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排序方式: 共有670条查询结果,搜索用时 240 毫秒
661.
Alberto Senz De Buruaga Jose C. De La Cal Jose M. Asua 《Journal of polymer science. Part A, Polymer chemistry》1999,37(13):2167-2178
A mathematical model for inverse microemulsion polymerization has been developed. The model has been used to fit experimental results of the effect of initiator concentration, light intensity, emulsifier concentration, and dispersed phase weight fraction on the monomer conversion evolution, particle size, and polymer molecular weight in the inverse microemulsion polymerization of 2-methacryloyl oxyethyl trimethyl ammonium chloride (MADQUAT) initiated by UV light in the presence of AIBN. A good fitting of the experimental data was achieved. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2167–2178, 1999 相似文献
662.
Alberto Senz De Buruaga Ignac Capek Jose C. De La Cal Jose M. Asua 《Journal of polymer science. Part A, Polymer chemistry》1998,36(5):737-748
The polymerization of inverse microemulsions of 2-methacryloyl oxyethyl trimethyl ammonium chloride stabilized by a blend of nonionic emulsifiers (a sorbitan sesquioleate and a sorbitan monooleate) and initiated by UV light in the presence of Azobis(isobutyronitrile) (AIBN) was investigated. The effect of initiator concentration, light intensity, emulsifier concentration, and dispersed phase weight fraction on the polymerization rate (Rp), number of polymer particles (Np), and polymer molecular weight (Mw) was studied. The application of this process to tubular reactors is discussed. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 737–748, 1998 相似文献
663.
Pedro Henrique Hermes Araújo Jos Carlos de la Cal Jos Maria Asua Jos Carlos Pinto 《Macromolecular theory and simulations》2001,10(8):769-779
A detailed dynamic mathematical model that describes the evolution of particle size distributions (PSDs) during emulsion copolymerization reactions in a continuous loop reactor was developed and compared with experimental data. The model is based on the assumption that two distinct particle populations exist: precursor particles and stable latex particles. Precursor particles are colloidally unstable and therefore may undergo coagulation with other precursors and be absorbed by stable latex particles. It is shown that the kinetic model is able to reproduce the rather complex dynamic behavior of the vinyl acetate/Veova10 emulsion copolymerization in a continuous loop reactor, including the development of oscillatory responses of PSDs during reaction start‐up. It is also shown that, for the studied polymerization system, oscillatory responses are obtained only when both particle populations are assumed to exist and when both coagulative and micellar particle nucleations are simultaneously considered. 相似文献
664.
665.
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
666.
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
667.
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
668.
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
669.
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
670.