全文获取类型
收费全文 | 511篇 |
免费 | 28篇 |
专业分类
化学 | 375篇 |
晶体学 | 5篇 |
力学 | 22篇 |
数学 | 40篇 |
物理学 | 97篇 |
出版年
2023年 | 7篇 |
2022年 | 11篇 |
2021年 | 17篇 |
2020年 | 17篇 |
2019年 | 20篇 |
2018年 | 12篇 |
2017年 | 12篇 |
2016年 | 22篇 |
2015年 | 16篇 |
2014年 | 19篇 |
2013年 | 16篇 |
2012年 | 28篇 |
2011年 | 46篇 |
2010年 | 30篇 |
2009年 | 18篇 |
2008年 | 39篇 |
2007年 | 30篇 |
2006年 | 26篇 |
2005年 | 35篇 |
2004年 | 22篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2000年 | 9篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 7篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1983年 | 2篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1968年 | 3篇 |
1966年 | 1篇 |
1963年 | 1篇 |
1960年 | 1篇 |
1912年 | 1篇 |
排序方式: 共有539条查询结果,搜索用时 15 毫秒
531.
Ruben M Payer D Landa A Comisso A Gattinoni C Lin N Collin JP Sauvage JP De Vita A Kern K 《Journal of the American Chemical Society》2006,128(49):15644-15651
Two-dimensional supramolecular honeycomb networks with cavities of an internal diameter of 2.95 nm were formed by the self-assembly of 4,4',4' '-benzene-1,3,5-triyl-tribenzoic acid (BTA) on a Ag(111) surface at room temperature. Annealing to higher temperatures resulted in two sequential phase transformations into closer-packed supramolecular arrangements. The phase transformations are associated with stepwise deprotonation of the carboxylic acid groups. The voids of the honeycomb network of BTA have a suitable size for the construction of hierarchical structures with guest molecules. Single molecules of the macrocyclic compound mt-33 were successfully confined inside 2D nanocavities of the honeycomb networks and released when the phase was transformed to the close-packed structure. 相似文献
532.
Michael L. Storme Ruben S. t'Kindt Jan F. Van Bocxlaer 《Journal of separation science》2009,32(14):2346-2352
A ‘multiple (trapping) large‐volume injection’ approach was developed for the analysis of peptides and proteins. In this way, a maximally 10‐fold gain in sensitivity could be achieved. The system involves the use of an automated 10‐port switching valve in combination with a 1 mm i.d. trapping/guard column and a 1 mm i.d.×150 mm analytical column. The optimized multiple injection/loading procedure allows quantitative measurements of peptides and protein lysates. Linear calibration curves (R2 ? 0.988) over a minimum of two orders of magnitude were generated for a range of peptide and protein standards with sensitivities equal to or even exceeding, those generally achieved only through increasing miniaturization (quantification limit ?0.5 pmol/mL). 相似文献
533.
534.
Fei Cong Riccardo S. Mega Jinhong Chen Craig S. Day Prof. Ruben Martin 《Angewandte Chemie (International ed. in English)》2023,62(15):e202214633
Herein, we report a Cu-mediated trifluoromethylation of carbonyl-type compounds and unactivated olefins enabled by visible-light irradiation via σ C(sp3)−C bond-functionalization. The reaction is distinguished by its modularity, mild conditions and wide scope—even in the context of late-stage functionalization—thus offering a complementary approach en route to valuable C(sp3)−CF3 architectures from easily accessible precursors. 相似文献
535.
Ruben Lizarbe 《Mathematische Nachrichten》2023,296(9):3877-3891
We prove that a generic holomorphic foliation on a weighted projective plane has no algebraic solutions when the degree is big enough. We also prove an analogous result for foliations on Hirzebruch surfaces. 相似文献
536.
Javier E. Alfonso-Ramos Ruben Van Lommel David Hernández-Castillo Prof. Frank De Proft Roy González-Alemán Prof. Erik V. Van der Eycken Gerardo M. Ojeda-Carralero 《European journal of organic chemistry》2023,26(3):e202201028
1,3-Dipolar cycloadditions are the preferred method to generate five-membered heterocyclic rings. Surprisingly, cycloadditions based on acyl-isocyanide ylides have remained underexplored by the chemical community. Acyl-isocyanide ylides readily react with dipolarophiles, such as substituted alkenes, to yield Δ1-pyrroline derivatives. As an explanation for the observed reactivity of this reaction is lacking, extensive density functional theory calculations were performed to scrutinize the mechanistic features of the transformation. Herein we explain the experimental outcome of the reaction using a variety of reactivity theories and predict opposed regioselectivity for electron-poor and electron-rich dipolarophiles. With the insights obtained, we hope to incentivize the design of new cycloaddition reactions based on the acyl-isocyanide ylides motif. 相似文献
537.
Wen-Jun Yue Prof. Ruben Martin 《Angewandte Chemie (International ed. in English)》2023,62(40):e202310304
An α-difluoroalkylation of benzyl amines with trifluoromethylarenes is disclosed herein. This protocol is characterized by its operational simplicity, excellent chemoselectivity and broad scope—even with advanced synthetic intermediates—, thus offering a new entry point to medicinally-relevant α-difluoroalkylated amines from simple, yet readily accessible, precursors. 相似文献
538.
Xin-Yang Lv Roman Abrams Prof. Ruben Martin 《Angewandte Chemie (International ed. in English)》2023,62(8):e202217386
Herein, we describe the development of a copper-catalyzed C(sp3)-amination of proaromatic dihydroquinazolinones derived from ketones. The reaction is enabled by the intermediacy of open-shell species arising from homolytic C−C bond-cleavage driven by aromatization. The protocol is characterized by its operational simplicity and generality, including chemical diversification of advanced intermediates. 相似文献
539.