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Double-activated porous carbons for high-performance supercapacitor electrodes

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Rare Metals 2017年第5期36卷 449-456页

作者： Jing Sun shu-Hua Yang Shan-Shan Li Bing-qiang cao Materials Center for Energy and Photoelectrochemical Conversion School of Material Science and EngineeringUniversity of JinanJinan 250022China

The double-activated porous carbons（DAPCs）with unique bimodal pore structure were prepared by activating commercial microporous carbon（CMCs） twice through KOH（double activation） at high temperature. The as-prepared DAPCs show larger surface area（833 m^2·g^-1）,and the pores are composed of micropores（size of-1.8 nm） and mesopores（size of -4.5 nm）. Such special hierarchical porous structures integrate the dual advantages of micropore and mesopore, having not only the high energy storage of the micropores but also the high-rate performance of the mesopores for supercapacitors（SCs）.As a result, the optimized DAPCs-3-1 exhibits a high specific capacitance of 277 F·g^-1 at 1 A·g^-1, enhanced rate performance of 197 F·g^-1 at a high current density of 10 A·g^-1, and excellent cycling stability with 94.2% capacity retention after 10,000 cycles in the 1 mol·L^-1 Na2SO4 electrolyte. The facile double activation could be a promising method to prepare suitable porous carbons with exceptional electrochemical properties for SCs.

关键词： Double activation Activated carbon Hierarchically porous carbons Supercapacitor

PVP/PAN-derived porous carbon fiber for zinc-ion hybrid supercapacitors

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Rare Metals 2024年第7期43卷 3066-3073页

作者： shu-Hua Yang Wen-Qing Fu Yan-Wei Cui Bing-qiang cao Materials Center for Energy and Photoelectrochemical Conversion School of Material Science and EngineeringUniversity of JinanJinan 250022China

Porous carbon fibers are promising cathodes for zinc-ion hybrid supercapacitors(ZHSs)owing to their abundant active sites,great conductivity,and stable physical and chemical ***,designing a proper preparation technique to regulate the microstructure of carbon fibers still remains a great ***,a poly vinylpyrrolidone/po-lyacry lonitrile(PVP/PAN)-derived porous carbon fiber is developed via the PVP/PAN blend electrospinning and hydrothermal selective PVP removal *** hydrothermal selective PVP removal strategy can effectively avoid a cross-linking between PVP and PAN during the traditional stabilization at air *** PVP/PAN-derived porous carbon fiber,the sufficient micropores provide abundant space for the Zn^(2+)storage,whereas the proper mesopores contribute to the fast ion *** hierarchical porous structures endow ZHSs with high specific capacity and high-rate *** ZHS assembled with the optimal PVP/PAN-derived porous carbon fiber(PVP-PANC-0.8)displays an outstanding specific capacity of 208 mAh·g^(-1),high rate capability(49.5%)from 0.5 to 5 A·g^(-1),and 72.25%capacity retention after 10,000 cycles at 0.5 A·g^(-1).

关键词： Zinc-ion hybrid supercapacitors Porous carbon fibers Hierarchical porous structures Electrospinning

Analysis of chaos behaviors of a bistable piezoelectric cantilever power generation system by the second-order Melnikov function

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Acta Mechanica Sinica 2017年第1期33卷 200-207页

作者： shu Sun shu-Qian cao Department of Mechanics School of Mechanical Engineering Tianjin University Tianjin 300350 China College of Science North China University of Science and Technology Tangshan 063009 China Tianjin Key Laboratory of Nonlinear Dynamics and Chaos Control Tianjin 300350 China

By applying the second order Melnikov function, the chaos behaviors of a bistable piezoelectric cantilever power generation system are analyzed. Firstly, the conditions for emerging chaos of the system are derived by the second order Melnikov function. Secondly, the effects of each item in chaos threshold expression are analyzed. The excitation frequency and resistance values, which have the most influence on chaos threshold value, are found. The result from the second order Melnikov function is more accurate compared with that from the first order Melnikov function. Finally, the attraction basins of large amplitude motions under different exciting frequency, exciting amplitude, and resistance parameters are given.

关键词： Bistable piezoelectric cantilever beam Second order Melnikov function Homoclinic bifurcation Basin of attraction

Preparation mechanism,physical characteristic and antitumor activity of nano-scheelite

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International Journal of Minerals,Metallurgy and Materials 2009年第4期16卷 468-474页

作者： Lin cao Fu-qiang Yang Jie-xin cao School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Peking University Health Science Center Beijing 100083 China

After preparing the EU^3＋-doped scheelite nano-material by Pechini method with the nanoparticles of 30-50 nm in diameter, X-ray diffraction （XRD）, transmission electron microscopy （TEM） and high resolution transmission electron microscopy （HRTEM） were used to show a microcosmic description of the particle morphology and crystal structure. The spectrum signature of the nano-scheelite, which was taken by fluorescence spectrometer, was used to discuss the difference of luminescent performance between the nano-scheelite and bulk scheelite. The atomic site of the nano-scheelite was intuitively shown through HRTEM images and HRTEM simulated images from the relation between luminescent properties and crystal structure, which was analyzed by spectrum probe. The results of antitumor activity examined by the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） method show that the inhibition of human promyelocytic leukemia cell line （HL60） is enhanced immediately with increasing the concentration and presents a reliance on the quantity. The results of fluorescence spectra and structure show that the antitumor activity has something to do with micro-structure and surface charge.

关键词： scheelite fluorescence spectrum atomic site anti-tumor activity

Progress on shelf and slope circulation in the northern South China Sea

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Science China Earth Sciences 2018年第5期61卷 560-571页

作者： Yeqiang shu qiang WANG Tingting ZU State Key Laboratory of Tropical Oceanography South China Sea Institute of Oceanology Chinese Academy of Sciences

Influenced by the seasonally reversed monsoons, water exchange through straits, and topography, the shelf and slope circulation in the northern South China Sea(NSCS) is complex and changeable. The typical current system in the NSCS consists of the slope current, South China Sea warm current(SCSWC), coastal current, and associated upwelling(in summer) and downwelling(in winter). This paper reviews recent advances in the study of NSCS shelf and slope circulation since the 1990 s,and summarizes the roles of Kuroshio intrusion, the monsoons, topography, and the buoyancy effect of the Pearl River plume in the shelf and slope current system of the NSCS. We also point out some potential scientific issues that require further study, such as the dynamic connection between the internal basin and shelf areas of the NSCS, the persistence of the SCSWC in winter, the temporo-spatial characteristics of downwelling during winter in the NSCS, and its material and energy transport.

关键词： The northern South China Sea Circulation Progress

Planar anisotropy of commercially pure titanium sheets

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Rare Metals 2013年第1期32卷 1-4页

作者： Qing-Dong Zhang qiang cao School of Mechanical Engineering University of Science and Technology Beijing

Commercially pure titanium （CP Ti） sheets show typical planar anisotropy due to the inherently crys- tallographic texture and manufacturing process. To char- acterize the planar anisotropic behaviors of CP Ti sheets in the forming process, uniaxial tensile tests of TA0 sheets were performed along rolling, transverse, and diagonal directions at room temperature; corresponding stress-strain curves and Lankford coefficients were obtained. Based on Hi11＇48 and Barlat＇89 yield functions, the planar anisotropy of TA0 sheets was investigated. In order to verify the accuracy of two models, we compared the experimental and predicted values of yield stress and Lankford coeffi- cients. It reveals that Barlat＇89 criterion with M = 10 is good agreement with experimental data, and the obtained function can be used in simulation of forming process.

关键词： Commercially pure titanium Planaranisotropy Yield criterion Barlat'89 model

A multifunctional stealthy material for wireless sensing and active camouflage driven by configurable polarization

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Journal of Materials Science & Technology 2023年第1期132卷 42-49页

作者： Min Zhang Mao-Sheng cao qiang-qiang Wang Xi-Xi Wang Wen-qiang cao Hui-Jing Yang Jie Yuan School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Department of Physics Beijing Technology and Business UniversityBeijing 100048China School of Electrical and Electronic Engineering Nanyang Technological University639798Singapore Department of Physics Tangshan Normal UniversityTangshan 063000China School of Information Engineering Minzu University of ChinaBeijing 100081China

The dipole species transformation and polarization relaxation configuration are achieved by changing the cobalt ion stoichiometry,which precisely tailors the electromagnetic attenuation performance of bismuth iron cobalt *** the stoichiometric ratio of Fe:Co is 19:1,the optimal reflection loss reaches-60 *** high electromagnetic attenuation performance significantly improve the linear sensitivity of the strain response and active customized stealth capability of the designed multifunctional capacitor-like ***,the wireless multifunctional design integrates energy attenuaten of electromagnetic wave with the wireless sensing and active camouflage functions for the first *** work provides an important step for the realization of electromagnetical multifunctional applications including electromag-netic protection and electromagnetic sensing in artificial beings,medical health and even space travel.

关键词： Electromagnetic absorption Polarization relaxation Electromagnetic sensing Active camouflage

Developing MXenes from Wireless Communication to Electromagnetic Attenuation

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Nano-Micro Letters 2021年第7期13卷 188-221页

作者： Peng He Mao-Sheng cao Wen-qiang cao Jie Yuan School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081People’s Republic of China School of Information Engineering Minzu University of ChinaBeijing 100081People’s Republic of China

There is an urgent global need for wireless communication utilizing materials that can provide simultaneous flexibility and high *** the harmful effects of electromagnetic(EM)radiation from wireless communication is a persistent research hot ***-dimensional(2D)materials are the preferred choice as wireless communication and EM attenuation materials as they are lightweight with high aspect ratios and possess distinguished electronic ***,as a novel family of 2D materials,have shown excellent properties in various fields,owing to their excellent electrical conductivity,mechanical stability,high flexibility,and ease of *** date,research on the utility of MXenes for wireless communication has been actively ***,MXenes have become the leading materials for EM ***,we systematically review the recent advances in MXene-based materials with different structural designs for wireless communication,electromagnetic interference(EMI)shielding,and EM wave *** relationship governing the structural design and the effectiveness for wireless communication,EMI shielding,and EM wave absorption is clearly ***,our review mainly focuses on future challenges and guidelines for designing MXene-based materials for industrial application and foundational research.

关键词： MXene Wireless communication Electromagnetic wave absorption Electromagnetic interference shielding

Indian monsoon drove the dispersal of the thoracica group of Scytodes spitting spiders

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Zoological Research 2024年第1期45卷 152-159页

作者： Yu-Fa Luo shu-qiang Li School of Life and Environmental Sciences Shaoxing UniversityShaoxingZhejiang 312000China Key Laboratory of Zoological Systematics and Evolution Institute of ZoologyChinese Academy of SciencesBeijing 100101China Southeast Asia Biodiversity Research Institute Chinese Academy of SciencesYezinNay Pyi Taw 05282Myanmar

We examined the global biogeography of the Scytodes thoracica group of spitting spiders based on 23 years of sampling at the species level(61 species in the thoracica group and 84 species of Scytodes)using DNA data from six *** results indicated that the thoracica group initially dispersed from Southeast Asia to East Africa between 46.5 and 33.0 million years ago,and dispersal events intensified between Southeast/South Asia and East/South Africa from the early to late *** timing of these events indicates that Asian-African faunal exchange of the thoracica group was driven by the Indian monsoon,and the pattern of dispersal suggests that colonialization took root when the Indian monsoon shifted from a North-South direction to an East-West direction from the middle Eocene.

关键词： Geological event Climate change Ballooning organism Faunal exchange Species distribution