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1.
The impact of SDT on arms race has been discussed in a model which includes intercontinental ballistic missiles, anti-FCBM satellites and anti-satellite weapons for U.S. and former Soviet Union. It is assumed that each side of U. S. and former Soviet Union wants to reach the biggest retaliatory capability for given expenditure. This problem is considered as a two-person game and the optimal configurations of the three kinds of weapons for both sides is calculated under different conditions. The results show that the SDI can not lead to the transition from an offensive mode to a defensive mode and can not also offer an effective protection against the threat of ICBMs. 相似文献
2.
李毅民 《声学学报:英文版》1986,(4)
In the first of these two papers,the expression for the total energy of vibration excited by impacthas been obtained.In this paper the energy equation of ringing noise was derived from the resultof the first paper.This energy equation indicates the approaches to control ringing noise.Thebuffering method was discussed here in detail.The experiment which has been conducted was describedalso. 相似文献
3.
李毅民 《声学学报:英文版》1986,(3)
Ringing noise is a main kind of impact noise.It arises from the subsequent free vibration whena body was striked.The total energy of ringing noise is only a small part of the total energy of vibra-tion excited by impact.In this paper,the equation of motion of a generalized distributed systemexerted by an impact force was solved.The expression for the total energy of vibration was derived fromthe solution of the equation.The result applies to every variety of structural parts,and it indicatesthe approaches to suppress the total excited energy of vibration. 相似文献
4.
XAFS CHARACTERIZATION ON THE ACTIVE SITES OF Ni/γ—Al2O3 CATALYSTS FOR NO—SCR BY PROPENE 总被引:1,自引:0,他引:1
MingMeng PeiyanLin YiluFu 《北京同步辐射装置》2001,(1):128-137
Ni/γ-Al2O3 catalysts show high catalytic activity for the selective catalytic reduction of NO by C3H6.The microstructures of nickel species were characterized by the spectroscopy of X-ray Absorption Near Edge Structures(XANES) and Extended X-ray Absorption Fine Structures(EXAFS).The resuts of XANES and EXAFS indicate that the nickel species in the sample calcined at 500℃mainly exist as highly dispersed NiO phase,Whereas in the samples calcined at750 and 950℃,the nickel species mainly exist as NiAl2O4-like spinel.The surace NiAl2O4-like spinel is the main active site for the selective reduction of No,and the highly dispersed NiO phase is the main active site for C3H6 oxidation. The formation of subsurface or buld NiAl2O4 spinel results in the reduction of surface spinel and cuases the decrease of activity for the selective catalytic reduction of NO by propene. 相似文献
5.
K.Ibrahim Z.Y.Wu J.Zhang M.I.Abbas F.Q.Liu H.J.Qian 《北京同步辐射装置》2001,(1):237-242
Valence band photoemission spectra(PES) for both bulk and nanocrystal CeO2 have been masured on and off resonance of Ce 4d-4f absorption edge.The PES show that the bulk and nanocrystal CeO2 of diameter ranging from 8nm to 50nm exhibit a peak near Fermi edge with binding energy of abiyt 1.8eV peak shows a strong dependence on excitation energy,although it looks like the contribution of Ce^3 ion following the data reported in literatures.However,According to the results of resonance photoemission and X-ray absorption spectra at O 1s edge,this electronic structure may be associated to the intermediate state charge transfer effcets. 相似文献