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   606篇
  免费   31篇
  国内免费   1篇
电工技术   13篇
综合类   1篇
化学工业   150篇
金属工艺   13篇
机械仪表   11篇
建筑科学   35篇
能源动力   17篇
轻工业   43篇
石油天然气   1篇
武器工业   1篇
无线电   47篇
一般工业技术   167篇
冶金工业   58篇
原子能技术   3篇
自动化技术   78篇
  2023年   8篇
  2022年   20篇
  2021年   21篇
  2020年   17篇
  2019年   13篇
  2018年   10篇
  2017年   16篇
  2016年   21篇
  2015年   20篇
  2014年   24篇
  2013年   53篇
  2012年   36篇
  2011年   35篇
  2010年   24篇
  2009年   21篇
  2008年   26篇
  2007年   25篇
  2006年   18篇
  2005年   25篇
  2004年   20篇
  2003年   18篇
  2002年   18篇
  2001年   8篇
  2000年   4篇
  1999年   4篇
  1998年   6篇
  1997年   3篇
  1995年   10篇
  1993年   4篇
  1991年   5篇
  1990年   7篇
  1989年   5篇
  1988年   4篇
  1985年   6篇
  1984年   7篇
  1983年   5篇
  1982年   6篇
  1981年   8篇
  1979年   3篇
  1978年   5篇
  1976年   3篇
  1973年   2篇
  1972年   2篇
  1968年   3篇
  1966年   3篇
  1938年   3篇
  1937年   3篇
  1928年   2篇
  1913年   3篇
  1912年   2篇
排序方式: 共有638条查询结果,搜索用时 15 毫秒
631.
Information Systems and e-Business Management - Management consulting (MC), as a knowledge-based industry, is regarded as fertile ground for digital transformation (DT). However, the changes that...  相似文献   
632.
Dense environmental barrier coatings (EBCs) are an essential prerequisite to exploit the advantages offered by SiC-based fiber reinforced ceramic matrix composites (CMCs) to increase efficiency in gas turbines. Today's state-of-the art materials for application as EBCs are rare-earth (RE) silicates which, however, form amorphous phases upon rapid quenching from the melt. This makes their processing by thermal spray a challenge. Recently, high velocity oxygen fuel (HVOF) spraying was proposed as potential solution since the melting degree of the feedstock can be controlled effectively. This work studies the deposition of ytterbium disilicate (YbDS) at short stand-off distances and variant total feed rates and oxy-fuel ratios of the working gas. It was found that the overall degree of crystallinity could be kept at high level above 90%. The kinetic energy transferred by impinging particles was found to be an effective parameter to control the densification of the coatings. Porosities well below 10% were achieved while fully dense coatings were impeded due to the progressive accumulation of stresses in the coatings.  相似文献   
633.
Multibody System Dynamics - The numerical and computation aspects of the Knife-edge Equivalent Contact (KEC) constraint and lookup table (LUT) methods are compared in this paper. The LUT method...  相似文献   
634.
Ions play significant roles in biological processes—they may specifically bind to a protein site or bind non-specifically on its surface. Although the role of specifically bound ions ranges from actively providing structural compactness via coordination of charge–charge interactions to numerous enzymatic activities, non-specifically surface-bound ions are also crucial to maintaining a protein’s stability, responding to pH and ion concentration changes, and contributing to other biological processes. However, the experimental determination of the positions of non-specifically bound ions is not trivial, since they may have a low residential time and experience significant thermal fluctuation of their positions. Here, we report a new release of a computational method, the BION-2 method, that predicts the positions of non-specifically surface-bound ions. The BION-2 utilizes the Gaussian-based treatment of ions within the framework of the modified Poisson–Boltzmann equation, which does not require a sharp boundary between the protein and water phase. Thus, the predictions are done by the balance of the energy of interaction between the protein charges and the corresponding ions and the de-solvation penalty of the ions as they approach the protein. The BION-2 is tested against experimentally determined ion’s positions and it is demonstrated that it outperforms the old BION and other available tools.  相似文献   
635.
Actin is an essential element of both innate and adaptive immune systems and can aid in motility and translocation of bacterial pathogens, making it an attractive target for bacterial toxins. Pathogenic Vibrio and Aeromonas genera deliver actin cross-linking domain (ACD) toxin into the cytoplasm of the host cell to poison actin regulation and promptly induce cell rounding. At early stages of toxicity, ACD covalently cross-links actin monomers into oligomers (AOs) that bind through multivalent interactions and potently inhibit several families of actin assembly proteins. At advanced toxicity stages, we found that the terminal protomers of linear AOs can get linked together by ACD to produce cyclic AOs. When tested against formins and Ena/VASP, linear and cyclic AOs exhibit similar inhibitory potential, which for the cyclic AOs is reduced in the presence of profilin. In coarse-grained molecular dynamics simulations, profilin and WH2-motif binding sites on actin subunits remain exposed in modeled AOs of both geometries. We speculate, therefore, that the reduced toxicity of cyclic AOs is due to their reduced configurational entropy. A characteristic feature of cyclic AOs is that, in contrast to the linear forms, they cannot be straightened to form filaments (e.g., through stabilization by cofilin), which makes them less susceptible to neutralization by the host cell.  相似文献   
636.
Information Systems and e-Business Management - Digital transformation affects all industries. This study targets how management consulting companies address this phenomenon. Based on a survey of...  相似文献   
637.
638.
An efficient three‐component reaction involving carbon monoxide with a range of aryl bromides and N‐substituted acetoacetamides is reported for the synthesis of β‐keto amides. This transformation is promoted by Pd‐catalysis followed by an acid‐mediated deacetylation upon work‐up, enabling a large number of β‐keto amides to be isolated. Finally, d213C‐dyclonine could be synthesized in three steps utilizing the developed catalytic system as the key step.

  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