Carbon monoxide laser emitting nanosecond pulses with 10 MHz repetition rate

Actively mode-locked electron-beam-sustained-discharge CO laser producing a train of ∼5-15 ns (FWHM) spikes following with repetition rate 10 MHz for both single-line and multiline mode of operation in the mid-IR range of ∼5 μm was experimentally studied. Total laser pulse duration was ∼0.5 ms for both mode-locked and free-running laser. Specific output energy in multiline CO laser mode of operation was up to 20 Jl⁻¹ Amagat⁻¹ and the laser efficiency up to 3.5%. The active mode-locking was achieved for single-line CO laser mode of operation in spectral range 5.2-5.3 μm. This sort of radiation can be used for pumping an optical parametric amplifier for optical stochastic cooling in relativistic heavy ion collider, for laser ablation, and for studying vibrational and rotational relaxation of CO and NO molecules.     

Hydrogen adsorption on model adsorbents from the viewpoint of the theory of volumetric filling of micropores

Hydrogen adsorption on model microporous adsorbents with slit-shaped pores was calculated on the basis of Dubinin’s theory of volumetric filling of micropores using the property of linearity of adsorption isosters. Model adsorbents with micropore widths of 0.5, 0.9, and 1.2 nm obtained by the successive exclusion of one, two, and three layers of hexagonal carbon in the crystalline lattice of graphite were used. Hydrogen adsorption was calculated in the structures with single-layer and two-layer carbon walls at temperatures 20, 33, 77, 200, 300, and 400 K and pressures up to 20 MPa. The maximal hydrogen desorption for the AU structure (1:3) with the pressure drop from 20 to 0.1 MPa was 8 wt.% at 200K. The parameters of the porous adsorbent structure were calculated.     

Proton Conductivity of Water in Mesoporous Materials

A model explaining a high proton conductivity of water in mesoporous materials has been proposed. The model is based on the theory of an intermediate phase of water with an ordered oxygen lattice and a destroyed proton lattice and involves various types of interaction of water molecules with an interface. The model is in fact based on an analogy of the interface and a liquid-like surface layer of ice. Possible methods for increasing the proton conductivity, experiments for testing the proposed model, and application of the results to the creation of efficient proton-exchange membranes have been discussed.     

Computing with a single qubit faster than the computation quantum speed limit

The possibility to save and process information in fundamentally indistinguishable states is the quantum mechanical resource that is not encountered in classical computing. I demonstrate that, if energy constraints are imposed, this resource can be used to accelerate information-processing without relying on entanglement or any other type of quantum correlations. In fact, there are computational problems that can be solved much faster, in comparison to currently used classical schemes, by saving intermediate information in nonorthogonal states of just a single qubit. There are also error correction strategies that protect such computations.     

Fabrication of Aquivion-type membranes and optimization of their elastic and transport characteristics

The solution casting technology was applied to manufacture thin polymer films (~?20–30 μm) from the ionomer solution of perfluorinated polymer with short side chains (an analogue of the commercial polymer Aquivion®). The influence of annealing temperature on the mechanical properties (elastic limit), proton conductivity, and heat capacity was investigated. The elastic limit, glass transition temperature, and proton conductivity of the samples were found to reach their maximum values at the annealing temperature 170?±?5 °C. Comparative studies of membrane-electrode assemblies (MEA) using the commercial (Nafion NR212) and solution-casted membranes were carried out. MEA with optimized Aquivion-type membranes showed satisfactory values of fuel crossover and maximum output power. The results of the conducted studies show that the prepared Aquivion-type membranes are very promising for practical application in MEA.     

On the possibility of determining the structure of proteins in experiments using X-ray free electron lasers in the nonstationary scattering mode

The problem of determining the structure of proteins by X-ray analysis using X-ray free electron lasers at pulse intensities several orders of magnitude higher than those achieved to date is considered. In this case, due to radiation damage, the sample loses a significant fraction of its electrons during the pulse, so the scattering occurs in the nonstationary mode. In the present study, simulations are used to determine the resulting specific features of the diffraction data that should be taken into account in analysis, which, however, do not preclude determining the 3D structures. Estimates of the achievable resolutions show the prospect of using the nonstationary scattering mode for determining the structure of the most complex objects, such as large, poorly crystallizable proteins and complexes with a high resolution.     

Structural and electrical characteristics of a hyperdoped silicon surface layer with deep donor sulfur states

Inhomogeneous hyperdoping of a 100-nm-thick silicon surface layer with sulfur atoms at concentrations above 2 × 10²¹ cm^?3 was obtained via its femtosecond laser ablation in a sulfur-containing organic solvent. Infrared transmission spectroscopy reveals distinct interband absorption peaks of donor sulfur states, which are absent in the initial crystalline silicon, and a broad absorption band of free carriers with a concentration of ～10¹⁸ cm^?3. The rather low free-carrier concentration is related to equilibrium room-temperature ionization of localized donor sulfur states, preserving their nondegenerate character owing to the strong electronion binding in the donor states.     

用广角X光衍射测定不同晶型间规聚苯乙烯结晶度

多晶型;用广角X光衍射测定不同晶型间规聚苯乙烯结晶度     

由一类非线性常微分方程的抛物线解所确定的扭波

通过求解与平面动力系统的两个平衡点相连接的抛物线解,获得了6种非线性行波方程的扭波解存在条件,并给出了这些扭波解的参数表达式,以及上述解存在的参数条件．