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   9558篇
  免费   607篇
  国内免费   21篇
电工技术   147篇
综合类   18篇
化学工业   2415篇
金属工艺   195篇
机械仪表   227篇
建筑科学   323篇
矿业工程   45篇
能源动力   227篇
轻工业   400篇
水利工程   83篇
石油天然气   66篇
无线电   821篇
一般工业技术   2477篇
冶金工业   1021篇
原子能技术   111篇
自动化技术   1610篇
  2023年   132篇
  2022年   364篇
  2021年   420篇
  2020年   291篇
  2019年   260篇
  2018年   329篇
  2017年   270篇
  2016年   366篇
  2015年   303篇
  2014年   451篇
  2013年   577篇
  2012年   566篇
  2011年   634篇
  2010年   440篇
  2009年   437篇
  2008年   453篇
  2007年   426篇
  2006年   335篇
  2005年   264篇
  2004年   236篇
  2003年   220篇
  2002年   208篇
  2001年   142篇
  2000年   128篇
  1999年   127篇
  1998年   201篇
  1997年   167篇
  1996年   108篇
  1995年   86篇
  1994年   81篇
  1993年   97篇
  1992年   65篇
  1991年   59篇
  1990年   59篇
  1989年   49篇
  1988年   49篇
  1987年   45篇
  1986年   39篇
  1985年   47篇
  1984年   48篇
  1983年   37篇
  1982年   33篇
  1981年   31篇
  1980年   28篇
  1979年   25篇
  1978年   36篇
  1977年   31篇
  1976年   65篇
  1975年   35篇
  1971年   24篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
IT/Business alignment   总被引:3,自引:2,他引:1  
Ohne Zusammenfassung
IT/Business alignment
  相似文献   
73.
Research on sexual abuse frequently fails to address the influence of the family as a risk factor for the onset of all kinds of sexual abuse and as a mediator of its long-term effects. Attachment theory provides a useful conceptual framework for understanding the familial antecedents and long-term consequences of sexual abuse. Themes associated with insecure parent–child attachment (rejection, role reversal/parentification, and fear/unresolved trauma) are frequently found in the dynamics of families characterized by sexual abuse, and specific categories of sequelae are related to probable attachment experiences. Implications for intervention and research on sexual abuse are suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
74.
Mortars of blast furnace slag blended with a geothermal silica waste at various replacement levels of 0%, 5%, 10%, 15%, and 20% were cured for up to 90 days. The binder was activated by 6 wt% Na2O equivalent of sodium hydroxide. Lime was added as an activating agent and also to promote pozzolanic reaction with the silica. It was found that the presence of the silica waste increased the reactivity of the cementitious materials, as measured by means of nonevaporable water. The compressive strength was increased in the presence of the silica, except at the highest replacement level of 20%, the optimum silica replacement was that of 5%–10%. The microstructures of blended slag showed less porosity than those of neat slag mortars. The lime was completely consumed after 90 days of hydration.  相似文献   
75.
76.
This study is a preliminary investigation of an integrative treatment aimed at improving the efficacy of cognitive therapy (CT) for depression. The development of the treatment protocol was based on process findings, which suggested that strategies used in CT to resolve alliance ruptures may actually exacerbate problems in the therapeutic relationship. The protocol integrates, within the traditional CT treatment manual, procedures to repair alliance ruptures that are derived from or consistent with humanistic and interpersonal therapies. Although conducted by inexperienced therapists, the integrative treatment led to greater improvement than a waiting-list condition. The results also compare favorably to previous findings for CT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
77.
In this introduction to a special issue of Computers and Composition, the authors critically review current literature on computer-assisted writing pedagogies that grapple with issues of sexuality. Although this body of work is small, it points to provocative ways to develop our students’ critical and rhetorical sensibilities about the constructions of sexuality in our culture. Further, such work innovatively addresses the place of networked communication technologies in the interrogation of such constructions. The authors conclude with both an introduction of the work in this special issue that addresses the intersection of sexuality studies and computer-assisted writing studies and with a call for additional work in this field.  相似文献   
78.
79.
A detailed kinetic mechanism is proposed for the oxidation of iso-octane, n-heptane, and mixtures of them in air (number of particles 43, number of reactions 284), which satisfactorily describes the distinctive features of low-temperature and high-temperature oxidation at an initial temperature of 1200 K, pressure of 15–40 absolute atmospheres or higher, and a fuel excess ratio of 0.5–2. The abbreviated mechanisms obtained to describe the auto-ignition of fuel with an octane number of 90 involve 27 particles (38 reactions) and 18 particles (22 reactions).N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, 117977. Translated from Fizika Goreniya i Vzyrva, Vol. 30, No. 6, pp. 15–25, November–December, 1994.  相似文献   
80.
We consider two stochastic simulation algorithms for the calculation of parametric derivatives of solutions of a population balance equation, namely, forward and adjoint sensitivity methods. The dispersed system is approximated by an N-particle stochastic weighted ensemble. The infinitesimal deviations of the solution are accounted for through infinitesimal deviation of the statistical weights that are recalculated at each coagulation. In the forward method these deviations of the statistical weights immediately give parametric derivatives of the solution. In the second method the deviations of the statistical weights are used to calculate a finite-mode approximation of the linearized version of the population balance equation. The linearized equation allows for the calculation of the eigenmodes and eigenvalues of the process, while the parametric derivatives of the solution are given by a Lagrange formalism.  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