半绝缘砷化镓Hall测量中的若干问题

建立了绝缘电阻大于10~(13)Ω和温度起伏小于0.1℃的半绝缘砷化镓Hall测量装置。研究了环境温度、湿度、漏电流、数据读取时间、测量电压、样品尺寸等因素对电阻率与迁移率的影响，并讨论了各种因素所引起的测量误差。

MBE生长的InAs薄膜Hall器件

利用GaAs衬底上的InAa薄膜制备的Hall器件，具有灵敏度高(在相同的电子浓度、室温附近灵敏度是GaAs Hall器件的1.5倍)，不等位电压温漂小等优点。可用于电流传感器、无刷电机等磁敏传感器中，具有广阔的应用前景。

InAs薄膜Hall器件

于2010-11-23批量导入

InAs薄膜Hall器件的材料生长与特性研究

报道了利用InAs外延薄膜制作霍尔器件，通过分子束外延技术在GaAs衬底上生长的InAs薄膜具有较高的迁移率和较好的温度特性。用这种材料制作的霍尔器件在每千欧姆内阻条件下灵敏度与GaAs平面Hall器件相比提高了50%。

A 3 Tesla Superconducting Magnet for Hall Sensor Calibration

A 3 T superconducting magnet with a 70 mm diameter warm bore and energy storage of 47 kJ has been successfully fabricated and tested, which can be used to calibrate Hall sensors in high magnetic field as well as conduct superconducting experiments. The magnet consists of three solenoid coils and an iron yoke. The homogeneity of the magnetic field in the region of interest (ROI) is +/- 6.0 x 10(-5). The coils of the magnet were fabricated with NbTi-Cu superconducting wire and the stray magnetic field is shielded by an iron yoke. The coils and yoke are fully immersed in a helium vessel. The optimized structural design, stress and quench simulation, fabrication and test results are presented in this paper.

ON HALL AND KIERS TOPOLOGICAL STATE AND TOTAL TOPOLOGICAL INDEX

The topological state and the total topological index, tau, have been tested systematically. Counterexamples are provided proving that the topological state method cannot determine classes of symmetrically equivalent atoms in a molecule fully correct. The

Robert Heinich, Michael Molenda, James D. Russell, Sharon E. Smaldino, Instructional Media and Technologies for Learning, Prentice-Hall, Inc., Englewood Cliffs, New Jersey 1996, ss. 446. Steven Hackbarth, The Educational Technology Handbook. A Comprehensive Guide, Educational Technology Publications Inc., Englewood Cliffs, New Jersey 1996, ss. 351

Recenzje i sprawozdania z książek

Accelerating self-consistent field convergence with the augmented Roothaan-Hall energy function.

Based on Pulay's direct inversion iterative subspace (DIIS) approach, we present a method to accelerate self-consistent field (SCF) convergence. In this method, the quadratic augmented Roothaan-Hall (ARH) energy function, proposed recently by Høst and co-workers [J. Chem. Phys. 129, 124106 (2008)], is used as the object of minimization for obtaining the linear coefficients of Fock matrices within DIIS. This differs from the traditional DIIS of Pulay, which uses an object function derived from the commutator of the density and Fock matrices. Our results show that the present algorithm, abbreviated ADIIS, is more robust and efficient than the energy-DIIS (EDIIS) approach. In particular, several examples demonstrate that the combination of ADIIS and DIIS ("ADIIS+DIIS") is highly reliable and efficient in accelerating SCF convergence.