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981.
982.
薄层色谱-紫外可见分光光度法测定食品中的苏丹红Ⅰ号 总被引:1,自引:0,他引:1
建立了测定食品中苏丹红Ⅰ号新方法:薄层色谱-紫外可见分光光度法.方法的线性回归方程为:A=0.00583 0.15105ρ,在0.50~10.0 μg/mL之间苏丹红Ⅰ号的浓度与吸光度之间呈线性关系,相关系数R=0.9992,检出限为0.05 μg/mL.测定结果与国家标准HPLC法对照,令人满意.可用于食品中苏丹红Ⅰ号的测定. 相似文献
983.
984.
The changes effected by the Coriolis acceleration in the frequencies of inplane vibrations of a rotating disk are calculated.
It is shown that the current practice to neglect this effect in everyday engineering calculations is quite justified. It is
also shown that when disks are spun at ultra high speeds, say exceeding the one that corresponds with one-tenth of the lowest
natural frequency of a stationary disk, the effect does become significant. 相似文献
985.
Summary If an electric field is applied between a horizontal heated wire and a concentric cylinder filled with gas, then, as first shown experimentally by Senftleben and Braun, the heat transfer from the wire is increased due to the electrostrictive forces which modify the circulation current of free convection. In analogy with the characteristic number of Grashof a new electrical characteristic number is introduced which makes it possible to represent the measurements of Senftleben and Braun in a single graph. From this graph the extra heat loss caused by an electric field of cylindrical symmetry around any horizontal wire in an arbitrary gas can be read off directly. 相似文献
986.
Summary Viscosities have been measured of thirty-seven organic liquids, with molecular weights ranging from 120 to 807, and the viscosity-temperature curves obtained are compared with those of n-paraffins. The influence of ring structures and polar groups on viscosity is discussed.N.V. De Bataafsche Petroleum Maatschappij, The Hague 相似文献
987.
The effects of gravitomagnetic force
on plasma oscillations are investigated
using the kinetic theory of homogeneous electrically neutral plasma in the
absence of external electric or magnetic field. The random phase assumption is employed neglecting the thermal motion of the electrons with respect to a fixed ion background. It is found that the gravitomagnetic force reduces the characteristic frequency of the plasma thus enhancing the refractive index of the medium. The estimates for the predicted effects are given for a typical white dwarf, pulsar, and neutron star. 相似文献
988.
Noether-Mei Symmetry of Mechanical System in Phase Space 总被引:1,自引:0,他引:1
In this paper, a new kind of symmetry and its conserved
quantities of a mechanical system in phase space are studied.
The definition of this new symmetry, i.e., a Noether-Mei symmetry,
is presented, and the criterion of this symmetry is also given.
The Noether conserved quantity and the Mei conserved quantity
deduced from the Noether-Mei symmetry of the system are obtained.
Finally, two examples are given to illustrate the application of the results. 相似文献
989.
We investigate the phenomena of spontaneous symmetry breaking
for φ4 model on a square lattice in the parameter space by using
the potential importance sampling method, which was proposed by Milchev,
Heermann, and Binder [J. Stat. Phys. 44 (1986) 749]. The critical
values of the parameters allow us to determine the phase diagram of the
model. At the same time, some relevant quantities such as
susceptibility and specific heat are also obtained. 相似文献
990.
In Phys. Lett. A 313 (2003) 343 we have found that the
self-reciprocal Hankel transformation (HT) is embodied in quantum
mechanics by a transform between two entangled state representations
of continuum variables. In this
work we study Hankel transforms and properties of Bessel function via
entangled state representations' transformation in quantum mechanics. 相似文献