全文获取类型
收费全文 | 166001篇 |
免费 | 29872篇 |
国内免费 | 17270篇 |
专业分类
化学 | 128320篇 |
晶体学 | 1846篇 |
力学 | 8567篇 |
综合类 | 1116篇 |
数学 | 19053篇 |
物理学 | 54241篇 |
出版年
2024年 | 435篇 |
2023年 | 2537篇 |
2022年 | 4678篇 |
2021年 | 4941篇 |
2020年 | 6068篇 |
2019年 | 6943篇 |
2018年 | 5473篇 |
2017年 | 4821篇 |
2016年 | 9124篇 |
2015年 | 9242篇 |
2014年 | 10618篇 |
2013年 | 13534篇 |
2012年 | 14447篇 |
2011年 | 14144篇 |
2010年 | 11048篇 |
2009年 | 10734篇 |
2008年 | 10851篇 |
2007年 | 9448篇 |
2006年 | 8688篇 |
2005年 | 7609篇 |
2004年 | 6180篇 |
2003年 | 5160篇 |
2002年 | 5662篇 |
2001年 | 4428篇 |
2000年 | 4003篇 |
1999年 | 3258篇 |
1998年 | 2449篇 |
1997年 | 2235篇 |
1996年 | 2165篇 |
1995年 | 1930篇 |
1994年 | 1734篇 |
1993年 | 1465篇 |
1992年 | 1296篇 |
1991年 | 1095篇 |
1990年 | 952篇 |
1989年 | 746篇 |
1988年 | 550篇 |
1987年 | 492篇 |
1986年 | 446篇 |
1985年 | 381篇 |
1984年 | 265篇 |
1983年 | 212篇 |
1982年 | 183篇 |
1981年 | 106篇 |
1980年 | 77篇 |
1979年 | 33篇 |
1978年 | 33篇 |
1976年 | 31篇 |
1975年 | 27篇 |
1957年 | 31篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
102.
103.
104.
105.
Triazines are widely used in agriculture around the world as selective pre‐ and post‐emergence herbicides for the control of broad leaf and grassy weeds. With high toxicity and persistence, triazines can contaminate the environment and crops, so the development of rapid and sensitive methods for the determination of different triazines is necessary. Capillary electrophoresis comprises a group of techniques used to separate chemical mixtures. Analytical separation is based on different electrophoretic mobilities. This review focuses on the analysis of triazine herbicides with different modes of capillary electrophoresis, including capillary zone electrophoresis, micellar electrokinetic capillary electrophoresis, capillary electrochromatography and nonaqueous capillary electrophoresis. Determinations of triazines in various matrices such as surface water, groundwater, vegetables, soil and grains are emphasized. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
106.
107.
Jia Yang Xingang Li Wenjun Li Xin Xi Qian Du Feng Pan Songqing Liu 《Biomedical chromatography : BMC》2020,34(8):e4857
Because of its unpredictable side effects and efficacy, the anticancer drug docetaxel (DTX) requires improved characterisation of its pharmacokinetic profiles through population pharmacokinetic studies. A sensitive and rugged LC–MS/MS method for the detection of DTX in human plasma was developed and optimised using paclitaxel as an internal standard (IS). The plasma samples underwent rapid extraction using hybrid solid-phase extraction-protein precipitation. The analyte and IS were separated with an isocratic system on a Zorbax Eclipse Plus C18 column using water containing 0.05% acetic acid along with 20 μM of sodium acetate and methanol (30/70, v/v) as the mobile phase. Quantification was performed using a triple quadrupole mass spectrometer through multiple reaction monitoring in positive mode, using the m/z 830.3 → 548.8 and m/z 876.3 → 307.7 transitions for DTX and paclitaxel, respectively. The range of the calibration curve was 1–500 ng/mL for DTX, and the linear correlation coefficient was >0.99. The accuracies ranged from −4.6 to 4.2%, and the precision was no higher than 7.0% for the analytes. No significant matrix effect was observed. Both DTX and the IS showed considerable recovery. This method was finally applied to the establishment of a population pharmacokinetic model to optimise the clinical use of DTX. 相似文献
108.
Wenqing Zhang Dr. Jiuxing Li Prof. Dr. Bruno Salena Prof. Dr. Yingfu Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(3):592-596
DNA detection is usually conducted under nondenaturing conditions to favor the formation of Watson–Crick base-paring interactions. However, although such a setting is excellent for distinguishing a single-nucleotide polymorphism (SNP) within short DNA sequences (15–25 nucleotides), it does not offer a good solution to SNP detection within much longer sequences. Here we report on a new detection method capable of detecting SNP in a DNA sequence containing 35–90 nucleotides. This is achieved through incorporating into the recognition DNA sequence a previously discovered DNA molecule that forms a stable G-quadruplex in the presence of 7 molar urea, a known condition for denaturing DNA structures. The systems are configured to produce both colorimetric and fluorescent signals upon target binding. 相似文献
109.
We numerically solve the time-dependent Ginzburg–Landau equations for two-gap superconductors using the finite-element technique. The real-time simulation shows that at low magnetic field, the vortices in small-size samples tend to form clusters or other disorder structures. When the sample size is large, stripes appear in the pattern. These results are in good agreement with the previous experimental observations of the intriguing anomalous vortex pattern, providing a reliable theoretical basis for the future applications of multi-gap superconductors. 相似文献
110.
Dr. Wan‐Ling Liu Ni‐Shin Yang Ya‐Ting Chen Stephen Lirio Cheng‐You Wu Prof. Chia‐Her Lin Prof. Hsi‐Ya Huang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(1):115-119
A green and sustainable strategy synthesizes clinical medicine warfarin anticoagulant by using lipase‐supported metal–organic framework (MOF) bioreactors (see scheme). These findings may be beneficial for future studies in the industrial production of chemical, pharmaceutical, and agrochemical precursors. 相似文献