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2D Ca/Nb-based perovskite oxide with Ta doping as highly efficient H_(2)O_(2)synthesis catalyst

Nano Research 2024年第6期17卷 4934-4942页

作者： Xingchen Yang Yang Gao Xiaohui Xu Wenqiang Xu Denghui wang bin Luo Dong Liu Tao Liang bin wang CAS Key Laboratory of Nanosystem and Hierarchical Fabrication National Center for Nanoscience and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Nanomaterials Centre School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnologythe University of QueenslandSt LuciaQLD 4072Australia State Key Laboratory of Organic–Inorganic Composites College of Chemical EngineeringCollege of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China Hangzhou Institute for Advanced Study University of Chinese Academy of SciencesHangzhou 310024China State Key Lab of Silicon Materials Zhejiang UniversityHangzhou 310027China

Perovskite oxides(POs)are emerging as a class of highly efficient catalysts for reducing oxygen to H_(2)*** a rich variety of POs-based catalysts have been developed by tuning the complex composition,a highly efficient PO catalyst that is able to alter the reaction pathway from a 4e−process to a 2e−process for H_(2)O_(2)production has rarely been *** modified the structure and composition of a Ca-and Nb-based PO material by realizing a uniform two-dimensional(2D)morphology and varied Ta doping,resulting in the 2D Ca_(2)Nb_(3−x)Ta_(x)O_(10)−(x=0,0.5,1,and 1.5)monolayer *** obtained catalysts exhibit a dominant 2e−pathway and show exceptional H_(2)O_(2)production *** typical Ca_(2)Nb_(2.5)Ta_(0.5)O_(10)−nanoflakes showed an onset potential of 0.735 V *** hydrogen electrode(RHE),a remarkably high selectivity over 95%across a wide range of 0.3-0.7 V,an impressively high Faradaic efficiency of 94%,and a notable H_(2)O_(2)productivity of 1571 mmol·gcat^(−1)·h^(−1).These findings highlight the great potential of 2D perovskite oxide nanoflakes as advanced electrocatalysts for 2e−oxygen reduction reaction.

关键词： perovskite oxide H_(2)O_(2) two-electron oxygen reduction reaction catalyst Ca_(2)Nb_(3-x)Ta_(x)O_(10)-nanoflakes

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Two-Dimensional Coupling Vibration Analysis of Laterally Acoustically Coupled Two-Port Thin-Film Bulk Acoustic Resonators

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Acta Mechanica Solida Sinica 2020年第4期33卷 464-478页

作者： Haoyu Huang Nian Li bin wang Zhenghua Qian bin Huang Tingfeng Ma Iren Kuznetsova State Key Laboratory of Mechanics and Control of Mechanical Structures College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China Faculty of Mechanical Engineering and Mechanics Ningbo UniversityNingbo 315000China Kotelnikov Institute of Radio Engineering and Electronics of RAS MoscowRussia 125009

In this paper,we present an approach to studying the mode coupling vibrations in two-port thin-film bulk acoustic wave resonator(FBAR)devices with two pairs of electrodes deposited on the zinc oxide *** two-dimensional plate theory established in our previous work is employed,which takes into account the coupling of the operating thickness-extensional mode with the extensional,flexural,fundamental and second-order thickness-shear *** propagation of straight-crested waves in the plate is studied,and the state-vector approach is successfully used to simplify the derivation *** a structurally symmetric device,the modes are separated into quasi symmetric and antisymmetric *** spectra and corresponding mode shapes are obtained under the stress-free boundary conditions,respectively,and then coupling effects and energy trapping phenomenon are discussed in *** results for structures with asymmetric electrode distributions are also *** is found that the choice of aspect ratio has a great effect on mode couplings of FBAR *** study will be useful for the design of FBAR filters and sensors.

关键词： FBAR RF filter Two-dimensional theory Mode coupling Trapped energy

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Shape embedding and retrieval in multi-ﬂow deformation

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Computational Visual Media 2024年第3期10卷 439-451页

作者： Baiqiang Leng Jingwei Huang Guanlin Shen bin wang School of Software Tsinghua UniversityBeijingChina Huawei Technologies ShenzhenChina

We propose a unified 3D ﬂow frameworkfor joint learning of shape embedding and deformationfor different categories. Our goal is to recovershapes from imperfect point clouds by fitting thebest shape template in a shape repository afterdeformation. Accordingly, we learn a shape embeddingfor template retrieval and a ﬂow-based network forrobust deformation. We note that the deformationﬂow can be quite different for different shapecategories. Therefore, we introduce a novel multi-hubmodule to learn multiple modes of deformation toincorporate such variation, providing a network whichcan handle a wide range of objects from differentcategories. The shape embedding is designed to retrievethe best-fit template as the nearest neighbor in a latentspace. We replace the standard fully connected layerwith a tiny structure in the embedding that significantlyreduces network complexity and further improvesdeformation quality. Experiments show the superiorityof our method to existing state-of-the-art methods viaqualitative and quantitative comparisons. Finally, ourmethod provides efficient and flexible deformation thatcan further be used for novel shape design.

关键词： deformation shape retrieval embedding reconstruction

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An elastic electrode model for wave propagation analysis in piezoelectric layered structures of film bulk acoustic resonators

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Acta Mechanica Solida Sinica 2017年第3期30卷 263-270页

作者： Feng Zhu Yuxing Zhang bin wang Zhenghua Qian State Key Laboratory of Mechanics and Control of Mechanical Structures College of Aerospace Engineering Nanjing Uniuersity of Aeronautics and Astronautics Nanjing 210016 China

Wave propagation in a piezoelectric layered structure of a film bulk acoustic resonator （FBAR/ is studied. The accurate results of dispersion relation are calculated using the proposed elastic electrode model for both electroded and unelectroded layered plates. The differences of calculated cut-off frequencies between the current elastic electrode model and the simplified inertial electrode model （often used in the quartz resonator analysis） are illustrated in detail, which shows that an elastic electrode model is indeed needed for the accurate analysis of FBAR. These results can be used as an accurate criterion to calibrate the 2-D theoretical model for a real finite-size structure of FBAR.

关键词： FBARs Elastic electrode Waves propagation Dispersion curves Inertial electrode

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Synthesis of GdF_3 from the Gd_2O_3-NH_4HF_2 system

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Rare Metals 2007年第5期26卷 482-487页

作者： HAO Zhanzhong ZHANG Jianliang wang bin ZHANG Xidong Metallurgical and Ecological Engineering School University of Science and Technology Beijing Beijing 100083 China Baotou Teachers College Baotou 014030 China

GdF3 was synthesized with Gd2O3 and NH4HF2 under atmospheric pressure and vacuum. The effects of pressure,temperature,and reactant ratio on the reaction process were investigated. A new mechanism for the synthesis of GdF3 was proposed. Powdered Gd2O3 started to react with NH4HF2 at low temperature,and the products were GdNH4F4,NH4F,NH3,and H2O. GdNH4F4 decomposed to GdF3 and NH4F after further high-temperature treatment,accompanying the volatilization and decomposition of NH4F. The whole process could be divided into three steps： synthesis,decomposition,and deamination. The initial and final reaction temperatures decreased under vacuum condition. An optimized process for the preparation of GdF3 was obtained： synthesis under atmospheric pressure at low temperature and decomposition and deamination under vacuum at high temperature.

关键词： inorganic chemistry Gd NH4HF2 synthesis

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Chemical Composition Effect on Microstructures and Mechanical Properties in Friction Stir Additive Manufacturing

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Acta Metallurgica Sinica(English Letters) 2022年第9期35卷 1494-1508页

作者： Jian-Yu Li Shi-Ning Kong Chi-Kun Liu bin-bin wang Zhao Zhang State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsDalian University of TechnologyDalian116024China

The variation of chemical compositions can affect the mechanical property of friction stir additive manufacturing(FSAM).Quantitative characterization of the relationship between the chemical composition and the mechanical property of FSAM components is key to control the quality of FSAM *** effect of chemical composition on the mechanical property of 6 xxx series aluminum alloy FSAM joint was studied by both experimental and numerical methods.A moving heat source model was established to simulate the heat transfer in FSAM *** average grain size was calculated by Monte Carlo model,and the precipitate evolution model was used to calculate the hardness and constitutive stress-strain *** validity of the numerical model was verified by *** indicate that the hardness and yield stress of 6 xxx series aluminum alloy FSAW joint can be enhanced by increasing silicon or magnesium *** increasing the content of magnesium(silicon),the volume fraction and the mean radius of MgSi can be increased when the content of silicon(magnesium) is *** the decrease in volume fraction,the average grain size can be *** changing the weight percentage of magnesium and silicon in different layers,the hardness and yield stress along the build direction can be controlled.

关键词： Friction stir additive manufacturing Chemical composition Mechanical property Microstructure Numerical model

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新型胆固醇侧部衍生物的合成研究

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化学学报 2010年第12期68卷 1247-1251页

作者：王斌张军华四川大学高分子材料工程国家重点实验室成都610065

由于胆固醇和氢化胆固醇均是较好的液晶基元,引起了广泛的关注和研究.在胆固醇分子中,C(3)上有一个羟基,C(5)=C(6)之间含有一个双键,双键的存在使得胆固醇分子具有较好的刚性,因此大量的研究工作都集中在利用C(3)上的羟基制备胆固醇衍生... 详细信息

由于胆固醇和氢化胆固醇均是较好的液晶基元,引起了广泛的关注和研究.在胆固醇分子中,C(3)上有一个羟基,C(5)=C(6)之间含有一个双键,双键的存在使得胆固醇分子具有较好的刚性,因此大量的研究工作都集中在利用C(3)上的羟基制备胆固醇衍生物.但是C(5)=C(6)之间的双键也是可以利用的官能团,可以在胆固醇分子的双键部位引入适当的官能团,而得到一些新的衍生物,因此,对胆固醇C(5)=C(6)位双键的化学修饰就成了本研究的重点.首次探讨了将6-溴己酸或丙烯酸通过双键环氧化,然后开环的方法连到胆固醇侧部双键位置,为合成新型的含胆固醇衍生物的聚合物研究奠定了基础.

关键词：胆固醇双键化学修饰胆固醇衍生物

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Deep Learning Based 2D Human Pose Estimation:A Survey

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Tsinghua Science and Technology 2019年第6期24卷 663-676页

作者： Qi Dang Jianqin Yin bin wang Wenqing Zheng School Beijing University of Posts and TelecommunicationsBeijing 100876China State Key Lab.of Intelligent Technology and Systems Tsinghua UniversityBeijing 100084China School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876China

Human pose estimation has received significant attention recently due to its various applications in the real world. As the performance of the state-of-the-art human pose estimation methods can be improved by deep learning, this paper presents a comprehensive survey of deep learning based human pose estimation methods and analyzes the methodologies employed. We summarize and discuss recent works with a methodologybased taxonomy. Single-person and multi-person pipelines are first reviewed separately. Then, the deep learning techniques applied in these pipelines are compared and analyzed. The datasets and metrics used in this task are also discussed and compared. The aim of this survey is to make every step in the estimation pipelines interpretable and to provide readers a readily comprehensible explanation. Moreover, the unsolved problems and challenges for future research are discussed.

关键词： human pose estimation deep learning computer vision

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Induced pluripotent stem cell technology for spinal cord injury: a promising alternative therapy

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Neural Regeneration Research 2021年第8期16卷 1500-1509页

作者： Yu Li Ping-Ping Shen bin wang Clinical Stem Cell Center the Affiliated Drum Tower Hospital of Nanjing University Medical SchoolSchool of Life ScienceNanjing UniversityNanjingJiangsu ProvinceChina State Key Laboratory of Pharmaceutical Biotechnology and The Comprehensive Cancer Center the Affiliated Drum Tower Hospital of Nanjing University Medical SchoolSchool of Life ScienceNanjing UniversityNanjingJiangsu ProvinceChina Clinical Stem Cell Center the Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjingJiangsu ProvinceChina

Spinal cord injury has long been a prominent challenge in the trauma repair process. Spinal cord injury is a research hotspot by virtue of its difficulty to treat and its escalating morbidity. Furthermore, spinal cord injury has a long period of disease progression and leads to complications that exert a lot of mental and economic pressure on patients. There are currently a large number of therapeutic strategies for treating spinal cord injury, which range from pharmacological and surgical methods to cell therapy and rehabilitation training. All of these strategies have positive effects in the course of spinal cord injury treatment. This review mainly discusses the problems regarding stem cell therapy for spinal cord injury, including the characteristics and action modes of all relevant cell types. Induced pluripotent stem cells, which represent a special kind of stem cell population, have gained impetus in cell therapy development because of a range of advantages. Induced pluripotent stem cells can be developed into the precursor cells of each neural cell type at the site of spinal cord injury, and have great potential for application in spinal cord injury therapy.

关键词： axon regeneration cell therapy functional recovery induced pluripotent stem cell mesenchymal stem cell neural cells neural precursor cell neural stem cell remyelination spinal cord injury stem cells

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Floral characteristics and pollination ecology of Manglietia ventii(Magnoliaceae),a plant species with extremely small populations(PSESP)endemic to South Yunnan of China

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Plant Diversity 2017年第1期39卷 52-59页

作者： bin wang Gao Chen Congren Li Weibang Sun Kunming Botanical Garden Kunming Institute of BotanyChinese Academy of SciencesKunming 650204YunnanChina Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650204YunnanChina University of Chinese Academy of Sciences Beijing 100049China

Manglietia ventii is a highly endangered plant species endemic to Yunnan province in China, where there are only five known small populations. Despite abundant flowering there is very low fruit and seed set,and very few seedlings in natural populations, indicating problems with reproduction. The causes of low fecundity in M. ventii are not known, largely because of insufficient knowledge of the species pollination ecology and breeding system. We conducted observations and pollination experiments, and analyzed floral scents to understand the pollinatoreplant interactions and the role of floral scent in this relationship, as well as the species breeding system. Like the majority of Magnoliaceae, M. ventii has protogynous and nocturnal flowers that emit a strong fragrance over two consecutive evenings. There is a closing period(the pre-staminate stage) during the process of anthesis of a flower, and we characterize the key flowering process as an "open-close-reopen" flowering rhythm with five distinct floral stages observed throughout the floral period of this species: pre-pistillate, pistillate, pre-staminate, staminate,and post-staminate. Flowers are in the pistillate stage during the first night of anthesis and enter the staminate stage the next night. During anthesis, floral scent emission occurs in the pistillate and staminate stages. The effective pollinators were weevils(Sitophilus sp.) and beetles(Anomala sp.), while the role of Rove beetles(Aleochara sp.) and thrips(Thrips sp.) in pollination of M. ventii appears to be minor or absent. The major chemical compounds of the floral scents were Limonene, b-Pinene, a-Pinene, 1,8-Cineole, Methyl-2-methylbutyrate, p-Cymene, Methyl-3-methyl-2-butenoate and 2-Methoxy-2-methyl-3-buten, and the relative proportions of these compounds varied between the pistillate and staminate stages. Production of these chemicals coincided with flower visitation by weevils and *** results of pollination experiments suggest that M

关键词： Floral scent Weevil Beetle Pollination Breeding system Conservation

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