全文获取类型
收费全文 | 12395篇 |
免费 | 2382篇 |
国内免费 | 1807篇 |
专业分类
化学 | 9586篇 |
晶体学 | 170篇 |
力学 | 812篇 |
综合类 | 101篇 |
数学 | 1564篇 |
物理学 | 4351篇 |
出版年
2024年 | 24篇 |
2023年 | 213篇 |
2022年 | 332篇 |
2021年 | 419篇 |
2020年 | 480篇 |
2019年 | 530篇 |
2018年 | 458篇 |
2017年 | 400篇 |
2016年 | 659篇 |
2015年 | 708篇 |
2014年 | 726篇 |
2013年 | 915篇 |
2012年 | 1154篇 |
2011年 | 1178篇 |
2010年 | 891篇 |
2009年 | 804篇 |
2008年 | 852篇 |
2007年 | 722篇 |
2006年 | 645篇 |
2005年 | 568篇 |
2004年 | 512篇 |
2003年 | 479篇 |
2002年 | 558篇 |
2001年 | 460篇 |
2000年 | 303篇 |
1999年 | 258篇 |
1998年 | 226篇 |
1997年 | 179篇 |
1996年 | 153篇 |
1995年 | 129篇 |
1994年 | 107篇 |
1993年 | 96篇 |
1992年 | 81篇 |
1991年 | 79篇 |
1990年 | 54篇 |
1989年 | 38篇 |
1988年 | 33篇 |
1987年 | 21篇 |
1986年 | 26篇 |
1985年 | 11篇 |
1984年 | 17篇 |
1983年 | 17篇 |
1982年 | 9篇 |
1981年 | 14篇 |
1980年 | 6篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1974年 | 5篇 |
1973年 | 3篇 |
1957年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Dan Chen Kaixin Du Xiaochen Niu Hongwei Zhang Xue Zhang Yu Tang Jianchun Zhao 《Biomedical chromatography : BMC》2022,36(3):e5288
Amlexanox, an anti-inflammatory and anti-allergic agent, has been widely used clinically for the treatment of canker sores, asthma, and allergic rhinitis. Recently, amlexanox has received considerable attention in curing nonalcoholic fatty liver diseases and hepatitis virus infection. Herein, we first established a sensitive high-performance liquid chromatography-tandem mass spectrum (LC–MS/MS) method for the determination of amlexanox in rat plasma. Propranolol was used as the internal standard (IS). Using a simple protein precipitation method, the amlexanox and IS were separated with Capcell Pak C18 column (2.0 × 50 mm, 5 μm) and eluted with water and acetonitrile each containing 0.1% formic acid using gradient elution condition at a flow rate of 0.4 mL·min−1. Amlexanox and IS were detected by a triple quadrupole mass in multiple reactive monitoring (MRM) under the transitions of m/z 299.2 → 281.2 and m/z 259.9 → 116.1 with positive electrospray ionization, respectively. The calibration curves of amlexanox were established with the range of 50 to 2000 ng·mL−1 (r2 > 0.99). The validation method consisted of selectivity, accuracy, precision, carryover effect, matrix effect, recovery, dilution effect, and stability. The fully validated method was successfully applied to the pharmacokinetic study of amlexanox in Wistar rats. 相似文献
2.
Let p ∈ [1, ∞), q ∈ [1, ∞), α∈ R, and s be a non-negative integer. Inspired by the space JNp introduced by John and Nirenberg(1961) and the space B introduced by Bourgain et al.(2015), we introduce a special John-Nirenberg-Campanato space JNcon(p,q,s) over Rn or a given cube of R;with finite side length via congruent subcubes, which are of some amalgam features. The limit space of such spaces as p →∞ is just the Campanato space which coincides with the space BMO(the space of functions with bounded mean oscillations)when α = 0. Moreover, a vanishing subspace of this new space is introduced, and its equivalent characterization is established as well, which is a counterpart of the known characterization for the classical space VMO(the space of functions with vanishing mean oscillations) over Rn or a given cube of Rn with finite side length.Furthermore, some VMO-H1-BMO-type results for this new space are also obtained, which are based on the aforementioned vanishing subspaces and the Hardy-type space defined via congruent cubes in this article. The geometrical properties of both the Euclidean space via its dyadic system and congruent cubes play a key role in the proofs of all these results. 相似文献
3.
Zeng Qing-Wei Wen Zhuo-Yu Fu Jun-Feng Zhou Nan-Run 《International Journal of Theoretical Physics》2021,60(9):3306-3333
International Journal of Theoretical Physics - A new quantum watermark algorithm is presented by combining maximum pixel difference partitioning with the least significant bit substitution... 相似文献
4.
5.
6.
7.
8.
10.