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Journal of Materials Science & Technology 2022年第17期112卷 184-194页

作者： Jiangtao Yu Shucai Zhang Huabing Li Zhouhua Jiang Hao Feng panpan xu Peide Han School of Metallurgy Northeastern UniversityShenyang 110819China Key Laboratory for Ecological Metallurgy of Multimetallic Ores(Ministry of Education) Shenyang 110819China College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China

Influence mechanism of B segregation on the microstructure evolution and hot ductility of S32654 at850-1250℃was systematically investigated through experimental research and theoretical calculation.The results demonstrated that the segregation of B at grain boundary(GB)played different roles in the microstructure evolution and hot ductility at various temperatures.At 850℃,B segregation inhibited Mo segregation at the GB and enhanced the GB cohesion.At 900-950℃,B segregation restricted the diffusion and segregation of Mo to the GB,inhibiting the precipitation ofσphase.At 1000-1050℃,B segregation accelerated the dislocation accumulation and limited the GB migration,promoting the nucleation and inhibiting the growth of DRX grains.At 1100-1150℃,B has little effect on the DRX due to sufficient energy supply by higher temperature.Under the above beneficial effects of B,the hot ductility of S32654 was improved to varying degrees at 850-1150℃.However,as the temperature increased to1200-1250℃,B segregation decreased the solidus temperature and enhanced the liquefaction cracking tendency,resulting in a deterioration of the hot ductility.

关键词： Super austenitic stainless steel Boron Hot ductility Grain boundary segregation Atom probe tomography

Dual-Ion Co-Regulation System Enabling High-Performance Electrochemical Artificial Yarn Muscles with Energy-Free Catch States

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Nano-Micro Letters 2023年第10期15卷 15-27页

作者： Ming Ren Lizhong Dong Xiaobo Wang Yuxin Li Yueran Zhao Bo Cui Guang Yang Wei Li Xiaojie Yuan Tao Zhou panpan xu Xiaona Wang Jiangtao Di Qingwen Li Key Laboratory of Multifunctional Nanomaterials and Smart Systems Advanced Materials Division Suzhou Institute of Nano-Tech and Nano‑BionicsChinese Academy of SciencesSuzhou 215123People’s Republic of China School of Nano‑Technology and Nano‑Bionics University of Science and Technology of ChinaHefei 230026People’s Republic of China Division of Nanomaterials and Jiangxi Key Lab of Carbonene Materials Jiangxi Institute of NanotechnologyNanchang 330200People’s Republic of China

Artificial yarn muscles show great potential in applications requiring low-energy consumption while maintaining high performance. However, conventional designs have been limited by weak ion-yarn muscle interactions and inefficient “rocking-chair” ion migration. To address these limitations, we present an electrochemical artificial yarn muscle design driven by a dual-ion co-regulation system. By utilizing two reaction channels, this system shortens ion migration pathways, leading to faster and more efficient actuation. During the charging/discharging process, PF_6~- ions react with carbon nanotube yarn, while Li~+ ions react with an Al foil. The intercalation reaction between PF_6~- and collapsed carbon nanotubes allows the yarn muscle to achieve an energy-free high-tension catch state. The dual-ion coordinated yarn muscles exhibit superior contractile stroke, maximum contractile rate, and maximum power densities, exceeding those of “rocking-chair” type ion migration yarn muscles. The dual-ion co-regulation system enhances the ion migration rate during actuation, resulting in improved performance. Moreover, the yarn muscles can withstand high levels of isometric stress, displaying a stress of 61 times that of skeletal muscles and 8 times that of “rocking-chair” type yarn muscles at higher frequencies. This technology holds significant potential for various applications, including prosthetics and robotics.

关键词： Artificial muscles Carbon nanotube yarns Electrochemical actuators Catch state Dual-ion co-regulation

Comparison and assessment of NDVI time series for seasonal wetland classification

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International Journal of Digital Earth 2018年第11期11卷 1103-1131页

作者： panpan xu Zhenguo Niu Ping Tang State Key Laboratory of Remote Sensing Science Institute of Remote Sensing and Digital EarthChinese Academy of SciencesBeijingPeople’s Republic of China University of Chinese Academy of Sciences BeijingPeople’s Republic of China

Satellite-based wetland mapping faces challenges due to the high spatial heterogeneity and dynamic characteristics of seasonal wetlands.Although normalized difference vegetation index(NDVI)time series(NTS)shows great potential in land cover mapping and crop classification,the effectiveness of various NTS with different spatial and temporal resolution has not been evaluated for seasonal wetland classification.To address this issue,we conducted comparisons of those NTS,including the moderate-resolution imaging spectroradiometer(MODIS)NTS with 500 m resolution,NTS fused with MODIS and Landsat data(MOD_LC8-NTS),and HJ-1 NDVI compositions(HJ-1-NTS)with finer resolution,for wetland classification of Poyang Lake.Results showed the following:(1)the NTS with finer resolution was more effective in the classification of seasonal wetlands than that of the MODIS-NTS with 500-m resolution and(2)generally,the HJ-1-NTS performed better than that of the fused NTS,with an overall accuracy of 88.12%for HJ-1-NTS and 83.09%for the MOD_LC8-NTS.Future work should focus on the construction of satellite image time series oriented to highly dynamic characteristics of seasonal wetlands.This study will provide useful guidance for seasonal wetland classification,and benefit the improvements of spatiotemporal fusion models.

关键词： NDVI time series seasonal wetland Poyang Lake satellite image time series

Edge Bundling in Information Visualization

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Tsinghua Science and Technology 2013年第2期18卷 145-156页

作者： Hong Zhou panpan xu Xiaoru Yuan Huamin Qu Shenzhen University the Hong Kong University of Science and Technology Peking University

The edge, which can encode relational data in graphs and multidimensional data in parallel coordinates plots, is an important visual primitive for encoding data in information visualization research. However, when data become very large, visualizations often suffer from visual clutter as thousands of edges can easily overwhelm the display and obscure underlying patterns. Many edge-bundling techniques have been proposed to reduce visual clutter in visualizations. In this survey, we briefly introduce the visual-clutter problem in visualizations. Thereafter, we review the cost-based, geometry-based, and image-based edge-bundling methods for graphs, parallel coordinates, and flow maps. We then describe the various visualization applications that use edge-bundling techniques and discuss the evaluation studies concerning the effectiveness of edge-bundling methods. An edge-bundling taxonomy is proposed at the end of this survey.

关键词： edge bundling visual clutter graph visualization parallel coordinates flow maps

MViewer： mobile phone spatiotemporal data viewer

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Frontiers of Computer Science 2014年第2期8卷 298-315页

作者： Jiansu PU Siyuan LIU panpan xu Huamin QU Lionel M. NI Department of Computer Science Hong Kong University of Science and Technology Hong Kong 999077 China iLab Heinz College Carnegie Mellon University Pittsburgh PA 15601 USA

Nowadays movement patterns and people＇s be- havioral models are needed for traffic engineers and city plan- ners. These observations could be used to reason about mobil- ity and its sustainability and to support decision makers with reliable information. The very same knowledge about human diaspora and behavior extracted from these data is also valu- able to the urban planner, so as to localize new services, orga- nize logistics systems and to detect changes as they occur in the movement behavior. Moreover, it is interesting to inves- tigate movement in places like a shopping area or a working district either for commercial purposes or for improving the service quality. These kinds of tracking data are made avail- able by wireless and mobile communication technologies. It is now possible to record and collect a large amount of mobile phone calls in a city. Technologies for object tracking have recently become affordable and reliable and hence we were able to collect mobile phone data from a city in China from January 1, 2008 to December 31, 2008. The large amount of phone call records from mobile operators can be considered as life mates and sensors of persons to inform how many peo- ple are present in any given area and how many are entering or leaving. Each phone call record usually contains the caller and callee IDs, date and time, and the base station where the phone calls are made. As mobile phones are widely used in our daily life, many human behaviors can be revealed by an- alyzing mobile phone data. Through mobile phones, we can learn the information about locations, communications be- tween mobile phone users during their daily lives.In this work, we propose a comprehensive visual analysissystem named as MViewer, Mobile phone spatiotemporal data Viewer, which is the first system to visualize and analyze the population＇s mobility patterns from millions of phone call records. Our system consists of three major components： 1） visual analysis of user groups in a base station; 2） visual anal- ysis of the mobi

关键词： visual analysis mobility pattern mobile phone

基于离差最大化-灰色关联的修补混凝土配合比评价

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材料导报 2024年第6期38卷 125-131页

作者：杨淑雁徐盼盼宋俊杰陈小龙宁夏大学土木与水利工程学院银川750021

针对西北地区损伤混凝土的复杂服役环境,采用硅粉取代率、水玻璃取代率、玄武岩纤维掺量以及UEA膨胀剂取代率为考察因素进行修补混凝土正交试验方案设计。基于流动性、力学性能和体积稳定性这三个评价性能,按照重要性排序引入了12个具... 详细信息

针对西北地区损伤混凝土的复杂服役环境,采用硅粉取代率、水玻璃取代率、玄武岩纤维掺量以及UEA膨胀剂取代率为考察因素进行修补混凝土正交试验方案设计。基于流动性、力学性能和体积稳定性这三个评价性能,按照重要性排序引入了12个具体试验指标(即3 d、7 d和28 d抗压强度,1 d、3 d、7 d、14 d、28 d、45 d、60 d和90 d膨胀率以及塌落度),进行测试。对于试验结果,建立了离差最大化-灰色关联体系进行修补混凝土配合比综合评价,优选出了一种流动性好、早期强度高且后期强度发展好的微膨胀修补混凝土配合比X4(A_(2)B_(1)C_(2)D_(3))。此外,该综合评价体系能够科学、合理地反映评价者对指标重要性的主观意见与实际试验的客观性,可用于多因素、多动态指标下混凝土配合比的优选与综合评价。

关键词：离差最大化灰色关联修补混凝土配合比评价

A Facile One-Step Synthesis of TiOe/Graphene Composites for Photodegradation of Methyl Orange

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Nano Research 2011年第3期4卷 274-283页

作者： Haijiao Zhang panpan xu Guidong Du Zhiwen Chen Kokyo Oh Dengyu Pan Zheng Jiao Institute of Nanochemistry and Nanobiology School of Environmental and Chemical Engineering Shanghai University Shanghai 200444 China Center for Environmental Science in Saitama 914 Kamitanadare Kazo Saitama Japan

TiO2/graphene composite photocatalysts have been prepared by a simple liquid phase deposition method using titanium tetrafluoride and electron beam (EB) irradiation-pretreated graphene as the raw materials. The products were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The effects of varying the synthesis parameters such as graphene content, concentration of titanium tetrafluoride solution and irradiation dose were investigated. It was found that the preparation conditions had a significant effect on the structure and properties of the final products. The irradiated graphene was covered with petal-like anatase TiO2 nanoparticles, which were more uniform and smaller in size than those in products synthesized without EB irradiation-pretreated graphene. The photocatalytic activities of the products were evaluated using the photocatalytic degradation of methyl orange as a probe reaction. The results showed that the products synthesized using EB irradiation-pretreated graphene exhibited higher photocatalytic activities than those using graphene without EB irradiation pretreatment.

关键词：石墨复合材料光催化降解一步合成甲基橙 X射线光电子能谱 TiO2纳米粒子复合光催化剂电子束辐照

鼻内镜、显微镜配合支撑喉镜在声带息肉手术中的应用对比

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现代科学仪器 2024年第2期41卷 38-41页

作者：陈红金玮徐盼盼安徽医科大学附属巢湖医院耳鼻喉头颈外科安徽巢湖238000

目的:对比鼻内镜、显微镜配合支撑喉镜在声带息肉手术中的应用效果。方法:选取79例声带前息肉患者,根据术式不同分为A组和B组,对比2组手术相关指标差异。结果:A组手术时间长于B组(P0.05)。结论:采取鼻内镜配合支撑喉镜治疗声带息肉的手... 详细信息

目的:对比鼻内镜、显微镜配合支撑喉镜在声带息肉手术中的应用效果。方法:选取79例声带前息肉患者,根据术式不同分为A组和B组,对比2组手术相关指标差异。结果:A组手术时间长于B组(P0.05)。结论:采取鼻内镜配合支撑喉镜治疗声带息肉的手术时间较长,但在声带息肉暴露困难患者的效果较好。除此之外,两种术式可灵活选择。

关键词：鼻内镜显微镜支撑喉镜声带息肉

Enabling rechargeable Li-MnO_(2) batteries using ether electrolytes

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SmartMat 2023年第5期4卷 131-138页

作者： Dawei Xia Hongpeng Gao Mingqian Li John Holoubek Qizhang Yan Yijie Yin panpan xu Zheng Chen Department of NanoEngineering University of California San DiegoLa JollaCaliforniaUSA Program of Materials Science and Engineering University of California San DiegoLa JollaCaliforniaUSA Program of Chemical Engineering University of California San DiegoLa JollaCaliforniaUSA Sustainable Power and Energy Center University of California San DiegoLa JollaCaliforniaUSA

A low-carbon future demands more affordable batteries utilizing abundant elements with sustainable end-of-life battery management.Despite the economic and environmental advantages of Li-MnO_(2)batteries,their applica-tion so far has been largely constrained to primary batteries.Here,we demonstrate that one of the major limiting factors preventing the stable cycling of Li-MnO_(2)batteries,Mn dissolution,can be effectively mitigated by employing a common ether electrolyte,1 mol/L lithium bis(trifluorometha-nesulfonyl)imide(LiTFSI)in 1,3-dioxane(DOL)/1,2-dimethoxyethane(DME).We discover that the suppression of this dissolution enables highly reversible cycling of the MnO_(2)cathode regardless of the synthesized phase and morphology.Moreover,we find that both the LiPF_(6)salt and carbonate solvents present in conventional electrolytes are responsible for previous cycling challenges.The ether electrolyte,paired with MnO_(2)cathodes is able to demonstrate stable cycling performance at various rates,even at elevated temperature such as 60℃.Our discovery not only represents a defining step in Li-MnO_(2)batteries with extended life but provides design criteria of electrolytes for vast manganese-based cathodes in rechargeable batteries.

关键词： ether-based electrolytes Li-MnO batteries Mn deposition Mn dissolution reuse of primary batteries

Molecular engineering tuning optoelectronic properties of thieno[3,2-b]thiophenes-based electrochromic polymers

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Science China Chemistry 2017年第1期60卷 63-76页

作者： Mengmeng Zhu Weishuo Li panpan xu Jingjing Shi Shan Shao Xiaosi Zhu Yitong Guo Yaowu He Zhao Hu Hongtao Yu Yanan Zhu Igor F.Perepichka Hong Meng School of Advanced Materials Peking University Shenzhen Graduate School School of Chemistry Bangor University

Thieno[3,2-b]thiophene(TT)monomers end-capped with 3,4-ethylenedioxythiophene(EDOT)moieties are electropolymerized to formπ-conjugated polymers with distinct electrochromic(EC)properties.Steric and electronic factors(electron donor and acceptor substituents)in the side groups of the TT core,as well as the structure of the polymer backbone strongly affect the electrochemical and optical properties of the polymers and their electrochromic characteristics.The studied polymers show low oxidation potentials,tunable from-0.78 to+0.30 V(vs.Fc/Fc^+)and the band gaps from 1.46 to 1.92 eV and demonstrate wide variety of color palettes in polymer films in different states,finely tunable by structural variations in the polymer backbone and the side chains.EC materials of different colors in their doped/dedoped states have been developed(violet,deep blue,light blue,green,brown,purple-red,pinkish-red,orange-red,light gray,cyan and colorless transparent).High optical contrast(up to 79%),short response time(0.57-0.80 s),good cycling stability(up to 91%at 2000 cycles)and high coloration efficiency(up to 234.6 cm2C^(-1))have been demonstrated and the influence of different factors on the above parameters of EC polymers have been discussed.

关键词：变色聚合物噻吩基光电性能分子工程调整电子供体乙撑二氧噻吩主链结构