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基于剩余碰撞时间的线控制动分层控制策略

江苏大学学报（自然科学版） 2025年第1期46卷 28-35,63页

作者：童叙王宇宁关艺博田韶鹏吴桐武汉理工大学现代汽车零部件技术湖北省重点实验室湖北武汉430070 武汉理工大学汽车零部件技术湖北省协同创新中心湖北武汉430070 武汉理工大学湖北省新能源与智能网联车工程技术研究中心湖北武汉430070 武汉理工大学佛山仙湖实验室广东佛山528200

针对不同制动工况需求的制动策略存在差异的情况,提出一种线控制动分层控制策略.在该分层策略的上层,利用二阶TTC安全碰撞时间模型计算出车辆与前车的剩余碰撞时间,以此作为依据进行制动策略的选取,并建立了汽车二自由度模型、车身法向... 详细信息

针对不同制动工况需求的制动策略存在差异的情况,提出一种线控制动分层控制策略.在该分层策略的上层,利用二阶TTC安全碰撞时间模型计算出车辆与前车的剩余碰撞时间,以此作为依据进行制动策略的选取,并建立了汽车二自由度模型、车身法向受力模型和Burckhardt轮胎模型;在该分层策略的下层,进行了制动力在轮间的分配,使用序列二次规划(SQP)方法,分别在一般制动、紧急制动、失稳制动3种工况下,以轮胎滑移率为对象建立优化函数,对车辆制动力进行了优化分配.使用MATLAB/Simulink和Carsim进行了联合仿真,对所提出3种工况下的制动分配策略进行了有效性验证.结果表明:在一般制动工况下,采用该策略时相比对照工况制动距离减少18.08%,制动时间减少25.12%;在紧急制动工况下,采用该策略时相比对照工况制动距离减少19.17%,制动时间减少12.79%;在失稳制动工况下,该策略可通过轮胎差扭来提升车辆的横向稳定性.采用文中制动策略显著提升了车辆的制动效能.

关键词：线控制动制动力优化分配分层控制序列二次规划方法 ECE法规制动仿真滑模控制碰撞时间

Aggregation of the Adsorbed Proteinsin Solution or on the Surface?

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Chinese Chemical Letters 2002年第3期13卷 262-265页

作者： tong Wen xu 不详

The adsorption of bovine serum albumin (BSA) on porous polyethylene (PE) membrane was studied based on adsorption and desorption measurements as well as FTIR analysis. A different mechanism was proposed which showed that a critical concentration existed in the adsorptional process. Below this concentration, the adsorption seems to be conducted in a normal side-on way; above this concentration, the adsorption is in an aggregation way.

关键词： Bovine serum albumin adsorption desorption FTIR.

Formation estimation and evolution mechanism of the pressure arch for non-circular tunnels under asymmetrical stress field

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Science China(Technological Sciences) 2024年第9期67卷 2919-2938页

作者： SUN ZhenYu ZHANG DingLi xu tong CHEN xu Key Laboratory for Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China

The tunneling-induced stress redistribution is dependent on the tunnel shape and the in-situ stress field, and the previous arch characterization method based on the circumferential or maximum principal stresses is only suitable for the circular tunnels under the hydrostatic stress field. In this study, a unified characterization method of the pressure arch for non-circular tunnels under the arbitrary stress field is proposed. By comparing the variations of compressive stress in different directions due to excavation, the ratio of the most significant increase in compressive stress is presented to characterize the arch effect, and the corresponding numerical algorithm is given. Since the proposed method takes the stress element as the basic analytical model, it can be easily applied to various complex excavation situations. Thereafter, combined with the established folding catastrophic model, an objective and unified quantitative method of the pressure arch boundaries is given. Using the proposed method, the longitudinal evolution of the pressure arch is analyzed. According to the expansion rate of the arch boundaries, three evolution stages including the initial formation, rapid expansion and stabilization are categorized. Parametric studies are conducted to illustrate the effect of ground properties and support stiffness on the pressure arch formation. It is found that the ground strength parameters and burial depth affect the arch range at a decreasing rate, while they have little effect on the arch shape. The lateral pressure coefficient has a significant effect on both the shape and range of the pressure arch. Increasing the support stiffness helps reduce the pressure arch range with a decreasing rate, while the synchronous variation of the elastic moduli of the surrounding rock and support does not affect the arch range under a certain relative elastic modulus. Finally, field monitoring is conducted to validate the proposed method in actual support design.

关键词： pressure arch stress redistribution numerical simulation quantitative characterization longitudinal evolution parametric study

Water Dissociation Phenomena on a Bipolar Membrane──Current-voltage Curve in Relation with IonicTransport and Limiting Current Density

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Chemical Research in Chinese Universities 2001年第4期17卷 457-464页

作者： xu tong-wen YANG Wei-hua Department of Applied Chemistry University of Science and Technology of ChinaHefei 230026P.R.China

The water dissociation mechanism on a bipolar membrane under the electrical field was investigated and characterized in terms of ionic transport and limiting current density. It is considered that the depletion layer exists at the junction of a bipolar membrane, which is coincided with the viewpoint of the most literatures, but we also consider that the thickness and conductivity of this layer is not only related with the increase of the applied voltage but also with the limiting current density. Below the limiting current density, the thickness of the depletion layer keeps a constant and the conductivity decreases with the increase of the applied voltage; while above the limiting current density, the depletion thickness will increase with the increase of the applied voltage and the conductivity keeps a very low constant. Based on the data reported in the literatures and independent determinations, the limiting current density was calculated and the experimental curves Ⅰ-Ⅴ in the two directions were com

关键词： Bipolar membrane Water dissociation Ionic transport Limiting current density

αB-crystallin malondialdehyde,superoxide dismutase, and lutathione peroxidase changes in X-ray irradiated rat lens

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International Journal of Ophthalmology(English edition) 2011年第4期4卷 365-370页

作者： Guo-xu xu, Guo-tong xu Department of Ophthalmology the Second Hospital of Soochow University Suzhou 215004 Jiangsu Province China tongji Eye Institute and Department of Regenerative Medicine Tongji University School of Medicine Shanghai 200092 China

AIM: To evaluate αB-crystallin malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPx) changes in X-ray irradiated rat lens. METHODS: Eight-week-old Sprague-Dawley male rats received X-ray irradiation to the head with rest of the body protected. The exposure dose ranged from 2 to 25 Grays (Gy). The cataract status were examined by slit lamp and rated with 'four-grade systems' post-irradiation. The lens MDA level, and the activities of SOD and GPx were measured in a short-term experiment post-irradiation, and αB-crystallin protein levels were quantified. RESULTS: The lenses of normal control and the X-ray irradiated groups with the dose up to 10 Gy remained transparent throughout the experiment. The lens first appeared tiny scatters, and even lamellar opacities in the posterior capsule 45 days post-irradiation with the dose of 15 Gy, and progressed slowly to the advance stage of cataract; while, for the higher dose (25 Gy), the opacity of lens appeared much earlier, and progressed more rapidly to mature stage of cataract within 1 month. At the end of the observation (90 days post-irradiation), almost all lenses became complete opacity with the higher dose (25 Gy). The degree of lens opacity was rated accordingly. The lens MDA level was increased, and SOD and GPx activities were decreased with a dose-dependent manner post-irradiation. The αB-crystallin protein level was decreased dose-dependently at the end point of observation. CONCLUSION: Oxidative events and αB-crystallin may play important roles in the pathogenesis of cataract in X-ray irradiated rat lens.

关键词： αB-crystallin malondialdehyde superoxide dismutase glutathione peroxidase X-ray irradiation cataract

Influence of Fill Point in Multiple-Heat-Sources Looped District Heating System with Distributed Variable-Speed Pumps

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Journal of Thermal Science 2020年第5期29卷 1206-1222页

作者： xu tong YAN Jing WANG Xinlei WANG Hai ZHU tong WANG Haiying Beijing Huajian Power Design and Research Institute Beijing 101400China School of Mechanical Enginecring Tongji UniversityShanghai 200092China

When regulating a pipe network according to user demand,hydraulic balance and power consumption are crucial factors for a multi-source looped-pipe network applying distributed variable-speed pumps compared to the conventional central circulating pump *** this paper,the influence of the fill point on power consumption and hydraulic balance of the multi-source looped-pipe network was studied.A mathematical model for electricity energy consumption analysis was built and calculated for a large sized looped-pipe network with multiple heat sources and distributed variable-speed *** hydraulic calculation models of each single element,such as pipe,distribution pump,valve,replenishment pump,heat source and substation,were built.A case located in Dezhou city,China was *** results showed that:the maximum power saving(39.2%)could be achieved when each heat source had its own fill point,but the heat sources would not meet their design flows;to meet the design flows of all the heat sources,only one fill point should be necessarily located near the heat source with the lowest flow rate to get the expected hydraulic stability and energy saving.

关键词： district heating central circulating pump distributed variable-speed pumps fill point energy saving

Anodic Oxidation on Structural Evolution and Tensile Properties of Polyacrylonitrile Based Carbon Fibers with Different Surface Morphology

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Journal of Materials Science & Technology 2012年第12期28卷 1123-1129页

作者： Zhaorui Li Jianbin Wang Yuanjian tong Lianghua xu National Carbon Fiber Engineering Research Center Beijing University of Chemical Technology Beijing 100029 China

Polyacrylonitrile （PAN） based carbon fibers with different surface morphology were electrochemically treated in 3 wt% NH4HCO3 aqueous solution with current density up to 3.47 A/m 2 at room temperature, and surface structures, surface morphology and residual mechanical properties were characterized. The crystallite size （La） of carbon fibers would be interrupted due to excessive electrochemical etching, while the crystallite spacing （d（002）） increased as increasing current density. The disordered structures on the surface of carbon fiber with rough surface increased at the initial oxidation stage and then removed by further electrochemical etching, which resulting in continuous increase of the extent of graphitization on the fiber surface. However, the electrochemical etching was beneficial to getting ordered morphology on the surface for carbon fiber with smooth surface, especially when the current density was lower than 1.77 A/m 2 . The tensile strength and tensile modulus could be improved by 17.27% and 5.75%, respectively, and was dependent of surface morphology. The decreasing density of carbon fibers probably resulted from the volume expansion of carbon fibers caused by the abundant oxygen functional groups intercalated between the adjacent graphite layers.

关键词： Carbon fibers Anodic oxidation Structural evolution Tensile property Surface morphology

Prevalence of Falls Among the Rural Elderly-Three PLADs of Western China, 2017–2018

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China CDC weekly 2020年第46期2卷 877-880页

作者： tong xu Hui Han National Center for Women and Children’s Health Chinese Center for Disease Control and PreventionBeijingChina

Summary What is already known about this topic?As population aging becomes serious in China,the elderly health problems stand out *** of falls of the elderly has become an important subject in China’s public health.

关键词： Rural Elderly elderly

Analysis of Stock Splits Based on Risk Theory: Empirical Evidence from the Chinese Stock Markets

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Journal of Systems Science and Information 2022年第1期10卷 19-34页

作者： Shujin WU tong xu MOE Key Laboratory of Advanced Theory and Application in Statistics and Data Science School of StatisticsEast China Normal UniversityShanghai 200062China School of Statistics East China Normal UniversityShanghai 200062China

The paper first analyzes price change due to stock splits in Chinese stock markets,which shows stock prices typically go up for stock *** theoretical analyses based on risk theory are presented to explain the reason,where the method comes from a new perspective and obtained theoretical conclusions show that stock splits typically make stock price go up if risk-compensation function is convex,and go down if risk-compensation function is *** prices typically go up for stock splits because risk-compensation functions are mainly *** obtained conclusions are consistent with the known results in the last three decades.

关键词： stock split risk theory price Chinese stock markets