Electrically-tunable magnetoresistance effect in magnetically modulated semiconductor heterostructure

We report on a theoretical study of magnetoresistance (MR) effect in a magnetically modulated semiconductor heterostructure (MMSH) under an applied bias, which can be constructed on surface of [Formula: see text] heterostructure by depositing two asymmetric ferromagnetic (FM) stripes. Bias-dependent transmission and conductance are calculated numerically, on the basis of both improved transfer matrix method (ITMM) and Landauer–Büttiker conductance theory. An obvious MR effect appears because of a significant difference of transmission between parallel and antiparallel (AP) magnetization configurations. Moreover, MR ratio can be tuned by the bias. These interesting features not only provide an alternative way to manipulate MR effect, but also may lead to an electrically-controllable MR device.

Symmetrical Effective Medium Resistivity Model with Sorting for Sandy Conglomerate

Sandy conglomerate reservoir has the characteristics of poor sorting, complex pore structure, heterogeneity, and so sandy conglomerate oil layer is difficult to identify. In this paper, based on symmetrical effective medium conductance theory and poor sorting of grains of sandy conglomerate, a symmetrical effective medium resistivity model for sandy conglomerate reservoir is established by dividing sandy conglomerate reservoir into three components, including a non-conductive matrix, gas and water. The log data is processed and interpreted with the proposed model, and the interpretation result compared with gas production test data. It shows that the model is applicable to evaluate the fluid property of sandy conglomerate reservoirs.

The John Sutton memorial lecture, 2009. Conductance systems: an integrative approach to the physiology of extreme conditions

This presentation explores the value of mechanical, electrical, and mathematical analogues in understanding and evaluating a variety of closely integrated transport processes in human biology. Particular attention is directed to a major interest of John Sutton: the factors limiting transport of oxygen from the atmosphere to the working muscles when exercising in a variety of hostile environments. In most circumstances, the limiting term in a closely linked chain of conductances seems to be in the blood stream, and its magnitude can be estimated by measurements of maximal oxygen intake. Despite recent criticisms of this index by those who have proposed a feed-forward control of maximal aerobic effort, conductance theory suggests that the main limitation of oxygen transport is normally maximal cardiac output. Therefore, careful laboratory determinations of maximal oxygen intake continue to provide a convenient integrating assessment of an individual’s cardiorespiratory function, with many important applications in sports medicine and exercise science.