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Guan H.,Ningxia University | Jia K.,Ningxia University | Jia K.,Ningxia Key Laboratory of Intelligent Sensing for Desert Information | Zhang Z.,Ningxia University
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2014

In the present study, Pingluo of Ningxia Province in China was taken as the study area, and spectral data obtained by Unispec-SC, the value of soil salt content measured by experiment were taken as the basic data. Hyper-spectral data processing method was used to analyze spectral characteristics of different levels of salinization area vegetation. Spectral data were transformed in 16 different approaches, including logarithm, root mean squares, and first order differentiation. Correlation analysis was carried out between the obtained spectra and soil salinity. The most sensitive bands was selected, soil index and vegetation index were built. Nonlinear regression was employed to establish soil salinization remote sensing monitoring model. The results show that by comparing various spectral transformations, the first order differential of soil spectral was the most sensitive to soil salinization degrees. The model was based on the spectral index, including SI and MSAVI, and it could monitor soil salinization accurately. The correlation between simulated values and measured values was 0.758 9. The soil salinization could be achieved rapidly in the area. ©, 2014, Chinese Society of Astronautics. All right reserved. Source

Feng C.-J.,Ningxia University | Wang P.,Ningxia University | Wang P.,Beifang University of Nationalities | Wang X.-M.,Ningxia University | Wang X.-M.,Ningxia Key Laboratory of Intelligent Sensing for Desert Information
Wuli Xuebao/Acta Physica Sinica | Year: 2015

Human behaviors are usually determined by some social and/or economic trend. In the past few years, many attempts have been made, in the field of complex scientific systems, to describe the dynamics of these behaviors quantitatively and have an accurate understanding of the corresponding mechanisms. In this paper, a generalized potential, that is, a migration desire function defined by the age of the migrating people, the migrating distance, and the so-called economic-population density of the emigration area, is proposed. It can be transformed into Hamilton-Jacobi equation by using a random dynamical method, Langevin equation, so that the decision-making behavior can be investigated, based on a statistic framework during a group migration process. By taking use of the multi-dimensional steepest descent method, the Hamilton-Jacobi equation is solved; the solution shows that the information entropy of the system varies, leading by a single peak, as the age of the migrating people increases. It also demonstrates that the second derivative of the migrating distance to the information entropy has a change of zero-crossing (which actually means a phase change). The third characteristic of the solution is that the information entropy follows another single peak as the economicpopulation density increases. A deeper analysis reveals the significance behind these findings and the corresponding mechanisms. So some new understandings of the group human behaviors can be obtained, and some worthy references can be provided for some related administrative offices. © 2015 Chinese Physical Society. Source

Lin X.-L.,Ningxia University | Lin X.-L.,Ningxia Key Laboratory of Intelligent Sensing for Desert Information | Pan F.-C.,Ningxia University | Pan F.-C.,Ningxia Key Laboratory of Intelligent Sensing for Desert Information
Journal of Superconductivity and Novel Magnetism | Year: 2014

In the field of a diluted magnetic semiconductor, a nontransition metal doped semiconductor or oxide is a way to avoid the ferromagnetic clusters of secondary phase. Since there is no d electron in such system, the origin of magnetism is a surprise. In this article, first-principles calculations were used to investigate the origin of magnetism in Al doped 4H-SiC. It is found that a hole was introduced into the SiC:Al system, which is located on one C atom adjacent to the Si vacancy. A neutral Si vacancy with a substituting Al lead to the formation of a net moment less than 1.0μ B, while the Al itself has no contribution to the magnetic moment, but plays a key role to form them. The coupling between such local moments is paramagnetic. © 2013 Springer Science+Business Media New York. Source

Jia K.-L.,Ningxia University | Jia K.-L.,Ningxia Key Laboratory of Intelligent Sensing for Desert Information | Zhang J.-H.,Ningxia University
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2014

The relationship between alkalinity and pH of the soil, reflectance spectra and red-edge parameters of the sunflower canopy in different growth periods under different alkalinity soil were analyzed, respectively. The results showed that the spectral reflectance of the sunflower canopy in different stage under different alkalinity soil is the same as the spectral reflectance characters of the other greenery canopy. Along with the advancement of the sunflower growth period, sunflower canopy spectral reflectance increases gradually at different stages, the spectral reflectance is higher at flowering stage than 7-leaf stage and budding stage, and there exists a high reflection peak at 809nm at flowering period. At the same time, the spectral reflectance is affected by salinity-alkalinity stress at different stages, in the near infrared shortwave band, the spectral reflectance of the sunflower canopy in different stage increases with the decreases in soil alkalinity. When the derivatives are applied to determine the wavelength of the red-edge, there is a shift phenomenon of the red edge. The red edges were at 702~720 nm during every growth period of the sunflower. The "blue shift" phenomenon is also emerged for red edge position and red edge sloped with the increase in the soil alkalinity. Conversely, at the same growth periods, the red edge positions and red edge slope move to longer wave bands with the decrease in soil alkalinity. There is a "red shift" phenomenon before flowering period and "blue shift" phenomenon after flowering period for the red edge position and red edge slope of canopy spectrum at the same soil alkalinity. Respectively. The red edges at different growth stages of the sunflower show very significant positive correlation and quadratic polynomial to alkalinity and pH of the soil. Therefore, we thought used the red edge features of greenery could indicate the soil alkalization degree, it providing scientific basis for monitoring soil alkalization degree by remote sensing. Source

Huo J.,Ningxia University | Huo J.,Ningxia Key Laboratory of Intelligent Sensing for Desert Information | Wang X.-M.,Ningxia University | Wang X.-M.,Ningxia Key Laboratory of Intelligent Sensing for Desert Information | And 4 more authors.
Physica A: Statistical Mechanics and its Applications | Year: 2016

Population migration typically occurs under some constraints, which can deeply affect the structure of a society and some other related aspects. Therefore, it is critical to investigate the characteristics of population migration. Data from the China Statistical Yearbook indicate that the regional gross domestic product per capita relates to the population size via a linear or power-law relation. In addition, the distribution of population migration sizes or relative migration strength introduced here is dominated by a shifted power-law relation. To reveal the mechanism that creates the aforementioned distributions, a dynamic model is proposed based on the population migration rule that migration is facilitated by higher financial gains and abated by fewer employment opportunities at the destination, considering the migration cost as a function of the migration distance. The calculated results indicate that the distribution of the relative migration strength is governed by a shifted power-law relation, and that the distribution of migration distances is dominated by a truncated power-law relation. These results suggest the use of a power-law to fit a distribution may be not always suitable. Additionally, from the modeling framework, one can infer that it is the randomness and determinacy that jointly create the scaling characteristics of the distributions. The calculation also demonstrates that the network formed by active nodes, representing the immigration and emigration regions, usually evolves from an ordered state with a non-uniform structure to a disordered state with a uniform structure, which is evidenced by the increasing structural entropy. © 2016 Elsevier B.V. All rights reserved. Source

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