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Numerical simulation of landscape evolution and mountain uplift history constrain——A case study from the youthful stage mountains around the central Hexi Corridor,NE Tibetan Plateau

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Science China Earth Sciences 2021年第3期64卷 412-424页

作者： Baotian PAN Shun CAI haopeng geng Key Laboratory of Western China’s Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou730000China

Landscape evolution models(LEMs)are essential tools for analyzing tectonic-climate interactions and reproducing landform-shaping *** this study we used a LEM to simulate the evolution of the mountains from the central Hexi Corridor in the northeastern Tibetan Plateau,where the climate is arid and the surface processes are relatively ***,there are pronounced differences in the topography between the mountains around the central Hexi *** East Jintanan Shan,West Jintanan Shan and Heli Shan are located in the northern part of the corridor;and the Yumu Shan in the southern ***,several representative areas were selected from these mountains to analyze the topographic characteristics,including the uniform valley spacing,local relief,and the outlet ***,a LEM for these areas was constructed using the Landlab platform,and the landscape evolution was *** uniform valley spacing and other topographic characteristics as the criteria,we compared the realistic and simulated terrain for different model ***,based on the similarity of the simulated and realistic terrain,we estimated the timing of the initial uplift and the uplift rate of the four mountain *** results are consistent with previous geological and geomorphological records from these youthful stage mountains that have not yet reached a steady *** findings demonstrate that LEMs combined with topographic characteristics are a reliable means of constraining the timing of the initial uplift and the uplift rate of the youthful stage *** approach can potentially be applied to other youthful stage mountains and it may become a valuable tool in tectonic geomorphology research.

关键词： Hexi Corridor Landscape evolution models Youthful stage mountains Topographic characteristics Uniform valley spacing

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How can a youthful mountain survive in a foreland setting?–Constraining the uplift threshold rate by numerical simulation

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Science Bulletin 2022年第12期67卷 1233-1235,M0003页

作者： haopeng geng Shun Cai Honghua Lü Baotian Pan Key Laboratory of Western China’s Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China College of Urban and Environmental Sciences Yancheng Teachers UniversityYancheng 224002China Key Laboratory of Geographic Information Science of Ministry of Education School of Geographic SciencesEast China Normal UniversityShanghai 200241China

Active orogenic belts provide natural laboratories for investigating the mechanisms of tectonic deformation and landscape *** their foreland basins,the relatively continuous sedimentary archives and varied geomorphic units have documented the history of the tectonic uplift of the adjacent orogenic *** records(e.g.,low-temperature thermochronology and sedimentology)can reveal the history of mountain building on a timescale of tens of millions of *** contrast,geomorphic evidence generally documents the history of much younger landforms.

关键词：前陆盆地背斜构造晚第四纪抬升速率天山北麓逆断裂造山带新近纪

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Spatial differences in rock uplift rates inferred from channel steepness indices along the northern flank of the Qilian Mountain,northeast Tibetan Plateau

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Chinese Science Bulletin 2010年第27期55卷 3205-3214页

作者： HU XlaoFei PAN BaoTian KIRBY Eric LI QingYang geng haopeng CHEN JiFeng Key Laboratory of Western China's Environmental Systems (MOE) Lanzhou University Lanzhou 730000 China Department of Geosciences Pennsylvania State University University Park PA16802 USA

The rate and distribution of deformation along the Qilian Mountain,on the northeastern Tibetan Plateau,is needed to understand the evolution of high topography associated with the ***,a number of empirical studies have provided support for the contention,common to most models of fluvial incision,that rock uplift rate exerts a first-order control on the gradient of longitudinal river *** the northern Qilian Mountain,this method is used to extract information about the spatial patterns of differential rock *** of the longitudinal profiles of bedrock channels reveals systematic differences in the channel steepness index along the trend of the frontal *** comparisons of channel steepness reveal that lithology and precipitation have limited influence on channel ***,there is little evidence suggesting that channel steepness is influenced by differences in the sediment *** argue that the distribution of channel steepness in the Qilian Mountain is mostly the result of differential rates of rock ***,channel steepness indices reveal a lower rock uplift rate in the eastern portion of the Qilian Mountain and a higher rate in the middle and *** highest rates appear to occur in the middle-west portions of the range,just to the west of the Yumu Shan.

关键词：青藏高原东北部隆升速率祁连山通道空间差异隆起北缘剖面分析

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Recent progress in interface modification for dye-sensitized solar cells

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Science China Chemistry 2010年第8期53卷 1669-1678页

作者： MA BeiBei,GAO Rui,WANG LiDuo,ZHU YiFeng,SHI YanTao,geng Yi,DONG haopeng & QIU Yong Key Lab of Organic Optoelectronics & Molecular Engineering of Ministry of Education Department of Chemistry,Tsinghua University,Beijing 100084,China Key Lab of Organic Optoelectronics & Molecular Engineering of Ministry of Education Department of Chemistry Tsinghua University Beijing China

Interface modification on the TiO2/dye/electrolyte interface of dye-sensitized solar cells (DSCs) is one of the most effective approaches to suppress the charge recombination,improve electron injection and transportation,and thus ameliorate the conversion efficiency and stability of *** research focusing on the photoanodes interface modification before sensitization in dye-sensitized solar cells has been carried out and ***,recent studies showed that post-modification after sensitization of the TiO2 electrode also plays a significant role on the TiO2/dye/electrolyte *** post-modification using the immersing method could deprotonate dye molecules,prohibit the dye aggregation and retard the recombination *** a result,it has great influence on the devices' photovoltaic *** interface modification could also provide an approach to broaden the response of the solar spectrum by introducing an alternative assembling *** in-situ meaning of using a co-adsorbent is employed to modify the interface in the DSCs,which could retard the aggregation of the dye molecules and enhance the conversion *** addition,electrolyte additives can be used to modify the TiO2/dye/electrolyte interface through some unique *** on the background of interface modification of photoanodes before sensitization,this review introduces various interface modifications after sensitization of dye-sensitized solar cells and their mechanisms.

关键词： dye-sensitized solar cell TiO2 electrode interface modification electron recombination

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寒冻风化控制的祁连山风化碎屑的空间分布

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冰川冻土 2022年第4期44卷 1347-1356页

作者：洪洋耿豪鹏潘保田兰州大学资源环境学院西部环境教育部重点实验室甘肃兰州730000 甘肃省石羊河流域野外科学观测研究站甘肃兰州730000

寒冻风化是冰缘地貌区及高寒山区的主要物理风化过程,其提供的风化碎屑物质是该区域崩塌等灾害性地貌过程的主要物质来源。由于寒冻风化对基岩的破碎是由温度控制的累积过程,过去温度变化对地貌演化具有重要意义,但其时间尺度的选取尚... 详细信息

寒冻风化是冰缘地貌区及高寒山区的主要物理风化过程,其提供的风化碎屑物质是该区域崩塌等灾害性地貌过程的主要物质来源。由于寒冻风化对基岩的破碎是由温度控制的累积过程,过去温度变化对地貌演化具有重要意义,但其时间尺度的选取尚需进一步探究。因此本文选取祁连山北部为研究区,通过对比分析风化碎屑的空间分布特征与不同时间尺度温度变化控制的平均寒冻风化强度的空间分布特征,探讨干旱半干旱高寒山区风化碎屑空间分布的主要控制因素。结果显示,万年尺度及十万年尺度平均寒冻风化强度的高值与风化碎屑边界存在较好的空间一致性,祁连山西段万年尺度平均寒冻风化强度的高值与风化碎屑边界的空间相关性优于十万年尺度。本研究同时指出,温度升高导致寒冻风化的作用区向高海拔区域移动,进而产生新的高风险灾害区域。本研究强调寒冻风化对灾害性地貌过程的调控作用,为全球变暖背景下灾害性地貌过程的预测提供了新的思路,可以成为防灾减灾决策的重要参考。

关键词：寒冻风化风化碎屑气候变化祁连山

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基于傅里叶变换的谷间距特征信息提取及其影响因素研究

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地球信息科学学报 2020年第3期22卷 399-409页

作者：蔡顺耿豪鹏郑炜珊潘保田兰州大学资源环境学院西部环境教育部重点实验室兰州730000

谷间距(Valley Spacing)是描述相邻沟谷距离的特征参数,它能较好地反映沟谷的次序等级和空间分布特征。本研究以黑河正义峡和兰州大岭岘2个样区为例,利用ArcGIS软件,将无人机测绘获取的0.12 m分辨率地表高程数据通过重采样生成不同分辨... 详细信息

谷间距(Valley Spacing)是描述相邻沟谷距离的特征参数,它能较好地反映沟谷的次序等级和空间分布特征。本研究以黑河正义峡和兰州大岭岘2个样区为例,利用ArcGIS软件,将无人机测绘获取的0.12 m分辨率地表高程数据通过重采样生成不同分辨率的数字地表模型。通过MATLAB软件,将不同分辨率、不同空间域的数字地表模型作为二维空间域信号进行傅里叶变换。通过傅里叶变换及频谱分析研究地形的频谱特征与地表谷间距之间的转换关系。分析结果显示:①当区域内只有一级沟谷时,频谱中谷间距特征信号的有效提取要求地形分辨率至少优于1/5谷间距,分辨率的粗略化则直接影响着地形频谱中谷间距特征信号的识别,但是分析空间域对频谱谷间距特征信号的捕获影响较小;②当区域内有多级沟谷时,分辨率优于1/3谷间距时即可有效提取到该级沟谷的谷间距特征信号,分辨率的粗略化和空间域的增大都会使得频谱中较低序次等级沟谷的谷间距特征信号减弱,而较高序次等级沟谷的谷间距特征信号增强。

关键词：数字地表模型谷间距傅里叶变换频谱分析无人机数字地形分析黄土高原河西走廊

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Mixed Dead-time Effect Suppression Strategy for Modular Multilevel Converters

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1075-1084页

作者： Zhi geng Minxiao Han School of Electrical and Electronic Engineering North China Electric Power UniversityBeijing 102206China IEEE

Dead time is necessary for the coupled power switches to prevent shoot-through,especially in the modular multilevel converters(MMCs)with a large number of power *** paper proposes a dead-time effect suppression strategy for MMCs with nearest level *** operational principles of MMCs are first *** to the operational features of MMCs,the method that removes a switching signal from the coupled switches and the reduced switching frequency voltage balancing algorithms(RSFVBAs)are mixed in the proposed *** the intervals that are furthest away from the zerocrossing points(ZCP)of arm currents,the single switching signal method can completely eliminate the dead-time effect(DTE).Alternatively,the DTE is suppressed by the RSFVBA in intervals that are close to the *** the combination of the two methods,the dependence of the DTE suppression method on currents is reduced and the influences of ZCP are also released without degrading the normal operation performance of ***,the output performance of MMCs is improved and the voltage stress on the arm inductor dramatically ***,the validation of the method is verified by the simulation results with the professional tool Matlab/Simulink.

关键词： Dead-time effect modular multilevel converters switching frequency voltage balancing algorithm

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Structural engineered living materials

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Nano Research 2024年第2期17卷 715-733页

作者： Yang geng Zian Jia Ling Li 635 Prices Fork Road Department of Mechanical EngineeringVirginia Polytechnic Institute and State UniversityBlacksburg VA24061USA

Biological structural materials not only exhibit remarkable mechanical properties but also often embody dynamic characteristics such as environmental responsiveness,autonomy,and self-healing,which are difficult to achieve in conventional engineering *** merging materials science,synthetic biology,and other disciplines,engineered living materials(ELMs)provide a promising solution to combine living organisms with abiotic components,thus facilitating the construction of functional“living”*** natural materials,ELMs possess vitality and hold immense application potential in areas such as medicine,electronics,and construction,captivating increasing research attention *** an emerging branch of ELMs,structural ELMs aim to mimic living biological structural materials by achieving desired mechanical performance while maintaining important“living”*** we summarize the recent progress and provide our perspectives for this emerging research *** first summarize the superiority of structural ELMs by reviewing biological structural materials and biomimetic material design ***,we provide a systematic discussion on the definition and classifications of structural ELMs,their mechanical performance,and physiological ***,we summarize some critical challenges faced by structural ELMs and highlight directions of future *** hope this review article can provide a timely summary of the state of the art and relevant perspectives for future development of structural ELMs.

关键词： structural materials engineered living materials(ELMs) structural ELMs composites mechanical properties

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Point defects in 2-D liquid crystals with a singular potential:Profiles and stability

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Science China Mathematics 2024年第11期67卷 2515-2540页

作者： Zhiyuan geng Wei Wang Basque Center for Applied Mathematics School of Mathematical Sciences Zhejiang University

We study radial symmetric point defects with degree k/2 in the 2-D disk or R2in the Q-tensor framework with a singular bulk energy,which is defined by Bingham ***,we obtain the existence of solutions for the profiles of radial symmetric point defects with degree k/2 in the 2-D disk or ***,we prove that the solution is stable for |k| = 1 and unstable for |k| > *** identities are derived and utilized throughout the proof of existence and stability/instability.

关键词： radial symmetric point defects singular bulk potential Bingham closure stability

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Boosting electrocatalytic nitrate reduction to ammonia via Cu_(2)O/Cu(OH)_(2)heterostructures promoting electron transfer

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Nano Research 2024年第6期17卷 4898-4907页

作者： Jing geng Sihan Ji Anhui Province International Research Center on Advanced Building Materials School of Materials Science and Chemical EngineeringAnhui Jianzhu UniversityHefei 230601China Anhui Province Key Laboratory of Advanced Building Materials Anhui Jianzhu UniversityHefei 230601China School of Energy Materials and Chemical Engineering Hefei UniversityHefei 230601China

Electrocatalytic nitrate(NO_(3)^(−))reduction to ammonia(NH_(3))offers a viable approach for sustainable NH_(3)production and environmental ***(Cu)possesses a distinctive electronic structure,which can augment the reaction kinetics of NO_(3)^(−)and impede hydrogen evolution reaction(HER),rendering it a promising contender for the electrosynthesis of NH_(3)from NO_(3)^(−).Nevertheless,the role of Cu_(2)O in copper-based catalysts still requires further investigation for a more comprehensive ***,the Cu_(2)O/Cu(OH)_(2)heterostructures are successfully fabricated through liquid laser irradiation using CuO nanoparticles as a *** and theoretical researches reveal that Cu_(2)O/Cu(OH)_(2)heterostructure exhibits enhanced electrocatalytic performance for NO_(3)^(−)to NH_(3)because Cu(OH)_(2)promotes electron transfer and reduces the valence state of Cu active site in Cu_(2)***−0.6 V(*** hydrogen electrode(RHE)),the NH_(3)yield reaches its maximum at 1630.66±29.72μg·h^(−1)·mgcat^(−1),while the maximum of Faraday efficiency(FE)is 76.95%±5.51%.This study expands the technical scope of copper-based catalyst preparation and enhances the understanding of the electrocatalytic mechanism of NO_(3)^(−)to NH_(3).

关键词： Cu_(2)O/Cu(OH)_(2)heterostructures electron transfer ammonia synthesis electrocatalysts nitrate

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