全文获取类型
收费全文 | 3066篇 |
免费 | 50篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 27篇 |
综合类 | 3篇 |
化学工业 | 652篇 |
金属工艺 | 46篇 |
机械仪表 | 54篇 |
建筑科学 | 154篇 |
矿业工程 | 43篇 |
能源动力 | 72篇 |
轻工业 | 253篇 |
水利工程 | 14篇 |
石油天然气 | 9篇 |
无线电 | 203篇 |
一般工业技术 | 351篇 |
冶金工业 | 875篇 |
原子能技术 | 23篇 |
自动化技术 | 341篇 |
出版年
2022年 | 37篇 |
2021年 | 48篇 |
2020年 | 24篇 |
2019年 | 23篇 |
2018年 | 25篇 |
2017年 | 36篇 |
2016年 | 44篇 |
2015年 | 35篇 |
2014年 | 42篇 |
2013年 | 235篇 |
2012年 | 76篇 |
2011年 | 94篇 |
2010年 | 78篇 |
2009年 | 90篇 |
2008年 | 78篇 |
2007年 | 115篇 |
2006年 | 87篇 |
2005年 | 79篇 |
2004年 | 78篇 |
2003年 | 69篇 |
2002年 | 75篇 |
2001年 | 51篇 |
2000年 | 42篇 |
1999年 | 59篇 |
1998年 | 52篇 |
1997年 | 52篇 |
1996年 | 62篇 |
1995年 | 53篇 |
1994年 | 66篇 |
1993年 | 52篇 |
1992年 | 45篇 |
1990年 | 58篇 |
1989年 | 44篇 |
1988年 | 40篇 |
1987年 | 39篇 |
1986年 | 50篇 |
1985年 | 41篇 |
1984年 | 48篇 |
1983年 | 38篇 |
1982年 | 46篇 |
1981年 | 37篇 |
1980年 | 35篇 |
1979年 | 53篇 |
1978年 | 42篇 |
1977年 | 40篇 |
1976年 | 26篇 |
1975年 | 34篇 |
1974年 | 43篇 |
1971年 | 26篇 |
1970年 | 25篇 |
排序方式: 共有3120条查询结果,搜索用时 0 毫秒
951.
Jean Philippe Michael Batty Geoffrey J. D. Hewings Roger L. Burford Emilio Haddad Dennis H. Sullivan Aribert B. Peters Lay James Gibson James M. Murray Michael Whitbread Wilbur A. Steger Marie A. Jarochowska John R. McKean Wal van Lierop Erwin S. Mayer K. Shimizu James L. Mulvihill F. J. Potgieter C. Murray Austin Brenton M. Barr Ronald Reed Boyce Marc Penouil John F. Jakubs Ernst A. Brugger Arthur Grey H. J. van Hunnik C. J. Robertson David E. Clarke A. H. Studenmund Gene R. Kirschner Milton Wilkinson Thomas W. Langford Gerald Hodge William R. Eadington Charles G. Schmidt 《The Annals of Regional Science》1982,16(3):103-158
952.
"3 factors importantly affect the successful achievement of the objectives of the comprehensive community mental health center approach: (1) The centers must be free from restrictions which dampen or thwart the emergence of new patterns of service. (2) The centers must be free to take advantage of demonstrated leadership capability from whatever source it may come—medical or nonmedical. (3) Under these conditions of exciting new programs and challenging opportunities for leadership and service, the provisions of H.R. 2985 become the crucial 3rd factor in the success of the centers. Initial staffing support becomes the key ingredient. The 50 State Psychological Associations which are constituent parts of the national organization are intimately concerned with this new legislation." (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
953.
954.
Responds to the J. B. Kruskal and R. N. Shepard (see record 1975-00098-001) work in which a solution to the problem of nonmetric factor analysis is offered. An investigation comparing this method and factor analysis of rank-ordered data suggests that the practicality of the Kruskal-Shepard method is limited by computational cost and sensitivity to random error. In situations in which linearity is questioned, an attractive practical alternative that is much less costly and substantially more robust to random error is linear principal-components analysis of the rank-ordered data. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
955.
Earle K. Plyler Eugene D. Tidwell Arthur G. Maki 《Journal of research of the National Institute of Standards and Technology》1964,(1):79-86
The frequencies of the vibration-rotation spectrum of N2O have been measured from 1830 cm−1 to 2270 cm−1. A number of weak bands have been measured and assigned to “hot bands’’ and isotopic species in normal abundance. By using the Ritz principle and previously measured bands the bending frequency (v2) is calculated as 588.780 cm−1. Frequencies are given for lines arising from the three principal transitions found in this region. 相似文献
956.
Studied the effects of item stem orientation (positive-negative), structure (open-closed), and inclusive alternatives on item difficulty and discrimination. Data were obtained from 1,124 undergraduates taking a regularly scheduled test. Results indicate that item difficulty was critically affected by all 3 independent variables with no interactions and that item discrimination was affected by the use of an inclusive alternative with a significant interaction between orientation and stem structure. Suggestions are made with respect to effective item-writing strategies. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
957.
Matarazzo Joseph D.; Wiens Arthur N.; Shealy Allen E. 《Canadian Metallurgical Quarterly》1978,46(3):571
10 pairs of brothers with a mean age of 24 yrs and a mean age of 13 yrs of education were individually examined with the WAIS some 10 mo apart by a highly experienced clinical psychologist who was unaware of the consanguineous relationship. The obtained correlation of .42 for Full Scale IQ is consistent with the median correlation of .49 reported by L. Erlenmeyer-Kimling and L. F. Jarvik (see record 1964-05563-001) in their review of the literature. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
958.
"Clinical psychology in Britain is a postwar development." Clinical psychology in the National Health Service is discussed in a major section of the article. "The past decade has… seen a rapid growth of clinical psychology in Britain from small beginnings. In 1945, 77 members of the British Psychological Society were identified as a group of professional psychologists in the field of mental health. Today some 400 are members of this group. "Psychologists in Britain have been vigorous in shaping their professional status. Training facilities are being extended and efforts made to extend them further. Higher degrees are encouraged. The structure of the psychological service is flexible, and adjustments have been made in response to new demands. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
959.
6th-grade school children were given systematically varied choices from among several toys in order to test 2 derivations from Festinger's theory of psychological dissonance (see 32: 347). This theory states: "the magnitude of dissonance and consequent amount of increased liking for the chosen alternative and decreased liking for the unchosen alternative increases with (a) the qualitative dissimilarity of alternatives, and (b) the number of alternatives." (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
960.
The MMPI was administered to 712 college freshmen and 114 seniors. The seniors also took the California F scale. A year later 312 of the freshmen retook the MMPI. The MMPI Pr scores piled up at the low end of the distribution. The Pr reliability was .81. Mean Pr decreased with advance in college. Mean Pr scores differed significantly for different college majors. Pr correlated significantly with the F scale; positively with Hs, D, Pd, Pt, Sc, and Ma; and negatively with K and Hy. Certain psychopathological factors are considered to be present in the authoritarian syndrome. 21 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献