Ionization of Atoms and the Thomas－Fermi Model for the Electric Field in Crystal Planar Channels

The electric field in the crystal planar channels is studied by the Thomas-Fermi method. The Thomas-Fermi equation and the corresponding boundary conditions are derived for the crystal planar channels. The numerical solution for the electric field in the channels between (110) planes of the single crystal silicon and the critical angles of channelling protons in them arc shown. Reasonable agreements with the experimental data are obtained. The results show that the Thomas-Fermi method for the crystal works well in this study, and a microscopic research of the channel electric field with the contribution of all atoms and the atomic ionization being taken into account is practical.

Influence of the channel electric field distribution on the polarization Coulomb field scattering in In_(0.18) Al_(0.82) N/AlN/GaN heterostructure field-effect transistors

By making use of the quasi-two-dimensional （quasi-2D） model, the current-voltage （l-V） characteristics of In0AsA10.82N/A1N/GaN heterostructure field-effect transistors （HFETs） with different gate lengths are simulated based on the measured capacitance-voltage （C-V） characteristics and I-V characteristics. By analyzing the variation of the electron mobility for the two-dimensional electron gas （2DEG） with electric field, it is found that the different polarization charge distributions generated by the different channel electric field distributions can result in different polarization Coulomb field scatterings. The difference between the electron mobilities primarily caused by the polarization Coulomb field scatterings can reach up to 1522.9 cm2/V.s for the prepared In0.38AI0.82N/A1N/GaN HFETs. In addition, when the 2DEG sheet density is modulated by the drain-source bias, the electron mobility presents a peak with the variation of the 2DEG sheet density, the gate length is smaller, and the 2DEG sheet density corresponding to the peak point is higher.

Effect of electronic stimulation at Neiguan(PC 6) acupoint on gene expression of adenosine triphosphate-sensitive potassium channel and protein kinases in rats with myocardial ischemia

OBJECTIVE:To investigate the effects of electronic stimulation at acupoints Neiguan(PC 6) and Lieque(LU 7) on the gene expression of the adenosine triphosphate(ATP)-Sensitive potassium channel(KATP:Kir6.1,Kir6.2,SUR2 A,and SUR2B) and protein kinases(PKA,PKG,and PKCβ2) in myocardial cells of rats with myocardial ischemia(Ml) induced by isoproterenol(ISO).METHODS:Rats were randomly divided into a control,model,Neiguan(PC 6),Lieque(LU 7),and non-acupoint groups.The Ml model was established by injecting rats with ISO.Electro-acupuncture treatment was given to the acupuncture groups,once a day for 7 days.Gene expression was analyzed with real-time PCR.RESULTS:The gene expression of KATP and protein kinases in the model group was higher than those in the control group(P < 0.05).After acupuncture treatment,the KATP and protein kinase expression levels were significantly lower in the Neiguan(PC 6)and Lieque(LU 7) groups compared with the model group[P < 0.05).The Neiguan(PC 6) group lowered these levels significantly more than that of the Lieque(LU 7) group(P < 0.05).No significant differences were observed between the model and non-acupoint groups(P > 0.05).CONCLUSION:Our findings suggest that electronic needling of Neiguan(PC 6) can both reduce the gene expression of KATP and protein kinases in rats with ISO-induced Ml.

The influence of the channel electric field distribution on the polarization Coulomb field scattering in AlN/GaN heterostructure field-effect transistors

Based on the measured capacitance–voltage（C–V） curves and current–voltage（I–V） curves for the prepared differently-sized AlN/GaN heterostructure field-effect transistors（HFETs）, the I–V characteristics of the AlN/GaN HFETs were simulated using the quasi-two-dimensional（quasi-2D） model. By analyzing the variation in the electron mobility for the two-dimensional electron gas（2DEG） with the channel electric field, it is found that the different polarization charge distribution generated by the different channel electric field distribution can result in different polarization Coulomb field（PCF） scattering. The 2DEG electron mobility difference is mostly caused by the PCF scattering which can reach up to 899.6 cm^2/（V·s）（sample a）, 1307.4 cm^2/（V·s）（sample b）,1561.7 cm^2/（V s）（sample c） and 678.1 cm^2/（V·s）（sample d）, respectively. When the 2DEG sheet density is modulated by the drain–source bias, the electron mobility for samples a, b and c appear to peak with the variation of the 2DEG sheet density, but for sample d, no peak appears and the electron mobility rises with the increase in the2 DEG sheet density.