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具有低噪声及高线性度的高性能MOCVD-SiN_(x)/AlN/GaN毫米波MIS-HEMTs

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红外与毫米波学报 2024年第2期43卷 200-206页

作者：袁静景冠军王建超汪柳高润华张一川姚毅旭魏珂李艳奎陈晓娟中国科学院微电子研究所高频高压器件与集成研发中心北京100029 中国科学院大学北京100029

文章在超薄势垒AlN/GaN异质结构上采用金属有机化学气相沉积(MOCVD)原位生长SiN_(x)栅介质,成功制备了高性能的SiN_(x)/AlN/GaN金属-绝缘体-半导体高电子迁移率晶体管(MIS-HEMTs)。深能级瞬态谱(DLTS)技术测试SiN_(x)/AlN的界面信息,显... 详细信息

文章在超薄势垒AlN/GaN异质结构上采用金属有机化学气相沉积(MOCVD)原位生长SiN_(x)栅介质,成功制备了高性能的SiN_(x)/AlN/GaN金属-绝缘体-半导体高电子迁移率晶体管(MIS-HEMTs)。深能级瞬态谱(DLTS)技术测试SiN_(x)/AlN的界面信息,显示其缺陷能级深度为0.236 eV,俘获截面为3.06×10^(-19)cm^(-2),提取的界面态密度为10^(10)~10^(12)cm^(-2)eV^(-1),表明MOCVD原位生长的SiN_(x)可以有效降低界面态。同时器件表现出优越的直流、小信号和噪声性能。栅长为0.15μm的器件在2 V的栅极电压(Vgs)下具有2.2 A/mm的最大饱和输出电流,峰值跨导为506 mS/mm,最大电流截止频率(fT)和最大功率截止频率(fMAX)分别达到了65 GHz和123 GHz,40 GHz下的最小噪声系数(NFmin)为1.07 dB,增益为9.93 dB。Vds=6 V时对器件进行双音测试,器件的三阶交调输出功率(OIP3)为32.6 dBm,OIP3/Pdc达到11.2 dB。得益于高质量的SiN_(x)/AlN界面,SiN_(x)/AlN/GaN MISHEMT显示出了卓越的低噪声及高线性度,在毫米波领域具有一定的应用潜力。

关键词： SiN_(x)栅介质 MOCVD MIS-HEMTs 界面态低噪声线性度毫米波

Characteristics of Membrane Fouling in an Anaerobic-(Anoxic/Oxic)~n-MBR Process

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Journal of China University of Mining and Technology 2007年第3期17卷 387-392页

作者： zhang chuan-yi DING yi YUAN Li-mei zhang Yan-qiu XI Dan-li School of Environment and Spatial Informatics China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China School of Environmental Science and Engineering Donghua University Shanghai 201620 China

The characteristics of membrane fouling and cleaning, in a hybrid MBR process, was investigated. Under the condition of sub-critical flux operation, a characteristic three-stage trans-membrane pressure （TMP） profile is observed as time passes. The initially extended period of slow pressure rise, followed by a somewhat faster rise, is then sup- planted by a sudden transition to rapid pressure rise. Membrane cleaning experiments and SEM examination make it apparent that the rapid TMP rise is mainly caused by the accumulation of a surface cake layer, which is a reversible fouling that can be removed by tap water washing. Fouling caused by a gel layer, which is an irreversible fouling, can be removed efficiently by chemical cleaning. NaC10 can oxidize the gel layer, which is formed mainly of macromo-lecular organic substances. The HC1 can remove inorganic particles formed by Ca^2＋, Mg^2＋ ions etc. The sequence of chemicals used in membrane cleaning has an influence on the cleaning result. The effect of the NaC1O＋HC1 cleaning procedure is superior to that of the HCI＋NaC1O one. Particle size distribution measurements （PSD） reveal that fine particles are inclined to deposit or attach on the membrane surface, or in the membrane pores, and caused rapid fouling.

关键词： membrane fouling trans-membrane pressure (TMP) cleaning floc cake layer particle size distribution (PSD)

全国妇联系统儿童活动中心建设发展的新进展新成效

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中国校外教育 2024年第3期 116-128页

作者：李善华张乂川黄链建李茂吉林省妇女儿童活动中心重庆市儿童活动中心上海市妇女儿童服务指导中心(巾帼园) 南昌市妇女儿童活动中心党支部

妇联所属儿童活动中心是妇联组织开展社会教育、服务儿童和家庭的重要平台,是提高儿童综合素质、开展社会实践的重要课堂,是加强未成年人思想道德建设、培育和践行社会主义核心价值观的重要阵地,在妇联工作中具有重要地位,在培养儿童成... 详细信息

妇联所属儿童活动中心是妇联组织开展社会教育、服务儿童和家庭的重要平台,是提高儿童综合素质、开展社会实践的重要课堂,是加强未成年人思想道德建设、培育和践行社会主义核心价值观的重要阵地,在妇联工作中具有重要地位,在培养儿童成长成才中担负重要责任。近年来,妇联所属儿童活动中心通过做精活动、做实品牌、做强平台等实践,在建设发展过程中取得以下进展与成效:强化政治引领,打造党建品牌;紧扣公益属性,完善服务功能;坚持上下联动,形成工作合力等。未来,妇联所属儿童活动中心将进一步切实担负起关心关爱儿童的重要责任,用心用情促进孩子们健康成长、全面发展。

关键词：校外教育妇女儿童工作儿童活动中心

Fine Sand and Clay Sediment Acoustic Properties of the Novel Sediment Sample from the Arabian Sea:Experimental Investigations and Biot−Stoll Model Validation

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China Ocean Engineering 2024年第1期38卷 169-180页

作者： Shahabuddin SHAIKH HUANG yi-wang zhang Ze-chuan Habib Hussain ZUBERI National Key Laboratory of Underwater Acoustic Technology and College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150001China

The present study explores the physical and acoustic characteristics of fine sand and clay in novel seabed marine sediments from of Pakistan coastline of the Arabian *** measured physical parameters included mean grain size,mass density,bulk density,salinity,porosity,permeability,pore size and mineralogical *** properties,including sound speed and attenuation,in the high frequency range of 90-170 kHz were analyzed.A controlled laboratory setup with the acoustic transmission method and Fourier transform techniques was utilized to examine the sound propagation and absorption of novel seabed *** standard deviation of mean sound speed in fresh water was 0.75 m/s,and attenuation was observed in the range of 0.43 to 0.61 dB/*** mean sound velocity in sand and clay varied from 1706 to 1709 m/s and 1602 to 1608 m/s,*** average attenuation was observed at 80 to 93 dB/m in sandy sediments and from 31.8 to 38.6 dB/m in clayey *** velocity variation within sandy sediment is low,consistent with expected results,and smaller than the predicted ***,clay sediment exhibited a positive linear correlation and low sound speed *** increased linearly with frequency for both ***,the laboratory results were validated by using the Biot−Stoll *** dispersion of sound speed in sandy and clayey sediments was consistent with the predictions of the Biot−Stoll *** attenuation aligned more with Biot−Stoll model predictions due to improved permeability,tortuosity and pore size parameter fitting.

关键词： physical and acoustic characteristics marine sediments sound speed attenuation Biot−Stoll model

Hot Compression Behavior and Tensile Property of a Novel Ni-Co-Based Superalloy Prepared by Electron Beam Smelting Layered Solidification Technology

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 283-292页

作者： Yong-Chao Gai Rui zhang chuan-Yong Cui Zi-Jian Zhou yi Tan yi-Zhou Zhou Xiao-Feng Sun Key Laboratory of Materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

The hot compression behavior and tensile strength after compression of a new Ni-Co-based superalloy produced using electron beam smelting layered(EBSL)solidification technology were *** compression tests were performed at temperatures of 1120℃and 1150℃,with strain rates of 1 s^(-1) and 0.01 s^(-1),reaching a true strain of *** strength was evaluated at room *** results revealed that this EBSL technology accelerates dynamic recrystallization(DRX),without compromising the strength of alloy.A significant correlation between the volume fraction of DRX and the strain rate was observed,with higher fractions at lower strain rates,leading to higher tensile ***,at the same strain rate,the specimens compressed at 1120℃exhibited higher tensile strength due to undissolvedγ′*** solution and aging heat treatment,the alloy maintained high tensile *** results suggested that the EBSL Ni-Co-based superalloy offers excellent prospects for practical applications.

关键词： Ni-Co-based superalloy Hot deformation Electron beam smelting Tensile strength

硫自养反硝化技术在污水深度处理中的研究和应用

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广州化工 2024年第15期52卷 112-114页

作者：张文华蔡巾兰孙家源齐琳郭宣钰张传义中国矿业大学环境与测绘学院江苏徐州221116

硫自养反硝化技术因其污泥产量低、效率高、无需额外投加碳源等优点而受到广泛关注。其中以铁硫化物作为电子供体的硫自养反硝化技术还能达到同步脱氮除磷的目的,进一步降低了出水氮、磷浓度,对于水体富营养化问题的解决有很大意义。介... 详细信息

硫自养反硝化技术因其污泥产量低、效率高、无需额外投加碳源等优点而受到广泛关注。其中以铁硫化物作为电子供体的硫自养反硝化技术还能达到同步脱氮除磷的目的,进一步降低了出水氮、磷浓度,对于水体富营养化问题的解决有很大意义。介绍了硫自养反硝化技术的生化原理,主要的电子供体,叙述了近些年应用于污水处理领域的技术和工艺,讨论今后的发展动态,旨在为未来硫自养反硝化工艺发展提供参考。

关键词：硫自养反硝化电子供体脱氮除磷

An Effective Approach for the Preparation of High Performance Thermal Conductive Polymer Composites Containing Liquid Metal

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Chinese Journal of Polymer Science 2024年第7期42卷 992-1001,I0010页

作者： Xin Chen Xue-Zhong zhang yi-Fei Yuan chuan-Liang Chen Lian-Hu Xiong Qiang Fu Hua Deng College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu610065China Department of Materials Science and Engineering Sichuan University-Pittsburgh InstituteSichuan UniversityChengdu610065China

The preparation of high-performance thermal conductive composites containing liquid metals(LM)has attracted significant ***,the stable dispersion of LM within polymer solution and effective property contribution of liquid metals remains significant challenges that need to be *** by the properties of the dendritic structure of the tree root system in grasping the soil,“shear-induced precipitation-interfacial reset-reprotonation”processing strategy is proposed to prepare nanocomposites based on aramid micron fibers(AMFs)with hierarchical dendritic *** to the combination of van der Waals force provided by hierarchical dendritic structure,electrostatic interaction between AMFs and LM,coordinative bonding of―NH to LM,together with interfacial re-setting and multi-step protonation,several features can be achieved through such strategy:conducive to the local filler network construction,improvement of interfacial interaction,improvement of the stability of filler dispersion in the solvent,and enhancement of mechanical and thermal properties of the *** resulting AMFsp H=4/LM films demonstrate a thermal conductivity of 10.98 W·m^(-1)·K^(-1)at 70%filler content,improvement of 126.8%compared to ANFs/LM film;while maintaining a strength of~85.88 MPa,improvement of 77%compared to AMFs/LM *** also possess insulation properties,enable heat dissipation for high power *** work provides an effective strategy for the preparation of high performance polymer composites containing liquid metal.

关键词： Shear-induced Reprotonation AMFs LM Filler dispersion

Self-assembly of perovskite nanocrystals:From driving forces to applications

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Journal of Energy Chemistry 2024年第1期88卷 561-578,I0013页

作者： yi Li Fei zhang School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300072China

Self-assembly of metal halide perovskite nanocrystals(NCs)into superlattices can exhibit unique collective properties,which have significant application values in the display,detector,and solar cell *** review discusses the driving forces behind the self-assembly process of perovskite NCs,and the commonly used self-assembly methods and different self-assembly structures are ***,we summarize the collective optoelectronic properties and application areas of perovskite superlattice ***,we conclude with an outlook on the potential issues and future challenges in developing perovskite NCs.

关键词： Self-assembly Metal halide perovskite Nanocrystals Driving forces

In vivo study of extracellular matrix coating enhancing fixation of the pedicle screw-bone＇s interface

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Chinese Medical Journal 2011年第23期124卷 3945-3952页

作者： LIU Guo-min zhang Xing-yi XU chuan-jie ZHU Xiao-min WANG Jun LIU yi Department of Ortiaopedics Department of Thoracic Surgery Changchun Jilin 130041 China

Based on in vivo research on the effect of the coating of the extracellular matrix composition of pedicle screws on the conduction and induction of bone formation in young sheep, the aim of this study was to investigate the application of coated pedicle screws in sheep with scoliosis whose spines are under constant development. Methods Four groups of pedicle screws were randomly implanted into bilateral L2-L5 pedicles of 2.5- to 3-month-old sheep. A static experiment was performed on one side and a loading test was performed on the other side by implanting connecting rods at the L2-L3 and L4-L5 segments. The changes in the force on the coated screws and the combination of the surface of the coated screws with the surrounding bone in the growth process of young sheep＇s spines with aging were observed. After 3 months, the lumbar vertebrae with the screws were removed and examined by micro-CT, histological, and biomechanical analyses. Results Under nonloading conditions, there is bone formation around the surfaces of coated screws. The bone forming on the surface of collagen/chondroitin sulfate/hydroxyapatite coating of pedicle screws is the most, the one of the collagen / chondroitin sulfate coating and hydroxyapatite coating is followed, and no significant difference between the two groups. In terms of the trabecular bone morphology parameters of the region of interest around the surface of the pedicle screws, such as bone mineral content, bone mineral density, tissue mineral content, tissue bone mineral density, bone volume fraction, and connection density, those associated with collagen/chondroitin sulfate/hydroxyapatite coatings are largest and those unassociated with coatings are smallest. Under nonloading conditions, the pullout strength of the collagen/chondroitin sulfate/hydroxyapatite-coated screws was largest, and that of the uncoated screws was minimal （P 〈0.01）. Under loading conditions, the maximum pullout strength of each group of pedicle screws was less

关键词： hydroxyapatite collagen chondroitin sulfate micro-CT biomechanics