Genetic diversity and population structure of a protected species: Polygala tenuifolia Willd.

Polygala tenuifolia Willd. is an important protected species used in traditional Chinese medicine. In the present study, amplified fragment length polymorphism (AFLP) markers were employed to characterize the genetic diversity in wild and cultivated P.

[An Identification Study on Field-Derived Spectra of Grassland Combustibles and Soil Based on Fractal Theory].

Grassland fire disaster is an important influence factor to grassland ecological system in China. Therefore, it is crucial to study on the monitoring, prediction and management of grassland fire. Remote Sensing (RS) provides detailed data and saves a lot of manpower, material resources and financial resources on the research of grassland fire.

[Analysis on Impact Factors of Thermal Polarized Radiation Characteristics of the Soil].

As an important content of the nature, soil has great influence on the formation of ecological system and human life. Therefore, the study of soil’s polarized thermal radiation characteristics has great practical significance. There have been few reports about the study of the polarized radiation characteristics of the soil in 2π space.

[Study of Retrieving the Sandy Surface Roughness Land Based on the Bidirectional Reflectance Model].

In the semiarid area, the structural nature of sandy land is changed due to wind erosion. Furthermore, assessing the changes in the composition and surface roughness in several spatial and temporal scales is significant for the wind erosion model calculations. As a noninvasive approach, remote sensing can be used to improve the study of sandy surface in time and space.

[Research on the Thermal Infrared Polarization Properties of Fresh Snow].

Snow can directly affect the surface energy balance and climate change and has a significant impact on human life and production. It is therefore of great significance to study the fresh snow emission spectroscopy properties by using the thermal infrared Polarization technique. This can provide a basis for quantitative thermal infrared remote sensing monitoring of snow as well as a deeper understanding of global warming and appropriate countermeasures.

[Study on quality assessment of Polygalae Radix based on HPLC-DAD fingerprint].

Objective: To establish an HPLC fingerprint to evaluate the quality of Polygalae Radix, root xylem, and those collected in different growth ages or harvest time.

Method: Separation was performed at 30 °C on a Kromasil C18 column (4.6 mm x 250 mm, 5 μm); the mobile phases was acetonitrile and 0.

[The research of the relationship between snow properties and the bidirectional polarized reflectance from snow surface].

In the context of remote sensing, the reflectance of snow is a key factor for accurate inversion for snow properties, such as snow grain size, albedo, because of it is influenced by the change of snow properties. The polarized reflectance is a general phenomenon during the reflected progress in natural incident light In this paper, based on the correct measurements for the multiple-angle reflected property of snow field in visible and near infrared wavelength (from 350 to 2,500 nm), the influence of snow grain size and wet snow on the bidirectional polarized property of snow was measured and analyzed. Combining the results measured in the field and previous conclusions confirms that the relation between polarization and snow grain size is obvious in infrared wavelength (at about 1,500 nm), which means the degree of polarization increasing with an increase of snow grain size in the forward scattering direction, it is because the strong absorption of ice near 1,500 nm leads to the single scattering light contributes to the reflection information obtained by the sensor; in other word, the larger grain size, the more absorption accompanying the larger polarization in forward scattering direction; we can illustrate that the change from dry snow to wet snow also influences the polarization property of snow, because of the water on the surface of snow particle adheres the adjacent particles, that means the wet snow grain size is larger than the dry snow grain size.

[Analysis of related factors of slope plant hyperspectral remote sensing].

In the present paper, the slope gradient, aspect, detection zenith angle and plant types were analyzed. In order to strengthen the theoretical discussion, the research was under laboratory condition, and modeled uniform slope for slope plant. Through experiments we found that these factors indeed have influence on plant hyperspectral remote sensing.

[Study on the thermal radiation polarization characteristics of ice].

As an important parameter of the global energy balance, climate, hydrological and ecological model, ice directly affects the energy balance of the earth-atmosphere system, weather and climate. It is of great significance to use the thermal infrared polarization technology to study ice thermal radiation. For the ice monitoring and the impact of global climate change on the ice, studies on ice thermal radiation polarization characteristics were conducted based on the wavelength, detection angle and azimuth angle.

[Autotoxicity of aqueous extracts from plant of cultivated Astragalus membranaceus var. mongholicus].

Objective: To exploring the relationship between continuous cropping obstacle and autotoxicity of Astragalus membranaceus var. mongholicus, autotoxic effect of plant aqueous extract were determined.

Methods: Distilled water (CK), aqueous extract of plant, including root, stem and leaf (12.

[Study on the nonlinear characteristics of the mixed pixel's reflectance in hyperspectral space].

Under the experimental condition of the 50 degree incidence zenith angle and 45 degree detection azimuth, 24 groups of reflectance spectral of the mixed pixel of lotus and water body acquired using the reflex platform and FieldSpec 3 Hi-Res portable spectrum instrument. The hyperspectral space was built based on the reflectance character. The relationship between similarity and the index of lotus area ratio was analyzed using the linear, logarithm and quadratic curve fitting, and the goodness of fitting is 63.

[Studies of the thermal radiation multi-angle polarization properties of snow].

This paper, catering to the need of the study of remote sensing for thermal radiation polarization properties of ground features, detects the thermal radiation multi-angle polarization properties of snow, and makes analysis of effects of four factors, i. e. detecting zenith angle, detecting azimuth angle, bands and polarizing angle, on the thermal radiation properties of snow.

[Analysis of the polarization properties of snow in a different melting state].

Nowdays, under the circumstance of global warming, the traditional study of solid-state snow can not meet the current needs. The present paper involves qualitative analysis of the polarization reflectance spectrum of snow in a different melting state. Special attention is paid to the investigation of the relationship among polarization angles, azimuth angles, the light incidence zenith angles, the detection zenith angles and the different types of snowmelt.

[Study on the thermal infrared polarization characteristics of the grassland withered plants].

With the development of remote sensing technology, it is important to study on the thermal infrared polarization characteristics of the land surface objects. In order to explore the thermal infrared polarization characteristics of the grassland withered plants, the samples of the grassland withered plants were measured indoor according to the thermal infrared polarized detection mechanism, using thermal infrared radiometer. The results showed that the thermal infrared polarized radiance and brightness temperature have increased with the viewing angle and have increased first and then decreased with the azimuth and polarized state.

[Effect of spectral resolution on black soil organic matter content predicting model based on laboratory reflectance].

Laboratory reflectance of Black soil samples was re-sampled with different spectral resolution, and the correlation between soil organic matter (OM) and reflectance, spectral variables was analyzed to study the effect of spectral resolution on black soil OM predicting model. The results are as follows: the spectral response range of black soil OM is between 445 and 1 380 nm, high OM content shades the spectral effect of other soil properties. The precision of black soil OM predicting models increases and decreases with spectral resolution, and the maximum accuracy is at 50 nm, which is wider than hyperspectral resolution, and narrower than the bandwidth of multispectral sensors; with the derivative of logarithmic reflectance reciprocal as input variables, the optimal black soil organic matter predicting model shows high accuracy, with R2 = 0.

[Study on the reflected and hyperspectral mixed-pixel character of aquatic plants and water].

A study on the reflected and hyperspectral mixed-pixel of aquatic plants and water was given by using a orthogonal experimental design with three factors and two levels. The results of F test suggest that for the single factors, the band and the area ratio of mixed-pixel on the reflected and hyperspectral mixed-pixel of the reflection effects are particularly significant, however, the detector angle had no significant effect under these experimental conditions; For the interaction, the band and the area ratio of mixed-pixel, the detector and the area ratio of mixed-pixel, the effects of these two interactions on the reflected and hyperspectral mixed-pixel are also particularly significant, This study did quantitative analysis of the factors affecting the reflected and hyperspectral mixed-pixel character and their interaction, and provided a new method for the indepth study of mixed-pixel.

[Effects of leaf hair on leaf reflectance and hyperspectral vegetation indices].

Many hyperspectral vegetation indices have been used to estimate the biochemical contents such as pigment content, nondestructively. These reflectance indices are influenced by leaf hair, and the existence of the leaf hair affects the performance of the indices on the estimation of the biochemical contents. The present research studied the possible effects of the leaf hair on the reflectance of the same leaf before and after removal of leaf hair.

[Studies of the thermal radiation characteristics of urban typical surface features].

The use of thermal infrared technology to monitor the land surface temperature has received mature development, and the acceleration of urbanization makes the urban heat effect emerge, thus, studies of the thermal radiation characteristics of urban typical surface features make great significance for the analysis of the causes and distribution of the thermal phenomenon. Based on the study of ground measured data of Baoding city, we have found that, the feature types, the observation time and wall orientations are principal factors that exert an influence on the thermal radiation brightness temperature of urban typical surface features. The results show that different types of surface features will significantly affect the brightness temperature, but "different things with the same spectrum" still exists; the observation time has direct impact on the intensity of thermal radiation and to a large extent on the brightness temperature difference of each channel; the brightness temperature of different wall orientations are also different, and the difference changes with the change in observation time.

[Influence of surface roughness on degree of polarization of biotite plagioclase gneiss varying with viewing angle].

Polarized reflectance is influenced by such factors as its physical and chemical properties, the viewing geometry composed of light incident zenith, viewing zenith and viewing azimuth relative to light incidence, surface roughness and texture, surface density, detection wavelengths, polarization phase angle and so on. In the present paper, the influence of surface roughness on the degree of polarization (DOP) of biotite plagioclase gneiss varying with viewing angle was inquired and analyzed quantitatively. The polarized spectra were measured by ASD FS3 spectrometer on the goniometer located in Northeast Normal University.

[Quantitative analysis of the polarized reflection factor of influence of oil film on water surface and their interaction].

In order to extract more reflection characteristic information of oil film on water surface by using remote sensing technology, the authors measured and analyzed the multi-angle hyperspectral polarized reflection information of oil film based on the traditional remote sensing researches. The authors used polarization as the indicator of quantitative study, adopted a three-factor-three-level orthogonal test to analyze the incident angle, oil film thickness, band, and the influence of oil film on water surface from their interaction between each other. The results of variance analysis of this orthogonal test show that: the three factors and their interaction between each other all have an influence on the polarization of oil film; the interaction between incident angle and thickness of oil slick, and the interaction between band and thickness of oil slick both show a significant impact on polarization.

[The multi-angle polarization spectral character of water and its applications in water color remote sensing].

The reflectance of pure water is very low at visible and near infrared bands. Its spectral characteristics are not obvious. Water always shows dark hue in optical remote sensing images.

[Analysis of influencing factors of snow hyperspectral polarized reflections].

Due to the need of snow monitoring and the impact of the global change on the snow, on the basis of the traditional research on snow, starting from the perspective of multi-angle polarized reflectance, we analyzed the influencing factors of snow from the incidence zenith angles, the detection zenith angles, the detection azimuth angles, polarized angles, the density of snow, the degree of pollution, and the background of the undersurface. It was found that these factors affected the spectral reflectance values of the snow, and the effect of some factors on the polarization hyperspectral reflectance observation is more evident than in the vertical observation. Among these influencing factors, the pollution of snow leads to an obvious change in the snow reflectance spectrum curve, while other factors have little effect on the shape of the snow reflectance spectrum curve and mainly impact the reflection ratio of the snow.

[Study on the main influencing factors of mixed-pixel spectral characteristics].

Hyperspectral remote sensing can improve the identification and classification of surface features through the spectrum comparing and matching to achieve classification and recognition. Because of the spatial resolution of the sensor as well as the difference in complexity and diversity on the ground, mixed pixels in the image are prevalent in remote sensing. The problem of subpixel unmixing is a prominent issue in the quantitative application of remote sensing.

[Study on the modeling of hyperspectral polarized reflection of clove lamina with chlorophyll content].

In the present study, the authors detected clove laminas in different states with multi-angle hyperspectral polarized reflections and measured their chlorophyll content at the same time. The authors analyzed hyperspectral polarized reflections of clove laminas from various viewing zenith angles, incidence angles, the relative azimuth angles, polarized states and chlorophyll content. The authors calculated quantitatively clove laminas in different states with multi-angle hyperspectral polarized reflection by USB2000, bidirectional polarized reflectance and polarized equipment, and built the regression models of polarized information-chlorophyll content.