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Minimum Time Overtaking Problem of Vehicle Handling Inverse Dynamics Based on Two Kinds of Safe Distances

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Chinese Journal of Mechanical Engineering 2018年第6期31卷 207-216页

作者： you-qun zhao Xing-Long Zhang Wen-Xin Zhang Fen Lin College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics

Overtaking accidents caused by improper operations performed by a driver occur frequently. However, most stud?ies on overtaking safety have neglected research into driver control input. A novel method is proposed to obtain the driver control input during the overtaking process. Meanwhile, to improve the safety of overtaking, two types of safe distances, and the time of the overtaking are considered. Path constraints are established when considering the two types of safe distances. An optimal control model is established to solve the minimum time maneuver under multiple constraints. Using the Gauss pseudospectral method, the optimal control problem is converted into a nonlinear pro?gramming problem, which is then solved through sequential quadratic programming(SQP). In addition, the e ective?ness of the proposed method is verified based on the results of a Carsim simulation. The simulation results show that by adopting an inverse dynamics method to solve the manipulation problem of the vehicle’s minimum overtaking time, the manipulation capability of a vehicle in completing an overtaking safely within the minimum time can be obtained. This method can provide a reference for research into the active safety of manned and unmanned vehicles.

关键词： Handling inverse dynamics Safe distance Overtaking Optimal control Simulation

Influence Analysis of Machining and Installation Errors on the Radial Stiffness of a Non-Pneumatic Mechanical Elastic Wheel

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Chinese Journal of Mechanical Engineering 2018年第4期31卷 92-100页

作者： you-qun zhao Zhen Xiao Fen Lin Ming-Min Zhu Yao-Ji Deng Department of Automotive Engineering College of Energy and Power EngineeringNanjing University of Aeronautics and Astronautics

Machining and installation errors are unavoidable in mechanical structures. However, the effect of errors on radial stiffness of the mechanical elastic wheel(ME-Wheel) is not considered in previous studies. To this end, the interval mathematical model and interval finite element model of the ME-Wheel were both established and compared with bench test results. The intercomparison of the influence of the machining and installation errors on the ME-Wheel radial stiffness revealed good consistency among the interval mathematical analysis, interval finite element simulation,and bench test results. Within the interval range of the ME-Wheel machining and installation errors, parametric analysis of the combined elastic rings was performed at different initial radial rigidity values. The results showed that the initial radial stiffness of the flexible tire body significantly influenced the ME-Wheel radial stiffness, and the inverse relationship between the hinge unit length or suspension hub and the radial stiffness was nonlinear. The radial stiffness of the ME-Wheel is predicted by using the interval algorithm for the first time, and the regularity of the radial stiffness between the error and the load on the ME-Wheel is studied, which will lay the foundation for the exact study of the ME-Wheel dynamic characteristics in the future.

关键词： Mechanical elastic wheel Stiffness characteristic Errors Interval algorithm Interval finite element

Estimation of Road Friction Coefficient in Different Road Conditions Based on Vehicle Braking Dynamics

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Chinese Journal of Mechanical Engineering 2017年第4期30卷 982-990页

作者： you-qun zhao Hai-Qing Li Fen Lin Jian Wang Xue-Wu Ji College of Energy&Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China School of Automotive Engineering Shandong Jiaotong UniversityJinan 250023China State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing 100084China

The accurate estimation of road friction coeffi- cient in the active safety control system has become increasingly prominent. Most previous studies on road friction estimation have only used vehicle longitudinal or lateral dynamics and often ignored the load transfer, which tends to cause inaccurate of the actual road friction coef- ficient. A novel method considering load transfer of front and rear axles is proposed to estimate road friction coef- ficient based on braking dynamic model of two-wheeled vehicle. Sliding mode control technique is used to build the ideal braking torque controller, which control target is to control the actual wheel slip ratio of front and rear wheels tracking the ideal wheel slip ratio. In order to eliminate the chattering problem of the sliding mode controller, integral switching surface is used to design the sliding mode sur- face. A second order linear extended state observer is designed to observe road friction coefficient based on wheel speed and braking torque of front and rear wheels. The proposed road friction coefficient estimation schemes are evaluated by simulation in ADAMS/Car. The results show that the estimated values can well agree with the actual values in different road conditions. The observer can estimate road friction coefficient exactly in real-time andresist external disturbance. The proposed research provides a novel method to estimate road friction coefficient with strong robustness and more accurate.

关键词： Road friction coefficient Real timeestimation External disturbance Different roadconditions

全谷物及杂豆添加量在小鼠与人体间剂量换算分析

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食品科学 2025年第2期46卷 118-125页

作者：支莉朱益清赵亮星陈睿赵卿宇王超薛勇沈群国家粮食产业(青稞深加工)技术创新中心国家粮油标准测试研究中心中国农业大学食品科学与营养工程学院北京100083

适量摄入全谷物及杂豆可以改善糖代谢和脂代谢,但摄入量过高可能产生不利影响。由于缺乏相应的换算关系,小鼠饲料中的摄入量无法直接作为人群摄入量的参考。本文介绍小鼠饲料中常见的全谷物及杂豆的添加量,并通过等效系数法、比表面积... 详细信息

适量摄入全谷物及杂豆可以改善糖代谢和脂代谢,但摄入量过高可能产生不利影响。由于缺乏相应的换算关系,小鼠饲料中的摄入量无法直接作为人群摄入量的参考。本文介绍小鼠饲料中常见的全谷物及杂豆的添加量,并通过等效系数法、比表面积法、体型系数法、食物比重法、体表面积指数法、能量换算法和营养素换算法探讨了小鼠饲料中全谷物及杂豆添加量与人群膳食推荐量之间的剂量效应关系。研究表明,当人群全谷物及杂豆推荐摄入量为50~150 g时,相当于在每日进食量为3 g的小鼠饲料中添加5%~50%的全谷物及杂豆。对于小鼠而言,饲料中全谷物及杂豆的添加量超过50%可能存在过量摄入的风险。本研究为未来建立全谷物及杂豆在小鼠饲料添加量与人群推荐摄入量之间的换算关系提供了重要参考。

关键词：剂量换算全谷物杂豆体表面积

Association between the SUMO4 M55V Polymorphism and Susceptibility to Type 2 Diabetes Mellitus:A Meta-analysis

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Biomedical and Environmental Sciences 2017年第4期30卷 288-295页

作者： ZHANG qun LIU Di zhao Zhong Yao SUN Qi DING Li Xiang WANG you Xin Chinese Center for Disease Control and Prevention Beijing 102206China Beijing Key Laboratory of Clinical Epidemiology School of Public HealthCapital Medical UniversityBeijing 100069China Department of Orthopedics Surgery Beijing Shijitan HospitalCapital Medical UniversityBeijing 100038China

Objective The aim of this study is to determine whether the SUMO4 M55V polymorphism is associated with susceptibility to type 2 diabetes mellitus （T2DM）. Methods A meta-analysis was performed to detect the potential association of the SUMO4 M55V polymorphism and susceptibility to T2DM under dominant, recessive, co-dominant （homogeneous and heterogeneous）, and additive models. Results A total of eight articles including 10 case-control studies, with a total of 2932 cases and 2679 controls, were included in this meta-analysis. The significant association between the SUMO4 M55V polymorphism and susceptibility to T2DM was observed in the dominant model （GG ＋ GA versus AA： OR = 1.21, 95% CI = 1.05-1.40, P = 0.009）, recessive model （GG versus GA ＋ AA： OR = 1.29, 95% CI = 1.07-1.356, P = 0.010）, homozygous model （GG versus AA： OR = 1.41, 95% CI = 1.06-1.56, P = 0.001）, and additive model （G versus A： OR = 1.18, 95% CI = 1.08-1.29, P = 0.001）, and marginally significant in the heterozygous model （GA versus AA： OR = 1.16, 95% CI = 0.98-1.36, P = 0.080）. In subgroup analyses, significant associations were observed in the Chinese population under four genetic models excluding the heterozygous model, whereas no statistically significant associations were observed in the Japanese population under each of the five genetic models. Conclusion The meta-analysis demonstrated that the G allele of the SUMO4 M55V polymorphism could be a susceptible risk locus to T2DM, mainly in the Chinese population, while the association in other ethnic population needs to be further validated in studies with relatively large samples.

关键词： SUMO4 Type 2 diabetes mellitus (T2DM) Polymorphisms Meta-analysis

Effects of temperature-gradient-induced damage of zirconia metering nozzles

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International Journal of Minerals,Metallurgy and Materials 2017年第9期24卷 999-1003页

作者： Liang zhao qun-hu Xue College of Materials and Mineral Resources Xi’an University of Architecture and TechnologyXi’an 710055China Shaanxi Techno-institute of Recycling Economy Xi’an 710055China

The effects of temperature-gradient-induced damage of zirconia metering nozzles were investigated through analysis of the phase composition and microstructure of nozzle samples. The analysis was carried out using X-ray diffraction and scanning electron microscopy after the samples were subjected to a heat treatment based on the temperatures of the affected, transition, and original layers of zirconia metering nozzles during the continuous casting of steel. The results showed that, after heat treatment at 1540, 1410, or 1300A degrees C for a dwell time of 5 h, the monoclinic zirconia phase was gradually stabilized with increasing heat-treatment temperature. Moreover, a transformation to the cubic zirconia phase occurred, accompanied by grain growth, which illustrates that the temperature gradient in zirconia metering nozzles affects the mineral composition and microstructure of the nozzles and accelerates damage, thereby deteriorating the quality and service life of the nozzles.

关键词： temperature gradient zirconia metering nozzles mineral composition microstructure damage mechanism

A new forwarding address for next generation networks

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第1期13卷 1-10页

作者： A-qun zhao Man-gui LIANG School of Computer and Information Technology Beijing Jiaotong University Beijing 100044 China

The forwarding address plays an important role in constructing a communication network. In this paper, a new forwarding address suitable for next generation networks named the vector address （VA） is proposed which is different from the forwarding address coding methods of current networks. The characteristics of the VA are analyzed. Complex network theory and a theoretical analysis method are introduced to study the average address length of the VA when used to construct a global network Simulation experiments in a practical network topology model are carried out to validate the results. The results show that not only can the VA construct a simpler, more secure, and more scalable network, but it also can accommodate many more users than an Internet Protocol （IP） network with the same address length.

关键词： Next generation networks (NGN) Forwarding address Vector address (VA) Complex network

CO_(2)geological sequestration potential of the low-rank coals in the southern margin of the Junggar Basin

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Frontiers of Earth Science 2023年第3期17卷 727-738页

作者： qun zhao Ze DENG Meng zhao Dexun LIU Research Institute of Petroleum Exploration&Development PetroChinaBeijing 100083China PetroChina Southwest Oil&Gasfield Company Chengdu 610051China

Carbon capture,utilization,and storage(CCUS)is considered one of the most effective measures to achieve net-zero carbon emissions by 2050,and low-rank coal reservoirs are commonly recognized as potential CO_(2)storage sites for carbon *** evaluate the geological CO_(2)sequestration potential of the low-rank coal reservoirs in the southern margin of the Junggar Basin,multiple experiments were performed on coal samples from that area,including high-pressure mercury porosimetry,low-temperature N2 adsorption,overburden porosity and permeability measurements,and high-pressure CH4 and CO_(2)isothermal adsorption *** with the geological properties of the potential reservoir,including coal seam development and hydrodynamic characteristics,the areas between Santun River and Sigong River in the Junggar Basin were found to be suitable for CO_(2)***,the coal-bearing strata from Santun River to Sigong River can be defined as“potentially favorable areas for CO_(2)eequetfraiion”To better guide the future field test of CO_(2)storage in these areas,three CO_(2)sequestration modes were defined:1)the broad syncline and faulted anticline mode;2)the monoclinic mode;3)the syncline and strike-slip fault mode.

关键词： CO_(2)geological sequestration coalbed methane low-rank coal coal reservoir Junggar Basin

Dynamic Vertical Climbing Mechanism of Chinese Dragon-Li Cats Based on the Linear Inverted Pendulum Model

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Journal of Bionic Engineering 2023年第1期20卷 136-145页

作者： qun Niu Jieliang zhao Lulu Liang Jin Xing School of Mechanical Engineering Beijing Institute of TechnologyBeijing100081China

Humans have long desired but never achieved the capacity to climb *** fundamental reason is that human hands and feet cannot climb vertical walls like geckos and *** lacking an adhesive structure can use the body’s dynamic effect to climb *** we investigated the dynamic wall climbing behavior of individuals who cannot remain stationary on the vertical *** the domestic cat as the experimental object,we constructed an experimental platform as the obstacle for the cat to climb the *** research indicated that domestic cats must meet the following physical conditions to do dynamic vertical wall climbing:vertical obstacles must have nonvertical surfaces,a horizontal run-up,and contact with nonvertical surfaces before the vertical speed reduces to *** we proposed a dynamic vertical wall climbing model with three contact states based on an investigation of domestic cats’dynamic wall climbing behavior and the LIP *** motion range of the LIP model’s generalized angular coordinates varies depending on the contact *** horizontal run-up action can improve the jumping height and obtain horizontal *** making contact with the vertical surface of the obstacle,the motion inertia in the horizontal direction can produce a reaction force on the contact surface,which can compensate for the influence of some *** alternating contact strategy lets cats switch different initial and end contact *** investigation clarifies the essential process underlying animals’dynamic vertical wall climbing and establishes the theoretical foundation for the legged robot to do dynamic vertical wall climbing.

关键词： Domestic cats Dynamics Vertical climbing LIP Bionic