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81.
Linda Lesniak-Foster 《Journal of Combinatorial Theory, Series B》1977,22(3):263-273
With each nonempty graph G one can associate a graph L(G), called the line graph of G, with the property that there exists a one-to-one correspondence between E(G) and V(L(G)) such that two vertices of L(G) are adjacent if and only if the corresponding edges of G are adjacent. For integers m ≥ 2, the mth iterated line graph Lm(G) of G is defined to be L(Lm-1(G)). A graph G of order p ≥ 3 is n-Hamiltonian, 0 ≤ n ≤ p ? 3, if the removal of any k vertices, 0 ≤ k ≤ n, results in a Hamiltonian graph. It is shown that if G is a connected graph with δ(G) ≥ 3, where δ(G) denotes the minimum degree of G, then L2(G) is (δ(G) ? 3)-Hamiltonian. Furthermore, if G is 2-connected and δ(G) ≥ 4, then L2(G) is (2δ(G) ? 4)-Hamiltonian. For a connected graph G which is neither a path, a cycle, nor the graph K(1, 3) and for any positive integer n, the existence of an integer k such that Lm(G) is n-Hamiltonian for every m ≥ k is exhibited. Then, for the special case n = 1, bounds on (and, in some cases, the exact value of) the smallest such integer k are determined for various classes of graphs. 相似文献
82.
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84.
The ion fractions, η+, of 10 keV argon particles, scattered from a damaged copper surface, are measured with a time of flight spectrometer. The damage was introduced by bombardment with argon ions. The scattering angle was 30°. The results for different angles of incidence, ψ, are reported. For Ψ < 10° the ion fraction is relatively high (~27% for Ψ = 4°) and decreases as Ψ increases. For Ψ = 15° the value of η+ is 7%, whereas for 21° < Ψ < 27° the value of η+ appears to be constant (~14%). An explanation is given by assuming interatomic ionization as well as neutralization processes along the trajectory of the scattered particles. The number of step-atoms, induced by ion bombardment, is estimated to be about 2 × 1014/cm2. 相似文献
85.
In KBr and RbBr doped with OH- and I- interstitial atomic hydrogen was produced in a configuration in which it is surrounded tetrahedrally by 3 Br- and 1 I- ions. Excitation in the absorption bands leads to a blue-green and an infrared fluorescence band (KBr: 2.53 and 1.35 eV). The absorption spectrum consists of 3 I-type and 1 broad Br-type charge transfer bands as could be shown from the excitation spectrum. The emission occurs only from relaxed I-type charge transfer states with a transition moment along the connection line Ho-I-. The results are discussed with a simple charge transfer model.In mit OH- and J- dotiertem KBr und RbBr wurde atomarer Wasserstoff auf Zwischengitterplatz in einer Konfiguration hergestellt, in welcher er tetraedrisch von 3 Br-- und 1 J--Ion umgeben ist. Anregung in den Absorptionsbanden führt zu einer blaugrünen und einer infraroten Fluoreszenzbande (KBr: 2,53 und 1,35 eV). Das Absorptionsspektrum besteht aus 3 jodartigen und einer breiten, bromartigen Charge-Transfer-Bande, wie mit Hilfe des Anregungsspektrums gezeigt werden konnte. Die Emission erfolgt nur aus den relaxierten, angeregten, jodartigen Charge-Transfer-Zuständen mit dem Übergangsmoment parallel zur Verbindungslinie Ho-I-. Die Ergebnisse werden anhand eines einfachen Charge-Transfer-Modells diskutiert. 相似文献
86.
87.
Th. Wercide heißen 《Zeitschrift für Physik A Hadrons and Nuclei》1927,42(5-6):480-480
88.
F. W. N. de Boer H. J. Wollersheim H. Emling H. Grein E. Grosse W. Spreng G. Eckert Th. W. Elze K. Stelzer Ch. Lauterbach 《Zeitschrift für Physik A Hadrons and Nuclei》1986,325(4):457-466
In a systematic study of nucleon transfer reactions accompanied by Coulomb excitation we have bombarded152Sm,160Gd and232Th with206, 208pb beams at incident energies close to the Coulomb barrier. Particle-gamma coincidence techniques were used to identify excited states of reaction products populated through inelastic scattering and in nucleon transfer reactions. One-neutron stripping and pick-up reactions on152Sm were observed leading to known states of the rotation alignedi 13/2-bands in153Sm and151Sm. In the160Gd+206, 208Pb systems no significant population of low lying states of product nuclei was found in the nucleon-transfer channels. Large cross sections were observed for one- and two-neutron pick-up from232Th at an incident energy of 6.4 MeV/u. Around the grazing angle they are of the same order of magnitude as the cross section measured for inelastic scattering. The results are analyzed in the framework of semiclassical models. 相似文献
89.
The microstructure of the metal semiconductor oxide which forms the heart of a dye-sensitized solar cell (DSSC) has proved to play a key role in the enhancement of photoelectric conversion efficiency of the cell. In this work, a numerical simulation of the system TiO2 photo-sensitive dye of a TiO2 DSSC focuses on the effect that the oxide porosity and the size of the pores have on the cell's performance. The steady-state numerical model used is based on the continuity and transport equations for charge species involved in the system, in connection to Poisson's equation. Light absorption coefficient is set dependent on both porosity and the size of pores in TiO2. At a first approximation, electron mobility is considered dependent upon porosity following an iteration procedure dependent also upon local field in the oxide. An effective dielectric constant dependent upon the porosity of TiO2, as well, is used in the model. Electron lifetime in the bulk is set dependent upon electron distribution following the iteration procedure with electron lifetime at the surface taking into consideration surface recombination. Results for different values of TiO2 porosity and pores' size in connection to the oxide thickness are discussed and found in accordance with results reported in the literature. 相似文献
90.
S. Mayer M. Boschung H. Hoedlmoser Th. Buchillier C. Bailat B. Bitterli 《Radiation measurements》2012,47(8):634-639
An intercomparison of the response of different photon and neutron detectors was performed in several measurement positions around a spent fuel cask (type TN 12/2B) filled with 4 MOX and 8 UO2 15 × 15 PWR fuel assemblies at the nuclear power plant Gösgen (KKG) in Switzerland. The instruments used in the study were both active and passive, photon and neutron detectors calibrated either for ambient or personal dose equivalent.The aim of the measurement campaign was to compare the responses of the radiation instruments to routinely used detectors.It has been shown that especially the indications of the neutron detectors are strongly dependent on the neutron spectra around the cask due to their different energy responses. However, routinely used active photon and neutron detectors were shown to be reliable instruments. 相似文献