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991.
S. Sasa A. Nakashima Y. Nakajima M. Inoue 《Physica E: Low-dimensional Systems and Nanostructures》2004,20(3-4):224
We fabricated nanoscale open-dot structures in an InAs surface inversion layer using an atomic-force-microscope oxidation process. Due to its superior nanofabrication capability, small open-dot structures with the feature size ranging between 100 and 300 nm were successfully fabricated. The magnetoresistance signal measured at 4.2 K showed reproducible fluctuations and a periodic oscillation component that varies in both amplitude and periodicity depending on the dot size. We show that the period of the oscillations corresponds to that of the Aharonov–Bohm effect and propose that the possible mechanism for the oscillations is due to the formation of a one-dimensional electron channel enclosing the open-dot structure as a result of the electron transfer from the InAs oxide to InAs. 相似文献
992.
K. Suzuki S. Miyashita K. Takashina Y. Hirayama 《Physica E: Low-dimensional Systems and Nanostructures》2004,20(3-4):232
We investigate the quantum Hall effect (QHE) in the InAs/GaSb hybridized electron–hole system grown on a conductive InAs substrate which act as a back-gate. In these samples, the electron density is constant and the hole density is controlled by the gate-voltage. Under a magnetic field perpendicular to the sample plane, the QHE appears along integer Landau-level (LL) filling factors of the net-carriers, where the net-carrier density is the difference between the electron and hole densities. In addition, longitudinal resistance maxima corresponding to the crossing of the extended states of the original electron and hole LLs make the QHE regions along integer-νnet discontinuous. Under tilted magnetic fields, these Rxx maxima disappear in the high magnetic field region. The results show that the in-plane magnetic field component enhances the electron–hole hybridization and the formation of minigaps at LL crossings. 相似文献
993.
S. Schweizer M. Secu J. -M. Spaeth L. W. Hobbs A. Edgar G. V. M. Williams 《Radiation measurements》2004,38(4-6):633-638
We found a significant PSL effect in Eu2+-doped fluorozirconate glasses (ZBLAN) which were additionally doped with Br− or Cl− ions. The PSL is attributed to the characteristic emission of Eu2+ present in nano-crystallites of BaBr2 or BaCl2, which form in the glass upon annealing. The metastable hexagonal form of BaX2 (X=Br,Cl) is always formed first before it is converted into the stable orthorhombic form. The particle size increases upon annealing and so does the PSL efficiency of the glass ceramic. However, there is a saturation of the PSL efficiency, which is for Br− doping about 9% and for Cl−-doping about 80% of the Eu-doped BaFBr standard. The particle size was determined by transmission electron microscopy (TEM). The TEM results show a clear tendency for bigger particles for longer annealing at the expense of its number. The particle size for the most efficient phosphor is about 100 nm. 相似文献
994.
The thermally stimulated properties of PbWO4 in the temperature range 90–400 K have been investigated on undoped and terbium-doped crystals after X-ray irradiation at 90 K. Doping with terbium changes the concentration of shallow traps, which are responsible for retrapping free electrons and holes. Light illumination can change the distribution of the traps. The optically stimulated luminescence is observed. The influence of light illumination on the TSL curves and emission properties is studied. The possible mechanism of TSL phototransformation is discussed. 相似文献
995.
A. N. Vasiliev V. N. Grishin A. M. Davidenko A. A. Derevschikov Yu. A. Matulenko Yu. M. Melnik A. P. Meschanin V. V. Mochalov L. V. Nogach S. B. Nurushev A. F. Prudkoglyad P. A. Semenov L. F. Soloviev V. L. Solovianov V. Yu. Khodyrev K. E. Shestermanov A. E. Yakutin N. S. Borisov V. N. Matafonov A. B. Neganov Yu. A. Plis Yu. A. Usov A. N. Fedorov A. A. Lukhanin 《Physics of Atomic Nuclei》2004,67(8):1487-1494
Results are presented that were obtained by measuring single-spin asymmetry in the inclusive production of neutral pions in the reaction p+p ↑→ π 0+X at x F≈0. A beam of 70-GeV protons was extracted directly from the vacuum chamber of the accelerator by means of a bent single crystal. For transverse momenta in the range 1.0<p T<3.0 GeV/c, the single-spin asymmetry independently measured by two detectors is zero within the errors. This result is in agreement with Fermilab data obtained at 200 GeV, but it is at odds with CERN data measured at 24 GeV. 相似文献
996.
V. M. Kalita A. F. Lozenko S. M. Ryabchenko P. A. Trotsenko T. M. Yatkevich 《Physics of the Solid State》2004,46(2):326-334
The forced magnetostriction and magnetization are measured in the easy-plane-type two-sublattice NiCl2 antiferromagnet (AFM) in the case where this AFM passes from the multidomain to a single-domain state. It is shown that, in accordance with the magnetoelastic nature of the multidomain state, the field dependences of the forced magnetostriction and magnetization are interrelated and affected by the transition from the multidomain to the single-domain state. The character of these dependences corresponds to the case where the magnetization and striction are proportional to the number of domains with an energetically favored orientation with respect to the external magnetic field. 相似文献
997.
Electric and spatial characteristics of a pulse-periodic microsecond barrier discharge are investigated in different geometries—triangular
prism, plate, and corrugated electrode—that are in contact with a dielectric plate and form a dihedral angle with it. It is
established that, in the space of the dihedral angle, the regions of discharge represent alternating cylindrical layers with
the axes lying on the contact line. The first conducting layer is formed at some distance from the contact edge of the electrode.
The number of layers and their localization are determined by the angle formed between an electrode and the dielectric plate.
A physical model explaining the main features of the structure formation is proposed. 相似文献
998.
999.
The effective dielectric, piezoelectric, and elastic constants of two-phase macroscopically piezoactive 3-0 and 3-3 composites
are calculated. It is assumed that one of the components is a polarized ferroelectric ceramic material and the other is an
inactive material with variable elastic properties. The limiting case when the elastic compliances of the inactive material
tend to infinity (porous ferroelectric ceramics) is considered. The adequacy of this model to production technologies of piezoelectric
composites is discussed. Computational results are compared with experimental data. 相似文献
1000.
A method for evaluating the energy spectra and temperature dependences of the yield of neutral and charged clusters that consist of N≥5 atoms and are produced by ion bombardment of metals is proposed. The results are presented in the form of simple formulas. Theoretical energy spectra of clusters emitted as a result of bombarding niobium, tantalum, and iron targets by atomic ions of gold or xenon and temperature dependences of the yield of silver clusters produced by bombarding the targets with xenon ions are compared with experimental data.
相似文献