We present a model related to the humidity to describe the conductivity of homogeneous DNA molecule, where the hydration of phosphate group and bases are taken into account. The calculated results show the oscillation...We present a model related to the humidity to describe the conductivity of homogeneous DNA molecule, where the hydration of phosphate group and bases are taken into account. The calculated results show the oscillation feature of dI/dV-V curves and the semiconductor behavior of DNA. With the relative humidity increasing, the voltage gap becomes narrow and the maximum of conductance increases nonlinearly. The conductivity of DNA approaches to stabilization when the relative humidity reaches a certain value. These results are in agreement with experimental measurements.展开更多
In this work the diffusion coefficients of Na+, K+, Ca2+, NO3- and Cl- ions were estimated in terms of measuring apparent direct current (DC) conductivities of latosol, red soil and yellow-brown earth containing, resp...In this work the diffusion coefficients of Na+, K+, Ca2+, NO3- and Cl- ions were estimated in terms of measuring apparent direct current (DC) conductivities of latosol, red soil and yellow-brown earth containing, respectively, NaNO3, KCI, and CaCl2 of different concentrations (0.005, 0.05, 0.10, and 0.15 mol / L) in the case of moisture contents ranging from wet to water saturation. The results showed that when bulk density, moisture content, and electrolyte concentration were constant, the diffusion coefficients of cations were in the order Na+> K+> Ca2+ except for Na+ and K+ in latosol, while the order for anions was NO3- > Cl-. The diffusion coefficients (Di) of cations and anions were linearly proportional to volumetric moisture content (θ) as electrolyte concentration and bulk density were unchanged. When moisture content and bulk density were constant, the diffusion coefficients of cations decreased, to varying extents, with the increase of electrolyte concentration, and the decrement in different soils followed the order yellow-brown earth > red soil > latosol, but the decrement order of different cations was Na+> K+ > Ca2+.展开更多
Time domain reflectometry (TDR) is a highly accurate and automatic method for determination of porous media water content and electrical conductivity. This paper focuses on the basic principle of TDR technology and it...Time domain reflectometry (TDR) is a highly accurate and automatic method for determination of porous media water content and electrical conductivity. This paper focuses on the basic principle of TDR technology and its application in Caijiachuan watershed, the Loess Plateau, China, the composition and structure of a set of TDR-TRIME. The installation, measurement and calibration of TRJME-TDR in the Loess Plateau has been introduced. The factors that can influence the veracity of the measurement by TDR have also been analyzed in the article.展开更多
基金The project supported by National Natural Science Foundation of China under Grant Nos. 60471049 and 60571062 and the Natural Science Foundation of Shandong Province of China under Grant No. Y2004G09.
文摘We present a model related to the humidity to describe the conductivity of homogeneous DNA molecule, where the hydration of phosphate group and bases are taken into account. The calculated results show the oscillation feature of dI/dV-V curves and the semiconductor behavior of DNA. With the relative humidity increasing, the voltage gap becomes narrow and the maximum of conductance increases nonlinearly. The conductivity of DNA approaches to stabilization when the relative humidity reaches a certain value. These results are in agreement with experimental measurements.
文摘In this work the diffusion coefficients of Na+, K+, Ca2+, NO3- and Cl- ions were estimated in terms of measuring apparent direct current (DC) conductivities of latosol, red soil and yellow-brown earth containing, respectively, NaNO3, KCI, and CaCl2 of different concentrations (0.005, 0.05, 0.10, and 0.15 mol / L) in the case of moisture contents ranging from wet to water saturation. The results showed that when bulk density, moisture content, and electrolyte concentration were constant, the diffusion coefficients of cations were in the order Na+> K+> Ca2+ except for Na+ and K+ in latosol, while the order for anions was NO3- > Cl-. The diffusion coefficients (Di) of cations and anions were linearly proportional to volumetric moisture content (θ) as electrolyte concentration and bulk density were unchanged. When moisture content and bulk density were constant, the diffusion coefficients of cations decreased, to varying extents, with the increase of electrolyte concentration, and the decrement in different soils followed the order yellow-brown earth > red soil > latosol, but the decrement order of different cations was Na+> K+ > Ca2+.
文摘Time domain reflectometry (TDR) is a highly accurate and automatic method for determination of porous media water content and electrical conductivity. This paper focuses on the basic principle of TDR technology and its application in Caijiachuan watershed, the Loess Plateau, China, the composition and structure of a set of TDR-TRIME. The installation, measurement and calibration of TRJME-TDR in the Loess Plateau has been introduced. The factors that can influence the veracity of the measurement by TDR have also been analyzed in the article.
