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   795篇
  免费   41篇
电工技术   8篇
化学工业   153篇
金属工艺   12篇
机械仪表   15篇
建筑科学   17篇
矿业工程   2篇
能源动力   15篇
轻工业   96篇
水利工程   12篇
石油天然气   3篇
无线电   61篇
一般工业技术   143篇
冶金工业   222篇
原子能技术   9篇
自动化技术   68篇
  2023年   10篇
  2022年   17篇
  2021年   32篇
  2020年   22篇
  2019年   25篇
  2018年   24篇
  2017年   30篇
  2016年   26篇
  2015年   15篇
  2014年   17篇
  2013年   37篇
  2012年   31篇
  2011年   50篇
  2010年   37篇
  2009年   31篇
  2008年   27篇
  2007年   28篇
  2006年   21篇
  2005年   17篇
  2004年   14篇
  2003年   16篇
  2002年   10篇
  2001年   12篇
  2000年   9篇
  1999年   8篇
  1998年   45篇
  1997年   26篇
  1996年   16篇
  1995年   22篇
  1994年   19篇
  1993年   9篇
  1992年   7篇
  1991年   5篇
  1990年   7篇
  1989年   3篇
  1987年   4篇
  1986年   3篇
  1985年   10篇
  1984年   7篇
  1983年   5篇
  1982年   5篇
  1981年   6篇
  1980年   11篇
  1979年   6篇
  1978年   5篇
  1977年   14篇
  1976年   10篇
  1973年   5篇
  1972年   3篇
  1971年   3篇
排序方式: 共有836条查询结果,搜索用时 15 毫秒
101.
Discusses articles by D. E. Polkinghorne (see record 1985-07630-001), G. S. Howard (see record 1985-07626-001), and M. J. Patton (see record 1985-07629-001), who recommended that counseling research be reoriented. The accepted definition of science, based primarily on the work of pre-20th-century physical scientists, does not fit in with the current advanced thinking about the philosophy of science. Similarities and differences in the 3 articles are considered, and problems that arise from the inadequacy of available psychometric and statistical techniques for the new kinds of research envisaged are discussed. It is concluded that the rethinking of some assumptions with regard to determinism and the way counseling is defined are necessary. (4 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
102.
The development of the competent self in adolescence, the interrelationship of psychotherapeutic and psychoeducational change, and the role of the high school counselor as a mental health gatekeeper were explored in a pre–post experimental–control design study of group counseling. 147 exemplary ("getting their lives together well and handling school well") and marginal ("having trouble getting their lives together and managing school") high school students participated. Precounseling assessments and patterns of change over the counseling period supported the 1st author's hierarchical competence configuration model of psychosocial functioning, consisting of self-attitudes, world-attitudes, and relevant behavioral attributes. Overall effectiveness of counseling was indicated at multiple levels by significant goal attainment (Kiresuk-Sherman Goal Attainment Scale) and by increased self-efficacy (Rotter's Internal–External Locus of Control Scale). The impact of counseling was significantly different for exemplary than for marginal students and for students from different race and sex subgroups. These findings confirm the interrelation of change patterns at behavioral and personality levels, the importance of sociocultural factors in individual psychosocial change patterns, and the potential therapeutic impact of relatively brief psychoeducational-psychotherapeutic interventions. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
103.
Plasmas or ionized gases, existing at temperatures as high as 50,000°C, constitute the highest controlled temperatures known. At these temperatures, reactions occur about which we have little or no knowledge. This paper explores. the various possibilities of using plasma devices for extractive metallurgy.  相似文献   
104.
When funds are tight, design and development are curtailed first; however, marketing is one of the last areas to go. That's the view of two recent electrical engineering graduates who spent last summer in a ten-week pilot program for junior marketing engineers. The marketing assistantship program described here was developed by the Hewlett-Packard Co. to acquaint engineering undergraduates with the job opportunities available in marketing. The authors soon realized that their initial impressions of this field were somewhat misleading.  相似文献   
105.
The performances of 1 g h?1 and 20 kg h?1 flash pyrolysers are compared for three Australian coals: Loy Yang brown coal (Victoria), Liddell bituminous coal (New South Wales), and Millmerran sub-bituminous coal (Queensland). The two reactors gave comparable yields of tar, char and C1–C3 hydrocarbon gases over a range of operating conditions for each particular coal. The yield of total volatile matter from Millmerran coal was similar from both reactors, as were the compositions of chars from Loy Yang coal and tars from the Liddell and Millmerran coals. For Millmerran coal, the yields of tar, C1–C3 gases and volatiles from the large reactor below 650 °C, were slightly lower than for the small reactor, possibly owing to a shorter retention time of Millmerran coal particles in the large-scale reactor. At a temperature near 600 °C tar yields were independent of tar concentration in the effluent gas, over a range 0.0025–0.1 kg m?3 for Liddell coal, 0.005–0.26 kg m?3 for Millmerran coal and 0.0045–0.09 kg m?3 for Loy Yang coal. The tar yields from Millmerran and Liddell coals at 600 °C in the large reactor, correlate directly with the atomic HC ratio of the parent coal, in the same manner as that found for a wider range of bituminous coals in the small-scale reactor.  相似文献   
106.
Using a national sample of hospital discharges, we found identical seasonal patterns for spontaneous abortions and conceptions but no significant seasonal variation in the rate of spontaneous abortions per 1,000 conceptions. The differences between our findings and those of previous investigators of spontaneous abortion may reflect our more comprehensive definition of spontaneous abortion, our more complete estimate of the monthly number of conceptions, and our more rigorous statistical analysis. The periodic regression analysis (PRA) reported in our study may be useful in other studies that monitor short-term trends.  相似文献   
107.
The Cartter Report and Roose-Andersen Reports (sponsored by the American Council of Education) on quality of graduate education in American universities have been used as a basis for national policy and funding judgments, and for institutional, academic discipline, and student applicant uses. It is argued that instead of serving the public purposes for which they were intended, these reports serve more directly private guild interests of the participating disciplines, particularly psychology. Reasons include the fact that psychology has become increasingly technician-oriented, and the sampling procedure used to select raters and the questions asked were biased. These issues could be better approached by defining appropriate models of excellent graduate programs, developing scales for rating the variables considered to contribute to excellence, and then assessing the validity of those measures. The consequences of present biased rating procedures are far too significant for society and students for psychologists to continue to ignore. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
108.
A workable psychology of individuality is "one that would generate good research ideas, which, in turn, would lead to steady increases in dependable knowledge." Individual uniqueness "is described primarily in terms of choice and organization, and I consider it the task of psychologists to make those concepts workable—to bring them into the general stream of thinking in research, assessment, and practical activities." Tyler stresses "the significance of concepts of choice and organization in an inclusive psychology of the development of the human individual… . At each stage of our lives, we impose limits on the next stage, by the choices we make and the ways in which we organize what we have experienced." (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
109.
110.
A useful review of issues of health and safety linked to legislation, as well as highlighting the most serious types of accidents identified in the survey.  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