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181.
182.
C. D'uston J. M. Bosqued F. Cambou V. V. Temny G. N. Zastenker O. L. Vaisberg E. G. Eroshenko 《Solar physics》1977,51(1):217-229
Solar wind and interplanetary magnetic field data were obtained by the PROGNOZ 1 and PROGNOZ 2 satellites during the period following the August 4, 1972 (0621 UT) solar flare. A thermalized plasma was recorded one hour after the shock followed two hours later by the plasma piston with a bulk velocity higher than 1700 km s-1. The comparison between the PROGNOZ and PIONEER 9 solar wind data shows an attenuation of the plasma properties with the deflection from the flare's meridian. 相似文献
183.
The tridiurnal wave in cosmic-ray intensity expected from a free space anisotropy is theoretically calculated for different cosmic-ray stations which are characterized by different shapes of asymptotic cones of acceptance. The amplitude A and the time of maximum Tmax are given for latitude dependence of the form cosn λ and rigidity dependence of the form , where λ and R are the latitude and rigidity respectively and n, β, R0 are constants. The values of A and Tmax, are calculated for different values of n, β and R0 for each station. The dependence of A and Tmax on the anisotropy parameters is studied for the proper selection of cosmic-ray stations whose data may be used in determining these parameters.Available experimental data were used to find the observed amplitudes of the tridiurnal variations at five stations using power spectrum analysis with hanning applied on the averaged trains. Minimum variance analysis of the theoretical and experimental amplitudes showed that β has a value between 1 and 2, R0 greater than 100 GV and n smaller than 3. 相似文献
184.
A one-dimensional model for thinning of the plasma sheet is developed on the basis of launching a fast mode MHD rarefaction wave propagating in the tailward direction along the plasma sheet. Behind the rarefaction wave the pressure is reduced, leading to thinning of the plasma sheet and also to an Earthward plasma flow with a speed on the order of the sound speed a0. The plasma sheet thickness is reduced by a factor of 2 if an Earthward plasma flow speed of 0.8a0 is induced. The predictions of the model are in reasonable agreement with observations. 相似文献
185.
Models are developed for the photochemistry of a CO2H2ON2 atmosphere on Mars and estimates are given for the concentrations of N, NO, NO2, NO3, N2O5, HNO2, HNO3, and N2O as a function of altitude. Nitric oxide is the most abundant form of odd nitrogen, present with a mixing ratio relative to CO2 of order 10?8. Deposition rates for nitrite and nitrate minerals could be as large as 3× 105 N equivalent atoms cm?2 sec?1 under present conditions and may have been higher in the past. 相似文献
186.
187.
Unsteady two-dimensional hydromagnetic flow of an electrically conducting viscous incompressible fluid past a semi-infinite porous flat plate with step function change in suction velocity is studied allowing a first order velocity slip at the boundary condition. The solution of the problem is obtained in closed form and the results are discussed with the aid of graphs for various parameters entering in the problem.Notations
B
intensity of magnetic field
-
H
magnetic field parameter,H=(M+1/4)1/2–1/2
-
h
rarefaction parameter
-
L
1
slip coefficient;
;I, mean free path of gas molecules;f, Maxwell's reflection coefficient
-
M
magnetic field parameter
-
r
suction parameter
-
t
time
-
t
dimensionless time
-
u
velocity of the fluid
-
u
dimensionless velocity of the fluid
-
U
velocity of the fluid at infinity
-
v
suction velocity
-
v
1
suction velocity att<=0
-
v
2
suction velocity att>0
-
x
distance parallel to the plate
-
y
distance normal to the plate
-
y
nondimensional distance normal to the plate
-
v
kinematic viscosity
-
electric conductivity of the fluid
-
density of the fluid
-
shear stress at the wall
-
nondimensional shear stress at the wall
- erf
error function
- erfc
complementary error function 相似文献
188.
A. S. Trew 《Astrophysics and Space Science》1982,82(1):223-228
The possible correlation noted between the intrinsic quasar luminosity and the absorption line expulsion velocity is re-examined using homogeneous data sets for metal and L only line systems. The method of analysis is chosen to enable any reasonable form of correlation to be found. No correlation is detected at a confidence level >10%. 相似文献
189.
C. Bartolini A. Bonifazi F. D'antona F. Fusi Pecci L. Oculi A. Piccioni R. Serra 《Astrophysics and Space Science》1982,83(1-2):287-310
The evolutionary status of hydrogen-poor stars is analyzed.Photoelectric observations of six objects are reported as a first step of a long-term project devoted to search for variability of a large sample of hydrogen-poor stars.The observed stars show phenomena of microvariability with an amplitude of the order of 0m. 1 or less.Two extreme helium stars have been examined: a period in the range of 0d.162-0d.164 has been found for BD+ 1002179, andP=0d.1079962 for BD+1303324.The mass-losing O subdwarf (sdO) BD+370 443 presents short-term fluctuations with a time-scale of several minutes and long-term variations on a scale of months. The standard sdO BD+750325 is probably non-variable, although light variations of very small amplitude (m0.03) with a time-scale of about 1 hr might be present. The high gravity sdO BD+2504655, which is very close to the white dwarf stage, also presents variability on a time-scale of about 13 minutes, and might be an analog of the recently discovered pulsating sdO, or hot white dwarf, PG 1159-035.The variability of the intermediate helium star HD 37776 is finally confirmed. 相似文献
190.
Using high-resolution pictures of the core of a unipolar sunspot observed with several cos values, we studied the center limb effect on the form of the bright umbral dots. The ratio of the apparent sizes in radial and tangential direction do not show the foreshortening effect typically observed in granular structures.On leave from University of Tabriz, Iran.Observational part of this work was done during a stay of S.K. at Sacramento Peak Observatory, U.S.A., as NRC Resident Research Associate. 相似文献