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61.
S. N. Shelud’ko 《Computational Mathematics and Mathematical Physics》2007,47(7):1197-1212
For a problem with a point source located in an infinite homogeneous plane-parallel barrier, the terms of a Neumann series describing the solution to the radiative transfer equation are analytically integrated in part with respect to all the mean free paths. 相似文献
62.
O. P. Ermolaev 《Journal of Applied Spectroscopy》1997,64(4):493-496
This study was carried out to investigate low-temperature (T=4.2 K) photoluminescence caused by interdopant recombination
transitions in n-germanium irradiated by fast (epicadmium) reactor neutrons and subjected to “complete” annealing (+450°C,
24 h). It is shown that lines of interdopant radiative recombination observed in initial and in irradiated and annealed specimens
are caused by both initial impurities and (mainly) dopants (As and Ga) implanted by transmutation as well as by defect sets
stable at long-time high-temperature annealing that do not contain fine dopants.
Belarusian State University, 4, F. Skorina Ave., Minsk, 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 64, No. 4, pp. 479–482, July–August, 1997. 相似文献
63.
本文在多组态Dirac-Fock(MCDF)理论框架下计算了水窗波段(λ:23.3~43.8A,相当于Z:34~46)的溴到铷的类钠离子1s~22s~22p~6nlj(n=3~15,l=0~6)各能级能量及各能级n_il_ij_i—n_kl_kj_k(n_i≤6,n_h≤15)间的电偶极辐射跃迁几率,并由此得出可能产生软X射线激光跃迁(4f-5g,4d-5f,4f-6g,4d-6f)的激光上能级的寿命,把计算得到的跃迁波长与实验测量值进行比较,其相对误差小于0.35%。 相似文献
64.
Spectroscopic properties of Er3+:CBS (CdSO4+B2O3 and R2SO4+CdSO4+B2O3, R2SO4=Li2SO4.H2O, Na2SO4, K2SO4 and Gd2(SO4)3.8H2O) glasses are reported. The assigned energy level data of Er3+(4f
11) in these glasses are analysed in terms of a parametrized model Hamiltonian. The standard deviations of the data fits are
between 39 and 47 cm−1 so that the energy level schemes of the Er3+(4f
11) ions in borosulphate (CBS) glasses are reasonably well reproduced. Radiative properties for the fluorescent levels of Er3+:CBS glasses are determined by using the Judd-Ofelt theory. The potential laser transitions are identified with the help of
predicted radiative properties which are compared and discussed with similar results. 相似文献
65.
66.
Hyung-gyu Jun Thomas R. Way Bjrn Lfgren Mats Landstrm Alvin C. Bailey Eddie C. Burt Timothy P. McDonald 《Journal of Terramechanics》2004,41(4):209-222
A Trelleborg Twin 421 Mark II 600/55-26.5 steel-reinforced bias-ply forwarder drive tire at inflation pressures of 100 and 240 kPa and dynamic loads of 23.9 and 40 kN was used at 5% travel reduction on a firm clay soil. Effects of dynamic load and inflation pressure on soil–tire contact pressures were determined using six pressure transducers mounted on the tire tread. Three were mounted on the face of a lug and three at corresponding locations on the undertread. Contact angles increased with decreases in inflation pressure and increases in dynamic load. Contact pressures on a lug at the edge of the tire increased as dynamic load increased. Mean and peak pressures on the undertread generally were less than those on a lug. The peak pressures on a lug occurred forward of the axle in nearly all combinations of dynamic load, inflation pressure, and pressure sensor location, and peak pressures on the undertread occurred to the rear of the axle in most of the combinations. Ratios of the peak contact pressure to the inflation pressure ranged from 0 at the edge of the undertread for three combinations of dynamic load and inflation pressure to 8.39 for the pressure sensor on a lug, near the tire centerline, when the tire was underinflated. At constant dynamic load, net traction and tractive efficiency decreased as inflation pressure increased. 相似文献
67.
F.?S.?IbrahimEmail author M.?A.?Mansour S.?M.?Abdel-Gaied 《Transport in Porous Media》2005,61(1):45-57
The problem of natural convective heat transfer for a non-Newtonian fluid from an impermeable vertical plate embedded in a fluid-saturated porous medium has been analyzed. Non-Darcian, radiative and thermal dispersion effects have been considered in the present analysis. The governing boundary layer equations and boundary conditions are cast into a dimensionless form and simplified by using a similarity transformation. The resulting system of equations is solved by using a double shooting Runge–Kutta method. The effect of viscosity index n, the conduction–radiation parameter R, the non-Darcy parameter Gr*, the thermal dispersion parameter Ds and the suction/injection parameter fw on the fluid velocities, temperatures and the local Nusselt number are discussed. 相似文献
68.
THEHAMILTONIANSTBUCTURESOF3DODEWITHTIME-INDEPENDENTINVARIANTSGuoZhong-heng(郭仲衡)(DepartmentofMathematics,PekingUniversity,Beij... 相似文献
69.
B.A. Goeckner D.R. Helmich T.A. McCarthy J.M. Arinez T.E. Peard J.E. Peters M.Q. Brewster R.O. Buckius 《Experimental Thermal and Fluid Science》1992,5(6):848-860
Experiments were conducted using porous ceramic inserts to enhance the radiative heat transfer from natural gas flames in a straight-through radiant tube burner. The performance of the radiant tube burner with partially stabilized zirconia and silicon carbide inserts is compared to a baseline case of no inserts at three levels of combustion air preheat. Spectral intensities, temperatures within the radiant tube burner, tube wall temperatures, and exhaust temperatures were measured to determine the effectiveness of the enhanced heat transfer due to the inserts. Exhaust emission constituents were also measured to determine the effect that the inserts have on exhaust products. NOx emissions are reduced by up to 30% with the inserts. The silicon carbide inserts have higher spectral intensities and total radiative energy transfer than partially stabilized zirconia inserts. Both inserts have enhanced radiant heat transfer compared to the no-insert configuration, with the radiative enhancement due to inserts as great as five times that of the no-insert configuration. The net result is increased tube wall temperatures and decreased exhaust temperatures with the ceramic inserts. 相似文献
70.
Three modes of propagation of a traveling-wave front over a noncold gas with different propagation velocities are found using
one thermodynamic model. When the indicated velocity is low, transition from constant values of the gas parameters on both
sides of the traveling-wave front proceeds continuously. An increase in the traveling-wave velocity leads to an isothermal
jump: the density and velocity of the gas undergo a strong discontinuity whereas the temperature varies continuously. With
a further increase in the traveling-wave velocity, the isothermal jump disappears and the flow becomes continuous again.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 4, pp. 15–25, July–August, 2006. 相似文献