The runoff in the upper Yellow River basin above Tangnag has been decreasing recently due to global climate warming and human activity influences since the end of the 1980s. The decrease not only badly affects hydropower and irrigation in the upper Yellow River areas, but also influences the environment of the whole Yellow River basin. Thus, it is necessary for the orderly development and utilization of water resources of the Yellow River basin to understand the future possible change, and the corresponding relationship between global warming with runoff in the upper Yellow River. The long-period evolution law and space-time distribution characteristics of the runoff in the Upper Yellow River are analysed based on data measured at some relational hydrometric and weather observation stations, and a new long-period trend forecast model called the Time Series-Markov Chain Forecast Model, are presented in this paper. The result shows that runoff in the upper Yellow River is located IN a low-flow period that started at the end of the 1980s, and the status will be changed in the future decade. The runoff will gradually increase in the future decade and mean runoff in the future decade will be larger than that in the former decade.
Hierarchically porous Ce/TiO2/graphitic carbon microsphere composites (xCe/TiO2/GCM, where x = 0.2, 1.0, 2.0, 5.0 mmol·L-1) were prepared for the first time by using a simple colloidal crystal template and characterized by X-ray diffraction, nitrogen adsorption and desorption, scanning electron microscopy, and ultraviolet-visible diffuse reflectance spectra. In addition, the photocatalytic activity of CO2 reduction by H2O under simulated solar irradiation was studied. The results showed that the Ce/TiO2/GCM composite material was characterized by large porosity, high concentration of metal compounds and graphitized carbon matrix, and the content of acetone solvent having a great impact on its form. In terms of the photocatalytic CO2 reaction, the CH4 and CO productions were 4.587 and 357.851 μmol·g-1, respectively. The 2Ce/TiO2/GCM photocatalyst gave the highest production rate for three products. Under simulated solar irradiation, the Ce/TiO2/GCM has excellent photocatalytic activity in the photoreduction of CO2 from H2O, which was related to the special composition and the Ce/TiO2/GCM structure.
Two soil sampling transects in Xinghuaying and Putian along the Zhengzhou-Kaifeng highway were chosen in this study,for the analysis of concentration,distribution,accumulation and potential risks of Pb,Cd,Ni,Cu,Zn and Cr in soils.The results showed that the maximum values of Cu,Cr,Cd,Zn and Pb derived from traffic were found from 10 m to 50 m from the highway.The longer the operation time of highway,the higher was the concentration of heavy metals in soils along highway;the higher the vehicle flow,the higher was the accumulation velocity.The orders of mean accumulation velocity and annual changing rate of heavy metals derived from traffic in two transects were Zn Pb Cr Cu Cd and Cd Cr Pb Zn Cu,respectively,and the values were higher in Putian transect than those in Xinghuaying transect.The potential risks of Pb,Cd,Cr and Cu in two transects were positive,with the higher risk of Cd and higher risk in Putian transect than those in Xinghuaying transect.The potential risks of Zn in Xinghuaying transect was negative,which meant soils had been polluted.
Characterization of phosphorus (P) and its risk of loss in urban soils in Kaifeng City, Henan Province were studied through field sampling and laboratory experiments. The spatial distribution of P and the map of risk of loss were obtained using geostatistical and spatial analysis techniques. The P content in urban soils ranged from 400 to 1427 mg·kg-1, the proportions of inorganic P in total P ranged from 65% to 99%, and Olsen-P and CaCl2-P in soils were 3.41-115.03 mg·kg-1 and 0.01-9.40 mg·kg-1, respectively. The composition of P was consistent in different urban areas and P concentrations were higher in residential areas. Spatial variations in P concentrations in soils were significant; the concentrations of P in eastern Kaifeng City were higher than those in western Kaifeng and the highest concentrations were detected in central Kaifeng. Olsen-P can be used as an indicator of the leaching risk of soil P. The critical value of leaching P from the soil was 22.18 mg·kg-1 and the concentration of Olsen-P in 33.64% of urban soil samples exceeded the critical value. The highest risk of P loss existed in central Kaifeng City.
Obtained an indicant used to evaluate the comprehensive quality of normal university students,through doing principal component analysis of 9 original variables.
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