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1.
Based on the analysis theory of random energy of train derailment, an analysis theory of random energy of train derailment in wind is suggested. Two methods are proposed -the time domain method and the frequency domain method of analysis theory of random energy of train derailment in wind. The curves of σ pw -v under various wind speeds are obtained through the computation. The original curve of σ p -v is expanded, which turns the analysis theory of random energy of train derailment into the all-weather theory. Train derailment condition has been established under wind action. The first and second criterions of train derailment have been proposed in light of wind action. The analysis of train derailment cases at home or abroad is made, in- cluding the first analysis of Xinjiang train derailment case encountered 13-level of gale, which explained the inevitability of train derailment. The analysis theory of random energy of train derailment in wind shows its validity and accuracy. The input energy σ pw of the transverse vibration of train-track(bridge)-wind system is linked to train speed. With the establishment of the analysis theory of random energy of train derailment in wind, It is likely to initiate an all-weather speed limit map for a train or any high-speed train.  相似文献   
2.
The γ-decay of excited states in 210Bi up to 3330 keV excitation energy has been studied using the 209Bi(d, pγ)210Bi reaction. From the observed decay scheme, tentative Jπ values are made for 25 states. The excitation energies, (d, p) strengths and decay branching ratios of these states are compared with those calculated using the two-particle shell-model wave functions of Kim and Rasmussen and Kuo and Herling.  相似文献   
3.
A search for the production of a bound trineutron state has been performed using the reaction 3He(π+)nnn at incident pion energies of 65, 75, and 120 MeV. No evidence for the existence of the 3n was found, and an upper limit for the production cross section of approximately 30 nb/sr (2σ confidence level) was obtained. Received: 22 October 1998  相似文献   
4.
The luminescent properties of terbium ions are used to investigate the interaction of adriamycin and cisplatin with GH3/B6 pituitary tumor cells. Clinically relevant concentrations of adriamycin were found to quench the intensity (IC50 = 0.6 μM) and excited-state lifetime (τ/τ0 = 0.73) of the Tb3+—GH3/B6 complex. Inspection of the Tb3+—GH3/B6 emission spectrum and the visible absorption spectrum of adriamycin strongly strongly suggests that the quenching of Tb3+ luminescence by adriamycin is due to dipole-dipole resonant energy transfer; and, according to Forster's theory (R0 = 33.6 Å), the adriamycin receptor site is located ca. 40 Å away from the bound probe, at the lipid/protein interface. The quenching of Tb3+ luminescence by cisplatin is best explained by a static energy-exchange mechanism; in that the cisplatin receptor site is contiguous with the Tb3+ binding site at the outer surface of the membrane. The data suggest that, in the plasma membrane of tumorigenic cells, the adriamycin and ciplatin receptor sites are intimately associated with the same calcium-binding protein.  相似文献   
5.
1 IntroductionInrecentyears,theintentionaloraccidentalreleaseofthechemicalwastesonsoilshasfurtherstimulatedcurrentinterestsinthemovementofchemicals.Displacementstudieshavebecomeimportanttoolsinsoilphysics,particularlyforpredictingthemovementofpestcides…  相似文献   
6.
Energy levels of 209Po have been populated with the 210Po(d, t)209Po and 210Po(p, d)209Po reactions at bombarding energies of 17.0 and 17.8 MeV respectively. Fifteen levels were observed below 2.7 MeV of excitation. Energy levels of 211Po were populated with the 210Po(d, p)211Po reaction, also at 17.0 MeV. Thirty-five levels, almost all new, were observed below 3.9 MeV of excitation. Comparison of experimental angular distributions with DWBA calculations allowed l-value assignments and extraction of spectroscopic factors for many levels. In 209Po the observed level structure is well described in terms of a simple particle-vibration coupling model. In 211Po the level structure is more complex and the simple model is not adequate.  相似文献   
7.
Lipochitooligosaccharides (LCOs) signal the symbiosis of rhizobia with legumes and the formation of nitrogen-fixing root nodules. LCOs 1 and 2 share identical tetrasaccharide scaffolds but different lipid moieties (1, LCO-IV(C16:1[9Z], SNa) and , LCO-IV(C16:2[2E,9Z], SNa)). The conformational behaviors of both LCOs were studied by molecular modeling and NMR. Modeling predicts that a small lipid modification would result in a different relative orientation of the lipid and tetrasaccharide moieties. Diffusion ordered spectroscopy reports that both LCOs form small aggregates above 1 mM. Nuclear Overhauser spectroscopy (NOESY) data, collected under monomeric conditions, reveals lipid-carbohydrate contacts only for 1, in agreement with the modeling data. The distinct molecular structures of 1 and 2 have the potential to contribute to their selective binding by legume proteins.  相似文献   
8.
Simulations of the gas fluidization of a cohesive powder were performed using the Stokesian Dynamics method and an agglomeration-deagglomeration model to investigate methods of improving the fluidizability of fine powders. Three techniques (a) high gas velocity (b) vibration-assisted fluidization and (c) tapered fluidizer were used in the simulations which provided detailed information on the bed microscopy such as the motion of 1 O0 particles in a fluidizing vessel along with the formation and destruction of cohesive bonds dudng collisions. While all three techniques were found to effectively improve the fluidizability of a strongly cohesive powder, we suggest a combination of high velocity fluidization assisted by extemal vibration of the fluidized bed to minimize entrainment of particles.  相似文献   
9.
10.
We numerically investigate the trade-offs between the dispersion properties,coupling efficiency,and geometrical constraints in dual-wire (twin-lead) terahertz (THz) waveguides.In particular,we show that their inherent linearly polarized quasi-transverse electromagnetic (TEM) modes exist for waveguide transverse dimensions comparable with the wavelength,enabling significant end-fire coupling (>10%) for numericalaperture limited Gaussian beams while supporting a relatively low-dispersion propagation of below 0.5 ps 2 /m,as desired for short-pulse time-domain spectroscopy applications.Starting from the dual-wire structure,we also demonstrate that low-dispersion tapers can be designed to improve coupling efficiency.  相似文献   
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