本文以Fe(NO3)3.9H2O,Zn(NO3)2.6H2O和N i(NO3)2.6H2O为原料,以柠檬酸为还原剂,采用燃烧法制备了ZnFe2O4和N i Fe2O4纳米粉体,采用X-射线粉末衍射仪(XRD)、高分辨率透射电子显微镜(TEM)、红外光谱(IR)和振动样品磁强计(VSM)等手段对样...本文以Fe(NO3)3.9H2O,Zn(NO3)2.6H2O和N i(NO3)2.6H2O为原料,以柠檬酸为还原剂,采用燃烧法制备了ZnFe2O4和N i Fe2O4纳米粉体,采用X-射线粉末衍射仪(XRD)、高分辨率透射电子显微镜(TEM)、红外光谱(IR)和振动样品磁强计(VSM)等手段对样品进行了表征,结果表明样品为尖晶石型铁酸锌纳米粉体和立方晶系的铁酸镍纳米粉体,其平均粒径约为22nm和32nm,并具有超顺磁性。展开更多
After finding the really self-consistent electromagnetic equations for a plasma, we proceed in a similar fashion to find how the magnetohydrodynamical equations have to be modified accordingly. Substantially this is d...After finding the really self-consistent electromagnetic equations for a plasma, we proceed in a similar fashion to find how the magnetohydrodynamical equations have to be modified accordingly. Substantially this is done by replacing the "Lorentz" force equation by the correct (in our case) force equation. Formally we have to use the vector potential instead of the magnetic field intensity. The appearance of the formulae presented is the one of classical vector analysis. We thus find a set of eight equations in eight unknowns, as previously known concerning the traditional MHD equations.展开更多
In this paper ,in the space that possesses restoring nucleus, we obtain analyticsolutions in the series form for the steady-state convection diffusion equation The solutions have the following characteristics: (1) the...In this paper ,in the space that possesses restoring nucleus, we obtain analyticsolutions in the series form for the steady-state convection diffusion equation The solutions have the following characteristics: (1) they ave given in the accurate form:(2)they can be calculated in the explicit way, without solving the eguations;(3) the error of the approximate solution will be monotonically decreased under the meaning of the norm of the spaces when a cardinal term is added in the procedure of numerical solution .Finally, we calculated the example in [2] the result shows that our solution is more accurate than that in [2].展开更多
In this paper, we study the regularity criteria for axisymmetric weak solutions to the MHD equa- tions in R3. Let we, Jo and ue be the azimuthal component of w, J and u in the cylindrical coordinates, respectively. Th...In this paper, we study the regularity criteria for axisymmetric weak solutions to the MHD equa- tions in R3. Let we, Jo and ue be the azimuthal component of w, J and u in the cylindrical coordinates, respectively. Then the axisymmetric weak solution （u,b） is regular on （0, T） if （wo,Jo） E Lq（O,T;Lp） or （oae,V（uoeo）） e Lq（0,T;Lp） with 3 ＋ 2 〈 2, 3 〈 p 〈 oo. In the endpoint case, one needs conditions （we, Jo） C LI（0, T;B∞∞） or （wo, V（uoeo）） C LI（0, T;B ∞∞）.展开更多
文摘本文以Fe(NO3)3.9H2O,Zn(NO3)2.6H2O和N i(NO3)2.6H2O为原料,以柠檬酸为还原剂,采用燃烧法制备了ZnFe2O4和N i Fe2O4纳米粉体,采用X-射线粉末衍射仪(XRD)、高分辨率透射电子显微镜(TEM)、红外光谱(IR)和振动样品磁强计(VSM)等手段对样品进行了表征,结果表明样品为尖晶石型铁酸锌纳米粉体和立方晶系的铁酸镍纳米粉体,其平均粒径约为22nm和32nm,并具有超顺磁性。
文摘After finding the really self-consistent electromagnetic equations for a plasma, we proceed in a similar fashion to find how the magnetohydrodynamical equations have to be modified accordingly. Substantially this is done by replacing the "Lorentz" force equation by the correct (in our case) force equation. Formally we have to use the vector potential instead of the magnetic field intensity. The appearance of the formulae presented is the one of classical vector analysis. We thus find a set of eight equations in eight unknowns, as previously known concerning the traditional MHD equations.
文摘In this paper ,in the space that possesses restoring nucleus, we obtain analyticsolutions in the series form for the steady-state convection diffusion equation The solutions have the following characteristics: (1) they ave given in the accurate form:(2)they can be calculated in the explicit way, without solving the eguations;(3) the error of the approximate solution will be monotonically decreased under the meaning of the norm of the spaces when a cardinal term is added in the procedure of numerical solution .Finally, we calculated the example in [2] the result shows that our solution is more accurate than that in [2].
基金The research of B.Q,Yuan was partially supported by the National Natural Science Foundation of China (No. 10771052, 11071057)Program for Science & Technology Innovation Talents in Universities of Henan Province (No. 2009HASTIT007)+1 种基金the Innovation Scientists and Technicians Troop Construction Projects of Henan Province (No. 104100510015)F.P,LI was supported by the young fund and excellent young teacher fund of Henan Polytechnic University (No. Q2011-144, 649177)
文摘In this paper, we study the regularity criteria for axisymmetric weak solutions to the MHD equa- tions in R3. Let we, Jo and ue be the azimuthal component of w, J and u in the cylindrical coordinates, respectively. Then the axisymmetric weak solution （u,b） is regular on （0, T） if （wo,Jo） E Lq（O,T;Lp） or （oae,V（uoeo）） e Lq（0,T;Lp） with 3 ＋ 2 〈 2, 3 〈 p 〈 oo. In the endpoint case, one needs conditions （we, Jo） C LI（0, T;B∞∞） or （wo, V（uoeo）） C LI（0, T;B ∞∞）.
