A class of new PN sequence with prime number periods of 4t +1 form (t is an integer)is constructed.The advantage of these PN sequencs over the m(M) sequence is their large number of alternative periods.They hav...A class of new PN sequence with prime number periods of 4t +1 form (t is an integer)is constructed.The advantage of these PN sequencs over the m(M) sequence is their large number of alternative periods.They have good pseudo random characteristics demonstrated by the expression of periodic autocorrelation function found out in this paper.展开更多
The group G of general coordinate transformations on the thermodynamic configuration space ε spanned by all the extensive variables keeps the first law of thermodynamics invariant. One can introduce a metric with Lor...The group G of general coordinate transformations on the thermodynamic configuration space ε spanned by all the extensive variables keeps the first law of thermodynamics invariant. One can introduce a metric with Lorentzian signature on the space ε, with the corresponding line element also being invariant under the action of G. This line element is identi6ed as the square of the proper entropy. Thus the second law of thermodynamics is also formulated invariantly and this lays down the foundation for the principle of thermal relativity.展开更多
By using the Monte Carlo method and numerical finite elementapproach, bistatic scattering from the fractal and Gaussian rough surfaces is studied. The difference between these two surfaces and their functional depende...By using the Monte Carlo method and numerical finite elementapproach, bistatic scattering from the fractal and Gaussian rough surfaces is studied. The difference between these two surfaces and their functional dependence on the surface parameters are discussed. Angular variation of bistatic scattering from the fractal surface is very significant, even for fairly smooth surface, whilst scattering from the Gaussian rough surface tends to the specular reflection. The slope of angular variation is linearly related with the fractal dimension. If an electrically_large target is placed over the rough surface, the fractal dimension inverted from bistatic scattering would be reduced. As the surfaces become very rough, scattering from different fractal and Gaussian surfaces would be not identified.展开更多
文摘A class of new PN sequence with prime number periods of 4t +1 form (t is an integer)is constructed.The advantage of these PN sequencs over the m(M) sequence is their large number of alternative periods.They have good pseudo random characteristics demonstrated by the expression of periodic autocorrelation function found out in this paper.
基金Supported by the National Natural Science Foundation of China under Grant No.10875059
文摘The group G of general coordinate transformations on the thermodynamic configuration space ε spanned by all the extensive variables keeps the first law of thermodynamics invariant. One can introduce a metric with Lorentzian signature on the space ε, with the corresponding line element also being invariant under the action of G. This line element is identi6ed as the square of the proper entropy. Thus the second law of thermodynamics is also formulated invariantly and this lays down the foundation for the principle of thermal relativity.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 49831060, 69771007) National 863-818-06-05.
文摘By using the Monte Carlo method and numerical finite elementapproach, bistatic scattering from the fractal and Gaussian rough surfaces is studied. The difference between these two surfaces and their functional dependence on the surface parameters are discussed. Angular variation of bistatic scattering from the fractal surface is very significant, even for fairly smooth surface, whilst scattering from the Gaussian rough surface tends to the specular reflection. The slope of angular variation is linearly related with the fractal dimension. If an electrically_large target is placed over the rough surface, the fractal dimension inverted from bistatic scattering would be reduced. As the surfaces become very rough, scattering from different fractal and Gaussian surfaces would be not identified.
