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1.
The results of the Monte Carlo simulation of the LORD experiment are presented for two types of antenna systems with various parameters. The effect of possible polarization mismatch and galactic noise “percolation” are taken into consideration.  相似文献   

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The inverse problem of reconstructing events in the LORD experiment is considered taking into account fuzzy information on the radiation length of lunar regolith over the lunar surface. It is shown that the solution of the inverse problem allows rather accurate diagnostics of the radiation length at various lunar surface points for a significant number of detected individual events.  相似文献   

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本文以同轴馈电的矩形微带天线作为阵单元,将8个相同的单元天线等间隔分布在一个同心圆面上以组成微带阵天线,并采用等幅但相邻单元间相位差为一常数的方式进行激励。基于三维高频结构电磁模拟软件仿真优化,在中心频率为6GHz处,根据不同的相位延迟得到不同模式的携有轨道角动量的方向图。仿真结论表明,该新颖的微带阵天线能产生携有轨道角动量的螺旋电磁波。  相似文献   

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本文以同轴馈电的矩形微带天线作为阵单元,将8个相同的单元天线等间隔分布在一个同心圆面上以组成微带阵天线,并采用等幅但相邻单元间相位差为一常数的方式进行激励。基于三维高频结构电磁模拟软件仿真优化,在中心频率为6 GHz处,根据不同的相位延迟得到不同模式的携有轨道角动量的方向图。仿真结论表明,该新颖的微带阵天线能产生携有轨道角动量的螺旋电磁波。  相似文献   

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The feasibility of using the lunar orbital radio detector to detect radio signals from cascades initiated by ultra-high-energy cosmic rays interacting with the lunar regolith is studied. Simulation by the Monte Carlo method demonstrates that, with the regolith thickness randomly distributed in the range 2–12 m, the detection of radio signals reflected from the lower boundary of the regolith (for particle energies W ≥ 1020 eV) increases the number of valid events severalfold. The additional contribution due to the reflected radio-frequency radiation greatly enhances the scientific potential of experiments with the lunar orbital radio detector.  相似文献   

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范祖辉 《物理》2005,34(4):240-245
文章对微波背景辐射的各向异性、偏振及宇宙电离的历史给出了评述性介绍.从大爆炸理论的预言,到观测的发现,到其各向异性及偏振的探测,微波背景辐射(CMB)向人们揭示了丰富的宇宙学信息.文章在对基本理论作了简单介绍后,着重讲述了最新的CMB的观测结果及其物理意义.特别对微波背景各向异性探测器(Wilkinson Microwave Anisotropy Probe,WMAP)的偏振观测及其对宇宙重新电离的限制给出了较详细的叙述.  相似文献   

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范祖辉 《物理》2005,34(04):240-245
文章对微波背景辐射的各向异性、偏振及宇宙电离的历史给出了评述性介绍.从大爆炸理论的预言,到观测的发现,到其各向异性及偏振的探测,微波背景辐射(CMB)向人们揭示了丰富的宇宙学信息.文章在对基本理论作了简单介绍后,着重讲述了最新的CMB的观测结果及其物理意义.特别对微波背景各向异性探测器(Wilkinson Microwave Anisotropy Probe, WMAP)的偏振观测及其对宇宙重新电离的限制给出了较详细的叙述.  相似文献   

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Light reflected or transmitted by a planetary atmosphere contains information about particles and molecules in the atmosphere. Therefore, accurate modeling of the radiation field may be used to retrieve information on atmospheric composition. In this paper, a multi-layer model for a vertically inhomogeneous atmosphere is implemented by using the doubling-adding method for a plane-parallel atmosphere. By studying the degree of linear polarization of the transmitted and reflected solar light in the Huggins bands, we find significant differences between tropospheric ozone and stratospheric ozone. The effects of tropospheric ozone change on the linear polarization are 10 times more than that of the same amount of stratospheric ozone change. We also show the aerosol effect on the linear polarization, but this effect is wavelength independent as compared to that caused by the tropospheric ozone change. The results provide a theoretical basis for the retrieval of tropospheric ozone from measurement of linear polarization of the scattered sunlight both from the ground and from a satellite.  相似文献   

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Parity-odd and parity-even correlations in neutron radiative capture are considered. We discuss the correlation mechanisms, their magnitudes, dependence on neutron energy and averaging over the final nuclear states. The total number of correlations when s- and p-wave neutron capture and E1 and M1 γ-transitions are taken into account, is equal to 17 (8 parity odd and 9 parity even). The correlations in the integrated γ-quantum spectrum are divided into three classes which contain information about different properties of the compound nucleus.  相似文献   

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《Physics letters. A》1987,121(4):197-200
Channeling radiation of 900 MeV electrons in (111) diamond planar channels has been investigated using the computer simulation method. Two characteristic maxima have been obtained in the radiation spectra, one of which is due to molecular-type channeling. The polarization characteristics of the channeling radiation from relativistic electrons in the molecular states and quasi-atomic ones are obtained.  相似文献   

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The all-particle energy spectrum of the Primary Cosmic Radiation obtained from the data of GAMMA array (3200 m a.s.l., 700 g/cm2 of atmospheric depth) is presented. The results are obtained by the event-by-event method of the E 0 -energy estimation which is developed using the EAS simulation with use of the software CORSICA and the SIBYLL interaction model with subsequent reconstruction of shower parameters taking into account the response of GAMMA detectors, reconstruction errors, as well as fluctuations of EAS development. By using this method an essential “bump”-shaped irregularity is observed in the all-particle spectrum at primary energies of ~7.4×107 GeV; the bump exceeds a smooth power-law fit to the data by about 4 standard deviations. From the results of studies of the systematic uncertainties of our methods conclusion is made that the observed irregularity has a physical nature rather than is caused by methodical errors. A model explaining this phenomenon is proposed.  相似文献   

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We investigate the importance of quantum orbital fluctuations in the orthorhombic and monoclinic phases of the Mott insulators LaVO(3) and YVO(3). First, we construct ab initio material-specific t(2g) Hubbard models. Then, by using dynamical mean-field theory, we calculate the spectral matrix as a function of temperature. Our Hubbard bands and Mott gaps are in very good agreement with spectroscopy. We show that in orthorhombic LaVO(3), quantum orbital fluctuations are strong and that they are suppressed only in the monoclinic 140 K phase. In YVO(3)the suppression happens already at 300 K. We show that Jahn-Teller and GdFeO3-type distortions are both crucial in determining the type of orbital and magnetic order in the low temperature phases.  相似文献   

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The results of the second stage of the RAMBAS (Radiation Mechanism of Biomolecular Asymmetry) experiment on the study of the radiation mechanism of the effect on chiral molecules are presented. The optical activity of samples containing racemic mixtures of amino acid complexes with heavy metals before and after their irradiation with an electron flux from a radioactive source was compared. It was shown that irradiation leads to asymmetric decomposition of amino acid complexes and amino acids themselves and chiral asymmetry formation. These results confirm the conclusions made in the first stage of the RAMBAS experiment and can be essential for solving the problem of the origin of life and the formation of chiral asymmetry of the biosphere.  相似文献   

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