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   6485篇
  免费   329篇
  国内免费   18篇
电工技术   79篇
综合类   10篇
化学工业   1180篇
金属工艺   237篇
机械仪表   319篇
建筑科学   123篇
矿业工程   1篇
能源动力   269篇
轻工业   518篇
水利工程   24篇
石油天然气   12篇
无线电   1383篇
一般工业技术   1298篇
冶金工业   501篇
原子能技术   87篇
自动化技术   791篇
  2024年   21篇
  2023年   78篇
  2022年   105篇
  2021年   182篇
  2020年   119篇
  2019年   130篇
  2018年   172篇
  2017年   153篇
  2016年   199篇
  2015年   162篇
  2014年   243篇
  2013年   457篇
  2012年   384篇
  2011年   484篇
  2010年   328篇
  2009年   380篇
  2008年   327篇
  2007年   278篇
  2006年   230篇
  2005年   239篇
  2004年   169篇
  2003年   181篇
  2002年   168篇
  2001年   130篇
  2000年   130篇
  1999年   115篇
  1998年   244篇
  1997年   134篇
  1996年   133篇
  1995年   118篇
  1994年   80篇
  1993年   88篇
  1992年   58篇
  1991年   54篇
  1990年   46篇
  1989年   43篇
  1988年   31篇
  1987年   31篇
  1986年   23篇
  1985年   21篇
  1984年   23篇
  1983年   19篇
  1982年   22篇
  1981年   13篇
  1980年   17篇
  1979年   6篇
  1978年   6篇
  1977年   8篇
  1976年   13篇
  1975年   9篇
排序方式: 共有6832条查询结果,搜索用时 0 毫秒
11.
12.
The transient receptor potential vanilloid 1 (TRPV1) ion channel plays an important role in the peripheral nociceptive pathway. TRPV1 is a polymodal receptor that can be activated by multiple types of ligands and painful stimuli, such as noxious heat and protons, and contributes to various acute and chronic pain conditions. Therefore, TRPV1 is emerging as a novel therapeutic target for the treatment of various pain conditions. Notably, various peptides isolated from venomous animals potently and selectively control the activation and inhibition of TRPV1 by binding to its outer pore region. This review will focus on the mechanisms by which venom-derived peptides interact with this portion of TRPV1 to control receptor functions and how these mechanisms can drive the development of new types of analgesics.  相似文献   
13.
Despite advances in medicine, mortality due to sepsis has not decreased. Pulsed electromagnetic field (PEMF) therapy is emerging as an alternative treatment in many inflammation-related diseases. However, there are few studies on the application of PEMF therapy to sepsis. In the current study, we examined the effect of PEMF therapy on a mouse model of lipopolysaccharide (LPS)-induced septic shock. Mice injected with LPS and treated with PEMF showed higher survival rates compared with the LPS group. The increased survival was correlated with decreased levels of pro-inflammatory cytokine mRNA expression and lower serum nitric oxide levels and nitric oxide synthase 2 mRNA expression in the liver compared with the LPS group. In the PEMF + LPS group, there was less organ damage in the liver, lungs, spleen, and kidneys compared to the LPS group. To identify potential gene targets of PEMF treatment, microarray analysis was performed, and the results showed that 136 genes were up-regulated, and 267 genes were down-regulated in the PEMF + LPS group compared to the LPS group. These results suggest that PEMF treatment can dramatically decrease septic shock through the reduction of pro-inflammatory cytokine gene expression. In a clinical setting, PEMF may provide a beneficial effect for patients with bacteria-induced sepsis and reduce septic shock-induced mortality.  相似文献   
14.
15.
We present a hierarchical test methodology for testing a SOC with heterogeneous cores, including the 1149.1-wrapped, P1500-wrapped, and BIST memory cores. We propose an 1149.1-based hierarchical test manager that also provides P1500 test control signals. This scheme includes a memory BIST interface, providing both serial and parallel access ports for BIST circuits. Our approach offers low area and pin overhead, and high flexibility  相似文献   
16.
17.
This paper concerns the analysis of convective instabilities and fully developed transport properties in Bénard convection. The onset of convective instabilities driven by surface-tension variations and buoyancy forces is analyzed theoretically by using the propagation theory we have developed. Based on these stability criteria, the subsequent transport correlations of fully developed buoyancy-driven convection in horizontal fluid layers are suggested. It is found that the present predictions are compared favorably with existing experimental results.  相似文献   
18.
19.

Certain measurement techniques (such as the asbestos method using phase contrast microscopy) require uniform deposits of the sample on a filter. The asbestos fiber analytical methods require such uniform deposition because the analysis only observes small, randomly chosen locations on the filter. In this study, a vibrating orifice monodisperse aerosol generator was used to generate methylene blue particles. The aerosols were dried by filtered compressed air and then neutralized by inducing a charge on the droplet stream that emerged from the vibrating orifice. An Aerodynamic Particle Sizer was used to measure the number concentration and size distribution of the generated aerosol particles. Meanwhile, the filter deposits were examined via image processing, combined with statistical methods for defining uniformity. In order to better define uniformity and make the indicator more universal, the uniformity was defined as the exponential of the negative CV (coefficient of variation) value which was a transformation for easily understanding the uniformity of the filter deposits. The experimental results demonstrated that, when aerosol counting was performed, the equal area approach was superior to the equivalent distance approach.  相似文献   
20.
A time-weighted integral transform is presented to identify a continuous SISO or MIMO parametric model based on a single dynamic test under open-loop or closed-loop operation. Moving-horizon algorithms are proposed to obtain unbiased estimates of the model parameters. The off-line algorithm in a least-squares form and the on-line algorithm in a recursive form are provided. An effective technique based on pattern recognition is also developed to determine the system order and time delay from observed data in a simple manner. Furthermore, the proposed method can be easily applied as a model reduction technique that results in an ideal model with delay for any specified order.  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