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721.
Schiller F Ruiz-Osés M Ortega JE Segovia P Martínez-Blanco J Doyle BP Pérez-Dieste V Lobo J Néel N Berndt R Kröger J 《The Journal of chemical physics》2006,125(14):144719
We present an analysis of the electronic structure of C60 adsorbed on a vicinal Au(111) surface at different fullerene coverages using photoemission, x-ray absorption, and scanning tunneling microscopy/spectroscopy (STS). STS provides a straightforward determination of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) levels with respect to the Fermi energy. At C60 coverages of 0.5 and 1 ML a 2.7 eV wide HOMO-LUMO gap is found. The near-edge x-ray absorption fine structure (NEXAFS) spectrum for the 0.5 ML C60 nanomesh structure displays a significant intensity at the low energy side of the LUMO exciton peak, which is explained as due to absorption into HOMO-LUMO gap states localized at individual C60 cluster edges. From 0.5 to 1 ML we observe a rigid shift of the HOMO-LUMO peaks in the STS spectra and an almost complete quenching of the gap states feature in NEXAFS. 相似文献
722.
Paula Ortega Ma Jesús Serramía Ma Angeles Muñoz-Fernández F. Javier de la Mata Rafael Gómez 《Tetrahedron》2010,66(18):3326-1108
A synthetic strategy has been developed for the preparation of new globular carbosilane dendrimers with mannose groups at the periphery. It consists of hydrosilylation reaction of allyl tetraacetylmannose with carbosilane dendrimers containing monohydrosilane end groups and the subsequent deacetylation reaction. Evaluation of dendrimer toxicities in dendritic cells by MTT assay were carried out, and evidence a good biocompatibility. 相似文献
723.
Recently, Escudero and Ortega (Insur. Math. Econ. 43:255–262, 2008) have considered an extension of the largest claims reinsurance with arbitrary random retention levels. They have analyzed
the effect of some dependencies on the Laplace transform of the retained total claim amount. In this note, we study how dependencies
influence the variability of the retained and the reinsured total claim amount, under excess-loss and stop-loss reinsurance
policies, with stochastic retention levels. Stochastic directional convexity properties, variability orderings, and bounds
for the retained and the reinsured total risk are given. Some examples on the calculation of bounds for stop-loss premiums
(i.e., the expected value of the reinsured total risk under this treaty) and for net premiums for the cedent company under
excess-loss, and complementary results on convex comparisons of discounted values of benefits for the insurer from a portfolio
with risks having random policy limits (deductibles) are derived.
相似文献
724.
For symplectic group actions which are not Hamiltonian there are two ways to define reduction. Firstly using the cylinder-valued momentum map and secondly lifting the action to any Hamiltonian cover (such as the universal cover), and then performing symplectic reduction in the usual way. We show that provided the action is free and proper, and the Hamiltonian holonomy associated to the action is closed, the natural projection from the latter to the former is a symplectic cover. At the same time we give a classification of all Hamiltonian covers of a given symplectic group action. The main properties of the lifting of a group action to a cover are studied. 相似文献
725.
P Borghetti J Lobo-Checa E Goiri A Mugarza F Schiller J Enrique Ortega EE Krasovskii 《J Phys Condens Matter》2012,24(39):395006
The photoemission cross-section of the Shockley surface state of Au(111) is studied over a wide range of photon energies both experimentally and theoretically. The measurements are fully understood based on the theoretical analysis within a one-step ab?initio theory of photoemission. The constant initial state spectrum is shown to be very sensitive to the structure of the topmost atomic layer. A maximum in the constant initial spectrum at 60?eV is identified as a fingerprint of the Au(111) surface reconstruction. 相似文献
726.
Laura M. Valdivieso Zarate Cesar A. Bravo Sanabria Gustavo E. Ramírez Caballero Fernando Martínez Ortega 《欧洲无机化学杂志》2023,26(33):e202300194
We report a highly selective (100 %) epoxidation of α-pinene and R-carvone using an oxygen atom transfer (OAT) reaction facilitated by a dioxo-Mo complex (Mo(VI)O2Cl2Ln) incorporated into the ligand 5,5’-dicarboxylate-2,2’-bipyridine (bpydc) within a Metal-Organic Framework (MOF) type UiO-67. Photo-stimulated (350 nm) OAT reaction was carried out with oxygen molecular used as the oxidant for 10 h. UiO-67 was synthesized with a mixture of the ligands 2,2′-biphenyl-5,5′-dicarboxylate (bpdc) and 2,2-bipyridine-5,5-dicarboxylate (bpydc) in different molar ratios (67 : 33, 50 : 50, 70 : 30, 0 : 100 bpdc : bpydc) to promote a higher presence of catalytic sites, i. e., the dioxo-Mo complex units. Furthermore, a post-synthetic exchange of Zr for Ti, between 64 : 36 to 78 : 22 Ti : Zr molar ratio, was performed to improve the optical properties of the MOF and promote the photoinduced OAT reaction. The Catalytic system was characterized by FTIR, XRD, 1H NMR, XPS, TGA, N2 adsorption/desorption and UV-Vis-DR. The amount of the epoxide monoterpene is proportional to the number of the dioxomolybdenum(VI) units (MoO2) incorporated in the UiO-67 (Zr/Ti), and the OAT reaction selectivity is due to the absence of the oxygen radicals in the medium of reaction. Besides, The Mo complex exhibited excellent stability after five cycles of use. 相似文献
727.
Hanfeng Zhou Panlong Li Dr. En Zhang Jonas Kunigkeit Xiongjun Zhou Katherina Haase Dr. Maria Rita Ortega Vega Shuwen Wang Xiaosa Xu Dr. Julia Grothe Prof. Stefan C. B. Mannsfeld Prof. Eike Brunner Prof. Katsumi Kaneko Prof. Stefan Kaskel 《Angewandte Chemie (International ed. in English)》2023,62(34):e202305397
Capacitive analogues of semiconductor diodes (CAPodes) present a new avenue for energy-efficient and nature-inspired next-generation computing devices. Here, we disclose the generalized concept for bias-direction-adjustable n- and p-CAPodes based on selective ion sieving. Controllable-unidirectional ion flux is realized by blocking electrolyte ions from entering sub-nanometer pores. The resulting CAPodes exhibit charge-storage characteristics with a high rectification ratio (96.29 %). The enhancement of capacitance is attributed to the high surface area and porosity of an omnisorbing carbon as counter electrode. Furthermore, we demonstrate the use of an integrated device in a logic gate circuit architecture to implement logic operations (‘OR’, ‘AND’). This work demonstrates CAPodes as a generalized concept to achieve p-n and n-p analogue junctions based on selective ion electrosorption, provides a comprehensive understanding and highlights applications of ion-based diodes in ionologic architectures. 相似文献