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Comparison on Thermodynamic Performances between Basic and Regenerative Sub-Critical Organic Rankine Cycles Coupled with Low Grade Heat Source

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IOP Conference Series: Materials Science and Engineering 2019年第1期473卷

作者： Pengfei Yuan Chao Zhang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control 300384 Tianjin China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education (Tianjin University of Technology) Tianjin 300384 China

The coupling effects of low grade heat source on thermodynamic performances of both the basic and regenerative sub-critical Organic Rankine cycle (ORC) systems are investigated and compared. Turbine inlet pressure and turbine inlet temperature are treated as independent variables. The system exergy efficiency is selected as the thermodynamic performance criterion. The waste hot water with temperature range of 373.15K to 423.15K is selected as the low grade heat source. Optimization studies are carried out by using eight common organic working fluids to recover heat energy, and relevant operating conditions are obtained respectively. The results indicate that both hot fluid inlet temperature and the allowable minimum hot fluid outlet temperature influence the optimal working fluid, relevant turbine inlet condition and system exergy efficiency. Optimal system exergy efficiency increases monotonously with increasing of hot fluid temperature for both ORC systems above. In comparison to the basic cycle configuration, optimal system exergy efficiency for the regenerative system using the same working fluid is not changed if relevant turbine inlet vapor is saturated, but is significantly improved if relevant turbine inlet vapor is overheating. Besides, the optimal working fluid is dependent on the heat source temperature and specific cycle configuration.

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Flow Mechanism of Cooling Effectiveness Improvement for the Cylindrical Film Cooling Hole with Contoured Craters

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IOP Conference Series: Materials Science and Engineering 2019年第1期473卷

作者： Linchao Bai Chao Zhang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control 300384 Tianjin China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education (Tianjin University of Technology) Tianjin 300384 China

In this paper, a typical cylindrical hole with contoured craters is investigated in terms of the downstream flow field by numerical method at blowing ratios of 0.5, 1 and 1.5. The flow field and the cooling effectiveness are analyzed using three-dimensional Reynolds-averaged Navier-Stokes equations with the shear stress transport turbulence model. In comparison to the cylindrical hole, the cratered hole shows a wider coolant coverage in lateral direction and a lower penetration into the mainstream flow due to the larger hole exit area. Moreover, the interaction between the coolant and the curved protrusion induces a new anti-kidney-shaped vortex pair, which can obviously improve the cooling coverage and thus the cooling effectiveness. The area-averaged cooling effectiveness for the cratered hole is always higher than that for the cylindrical hole at all three blowing ratios.

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Micro-Mechanism of Silicon-Based Waveguide Surface Smoothing in Hydrogen Annealing

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Chinese Physics Letters 2016年第12期33卷 110-114页

作者：段倩倩任馨宇菅傲群张辉冀健龙张强张文栋桑胜波 Micro Nano System Research Center College of Information EngineeringTaiyuan University of Technology(Ministry of Education)Taiyuan University of Technology Key Laboratory of Advanced Transducers and Intelligent Control System(Ministry of Education) Taiyuan University of Technology

The micro-mechanism of the silicon-based waveguide surface smoothing is investigated systematically to explore the effects of silicon-hydrogen bonds on high-temperature hydrogen annealing waveguides. The effect of silicon- hydrogen bonds on the surface migration movement of silicon atoms and the waveguide surface topography are revealed. The micro-migration from an upper state to a lower state of silicon atoms is driven by silicon- hydrogen bonding, which is the key to ameliorate the rough surface morphology of the silicon-based waveguide. The process of hydrogen annealing is experimentally validated based on the simulated parameters. The surface roughness declines from 1.523nm to 0.461 nm.

关键词： of on Micro-Mechanism of Silicon-Based Waveguide Surface Smoothing in Hydrogen Annealing in is

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Nanodevices: Record‐Low‐Threshold Lasers Based on Atomically Smooth Triangular Nanoplatelet Perovskite (Adv. Funct. Mater. 2/2019)

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advanced Functional Materials 2019年第2期29卷

作者： Guohui Li Tao Che Xingqi Ji Shaoding Liu Yuying Hao Yanxia Cui Shengzhong Liu Key Lab of Advanced Transducers and Intelligent Control System of Ministry of Education College of Physics and Optoelectronics Key Laboratory of Interface Science and Engineering in Advanced Materials Taiyuan University of Technology Taiyuan 030024 P. R. China State Key Laboratory of Quantum Optics and Quantum Optics Devices Shanxi University Taiyuan 030006 P. R. China Key Laboratory of Applied Surface and Colloid Chemistry National Ministry of Education Shaanxi Engineering Lab for Advanced Energy Technology School of Materials Science and Engineering Shaanxi Normal University Xi'an 710119 P. R. China

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Theoretical prediction and experimental testing of mechanical properties for 3d printed silk fibroin-type II collagen scaffolds for cartilage regeneration

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MCB Molecular and Cellular Biomechanics 2018年第2期15卷 85-98页

作者： Gao, Lilan Yuan, Qingxian Li, Ruixin Chen, Lei Zhang, Chunqiu Zhang, Xizheng Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin30000 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300000 China Hospital of Stomatolgy NanKai University Tianjin300000 China

Silk fibroin-type II collagen scaffold was made by 3D printing technique and freeze-drying method, and its mechanical properties were studied by experiments and theoretical prediction. The results show that the three-dimensional silk fibroin-typeII collagen scaffold has good porosity and water absorption, which is (89.3%+3.26%) and (824.09%+93.05%), respectively. With the given strain value, the stress of scaffold decreases rapidly firstly and then tends to be stable during the stress relaxation. Both initial and instantaneous stresses increase with increase of applied strain value. The creep strains of scaffold with different stress levels show the two stages: the rapidly increasing stage and the second stable stage. It is noted that the scaffold with compressive stress of less than 35 kPa can recover when the compressive stress is removed. However when the compressive stress is higher than 50 kPa, the scaffold is damaged and its structure is destroyed. Not only the compressive property but tensile property of scaffold are dependent on the applied displacement rate or strain rate. Its compressive elastic modulus and tensile modulus increase with increase of strain rate or displacement rate. The nonlinear relaxation model and creep model were constructed respectively and applied to predict the stress relaxation behavior and creep behavior of scaffold. It is found that there are good agreements between the experimental data and predictions, which mean that the built theoretical model can predict the mechanical behavior of scaffold. Copyright © 2018 Tech Science Press.

关键词： Strain rate

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Influence of Micro-texture Parameters on Bone Drilling Force and Torque: A Finite Element Model

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IOP Conference Series: Materials Science and Engineering 2019年第1期470卷

作者： Yahui Hu Xiangjun Li Chuncheng Chen Lili Su Qingchun Zheng Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin 300384 China Tianjin University of Technology 391 Binshui West Road Xiqing District Tianjin 300384 China.

The micro-texture on the tool surface is an effective way to improve the quality of the drilling. While high-performance micro-texture plays an important role in improving the quality of working surface and prolonging the life of tool. In this study, a three-dimensional finite element model was established to study the relationship between drilling thrust, torque and microstructure parameters (micro-pit depth, micro-pit diameter and micro-pit spacing) during drilling of cortical bone. The model was validated by cortical bone drilling using a micro-structured tool. On basis of this, the thrust and torque prediction models of the micro-texture parameters were obtained. The results indicate that the thrust and torque increased with the increase of micro-pit diameter; while the increase of the micro-pit spacing caused the thrust and torque to decrease. When the depth of the micro-pit increased, the thrust and torque decreased first and then increased, and we found that the effect of micro-pit spacing and micro-pit depth on force and torque is insignificant.

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An approach of joint-space trajectory generation 5

An approach of joint-space trajectory generation

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5th International Workshop on advanced Computational Intelligence and intelligent Informatics, IWACIII 2017

作者： Chen, Xin Jiang, Chen-Xu Zhou, Li School of Automation China University of Geosciences Wuhan430074 China Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex System Wuhanz430074 China School of Arts and Communication China University of Geosciences Wuhan430074 China

Trajectory generation is a prerequisite for robot control system and is divided into two regions, Cartesian space and joint space. This paper presents an approach to generate the trajectory in joint-space. This method uses normalization and transformation of the sine function to generate the desired trajectory, which is more smooth and continuous than the parabolic method in multiple time derivatives of the joint parameter. Compared with the third order polynomial method, this approach can depress the unacceptable infinite spikes in the jerk, which is the derivative of acceleration. Besides, the using of normalization in this approach is to make it more convenient and efficient be applied.

关键词： Trajectories

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Author Correction: Effects of Precipitates Evolution on Low Stress Creep Properties in P92 Heat-resistant Steel

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Scientific reports 2019年第1期9卷 9567页

作者： Hongguang Han Junjie Shen Jiaxing Xie Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin 300384 China. National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin 300384 China. Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin 300384 China. 58920151@***. National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin 300384 China. 58920151@***.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

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An automated pulmonary parenchyma segmentation method based on an improved region growing algorithm in PET-CT imaging

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Frontiers of Computer Science 2016年第1期10卷 189-200页

作者： Juanjuan ZHAO Guohua JI Xiaohong HAN Yan QIANG Xiaolei LIAO College of Computer Science and Technology Taiyuan University of Technology Taiyuan 030024 China Key Laboratory of Advanced Transducers and Intelligent Control Systems Taiyuan University of Technology Taiyuan 030024 China

To address the incomplete problem in pulmonary parenchyma segmentation based on the traditional methods, a novel automated segmentation method based on an eight- neighbor region growing algorithm with left-right scanning and four-corner rotating and scanning is proposed in this pa- per. The proposed method consists of four main stages： image binarization, rough segmentation of lung, image denoising and lung contour refining. First, the binarization of images is done and the regions of interest are extracted. After that, the rough segmentation of lung is performed through a general region growing method. Then the improved eight-neighbor region growing is used to remove noise for the upper, mid- dle, and bottom region of lung. Finally, corrosion and ex- pansion operations are utilized to smooth the lung boundary. The proposed method was validated on chest positron emis- sion tomography-computed tomography （PET-CT） data of 30 cases from a hospital in Shanxi, China. Experimental results show that our method can achieve an average volume overlap ratio of 96.21 ± 0.39% with the manual segmentation results. Compared with the existing methods, the proposed algorithm segments the lung in PET-CT images more efficiently and ac- curately.

关键词： pulmonary parenchyma segmentation bot-tom region of lung image binarization iterative threshold seeded region growing four-corner rotating and scanning,denoising contour refining PET-CT

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Stability and Neimark-Sacker bifurcation analysis for single gene discrete system with delay

Stability and Neimark-Sacker bifurcation analysis for single...

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Chinese control Conference

作者： Feng Liu Qicheng Mei Fenglan Sun Xinmei Wang Hua O. Wang Hubei key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Wuhan China School of Automation China University of Geosciences Wuhan China Research Center of System Theory and Application Chongqing University of Posts and Telecommunications Chongqing China Department of Mechanical Engineering Boston University Boston MA USA

The network structure and functional properties of gene regulatory system and their relationships arc an important research field in systems biology. In this paper, a new improved model is proposed based on the study of gene expression process. The model takes into account the effect of protein concentration on the gene expression, so as to obtain a new bifurcation point and improve the performance of the system. The validity of the model is verified by theoretical analysis and data simulation.

关键词： Mathematical model Proteins Stability analysis Bifurcation Biological system modeling Delays RNA

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