全文获取类型
收费全文 | 3032篇 |
免费 | 439篇 |
国内免费 | 338篇 |
专业分类
化学 | 2191篇 |
晶体学 | 35篇 |
力学 | 251篇 |
综合类 | 17篇 |
数学 | 368篇 |
物理学 | 947篇 |
出版年
2024年 | 21篇 |
2023年 | 81篇 |
2022年 | 151篇 |
2021年 | 141篇 |
2020年 | 174篇 |
2019年 | 139篇 |
2018年 | 136篇 |
2017年 | 114篇 |
2016年 | 151篇 |
2015年 | 187篇 |
2014年 | 192篇 |
2013年 | 238篇 |
2012年 | 248篇 |
2011年 | 268篇 |
2010年 | 186篇 |
2009年 | 159篇 |
2008年 | 168篇 |
2007年 | 143篇 |
2006年 | 127篇 |
2005年 | 92篇 |
2004年 | 77篇 |
2003年 | 65篇 |
2002年 | 79篇 |
2001年 | 72篇 |
2000年 | 57篇 |
1999年 | 48篇 |
1998年 | 46篇 |
1997年 | 37篇 |
1996年 | 36篇 |
1995年 | 22篇 |
1994年 | 22篇 |
1993年 | 20篇 |
1992年 | 19篇 |
1991年 | 20篇 |
1990年 | 14篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 6篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 6篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1979年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1964年 | 1篇 |
1957年 | 1篇 |
1936年 | 1篇 |
排序方式: 共有3809条查询结果,搜索用时 15 毫秒
41.
Shang Chen Chenyan Ren Yuan Ji Dongke Liu Xinke Zhang Fengshan Wang 《Molecules (Basel, Switzerland)》2022,27(13)
Thymus immunosuppressive pentapeptide (TIPP) is a novel anti-inflammatory peptide with high efficacy and low toxicity. This study aims to establish a selective LC-MS/MS method for analyzing the analyte TIPP in biological samples, laying the foundation for further PK and PD studies of TIPP. Protein precipitation was conducted in acetonitrile supplemented with 2% formic acid and 25 mg/mL dithiothreitol as a stabilizer, which was followed by backwashing the organic phase using dichloromethane. The chromatographic separation of TIPP was achieved on a C18 column with a gradient elution method. During positive electrospray ionization, TIPP was analyzed via multiple-reaction monitoring. The linear relationships between the concentration of TIPP and peak area in murine plasma cell lysates, supernatants, and the final cell rinse PBS were established within the ranges of 20–5000 ng/mL, 1–200 ng/mL, 10–200 μg/mL, and 0.1–20 ng/mL, respectively (r2 > 0.99). Validated according to U.S. FDA guidelines, the proposed method was proved to be acceptable. Such a method had been successfully applied to investigate the pharmacokinetics of TIPP in mice via subcutaneous injection. The plasma half-life in mice was 5.987 ± 1.824 min, suggesting that TIPP is swiftly eliminated in vivo. The amount of TIPP uptake by RBL-2H3 cells was determined using this method, which was also visually verified by confocal. Furthermore, the effective intracellular concentration of TIPP was deduced by comparing the intracellular concentration of TIPP and degrees of inflammation, enlightening further investigation on the intracellular target and mechanism of TIPP. 相似文献
42.
43.
44.
A Si-substituted rhodamine based water-soluble fluorescent probe bearing a tetrathia-azacrown was designed for fluorescence imaging of Cu+ with substantial affinity and selectivity.In physiological condition,the developed probe with outstanding water-solubility exhibits ultrahigh sensitivity to Cu+,ensuring the reliable fluorescence imaging in vivo. 相似文献
45.
Main observation and conclusion
We previously reported that a series of tetraphenylethylene(TPE)-containing all-hydrocarbon conjugated polymers exhibited a spe-... 相似文献
46.
The development of novel organic electrode materials is of great significance for improving the reversible capacity and cycle stability of rechargeable batterie... 相似文献
47.
48.
Weidong Shang Sheng‐Nan Su Rong Shi Ze‐Dong Mou Guo‐Qiang Yu Xia Zhang Dawen Niu 《Angewandte Chemie (International ed. in English)》2021,60(1):385-390
We here report glycosyl sulfoxides appended with an aryl iodide moiety as readily available, air and moisture stable precursors to glycosyl radicals. These glycosyl sulfoxides could be converted to glycosyl radicals by way of a rapid and efficient intramolecular radical substitution event. The use of this type of precursors enabled the synthesis of various complex C‐linked glycoconjugates under mild conditions. This reaction could be performed in aqueous media and is amenable to the synthesis of glycopeptidomimetics and carbohydrate‐DNA conjugates. 相似文献
49.
METHANE REFORMING WITH CARBON DIOXIDE TO PRODUCE SYNGAS?a?aCATALYST REGENERATION 总被引:1,自引:0,他引:1 下载免费PDF全文
Yongchen Shang Hengyong Xu Guolin Xu Shenglin Liu Guoxing Xiong Shishan Sheng 《天然气化学杂志》1999,8(1):61-67
The regeneration conditions of the deactivated catalyst 18wt%NiO/a-A12O3 used in methane reforming with carbon dioxide were studied by using a fix-bed flow reactor and TPR technique. When the deactivated catalyst was reduced at 1 123 K in a conventional regeneration process, the activity increased a little, but was still much lower than that of the fresh catalyst. When the deactivated catalyst was reduced, then treated in site With an activity-rejuvenating agent of 5-10 vo1% C (aqueous hydrogen peroxide solution) and reduced again at 1123K, the activity was renewed to approach that of the fresh one. 相似文献
50.