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941.
V. I. Alfyorov 《Fluid Dynamics》2004,39(6):988-998
Many studies devoted to both the theoretical and the experimental analysis of the problem of controlling the aerodynamic characteristics of vehicles using local heat-generating zones organized by means of external fuel combustion or directly as a result of the Joule dissipation of an electric current have recently been published. In this study attention is concentrated on the latter case.Translated from Izvestiya Rossiiskoi Academii Nauk, Mekhanika Zhidkosti i Gaza, No. 6, 2004, pp. 163–175. Original Russian Text Copyright © 2004 by Alfyorov. 相似文献
942.
LI Zhaohui 《Chinese Journal of Lasers》2002,11(5):321-323324
A novel Yb3+-doped fiber ring cavity laser pumped by a 977 nm laser diode is presented with its output laser wavelength of 1060 nm. Based on a fiber Bragg grating (FBG), the laser exhibits 0.20 nm line-width, 7.5 mW laser output power, 40 dB signal-to-noise ratio (SNR) and 66% slope efficiency.This paper proposed a ray-tracing model for the Martinez stretcher, derived the calculation formulae for the stretcher of a grating-spherical mirror system and discussed the error for the total dispersion resulted from the spatial dispersion. The calculated results show that the error could be ignored for the beam returned to the stretcher for the second pass in the wavelength range of 750 nm and 850 nm. 相似文献
943.
Lee Dae-Won Lee Jung-Hyun Chun Bae-Hyeock Lee Kwan-Young 《Plasma Chemistry and Plasma Processing》2003,23(3):519-539
The direct hydroxylation of benzene using molecular oxygen by atmospheric pulse DC corona discharge was investigated. The conversion of benzene increased with the increase of oxygen content and input voltage but the selectivity of phenol decreased due to the formation of polymerized products. The reactivity was also influenced by the kind and content of background inert gas. By using argon as background gas, we could get 2.2% of phenol yield at 60°C and 1 atm with energy consumption of 50 W. The strategy of reductive oxidation, which added hydrogen to the reactant, was not favorable to the phenol formation in this reaction system. The polymerized product showed the oligomeric character and the analysis of its chemical structure with FT–IR was presented. 相似文献
944.
M.C. Saint-Lager Y. Jugnet L. Piccolo J.C. Bertolini O. Robach C. Walker 《Surface science》2005,587(3):229-235
The (N × 1) reconstruction (N = 5-6) of the clean Pd8Ni92(1 1 0) surface has been investigated by surface X-ray diffraction. A good fit with experimental data collected under UHV conditions is obtained when introducing undulations in the outer dense rows, constituted mainly of Pd atoms which strongly segregate to the surface. This reconstruction can be regarded as a way to relax the strains induced on the bigger Pd surface atoms, at least partially. The modifications of the surface were studied under butadiene then hydrogen as well as during butadiene hydrogenation at elevated pressure at 300 K and the (N × 1) reconstruction was found to be still present. The main changes are observed under pure hydrogen and during butadiene hydrogenation. 相似文献
945.
V. I. Bukreev 《Journal of Applied Mechanics and Technical Physics》2006,47(5):679-687
A review of the information available in the literature is given, and new experimental data on the depth and discharge at
the dam site after a total and a partial dam break are presented. It is shown that in the case of a partial dam break with
the formation of a rectangular breach, the specific discharge per unit width of the breach is higher than the specific discharge
in the case of a total dam break with the same excess initial energy in the headwater.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 5, pp. 77–87, September–October, 2006. 相似文献
946.
947.
介绍了一种水冷、陶瓷封接结构的空心阴极放电装置.研究了He、H_2、N_2在120nm~20Onm范围内该装置的真空紫外辐射特性,获得了100~600mA电流范围内的辐射强度与放电电流的关系,以及充气气压变化对它的影响.实验表明:在实验条件下,主要发射谱线为氮的原子线和氦的离子线;辐射谱线强度在0.03~0.72mW·cm~(-2);气压改变时,N_2、H_2辐射强度有一极大值,而He的离子线辐射强度则出现二个极大;在He/H_2混合气体放电时,随着He的加入,氢分子带光谱有明显下降. 相似文献
948.
949.
从转动矩阵理论与实验两方面研究了结合脉冲梯度场的选择性形状脉冲的相位特性,结果表明:单梯度自旋回波(SPFGSE)和双梯度自旋回波(DPFGSE)对于对称和反对称的形状脉冲,都能很好地克服其相位畸变;而双梯度自旋回波(DPFGSE)对于非对称的形状脉冲也能克服其相位畸变;双选择性单梯度自旋回波无法克服形状脉冲的相位畸变. 相似文献
950.
杨自祥 《核聚变与等离子体物理》1988,(1)
磁通计是一个被低电感电阻短路的自积分单匝线圈。由于它具有时间响应快,抗干扰能力强,不影响束流传输等优点,主要用于测量脉冲电子束加速器的二极管发射电流。同时,也可做为电流探针,用来监测其它快速变化的电流。 相似文献