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991.
《European Journal of Operational Research》2006,173(2):405-418
In this paper, we introduce several generalized convexity for a real-valued set function and establish optimality and duality results for a multi-objective programming problem involving generalized d-type-I and related n-set functions. 相似文献
992.
Adhesion and bonding of the Al/TiC interface 总被引:1,自引:0,他引:1
The electronic structure and adhesion of Al/TiC(0 0 1) interface are examined by density functional theory. Our results show the preferred configuration is the Al atom above the ceramic’s metalloid atom. The calculated adhesion explains the conflicting experimental results of the Wad from the aspect of the establishing different chemical equilibrium bonds at the different temperatures. By applying several analysis methods we have thoroughly characterized the interfacial electronic structure. For the Ti-site the interfacial Al and Ti atoms form the metal/covalent bond, while for the C-site the interfacial Al and C atoms form the polar covalent interaction. In addition, we examine the effects of Mg and Si alloying elements at the interface, and find that Mg greatly deteriorates the interface and Si slightly improves the interface. The cleavage may take place preferentially at the interface with the help of interface strain energy, especially with the addition of Mg. This is in good agreement with the experimental result. 相似文献
993.
994.
Two new iridoid glycosides,named scrophularianoids A(1) and B(2),were isolated from the roots of Scrophularia ningpoensis.The chemical structures were established on the basis of extensive analyses of spectroscopic data.Compounds 1 and 2 were inactive in our preliminary in vitro myocardial protective bioassay. 相似文献
995.
The bipyridine (bipy) and its cobalt complex (Co-bipy) were tested as corrosion inhibitors for N80 carbon steel in 0.1 M H2SO4 solution by electrochemical polarization and electrochemical impedance spectroscopy (EIS) method. Scanning electron microscopy (SEM) techniques were used to characterize the mild steel surface. The test results showed that the complex and ligand are mixed-type inhibitors and the compounds are adsorbed on the steel surface according to Temkin adsorption isotherm. The inhibition efficiency of the inhibitors follows the trend Co-bipy > bipy. The adsorption of the inhibitors can be classifies as physical adsorption. 相似文献
996.
Ying Li Zhenrui Gao Chunlan Piao Kaiwen Lu Zhiping Wang Min-Long Cui 《Applied biochemistry and biotechnology》2014,172(4):1807-1817
In this study, we developed a rapid and efficient method for in vitro propagation and Agrobacterium tumefaciens-mediated transformation of Digitalis purpurea L. (syn. foxglove), an important medicinal plant. Mature leaf explants of D. purpurea were used for 100 % adventitious shoot regeneration on Murashige and Skoog (MS) medium supplemented with 1 mg L?1 thidiazuron (TDZ) (a cytokine) and 0.1 mg L?1 1-naphthaleneacetic acid (NAA) (an auxin). Transformation was achieved by inoculating leaf explants with the A. tumefaciens strains GV2260/pBI121 or GV3101/pBI121. The binary vector pBI121 contained the reporter β-glucuronidase gene (GUS) and kanamycin selection marker nptII. Kanamycin-resistant shoots were regenerated directly on the selection medium 4–6 weeks after co-cultivation. Approximately, 52.2 and 60 % of kanamycin-resistant shoots transformed with Agrobacterium strains GV2260 and GV3101, respectively, showed strong GUS staining by histochemical assay. Furthermore, PCR and Southern blot analysis confirmed the presence of nptII and GUS on the chromosome of the transformed D. purpurea plants, and stable GUS expression was detected in the transformants by RT-PCR analysis. This efficient method of shoot regeneration and genetic transformation of D. purpurea will provide a powerful tool to increase and produce valuable components such as digitoxin, digoxin, and digoxigenin in D. purpurea through improved secondary metabolic pathways via a biotechnological approach. 相似文献
997.
Xiao-Lan Hu Xi-Qing Bian Xin Wu Jian-Yong Li Hui-Ming Hua Yue-Hu Pei Ai-Hong Han Jiao Bai 《Tetrahedron letters》2014
Penioxalamine A (1), a novel prenylated spiro-oxindole alkaloid having a unique seven-membered nitrogen heterocycle system, was isolated from the fungus Penicillium oxalicum TW01-1. The structure of 1 was elucidated on the basis of the spectral data, single-crystal X-ray diffraction, and CD analysis. Compound 1 showed moderate cytotoxicity against HL-60 cell line. The possible biosynthetic pathway of 1 was also proposed. 相似文献
998.
999.
In this study, biodegradable polymeric nanocapsules were prepared by sequential deposition of food-grade polyelectrolytes through the self-assembling process onto the oil (medium chain triglycerides) droplets enriched with curcumin (lipophilic bioactive compound). Optimum conditions were used to prepare ultrasound-assisted nanoemulsions stabilized by octenyl-succinic-anhydride (OSA)-modified starch. Negatively charged droplets (−39.4 ± 1.84 mV) of these nanoemulsions, having a diameter of 142.7 ± 0.85 nm were used as templates for the fabrication of nanocapsules. Concentrations of layer-forming cationic (chitosan) and anionic (carboxymethylcellulose) biopolymers were optimized based on the mean droplet/particle diameter (MDD/MPD), polydispersity index (PDI) and net charge on the droplets/capsules. Prepared core–shell structures or nanocapsules, having MPD of 159.85 ± 0.92 nm, were characterized by laser diffraction (DLS), ζ-potential (ZP), atomic force microscopy (AFM), transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). Furthermore, physical stability of curcumin-loaded nanocapsules in suspension was determined and compared at different storage temperatures. This study may provide information regarding the formation of ultrasound-assisted polymeric nanocapsules from the nanoemulsion templates which could be helpful in the development of delivery systems for lipophilic food bioactives. 相似文献
1000.
The structural, phase stabilities, mechanical, electronic and thermodynamic properties of intermetallic phases in Zr–Sn system are investigated by using first-principles method. The equilibrium lattice constants, enthalpy of formation (ΔHform) and elastic constants are obtained and compared with available experimental and theoretical data. The configuration of Zr4Sn is measured with reasonable precision. The ΔHform of five hypothetical structures are obtained in order to find possible metastable phase for Zr–Sn system. The mechanical properties, including bulk modulus, shear modulus, Young's modulus and Poisson's ratio, are calculated by Voigt–Reuss–Hill approximation and the Zr5Sn4 and Zr5Sn3 show excellent mechanical properties. The electronic density of states for Zr5Sn4, Zr5Sn3 and cP8-Zr3Sn are calculated to further investigate the stability of intermetallic compounds. Through the quasi-harmonic Debye model, the Debye temperature, heat capacity and thermal expansion coefficient under temperature of 0–300 K and pressure of 0–50 GPa for Zr5Sn3 and Zr5Sn4 are deeply investigated. 相似文献