An improved method is proposed for the extraction of the symmetry energy coefficient relative to the temperature,a_(sym)/T,in the heavy-ion reactions near the Fermi energy region,based on the modified Fisher Model.Thi...An improved method is proposed for the extraction of the symmetry energy coefficient relative to the temperature,a_(sym)/T,in the heavy-ion reactions near the Fermi energy region,based on the modified Fisher Model.This method is applied to the primary fragments of antisymmetrized molecular dynamics(AMD)simulations for ^(46)Fe+^(46)Fe,^(40)Ca+^(40)Ca and ^(48)Ca+^(48)Ca at 35 MeV/nucleon,in order to make direct comparison to the results from the K(N,Z)method of Ono et al.In our improved method,the extracted values of a_(sym)/T increase as the size of isotopes increases whereas,in the K(N,Z)method,the results show rather constant behavior.This increase in our result is attributed to the surface contribution of the symmetry energy in finite nuclei.In order to evaluate the surface contribution,the relation a_(sym)/T=[a_(sym)^((V))(1-k_(S/V) A^(-1/3))]/T is applied and k_(S/V)=1.20~1.25 was extracted.This value is smaller than those extracted from the mass table,reflecting the weakened surface contribution at higher temperature regime.Δμ/T,the difference of the neutron-proton chemical potentials relative to the temperature,is also extracted in this method at the same time.The average values of the extractedΔμ/T,Δμ/T show a linear dependence on the proton-neutron a_(sym)metry parameter of the system,δ_(sys),andΔμ/T=(15.1±0.2)δ_(sys)-(0.5±0.1)is obtained.展开更多
The medical and economic importance of ticks has long been recognized due to their ability to transmit diseases to humans and animals. Ticks cause great economic losses to livestock, and adversely affect livestock hos...The medical and economic importance of ticks has long been recognized due to their ability to transmit diseases to humans and animals. Ticks cause great economic losses to livestock, and adversely affect livestock hosts in several ways. Loss of blood is a direct effect of ticks acting as potential vector for haemo-protozoa and helminth parasites. Blood sucking by large numbers of ticks causes reduction in live weight and anemia among domestic animals, while their bites also reduce the quality of hides. However, major losses caused by ticks are due to their ability to transmit protozoan, rickettsial and viral diseases of live-stock, which are of great economic importance world-wide. There are quite a few methods for controlling ticks, but every method has certain shortcomings. The present review is focused on ticks importance and their control.展开更多
A novel controllable hybrid-anode AlGaN/GaN field-effect rectifier(HA-FER)with low operation voltage(LOV)is proposed.Its mechanism can be explained by the field-controlled energy band model.This model reveals that the...A novel controllable hybrid-anode AlGaN/GaN field-effect rectifier(HA-FER)with low operation voltage(LOV)is proposed.Its mechanism can be explained by the field-controlled energy band model.This model reveals that the electric field in the AlGaN layer alters the energy band to result in a variation of the two-dimensional electron gas(2DEG)at AlGaN/GaN interface;the field can be changed by the thickness d of the AlGaN layer and the applied bias.As the d reduces below the critical thickness,the 2DEG vanishes and then the channel is pinched off.Therefore,the threshold voltage of HA-FER can be designed as low as 0 V leading to LOV(<1 V).The analytical characteristic of the HA-FER is calculated and validated by the simulated results.These results also demonstrate that the forward properties of HA-FER are superior to the conventional SBD due to the high Schottky barrier.展开更多
文摘An improved method is proposed for the extraction of the symmetry energy coefficient relative to the temperature,a_(sym)/T,in the heavy-ion reactions near the Fermi energy region,based on the modified Fisher Model.This method is applied to the primary fragments of antisymmetrized molecular dynamics(AMD)simulations for ^(46)Fe+^(46)Fe,^(40)Ca+^(40)Ca and ^(48)Ca+^(48)Ca at 35 MeV/nucleon,in order to make direct comparison to the results from the K(N,Z)method of Ono et al.In our improved method,the extracted values of a_(sym)/T increase as the size of isotopes increases whereas,in the K(N,Z)method,the results show rather constant behavior.This increase in our result is attributed to the surface contribution of the symmetry energy in finite nuclei.In order to evaluate the surface contribution,the relation a_(sym)/T=[a_(sym)^((V))(1-k_(S/V) A^(-1/3))]/T is applied and k_(S/V)=1.20~1.25 was extracted.This value is smaller than those extracted from the mass table,reflecting the weakened surface contribution at higher temperature regime.Δμ/T,the difference of the neutron-proton chemical potentials relative to the temperature,is also extracted in this method at the same time.The average values of the extractedΔμ/T,Δμ/T show a linear dependence on the proton-neutron a_(sym)metry parameter of the system,δ_(sys),andΔμ/T=(15.1±0.2)δ_(sys)-(0.5±0.1)is obtained.
基金Project (No. 2005C12015) supported by the Department of Science and Technology of Zhejiang Province, China
文摘The medical and economic importance of ticks has long been recognized due to their ability to transmit diseases to humans and animals. Ticks cause great economic losses to livestock, and adversely affect livestock hosts in several ways. Loss of blood is a direct effect of ticks acting as potential vector for haemo-protozoa and helminth parasites. Blood sucking by large numbers of ticks causes reduction in live weight and anemia among domestic animals, while their bites also reduce the quality of hides. However, major losses caused by ticks are due to their ability to transmit protozoan, rickettsial and viral diseases of live-stock, which are of great economic importance world-wide. There are quite a few methods for controlling ticks, but every method has certain shortcomings. The present review is focused on ticks importance and their control.
基金Supported by the National Natural Science Foundation of China under Grant No 60906037the Fundamental Research Funds for the Central Universities(ZYGX2009J027)Foundation of State Key Laboratory of Electronic Thin Films and Integrated Devices.
文摘A novel controllable hybrid-anode AlGaN/GaN field-effect rectifier(HA-FER)with low operation voltage(LOV)is proposed.Its mechanism can be explained by the field-controlled energy band model.This model reveals that the electric field in the AlGaN layer alters the energy band to result in a variation of the two-dimensional electron gas(2DEG)at AlGaN/GaN interface;the field can be changed by the thickness d of the AlGaN layer and the applied bias.As the d reduces below the critical thickness,the 2DEG vanishes and then the channel is pinched off.Therefore,the threshold voltage of HA-FER can be designed as low as 0 V leading to LOV(<1 V).The analytical characteristic of the HA-FER is calculated and validated by the simulated results.These results also demonstrate that the forward properties of HA-FER are superior to the conventional SBD due to the high Schottky barrier.
