全文获取类型
收费全文 | 4097篇 |
免费 | 534篇 |
国内免费 | 532篇 |
专业分类
化学 | 3166篇 |
晶体学 | 36篇 |
力学 | 280篇 |
综合类 | 55篇 |
数学 | 471篇 |
物理学 | 1155篇 |
出版年
2024年 | 4篇 |
2023年 | 80篇 |
2022年 | 90篇 |
2021年 | 146篇 |
2020年 | 189篇 |
2019年 | 181篇 |
2018年 | 147篇 |
2017年 | 139篇 |
2016年 | 205篇 |
2015年 | 177篇 |
2014年 | 239篇 |
2013年 | 319篇 |
2012年 | 328篇 |
2011年 | 413篇 |
2010年 | 270篇 |
2009年 | 235篇 |
2008年 | 249篇 |
2007年 | 231篇 |
2006年 | 191篇 |
2005年 | 180篇 |
2004年 | 152篇 |
2003年 | 120篇 |
2002年 | 108篇 |
2001年 | 95篇 |
2000年 | 83篇 |
1999年 | 98篇 |
1998年 | 83篇 |
1997年 | 56篇 |
1996年 | 65篇 |
1995年 | 52篇 |
1994年 | 49篇 |
1993年 | 30篇 |
1992年 | 40篇 |
1991年 | 14篇 |
1990年 | 27篇 |
1989年 | 13篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 12篇 |
1985年 | 8篇 |
1984年 | 11篇 |
1983年 | 8篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1971年 | 1篇 |
1957年 | 2篇 |
排序方式: 共有5163条查询结果,搜索用时 15 毫秒
1.
Yin Qingqing Xu Fen Sun Lixian Li Yaying Liao Lumin Wang Tao Guan Yanxun Xia Yongpeng Zhang Chenchen Wei Sheng Zhang Huanzhi Li Bin 《Journal of Thermal Analysis and Calorimetry》2022,147(12):6583-6592
Journal of Thermal Analysis and Calorimetry - Polyethylene glycol (PEG) is widely used as phase change materials (PCMs). However, the leakage and low thermal conductivity issues restrict its... 相似文献
2.
Nonlinear Dynamics - To describe the particular mechanical behaviors of beams with both uniform and non-uniform cross sections, such as the bidirectional bending, torsion-bending coupling, the... 相似文献
3.
Nonlinear Dynamics - The modal truncation is usually used in the dynamic response analysis of flexible multibody systems, in which, appropriate selection of modal shapes is very critical to achieve... 相似文献
4.
Journal of Visualization - Convolutional neural networks (CNNs) have achieved breakthrough performance in image recognition and classification. However, it is still a challenge for CNNs to classify... 相似文献
5.
Chinese Annals of Mathematics, Series B - In the present article, the authors find and establish stability of multiplier ideal sheaves, which is more general than strong openness. 相似文献
6.
Chen Yujie Sang Weixuan Chen Rong Liu Xue Li Xiaoyan Guan Fenfen Li Xun Xiao Hui 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(1):367-373
Journal of Radioanalytical and Nuclear Chemistry - The nanoscale zero-valent nickel (nano-Ni0) was prepared by liquid-phase reduction method and characterized by BET, XPS, FT-IR and XRD and be used... 相似文献
7.
Ziritaxestat is a first-in-class autotoxin inhibitor. The purpose of this study was to develop a liquid chromatography/electrospray ionization tandem mass spectrometric (LC–MS/MS) method for the determination of ziritaxestat in rat plasma. The plasma sample was deproteinated using acetonitrile and then separated on an Acquity BEH C18 column with water containing 0.1% formic acid and acetonitrile as mobile phase, which was delivered at 0.4 ml/min. Ziritaxestat and the internal standard (crizotinib) were quantitatively monitored with precursor-to-product transitions of m/z 589.3 > 262.2 and m/z 450.1 > 260.2, respectively. The total running time was 2.5 min. The method showed excellent linearity over the concentration range 0.5–2000 ng/ml, with correlation coefficient >0.9987. The extraction recovery was >82.09% and the matrix effect was not significant. Inter- and intra-day precisions (RSD) were <11.20% and accuracies were in the range of −8.50–7.45%. Ziritaxestat was demonstrated to be stable in rat plasma under the tested conditions. The validated LC–MS/MS method was successfully applied to study the pharmacokinetic profiles of ziritaxestat in rat plasma after intravenous and oral administration. Pharmacokinetic results demonstrated that ziritaxestat displayed a short half-life (~3 h) and low bioavailability (20.52%). 相似文献
8.
Yimei Wang Yi Qiao Xiaomin Xu Xiaohong Ding Weiwei Li Bo Yuan Haiyan Xu 《Biomedical chromatography : BMC》2019,33(8)
A sensitive and reliable LC–MS/MS method was developed and validated for simultaneous quantification of the major components of Huangqi–Honghua extact in rat plasma, including hydroxysafflor yellow A (HSYA), astragaloside IV (ASIV), calycosin‐7‐O‐β‐d ‐glucoside (CAG), calycosin, calycosin‐3′‐O‐glucuronide (C‐3′‐G) and calycosin‐3′‐O‐sulfate (C‐3′‐S). After extraction by protein precipitation with acetonitrile and methanol from plasma, the analytes were separated on a Hypersil BDS C18 column by gradient elution with acetonitrile and 5 mM ammonium acetate. The detection was carried out on a triple quadrupole tandem mass spectrometer equipped with electrospray ionization source switched between negative and positive modes. HSYA was monitored in negative ionization mode from 0 to 4.9 min, and ASIV, CAG, calycosin, C‐3′‐G and C‐3′‐S were determined in positive ionization mode from 4.9 to 10 min. The lower limits of quantification of the analytes were 6.25 ng/mL for HSYA, 0.781 ng/mL for CAG and 1.56 ng/mL for ASIV and calycosin. The intra‐ and inter‐assay precision (RSD) values were within 13.43%, and accuracy (RE) ranged from ?8.75 to 9.92%. The validated method was then applied to the pharmacokinetic study of HSYA, ASIV, CAG, calycosin, C‐3′‐G and C‐3′‐S in rat after an oral administration of Huangqi–Honghua extract. 相似文献
9.
10.
Wang Xiaobo Ma Yongpeng Li Zhenxing Han Guanglu Guan Xidong Fan Kaiqi 《Journal of Applied Spectroscopy》2022,89(3):586-592
Journal of Applied Spectroscopy - A multi-ion chromogenic sensor based on a terpyridine moiety was developed for the semiquantitative, visual, and sensitive speciation analysis of Fe2+ and Co2+... 相似文献