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81.
T. Mochiku Y. Hata T. Wuernisha Y. Matsushita Y. Katsuya S. Ishimaru M. Tanaka K. Kobayashi A. Hoshikawa T. Ishigaki H. Yasuoka K. Hirata 《Physica C: Superconductivity and its Applications》2009,469(15-20):960-964
Heavily Fe-substituted Ba2YCu3O6+δ-type compound FeSr2YCu2O6+δ exhibits superconductivity around 60 K, only when it is annealed in N2 and subsequently in O2. Cationic distribution in this compound is strongly dependent on ionic radius at the Y site, and its superconducting properties are affected by the cationic distribution. In contrast, although the compound with the substitution of fluorite-type unit for Y has cationic order, it does not exhibit superconductivity. We have analyzed the crystal structure of the compounds with the substitution of other lanthanoid elements for Y and with substitution of fluorite-type unit for Y. 相似文献
82.
We construct a statistical model of crystal melting to count BPS bound states of D0 and D2 branes on a single D6 brane wrapping
an arbitrary toric Calabi-Yau threefold. The three-dimensional crystalline structure is determined by the quiver diagram and
the brane tiling which characterize the low energy effective theory of D branes. The crystal is composed of atoms of different
colors, each of which corresponds to a node of the quiver diagram, and the chemical bond is dictated by the arrows of the
quiver diagram. BPS states are constructed by removing atoms from the crystal. This generalizes the earlier results on the
BPS state counting to an arbitrary non-compact toric Calabi-Yau manifold. We point out that a proper understanding of the
relation between the topological string theory and the crystal melting involves the wall crossing in the Donaldson-Thomas
theory. 相似文献
83.
Multiple-ion-sensing functions are integrated on a capillary-assembled microchip (CAs-CHIP). Since the CAs-CHIPs are fabricated by embedding various chemically functionalized square capillaries onto a lattice PDMS channel plate having same channel dimensions as outer dimensions of square capillaries, integration of parallel multiple-ion-sensing is easily realized. Here, three ion-sensing capillaries are prepared and used for integrating these functions onto a single microchip. Ion-sensing square capillaries (sodium, potassium, calcium) are prepared by attaching ion-selective optode membranes to inner wall of capillaries, and are characterized in terms of response time, response range, and ion selectivity. Finally, fully characterized ion-sensing capillaries are embedded into PDMS channel plate in parallel to fabricate a multiple-ion-sensing chip. The CAs-CHIP-based strategy is promising for integrating multiple chemical sensing functions onto a single microchip. 相似文献
84.
Ochiai M Tada N Murai K Goto S Shiro M 《Journal of the American Chemical Society》2006,128(30):9608-9609
Stable aliphatic bromonium ylides (RfSO2)2C--Br+C6H4-p-CF3 (Rf = CF3, CF3(CF2)3) have been synthesized and structurally characterized for the first time. X-ray crystallographic analyses indicated a ylide structure with an sp2 hybridization of the ylide carbanions and with little double-bond character for the ylidic bond. The bromonium ylides selectively undergo transfer of the aryl group to nitrogen heterocycles, such as pyridines, yielding N-arylpyridinium salts. This is in a marked contrast to the reaction of the iodonium ylides, which produces pyridinium ylides through transylidations. 相似文献
85.
Masahito Yamazaki 《Letters in Mathematical Physics》2018,108(4):1137-1146
We propose a new generalization of the Yang–Baxter equation, where the R-matrix depends on cluster y-variables in addition to the spectral parameters. We point out that we can construct solutions to this new equation from the recently found correspondence between Yang–Baxter equations and supersymmetric gauge theories. The \(S^2\) partition function of a certain 2d \({\mathcal {N}}=(2,2)\) quiver gauge theory gives an R-matrix, whereas its FI parameters can be identified with the cluster y-variables. 相似文献
86.
Nucleophilic addition of imidazolines to 1-halo-1-alkynes takes place by simple heating in DMF without any additives to give (Z)-N-(1-halo-1-alken-2-yl)imidazolines in good yield and in a highly regio- and stereoselective manner. These reaction conditions are also valid for the similar addition of imidazoles. 相似文献
87.
Hitomi Y Arakawa K Funabiki T Kodera M 《Angewandte Chemie (International ed. in English)》2012,51(14):3448-3452
Selective oxidation: The success of the title reaction is caused by the strong electron donation from the amidate moiety of the dpaq ligand to the iron center (dpaq=2-[bis(pyridin-2-ylmethyl)]amino-N-quinolin-8-yl-acetamidate). This process facilitates the O?O bond heterolysis of the intermediate Fe(III) OOH species to generate a selective oxidant without forming highly reactive hydroxyl radicals. 相似文献
88.
Nanochannel with uniform and Janus surfaces: shear thinning and thickening in surfactant solution 总被引:1,自引:0,他引:1
On basis of molecular simulation of confined surfactant solutions, we show that by adding chemical patterns on the inner surface of nanochannels dynamical properties of the confined surfactant solutions could be modified from shear thinning to shear thickening. To this end, we select uniformly hydrophobic and hydrophilic surfaces as well as a stripe-patterned Janus surface as three prototype confining surfaces of nanochannels. In all three nanochannels, when the surfactant solution is under relatively low shear rates, it shears thin. Under moderate shear rates, a sharp decrease in the shear viscosity could occur due to surfactant morphology transition. Under relatively high shear rates, a shear-thinning-to-thickening transition can emerge due to the tendency of stratification normal to the confining surface. Our simulation study offers a guide to steering dynamic properties of surfactant fluids in nanofluidic devices through engineering surfaces of nanochannels by design. 相似文献
89.
The water-surface interaction is a research target of great importance for a broad spectrum of technological applications and fundamental scientific disciplines. In the present study, a comparative analysis is performed to clarify the structural and diffusion properties of water on a number of oxide surfaces. Based on the molecular dynamics (MD) simulation method, the water-surface interaction mechanism was investigated for the oxide materials TiO2 (anatase), Al2O3 (corundum), and Fe2O3 (hematite). A comparison of the water-TiO2 interaction with the water-Al2O3 and water-Fe2O3 systems demonstrates the specificity of the adsorption and layer formation on the atomic/molecular level scale. The obtained MD analysis data point to a considerable enhancement of water-TiO2 surface adsorption and a relatively high density distribution profile near the surface. The novel data on water structure and diffusion on oxide surfaces are discussed from the point of view of possible material innovation and design. 相似文献