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Numerical insight into heat transfer enhancement by granules inner-migration in a moving bed:A performance comparison between slanted-stick and plow-shaped agitator

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Particuology 2024年第6期89卷 109-116页

作者： Binfan Jiang hao Pei Dehong xia Haiyang Wang School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China Shunde Graduate School of University of Science and Technology Beijing Guangdong 528399China Jianlong Group&USTB Joint Laboratory Beijing 100083China

Waste heat recovery of high-temperature granules is one of the most promising sustainable energy supply and carbon reduction ways for industry.A moving bed indirect heat exchanger(MBIHE)with inner-migration was proposed for granular heat *** migration and the enhanced heat transfer induced by two types of agitators(i.e.,agitator with slanted stick A_(s)and with plow-shaped surface A_(p))in the MBIHE are analyzed based on DEM coupled with *** to the effective agitation,the average heat transfer coefficient in the granule side is enhanced to∼3 times compared to that without *** heat recovery efficiency in the moving bed reached more than 70%with the agitations of either A_(s)or A_(p).The heat efficiency of A_(s)is∼7%higher than that of A_(p),but with at least 60%greater rotational *** ensure reliable agitation,the A_(p)is suggested to be adopted in the MBIHE to induce granule migration.

关键词： Waste heat recovery High-temperature granule Granule migration Heat transfer enhancement Industry energy saving

Optimization of extraction method for quantitative analysis of Si/Al in soil phytoliths

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Acta Geochimica 2023年第6期42卷 1007-1016页

作者： Yongsheng chu Yue xia xiaoying Li Fushun Wang School of Environmental and Chemical Engineering Shanghai University99 Shangda RoadBaoshanP.O.Box 144Shanghai 200433China

Elemental information carried by phytoliths plays a crucial indicative role in geochemical *** instance,it serves as an indicator of the carbon pool effect in phytoliths and aids in the elucidation of silicon ***,early extraction methods for soil phytoliths primarily focused on obtaining their morphological and quantitative information,lacking efficient techniques for quantitative elemental *** this study,we aimed to extract Si/Al information from soil *** the need for complete extraction of phytolith,six extraction methods were developed and further by alkaline dissolution to determine Si/*** methods were compared in terms of enrichment capacity,the weight of extracted phytoliths,and Si/Al *** results indicated that the addition of Ammonia-Catechol in the commonly used heavy liquid flotation method effectively improved phytolith extraction capability and the accuracy of Si/Al ***,the inclusion of an acetic acid step before alkaline dissolution further removed surface-adsorbed impurities and enhanced the analytical quality of Si/Al in *** comparison of the data in this study with other published data shows that our method is relatively *** improved method proposed in this study can provide a new idea for the quantitative analysis of other elements in soil phytoliths.

关键词： Soil phytolith Extraction method Silica–aluminum ratio Ammonia–Catechol

Identification of differential brain regions in MCI progression via clustering-evolutionary weighted SVM ensemble algorithm

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Frontiers of Computer Science 2021年第6期15卷 165-173页

作者： xia-an BI Yiming XIE hao WU Luyun XU Hunan Provincial Key Laboratory of Intelligent Computing and Language Information Processing Hunan Normal UniversityChangsha 410081China College of Information Science and Engineering Hunan Normal UniversityChangsha 410081China Business School of Hunan Normal University Changsha 410081China

Mild cognitive impairment(MCI)as the potential sign of serious cognitive decline could be divided into two stages,i.e.,late MCI(LMCI)and early MCI(EMCI).Although the different cognitive states in the MCI progression have been clinically defined,effective and accurate identification of differences in neuroimaging data between these stages still needs to be further *** this paper,a new method of clustering-evolutionary weighted support vector machine ensemble(CEWSVME)is presented to investigate the alterations from cognitively normal(CN)to EMCI to *** CEWSVME mainly includes two *** first step is to build multiple SVM classifiers by randomly selecting samples and *** second step is to introduce the idea of clustering evolution to eliminate inefficient and highly similar SVMs,thereby improving the final classification ***,we extracted the optimal features to detect the differential brain regions in MCI progression,and confirmed that these differential brain regions changed dynamically with the development of *** exactly,this study found that some brain regions only have durative effects on MCI progression,such as parahippocampal gyrus,posterior cingulate gyrus and amygdala,while the superior temporal gyrus and the middle temporal gyrus have periodic effects on the *** work contributes to understanding the pathogenesis of MCI and provide the guidance for its timely diagnosis.

关键词： machine learning MCI progression optimal feature extraction differential brain regions functional magnetic resonance imaging

A Correction Factor-Based General Thermal Resistance Formula for Heat Exchanger Design and Performance Analysis

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Journal of Thermal Science 2021年第3期30卷 892-901页

作者： hao Junhong CHEN Qun LI xia Zhao Tian Key Laboratory of Power Station Energy Transfer Conversion and System of Ministry of Education School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing 102206China Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China

Methods for the analysis of heat exchangers with various flow arrangements modeling,design,and performance are essential for heat transfer system modeling and its integration with other energy system *** paper proposes the use of the linear-transfer law for the heat exchanger design and performance analysis as a function of the thermal resistance related to the ratio of a linear temperature difference to the total heat transfer ***,we derived a correction factor that represents the influence of the flow arrangement on the heat transfer performance by the effective thermal conductance,as a function of correction factor,heat transfer coefficient,and surface *** on the effective thermal conductance,we propose the hot-end NTU and cold-end NTU for deriving a standardized and general thermal resistance formula for different types of heat exchangers by the combination of the correction factor with linear-transfer ***,for parallel-flow,cross-flow,and 1-2 Tubular Exchanger Manufacturers Association(TEMA)E shell-and-tube heat exchangers,we derived and obtained alternative correction factor expressions without introducing any *** cases about heat exchanger design and performance analysis show that the calculation processes using the correction factor-based general thermal resistance are straightforward without any iteration and the calculation results are ***,the experimental validation shows that the general thermal resistance formula is appropriate for analyzing the heat transfer *** is,the correction factor-based general thermal resistance formula provides a standardized model for heat exchanger analysis and heat transfer/integrated energy system modeling using the heat current method.

关键词： general thermal resistance formula correction factor heat current model linear-transfer law heat exchanger

Effect of grain boundary on the mechanical behaviors of irradiated metals: a review

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Science China(Physics,Mechanics & Astronomy) 2016年第6期59卷 24-34页

作者： xia Zi xiao Hai Jian chu Hui Ling Duan State Key Laboratory for Turbulence and Complex System Department of Mechanics and Engineering Science College of EngineeringPeking University HEDPS Center for Applied Physics and Technology Peking University Department of Mechanics and Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai University

The design of high irradiation-resistant materials is very important for the development of next-generation nuclear reactors. Grain boundaries acting as effective defect sinks are thought to be able to moderate the deterioration of mechanical behaviors of irradiated materials, and have drawn increasing attention in recent years. The study of the effect of grain boundaries on the mechanical behaviors of irradiated materials is a multi-scale problem. At the atomic level, grain boundaries can effectively affect the production and formation of irradiation-induced point defects in grain interiors, which leads to the change of density, size distribution and evolution of defect clusters at grain level. The change of microstructure would influence the macroscopic mechanical properties of the irradiated polycrystal. Here we give a brief review about the effect of grain boundaries on the mechanical behaviors of irradiated metals from three scales: microscopic scale, mesoscopic scale and macroscopic scale.

关键词： mechanical behaviors irradiation effect grain boundary multi-scale modeling

Dynamic output feedback control of systems with event-driven control inputs

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Science China(Information Sciences) 2020年第5期63卷 24-37页

作者： Jinhui ZHANG hao XU Li DAI Yuanqing xia School of Automation Beijing Institute of Technology

In this paper, a dynamic output feedback control problem is investigated for systems with eventdriven control inputs. With both continuous and sampled output measurements in the systems, two types of dynamic output feedback controllers are designed based on a predefined event-driven scheduler for the control signals, respectively. With the proposed event-driven control scheme, the Zeno behavior can be avoided, and the states of closed-loop systems are also guaranteed to be globally uniformly ultimately bounded. Detailed parameters of the event-driven controllers are constructed under the stabilizable conditions of the closedloop systems. Finally, both the effectiveness and merits of the proposed design techniques are verified by the numerical examples.

关键词： networked control systems NCSs event-driven control dynamic output feedback control

春季低温下底质氧化还原电位对沉水植物苦草和菹草生长的影响研究

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环境工程技术学报 2025年第1期15卷 150-157页

作者：杨好郭新超袁静张玉宝储昭升西安建筑科技大学环境与市政工程学院中国环境科学研究院

为研究底质不同氧化还原电位(ORP)条件对沉水植物生长生理的影响,以沉水植物菹草和苦草为研究对象,通过改变底质ORP,分析不同ORP对菹草和苦草株高、鲜重以及生理生化指标的影响。结果表明,当底质ORP大于−70 mV时,有利于苦草和菹草的生长... 详细信息

为研究底质不同氧化还原电位(ORP)条件对沉水植物生长生理的影响,以沉水植物菹草和苦草为研究对象,通过改变底质ORP,分析不同ORP对菹草和苦草株高、鲜重以及生理生化指标的影响。结果表明,当底质ORP大于−70 mV时,有利于苦草和菹草的生长;而当ORP小于−100 mV时,苦草和菹草的生长受到抑制。随着ORP的降低,苦草和菹草株高和鲜重的增长速率减缓,过氧化物酶(POD)活性、丙二醛(MDA)含量升高,总叶绿素含量和可溶性蛋白降低。主成分分析显示,苦草的株高、鲜重及总叶绿素含量与ORP呈显著正相关,POD活性、MDA含量与ORP呈显著负相关。菹草的总叶绿素含量与ORP呈显著正相关,POD活性、MDA含量和及可溶性蛋白含量与ORP呈显著负相关。随着底质厌氧程度增强,对苦草和菹草的胁迫也随之增强,且苦草的耐受性较菹草更差。研究显示,为了恢复沉水植物的生长,应改善底质的氧化还原条件,为沉水植物提供更加适宜的生长环境,以促进湖泊生态系统的稳定发展。

关键词：底质氧化还原电位(ORP) 菹草苦草过氧化物酶(POD) 丙二醛(MDA)

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姜黄素对肝损伤的改善作用及其机制研究进展

中国医院药学杂志 2025年第1期45卷 99-107页

作者：张文君夏江王昊杨硕刘婷朱婷哈尔滨商业大学药学院黑龙江哈尔滨150076 哈尔滨商业大学药物工程技术研究中心黑龙江哈尔滨150076

姜黄素是从姜黄属植物根茎中提取的一种具有丰富生物活性的多酚类天然化合物。该文综述了近年来国内外关于姜黄素治疗不同类型肝损伤的实验研究,探讨了其保肝作用及相关机制。以实验动物肝损伤模型为基础,总结了姜黄素在化学性、药物性... 详细信息

姜黄素是从姜黄属植物根茎中提取的一种具有丰富生物活性的多酚类天然化合物。该文综述了近年来国内外关于姜黄素治疗不同类型肝损伤的实验研究,探讨了其保肝作用及相关机制。以实验动物肝损伤模型为基础,总结了姜黄素在化学性、药物性、酒精性、非酒精性和免疫性诱导的肝损伤模型中的治疗作用,并分析了其改善实验性肝损伤的机制,为深入研究姜黄素在肝损伤保护中的作用提供了参考。

关键词：姜黄素肝损伤抗炎抗氧化作用机制

A Note on Directed Genera of Some Tournaments

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Acta Mathematicae Applicatae Sinica 2018年第3期34卷 478-484页

作者： Jian-bing LIU Rong-xia hao Department of Mathematics Beijing Jiaotong University

An embedding of a digraph in an orientable surface is an embedding as the underlying graph and arcs in each region force a directed cycle. The directed genus is the minimum genus of surfaces in which the digraph can be directed embedded. Bonnington, Conder, Morton and McKenna [J. Cornbin. Theory Ser. B,85（2002） 1-20] gave the problem that which tournaments on n vertices have the directed genus [（n-3）（n-4）/12]the genus of Kn. In this paper, we use the current graph method to show that there exists a tournament, whichhas the directed genus[（n-3）（n-4）/12], on n vertices if and only if n = 3 or 7 （mod 12）.

关键词： digraph directed embedding directed genus surfaces