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111.
A. S. Fedorov D. A. Fedorov Z. I. Popov Yu. E. Anan’eva N. S. Eliseeva A. A. Kuzubov 《Journal of Experimental and Theoretical Physics》2011,112(5):820-824
The effect of isolated vacancies on the elastic properties of a graphene sheet has been investigated by the ab initio density
functional method. An almost inverse linear dependence of the Young’s modulus on the concentration of vacancies has been revealed.
The height of potential barriers for the motion of vacancies in various directions has been calculated as a function of various
independent applied strains. The velocity of vacancies at various temperatures has been calculated as a function of applied
strains using the transition state theory. 相似文献
112.
N. V. Volkov I. V. Oleinikov E. A. Anan’eva 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2011,5(2):236-239
The results of study of ion-cleaned and -implanted surfaces of polycrystalline Be, Al, Ti, Fe, Cu, Mo, Zr, and W using optical
and infrared (IR) spectroscopy are presented. It is shown that major changes in the optical reflectance spectra are observed
in the range of 190–250 nm and are associated with both the formation of scattering centers and features of the chemical state
of near-surface layers of materials. It is established using IR spectroscopy that treatment by Ar+ ion beam with a broad energy spectrum increases the reflection coefficient of the modified surface and additional resonance
lines related to the formation of oxides themselves and hydroxyl groups are revealed in the reflectance spectrum in the case
of formation of oxide film on the surface. 相似文献
113.
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116.
I.M. Anan’ evskii 《Journal of Applied Mathematics and Mechanics》2010,74(1):95-107
An approach to the construction of a feedback control for non-linear Lagrange mechanical systems with uncertain parameters is developed. A Lagrange mechanical system with uncertain parameters, which is subject to the action of potential forces, control forces and unknown perturbations is considered is considered. It is assumed that the potential forces can be considerably greater than the control forces which, in their turn, are greater than the perturbations. An approach to the construction of a control, is proposed which enables one to bring a system from an arbitrary initial state to a specified final state in a finite time using a bounded control. A procedure, in which the specified nominal trajectory of the motion is tracked, is used. Initially, the trajectory, joining the specified initial and final states of the system, is constructed for a certain dynamical system which is close to the initial system but with completely known parameters. Then, using deviation equations, a control is constructed which brings the initial system onto this nominal trajectory in a finite time and subsequently forces the system to move along this nominal trajectory up to the final state. The control law used in tracking the nominal trajectory is based on a linear feedback, the gains of which depends on the discrepancy between the real trajectory and the nominal trajectory. The gain increase and tend to infinity as the discrepancies tend to zero but the control forces remain bounded and satisfy the conditions imposed on them. The results of numerical modelling of the controlled motions of a plane double pendulum are presented as an illustration. 相似文献
117.
Asaka T Anan Y Nagai T Tsutsumi S Kuwahara H Kimoto K Tokura Y Matsui Y 《Physical review letters》2002,89(20):207203
Magnetic domain structures of Nd(1/2)Sr(1/2)MnO3 were investigated by means of low-temperature Lorentz electron microscopy. On cooling, magnetic domain walls started to appear at 250 K, and they were oriented straight along the [100] and [110] directions. With a further decrease in temperature, the volume of each magnetic domain increased with discontinuous domain-wall jumps. A characteristic granular image was observed at around 140 K, near the charge-ordering transition temperature. We consider that this originated from ferromagnetic nanoclusters that appeared in the antiferromagnetic matrix. 相似文献
118.
A. S. Anan’ev O. I. Kon’kov V. M. Lebedev A. N. Novokhatski E. I. Terukov I. N. Trapeznikova 《Semiconductors》2002,36(8):941-943
Boron carbide films were grown using glow discharge decomposition of C2B10H12 powder sublimation products. The film composition found as a-B0.52C0.48:H using nuclear reaction and infrared spectroscopy techniques was shown to depend weakly on the discharge gas (Ar or He) and the substrate temperature (20–100°C). The optical band gap was found to be about 3.8 eV; the resistivity varied from 106 to 105 Ω cm as the substrate temperature increased. Weak photoluminescence with a peak at 475 nm indicates that there is an acceptor level in the band gap which correlates with the conduction activation energy. 相似文献
119.
Sabiha Anan Mohammad Ibrahim Khan Mir Md Saki Kowsar Kaushik Deb Pranab Kumar Dhar Takeshi Koshiba 《Entropy (Basel, Switzerland)》2021,23(3)
Foggy images suffer from low contrast and poor visibility problem along with little color information of the scene. It is imperative to remove fog from images as a pre-processing step in computer vision. The Dark Channel Prior (DCP) technique is a very promising defogging technique due to excellent restoring results for images containing no homogeneous region. However, having a large homogeneous region such as sky region, the restored images suffer from color distortion and block effects. Thus, to overcome the limitation of DCP method, we introduce a framework which is based on sky and non-sky region segmentation and restoring sky and non-sky parts separately. Here, isolation of the sky and non-sky part is done by using a binary mask formulated by floodfill algorithm. The foggy sky part is restored by using Contrast Limited Adaptive Histogram Equalization (CLAHE) and non-sky part by modified DCP. The restored parts are blended together for the resultant image. The proposed method is evaluated using both synthetic and real world foggy images against state of the art techniques. The experimental result shows that our proposed method provides better entropy value than other stated techniques along with have better natural visual effects while consuming much lower processing time. 相似文献
120.
The jet flows induced around a submerged channel due to the hot inner channel walls and the flow inside the channel are calculated. The formation of high-and low-density regions at the inlet and outlet of the channel is detected. The dependence of the flow rate on the channel orientation relative to the gravity force is analyzed. The onset of coherent flow structures results in the development of unsteady oscillating flows. Natural convection in the fluid is studied using the JoinCAD/FEM program package. The regularized Oberbeck-Boussinesq equations are solved using a finite-element method with the same order of the approximating functions. 相似文献