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Zero-Magnetic-Field Oscillation of Spin Transfer Nano-Oscillator with a Second-Order-Perpendicular-Anisotropy Free Layer

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Chinese Physics Letters 2016年第3期33卷 107-110页

作者：郭园园赵飞飞薛海斌刘喆颉 Key Laboratory of Advanced Transducers & Intelligent Control System(Ministry of Education) Taiyuan University of Technology College of Physics & Optoelectronics Taiyuan University of Technology

The zero-magnetic-field oscillation behavior of spin torque nano-oscillator （STNO） with a perpendicularly mag- netized free layer with second-order uniaxial anisotropy is studied theoretically based on the Landau-Lifshitz- Cilbert-Slonczewski equation. It is demonstrated numerically that the second-order uniaxial anisotropy plays a significant role in the occurrence of a zero-magnetic-field steady-state precession, which can be understood in terms of the energy balance between the energy accumulation due to the spin torque and the energy dissipation due to the Gilbert damping. In particular, a relatively large zero-magnetic-field-oscillation current region, in which the corresponding microwave frequency is increased while the threshold current still maintains an almost constant value, can be obtained by modulating the second-order uniaxial anisotropy of the free layer. These results suggest a tunable zero-magnetic-field STNO, and it may be a promising configuration for STNO＇s applications in future wireless communications.

关键词： of on in is it as Zero-Magnetic-Field Oscillation of Spin Transfer Nano-Oscillator with a Second-Order-Perpendicular-Anisotropy Free Layer with

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A threshold segmentation method for non-uniform illumination image based on brightness equalization

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IOP Conference Series: Materials Science and Engineering 2019年第5期569卷

作者： Hui Guo Peng Chen Shun Huang Cong Hu Lijun Zhang School of Automation China University of Geosciences Wuhan 430074 China Hubei key laboratory of Advanced Control and Intelligent Automation for Complex System Wuhan 430074 China

In the process of image acquisition, non-uniform illumination images are common due to poor lighting, surface reflection, or a combination of these two factors. In order to improve the quality of image segmentation, an image threshold segmentation method is proposed for non-uniform illumination images. First, the brightness of different regions in the image is compensated to make the brightness background of the whole image consistent. Second, the gradation histogram of the processed image is obtained and simulated into Gaussian distribution curve, then the inflection points of the curve are calculated. Finally, the two inflection points are set as thresholds to segment the image after brightness equalization. This method eliminates the influence of non-uniform illumination to a certain extent and gets a better segmentation effect. Experiments were carried out on images containing several different types of non-uniform illumination. The results demonstrate that the proposed method outperforms the compared enhancement algorithms in threshold segmentation.

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Image retrieval based on convolutional neural network and linear discriminate analysis

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IOP Conference Series: Materials Science and Engineering 2019年第5期569卷

作者： Wei Xia Cong Hu Xianghui Cheng Peng Chen Xing Jin School of Automation China University of Geosciences Wuhan 430074 China Hubei key laboratory of Advanced Control and Intelligent Automation for Complex System Wuhan 430074 China

Image retrieval is a hot research topic in the field of computer vision image processing, and the user queries the image database for similar images and produces a list of recommendations. The paper firstly sets forth the research status of image retrieval, then the convolution neural network is briefly introduced. Due to the traditional image retrieval and recommendation system use manual extraction of image features is relatively cumbersome, and the retrieval accuracy is not high research status, the paper proposes an image retrieval method based on the improved convolutional neural network and linear discriminate analysis. Caltech256 and CIFAR-10 datasets were trained using the model in this paper, experimental, results show that the proposed method can effectively improve the performance of retrieval.

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Development of a New Fluid Shearing system for Cell Culture in Vitro

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IOP Conference Series: Materials Science and Engineering 2019年第1期626卷

作者： Pengfei Wu Xin Wang Lilan Gao Chunqiu Zhang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin 300384 China

Cells in organisms are surrounded by fluid environment, and the fluid shear force produced by this fluid affects the morphology and behaviour of cells. The stimulation of cells in a bioreactor is a key area of research in tissue engineering and regenerative medicine. This paper introduces a fluid shear system for cell culture in vitro. The main component of system is a perfusion chamber, which consists of an inoculation room and a perfusion cap. The inoculation room is used for the common laboratory consumables of microorganism or cell culture, such as petri dish, six-well plate and so on. It can realize to six independent experiments of fluid shear; the new type of perfusion cap was designed to obtain a reasonable cavity by hydrodynamic simulation. The cap was produced by casting technology. It not only has the function of cap with nozzles, but also has the function of sealing. With peristaltic pumps, nozzles, liquid storage bottles and so on, the fluid shearing system which can provide uniform, controllable and up to 60 dyn/cm2 shear stress along the bottom surface is constructed, and is easy to operate and can be personalized.

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Whispering Gallery Mode Resonances of Perovskite Nanoplatelets

Whispering Gallery Mode Resonances of Perovskite Nanoplatele...

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第四届新型太阳能电池学术研讨会

作者： Guohui Li Weimin Kong Qiangbing Liang Xingqi Ji Ting Ji Yuying Hao Yanxia Cui Key Laboratory of Advanced Transducers and Intelligent Control System (Ministry of Education) College of Physics and Optoelectronics Taiyuan University of Technology

Organic-inorganic hybridized perovskites have attracted more and more attention due to their advantages such as high absorption coefficients, direct band-gap, long carrier lifetimes, balanced electron/hole mobility, ***-scaled perovskites, which possess naturally-formed optical feedback, can excite resonance under certain incident light and realize the precise light management as *** 2014, Ha et *** lead halide perovskite nanoplatelets with regular triangular or hexagonal morphologies by vapor phase deposition techniques on mica plate [1].Later, they realized lasing based on the whispering-gallery modes at the near-infrared range using the prepared perovskite nanoplatelets [2].Here, we first synthesized lead iodide nanoplatelets with well-defined crystal boundaries and then successfully conversed the pre-grown lead iodide template into perovskite nanoplatelets by placing the substrate exactly above the methyl iodide amine powder in Ar gas condition with all valves of the quartz tube *** a continuous-wave laser at 325 nm, we measured the photoluminescence spectra of different perovskite nanoplatelets and observed the whispering gallery modes over the spontaneous emission band.

关键词： Perovskite Whispering gallery mode Nanoplatelet Vapor phase Resonance

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Synchronization of fractional-order gene regulatory network with delay 36

Synchronization of fractional-order gene regulatory network ...

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第36届中国控制会议

作者： Feng Liu Zhe Zhang Ren Jie Sun Fenglan School of Automation China University of Geosciences Hubei key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Research Center of System Theory & Application Chongqing University of Posts and Telecommunications

ISBN: (纸本)9781538629185

This paper investigates the problem of Synchronous control of Fractional gene regulatory *** on the Lyapunov stability judgment method,we apply two kinds of control method,adaptive projection control and adaptive sliding mode control,for making system ***,a numerical simulation example is provided to verify the effectiveness and the benefit of the proposed synchronicity criterion.

关键词： Fractional-order synchronization adaptive projection control adaptive sliding mode control

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Design and kinematic analysis of a novel over constrained parallel manipulator

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Paper Asia 2018年第Compendium3期2018卷 87-93页

作者： Zhang, Chao Li, Bin Guo, Peng Zhao, Xinhua Yang, Yuwei Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education [Tianjin University of Technology United States

In this paper, a novel over constrained 2-RRU&RSR parallel manipulator is proposed and analysed. This mechanism is composed of a moving platform and a base, which connected by two identical RRU limbs and one RSR limb. Here, R stand for the revolute, U and S represent universal and spherical joints respectively. Three revolute joints, fixed on the base, are set to be actively actuated. The moving platform of the structure can realize two rotational and one translational freedoms. The design process and kinematic performances are studied in this paper. Firstly, the configuration design and structure characteristics of the mechanism are expounded. Secondly, the number and the properties of degrees of freedom (DOF) of the mechanism are analysed using screw theory. Thirdly, the kinematic problems, including the inverse analyses and the forward position analyses, are solved analytically. Then, the performance of the mechanism, such as reachable workspace, transmission capability, are analysed. Finally, some numerical examples and conclusions of the mechanism are pointed out, and the potential applications of the mechanism are suggested.

关键词： Degrees of freedom (mechanics)

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The distributed parameter model of hydraulic axial piston motor and its application in hydraulic excavator swing system

The distributed parameter model of hydraulic axial piston mo...

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作者： Gao, Youshan Huang, Weinan Quan, Long Lan, Yuan Huang, Jiahai Key Laboratory of Advance Transducers and Intelligent Control System Ministry of Education School of Mechanical Engineering Taiyuan University of Technology Taiyuan030024 China School of Mechanical Engineering Taiyuan University of Science and Technology Taiyuan China

Hydraulic axial piston motor is one of the fundamental components in hydraulic systems;it is widely used in engineered machine, especially in high-power drive or reciprocating motion, such as hydraulic excavator. For hydraulic axial piston motor efficient planning, in addition designing and controlling are required for system operating safety and efficiency. Simulation delivers an advantage over analytical approaches and allows better understanding of the motor performance. For multi-piston hydraulic motor, one of the simulation methods, distributed parameter model, could analyze the detailed performance in each piston chamber. Therefore, in this study, we investigate the characteristics of hydraulic axial piston motor by setting up a distributed parameter model based on physical prototype, which includes mechanical-hydraulics coupling process. The effects of the dynamic pressure inside the piston chamber, the fluidic compressibility and other related parameters are considered in the coupling process. At the same time, the distributed parameter model of hydraulic axial piston motor was used in the simulation model of hydraulic excavator. The results indicate that in two-way hydraulic axial piston motor, the valve plane should adopt symmetrical structure, and silencing groove set should be put on both ends of the valve plane slots, which could reduce pressure ripple and overshoot in the piston chamber. Furthermore, the torque characteristics are highly affected by the clearance between the piston and the cylinder bore. Through this research, we may have a better understanding about the mechanism of output torque fluctuation in hydraulic axial piston motor, and the pressure ripple and overshoot in the piston chamber due to through-flow area discontinuity between the silencing groove and the ends of the valve plane slots. The model is verified using a nine-piston hydraulic motor in hydraulic excavator. © Institution of Mechanical Engineers.

关键词： Pistons

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A NSGA-II based Peak Load Shifting Optimization Method for Customers with Distributed Generators Considering Time-of-use Price

A NSGA-II based Peak Load Shifting Optimization Method for C...

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Chinese control Conference

作者： Hao Zhou Min Ding Bo Hu Qingyi Wang Zhili Tan Danyun Li Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex System Wuhan P. R. China Global Energy Interconnection Development and Cooperation Organization Beijing P. R. China

With the extensive use of distributed generation, the traditional demand response analysis cannot meet the current requirements. This paper proposes a NSGA-II based peak load shifting optimization method for customers with distributed generators considering time-of-use price. Firstly, a fuzzy classification method divides the daily power into three time segments, peak hours, flat hours and valley hours. Secondly, on the basis of the time-of-use price, a peak load shifting optimization model is built with constraints and the objectives of minimizing the peak load, maximizing the valley load, and minimizing the peak-valley difference. Then, a NSGA-II based optimization method solves the optimal model and obtains the optimal electricity prices of different time segments to shift the peak load and the valley load. Finally, the simulation results shows the effectiveness of the proposed method.

关键词： Load management Load modeling Real-time systems Mathematical model Distributed power generation Optimization Heuristic algorithms

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Fabrication of ordered micro- and nano-scale patterns based on optical discs and nanoimprint

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Optoelectronics Letters 2016年第4期12卷 241-244页

作者：郭慧晶张校亮李晓春 Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi ProvinceColleges of Physics and Optoelectronics Taiyuan University of Technology

A simple method to fabricate one-dimensional(1-D) and two-dimensional(2-D) ordered micro- and nano-scale patterns is developed based on the original masters from optical discs, using nanoimprint technology and soft stamps. Polydimethylsiloxane(PDMS) was used to replicate the negative image of the 1-D grating pattern on the masters of CD-R, DVD-R and BD-R optical discs, respectively, and then the 1-D pattern on one of the PDMS stamps was transferred to a blank polycarbonate(PC) substrate by nanoimprint. The 2-D ordered patterns were fabricated by the second imprinting using another PDMS stamp. Different 2-D periodic patterns were obtained depending on the PDMS stamps and the angle between the two times of imprints. This method may provide a way for the fabrication of complex 2-D patterns using simple 1-D masters.

关键词： Compact disks Fabrication Microchannels Nanotechnology Optical data storage Optical disk storage Polydimethylsiloxane Silicones

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