首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   80493篇
  免费   674篇
  国内免费   112篇
化学   42799篇
晶体学   1276篇
力学   3334篇
综合类   1篇
数学   8209篇
物理学   25660篇
  2022年   646篇
  2021年   903篇
  2020年   997篇
  2019年   1135篇
  2018年   1619篇
  2017年   1710篇
  2016年   2260篇
  2015年   1135篇
  2014年   1865篇
  2013年   3546篇
  2012年   2999篇
  2011年   3351篇
  2010年   2719篇
  2009年   2696篇
  2008年   3057篇
  2007年   2912篇
  2006年   2849篇
  2005年   2459篇
  2004年   2265篇
  2003年   2102篇
  2002年   2178篇
  2001年   2266篇
  2000年   1678篇
  1999年   1286篇
  1998年   1165篇
  1997年   1070篇
  1996年   927篇
  1995年   871篇
  1994年   842篇
  1993年   848篇
  1992年   891篇
  1991年   966篇
  1990年   911篇
  1989年   930篇
  1988年   866篇
  1987年   804篇
  1986年   773篇
  1985年   919篇
  1984年   1014篇
  1983年   853篇
  1982年   865篇
  1981年   776篇
  1980年   741篇
  1979年   808篇
  1978年   928篇
  1977年   959篇
  1976年   854篇
  1975年   815篇
  1974年   842篇
  1973年   797篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Russian Journal of General Chemistry - Aminophosphabetaines, i.e., isobutyl {[alkyl(dimethyl)ammonio]methyl}phosphonates with higher alkyl substituents at the nitrogen atom, were obtained by a...  相似文献   
2.
Kinetics and Catalysis - The results of studies in the field of synthesis and characterization of layered double hydroxides (LDHs) obtained using solid-phase reactions are summarized. The effect of...  相似文献   
3.
Mechanics of Composite Materials - Carbon fiber (CF)/ polyamide (PA6) composites are one of the most promising thermoplastic materials for automobile applications. However, the interfacial...  相似文献   
4.
Russian Journal of Applied Chemistry - A method for the disposal of hydrolysis lignin waste based on its modification with ZnCl2 and FeCl3 and subsequent carbonization at 800°C was proposed....  相似文献   
5.
Mathematical Notes - Subspaces of the space of analytic functions on a convex domain in the complex plane that are invariant with respect to the differentiation operator are studied. The problem of...  相似文献   
6.
Crystallography Reports - Two LiInSe2 single crystals, grown under different conditions, have been studied. Characteristics of these crystals for neutron detection have been compared using...  相似文献   
7.
Journal of Russian Laser Research - We analyze the way of advancing to tender X-rays the short-wavelength bound of the operating range of flat-field grating spectrographs. We design two VLS grating...  相似文献   
8.
Ukrainian Mathematical Journal - We establish new criteria of compatibility for a linear system of equations (equivalent to the Kronecker–Capelli theorem) or inequalities (equivalent to the...  相似文献   
9.
Crystallography Reports - The specific features of the formation of crystallites in gallium arsenide crystals grown by the Czochralski method have been investigated. The crystallites are found to...  相似文献   
10.
Riociguat is novel antihypertensive drug for treatment of pulmonary hypertension. As such, it is still being tested in many clinical and pharmacokinetic trials. Existing methods that determine serum riociguat and desmethylriociguat (DMR) are based solely on liquid chromatography with mass spectrometry. Therefore, we present a novel capillary electrophoresis with mass spectrometry method (CE-MS) for their determination in human serum as alternative method for ongoing trials. Complete resolution of both analytes was achieved by means of pH optimization of ammonium formate background electrolytes that are fully compatible with ESI/MS detection. Simple liquid-liquid extraction was used as sample pretreatment. The calibration dependence of the method was linear (in the range of 10–1000 ng/mL), with adequate accuracy (90.1–114.9%) and precision (13.4%). LOD and LOQ were arbitrarily set at 10 ng/mL for both analytes. Clinical applicability was validated using serum samples from patients treated with riociguat in pharmacokinetic study and the results corresponded with reference HPLC-MS/MS values. Capillary electrophoresis proved to be sensitive and selective tool for the analysis of riociguat and DMR.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号