【Result】The soil water storage was 600 mm in the 0-200 cm soil profile of fallowing plots in the summer of 364 mm precipitation(including 82 mm of irrigation). It was 204 mm more than that before seeding,and 39 mm more than that of maize-planting plots.
The results showed that the average concentration of Al 3+ in throughfall (0.393 3 mg·L -1 ) was slightly higher than that in precipitation (0.329 mg·L -1 ). The average concentrations of Al 3+ soil solutions were much higher than in precipitation and were about 4.7 times and 3.8 times higher in soil water collected at 30 cm depth and runoff, respectively.
The water lost through sur face flow and infiltration out of the net precipitation(including throughfall and stemflow)accounted for3.0%and23.0%of the annual precipitation respectively.
The precipitation (cluster 1, cluster 2 and cluster 3)controlled by north flows including northeast monsoon flow and frontal system flow was strongly acidic and was caused by pollutants during long distance transportation. cluster 4, cluster 5 and cluster 6 that had a relatively high ion concentration were mainly polluted by source of close quarters.
(2)fluid inclusions in the core came from magmatic water(δ 18 O H 2O =4.7‰～6.2‰) and these in the rim belong to atmospheric water(δ 18 O H 2O =-6.1‰～-8.4‰);
Temperature is dominant factor for carbon absorption and is quantitative with standard regression coefficient between NEP and temperature and precipitation.
The amounts of annual fog throughfall plus fog interception accounted for 16.4%±1.0% of total annual precipitation which includes fog throughfall, fog interception and rainfall.
The water-soluble glucan was obtained from Pleurotus florida fruit bodies by hot water extraction, ethanol precipitation, DEAE cellulose dialysis and Sephadex G-75 gel filtration.
Preparation and characterization of nanocrystalline ZnO by direct precipitation method
Nanocrystalline ZnO was prepared with ZnCl2·2H2O and (NH4)2CO3 as raw materials by direct precipitation method.
The ion-exchanger LiAlTiO4 of spinel type was prepared by the common precipitation/hydrothermal crystallization method, and was acid-modified.
The precursors of Fe2O3-SiO2 mixed oxides prepared through co-precipitation method were modified by microwave hydrothermal treatment for the first time.
The analysis of summer rainfall intensity in China is carried on for the purpose of practical application of climatic data to the natural resources development. It contains three main parts: 1) a brief survey of the distribution of mean intensity of rain in summer months; 2) an investigation of the record maxima of rainfall intensity at different stations in respective geographical regions; 3) a statistical analysis of the time variations of yearly maximum intensities at 12 representative stations and a calculation...
The analysis of summer rainfall intensity in China is carried on for the purpose of practical application of climatic data to the natural resources development. It contains three main parts: 1) a brief survey of the distribution of mean intensity of rain in summer months; 2) an investigation of the record maxima of rainfall intensity at different stations in respective geographical regions; 3) a statistical analysis of the time variations of yearly maximum intensities at 12 representative stations and a calculation of expected values of daily rainfall intensity for different ranges of time period.
Since the beginning of the last half century, the science of hydrology through successive steps of development has advanced to the realm of quantitative analysis. Engineers employed empirical methods to compute river discharges from precipitation data in answer to the ever-increasing demands made upon hydrologic analyses for engineering works. Yet for the phenomena of conflux of flows from precipitations, there exist only meager and fragmental quantitative analyses, without, so far, a systematic study of their...
Since the beginning of the last half century, the science of hydrology through successive steps of development has advanced to the realm of quantitative analysis. Engineers employed empirical methods to compute river discharges from precipitation data in answer to the ever-increasing demands made upon hydrologic analyses for engineering works. Yet for the phenomena of conflux of flows from precipitations, there exist only meager and fragmental quantitative analyses, without, so far, a systematic study of their underlying theories recorded in literature. On account of this, the progress of hydrology in respect to theory as well as to prac- tice has been retarded. By means of hydrodynamic analysis, the author has tentatively made an approach to the establishment of such a scheme of theories, in which he divided the rainfall-runoff phenomena into three parts for separate analyses, i. e., the occurrence of runoff due to rainfall at a surface point, the surface flow, and. the conflux of channel flows. This paper is devoted to the first part, which is, in essence, an analysis of the basic hydrologic phenomena. The theories thus established may be used as a guide for various hydrologic analyses in practice, may be based upon to examine the validity of various methods of hydrologic calculations, and may be further used to develop an approximate yet rational method for computing discharges from precipitation data. In this paper, the author proposes a scheme of underlying theories for analyzing the hydrograph of surface flow due to rainfall at a point, in which the essence of basic hydrologic phenomena is revealed, and this is accompanied with calculations of an example. In the earlier years, R. E. Horton established a theory of correlations of rainfall and runoff from small drainage basins by analyzing the data of Homer's sprinkler experiments. Thereafter, researchers basing upon his theories and methods analyzed the relations between rainfall and runoff by sprinkler experiments or data from natural areas. On account of the fact that Horton's analysis does not begin with an accurate hydrodynamical viewpoint, problems are bound to arise in practice due to defects in the underlying theories. Shortcomings of Homer's analysis on the basis of the author's theories are pointed out and the practical value of sprinkler experiments estimated. A method proposed by E. V. Bodakoff for computing discharges due to storms on small basins has raised wide discussions among the Soviet scholars, many of whom hold different views. The author hereby points out the main shortcomings of Bodakoff's method, and gives a numerical example with results compared with those computed by the author's method, thus showing the limitations of Bodakoff's method in practical applications.
This is a brief report of a preliminary survey of certain rain-bearing systems over China in later spring and summer. In the first part, a general description of the methods of analysis used in this survey is given. As the temperature and wind fields are weak, and the precipitation is heavy, smaller intervals for the isotherms and contours in the constant pressure surface and pseudo-equivalent potential instead of potential temperature in the cross section analysis are used.In the second part, there are descriptions...
This is a brief report of a preliminary survey of certain rain-bearing systems over China in later spring and summer. In the first part, a general description of the methods of analysis used in this survey is given. As the temperature and wind fields are weak, and the precipitation is heavy, smaller intervals for the isotherms and contours in the constant pressure surface and pseudo-equivalent potential instead of potential temperature in the cross section analysis are used.In the second part, there are descriptions of the structure and development of five frequently observed rain-bearing systems i.e. cold front, blocking high and cold vortex, monsoon heat low, warm front and typhoon.The last part consists of discussions of some points of view in synoptic meteorology in China. It is stated that the monsoon precipitation is various in intensity and duration according the large-scale flow patterns. The difference of moisture content in the middle troposphere as a criterion for the identification of equatorial or tropical maritime air mass is proved to be missleading. It is shown that the upper air moist content is high only within the raining region near the polar or equatorial front. To the south of the equatorial front within the so-called equatorial air mass, the moist content in the middle troposphere is as low as within the tropical maritime air mass. It is the convergence and lifting of the tropical air mass which releases the convective instability and induces the surface moist air rising to the middle troposphere. The phenomenon of the forward-inclination of the so-called North-West Trough based on the time cross-section of wind is proved to be a mistake by combining two systems into one trough. The terminology of shear line, and the correct application of synoptic models in weather analysis and forecas-ting are also discussed.
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