全文获取类型
收费全文 | 827篇 |
免费 | 18篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 33篇 |
化学工业 | 220篇 |
金属工艺 | 8篇 |
机械仪表 | 16篇 |
建筑科学 | 55篇 |
矿业工程 | 7篇 |
能源动力 | 19篇 |
轻工业 | 133篇 |
水利工程 | 9篇 |
无线电 | 31篇 |
一般工业技术 | 95篇 |
冶金工业 | 116篇 |
原子能技术 | 5篇 |
自动化技术 | 101篇 |
出版年
2019年 | 7篇 |
2016年 | 12篇 |
2015年 | 15篇 |
2014年 | 13篇 |
2013年 | 26篇 |
2012年 | 32篇 |
2011年 | 30篇 |
2010年 | 21篇 |
2009年 | 23篇 |
2008年 | 30篇 |
2007年 | 36篇 |
2006年 | 24篇 |
2005年 | 26篇 |
2004年 | 27篇 |
2003年 | 20篇 |
2002年 | 15篇 |
2001年 | 12篇 |
2000年 | 14篇 |
1999年 | 21篇 |
1998年 | 18篇 |
1997年 | 14篇 |
1996年 | 14篇 |
1995年 | 15篇 |
1994年 | 7篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 15篇 |
1990年 | 16篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1986年 | 9篇 |
1985年 | 7篇 |
1984年 | 14篇 |
1983年 | 10篇 |
1982年 | 9篇 |
1981年 | 10篇 |
1980年 | 7篇 |
1979年 | 10篇 |
1978年 | 12篇 |
1977年 | 14篇 |
1976年 | 7篇 |
1975年 | 14篇 |
1974年 | 11篇 |
1973年 | 18篇 |
1972年 | 11篇 |
1971年 | 10篇 |
1970年 | 16篇 |
1969年 | 9篇 |
1968年 | 7篇 |
1967年 | 7篇 |
排序方式: 共有848条查询结果,搜索用时 437 毫秒
841.
842.
Wilson G. Terence; Loeb Katharine L.; Walsh B. Timothy; Labouvie Erich; Petkova Eva; Liu Xinhua; Waternaux Christine 《Canadian Metallurgical Quarterly》1999,67(4):451
This article extends the acute outcome findings from a study comparing psychological and pharmacological interventions for bulimia nervosa (B. T. Walsh et al., 1997) by examining 3 additional domains: predictive factors, therapeutic alliance, and time course of change. One hundred twenty women were randomized to cognitive-behavioral therapy (CBT), supportive psychotherapy (SPT) plus antidepressant medication or a placebo, or a medication-alone condition. Results indicate that high baseline frequencies of binge eating and vomiting, as well as a positive history of substance abuse or dependence, are negative prognostic indicators. Although a greater overall therapeutic alliance may increase the likelihood of remission, symptom change over the course of treatment may have as much of an impact on patient ratings of alliance as the reverse. CBT was significantly more rapid than SPT in reducing binge eating and vomiting frequencies. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
843.
Used longitudinal data from 1,308 Ss to describe the situational variety of adolescent alcohol and marijuana use over the age period of 12–21 yrs. The relationships among 3 facets of use (intensity, functional elaboration, and lack of situational constraint of use) were examined. The 3 facets of use were found to increase simultaneously with increasing age and to be positively correlated with each other. Marijuana use was found to be situationally less constrained than alcohol use from the age of 15 yrs on. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
844.
Katja Schmölz Agnes Felber Mark Wolfgang Melanie Thaler Josef Wieser Simone Persiano Giacomo Bertoldi Erich Tasser 《河流研究与利用》2023,39(6):1037-1053
Stream ecosystems are diverse and dynamic habitats that are strongly influenced by the direct and indirect consequences of human interventions. Several initiatives have been started all over Europe to satisfy the European guidelines for the protection of local water bodies, but a standardised procedure across national borders fulfilling all relevant aspects and parameters of the Water Framework Directive (WFD) does not exist. In this context, we propose a new methodical approach based on salmonid fish populations to assess stream quality to increase the comparability of individual assessments due to standardized survey and evaluation methods for hydromorphology. Our approach is based on the Austrian and Italian methods, which account for the European standards, and it has been tested in 81 stream sections representative of different site and anthropogenic use conditions in the European Alps. The assessment procedure is composed of a set of 11 indicators, which were selected to evaluate longitudinal and lateral morphological and temporal dynamics of morphological and hydrological conditions. The indicators were combined into three indices, the morphology (IM), hydrology (IH), and hydromorphology indices (IHM), to obtain a holistic picture with as few parameters as possible. The definition of indicators and indices, their methodical implementation and practical testing in the field, were carried out by an interdisciplinary team of international experts. The resulting and tested field manual is included with this publication as Supplementary material. The applicability, strengths, and weaknesses of the approach are discussed in the present paper. 相似文献
845.
846.
Erich Frank 《Starch - St?rke》1980,32(1):1-4
Possibilities of Energy Saving in Evaporation, with Industrial Examples. In order to render the evaporation process still more economical than up to now the energy consumption or part of the energy consumption of an evaporation plant is covered by waste heat, e. g. by vapour produced in processes proceeding under low vacuum. Mixtures of water vapour and air, e. g. from driers, are also suitable for heating vacuum evaporation plants. Evaporators which shall consume small quantities of steam and cooling water only will be equipped with mechanical vapour compressors. This, however, involves high investment costs. 相似文献
847.
848.