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991.
Broadband chaotic oscillations were monitored in a depressed potential collector of a traveling-wave oscillator (TWO). This signal appears due to the oscillations of a virtual cathode, which is formed in the spent electron beam under the action of retarding fields existing in the multistage depressed collector. 相似文献
992.
V. V. Mamutin O. V. Bondarenko A. P. Vasil’ev A. G. Gladyshev A. Yu. Egorov N. V. Kryzhanovskaya V. S. Mikhrin V. M. Ustinov 《Technical Physics Letters》2007,33(5):384-387
The optical properties of heterostructures comprising InAs/InGaAsN quantum wells in strain-compensated GaAsN/InGaAsN superlattices have been studied. It is demonstrated that, using such superlattices of various design and thickness and with additional InAs monolayer spacers, it is possible to control the wavelength of room-temperature emission from InGaAsN quantum wells within 1.3–1.6 μm without deteriorating the output radiation characteristics, which opens additional prospects for the development of lasers on GaAs substrates for telecommunication applications. 相似文献
993.
M. I. Danielyan K. S. Kulakov S. L. Kulakov V. L. Tumanov M. E. Kompan 《Technical Physics Letters》2007,33(7):597-599
A considerable (~1.4-fold) increase in the average output power of a chemical current source has been achieved by means of a periodic pulsed manipulation of the load. A scheme used for the pulse-train loading is presented and mechanisms ensuring an increase in the average output power of the current source are considered. 相似文献
994.
A. Aryshev S. Araki P. Karataev T. Naito N. Terunuma J. Urakawa 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2007,580(3):1544-1551
A fast room temperature microwave detection system based on the Schottky Barrier-diode detector was created at the KEK ATF (Accelerator Test Facility). It was tested using Coherent Synchrotron Radiation (CSR) generated by the 1.28 GeV electron beam in the damping ring. The speed performance of the detection system was checked by observing the CSR from a multi-bunch (2.8 ns bunch separation time) beam. The theoretical estimations of CSR power yield from an edge of bending magnet as well as new injection tuning method are presented. A very high sensitivity of CSR power yield to the longitudinal electron distribution in a bunch is discussed. 相似文献
995.
V. Yu. Karpov 《Materials Science》2007,43(5):746-749
We developed a new type of porous materials with anisotropic structure based on a large number of metals. It is shown that
these material, called gasars, have properties different from the properties of the other porous materials. Thus, the strength
of gasars is much higher than the strength of powder materials with the same porosity and their impact toughness is readily
regulated by the sizes of the pores. The internal structures of gasars and possible versions of the types of pores in these
materials are strongly diversified, which makes the spectrum of their possible applications very wide. We discuss some specific
directions of the potential applications of gasars. The results of measurements of the thermal conductivity of gasars and
monolithic specimens are presented. It is shown that, for a certain level of porosity, the specific thermal conductivity of
gasars is higher than for monolithic materials. We also make some basic conclusions concerning the characteristics of new
porous materials.
__________
Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 43, No. 5, pp. 125–127, September–October, 2007. 相似文献
996.
Ér. V. Kal’yanov 《Technical Physics Letters》2007,33(6):451-453
A new simple model of a system with chaotic dynamics, based on the equations of bistable systems, is considered. The possibility of converting harmonic signals into chaotic oscillations, which represent intermittent irregular and switching quasi-regular motions, is demonstrated by numerical methods. The mechanism of chaotization is analyzed using the results of numerical calculations. 相似文献
997.
D. I. Zolotarevskaya 《Journal of Engineering Physics and Thermophysics》2007,80(5):977-988
This paper considers problems on the rolling of rigid driven and driving cylinders slipping on a compactible viscoelastic
base. As a result of the investigation of the process of propagation of viscoelastic decaying strain waves in a deformable
medium caused by a cylinder rolling over it and the action of the sliding friction forces, formulas and calculation algorithms
have been obtained for determining the indices of the stressed-strained state and compactness of the base, the rolling resistance
of the driven and diving cylinders, and the driving force of the driving cylinder. Calculations of these indices have been
performed for the cases of cylinders rolling over a soil whose viscoelastic properties have been investigated experimentally.
__________
Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 5, pp. 122–132, September–October, 2007. 相似文献
998.
L. I. Ognev 《Technical Physics Letters》2007,33(11):972-975
Numerical simulations of the heating of a carbon dust particle (pellet) in hydrogen plasma showed that the character of heating depends in a threshold manner on the initial temperature of the pellet. The heating proceeds at a high rate if the initial temperature is above a certain threshold (“hot” regime), and at a much lower rate for an initial temperature below this threshold (“cold” regime). An important factor in this process is thermionic emission, which leads to positive charging of a pellet in hydrogen plasma due to electron emission from the surface in the hot regime. In the cold regime, the pellet acquires a negative charge that retards the electron flux from plasma to the particle. A method for the experimental observation of this effect is proposed. 相似文献
999.
Using the neuromorphic approach, we propose an analog very large-scale integration (VLSI) implementation of an oscillatory segmentation algorithm based on local excitatory couplings and global inhibition. The original model has been simplified and adapted for its efficient VLSI implementation while preserving its segmentation properties. To demonstrate the feasibility of the approach, a 16/spl times/16-pixel testchip has been manufactured. Extensive experimental results demonstrate that it can properly segment binary images. Power consumption, segmentation time per cell, and system complexity are very low compared to other hardware and software implementation schemes. We also show two main differences between the original algorithm and the analog approach. First, the network is noise tolerant without the need of additional elements and second, delays between oscillators due to the combination of mismatch and output capacitances have to be accounted for network performance. 相似文献
1000.
I. V. Zolotukhin I. M. Golev E. K. Belonogov V. P. Ievlev D. A. Derzhnev A. E. Markova 《Technical Physics Letters》2003,29(12):1006-1008
We have studied the structure and thermo emf of a nanotubular carbon deposit formed in electric arc discharge plasma. The deposit contains flocky granules with dimensions of 15–20 μm within a 20–60 μm-thick layer on the substrate surface. This deposit is characterized by a sufficiently high thermo emf (60 μV/K) and electric conductivity (600 Ω−1 m−1). 相似文献