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41.
The considered mathematical model of the decomposition of valerate presents three unknown kinetic parameters, two unknown
stoichiometric coefficients, and three unknown initial concentrations for biomass. Applying a structural identifiability study,
we concluded that it is necessary to perform simultaneous batch experiments with differenitial conditions for estimating these
parameters. Four simultaneous batch experiments were conducted at 55°C, characterized by four different initial acetate concentrations.
Product inhibition of valerate degradation by acetate was considered. Practical identification was done optimizing the sum
of the multiple determination coefficients for all measured state viariables and for all experiments simultaneously. The estimated
values of kinetic parameters and stoichiometric coefficients were characterized by the parameter correlation matrix, the confidence
interval, and the student's t-test at 9% significance level with positive results except for the saturation constant, for which more eperiments for improving
its identifiability should be conducted. In this article, we discussekinetic parameter estimation methods. 相似文献
42.
Merle A. Battiste James M. Coxon Gregory W. Simpson Peter J. Steel Alan J. Jones 《Tetrahedron》1984,40(16):3137-3144
The reaction of endo-tricyclo[3.2.1.02,4]oct-6-ene 1 with methanol in the presence of catalytic amounts of toluene-p-sulphonic acid has been shown to give 2-exo- and endo-methoxybicyclo[3.2.1]oct-3-ene (2c) and (2d) and 2-endo-methoxybicyclo[3.2.1]oct-6-ene (13). The formation of 2-exo- methoxybicyclo[3.2.1]oct-3-ene (2c), the major product of reaction, has been probed by deuterium labelling experiments and a series of 6-exo-7-exo- dideuterobicyclo[3.2.1]oct-3-enes synthesised for 2H, 1H and 13C NMR spectral analysis in order unambiguously to determine the stereochemistry of proton attack on endo-tricyclo[3.2.1 02,4]oct-6-ene (1). The formation of 2-exo-methoxybicyclo[3.2.1]oct-3-ene (2c) has been determined to involve corner protonation of the cyclopropyl moiety and skeletal rearrangement to an allylic cation with a small but measurable memory effect 相似文献
43.
44.
Rafael Abela Christopher Baines Xavier Donath Dierk Herlach David Maden Ivan D. Reid Dieter Renker György Solt Ulrich Zimmermann 《Hyperfine Interactions》1994,87(1):1105-1110
TheSR Facility Instruments presently available at PSI and the envisaged medium- and long-term developments are presented. The plans focus on further upgrades of the existing instruments and the development of new techniques using the very high fluxes becoming available at PSI, in particular the setup of a beamline with a fast kicker for muons on request (MORE) and the development of very low energy muon beams. 相似文献
45.
Frank Merle 《Communications in Mathematical Physics》1996,175(2):433-455
We consider the Zakharov equations in
N
(for N=2,N=3). We first establish a viriel identity for such equations and then prove a blow-up result for solutions with a negative energy. 相似文献
46.
Michel Josse Xavier Gerbaux Armand Hadni 《International Journal of Infrared and Millimeter Waves》1993,14(7):1381-1387
Conclusion We have presented the possibility to make optical coatings on quartz in the FIR and we have got a transmission coefficient as high as 97% at room temperature. It will rise probably close to 100% at liquid helium temperature where the quartz two-phonon difference processes are frozen. The use of polyethylene or TPX is also possible to make plates and lenses. The reflectivity losses are smaller because the refractive index is much smaller, but they cannot be further reduced by any coating because there is no transparent material with n1.2 in the FIR. These lenses are very useful in the FIR (except around 60 cm–1 if they are made of polyethylene). TPX is quite transparent over the whole FIR range, and also in the visible with nearly the same refractive index as in the FIR. Alignments can be made with visible light, and still work in the FIR. 相似文献
47.
Nam K Prat-Resina X Garcia-Viloca M Devi-Kesavan LS Gao J 《Journal of the American Chemical Society》2004,126(5):1369-1376
Reactive flux molecular dynamics simulations have been carried out using a combined QM/MM potential to study the dynamics of the nucleophilic substitution reaction of dichloroethane by a carboxylate group in haloalkane dehalogenase and in water. We found that protein dynamics accelerates the reaction rate by a factor of 2 over the uncatalyzed reaction. Compared to the thermodynamic effect in barrier reduction, protein dynamic contribution is relatively small. However, analyses of the friction kernel reveal that the origins of the reaction dynamics in water and in the enzyme are different. In aqueous solution, there is significant electrostatic solvation effect, which is reflected by the slow reorganization relaxation of the solvent. On the other hand, there is no strong electrostatic coupling in the enzyme and the major effect on reaction coordinate motion is intramolecular energy relaxation. 相似文献
48.
Churruca F SanMartin R Carril M Urtiaga MK Solans X Tellitu I Domínguez E 《The Journal of organic chemistry》2005,70(8):3178-3187
Novel dibenzo[a,c]phenanthridines are prepared regioselectively by the application of a straightforward synthetic pathway, starting from new 3,4-diaryl- and 3,4-dihydro-3,4-diarylisoquinolines prepared via Ritter-type heterocyclization and the more classical two-step reductive amination/Bischler-Napieralski cyclization of triarylethanones, respectively. A comparative study of nonphenolic oxidative coupling methodologies provides a highly efficient procedure, based on the hypervalent iodine reagent phenyliodine(III) bis(trifluoroacetate) (PIFA), to accomplish the final coupling step. 相似文献
49.
Villamena FA Merle JK Hadad CM Zweier JL 《The journal of physical chemistry. A》2005,109(27):6089-6098
The formation of the superoxide radical anion (O2*-) adduct of the nitrone 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as detected by electron paramagnetic resonance (EPR) spectroscopy is one of the most common techniques for O2*- detection in chemical and biological systems. However, the nature of DMPO-O2H has confounded spin-trapping investigators over the years, since there has been no independently synthesized DMPO-O2H to date. A density functional theory (DFT) approach was used to predict the isotropic hyperfine coupling constants arising from the N, beta-H, and gamma-H nuclei of DMPO-O2H using explicit interactions with water molecules as well as via a bulk dielectric effect employing the polarizable continuum model (PCM). Theoretical calculation on the thermodynamics of DMPO-O2H decay shows favorable intramolecular rearrangement to form a nitrosoaldehyde and a hydroxyl radical as products, consistent with experimental observations. Some pathways for the bimolecular decomposition of DMPO-O2H and DMPO-OH have also been computed. 相似文献
50.