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1.
The spectrum of the maximum values of the variable component of the radio source J0157+7442 is presented. The flux densities
obtained on the RATAN-600 radio telescope at centimeter wavelengths in 2009 and 2010 are minimum for all observations of the
source, and it was assumed that the variable component was absent in these years. After subtracting these RATAN-600 data from
the upper envelope of all available flux density data, the spectrum of the variable component was obtained. The form of the
spectrum of the variable component is typical of a nonuniform, spherically symmetric source with synchrotron self-absorption. 相似文献
2.
Yu. V. Balabin É. V. Vashenyuk O. V. Mingalev A. I. Podgorny I. M. Podgorny 《Astronomy Reports》2005,49(10):837-846
Analysis of the relativistic proton spectra of solar flares occurring in the 23rd solar activity cycle derived from data of a worldwide neutron monitor network and numerical modeling both provide evidence for the acceleration of charged particles by an electric field that arises in coronal current sheets during reconnection. The method used to obtain the spectra is based on simulating the response of a neutron monitor to an anisotropic flux of relativistic solar protons with specified parameters and determining the characteristics of the primary relativistic solar protons by fitting model responses to the observations. Studies of the dynamics of the energy spectra distinguish two populations of relativistic protons in solar cosmic-ray events: the so-called fast component, which arrives at the flux front of the solar cosmic rays, followed by the delayed slow component. The fast component is characterized by strong anisotropy and an exponential energy spectrum, in agreement with the spectrum yielded by mathematical modeling of particle acceleration by an electric field directed along the X line of the magnetic field. The slow component, whose propagation is probably diffusive, has a power-law spectrum. 相似文献
3.
Simultaneous observations on the RATAN-600 radio telescope at 0.97, 2.3, 3.9, 7.7, 11.1, and 21.7 GHz during the period from January 3 to February 25, 1998, revealed variability of 0524+034 on time scales not exceeding 10 days. The variations are correlated at all frequencies where the parameters of the variability could be determined, including in the optically thick part of the spectrum. The mean spectrum of the variable component was derived and is in agreement with the spectrum of a homogeneous, spherically symmetrical source. In the optically thin part of the spectrum, the spectral index of the variable component is α=?0.2, reflecting the initial energy distribution of the relativistic electrons. It is argued that the variable emission is associated with the acceleration of electrons and amplification of the magnetic field and that adiabatic expansion can be neglected. It is proposed that the observed variability is due to illumination of inhomogeneities in the jet by a shock front passing through them and that the light curve reflects the distribution and characteristic sizes of these inhomogeneities (0.14–0.5 pc for angles to the line of sight not exceeding 10°, Lorentz factor γ=10, and adopted redshift z=0.5). In 0524+034, in addition to the rapidly variable component, there are two slowly varying components, one of which has α=?0.7 in the optically thin part of the spectrum. 相似文献
4.
July temperatures for the past 6000 yr at 11 sites in northern Canada have been predicted by transfer-function equations. Normalized departures from the mean of each time series at 250-yr intervals are analyzed by principal component (eigenvector) analysis. An initial analysis included 9 sites and the first three principal components accounted for 85.7% of the variance. Maps of the loadings on the principal components show broad spatial coherence on all three components. Temporal coefficients (principal component scores) illustrate major regional and local midsummer temperature variations. An additional 2 sites were then included but the spatial pattern of the loadings remained essentially unchanged. A further test of this approach, with a view toward predicting paleoclimates of northern regions, was to use the spatial coefficients (loadings) to estimate the July temperature departures at an “unknown” site (Long Lake, Keewatin). This reconstruction compares favorably with an independent transfer-function reconstruction (Kay, 1979). Power spectrum analysis of the significant principal component scores (temperature departures) over the 6000 yr showed that the temporal fluctuations associated with the first three principal components follow a “red noise” spectrum, indicative of strong persistence in the reconstructed climatic records. The scores on the fourth principal component approximate a “white noise” spectrum. A peak in power between 2000 and 3000 yr occurs in the variance spectrum of the second principal component (significance 10%). We conclude that eigenvector analysis of Holocene paleoclimatic data has considerable power and may be useful for identifying regional and local climatic variations. 相似文献
5.
We have studied the brightness and color variations of the symbiotic nova HM Sge based on longterm UBVRJHKLM photometry of the star and data on its energy distribution in the middle infrared (7.7–22.7 µm) obtained with the low-resolution spectrometers of the IRAS satellite and ISO orbital observatory. We have also calculated models for the steady-state, spherically symmetrical, extended dust envelope of the star for two extreme heating cases: heating only by radiation from the cool component of the system and by the combined radiation from both components. Model fitting to the IRAS and ISO data indicates that models with a single, central Mira-type source are more appropriate. This indicates that the radiation of the hot component is largely processed by the surrounding gas, and does not substantially affect the infrared spectrum of the symbiotic nova directly. The mean spectral energy distribution based on 1983 IRAS data differs appreciably from the ISO spectrum obtained on October 1, 1996. The observed evolution of the envelope spectrum probably reflects an increase of the density and decrease of the temperature of the dust grains near the inner boundary of the envelope, related to a decrease of the luminosity and increase of the temperature of the hot component. We estimate the total mass-loss rate, velocity of gas expansion at the outer envelope boundary, and upper limit for the mass of the central source of radiation. 相似文献
6.
Brightness and color variations of V1016 Cyg are studied using many years of UBVRJHKLM photometric observations and information about its spectral energy distribution in the intermediate IR (7.7 to 22.7 µm) obtained with the IRAS and ISO low-resolution spectrometers. Models for its stationary, spherically symmetrical, extended dust envelope are computed for two cases of heating: by the radiation of the cool component only and by the combined radiation from both components. Model fitting of the IRAS and ISO observations shows that the model with a single central source—the Mira star—provides a better fit to the data, indicating that the hot component’s radiation is appreciably reprocessed by the ambient gas medium and has almost no direct influence on the IR spectrum of the symbiotic nova. The mean spectral energy distributions measured by IRAS in 1983 and ISO on October 1, 1996, differ considerably. The observed evolution of the envelope’s spectrum probably reflects an increasing grain concentration and decreasing grain temperature at the inner edge of the envelope, associated with decreased luminosity and increased temperature of the hot component. The total mass-loss rate, gas-expansion velocity at the outer edge of the envelope, and upper limit to the mass of the central radiation source are estimated. 相似文献
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8.
The gravity solid tide signal includes daily wave, half-day wave and annual wave and moon wave harmonic component, but the energy of day wave and half-day wave component is relatively strong, and the energy of annual wave and moon wave component is relatively weak. In order to effectively extract these harmonic components with large energy differences and reveal the modulation relationship between them, according to the cause of gravity tide, a gravity solid tide signal decomposition model is used to compare the tidal harmonic components with different strengths. The form of the independent component is decomposed into different orthogonal directions. At the same time, a new optimization algorithm is used to improve the independent component analysis algorithm and separate the independent components of different orthogonal directions. In the spectral correlation analysis of the components of independent components, the autocorrelation operation will make the strong component stronger and the weak component weaker. For this problem, the cross-correlation spectrum between independent components is used to reveal the gravity tide signal., the modulation relationship between harmonic components. The experimental results show that the proposed algorithm not only effectively separates the independent components with large intensity difference in the gravity tide signal from the perspective of additive decomposition, but also reveals the multiplicative modulation relationship between the corresponding tidal harmonics based on the cross-correlation spectrum. 相似文献
9.
根据光学成像原理和地形结构的分形特征,提出了遥感图像的地形结构-岩性组分模型和分离算法,并用于ETM图像分解和岩类α-f(α)多重分形特征研究。通过对不同地区二长花岗岩体和沉积变质岩ETM原图像、地形结构子图像和岩性组分子图像的多重分形谱对比分析,发现原始ETM图像的多重分形谱与岩石类型和地形没有明显的对应关系。图像分解后,不同地区的二长花岗岩具有十分相似的岩性组分多重分形谱和不同的地形结构多重分形谱;相反,同一地区的不同类型岩石具有相似的地形结构多重分形谱和不同的岩性组分多重分形谱。因此,利用地形结构-岩性组分分类算法,并结合α-f(α)多重分形谱分形,可以有效地区分岩石类型。 相似文献
10.
Interplanetary-scintillation observations of the radio source B0531+194 (J0534+1927) obtained over a wide range of elongations at 111 MHz using the Big Scanning Antenna of the Lebedev Physical Institute are presented. Near the Sun, the temporal spectra of the scintillations have a two-component form, corresponding to the superposition of refractive and diffractive scintillations that is characteristic of the saturated regime. A method for estimating the angular size of the scintillating component based on measurement of the break frequency in the diffractive part of the scintillation spectrum is presented. The scintillating component as a fraction of the total flux can be determined using the maximum scintillation index. The angular size of the scintillating component in B0531+194 is found to be 0.24″ ± 0.05″, and the ratio of the fluxes in the core and halo to be roughly one-third. The flux density in the compact radio component is 5 Jy. The estimated parameters of the angular structure of the source are compared with observations at other frequencies. 相似文献
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The release kinetics of Xe of the isotopically normal component of noble gases (P3 component) from the coarse-grained fraction of nanodiamonds from the Orgueil (CI) meteorite and the kinetics of 4He release from lunar soil were studied by means of a numerical simulation. It is demonstrated that the release of these gases as a peak with a single pronounced maximum may not correspond to the diffusion model with a single activation energy and can in fact be controlled by a spectrum of activation energies with a number of peaks a number of peaks remaining unresolved at stepped pyrolysis. In particular, the amount of Xe-P3 preserved in nanodiamonds during thermal metamorphism of the Orgueil meteorite calculated using parameters of the diffusion process (activation energy and frequency factor) that were determined in the model with a single activation energy indicates that practically all Xe should be lost during a very short time. These losses are inconsistent with both the duration of thermal metamorphism of the meteorite parent bodies and the Xe-P3 concentrations measured in these meteorites. A much higher preservation of Xe-P3 during thermal metamorphism lasting for hundreds of years follows from calculations based on diffusion with a spectrum of activation energiesa for Xe release. The results of isothermal pyrolysis of a nanodiamonds fraction from Orgueil confirms a presence of several activation energies for Xe-P3 release from the nanodiamonds. The application of the diffusion model with a spectrum of activation energies to He release from lunar soil samples also shows that He can be retained in these samples at 20°C during a much longer time than it follows from the model with a single activation energy (Anufriev, 2010). 相似文献
14.
Naoya Suzuki Naoto Ebuchi Chaofang Zhao Isao Watabe Yasuhiro Sugimori 《Journal of Earth System Science》2002,111(3):305-313
Relationship between the non-dimensional roughness length and inverse of wave age has been discussed without consideration
of wave directions, though wind wave field consists of various directional component waves. In this study we observe wave
heights by an array of four wave gauges at the Hiratsuka Tower of (Independent Administrative Institution) National Research
Institute for Earth Science and Disaster Prevention (NIED), Japan, and discuss the effect of wave directionality. As a result,
the data sets were classified into two different groups according to the directional wave spectrum distribution. In case 1
only swell and wind waves exist and in case 2 there exist wave components from several directions. It is shown that the case
of multiple-directional component waves (case 2) may affect the non-dimensional roughness length and friction velocity. 相似文献
15.
为提高多种典型人工神经网络应用于降水预报的精度与稳定性并做出优选,对太湖流域湖西区丹徒、丹阳、金坛、溧阳、宜兴5站的年降水量时间序列建立基于组成成分分析的人工神经网络模型,并通过平均相对误差、平均绝对误差、均方根误差及合格率4项评价指标对比分析预报效果。该模型采用Mann-Kendall法、秩和检验法、谱分析法进行组成成分分析;建立BP网络、小波神经网络、RBF网络、GRNN网络及Elman网络模拟并预测随机成分,与确定性成分叠加得年降水量预报结果。在湖西区的研究结果表明,基于组成成分分析的人工神经网络模型的拟合及预测精度高于原始人工神经网络和线性自回归模型,GRNN网络的预测精度与稳定性高于其他4类神经网络。 相似文献
16.
缅甸 Mong Hsu 红宝石的颜色成因 总被引：1，自引：1，他引：0
摘 要 Mong Hsu 红宝石原石具有独特的暗蓝至紫色的核心色带即黑心。这种黑心可以借
助热处理法加以去除从而改善其颜色。通过对 Mong Hsu 红宝石化学成分及可见光谱的研
究阐明了其颜色成因与化学成分的关系分析了蓝紫色调的形成机理这些均为红宝石的
热处理提供了理论依据。 相似文献
17.
广西金牙金矿床的有机地球化学特征 总被引：5，自引：0，他引：5
从矿石和围岩可溶有机质的生物标志化合物,非烃的红外光谱学特征,以及有机包裹体的光学和谱学特征等方面论述了金牙金矿的有机地球化学特征及其有机流体的成矿作用,查明了参与成矿的有机质主要来源于菌藻类等低等生物,本有机质的成分、结构、成熟度和胡成矿作用的进行而不断演化。在有机碳、金含量及藻类成矿作用模拟实验的分析基础上,认为流体有机质参与成矿的方式主要是活化萃取、还原沉淀,而干酪根则对金起集作用。 相似文献
18.
小波时频能量谱是在小波变换时频分析基础上 ,计算小波频谱能量。将小波变换时频能量谱技术与层序地层学理论相结合 ,以寻找不同类型沉积旋回与小波能量谱之间的对应关系 ,为地震层序的划分以及沉积相分析提供理论依据。通过对理论模型和实际资料的计算表明 ,小波时频能量谱方法分析研究沉积旋回体是可行的 ,可揭示地下沉积旋回体相关信息 ,有利于研究沉积旋回体的内部结构和物质成分的分布 相似文献
19.
High resolution observations in the region of the Hα, HeII λ 4686, and Hγ lines in the spectrum of the symbiotic binary Z
And were performed during a small-amplitude flare at the end of 2002. The profiles of the hydrogen lines were double-peaked,
and suggest that the lines may be emitted mainly by an optically thin accretion disk. Since the Hα line is strongly contaminated
by emission from the envelope, the Hγ line is used to investigate the properties of the accretion disk. The Hα line has broad
wings, believed to be determined mostly by radiation damping, although the high-velocity stellar wind from the compact object
in the system may also contribute. The Hγ line has a broad emission component, assumed to be emitted mainly from the inner
part of the accretion disk. The HeIIλ 4686 line also has a broad emission component, but is believed to arise in a region
of high-velocity stellar wind. The outer radius of the accretion disk can be calculated from the shift between the peaks.
Assuming that the orbital inclination can range from 47° to 76°, we estimate the outer radius to be 20–50 R⨀. The behavior of the observed lines can be interpreted in the model proposed for the line spectrum during the first large
2000–2002 flare of this binary. 相似文献
20.
"三联式"资源定量预测与评价--数字找矿理论与实践探讨 总被引：42，自引：4，他引：38
随着信息技术的发展,矿产勘查已步入数字化,定量化研究的新阶段。“三联式”成矿预测及资源评价途径正是“数字找矿”的创新探索。“三联式”成矿预测以地质异常分析为基础,以成矿多样性分析与矿床谱系研究为指导,将地质异常,成矿多样性及矿床谱系三方面定量化研究紧密结合形成矿产预测及定量评价的有机切入点,是实现全面数字找矿的必由之路,也是矿产勘查评价领域应用信息技术的基础和前提。 相似文献