全文获取类型
收费全文 | 208篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 9篇 |
化学工业 | 15篇 |
金属工艺 | 3篇 |
机械仪表 | 3篇 |
建筑科学 | 7篇 |
能源动力 | 2篇 |
轻工业 | 5篇 |
水利工程 | 2篇 |
无线电 | 21篇 |
一般工业技术 | 37篇 |
冶金工业 | 93篇 |
自动化技术 | 15篇 |
出版年
2021年 | 2篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 16篇 |
2012年 | 5篇 |
2011年 | 5篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 3篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 10篇 |
1998年 | 23篇 |
1997年 | 15篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1977年 | 1篇 |
1976年 | 5篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1967年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
1961年 | 1篇 |
1960年 | 1篇 |
1959年 | 2篇 |
排序方式: 共有212条查询结果,搜索用时 15 毫秒
151.
BACKGROUND: There are cogent reasons why public health specialists should take an active interest in and measure the psychological health and well-being of populations. The literature was searched and reviewed with the aim of evaluating survey instruments that would enable public health specialists to measure the psychological health and well-being of populations. METHODS: The search and review were restricted to instruments that were applicable to adults of working age, and that did not focus on psychotic disorder or organic brain disorder. An attempt was also made to identify instruments that were designed to measure some form of positive well-being and could be applied in population-based surveys. Detailed evaluation was then carried out of two or three instruments that appeared representative of a particular field or approach. RESULTS: The literature search revealed three major fields of research, 'Psychiatric Epidemiology', 'Stress Studies' and 'Subjective Well-being'. Accordingly, the results of the review are presented under these three headings. Results pertaining to commonly used survey instruments in the field of 'Psychiatric Epidemiology' are presented. (Those on 'Stress Studies' and 'Subjective Well-being' are presented in Part 2 of this study.) CONCLUSIONS: Although some questionnaires in the field of 'Psychiatric Epidemiology', such as the General Health Questionnaire and the HAD Scale, offer a valid and convenient means of measuring degrees of neurotic disorder in a population, they do not measure any form of positive well-being. In Part 2, methods of measurement from the other two fields are reviewed and overall conclusions are drawn about the options available to public health specialists. 相似文献
152.
This paper is the second of two parts describing the procedure of, and results from, a series of tests on ring and orthogonally stiffened thin-walled shells. The primary purpose of the work was to investigate the collapse behaviour of the shells subjected to simulated damage and then tested under a combination of external pressure and axial compressive loading.The test specimens consisted of two five-bay cylinders stiffened with plain ring stiffeners; two three-bay cylinders stiffened with T-ring stiffeners and two three-bay orthogonally stiffened cylinders, one with twenty stringers, and the other with forty.This Part II deals with the tests on the T-ring and orthogonally stiffened shells. It is concluded from the test results that the T-ring stiffeners were much more effective than the corresponding plain-rings with regard to limiting the deformations which would result from minor impacts and practical conditions of loading. It is generally recommended that plain rings should not be used in shells which form parts of structural components potentially liable to damage from a minor collision, etc. It is also recommended that further work be done, including analysis and testing, to determine the optimum design of T-ring stiffeners to limit the effects of damage in an effective manner. 相似文献
153.
Techniques were tested to ascertain the best method for preparing the surfaces of delicate plant cuticles for microscopic examination at magnifications not exceeding 10,000. Using scanning electron microscopy, comparative examinations were made of cuticles of fresh material, ambient dried, freeze dried, critical point dried, and frozen material kept at low temperature. Micrographs were compared with material examined using light microscopy which acted as a control at low magnification. Cuticles of the leaves of runner bean, Coleus and the petals of Nicotiana, showed best surface preservation and least wrinkling when frozen, held at low temperature, and examined on a cryostage. 相似文献
154.
Passner A. Gibbs H. Gossard A. McCall S. Venkatesan T. Wiegmann W. 《Quantum Electronics, IEEE Journal of》1980,16(12):1283-1285
Lasing was observed in a 4.5 μm thick GaAs MBE-grown heterostructure (0.2 μm Al0.42 Ga0.58 As, 4.1 μm GaAs, 0.21 μm AlGaAs). The laser was driven by pulses from a mode-locked Ar laser (514.5 nm) with a maximum of 20 W peak power in 100 ps long pulses focused to 25 μm. The lasing occured along the pump axis within a cavity defined by the coated AlGaAs surfaces. 相似文献
155.
MF Piercey AH Tang RA Lahti PF VonVoigtlander PJ Schreur RB McCall JT Lum-Ragan WE Hoffmann SR Franklin RA Code 《Canadian Metallurgical Quarterly》1994,268(3):1304-1310
U-67413B (4-hydroxydipropylaminodihydrophenalene) bound with high affinity to both 5-hydroxytryptamine (HT)1A and D2-dopamine (DA) receptor sites. U-67413B depressed 5-HT and DA cell firing rates and depressed synthesis of both neurotransmitters. The drug depressed mouse body temperatures by an amount similar to that for buspirone, gepirone and ipsapirone, but less than that for 8-hydroxy-N,N-dipropyl-2-aminotetralin. In rats, it produced the 5-HT1A behavioral syndrome. In contrast to 5-HT1A agonists having DA antagonist effects, U-67413B mildly depressed rather than stimulated firing rates of noradrenaline (NA) neurons in the locus ceruleus by a non-alpha-2 receptor mechanism. In behavioral tests designed to measure anxiolytic activities, U-67413B was a slightly more effective anxiolytic than standard 5-HT1A anxiolytics (buspirone, gepirone and ipsapirone). The data are consistent with the hypothesis that effects of 5-HT1A agonists on NA neuron activity are mediated through effects on dopaminergic mechanisms, and that effects on NA neurons could modulate anxiolytic activities of 5-HT1A agonists. 相似文献
156.
Presents some principles of promoting interdisciplinary education and research within a university and of facilitating mutually beneficial and productive relations between university faculty and community human service providers. They are illustrated with examples from the operation of the University of Pittsburgh Office of Child Development, which serves these goals for more than 700 faculty and 585 community agencies concerned with children, youth, and families. (0 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
157.
158.
159.
160.