全文获取类型
收费全文 | 489篇 |
免费 | 15篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 7篇 |
综合类 | 2篇 |
化学工业 | 161篇 |
金属工艺 | 10篇 |
机械仪表 | 17篇 |
建筑科学 | 5篇 |
能源动力 | 80篇 |
轻工业 | 11篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 15篇 |
一般工业技术 | 91篇 |
冶金工业 | 15篇 |
原子能技术 | 2篇 |
自动化技术 | 86篇 |
出版年
2022年 | 8篇 |
2021年 | 9篇 |
2020年 | 4篇 |
2019年 | 9篇 |
2018年 | 7篇 |
2017年 | 11篇 |
2016年 | 18篇 |
2015年 | 16篇 |
2014年 | 17篇 |
2013年 | 39篇 |
2012年 | 39篇 |
2011年 | 38篇 |
2010年 | 30篇 |
2009年 | 35篇 |
2008年 | 36篇 |
2007年 | 20篇 |
2006年 | 12篇 |
2005年 | 13篇 |
2004年 | 15篇 |
2003年 | 12篇 |
2002年 | 12篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 11篇 |
1997年 | 2篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 8篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 3篇 |
1938年 | 3篇 |
排序方式: 共有506条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
5.
6.
Nicotin und Ioan D. Vldescu 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1938,75(5):450-457
Ohne Zusammenfassung 相似文献
7.
8.
IM Boier Martin DC Marinescu RE Lynch TS Baker 《Canadian Metallurgical Quarterly》1997,120(2):146-157
Interferon-gamma (IFN-gamma) has the most potent immunomodulatory activity of all the interferons. This phase II-B study was performed to define time- and dose-dependent immunomodulatory effects mediated by IFN-gamma in a subset of patients with melanoma treated in the dose-seeking therapeutic trial conducted by the Eastern Cooperative Oncology Group E4687 (13). The effects of IFN-gamma (Genentech, San Francisco, CA) were evaluated for phenotype and function of peripheral blood lymphocytes obtained twice prestudy, and on days 2, 9, and 29 of IFN-gamma therapy for 50 patients. Early significant increases in CD4/CD8 ratio (p = 0.001) were noted, largely due to a rise in CD4+ and fall in CD8+ T-cell populations sustained through day 29 at only the lowest dosage. Increased natural killer cell (NK) activity (p = 0.001 on day 9; p = 0.01 on day 29) was accompanied by durable increases in circulating activated NK cells (CD56+DR+% p = 0.001, day 9; p = 0.001, day 29). After initial depression of CD56+ and CD16+ cells on day 2, the total percent of CD56+ and CD16+ cells increased significantly by day 29. Increases in NK cell activity were maximal at doses > or =0.1 mg. Monocyte CD14+ expression of DQ+ rose early (p = 0.011 and 0.001 on days 2 and 9), accompanied by elevation in CD14+DR+ cells that was less significant. Immunomodulatory effects of IFN-gamma reported in this trial have major implications for interpretation of past and current clinical trials, and the design of future trials. This is the first trial in which IFN-gamma has been shown to have significant effects on the T-cell compartment of the immune system. 相似文献
9.
Maria Bercea Silvia Ioan Bogdan C. Simionescu Cristofor I. Simionescu 《Polymer Bulletin》1992,27(5):571-575
Summary Systematic studies on solution properties of ultrahigh molecular weight polymers showed the existence of some special features as compared to usual length polymers. The paper discusses the possible appearance of branched structures in the polymerization process, structures able to influence the mentioned features. From experimental data on poly(methyl methacrylate), poly(butyl methacrylate) and polyacrylonitrile it appears that branching can be excluded, and the very high molecular weight domain considered may be responsible for the modifications observed in the molecular weight dependences on 2>, A2 or []. 相似文献
10.
An unsaturated adduct has been synthesized by the Diels-Alder reaction between resin acids and diallyl maleate. The obtained polymerizable product can be used both as monomer in the formation of allyl polymers and crosslinking agent. The monomer and its polymers were investigated by usual physical and chemical methods. The synthesized polymers present a linear structure, possibly associated with intramolecular cyclization at low molecular weights, or a three-dimensional structure at high conversions. They are fairly thermostable substances with carboxylic groups in the polymer chain. 相似文献