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1.
Low-frequency Raman scattering in the orientationally disordered phase of a polycrystalline C60 film is investigated. By analogy with disordered media (glasses), the low-frequency Raman spectra are interpreted in terms of light scattering by localized vibrational states.  相似文献   
2.
The results on etching of sapphire substrates with different orientation are discussed. High temperature etching in hydrogen stream and etching in the mixture of H3PO4 and H2SO4 were used in experiments. The relation of etching rates for different sapphire orientations were established in both cases. The conditions of nonselective etching were determined.  相似文献   
3.
The growth kinetics of GaN on Sapphire was analyed on the base of some experimental data such as: the growth rate temperature depandence, on the base of some experimental data such as: the growth rate temperature dependence, the grwoth rate dependence on the gas flow velocity, the growth rate depandence on the crystallographic and spatial orientation of the substrate. The limiting stage of the epitaxy process was established at different growth conditions. The morphology of GaN epitaxial layers obtained at these conditions is described.  相似文献   
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5.
In this Letter we describe a method for population transfer using intense, ultrafast laser pulses. The selectivity is accomplished by careful shaping of light-induced potentials (LIPs). Creation and control of the LIPs is accomplished by choosing pairs of pulses with proper frequency detunings and time delays. As an example, selective population transfer is demonstrated for a three-state model of the sodium dimer.  相似文献   
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7.
The properties of a superconducting flux quantum bit (qubit) in the quasidispersive mode, where the frequency of a probe signal is lower than the qubit excitation frequency but is close to it, have been experimentally studied. It has been shown that all parameters of the qubit inductively coupled to a coplanar resonator can be determined at the single-frequency excitation from the analysis of the frequency responses of the transmission of the probe signal at the output of this resonator. Under the additional excitation of the qubit by the signal at the second harmonic of the cavity, resonance dips have been observed because of resonance between the probe signal and induced Rabi splitting. It has been shown that the positions of these dips are in good agreement with the parameters of the qubit that are obtained by analyzing the amplitude–frequency response within the width of the fundamental resonance frequency.  相似文献   
8.
A superconducting magnet system (SMS) for the multicharged ion source DECRIS-SC was designed and manufactured at the Joint Institute for Nuclear Research. Successful tests of the SMS were conducted in late 2003 and early 2004. The peculiarities of this system are stipulated by the use of a cryocooler 1 W in power for the cryostating of the magnet and also by the special configuration of the magnetic field demanded for the source of ions. Four coils ensure the induction of a magnetic field on the axes of the source of up to 3 T (the stopper ratio of ~6), which considerably extends the possibilities of the ion source from the point of view of producing intense highly charged ion beams. The problem of compensating the large forces of interaction between the coils and surrounding iron yoke in this magnet has been successfully solved, and a reliable suspension of the magnet in a cryostat realized. To compound the windings, which work in vacuum at indirect cryostating, prepreg (thermosetting fiberglass fabric impregnated with epoxide) is used. A new technology of superconducting magnet protection has been applied with the help of sectionalized windings, using passive elements of protection based on “cold” diodes and resistances. A new technology of active protection has also been applied, with normal zone detectors and heaters.  相似文献   
9.
It is shown that a position of an optical absorption edge (OAE) of amorphous AsSe and As2S3 films irradiated by light up to saturation is independent on Texp the temperature at which the sample is exposed, and the amplitude of a reversible photoinduced shift of OAE ΔE is determined by its thermal shift ΔE as it is heated from Texp up to the glass-transition temperature Tg. So, in order to obtain maximum photoinduced changes we need to use materials with maximum thermal variations of the forbidden zone width, and to tend to a greater difference between Tg and Texp. The obtained results are well explained within the scope of the local heating model.  相似文献   
10.
The microscopic mechanisms governing the absolute negative photoconductivity in solids (jph = σph, σph < 0) discovered recently in concentrated ruby crystals are described. It is shown that in hopping models of photoconductivity the contribution to the current, connected with the field-induced asymmetry of processes of electron photoexcitation and recombination, dominates. It is predicted that the sign of σph(ω) changes as a transition over an absorption resonance is performed.  相似文献   
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