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911.
Biphenyl derivative N-allyl-N′-(4′-nitro[1,1′-biphenyl]-4-yl)thiourea (BP1) was synthesized as a functional fluorescent sensor for protons and their photophysical properties were studied. The influence of environment protonation on photophysical properties of the biphenyls in solutions was investigated using UV absorption, steady-state and time-resolved fluorescence spectroscopy. Semi-empirical and DFT calculations and optimization of the molecular structure of the biphenyl derivatives in vacuum, in polar solvents and in a proton-rich environment were conducted using the HyperChem, Amsol and Gaussian3 software package. Fluorescence quenching with addition of acidic acid was observed and the Stern-Volmer quenching rate constant was about 3.0×109 M−1 s−1. Intermolecular hydrogen bonds formations by the protons with the sulphur being substituted to the biphenyls generate charge movement and strong increase (×5) of the dipole moment of the fluorophore. 相似文献
912.
The di-gamma and di-gluon decay widths of P-wave cc mesons are computed in nonrelativistic phenomenological quark-antiquark potential of the type V (r) =-4 3 α s r+ Ar ν with different choices of ν using spectroscopic parameters.The numerically obtained radial solutions are employed to obtain the di-gamma and di-gluon decay widths.The computed decay widths are consistent with other model predictions as well as with the known experimental values in the range of potential index 0.7 ≤ν≤ 1.1. 相似文献
913.
Dong Xi XiaoPing Luo QiangHua Lu KaiLun Yao ZuLi Liu Qin Ning 《Journal of nanoparticle research》2008,10(3):393-400
Gold-coated iron oxide nanoparticle Hepatitis B virus (HBV) DNA probes were prepared, and their application for HBV DNA measurement
was studied. Gold-coated iron oxide nanoparticles were prepared by the citrate reduction of tetra-chloroauric acid in the
presence of iron oxide nanoparticles which were added as seeds. With a fluorescence-based method, the maximal surface coverage
of hexaethiol 30-mer oligonucleotides and the maximal percentage of hybridization strands on gold-coated iron oxide nanoparticles
were (120 ± 8) oligonucleotides per nanoparticle, and (14 ± 2%), respectively, which were comparable with those of (132 ± 10)
and (22 ± 3%) in Au nanoparticle groups. Large network aggregates were formed when gold-coated iron oxide nanoparticle HBV
DNA gene probe was applied to detect HBV DNA molecules as evidenced by transmission electron microscopy and the high specificity
was verified by blot hybridization. Our results further suggested that detecting DNA with iron oxide nanoparticles and magnetic
separator was feasible and might be an alternative effective method. 相似文献
914.
Dariush Souri Mohammad Elahi Mohammad S. Yazdanpanah 《Central European Journal of Physics》2008,6(2):306-310
The ternary 70P2O5-10Li2MoO4-20Li2O and 70P2O5-10Na2MoO4-20Na2O glasses, prepared by the press-melt quenching technique, were studied at temperatures between 298 and 418 K for their high
dc electric field properties. For the above purpose, the effect of a strong electric field on the dc conduction of these amorphous
bulk samples was investigated using the gap-type electrode configuration. At low electric fields, the current-voltage (I — V) characteristics have a linear shape, while at high electric fields (> 103 V/cm), bulk samples show nonlinear effects (nonohmic conduction). Current-voltage curves show increasing departure from Ohm’s
law with increasing current density, leading to critical phenomena at a maximum voltage (threshold voltage), known as switching
(switch from a low-conduction state to a higher-conduction state at threshold voltage). The Pool-Frenkel high-field effect
was observed at electrical fields of about 103–104 V/cm; then the lowering factor of the potential barrier, the high frequency dielectric constant, and the refractive index
of these glasses were determined.
相似文献
915.
Resonances of a hydrogen atom in strong parallel electric and magnetic fields using B-spline basis sets 下载免费PDF全文
The B-spline basis set plus complex scaling method is applied to the numerical calculation of the exact resonance parameters Er and Г/2 of a hydrogen atom in parallel electric and magnetic fields. The method can calculate the ground and higher excited resonances accurately and efficiently. The resonance parameters with accuracies of 10^-9 - 10^-12 for hydrogen atom in parallel fields with different field strengths and symmetries are presented and compared with previous ones. Extension to the calculation of Rydberg atom in crossed electric and magnetic fields and of atomic double excited states in external electric fields is discussed. 相似文献
916.
This paper is intended to apply the potential integration method to the differential equations of the Birkhoffian system. The method is that, for a given Birkhoffian system, its differential equations are first rewritten as 2n first-order differential equations. Secondly, the corresponding partial differential equations are obtained by potential integration method and the solution is expressed as a complete integral. Finally, the integral of the system is obtained. 相似文献
917.
918.
The ionization spectrum of sulfur dioxide has been successfully studied by using the symmetry-adapted-cluster configuration-interaction (SAC-CI) general-R and SD-R methods and the basis set correlation-consistent polarized valence triple-zeta (cc-pVTZ). The SAC-CI general-R method reproduces the experimental spectrum well for both the main peaks and the satellite peaks of ionization spectrum of SO2. The sequence of ionic states corresponding to main peaks of SO2 has been re-determined according to the SAC-CI conclusions and it is reordered as X^2A1, A^2B2, B2A2, C^2B1,D^2A1, E^2B2 and F^2A1. Besides, the equilibrium structures and adiabatic ionization potentials (AIPs) of ionic states of main peaks of SO2 are calculated by using the SAC-CI SD-R method. 相似文献
919.
Considering the perturbation, the results of theoretical calculation of five Rydberg series energy levels 6s2ns^2S1/2 (n = 7 - 20), 6s^2nd^2D3/2 (n = 6 - 20), 6s^2nd^2D5/2 (n = 6 - 20), 6s^2np^2P1/2^0 (n = 7- 20), and 6s^2np^2P3/2^0 (n = 7-20) for Tl I are presented using the weakest bound electron potential model (WBEPM) theory. Furthermore, the radiative lifetimes of this five series are also calculated. The calculated values of energy levels and lifetimes are in good agreement with the experimental results. 相似文献
920.
Nine low-lying electronic states of the AsP molecule, including Σ , Ⅱ, and △ symmetries with singlet, triplet, and quintet spin multiplicities, are studied using multi-reference configuration interaction method.The potential energy curves and the spectroscopic constants of these nine states are determined, and compared with the experimental observed data as well as other theoretical works available at present.Three quintet states are reported for the first time.Furthermore, the analytical potential energy functions of these states are fitted using Murrell-Sorbie function and least square fitting method. 相似文献