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Evaluating performance dependency of a geomorphologic instantaneous unit hydrograph-based hydrological model on DEM resolution

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Water Science and engineering 2022年第3期15卷 179-188页

作者： cheng Yao Zhi-jia Li Ke Zhang Ying-chun Huang Jing-feng Wang Satish Bastola College of Hydrology and Water resources Hohai UniversityNanjing 210098China Yangtze Institute for Conservation and Development Hohai UniversityNanjing 210098China State Key Laboratory of Hydrology-Water resources and Hydraulic engineering Hohai UniversityNanjing 210098China china Meteorological Administration-Hohai university Joint Laboratory for Hydrometeorological Studies Hohai UniversityNanjing 210098China School of civil and Environmental engineering Georgia Institute of TechnologyAtlanta 30332USA Department of civil and Environmental engineering University of New OrleansNew Orleans 70148USA

The digital elevation model(DEM)is a type of model that has been widely used in terrain analysis and hydrological *** resolution influences the hydrological and geomorphologic features of delineated catchments and consequently affects hydrological *** study investigated the impacts of DEM resolution on the performance of the XAJ-GIUH hydrological model,a model coupling the widely used Xinanjiang(XAJ)hydrological model with the geomorphologic instantaneous unit hydrograph(GIUH),in flood simulations in small and medium-sized *** test the model performance,the model parameters were calibrated at a fine DEM resolution(30 m)and then directly transferred to the simulation runs using coarser ***,model recalibration was conducted at coarser DEM *** the simulation runs with the model parameters calibrated at the 30-m resolution,the DEM resolution slightly affected the overall shape of the simulated flood hydrographs but presented a greater impact on the simulated peak discharges in the two study *** XAJ-GIUH model consistently underestimated the peak discharges when the DEM resolution became *** qualified ratio of peak simulations decreased by 35%when the DEM resolution changed from 30 m to 600 ***,model recalibration produced comparable model per-formances when DEMs with different resolutions were *** study showed that the impact of DEM resolution on model performance can be mitigated by model recalibration to some extent,if the DEM resolution is not too coarse.

关键词： DEM resolution XAJ-GIUH model Flood simulation Model recalibration Small and medium-sized catchments

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基于元胞传输模型的终端区交通流特性研究

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航空计算技术 2024年第2期54卷 16-19,25页

作者：梁海军骆春阳程万臻于承玉中国民用航空飞行学院四川广汉618000 四川华西安装工程有限公司四川成都610000

为阐明终端区交通流时空演变规律,揭示其拥堵机理,构建了基于元胞传输模型(CTM)的宏观交通流模型,根据航线连接、汇聚、分流等结构特点,定义一般、汇聚、发散三种元胞构型,并引入元胞优先级和发散系数概念解决交叉航线的流量分配问题;... 详细信息

为阐明终端区交通流时空演变规律,揭示其拥堵机理,构建了基于元胞传输模型(CTM)的宏观交通流模型,根据航线连接、汇聚、分流等结构特点,定义一般、汇聚、发散三种元胞构型,并引入元胞优先级和发散系数概念解决交叉航线的流量分配问题;基于所提出的模型,利用AnyLogic搭建终端区交通流仿真平台,使用实测ADS-B数据验证模型的准确性;最后基于管制间隔、管制速度等变量对模型进行敏感性分析。结果表明,提出的CTM模型可准确建模进离场航班流;终端区交通流量、密度与流速三者之间存在明显关联;管制间隔和速度通过影响元胞内临界密度,间接控制交通流运行状态;基于CTM推演终端区交通流时空运行态势,将有助于缓解交通拥堵,提升系统整体运行效率。

关键词：终端区流体特性元胞传输模型 AnyLogic仿真敏感性分析

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预制剪力墙震损修复抗震性能试验研究

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工程力学 2024年第10期41卷 24-32页

作者：王心宇杨参天李爱群李晓园刘谦敏程庆乐北京建筑大学土木与交通工程学院北京100044 北京建筑大学大型多功能振动台阵实验室北京102616 北京市建筑设计研究院有限公司北京100045

中国现阶段以及未来将存在较大数量的装配式建筑,装配式建筑的抗震韧性成为研究热点。该研究针对抗震韧性中的震损修复问题展开研究,以灌浆套筒连接预制剪力墙为研究对象,参照现有现浇构件的震损修复方法,考虑初始灌浆缺陷对预制剪力墙... 详细信息

中国现阶段以及未来将存在较大数量的装配式建筑,装配式建筑的抗震韧性成为研究热点。该研究针对抗震韧性中的震损修复问题展开研究,以灌浆套筒连接预制剪力墙为研究对象,参照现有现浇构件的震损修复方法,考虑初始灌浆缺陷对预制剪力墙震损特征的影响,对两个震损预制剪力墙进行了严重损伤状态下的修复。随后进行了拟静力试验,并与现浇剪力墙的抗震性能进行了对比。试验结果表明:现浇构件中常用的置换混凝土加固法同样适用于震损预制剪力墙构件,尽管钢筋屈服前混凝土的裂缝开展与现浇试件存在一定差别,但修复后的试件也呈现出了弯曲破坏模式;修复后试件的承载力、变形能力和耗能能力与现浇试件基本一致,灌浆缺陷虽然会影响预制剪力墙构件的震损模式,但对震损修复后的试件的抗震性能影响较小;采用现有置换混凝土加固法修复震损预制剪力墙,基本可实现与现浇剪力墙构件一致的抗震性能。该研究的成果可为灌浆套筒剪力墙构件的损失后果函数研究以及该类结构的抗震韧性设计方法研究提供重要参考。

关键词：预制剪力墙震损修复抗震性能拟静力试验灌浆缺陷

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被困空腔对T-bar循环贯入软黏土流动特性影响的试验研究

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长江科学院院报 2024年第5期41卷 108-115页

作者：李永靖郑晓明田英辉王乐张春会王智超岳宏亮辽宁工程技术大学土木工程学院辽宁阜新123000 山东商务职业学院建筑工程学院山东烟台264670 墨尔本大学基础设施工程系墨尔本3010 天津大学建筑工程学院天津300350 河北省岩土与结构体系防灾减灾技术创新中心石家庄050018 湘潭大学土木工程学院湖南湘潭411104 河北科技大学建筑工程学院石家庄050018

为观测和分析T-bar循环贯入过程中被困空腔对软黏土流动特性的影响,利用Laponite rD、焦磷酸钠和去离子水配制透明黏土,自制由加载设备、CCD相机、激光器和控制系统组成的T-bar循环贯入试验装置,开展T-bar在透明黏土中的循环贯入试验。... 详细信息

为观测和分析T-bar循环贯入过程中被困空腔对软黏土流动特性的影响,利用Laponite rD、焦磷酸钠和去离子水配制透明黏土,自制由加载设备、CCD相机、激光器和控制系统组成的T-bar循环贯入试验装置,开展T-bar在透明黏土中的循环贯入试验。结果表明:T-bar初次贯入过程中,被困空腔影响土体绕探头的流动,土体不能进入全流动状态;T-bar初次上拔过程中,被困空腔与探头发生脱离,悬浮于探头上方,对土体流动的影响逐渐减弱,T-bar上拔2.探头直径深度时土体流动不再受被困空腔影响,进入到全流动状态;第2.第10次循环贯入过程中,被困空腔稳定悬浮于土中,不影响土体流动,T-bar贯入1倍探头直径深度时土体流动表现为全流动状态;被困空腔对于T-bar循环贯入测试结果无显著影响,在T-bar初次贯入被困空腔阶段下通过T-bar循环贯入测试软黏土重塑强度是合理的。

关键词：透明黏土 T-bar 循环贯入试验被困空腔流动特性

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Advances of machining techniques for gradient structures in multi-principal-element alloys

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rare Metals 2022年第12期41卷 4015-4026页

作者： Bo Li chun-Ming Niu tian-Long Zhang Gong-Yu Chen Gang Zhang Dong Wang Xiao-Ye Zhou Jia-Ming Zhu School of civil engineering Shandong UniversityJinan 250061China School of Materials Science and engineering University of Science and Technology BeijingBeijing 100083China Department of Materials Science and engineering College of Science and EngineeringHong Kong Institute for Advanced StudyCity University of Hong KongHong Kong 999077China School of physics and Optoelectronics technology Baoji University of Arts and SciencesBaoji 721016China Center of Microstructure Science Frontier Institute of Science and TechnologyXi'an Jiaotong UniversityXi’an 710049China Guangdong province Key Laboratory of Durability for Marine civil engineering School of Civil and Transportation EngineeringShenzhen UniversityShenzhen 518060China

Multi-principal-element alloys(MpEAs)are attracting increasing attentions because of their high strength and ductility,high fracture toughness,excellent corrosion resistance,outstanding thermal-softening resistance and high oxidation ***,gradient structures(GSs)have been shown to be effective in alleviating the strength-ductility trade-off although strength and ductility are mutually exclusive properties for metals,which provides an opportunity for developing highperformance ***,we summarized four processing methods for creating GSs in MpEAs,including rotationally accelerated shot peening(rASp),ultra-precision machining technology(UpMT),cyclic dynamic torsion(CDT),and ultrasonic surface rolling processing(USrp).principles,advantages,disadvantages,and typical applications of these methods are discussed in this work.

关键词： Gradient structures(GSs) Multi-principalelement alloys(MpEAs) Strength-ductility trade-off Advanced processing technology

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A rapid assessment method for calculating the drag coefficient in wave attenuation by vegetation

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Acta Oceanologica Sinica 2021年第5期40卷 30-35页

作者： Zhilin Zhang Bensheng Huang Hongxiang Ji Xin tian Jing Qiu Chao Tan Xiangju cheng Guangdong research Institute of Water resources and Hydropower Guangzhou 510630China State and Local Joint engineering Laboratory of Estuarine and Hydraulic technology Guangzhou 510630China Guangdong Key Laboratory of Hydrodynamic research Guangzhou 510630China Technical research Center of Guangdong-Hong Kong-Macao Greater Bay Area’s Water Safety Guarantee Guangzhou 510630China Department of Water Management Delft University of TechnologyDelft 2628 CNthe Netherlands School of civil engineering and Transportation South China University of TechnologyGuangzhou 510640China

Vegetation in wetlands is a large-scale nature-based resource that can provide multiple benefits to human beings and the environment,such as wave attenuation in coastal ***,there are two main calibration approaches to calculate the attenuation of wave driven by *** first method is a straightforward one based on the exponential attenuation of wave height in the direction of wave transmission,which,however,overlooks the crucial drag coefficient(CD).The other method is in accordance with more complicate equations for predicting the damping factor,which is regarded as a function of *** this study,a new relation,combining these above two conventional approaches,is proposed to predict the CD in an operative *** show that values yielded by the new assessment method perform a strong linear relationship with a collection of historical observations,with a promising r2.value of ***,the linear regression derives a new predictive equation for the bulk drag ***,a calibrated value of 4 for the empirical plant drag coefficient(Cp)is ***,this new equation,with the superiority of the convenient exponential regression,is expected to be a rapid assessment method for calculating wave attenuation by vegetation and predicting the drag coefficient.

关键词： wave attenuation by vegetation nature-based coast drag coefficient empirical validation

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滴灌条件下散水介质规格对龟裂碱土水盐运移特征的影响

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土壤通报 2024年第4期55卷 944-952页

作者：黄鹏飞黄艳丽康跃虎万书勤李晓彬刘春成中国农业科学院农田灌溉研究所河南新乡453004 新乡学院土木工程与建筑学院河南新乡453003 中国科学院地理科学与资源研究所陆地水循环及地表过程重点实验室北京100101 中国科学院大学资源与环境学院北京100049 中国农业科学院农业资源与农业区划研究所北京100081

【目的】探讨滴灌改良利用龟裂碱土方法中散水介质规格对剖面水盐运移特征的影响,研究结果为散水介质规格的选择提供科学依据。【方法】通过室内土柱模拟试验,在一维和二维条件下对比分析了不同散水介质规格对龟裂碱土水盐运移特征的影... 详细信息

【目的】探讨滴灌改良利用龟裂碱土方法中散水介质规格对剖面水盐运移特征的影响,研究结果为散水介质规格的选择提供科学依据。【方法】通过室内土柱模拟试验,在一维和二维条件下对比分析了不同散水介质规格对龟裂碱土水盐运移特征的影响。【结果】一维垂直入渗条件下,平铺型散水介质的深度在0~10 cm越小或10~15 cm越大,均能获得较高的垂直湿润峰扩散速度,随散水介质深度减小,灌水频率增加,促进了盐分淋洗。二维入渗条件下,垂直湿润峰入渗速率大于水平湿润峰入渗速率,稳定入渗阶段两者均随半球型散水介质直径的增加而下降,但单位灌溉水盐分淋洗效率降低,单位时间盐分淋洗效率不变,散水介质直径≥2. cm时水分扩散速率变化趋缓。【结论】不同散水介质规格改变了灌水频率和单次灌水量,进而影响龟裂碱土的水分入渗和盐分淋洗过程。实际应用中在考虑灌溉水淋洗效率的同时要兼顾经济效益,满足一年生植物生长需求后散水介质深度越小越好,而多年生作物采用半球型散水介质时直径不易超过2. cm。

关键词：盐碱地改良龟裂碱土滴灌散水介质水盐运移

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水性环氧树脂-聚丙烯纤维改性水泥基快速修补砂浆性能研究

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功能材料 2024年第1期55卷 1031-1037页

作者：田耀刚鲁涛赵成蒋静纪括王振军长安大学材料科学与工程学院西安710064 西北民航机场建设集团有限责任公司西安710065

为改善机场道面修补砂浆脆性大和粘结性能差等问题,本文利用水性环氧树脂(WEr)、聚丙烯(pp)纤维和硫铝酸盐水泥(SAC)制备出一种快速修补砂浆,并对其工作性能、力学性能、阻尼性能和耐硫酸盐腐蚀性能进行研究。结果表明,pp纤维和WEr可显... 详细信息

为改善机场道面修补砂浆脆性大和粘结性能差等问题,本文利用水性环氧树脂(WEr)、聚丙烯(pp)纤维和硫铝酸盐水泥(SAC)制备出一种快速修补砂浆,并对其工作性能、力学性能、阻尼性能和耐硫酸盐腐蚀性能进行研究。结果表明,pp纤维和WEr可显著提高快速修补砂浆韧性和粘结性能,使得快速修补砂浆2.h抗压、抗折强度和粘结强度分别达到2..3,5.1和3.7Mpa,满足民用机场规范要求,同时可改善快速修补砂浆的阻尼性能和抗硫酸盐侵蚀性能。

关键词：快速修补砂浆水性环氧树脂聚丙烯纤维阻尼性能耐久性

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Damage and deterioration mechanism and curing technique of concrete structure in main coal cleaning plants

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Mining Science and technology 2009年第6期19卷 750-755页

作者： LV Heng-lin ZHAO cheng-ming SONG Lei MA Ying XU chun-hua School of Architecture and civil engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221116 China State Key Laboratory for Geomechanics and Deep Underground engineering Xuzhou Jiangsu 221008 China Wuhan Design ＆ research Institute of Sinocoal International engineering Group Wuhan Hubei 430064 China

Concrete structures in main coal cleaning plants have been rebuilt and reinforced in the coal mines of the Shanghai Datun Energy Sources Co. Ltd., the first colliery of the pingdingshan Coal Co. Ltd. and the Sanhejian mine of the Xuzhou Mining Group Co. Ltd. In these projects, the operating environment and reliability of concrete structures in the main plants of the three companies were investigated and the safety of the structures inspected. Qualitative and quantitative analyses were made on the special natural, technological and mechanical environments around the structures. On the basis of these analyses, we discuss the long-term, combined actions of the harsh natural (corrosive gases, liquids and solids) and mechanical environments on concrete structures and further investigated the damage and deteriorating mechanisms and curing techniques of concrete structures in the main coal cleaning plants. Our study can provide a theoretical basis for ensuring the reliability of concrete structures in main coal cleaning plants.

关键词： main coal cleaning plants concrete structure operating environment reliability detection and inspection damage anddeteriorating mechanisms curing technique

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Unsteady aerodynamics modeling for flight dynamics application

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Acta Mechanica Sinica 2012年第1期28卷 14-23页

作者： Qing Wang Kai-Feng He. Wei-Qi Qian tian-Jiao Zhang Yan-Qing cheng Kai-Yuan Wu State Key Laboratory of Aerodynamics 621000 MianyangChina Computational Aerodynamics Institute China Aerodynamics Research and Development Center621000 MianyangChina Scientific research Base of Flight technology and Safety Civil Aviation Flight University of China618307 GuanghanChina

In view of engineering application, it is practicable to decompose the aerodynamics into three components： the static aerodynamics, the aerodynamic increment due to steady rotations, and the aerodynamic increment due to unsteady separated and vortical flow. The first and the second components can be presented in conventional forms, while the third is described using a one-order differential equation and a radial-basis-function （rBF） network. For an aircraft configuration, the mathematical models of 6- component aerodynamic coefficients are set up from the wind tunnel test data of pitch, yaw, roll, and coupled yawroll large-amplitude oscillations. The flight dynamics of an aircraft is studied by the bifurcation analysis technique in the case of quasi-steady aerodynamics and unsteady aerodynam- ics, respectively. The results show that：（1） unsteady aerodynamics has no effect upon the existence of trim points, but affects their stability; （2. unsteady aerodynamics has great effects upon the existence, stability, and amplitudes of periodic solutions; and （3） unsteady aerodynamics changes the stable regions of trim points obviously. Furthermore, the dynamic responses of the aircraft to elevator deflections are inspected. It is shown that the unsteady aerodynamics is beneficial to dynamic stability for the present aircraft. Finally, the effects of unsteady aerodynamics on the post-stall maneuverability

关键词： Unsteady aerodynamics High angle of attack Mathematical model Flight dynamics - Bifurcation analysis post-stall maneuver

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