This paper presents an experimental study to determine the tensile properties of the envelope fabric Uretek3216L under biaxial cyclic loading.First the biaxial cyclic tests were carefully carried out on the envelope m...This paper presents an experimental study to determine the tensile properties of the envelope fabric Uretek3216L under biaxial cyclic loading.First the biaxial cyclic tests were carefully carried out on the envelope material to obtain the stress-strain data and the corresponding nonlinearity and orthotropy of the material were analyzed. Then for some determination options with different stress ratios the least squares method minimizing the strain terms was used to calculate the elastic constants from the experimental data.Finally the influences of the determination options with different stress ratios and the reciprocal relationship on the elastic constants were discussed.Results show that the orthotropy of the envelope material can be attributed to the unbalanced crimp of their constitutive yarns in warp and weft directions and the elastic constants vary noticeably with the determination options as well as the normalized stress ratios.In real design practice it is more reasonable to use constants determined for specific stress states in particular stress ratios depending on the project＆#39;s needs.Also calculating the structures with two limitative sets of elastic constants instead of using only one set is recommendable in light of the great variety of the constant＆#39;s values.展开更多
The quark potential model is used to investigate the low-energy elastic scattering of πN system. The model potential consists of the t-channel and s-channel one-gluon exchange potentials and the harmonic oscillator c...The quark potential model is used to investigate the low-energy elastic scattering of πN system. The model potential consists of the t-channel and s-channel one-gluon exchange potentials and the harmonic oscillator confining potential. By means of the resonating group method, a nonlocal effective potential for the πN system is derived from the interquark potentials and used to calculate the πN elastic scattering phase shifts. By considering the effect of QCD renormalization, the suppression of the spin-orbital coupling and the contribution of the color octet of the clusters （qq） and （qqq）, the numerical results are in fairly good agreement with the experimental data. The same model and method are employed to investigate the possible πN resonances. For this purpose, the resonating group equation is transformed into a standard Schrodinger equation in which the nonlocal effective πN interaction potential is included. Solving the Schrodinger equation by the variational method, we are able to reproduce the masses of some currently concerned πN resonances.展开更多
With the values of parameters obtained from improved ligand-field theory,by taking into account all theirreducible representations and their components in EPI as well as all the levels and the admixtures of basic wave...With the values of parameters obtained from improved ligand-field theory,by taking into account all theirreducible representations and their components in EPI as well as all the levels and the admixtures of basic wavefunc-tions within d^3 electronic configuration,the R-line thermal broadenings(TB)of both MgO:Cr^(3+)and MgO:V^(2+)havemicroscopic-theoretically been calculated.The results are in very good agreement with the experimental data.It is foundthat the R-line TB of MgO:Cr^(3+)or MgO:V^(2+)comes from the first-order term of EPI.The elastic Raman scattering ofacoustic phonons plays a dominant role in R-line TB of MgO:Cr^(3+)or MgO:V^(2+).展开更多
基金The National Natural Science Foundation of China(No.51278299,50878128)
文摘This paper presents an experimental study to determine the tensile properties of the envelope fabric Uretek3216L under biaxial cyclic loading.First the biaxial cyclic tests were carefully carried out on the envelope material to obtain the stress-strain data and the corresponding nonlinearity and orthotropy of the material were analyzed. Then for some determination options with different stress ratios the least squares method minimizing the strain terms was used to calculate the elastic constants from the experimental data.Finally the influences of the determination options with different stress ratios and the reciprocal relationship on the elastic constants were discussed.Results show that the orthotropy of the envelope material can be attributed to the unbalanced crimp of their constitutive yarns in warp and weft directions and the elastic constants vary noticeably with the determination options as well as the normalized stress ratios.In real design practice it is more reasonable to use constants determined for specific stress states in particular stress ratios depending on the project＆#39;s needs.Also calculating the structures with two limitative sets of elastic constants instead of using only one set is recommendable in light of the great variety of the constant＆#39;s values.
基金The project supported by National Natural Science Foundation of China under Grant No.10675054
文摘The quark potential model is used to investigate the low-energy elastic scattering of πN system. The model potential consists of the t-channel and s-channel one-gluon exchange potentials and the harmonic oscillator confining potential. By means of the resonating group method, a nonlocal effective potential for the πN system is derived from the interquark potentials and used to calculate the πN elastic scattering phase shifts. By considering the effect of QCD renormalization, the suppression of the spin-orbital coupling and the contribution of the color octet of the clusters （qq） and （qqq）, the numerical results are in fairly good agreement with the experimental data. The same model and method are employed to investigate the possible πN resonances. For this purpose, the resonating group equation is transformed into a standard Schrodinger equation in which the nonlocal effective πN interaction potential is included. Solving the Schrodinger equation by the variational method, we are able to reproduce the masses of some currently concerned πN resonances.
基金supported partially by National Natural Science Foundation of China under Grant No.40841012
文摘With the values of parameters obtained from improved ligand-field theory,by taking into account all theirreducible representations and their components in EPI as well as all the levels and the admixtures of basic wavefunc-tions within d^3 electronic configuration,the R-line thermal broadenings(TB)of both MgO:Cr^(3+)and MgO:V^(2+)havemicroscopic-theoretically been calculated.The results are in very good agreement with the experimental data.It is foundthat the R-line TB of MgO:Cr^(3+)or MgO:V^(2+)comes from the first-order term of EPI.The elastic Raman scattering ofacoustic phonons plays a dominant role in R-line TB of MgO:Cr^(3+)or MgO:V^(2+).
