全文获取类型
收费全文 | 399115篇 |
免费 | 4433篇 |
国内免费 | 1272篇 |
专业分类
化学 | 213271篇 |
晶体学 | 4733篇 |
力学 | 18208篇 |
综合类 | 16篇 |
数学 | 45454篇 |
物理学 | 123138篇 |
出版年
2020年 | 3009篇 |
2019年 | 3292篇 |
2018年 | 4097篇 |
2017年 | 4104篇 |
2016年 | 6439篇 |
2015年 | 4291篇 |
2014年 | 6364篇 |
2013年 | 17170篇 |
2012年 | 13211篇 |
2011年 | 16333篇 |
2010年 | 11111篇 |
2009年 | 11022篇 |
2008年 | 15193篇 |
2007年 | 15446篇 |
2006年 | 14570篇 |
2005年 | 13358篇 |
2004年 | 12154篇 |
2003年 | 10882篇 |
2002年 | 10138篇 |
2001年 | 11609篇 |
2000年 | 8736篇 |
1999年 | 6520篇 |
1998年 | 5404篇 |
1997年 | 5476篇 |
1996年 | 5161篇 |
1995年 | 5021篇 |
1994年 | 5093篇 |
1993年 | 4661篇 |
1992年 | 5385篇 |
1991年 | 5406篇 |
1990年 | 5090篇 |
1989年 | 4982篇 |
1988年 | 5050篇 |
1987年 | 4947篇 |
1986年 | 4645篇 |
1985年 | 6478篇 |
1984年 | 6752篇 |
1983年 | 5560篇 |
1982年 | 5809篇 |
1981年 | 5659篇 |
1980年 | 5575篇 |
1979年 | 5560篇 |
1978年 | 5919篇 |
1977年 | 5849篇 |
1976年 | 5872篇 |
1975年 | 5526篇 |
1974年 | 5478篇 |
1973年 | 5698篇 |
1972年 | 3839篇 |
1971年 | 3018篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Susan C. Scott Nicole M. Anders Ping He Avelina Hemingway Steven D. Gore Christine L. Hann Michelle A. Rudek 《Biomedical chromatography : BMC》2022,36(3):e5289
The Bcl-2 family small molecule inhibitor navitoclax is being clinically evaluated to treat multiple cancers including lymphoid malignancies and small cell lung cancer. A sensitive and reliable method was developed to quantitate navitoclax in human plasma using liquid chromatography with tandem mass spectrometry with which to perform detailed pharmacokinetic studies. Sample preparation involved protein precipitation using acetonitrile. Separation of navitoclax and the internal standard, navitoclax-d8, was achieved with a Waters Acquity UPLC BEH C18 column using isocratic flow over a 3 min total analytical run time. A SCIEX 4500 triple quadrupole mass spectrometer operated in positive electrospray ionization mode was used for the detection of navitoclax. The assay range was 5–5,000 ng/ml and proved to be accurate (89.5–104.9%) and precise (CV ≤ 11%). Long-term frozen plasma stability for navitoclax at −70°C was at least 43 months. The method was applied for the measurement of total plasma concentration of navitoclax in a patient receiving a 250 mg daily oral dose. 相似文献
42.
Chemistry of Natural Compounds - 相似文献
43.
Sakhautdinova G. F. Sakhautdinov I. M. Mustafin A. G. Yunusov M. S. 《Chemistry of Natural Compounds》2022,58(1):185-186
Chemistry of Natural Compounds - 相似文献
44.
Chemistry of Natural Compounds - O- and N-propylamino-derivatives of betulin and betulonic acid oxime and methyl ester were synthesized. Their antitumor activity against a panel of 60 human cancer... 相似文献
45.
Automotive proton exchange membrane fuel cell stacks need to meet manufacturer specified rated beginning-of-life (BOL) performance before being assembled into vehicles and shipped off to customers. The process of “breaking-in” of a freshly assembled stack is often referred to as “conditioning.” It has become an intensely researched area especially in automotive companies, where imminent commercialization of fuel cell electric vehicles (FCEVs) demands a short, energy- and cost-efficient, and practical conditioning protocol. Significant advances in reducing the conditioning time from 1 to 2 days to as low as 4h or less, in some cases without the use of additional inert gases such as nitrogen, and with minimal use of hydrogen, and specialized test stations will be discussed. 相似文献
46.
Yang T. L. Kao C. L. Kuo C. E. Yeh H. C. Li W. J. Li H. T. Chen C. Y. 《Chemistry of Natural Compounds》2022,58(5):825-827
Chemistry of Natural Compounds - A novel bibenzyl derivative, hydrangchinenin (1), was isolated from the stems of Hydrangea chinensis Maxim. (Hydrangeaceae). Its structure was determined on the... 相似文献
47.
Chuprin A. S. Belova S. A. Bugaenko M. G. Vologzhanina A. V. Loktev A. S. Voloshin Ya. Z. Buznik V. M. Dedov A. G. 《Kinetics and Catalysis》2022,63(1):108-116
Kinetics and Catalysis - A new ruthenium(II) cage complex with polar terminal groups in the apical substituents has been synthesized; the molecular design of the complex contributes to the... 相似文献
48.
Moscow University Chemistry Bulletin - This review is devoted to the development, properties, and application of biosensors based on graphene nanomaterials. It is shown that such biosensors are... 相似文献
49.
High Energy Chemistry - Modification of Polyvinylidene fluoride (PVDF) by radiation grafting is a research hotspot in recent years. In this study, the monomer 2-Hydroxyethyl methacrylate (HEMA) was... 相似文献
50.
Romanenko G. V. Fokin S. V. Bogomyakov A. S. Zueva E. M. Ovcharenko V. I. 《Journal of Structural Chemistry》2022,63(3):441-450
Journal of Structural Chemistry - The structures of Ni(II), Cu(II), and Zn(II) complexes with anions of 2,5-pyrrolyl-disubstituted nitronyl nitroxide (L1) and iminonitroxide (L2) diradicals (HL1 is... 相似文献