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Special Issue of Single-atom Catalysis

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Chemical Research in Chinese Universities 2022年第5期38卷 I0001-I0004页

作者： WU yuen SU Chenliang WANG Yanggang University of Science and Technology of China Hefei 230026P.R.China Shenzhen University Shenzhen 518060P.R.China Southern University of Science and Technology Shenzhen 518055P.R.China

Single-atom catalysts(SACs)are a new type of heterogeneous catalysts formed by isolated metal atoms anchored on kinds of *** are distinctly distinguished from traditional catalysts by characterizing with unique electronic structure,quantum size effect and unsaturated coordination environment,etc.,which brought subverted effects on traditional catalytic fields once upon the *** unique chemical and physical properties impart SACs with outstanding catalytic performance,embodying nearly 1o0%atom utilization,high catalytic activity and excellent *** invariably have been the"hotspot"in catalysis research field during the last decade,shining brilliantly in applications of electro-,photo-and thermal *** particular,the advent of SACs points towards a possibility of the substantial cost reduction of precious metal catalysts in the *** themed issue selected advanced studies on design,synthesis,characterization,and application of SACs,dedicating to assisting readers in a comprehensively and in-depth understanding of SACs.

关键词： durability catalysis invar

SEPRAN: A Versatile Finite-Element Package for a Wide Variety of Problems in Geosciences

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Journal of Earth Science 2015年第1期26卷 89-95页

作者： Arie van den Berg Guus Segal David A.yuen Department of Theoretical Geophysics Institute of Earth SciencesUtrecht University3508 TC UtrechtThe Netherlands Faculty of Electrical Engineering Mathematics and Computer ScienceTU DelftThe Netherlands Department of Earth Sciences and Minnesota Supercomputing Institute University of MinnesotaMinneapolis MN 55455USA School of Environmental Studies China University of Geosciences

Numerical modelling of geological processes, such as mantle convection, flow in porous media, and geothermal heat transfer, has become quite common with the increase in computing and the availability of usable software. Today modelling these dynamical processes entails the solving of the governing equations involving the mass, momentum, energy and chemical transport. These equations represent partial differential equations and must be solved on powerful enough computers because they require sufficient spatial and temporal resolution to be useful. We describe here the salient and outstanding features of the SEPRAN software package, developed in the Netherlands, as a case study for a robust and user-friendly soft- ware, which the geological community can utilize in handling many thermal-mechanical-chemical problems found in geology, which will include geothermal situations, where many types of partial differential equations must be solved at the same time with thermodynamical input parameters.

关键词： SEPRAN finite element package geodynamic and planetary modelling geothermal groundwater flow.

Submicron Volume Roughness & Asperity Contact Friction Model for Principle Slip Surface in Flash Heating Process

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Journal of Earth Science 2015年第1期26卷 96-107页

作者： Bojing Zhu David A.yuen Yaolin Shi Huihong Cheng Carbon Capture & Store & Rock Mechanics & Fluid Dynamic Laboratory Department of Earth SciencesDurham UniversityDH1 3LEUK Department of Earth Sciences and Minnesota Supercomputing Institute University of MinnesotaMinneapolis MN 55455USA School of Environmental Studies China University of Geosciences Key Laboratory of Computational Geodynamics of Chinese Academy of Sciences College of Earth ScienceUniversity of Chinese Academy of Sciences

Based on focused ion beam and shear friction apparatus data, the multi-resolutions （0.2 nm-5μm） volume roughness ＆ asperity contact （VR ＆ AC） three-dimensional structure on principle slip surface interface-surface （PSS-IS） is measured on high performance computational platform; and physical plastic-creep friction model is established by using hybrid hyper-singular integral equation ＆ lattice Boltzmann ＆ lattice Green function （BE-LB-LG）. The correlation of rheological property and VR ＆ AC evolution under transient （10 μs） macro-normal stress （18-300 MPa） and slip rate （0.25-7.5 m/s） are obtained; and the PSS-IS friction in co-seismic flash heating is quantitative analyzed for the first time.

关键词： VR & AC BE-LB-LC submicron-scale structure measurement plastic-creep model,friction model.

A single pulse study of PSR J1752+2359

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Research in Astronomy and Astrophysics 2021年第9期21卷 262-268页

作者： Sheng-Nan Sun Wen-Ming Yan Na Wang Rai yuen Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China Xinjiang Key Laboratory of Radio Astrophysics 150 Science 1-StreetUrumqi 830011China

The single pulse observation of PSR J1752+2359 at 1250 MHz made using the Five-hundredmeter Aperture Spherical radio Telescope(FAST)is *** show that the pulsar exhibits two distinct emission states:a normal state with continuous normal pulse emission and a rotating radio transient(RRAT)-like state with sporadic *** makes PSR J1752+2359 the third pulsar that exhibits switching between RRAT-like and pulsar-like *** data show that,during the observation,20 per cent of the time for this pulsar was in the normal state and 80 per cent in the RRAT-like state.A quasiperiodic switching,with a periodicity of around 568 spin periods,between the two states was *** pulse energies for the two states both follow log-normal *** demonstrate that the polarization profiles and the linear polarization position angle(PA)swings differ significantly between the two *** is a phase offset of about 0°.35 between the pulse profile peaks of the two *** argue that the emission geometry in the magnetosphere may be different for the two states.

关键词： stars neutron-pulsars general-pulsars individual(PSR J1752+2359)

Analysis of the microbunching instability in a mid-energy electron linac

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Chinese Physics C 2015年第3期39卷 87-94页

作者：黄大章顾强王震张猛 King yuen Ng Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai Institute of Applied Physics Chinese Academy of Sciences Fermi National Accelerator Laboratory BataviaIllinois 60510 USA

Microbunching instability usually exists in the linear accelerator （linac） of a free electron laser （FEL） facility. If it is not controlled effectively, the beam quality will be damaged seriously and the machine will not operate properly. In the electron linac of a soft X-ray FEL device, because the eiectron energy is not very high, the problem can become even more serious. As a typical example, the microbunching instability in the linac of the proposed Shanghai Soft X-ray Free Electron Laser facility （SXFEL） is investigated in detail by means of both analytical formulae and simulation tools. In the study, a new mechanism introducing random noise into the beam current profile as the beam passes through a chicane-type bunch compressor is proposed. The higher-order modes that appear in the simulations suggest that further improvement of the current theoretical model of the instability is needed.

关键词： Free Electron Laser (FEL) electron linear accelerator (linac) microbunching instability

Ruin Probabilities in Cox Risk Models with Two Dependent Classes of Business

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Acta Mathematica Sinica,English Series 2007年第7期23卷 1281-1288页

作者： Jun Yi GUO Kam C.yuen Ming ZHOU School of Mathematical Sciences and LPMC Nankai University Department of Statistics and Actuarial Science The University of Hong Kong

In this paper we consider risk processes with two classes of business in which the two claim-number processes are dependent Cox processes. We first assume that the two claim-number processes have a two-dimensional Markovian intensity. Under this assumption, we not only study the sum of the two individual risk processes but also investigate the two-dimensional risk process formed by considering the two individual processes separately. For each of the two risk processes we derive an expression for the ruin probability, and then construct an upper bound for the ruin probability. We next assume that the intensity of the two claim-number processes follows a Markov chain. In this case, we examine the ruin probability of the sum of the two individual risk processes. Specifically, a differential system for the ruin probability is derived and numerical results are obtained for exponential claim sizes.

关键词： Cox risk model ruin probability Markov process infinitesimal generator

Acid-stable antimonate based catalysts for the electrocatalytic oxygen evolution reaction

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Nano Research 2023年第4期16卷 4691-4697页

作者： Xiaoping Gao Huang Zhou Zhe Wang Gang Zhou Jin Wang yuen Wu College of Materials Science and Engineering Shenzhen UniversityShenzhen 518071China School of Chemistry and Materials Science University of Science and Technology of ChinaHefei 230026China Preservation Technology Advanced Research CenterHefei Hualing Co.LtdHefei 230000China School of Science Hubei University of TechnologyWuhan 430068China

Acid-stable and highly active catalysts for the electrocatalytic oxygen evolution reaction(OER)are paramount to the advancement of electrochemical technologies for clean energy conversion and *** this work,based on the density functional theory(DFT)calculations,we systematically investigated the MSb_(2)O_(6)(M=Fe,Co,and Ni)and transition metal(TM)doped MSb_(2)O_(6)(TM-MSb_(2)O_(6),TM=Mn,Fe,Co,Ni,Cu,Zn,Ru,Rh,Pd,Ir,and Pt)as potential antimonate-based electrocatalysts for the *** stability and OER activity of these considered electrocatalysts were systematically studied under acidic *** was found that Rh-NiSb_(2)O_(6),Pt-CoSb_(2)O_(6),Rh-FeSbO4,and Co-NiSb_(2)O_(6)can serve as efficient and stable OER electrocatalysts,and their OER catalytic activities are better than that of the current state-of-the-art OER catalyst(IrO2).Our findings highlight a family of promising antimonate-based OER electrocatalysts for future experimental verification.

关键词： oxygen evolution reaction antimonates acid-stable oxides electrocatalysis density functional theory

Progress of China＇s Market Institution： Requiring a Stringent Implementation of Policies

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Fudan Journal of the Humanities and Social Sciences 2014年第4期7卷 601-619页

作者： Laurence Chin Yau yuen c/o Fuxiang Bay Hengqin New Area Zhuhai 519031 Guangdong China

Since reform, China＇s market institution has been gradually evolving, but is still facing insufficient competition owing to lower transparency, administrative interventions, and territorial limitations in certain areas. This paper reviews the applicability of market hypotheses to China, and analyzes the implications with respect to various markets and the resolution of the Third Plenary Session of the Eighteenth Central Committee Congress. It is vital for the relevant authorities to reinforce implementation of the resolution＇s initiatives. Following the new policies, it is expected that the market institution will be advanced to a higher level.

关键词： Resolution Market institution Markets Chinese enterprise Rural land

Thermodynamic analysis of reaction pathways and equilibrium yields for catalytic pyrolysis of naphtha

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Frontiers of Chemical Science and Engineering 2022年第12期16卷 1700-1712页

作者： Dongyang Liu Yibo Zhi yuen Bai Liang Zhao Jinsen Gao Chunming Xu State Key Laboratory of Heavy Oil Processing China University of Petroleum(Beijing)Beijing 102249China

The chain length and hydrocarbon type significantly affect the production of light olefins during the catalytic pyrolysis of ***,for a better catalyst design and operation parameters optimization,the reaction pathways and equilibrium yields for the catalytic pyrolysis of C_(5-8)n/iso/cyclo-paraffins were analyzed *** results revealed that the thermodynamically favorable reaction pathways for n/iso-paraffins and cyclo-paraffins were the protolytic and hydrogen transfer cracking pathways,***,the formation of light paraffin severely limits the maximum selectivity toward light *** dehydrogenation cracking pathway of n/iso-paraffins and the protolytic cracking pathway of cyclo-paraffins demonstrated significantly improved selectivity for light *** results are thus useful as a direction for future catalyst improvements,facilitating superior reaction pathways to enhance light *** addition,the equilibrium yield of light olefins increased with increasing the chain length,and the introduction of cyclo-paraffin inhibits the formation of light *** temperatures and low pressures favor the formation of ethylene,and moderate temperatures and low pressures favor the formation of propylene.n-Hexane and cyclohexane mixtures gave maximum ethylene and propylene yield of approximately 49.90%and 55.77%,*** work provides theoretical guidance for the development of superior catalysts and the selection of proper operation parameters for the catalytic pyrolysis of C_(5-8)n/iso/cyclo-paraffins from a thermodynamic point of view.

关键词： naphtha catalytic pyrolysis reaction pathway equilibrium yield