  1960年   7篇
排序方式: 共有1652条查询结果,搜索用时 625 毫秒
1.
Lipoxins (LXs) are autacoids, specialized proresolving lipid mediators (SPMs) acting locally in a paracrine or autocrine fashion. They belong to a complex superfamily of dietary small polyunsaturated fatty acid (PUFA)–metabolites, which direct potent cellular responses to resolve inflammation and restore tissue homeostasis. Together, these SPM activities have been intensely studied in systemic inflammation and acute injury or infection, but less is known about LX signaling and activities in the central nervous system. LXs are derived from arachidonic acid, an omega‐6 PUFA. In addition to well‐established roles in systemic inflammation resolution, they have increasingly become implicated in regulating neuroinflammatory and neurodegenerative processes. In particular, chronic inflammation plays a central role in Alzheimer's disease (AD) etiology, and dysregulated LX production and activities have been reported in a variety of AD rodent models and clinical tissue samples, yet with complex and sometimes conflicting results. In addition, reduced LX production following retinal injury has been reported recently by the authors, and an intriguing direct neuronal activity promoting survival and homeostasis in retinal and cortical neurons is demonstrated. Here, the authors review and clarify this growing literature and suggest new research directions to further elaborate the role of lipoxins in neurodegeneration.  相似文献   
2.
3.
Research suggests that schizotypal personality disorder (SPD) is a part of the spectrum of schizophrenia-related illnesses. This article hypothesizes that a deficit in the representation and maintenance of context is a core cognitive disturbance in schizophrenia and that SPD individuals should demonstrate context-processing deficits. To test this hypothesis, the authors administered 3 versions of their AX-CPT task, designed to assess context processing, to 35 healthy controls and 26 individuals with DSM-IV SPD. They also administered working memory and selective attention tasks. SPD individuals displayed context representation deficits similar to those found in schizophrenia but did not show the same additional deficits in context maintenance. Context processing was strongly associated with working memory and selective attention performance in the SPD individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
4.
The global market for liquid mixed‐metal stabilizers is migrating toward heavy‐metal‐free products, Historically, these systems have not been performance and cost competitive. High efficiency calcium‐zinc stabilizers have the potential to replace heavy‐metal‐based products. The intrinsic value of non‐phenolic lubricating calcium intermediates and calcium‐zinc stabilizers is discussed.  相似文献   
5.
6.
2-Hydroxy-5-methyllaurophenone oxime (FLM 5011) is an inhibitor of lipoxygenase with antiinflammatory and antiallergic actions. We incubated FLM 5011 on the human immortal cell line Hep G2 and found a similar metabolite spectrum as in rat urine and faeces. We also measured the cytotoxicity of FLM 5011 on Hep G2 monolayers by the amido black assay and found that the influence of cell proliferation is partly due to apoptotic activities. Although the metabolic activity of Hep G2 cells is lower compared to rat hepatocyte cultures they are a suitable test system for biotransformation studies. Their higher proliferation rate allows toxicity to be characterised more exactly.  相似文献   
7.
移动终端是一种采用先进通信协议栈的复杂系统,它需要具有与许多网络供应商设备的互操作性、支持先进而丰富的多媒体应用程序,而且,所有这些都必需在一个资源有限的嵌入式系统的约束条件下实现。提供一个满足上述要求的软件解决方案需要考虑许多方面的问题并经历诸多阶段。成功的要素是:平台质量、应用程序集成质量和产品质量。平台质量能让制造商用来生成多种设计方案的移动手机参考设计,必须提供一个用于制造高品质终端用户产品的优质平台。移动手机软件包括三个关键部分——协议栈、应用程序架构和应用程序。协议栈毫无疑问是最为复杂的…  相似文献   
8.
The processing costs involved in regional accent normalization were evaluated by measuring differences in lexical decision latencies for targets placed at the end of sentences with different French regional accents. Over a series of 6 experiments, the authors examined the time course of comprehension disruption by manipulating the duration and presentation conditions of accented speech. Taken together, the findings of these experiments indicate that regional accent normalization involves a short-term adjustment mechanism that develops as a certain amount of accented signal is available, resulting in a temporary perturbation in speech processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
9.
Voting in Multi-Agent Systems   总被引:1,自引:0,他引:1  
  相似文献   
10.
A virtual roundtable (featuring panelists Steven Bellovin, Terry Benzel, Bob Blakely, Dorothy Denning, Whitfield Diffie, Jeremy Epstein, and Paulo Verissimo) discussing the next 15 years in computer security.  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