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Modeling,Simulation and Experiment of Electro-hydraulic Screw Down Servo System of Seamless Tube Rolling Mill

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Chinese Journal of Mechanical Engineering 2011年第1期24卷 113-120页

作者： xu xiaoqing QUAN Long LI Bin GUO Jibao Institute of Mechatronics Engineering Taiyuan University of Technology Taiyuan 030024 China Taiyuan Tongze Heavy Industry Co. Ltd. Taiyuan 030032 China

Electro-hydraulic screw down servo system（HSDS） is widely used in seamless tube rolling mill in western *** in Chinese companies,mechanical screw down system（MSDS） is popularly equipped and has a serious disadvantage that the roller would often be locked when it is *** the purpose of designing the first set of domestic twin-roller,four-cylinder and six-framework electro-hydraulic HSDS of seamless tube rolling mill,an experiment system that can simulate the process of seamless tube rolling is constructed.A digital simulation model of the experiment system is built with AMESim software and validated by comparing the simulation results with experiment *** sudden load response of the screw piston position is studied with the built model and the experiment *** improve the HSDS＇s positioning accuracy with large load,a hybrid control scheme of combining load disturbance feedforward compensation（LDFC） method based on servo valve＇s pressure-stroke feature and anti-saturation integral control（ASIC） is *** results of simulation and experiment indicate that the transient response time of the single-roller HSDS with the proposed scheme decreases from 0.65 s to less than 0.2 s without static *** improve the system dynamic stiffness and production qualified rate,a flow rate feedforward compensation（FFC） control strategy based on oil compressibility to dynamic position error is *** FFC strategy is validated with experiments in which the transient error caused by sudden load is reduced to less than 25% of that without *** extending the simulation model to HSDS of a twin-roller,four-cylinder rolling mill,analyzing the mill deformation,and applying the LDFC,ASIC and FFC to the HSDS,the dynamic performance and positioning accuracy of compensated multi-roller HSDS at biting moment are *** research results provide a theoretical and experimental basis for the design of HSDS of seamless steel tube rolling mill.

关键词： tube rolling mill servo system digital simulation load stiffness

Dynamic and Static Characteristics of Double Push Rods Electromechanical Converter

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Chinese Journal of Mechanical Engineering 2019年第4期32卷 116-126页

作者： xuping Wang Long Quan Shiyi Luan xiaoqing xu College of Electrical and Power Engineering Taiyuan University of Technology Taiyuan 030024China Institute of Mechanical Engineering Taiyuan University ofTechnology Taiyuan 030024 China

Due to the influence of material characteristics and winding power, single output electromagnet has limited ability to improve the dynamic characteristic of electro-hydraulic valve. Therefore, an electromechanical converter with double push rods is proposed in this paper, which can simultaneously output two electromagnetic forces, can push or pull the valve core and sleeve according to the current direction and realize rapid operation of load. According to the electromagnetic principle and the magnetic circuit analysis method, the mathematical model and equivalent circuit of the electromechanical converter with double push rods are established. Through the finite element simulation model of the electromechanical converter with double push rods with the same magnetization directions, the changing rules of its magnetic field distribution and force–displacement behaviors are studied and analyzed. According to the analysis results, the electromagnetic mechanical parameters and mechanical structure of the electromechanical converter with double push rods are determined, and the prototype is made. The test platform for the push-pull characteristics of the electromechanical converter with double push rods is built, and its static and dynamic characteristics are tested and analyzed. The results show that the thrust and pull output characteristics of the internal and external push rods are basically consistent with the simulation output, and proportional to the current density of the coil;the push-pull hysteresis of internal and external push rods output force is less than 5%;and the dynamic time response characteristics of the displacement and force are obtained. The hysteresis e ect of output force is improved e ectively through the H bridge drive control circuit modulated by PWM. Compared with the displacement response of a singlewinding electromagnet with a similar volume, it can e ectively improve the dynamic displacement response. Followup work will further optimize th

关键词： Moving coil motor Double push rods electromagnet Proportional solenoid valve Response characteristics

A New Kind of Pilot Controlled Proportional Direction Valve with Internal Flow Feedback

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Chinese Journal of Mechanical Engineering 2010年第1期23卷 60-65页

作者： QUAN Long xu xiaoqing YAN Zheng ZHANG Xiaojun Institute of Mechatronics Engineering Taiyuan University of Technology Taiyuan 030024 China

Proportional direction valve is one of the most fundamental elements in electronic-hydraulic control technique. Its function is to control the operating speed, direction, position, and strength of output force of the hydraulic actuator continuously. Considering the different application and the cost, the existing technique mainly includes the internal feedback valve used in open loop system, and the electronic closed loop controlled valve used in closed loop system. Because of their different mechanical structure and the gre at different in performance, it brings inconvenience for customer to select, also inconvenience for enterprise to produce. Aiming at this problem, the idea of combining the above two kinds of valves into one body is proposed first, and then the new valve＇s structure to realize this target is designed. The idea intends to apply the displacement pilot flow feedback control principle in present 2-position 2-way valve system to the proportional direction valve of 3-position 4-way system. Newly designed feed forward controller can decouple the interference between the internal feedback and the electronic closed loop. Redundant conversion is designed to electronic switch mode. Experiment on dynamic and static characteristic of new proportional direction valve in internal feedback control mode and electronic closed loop control mode is discussed to prove the new theory is correct. Although the new valve is of excellent dynamic response characteristic, its steady control characteristic in open loop control mode needs to be improved further. The research results prepare one new fundamental element for electronic-hydraulic control technology.

关键词： pilot flow feedback proportional direction valve working principle characteristic research

Accuracy assessment of global vertical displacement loading tide models for the equatorial and Indian Ocean

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Acta Oceanologica Sinica 2024年第9期43卷 11-25页

作者： xiaoqing xu Haidong Pan Fei Teng Zexun Wei First Institute of Oceanography and Key Laboratory of Marine Science and Numerical ModelingMinistry of Natural ResourcesQingdao 266061China Laboratory for Regional Oceanography and Numerical Modeling Qingdao Marine Science and Technology CenterQingdao 266237China Shandong Key Laboratory of Marine Science and Numerical Modeling Qingdao 266061China

The three-dimensional displacements caused by ocean loading effects are significant enough to impact spatial geodetic measurements on sub-daily or longer timescales,particularly in the vertical ***,most tide models incorporate the distribution of vertical displacement loading tides;however,their accuracy has not been assessed for the equatorial and Indian Ocean *** Positioning System(GPS)observations provide high-precision data on sea-level changes,enabling the assessment of the accuracy and reliability of vertical displacement tide ***,because the tidal period of the K_(2) constituent is almost identical to the orbital period of GPS constellations,the estimation of the K_(2) tidal constituent from GPS observations is not *** this study,the principle of smoothness is employed to correct the systematic error in K_(2) estimates in GPS observations through quadratic *** the adjusted harmonic constants from 31 GPS stations for the equatorial and Indian Ocean,the accuracy of eight major constituents from five global vertical displacement tide models(FES2014,EOT11a,GOT4.10c,GOT4.8,and NAO.99b)is evaluated for the equatorial and Indian *** results indicate that the EOT11a and FES2014 models exhibit higher accuracy in the vertical displacement tide models for the equatorial and Indian Ocean,with root sum squares errors of 2.29 mm and 2.34 mm,***,a brief analysis of the vertical displacement tide distribution characteristics of the eight major constituents for the equatorial and Indian Ocean was conducted using the EOT11a model.

关键词： accuracy assessment vertical displacement loading tide models tidal admittance equatorial and Indian Ocean GPS constellation

A harmonic analyzed parameterization of tide-induced mixing for ocean models

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Acta Oceanologica Sinica 2018年第7期37卷 1-7页

作者： WEI Zexun SUN Junchuan TENG Fei xu Tengfei WANG Yonggang xu xiaoqing FANG Guohong The First Institute of Oceanography State Oceanic Administration Functional Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and Technology

The tide-induced mixing plays an important role in the regulation of ocean *** simulation of continental shelf circulation is found to exhibit an unreasonable vertical thermohaline structure without consideration of tide *** this study,we establish a harmonic analyzed parameterization of tide-induced（HAT） mixing,by which means to derive time-depended function of mixing coefficient based on harmonic analysis of the vertical mixing *** employing HAT mixing parameterization scheme,a series of numerical experiments are conducted for the Yellow *** results show that an ocean circulation model with the HAT mixing involved is capable of reproducing the reasonable thermohaline structure of the Yellow Sea Cold Water Mass,similar to structures produced by explicit tidal forcing on the open *** advantage of the HAT method is its faster computation time,compared with models that directly resolve explicit tidal *** HAT parameterization for the tide-induced mixing has potential to improve both the accuracy and efficiency of ocean circulation and climate models.

关键词： tide-induced mixing harmonic analysis parameterization ocean circulation models Yellow Sea Cold Water Mass

Coupling and Coordination Characteristics and Influencing Factors of the Livable Environment System for the Elderly in China

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Chinese Geographical Science 2022年第6期32卷 1052-1068页

作者： CHEN Xiaohong ZHANG Mingxuan WANG Ying xu xiaoqing LIU Shuang MA Lingyu College of Geography Science of Harbin Normal University Harbin 150025China

The construction of a livable environment for the elderly is an important measure to address the challenges of aging and improve their livelihood and *** on China’s national conditions and combined with the actual development needs of the cities,it is of great significance to explore the coupling and coordination characteristics and influencing factors within the livable environment system for the elderly for the coordination and stable *** article was based on the three subsystems of’living service environment,socioeconomic environment and ecological livable environment’,following the research framework of’process-pattern-trend-impact’,constructs an evaluation index system for the livable environment for the *** weight-TOPSIS evaluation model,coupling coordination degree model,center of gravity and standard deviation ellipse model and the geographic detector model were used starting from the evolution of coupling coordination types to study the spatial and temporal pattern and dynamic trend characteristics and influencing factors of internal coupling coordination types in the livable environment system for the elderly from2010 to *** results showed that:1)The coordinated development of life service environment system and ecological livable environment system(LE)and socioeconomic environment system and ecological livable environment system(SE)in the livable environment for the elderly decreased from the intermediate coordination level coordination areas to the low-level quality improvement and optimization areas:coordinated transition *** overall development level of life service environment system and socioeconomic environment system(LS)was low,and it was always at a low level.2)The coupling degree of livable environment system for the elderly was high,the coupling coordination type shown a gradually decreasing layer structure with Zhejiang,Beijing and Guangdong high-level leading demonstration areas as the axis belt.

关键词： livable environment system the elderly coupling coordination degree spatial and temporal pattern dynamic trend influencing factors China

Exopolysaccharides from lactic acid bacteria,as an alternative to antibiotics,on regulation of intestinal health and the immune system

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Animal Nutrition 2023年第2期13卷 78-89页

作者： Shuo Yang xiaoqing xu Qing Peng Lan Ma Yu Qiao Bo Shi Feed Research Institute Chinese Academy of Agricultural SciencesBeijing100081China

Over-use or misuse of antibiotics in livestock and poultry production contributes to the rising threat of antibiotic resistance in animals and has negative ecological *** from lactic acid bacteria(LAB-EPS)are a class of biological macromolecules which are secreted by lactic acid bacteria to the outside of the cell wall during their growth and *** studies demonstrated that LAB-EPS have anti-inflammatory and antimicrobial activities and are able to regulate intestinal health and the immune system in *** are biodegradable,nontoxic and bio-compatible,which are considered as ideal alternatives to *** review aims to discuss and summarize recent research findings of LAB-EPS on regulation of intestinal health and the immune system in animals,and thus provide scientific justification for commercial applications of LAB-EPS in livestock.

关键词： Lactic acid bacteria Exopolysaccharides Intestinal health Immune function

Design for manufacturability and reliability in extreme-scaling VLSI

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Science China(Information Sciences) 2016年第6期59卷 96-118页

作者： Bei YU xiaoqing xu Subhendu ROY Yibo LIN Jiaojiao OU David Z.PAN CSE Department The Chinese University of Hong Kong ECE Department University of Texas at Austin Cadence Design Systems Inc.

In the last five decades, the number of transistors on a chip has increased exponentially in accordance with the Moore’s law, and the semiconductor industry has followed this law as long-term planning and targeting for research and development. However, as the transistor feature size is further shrunk to sub-14 nm nanometer regime, modern integrated circuit(IC) designs are challenged by exacerbated manufacturability and reliability issues. To overcome these grand challenges, full-chip modeling and physical design tools are imperative to achieve high manufacturability and reliability. In this paper, we will discuss some key process technology and VLSI design co-optimization issues in nanometer VLSI.

关键词： design for manufacturability design for reliability VLSI CAD

Cotidal charts and tidal power input atlases of the global ocean from TOPEX/Poseidon and JASON-1 altimetry

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Acta Oceanologica Sinica 2012年第4期31卷 11-23页

作者： WANG Yihang FANG Guohong WEI Zexun WANG Yonggang WANG Xinyi xu xiaoqing Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Ningbo University Ningbo 315211 China First Institute of Oceanography State Oceanic Administration Qingdao 266061 China State Key Laboratory of Satellite Ocean Environment Dynamics Hangzhou 310012 China Graduate School Chinese Academy of Sciences Beijing 100039 China

The global distributions of eight principal tidal constituents, M2, S2, K1, O1, N2, K2, P1, and Q1, are derived using TOPEX/Poseidon and JASON-1（T/P-J） satellite altimeter data for 16 a. The intercomparison of the derived harmonics at 7000 subsatellite track crossover points shows that the root mean square （RMS） values of the tidal height differences of the above eight constituents range from 1.19 cm to 2.67 cm, with an average of about 2 cm. The RMS values of the tidal height differences between T/P-J solutions and the harmonics from ground measurements at 152 tidal gauge stations for the above constituents range from 0.34 cm to 1.08 cm, and the relative deviations range from 0.031 to 0.211. The root sum square of the RMS differences of these eight constituents is 2.12 cm, showing the improvement of the present model over the existing global ocean tidal models. Based on the obtained tidal model the global ocean tidal energetics is studied and the global distribution of the tidal power input density by tide-generating force of each constituent is calculated, showing that the power input source regions of semidiurnal tides are mainly concentrated in the tropical belt between 30S and 30N, while the power input source regions of diurnal tides are mainly concentrated off the tropic oceans. The global energy dissipation rates of the M2, S2, K1, O1, N2, P1, K2 and Q1 tides are 2.424, 0.401, 0.334, 0.160, 0.113, 0.035, 0.030 and 0.006 TW, respectively. The total global tidal dissipation rate of these eight constituents amounts to 3.5 TW.

关键词： satellite altimetry global ocean tides tidal energetics tidal power input