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Mechanical,Microstructural and Tribological Properties of Reactive Magnetron Sputtered Cr-Mo-N Films

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Journal of Materials Science & Technology 2015年第1期31卷 55-64页

作者： Dongli qi Hao Lei Tiegang Wang Zhiliang pei Jun Gong Chao Sun Surface Engineering of Materials Division Institute of Metal ResearchChinese Academy of Sciences

The Cr-Mo-N films were deposited on high speed steel（HSS） substrates by a DC reactive magnetron sputtering equipment coupled with two horizontal magnetron *** effects of substrate negative bias voltage（Vb）,substrate temperature（Ts） and gas flow ratio（R= N2/（N2+ Ar）） on the microstructure,morphology,as well as the mechanical and tribological properties of the Cr-Mo-N films were investigated by virtue of X-ray diffraction（XRD） analysis,X-ray photoelectron spectroscopy（XPS）,field emission scanning electron microscopy（FESEM）,atomic force microscopy（AFM）,nano-indentation test,ball-on-disk tribometer,and Rockwell indenter et *** increasing Vbto-100 V,the preferred orientation of the films changed from（111） to（200） and their mechanical and tribological properties were improved gradually,*** was also found that Tsgave a significant effect on mechanical property *** the Tsreached 300 ℃,the film obtained the highest hardness and effective elastic modulus of approximately 30.1 and 420.5 GPa,respectively and its critical load increased to about 54 *** increasing R,the phase transformation from body-centered-cubic（bcc） Cr and hexagonal CrMoNxmultiphase to single face-centered-cubic（fcc） solid solution phase was *** correlations between values of hardness（H）,effective elastic modulus（E*）,HIE*,H3/E*2,elastic recovery（1/14） and tribological properties of the films were also *** results showed that the elastic recovery played an important role in the tribological behavior.

关键词： Cr-Mo-N films DC magnetron sputtering Hardness Cri

Ballistic Performance and Damage Characteristics of Chemical Vapor Infiltration Quasi 3D-Cf/SiC Composites

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Journal of Wuhan University of Technology(Materials Science) 2016年第1期31卷 118-122页

作者：何旭道程兴旺 wang qi wang pei National Key Laboratory of Science and Technology on Materials under Shock and Impact Beijing Institute and Technology Beijing 100081 China

To investigate the ballistic performance and damage characteristics of quasi threedimensional（3D） needle-punched Cf/SiC composites prepared by chemical vapor infiltration（CVI）,penetration experiments were conducted by using 7.62 mm armor piercing incendiary（API）.Macro and micro fracture morphologies were then observed on recycled *** results show that the protection coefficient of 3D Cf/SiC composites is *** porosity and many micro thermal stress cracks may directly lead to the lower ballistic *** fracture morphology was observed on the crater *** low dynamic fracture strength along layer direction may be attributed to the voids and microcracks caused by residual thermal *** damage characteristics of Cf/Si C composites include matrix cracking,fiber bundle cracking,interfacial debonding,fiber fracture,and fiber bundle *** interfacial debonding and fiber fracture may play major roles in energy absorption.

关键词： CVI-Cf/SiC composites material ballistic performance damage characteristics

Antagonizing Aspergillus parasiticus and Promoting Peanut Growth of Bacillus Isolated from Peanut Geocarposphere Soil

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Journal of Integrative Agriculture 2014年第11期13卷 2445-2451页

作者： XIAO Wei YAN pei-sheng WU Han-qi LIN Feng School of Marine Science and Technology Harbin Institute of Technology

A set of 38 Bacillus strains isolated from peanut geocarposphere soil were screened as potential biological control agent anti-Aspergillus parasiticus. Tip-culture method with rapid and quantitative characteristics was used to determine anti-A. parasiticus activity and the process of isolation could be accelerated with this method. 12 out of 38 Bacillus strains showed high anti-alfatoxin production activity. These 12 Bacillus strains were selected to identify the characteristics of promoting peanuts germination rate. Pot experiment in greenhouse was carried out by using these strains which can promote peanuts germination. Phytohormones in the fermentation broth were also detected as another important reference factor to select the isolates as biological control agent with PGPR features. These Bacillus strains isolated from peanut geocarposphere soil not only had high ability anti-Aspergillus parasiticus, but also promoted peanut growth. Therefore, these Bacillus strains were well adapted to peanut production in the ifeld as biological control agent with plant growth promoting rhizobacteria （PGPR） features.

关键词： Bacillus strains anti-Aspergillus parasiticus PGPR features peanut

Development of a preliminary slope stability calculation method based on internal horizontal displacements

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Journal of Mountain Science 2018年第5期15卷 1129-1136页

作者： pei Hua-fu ZHANG Si-qi BORANA Lalit YUAN Bing Department of Geotechnical Engineering Dalian University of Technology Dalian 116024 China Department of Civil Engineering Indian Institute of Technology Indore Indore 453552 India. Shenzhen Graduate school Harbin Institute of Technology Shenzhen 518055 China

This paper proposes a horizontal displacement-based approach to determine the potential slip surface of the slope. Firstly, a group of in-situ inclinometers with an appropriate spacing in the horizontal direction is located in the model *** equation of horizontal displacement with time for each in-situ inclinometer is fitted during the whole simulation process. Furthermore, the intersection of each inclinometer with potential slip surface is determined by using an optimization model. The slip surface can be obtained by using least square fitting method. Finally, the feasibility and accuracy of the method are validated by a series of numerical simulations. It is noted that the optimization model taking the maximum value of displacement increment gradient as an objective has higher accuracy when compared with other optimization models. This method employed in this study provides a preliminary approach to determine the real-time slope stability based on displacement, which can also be measured by using conventional instruments on site.

关键词： Slip surface Slope stability analysis Optimization model Numerical simulation Displacement.

一种基于RBAC的国土调查数据访问控制模型

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地理空间信息 2025年第1期23卷 17-20,33页

作者：祁琼张莉裴利利张斌湖北省空间规划研究院湖北武汉430071 松滋市自然资源和规划局湖北松滋434200 武汉大学资源与环境科学学院湖北武汉430079

对事前防范访问控制进行了研究,提出了针对国土调查数据的访问控制模型(LSD-RBAC)。该模型对RBAC模型进行空间重定义,对主客体进行时空扩展。结合国土调查数据的移动应用场景,关注主体的移动特征;在权限中扩展了时空范围、要素图层、属... 详细信息

对事前防范访问控制进行了研究,提出了针对国土调查数据的访问控制模型(LSD-RBAC)。该模型对RBAC模型进行空间重定义,对主客体进行时空扩展。结合国土调查数据的移动应用场景,关注主体的移动特征;在权限中扩展了时空范围、要素图层、属性特征等约束,支持细粒度的访问控制。根据LSD-RBAC模型和国土调查数据的访问控制过程,设计并实现了移动环境下访问控制系统。结果表明,LSD-RBAC模型能完成多条件约束下的国土调查数据访问控制。

关键词：空间数据处理国土调查数据访问控制

维普期刊数据库博看期刊

Vibration Response and Stress Analysis of Planar Elastic Tube Bundle Induced by Fluid Flow

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Chinese Journal of Mechanical Engineering 2018年第2期31卷 89-96页

作者： De-Rong Duan pei-qi Ge Wen-Bo Bi Yan-Ying Dong School of Mechanical Engineering Shandong University Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education Shandong University

Flow?induced vibration plays a positive role on heat transfer enhancement. Meanwhile, it is also a negative factor for fatigue strength. Satisfying the fatigue strength is the primary prerequisite for heat transfer enhancement. This paper numerically studied the flow?induced vibration of planar elastic tube bundle based on a two?way fluid–structure interaction(FSI) calculation. The numerical calculation involved the unsteady, three?dimensional incompressible governing equations solved with finite volume approach and the dynamic balance equation of planar elastic tube bundle solved with finite element method combined with dynamic mesh scheme. The numerical approach was verified by comparing with the published experimental results. Then the vibration trajectory, deformation and stress contour of planar elastic tube bundle were all studied. Results show that the combined movement of planar elastic tube bundle represents the agitation from inside to outside. The vibration of out?of?plane is the main vibration form with the typically sinusoidal behavior because the magnitude of displacement along the out?of?plane direction is the 100 times than the value of in?plane direction. The dangerous point locates in the innermost tube where the equivalent stress can be utilized to study the multiaxial fatigue of planar elastic tube bundle due to the alternating stress concentration. In the velocity range of 0.2-3 m/s, it is inferred that the vibration amplitude plays a role on the stress response and the stress amplitude is susceptible to the fluid velocity. This research paves a way for studying the fatigue strength of planar elastic tube bundle by flow?induced vibration.

关键词： Flow?induced vibration Planar elastic tube bundle Vibration response Stress analysis

Rietveld quantification of γ-C_2S conversion rate supported by synchrotron X-ray diffraction images

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第11期14卷 815-821页

作者： Pi-qi ZHAO Xian-ping LIU Jian-guo WU pei-ming WANG School of Materials Science and Engineering Tongji University Key Laboratory of Advanced Civil Engineering Materials (Tongji University) Ministry of Education

The pure γ-Ca2SiO4 （]t-C2S） phase was prepared at 1623 K of calcining temperature, 10 h of holding time and furnace cooling. The 13-C2S phase was obtained through γ-C2S conversion with the following calcination system which was adopted at 1473 K of calcining temperature, 1 h of holding time and then water-cooling. The conversion rate of γ-C2S was studied by the Rietveld quantitative laboratory X-ray powder diffraction supported by synchrotron X-ray diffraction images. The refinement results show that the final conversion rate of γ-C2S is higher than 92%. The absolute error of the γ-C2S conversion rate between two Rietveld refinements （sample with or without α-Al2O3） is 3.6%, which shows that the Rietveld quantitative X-ray diffraction analysis is an appropriate and accurate method to quantify the γ-C2S conversion rate.

关键词： β-C28 γ-C28 Rietveld quantification Synchrotron X-ray diffraction image

Ageing Hardening Mechanism and Corrosion Resistance in the Fe65Cr13Cu3(CoMnMoNiAlTi)19 Medium-Entropy Stainless Alloy

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Acta Metallurgica Sinica(English Letters) 2021年第11期34卷 1601-1608页

作者： Ben-qi Xu Hui Zhang Dong Ma Qun-Shuang Ma Li-Zhai pei Key Laboratory of Green Fabrication and Surface Technology of Advanced Metal Materials(Ministry of Education) Anhui University of Technology243002Ma'anshanChina School of Materials Science and Engineering Anhui University of TechnologyMa'anshan 243002China

The ageing hardening mechanism of a newly designed Fe65Cr13Cu3(CoMnMoNiAlTi)19 medium-entropy stainless alloy(ME-SA)with a simple bcc solid solution matrix was *** kind of ME-SA possessed a higher ageing hardness of approximately 584 HV and higher compressive stress and corrosion resistance than those of the conventional precipitation hardening stainless steel 17-4 PH(Cr17Ni4Cu4 Nb),which has comparable compressive *** well-dispersed B2-ordered phase in the cast state transformed to a D03 crystal structure with a higher ordering degree and reduced the precipitate size after ageing at 500℃,thus promoting a great ageing hardening effect.

关键词： Medium-entropy stainless alloy Ordered phase transition Aging hardening Corrosion resistance

Large eddy simulation of cloud cavitation and wake vortex cavitation around a trailing-truncated hydrofoil

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Journal of Hydrodynamics 2022年第5期34卷 893-903页

作者： Ting-yun Yin Giorgio Pavesi Ji pei Shou-qi Yuan Xing-cheng Gan National Research Center of Pumps Jiangsu UniversityZhenjiang212013China Department of Industrial Engineering University of PaduaPaduaItaly Turbomachinery and Energy Systems Group University of PaduaPaduaItaly

The cavitation has received considerable attention for decades because of its negative influence on the performance and the safety of the hydraulic *** this study,a large eddy simulation is carried out to numerically investigate the unsteady cavitating flow around a trailing-truncated NACA 0009 hydrofoil for determining the underlying physical *** types of cavitation morphologies are identified:The large-scale bubble cluster and the von Kármán vortex cavity,named as the cloud cavitation and the wake vortex cavitation,*** is shown that the velocity profiles obtained over the hydrofoil suction surface are in good agreement with the experimental data,indicating the accuracy of the current *** dynamic evolution of the sheet/cloud cavity is also well reproduced,covering the sheet cavity breakup,the sheet/cloud transformation,and the collapse of the cloudy bubble *** wake-vortex cavitation is caused by the blunt geometry at the hydrofoil trailing edge,where pairs of vortex cavities are *** the cloud and vortex cavities significantly affect the lift oscillation,which makes it difficult to decompose the *** fundamental shedding mechanisms of the wake vortex cavitation are discussed based on the finite-time Lyapunov exponent ***,the suction-side bubble grows and squeezes the giant pressure bubble away from the trailing *** the pressure bubble detaches,a new counterclockwise vortex or a new bubble appears at the pressure side,thus lifting the ridge towards the suction trailing edge and generating a strong vortex eye that pinches off the trailing portion of the suction-side bubble.

关键词： Cloud cavitation wake vortex cavitation trailing-truncated hydrofoil large eddy simulation