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Regulating ambient pressure approach to graphitic carbon nitride towards dispersive layers and rich pyridinic nitrogen

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Chinese Chemical Letters 2020年第6期31卷 1603-1607页

作者： Guangchao Sun fangzhou zhang Qiusheng Xie Wei Luo Jianping Yang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China Shanghai Shanshan Tech Co. LtdShanghai 201209China

An ambient pressure-induced calcination process was proposed to prepare g-C3 N4 with different *** porcelain boat with designed porosity is used to control the ambient pressure to change the diffusion behavior of the reaction molecules,thereby controlling the layer structure and rich pyridinic N content of g-C3 N4,thus renders superior lithium storage performance.

关键词： Ambient pressure Porosity Spreading behavior Carbon nitride Lithium-ion battery

Time-frequency analysis of Li solid-phase diffusion in spherical active particles under typical discharge modes

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Journal of Energy Chemistry 2022年第4期31卷 209-224页

作者： Qiu-An Huang Yuxuan Bai Liang Wang Juan Wang fangzhou zhang Linlin Wang Xifei Li Jiujun zhang Institute for Sustainable Energy/College of Science Shanghai UniversityShanghai 201800China Shaanxi Key Laboratory of Nanomaterials and Nanotechnology School of Mechanical and Electrical EngineeringXi’an University of Architecture and TechnologyXi’an 710055ShaanxiChina Institute of Materials/School of Materials Science and Engineering Shanghai UniversityShanghai 200072China Xi’an Key Laboratory of New Energy Materials and Devices Institute of Advanced Electrochemical Energy&School of Materials Science and EngineeringXi’an University of TechnologyXi’anShaanxi 710048China

Li transient concentration distribution in spherical active material particles can affect the maximum power density and the safe operating regime of the electric vehicles(EVs). On one hand, the quasiexact/exact solution obtained in the time/frequency domain is time-consuming and just as a reference value for approximate solutions;on the other hand, calculation errors and application range of approximate solutions not only rely on approximate algorithms but also on discharge modes. For the purpose to track the transient dynamics for Li solid-phase diffusion in spherical active particles with a tolerable error range and for a wide applicable range, it is necessary to choose optimal approximate algorithms in terms of discharge modes and the nature of active material particles. In this study, approximation methods,such as diffusion length method, polynomial profile approximation method, Padé approximation method,pseudo steady state method, eigenfunction-based Galerkin collocation method, and separation of variables method for solving Li solid-phase diffusion in spherical active particles are compared from calculation fundamentals to algorithm implementation. Furthermore, these approximate solutions are quantitatively compared to the quasi-exact/exact solution in the time/frequency domain under typical discharge modes, i.e., start-up, slow-down, and speed-up. The results obtained from the viewpoint of time-frequency analysis offer a theoretical foundation on how to track Li transient concentration profile in spherical active particles with a high precision and for a wide application range. In turn, optimal solutions of Li solid diffusion equations for spherical active particles can improve the reliability in predicting safe operating regime and estimating maximum power for automotive batteries.

关键词： Li solid-phase diffusion Discharge mode Approximate algorithm Quasi-exact/exact solution Time-frequency analysis

Efficient Photocatalytic Degradation of the Persistent PET Fiber‑Based Microplastics over Pt Nanoparticles Decorated N‑Doped TiO_(2) Nanoflowers

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Advanced Fiber Materials 2022年第5期4卷 1094-1107页

作者： Dawang Zhou Hongxia Luo fangzhou zhang Jing Wu Jianping Yang Huaping Wang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China Co‑Innovation Center for Textile Industry Innovation Center for Textile Science and TechnologyDonghua UniversityShanghai 201620China

Fiber-based microplastics(FMPs)are highly persistent and ubiquitously exist in the wastewater of textile industry and urban *** remains challenging to completely remove such newly emerged organic pollutants by the predominant physical *** this work,we investigated a photocatalytic degradation catalyzed by TiO_(2) catalyst to demonstrate the feasibility of implementing efficient chemical protocol to fast degrading polyethylene terephthalate(PET)-FMPs(a major FMP type existing in environment).The result shows that a hydrothermal pretreatment(180℃/12 h)is necessary to induce the initial rough appearance and molecular weight *** the comprehensive action of the nano-flower shaped N doped-TiO_(2) catalyst(Pt@N-TiO_(2)-1.5%)on the relatively low molecular weight intermediates,an approximate 29%weight loss was induced on the pretreated PET-FMPs,which is about 8 times superior to the untreated *** work not only achieves a superior degradation effect of PET-FMPs,but also provides a new inspiration for the proposal of reduction strategies in the field of environmental remediation in the future.

关键词： Microplastics Fiber-based microplastics Polyethylene terephthalate Photocatalytic degradation Hydrothermal pretreatment

Controllable synthesis of one-dimensional silicon nanostructures based on the dual effects of electro-deoxidation and the Kirkendall effect

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Nano Research 2024年第9期17卷 7814-7823页

作者： Jianxin Tu Shuo Yu Kui Hao Le Sun Ruicheng Bai fangzhou zhang Aijun Li Hong Liu Institute of Materials School of Materials Science and EngineeringShanghai UniversityShanghai 200444China Department of Applied Physics The Hong Kong Polytechnic UniversityKowloon 999077Hong KongChina Shaoxing institute of technology Shanghai UniversityShanghai 200444China

In this study,we successfully synthesized silicon nanotubes(Si-NTs)and silicon nanowires(Si-NWs)in a controllable manner using a catalyst-and template-free method through the direct electrolysis of SiO_(2)in a molten CaCl_(2)-CaO system,while also proposing a novel formation mechanism for ***-NWs are formed through electro-deoxidation when the cell voltage is within the range of CaO decomposition voltage and SiO_(2)decomposition *** subsequently adjusting the voltage to a value between the decomposition potentials of CaCl_(2)and CaO,in-situ electro-deoxidation of CaO takes place on the surface of the synthesized Si-NWs,leading to the formation of a Ca *** formation of Ca-Si diffusion couple leads to the creation of vacancies within the Si-NWs,as the outward diffusion rate of Si exceeds the inward diffusion rate of *** differential diffusion rates between Si and Ca in a diffusion couple exhibit an analogy to the Kirkendall *** vacancies gradually accumulate and merge,forming large voids,which ultimately result in the formation of hollow *** a subsequent dealloying process,the removal of the embedded calcium leads to the formation of *** the application of a carbon coating,the Si-NTs@C composite showcases a high initial discharge capacity of 3211 mAh·g^(-1)at 1.5 A·g^(-1)and exhibits exceptional long-term cycling stability,maintaining a capacity of 977 mAh·g^(-1)after 2000 cycles at 3.0 A·g^(-1).

关键词： silicon nanotubes silicon nanowires lithium-ion battery Kirkendall effect

Achieving effective broadband microwave absorption with Fe_(3)O_(4)@C supraparticles

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Journal of Materiomics 2021年第1期7卷 80-88页

作者： Li Su Jiaxin Ma fangzhou zhang Yuchi Fan Wei Luo Lianjun Wang Wan Jiang Jianping Yang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai201620China Institute of Functional Materials Donghua UniversityShanghai201620China

The X band(8 GHz-12 GHz)is the electromagnetic wave band emitted by most electronic instruments in our life,which will cause electromagnetic pollution harm to human *** to the coexistence of magnetic loss and dielectric loss,the modified Fe_(3)O_(4)-carbon-based nanomaterial exhibit strong electromagnetic(EM)wave absorptive ***,there is a problem that the effective absorption bandwidth(EAB,the frequency bandwidth of reflection loss is less than-10 dB)of the X band is *** the EAB value of Fe_(3)O_(4)-carbon-based materials is of great significance for reducing electromagnetic ***,an emulsion-based self-assembly technique and ligand carbonization treatment have been used to construct the Fe_(3)O_(4)@C supraparticles for the evaluation of EM *** Fe_(3)O_(4)@C supraparticles exhibit excellent EM absorption properties,which can achieve full coverage of X band from 6.52 GHz to 12.9 GHz at a sample thickness of 3 ***,the optimum EAB value of Fe_(3)O_(4)@C supraparticles is up to 8.55 GHz from 9 to 18 GHz at a sample thickness of 2.5 *** Fe_(3)O_(4)@C supraparticles with superlattice structure will have potential development prospects in the application of broadband absorption.

关键词： Fe_(3)O_(4)nanoparticles Carbon shell Suparparticles Self-assembly Microwave absorption

Facile carbon cloth activation strategy to boost oxygen reduction reaction performance for flexible zinc-air battery application

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Carbon Energy 2022年第5期4卷 762-775页

作者： Revanasiddappa Manjunatha Jingchao Yuan Li Hongwei Shu-Qi Deng Ejikeme R.Ezeigwe Yinze Zuo Li Dong Aijun Li Wei Yan fangzhou zhang Jiujun zhang Institute for Sustainable Energy College of SciencesShanghai UniversityShanghaiChina Research Center for Composite Materials Shanghai UniversityShanghaiChina Zhaoqing Leoch Battery Technology Co.Ltd. Guangdong ProvinceChina College of Materials Science and Engineering Fuzhou UniversityFuzhouChina

Flexible and all-solid-state zinc-air batteries(ZABs)are highly useful and also in demand due to their theoretical high energy densities and special *** limitation in their performance arises due to their catalyst-coated cathode electrodes in terms of catalytic activity and stability as well as *** this paper,a novel and environmentally friendly activation strategy is developed to activate the carbon cloth(CC)for the *** activated CC serves as a catalyst-free air cathode with high conductivity,excellent mechanical strength,and flexibility,in addition to low *** strategy is performed by simply electro-oxidizing and electroreducing CC under ultrahigh direct current(DC)voltage in a diluted NH4Cl aqueous *** is found that the electro-oxidation not only results in the formation of a graphene-like exfoliated carbon layer on the surface of CC but also induces the incorporation of oxygen-containing groups and doping of nitrogen and chloride *** the electroreduction,theπ-conjugated carbon network of CC is partially restored,leading to the recovery of *** an electroactivated CC shows excellent oxygen reduction reaction *** aqueous flexibility and all-solid-state ZABs are assembled using such an electroactivated CC cathode without any catalyst *** ZABs can achieve good durability and deliver high peak power density and an energy density as high as 690 Wh kg^(−1),demonstrating the excellent potential of this electroactivated CC in practical devices.

关键词： carbon cloth,catalyst-free electroactivation nitrogen and chlorine co-doping oxygencontaining groups ultrahigh and ultralow direct current voltage

Atomic Cu Sites Engineering Enables Efficient CO_(2)Electroreduction to Methane with High CH_(4)/C_(2)H_(4)Ratio

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Nano-Micro Letters 2023年第12期15卷 361-375页

作者： Minhan Li fangzhou zhang Min Kuang Yuanyuan Ma Ting Liao Ziqi Sun Wei Luo Wan Jiang Jianping Yang Institute of Functional Materials State Key Laboratory for Modification of Chemical Fibers and Polymer MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai 201620People’s Republic of China College of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001People’s Republic of China School of Mechanical Medical and Process EngineeringSchool of Chemistry and PhysicsQueensland University of Technology2 George StreetBrisbaneQLD 4001Australia

Electrochemical reduction of CO_(2)into high-value hydrocarbons and alcohols by using Cu-based catalysts is a promising and attractive technology for CO_(2)capture and utilization,resulting from their high catalytic activity and *** mobility and accessibility of active sites in Cubased catalysts significantly hinder the development of efficient Cu-based catalysts for CO_(2)electrochemical reduction reaction(CO_(2)RR).Herein,a facile and effective strategy is developed to engineer accessible and structural stable Cu sites by incorporating single atomic Cu into the nitrogen cavities of the host graphitic carbon nitride(g-C_(3)N_(4))as the active sites for CO_(2)-to-CH_(4)conversion in CO_(2)*** regulating the coordination and density of Cu sites in g-C_(3)N_(4),an optimal catalyst corresponding to a one Cu atom in one nitrogen cavity reaches the highest CH_(4)Faraday efficiency of 49.04%and produces the products with a high CH_(4)/C_(2)H_(4)ratio over *** work provides the first experimental study on g-C_(3)N_(4)-supported single Cu atom catalyst for efficient CH_(4)production from CO_(2)RR and suggests a principle in designing highly stable and selective high-efficiency Cu-based catalysts for CO_(2)RR by engineering Cu active sites in 2D materials with porous crystal structures.

关键词： CO_(2)RR Cu single-atom catalyst g-C_(3)N_(4) Methane CH_(4)/C_(2)H_(4)ratio

Application of Mobile Learning System in Operating System Course

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Communications and Network 2013年第2期5卷 157-160页

作者： Lingling Guo Yu Fu Xiaozhe Yin Man Yuan fangzhou zhang Juntao Gao School of Computer & Information Technology Northeast Petroleum University Daqing China

With the rapid development of mobile communication and computer network technologies, the new mobile learning mode has been accepted by more and more people. In this paper, taking the learning system under mobile environment and from the perspective of necessary theoretic knowledge and relative technologies for mobile learning, the structural frame of the mobile learning system was discussed and constructed. According to this structural frame, the learning system under mobile environment was designed and applied into the OS course.

关键词： Mobile Communication Technology Mobile Learning Operating System

采用J2EE安全机制支持RBAC模型的研究和实现

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计算机工程 2006年第13期32卷 125-127页

作者：张方舟王东安李生秦刚宋成中国科学院网络信息中心R&D室

实现了用J2EE安全机制来支持RBAC模型的方法。给出了J2EE保护系统的配置,并设计一个鉴权决定算法。用J2EE安全的描述语言定义了RBAC模型,给出了实现J2EE安全服务的需求。通过在国家科技基础条件平台的部署和应用,取得了预期的效果。

关键词： RBAC J2EE 访问控制鉴权