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991.
H. Yamada E. B. Starikov D. Hennig 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,59(2):185-192
We numerically investigate quantum diffusion of an electron in a
model of poly(dG)-poly(dC) and poly(dA)-poly(dT) DNA
polymers with fluctuation of the parameters due to the impact of colored noise.
The randomness is introduced by fluctuations of distance between two consecutive bases
along the stacked base pairs.
We demonstrate that in the model the decay time of the correlation can control the spread of the
electronic wavepacket.
Furthermore it is shown that in a motional narrowing regime the averaging over fluctuation
causes ballistic propagation of the wavepacket,
and in the adiabatic regime the electronic states are affected by localization. 相似文献
992.
Shigenori Matsushima Kenji Takehara Kenji Yamada Masao Arai 《Journal of Physics and Chemistry of Solids》2007,68(2):206-210
The electronic structure of S-doped TiO2 with an optimized anatase structure was calculated within the framework of the density functional theory (DFT). For the calculation we built four kinds of supercells; type-A and B supercells consist of 12 and 48 atoms and a centered Ti atom is substituted for an S atom, while type-C and D supercells consist of 12 and 48 atoms and a centered O atom is substituted for an S atom. The supercells (type-B and D) were employed to adjust the S-concentration in TiO2 to an experimental value of a few %. The changes of the lattice parameters are not significant in the type-A and B supercells. The phase transition from the tetragonal to the orthorhombic occurs in the type-C and D supercells. In the small supercell (type-A), S-related states are located in the range of −1.6 to 0 eV, and the S-states are band-like. In contrast, in the large supercell (type-B), S-related states appeared at about 0.9 eV above the top of the valence band, and the S-states are atomic-like. The localization of the S-related states is remarkable in the type-B supercell. In the type-D supercell, the S-related states were merged with the top of the valence band, and as a result the band-gap energy is narrowed by 0.7 eV. Despite a low S-concentration (3%) in the type-D supercell, the S-related states are somewhat band-like. 相似文献
993.
Masahisa Okada Yasusei Yamada Pin Jin Masato Tazawa Kazuki Yoshimura 《Applied Surface Science》2007,254(1):156-159
Nitridation of TiO2 films is performed by the simultaneous irradiation of low-energy N2+ and H2+ ions under substrate-heating condition. Spectroscopic observations of the resultant films clarify the formation of nitrogen-substituted TiO2 (TiO2−xNx) with large N fractions and the agglomeration of undesirable oxynitride species attributed to the deep states in the band gap. We find that the addition of a thin TiO2 cap layer on the ion-irradiated films improves the nitrogen bonding structure and distribution near the surfaces, leading to a good photocatalytic performance even in the visible region. 相似文献
994.
We introduce a deterministic dealer model which implements most of the empirical laws, such as fat tails in the price change distributions, autocorrelation of price change and non-Poissonian intervals. We also clarify the causality between microscopic dealers’ dynamics and macroscopic market's empirical laws. 相似文献
995.
N. Toyosugi H. Yamada D. Minkov M. Morita S. Imai T. Yamaguchi 《Journal of synchrotron radiation》2007,14(2):212-218
The tabletop synchrotron light sources MIRRORCLE‐6X and MIRRORCLE‐20SX, operating at electron energies Eel = 6 MeV and Eel = 20 MeV, respectively, can emit powerful transition radiation (TR) in the extreme ultraviolet (EUV) and the soft X‐ray regions. To clarify the applicability of these soft X‐ray and EUV sources, the total TR power has been determined. A TR experiment was performed using a 385 nm‐thick Al foil target in MIRRORCLE‐6X. The angular distribution of the emitted power was measured using a detector assembly based on an NE102 scintillator, an optical bundle and a photomultiplier. The maximal measured total TR power for MIRRORCLE‐6X is Pmax? 2.95 mW at full power operation. Introduction of an analytical expression for the lifetime of the electron beam allows calculation of the emitted TR power by a tabletop synchrotron light source. Using the above measurement result, and the theoretically determined ratio between the TR power for MIRRORCLE‐6X and MIRRORCLE‐20SX, the total TR power for MIRRORCLE‐20SX can be obtained. The one‐foil TR target thickness is optimized for the 20 MeV electron energy. Pmax? 810 mW for MIRRORCLE‐20SX is obtained with a single foil of 240 nm‐thick Be target. The emitted bremsstrahlung is negligible with respect to the emitted TR for optimized TR targets. From a theoretically known TR spectrum it is concluded that MIRRORCLE‐20SX can emit 150 mW of photons with E > 500 eV, which makes it applicable as a source for performing X‐ray lithography. The average wavelength, = 13.6 nm, of the TR emission of MIRRORCLE‐20SX, with a 200 nm Al target, could provide of the order of 1 W EUV. 相似文献
996.
Masamichi Akimoto 《Applied biochemistry and biotechnology》1998,74(1):31-41
In order to decrease the content of linoleoyl moiety in soybean oil, soybean oil that contains 22.8% oleoyl, 54.8% linoleoyl, and 7.1% α-linolenoyl moieties as molar acyl moiety composition was interesterified in hexane with oleic acid or α-linolenic acid, using an immobilized sn-l,3-specific lipase (Lipozyme® IM) fromMucor miehei. The reactions were carried out in a batch reactor at 37°C in the following system: molar ratio of fatty acid to soybean oil = 1.0 ~ 6.0, 5.0 mL of hexane/500 μmol soybean oil, and 10.0 or 15.0 batch interesterification units of enzyme/500 μmol soybean oil. Under these reaction conditions, the rates of interesterification of acyl moieties in soybean oil were of the order: stearoyl > palmitoyl > linoleoyl > oleoyl > α-linolenoyl, and the reaction with oleic acid occurred without a significant loss of α-linolenoyl moiety. At the molar ratio of 3.0 and the reaction time of 6 h, triacylglycerols (TGs), which contain 50.8% oleoyl, 38.8% linoleoyl, and 5.4% α-linolenoyl moieties, were produced in the reaction with oleic acid; TGs that contain 13.5% oleoyl, 40.8% linoleoyl, and 40.4% α-linolenoyl moieties were obtained with α-linolenic acid. Approximately 86-88% of the interesterification of linoleoyl moiety, which occurred in 10 h, took place within 1 h. 相似文献
997.
The stabilities of human insulin (HI) in aqueous solutions were investigated in the pH range of 4.0-7.0 in the presence (1.0-3.0 x 10(-3) M) and absence of sodium bisulfite (SBS) both in the dark and under scattered light (1000 lux) using high performance liquid chromatography. Increasing concentrations of SBS tended to degrade HI. In the presence of SBS, with an increase in the pH value, the stability of HI decreased in the pH range of 4.0-7.0. There was a partial difference in the stability of HI in the presence of SBS in the dark and that under scattered light. HI was stabilized by glucose in the presence of SBS in the dark, and the stability of HI was revealed to depend on the concentration of free SBS. The reason for this phenomenon was postulated to be the formation of bisulfite-glucose adduct. 相似文献
998.
999.
Kazuo Sasazawa Yuko Yamada Akiko Fujisawa Toshikazu Saitoh Katsuya Ueno Kazuya Oharu Hideo Sawada 《Colloid and polymer science》2005,283(7):812-816
Self-assembled fluorinated molecular aggregates formed by fluoroalkyl end-capped N-(1,1-dimethyl-3-oxobutyl)acrylamide oligomers, N,N-dimethylacrylamide oligomers, and acrylic acid oligomers in methanol could selectively recognize fluoresceins as guest molecules to form a new class of fluorinated aggregates-fluorescein nanocomposites. These fluorinated fluorescein nanocomposites that are obtained exhibit an extraordinarily enhanced light absorption (max ca. 440 nm) compared to that (maxs 452, 480 nm) of the parent fluorescein in the absence of fluorinated aggregates. 相似文献
1000.
Masayoshi?OkuboEmail author Teruhisa?Fujibayashi Masahiro?Yamada Hideto?Minami 《Colloid and polymer science》2005,283(9):1041-1045
Snowman/confetti-shaped, micron-sized, monodisperse composite particles were prepared by seeded dispersion polymerizations of n-butyl methacrylate (nBMA) with 1.28 and 2.67 m-sized polystyrene (PS) seed particles, respectively, in an ethanol/water (80/20, w/w) medium. These nonspherical composite particles consisted of one or several poly(nBMA) protuberances on the surfaces of the spherical PS particles.Part CCLXII of the series Studies on Suspension and Emulsion 相似文献