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含硒表界面化学

高等学校化学学报 2021年第4期42卷 997-1004页

作者：夏嘉豪许华平清华大学化学系北京100084

硒是人体必需的一种微量元素,本课题组近年的研究表明含硒化学键具有诸多独特的化学性质.二硒键具有氧化还原双重响应性,同时是一类光响应的动态共价键,能够在可见光辐照下发生可逆的交换反应.将含硒化学键这些独特的性质与表界面化学... 详细信息

硒是人体必需的一种微量元素,本课题组近年的研究表明含硒化学键具有诸多独特的化学性质.二硒键具有氧化还原双重响应性,同时是一类光响应的动态共价键,能够在可见光辐照下发生可逆的交换反应.将含硒化学键这些独特的性质与表界面化学相结合可以赋予体系独特的响应行为.本文综合评述了本课题组近年来在含硒表界面化学领域的研究进展:采用单分子力谱揭示了含硒化学键相互作用的力学规律;通过表界面化学实现了二硒键动态平衡的调控;基于二硒键氧化还原及可见光响应性实现了表界面可逆修饰、二维材料功能化及层层组装膜材料的制备,在生物医用、液体输运等领域具有潜在应用价值.

关键词：硒表界面动态共价键刺激响应

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乡村旅游研究30年:国内外文献回顾与展望

华中师范大学学报（自然科学版） 2024年第1期58卷 1-12页

作者：李志飞夏家豪湖北大学旅游学院武汉430062 湖北大学乡村旅游研究中心武汉430062

乡村振兴是国家实现共同富裕目标的重要一环,乡村旅游是推动乡村振兴的重要手段之一.文章借助CiteSpace可视化软件,选取CNKI中国知网1 118篇中文文献和Web of Science(WOS)核心数据库1 803篇英文文献作为数据样本,对近30年来国内外乡村... 详细信息

乡村振兴是国家实现共同富裕目标的重要一环,乡村旅游是推动乡村振兴的重要手段之一.文章借助CiteSpace可视化软件,选取CNKI中国知网1 118篇中文文献和Web of Science(WOS)核心数据库1 803篇英文文献作为数据样本,对近30年来国内外乡村旅游高质量文献进行梳理和总结,分析和对比国内外乡村旅游研究的进程和热点,并对乡村旅游未来的研究趋势进行展望.结果表明:1)国内对乡村旅游的研究呈现三个阶段的特点;2)国内研究热点聚焦于乡村旅游的社区参与、产业融合和产业升级等方面;国外研究热点关注于乡村旅游目的地形象、可持续乡村旅游以及大数据在乡村旅游中的应用等方面;3)未来乡村旅游研究可从利益分配问题、多学科的拓展研究、经验本土化、数字化、乡村振兴政策结合、人与自然的协调等六个方面展开进一步的研究.

关键词：乡村旅游文献回顾研究展望

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基于核相关滤波和运动模型的多目标轨迹跟踪

汽车工程 2019年第10期41卷 1179-1188页

作者：廖家才曹立波夏家豪张晓吴强湖南大学汽车车身先进设计制造国家重点实验室

在自动驾驶系统中,基于视觉的车辆前方多目标检测和轨迹跟踪能够为前方目标的姿态估计、行为分析提供有效信息。针对协同运动信息和核相关滤波跟踪信息的多目标跟踪的不足,使用卷积神经网络YOLOv2检测目标,提出了融合核相关滤波和目标... 详细信息

在自动驾驶系统中,基于视觉的车辆前方多目标检测和轨迹跟踪能够为前方目标的姿态估计、行为分析提供有效信息。针对协同运动信息和核相关滤波跟踪信息的多目标跟踪的不足,使用卷积神经网络YOLOv2检测目标,提出了融合核相关滤波和目标运动信息的多目标轨迹跟踪方法,目的是将运动信息融入到图像特征跟踪容器中,优化运动模型,减少环境噪声造成的目标跟踪丢失、偏离。提出了基于运动信息改进核相关滤波跟踪尺度不变性算法。建立了多目标的检测跟踪容器,提出了结合目标属性、重合度、运动状态、跟踪状态的多目标匹配方法。实验表明,本文算法能够实现一定场景下的多目标的持续实时轨迹跟踪,平均有效跟踪率为92.5%。

关键词：自动驾驶系统多目标跟踪核相关滤波 YOLOv2 卡尔曼滤波

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基于视觉的护栏清洗车偏离预警系统

汽车安全与节能学报 2019年第1期10卷 46-53页

作者：廖家才曹立波夏家豪程小建彭旭汽车车身先进设计制造国家重点实验室湖南大学长沙福田汽车科技有限公司

为了获得护栏清洗车与护栏之间的准确距离信息,避免驾驶员进行观察护栏位置的同时操作车辆而导致分心驾驶和疲劳驾驶,提出一种基于视觉的护栏检测方法并应用在护栏清洗车偏离预警系统。使用双目立体视觉获得护栏的准确距离值;结合摄像... 详细信息

为了获得护栏清洗车与护栏之间的准确距离信息,避免驾驶员进行观察护栏位置的同时操作车辆而导致分心驾驶和疲劳驾驶,提出一种基于视觉的护栏检测方法并应用在护栏清洗车偏离预警系统。使用双目立体视觉获得护栏的准确距离值;结合摄像头标定和标记分水岭算法分割护栏所在区域,并使用Hough变换直线检测算法提取护栏分割区域内的直线特征;通过约束直线检测参数和直线检测数量实现护栏检测。使用恒定速运模型条件下的Kalman滤波器跟踪护栏位置,结合特征检测信息和位置跟踪信息进行决策和预警。结果表明:偏离预警系统平均预警准确率为89.40%,因此在工程环卫车辆上具有一定的实用价值。

关键词：主动安全护栏清洗车偏离预警系统立体视觉分水岭算法 Hough变换直线检测 Kalman滤波

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热力学促进剂对瓦斯水合物相平衡的影响

黑龙江科技大学学报 2016年第3期26卷 235-239页

作者：吴强张家豪高霞刘传海黑龙江科技大学安全工程学院哈尔滨150022 黑龙江科技大学瓦斯等烃气输运管网安全基础研究实验室哈尔滨150022 黑龙江科技大学建筑工程学院哈尔滨150022

为研究热力学促进剂对瓦斯水合物相平衡的影响,利用全透明瓦斯水合分离实验装置,获取TBAB、THF和CP三种促进体系中瓦斯水合物生成的相平衡参数,结合Chen-Guo模型计算值分析实验数据。结果表明:三种热力学促进剂均能改善水合物相平衡条件... 详细信息

为研究热力学促进剂对瓦斯水合物相平衡的影响,利用全透明瓦斯水合分离实验装置,获取TBAB、THF和CP三种促进体系中瓦斯水合物生成的相平衡参数,结合Chen-Guo模型计算值分析实验数据。结果表明:三种热力学促进剂均能改善水合物相平衡条件,THF、TBAB和CP平均压降分别为36.5、14.9、5.1 MPa,最大压降分别为38.8、17.2、6.5 MPa,其影响效果由大到小依次为THF、TBAB、CP。

关键词：瓦斯混合气相平衡热力学促进剂基础水合物

Recent developments on catalytic membrane for gas cleaning

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Chinese Journal of Chemical Engineering 2019年第6期27卷 1391-1402页

作者： jiahao Chen Zhaoxiang Zhong Yongsheng xia Xuebin Ke Weihong Xing State Key Laboratory of Materials-Oriented Chemical Engineering National Engineering Research Center for Special Separation MembraneNanjing Tech UniversityNanjing 210009China Faculty of Science and Engineering School of Engineering and Computer ScienceUniversity of HullHU67RXUnited Kingdom

Catalytic membrane, a novel membrane separation technology that combines catalysis and separation, exhibits significant potential in gas purification such as formaldehyde, toluene and nitrogen oxides(NO_x). The catalytic membrane can remove solid particles through membrane separation and degrade gaseous pollutants to clean gas via a catalytic reaction to achieve green emissions. In this review, we discussed the recent developments of catalytic membranes from two aspects: preparation of catalytic membrane and its application in gas *** membranes are divided into organic catalytic membranes and inorganic catalytic membranes depending on the substrate materials. The organic catalytic membranes which are used for low temperature operation(less than 300 °C) are prepared by modifying the polymers or doping catalytic components into the polymers through coating, grafting, or in situ growth of catalysts on polymeric membrane. Inorganic catalytic membranes are used at higher temperature(higher than 500 °C). The catalyst and inorganic membrane can be integrated through conventional deposition methods, such as chemical(physical) vapor deposition and wet chemical deposition. The application progress of catalytic membrane is focused on purifying indoor air and industrial exhaust to remove formaldehyde, toluene, NO_x and PM2.5, which are also summarized. Perspectives on the future developments of the catalytic membranes are provided in terms of material manufacturing and process optimization.

关键词： Catalytic membranes Gas cleaning Membrane Catalysts

Numerical and theoretical study of large-scale failure of strata overlying sublevel caving mines with steeply dipping discontinuities

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1799-1815页

作者： Kaizong xia Zhiwei Si Congxin Chen xiaoshuang Li Junpeng Zou jiahao Yuan State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China University of Chinese Academy of Sciences Beijing 100049China School of Urban Construction Changzhou UniversityChangzhou 213164China Faculty of Engineering China University of Geosciences(Wuhan)Wuhan 430074China

The deformation and fracture evolution mechanisms of the strata overlying mines mined using sublevel caving were studied via numerical ***,an expression for the normal force acting on the side face of a steeply dipping superimposed cantilever beam in the surrounding rock was deduced based on limit equilibrium *** results show the following:(1)surface displacement above metal mines with steeply dipping discontinuities shows significant step characteristics,and(2)the behavior of the strata as they fail exhibits superimposition ***,failure first occurs in certain superimposed strata slightly far from the ***,with the constant downward excavation of the orebody,the superimposed strata become damaged both upwards away from and downwards toward the *** process continues until the deep part of the steeply dipping superimposed strata forms a large-scale deep fracture plane that connects with the *** deep fracture plane generally makes an angle of 12°-20°with the normal to the steeply dipping *** effect of the constant outward transfer of strata movement due to the constant outward failure of the superimposed strata in the metal mines with steeply dipping discontinuities causes the scope of the strata movement in these mines to be larger than *** strata in the metal mines with steeply dipping discontinuities mainly show flexural toppling ***,the steeply dipping structural strata near the goaf mainly exhibit shear slipping failure,in which case the mechanical model used to describe them can be simplified by treating them as steeply dipping superimposed cantilever *** taking the steeply dipping superimposed cantilever beam that first experiences failure as the key stratum,the failure scope of the strata(and criteria for the stability of metal mines with steeply dipping discontinuities mined using sublevel caving)can be obtained via iterative computations from the ke

关键词： sublevel caving mines universal distinct element code(UDEC)numerical approach large-scale ground movement steeply dipping superimposed cantilever beam toppling failure

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体型和羽速对汶上芦花鸡蛋品质的影响

黑龙江畜牧兽医 2021年第7期 71-73页

作者：沈国蕊夏佳豪滕军王文文贾正民贾正国李显耀唐辉山东农业大学动物科技学院山东泰安271018 山东金秋农牧科技有限公司山东济宁272000

为了了解体型和羽速对汶上芦花鸡蛋品质的影响,试验对42周龄大型快羽、大型慢羽、小型快羽、小型慢羽4个品系汶上芦花鸡所产鸡蛋的蛋品质进行测定,采用SAS 9.2软件的GLM程序对相关数据进行分析,观察体型、羽速及其交互作用对蛋品质的影... 详细信息

为了了解体型和羽速对汶上芦花鸡蛋品质的影响,试验对42周龄大型快羽、大型慢羽、小型快羽、小型慢羽4个品系汶上芦花鸡所产鸡蛋的蛋品质进行测定,采用SAS 9.2软件的GLM程序对相关数据进行分析,观察体型、羽速及其交互作用对蛋品质的影响,并计算4个品系汶上芦花鸡各项蛋品质指标的变异系数。结果表明:蛋重和哈氏单位在不同体型、羽速间均差异显著(P<0.05),蛋形指数、蛋壳厚度和蛋黄色泽在不同羽速间差异显著(P<0.05)。两个因素交互后,4个品系汶上芦花鸡在蛋重、蛋黄色泽和哈氏单位上存在差异;与其他3个品系相比,大型快羽品系的鸡蛋最重,大型慢羽品系的哈氏单位最大,快羽鸡的蛋重和蛋黄色泽优于慢羽鸡。蛋壳强度的变异系数较大,性状整齐度较差。说明汶上芦花鸡的蛋重和哈氏单位受羽速和体型这两个因素的共同影响,蛋黄色泽受羽速影响较大,多数蛋品质性状有良好的遗传改良前景。

关键词：汶上芦花鸡蛋品质品系体型羽速交互

Estimating shear strength of high-level pillars supported with cemented backfilling using the HoekeBrown strength criterion

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 454-469页

作者： Kaizong xia Congxin Chen Xiumin Liu Yue Wang Xuanting Liu jiahao Yuan State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China

Deep metal mines are often mined using the high-level pillars with subsequent cementation backfilling(HLSCB)mining *** the design stage,it is therefore important to have a reasonable method for determining the shear strength of the high-level pillars(*** and internal friction angle)when they are supported by cemented *** this study,a formula was derived for the upper limit of the confining pressure σ3max on a high-level pillar supported by cemented backfilling in a deep metal mine.A new method of estimating the shear strength of such pillars was then proposed based on the Hoek eBrown failure *** analysis indicates that the horizontal stress σhh acting on the cemented backfill pillar can be simplified by expressing it as a constant value.A reasonable and effective value for σ3max can then be *** value of s3max predicted using the proposed method is generally less than 3 *** this range,the shear strength of the high-level pillar is accurately calculated using the equivalent MohreCoulomb *** proposed method can effectively avoid the calculation of inaccurate shear strength values for the high-level pillars when the original HoekeBrown criterion is used in the presence of large confining pressures,*** situation in which the cohesion value is too large and the friction angle is too small can effectively be *** proposed method is applied to a deep metal mine in China that is being excavated using the HLSCB *** shear strength parameters of the high-level pillars obtained using the proposed method were input in the numerical *** numerical results show that the recommended level heights and sizes of the high-level pillars and rooms in the mine are rational.

关键词： Deep metal mines High-level pillars HoekeBrown strength criterion Cemented backfilling Confining pressure Shear strength