全文获取类型
收费全文 | 3470篇 |
免费 | 9篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 14篇 |
综合类 | 1篇 |
化学工业 | 127篇 |
金属工艺 | 17篇 |
机械仪表 | 2篇 |
建筑科学 | 2篇 |
能源动力 | 4篇 |
轻工业 | 76篇 |
水利工程 | 3篇 |
石油天然气 | 10篇 |
无线电 | 24篇 |
一般工业技术 | 54篇 |
冶金工业 | 3128篇 |
原子能技术 | 1篇 |
自动化技术 | 18篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 13篇 |
2020年 | 10篇 |
2019年 | 8篇 |
2018年 | 7篇 |
2017年 | 3篇 |
2016年 | 12篇 |
2015年 | 4篇 |
2014年 | 8篇 |
2013年 | 23篇 |
2012年 | 9篇 |
2011年 | 17篇 |
2010年 | 16篇 |
2009年 | 18篇 |
2008年 | 14篇 |
2007年 | 14篇 |
2006年 | 8篇 |
2005年 | 10篇 |
2004年 | 5篇 |
2003年 | 11篇 |
2002年 | 6篇 |
2000年 | 5篇 |
1999年 | 119篇 |
1998年 | 1014篇 |
1997年 | 599篇 |
1996年 | 383篇 |
1995年 | 185篇 |
1994年 | 191篇 |
1993年 | 188篇 |
1992年 | 29篇 |
1991年 | 19篇 |
1990年 | 20篇 |
1989年 | 28篇 |
1988年 | 31篇 |
1987年 | 23篇 |
1986年 | 27篇 |
1985年 | 17篇 |
1984年 | 5篇 |
1983年 | 11篇 |
1982年 | 28篇 |
1981年 | 27篇 |
1980年 | 26篇 |
1979年 | 3篇 |
1978年 | 10篇 |
1977年 | 86篇 |
1976年 | 167篇 |
1975年 | 7篇 |
1974年 | 2篇 |
1965年 | 2篇 |
排序方式: 共有3481条查询结果,搜索用时 15 毫秒
1.
Heiba Zein K. Mohamed Mohamed Bakr Farag Noura M. Badawi Ali 《Journal of Materials Science: Materials in Electronics》2022,33(13):10388-10398
Journal of Materials Science: Materials in Electronics - Nano Mn0.95M0.05S (M ≡ Cu, Mg) samples were produced using molten salt solid state reaction method. Rietveld analysis of X-ray... 相似文献
2.
Radiochemistry - Azathioprine, an antitumor agent, was labeled with 99mTc using stannous chloride dihydrate as a reducing agent. Factors such as the amounts of the reducing agent and substrate, pH,... 相似文献
3.
Math1 is essential for genesis of cerebellar granule neurons 总被引:1,自引:0,他引:1
N Ben-Arie HJ Bellen DL Armstrong AE McCall PR Gordadze Q Guo MM Matzuk HY Zoghbi 《Canadian Metallurgical Quarterly》1997,390(6656):169-172
4.
5.
6.
PURPOSE: The purpose of this analysis was to appreciate the management of visually handicaped children outside specialized structures. We also assessed relays between primary physicians, hospitals and specialized structures. METHOD: A 12-question survey was sent to 144 liberal ophthalmologists of the North of France. The questionnary included 12 questions. We compared the results to litterature. RESULTS: The response-rate was 59.6%. This study indicated that the observed children by the liberal ophtalmologists had more simple diseases than in specialized structures. In hospitals, it seemed that the ophtalmologists diagnosed more severe diseases. These practitioners diagnosed some of these diseases. However some of diagnosis were to late. This study showed that specialized structures were not enough known by the practitioners who detected this handicap and that the families prefered the taking in charge near their home. CONCLUSION: We demonstrated the necessary organisation of precocious and systematic detection, and the necessary information to all practitioners on specialized structures. 相似文献
7.
8.
Flow cytometry is a unique technology useful in the examination of effects of immunotoxic agents on target cells of the immune system. The purpose of this workshop was to provide an overview of the use of flow cytometry in new and established models of immunotoxicity, with emphasis on the potential applications, assay validation, and potential pitfalls. This overview begins with a discussion of methods useful in the assessment of Ca2+-dependent mechanisms of lymphoid cell activation in surface marker-defined human B cells, T cells, and monocytes. A discussion of the use of flow cytometry in analysis of apoptosis is also presented in this paper. The second paper presents data on the development and use of flow cytometry as an alternative to a Cr51 release assay for an assessment of cytotoxic T cell activation. The use of surface markers for characterizing and distinguishing the effects of chemical irritants from sensitizers is next presented, followed by an overview of the use of fluorescent probes to assess cell thiol status and overall oxidant-induced injury to lymphoid cells. Finally, an interlaboratory study designed to compare and evaluate the use of flow cytometry procedures in rat splenic cell subtyping is presented. Overall, these studies demonstrate the utility of flow cytometry assays in immunotoxicologic research, but further efforts are needed in the validation of many of these assays for routine use in immunotoxicologic testing. 相似文献
9.
O Hanisch CA Cortella MM Boskovic RA James J Slots UM Wikesj? 《Canadian Metallurgical Quarterly》1997,68(1):59-66
Factor V Leiden mutation was initially detected in thrombophilic patients and relatives by PCR RFLP (Restriction Fragment Length Polymorphism) according to Bertina (1). This technique presents some drawbacks and the current trend is to simplify the diagnosis. We describe a technique of Allele Specific Amplification (ASA) which is optimized in terms of reliability: an additional mismatch in antepenultimate position enables to obtain the same specificity as PCR RFLP. Furthermore, coamplification of internal control warrants an optimal sensitivity. All the PCR have been simplified: the DNA extraction improvement allows to analyse the genotype with only a few microliters of whole blood whatever the anticoagulant and the procedure of preservation (freezing, dried blood spots, storage at +4 degrees C for several days). This technique saves time. Moreover, full automation of the ASA technique may be shortened thanks to the lack of extraction and the positive/negative reading of the PCR signal. 相似文献
10.