全文获取类型
收费全文 | 835篇 |
免费 | 16篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 33篇 |
化学工业 | 223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 | 12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 | 15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854条查询结果,搜索用时 15 毫秒
81.
82.
83.
Erich Bukovics 《Computing》1970,5(3):185-188
Ohne Zusammenfassung 相似文献
84.
Erich Hofstädter 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1909,17(8):436-441
Ohne ZusammenfassungMitteilung aus dem Hygienischen Institut der Universität Tübingen. 相似文献
85.
86.
Gering F Weiss W Wirth E Stapel R Jacob P Müller H Pröhl G 《Radiation protection dosimetry》2004,109(1-2):25-29
An overview of existing approaches on assessing and evaluating the radiological situation in the late phase of a nuclear accident is given in this paper. Special attention is paid to the weak points of existing approaches and to problems to be solved in the future. Assessment of the radiological situation can be based on both monitoring data and model predictions. Approaches have been developed for many years in both categories and have meanwhile reached some kind of maturity and also operational applicability. Nevertheless, some areas exist where significant improvements could be achieved in the near future, e.g. by combining monitoring data and model predictions, by improving the modelling of urban areas or by improving existing radioecological models. 相似文献
87.
88.
Morgan Thomas J.; Morgenstern Jon; Blanchard Kimberly A.; Labouvie Erich; Bux Donald A. 《Canadian Metallurgical Quarterly》2004,18(4):316
Urges to use substances is an important construct in understanding the maintenance of substance use as well as relapse. There is a need to evaluate single instruments measuring global urges to use substances (including alcohol). The Obsessive Compulsive Drinking Scale (OCDS; R. F. Anton, D. H. Moak, & P. Latham, 1995) was revised and tested as a single measure of urges to use substances. Participants were 252 adults entering outpatient substance abuse treatment. Results suggest that the revised scale (OCDS-R) primarily assesses 1 global factor for urges to use substances. In addition, strong support was found for the reliability and concurrent validity of the OCDS-R, although results for its predictive validity were mixed. The OCDS-R is a brief, psychometrically sound self-report instrument that has applicability within clinical and research settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
89.
90.
Immunoglobulin A (IgA) plays an essential role in the local defence mechanism and is part of the immunologic system. It is transported to the endothelial surface either as a monomer or as a dimer of two molecules of IgA connected by a j-chain and attached to a secretory component. The aim of the present study was to assess the relation of salivary IgA to the age of children and to assess a possible influence by acute and chronic respiratory diseases. IgA was measured in the saliva of altogether 230 children by means of radial immunodiffusion (LC-IgA Partigen, Behring) following a standardised protocol. Relation to age was measured in 159 healthy children aged one month to 15 years. The median of IgA was 36 mg/l with a range of 3.5-291 mg/l. There was no statistically significant relationship between salivary IgA and the age of the children. Median IgA in the saliva of children without any respiratory disorders (n = 169) was 36 mg/l (3.5-291 mg/l), of children with acute respiratory diseases (n = 33) 51 mg/l (3.5-257 mg/l) and of children with chronic respiratory diseases (n = 28) 47 mg/l (3.5-165 mg/l). There was no statistically significant difference between these three groups. In conclusion, the results of this study show that IgA in the saliva of children may not be related to age or influenced by acute or chronic respiratory diseases. 相似文献