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Structural and microwave absorption properties of CoFe_(2)O_(4)/residual carbon composites

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International Journal of Minerals,Metallurgy and materials 2025年第1期32卷 221-232页

作者： Yuanchun Zhang Shengtao Gao Xingzhao Zhang Dacheng ma Chuanlei zhu Jun He Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining Anhui University of Science and TechnologyHuainan 232001China School of Chemical and Blasting Engineering Anhui University of Science and TechnologyHuainan 232001China

Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary *** this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal *** mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these ***,compared with pure residual carbon materials,this composite offers superior capabilities in microwave *** 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 ***,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of *** study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality.

关键词： coal gasification slag residual carbon hydrothermal method microwave absorption CoFe_(2)O_(4)

亚洲和北美干湿变化及其与海表温度异常的关系

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地球物理学报 2009年第5期52卷 1184-1196页

作者：华丽娟马柱国中国科学院研究生院地球科学学院北京100049 中国科学院东亚区域气候-环境重点实验室中国科学院大气物理研究所东亚中心北京100029 中国科学院东亚区域气候-环境重点实验室中国科学院大气物理研究所东亚中心北京100029

利用多通道奇异谱方法(MSSA)分析了1953～2003年亚洲和北美Palmer干旱指数(PISI)与热带和北半球温带海洋海表面温度异常(SSTA)的主要周期振荡特征及其相互联系.结果表明:亚洲和北美PDSI以及SSTA均存在明显的3～6年的年际以及10年左右的... 详细信息

利用多通道奇异谱方法(MSSA)分析了1953～2003年亚洲和北美Palmer干旱指数(PISI)与热带和北半球温带海洋海表面温度异常(SSTA)的主要周期振荡特征及其相互联系.结果表明:亚洲和北美PDSI以及SSTA均存在明显的3～6年的年际以及10年左右的年代尺度振荡;此外,亚洲PDSI还存在显著的6～8年的年际振荡.SSTA的年际振荡主要体现了ENSO的变化特征,而其年代尺度振荡的空间分布具有热带太平洋和北太平洋共同作用的类ENSO型.同时,MSSA的分析结果给出了亚洲和北美主要振荡信号的时间和空间演变特征.相关性分析表明,亚洲和北美PDSI的年际及年代尺度振荡均显示明显的对SSTA强迫信号的响应.对于年际振荡,亚洲PISI对SSTA响应强于北美,但年代尺度振荡则反之.此外,亚洲和北美PISI对于SSTA信号响应的关键区域也随时间尺度的不同而发生变化.亚洲的西西伯利亚、青藏高原东西两侧以及中西伯利亚东部在年际和年代尺度上均为受SSTA影响最显著的区域;在年际尺度上,北美中部地区的干湿变化与SSTA存在显著相关,而在年代尺度上,美国西部更易受SSTA年代尺度振荡的影响.

关键词： Palmer干旱指数(PDSI) MSSA方法干湿变化海表面温度

Yielding performance of compact yielding anchor cable in working state:Analytical theory and experimental evaluation of yielding resistance enhancement effect

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International Journal of Mining Science and Technology 2025年第1期35卷 101-120页

作者： Zhenyu Wang Bo Wang Xinxin guo Jinjin Li Zhenwang ma State Key Laboratory of Intelligent Geotechnics and Tunnelling Southwest Jiaotong UniversityChengdu 610031China State Key Laboratory of Geohazard Prevention and Geoenvironmental Protection Chengdu University of TechnologyChengdu 610059China China Design Group Co. Ltd.Nanjing 210001China

To elucidate the yielding performance of compact yielding anchor cables in working state,a yielding mechanical model incorporating extrusion friction and fastening rotation under confining pressure is *** yielding resistance enhancement effect(ω)caused by working environment constraints is evaluated through multi-layer composite sleeve hole expansion analysis,forming a theoretical framework for calculating the working yielding *** and in-situ pull-out tests are conducted to determine the yielding performance and validate the analytical *** main conclusions are:(1)Yielding force and energy-release capacity increase withω,significantly outperforming the unconfined state.(2)In-situ tests under varying rockmass and geostress conditions(F1–F3)determine the yielding force increases to 183.4–290.1,204.0–290.8,and 235.0–327.1 kN.(3)The slight deviation(–12.5%to 6.2%)between the theoretical and measured yielding force confirms that the analytical theory effectively describes the working yielding performance.(4)ωincreases with higher geostress and improved rock mechanical properties,with initial geostress(σ_(0))and elastic modulus of surrounding rock(E_(3))identified as critical parameters.

关键词： Compact yielding anchor cables Working state Yielding resistance enhancement effect Yielding mechanical performance Pull-out test

试论民族院校研究生思想政治教育——以西北民族大学为例

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中南民族大学学报（人文社会科学版） 2008年第4期28卷 178-180页

作者：马国柱西北民族大学研究生处甘肃兰州730030

民族院校是我国高等教育的一个组成部分,承担着为我国少数民族地区培养高素质人才的历史使命。研究民族院校研究生的思想政治教育工作,有利于提高高层次人才培养质量,促进少数民族地区经济建设、科技进步和社会发展,关系到创建和谐社会... 详细信息

民族院校是我国高等教育的一个组成部分,承担着为我国少数民族地区培养高素质人才的历史使命。研究民族院校研究生的思想政治教育工作,有利于提高高层次人才培养质量,促进少数民族地区经济建设、科技进步和社会发展,关系到创建和谐社会和全面建设小康社会。

关键词：民族院校研究生思想政治教育

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中国干旱和半干旱带的10年际演变特征

地球物理学报 2005年第3期48卷 519-525页

作者：马柱国符淙斌中国科学院东亚区域气候-环境重点实验室

利用Thornthwaite的干湿分类函数,对近10 0年中国干旱和半干旱区界限的10年际变动特征进行了分析.结果发现:近5 0年,在东北中部和华北北部,干旱和半干旱边界呈波动式东移,有明显向东扩展的趋势;在华北南部和陕西南部,半干旱边界也呈波... 详细信息

利用Thornthwaite的干湿分类函数,对近10 0年中国干旱和半干旱区界限的10年际变动特征进行了分析.结果发现:近5 0年,在东北中部和华北北部,干旱和半干旱边界呈波动式东移,有明显向东扩展的趋势;在华北南部和陕西南部,半干旱边界也呈波动式南扩,其中陕西南部半干旱边界向南扩展的范围最大.近10 0年,10年际的干旱和半干旱边界也呈波动式摆动且存在向东和向南扩展的趋势,但在华北南部与东北中部两个地区以2 0世纪2 0年代前后干旱和半干旱的范围最大、最强.干旱和半干旱分界线的位置变化与区域升温和降水减少密切相关.

关键词：干旱和半干旱干湿分类函数 10年际降水和气温

Achievable Rate Analysis and Optimization of Double-RIS Assisted Spatially Correlated MIMO with Statistical CSI

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China Communications 2025年第1期22卷 139-157页

作者： Xu Kaizhe guo Jiajia Zhang Jun Jin Shi ma Shaodan Department of Communications and Networking Xi’an Jiaotong-Liverpool UniversitySuzhou 215123China State Key Laboratory of Internet of Things for Smart City University of MacaoMacao SARChina Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and TelecommunicationsNanjing 210003China National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China State Key Laboratory of Internet of Things for Smart City and the Department of Electrical and Computer Engineering University of MacaoMacao SARChina

Reconfigurable intelligent surface(RIS)is a novel meta-material which can form a smart radio environment by dynamically altering reflection directions of the impinging electromagnetic *** the prior literature,the inter-RIS links which also contribute to the performance of the whole system are usually neglected when multiple RISs are *** this paper we investigate a general double-RIS assisted multiple-input multiple-output(MIMO)wireless communication system under spatially correlated non line-of-sight propagation channels,where the cooperation of the double RISs is also *** design objective is to maximize the achievable ergodic rate based on full statistical channel state information(CSI).Specifically,we firstly present a closedform asymptotic expression for the achievable ergodic rate by utilizing replica method from statistical *** a full statistical CSI-enabled optimal design is proposed which avoids high pilot training overhead compared to instantaneous CSI-enabled *** further reduce the signal processing overhead and lower the complexity for practical realization,a common-phase scheme is proposed to design the double *** results show that the derived asymptotic ergodic rate is quite accurate even for small-sized antenna *** the proposed optimization algorithm can achieve substantial gain at the expense of a low overhead and ***,the cooperative double-RIS assisted MIMO framework is proven to achieve superior ergodic rate performance and high communication reliability under harsh propagation environment.

关键词： common reflection pattern double RISs large system analysis MIMO replica method

Physicochemical characteristics of airborne microplastics of a typical coastal city in the Yangtze River Delta Region,China

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Journal of Environmental Sciences 2025年第2期148卷 602-613页

作者： Pengju Liu Longyi Shao Ziyu guo Yaxing Zhang Yaxin Cao Xuying ma Lidia Morawska State Key Laboratory of Coal Resources and Safe Mining&College of Geoscience and Surveying Engineering China University of Mining and Technology(Beijing)Beijing 100083China College of Geomatics Xi’an University of Science and TechnologyXi’an 710054China International Laboratory for Air Quality and Health(ILAQH) Queensland University of TechnologyBrisbaneQLD 4000Australia

Airborne microplastics(MPs)are important pollutants that have been present in the environment for many years and are characterized by their universality,persistence,and potential *** study investigated the effects of terrestrial and marine transport of MPs in the atmosphere of a coastal city and compared the difference between daytime and *** direct infrared imaging(LDIR)and polarized light microscopy were used to characterize the physical and chemical properties of MPs,including number concentration,chemical types,shape,and *** trajectories were used to distinguish the air masses from marine and terrestrial *** chemical types were detected by LDIR,with rubber(16.7%)and phenol-formaldehyde resin(PFR;14.8%)being major *** main morphological types of MPs were identified,and fragments(78.1%)are the dominant *** in the atmosphere were concentrated in the small particle size segment(20-50μm).The concentration of MPs in the air mass from marine transport was 14.7 items/m^(3)-lower than that from terrestrial transport(32.0 items/m^(3)).The number concentration of airborne MPs was negatively correlated with relative *** from terrestrial transport were mainly rubber(20.2%),while those from marine transport were mainly PFR(18%).MPs in the marine transport air mass were more aged and had a lower number concentration than those in the terrestrial transport air *** number concentration of airborne MPs is higher during the day than at *** findings could contribute to the development of targeted control measures and methods to reduce MP pollution.

关键词： Airborne microplastics(MPs) Laser direct infrared imaging(LDIR) Polarized light microscopy Terrestrial transport marine transport Relative humidity

Near-perfect replication on amorphous alloys through active force modulation based on machine learning/neural network parameter prediction

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Science China(Physics,Mechanics & Astronomy) 2025年第1期68卷 177-187页

作者： Senkuan Meng Zheng Wang Ruisong zhu Ruijie Liu Jiang ma Lina Hu Weihua Wang Key Laboratory for Liquid-Solid Structural Evolution and Processing of materials(Ministry of Education) School of Materials Science and EngineeringShandong UniversityJinan 250061China College of Mechatronics and Control Engineering Shenzhen UniversityShenzhen 518060China Songshan Lake materials Laboratory Dongguan 523808China Institute of Physics Chinese Academy of SciencesBeijing 100190China

As a microforming technique,micro/nano-structural replication possesses advantages of high precision and *** the remarkable superplasticity in the supercooled liquid region,amorphous alloys or metallic glasses(MGs)are regarded as ideal materials for miniature ***,due to the intrinsic metastable nature of supercooled liquids,the design of imprinting processes for MGs poses a *** the past,process parameters have largely relied on trial-and-error *** this work,a low-frequency active force modulation system is employed to apply a stable,precise,and real-time feedback stress field for imprinting of MG ***-frequency vibrations can facilitate the filling of microstructures on the template surface by reducing the effective viscosity of the supercooled *** the dataset composed of orthogonal experiments,a machine learning strategy based on back-propagation(BP)neural networks was utilized to construct a 3D parameter space for temperature,stress,and time,and to predict the corresponding filling ***,the optimal combination of imprinting process parameters was identified,and its filling ratio was experimentally validated to reach as high as *** near-perfect replication of microstructures confirms the superiority of the active force modulation system and the data-driven strategy of machine learning-assisted parameter *** the same time,this one-step microforming process provides a new approach to addressing the accuracy-cost trade-off dilemma in precision manufacturing.

关键词： metallic glass amorphous alloy microforming imprinting machine learning

Buried interface bridging for inverted cesium-formamidinium triiodide perovskite solar cells with long operational stability

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Science China Chemistry 2025年第1期68卷 163-173页

作者： Chenhui Zhang Chunjun Liang Fulin Sun Ting zhu Xinghai Huang Yuzhu guo Xinyu guo Kunyang Ge Dan Li Fangtian You Zhiqun He Key Laboratory of Luminescence and Optical Information Ministry of EducationInstitute of Optoelectronic TechnologyBeijing Jiaotong UniversityBeijing 100044China Department of Physics School of Physical Science and EngineeringBeijing Jiaotong UniversityBeijing 100044China

In the field of perovskite solar cells(PSCs),the research on defects in the buried interface has been relatively limited due to its non-exposure;however,this interface significantly impacts the performance enhancement of inverted *** study employs phenylethylammonium chloride(PEACl)molecules as a buffer layer to modify the buried interface of p-i-n structured PSCs,aiming to enhance the uniformity of self-assembled monolayers(SAMs)and facilitate the uniform nucleation and growth of perovskite films on the ***,the introduction of the PEACl buffer layer effectively passivates defects at the bottom of the perovskite layer and notably enhances the crystal quality of the perovskite film by mitigating residual stress,thereby reducing nonradiative recombination *** these optimizations,the ma-free PSCs treated with PEACl achieve a power conversion efficiency(PCE)of 24.11%,with significant improvements in storage,thermal stability,and operational *** noteworthy is the device's performance in an unencapsulated state,whereas after 1,500 hours of continuous light operation stability testing,it retains 97%of its original *** study not only enriches the systematic understanding of the characteristics of the buried interface in PSCs but also contributes significantly to advancing the commercial production of perovskite photovoltaic technology.

关键词： defect-induced recombination buried interfaces inverted perovskite solar cells crystallization lattice mismatch