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On Modeling Drilling Load in Lunar Regolith Simulant

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Chinese Journal of Mechanical Engineering 2018年第1期31卷 41-52页

作者： Qi-quan quan Chong-Bin Chen Zong-quan Deng Jun-yue Tang De-Wei Tang State Key Laboratory of Robotics and System Harbin Institute of Technology

Drilling and coring, as effective ways to obtain lunar regolith along the longitudinal direction, are widely applied in the lunar sampling field. Conventionally, modeling of drill-soil interaction was divided into soil cutting and screw conveyance processes, ignoring the differences in soil mechanical properties between them. To improve the modeling accuracy, a hypothesis that divides the drill-soil interaction into four parts: cuttings screw conveyance, cuttings extruding, cuttings bulldozing, and in situ simulant cutting, is proposed to establish a novel model based on the passive earth pressure theory. An iterative numerical calculation method is developed to predict the drilling loads. A drilling and coring testbed is developed to conduct experimental tests. Drilling experiments indicate that the drilling loads calculated by the proposed model match well the experimental results. The proposed research provides the instructions to adopt a suitable drilling strategy to match the rotary and penetrating motions, to increase the safety and reliability of drilling control in lunar sampling missions.

关键词： Lunar regolith drilling Lunar regolith simulant Drill-simulant interaction Screw conveyance

Synthesis of Copper Oxalate Nanorods by a Simple One-step Solid-state Chemical Reaction Method

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Chemical Research in Chinese Universities 2005年第2期21卷 134-136页

作者： CAOya-li JIADian-zeng LIULang XIAODing-quan XINXin-quan InstituteofAppliedChemistry XinjiangUniversityUrumqi830046P.R.China DepartmentofMaterialsScience SichuanUniversityChengdu610064P.R.China StateKeyLaboratoryofCoordinationChemistry NanjingUniversityNanjing210093P.R.China

Copper oxalate nanorods were successfully prepared by means of a simple one-step solid-state reaction method with the assistance of a suitable surfactant, polyethylene glycol 400. The product with uniform rod-like morphology was characterized by XRD, TEM and SEM. The formational mechanism of the rod-like structure was also preliminary discussed.

关键词： Nanorod Nanostructure Solid-state reaction Copper oxalate

Fully enclosed hybrid electromagnetic-triboelectric nanogenerator to scavenge vibrational energy

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Nano Research 2016年第8期9卷 2226-2233页

作者： Ting quan ya yang Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences National Center for Nanoscience and Technology Beijing 100083 China

We propose a fully enclosed hybrid nanogenerator consisting of five elec- tromagnetic generators （EMGs） and four triboelectric nanogenerators （TENGs）. Under a vibration frequency of 15.5 Hz, one TENG can deliver a high output voltage of approximately 24 V and a low output current of approximately 24 μA, whereas one EMG can deliver a low output voltage of approximately 0.8 V and a high output current of approximately 0.5 mA. By integrating five rectified EMGs in series and four rectified TENGs in parallel, the hybrid nanogenerator can be used to charge a home-made Li-ion battery from 1 to 1.9 V in 6.3 h. By using the hybrid nanogenerator to scavenge the vibrational energy produced by human hands, a temperature-humidity sensor can be sustainably powered by the nanogenerator, which is capable of charging the 200 ~F system power capacitor from 0 to 2 V in 15 s, and sustainably power the sensor in 29 s.

关键词： hybrid nanogenerator electromagnetic triboelectric vibration energy Li-ion battery

New Method to Improve Dynamic Stiffness of Electro-hydraulic Servo Systems

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Chinese Journal of Mechanical Engineering 2013年第5期26卷 997-1005页

作者： BAI yanhong quan Long Key Laboratory of Advanced Transducers and Intelligent Control System of Ministry of Education Taiyuan University of Technology School of Electronics Information Engineering Taiyuan University of Science and Technology

Most current researches working on improving stiffness focus on the application of control *** controller in closed-loop hydraulic control system takes effect only after the controlled position is deviated,so the control action is *** dynamic performance against force disturbance and dynamic load stiffness can’t be improved evidently by advanced control *** this paper,the elementary principle of maintaining piston position unchanged under sudden external force load change by charging additional oil is *** this basis,the conception of raising dynamic stiffness of electro hydraulic position servo system by flow feedforward compensation is put *** a scheme using double servo valves to realize flow feedforward compensation is presented,in which another fast response servo valve is added to the regular electro hydraulic servo system and specially utilized to compensate the compressed oil volume caused by load impact in *** two valves are arranged in parallel to control the cylinder ***,the model of flow compensation is derived,by which the product of the amplitude and width of the valve’s pulse command signal can be *** determination rules of the amplitude and width of pulse signal are concluded by analysis and *** the proposed scheme,simulations and experiments at different positions with different force changes are *** simulation and experimental results show that the system dynamic performance against load force impact is largely improved with decreased maximal dynamic position deviation and shortened settling *** is,system dynamic load stiffness is evidently *** paper proposes a new method which can effectively improve the dynamic stiffness of electro-hydraulic servo systems.

关键词： electro-hydraulic servo system flow feedforward compensation dynamic load stiffness double-valve actuation

Consistency check of degradation mechanism between natural storage and enhancement test for missile servo system

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Journal of Systems Engineering and Electronics 2019年第2期30卷 415-424页

作者： Wang Xu Sun quan College of Information Systems and Management National University of Defense Technology The Second Academy of China Aerospace Science and Industry Corporation Hunan Ginkgo Reliability Technology Institute Limited Corporation

Reliability enhancement testing(RET) is an accelerated testing which hastens the performance degradation process to surface its inherent defects of design and manufacture. It is an important hypothesis that the degradation mechanism of the RET is the same as the one of the normal stress condition. In order to check the consistency of two mechanisms, we conduct two enhancement tests with a missile servo system as an object of the study, and preprocess two sets of test data to establish the accelerated degradation models regarding the temperature change rate that is assumed to be the main applied stress of the servo system during the natural storage. Based on the accelerated degradation models and natural storage profile of the servo system, we provide and demonstrate a procedure to check the consistency of two mechanisms by checking the correlation and difference of two sets of degradation data. The results indicate that the two degradation mechanisms are significantly consistent with each other.

关键词： reliability enhancement testing (RET) degradation model accelerated equation consistency check Pearson correlation coefficient

Micromagnetic simulation of FeCo write head in perpendicular recording hard disk drives

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Rare Metals 2006年第Z1期25卷 502-508页

作者： quan Liang WEI Dan Lab of Advanced Materials Department of Materials Science and Engineering Tsinghua University Beijing 100084 China Lab of Advanced Materials Department of Materials Science and Engineering Tsinghua University Beijing 100084 China

The single-pole tip (SPT) heads made of the high saturation FeCo ferromagnetic metals are crucial for the actualization of ultrahigh density perpendicular recording. The effective head field distribution in the medium is of key importance for the design of the SPT head, which would be analyzed by micromagnetic simulations in this work. Two 3D micromagnetic models of the SPT head were established to select a more appropriate method of modeling, with a magnetostatic image effect or a real soft magnetic material to model the image of the SPT head in soft under layer (SUL). The results from these two designs were tested and compared to the ideal head field calculated by the Jacobi finite element method (FEM); and the design with the real soft magnetic material as image was proved suitable for simulating the ultrahigh density perpendicular recording write head.

关键词： SPT head perpendicular recording micromagnetic simulation image

双轴应变对NbSe_(2)/MoSi_(2)N_(4)肖特基势垒的调控

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原子与分子物理学报 2025年第5期42卷 182-188页

作者：张宇哲安梦雅谢泉贵州大学大数据与信息工程学院新型光电子材料与技术研究所贵阳550025

最近一种高质量的二维(Two-dimensional,2D)半导体材料MoSi_(2)N_(4)(MSN)在实验上被成功合成,具有优异的电气和机械性能.尽管最近有大量的研究致力于揭示MSN的材料特性,但到目前为止,对MSN的电接触物理特性的探索还比较少.在这项工作中... 详细信息

最近一种高质量的二维(Two-dimensional,2D)半导体材料MoSi_(2)N_(4)(MSN)在实验上被成功合成,具有优异的电气和机械性能.尽管最近有大量的研究致力于揭示MSN的材料特性,但到目前为止,对MSN的电接触物理特性的探索还比较少.在这项工作中,构建了金属-半导体NbSe_(2)/MSN肖特基结并使用第一性原理密度泛函理论计算研究了该肖特基结的材料特性.发现NbSe_(2)/MSN接触具有超低肖特基势垒高度(Schottky barrier height,SBH),这有利于纳米电子学应用.SBH可以通过施加双轴应变的方式进行有效的调控.当施加拉伸应变时能实现NbSe_(2)/MSN肖特基结由p型肖特基接触转变为p型欧姆接触,而当施加较大的压缩应变时能实现p型肖特基接触和n型肖特基接触之间的转换.我们的研究结果为MSN的2D电触点的物理特性提供了见解,并将为设计基于MSN的2D纳米器件的高性能电触点提供关键的一步.

关键词： MoSi_(2)N_(4) NbSe_(2) 肖特基结欧姆接触

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Self-Sustaining of Critical Park Microgrids Integrating Mobile Emergency Generators Subjective to Major Outage

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1441-1453页

作者： quan Sui Lei Zhang School of Electrical and Information Engineering Zhengzhou UniversityZhengzhou 450001China School of Electrical and New Energy Three Gorges UniversityYichang 443002China

In the event of a major power outage,critical park microgrids(PMGs)could be self-sustaining if mobile emergency generators(MEGs)are stationed to share ***,the need for privacy protection and the value of flexible power support on minute-time scales have not been given enough *** address the problem,this paper proposes a new self-sustaining strategy for critical PMGs integrating ***,to promote the cooperation between PMG and MEG,a bi-level benefit distribution mechanism is designed,where the participants'multiple roles and contributions are identified,and good behaviors are also ***,to increase the alliance benefits,three loss coordination modes are presented to guide the power exchange at the minute level between the MEG and PMG,considering the volatility of renewable generation and *** this basis,a multi-time scale power-energy scheduling strategy is formulated via the alternating direction method of multipliers(ADMM)to coordinate the PMG and ***,a dimensionality reduction technology is designed to equivalently simplify the optimization problem to facilitate the adaptive-step-based ADMM *** studies indicate that the proposed strategy achieves the self-sustaining of PMGs integrating MEGs while increasing the economy by no less than 3.1%.

关键词： Distributed optimization loss coordination mode mobile emergency generator park microgrid power-energy self-sustaining privacy protection

Nonlinear autopilot design for interceptors with tail fins and pulse thrusters via θ–D approach

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Journal of Systems Engineering and Electronics 2014年第2期25卷 273-280页

作者： quan Li Di Zhou School of Astronautics Harbin Institute of Technology

The missile autopilot for an interceptor with tail fins and pulse thrusters is designed via the θ-D approach. The nonlin- ear dynamic model of the pitch and yaw motion of the missile is transformed into a linear-like structure with state-dependent coef- ficient （SDC） matrices. Based on the linear-like structure, a θ-D feedback controller is designed to steer the missile to track refer- ence acceleration commands. A sufficient condition that ensures the asymptotic stability of the tracking system is given based on Lyapunov＇s theorem. Numerical results show that the proposed autopilot achieves good tracking performance and the closed-loop tracking system is asymptotically stable.

关键词： blended control nonlinear control suboptimal control,θ-D approach.