全文获取类型
收费全文 | 57191篇 |
免费 | 6639篇 |
国内免费 | 4611篇 |
专业分类
化学 | 36344篇 |
晶体学 | 653篇 |
力学 | 3904篇 |
综合类 | 302篇 |
数学 | 7116篇 |
物理学 | 20122篇 |
出版年
2023年 | 805篇 |
2022年 | 1421篇 |
2021年 | 1554篇 |
2020年 | 1730篇 |
2019年 | 1715篇 |
2018年 | 1620篇 |
2017年 | 1532篇 |
2016年 | 2251篇 |
2015年 | 1999篇 |
2014年 | 2542篇 |
2013年 | 3260篇 |
2012年 | 3807篇 |
2011年 | 3959篇 |
2010年 | 2886篇 |
2009年 | 2845篇 |
2008年 | 3037篇 |
2007年 | 2807篇 |
2006年 | 2593篇 |
2005年 | 2051篇 |
2004年 | 1717篇 |
2003年 | 1548篇 |
2002年 | 1526篇 |
2001年 | 1278篇 |
2000年 | 1200篇 |
1999年 | 1082篇 |
1998年 | 965篇 |
1997年 | 912篇 |
1996年 | 910篇 |
1995年 | 823篇 |
1994年 | 730篇 |
1993年 | 666篇 |
1992年 | 662篇 |
1991年 | 574篇 |
1990年 | 567篇 |
1989年 | 498篇 |
1988年 | 410篇 |
1987年 | 407篇 |
1986年 | 381篇 |
1985年 | 424篇 |
1984年 | 387篇 |
1983年 | 329篇 |
1982年 | 333篇 |
1978年 | 329篇 |
1977年 | 322篇 |
1976年 | 404篇 |
1975年 | 359篇 |
1974年 | 388篇 |
1973年 | 396篇 |
1972年 | 369篇 |
1971年 | 332篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Jian Lin Yitao Li Xiaoyun Hu Weilin Chi Shuiming Zeng Junxing Xu 《Journal of heterocyclic chemistry》2021,58(1):226-240
Very long chain fatty acids (VLCFAs) are one of the most principal and promising targets for herbicides discovery. In order to explore and find novel VLCFAs inhibitors with higher herbicidal activity and improved crop safety, a variety of new 3-{[(5,5-dimethyl-4,5-dihydroisoxazol-3-yl)sulfonyl]methyl}benzo[d]isoxazole derivatives were reasonably designed and synthesized. The results of greenhouse experiments indicated that several compounds exhibited good herbicidal activity against Digitaria sanguinalis, Echinochloa crus-galli, and Setaria faberii at rates of 150 g ai/ha. Compounds g4 and h1 displayed promising herbicidal activity against D sanguinalis and E crus-galli at rates of 75 g ai/ha, which is better than commercial pyroxasulfone and S-metolachlor. Moreover, compound h1 displayed higher activity against E crus-galli, D sanguinalis, and S faberii than pyroxasulfone and S-metolachlor even at a rate of 37.5 and 18.75 g ai/ha. Furthermore, both of the compounds g4 and h1 were much safer to these tested crops, especially to rice, wheat and rape, at the rate of 150 g ai/ha than pyroxasulfone. Therefore, h1 may act as a new lead structure for novel herbicides discovery. 相似文献
992.
Chao Rong Wu Yan-Wei Lu Ling Xu Wei-Feng Wang Chang-Yun Shao Chang-Lun 《Chemistry of Natural Compounds》2021,57(2):343-345
Chemistry of Natural Compounds - Benzomalvins B, C, and E (1, 2, and 3) were simultaneously obtained from the marine fungus Aspergillus sp. isolated from the soft coral Sinularia sp., collected... 相似文献
993.
Zhen Wang Ziyang Li Tian Su Xiao Han Zhanwu Hou Yupeng Zheng Jiachen Liu Jun Xu Jeffy Yang Huadong Liu 《Electrophoresis》2021,42(6):793-799
Western blot (protein immunoblot) is a widely used analytical technique in molecular biology. Utilizing the specific recognizing primary antibody, proteins immobilized on various matrix are investigated by subsequent visualization steps, for example, by the horse radish peroxidase conjugated secondary antibody incubation. Methods to improve the sensitivity in protein identification or quantification are appreciated by biochemists. Herein, we report a new strategy to amplify Western blot signals by constructing a probe with proximal labeling and IgG targeting abilities. The R118G mutation attenuated the biotin-AMP binding affinity of the bacterial biotin ligase BirA*, offering a proximity-dependent labeling ability, which could be used as a signal amplifier. We built a BirA*-protein A fusion protein (BioEnhancer) that specifically binds to IgG and adds biotin tags to its proximal amine groups, enhancing the immunosignal of target proteins. In our experiments, the BioEnhancer system amplified the immunosignal by tenfold compared to the standard western blot. Additionally, our strategy could couple with other signal enhancement methods to further increase the western blot sensitivity. 相似文献
994.
Sulyaeva V. S. Gatapova E. Ya. Kozhevnikov A. K. Rogilo D. I. Saraev A. A. Yushina I. V. Khomyakov M. N. Shapovalova A. A. Shayapov V. R. Bhaskar N. Tu R. Kosinova M. L. 《Journal of Structural Chemistry》2021,62(8):1309-1324
Journal of Structural Chemistry - We report a comprehensive study of the effect of the chemical structure of boron carbonitride films on the variability of their functional characteristics. The... 相似文献
995.
Rassolov A. V. Ivanov G. A. Bragina G. O. Baeva G. N. Smirnova N. S. Kazakov A. V. Usachev N. Ya. Stakheev A. Yu. 《Kinetics and Catalysis》2021,62(5):641-650
Kinetics and Catalysis - The catalytic performance of a bimetallic RhIn/SiO2 catalyst was studied in the liquid-phase hydrogenation of nitrobenzene. The formation of intermetallic Rh1In1... 相似文献
996.
Shabatina T. I. Morozov Yu. N. Solovyov A. V. Shabatin A. V. Vernaya O. I. Fedorov V. V. Melnikov M. Ya. 《Moscow University Chemistry Bulletin》2021,76(3):196-202
Moscow University Chemistry Bulletin - A combined cryochemical method is proposed for the dimensional and structural modification of drugs. This method forms a molecular flow of a substance... 相似文献
997.
Tian Miao Xu Dehui Li Bing Wang Shuai Qi Miao Zhang Hao Liu Zhijie Liu Dingxin Chen Hailan Kong Michael G. 《Plasma Chemistry and Plasma Processing》2021,41(2):591-605
Plasma Chemistry and Plasma Processing - Cold atmospheric plasma (CAP) is a novel technology which is widely used in the biomedical field and has developed quickly over the past few years,... 相似文献
998.
Zhang Wen Liu Yang Song Dengpeng Guo Heng Hu Jinbang Wang Yunli Xu Weilin 《Cellulose (London, England)》2021,28(9):5911-5922
Cellulose - Traditional cotton fiber dyeing requires an abundance of salt, which leads to environmental pollution. Consequently, decreasing or eliminating the use of salt has become the primary... 相似文献
999.
针对偶氮基光敏分子存在放热速率慢和温度难以控制的难点,在分子结构设计基础上,采用氧化偶合法制备了具有固-液相变功能的4,4′-对-二正己基偶氮苯(AZO-L6).由于分子间作用力较低,偶氮苯分子呈现低熔、快异构化的特点,在发生反-顺异构化转变时大幅降低分子的熔点.固-液相变过程实现了光热能和相变焓的存储,在结构回复时同时放出储存的能量(231.8 kJ/kg),并将相变偶氮苯应用于可穿戴聚合物复合织物中.结果显示储能后的相变偶氮苯分子在蓝光(440 nm)刺激下在60 s内可将材料温度提升0.8℃,获得了具有自加热功能的可穿戴复合织物,为探索多功能自保温可穿戴装置提供了研究思路. 相似文献
1000.