The Effective Degree of Freedom of Low Energy QCD

The adiabatic effective baryon-baryon interactions and dibaryon candidates are studied syst ematicallywith three constituent quark models based on different effective degrees of freedom: Glozman-Riska-Brown Goldstoneboson exchange model based on constituent quark and Goldstone boson coupling; Fujiwara model based on constituentquark gluon coupling and Nijmegen one-boson exchange; QDCSM based on constituent quark and gluon coupling withquark delocalization and color screening. We find that the three models predicted the similar effective baryon-baryoninteractions for roughly two thirds among the 64 states consisted of octet and decuplet baryons. The differences amongthree models and their separate characteristics are also studied.

Effect of Quasi-Fermi Level on the Degree of Electron Spin Polarization in GaAs

With spin-polarized-dependent band gap renormalization effect taken into account, the energy-dependent evolu- tion of electron spin polarization in GaAs is calculated at room temperature and at a low temperature of 1OK. We consider the exciting light with right-handed circular polarization, and the calculation results show that the degree of electron spin polarization is dependent strongly on the quasi-Fermi levels of ｜1/2） and ｜- 1/2） spin conduction bands. At room temperature, the degree of electron spin polarization decreases sharply from 1 near the bottom of the conduction band, and then increases to a stable value above the quasi-Fermi level of the ｜- 1/2） band. The greater the quasi-Fermi level is, the higher the degree of electron spin polarization with excessive en- ergy above the quasi-Fermi level of the ｜- 1/2） band can be achieved. At low temperature, the degree of electron spin polarization decreases from 1 sharply near the bottom of the conduction band, and then increases with the excessive energy, and in particular, up to a maximum of i above the quasi-Fermi level of the ｜1/2） band.

The Quantitative Analysis on Leverage and its Effects

Leverage of modem enterprise＇s financial management includes operating leverage and financial leverage. Both of them exist objectively, are not changeable with human＇s minds. They enlarge enterprise＇s benefit and risk, so they have both positive and negative effects. The degrees of them are measured as DOL and DFL. In financial management, the relationship between DOL and operating risk has regularity in quantity, and so does the relationship between DFL and financial risk.

Supporting Earth Pressures for Foundation Excavation Considering Suction Stress of Soil

The infiltration,evaporation and variation of the groundwater table have significant effects on the suction stress of the soils and the supporting earth pressures of the foundation excavation.The distribution of the suction stresses above the ground water table is derived under different fluxes at the ground surface,according to the soil-water characteristic parameters and the effective degree of saturation.In consideration of the cohesive stress formed from the soil suction stress and the relevant anti sliding effect,the calculation model of supporting earth pressures for foundation excavation is established by the variational limit equilibrium method under the steady flow condition.The evolution of the supporting earth pressures is studied in detail for foundation excavation under different fluxes at the ground surface.The effects of the soil-water characteristic parameters,the ground water table and the internal friction angle on the supporting earth pressures are discussed.The results show that the suction stress is reduced because of the infiltration,and thus the supporting earth pressure increases.The larger the air-entry pressures and the pore size are,the smaller the supporting earth pressures are.The higher the ground water table is,the larger the supporting earth pressures are.In order to reduce the construction risk,the effects of the suction stress and the evolution of the potential critical sliding surface should be considered during the calculation of the supporting earth pressures.