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Simulation Analysis and Verifcation of Temperature and Stress of Wheel-Mounted Brake Disc of a High-Speed Train

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Chinese Journal of Mechanical Engineering 2022年第4期35卷 331-339页

作者： junsheng qu Wenjing Wang Ziyu Dong Wei Shan School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Department of Locomotive&Vehicle China National Railway Group Co.LtdBeijing 100844China

During the braking process,a large amount of heat energy is generated at the friction surfaces between the brake disc and pads and rapidly dissipates into the disc volume.In this paper,a three-dimensional thermo-mechanical coupling model of high-speed wheel-mounted brake discs containing bolted joints and contact relationships is established.The direct coupling method is used to analyze the temperature and stress of the brake discs during an emergency braking event with an initial speed of 300 km/h.A full-scale bench test is also conducted to monitor the temperatures of the friction ring and bolted joints.The simulation result shows that the surface temperature of the friction ring reaches its peak value of 414°C after 102 s of braking,which agrees well with the bench test result.The maximum alternating thermal stress occurs in the bolt hole where the maximum circumferential compressive stress is−658 MPa and the maximum circumferential tensile stress is 134 MPa.During the braking process,the out-of-plane deformation of the middle part of the friction ring is larger than that of the edge,which increases the axial tensile load of the connecting bolt.This work provides support for the design of brake discs and connecting bolts.

关键词： High speed train Wheel-mounted brake disc Temperature feld Stress feld Thermo-mechanical coupling model Bolt

误诊为亚急性甲状腺炎的急性化脓性甲状腺炎合并颈深部间隙感染伴Lemierre综合征1例报道并文献复习

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中国综合临床 2024年第2期40卷 123-127页

作者：王健楠别瑶阚成霞曹志斌曲俊生张琪孙晓东惠宗光潍坊医学院附属医院内分泌与代谢病科潍坊261031

急性化脓性甲状腺炎(acute suppurative thyroiditis,AST)是一种罕见的甲状腺疾病,多由金黄色葡萄球菌等感染所致,发病初期与亚急性甲状腺炎(subacute thyroiditis,SAT)难以鉴别。现报道1例最初被误诊为SAT的青年男性患者的临床资料,但... 详细信息

急性化脓性甲状腺炎(acute suppurative thyroiditis,AST)是一种罕见的甲状腺疾病,多由金黄色葡萄球菌等感染所致,发病初期与亚急性甲状腺炎(subacute thyroiditis,SAT)难以鉴别。现报道1例最初被误诊为SAT的青年男性患者的临床资料,但临床确切诊断为患有AST合并颈深部间隙感染(deep neck space infections,DNSIs)并伴有Lemierre综合征,并结合相关文献分析其临床特征和治疗过程,希望能提高临床医师对这种疾病的认识。

关键词：急性化脓性甲状腺炎颈深部间隙感染亚急性甲状腺炎 Lemierre综合征

STUDY ON AN OBJECT-ORIENTED FEATURE-BASED CAD OF HYDRAULIC MANIFOLD BLOCK

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Chinese Journal of Mechanical Engineering 2000年第3期13卷 206-211页

作者： Wang Rongliang Ye Bing qu junsheng Chen Ying 浙江大学流体传动及控制国家重点实验室浙江杭州

The technique of object-oriented feature-based solid modeling and its application in the CAD of hydraulic manifold block (HMB) are discussed. The research can greatly improve the convenience and efficiency of product ... 详细信息

关键词： CAD STUDY ON AN OBJECT-ORIENTED FEATURE-BASED CAD OF HYDRAULIC MANIFOLD BLOCK ACIS

Glucagon-Like Peptide-1 receptor expression increased in the brain of type 2 diabetic rats after duodenal-jejunal bypass surgery

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Glucagon-Like Peptide-1 receptor expression increased in the...

Time-Periodic Solutions to quasilinear Hyperbolic Systems on General Networks

中华医学会第十二次全国内分泌学学术会议

作者： RUIYAN PAN QINGTAO YAN junsheng qu JIMA XU HAILIN HAN YIJUN ZHANG MEIHUA qu Department of Pharmacology Wei Fang Medical College Department of Pediatric Surgery Weifang People’s Hospital Department of Endocrinology Affiliated Hospital of Weifang Medical University Department of Gastroenterology Affiliated Hospital of Weifang Medical University

Objective To observe the expression of glucagon-like peptide-1 receptor(GLP-1R) in brain after Duodenal-jejunal Bypass(DJB) in type 2 diabetes mellitus(T2DM) rats.Methods A T2DM rat model was induced by a high fat diet and low doses of streptozotocin(STZ,35 mg/kg).A group of rats were operated by DJB.Body weight,the amount of food and drink consumption, fasting blood glucose and oral glucose tolerance test, insulin resistance were examined before and 1,2,8 weeks after

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Chinese Annals of Mathematics,Series B 2024年第1期45卷 41-72页

作者： Peng qu School of Mathematical Sciences Fudan UniversityShanghai 200433China

For quasilinear hyperbolic systems on general networks with time-periodic boundary-interface conditions with a dissipative structure,the existence and stability of the time-periodic classical solutions are discussed.

关键词： Time-periodic solution quasilinear hyperbolic system General net-work Classical solution Asymptotic stability

Flat jet electrochemical milling of TC4 alloy with tailoring backward parallel flow

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Chinese Journal of Aeronautics 2024年第4期37卷 574-592页

作者： Huanghai KONG Ningsong qu College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

In flat jet electrochemical milling, the electrolyte forms a backward parallel flow after impacting the workpiece, resulting in a weak current density distribution on the workpiece. Poor surface quality usually occurs on the machined titanium alloy surface because it inevitably suffers from the weak current density. In this study, a method of flat jet electrochemical milling with tailoring the backward parallel flow was proposed to eliminate the negative effects caused by the weak current density. Multiphysics simulations are carried out to comprehend the mechanism of flat jetEC milling with tailoring backward parallel flow and better construct the novel tool electrode.Experiments on flat jet electrochemical milling of TC4 alloy with and without tailoring backward parallel flow are conducted. The results reveal that, compared with flat jet electrochemical milling without tailoring backward parallel flow, the recommended tool reduces the surface roughness by86% to 93%, and improves the material removal rate by 93% to 163% with different feed rates.Additionally, the recommended tool is more conducive to maintaining the inherent hardness of the material. Finally, a surface with low Sa of 0.37 μm is obtained.

关键词： Flat jet electrochemical milling TC4 alloy Surface roughness Micro-hardness Material removal rate

Physiological and psychological responses to tended plant communities with varying color characteristics

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Journal of Forestry Research 2024年第1期35卷 183-201页

作者： Siyuan Zheng Yanzhen Zhou Haiyan qu School of Architecture and Urban Planning Shenyang Jianzhu UniversityShenyang 110168People’s Republic of China

Exposure to plants has been reported to promote health and reduce stress,and plant color has direct impacts on physical and mental health.We used images of common types of tended plant communities in Shenyang,China,with combinations of yellow,green,and red foliage,as experimental stimuli.A total of 27 images were used as visual stimuli.We used electroencephalography to measureαwave activity(8-13 Hz)in 40 subjects while they viewed visual stimuli.These data were combined with subjective questionnaire data to analyze the relaxing effect of images of tended plant communities with different color types and proportions on people.The results revealed that,although there were slight differences between the electroencephalography and psychological findings,women were significantly more relaxed than men after viewing the images.Physiological and psychological responses varied with the types and proportions of colors in the tended plant communities:those of foliage with combinations of two or three colors induced stronger responses than images with a single color.Specifically,(1)for one-color plant communities,green or yellow plant communities induced a stronger relaxation effect than red plant communities;(2)for two-color plant communities,the optimal color proportion was 55%+45%,and the green+yellow and green+red color combinations induced a stronger relaxation effect;(3)for three-color plant communities,the relaxation effect was strongest when the color proportion was 55%green+25%yellow+20%red.These data would provide a plant color matching in future plant landscape design,which may be helpful for creating healthy and relaxing environments.

关键词： Plant community Color type Color ratio Electroencephalography Subjective questionnaire

Bacterial Cellulose/Zwitterionic Dual-network Porous Gel Polymer Electrolytes with High Ionic Conductivity

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 596-605页

作者：侯朝霞 WANG Haoran qu Chenying Liaoning Province Key Laboratory of Micro-nano Materials Research and Development School of Mechanical EngineeringShenyang UniversityShenyang 110044China

Bacterial cellulose(BC)was innovatively combined with zwitterionic copolymer acrylamide and sulfobetaine methacrylic acid ester[P(AM-co-SBMA)]to build a dual-network porous structure gel polymer electrolytes(GPEs)with high ionic conductivity.The dual network structure BC/P(AM-co-SBMA)gels were formed by a simple one-step polymerization method.The results show that ionic conductivity of BC/P(AM-co-SBMA)GPEs at the room temperature are 3.2×10^(-2) S/cm@1 M H_(2)SO_(4),4.5×10^(-2) S/cm@4 M KOH,and 3.6×10^(-2) S/cm@1 M NaCl,respectively.Using active carbon(AC)as the electrodes,BC/P(AM-co-SBMA)GPEs as both separator and electrolyte matrix,and 4 M KOH as the electrolyte,a symmetric solid supercapacitors(SSC)(AC-GPE-KOH)was assembled and testified.The specific capacitance of AC electrode is 173 F/g and remains 95.0%of the initial value after 5000 cycles and 86.2%after 10,000 cycles.

关键词： bacterial cellulose zwitterion gel polymer electrolytes ionic conductivity dual-network structure

Effects of wind speed,underlying surface,and seed morphological traits on the secondary seed dispersal in the Tengger Desert,China

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Journal of Arid Land 2024年第4期16卷 531-549页

作者： qu Wenjie ZHAO Wenzhi YANG Xinguo WANG Lei ZHANG Xue qu Jianjun Northwest Institute of Eco-Environment and Resources Chinese Academy of SciencesLanzhou 730000China Key Laboratory of Restoration and Reconstruction of Degraded Ecosystems in Northwestern China of Ministry of Education Ningxia UniversityYinchuan 750021China University of Chinese Academy of Sciences Beijing 100049China School of Ecology and Environment Ningxia UniversityYinchuan 750021China

The maintenance of sand-fixing vegetation is important for the stability of artificial sand-fixing systems in which seed dispersal plays a key role.Based on field wind tunnel experiments using 11 common plant species on the southeastern edge of the Tengger Desert,China,we studied the secondary seed dispersal in the fixed and semi-fixed sand dunes as well as in the mobile dunes in order to understand the limitations of vegetation regeneration and the maintenance of its stability.Our results indicated that there were significant variations among the selected 11 plant species in the threshold of wind speed(TWS).The TWS of Caragana korshinskii was the highest among the 11 plant species,whereas that of Echinops gmelinii was the lowest.Seed morphological traits and underlying surface could generally explain the TWS.During the secondary seed dispersal processes,the proportions of seeds that did not disperse(no dispersal)and only dispersed over short distance(short-distance dispersal within the wind tunnel test section)were significantly higher than those of seeds that were buried(including lost seeds)and dispersed over long distance(long-distance dispersal beyond the wind tunnel test section).Compared with other habitats,the mobile dunes were the most difficult places for secondary seed dispersal.Buried seeds were the easiest to be found in the semi-fixed sand dunes,whereas fixed sand dunes were the best sites for seeds that dispersed over long distance.The results of linear mixed models showed that after controlling the dispersal distance,smaller and rounder seeds dispersed farther.Shape index and wind speed were the two significant influencing factors on the burial of seeds.The explanatory power of wind speed,underlying surface,and seed morphological traits on the seeds that did not disperse and dispersed over short distance was far greater than that on the seeds that were buried and dispersed over long distance,implying that the processes and mechanisms of burial and long-distance dispersal are more complex.In summar

关键词： seed dispersal seed morphological traits wind speed vegetation regeneration wind tunnel Tengger Desert