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Thermal shock of subsurface material with plastic flow during scuffing

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Friction 2023年第1期11卷 64-75页

作者： Chuanwei ZHANG Han ZHAI Dong SUN dezhi zheng Xiaoli ZHAO Le GU Liqin WANG MIIT Key Laboratory of Aerospace Bearing Technology and Equipment Harbin Institute of TechnologyHarbin 150001China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150080China

The thermal shock of subsurface material with shear instability and severe plastic flow during scuffing was investigated.The scuffing damage of M50 steel was tested using a high-speed rolling-sliding contact test rig,and the transient temperature during scuffing was calculated using the Fourier transform method considering the effects of both frictional heat and plastic work.The results show that a thermal shock with a rapid rise and subsequent rapid decrease in the contact temperature is generated in the subsurface layers.The frictional power intensity generates a high temperature rise,leading to the austenitization of the subsurface material.Consequently,the plastic flow is generated in the subsurface layer under the high shear stress,and the resulting plastic strain energy generates a further temperature increase.Subsequently,a rapid decrease in the contact temperature quenches the material,resulting in clear shear slip bands and retained austenite in the subsurface layers of the M50 steel.

关键词： scuffing thermal shock high temperature plastic flow

Dual Attention Based Feature Pyramid Network

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China Communications 2020年第8期17卷 242-252页

作者： Huijun Xing Shuai Wang dezhi zheng Xiaotong Zhao College of Software Beihang UniversityBeijing 100191China Research Institute for Frontier Science Beihang UniversityBeijing 100191China School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

Object detection could be recognized as an essential part of the research to scenarios such as automatic driving and pedestrian detection, etc. Among multiple types of target objects, the identification of small-scale objects faces significant challenges. We would introduce a new feature pyramid framework called Dual Attention based Feature Pyramid Network(DAFPN), which is designed to avoid predicament about multi-scale object recognition. In DAFPN, the attention mechanism is introduced by calculating the topdown pathway and lateral pathway, where the spatial attention, as well as channel attention, would participate, respectively, such that the pyramidal feature maps can be generated with enhanced spatial and channel interdependencies, which bring more semantical information for the feature pyramid. Using the COCO data set, which consists of a considerable quantity of small-scale objects, the experiments are implemented. The analysis results verify the optimized performance of DAFPN compared with the original Feature Pyramid Network(FPN) specifically for the identification on a small scale. The proposed DAFPN is promising for object detection in an era full of intelligent machines that need to detect multi-scale objects.

关键词： object detection convolutional neural networks feature pyramid

A high-precision multi-dimensional microspectroscopic technique for morphological and properties analysis of cancer cell

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Light(Science & Applications) 2023年第6期12卷 1117-1126页

作者： Lirong Qiu Yunhao Su Ke-Mi Xu Han Cui dezhi zheng Yuanmin Zhu Lin Li Fang Li Weiqian Zhao MIIT Key Laboratory of Complex-field Intelligent Exploration School of Optics and PhotonicsBeijing Institute of Technology100081 BeijingChina Department of Gastroenterology Aerospace Central HospitalPeking University Aerospace School of Clinical Medicine100081 BeijingChina Department of Pathology Aerospace Central HospitalPeking University Aerospace School of Clinical Medicine100081 BeijingChina

Raman and Brillouin scattering are sensitive approaches to detect chemical composition and mechanical elasticity pathology of cells in cancer development and their medical treatment researches.The application is,however,suffering from the lack of ability to synchronously acquire the scattering signals following three-dimensional(3D)cell morphology with reasonable spatial resolution and signal-to-noise ratio.Herein,we propose a divided-aperture laser differential confocal 3D Geometry-Raman-Brillouin microscopic detection technology,by which reflection,Raman,and Brillouin scattering signals are simultaneously in situ collected in real time with an axial focusing accuracy up to 1 nm,in the height range of 200μm.The divided aperture improves the anti-noise capability of the system,and the noise influence depth of Raman detection reduces by 35.4%,and the Brillouin extinction ratio increases by 22 dB.A high-precision multichannel microspectroscopic system containing these functions is developed,which is utilized to study gastric cancer tissue.As a result,a 25%reduction of collagen concentration,42%increase of DNA substances,17%and 9%decrease in viscosity and elasticity are finely resolved from the 3D mappings.These findings indicate that our system can be a powerful tool to study cancer development new therapies at the sub-cell level.

关键词： elasticity dimensional spectroscopic

Study on dynamic response of high speed train window glass under tunnel aerodynamic effects

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Railway Sciences 2023年第2期2卷 211-224页

作者： Xiaogen Liu Shuang Qi Detian Wan dezhi zheng The State Key Laboratory of Green Building Materials China Building Materials AcademyBeijingChina China Testing&Certification International Group Co. LtdChina Building Materials AcademyBeijingChina

Purpose-This paper aims to analyze the bearing characteristics of the high speed train window glass under aerodynamic load effects.Design/methodology/approach-In order to obtain the dynamic strain response of passenger compartment window glass during high-speed train crossing the tunnel,taking the passenger compartment window glass of the CRH3 high speed train onWuhan-Guangzhou High Speed Railway as the research object,this study tests the strain dynamic response and maximum principal stress of the high speed train passing through the tunnel entrance and exit,the tunnel and tunnel groups as well as trains meeting in the tunnel at an average speed of 300 km$h-1.Findings-The results show that while crossing the tunnel,the passenger compartment window glass of high speed train is subjected to the alternating action of positive and negative air pressures,which shows the typical mechanic characteristics of the alternating fatigue stress of positive-negative transient strain.The maximum principal stress of passenger compartment window glass for high speed train caused by tunnel aerodynamic effects does not exceed 5 MPa,and the maximum value occurs at the corresponding time of crossing the tunnel groups.The high speed train window glass bears medium and low strain rates under the action of tunnel aerodynamic effects,while the maximum strain rate occurs at the meeting moment when the window glass meets the train head approaching from the opposite side in the tunnel.The shear modulus of laminated glass PVB film that makes up high speed train window glass is sensitive to the temperature and action time.The dynamically equivalent thickness and stiffness of the laminated glass and the dynamic bearing capacity of the window glass decrease with the increase of the action time under tunnel aerodynamic pressure.Thus,the influence of the loading action time and fatigue under tunnel aerodynamic effects on the glass strength should be considered in the design for the bearing performance of high speed train window glass.Originality/

关键词： High speed train window glass Tunnel aerodynamic effect Strain dynamic response Maximum principal stress Strain rate Bearing characteristics

智能无人集群系统跨域协同技术研究现状与展望

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中国工程科学 2024年第1期26卷 117-126页

作者：江碧涛温广辉周佳玲郑德智卫星信息智能处理与应用技术重点实验室北京100192 东南大学数学学院南京211189 北京理工大学前沿交叉科学研究院北京100081 空地一体新航行系统技术全国重点实验室北京100081

随着智能化技术和无人系统技术的快速发展,智能无人集群系统跨域协同的概念应运而生并得到了广泛关注与深入研究,智能无人集群系统跨域协同技术逐渐成为世界各国抢占无人系统技术竞争中的制高点。本文从我国智能无人集群系统跨域协同技... 详细信息

随着智能化技术和无人系统技术的快速发展,智能无人集群系统跨域协同的概念应运而生并得到了广泛关注与深入研究,智能无人集群系统跨域协同技术逐渐成为世界各国抢占无人系统技术竞争中的制高点。本文从我国智能无人集群系统跨域协同技术的发展需求出发,梳理了海空、空地以及海陆/海陆空等典型无人场景跨域协同技术的研究现状;深入分析了智能无人集群系统跨域协同技术的发展现状、技术需求以及未来的重点研究方向。最后,从总体思路、体系架构、理论创新和技术攻关4个层面,提出了推动智能无人集群系统跨域协同技术稳健与快速发展的对策建议,以期促进我国无人系统应用能力的持续提升。

关键词：智能无人集群系统跨域协同协同控制 “空天地海”一体化网络

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静电纺PMMA纤维生物膜的制备及性能

工程塑料应用 2024年第2期52卷 136-141页

作者：郑高峰张心怡吴德志卓丽云省部共建精密电子制造技术与装备国家重点实验室广州510006 厦门大学萨本栋微米纳米科学技术研究院福建厦门361102 柔性制造装备集成福建省高校重点实验室(厦门工学院) 福建厦门361021 厦门工学院机械电气与信息工程学院福建厦门361021

为了获得净水效果好的纤维生物膜载体材料,通过静电纺丝工艺制备聚甲基丙烯酸甲酯(PMMA)生物膜载体,通过多种表征方法测试PMMA与无纺布生物膜载体间的性能差异,完成了生物膜载体的结构(表面形貌、比表面积、孔隙率)和润湿性(水接触角和... 详细信息

为了获得净水效果好的纤维生物膜载体材料,通过静电纺丝工艺制备聚甲基丙烯酸甲酯(PMMA)生物膜载体,通过多种表征方法测试PMMA与无纺布生物膜载体间的性能差异,完成了生物膜载体的结构(表面形貌、比表面积、孔隙率)和润湿性(水接触角和吸水率)的测试。结果表明,静电纺丝工艺制备的PMMA纤维膜的纤维直径为100~900 nm,比表面积达到19.2 m^(2)/g,孔隙率达到80%,而无纺布的纤维直径为微米级,比表面积为0.3659 m^(2)/g,表明制备的PMMA纤维生物膜属于小直径、高比表面积的载体,可为微生物提供更多的附着位点及孔隙,更有利于微生物的附着。同时PMMA纤维膜表面水接触角为133.25°,吸水率达到313%,相较无纺布的吸水率(75%)明显上升,有效提高了载体在污水中的浸润性。最后,在相同条件下对PMMA和无纺布生物膜载体进行养菌挂膜试验。发现PMMA纤维生物膜载体处理污水的效果明显高于无纺布:养菌6 d后,PMMA纤维生物膜载体的挂膜量比继续处于快速上升趋势,而无纺布生物膜载体的挂膜量比变化很小;养菌15 d后,PMMA纤维生物膜载体的挂膜量比达到227.1%,而无纺布生物膜载体的挂膜量比仅为109.23%。

关键词：静电纺丝纤维生物膜表征分析挂膜量比

准噶尔盆地沙湾凹陷三叠系超深层碎屑岩储层特征及主控因素——以征10井区克拉玛依组为例

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油气地质与采收率 2024年第4期31卷 164-173页

作者：王捷王千军郑胜刘德志刘博奥徐天野中国石化胜利油田分公司勘探开发研究院山东东营257015

超深层碎屑岩储层由于埋藏深度大,储层物性一般较差,单井油气产能低,但中国石化探区沙湾凹陷近期钻探的征10井却在埋深6700m的三叠系克拉玛依组钻遇了优质厚层储层,常规测试即获得高产工业油气流。为了揭示该套储层的特征及有利储层主... 详细信息

超深层碎屑岩储层由于埋藏深度大,储层物性一般较差,单井油气产能低,但中国石化探区沙湾凹陷近期钻探的征10井却在埋深6700m的三叠系克拉玛依组钻遇了优质厚层储层,常规测试即获得高产工业油气流。为了揭示该套储层的特征及有利储层主控因素,明确该地区超深层碎屑岩勘探方向,降低该区下步油气勘探的风险,通过岩心、测井、铸体薄片、物性、扫描电镜等资料综合分析,并结合储层成岩演化,探讨了该区三叠系克拉玛依组储层岩石学特征、物性特征、孔隙特征及有利储层主控因素。研究结果表明:征10井区三叠系克拉玛依组超深层碎屑岩为辫状河三角洲前缘沉积,岩性以砂砾岩、含砾细砂岩及细砂岩为主,岩石类型主要为长石岩屑砂岩,成分成熟度较低;储集空间类型以剩余原生孔隙与溶蚀孔隙为主,储层平均孔隙度为9.1%,平均渗透率为2.85mD,整体属于特低孔特低渗透及低孔低渗透储层。有利沉积相带、建设性成岩作用及异常高压共同控制了该区有利储层的发育及分布。其中,沉积微相是有利储层发育的基础,辫状河三角洲前缘水下分流河道中沉积的细砂岩分选及磨圆较好,泥质杂基含量低,储层物性较好,是有利储层发育的优势相带;早期成岩过程中产生的钠长石胶结物后期被酸性溶蚀使得溶蚀孔隙增加,是重要的建设性成岩作用;油气持续充注所形成的异常高压,形成时间早且长期持续发育,起到了重要的建设作用。研究成果对该地区下步超深层油气勘探具有指导作用。

关键词：超深层碎屑岩储层特征主控因素克拉玛依组沙湾凹陷

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啤酒糟在反刍动物中的应用研究进展

中国草食动物科学 2024年第2期44卷 69-72页

作者：杨海峰王德志郑文凯杨进喜刘永军宁夏农垦乳业股份有限责任公司银川750001 宁夏博瑞饲料有限公司银川750001

我国蛋白类饲料原料长期依赖进口,随着国际局势的变化,大豆和豆粕饲料原料价格不断上升,造成我国养殖成本不断飙升,养殖利润大幅度压缩,严重制约了我国畜牧业的健康发展。开发利用蛋白类替代饲料原料对我国畜牧业的可持续发展具有积极... 详细信息

我国蛋白类饲料原料长期依赖进口,随着国际局势的变化,大豆和豆粕饲料原料价格不断上升,造成我国养殖成本不断飙升,养殖利润大幅度压缩,严重制约了我国畜牧业的健康发展。开发利用蛋白类替代饲料原料对我国畜牧业的可持续发展具有积极的推动作用。啤酒糟(BSG)是啤酒生产过程中的副产品,富含膳食纤维、蛋白质和必需氨基酸以及矿物质、多酚、维生素和脂质等营养物质,具有调节生产性能、维持瘤胃发酵稳定和成本低廉等优点,是理想的蛋白类饲料原料。文章主要针对BSG的营养特性以及BSG对反刍动物中养分消化代谢和生产性能的影响进行了综述,以期为BSG在反刍动物生产中的利用提供参考。

关键词：啤酒糟反刍动物生产性能

基于层次分析-熵权法优化酶解法提取铁皮石斛抗氧化物的工艺研究

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现代食品 2024年第8期30卷 219-224页

作者：何琴郑维军孙人杰吴德智贵州中医药大学贵州贵阳550025

本文以实验的方式分析了优化纤维素酶法对铁皮石斛抗氧化物的提取工艺。经研究分析发现,AHP-EWM的综合评分可反映客观试验数据,纤维素酶法提取铁皮石斛抗氧化物质稳定、可行,对其抗氧化物的研究具有一定的指导意义。

关键词：铁皮石斛纤维素酶法多糖抗氧化层次分析法熵权法响应面法