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361.
A.D. Danilov A.V. Konstantinova 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2019,63(1):359-370
Long-term changes in the E-layer critical frequency, foE, at three stations of the European region (Juliusruh, Slough and Rome) and also at Moscow and Wakkanai stations are analyzed by the method developed by the authors and described in detail in the previous papers. It is found that Juliusruh and Slough stations demonstrate a well-pronounced change in foE (a trend) during two previous decades. At the same time, the same features of the behavior of the aforementioned trend k(foE) are obtained. The trend is positive and negative in the morning and evening hours, respectively. Similar diurnal behavior of k(foE) is found also for Moscow station but with lower absolute values of the trends. A well-pronounced seasonal behavior of k(foE) is detected at Juliusruh and Slough: the trend is minimal and maximal in the summer period and at the end of fall—beginning of winter, respectively. The maximal amplitude in the morning hours reaches +0.04?MHz per year, whereas the minimal amplitude in evening hours is ?0.06?MHz per year. No systematic changes exceeding by the magnitude 0.01?MHz per year are found for Rome and Wakkanai stations. It is assumed that the observed trends are related to changes (trends) in the meridional wind bringing NO molecules from the auroral oval to lower latitudes. 相似文献
362.
We consider the stability of stationary motions of a model of a spacecraft as a system of coaxial bodies with small asymmetry caused by the shift of the axes of dynamic symmetry of bodies relative to the axis of rotation. We determine the stationary motions of the system; their stability is studied with respect to both the projections of angular velocity and the position of the axis of rotation. The sufficient conditions for the stability of these stationary motions are obtained by constructing a Lyapunov function, and the necessary conditions are obtained by analyzing the corresponding linearized equations of perturbed motion. 相似文献
363.
364.
Devajyoti Dutta Sanjay Sharma G.K. Sen B.A.M. Kannan S. Venketswarlu R.M. Gairola J. Das G. Viswanathan 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
By using a Doppler Weather Radar (DWR) at Shriharikota (13.66°N & 80.23°E), an Artificial Neural Network (ANN) based technique is proposed to improve the accuracy of rain intensity estimation. Three spectral moments of a Doppler spectra are utilized as an input data to an ANN. Rain intensity, as measured by the tipping bucket rain gauges around the DWR station, are considered as a target values for the given inputs. Rain intensity as estimated by the developed ANN model is validated by the rain gauges measurements. With the help of a developed technique, reasonable improvement in the estimation of rain intensity is observed. By using the developed technique, root mean square error and bias are reduced in the range of 34–18% and 17–3% respectively, compared to Z–R approach. 相似文献
365.
The requirements for skid landing gear static strength ensuring are examined based on the comparative analysis of the Airworthiness Standards requirements. Probabilistic principle of determining the safety factor of the skid landing gear is presented. The analysis of the experimental data on bench and flight tests is performed for calculating the actual value of this factor. 相似文献
366.
Y. Wu D.Y. Yang P.F. Tu Y.Z. Tian Y.H. Guo X.M. Wang X.B. Li 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
The dried, fleshy stems of Cistanche deserticola (Orobanchaceae) are popular tonics in Traditional Chinese Medicine (TCM) to treat the inability of kidney in expelling extra fluid in the body, causing fluid retention, and reform reproductive system. However, the wild plants of C. deserticola have become endangered due to habitat downsizing and over-harvesting for its medicinal usages. The present research was carried out for the following purposes: (1) promoting the space-breeding research; (2) providing molecular evidence for agricultural selective breeding; and (3) protecting this endangered herbal medicine and conserving its genetic resources. 相似文献
367.
We considered the influence of temperature on the nitric oxide emission under combustion of the near-stoichiometric mixtures
with and without water feed. We revealed the advantage of the method of fuel-water-air mixture combustion over that of the
leaned mixture combustion. 相似文献
368.
N. D. Akhmetov M. M. Gimadeev V. N. Drulis V. A. Krivosheev T. V. Rzaeva 《Russian Aeronautics (Iz VUZ)》2011,54(1):108-113
A technique for calculating the energy parameters of shock waves at electrical discharge in water is presented for the transition
region of discharge channel expansion using as the base the predetermined characteristics of discharge circuit. The technique
is based on the solution of energy transport equation that is similar in form to that of radiative transfer. The validity
of the presented approach was experimentally verified. 相似文献
369.
The results of investigating free oscillations of the International Space Station construction appearing during spacecraft docking and undocking are described. The study is carried out using the measurement
data of the low-frequency MAMS accelerometer. Several intervals of measurements performed in 2005 and 2006 were chosen to
be studied. For chosen intervals, only the data intervals corresponding to the process of free attenuation of the oscillations
construction elements were analyzed. Characteristic frequencies of elastic oscillations of the station construction and attenuation
coefficients corresponding to them are found. The comparative analysis of the results obtained for various docking ports (nodes)
is carried out. The described study is performed as a part of the technical experiment “The ISS Environment” carried out onboard the station in accordance with the Russian program of scientific and engineering experiments. 相似文献
370.
H.S. Ahluwalia J. Jackiewicz 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
The decay phase of the sunspot cycle 23 exhibited two unusual features. First, it lasted too long. Second, the interplanetary magnetic field intensity at earth orbit reached the lowest value since in situ measurements in space began in October 1963. These physical anomalies significantly altered the early forecasts for the sunspot activity parameters for cycle 24, made by several colleagues. We note that there was a significant change in the solar behavior during cycle 22. We discuss the observed trends and their effect on our empirical solar activity forecast technique, leading to our prediction for cycle 24 parameters; cycle 24 will be only half as active as cycle 23, reaching its peak in May 2013. We speculate on the possible implications of this outcome on future earth climate change and the ensuing socio-economic consequences. 相似文献