全文获取类型
收费全文 | 215148篇 |
免费 | 3760篇 |
国内免费 | 460篇 |
专业分类
化学 | 122480篇 |
晶体学 | 2797篇 |
力学 | 7370篇 |
综合类 | 5篇 |
数学 | 26320篇 |
物理学 | 60396篇 |
出版年
2021年 | 1768篇 |
2020年 | 2163篇 |
2019年 | 2180篇 |
2018年 | 3040篇 |
2017年 | 2947篇 |
2016年 | 4980篇 |
2015年 | 3567篇 |
2014年 | 4346篇 |
2013年 | 10393篇 |
2012年 | 9167篇 |
2011年 | 10195篇 |
2010年 | 6923篇 |
2009年 | 6493篇 |
2008年 | 9523篇 |
2007年 | 9126篇 |
2006年 | 8628篇 |
2005年 | 8055篇 |
2004年 | 7072篇 |
2003年 | 6208篇 |
2002年 | 5842篇 |
2001年 | 6864篇 |
2000年 | 5251篇 |
1999年 | 4006篇 |
1998年 | 2824篇 |
1997年 | 2820篇 |
1996年 | 2909篇 |
1995年 | 2495篇 |
1994年 | 2561篇 |
1993年 | 2377篇 |
1992年 | 2861篇 |
1991年 | 2826篇 |
1990年 | 2665篇 |
1989年 | 2571篇 |
1988年 | 2529篇 |
1987年 | 2499篇 |
1986年 | 2316篇 |
1985年 | 2943篇 |
1984年 | 2937篇 |
1983年 | 2344篇 |
1982年 | 2334篇 |
1981年 | 2176篇 |
1980年 | 2108篇 |
1979年 | 2393篇 |
1978年 | 2469篇 |
1977年 | 2391篇 |
1976年 | 2332篇 |
1975年 | 2174篇 |
1974年 | 2157篇 |
1973年 | 2207篇 |
1972年 | 1422篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
21.
Dr. Joaquim Torra Dr. Felipe Viela Dr. Diego Megías Dr. Begoña Sot Prof. Cristina Flors 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(19):e202200026
CRANAD-2 is a fluorogenic curcumin derivative used for near-infrared detection and imaging in vivo of amyloid aggregates, which are involved in neurodegenerative diseases. We explore the performance of CRANAD-2 in two super-resolution imaging techniques, namely stimulated emission depletion (STED) and single-molecule localization microscopy (SMLM), with markedly different fluorophore requirements. By conveniently adapting the concentration of CRANAD-2, which transiently binds to amyloid fibrils, we show that it performs well in both techniques, achieving a resolution in the range of 45–55 nm. Correlation of SMLM with atomic force microscopy (AFM) validates the resolution of fine features in the reconstructed super-resolved image. The good performance and versatility of CRANAD-2 provides a powerful tool for near-infrared nanoscopic imaging of amyloids in vitro and in vivo. 相似文献
22.
Smirnova T. D. Zhelobitskaya E. A. Danilina T. G. 《Journal of Analytical Chemistry》2022,77(8):1000-1004
Journal of Analytical Chemistry - Silver nanoparticles modified with Eu3+ ions increase the intensity of the fluorescence signal by a factor of 125 in an analytical system containing doxycycline as... 相似文献
23.
Mathematical Notes - The notion of a $$\lambda$$ -generalized-search multivalued functional on an $$f$$ -quasimetric space is introduced. An existence theorem for zeros of such functionals is... 相似文献
24.
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
25.
Tomáš Hložek Martin Štícha Miroslava Bursová Ivan Jelínek Petr Tůma Radomír Čabala 《Electrophoresis》2020,41(18-19):1564-1567
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
26.
Attila Kovács 《International journal of quantum chemistry》2020,120(1):e26051
Lanthanide dinitrogen complexes, Ln(N2) x (x = 1-8), were investigated by Density Functional Theory computations using the B3LYP exchange-correlation functional in conjunction with quasirelativistic pseudopotentials for Ln. After a recent study on the lanthanum complexes (A. Kovács, Structural Chemistry 2018 , 29, 1825), the present study aimed to probe the changes upon variously filled 4f subshells of Ln on the structures, stabilities, and bonding properties in related complexes of Nd, Ho, and Lu. The bonding properties were assessed on the basis of natural atomic charges, Ln valence orbital populations, and analysis of bonding molecular orbitals. 相似文献
27.
The influence of different referencing methods on the accuracy of δ13C value measurement of ethanol fuel by gas chromatography/combustion/isotope ratio mass spectrometry 下载免费PDF全文
28.
29.
30.
The European Physical Journal Special Topics - The removal of suspended particles from the interior of a thermocapillary liquid bridge via a finite-particle-size effect restricting the particle... 相似文献