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A review of edge-based 3D tracking of rigid objects

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Virtual Reality & Intelligent Hardware 2019年第6期1卷 580-596页

作者： pengfei han Gang ZHAO School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China MIIT Key Laboratory of Aeronautics Intelligent Manufacturing Beihang UniversityBeijing 100191China

Three-dimensional(3D)tracking of rigid objects plays a very important role in many areas such as augmented reality,computer vision,and *** works have been done to pursue more stable,faster,and more accurate 3D *** various tracking methods,edge-based 3D tracking has been widely used owing to its many ***,edge-based methods can be mainly divided into two categories,methods without and those with explicit edges,depending on whether explicit edges need to be *** on this,representative methods in both categories are introduced,analyzed,and compared in this ***,some suggestions on the choice of methods in different application scenarios and research directions in the future are given.

关键词： Augmented reality 3D tracking Edge CAD model

An improved modeling of precipitation phase and snow in the Lancang River Basin in Southwest China

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Science China(Technological Sciences) 2021年第7期64卷 1513-1527页

作者： han ZhongYing LONG Di han pengfei HUANG Qi DU MingDa HOU AiZhong State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing100084China Hydrological Forecast Center Ministry of Water Resources of the People’s Republic of ChinaBeijing100053China

Precipitation phase(e.g., rainfall and snowfall) and snow(e.g., snowpack and snowmelt runoff) in high-mountain regions may largely affect runoff generation, which is critical to water supply, hydropower generation, agricultural irrigation, and ecosystems downstream. Accurately modeling precipitation phase and snow is therefore fundamental to developing a better understanding of hydrological processes for high-mountain regions and their lower reaches. The Lancang River(LR, or the Upper Mekong River)in China, among the most important transboundary rivers originating from the Tibetan Plateau, features active dam construction and complex water resources allocation of various stakeholders in Southeast Asian countries under climate change. This study aims to improve precipitation phase and snow modeling for the LR basin with a hydrological model and multisource remotely sensed data. Results show that joint use of the Moderate Resolution Imaging Spectroradiometer(MODIS) land surface temperature product with high spatial resolution(1 km×1 km) and an air temperature product can more precisely distinguish precipitation phase than air and wet-bulb temperature products in the LR basin. Snowfall and snowmelt were found to be controlled primarily by rainfall and snowfall temperature thresholds in snow modeling. The rainfall and snowfall temperature thresholds derived from the hydrological model through calibration with remotely sensed snowpack at basin scales were considerably lower than those derived from in situ observations. Rainfall and snowfall temperature thresholds derived from in situ observations could lead to the overestimation of snowmelt runoff due mostly to the lack of representation of point-based measurements at basin scales. This study serves as a basis for better modeling and predicting snow for the LR basin and potentially other similar basins globally.

关键词： distributed hydrological model snowfall snow water equivalent snowmelt Lancang River Basin

Double-uncertainty optimal operation of hybrid AC/DC microgrids with high proportion of intermittent energy sources

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Journal of Modern Power Systems and Clean Energy 2017年第6期5卷 838-849页

作者： Peng LI pengfei han Shuai HE Xiaoxiao WANG Department of Electrical and Electronic Engineering North China Electric Power UniversityBaoding 071003Hebei ProvinceChina

This paper applies double-uncertainty optimization theory to the operation of AC/DC hybrid microgrids to deal with uncertainties caused by a high proportion of intermittent energy sources.A fuzzy stochastic expectation economic model for day-ahead scheduling based on uncertain optimization theory is proposed to minimize the operational costs of hybrid AC/DC *** fuzzy stochastic alternating direction multiplier method is proposed to solve the double-uncertainty optimization problem.A real-time intra-day unbalanced power adjustment model is established to minimize real-time adjustment *** comparative analysis of deterministic optimization,stochastic optimization and fuzzy stochastic optimization of day-ahead scheduling and real-time adjustment,the validity of fuzzy stochastic optimization based on a fuzzy stochastic expectation model is proved.

关键词： Double-uncertainty optimization Fuzzy stochastic ADMM Fuzzy stochastic expected value model High proportion of intermittent energy sources Hybrid AC/DC microgrid

Synthetic Control Method for Crystallite Size of MOF-5

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Chemical Research in Chinese Universities 2014年第3期30卷 356-361页

作者： han pengfei YUAN Changfu XU Junyi LIU Jin School of Metallurgy and Environment Central South University Changsha 410083 t~ R. China

We reported a dripping solvothermal method for synthesizing metal-organic framework-5（MOF-5）. It started from separately dissolving Zn（NO3）2 and terephthalic acid（H2BDC） in dimethyl formamide（DMF）, and then dripping one solution into the other. Results of SEM, XRD and laser particle size distribution show that regular cubic-shaped and micro-crystallite powder of MOF-5 can be obtained. The d0.5（volume-median-diameter） values are 4.32 μm for particles prepared by dripping Zn（NO3）2 into H2BDC（ZH） and 9.32 μm for those prepared by dripping H2BDC into Zn（NO3）2（HZ）, much smaller than 22,7 μm that of particles prepared by the traditional adding water solvothermal method（L）. The standard deviations of the particle size distributions fitted by the GaussAmp model are 2.49, 4.38 and 15.4 respectively for ZH, HZ and L, further revealing narrower size distributions of particles prepared by the dripping method. In addition, the Langmuir specific surface areas are 923 m^2/g for ZH and 868 m^2/g for HZ. The TGA results present mass losses of 4.18% and 3.62% at 105 ℃, 17.19% and 14.78% at 245 ℃, 39.04% and 34.85% at 600℃ separately for ZH and HZ, which correspond to the removal of H20, DMF and the decomposition of MOF-5. This indicates that MOF-5 has a strong adsorption ability for small molecules. Besides, the mass loss of 48.39%（ZH） and 41.02%（HZ）between 400 ℃ and 600 ℃ are less than the theoretical value of 57.81% for MOF-5 decomposition to ZnO, suggesting that an impure phase with an extra amount of ZnO may exist in the cavities of MOF-5.

关键词： Metal-organic framework-5(MOF-5) Dripping solvothermal method Size distribution

Validation and application of water levels derived from Sentinel-3A for the Brahmaputra River

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Science China(Technological Sciences) 2019年第10期62卷 1760-1772页

作者： HUANG Qi LI XingDong han pengfei LONG Di ZHAO FanYu HOU AiZhong State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing100084China Hydrological Forecast Center Ministry of Water Resources of the People’s Republic of ChinaBeijing100053China

For the first time ever, this study aims at applying Sentinel-3 A to the Great Brahmaputra River(GBR) and validating water levels derived from this newly-launched altimetry satellite mission. The GBR is divided into three primary parts:(1) a large section of the Yarlung Zangbo River in China, also termed the Upper Brahmaputra River(UBR) in this study, featured by high elevation,complex terrain, narrow river widths(from less than 100 to 400 m), and limited in situ measurements;(2) the Middle Brahmaputra River(MBR) with widths varying from ~400 m to ~1 km;(3) the Lower Brahmaputra River(LBR), dominated by braided channels with wide river channels(up to several kilometers). For the altimetry data, both waveform retracking and hooking effect correction were applied to mitigate the influence caused by land contamination and to improve the accuracy of water level retrievals. Water levels were derived from 41 virtual stations(VSs) across the GBR and different retracking algorithms were compared with in situ data from two gauging stations in the UBR. Time series of altimetry-based water levels were categorized into three types based on the quality: no data(type 1), degraded(type 2), and good(type 3). Results showed that the VSs(type 1) only existed in the mountainous regions, accounting for ~ a half of the total in the UBR. Validation with the gauged water levels showed that the TIC algorithm performed best among all of the retrackers applied, followed by the Ice-1 algorithm. The standard deviation of the difference between the gauged and TIC-derived water levels ranged from 0.41 to 0.76 m among four different VSs(type 3). In addition, the quality of VSs in the LBR was best, followed by the MBR. Our study has demonstrated the capability of Sentinel-3 A in monitoring water levels in the GBR, thereby paving the way for future applications such as discharge estimation and hydrologic/hydrodynamic applications.

关键词： water levels Sentinel-3A Brahmaputra River mountainous regions

A photonanozyme with light-empowered specific peroxidasemimicking activity

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Nano Research 2022年第10期15卷 9073-9081页

作者： Sili Lin Wenlong Tan pengfei han Xu Li Jinzhao Li Zhou Nie Kun Li State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringHunan Provincial Key Laboratory of Biomacromolecular Chemical BiologyHunan UniversityChangsha 410082China

Although nanozymes have been widely developed,directly utilizing light to drive catalytic reactions like natural photoenzymes still remains ***,we propose that photonanozymes(PNZs),as a novel kind of nanozyme,exclusively possess enzyme-mimicking activity under *** in the presence of visible light,the as-synthesized TiO_(2) proposed in this contribution shows excellent specificity of peroxidase-like without any oxidase-or catalase-like *** driving force of the light-empowered peroxidase-like photonanozymatic activity is explicated in terms of the photogenerated hot charge carriers in TiO_(2) PNZs and the accompanied reactive oxygen *** co-substrates for photonanozymatic reaction over TiO_(2) PNZs facilitate the formation of the precarious and reactive peroxo-oxygen bridge between TiO_(2) and H_(2)O_(2),enabling the catalytic *** the TiO_(2) PNZ-based biosensing platform for visual glucose detection exemplifying the concept of the application of PNZs,this work may evoke more inspirations to explore strategies for enlarging the scope of photoenzyme mimics.

关键词： photonanozyme titanium dioxide peroxidase mimics specificity biosensors

Preface to the Special Issue on Carbon Neutrality: Important Roles of Renewable Energies, Carbon Sinks, NETs, and non-CO_(2) GHGs

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Advances in Atmospheric Sciences 2022年第8期39卷 1207-1208页

作者： Junji CAO Ning ZENG Yi LIU Bengang LI pengfei han Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China Department of Atmospheric and Oceanic Science and Earth System Science Interdisciplinary CenterUniversity of MarylandCollege Park 20742MarylandUSA State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Carbon Neutrality Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing100029China Sino-French Institute for Earth System Science Laboratory for Earth Surface ProcessesCollege of Urban and Environmental SciencesPeking UniversityBeijing 100871China

The year 2020 witnessed milestone commitments to carbon neutrality with the EU,China,USA,Japan,South Korea,Canada,and South Africa,each pledging to reach net-zero carbon *** that have adopted or have considered net-zero targets now represent 63%of the total contributions to global greenhouse gas(GHG)*** the efforts of all parties,the 26th Conference of the Parties(COP26)achieved a package of outcomes in the Glasgow Climate ***,a breakthrough consensus was reached on reducing coal,controlling methane,and halting deforestation(Wang et al.,2022,Page 1209).To achieve net-zero carbon,we need to take action to implement the Paris Agreement and the Glasgow Climate Pact Since the global temperature slowdown of the nationally determined contributions(NDC)scenario is only 0.6°C,all countries need to pursue stricter carbon reduction policies for a more sustainable world.(Fu et al,2022,Page 1209).

关键词： breakthrough neutral methane

文献计量学和可视化研究青少年特发性脊柱侧弯后路手术治疗的趋势

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齐齐哈尔医学院学报 2025年第3期46卷 278-286页

作者：吴涛廖长胜贺方正韩鹏飞长治医学院研究生处山西长治046000 长治医学院附属和平医院骨科山西长治046000

目的调查青少年特发性脊柱侧弯后路手术的全球现状,了解全球趋势及研究热点,以便更好指导临床实践和科研工作。方法从Web of Science的科学引文索引(SCI-E),检索1983—2024年与青少年特发性脊柱侧弯后路手术相关的研究论文。使用文献... 详细信息

目的调查青少年特发性脊柱侧弯后路手术的全球现状,了解全球趋势及研究热点,以便更好指导临床实践和科研工作。方法从Web of Science的科学引文索引(SCI-E),检索1983—2024年与青少年特发性脊柱侧弯后路手术相关的研究论文。使用文献计量学方法对源数据进行研究和索引。可视化研究采用VOS viewer软件进行文献耦合、合著、共引和共现分析,分析青少年特发性脊柱侧弯后路手术的研究发表趋势。结果共纳入文献1502篇。在全球范围内,相关的研究兴趣和出版物数量每年都在增加。美国对全球研究贡献最大,被引用最多,h指数最高。《Spine》杂志发表数量最多。华盛顿大学、加州大学、南京大学、费城儿童医院以及圣地亚哥拉迪儿童医院是贡献最大的机构。结论从目前全球的研究趋势来看,关于青少年特发性脊柱侧弯后路手术的论文将会不断增加。美国是该领域最大的贡献者。大部分精力被投入到青少年特发性脊柱侧弯后路手术的发病机制、手术方式及组织工程研究中,这可能是研究的下一个热点。

关键词：青少年特发性脊柱侧弯治疗全球趋势文献计量学可视化研究

华北“23·7”强降雨事件对不同埋深地下水的补给机理:以雄安新区为例

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地学前缘 2025年第1期32卷 432-439页

作者：欧阳恺皋蒋小伟杜亚楠张志远韩鹏飞吴业楠王旭升中国地质大学(北京)地下水循环与环境演化教育部重点实验室北京100083 雄安城市规划设计研究有限公司河北保定071700

降雨能否穿透厚包气带到达潜水面是地下水补给领域争议较大的问题。华北平原“23·7”极端降雨事件相当于华北平原的一次大型入渗试验,为分析潜水埋深如何控制地下水补给提供了契机。本研究以雄安新区白洋淀周边潜水浅埋区4口自动监测... 详细信息

降雨能否穿透厚包气带到达潜水面是地下水补给领域争议较大的问题。华北平原“23·7”极端降雨事件相当于华北平原的一次大型入渗试验,为分析潜水埋深如何控制地下水补给提供了契机。本研究以雄安新区白洋淀周边潜水浅埋区4口自动监测井和容城县境内潜水深埋区6口自动监测井为例,分析不同埋深地下水对2023年3日内累积降雨量为289.2 mm的极端降雨事件的响应规律。在潜水浅埋区,暴雨开始后约16 h垂向入渗至潜水面,潜水抬升幅度达1.36~1.79 m;在潜水深埋区,暴雨后河水水位迅速抬升并引发渗漏形成水丘,在潜水回水作用下离南拒马河距离小于6 km的潜水位以较快速度抬升1.38~3.67 m。本研究表明,降雨沿着包气带的垂向入渗是潜水浅埋区地下水的补给来源,暴雨后河水入渗引发的潜水回水是河道附近潜水深埋区地下水补给的主要来源。本文加深了对不同埋深潜水补给机理的认识,对今后分析华北平原乃至其他地下水超采区的水位回升控制机理、生态补水效果具有重要指导意义。

关键词：地下水补给潜水回水生态补水厚包气带白洋淀