Results showed that sediment yielded from slope chiefly come from arable land and bare land located at slope,and the quantity of sediment yielded from arable land located at the slope above 25°accounted for about 50% of the total sediment yielded from slope.
Tntensifying Rainfed Agricultural Construction to Promote Rainfed Agricultural Development Checking Rainfall Water and Making it Penetrate into the Ground Where It falls and Highly Effective Use of Technical System
The results obtained from the fixed position experiment on Brown Earth at Shenyang Agricultural University in 1987- 1991 showed that the soil avalable zinc content was greatly different in some fertilization treatments. The content of it in CK and N2 treatments was below 1μgg-1, whereas over 1.22 μgg-1 in the manure-applied treatments.
Through continously all day long observing four different height wind velocity, 0.5 m,1.0 m,1.5 m and 2.0 m, which over bare ground and grassland, the results of statistically analysing lots of data observed show that the best height in determining the earth surface rough degree are 1 5 m and 2.0 m; the best wind velocity range is 4￣6 m/s.
Changes of soil moisture in 0~5 cm layer and concentrations of soil nitrate in 10～20 cm layer in the fallow and the wheat fields were the reasons of the variance of soil N_2O discharge fluxes measured at earth surface by 85.23% and 92.11%, respectively, and thus they can be regarded as the main causes of the increase of soil N_2O discharge fluxes under clear plastic film mulching.
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.