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Impact dampers have gained much research interest over the past decades that resulted in several analytical and experimental studies being conducted in that area. The main emphasis of such research was on developing and enhancing these popular passive control devices with an objective of decreasing the three parameters of contact forces, accelerations, and noise levels. To that end, the authors of this paper have developed a novel impact damper, called the Linear Particle Chain (LPC) impact damper, which mainly consists of a linear chain of spherical balls of varying sizes. The LPC impact damper was designed utilizing the kinetic energy of the primary system through placing, in the chain arrangement, a small-sized ball between each two large-sized balls. The concept of the LPC impact damper revolves around causing the small-sized ball to collide multiple times with the larger ones upon exciting the primary system. This action is believed to lead to the dissipation of part of the kinetic energy at each collision with the large balls. 相似文献
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K. Ganesan S. Ilango Mariyappan Shanmugam M. Farrokh Baroughi M. Kamruddin A.K. Tyagi 《Current Applied Physics》2013,13(9):1865-1869
The loss of local dielectric integrity in ultrathin Al2O3 films grown by atomic layer deposition is investigated using conducting atomic force microscopy. I–V spectra acquired at different regions of the samples by constant and ramping voltage stress are analyzed for their pre- and post-breakdown signatures. Based on these observations, the thickness dependent dielectric reliability and failure mechanism are discussed. Our results show that remarkable enhancement in breakdown electric field as high as 130 MV/cm is observed for ultrathin films of thickness less than 1 nm. 相似文献
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Rekhila Gharib Gabes Yamina Brahimi Razika Bessekhouad Yassine Mahroua Ousama Trari Mohamed 《Journal of Sol-Gel Science and Technology》2018,85(3):677-683
Journal of Sol-Gel Science and Technology - Benzamide is successfully degraded on the novel heterosystem NiMn2O4/TiO2 under visible light. The nanosized spinel is synthesized by the sol–gel... 相似文献
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Following Sam Payne?s work, we study the existence problem of nontrivial vector bundles on toric varieties. The first result we prove is that every complete fan admits a nontrivial conewise linear multivalued function. Such functions could potentially be the Chern classes of toric vector bundles. Then we use the results of Cortiñas, Haesemeyer, Walker and Weibel to show that the (non-equivariant) Grothendieck group of the toric 3-fold studied by Payne is large, so the variety has a nontrivial vector bundle. Using the same computation, we show that every toric 3-fold X either has a nontrivial line bundle, or there is a finite surjective toric morphism from Y to X, such that Y has a large Grothendieck group. 相似文献
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Digital particle image velocimetry/thermometry (DPIV/T) is a technique whereby the velocity and temperature fields are obtained
using thermochromic liquid crystal (TLC) seeding particles in water. In this paper, the uncertainty levels associated with
temperature and velocity measurements using DPIV/T are studied. The study shows that large uncertainties are encountered when
the temperature is measured from individual TLC particles. Therefore, an averaging procedure is presented which can reduce
the temperature uncertainties. The uncertainty is reduced by computing the average temperature of the particles within the
common specified sampling window used for standard DPIV. Using this procedure, the velocity and temperature distributions
of an unsteady wake behind a heated circular cylinder are measured experimentally at Re=610. The instantaneous DPIV/T measurements
are shown to be useful for computing statistical flow quantities, such as mean and velocity-temperature correlations.
Received: 3 January 2000/Accepted: 26 June 2000 相似文献
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S. A. Beyramabadi M. Khashi A. Morsali A. Gharib H. Chegini 《Journal of Structural Chemistry》2018,59(6):1326-1334
An unsymmetrical tridentate Schiff base 4-((E)-(2-amino-5-nitrophenylimino)methyl)-5-(hydroxymethyl)- 2-methylpyridin-3-ol is newly synthesized and characterized experimentally. Its geometrical parameters, the assignment of IR bands and NMR chemical shifts are also computed by the density functional theory (DFT) method. In addition, the atoms in molecules (AIM) analysisis employed to investigate its geometry. Only one of the diamine–NH2 groups undergoes the condensation reaction. In the structure of the synthesized Schiff base, the remaining aminogroup lies in the para position with respect to the nitro group (isomer 1). In both gas and solution phases, isomer 1 is more stable than isomer 2 with the meta orientation of the amino and nitro groups. The NMR chemical shifts and the AIM analysis show that isomer 1 is a more favorite structure for the synthesized Schiff base. It has no planar structure. The phenolic proton is engaged in the intramolecular hydrogen bond with the azomethine nitrogen atom. The experimental results are in good agreement with the theoretical ones, confirming the validity of the optimized geometry. 相似文献