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SPH Modelling of the Vortex-Induced Vibration of A Near-Wall Cylinder

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China Ocean Engineering 2023年第3期37卷 355-368页

作者： WEN Hong-jie ZHAO Yu-meng ZHU gan-cheng ZHU Liang-sheng REN Bing School of Civil Engineering and Transportation South China University of TechnologyGuangzhou 510641China China State Construction Engineering Corporation Limited Beijing 100029China Institute of Ocean Engineering Ningbo UniversityNingbo 315211China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China

The frequency-locked phenomenon commonly occurs in the vortex-induced vibration(VIV)of bluff *** simulation of this lock-in behavior is challenging,especially when the structure is positioned in close proximity to a solid *** establish a robust simulator,an enhanced smoothed particle hydrodynamic(SPH)model is *** SPH model incorporates a particle shifting algorithm and a pressure correction algorithm to prevent cavity formation in the structure's wake area.A damping zone is also established near the outlet boundary to dissipate the vortices that shed from the ***,GPU parallel technology is implemented to enhance the SPH model's computational *** validate the mo del,the predicted results are compared with the available refere nce data for flow past both stationary and oscillating *** verified SPH model is then employed to comparatively investigate the motion re sponse,lift characteristic,and vortex shedding mode of cylinders with and without accounting for the effect of boundary *** analyses demonstrate that the developed SPH model is a proficient tool for efficiently simulating the vibration of near-wall bluff bodies at low Reynolds number.

关键词： SPH model VIV near-wall cylinder Reynolds number GPU

Preliminary Investigation on the Causes of Odd Vibration of Buildings in Guilin City——a Study on the Resonance between Buildings and the Underlying Soil Layer

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Acta Geologica Sinica(English Edition) 2020年第1期94卷 152-161页

作者： ZHANG Fawang gan Fuping LUAN Song meng Yan ZHENG Zhijie LI Weixuan Institute of Karst Geology Chinese Academy of Geological SciencesGuilin 541004China

A residential building in Guilin City, China, underwent an up-and-down vibration with an amplitude of 2 cm. By eliminating several causes such as earthquake, wind and construction, in combination with the unique karst geological conditions of Guilin, it was inferred that the effect of turbulent karst water is the main contributor to the occurrence of this vibration. Therefore, a geophysical survey was undertaken on the vibration zone and its surroundings. The resutls suggest that the soil in the upper part of the karst grooves shows conspicuous traces of disturbance and the water content has low resistance. A comprehensive analysis indicates that there is a karst strong runoff zone beneath the area. According to the water level and water temperature data collected automatically by the instrument, it can be concluded that the groundwater level had changed significantly twice during this period, so it was determined that the denudation of groundwater strong runoff causes the overlying soil layer to collapse, forming a soil-water soft-flow material with mixed phase. Since the building in this area was supported by friction piles, the groundwater-soil soft-flow material with mixed phase has intense plasticity, and the up-and-down vibration resulted in the change of the friction piles, which caused the up-and-down vibration of the building structure.

关键词： karst building vibration groundwater strong runoff

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轨道交通用焊接产品典型失效案例分析

轨道交通材料 2024年第2期3卷 65-70页

作者：王日艺刘晓军刘猛甘芙蓉中车南京浦镇车辆有限公司江苏南京210031

为了探究轨道交通焊接产品典型失效原因及其影响因素,采用化学成分分析、机械性能测试、金相检验、扫描电镜及能谱分析等方法,对多种轨道交通用焊接产品失效件进行分析。结果表明:轨道交通用焊接产品的失效主要有焊接制造过程中产生的... 详细信息

为了探究轨道交通焊接产品典型失效原因及其影响因素,采用化学成分分析、机械性能测试、金相检验、扫描电镜及能谱分析等方法,对多种轨道交通用焊接产品失效件进行分析。结果表明:轨道交通用焊接产品的失效主要有焊接制造过程中产生的焊接裂纹,焊修时期引发的焊补缺陷以及结构设计不当导致的各种缺陷。分析认为焊接产品的失效主要受到焊接工艺缺陷、焊接件服役环境、焊接结构设计不当以及焊修措施不良等因素的影响。并梳理出焊接产品失效原因与失效影响因素的鱼骨图,为提升焊接产品的使用寿命和质量控制提供了理论依据。

关键词：轨道交通失效焊接裂纹焊补缺陷焊接结构设计

基于SSR标记的花椰菜育种种质遗传多样性分析

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农业生物技术学报 2024年第9期32卷 1982-1995页

作者：宋晓玉韩硕甘德芳宋顺华刘凡郭宁孟淑春北京市农林科学院蔬菜研究所/蔬菜生物育种全国重点实验室/国家蔬菜工程技术研究中心/农业农村部蔬菜种子质量检验测试中心安徽农业大学园艺学院

花椰菜(Brassica oleracea var. botrytis)起源于欧洲，我国种质资源的遗传多样性较狭窄，亟待开展种质创新及创新种质的评价技术等研究。利用小孢子培养技术创制双单倍体(double haploid, DH)不但能缩短育种年限而且也是种质创新的重... 详细信息

花椰菜(Brassica oleracea var. botrytis)起源于欧洲，我国种质资源的遗传多样性较狭窄，亟待开展种质创新及创新种质的评价技术等研究。利用小孢子培养技术创制双单倍体(double haploid, DH)不但能缩短育种年限而且也是种质创新的重要手段。花椰菜小孢子再生株后代的遗传多样性评估，是利用双单倍技术进行种质创新和育种应用要解决的关键问题。本研究筛选出29对带型清晰稳定、多态性较好的SSR引物，PIC变幅为0.29～0.57，平均值为0.42。利用这29对引物，对由66份DH系和18份高代自交系组成的84份花椰菜育种种质群体进行标记分型研究。结果显示，材料的遗传距离主要集中在0.3～0.6，平均为0.56，遗传相似系数在0.50～0.97之间，平均为0.57，在遗传相似系数为0.55时，将材料共分为4组。通过DH材料的亲缘关系分析发现，F1杂种的DH系后代材料中能够获得遗传多样性较高的材料，DH育种可以作为花椰菜种质创新的重要手段。本研究为花椰菜遗传多样性的评价与利用提供理论支撑和技术支持。

关键词：花椰菜 SSR标记双单倍体遗传多样性聚类分析

Analysis of Phthalate Esters in Air, Soil and Plants in Plastic Film Greenhouse

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Chinese Chemical Letters 2002年第6期13卷 557-560页

作者： Xi Kui WANG Wei Lin GUO Ping Rui meng Jia An gan College of Chemistry and Environmental Science University of JinanJinan 250022

The phthalate esters such as DMP, DEP, DBP and DEHP in air, soil and plant samples in plastic film greenhouse were clean up with fine silica gel column and determined with HPLC. It was found that the concentrations of PEs in air and soil samples in plastic film greenhouse are much higher than those of contrast samples. But concentrations of PEs in plants in plastic film greenhouse are not remarkably affected by the pollution of air and soil.

关键词： Phthalate esters plastic film greenhouse analysis.

Experimental studies on ozonation of ethylenethiourea

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Journal of Environmental Sciences 2011年第1期23卷 65-69页

作者： Xinyu Dong Junwang meng Bo Yang Yang Zhang Jie gan XiShu Jinian Shu Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China. E-mail: xinyudong@***

The experimental study on ozonation of ethylenethiourea （ETU） is conducted. The reaction of gas-phase ETU with 0.63 × 10^-6 mol/L ozone is carried out in a 200-L reaction chamber. The secondary organic aerosol （SOA） resulted from the ozonation of gas-phase ETU is observed with a scanning mobility particle size （SMPS）. The rapid exponential growth of SOA reveals that the atmospheric lifetime of ETU vapor towards ozone reaction is less than four days. The ozonation of dry ETU particles, ETU-contained water droplets and ETU aqueous solution is investigated with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer （VUV- ATOFMS）. The formation of 2-imidazoline is observed in the ozonation of dry ETU particles and ETU-contained water droplets. The formation of 2-imidazoline and ethvlenerea is observed in the ozonation of ETU aqueous solution.

关键词： ethylenethiourea pesticide ozonation VUV photoionization AMS

LQR-GA Controller for Articulated Dump Truck Path Tracking System

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Journal of Shanghai Jiaotong university(Science) 2019年第1期24卷 78-85页

作者： meng Yu gan Xin WANG Yu GU Qing School of Mechanical Engineering University of Science and Technology Beijing

This paper designs a novel controller to improve the path-tracking performance of articulated dump truck(ADT). By combining linear quadratic regulator(LQR) with genetic algorithm(GA), the designed controller is used to control linear and angular velocities on the midpoint of the front frame. The novel controller based on the error dynamics model is eventually realized to track the path high-precisely with constant speed. The results of simulation and experiment show that the LQR-GA controller has a better tracking performance than the existing methods under a low speed of 3 m/s. In this paper, kinematics model and simulation control models based on co-simulation of ADAMS and Matlab/Simulink are established to verify the proposed strategy. In addition, a real vehicle experiment is designed to further more correctness of the conclusion. With the proposed controller and considering the steering model in the simulation, the control performance is improved and matches the actual situation better. The research results contribute to the development of automation of ADT.

关键词： articulated dump truck(ADT) path tracking steering analysis linear quadratic regulator(LQR) genetic algorithm(GA) controller

基于BERT与生成对抗的民航陆空通话意图挖掘

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系统工程与电子技术 2024年第2期46卷 740-750页

作者：马兰孟诗君吴志军中国民航大学空中交通管理学院天津300300 中国民航大学电子信息与自动化学院天津300300 中国民航大学安全科学与工程学院天津300300

针对民航陆空通话领域语料难以获取、实体分布不均,以及意图信息提取中实体规范不足且准确率有待提升等问题,为了更好地提取陆空通话意图信息,提出一种融合本体的基于双向转换编码器(bidirectional encoder representations from transf... 详细信息

针对民航陆空通话领域语料难以获取、实体分布不均,以及意图信息提取中实体规范不足且准确率有待提升等问题,为了更好地提取陆空通话意图信息,提出一种融合本体的基于双向转换编码器(bidirectional encoder representations from transformers,BERT)与生成对抗网络(generative adversarial network,gan)的陆空通话意图信息挖掘方法,并引入航班池信息对提取的部分信息进行校验修正,形成空中交通管制(air traffic control,ATC)系统可理解的结构化信息。首先,使用改进的gan模型进行陆空通话智能文本生成,可有效进行数据增强,平衡各类实体信息分布并扩充数据集;然后,根据欧洲单一天空空中交通管理项目定义的本体规则进行意图的分类与标注;之后,通过BERT预训练模型生成字向量并解决一词多义问题,利用双向长短时记忆(bidirectional long short-term memory,BiLSTM)网络双向编码提取上下句语义特征,同时将该语义特征送入条件随机场(conditional random field,CRF)模型进行推理预测,学习标签的依赖关系并加以约束,以获取全局最优结果;最后,根据编辑距离(edit distance,ED)算法进行意图信息合理性校验与修正。对比实验结果表明,所提方法的宏平均F_(1)值达到了98.75%,在民航陆空通话数据集上的意图挖掘性能优于其他主流模型,为其加入数字化进程奠定了基础。

关键词：民航陆空通话信息提取生成对抗网络本体双向转换编码器

Cu离子分子筛催化材料在去除NO_(x)方面应用的研究进展

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材料导报 2024年第2期38卷 42-50页

作者：孟令钦崔素萍甘延玲王亚丽马晓宇北京工业大学材料与制造学部北京100124 中山大学环境科学与工程学院广州510275

控制大气中氮氧化物的排放对环境和人体健康有着至关重要的作用,应用于NO_(x)去除的技术有很多,其中选择性催化还原(NH3-SCR)技术是去除NO_(x)极有效的技术之一,利用CO去除NO_(x)为烟气脱硝(CO-SCR)提供了一种简单且低成本的技术,直接... 详细信息

控制大气中氮氧化物的排放对环境和人体健康有着至关重要的作用,应用于NO_(x)去除的技术有很多,其中选择性催化还原(NH3-SCR)技术是去除NO_(x)极有效的技术之一,利用CO去除NO_(x)为烟气脱硝(CO-SCR)提供了一种简单且低成本的技术,直接催化分解NO_(x)被认为是去除NO_(x)最理想、最环保的技术。Cu离子分子筛作为去除NO_(x)的高效催化剂,具有宽温度窗口和良好的水热稳定性。本文综述了Cu交换分子筛在去除NO领域的研究进展,讨论了Cu离子分子筛在NH3-SCR、CO-SCR以及直接催化分解NO中的应用,着重总结了Cu离子参与去除NO的反应机理,归纳了分子筛中Cu活性位点对脱硝性能的影响,还讨论了铜离子分子筛的抗H_(2)O和SO_(2)中毒性能,展望了Cu离子分子筛未来可能的发展方向。

关键词： Cu离子分子筛 NO_(x)去除 NH3-SCR NO直接分解 CO-SCR