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Examination was performed into nonlinear acoustic effects (cavitation, acoustic flow, and radiation pressure) induced by propagation of intense (>amp;gt;0.1 W/cm2) kilohertzrange frequency ultrasonic vibrations through liquids.


Momentum, radiation pressure, and other secondorder quantities in ideal gas (liquid) in some boundaryvalue problems


In this case, the momentum and the related mass transfer and radiation pressure are caused by variations in the wave profile (envelope).


The spacetime correlation function of thermal acoustic radiation pressure is measured for a stationary heated source (a narrow plasticine plate).


One of the promising fields of research is the development of tactile displays for transmission of sensory data to a human by an acoustic method based on the effect of radiation pressure.

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 A study of the relation between velocity separation of double peaks △V of maser source and associated variable's period Ⅱ is presented in this paper. A linear correlation between △V_(OH) (or △V_(SIO)) and П has been obtained, the correlation coefficient r is greater than 0.9. It indicates that the model of expanding shell of a maser star is correct. We adopt the mechanism of mass loss due to radiationpressuredriven stellar wind, discussed the calculation method of mass loss rate for these LPV(long period variable),... A study of the relation between velocity separation of double peaks △V of maser source and associated variable's period Ⅱ is presented in this paper. A linear correlation between △V_(OH) (or △V_(SIO)) and П has been obtained, the correlation coefficient r is greater than 0.9. It indicates that the model of expanding shell of a maser star is correct. We adopt the mechanism of mass loss due to radiationpressuredriven stellar wind, discussed the calculation method of mass loss rate for these LPV(long period variable), and calculated the mass loss rates for different periods by means of the statistcal correlation of △V,П. Our results are in agreement with other estimated values of optical or infrared observations. The distribution of velocity of matter flow which has been obtained in this paper is used to calculate the position of SiO shell, it is consistent with the anticipated result. The results may be tested by high resolving power observation in the future.  本文对与长周期变星成协的OH和SiO脉泽源的两个参量周期Π和双峰间隔△V进行了相关统计,结果表明它们之间的相关系数γ>0.9,这说明脉泽源的膨胀壳层模型是正确的。采用辐射压驱动恒星风的质量损失机理,用本文统计的结果计算了长周期变星的质量损失率,得到了与观测一致的结果,利用本文所得到的物质流速的分布推算了不同Π的SiO脉泽壳层的位置,与当前人们推测位置是一致的,这一结果有待今后用高分辨率的毫米波观测检验。  In this paper we 've started from the spectral class, pulsation period and associated maser's spectrum of Mira variables, adopted the mechanism of mass loss due to radiationpressuredriven stellar wind, we 've discussed the expressions for opacity coefficient of dust and mass loss rate of Mira variables. Then we've calculated the values of mass loss rates for 42 Mira variables which possess double peaks OHmaser's spectrum. Besides, we 've found the relations between mass loss rate and stellar luminosity, pulsation... In this paper we 've started from the spectral class, pulsation period and associated maser's spectrum of Mira variables, adopted the mechanism of mass loss due to radiationpressuredriven stellar wind, we 've discussed the expressions for opacity coefficient of dust and mass loss rate of Mira variables. Then we've calculated the values of mass loss rates for 42 Mira variables which possess double peaks OHmaser's spectrum. Besides, we 've found the relations between mass loss rate and stellar luminosity, pulsation period and associated maser 's velocity. In detail refer to Fig. 1, Fig. 2, and Fig. 3. The correlation coefficients between fitting straight line and values calculated are 0.914, 0.830, 0.786, respectively. However, there is not apparent correlation between mass loss rate and effective temperature of stellar surface. Finally, we Ve obtained the following views:1.The results calculated are in agreemant with Keimer's semiexperience relation, and it supports the "expanding shell" model of circumstellar masers.2.As compared with the theory of earlytype star's mass loss, it has been pointed that the stellar wind's theory of latetype star must be improved in future.  本文从Mira变星的光谱型、周期以及与之成协的OH脉泽频谱出发,按辐射压驱动恒星风的质量损失机制,计算了42个有OH脉泽双峰频谱资料的Mira变星的质量损失率,从而找出了Mira变星质量损失率与恒星光度、脉动周期以及成协脉泽源速度的关系.在质量损失率和表面有效温度之间未见明显的依赖性.文中最后对所得结果进行了简单的讨论.  For orbit improvement, a extended Kalman filter has been suggested in this paper. Processing in real time a few passes of laser ranging observation data from only one tracking station, the satellite position in current future could be precisely predicted. The dynamical model included the effects of the earth nonspherical shape, atmospheric drag, solar radiation pressure as well as lunar and solar perturbations. In computing these kinds of perturbations, the earth gravitational potential was developed up to... For orbit improvement, a extended Kalman filter has been suggested in this paper. Processing in real time a few passes of laser ranging observation data from only one tracking station, the satellite position in current future could be precisely predicted. The dynamical model included the effects of the earth nonspherical shape, atmospheric drag, solar radiation pressure as well as lunar and solar perturbations. In computing these kinds of perturbations, the earth gravitational potential was developed up to llth degree and 11th order for all of zonal, sectorial and tesseral harmonic terms; exponential model was adopted for the distribution of atmospheric density; the earth shadow was assumed in cylindrical shape; the rotating Kepler's elliptical orbits were adopted in computing the geocentric coordinates of the moon and the sun. For the estimation of satellite state, the extended sequential estimation algorithm was applied. The numerical method was used to integrate state vector and error covariance matrix. As the tests, two examples using simulated and real laser ranging data of LAGEOS satellite respectively were presented. The applications demonstrate that the rather accurate satellite position of subsequent passes required for laser pointing could be predicted, by using the extended sequential filter structured in here and processing a few passes, a relatively small number of range observation data, even though these data were from only one station. Whatever, more passes were processed, more accuracy could be reached. The computer program constructed according to this method is able to run on a minicomputer, such as PDP 11/60, while at the same time, it maintains the required accuracy for orbit prediction. So the extended Kalman filter is a convenient and useful means for those tracking stations, where no large computers are available.  本文借用推广的卡尔曼(Kalman)滤波法实时处理几圈单站的激光测距资料来改进卫星的轨道,以达到精密预报此后近期内卫星位置的目的。在建立动力学模型中,计及了地球扁球形的摄动、大气阻力、太阳辐射压的效应以及日月引力摄动。在计算这些摄动过程中,地球重力位对带谐、扇谐和田谐项都展开到了第11次和第11阶;大气密度分布采用简化的“指数模型”;地影假定呈圆柱形;并以旋转的开普勒轨道求日月的地心坐标。在卫星的状态估计过程中应用推广的序列估计算法,借助数值积分方法积分状态向量和协方差矩阵。利用激光卫星LAGEOS的测距模拟资料和真实数据分别对本方法进行了检验。结果表明:应用本方法即使处理单站的少数几圈的观测数据,可相当精确地预报卫星在此后几圈的位置。如果处理更多圈数的数据,则卫星的预报可以达到更高的精度。并且由于按照本方法建立起来的计算程序可以在小型电子计算机,例如PDP11/60上实施,同时保持应有的精度,因此它颇具有实用的价值。   << 更多相关文摘 
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