Variability in cardiovascular spectra was first described by Stephan Hales in 1733.Traube and Hering initially noted respirophasic variation of the arterial pressure waveform in 1865 and Sigmund Mayer noted a lower fr...Variability in cardiovascular spectra was first described by Stephan Hales in 1733.Traube and Hering initially noted respirophasic variation of the arterial pressure waveform in 1865 and Sigmund Mayer noted a lower frequency oscillation of the same in anesthetized rabbits in 1876.Very low frequency oscillations were noted by Barcroft and Nisimaru in 1932,likely representing vasogenic autorhythmicity.While the origins of Traube Hering and very low frequency oscillatory variability in cardiovascular spectra are well described,genesis mechanisms and functional significance of Mayer waves remain in controversy.Various theories have posited baroreflex and central supraspinal mechanisms for genesis of Mayer waves.Several studies have demonstrated the persistence of Mayer waves following high cervical transection,indicating a spinal capacity for genesis of these oscillations.We suggest a general tendency for central sympathetic neurons to oscillate at the Mayer wave frequency,the presence of multiple Mayer wave oscillators throughout the brainstem and spinal cord,and possible contemporaneous genesis by baroreflex and vasomotor mechanisms.展开更多
We study graph weights which naturally occur in Mayer’s theory and Ree-Hoover’s theory for the virial expansion in the context of an imperfect gas. We pay particular attention to the Mayer weight and Ree-Hoover weig...We study graph weights which naturally occur in Mayer’s theory and Ree-Hoover’s theory for the virial expansion in the context of an imperfect gas. We pay particular attention to the Mayer weight and Ree-Hoover weight of a 2-connected graph in the case of the hard-core continuum gas in one dimension. These weights are calculated from signed volumes of convex polytopes associated with the graph. In the present paper, we use the method of graph homomorphisms, to develop other explicit formulas of Mayer weights and Ree-Hoover weights for infinite families of 2-connected graphs.展开更多
The virial expansion, in statistical mechanics, makes use of the sums of the Mayer weight of all 2-connected graphs on n vertices. We study the Second Mayer weight ωM(c) and the Ree-Hoover weight ωRH(c) of a 2-conne...The virial expansion, in statistical mechanics, makes use of the sums of the Mayer weight of all 2-connected graphs on n vertices. We study the Second Mayer weight ωM(c) and the Ree-Hoover weight ωRH(c) of a 2-connected graph c which arise from the hard-core continuum gas in one dimension. These weights are computed using signed volumes of convex polytopes naturally associated with the graph c. In the present work, we use the method of graph homomorphisms, to give new formulas of Mayer and Ree-Hoover weights for special infinite families of 2-connected graphs.展开更多
The coal processing methods used at the Zarand coal washery plant are the heavy medium bath,jigs,and flotation.The coal-containing materials that are fed to the plant are acquired from different mines,and they have di...The coal processing methods used at the Zarand coal washery plant are the heavy medium bath,jigs,and flotation.The coal-containing materials that are fed to the plant are acquired from different mines,and they have different washability properties.In this paper,the validity of Mayer curve (M-curve),the conventional method for determining coal washability,was evaluated on blending of raw coals that are fed to the plant.Washability curves were prepared for the hand-blended samples and compared with the washability predicted by the Mayer curves.Different samples from different seams and mines were blended by hand in 50:50 ratios,and sink and float tests were performed;the resulting washability curves were in good agreement with the washability curves predicted using the Mayer method for the same blending ratio.This work resulted in the preparation of the optimum plant feed that can be achieved from the blending of different coal samples to produce the best plant yield at a given ash content.展开更多
文摘Variability in cardiovascular spectra was first described by Stephan Hales in 1733.Traube and Hering initially noted respirophasic variation of the arterial pressure waveform in 1865 and Sigmund Mayer noted a lower frequency oscillation of the same in anesthetized rabbits in 1876.Very low frequency oscillations were noted by Barcroft and Nisimaru in 1932,likely representing vasogenic autorhythmicity.While the origins of Traube Hering and very low frequency oscillatory variability in cardiovascular spectra are well described,genesis mechanisms and functional significance of Mayer waves remain in controversy.Various theories have posited baroreflex and central supraspinal mechanisms for genesis of Mayer waves.Several studies have demonstrated the persistence of Mayer waves following high cervical transection,indicating a spinal capacity for genesis of these oscillations.We suggest a general tendency for central sympathetic neurons to oscillate at the Mayer wave frequency,the presence of multiple Mayer wave oscillators throughout the brainstem and spinal cord,and possible contemporaneous genesis by baroreflex and vasomotor mechanisms.
文摘We study graph weights which naturally occur in Mayer’s theory and Ree-Hoover’s theory for the virial expansion in the context of an imperfect gas. We pay particular attention to the Mayer weight and Ree-Hoover weight of a 2-connected graph in the case of the hard-core continuum gas in one dimension. These weights are calculated from signed volumes of convex polytopes associated with the graph. In the present paper, we use the method of graph homomorphisms, to develop other explicit formulas of Mayer weights and Ree-Hoover weights for infinite families of 2-connected graphs.
文摘The virial expansion, in statistical mechanics, makes use of the sums of the Mayer weight of all 2-connected graphs on n vertices. We study the Second Mayer weight ωM(c) and the Ree-Hoover weight ωRH(c) of a 2-connected graph c which arise from the hard-core continuum gas in one dimension. These weights are computed using signed volumes of convex polytopes naturally associated with the graph c. In the present work, we use the method of graph homomorphisms, to give new formulas of Mayer and Ree-Hoover weights for special infinite families of 2-connected graphs.
基金supports for this work that were received from the Zarand coal washing R&D center and Science and Research Branch (Tehran) of Islamic Azad University
文摘The coal processing methods used at the Zarand coal washery plant are the heavy medium bath,jigs,and flotation.The coal-containing materials that are fed to the plant are acquired from different mines,and they have different washability properties.In this paper,the validity of Mayer curve (M-curve),the conventional method for determining coal washability,was evaluated on blending of raw coals that are fed to the plant.Washability curves were prepared for the hand-blended samples and compared with the washability predicted by the Mayer curves.Different samples from different seams and mines were blended by hand in 50:50 ratios,and sink and float tests were performed;the resulting washability curves were in good agreement with the washability curves predicted using the Mayer method for the same blending ratio.This work resulted in the preparation of the optimum plant feed that can be achieved from the blending of different coal samples to produce the best plant yield at a given ash content.
