Prompt neutron decay constant is the major characteristic parameter.

The prompt neutron decay constant was measured by using reactor noise technology at delayed criticality for 300# pool research reactor.

Experiments were performed for determing prompt neutron decay constantαof highly enriched uranium spherical shell by randomly pulsed neutron method with a ~(252)Cf source,αvalues from both least squares analysis of single exponential and two exponential fittings are in agreement and it is 100μs~(-1).

The relation of directions of phase constant and attenuation constant in conductive media;

The electric properties of coaxial cable, such as its characteristic impedance, screening attenuation, attenuation constant, and loss of echo wave, are related to the physical mechanism of the skim effective resistance, electromagnetic field, distribution par.

By the experiments,factors that effect decay of residual chlorine that happens in bulk water are analyzed and observed that the bulk decay constant changes associated with the water temperature,initial chlorine concentration,and total organic carbon.

In this paper laser excited(excitation at 266nm) fluorescence decay constants of YAP:Ce scintillation crystals with different sizes and various Ce~(3+)dopant concentrations were measured.

The characteristic impedance,acoustic theory,absorption coefficient and decay constant of the sound absorption functional rubber were introduced,and their research progress and applications were investigated.