Srx Physics 

Abstract: I work out the Newtonian and general relativistic effects due to an isotropic mass loss M ˙ / M of a body on the orbital motion of a test particle around it; the present analysis is also valid for a variation G ˙ / G of the Newtonian constant of gravitation. Concerning the Newtonian case, I use the Gauss equations for the variation of the elements and obtain negative secular rates for the osculating semimajor axis a , the eccentricity e , and the mean anomaly ℳ , while the argument of pericenter ω does not experience secular precession; the longitude of the ascending node Ω and the inclination i remain unchanged as well. The true orbit, instead, expands, as shown by a numerical integration of the equations of motion with MATHEMATICA; in fact, this is in agreement with the seemingly counter-intuitive decreasing of a and e because they refer to the osculating Keplerian ellipses which approximate the trajectory at each instant. A comparison with the results obtained with different approaches by other researchers is made. General relativity induces positive secular rates of the semimajor axis and the eccentricity completely negligible in the present and future evolution of the solar system.

Abstract: The infrared (IR) spectra of (100-x) TeO 2 –x WO 3 glasses reveal that the glass network consists of [ TeO 3 ]/[ TeO 3 + 1 ], [ TeO 4 ], [ WO 4 ], and [ WO 6 ] groups as basic structural units. Addition of WO 3 oxide to the binary TeO 2 –W O 3 glasses increases the amount of lower coordination of [ TeO 3 ]/[ TeO 3 + 1 ] units and decreases the higher coordination of [ TeO 4 ] units and also the formation of Te–O–W linkages at the expense of Te–O–Te linkages. The IR spectra of 60 TeO 2 –(40-x) WO 3 –xPbO glasses reveal that the glass network consists of [ TeO 3 ], [ TeO 4 ], [ WO 4 ], [ WO 6 ], and [ PbO 4 ] units. Changes in the coordination state of tellurium and tungsten ions occur when the PbO and WO 3 concentrations are varied. The dual role of the lead ions is confirmed in 60 TeO 2 –(40-x) WO 3 –xPbO glass system. The W ion coordination state changes from 4 to 6 when WO 3 concentration increases beyond 30 mol% in both (100-x) TeO 2 –x WO 3 and 60 TeO 2 –(40-x) WO 3 –xPbO glass systems. The IR spectra of 60 B 2 O 3 –10 TeO 2 –(30-x)ZnO–xPbO glasses reveal that the glass network consists of [ TeO 3 ], [ BO 3 ], and [ BO 4 ] groups.

Abstract: We study the effects of random long-range connections (shortcuts) on the firing patterns in a network composed of Hindmarsh-Rose neurons. It is found that the system can achieve the transition of neural firing patterns from the lower period state to the higher one, when the number of shortcuts in the neural network is greater than a threshold, indicating that the nervous system may make the optimal response to the change of stimulation by a corresponding adjustment of the shortcuts. Then we discuss the transition degree of firing patterns of neural network and its critical characteristics for different external stimulation current. Furthermore, the influences of coupling strength on such transition behavior of neural firing patterns are also considered. Our results may be useful in comprehending the real mechanism in neural coding and information transmission in neurobiological systems.

Abstract: Quasilinear theory is developed by using canonical variables for a relativistic plasma. It is self-consistent, including momentum, pitch angle, and spatial diffusions. By assuming the wave field as a superposition of known toroidal and poloidal Fourier modes, the quasilinear diffusion coefficients are written in a form which can be directly evaluated using the output of a spectral full-wave solver of Maxwell equations in toroidal plasmas. The formalism is special for tokamas and, therefore, simple and suitable for simulations of cyclotron heating, current drive, and radio-frequency wave-induced radial transport in ITER.