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Characterization of hot deformation behavior of wear-resistant steel BTWl using processing maps and constitutive equations

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Journal of Iron and Steel Research International 2018年第10期25卷 1054-1061页

作者： Peng-tao Liu qing-xue Huang Li-feng Ma tao Wang College of Mechanical Engineering Taiyuan University of Technology Taiyuan 030024 Shanxi China Shanxi Provincial Key Laboratory of Metallurgical Equipment Design and Technology Taiyuan University of Science and Technology Taiyuan 030024 Shanxi China Heavy Machinery Engineering Research Center of the Ministry Education Taiyuan University of Science and Technology Taiyuan 030024 Shanxi China

In order to predict flow instability of wear-resistant steel BTW1, the hot compressions of wear-resistant steel BTW1 were firstly performed at the temperature of 900-1150 ℃ and at the strain rate of 0.05-15 s-1. Then, the constitutive relation was established based on Arrhenius-type hyperbolic sine equation. The results demonstrated that the flow stress depended on the deformation temperature and strain rate. When the deformation temperature kept constant, the flow stress increased as the strain rate increased. When the strain rate remained constant, the flow stress decreased as the temperature increased. The flow stresses calculated by constitutive equations were in a good agreement with experimental results. The apparent activation energy for deformation in the above processing region was estimated to be 369 kJ tool-1. A processing map could be obtained by the superimposition of an instability map on a power dissipation map. Based on the analysis of processing map and the microstructures, the theological instability regimes of strain rate and temperature for hot deformation of wear-resistant steel BTWl had been identified.

关键词： Wear-resistant steel BTW 1 Processing map Constitutive equation Hot deformation Dynamicrecrystallization

Research and development of fringe projection-based methods in 3D shape reconstruction

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第6期7卷 1026-1036页

作者： WU Lu-shen PENG qing-jin Department of Mechanical and Electronic Engineering Nanchang University Nanchang 330029 China Department of Mechanical and Industrial Engineering University of Manitoba R3T 5V6 Canada

This paper discusses current research and development of fringe projection-based techniques. A system based on Fourier transform profilometry (FTP) is proposed for three-dimensional (3D) shape recovery. The system improves the method of phase unwrapping to gain accurate 3D shapes of objects. The method uses a region-growing algorithm for the path prediction guided by the quality map to increase the recovering accuracy and provides a fast and simple tool for 3D shape recovery. The shape measurement and data recovery are integrated to offer a new method of 3D modelling. Examples are presented to verify the feasibility of the proposed method.

关键词： 3D modelling Fringe projection Quality map 3D measurement Reverse engineering

Metallo-aerogels derived from chitosan with encapsulated metal nanoparticles as robust,efficient and selective nanocatalysts towards reduction of nitroarenes

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Nano Research 2021年第1期14卷 59-65页

作者： Yajing shen qingshu Zheng Jianhong Liu tao Tu Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Department of ChemistryFudan University2005 Songhu RoadShanghai 200438China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China College of Chemistry and Molecular Engineering Zhengzhou University100 Kexue avenueZhengzhou 450001China

A series of robust metallo-aerogels are readily fabricated by pyrolysis of xerogels derived from chitosan-metal(M=Fe,Co,Ni)*** to the strong coordination between metal ions and the functional groups(NH2 and OH)of chitosan,metallo-aerogels consisting of encapsulated metal-nanoparticles(MNPs)by graphite shells were obtained,as supported by various characterizations including high-resolution transmission electron microscope(HR-TEM),X-ray diffraction(XRD),and *** resulting metalloaerogels could be functioned as highly stable,efficient and selective nanocatalysts towards the hydrogenation of nitroarenes to amines at low catalyst loading(1.2 mol.%-2.4 mol.%).Remarkably,the metallo-aerogels could be reused for more than 30 runs without obvious loss of activity and *** distinguished performances were attributed to the graphitic shells formed during the pyrolysis,which hampered the possible aggregation of MNPs,prevented metal leaching and increased their stability.

关键词： metallo-aerogels nanocatalysts nitroarenes reduction pyrolysis

Inhibition character of crotonaldehyde manufacture wastewater on biological acidification

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Frontiers of Environmental Science & Engineering 2021年第6期15卷 293-302页

作者： tao Liu Yudong Song Zhiqiang shen Yuexi Zhou State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Research Center of Environmental Pollution Control Engineering Technology Chinese Research Academy of Environmental SciencesBeijing 100012China School of Environment Tsinghua UniversityBeijing 100084China

This work aims to investigate the inhibitory effect of crotonaldehyde manufacture wastewater(CMW)on biological *** reveal the inhibitory effect of wastewater to the anaerobic granular sludge(AnGS),variations of the specific acidogenic activity(SAA)and activities of key enzymes were *** results indicated that the dosage of CMW causing a 50%effect concentration(EC50)on the activity of total volatile fatty acids(TVFA)production was 380 mg COD/g *** inhibitory effect of individual toxicants in CMW on the activity of TVFA production were in the order of crotonaldehyde>ethyl sorbate>(E,E)-2,4-hexadienal,and their inhibitory degrees on individual VFA productions were acetic acid(Ac)>n-butyric acid(n-Bu),which could correspond to the variations in the activities of acetate kinase(AK)and butyrate kinase(BK).Furthermore,the combined effect of three toxicants on the activity of TVFA production was significantly higher than that of any individual toxicant,and the contribution of the relative toxicity to CMW was 77.27%.Additionally,the biodegradation products of the main toxicants indicated that the removal of crotonaldehyde and(E,E)-2,4-hexadienal was primarily due to the hydrogenation of alkene and aldehyde and the oxidation of ***,the removal of ethyl sorbate was primarily based on *** conclusion,biological acidification has a limited ability to treatment CMW,therefore,a further pretreatment technology should be used to remove the main toxicant of wastewater.

关键词： Crotonaldehyde manufacture wastewater Biological acidification Volatile fatty acids Inhibition Toxic units

Growth kinetics and mechanism of microarc oxidation coating on Ti-6Al-4V alloy in phosphate/silicate electrolyte

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International Journal of Minerals,Metallurgy and Materials 2022年第11期29卷 1991-1999页

作者： Dajun Zhai tao Qiu Jun shen Keqin Feng College of Materials Science and Engineering Chongqing UniversityChongqing 400044China School of Mechanical Engineering Sichuan UniversityChengdu 610065China

Microarc oxidation(MAO)is an effective surface treatment method for Ti alloys to allow their application in extreme ***,binary electrolytes consisting of different amounts of sodium phosphate and sodium silicate were designed for *** surface morphology,composition,and properties of MAO coatings on Ti-6Al-4V alloy treated in 0.10 mol/L electrolyte were investigated to reveal the effect of PO_(4)^(3-)and SiO_(3)^(2-)ray diffraction,and potentiodynamic *** results showed that PO_(4)^(3-)is beneficial for generating microarcs and forming pores within the coating,resulting in a thick but porous ***_(3)^(2-)eration of microarcs,resulting in a thin dense *** thickness,density,phases content,and polarization resistance of the MAO coatings are primarily affected by the intensity of microarcs for low SiO_(3)^(2-)ciently *** thickness of MAO coatings obtained in P/Si electrolytes shows a piecewise linear increase with increasing process time during the three stages of microarc ***_(3)^(2-)discharge,but slows down the growth of the coating formed in the next stage.

关键词： microarc oxidation titanium alloy phosphate silicate growth kinetics growth mechanism

Effects of the Spatial Coupling of Water and Fertilizer on the Chlorophyll Fluorescence Parameters of Winter Wheat Leaves

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Agricultural Sciences in China 2011年第12期10卷 1923-1931页

作者： shen Yu-fang LI Shi-qing State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau/Northwest A＆F University Yangling 712100 P.R.China

Wheat is an important agricultural crop in the Loess region of China, where there is drought stress and low availability of soil nitrogen and phosphorus. Using a pulse modulation fluorometer, we studied the effects of water, nitrogen, and phosphorus on the kinetic parameters of chlorophyll fluorescence in winter wheat. The wheat was grown in layered columns of Eum-Orthic Anthrosol （Cinnamon soil）, with the water content and nutrient composition of each layer controlled. The results showed that the kinetic parameters of chlorophyll fluorescence were sensitive to water stress. The basic fluorescence （F0） of leaves was higher in the dry treatment （0-30 cm layer at 40-45% of field capacity, 30-90 cm at 75-80% of field capacity） compared to the wet treatment （entire soil column at 75-80% of field capacity）. The maximal fluorescence （Fm）, the variable fluorescence （Fv）, the photochemical efficiency （Fv/Fm） and potential activites （Fv/F0） of photosystem 2 （PS2） were significantly lower in the dry treatment. Although drought stress impaired PS2 function, this effect was significantly ameliorated by applying P or NP fertilizer, but not N alone. P application increased FJFm, both in well-watered and water stressed plants, especially when fertilizer was applied throughout the column or within the top 30 em of soil. A combined fertilizer improved photosynthesis in well watered plants, with Fm and F,fFm being the highest when fertilizer was applied throughout the columns. For drought stressed, plants FJFm was significantly greater when combined fertilizer was added within the top 30 cm of soil. We concluded that, when growing winter wheat in both arid and semi-arid parts of the Loess region of China, it is important to guarantee the nutrient supply in the top 30 cm of the soil.

关键词： water stress nutrient spatial coupling chlorophyll fluorescence column experiment

Quantum transport in topological semimetals under magnetic fields

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Frontiers of physics 2017年第3期12卷 43-60页

作者： Hai-Zhou Lu Shun-qing shen Department of Physics The University of Hong Kong Pokfulam Road Hong Kong China

Topological semimetals are three-dimensional topological states of matter, in which the conduction and valence bands touch at a finite number of points, i.e., the Weyl nodes. Topological semimetals host paired monopoles and antimonopoles of Berry curvature at the Weyl nodes and topologically protected Fermi arcs at certain surfaces. We review our recent works on quantum transport in topo- logical semimetals, according to the strength of the magnetic field. At weak magnetic fields, there are competitions between the positive magnetoresistivity induced by the weak anti-localization effect and negative magnetoresistivity related to the nontrivial Berry curvature. We propose a fitting formula for the magnetoconductivity of the weak anti-localization. We expect that the weak localization may be induced by inter-valley effects and interaction effect, and occur in double-Weyl semimetals. For the negative magnetoresistance induced by the nontrivial Berry curvature in topological semimetals, we show the dependence of the negative magnetoresistance on the carrier density. At strong magnetic fields, specifically, in the quantum limit, the magnetoconductivity depends on the type and range of the scattering potential of disorder. The high-field positive magnetoconductivity nmy not be a com- pelling signature of the chiral anomaly. For long-range Gaussian scattering potential and half filling, the magnetoconductivity can be linear in the quantum limit. A minimal conductivity is found at the Weyl nodes although the density of states vanishes there.

关键词： topological semimetal magnetoconductivity magnetoresistance localization,anti-localization chiral anomaly

An Implementation Model of Parlay MMCCS API Based on SIP

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The Journal of China Universities of Posts and Telecommunications 2006年第2期13卷 43-49页

作者： GUAN You-qing shen Su-bin Research Center of Network Technology Nanjing University of Posts and Telecommunications Nanjing 210003 P.R. China

Parlay Multi Media Call Control Services （ MMCCS） Application Programming Interfaces （API） based on Session Initiation Protocol （SIP） is essential for the implementation of Parlay Call Control （ CC） API. This paper first proposes an implementation model of Parlay MMCCS API based on SIP, then presents a mapping between SIP and MMCCS AP1 as far as methods and parameters are concerned, illustrates corresponding relationships between different components of SIP and MMCCS API by means of an application collaboration diagram, and finally presents an application using Java codes as well as some SIP messages. The application shows that a majority of MMCCS API based on SIP can be implemented and therefore verifies our mapping between MMCCS API and SIP.

关键词： SIP parlay MMCCS API

“标准地”改革背景下的地方产业空间挖掘策略研究

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城市建筑 2025年第1期22卷 70-73,84页

作者：蔡凌雁王青梁涛南京市城市规划编制研究中心

经济社会高质量发展的时代背景对产业发展提出新的诉求。土地是保障产业项目落地的基础要素,如何从土地资源中挖掘产业空间潜力,支持产业用地供应改革,是新形势下产业发展面临的直接诉求。文章提出以详细规划“地块”为单元,融合多源管... 详细信息

经济社会高质量发展的时代背景对产业发展提出新的诉求。土地是保障产业项目落地的基础要素,如何从土地资源中挖掘产业空间潜力,支持产业用地供应改革,是新形势下产业发展面临的直接诉求。文章提出以详细规划“地块”为单元,融合多源管理数据,构建产业空间分类挖潜路径,服务于产业用地“标准地”供应,为“地等项目”产业用地空间要素保障研究提供参考。

关键词：产业用地标准地土地要素空间挖掘

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