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旋流泵叶轮位置对性能影响与无叶腔流场测定

农业机械学报 2010年第11期41卷 57-62页

作者：沙毅侯丽艳浙江科技学院机械与汽车工程学院杭州310023 江苏大学能源与动力工程学院镇江212013

以研制32WB8-12型旋流泵为试验样机,通过改变叶轮轴向位置的外特性试验,得出泵qv-H、qv-P、qv-η和qv-NPSHc性能曲线变化规律;同时用5孔球形探针对泵无叶腔流场进行测量,得到流场5个测点绝对速度v、圆周速度vu、径向速度vr、轴向速度vz... 详细信息

以研制32WB8-12型旋流泵为试验样机,通过改变叶轮轴向位置的外特性试验,得出泵qv-H、qv-P、qv-η和qv-NPSHc性能曲线变化规律;同时用5孔球形探针对泵无叶腔流场进行测量,得到流场5个测点绝对速度v、圆周速度vu、径向速度vr、轴向速度vz和静压ps变化情况。试验结果证明旋流泵qv-NPSHc曲线小流量范围与离心泵等呈相反趋势;随着叶轮伸入无叶腔尺度S的加大,泵扬程、效率和抗汽蚀性能均有提高。分析表明:无叶腔轴向旋涡运动为主流,存在回流运动;解释了外特性与内部流动参数之间的转化和因果关系;阐明旋流泵抽吸及扬程形成的原理。

关键词：旋流泵叶轮位置流场特性汽蚀余量

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叶片厚度对轴流泵性能影响及内部流场分析

农业工程学报 2012年第18期28卷 75-81,F0003,F0004页

作者：沙毅侯丽艳浙江科技学院机械与汽车工程学院杭州310023 烟台冰轮股份有限公司烟台264000

为研究叶片厚度对轴流泵性能影响及其内部流场变化规律,该文采用圆弧法和流线法进行比转速550、转速2900r/min的QY90-4.4-1.5型潜水轴流泵水力模型设计,完成产品开发及样机型式试验。通过加厚叶轮叶片进行对比试验,阐明泵流量—扬程、... 详细信息

为研究叶片厚度对轴流泵性能影响及其内部流场变化规律,该文采用圆弧法和流线法进行比转速550、转速2900r/min的QY90-4.4-1.5型潜水轴流泵水力模型设计,完成产品开发及样机型式试验。通过加厚叶轮叶片进行对比试验,阐明泵流量—扬程、流量—轴功率和流量—效率曲线产生差别的原因。采用计算流体动力学(CFD)方法进行叶片厚度对流场影响的数值计算,得到最优工况叶片表面相对速度分布和不同工况叶片表面静压分布。经过分析,阐明薄叶片总体性能优于厚叶片,但抗汽蚀性能可能劣于厚叶片。厚叶片翼型脱流、叶片进出口出现回流及二次流情况更为严重,水力损失较大,是泵效率等性能参数偏低的主要原因。

关键词：水力模型流场流量轴流泵叶片厚度性能试验计算流体动力学

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管理工具定义困境的哲学之思

学术交流 2016年第3期 49-54页

作者：侯丽岩黑龙江大学政府管理学院哈尔滨150080 佳木斯大学商学院黑龙江佳木斯154002

管理工具的"繁荣"是一种表面乱象,管理工具的概念"黑箱化"。管理工具定义困境主要表现为技术单维之困和泛化无界之困。其主要根源囿于管理学研究视角的科学主义认识论与方法论。只有借助于哲学的反思、批判和超越的精神力量,透过纷繁复... 详细信息

管理工具的"繁荣"是一种表面乱象,管理工具的概念"黑箱化"。管理工具定义困境主要表现为技术单维之困和泛化无界之困。其主要根源囿于管理学研究视角的科学主义认识论与方法论。只有借助于哲学的反思、批判和超越的精神力量,透过纷繁复杂和扑朔迷离的管理工具现象,反思管理工具的本体性问题。在管理哲学视阈下,在事实与价值相统一的有效机制内,在"道""术"有机结合的"场域"内诠释管理工具的概念,是思考走出和超越管理工具定义困境之理路。

关键词：管理工具定义困境管理哲学有效机制

NADPH oxidase contributes to learning and memory deficits in a mouse model of Parkinson's disease

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Preparation of Laser Cladding Coating Undercooling Cu-based Alloy and Co on Non-equilibrium Solidification Structure

中国毒理学会第七次全国会员代表大会暨中国毒理学会第六次中青年学者科技论坛

作者： Fuqiang Sun liyan hou Yuning Che Lin Zhang Qingshan Wang School of Public Health Dalian Medical University Academy of Integrative Medicine Dalian Medical University

Background: Aside from classical motor deficits, Parkinson’s disease(PD) patients also experience various nonmotor symptoms, including cognitive deficits. We previously reported that the activation of NADPH oxidase contributes to dopaminergic neurodegeneration and motor deficits in PD. However, whetherNADPH oxidase is involved in non-motor symptoms, especially cognitive dysfunction in PD remains unknown. This study is undertaken to characterize the effects of inhibition of NADPH oxidase by a widely used NADPH oxidase inhibitor apocynin on learning and memory deficits in paraquat and maneb(P+M)-induced mouse PD ***: Three-month old mice were randomly divided into 4 groups, i.e. control, P+M,apocynin+P+M and apocynin alone groups. Mice in P+M group were administrated with combined paraquat(P, 10 mg/kg) and maneb(M, 30 mg/kg) for consecutive 6 weeks(twice per week).Mice in apocynin+P+M group were received with apocynin(1 mg/ml in drinking water) 2 days before P+M treatment. Learning and memory performance was measured by using Morris Water Maze test. Neuroinflammation, oxidative stress, and neuronal death in mice brains were measured by using immunohistochemistry, qPCR or Western blots ***: We found that mice injected with P+M displayed progressive impairments of spatial learning and memory, which was associated with reduced tyrosine hydroxylase expression as well as increased neurodegeneration, synaptic loss, α-synuclein expression and Ser129-phosphorylation in the hippocampus. Interestingly, apocynin treatment significantly ameliorated learning and memory deficits as well as hippocampal neurodegeneration and α-synuclein pathology in mice treated with these two pesticides. Mechanistically, we found that apocynin mitigated P+M-induced NADPH oxidase activation and related oxidative stress. Furthermore, reduced microglial activation and M1 polarization were observed in apocynin+P+M co-treated mice compared with P+M alone group. Finally, apocynin inhi

关键词： Parkinson’s disease Nonmotor symptoms Cognitive deficits NADPH oxidase Neuroinflammation

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Journal of Wuhan University of Technology(Materials Science) 2024年第2期39卷 463-472页

作者：田徐铭 CAO Shichao hou Kai hou Xiaopeng WANG Hongfu 张煜 Department of Outpatient Xinzhou People’s HospitalXinzhou 034099China School of Mechanical Engineering North University of ChinaTaiyuan 030051China Department of Neurosurgery Xinzhou People’s HospitalXinzhou 034099China Department of Orthopedics Xinzhou People’s HospitalXinzhou 034099China

The effect of the gradient content of Co element on the solidification process of Cu-based alloy under deep under cooling conditions was *** non-equilibrium solidification structure of the under cooled alloy samples were *** is found that the rapidly solidified alloy has undergone twice grain refinement during the undercooling *** and significance of the maximum undercooling refinement structure of Cu60Ni35Co5 at T=253 K were ***-density defects were observed,such as dislocations,stacking faults networks,and twinning *** standard FCC diffraction pattern represents that it is still a single-phase *** on the metallographic diagram,EBSD and TEM data analysis,it is illustrated that the occurrence of grain refinement under high undercooling is due to stress induced *** addition,the laser cladding technology is used to coat Co-based alloy(Stellite12) coating on 304 stainless steel substrate;the microstructure of the coating cross-section was *** was found that the microstructure of the cross-section is presented as columnar crystals,planar crystals,and disordered growth direction,so that the coating has better hardness and wear *** electrochemical corrosion of the substrate and coating,it can be seen that the Co and Cr elements present in the coating are more likely to form a dense passivation film,which improved the corrosion resistance of the coating.

关键词： non-equilibrium solidification structure undercooling recrystallization laser cladding coating

Integral Operators Between Fock Spaces

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Chinese Annals of Mathematics,Series B 2024年第2期45卷 265-278页

作者： Yongqing LIU Shengzhao hou School of Mathematics and Statistics Changshu Institute of TechnologySuzhou 215006JiangsuChina School of Mathematical Sciences Soochow UniversitySuzhou 215006JiangsuChina

In this paper,the authors study the integral operator■induced by a kernel functionφ(z,·)∈F_α~∞between Fock *** 1≤p≤∞,they prove that S_φ:F_α^(1)→F_α^(p)is bounded if and only if■where k_(a)is the normali... 详细信息

关键词： Fock spaces Integral operators Normalized reproducing kernel

In-Plane Dynamic Crushing Behaviors of a Vertex-Based Hierarchical Auxetic Honeycomb

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Acta Mechanica Solida Sinica 2024年第1期37卷 53-62页

作者： Yichen Zan Xiuhui hou Zichen Deng School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi'an 710072China MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical UniversityXi'an 710072China School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of TechnologyDalian 116024China

Auxetic metamaterials,which exhibit the negative Poisson’s ratio(NPR)effect,have found wide applications in many engineering ***,their high porosity inevitably weakens their bearing capacity and impact *** improve the energy absorption efficiency of auxetic honeycombs,a novel vertex-based hierarchical star-shaped honeycomb(VSH)is designed by replacing each vertex in the classical star-shaped honeycomb(SSH)with a newly added self-similar *** analytical model is built to investigate the Young’s modulus of VSH,which shows good agreement with experimental results and numerical *** in-plane dynamic crushing behaviors of VSH at three different crushing velocities are investigated,and empirical formulas for the densification strain and plateau stress are *** results reveal more stable deformation modes for VSH,attributed to the addition of self-similar star-shaped ***,compared with SSH under the same relative densities,VSH exhibits better specific energy absorption and higher plateau ***,VSH is verified to be a better candidate for energy absorption while maintaining the auxetic *** study is expected to provide a new design strategy for auxetic honeycombs.

关键词： Vertex-based hierarchical star-shaped honeycomb Auxetic honeycomb Energy absorption Plateau stress Negative Poisson's ratio

An Improved Method for Approximating the Infinite-Horizon Value Function of the Discrete-Time Switched LQR Problem

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Journal of Systems Science & Complexity 2024年第1期37卷 22-39页

作者： hou Tan LI Yuanlong LIN Zongli Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of System Control and Information Processing Ministry of Education of ChinaShanghai 200240China Shanghai Engineering Research Center of Intelligent Control and Management Shanghai 200240China Charles L.Brown Department of Electrical and Computer Engineering University of VirginiaCharlottesvilleVA 22904-4743USA

This paper considers the problem of approximating the infinite-horizon value function of the discrete-time switched LQR *** particular,the authors propose a new value iteration method to generate a sequence of monotonically decreasing functions that converges exponentially to the value *** method facilitates us to use coarse approximations resulting from faster but less accurate algorithms for further value iteration,and thus,the proposed approach is capable of achieving a better approximation for a given computation time compared with the existing *** numerical examples are presented in this paper to illustrate the effectiveness of the proposed method.

关键词： Optimal control switched linear systems switched LQR problem.

Theoretical study on the stability of nanobubbles and its verification in molecular dynamics simulation

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Particuology 2024年第4期87卷 99-105页

作者： Sheng Mi Chaofeng hou Wei Ge School of Chemical Engineering and Technology Tianjin UniversityTianjin300072China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing.100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China

The stability of vapor nanobubbles in bulk liquid was investigated theoretically and the critical bubble size was derived from macroscale thermodynamic equations,below which the system destabilizes with sharp drop in *** critical size was quantitatively verified in molecular dynamic simulation using the Lennard-Jones model of argon,where stronger attraction between the molecules at lower density is found to contribute most to the drop of system pressure and,as the Laplace pressure on the curved bubble interface fails to balance the pressure difference across the interface,the bubbles become *** theoretical model could be extended to other systems where reliable equations of state and interfacial tension are available.

关键词： Nanobubble Stability Phase diagram Critical size