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An X-ray luminosity analysis for FRIs and FRIIs

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Science China(Physics,Mechanics & Astronomy) 2009年第9期52卷 1434-1441页

作者： ZHANG ChunLing FAN JunHui Center for Astrophysics Guangzhou UniversityGuangzhou 510006China

Radio galaxies are divided into two groups according to their luminosities at 178 MHz, namely Fa- naroff-Riley type Is (FRIs) and Fanaroff-Riley type IIs (FRIIs) with FRIs showing lower radio luminosities than FRIIs. In this paper, the X-ray data are compiled for 183 radio galaxies (61 FRIs and 122 FRIIs), from the available literature, for the analysis of the X-ray properties. The 1 keV X-ray luminosities are calculated and discussed for the two groups, and an averaged X-ray luminosity of logLX1 keV = 41.30±2.51 erg·s-1·keV-1 is found for FRIs, which is lower than that for FRIIs, logLX1 KeV = 43.39±3.06 erg·s-1·keV-1. A Kolmogorov-Smirnov (K-S) test indicates that the probability for the X-ray luminosity distributions of the two groups to be from the same parent distribution is 1.44×10-10. We also discuss the origin and the mechanism of the X-ray emission for FRIs and FRIIs.

关键词： active galactic nuclei radio galaxies relativistic beaming

Volatile organic compounds concentration profiles and control strategy in container manufacturing industry:Case studies in China

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Journal of Environmental Sciences 2021年第6期33卷 296-306页

作者： Yunting Ke Ruiyuan Liu Xiaofang Chen Yang Feng Ping Gao Haomin Huang Liya Fan Daiqi Ye School of Environment and Energy South China University of TechnologyGuangzhou 510006China Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control(SCUT) Guangzhou 510006China National Engineering Laboratory for VOCs Pollution Control Technology and Equipment(SCUT) Guangzhou 510006China Guangdong Provincial Engineering and Technology Research Centre for Environmental Risk Prevention and Emergency Disposal(SCUT) Guangzhou 510006China

Volatile organic compounds(VOCs),important precursors of ozone(O_(3))and fine particulate matter(PM_(2.5)),are the key to curb the momentum of O_(3)growth and further reducing PM_(2.5)in *** manufacturing industry is one of the major VOC emitters,and more than 96%containers of the world are produced in China,with the annual usage of coatings of over 200,000 tons in recent *** is the first research on the emission characteristics of VOCs in Chinese container manufacturing industry,including concentration and ozone formation potential(OFP)of each *** result shows that the largest amounts of VOCs are emitted during the pretreatment process,followed by the paint mixing process and primer painting process,and finally other sprays *** average VOC concentrations in the workshops,the exhausts before treatment and the exhausts after treatment are ranging from 82.67–797.46,170–1,812.65,66.20–349.63 mg/m^(3),***,alcohols and ethers are main species,which contribute more than 90%OFP *** on the emission characteristics of VOCs and the technical feasibility,it is recommended to set the emission limit in standard of benzene to 1.0 mg/m^(3),toluene to 10 mg/m^(3),xylene to 20 mg/m^(3),benzenes to 40 mg/m^(3),alcohols and ethers to 50 mg/m^(3),and VOCs to 100 mg/m^(3).The study reports the industry emission characteristics and discusses the standard limits,which is a powerful support to promote VOCs emission reduction,and to promote the coordinated control of PM_(2.5)and O_(3)pollution.

关键词： Container manufacturing Volatile organic compounds(VOCs) Emission characteristics Control strategy

Teleporting an Unknown Two-qubit Entangled State via Ion-Trap Systems

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Chinese Physics Letters 2009年第1期26卷 130-131页

作者：艾凌艳杜刚朱诗亮张智明 Laboratory of Photonic Information Technology South China Normal University Guangzhou 510006 Institute for Condensed Matter Physics South China Normal University Guangzhou 510006

We propose a scheme for teleportation of an unknown two-qubit entangled state via trapped ions. In this scheme, we use the GHZ state as a quantum channel and the success probability can reach 1. The distinct advantage of our scheme is insensitive to the heating of the vibrational mode. In addition, Bell-state measurement is not required.

关键词： field emission molybdenum dioxide enhancement factor

Extragalactic H_2O Megamaser Sources:Central Black Holes,Nuclear X-ray and Maser Emissions

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Chinese Journal of Astronomy and Astrophysics 2008年第5期8卷 547-554页

作者： Jiang-Bo Su Jiang-Shui Zhang Jun-Hui Fan Center for Astrophysics Guangzhou University Guangzhou 510006 China

Extragalactic H2O megamasers are typically found within the innermost few parsecs of active galaxy nuclei （AGN） and the maser emission is considered to be excited most likely by the X-ray irradiation of the AGN. We investigate a comprehensive sample of extragalactic H2O masers in a sample of 38 maser host AGN to check potential correlations of the megamaser emission with parameters of the AGN, such as X-ray luminosity and black hole （BH） masses. We find a relation between the maser luminosities and BH masses LH2O∝MBH^3.6±0.4 which supports basically the theoretical prediction. The relation between the maser emission and X-ray emission is also confirmed.

关键词： galaxies active -galaxies nuclei -masers

Engagement Angle Modeling for Multiple-circle Continuous Machining and Its Application in the Pocket Machining

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Chinese Journal of Mechanical Engineering 2017年第2期30卷 256-271页

作者： Shixiong WU Wei MA Haiping BAI Chengyong WANG Yuexian SONG Mechanical and Electrical Engineering Institute GuangdongUniversity of TechnologyGuangzhou 510006China

The progressive cutting based on auxiliary paths is an effective machining method for the material accumulating region inside the mould pocket. But the method is commonly based on the radial depth of cut as the control parameter, further more there is no more appropriate adjustment and control approach. The end-users often fall to set the parameter correctly, which leads to excessive tool load in the process of actual machining. In order to make more reasonable control of the machining load and toolpath, an engagement angle modeling method for multiplecircle continuous machining is presented. The distribution mode of multiple circles, dynamic changing process of engagement angle, extreme and average value of engage- ment angle are carefully considered. Based on the engagement angle model, numerous application techniques for mould pocket machining are presented, involving the calculation of the milling force in multiple-circle continuous machining, and rough and finish machining path planning and load control for the material accumulating region inside the pocket, and other aspects. Simulation and actual machining experiments show that the engagement angle modeling method for multiple-circle continuous machining is correct and reliable, and the related numerous application techniques for pocket machining are feasible and effective. The proposed research contributes to the analysis and control tool load effectively and tool-path planning reasonably for the material accumulating region inside the mould pocket.

关键词： Pocket · Engagement angle · Milling force Circle · High·speed machining

Topology optimization of a 6-DOF spatial compliant mechanism based on Stewart propotype platform

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Acta Mechanica Sinica 2019年第5期35卷 1044-1059页

作者： Dachang Zhu Wanghu Zhan School of Mechanical and Electrical Engineering Guangzhou UniversityGuangzhou 510006China

To improve the global stiffness and conveniently build a model of a compliant mechanism with spatial multiple degrees of freedom(DOF),the topology optimization method,combined with the isomorphic mapping matrix,is proposed in this paper for structure synthesis of a 6-DOF spatial compliant *** using the differential approximation method,the Jacobian matrix of the Stewart prototype platform is calculated as the isomorphic mapping matrix,and its eigenvalues and eigenvectors are *** the isomorphic mapping matrix with the solid isotropic material with the penalization topology optimization method,the topological model of the 6-DOF spatial compliant mechanism is constructed,and a topological structure of the 6-DOF spatial compliant mechanism is derived which has the same differential kinematic characteristics as the Gough-Stewart prototype *** actuators are mounted inside the topological structure during the three-dimensional printing manufacturing process,and its driver directions are in accordance with the driver configuration directions of the Gough-Stewart prototype *** effectiveness of the proposed method for topological structure synthesis of the 6-DOF spatial compliant mechanism is demonstrated through several numerical examples and experimental studies.

关键词： 6-DOF spatial compliant mechanism Stewart prototype platform Isomorphic mapping Jacobian matrix Topology optimization

Enhanced photocatalytic activity of rGO/TiO2 for the decomposition of formaldehyde under visible light irradiation

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Journal of Environmental Sciences 2018年第11期30卷 138-146页

作者： Lian Yu Long Wang Xibo Sun Daiqi Ye College of Environment and Energy South China University of Technology Guangzhou 510006 China Cuangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control Guangzhou 510006 China National Engineering Laboratory for VOCs Pollution Control Technology and Equipment South China University of Technology Guangzhou 510006 China

Due to the low concentration of indoor air contaminants, photocatalytic technology shows low efficiency for indoor air purification. The application of TiO2 for photocatalytic removal of formaldehyde is limited, because TiO2 can only absorb ultraviolet （UV） light. Immobilization of TiO2 nanoparticles on the surface of graphene can improve the visible light photocatalytic activity and the adsorption capacity. In this study, rGO （reduced graphene oxide）/TiO2 was synthesized through a hydrotherrnal method using titanium tetrabutoxide and graphene oxide as precursors, and was used for the degradation of low concentration formaldehyde in indoor air under visible light illumination. Characterization of the crystalline structure and morphology of rGO/TiO2 revealed that most GO was reduced to rGO during the hydrothermal treatment, and anatase TiO2 nanoparticles （with particle size of 15-30 nm） were dispersed well on the surface of the rGO sheets, rGO/TiO2 exhibited excellent photocatalyfic activity for degradation of formaldehyde in indoor air and this can be attributed to the role ofrGO, which can act as the electron sink and transporter for separating photo-generated electron-hole pairs through interfacial charge transfer. Furthermore, rGO could adsorb formaldehyde molecules from air to produce a high concentration of formaldehyde on the surface of rGO/ TiO2. Under visible light irradiation for 240 min, the concentration of formaldehyde could be reduced to 58.5 ppbV. rGO/TiO2 showed excellent moisture-resistance behavior, and after five cycles, rGO/TiO2 maintained high photocatalytic activity for the removal of formaldehyde （84.6%）. This work suggests that the synthesized rGO/TiO2 is a promising photocatalyst for indoor formaldehyde removal.

关键词： Reduced graphene oxide (rGO) rGO/TiO2 nanocomposites Visible light photocatalysis Indoor air Formaldehyde

Theoretical Study on the Structures and Magnetic Properties of Metal String Complexes Containing Rigid Equatorial Ligands [Ni3(L)4(NCS)2] (L = dzp-, mpmpa-, mppda-, mptpa-)

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Chinese Journal of Structural Chemistry 2017年第7期36卷 1077-1085页

作者：班颖陈蓉李波许旋徐志广 School of Chemistry & Environment South China Normal University Guangzhou 510006 China Key Laboratory of Materialsfor Energy Conversion and Storage of Guangzhou Guangzhou 510006 China Key Laboratory of Theoretical Chemistry of Environment Ministry of Education Guangzhou 510006 China

Density functional theory at the BP86 level was used to investigate the influence of equatorial ligands on the Ni–Ni interactions and magnetic coupling properties of metal string complexes [Ni3（L）4（NCS）2] （L represents the rigid equatorial ligands; L = dzp- （1）, mpmpa- （2）, mppda- （3）, mptpa- （4））. The following conclusions can be drawn. （1） With increasing the radius of the connecting atom in the cental ring in equatorial ligands, the two pyridine rings bend down, resulting in the decreasing distance between the two pyridine-nitrogen atoms and the Ni–Ni distance. Therefore, the strength order of the Ni–Ni interaction is 4 〉 2 〉 3 〉 1. The Ni–Ni interactions in 2 and 4 are stronger than those in Ni3（dpa）4（NCS）2 containing no-rigid equatorial ligands. （2） The calculated -Jab is 4 〉 2 〉 3 〉 1. There are two types of magnetic exchange pathways in these complexes： the σ-type pathway through the Ni36＋ chains and the δ-type pathway through the equatorial ligands. The magnetic coupling through the metals is the dominant part. Hence, the magnetic coupling strength increases with increasing the Ni–Ni interaction. Modifying the radius of the connecting atom may be one of the means to fine tuning of magnetic coupling strength of this kind of metal string complexes.

关键词： metal string complex rigid equatorial ligands density functional theory magnetic coupling constant

Effect of lithium content on the mechanical and corrosion behaviors of HCP binary Mg–Li alloys

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Journal of Magnesium and Alloys 2021年第2期9卷 569-580页

作者： Chuanqiang Li Yibin He Huaipei Huang School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006China

The microstructure,crystallographic texture,mechanical properties and corrosion resistance of as-extruded HCP Mg-x Li(x=1,3,5;in wt%)alloys were *** results indicated that the HCP Mg-5 Li alloy with high lithium content exhibited a low degree of dynamic recrystallization(DRX)compared with Mg-1 Li and Mg-3 Li ***,the 45°base(0001)texture of Mg-1 Li alloy could turn into(11–20)and(10–10)prismatic texture of Mg-3 Li and Mg-5 Li alloys with c-axis approximately parallel to transverse direction(TD).As a result,the strong prismatic texture resulted in the mechanical anisotropy of as-extruded Mg-3 Li and Mg-5 Li alloys with higher mechanical strength and low elongation along extrusion direction(ED)(reverse for TD sample).Regarding of corrosion behaviors,filiform corrosion occurred in the three Mg–Li alloys,whilst the high lithium content could mitigate the groove-like corrosion and improve the corrosion resistance of Mg-5 Li alloy,which was ascribed to the refined grains,prismatic texture and surface film.

关键词： Mg-Li alloys Recrystallization Texture Mechanical properties Corrosion behavior