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101.
SARS-CoV-2, or severe acute respiratory syndrome coronavirus 2, represents a new strain of Coronaviridae. In the closing 2019 to early 2020 months, the virus caused a global pandemic of COVID-19 disease. We performed a virtual screening study in order to identify potential inhibitors of the SARS-CoV-2 main viral protease (3CLpro or Mpro). For this purpose, we developed a novel approach using ensemble docking high-throughput virtual screening directly coupled with subsequent Linear Interaction Energy (LIE) calculations to maximize the conformational space sampling and to assess the binding affinity of identified inhibitors. A large database of small commercial compounds was prepared, and top-scoring hits were identified with two compounds singled out, namely 1-[(R)-2-(1,3-benzimidazol-2-yl)-1-pyrrolidinyl]-2-(4-methyl-1,4-diazepan-1-yl)-1-ethanone and [({(S)-1-[(1H-indol-2-yl)methyl]-3-pyrrolidinyl}methyl)amino](5-methyl-2H-pyrazol-3-yl)formaldehyde. Moreover, we obtained a favorable binding free energy of the identified compounds, and using contact analysis we confirmed their stable binding modes in the 3CLpro active site. These compounds will facilitate further 3CLpro inhibitor design. 相似文献
102.
Yue Liu Andy Dang Jan Urban Frantiek Ture
ek 《Angewandte Chemie (International ed. in English)》2020,59(20):7772-7777
Adenosine radicals tagged with a fixed‐charge group were generated in the gas phase and structurally characterized by tandem mass spectrometry, deuterium labeling, and UV/Vis action spectroscopy. Experimental results in combination with Born–Oppenheimer molecular dynamics, ab initio, and excited‐state calculations led to unambiguous assignment of adenosine radicals as N‐7 hydrogen atom adducts. The charge‐tagged radicals were found to be electronically equivalent to natural DNA nucleoside radicals. 相似文献
103.
104.
Jinxia Gua b Zhipeng Baib Weifang Lib Liping Wua Aixia Liuc Haiyan Dongd Yiyang Xiec a Tianjin Institute of Urban Construction Tianjin China b State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention Control College of Environmental Science Engineering Nankai University Tianjin China c Tianjin Institute of Meteorological Instruments Tianjin China d Tianjin Environmental Monitoring Central Station Tianjin China 《中国颗粒学报》2011,(3)
PM2.5 samples for 24 h were collected during winter in Tianjin,China. The ambient mass concentration and chemical composition of the PM2.5 were determined. Ionic species were analyzed by ion chromatog-raphy,while carbonaceous species were determined with the IMPROVE thermal optical reectance(TOR) method,and inorganic elements were measured by inductively coupled plasma-atomic emission spec-trometer. The daily PM2.5 mass concentrations ranged from 48.2 to 319.2 g/m3 with an arithmetic average of 144.6 g/m3. ... 相似文献
105.
Böker A Elbs H Hänsel H Knoll A Ludwigs S Zettl H Urban V Abetz V Müller AH Krausch G 《Physical review letters》2002,89(13):135502
We investigate the microscopic mechanisms responsible for microdomain alignment in block copolymer solutions exposed to an electric field. Using time-resolved synchrotron small-angle x-ray scattering, we reveal two distinct processes, i.e., grain boundary migration and rotation of entire grains, as the two dominant microscopic mechanisms. The former dominates in weakly segregating systems, while the latter is predominant in strongly segregated systems. The kinetics of the processes are followed as a function of polymer concentration and temperature and are correlated to the solution viscosity. 相似文献
106.
The previously described reduction of the effective rotational Hamiltonian for semirigid molecules of C3v or D3 point group symmetry [M. R. Aliev and V. T. Aleksanyan, Opt. Spectrosc.24, 201–206 (1968)] has been extended to nonrigid molecules with a significant inversion splitting of the energy levels (e.g., NH3, H3O+, CH3?, or SiH3 molecules). Although for semirigid molecules like PH3 or AsH3, the parameters α and η′3 which appear in the terms α[J+3 + J?3, Jz]+ and η′3(J+6 + J?6) are almost completely correlated, the effects of the inversion splitting and the accidental resonance which can occur between the interacting rotational levels in nonrigid molecules make it possible to determine α and η′3 separately. The results of fitting the experimental data for 14NH3 and 15NH3 [?. Urban, Romola D'Cunha, K. Narahari Rao, and D. Papou?ek, Canad. J. Phys.62, 1775–1791 (1984); Romola D'Cunha, ?. Urban, K. Narahari Rao, L. Henry, and A. Valentin, J. Mol. Spectrosc.111, 352–360 (1985)] are in agreement with this conclusion. The possibility of the determination of the sign of η3 from a simultaneous analysis of the allowed and Δk = ±3 forbidden transitions in semirigid XY3 molecules has been discussed. 相似文献
107.
In the orthorhombic phase of KnbO3 an EPR spectrum of Fe3+ substitutional for Nb5+ has been observed with the main axis parallel to the pseudocubic one of the orthorhombic phase. The cubic parameter a is very close to the one in BaTiO3. A second spectrum probably due to local charge compensation is also reported. 相似文献
108.
Karsten Krohn 《Tetrahedron letters》1980,21(37):3557-3560
Naturally occurring quinones such as 7-methyljuglone, chrysophanol, emodin, helminthosporin, phomarin and physcion were prepared via Diels-Alder reaction and PCC-oxidation of the allylic alkohols obtained from the adducts. 相似文献
109.
110.
The dependence of the displacement cross section of Cu on electron energy and crystal orientation has very accurately been determined by high-voltage electron microscopy. The minimum displacement threshold energy of (9.5 ± 0.5) eV occurs at an angle of 10° from 〈110〉 directions. 相似文献