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Experimental Study on Cooling Down Process of a Nitrogen-Charged Cryogenic Loop Heat Pipe

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Journal of Thermal Science 2023年第1期32卷 153-165页

作者： ZHAO ya'nan yan Tao LIANG Jingtao Key Laboratory of Space Energy Conversion Technology Technical Institute of Physics and ChemistryChinese Academyof SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Cryogenic loop heat pipes are highly efficient heat transfer devices at cryogenic temperature range,which have promising application prospects in satellites,spacecrafts,electronics,and so *** down process is a most critical process for a CLHP before *** present,secondary loop is a major way for a CLHP to fulfil cooling down and most studies are concentrated on heat transfer characteristics during normal ***,few investigations have been carried out on the cooling down *** this paper,the cooling down process of a nitrogen-charged CLHP assisted with a secondary loop was experimentally investigated.A simple qualitative approach to estimate the cooling down time was proposed according to the law of conservation of *** two flow paths of the working fluid in the CLHP during the cooling down process were *** studies on the cooling down process with various secondary heat loads and working fluid inventory were presented in *** the increase of secondary heat load,the elapsed time of Stage III decreased significantly due to the larger mass flow rate in Path *** addition,the effect of the working fluid inventory on the cooling down time was generally small in the range from 2.99 MPa to 3.80 ***,with 2.80 MPa working fluid inventory,it required much longer cooling down time,which was because of the lack of liquid in the CLHP with low working fluid ***,the influence of gravity on the temperature variation of the components during the experiments was *** work is beneficial for better understanding of the cooling down process and optimizing of CLHPs.

关键词： cryogenic loop heat pipe secondary loop cooling down heat transfer

Characterization and mechanism of dissolution behavior of Al_(2)O_(3)/MgO oxides in molten slags

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Journal of Iron and Steel Research International 2022年第11期29卷 1711-1722页

作者： yan-zhu Huo Hua-zhi Gu Ao Huang Bei-yue Ma Liu-gang Chen Guang-qiang Li ya-wei Li The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina Henan Key Laboratory of High Temperature Functional Ceramics Zhengzhou UniversityZhengzhou 450001HenanChina

Al_(2)O_(3)-and MgO-based oxides are among the most common oxides in the steelmaking *** exist as the main components of refractories,inclusions,or ***_(2)O_(3)-and MgO-based oxides interact with molten slags continuously during the steel smelting process,which may lead to the dissolution and absorption of the oxides by molten slags,or reactions between oxides and molten slags to form intermediate *** the dissolution behavior of Al_(2)O_(3)-and MgO-based oxides in molten slags is important for prolonging the service life of refractories and removing inclusions in molten ***,Al_(2)O_(3)-and MgO-based oxides are considered,and the test methods,dissolution mechanisms,and influencing factors are comprehensively introduced,which can provide a foundation for refractories wear and high-quality steel smelting.

关键词： Al_(2)O_(3)/MgO oxide Slag corrosion Refractory wear Inclusion Dissolution mechanism

On Connected Components of Skew Group Algebras

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Acta Mathematica Sinica,English Series 2023年第5期39卷 799-813页

作者： Jian Min CHEN qiang DONG ya Nan LIN School of Mathematical Sciences Xiamen UniversityXiamen 361005P.R.China

Let A be a basic connected finite dimensional associative algebra over an algebraically closed field k and G be a cyclic *** is a quiver QGwith relationsρG such that the skew group algebras A[G]is Morita equivalent to the quotient algebra of path algebra kQGmodulo ideal(ρG).Generally,the quiver QGis not *** this paper we develop a method to determine the number of connect components of ***,we introduce the notion of weight for underlying quiver of A such that A is G-graded and determine the connect components of smash product A#kG*.

关键词： Smash product skew group algebra n-translation algebra path algebra connected component

高光谱预处理方法与多模型在分类判别中的对比研究

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光谱学与光谱分析 2025年第1期45卷 125-132页

作者：居雷于洁吴炎淼李丽卢天丁亚萍束茹欣上海烟草集团有限责任公司技术中心上海200082 上海大学化学系上海200444 上海数之微信息科技有限公司上海200444

高光谱技术能够快速、无损地获取丰富的信息,在植物研究和监测中已成为一种广泛应用的工具。茄科植物作为一种重要的经济农作物,与高光谱技术结合进行研究具有巨大的应用潜力。本研究采用高光谱技术对茄科植物的初烤后不同部位叶片进行... 详细信息

高光谱技术能够快速、无损地获取丰富的信息,在植物研究和监测中已成为一种广泛应用的工具。茄科植物作为一种重要的经济农作物,与高光谱技术结合进行研究具有巨大的应用潜力。本研究采用高光谱技术对茄科植物的初烤后不同部位叶片进行分类研究。采用Field Spec 3光谱辐射仪对293份不同部位的茄科植物粉末样本进行高光谱采样,采用S-G平滑以及一阶导数和二阶导数的方法对数据进行预处理,用于信息增强和去除噪声,并通过偏最小二乘法对数据进行降维,以减少冗余特征。基于降维数据,采样支持向量机、逻辑回归、K近邻、决策树、随机森林和梯度提升决策树这六种机器学习算法建立分类模型。结果显示,在分类任务中,经过一阶导数处理后,支持向量机模型最佳,在训练集和测试集上分别实现了100.0%和84.7%的准确率。经网格参数优化后确定最优参数为:最大深度不限制,最小样本分割数为4,估计器数量为200。参数优化后五折交叉验证准确率为88.1%,训练集准确率为100%,测试集准确率为86.4%。研究结果表明,预处理方法结合降维方法能够增强数据信息使得分类模型能够更好地捕捉茄科植物样本的特征。该研究对于快速、准确、无损地区分茄科植物的部位具有重要意义。

关键词：高光谱部位分类机器学习

Screening of plane S waves by an array of rigid piles in poroelastic soil

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第5期9卷 589-599页

作者： Yuan-qiang CAI Guang-ya DING Chang-jie XU MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang Universiry Hangzhou 310027 China College of Architecture and Civil Engineering Wenzhou University Wenzhou 325035 China

An array of rigid piles used as a screening barrier for plane shear (S) waves is investigated in a homogeneous unbounded space. The dynamic poroelastic theory of Biot is employed, under the assumption of an incompressible solid grain. Using Fourier-Bessel series, the problem of multiple scattering is solved by imposing continuity conditions and equilibrium conditions at the soil-pile interfaces with the translational addition theorem. A parametric analysis is conducted to investigate the influence of the permeability of poroelastic soil, separation between piles, number of piles and frequency of incident waves on screening effectiveness of the barrier, and the results are compared with those in an elastic soil medium. Computed results show that the intrinsic permeability of the soil medium displays an apparent effect on the screening of plane S waves.

关键词： Array of rigid piles Poroelastic soil Theory of Biot Scattering Screening effectiveness

Towards direct superlubricity and superlow wear via amino modification of polyhydroxy alcohol solutions

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Friction 2024年第9期12卷 1980-1990页

作者： qiang MA Chengpeng yan Rui yan Xin XU Haifeng WANG State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi'an 710072China Chongqing Innovation Center Northwestern Polytechnical UniversityChongqing 401135China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518063China

Friction remains as the primary mode of energy dissipation and components wear,and achieving superlubricity shows high promise in energy conservation and lifetime wear *** results in this work demonstrate that direct superlubricity combined with superlow wear can be realized for steel/Si_(3)N_(4)contacts on engineering scale when polyhydroxy alcohol solution was selectively modified by amino *** direct superlubricity occurs because 3-amino-1,2-propanediol molecules at the friction interface could be induced to rotate and adsorb vertically on the friction surface,forming in-situ thick and dense molecular films to passivate the asperity ***,amino modification is also conducive to improving the lubrication state from boundary to mixed lubrication regime by strengthening the intermolecular hydrogen bonding interaction,presenting enhanced load-bearing capability and reduced direct solid asperity ***,direct superlow average friction of 0.01 combined with superlow wear are achieved *** design principle of direct superlubricity and superlow wear in this work indeed offers an effective strategy to fundamentally improve energy efficiency and provide lifetime wear protection for moving mechanical assemblies.

关键词： direct superlubricity amino modification molecular layer superlow wear

Effects of oceanic ice cover and density stratification on the propagation of hydroacoustic waves

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Journal of Hydrodynamics 2022年第6期34卷 1151-1155页

作者： ya-dong Liu Dong-qiang Lu Ming-song Zou Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai UniversityShanghai200072China China Ship Scientific Research Center Wuxi214082China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai200072China

The propagation characteristic of hydroacoustic waves is studied for an ideal compressible two-layer fluid with different densities covered by an elastic ice *** conditions are simplified by adopting linear assumption and then the dispersion relation is *** analysis and visualization of the dispersion relation present the introduction of compressibility leads to the appearance of hydroacoustic wave modes while the density stratification leads to the appearance of interfacial wave *** ice thickness and the density ratio of the two fluid layers increase the wave number and group speed of hydroacoustic waves at the same frequency while the phase speed decreases.

关键词： Ocean ice sheet density stratified fluid hydroacoustic propagation

Multilinear Singular Integral Operators with Generalized Kernels and Their Multilinear Commutators

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Acta Mathematica Sinica,English Series 2017年第11期33卷 1443-1462页

作者： yan LIN ya Yuan XIAO School of Sciences China University of Mining and Technology Department of Mathematical Sciences Ball State University

In this paper, the authors study a class of multilinear singular integral operators with generalized kernels and their multilinear commutators with BMO functions. By establishing the sharp maximal estimates, the boundedness on product of weighted Lebesgue spaces and product of variable exponent Lebesgue spaces is obtained, respectively. Moreover, the endpoint estimate of this class of mutilinear singular integral operators is also established. These results can improve the corresponding known results of classical multilinear Calder6n-Zygmund operators and multilinear Calderon-Zygmund operators with Dini type kernels.

关键词： Multilinear singular integral sharp maximal function multilinear commutator BMO function

Bi-extrapolated subgradient projection algorithm for solving multiple-sets split feasibility problem

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Applied Mathematics(A Journal of Chinese Universities) 2014年第3期29卷 283-294页

作者： DANG ya-zheng GAO yan College of Computer Science and Technology (Software College) Henan Polytechnic University School of Management University of Shanghai for Science and Technology

This paper deals with a bi-extrapolated subgradient projection algorithm by intro- ducing two extrapolated factors in the iterative step to solve the multiple-sets split feasibility problem. The strategy is intend to improve the convergence. And its convergence is proved un- der some suitable conditions. Numerical results illustrate that the bi-extrapolated subgradient projection algorithm converges more quickly than the existing algorithms.

关键词： Multiple-sets split feasibility problem subgradient accelerated iterative algorithm convergence.