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101.
102.
Yong Sam Chung Sun Ha Kim Gwang Min Sun Jong Myoung Lim Jong Hwa Moon Kye Hong Lee Young Jin Kim Jong Il Choi Ju Woon Lee 《Journal of Radioanalytical and Nuclear Chemistry》2012,291(1):223-229
The analysis of mineral contents in space foods is needed to obtain an information on a comprehensive elemental composition
as well as the investigation on the effects of human nutrition and health based on the dietary intake of mineral elements.
Recently, six items of new Korean space foods (KSFs) such as kimchi, bibimbap, bulgogi, a ramen, a mulberry beverage and a
fruit punch which was developed by the KAERI, and the contents of more than 15 elements in the samples were examined by using
instrumental neutron activation analysis (INAA). Five biological certified reference materials, NIST SRM were used for analytical
quality control. The results were compared with those of common Korean foods reported, and these results will be applied toward
the identification of irradiated foods. 相似文献
103.
Natalia V. Vorontsova Galina S. Bystrova Dmitrii Yu. Antonov Anna V. Vologzhanina Ivan A. Godovikov Michail M. Il’in 《Tetrahedron: Asymmetry》2010,21(6):731-738
New planar-chiral hydroxycarbonyl [2.2]paracyclophane derivatives, 4-acetyl-13-bromo-5-hydroxy[2.2]paracyclophane (Br-АНРС, 63%) and 4-benzoyl-13-bromo-5-hydroxy[2.2]paracyclophane (Br-BHPC, 53%), were synthesized and reacted with the enantiomers of α-phenylethylamine to form corresponding Schiff bases, 12-bromo-4-hydroxy-5[1-(1-phenyl-ethylimino)-ethyl]-[2.2]paracyclophane and 12-bromo-4-hydroxy-5[1-(1-phenyl-ethylimino)-(phenyl)methylen-[2.2]paracyclophane. The diastereomers of the imines were resolved and their absolute configurations and consequently the corresponding configurations of the enantiomers of Br-АНРС were determined by X-ray diffraction. Enantiomerically pure Schiff bases were applied as ligands to form catalysts for the enantioselective addition reaction of diethylzinc with benzaldehyde where 1-phenylpropanol was obtained with 77–91% ee. 相似文献
104.
105.
Jong‐Dae Lee Il‐Hwan Suh Sang Ook Kang 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(5):o151-o153
The title compound, C38H48NOP, isolated from the reaction of (2‐diphenylphosphanyl‐4,6‐di‐tert‐butyl)phenol with 2,6‐diisopropylphenyl azide at 273 K, can act as an N,O‐bidentate ligand. Crystal structure analysis shows a deviation from ideal tetrahedral symmetry around the P atom. The molecule exists as a monomer in the solid state, whose conformation is stabilized via multiple intramolecular hydrogen bonds. Geometric parameters from both experimental and theoretical calculations are compared. 相似文献
106.
SNO measurements strongly constrain the central temperature of the Sun, to within a precision of much less than 1%. This result can be used to probe the parameter space of supersymmetric dark matter. In this first analysis we find a lower limit for the weakly interacting massive particle (WIMP) mass of 60 GeV. Furthermore, in the event that WIMPs create a quasi-isothermal core, they will produce a peculiar distribution of the solar neutrino fluxes measured on Earth. Typically, a WIMP with a mass of 100 GeV and annihilation cross section of 10(-34) cm(3)/sec will decrease the neutrino predictions, by up to 4% for the Cl, by 3% for the heavy water, and by 1% for the Ga detectors. 相似文献
107.
Abstract Nonlinear oscillations of magnetization (with a fundamental harmonic frequency of ≈0.5 GHz) emerging during 90°-pulsed magnetization of garnet ferrite films with easy-plane anisotropy are studied. Analysis of longitudinal and transverse magnetization signals and of the magnetization vector hodograph plotted on their basis shows that the weak dependence of the oscillation intensity on duration t f of the magnetizing magnetic field pulse (upon its variation from 0.4 to 6–8 ns), which is typical of these films, can be explained by the presence of biaxial anisotropy in the plane of actual films. 相似文献
108.
P. G. Baranov B. Ya. Ber O. N. Godisov I. V. Il’in A. N. Ionov E. N. Mokhov M. V. Muzafarova A. K. Kaliteevskii M. A. Kaliteevskii P. S. Kop’ev 《Physics of the Solid State》2005,47(12):2219-2232
The spatial distributions of the unpaired-electron wave functions of shallow N donors in SiC crystals and of shallow P and As donors in silicon crystals were determined by studying crystals with a modified content of the 29Si and 13C isotopes having a nonzero nuclear magnetic moment. As follows from the present EPR and available ENDOR data, the distribution of donor electrons in SiC depends substantially on the polytype and position in the lattice; indeed, in 4H-SiC, the unpaired electrons occupy primarily the Si s and p orbitals, whereas in 6H-SiC these electrons reside primarily in the s orbitals of C. The electron distributions for the N donor in the hexagonal position, which has a shallow level close to that obtained for this material in the effective-mass approximation, and for the donor occupying the quasi-cubic position differ substantially. The EPR spectrum of N in quasi-cubic positions was observed to have a hyperfine structure originating from a comparatively strong coupling with the first two coordination shells of Si and C, which were unambiguously identified. The effective-mass approximation breaks down close to the N donor occupying the quasi-cubic position, and the donor structure and the donor electron distribution become less symmetric. In silicon, reduction of the 29Si content brought about a substantial narrowing of the EPR line of the shallow P and As donors and an increase in the EPR signal intensity, as well as a noticeable increase in the spin-lattice relaxation time T1. This offers the possibility of selectively studying these spectra by optically exciting a region of the crystal in order to shorten T1 and thereby precluding EPR signal saturation only in the illuminated part of the material. This method may be used to advantage in developing materials for quantum computers based on donors in silicon and SiC. 相似文献
109.
A.?JaakkolaEmail author A.?Shevchenko K.?Lindfors M.?Hautakorpi E.?Il’yashenko T. H.?Johansen M.?Kaivola 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2005,35(1):81-85
We introduce a new choice of material for the creation of microscopic
magnetic
potentials for the trapping and guiding of ultracold neutral atoms.
The potentials are created above a ferrimagnetic, transparent (BiYTmGd)3(FeGa)5O12
film by patterning the magnetic-domain structure in the film with
a magneto-optical recording method. Patterns with linewidth down to
2 μm have been achieved, enabling trap frequencies of the order
of 100 kHz for 87Rb atoms in the state |F=1, mF=-1〉.
The main advantages of the material are: 1) magnetic-field noise
is suppressed due to the dielectricity of the material and the absence
of electric currents, 2) trapped atoms can be addressed optically
through the transparent film, and 3) the film can be repatterned,
which enables different experiments with the same component. 相似文献
110.
Kim YY Park CI Cho SH Han SW 《The Journal of the Acoustical Society of America》2005,117(6):3459-3468
For the efficient long-range nondestructive structural health inspection of pipes, guided waves have become widely used. Among the various guided wave modes, the torsional wave is most preferred since its first branch is nondispersive. Our objective in this work is to develop a new magnetostrictive transducer configuration to transmit and receive torsional waves in cylindrical waveguides. The conventional magnetostrictive transducer for the generation and measurement of torsional waves consists of solenoid coils and a nickel strip bonded circumferentially to test pipes. The strip must be premagnetized by a permanent magnet before actual measurements. Because of the premagnetization, the transducer is not suitable for the long-term on-line monitoring of pipes buried underground. To avoid the cumbersome premagnetization and to improve the transduction efficiency, we propose a new transducer configuration using several pieces of nickel strips installed at 45 degrees with respect to the pipe axis. If a static bias magnetic field is also applied, the transducer output can be substantially increased. Several experiments were conducted to study the performance of the proposed transducer configuration. The proposed transducer configuration was also applied for damage detection in an aluminum pipe. 相似文献