共查询到20条相似文献，搜索用时 15 毫秒
1.
Wilbur K. Brown 《Journal of Astrophysics and Astronomy》1989,10(1):89-112
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O. T. Matsuura 《Solar physics》1969,9(1):173-182
A magnetohydrodynamic (MHD) approach is presented that appears to be comprehensive for the interpretation of the recently discovered microwave solar events, in which only the degree of circular polarization changes, without any increase in the output of the total solar flux. On the basis of this explanation experimental evidence is suggested for Alfvén waves, in relation to the velocity fields in the solar chromosphere. 相似文献
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B.N. Maehlum K. Måseide K. Aarsnes A. Egeland B. Grandal J. Holtet T.A. Jacobsen N.C. Maynard F. Søraas J. Stadsnes E.V. Thrane J. Trøim 《Planetary and Space Science》1980,28(3):259-278
A “mother-daughter” rocket was launched from Andøya, Norway, February 1 1976 over two auroral structures. The “daughter” payload carried a 10keV electron accelerator and the “mother” carried a series of diagnostic instruments for monitoring optical and wave effects generated through beam-atmospheric interactions and production of secondary electrons.The experimental details are presented in this paper together with a survey of some of the results. This paper is also intended as a reference for a series of accompanying papers. 相似文献
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A precise two-dimensional positioning device has been developed for use in conjunction with a resonant scattering spectrometer to study the spatial distribution of solar velocity fields. The principle of operation and constructional details are discussed and the experimental performance is evaluated. As an illustration of its use preliminary data obtained from a meridional scan are presented.Proceedings of the 14th ESLAB Symposium on Physics of Solar Variations, 16–19 September 1980, Scheveningen, The Netherlands. 相似文献
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A. V. Megn S. Ya. Braude S. L. Rashkovsky V. A. Shepelev N. K. Sharykin V. V. Galanin O. A. Litvinenko G. A. Inyutin A. D. Khristenko G. S. Podgorny 《Astrophysics and Space Science》1993,201(1):79-90
The observation results of the supernova remnant Cassiopeia A, obtained with the aid of two decameter radio interferometers at 20 and 25 MHz, are presented. The so obtained dependences of the visibility function modulus on the hour angle are compared with calculations based on the brightness distribution measurements of this source using the VLA at 1381 MHz. Discrepancies between the experimental data and the calculations considerably increase with the decrease in the frequency. It is suggested that interstellar medium absorption, causing a distortion in the source spectrum over the decameter range, may be responsible for changes in the Cas A brightness distribution at these frequencies as well. 相似文献
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S.S. Sazhin 《Planetary and Space Science》1984,32(10):1263-1271
A quasilinear model for hiss-type mid-latitude VLF emissions is presented. It can be considered as an improved version of the models which were earlier suggested by Etcheto et al. (1973) and Sazhin (1977). When using this model it is predicted that the considered emissions are excited near the inner boundary of the plasmapause by the electrons in the energy range 2–5 keV, which is compatible with the available experimental data. 相似文献
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A comparative study of simulated air shower longitudinal profiles is presented. An appropriate thinning level for the calculations is first determined empirically. High statistics results are then provided, over a wide energy range (1014.0–1020.5 eV), for proton and iron primaries, using four combinations of the
and
program frameworks, and the SIBYLL and QGSjet high energy hadronic interaction models. These results are compared to existing experimental data. The way in which the first interaction controls Xmax is investigated, as is the distribution of Xmax. 相似文献
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Jackson William M. Xu Dadong Huang Jianhua Price Roosevelt J. Volman David H. 《Earth, Moon, and Planets》2000,89(1-4):197-220
New experimental methods for studying photochemical reactions aregiven and the strength and weakness are briefly discussed. References and bibliographies for these photochemical studies are presented. A case study of carbon disulfide (CS2) that uses vacuum ultraviolet lasers, time-of-flight mass spectrometry, molecular beams and ion velocity imaging to measure andcharacterize the products is described. These results are compared with previous studies and the difficulties involved in understanding these results are pointed out. 相似文献
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A new method of determination of the scattered light intensity, , by a unit-volume of interplanetary space is presented. From ground base Zodiacal Light measurements and the experimental results of Pioneer X the density, ρ(r), and phase functions, σ(ε), are obtained without any previous assumptions about them. 相似文献
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P. Quinet P. Palmeri E. Biémont † M. M. McCurdy G. Rieger E. H. Pinnington M. E. Wickliffe J. E. Lawler 《Monthly notices of the Royal Astronomical Society》1999,307(4):934-940
By a combination of radiative lifetimes measured using the fast-beam-laser method and experimental branching ratios deduced from Fourier transform spectrometer spectra, it has been possible to derive experimental f -values for Lu ii lines observed in the visible and near-ultraviolet regions. These data are compared with relativistic Hartree–Fock calculations, taking core polarization effects into account, and a set of additional oscillator strengths of astrophysical interest is presented. 相似文献
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The operational principles, current experimental status, and astronomical potential of a promising new class of optical photon detector based on superconductors is presented. 相似文献
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P. G. Johnson 《Astrophysics and Space Science》1978,56(2):439-442
The effect of cooling a Westinghouse WL 30677 phosphor output fibre optic image tube has been investigated by both numerical and experimental means. The design of a housing for the image tube is presented. 相似文献
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Charles J. Pellerin Jr. 《Solar physics》1975,41(2):449-458
A detailed study of the charge composition of heavy solar cosmic rays measured in the January 25, 1971 solar flare including differential fluxes for the even charged nuclei from carbon through argon is presented. The measurements are obtained for varying energy intervals for each nuclear species in the energy range from 10 to 35 MeV nucleon?1. In addition, abundances relative to oxygen are computed for all the above nuclei in the single energy interval from 15 to 25 MeV nucleon?1. This interval contains measurements for all of the species and as a result requires no spectral extrapolations. An upper limit for the abundance of calcium nuclei is also presented. These measurements, when combined with other experimental results, enable the energy dependence of abundance measurements as a function of nuclear charge to be discussed. It is seen that at energies above about 10 MeV nucleon?1, the variations of abundance ratios are limited to about a factor of 3 from flare to flare, in spite of large variations in other characteristics of these solar events. 相似文献
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J. Hawreliak J. Colvin J. Eggert D. H. Kalantar H. E. Lorenzana S. Pollaine K. Rosolankova B. A. Remington J. Stölken J. S. Wark 《Astrophysics and Space Science》2007,307(1-3):285-289
X-ray diffraction is a widely used technique for measuring the crystal structure of a compressed material. Recently, short
pulse x-ray sources have been used to measure the crystal structure in-situ while a sample is being dynamically loaded. To
reach the ultra high pressures that are unattainable in static experiments at temperatures lower than using shock techniques,
shockless quasi-isentropic compression is required. Shockless compression has been demonstrated as a successful means of accessing
high pressures. The National Ignition Facility (NIF), which will begin doing high pressure material science in 2010, it should
be possible to reach over 2 TPa quasi-isentropically. This paper outlines how x-ray diffraction could be used to study the
crystal structure in laser driven, shocklessly compressed targets the same way it has been used in shock compressed samples.
A simulation of a shockless laser driven iron is used to generate simulated diffraction signals, and recent experimental results
are presented. 相似文献
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H. L. Xu S. Svanberg R. D. Cowan P.-H. Lefèbvre P. Quinet E. Biémont 《Monthly notices of the Royal Astronomical Society》2003,346(2):433-440
Radiative lifetime measurements were performed with time-resolved laser-induced fluorescence techniques for 24 levels of Nd ii in the energy range 20 500–32 500 cm−1 . For 17 levels, no previous experimental data exist. These results have allowed the testing of new theoretical calculations with the relativistic Hartree–Fock method taking configuration interactions and core-polarization effects into account, and a satisfying agreement has been found for this complex ion. A new set of calculated oscillator strengths, accurate within a few per cent for the strongest transitions, is presented for 107 lines of astrophysical interest appearing in the wavelength range 358.0–1100.0 nm. These results will be useful to evaluate abundance values of neodymium in chemically peculiar stars in relation with cosmochronology. 相似文献
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Zhen Wang Yiqing Guo Hui Cai Jinfan Chang Tianlu Chen Danzengluobu Youliang Feng Qi Gao Quanbu Gou Yingying Guo Chao Hou Hongbo Hu Labaciren Cheng Liu Haijin Li Jia Liu Maoyuan Liu Bingqiang Qiao Xiangli Qian Xiangdong Sheng Zhen Tian Qun Wang Liang Xue Yuhua Yao Shaoru Zhang Xueyao Zhang Yi Zhang 《Experimental Astronomy》2018,45(3):363-377
A scintillation detector array composed of 115 detectors and covering an area of about 20000 m2 was installed at the end of 2016 at the Yangbajing international cosmic ray observatory and has been taking data since then. The array is equipped with electronics from Large High Altitude Air Shower Observatory Square Kilometer Complex Array (LHAASO-KM2A) and, in turn, currently serves as the largest debugging and testing platform for the LHAASO-KM2A. Furthermore, the array was used to study the performance of a wide field-of-view air Cherenkov telescope by providing accurate information on the shower core, direction and energy, etc. This work is mainly dealing with the scintillation detector array. The experimental setup and the offline calibration are described in detail. Then, a thorough comparison between the data and Monte Carlo (MC) simulations is presented and a good agreement is obtained. With the even-odd method, the resolutions of the shower direction and core are measured. Finally, successful observations of the expected Moon’s and Sun’s shadows of cosmic rays (CRs) verify the measured angular resolution. 相似文献
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