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Research on concrete structure defect repair based on three-dimensional printing

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Frontiers of Structural and Civil Engineering 2024年第5期18卷 731-742页

作者： Yang GU Wei LI xupeng YAO Guangjun liu School of Mechanical Engineering Tongji UniversityShanghai 201804China College of Civil Engineering Tongji UniversityShanghai 200092China Shanghai Engineering Research Center for Safety Intelligent Control of Building Machinery Shanghai 200032China

Quality assurance and maintenance play a crucial role in engineering construction,as they have a significant impact on project *** common issue in concrete structures is the presence of *** enhance the automation level of concrete defect repairs,this study proposes a computer vision-based robotic system,which is based on three-dimensional(3D)printing technology to repair *** system integrates multiple sensors such as light detection and ranging(LiDAR)and *** is utilized to model concrete pipelines and obtain geometric parameters regarding their ***,a convolutional neural network(CNN)is employed with a depth camera to locate defects in concrete ***,a method for coordinate transformation is presented to convert the obtained coordinates into executable ones for a robotic ***,the feasibility of this concrete defect repair method is validated through simulation and experiments.

关键词： concrete defect detection 3D printing deep learning point cloud data

Effects of thermal activation conditions on the microstructure regulation of corncob-derived activated carbon for hydrogen storage

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Journal of Energy Chemistry 2014年第5期23卷 601-608页

作者： Dabin Wang Zhen Geng Cunman Zhang Xiangyang Zhou xupeng liu Clean Energy Automotive Engineering Center Tongji University School of Automotive Studies Tongji University School of Materials Science and Technology Tongji University

Activated carbons derived from corncob （CACs） were prepared by pyrolysis carbonization and KOH activation. Through modifying activation conditions, samples with large pore volume and ultrahigh BET specific surface area could be obtained. The sample achieved the highest hydrogen uptake capacity of 5.80 wt% at 40 bar and -196℃ The as-obtained samples were characterized by N2-sorption, transmission electron microscopy （TEM） and scanning electron microscopy （SEM）. Besides, thermogravimetric analysis was also employed to investigate the activation behavior of CACs. Detailed investigation on the activation parameters reveals that moderate activation temperature and heating rate are favorable for preparing CACs with high surface area, large pore volume and optimal pore size distribution. Meanwhile, the micropore volume between 0.65 nm and 0.85 nm along with BET surface area and total pore volume has great effects on hydrogen uptake capacities. The present results indicate that CACs are the most promising materials for hydrogen storage application.

关键词： corncob-derived activated carbon KOH activation activation conditions hydrogen storage

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蛇形机器人蜿蜒运动的摩擦机理及推进条件

机械工程学报 2021年第21期57卷 189-201页

作者：刘旭鹏郜志英臧勇张立元北京科技大学机械工程学院北京100083

针对带有从动轮的蛇形机器人,考虑实际结构中从动轮在蛇形机器人关节连杆上的安装位置,建立蛇形机器人蜿蜒运动的动力学模型。提出一种库伦-粘滞混合摩擦力模型,整体的库伦摩擦力特性和临界点处的粘滞摩擦力特性,避免了库伦摩擦力模型... 详细信息

针对带有从动轮的蛇形机器人,考虑实际结构中从动轮在蛇形机器人关节连杆上的安装位置,建立蛇形机器人蜿蜒运动的动力学模型。提出一种库伦-粘滞混合摩擦力模型,整体的库伦摩擦力特性和临界点处的粘滞摩擦力特性,避免了库伦摩擦力模型本身的非光滑性,以提高动力学模型的求解效率与计算稳定性。基于改进的动力学与摩擦力模型,利用摩擦系数比来表征法向与切向摩擦力的各向异性程度,通过对蜿蜒运动的仿真分析,讨论了摩擦系数比对前向运动速度与推进效率的影响规律,并对运动过程中蛇形机器人各个关节模块的速度和摩擦力变化进行了分析,明确了蛇形机器人蜿蜒运动的摩擦学机理,解释了蛇的蜿蜒抬起运动能够有效减少摩擦阻力而适用于高速运动的原因。最后通过带从动轮的蛇形机器人样机实验,对实现蜿蜒运动的摩擦学推进条件进行了验证。研究对于实现蛇形机器人的结构优化,步态规划与运动控制具有重要的理论意义与实际指导价值。

关键词：蛇形机器人蜿蜒运动混合摩擦力各向异性摩擦机理

PDGFR in PDGF-BB/PDGFR Signaling Pathway Does Orchestrates Osteogenesis ina Temporal Manner

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Research 2024年第1期2023卷 33-48页

作者： Fangqian Wang Yuxiao Ye Zengjie Zhang Wangsiyuan Teng Hangxiang Sun xupeng Chai Xingzhi Zhou Jiayu Chen Haochen Mou Yinwang Eloy Xiaoqiang Jin Liang Chen Zhenxuan Shao Yan Wu Yue Shen An liu Peng Lin Jianwei Wang Xiaohua Yu Zhaoming Ye Department of Orthopedic Surgery the Second Affiliated HospitalZhejang University School of MedicineHangzhou CityZhejiang ProvincePR China Orthopedics Research Institute of Zhejang University Hangzhou CityZhejiang ProvincePR China Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province Hangzhou CityZhejiang ProvincePR China School of Material Science and Engineering University of New South WalesSydney 2052Australia

Platelet-derived growth factor-BB(PDGF-BB)/platelet-derived growth factor receptor-β(PDGFR-β)pathway is conventionally considered as an important pathway to promote osteogenesis;however,recent study suggested its role during osteogenesis to be *** the differential functions of this pathway during 3 stages of bone healing,we hypothesized that temporal inhibition of PDGF-BB/PDGFR-βpathway could shift the proliferation/differentiation balance of skeletal stem and progenitor cells,toward osteogenic lineage,which leads to improved bone *** first validated that inhibition of PDGFR-βat late stage of osteogenic induction effectively enhanced differentiation toward *** effect was also replicated invivo by showing accelerated bone formation when block PDGFR-βpathway at late stage of critical bone defect healing mediated using ***,we found that such PDGFR-βinhibitor-initiated bone healing was also effective in the absence of scaffold implantation when administrated ***,timely inhibition of PDGFR-βblocked extracellular regulated protein kinase 1/2 pathway,which shift proliferation/differentiation balance of skeletal stem and progenitor cell to osteogenic lineage by upregulating osteogenesis-related products of Smad to induce *** study offered updated understanding of the use of PDGFR-βpathway and provides new insight routes of action and novel therapeutic methods in the field of bone repair.

关键词： healing sized implantation

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泡沫铝连接件焊接工艺的应用现状与展望

材料导报 2017年第19期31卷 66-71页

作者：黄本生赵星吴序鹏刘段苏曾强西南石油大学材料科学与工程学院成都610500

泡沫铝兼具结构与功能特性,为充分发挥泡沫铝的各种性能,常将其与致密金属进行复合得到三明治结构,以提高其综合力学性能并降低成本。三明治结构的连接方法众多,而焊接手段是最可靠的连接方式。首先介绍了泡沫铝的性能特点及焊接难点,... 详细信息

泡沫铝兼具结构与功能特性,为充分发挥泡沫铝的各种性能,常将其与致密金属进行复合得到三明治结构,以提高其综合力学性能并降低成本。三明治结构的连接方法众多,而焊接手段是最可靠的连接方式。首先介绍了泡沫铝的性能特点及焊接难点,综述了其焊接方法,包括常规电弧焊、激光焊、钎焊、扩散焊、搅拌摩擦焊、等离子焊以及超声波焊,再对各工艺的局限性进行阐述,最后对泡沫铝连接件焊接工艺的发展方向进行浅析。

关键词：泡沫铝焊接手段钎焊扩散焊瞬间液相扩散连接

氮掺杂缺陷TiO_(2)增强光催化净化NO性能

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稀有金属 2023年第1期47卷 145-155页

作者：郭福荣周彪刘旭鹏邢攀刘修凡艾智慧华中师范大学化学学院农药与化学生物学教育部重点实验室湖北武汉430074

半导体光催化技术能利用太阳能有效去除大气低浓度NOx,因而具有广泛应用前景。半导体光催化净化效率依赖于材料的表界面结构,而在氧空位参与的光催化分子氧活化过程中,缺陷氧化物光催化剂会面临氧填充而失活的问题。本文通过溶液-凝胶... 详细信息

半导体光催化技术能利用太阳能有效去除大气低浓度NOx,因而具有广泛应用前景。半导体光催化净化效率依赖于材料的表界面结构,而在氧空位参与的光催化分子氧活化过程中,缺陷氧化物光催化剂会面临氧填充而失活的问题。本文通过溶液-凝胶法合成了氮掺杂缺陷二氧化钛光催化剂(TiO_(2-x-y)N_(y)),TiO_(2-x-y)N_(y)可见光光催化净化低浓度(600×10^(-9))NO的效率高达72%(20 min),而TiO_(2)-x去除NO的效率仅为55%,且TiO_(2-x-y)N_(y)循环后仍能保持70%的NO去除率。光电流和交流阻抗测试结果表明氮的掺杂能够有效提高材料的载流子动力学分离效率。活性物种捕获实验表明能够产生更多的超氧自由基(·O_(2)^(–)),氮掺杂显著增强催化剂活化分子氧的能力。NO-程序升温脱附(NO-TPD),O_(2)^(-)程序升温脱附(O_(2)-TPD),原位电子顺磁共振(in-situ EPR)和差分电荷计算等结果表明TiO_(2-x-y)N_(y)催化剂表面的氧空位位点优先吸附活化O_(2),多电子中心的N能够传递电子修复氧空位,氧空位位点能持续活化分子氧,并捕获空穴促进载流子分离,从而提高TiO_(2)-x-yNy光催化净化NO效率。

关键词：二氧化钛氧空位(OVS) 氮掺杂氮氧化物

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K均值聚类改进与行驶工况构建研究

汽车技术 2019年第11期 57-62页

作者：刘子谭朱平刘旭鹏刘钊上海交通大学上海200240 上汽大众汽车有限公司上海201805

采集了广州市2 800万个样本数据,采用相关指标比较分析K均值聚类、K中心点聚类、模糊聚类、高斯混合聚类4种方法,并以90%置信区间作为初始中心选取范围提高K均值聚类稳定性。运用改进后的K均值聚类构建广州市行驶工况,平均相对误差小于... 详细信息

采集了广州市2 800万个样本数据,采用相关指标比较分析K均值聚类、K中心点聚类、模糊聚类、高斯混合聚类4种方法,并以90%置信区间作为初始中心选取范围提高K均值聚类稳定性。运用改进后的K均值聚类构建广州市行驶工况,平均相对误差小于6%,并与美国、欧洲、日本、中国等地区的典型行驶工况进行比较。结果表明,广州市行驶工况具有车辆加减速频繁、怠速与低速段工况占比高的特点,与国内现行NEDC以及中国QC/T 759-2006工况存在一定差异。

关键词： K均值聚类短行程主成分分析汽车行驶工况

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强夯法在处理填土地基中的应用

勘察科学技术 2005年第4期 36-37,50页

作者：刘序鹏中铁十四局集团有限公司济南市250014

该文对强夯法处理杂填土地基的加固原理和施工工艺进行了论述,分析了强夯法处理地基的基本要点和加固效果,为强夯法加固地基提供了可借鉴的资料。

关键词：强夯加固机理夯击能地基承载力强夯法处理杂填土地基应用施工工艺加固原理加固效果

Rice OsUBR7 modulates plant height by regulating histone H2B monoubiquitination and cell proliferation

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Plant Communications 2022年第6期3卷 251-266页

作者： Yangyi Zheng Sensen Zhang Yanqiu Luo Fuquan Li Jiantao Tan Bin Wang Zhe Zhao Huifang Lin Tingting Zhang Jianhong liu xupeng liu Jingxin Guo Xianrong Xie Letian Chen Yao-Guang liu Zhizhan Chu State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources College of Life SciencesSouth China Agricultural UniversityGuangzhou 510642China Guangdong Laboratory for Lingnan Modern Agriculture Guangzhou 510642China Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms South China Agricultural UniversityGuangzhou 510642China

Plant height is an important agronomic trait for lodging resistance and ***,we report a new plantheight-related gene,OsUBR7 in rice(Oryza sativa L.);knockout of OsUBR7 caused fewer cells in internodes,resulting in a semi-dwarf ***7 encodes a putative E3 ligase containing a plant homeodomain finger and a ubiquitin protein ligase E3 component N-recognin 7(UBR7)***7 interacts with histones and monoubiquitinates H2B(H2Bub1)at lysine148 in coordination with the E2 conjugase ***7 mediates H2Bub1 at a number of chromatin loci for the normal expression of target genes,including cell-cycle-related and pleiotropic genes,consistent with the observation that cell-cycle progression was suppressed in the osubr7 mutant owing to reductions in H2Bub1 and expression levels at these *** genetic divergence of OsUBR7 alleles among japonica and indica cultivars affects their transcriptional activity,and these alleles may have undergone selection during rice ***,our results reveal a novel mechanism that mediates H2Bub1 in plants,and UBR7 orthologs could be utilized as an untapped epigenetic resource for crop improvement.

关键词： histone H2B monoubiquitination E3 ligase UBR7 plant height rice