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Contact Mechanism of Rail Grinding with Open-Structured Abrasive Belt Based on Pressure Grinding Plate

Chinese Journal of Mechanical Engineering 2023年第2期36卷 341-351页

作者： Zhiwei Wu Wengang Fan chang qian Guangyou Hou School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Key Laboratory of Vehicle Advanced Manufacturing Measuring and Control TechnologyMinistry of EducationBeijing 100044China Railway Engineering Research Institute China Academy of Railway SciencesBeijing 100081China

The current research of abrasive belt grinding rail mainly focuses on the contact mechanism and structural *** with the closed structure abrasive belt grinding,open-structured abrasive belt grinding has excellent performance in dynamic stability,consistency of grinding quality,extension of grinding mileage and improvement of working ***,in the contact structure design,the open-structured abrasive belt grinding rail using a profiling pressure grinding plate and the closed structure abrasive belt using the contact wheel are different,and the contact mechanisms of the two are *** this paper,based on the conformal contact and Hertz theory,the contact mechanism of the pressure grinding plate,abrasive belt and rail is *** finite element simulation and static pressure experiment,the contact behavior of pressure grinding plate,abrasive belt and rail under single concentrated force,uniform force and multiple concentrated force was studied,and the distribution characteristics of contact stress on rail surface were *** results show that under the same external load,there are three contact areas under the three loading *** outer contour of the middle contact area is rectangular,and the inner contour is *** the contact area at both ends,the stress is extremely small under a single concentrated force,the internal stress is drop-shaped under a uniform force,and the internal stress under multiple concentration forces is *** with the three,the maximum stress is the smallest and the stress distribution is more uniform under multiple concentrated ***,the multiple concentrated forces is the best grinding pressure loading *** research provides support for the application of rail grinding with open-structured abrasive belt based on pressure grinding plate,such as contact mechanism and grinding pressure mode selection.

关键词： Rail grinding Abrasive belt Pressure grinding plate Contact stress

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Properties of color-flavor locked strange quark matter and strange stars in a new quark mass scaling

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Science China(Physics,Mechanics & Astronomy) 2013年第9期56卷 1730-1734页

作者： chang qian CHEN ShiWu PENG GuangXiong XU JianFeng College of Physics University of Chinese Academy of Sciences Theoretical Physics Center for Science Facilities Institute of High Energy Physics

Considering the effect of one-gluon-exchange interaction between quarks,the color-flavor locked strange quark matter and strange stars are investigated in a new quark mass density-dependent *** is found that the color-flavor locked strange quark matter can be more stable if the one-gluon-exchange effect is *** lower density behavior of the sound velocity in this model is different from the previous ***,the new equation of state leads to a heavier acceptable maximum mass,supporting the recent observation of a compact star mass as large as about 2 times the solar mass.

关键词： color-flavor locked strange quark matter one-gluon-exchange effect

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Experimental study on discharge coefficient of a gear-shaped weir

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Water Science and Engineering 2018年第3期11卷 258-264页

作者： Jing Zhang qian chang Qing-hua Zhang Shu-ning Li College of Water Conservancy and Civil Engineering Shandong Agricultural University River Management Bureau Huaihe River Commission of the Ministry of Water Resources

This study focused on hydraulic characteristics around a gear-shaped weir in a straight channel. Systematic experiments were carried out for weirs with two different gear heights and eight groups of geometrical parameters. The impacts of various geometrical parameters of gear-shaped weirs on the discharge capacity were investigated. The following conclusions are drawn from the experimental study:(1) The discharge coefficient(m_c) was influenced by the size of the gear: at a constant discharge, the weir with larger values of a/b(a is the width of the gear, and b is the width between the two neighboring gears) and a/c(c is the height of the gear) had a smaller value of m_c. The discharge capacity of the gear-shaped weir was influenced by the water depth in the weir.(2) For type C1 with a gear height of 0.01 m, when the discharge was less than 60m^3/h and H_1=P 1.0, m_c slowly decreased with the increases of the discharge and H_1=P for a=b 1.0 and a=c 1.0, and slowly increased with the discharge and H_1=P for a=b > 1.0 and a=c > 1.0.(3) A formula of m_cfor gear-shaped weirs was established based on the principle of weir flow, with consideration of the water depth in the weir, the weir height and width, and the height of the gear.

关键词： Experimental study Discharge coefficient Discharge capacity Gear-shaped weir Geometrical parameter

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Convenient synthesis of chiral H_4-BINOL via direct hydrogenation of BINOL

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Chinese Chemical Letters 2010年第11期21卷 1277-1280页

作者： qian chang Ding Yun Feng Du Xin Sheng Li Dong Cheng Xu Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces Institute of Physical Chemistry Zhejiang Normal University Jinhua 321004 China

A simple,highly effective hydrogenation of chiral BINOL to provide H_4-BINOL in multigram scale with good yield（up to 78% yield） was developed.A series of heterogeneous catalysts was tested in the hydrogenation;;the best result was obtained with 5%Pd/ C in EtOH under the H_2 pressure of 50 bar for 2 *** method is a more useful method for practical synthesis of optically pure H4- BINOL than other available methods.

关键词： Hydrogenation 1 1'-Bi-2-naphthol 5 6 7 8-Tetrahydro-1 1'-bi-2-naphthol Chiral Pd/C

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The determination of sedimentary environment and associated energy in deep-buried marine carbonates:insights from natural gamma ray spectrometry log

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Frontiers of Earth Science 2024年第1期18卷 204-218页

作者： Jingyan LIU qian chang Junlong ZHANG Hui CHAI Feng HE Yizan YANG Shiqiang XIA School of Energy Resources China University of Geosciences(Beijing)Beijing 100083China Exploration and Development Research Institute Daqing Oilfield CompanyPetroChinaDaqing 163712China China National Oil and Gas Exploration and Development Co. Ltd(CNODC)Beijing 100032China Beijing Research Institute of Uranium Geology Beijing 100029China College of Mining Engineering North China University of Science and TechnologyTangshan 063210China

It has always been challenging to determine the ancient sedimentary environment and associated energy in deep-buried marine *** energy represents the hydrodynamic conditions that existed when the carbonates were *** energy includes light and chemical energies in compounds and kinetic energy in currents and mass ***-buried marine carbonates deposited during the Ordovician depositional period in the eastern Tarim Basin result from a complex interplay of tectonics,sedimentation,and *** a result,determining the ancient sedimentary environment and associated energy is *** natural gamma-ray spectrometry(GRS)log(from 12 wells)is used in this paper to conduct studies on the sedimentary environment and associated energy in deep-buried marine *** findings show that the values of thorium(Th),uranium(U),potassium(K),and gamma-ray without uranium(KTh)in a natural GRS log can reveal lithological associations,mineral composition,diagenetic environment,stratigraphic water activity,and ancient climatic *** the Ordovician,quantitative analysis and determination of sedimentary environment energy are carried out using a comprehensive calculation of natural GRS log parameters in typical wells(penetrating through the Ordovician with cores and thin sections)of well GC4,well GC6,well GC7,and well *** results show that GRS log can determine different lithology associations in typical wells than a sieve residue ***,cores and thin sections can be used to validate the determination of lithology *** on the determination of lithology associations,the lithology associations that reflect the sedimentary environment and associated energy can be analyzed in a new ***,the sedimentary environment energy curve derived from a natural GRS log can reveal hydrodynamic fluctuations during depositional periods,which will aid in the discovery of carbonate reservoirs,establishing sequence stratigra

关键词： ancient sedimentary environment energy of sedimentary environment marine deep-buried carbonates natural GRS the Ordovician eastern Tarim Basin

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Origins of two types of serpentinites from Hong’an， western Dabie Orogen， Central China and associated fluid/melt-rock interactions: Implications from geochemistry and mineralogy study

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Journal of Earth Science 2022年

作者： Yu-Chen Liu chang-qian Ma School of Earth Sciences， China University of Geosciences

A cluster of serpentinite bodies have been recognized tectonically emplaced within the greenschist-amphibolite-facies metamorphic terrane in Hong’an， western Dabie orogen， central China. Two types of serpentinites are identified on the basis of integrated petrography， mineralogical and geochemical study. The first type represented by Yinshanzhai serpentinite complex (Group 1) comprises heterogeneous lithology as a massive serpentinite matrix “intruded” by antigorite-enriched serpentinite lenses. They are both pseudomorphic textured with different mineral assemblages indicating an increasing temperature-pressure condition. Serpentinite matrix (Group 1a) is chemically characterized by high MgO/SiO2， low Al2O3/SiO2， Ti and Ca contents suggesting a depleted mantle wedge origin. Coexistence of compositionally-heterogeneous chromite of high-Cr# (0.78～0.96) and intermediate-Cr# (0.59～0.70) pristine cores indicates extensive mantle melting. Meanwhile， extremely high Fo olivine relicts (96～97) with considerably higher MnO and lower NiO contents than mantle olivine indicates that they are metamorphic products from serpentine decomposition. Accordingly， we propose that Yinshanzhai serpentinite complex experienced two episodes of hydration. The serpentinite lenses (Group 1b) show higher SiO2and lower MgO concentrations. Nevertheless， trace elements of the Group 1a and 1b are consistent: U-shaped REE patterns， positive Eu anomalies and enrichment of LILE (i.e.， Cs， U) are all identified to be forearc properties. They are affected by reductive slab-derived fluids in forearc mantle with f(O)2of 1 to 2 logarithmic units below f(O)2of fayalite-magnetite-quartz buffer (FMQ-2～FMQ-1). The second type are antigorite-serpentinites (Group 2) represented by Ximaoshan and Wangchunwan blocks. They are non-pseudomorphic with no primary framework silicate survived. Fertile compositions (i.e.， higher Al2O3and Al2O3/SiO2， nearly flat REE patterns) and conjointly enrichment of LILE with HFSE sugg

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A NOVEL SVM FOR GROUND PENETRATING SYNTHETIC APERTURE RADAR LANDMINE DETECTION

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Journal of Electronics(China) 2008年第1期25卷 70-75页

作者： Jin Tian Zhou Zhimin Song qian chang Wenge School of Electronic Science and Engineering National University of Defense Technology Changsha 410073 China

The use of vehicle- or air-borne Ground Penetrating Synthetic Aperture Radar (GPSAR) to quickly detect landmines over large areas is becoming a trend. However, producing too many false alarms in GPSAR landmine detection is a major challenge in practical applications of GPSAR. Support Vector Machine (SVM), employing structural risk minimization theory, does not need large amounts of training data, which makes it suitable for solving the landmine detection problem. In this paper, a novel SVM with a hypersphere instead of a hyperplane classification boundary is proposed for landmine detection in GPSAR. The HyperSphere-SVM (HS-SVM) can be trained with both landmine and clutter data, or with landmine data only, which are called the two-class HS-SVM and the one-class HS-SVM, respectively. The HS-SVM has better generalization capability than the traditional HyperPlane-SVM (HP-SVM) with respect to varying operating conditions. Quantitative comparisons have been made using real data collected with the rail-GPSAR landmine detection system, which show that both the two-class and the one-class HS-SVMs have better detection performance than the HP-SVM.

关键词： Synthetic Aperture Radar (SAR) Ground penetrating Support Vector Machine (SVM) Landmine detection

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Deep recycling of volatile elements in the mantle:Evidence from the heterogeneous B isotope in intra-plate basalts

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Geoscience Frontiers 2024年第6期15卷 303-320页

作者： Yan-Qing Li Hiroshi Kitagawa chang-qian Ma Eizo Nakamura Chie Sakaguchi Katsura Kobayashi Xiang-Yun Hu School of Geosciences Yangtze UniversityWuhan 430100China International Center for Isotope Effects Research School of Earth Sciences and EngineeringNanjing UniversityNanjing 210023China Pheasant Memorial Laboratory Institute for Planetary MaterialsOkayama University at Misasa682-0193 MisasaTottoriJapan Schoole of Earth Sciences China University of GeosciencesWuhan 430074China Institute of Geophysics&Geomatics China University of GeosciencesWuhan 430074China

Volatiles in the mantle are crucial for Earth’s geodynamic and geochemical *** the deep recycling of volatiles is key for grasping mantle chemical heterogeneity,plate tectonics,and long-term planetary *** subduction transfers abundant volatile elements from the Earth’s surface into the mantle,the fate of hydrous portions within subducted slabs during intensive dehydration processes remains *** isotopes,only efficiently fractionating near the Earth’s surface,are valuable for tracing volatile recycling *** this study,we document a notably large variation inδ^(11)B values(−14.3‰to+8.2‰)in Cenozoic basalts from the South China *** basalts,associated with a high-velocity zone beneath East China,are suggested to originate from the mantle transition *** the majority exhibitδ^(11)B values(−10‰to−5‰)resembling the normal mantle,their enriched Sr-Nd-Pb isotope compositions and fluid-mobile elements imply hydrous components in their source,including altered oceanic crust and *** normalδ^(11)B values are attributed to the dehydration *** highδ^(11)B values in the basalts indicate the presence of subducted serpentinites in their mantle source.A small subset of samples with lowδ^(11)B values and radiogenic isotope enrichments suggests a contribution from recycled detrital sediments,though retaining minimal volatile elements after extensive *** findings provide compelling evidence that serpentinites within subducted slabs predominantly maintain their hydrous nature during dehydration processes in subduction *** may transport a considerable amount of water into deep mantle reservoirs,such as the mantle transition zone.

关键词： Intra-plate basalts Boron isotopes Serpentinite Volatile recycling Mantle heterogeneity

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A new dual-ion battery based on amorphous carbon

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Science Bulletin 2019年第21期64卷 1634-1642页

作者： Wei(Alex)Wang Hanxin Huang Bin Wang chang qian Peihao Li Jinhui Zhou Zibin Liang Chao Yang Shaojun Guo Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing 100871China BIC-ESAT College of EngineeringPeking UniversityBeijing 100871China Beijing Key Laboratory for Magnetoeletric Materials and Devices(BKL-MEMD) Peking UniversityBeijing 100871China Department of Energy and Resources Engineering College of EngineeringPeking UniversityBeijing 100871China

The Na-based dual-ion batteries(NDIBs),combining the advantages of Na-ion batteries and dual-ion batteries,are attracting more attention due to their merits of abundant source,low cost and high energy ***,the main challenges faced by NDIBs are their low capacity and poor ***,we report a new ion storage mechanism for high-performance NDIBs using amorphous carbon(AOMC)as *** the graphite carbon that can only accommodate the PF6-anion(typical DIB system),the AOMC herein can both accommodate Na+cation and PF6-anion due to its amorphous feature,which is conceptually new dual-ion system for achieving much higher ***-situ X-ray photoelectron spectroscopy,X-ray diffraction and Raman studies reveal that the disordered carbon in the AOMC can be transformed to the partial graphitic stacking in short range,improving both capacity and cycling stability of *** a consequence,the AOMC delivers a highly reversible storage capacity of 136 mAhg-1 for 800 cycles at a very high current density of 2.0 Ag-1,much higher than all the reported *** concept can be generalized to develop high-performance dual-ion full cell using sodium ion preintercalated materials as anode and AOMC as cathode.

关键词： Na-based dual-ion batteries Amorphous carbon Storage mechanism Larger interlayer spacing

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Boosting the photodynamic therapy efficiency with a mitochondria-targeted nanophotosensitizer

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Chinese Chemical Letters 2019年第6期30卷 1293-1296页

作者： Limin Yang Peng Gao Yuanlei Huang Xiao Lu qian chang Wei Pan Na Li Bo Tang College of Chemistry Chemical Engineering and Materials Science Key Laboratory of Molecular and Nano Probes Ministry of Education Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong Institute of Molecular and Nano Science Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals Shandong Normal University

Photodynamic therapy (PDT) is an attractive clinical technique for cancer treatment. However, the poor solubility and weak cellular internalization of the molecule-photosensitizers, as well as the exceedingly short lifetime and limited diffusion distance of the generated reactive oxygen species (ROS) in cytoplasm directly restricted the therapeutic efficiency of conventional PDT. In this study, we proposed a facile strategy for improving PDT of cancer based on a mitochondria-targeted nanophotosensitizer. The molecule-photosensitizer chlorin e6 was covalently attached on the internal and external surfaces of the mesoporous silica nanoparticles. Then, the triphenylphosphonium was anchored on the nanoparticles for selectively targeting mitochondria. When irradiated with laser, the nanophotosensitizer can generate a large amount of ROS in mitochondria, thus causing the mitochondrial dysfunction and irreversible cell apoptosis. In vitro and in vivo studies demonstrated that the nanophotosensitizer could boost the treatment efficiency against cancer cells and xenograft tumor models.

关键词： Mitochondria Nanophotosensitizer Photodynamic therapy Reactive oxygen species Enhanced treatment efficiency

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