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441.
Car-Parrinello simulations and static density-functional theory calculations reveal how hydrogen promotes growth of epitaxial, ordered Si films in plasma-enhanced chemical vapor deposition at low-temperature conditions where the exposed Si(001)-(2x1) surface is fully hydrogenated. Thermal H atoms, indeed, are shown to selectively etch adsorbed silyl back to the gas phase or to form adsorbed species which can be easily incorporated into the crystal down to T approximately 200 degrees C and start diffusing around T approximately 300 degrees C. Our results are well consistent with earlier experiments. 相似文献
442.
Esteban Bertsch Sebastián Suñer Dr. Silvana Pinheiro Prof. Dr. William J. Zamora 《Chemphyschem》2023,24(24):e202300548
Lipophilicity is a physicochemical property with wide relevance in drug design, computational biology, food, environmental and medicinal chemistry. Lipophilicity is commonly expressed as the partition coefficient for neutral molecules, whereas for molecules with ionizable groups, the distribution coefficient (D) at a given pH is used. The logDpH is usually predicted using a pH correction over the logPN using the pKa of ionizable molecules, while often ignoring the apparent ion pair partitioning . In this work, we studied the impact of on the prediction of both the experimental lipophilicity of small molecules and experimental lipophilicity-based applications and metrics such as lipophilic efficiency (LipE), distribution of spiked drugs in milk products, and pH-dependent partition of water contaminants in synthetic passive samples such as silicones. Our findings show that better predictions are obtained by considering the apparent ion pair partitioning. In this context, we developed machine learning algorithms to determine the cases that should be considered. The results indicate that small, rigid, and unsaturated molecules with logPN close to zero, which present a significant proportion of ionic species in the aqueous phase, were better modeled using the apparent ion pair partitioning . Finally, our findings can serve as guidance to the scientific community working in early-stage drug design, food, and environmental chemistry. 相似文献
443.
Tiago F. T. Cerqueira Sun Lin Maximilian Amsler Stefan Goedecker Silvana Botti Miguel A. L. Marques 《ChemInform》2015,46(38):no-no
Ab initio global structural prediction and specifically, the minima hopping method combined with high‐throughput calculations are used to explore the periodic table in search of novel oxide phases. 相似文献
444.
Rojas Víctor Cáceres Gustavo López Silvana Henríquez Rodrigo Grez Paula Schrebler Ricardo Navarrete Emilio Herrera Francisco Caballero Álvaro Gómez-Cámer Juan Luis Aristizábal Juliet Muñoz Eduardo 《Journal of Solid State Electrochemistry》2023,27(4):865-872
Journal of Solid State Electrochemistry - In this work, the performance of copper (II) hexacyanoferrate(III) (CuHCF) as a cathode material for sodium-ion batteries was studied. The compound was... 相似文献
445.
Jun Okuda Thomas Kleinhenn Peter Knig Insa Taden Silvana Ngo Ilya L. Rushkin 《Macromolecular Symposia》1995,95(1):195-202
Mono(cyclopentadienyl)titanium complexes of the general formula Ti(η5-C5R5)X2OR' were designed as structurally well-defined mononuclear initiators for the ring-opening polymerization of four-, six-, and seven-membered lactones. Living pseudo-anionic mechanism with acyl-oxygen cleavage is suggested by various NMR spectroscopic studies as well as the isolation of the mono(insertion) products. The nature of the ancillary ligands lead to significant changes in the polymerization activity and is discussed in terms of electronic and steric effects. 相似文献
446.
Prof. Dr. Antonio Doménech-Carbó Silvana López Bastián Chandía Gustavo Cáceres Prof. Dr. Eduardo Muñoz 《Chemphyschem》2023,24(9):e202200853
The cation-insertion solid state electrochemistry of a potassium copper(II) hexacyanoferrate in contact with LiClO4/DMSO, NaPF6/DMSO, and KPF6/DMSO electrolytes has been theoretically and experimentally studied using the voltammetry of immobilized particles methodology. Voltammetric data, combined with SEM/EDS analysis permit to determine a K0.876CuII1.328FeIII0.049[FeIII0.318FeII0.682(CN)6] stoichiometry for the synthesized solid. Separation of electronic and ionic contributions to Gibbs energy changes can be made based on cyclic voltammetric and open circuit potential measurements. These parameters can be combined to measure values of the Gibbs energy of cation-independent electron transfer of 7.2±0.4 (K+), 7.1±0.5 (Na+) kJ mol−1, in close agreement with the expected independence of this parameter on the electrolyte cation. The reduction Fe(III) centers bound to cyano groups exhibit a cation-dependent, essentially Nernstian character which can be described in terms of Na+ and K+ insertion/deinsertion while in the case of Li+ electrolytes there is significant co-cation diffusion. Chronoamperometric data provide estimates of the diffusion coefficients of Na+, and K+ ions through the solid around 10−9 cm2 s−1. 相似文献