On the background of the scarcity of the earth resources in our country, with the fast development of urbanization and industrilization the demand for the land, especially non-agricultural land increases a lot . As a result, the plowland in a certain region decreases, and the contradiction between man and the land is standing out.
the energy costcalculation of He extraction by vacuum heating degassing during lunar day,the cost calculation ofcryogenic isotopic seperation 3He/ 4He during the lunar night,the energy cost for earth / moontransportation of liquid 3He,the energy payback calculation of fusion power burning 3He based lu-nar source,and finally the comparison of the energy multiplication with that for 253U productionof nuclear fuel and for coal mining.
Secondly,the paper lays emphasis on exposition of disadvantages of territory resources,pointing out that Jiangsu is typical province restricted in resources and that the high tension of relationship between man and earth,the frequent climatic damages and the prominent environmental problems have seriously restricted the regional sustainable development.
Our study indicates that the model can be applied to study the interaction between land surface processes and atmospheric boundary layers over various underlying surfaces and their regional climate effects.
Regularities of wind-erosion of different land-use types in Yongding River sandy land, Beijing
The threshold wind velocity of a number of variables was studied in four different land-use types: farm land, forestland, wild grassland and a flood plain in the Yongding River sandy land in Beijing.
The following conclusions were drawn: 1) The order of decreasing threshold of wind speed for sand displacement and surface roughness were forestland, wild grassland, farm land, sparse wild grassland and flood plain.
At a height of 0-20 cm, the height increased while the sediment discharge percent of sand flux decreased; there were significant differences in the sand flow formation under different land-use types.
We develop methods that give rise to natural monomial bases for such rings over their ground fields and explicitly determine precisely which monomials are zero in the ring of coinvariants.
Direct current magnetic susceptibility measurement in the 2-300 K temperature range supports a high-spin ground state.
Meanwhile, the measurement of water vapor in daytime has been taken, and the profiles of water vapor mixing ratio at ground level have been detected.
Low velocity target detection based on time-frequency image for high frequency ground wave radar
The Doppler spectral broadening resulted from non-stationary movement of target and radio-frequency interference will decrease the veracity of target detection by high frequency ground wave (HFGW) radar.
Exploitation of rare earth catalysts in polymer syntheses
The studies over forty years on rare earth catalysts in polymer syntheses of diene, alkyne, alkylene oxide, thiirane, carbon dioxide copolymerization, lactide, caprolactone, cyclic carbonate and so forth in China have been reviewed.
Synthesis and characterization of rare earth complexes with Phthalaldehyde-lysine Schiff base
The spectra indicate that the energy transfer takes place from the triplet excited state of MLCT (metal-to-ligand charge transfer) state for Sr2CeO4 (sensitizer) to the rare earth ions (activator).
Biological effect of rare-earth lanthanum nitrate on the growth of Escherichia coli B was studied using the calorimetric method.