全文获取类型
收费全文 | 31169篇 |
免费 | 1558篇 |
国内免费 | 440篇 |
专业分类
化学 | 20919篇 |
晶体学 | 252篇 |
力学 | 733篇 |
综合类 | 45篇 |
数学 | 4905篇 |
物理学 | 6313篇 |
出版年
2023年 | 252篇 |
2022年 | 245篇 |
2021年 | 389篇 |
2020年 | 559篇 |
2019年 | 532篇 |
2018年 | 687篇 |
2017年 | 614篇 |
2016年 | 1204篇 |
2015年 | 966篇 |
2014年 | 1050篇 |
2013年 | 2107篇 |
2012年 | 2012篇 |
2011年 | 2148篇 |
2010年 | 1271篇 |
2009年 | 1174篇 |
2008年 | 1867篇 |
2007年 | 1863篇 |
2006年 | 1629篇 |
2005年 | 1484篇 |
2004年 | 1257篇 |
2003年 | 1035篇 |
2002年 | 933篇 |
2001年 | 713篇 |
2000年 | 654篇 |
1999年 | 497篇 |
1998年 | 351篇 |
1997年 | 329篇 |
1996年 | 419篇 |
1995年 | 305篇 |
1994年 | 332篇 |
1993年 | 318篇 |
1992年 | 300篇 |
1991年 | 250篇 |
1990年 | 239篇 |
1989年 | 210篇 |
1988年 | 189篇 |
1987年 | 190篇 |
1986年 | 177篇 |
1985年 | 261篇 |
1984年 | 252篇 |
1983年 | 164篇 |
1982年 | 173篇 |
1981年 | 172篇 |
1980年 | 162篇 |
1979年 | 108篇 |
1978年 | 116篇 |
1977年 | 122篇 |
1976年 | 94篇 |
1975年 | 102篇 |
1973年 | 76篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
Tian Xiu-Zhi Yang Rui Ma Jia-Jia Ni Yong-Hao Deng Hai-Bo Dai Lei Tan Jiao-Jun Zhang Mei-Yun Jiang Xue 《高分子科学》2022,40(7):789-798
Chinese Journal of Polymer Science - Antistatic and strength properties are of vital importance for polyurethane rubber used in moving parts of many industrial instruments. Herein, polyurethane was... 相似文献
2.
Bazarra Noelia Castejón Alberto Fernández José R. Quintanilla Ramón 《Meccanica》2021,56(12):3025-3037
Meccanica - In this work we study, from the numerical point of view, a one-dimensional thermoelastic problem where the thermal law is of type III. Quasi-static microvoids are also assumed within... 相似文献
3.
Verdecho María-José Alarcón-Valero Faustino Pérez-Perales David Alfaro-Saiz Juan-José Rodríguez-Rodríguez Raúl 《Central European Journal of Operations Research》2021,29(4):1231-1251
Central European Journal of Operations Research - Sustainability practice within supply chains remains in an early development phase. Enterprises still need tools that support the integration of... 相似文献
4.
Set-Valued and Variational Analysis - In a Hilbert framework ℌ, we study the convergence properties of a Newton-like inertial dynamical system governed by a general maximally monotone... 相似文献
5.
6.
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
7.
Meccanica - In this study, a frictional moving contact problem between an electrically conducting rigid cylindrical punch and a functionally graded piezoelectric material (FGPM) layer bonded to a... 相似文献
8.
Analysis and pharmacokinetic study of polyphyllin H in beagle dog plasma after oral administration of Rhizoma Paridis Extracts by LC‐MS/MS
下载免费PDF全文
![点击此处可从《Biomedical chromatography : BMC》网站下载免费的PDF全文](/ch/ext_images/free.gif)
9.
10.
Biodistribution study of free and microencapsulated 6‐methylcoumarin in Wistar rats by HPLC
下载免费PDF全文
![点击此处可从《Biomedical chromatography : BMC》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Aura Rocío Hernández Luis Fernando Ospina Diana Marcela Aragón 《Biomedical chromatography : BMC》2015,29(2):176-181
A sensitive, specific and reproducible HPLC method has been developed and validated for the quantitative determination of 6‐methylcoumarin (6MC) in plasma and other tissues in Wistar rats. A C18 column was used with UV detection at 321 nm and a gradient system consisting of methanol‐deionized water was used as mobile phase. The retention time for 6MC was 14.921 min and no interfering peaks were observed for any of the matrices. Linear relationships (r2 > 0.997) were obtained between the peak height ratios and the corresponding biological sample concentrations over the range 0.4–12.8 µg/mL. Precision and accuracy were evaluated; the coefficient of variation and the relative error for all of the organs were <2 and 7%, respectively. The limit of quantitation was 0.20 µg/mL for the heart and 0.30 µg/mL for the other tissues evaluated. This HPLC method was successfully used in the determination of 6MC in the biodistribution study after administration of 200 mg/kg of both 6MC‐free and 6MC‐loaded polymeric microparticles. In this study, extensive 6MC was found, in both free and microencapsulated forms, in all the organs tested. The 6MC‐free showed a range of between 1.7 and 11.5 µg/g, while the microencapsulated 6MC showed concentrations of between 6.35 and 17.7 µg/g, suggesting that 6MC improved absorption rate. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献