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151.
The excitation function (EF) data for dissipative processes in 19F + 27Al system in the incident energy interval from 113.5 to 130 MeV are used to obtain the dependence of the charge variance and of the interaction time as a function of the incident energy. Fluctuations are observed in the EFs of both these secondary observables. Their correlation is supported by a mechanism based on stochastic exchange of nucleons.  相似文献   
152.
This paper deals with the enhancement of electromechanical control of vibration on a thin plate submitted to non-ideal excitation. Modelling of the systems displays the non-ideal source used as external excitation above the structure on a particular surface and control force acting at specific points under the structure. The electromechanical device is composed by a RL circuit with a saturated inductance and stings connected to the plate is used as connection between the structure and the controller. Routh–Hurwitz criteria are used to obtain the stability condition of the controlled system and some dynamics exploration leads us to the condition for which the amplitude of vibration is reduced in the mechanical structure.  相似文献   
153.
On the basis of a simplified mathematical model there is calculated the probability of a photon of characteristic K series radiation excited by a photon of low energy gamma radiation hitting the detector. There are also included the probabilities for coherently and incoherently scattered primary radiation considering electron binding energies.  相似文献   
154.
The sealed,tuned liquid column gas damper (TLCGD) with gas-spring effect extends the frequency range of application and efficiently increases the modal structural damping.Active tuned liquid column gas damper (ATLCGD) is developed for the vibration control of plane asymmetric buildings subjected to earthquake excitation,improving the performance of the passive control scheme.The active behaviour is obtained by adjusting the pressure at the end of the liquid column using a pressurised reservoir.The classical linear quadratic regulator (LQR) design is presented as a straightforward approach to optimal control.Numerical simulations indicate a significant vibration reduction of plane asymmetric buildings by active control within the strong motion of the dynamic response.  相似文献   
155.
This presented study is to make comparison of cross sections to produce 117Sb and 90Nb via different reactions with particle incident energy up to 70 MeV as a part of systematic studies on particle-induced activations on enriched Sn, Y2O3 and ZrO2 targets, theoretical calculation of production yield, calculation of required thickness of target and suggestion of optimum reaction to produce Antimony-117 and Niobium-90.  相似文献   
156.
The odd-parity high-lying states of the Sm atom are investigated systematically by a three-color resonant excitation scheme with two different excitation paths.The two intermediate states,4f 6 6s7s 7 F 0 and 4f 6 6s7s 7 F 1 are employed for paths I and II,respectively.Fifty-seven bound states are detected with paths I and II in the energy range between 44188 and 45515 cm 1,while 64 autoionizing states are found in the energy range from 45528 to 45761 cm 1.Not only the level energies of all observed states,b...  相似文献   
157.
The theoretical and experimental analysis of the open resonator with the reflection diffraction comb grating has been presented. This resonator has excitation where is close to the monofrequency mode. This results may be used for the elaboration of mm-wave quasi-optical devices such as generators, mixer, converter, wavemeters and others.  相似文献   
158.
双光子技术在三维成像和三维存储技术中的应用   总被引:3,自引:0,他引:3  
汪洁  唐志列  徐险峰 《光学技术》2002,28(4):296-298
对双光子过程的空间分辨能力进行了理论分析。阐明了双光子技术在三维成像和三维存储中的独特优势。着重介绍了双光子技术与扫描共焦显微术、近场显微术相结合进行三维成像 ,以及一种多焦点多光子显微术和用连续光源激发的双光子三维成像技术的研究和进展情况。对建立在共焦显微镜基础之上的双光子三维光存储和微细加工方面的研究也作了回顾与展望  相似文献   
159.
Separating multidimensional problems into that of a relevant system which is coupled to a bath of harmonic oscillators is a common concept in condensed phase theory. Focusing on the specific problem of intramolecular proton transfer in an isolated tropolone derivative, we consider the reactive proton moving in the plane of the molecule as the system and the remaining substrate normal modes as the bath. An all-Cartesian system-plus-substrate Hamiltonian is constructed employing density functional theory. It is then used to determine the temperature-dependent effective reduced reaction Hamiltonian and the state-to-state dissipation rates induced via the system-substrate coupling up to the bi-quadratic order. The important substrate modes for the T1-relaxation and the pure T2-dephasing rates, which are either intra- or inter-well in nature, are identified numerically and analyzed physically with molecular details. Received 19 November 2001 and Received in final form 19 February 2002  相似文献   
160.
We measured the fluorescence intensity and anisotropy decays of 1,6-diphenyl-1,3,5-hexatriene (DPH)-labeled membranes resulting from simultaneous two-photon excitation of fluorescence. Comparison of these two-photon data with the more usual one-photon measurements revealed that DPH displayed identical intensity decays, anisotropy decays, and order parameters for one- and two-photon excitation. While the anisotropy data are numerically distinct, they can be compared by use of the factor 10/7, which accounts for the two-photon versus one-photon photoselection. The increased time 0 anisotropy of DPH can result in increased resolution of complex anisotropy decays. Global analysis of the one- and two-photon data reveals consistency with a single apparent angle between the absorption and the emission oscillators. The global anisotropy analysis also suggests that, except for the photoselection factor, the anisotropy decays are the same for one-and two-photon excitation. This ideal behavior of DPH as a two-photon absorber, and its high two-photon cross section, makes DPH a potential probe for confocal two-photon microscopy and other systems where it is advantageous to use long-wavelength (680- to 760-nm) excitation.  相似文献   
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