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跨海桥梁基础波浪力断面对比与研究

铁道标准设计 2024年第2期68卷 80-85,92页

作者：崔苗苗毕昕宇李鑫祝兵中铁第四勘察设计院集团有限公司武汉430063 西南交通大学土木工程学院成都610031

桥梁基础在波浪环境下的施工安全关乎桥梁建设的稳定性,需要给予足够的重视。利用数值模拟手段,基于改进的RNG κ-ε模型,采用VOF法模拟自由液面,在保持相同迎浪断面的情况下,建立圆形、圆端形、矩形和多边形4种不同断面形式桥梁基础受... 详细信息

桥梁基础在波浪环境下的施工安全关乎桥梁建设的稳定性,需要给予足够的重视。利用数值模拟手段,基于改进的RNG κ-ε模型,采用VOF法模拟自由液面,在保持相同迎浪断面的情况下,建立圆形、圆端形、矩形和多边形4种不同断面形式桥梁基础受波浪作用的三维数值模型,对比其受力差异,并结合流场数据加以分析。结果表明:相同波浪条件下4种不同断面形式的结构所受到水平波浪力中以圆形结构为最小,矩形结构为最大,其总水平波浪力幅值较圆形结构增大10%左右;桥梁基础结构在波浪的作用下,基础周围会受到绕流作用,使得结构部分位置处的流速增大并出现流速集中现象,在矩形结构周围这一现象最为突出,多边形结构的情况与之类似,而圆形及圆端形结构的流速集中现象则相对较弱;按规范计算得到的等效圆柱波浪力相较于数值模拟结果大23%~29%,按等效方柱计算得到的波浪力相较于数值模拟结果大10%~13%。从工程设计的角度看,采用圆弧形的结构设计有助于减小波浪荷载和削弱桥梁基础局部的流速增大与流速集中现象。

关键词：跨海桥梁桥梁基础波浪力结构比选数值模拟

公铁混合布置大跨度斜拉桥主梁断面形式研究--以赣江公铁大桥西支主桥设计为例

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铁道标准设计 2024年第1期68卷 96-101页

作者：郭安娜王新国崔苗苗周刚中铁第四勘察设计院集团有限公司武汉430063

以赣江公铁两用大桥西支主桥设计为例,研究一种适应上层8车道公路、下层对称双线铁路+4车道公路混合布置的主梁断面形式。提出带挑臂双索面箱桁组合断面、带挑臂单索面箱桁组合断面、矩形箱桁组合断面、矩形钢桁梁断面4种主梁断面方案,... 详细信息

以赣江公铁两用大桥西支主桥设计为例,研究一种适应上层8车道公路、下层对称双线铁路+4车道公路混合布置的主梁断面形式。提出带挑臂双索面箱桁组合断面、带挑臂单索面箱桁组合断面、矩形箱桁组合断面、矩形钢桁梁断面4种主梁断面方案,采用有限元软件分析各方案静动力性能及受力特点,综合考虑方案构造特点、技术指标、工程数量、公铁运营安全、景观效果等,确定该桥选用带挑臂双索面箱桁组合断面。该桥斜拉索最大索力16000 kN,锚固在下层钢箱梁两侧,通过有限元实体分析对锚拉板和钢锚箱式两种索梁锚固形式进行比选研究,钢锚箱形式受力合理、应力水平低、经济性好,设计采用钢锚箱形式。带挑臂双索面箱桁组合断面桥面空间布置合理、下层公铁行车干扰小、梁端竖向变形最小、经济性好,是一种适应公铁混合布置大跨度斜拉桥主梁断面形式。

关键词：公铁两用桥斜拉桥公铁混合布置主梁断面带挑臂双索面箱桁组合断面钢锚箱设计

昌九高铁扬子洲赣江公铁大桥西支主桥桥塔设计

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世界桥梁 2024年第2期52卷 14-20页

作者：郭安娜严爱国王新国崔苗苗周刚中铁第四勘察设计院集团有限公司湖北武汉430063

昌九高铁扬子洲赣江公铁大桥西支主桥采用竖琴形索面箱桁组合梁斜拉桥,跨径布置为(48+144+320+144+48)m。根据桥梁结构特点,针对花瓶形、H形和钻石形桥塔方案,从结构受力、景观效果、施工难度、经济性等方面进行比选,最终采用适应宽主... 详细信息

昌九高铁扬子洲赣江公铁大桥西支主桥采用竖琴形索面箱桁组合梁斜拉桥,跨径布置为(48+144+320+144+48)m。根据桥梁结构特点,针对花瓶形、H形和钻石形桥塔方案,从结构受力、景观效果、施工难度、经济性等方面进行比选,最终采用适应宽主梁、竖琴形索面的花瓶形桥塔。2座桥塔高度分别为143.5 m和147.1 m,采用C50钢筋混凝土结构,由上、中、下塔柱组成,塔柱圆弧过渡,设上、下2道横梁,下横梁采用预应力混凝土结构,上横梁由2道反向圆弧的预应力混凝土小横梁和中间的装饰性钢结构共同组成“昌”字造型。索塔锚固区采用钢锚箱锚固体系与预应力锚固体系相结合的方式。桥塔下塔柱采用翻模法施工,中、上塔柱外部采用爬模法施工、内部采用翻模法施工。对桥塔进行整体静力、局部应力、稳定性及抗震分析,结果表明桥塔强度、刚度、稳定性及抗震性能均满足规范要求。

关键词：斜拉桥公路铁路两用桥花瓶形桥塔文字装饰横梁索塔锚固受力分析桥梁设计

Low-frequency blue energy harvesting for sustainable and active anticorrosion

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Nano Research 2023年第9期16卷 11871-11877页

作者： miaomiao cui Yawei Feng Hao Wu Yuankai Jin Wanbo Li Zuankai Wang Department of Mechanical Engineering City University of Hong KongHong KongChina Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHong KongChina School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China Interdisciplinary Research Center for Engineering Science School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Engineering materials serving in marine surroundings are inevitably *** corrosive marine conditions can also be utilized to harvest kinetic ocean wave energy to solve this *** water–solid triboelectrification to harvest lowfrequency wave energy for active anticorrosion is *** techniques are efficient in harnessing environmental energy with frequencies higher than 3 Hz,whereas the dominated ocean waves with optimal wave spectral density fluctuate from 0.45 to 1.5 ***,we proposed a highly efficient and sustainable blue energy-powered cathodic protection(BECP)strategy by fusing water–solid triboelectric nanogenerators and cathodic protection *** the highly efficient triboelectrification between the moving water and hydrophobic fluorinated ethylene propylene tube,we developed the built-in power module,enabling the harvest of ocean wave energy lower than 1.5 *** generated volumetric current density is 28.9 mA·m^(-3),5–20 times higher than the values of the reported ***,the proposed BECP performs comparably to conventional cathodic protection in corrosion ***,the proposed approach can be easily applied to ships,buoys,and other offshore platforms to simultaneously realize blue energy harvesting and engineering material protection,providing an alternative to traditional active protection technology.

关键词： corrosion inhibition blue energy harvesting triboelectric nanogenerator cathodic protection

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公铁同层桥梁防眩设施及防眩效果研究

中国铁道科学 2024年第4期45卷 48-56页

作者：张迅徐艺涵孔德睿陈柯儿李小珍王德志崔苗苗西南交通大学土木工程学院四川成都610031 西南交通大学桥梁智能与绿色建造全国重点实验室四川成都611756 中铁第四勘察设计院集团有限公司湖北武汉430063

以某公铁同层桥梁为背景,以道路失能眩光造成的阈值增量为评价指标,基于DIALux光学仿真分析软件,结合现场试验进行公铁同层桥梁防眩设施研究,并从屏障结构和列车光源2个层面开展影响屏障防眩效果的参数分析。结果表明:屏障高度和遮光角... 详细信息

以某公铁同层桥梁为背景,以道路失能眩光造成的阈值增量为评价指标,基于DIALux光学仿真分析软件,结合现场试验进行公铁同层桥梁防眩设施研究,并从屏障结构和列车光源2个层面开展影响屏障防眩效果的参数分析。结果表明:屏障高度和遮光角需大于某一阈值才能满足防眩要求,本案例为3.0 m和12°;当屏障开孔率较大或者光源灯柱角度和光通量较大时,需要进一步校核眩光指标,以免其漏光严重;灯柱角度和屏障材料基本不影响眩光水平;影响眩光水平的主要因素为屏障高度、遮光角和列车灯光通量。

关键词：公铁同层桥梁防眩屏障道路失能眩光阈值增量光通量防眩效果 DIALux仿真

On geometric structure of generalized projections in C~*-algebras

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Science China Mathematics 2018年第7期61卷 1187-1200页

作者： miaomiao cui Guoxing Ji School of Mathematics and Information Science Shaanxi Normal University

Let H be a Hilbert space and A ■ B(H) be a C~*-subalgebra. This paper is devoted to studying the set gP of generalized projections in A from a differential geometric point of view, and mainly focuses on geodesic curves. We prove that the space gP is a C~∞ Banach submanifold of A, and a homogeneous reductive space under the action of Banach Lie group U_A of A. Moreover, we compute the geodesics of gP in a standard fashion, and prove that any generalized projection in a prescribed neighbourhood of p∈gP can be joined with p by a unique geodesic curve in gP.

关键词： generalized projections Banach manifold geodesics

Warming and elevated nitrogen deposition accelerate the invasion process of Solidago canadensis L.

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Ecological Processes 2022年第1期11卷 890-901页

作者： Guangqian Ren Bin Yang miaomiao cui Zhicong Dai Yan Xiang Haiyan Zhang Guanlin Li Jian Li Qaiser Javed Daolin Du Institute of Environment and Ecology Academy of Environmental Health and Ecological SecuritySchool of the Environment and Safety EngineeringJiangsu UniversityZhenjiang 212013China School of Agricultural Engineering Jiangsu UniversityZhenjiang 212013China School of Inspection and Testing Certification Changzhou Vocational Institute of EngineeringChangzhou 213164China Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment Suzhou University of Science and TechnologySuzhou 215009China

Background:Invasive species can threaten native diversity and alter ecosystem processes while interacting with other components of global environmental *** plants are becoming increasingly problematic and this can be stimulated by changes in the ***,existing studies have primarily investigated the effects of environmental change on a specific stage of plant invasion rather than the continuous invasion ***:A space-for-time substitution experiment was performed to investigate how warming and nitrogen deposition affects the invasion process of a ***,different ratios of invasive Solidago canadensis *** native Artemisia argyi *** Van were employed as a proxy to represent successive levels of invasion.A total of seven treatments were applied in the experiment:ambient(CK),N addition(+5,+12 g m^(−2)year^(−1)),warming(+1.15,+1.86℃)and their interaction(5 g N m^(−2)year^(−1)+1.15℃,12 g N m^(−2)year^(−1)+1.86℃).The growth performance and competitiveness of *** were ***:The competitiveness of Solidago canadensis decreased linearly with its invasion degree(p<0.05).Non-linear regression showed that *** invasion levels of 53%,53%,68%,55%and 58%were the critical thresholds for shifting the direction or magnitude of chlorophyll,leaf nitrogen,leaf shape index,diameter,and root/shoot ratio,*** with the ambient treatment(CK,no warming and no N addition),the diameter,height,bio-mass and relative competitiveness of *** were each limited by warming,to a certain extent,whereas these and the above parameters were significantly increased by nitrogen *** interaction of increased temperature and nitrogen deposition led to significant increases in the growth and competitiveness of ***,and this effect was detected in every stage of the invasion,throughout the invasion ***:Environmental change might have a continuous,progressive,and augmenta

关键词： Environmental change Phenotypic trait Competitiveness Solidago canadensis L. Invasion process

Strategies for improving extraction capacity through preorganization structure:A novel 5,6-bicyclicmalonamide extractant(THPPD)

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Journal of Rare Earths 2024年第4期42卷 768-774页

作者： miaomiao Zhang Zhen Yang Yuhua cui Jianhui Su Heng Zhao Chengjin Xu Xiaolei Liu Guoxin Sun Xiujing Peng Yu cui School of Chemistry and Chemical Engineering University of JinanJinan250022China Institute for Smart Materials&Engineering University of JinanJinan250022China Shandong Institute for Food and Drug Control Jinan250101China

Rational design of extractant structure to improve the extraction and separation capacity of rare earth elements(REEs)is a long-standing ***,a new strategy was proposed to improve the stability of the chelating structure formed by malonamide and *** stability of the chelating structure is greatly improved by using a double-ring framework structure which makes the two carbonyl groups of malonamide unable to rotate freely and both of them point to the metal ion *** benzyl groups were used to construct the hydrophobicity of the extractant and the organic shell of the extracted ***-pyrrolo-pyridine-dione(THPPD)was designed and *** structure reduces the energy consumed by rotating carbonyl group in the coordination with metal ions and then improves the extraction ability of *** crystal structure was preorganized as expected,with the two carbonyls pointing in a favorable coordination direction to the structural complement of the metal *** extraction behaviors of REEs with THPPD in a nitric acid medium were *** with N,N’-dibenzyl-N,N’-dimethylmalonamide(DBDM-MA)with a chain structure,the extraction capacity of THPPD is 360 times higher than that of DBDM-MA at 5.0 mol/L sodium ***,the binding energy and Gibbs free energy were investigated by density functional theory(DFT)in conjunction with the *** theoretical results show that THPPD has more effective interaction with Pr(NO_(3))3 than *** construction of chelating groups conformation is a worthy direction to improve the coordination ability and even selectivity of extractant.

关键词： Rare earth elements Extraction separation 5,6-bicyclicdiamide extractant

Facile preparation and efficient MnxCoy porous nanosheets for the sustainable catalytic process of soot

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Green Energy & Environment 2024年第3期9卷 516-528页

作者： miaomiao Hu Kun Zhou Tingyi Zhao Zheng Li Xianhai Zeng Di Yu Xuehua Yu Mingqin Zhao Zhihui Shao Qixiang Xu Bing cui Flavors and Fragrance Engineering&Technology Research Center of Henan Province College of Tobacco ScienceHenan Agricultural UniversityZhengzhou450002China School of Ecology and Environment Zhengzhou UniversityZhengzhou450001China College of Energy Xiamen UniversityXiamen361102China College of Chemistry and Chemical Engineering Shenyang Normal UniversityShenyang110034China

The pursuit of high-performance is worth considerable effort in catalysis for energy efficiency and environmental sustainability. To develop redox catalysts with superior performance for soot combustion, a series of Mn_(x)Co_(y) oxides were synthesized using MgO template *** method greatly improves the preparation and catalytic efficiency and is more in line with the current theme of green catalysts and sustainable development. The resulting Mn_(1)Co_(2.3) has a strong activation capability of gaseous oxygen due to a high concentration of Co^(3+) and Mn^(3+). The Mn doping enhanced the intrinsic activity by prompting oxygen vacancy formation and gaseous oxygen adsorption. The nanosheet morphology with abundant mesoporous significantly increased the solid–solid contact efficiency and improved the adsorption capability of gaseous reactants. The novel design of Mn_(1)Co_(2.3)oxide enhanced its catalytic performance through a synergistic effect of Mn doping and the porous nanosheet morphology, showing significant potential for the preparation of high-performance soot combustion catalysts.

关键词： Soot combustion Intrinsic activity Contact efficiency Mn doping DFT