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41.
An approach based on a modified Galerkin method is proposed for solving interior diffraction problems. The solution procedure is demonstrated by computing the junction of two planar waveguides through a waveguide segment filled with an arbitrary dielectric material.  相似文献   
42.
The cross sections for nuclide production in thin natWand 181Ta targets irradiated by 0.04–2.6-GeV protons have been measured by direct γ spectrometry using two γ spectrometers with the resolutions of 1.8 and 1.7 keV in the 60Co 1332-keV γ line. As a result, 1895 yields of radioactive residual product nuclei have been obtained. The 27Al(p, x)22Na reaction has been used as a monitor reaction. The experimental data have been compared with the MCNPX (BERTINI, ISABEL), CEM03.02, INCL4.2, INCL4.5, PHITS, and CASCADE07 calculations.  相似文献   
43.
The cross sections for nuclide production in thin 56Fe and natCr targets irradiated by 0.04–2.6-GeV protons are measured by direct γ spectrometry using two γ spectrometers with the resolutions of 1.8 and 1.7 keV for the 60Co 1332-keV γ line. As a result, 649 yields of radioactive residual product nuclei have been obtained. The 27Al(p, x)22Na reaction has been used as a monitor reaction. The experimental data are compared with the MCNPX (BERTINI, ISABEL), CEM03.02, INCL4.2, INCL4.5, PHITS, and CASCADE07 calculations.  相似文献   
44.
A method is proposed for solving the boundary value problem of electromagnetic waves propagating in an open dielectric waveguide with an arbitrary cross section. The method combines the representation of solutions in the form of a continuous spectrum, the Fourier integral method, and the Galerkin variational procedure.  相似文献   
45.
In experiments on P-200 and SKN-40 elastomers plasticized with pseudosofteners (dibutyl phthalate and medical liquid petrolatum, respectively) it has been established that their autohesion strength falls with increase in storage time. When various amounts of incompatible plasticizers are introduced, the autohesion strength falls to a certain limit, after which it remains constant. Radioactive measurements on P-200 plasticized with radioactive dibutyl phthalate have shown that the autohesion strength of an elastomer system is directly related with the amount of pseudosoftener migrating to the surface.Mekhanika Polimerov, Vol. 2, No. 6, pp. 857–861, 1966  相似文献   
46.
Physics of Atomic Nuclei - Measured cross sections of the production of tritium in thin 27Al, natNi, and natW targets irradiated with protons with energies ranging from 40 to 2600 MeV are...  相似文献   
47.
By means of a multinuclear NMR study of the complexes formed between AlCl3 and either Cp2TiCl2 or Cp2Ti(CH2SiMe3)Cl in methylene chloride solution, isomeric forms of the resulting 1:1 complexes have been detected. The influence of temperature, concentration, ratio of the titanocene chloride to aluminum chloride and nature of the solvent upon the 1H, 13C and 27Al NMR spectra has been investigated. The spectral changes caused by the foregoing factors give compelling evidence for a equilibrium in such Cp2Ti(R)Cl · AlCl3 complexes (R = Cl, CH2SiMe3) between contact ion pairs, Cp2TiR · Cl · AlCl3, and solvent-separated ion pairs, Cp2TiR+ AlCl4. Upon experimental variations in temperature, concentration, solvent and ratio of RnAlCl3−n to the titanium catalyst, the polymerization activity of the catalyst system towards ethylene was markedly altered. Such changes in activity support the conclusion that the most active sites for polymerization in such systems are the solvent-separated ion pairs.  相似文献   
48.
The polymerization activity of the following three catalyst systems towards ethylene has been investigated and compared: 1) methyltitanocene chloride-Me2AlCl 2) η3-allyltitanocene-Me2AlCl and 3) titanium dichloride tetrahydrofuranate-Me2AlCl. The first two catalysts formed homogeneous phases and produced linear polymer; the last catalyst functioned in a heterogeneous medium and formed crosslinked polymer. The titanium(IV) catalyst was about 30 times more active than the titanium(III) system and the titanium(II) catalyst on MgCl2 could be made 8 times more active than the titanium(IV) system. A novel mechanism is proposed to explain the behavior and activity of the titanium(II) system.  相似文献   
49.
We consider the following basic geometric problem: Given , a 2‐dimensional black‐and‐white figure is ?far from convex if it differs in at least an ? fraction of the area from every figure where the black object is convex. How many uniform and independent samples from a figure that is ?far from convex are needed to detect a violation of convexity with constant probability? This question arises in the context of designing property testers for convexity. We show that uniform samples (and the same running time) are necessary and sufficient for detecting a violation of convexity in an ?‐far figure and, equivalently, for testing convexity of figures with 1‐sided error. Our algorithm beats the lower bound by Schmeltz [32] on the number of samples required for learning convex figures under the uniform distribution. It demonstrates that, with uniform samples, we can check if a set is approximately convex much faster than we can find an approximate representation of a convex set.  相似文献   
50.
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