全文获取类型
收费全文 | 9655篇 |
免费 | 1172篇 |
国内免费 | 1651篇 |
专业分类
化学 | 5872篇 |
晶体学 | 114篇 |
力学 | 539篇 |
综合类 | 71篇 |
数学 | 2482篇 |
物理学 | 3400篇 |
出版年
2024年 | 20篇 |
2023年 | 307篇 |
2022年 | 381篇 |
2021年 | 449篇 |
2020年 | 547篇 |
2019年 | 360篇 |
2018年 | 365篇 |
2017年 | 452篇 |
2016年 | 442篇 |
2015年 | 504篇 |
2014年 | 798篇 |
2013年 | 1029篇 |
2012年 | 1021篇 |
2011年 | 1004篇 |
2010年 | 764篇 |
2009年 | 808篇 |
2008年 | 541篇 |
2007年 | 579篇 |
2006年 | 465篇 |
2005年 | 293篇 |
2004年 | 172篇 |
2003年 | 151篇 |
2002年 | 132篇 |
2001年 | 165篇 |
2000年 | 123篇 |
1999年 | 154篇 |
1998年 | 66篇 |
1997年 | 55篇 |
1996年 | 43篇 |
1995年 | 46篇 |
1994年 | 39篇 |
1993年 | 51篇 |
1992年 | 40篇 |
1991年 | 31篇 |
1990年 | 23篇 |
1989年 | 9篇 |
1988年 | 11篇 |
1987年 | 2篇 |
1986年 | 8篇 |
1985年 | 7篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1976年 | 1篇 |
1959年 | 4篇 |
1957年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
De-en Han Yanmei Shi Ping Tian Hengchao Wei Mingsan Miao Xiu-min Li 《Biomedical chromatography : BMC》2020,34(7):e4838
A rapid and sensitive method was developed and validated for the quantitative determination of xanthopurpurin (XPP) in rat plasma using ultra-performance liquid chromatography-electrospray ionization-Orbitrap mass spectrometry. XPP inhibits IgE production and prevents peanut-induced anaphylaxis. The XPP and emodin (internal standard) were determined in negative ion mode with m/z 239.0350 → 211.0400 and 269.0455 → 241.0507, respectively. The separation process was achieved using an ACQUITY UPLC HSS T3 column with acetonitrile and 0.1% formic acid in water (85:15). The linear range was 0.5–100 ng/mL, and the correlation coefficient (r2) was > 0.993. The inter-day and intra-day precision was within an acceptable range of 15%. The extraction recovery and matrix effect were 78.9–87.2% and 94.3–98.5%, respectively. Under different conditions, the XPP was stable in the range of 5.6–10.6%. This method was successfully applied to study the pharmacokinetics of XPP with an oral dose of 10.0 mg/kg and intravenous dose of 2.0 mg/kg in rats. The absolute oral bioavailability of XPP was 4.6%. 相似文献
12.
Jinhua Gao Yuanfang Tao Dr. Jian Zhang Nannan Wang Xin Ji Dr. Jinling He Prof. Yubing Si Prof. Weili Zhao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(48):11246-11256
Our previous discovery suggested that substituents on the 1,7 positions delicately modulate the sensing ability of the meso-arylmercapto boron-dipyrromethene (BODIPY) to biothiols. In this work, the impact of delicate modulations on the sensing ability is investigated. Therefore, 1,7-dimethyl, 3,5-diaryl substituted BODIPY is designed and developed and its conformationally restricted species with a meso-arylmercapto moiety ( DM-BDP-SAr and DM-BDP-R-SAr ) as selective fluorescent probes for Cys. Moreover, the lysosome-target probes ( Lyso-S and Lyso-D ) based on DM-BDP-SAr carrying one or two morpholinoethoxy moieties were developed. They were able to detect Cys selectively in vitro with low detection limits. Both Lyso-S and Lyso-D localized nicely in lysosomes in living HeLa cells and exhibited red fluorescence for Cys. Moreover, a novel fluorescence quenching mechanism was proposed from the calculations by density functional theory (DFT). The probes may go through intersystem crossing (from singlet excited state to triplet excited state) to result in fluorescence quenching. 相似文献
13.
Russian Journal of Coordination Chemistry - Two Mo(VI) clusters, (H2L)3[Mo7O12(μ2-O)8(μ3-O)4] · 3H2O (I) and (H2L)2[Mo8O14(μ2-O)6(μ3-O)4(μ5-O)2] · 4DMF (II),... 相似文献
14.
15.
Nonlinear Dynamics - In this paper, the Riemann–Hilbert approach is systematically established for the Newell-type long-wave–short-wave equation. Firstly, we start spectral analysis... 相似文献
16.
YOU Mingqing 《力学与实践》2019,41(4):436
偏心转子惯性力引起的底座运动受到地面摩擦的影响,与光滑情形的理论结果存在定性差异。转子逆时针匀速旋转的惯性力若小于构件总重,则底座随摩擦因子增加而出现连续、一次停顿和两次停顿的振动及完全静止的4种状态。因惯性力对正压力及摩擦力的影响,底座在连续及一次停顿的振动时右向位移较大;而底座跳起时如``蛤蟆夯'则整体向左移动。 相似文献
17.
We establish the global well-posedness of a strong solution to the 3D tropical climate model with damping. We prove that there exists the global and unique solution for α, β, γ satisfying one of the following three conditions: (1) ; (2) ; (3) . 相似文献
18.
19.
The works on the procedure of fluorescent sensors for the detection of biological analytes are extremely momentous.Among diverse analytical approaches,fluorescence is the most eye-catching due to its high sensitivity,selectivity,rapidity,robustness,ease of measurement and non-destructive approaches.Herein,we show different fluorescent probes synthesized for estimation and detection of biological analytes(H2S,SO32-/HSO3-,H2O2<... 相似文献
20.