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811.
Laboratory measurements of the absorption cross-section of the Schumann-Runge continuum of O2 at the temperatures 90 and 295 K have been made in the wavelength region 130-175 nm. The absolute absorption cross-sections at the same temperatures have been measured at several discrete wavelengths through the region. The absolute cross-sections of the O2 continuum have been used to put relative cross-sections on a firm absolute basis throughout the region 130-175 nm. These recalibrated cross-sections are available as numerical compilations. 相似文献
812.
813.
814.
We study the unidirectional flow of mobile objects through obstacles on a square lattice. Two models are presented: one is the lattice gas model consisting of translational particles and the other is that of turning particles. Fundamental diagrams for the two models are presented. The traffic flow of translational particles is compared with that of turning particles. In the traffic flow of translational particles, the fundamental diagram shows a trapezoid shape in the random configuration of obstacles, while it shows a parabolic shape in the periodic configuration of obstacles. The traffic flow of turning particles with a back step shows a similar behavior to that of translational particles. In the traffic flow of turning particles without backward moves, the current becomes zero when the density is higher than a critical density. In the traffic flow of turning particles without a back step, the dynamical transition between free traffic and a perfectly jammed state occurs at the critical density, while dynamical transition does not occur in traffic flow of translational particles. 相似文献
815.
816.
Wen Ji Yuan Takao Yasuhara Tetsuro Shingo Kenichiro Muraoka Takashi Agari Masahiro Kameda Takashi Uozumi Naoki Tajiri Takamasa Morimoto Meng Jing Tanefumi Baba Feifei Wang Hanbai Leung Toshihiro Matsui Yasuyuki Miyoshi Isao Date 《BMC neuroscience》2008,9(1):1-11
Background
A recent human clinical trial of an Alzheimer's disease (AD) vaccine using amyloid beta (Aβ) 1–42 plus QS-21 adjuvant produced some positive results, but was halted due to meningoencephalitis in some participants. The development of a vaccine with mutant Aβ peptides that avoids the use of an adjuvant may result in an effective and safer human vaccine.Results
All peptides tested showed high antibody responses, were long-lasting, and demonstrated good memory response. Epitope mapping indicated that peptide mutation did not lead to epitope switching. Mutant peptides induced different inflammation responses as evidenced by cytokine profiles. Ig isotyping indicated that adjuvant-free vaccination with peptides drove an adequate Th2 response. All anti-sera from vaccinated mice cross-reacted with human Aβ in APP/PS1 transgenic mouse brain tissue.Conclusion
Our study demonstrated that an adjuvant-free vaccine with different Aβ peptides can be an effective and safe vaccination approach against AD. This study represents the first report of adjuvant-free vaccines utilizing Aβ peptides carrying diverse mutations in the T-cell epitope. These largely positive results provide encouragement for the future of the development of human vaccinations for AD. 相似文献817.
Y. Satou T. Nakamura N. Fukuda T. Sugimoto Y. Kondo N. Matsui Y. Hashimoto T. Nakabayashi T. Okumura M. Shinohara T. Motobayashi Y. Yanagisawa N. Aoi S. Takeuchi T. Gomi Y. Togano S. Kawai H. Sakurai H.J. Ong T.K. Onishi S. Shimoura M. Tamaki T. Kobayashi H. Otsu Y. Matsuda N. Endo M. Kitayama M. Ishihara 《Physics letters. [Part B]》2008
The neutron-rich carbon isotopes 19,17C have been investigated via proton inelastic scattering on a liquid hydrogen target at 70 MeV/nucleon. The invariant mass method in inverse kinematics was employed to reconstruct the energy spectrum, in which fast neutrons and charged fragments were detected in coincidence using a neutron hodoscope and a dipole magnet system. A peak has been observed with an excitation energy of 1.46(10) MeV in 19C, while three peaks with energies of 2.20(3), 3.05(3), and 6.13(9) MeV have been observed in 17C. Deduced cross sections are compared with microscopic DWBA calculations based on p-sd shell model wave functions and modern nucleon–nucleus optical potentials. Jπ assignments are made for the four observed states as well as the ground states of both nuclei. 相似文献
818.
The structural–microstructural characterization and defect structure of Ru based magnetosuperconductor RuSr2Eu1.6Ce0.4Cu2O10−δ has been investigated by selected area electron diffraction pattern and high resolution electron microscopy. Under the present investigations, RuSr2Eu1.6Ce0.4Cu2O10−δ magnetosuperconductor shows the presence of both Ru-1222 and Ru-1212 phases. Analysis of the selected area electron diffraction pattern indicates superstructure in Ru-1212 while Ru-1222 phase does not show the presence of superlattice structure. A careful and detailed investigations of the HRTEM image shows the presence of defects like 90° domains, intergrowths, and dislocations. 相似文献
819.
We demonstrate atomic-column imaging by scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS). The silicon atomic-columns of a beta-Si3N4 (0 0 1) specimen are clearly resolved. The atomic-site dependence and the energy-loss dependence of the spatial resolution are elucidated on the basis of the experimental results and multislice calculations. We describe two decisive factors for realizing atomic-column imaging in terms of localization in elastic and inelastic scattering. One is the channeling of the incident probe due to dynamical diffraction, which has atomic-site dependence. The other is the localization in inelastic scattering; in addition to the energy-loss dependence of delocalization, we point out its dependence on the offset energy from the ionization energy, i.e., an additional localization factor concerning the Bethe surface. The present atomic-column observation of the Si-L core-loss image indicates that the local approximation, which can be interpreted intuitively, is achievable under appropriate experimental conditions, such as high-energy-loss, a small convergence angle and a large collection angle (e.g., 400 eV, 15 and 30 mrad, respectively). 相似文献
820.
Matsui F Matsushita T Kato Y Hashimoto M Inaji K Guo FZ Daimon H 《Physical review letters》2008,100(20):207201
Up until now there has been no direct method for detecting the electronic and magnetic structure of each atomic layer at the surface, which is an essential analysis technique for nanotechnology. For this purpose, we have developed a new method, diffraction spectroscopy, based on the photon energy dependence of the angular distribution of Auger electron emission. We have applied this method to analyze the magnetic structure of a Ni ultrathin film on a Cu(001) surface around the spin reorientation transition. Atomic-layer resolved x-ray absorption and magnetic circular dichroism spectra were obtained. Surface and interior core-level shifts and magnetic moments are determined for each atomic layer individually. 相似文献