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Journal of Materials Science & Technology 2022年第4期99卷 1-8页

作者： Renquan Wang Tingchuan Zhou zhiyong zhong College of Materials Science and Engineering Sichuan UniversityChengdu 610065China Key Laboratory of Advanced Special Materials&Technology Ministry of EducationChengdu 610065China State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of ChinaChengdu 610054China

Low-temperature fired ferrites or ceramics are usually processed by using low-melting materials(e.g.,glasses,oxides,and eutectics)as sintering aids to obtain compact and uniform ***,a dual-strategy of co-doping with V_(2)O_(5)and Sb_(2)O_(3)oxides and forming a eutectic liquid phase has been employed to reduce the melting point of LiZn ferrite ceramics in an effective *** results indicate that miniscule amounts of V_(2)O_(5)and Sb_(2)O_(3)co-doping contribute in producing dense and uniform microstructures with enhanced magnetic performance by low-temperature *** phase structural and microstructural evolutions have been studied in *** their correlations with magnetic properties have been *** magnetic performance(B_(s)=475.4 mT,M_(s)=82.51 emu/g,B_(r)/B_(s)=0.85,H_(c)=2.2 Oe,ΔH=153.8 Oe)of the LiZn-based ferrite ceramics is achieved by optimized composition and microstructure,which shows great potential for microwave applications including phase shifters and *** importantly,such a co-doping strategy can be also extended to other material systems,like dielectric ceramics,hexagonal ferrites or piezoelectric ceramics.

关键词： Low-temperature firing Eutectic liquid phase Magnetic properties Uniform microstructure FMR line width

A review of Fe_3O_4 thin films:Synthesis,modification and applications

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Journal of Materials Science & Technology 2018年第8期34卷 1259-1272页

作者： Xiaoyi Wang Yulong Liao Dainan Zhang Tianlong Wen zhiyong zhong Center for Applied Chemistry University of Electronic Science and Technology of China State Key Laboratory of Electronic Thin Film and Integrated Devices University of Electronic Science and Technology of China

Magnetite （Fe3O4） has been used for thousands of years as one of the important magnetic materials. The rapid developments of thin film technology in the past few decades attract the attention of material scientists on the fabrication of magnetite thin films. In this article, we present an overview of recent progress on Fe3O4 thin films. The widely used preparation methods are surveyed, and the effect of sub- strates is discussed. Specifically the modified Fe3O4 thin films exhibit excellent electrical and magnetic properties compared with the pure films. It is noteworthy that modified Fe3O4 thin films can be put into two categories：（1） doped films, where foreign metal ions substitute iron ions at A or B sites： and （2） hybrid films, where magnetite phases are mixed with other materials. Notably, Fe3O4 thin films show great potentials in many applications such as sensors and batteries. It is expected that the investigations of Fe3O4 thin films will give us some breakthroughs in materials science and technology.

关键词： Fe3O4 Thin film Preparation method Modified film Material science

The Learning Effectiveness of Smart Classrooms:A Meta-Analysis of 48 Empirical Studies

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Frontiers of Education in China 2023年第3期18卷 245-266页

作者： zhong zhiyong HE Wenying School of Education Minzu University of ChinaBeijing 100081China

As an important teaching method in the era of education informatization 2.0,the smart classroom has become a hot topic in terms of whether it can really improve students’learning *** scholars have carried out empirical studies in this field,but the conclusions are not the *** the use of meta-analysis,this study quantitatively analyzes 48 experimental and quasi-experimental studies in China and other countries to explore the smart classroom’s effect and influencing *** results show that,on the whole,the smart classroom has a better-than-average promotion effect on students’learning effectiveness;from the perspective of moderating variables,the learning outcome of smart classrooms is influenced by the factors of learning stage,knowledge type,teaching cycle,class scale,and equipment condition,but is not moderated by the factors of subject,teaching strategy,and evaluation ***,smart classrooms can become a suitable partner for large-class teaching,short-term courses,and experimental ***,the misuse of technology and equipment should be avoided in the application process.

关键词： smart classrooms learning effectiveness meta-analysis

Nucleation field,reversal mechanism and coercivity paradox in two-phased magnetic nanosystem

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Science China(Physics,Mechanics & Astronomy) 2011年第7期54卷 1249-1253页

作者： ZHAO GuoPing ZHANG HuaiWu zhong zhiyong CHEN Lang College of Physics and Electronic Engineering Sichuan Normal University Chengdu 610066 China State Key Laboratory of Electronic Thin Films and lntegrated Devices University of Electronic Science and Technology of China Chengdu 610054 China School of Materials Science and Engineering Nanyang Technological University Singapore 639798 Singapore

The magnetic reversal mechanism has been determined within a micromagnetic model reliably for a two-phased magnetic nanosystem, with the formulae for nucleation fields derived analytically. It is found that the nucleation field HN decreases uni- formly as the size of the soft phase Ls increases whereas it increases with the size of the hard phase Lh. The analysis shows that whilst the effect of Lh could be ignored in most cases, where the nucleation field is dominated by the Ls and the calculation could be significantly simplified, the overly simple inverse square law between Hu and the soft layer thickness Ls adopted by the previous researchers is not a good approximation. While nucleation is the beginning of the magnetic reversal, pinning is the dominant coercivity mechanism in both two-phased and single-phased magnetic materials, where the crystalline defects exist. Comparison with the experimental data confirms this conclusion, indicating that Brown＇s paradox results from the much lower effective anisotropy in both single-phased and composite materials, as speculated in the literature.

关键词： coercivity mechanism multilayers micromagnetic calculation

Review of Water-Assisted Crystallization for TiO_2 Nanotubes

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Nano-Micro Letters 2018年第4期10卷 366-393页

作者： Xiaoyi Wang Dainan Zhang Quanjun Xiang zhiyong zhong Yulong Liao State Key Laboratory of Electronic Thin Film and Integrated Devices University of Electronic Science and Technology of China Center for Applied Chemistry University of Electronic Science and Technology of China

TiO_2 nanotubes(TNTs) have drawn tremendous attention owing to their unique architectural and physical properties. Anodizing of titanium foil has proven to be the most efficient method to fabricate well-aligned TNTs,which, however, usually produces amorphous TNTs and needs further thermal annealing. Recently, a water-assisted crystallization strategy has been proposed and investigated by both science and engineering communities. This method is very efficient and energy saving, and it circumvents the drawbacks of thermal sintering approach. In this paper, we review the recent research progress in this kind of lowtemperature crystallization approach. Here, various synthetic methods are summarized, and the mechanisms of the amorphous–crystalline transformation are analyzed. The fundamental properties and applications of the low-temperature products are also discussed. Furthermore, it is proved that the water-assisted crystallization approach is not only applicable to TNTs but also to crystallizing other metal oxides.

关键词： TiO2nanotube Crystallization Waterassisted Low-temperature

Characterization of the charge transport and electrical properties in solution-processed semiconducting polymers

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Science China(Physics,Mechanics & Astronomy) 2012年第5期55卷 786-791页

作者： WANG LiGuo ZHANG HuaiWu TANG XiaoLi LI YuanXun zhong zhiyong State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of ChinaChengdu 610054China

The conventional charge transport models based on density- and field-dependent mobility, only having a non-Arrhenius tem- perature dependence, cannot give good current-voltage characteristics of poly （2-methoxy-5-（2＇-ethylhexyloxy）-p-phenylene vinylene）（MEH-PPV） hole-only devices. In this paper, we demonstrate that the current-voltage characteristics can give a good unified description of the temperature, carrier density mad electric field dependence of mobility based on both the Arrhenius temperature dependence and the non-Arrhenius temperature dependence. Fu^hermore, we perform a systematic study of charge transport and electrical properties for MEH-PPV. It is shown that the boundary carrier density has an important effect on the current-voltage characteristics. Too large or too small values of boundary carrier density will lead to incorrect cur- rent-voltage characteristics. The numerically calculated carrier density is a decreasing function of the distance to the interface, and the numerically calculated electric field is an increasing function of the distance. Both the maximum of carrier density and the minimum of electric field appear near the interface.

关键词： charge transport electrical properties semiconducting polymers

Research on Psychological Carrying Capacity of Tourism Destination

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Chinese Journal of Population,Resources and Environment 2009年第1期7卷 47-50页

作者： Fan zhiyong zhong Sheng School of Economics and Management Wuhan University Wuhan Hubei 430072 China

As a part of the carrying capacity system of tourism destination, tourism psychological carrying capacity and its makeup are very important indexes which reflect the harmoni-ous development of tourism destination develops harmoniously, but the academy has not paid enough attention to them. Based on the concept and connotation of psychological carrying ca-pacity, this paper explains the influencing factors which affect the psychological capacity of the tourist and the resident after the acknowledged concept, and then designs a harmonious de-velopment model of tourism destination. Finally, it offers some countermeasures against the overloading psychological capac-ity.

关键词： psychological capacity harmony tourism destination overloading

Influence of structure of integrated optical thin-film filter on performance

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Science China Technological Sciences 2013年第3期56卷 563-566页

作者： WU YiLong LIU Shuang WEI GuangLu LU RongGuo LIU Yong zhong zhiyong School of optoelectronic information University of Electronic Science and Technology of China

Thermo-optic tunable thin-film filter based on Fabry-Perot(F-P) cavity structure is a very attractive alternative integrated optical *** this simulation-based paper,the key performance of typical thermo-optic tunable F-P filter is discussed by analyzing the structure of Distributed Bragger Reflectors(DBR) and the thermo-optic property of cavity thin-film *** results indicate a negative correlation between the number of DBR periodical layers and full width at half maximum(FWHM),and a proportional relation between thermal-optic coefficient of material and tuning *** addition,the cavity is more sensitive to the optical property than the reflection layers according to the analysis of thickness error of the *** to solve slow thermal response without incurring other performance loss,a novel structure of the suspended cavity is proposed,in which only the cavity is heated.

关键词： tunable filter Distributed Bragger Reflectors(DBR) Fabry-Perot cavity thickness error suspended cavity structure

Realization of low contact resistance close to theoretical limit in graphene transistors

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Nano Research 2015年第5期8卷 1669-1679页

作者： Hua zhong zhiyong Zhang Bingyan Chen Haitao Xu Dangming Yu Le Huang Lianmao Peng Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics Peking University Beijing 100871 China

Realizing low contact resistance between graphene and metal electrodes remains a well-known challenge for building high-performance graphene devices. In this work, we attempt to reduce the contact resistance in graphene transistors and further explore the resistance limit between graphene and metal contacts. The Pd/graphene contact resistance at room temperature is reduced below the 100 Ω·μm level both on mechanically exfoliated and chemical-vapor-deposition graphene by adopting high-purity palladium and high-quality graphene and controlling the fabrication process to not contaminate the interface. After excluding the parasitic series resistances from the measurement system and electrodes, the retrieved contact resistance is shown to be systematically and statistically less than 100 Ω·μm, with a minimum value of 69 Ω·μm, which is very close to the theoretical limit. Furthermore, the contact resistance shows no clear dependence on temperature in the range of 77-300 K; this is attributed to the saturation of carrier injection efficiency between graphene and Pd owing to the high quality of the graphene samples used, which have a sufficiently long carrier mean-free-path.

关键词： graphene field-effect transistors contact resistance metal-graphene interface transfer length method

Microstructure and magnetic properties of CoFe_2O_4 thin films deposited on Si substrates with an Fe_3O_4 under-layer

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Science China(Physics,Mechanics & Astronomy) 2011年第7期54卷 1235-1238页

作者： zhong zhiyong ZHANG HuaiWu TANG X iaoLi JING YuLan BAI FeiMing LIU Shuang State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China Chengdu 610054 China School of Optoelectronic Information University of Electronic Science and Technology of China Chengdu 610054 China

The microstructure and magnetic properties of cobalt ferrite thin films deposited by the sputtering method on an Fe3o4 un- der-layer were investigated at different post-annealing temperatures. Results show that the Fe3o4 under-layer can accelerate the grain growth of cobalt ferrite films due to the phase transformation of the Fe3o4 under-layer at about 400℃-500℃. By intro- ducing the Fe3O4 under-layer, cobalt ferrite nanocrystalline thin films with high coercivity can be obtained at lower post-annealing temperatures.

关键词： magnetic materials magnetic thin filims cobalt ferrite