随着"一带一路"倡议的建设进展,结合我校"电路"课程教学经验及多国来华留学生差异背景,提出引进融合、基础拓展、交叉创新相结合的高校来华留学生电路课程教学新措施,进一步提高来华留学生电路课程教学水平,满足我国高等教育国际化发展要求.

随着"一带一路"倡议进入全面建设阶段,高等教育国际化趋势愈加明显,来华留学生数量逐年增加.在此背景下,对电类专业来华留学生在《电路》课程学习方面进行了探索和研究,主要针对来华留学生学习基础层次不同、教学资料不足、实践环节特色不明显等进行了教学方面的研究和改进,以期提高教育国际化背景下的全英文教学水平和教学效果.

Gyroscope accuracy is closely related to its noise.To develop a novel superfluid matter wave interference gyroscope with high accuracy,its noise should be studied systematically.First,according to the generating mechanism of gyroscope noise,its origins are analyzed.The noise types are classified as thermal,locking value fluctuation,temperature fluctuation,frequency fluctuation and detecting element noise.Then,based on the mathematic model of each noise,the gyroscope noise is analyzed by utilizing some common parameters.The results show that thermal noise is relevant to the gyroscope structure parameter and working parameter,but is irrelevant to detected angular velocity.Locking fluctuation noise is only relevant to structure parameter;the other noises are all related to structure parameter,working parameter and detected angular velocity.Detecting element,frequency and locking value fluctuation noises are the primary factors that contribute to gyroscope output noise.In the range of the changing value of angular velocity,the gyroscope output noise changes nonlinearly with arange from the order of-7 to-6 in 1 Hz bandwidth.

In this paper,a method to extract the information of corresponding angular velocity and an effective scheme to expand the measurement range(amplitude-locking technology) are proposed,according to the problems of the extraction of variable input angular velocity information and the insufficient range existing in the development of the superfluid gyroscope based on AC Josephson Effect.The information extraction method is based on regarding the angular velocity as a constant in sampling time intervals,and then the angular velocity information can be extracted from the thin-film displacement vibration amplitude.The key point of amplitude-locking method is to make the amplitude continuously-locked at a certain point to calculate the feedback phase in real time.The errors in the system are corrected and compensated.The results of the simulation and analysis show that the two solutions are all feasible.

建立了4He量子干涉仪陀螺的数学模型,包括驱动方程,流量方程和位置方程.该数学模型可以完整地描述4He量子干涉仪陀螺系统.由驱动方程可知,采用热驱动的陀螺能够长期工作,但采用压力驱动的陀螺只能短时间工作.由流量方程可知,流过弱连接的超流体流量中,不仅含有表示旋转通量的交流流量,还含有由驱动引起的其他流量.位置方程表达了薄膜的位移,该位移是陀螺系统中唯一能被检测的物理量.基于实验参数的仿真验证了数学模型的有效性.根据本文建立的数学模型,可以进一步研究4He量子干涉仪陀螺的性能和分析该陀螺的误差.

The superfluid gyroscope based on low temperature physics science is a new kind of potential high accuracy gyroscope.This paper reviews the progress of research in the field of superfluid gyroscopes.First,several important types of superfluid gyroscopes are analyzed through a comparison of their principles of operation and characteristics.Then,the research trend of superfluid gyroscopes is presented.Moreover,the most hopeful type of superfluid gyroscope based on alternating current(AC) Josephson effect in superfluid is analyzed in detail.The sensitivity and advantages in size and work temperature of such a superfluid gyroscope are estimated.Finally,the possibility of improvements in work principle is analyzed,and the needs of manufacture,refrigeration and error control are summarized so as to develop the technology of superfluid gyroscope based on AC Josephson effect.

Thermal noise is closely related with steady state and resolution of superfluid gyroscope. In this paper, the thermal noise model of superfluid gyroscope was established by using the standard deviation of superfluid’s phase difference across the weak link. Based on this model, the impacts of thermal noise on Josephson oscillation effect and gyroscope’s resolution were analysed, and the ways to suppress the thermal noise were studied. Simulation results show that, by increasing the number of aperture to thousands and setting the temperature and aperture’s diameter to 2.169 K and 70 nm respectively, the thermal noise can be suppressed to the order of 10-9 rad/(s·Hz1/2), then the gyroscope has the ability to detect very small angular velocity.

A new concept gyroscope based on superfluid Josephson effect was described and analyzed to improve the performance greatly. It is a new Sagnac effect that an interferometer “loop”, formed by placing double weak links in a toroid filled with superfluid He4, can detect the interference of superfluid matter waves generated by the AC Josephson oscillation in weak links. In this paper, the potential advantages of superfluid gyroscope were estimated. The most important advantage is the very high sensitivity which could be increased theoretically by a factor of 1010 than the sensitivity of traditional Ring Laser Gyroscope. But such a superfluid gyroscope still faces some difficulties when it is used as an angular velocity measuring device for navigation, the most important one is the conflict between the high sensitivity and wide measurement range. Then, two methods were discussed to solve that conflict which is a key problem in current superfluid gyroscope research. The first method is “flux-locking”, which is a technique used in superconducting dc-SQUIDs. The principle of the method and analysis of performance were presented. It can increase measurement range to 500 times of original one. In another hand, such a superfluid gyroscope should work in a situation with limited angular acceleration. Author presented another method, called “history tracing”, and its work principle. The performance of the second method also be studied, and results showed that “history tracing” overcomes the problem of measurement range totally. Comparisons showed that “history tracing” is a better choice to develop high performance superfluid gyroscope.

The principle and typical project of the superfluid cryogenic gyroscope using ac-Josephson effects is studied to develop a high precision gyroscope based on superfluid.Mathematical model of the gyroscope including ac-Josephson effects,relations between rotation and ac-Josephson frequency,and signal detection method is obtained. The process of gyroscope sensing constant angular velocity(earth rotation) is simulated.Scouting angular velocity changes with time and the effects on precision due to structural parameters such as sense area and diaphragm area are studied.Simulation results show that it is feasible to develop a new high precision gyroscope based on ac-Josephson effects.

The particle degeneracy severely limits particle filter's application in engineering projects.This paper first makes a thorough analysis on particle filtering,and proposes an improved algorithm based on 2-order interpolation filtering.By computing more accurate importance density,this algorithm restricts the particle degeneracy and at the same time reduces the workload of calculation.A simulation experiment on the reentry of guided missiles shows the effectiveness of the algorithm.

This paper presents the recent research status of quantum gyroscope and superfluid gyroscope based on the new physical effects of cryogenic Bose-Einstein condensation.The physical effects,operating principles and technical status of the two new types of gyroscopes were described.The quantum gyroscope is based on the Sagnac effect of mater wave,and its precision is several orders higher than that of optical gyroscope.The superfluid gyroscope is based on the superfluid’s low-viscosity and the quantum’s vortex properties,and can obtain super-high precision in principle.At last,the paper analyzes the development prospect of the two types of gyroscopes.