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   16062篇
  免费   603篇
  国内免费   48篇
电工技术   172篇
综合类   26篇
化学工业   2879篇
金属工艺   319篇
机械仪表   303篇
建筑科学   948篇
矿业工程   57篇
能源动力   394篇
轻工业   1248篇
水利工程   176篇
石油天然气   55篇
武器工业   1篇
无线电   1199篇
一般工业技术   2693篇
冶金工业   3695篇
原子能技术   72篇
自动化技术   2476篇
  2023年   67篇
  2022年   128篇
  2021年   252篇
  2020年   173篇
  2019年   195篇
  2018年   287篇
  2017年   242篇
  2016年   354篇
  2015年   271篇
  2014年   431篇
  2013年   930篇
  2012年   709篇
  2011年   966篇
  2010年   751篇
  2009年   709篇
  2008年   824篇
  2007年   832篇
  2006年   701篇
  2005年   668篇
  2004年   567篇
  2003年   457篇
  2002年   541篇
  2001年   352篇
  2000年   334篇
  1999年   316篇
  1998年   514篇
  1997年   388篇
  1996年   303篇
  1995年   317篇
  1994年   274篇
  1993年   270篇
  1992年   207篇
  1991年   110篇
  1990年   203篇
  1989年   183篇
  1988年   166篇
  1987年   164篇
  1986年   128篇
  1985年   182篇
  1984年   175篇
  1983年   121篇
  1982年   106篇
  1981年   99篇
  1980年   75篇
  1979年   79篇
  1978年   65篇
  1977年   68篇
  1976年   107篇
  1974年   50篇
  1973年   44篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
51.
Thin film formation of graphite by chemical vapor deposition using 2-methyl-1,2′-naphthyl ketone as a starting material was carried out on Ni film substrates. On Ni films directly deposited on quartz glass, the graphite films were obtained when the Ni film thickness was above 1 000 Å and above 5 000 Å at 700 °C and 1 000 °C, respectively. Depositions on thinner Ni film substrates comprise amorphous carbon (a-C) or graphite tubes which was owing to the thermal coagulation of the Ni film into droplets. On the other hand, graphite film was obtained on the Ni film with thickness 10 Å when a-C was inserted between the Ni film and the quartz glass. The coagulation of the Ni film is considered to be avoided by inserting a-C layer.  相似文献   
52.
TACT, a freeware program from the University of Toronto's Centre for Computing in the Humanities, is a highly sophisticated tool for text retrieval; although written for experienced critics and researchers, it can teach undergraduate students to read literature in new, fresh ways. Without requiring that the user become either a programmer, linguist, mathematician, or statistician,TACT introduces the literature student to the computer as a research tool. Studies of imagery and symbolism, of structural patterns, and of prosody can result from the student's careful tagging of a literary text and can yield significant insights into the work of literature. Students who use the computer as such a tool learn to read literary texts more closely and to think more clearly about literary problems.  相似文献   
53.
54.
The present study examines the concurrent and predictive relationships between therapist psychodynamic-interpersonal activity and therapist-rated alliance. Ratings from 45 patient and therapist dyads engaged in short term psychodynamic psychotherapy from a point early (3rd or 4th session) and late (the session at which 90% of the treatment was completed) in treatment were used. The results suggest that therapists who have positive views of the alliance early in treatment also have positive views of the alliance later in treatment. Therapists who used psychodynamic-interpersonal activities early in treatment also made use of psychodynamic-interpersonal activities later in treatment. Moreover, the use of psychodynamic-interpersonal activities early in treatment was positively related to both global and specific aspects of therapist-rated alliance late in treatment. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
55.
56.
Premature and ill term babies born in regional Australia must be moved to another hospital with Neonatal Intensive Care Unit (NICU) facilities. Transferred pre-term and critically ill term babies have higher mortality rates and much higher rates of long term disability than similar babies born in hospitals with NICU facilities. This paper details the Bush Babies Broadband project that aims to significantly improve the quality of treatment for babies born in rural, remote as well as urban areas by providing the first on-demand virtual NICU architecture in Australia. Real-time data collected from medical monitors and ventilators attached to the baby, audiovisual streams and static physiological data such as X-ray images are transmitted to the consulting Neonatologist to gain a better picture of the patient's condition than is currently available. The key contribution of this significant research is the infrastructure providing a mechanism for Neonatologists to receive information directly from a regional hospital, thereby preventing, in some cases, the immediate need to move the baby. A key benefit of this framework is that it is available to link regional hospitals with the supporting NICU Neonatologist ‘on demand’ eliminating the need to establish permanent point to point connections. This paper further describes the application of that architecture to a specific pilot connecting the Bathurst regional hospital with Neonatologists within the NICU at Nepean Hospital, Penrith Australia.  相似文献   
57.
我去了德国慕尼黑一年两次的Electronica贸易展,最近才从这次欧洲之行返回.我很高兴地告诉大家:高速互联网接入目前在整个西欧得到了广泛使用.  相似文献   
58.
Internet pornography, especially child pornography, has been a significant concern in British society for several years. This article seeks to examine the prevalence and impact of such material, the way public concern has developed, and media and legislative reactions to this concern. It suggests that a more rational debate of the actual and likely dangers in this sphere is necessary in order both to protect and serve the interests of justice.  相似文献   
59.
Personality processes relating to social perception have been shown to play a significant role in the experience of stress. In 5 studies, the authors demonstrate that early stage attentional processes influence the perception of social threat and modify the human stress response. The authors first show that cortisol release in response to a stressful situation correlates with selective attention toward social threat. Second, the authors show in 2 laboratory studies that this attentional pattern, most evident among individuals with low self-esteem, can be modified with a repetitive training task. Next, in a field study, students trained to modify their attentional pattern to reduce vigilance for social threat showed lower self-reported stress related to their final exam. In a final field study with telemarketers, the attentional training task led to increased self-esteem, decreased cortisol and perceived stress responses, higher confidence, and greater work performance. Taken together, these results demonstrate the impact of antecedent-focused strategies on the late-stage consequences of social stress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
60.
Two experiments involving 99 undergraduate participants sought to examine the influence of mood states on encoding speed within lexical decision and pronunciation tasks. Mood states were measured naturalistically in Experiment 1 and manipulated in Experiment 2. Stimuli consisted of nouns representing useful (e.g., food) and nonuseful (e.g., lint) objects. Mood states had no implications for initial encoding speed. However, when the same words were presented a 2nd time (i.e., repeated), happy individuals displayed a tendency to encode useful words faster than nonuseful ones. Thus, mood states influenced repetition priming on the basis of stimulus valence. The authors propose that happiness sensitizes individuals to useful or rewarding objects, which in turn creates a stronger memory trace for such stimuli in the future. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  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