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71.
Rosa M. Claramunt Pilar Cornago M. Dolores Santa María Verónica Torres Elena Pinilla M. Rosario Torres 《Supramolecular chemistry》2013,25(4):349-356
The X-ray structure and the solid-state NMR measurements, mainly 15N CPMAS of the labelled compound, allow to determine the static and dynamic properties of 3(5)-ethyl-5(3)-phenyl-1H-pyrazole. The compound is a tetramer formed by three 5-ethyl-3-phenyl-1H-pyrazole and one 3-ethyl-5-phenyl-1H-pyrazole tautomers in dynamic equilibrium with the complementary situation. 相似文献
72.
Reconstitution of Nucleosome Demethylation and Catalytic Properties of a Jumonji Histone Demethylase
Carrie Shiau Michael J. Trnka Alen Bozicevic Idelisse Ortiz Torres Bassem Al-Sady Alma L. Burlingame Geeta J. Narlikar Danica Galonić Fujimori 《Chemistry & biology》2013,20(4):494-499
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73.
Giovanni Bottari Claudia Dammann Tomás Torres Thomas Drewello 《Journal of the American Society for Mass Spectrometry》2013,24(9):1413-1419
Two novel monofunctionalized fulleropyrrolidine derivatives (Prato adducts) were prepared and characterized by matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI). MALDI experiments conducted in the positive-ion mode on pure and mixed samples of both monofunctionalized fullerene derivatives revealed the efficient formation of bisadducts (in the case of the pure samples) and mixed bisadducts (in the case of a mixed sample). Bisadducts were not observed in the ESI experiments and thus not present in the sample. A mechanism for the MALDI formation of these bisadduct ions is proposed in which an azomethine ylide fragment is formed in situ from the monofunctionalized fulleropyrrolidine species upon laser irradiation. This fragment, which can survive as an intact moiety in the gas phase in the special environment provided by the MALDI experiment, is then able to attach to a fulleropyrrolidine monoadduct which acts as a dipolarophile, thus leading to the formation of a bisadduct fullerene derivative. The unprecedented re-attachment of the azomethine ylide implies that the establishment of the ligand attainment of Prato adducts based on MALDI analysis alone can lead to wrong assignments. Figure
? 相似文献
74.
Dr. Ángel J. Jiménez Michael Sekita Dr. Esmeralda Caballero Dr. M. Luisa Marcos Dr. M. Salomé Rodríguez‐Morgade Prof. Dr. Dirk M. Guldi Prof. Tomás Torres 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(43):14506-14514
In a novel electron‐donor–acceptor conjugate, phthalocyanine (Pc) and perylenediimide (PDI) are connected through a trans‐platinum(II) diacetylide linker to yield Pc‐Pt‐PDI 1 . In the ground state, the presence of PtII disrupts the electronic communication between the two electroactive components, as revealed by UV/Vis spectroscopy and electrochemical studies. The photophysical behavior of 1 is compared with that of the corresponding Pc‐PDI electron‐donor–acceptor conjugate 2 in terms of charge separation and charge recombination. The insertion of PtII between Pc and PDI impacts the results in a longer‐lived Pc . +/PDI . ? radical ion‐pair state. In addition, the intermediately formed Pc triplet excited state is formed with higher quantum yields in 1 than in 2 . 相似文献
75.
Ground state solution for differential equations with left and right fractional derivatives
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César Torres 《Mathematical Methods in the Applied Sciences》2015,38(18):5063-5073
In this work, we study the existence of positive solutions for a class of fractional differential equation given by (1) where . Using the mountain pass theorem and comparison argument, we prove that (1) at least has one nontrivial solution. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
76.
A two‐step reaction scheme leading to singlet carbene species that can be detected under matrix conditions for the reaction of Zr(3F) with either CH3F or CH3CN
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Ana E. Torres Guadalupe Castro Ricardo Pablo‐Pedro Fernando Colmenares 《Journal of computational chemistry》2014,35(11):883-890
The results obtained from CASSCF‐MRMP2 calculations are used to rationalize the singlet complexes detected under matrix‐isolation conditions for the reactions of laser‐ablated Zr(3F) atoms with the CH3F and CH3CN molecules, without invoking intersystem crossings between electronic states with different multiplicities. The reaction Zr(3F) + CH3F evolves to the radical products ZrF· + ·CH3. This radical asymptote is degenerate to that emerging from the singlet channel of the reactants Zr(1D) + CH3F because they both exhibit the same electronic configuration in the metal fragment. Hence, the caged radicals obtained under cryogenic‐matrix conditions can recombine through triplet and singlet paths. The recombination of the radical species along the low‐multiplicity channel produces the inserted structures H3C? Zr? F and H2C?ZrHF experimentally detected. For the Zr(3F) + CH3CN reaction, a similar two‐step reaction scheme involving the radical fragments ZrNC· + ·CH3 explains the presence of the singlet complexes H3C? Zr? NC and H2C?Zr(H)NC revealed in the IR‐matrix spectra upon UV irradiation. © 2014 Wiley Periodicals, Inc. 相似文献
77.
Significant nonlinear‐optical switching capacity in atomic clusters built from silicon and lithium: A combined ab initio and density functional study
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Panaghiotis Karamanis Nicolás Otero Claude Pouchan Juan José Torres William Tiznado Aggelos Avramopoulos Manthos G. Papadopoulos 《Journal of computational chemistry》2014,35(11):829-838
Starting from a hypothetical but fundamental charge/discharge sequence, the topic of nonlinear optical switching in atomic clusters built from silicon and alkali metals is opened up. The outcomes presented in this work, obtained with ab initio methods of exceptional predictive capabilities, offer strong evidences that sizable hyperpolarizability contrasts between neutral and charged alkali metal doped cluster forms might be simultaneously accomplished. The observed switching procedure involves redox polyatomic clusters formed by Si atoms. These centers function as electron acceptors at the ground state and as electron donors at the excited states facilitating low energy charge transfer transitions upon electronic excitation. © 2014 Wiley Periodicals, Inc. 相似文献
78.
Oscar B. Torres Rashmi Jalah Kenner C. Rice Fuying Li Joshua F. G. Antoline Malliga R. Iyer Arthur E. Jacobson Mohamed Nazim Boutaghou Carl R. Alving Gary R. Matyas 《Analytical and bioanalytical chemistry》2014,406(24):5927-5937
A potential new treatment for drug addiction is immunization with vaccines that induce antibodies that can abrogate the addictive effects of the drug of abuse. One of the challenges in the development of a vaccine against drugs of abuse is the availability of an optimum procedure that gives reproducible and high yielding hapten-protein conjugates. In this study, a heroin/morphine surrogate hapten (MorHap) was coupled to bovine serum albumin (BSA) using maleimide-thiol chemistry. MorHap-BSA conjugates with 3, 5, 10, 15, 22, 28, and 34 haptens were obtained using different linker and hapten ratios. Using this optimized procedure, MorHap-BSA conjugates were synthesized with highly reproducible results and in high yields. The number of haptens attached to BSA was compared by 2,4,6-trinitrobenzenesulfonic acid (TNBS) assay, modified Ellman’s test and matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Among the three methods, MALDI-TOF MS discriminated subtle differences in hapten density. The effect of hapten density on enzyme-linked immunosorbent assay (ELISA) performance was evaluated with seven MorHap-BSA conjugates of varying hapten densities, which were used as coating antigens. The highest antibody binding was obtained with MorHap-BSA conjugates containing 3–5 haptens. This is the first report that rigorously analyzes, optimizes and characterizes the conjugation of haptens to proteins that can be used for vaccines against drugs of abuse. The effect of hapten density on the ELISA detection of antibodies against haptens demonstrates the importance of careful characterization of the hapten density by the analytical techniques described. 相似文献
79.
Lie symmetries and solitons in nonlinear systems with spatially inhomogeneous nonlinearities 总被引:1,自引:0,他引:1
Belmonte-Beitia J Pérez-García VM Vekslerchik V Torres PJ 《Physical review letters》2007,98(6):064102
Using Lie group theory and canonical transformations, we construct explicit solutions of nonlinear Schr?dinger equations with spatially inhomogeneous nonlinearities. We present the general theory, use it to show that localized nonlinearities can support bound states with an arbitrary number solitons, and discuss other applications of interest to the field of nonlinear matter waves. 相似文献
80.
We experimentally demonstrate a new technique to control the type of frequency correlations of entangled photon pairs generated by spontaneous parametric downconversion. Frequency-correlated and frequency-anticorrelated photons are produced when a broadband pulse is used as a pump. The method is based on the control of the group velocities of the interacting waves and can be applied in any nonlinear medium and frequency band of interest. 相似文献