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Chinese Journal of Chemistry 2016年第9期34卷 878-886页

作者： Wei Chen Munil sin Ping-Jie Wei Qian-Ling Zhang Jin-Gang Liu Department of Chemistry East China University of Science and Technology Shanghai 200237 China Shenzhen Key Laboratory of Functional Polymer College of Chemistry and Environmental Engineering Shenzhen University Shenzhen Guangdong 518060 China

As alternatives to Pt-based electrocatalysts, the development of nonprecious metal catalysts with high performance in the cathodic oxygen reduction reaction （ORR） is highly desirable for widespread use in fuel cells. Here we report a simple approach for preparing pentabasic （Fe, B, N, S, P）-doped reduced graphene oxide （rGO） via a two-step doping method of adding boric acid and ferric chloride to ternary （N, S, P）-doped rGO （NSPG）. Electro- chemical investigation of the composites for the ORR revealed that simultaneously doping appropriate amounts of Fe and B into the NSPG produced a synergistic effect that endowed the prepared catalyst with both a positively shifted ORR half-wave potential and high selectivity for the 4e^-reduction of O2. The optimized Fe2B-NSPG catalyst approached a 4e^- process for the ORR with a half-wave potential （E1/2=0.90 V vs. RHE） even 30 mV higher than that of the commercial Pt/C catalyst in alkaline solution. Furthermore, relative to the Pt/C catalyst, the Fe2B-NSPG demonstrated superior stability and excellent tolerance of the methanol cross-over effect. This simple method afforded pentabasic （Fe, B, N, S, P）-doped rGO as a promising nonpreeious metal catalyst used for alkaline fuel cells.

关键词： oxygen reduction reaction reduced graphene oxide multiple dopant electrocatalysis

Symmetry-driven half-integer conductance quantization in Cobalt–fulvalene sandwich nanowire

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npj Computational Materials 2023年第1期9卷 314-321页

作者： Zhuoling Jiang Kah-Meng Yam Yee sin Ang Na Guo Yongjie Zhang Hao Wang Chun Zhang Department of Physics and Centre for Advanced 2D Materials National University of SingaporeSingapore 117551Singapore Science Mathematics and Technology(SMT)ClusterSingapore University of Technology and DesignSingapore 487372Singapore Department of Chemistry National University of SingaporeSingapore 117543Singapore National University of singapore Chongqing Research Institute 401123 ChongqingChina

Precise manipulation and monitoring spin transport in one-dimensional (1D) systems is a long-sought goal in the field of nano-spintronics. Based on first-principles calculations, we report the observation of half-integer conductance quantization in the Cobalt-fulvalene sandwich nanowire. Compared with a pure monatomic Cobalt wire, the introduction of fulvalene molecules leads to threeimportant features: Firstly, the strong coupling between the fulvalene and the Cobalt prevents the contamination of the ambientair, ensuring both chemical and physical stabilities;Secondly, the fulvalene symmetry-selectively filters out most of the d-typeorbitals of the Cobalt while leaving a single d-type orbital to form an open spin channel around the Fermi level, which offers amechanism to achieve the observed half-integer conductance;Thirdly, it maintains a superexchange coupling between adjacent Coatoms to achieve a high Curie temperature. Spin transport calculations show that this half-metallic nanowire can serve as a perfectspin filter or a spin valve device, thus revealing the potential of Cobalt-fulvalene sandwich nanowire as a promising building blockof high-performance spintronics technology.

关键词： sandwich coupling transport

Smart Proactive Caching Scheme for Fast Authenticated Handoff in Wireless LAN

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Journal of Computer Science & Technology 2007年第3期22卷 476-480页

作者： sin-Kyu Kim Jae-Woo Choi Dae-Hun Nyang Gene-Beck Hahn Joo-Seok Song Electronics Telecommunications Research Institute Daejeon Korea Graduate School of Information Technology and Telecommunications Inha University IncheonKorea Mobile Communication Technology Research Lab LG Electronics AnyangKorea Department of Computer Science Yonsei University SeoulKorea

Handoff in IEEE 802.11 requires the repeated authentication and key exchange procedures, which will make the provision of seamless services in wireless LAN more difficult. To reduce the overhead, the proactive caching schemes have been proposed. However, they require too many control packets delivering the security context information to neighbor access points. Our contribution＇ is made in two-fold： one is a significant decrease in the number of control packets for proactive caching and the other is a superior cache replacement algorithm.

关键词： wireless local area network (LAN) security authentication simulation

Heavy metal pollution assessment in marine sediments in the Northwest coast of Sabah,Malaysia

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China Geology 2023年第4期6卷 580-593页

作者： sin-Yi Ling Asis Junaidi Abdullah Mohd-Harun Musta Baba Faculty of Science and Natural Resources Universiti Malaysia SabahKota KinabaluSabah 88400Malaysia Small Island Research Center Universiti Malaysia SabahKota KinabaluSabah 88400Malaysia

Heavy metal contents along the Northwest coast of Sabah were determined to interpret the pollution level in the marine sediment. The metal abundance is regulated by the physico-chemical properties such as the average sediment pH(7.82, 9.00 and 8.99), organic matter(0.62%, 1.60%, and 2.27%), moisture content(25.00%, 29.70%, and 15.00%) and sandy texture in Kota Belud, Kudat and Mantanani Island,respectively. The major elements show Ca>Fe>Mg>Al>Mn for all study sites, while the heavy metals show Ni>Cr>Zn>Cu>Co>Pb, Cr>Ni>Zn>Cu>Pb>Co and Zn>Pb>Cr>Ni, for Kota Belud, Kudat and Mantanani Island, respectively. The pollution degree of heavy metals was evaluated by using the Sediment Quality Assessment(SQA). The SQA parameters indicated none to moderate pollution in Kota Belud that shows Class 0, Class 1 and Class 2 pollution. The parameters also indicated none to low pollution in Kudat and Mantanani Island that show only Class 0 pollution. The enrichment factor(EF) suggested minor to moderately severe metal enrichment by anthropogenic sources in Kota Belud, whereas only minor enrichment in Kudat and Mantanani Island. The modified pollution degree(MCD<1.5) and pollution load index(0 PLI<1) indicating only low pollution level in the marine sediments for all study sites. The objectives of this study are:(1) to determine the physico-chemical parameters of sediments,(2) interpret the heavy metal contents and(3) evaluate the sediment quality.

关键词： Physico-chemical properties Sediment quality Major elements Heavy metal pollution Ni-Cr-Zn-Cu-Co-Pb pollution Marine sediment Coastline

Comprehensive evaluation of marine waste heat recovery technologies based on Hierarchy-Grey correlation analysis

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Journal of Ocean Engineering and Science 2019年第4期4卷 308-316页

作者： Jong Ju-Yong Rim Chang-Hyon Choi Myong-sin Om Hyon-Chol Department of Energy Science Kim Il Sung UniversityPyongyangDemocratic People’s Republic of Korea College of Mechanical Science and Technical KimCheak University of TechnologyPyongyangDemocratic People’s Republic of Korea

In this study,comprehensive evaluation of the technologies on waste heat recovery technologies for maritime applications has been carried *** have focused our research on exhaust gas turbine system(EGT),thermodynamic organic rankine cycle(RC),Kalina cycle(KC)and thermoelectric generators(TG),which are the most appropriate and most up-to-date techniques for recovering power from marine *** technology has its own advantages and disadvantages,so the comprehensive evaluation of these technologies is essential to accurately determine which technology will be applied to which *** belongs to the multi-criteria decision(MCDM)*** combined assessment methodology,consisting of gray correlation and analysis hierarchy processes,has been applied to evaluate four waste heat recovery techniques in terms of technical,economic,social and environmental *** to the comparison results,the exhaust gas turbine system has been evaluated as the most promising technology among the various WHR technologies that can be applied to marine *** analysis suggests that if investment cost of TG falls to about the same level as the one of EGT,TG could be the best method among these *** of investment cost of TG technology could be realized by development of low cost thermoelectric *** have analyzed the correlation between each cost through DOE analysis and investigate the effect of individual costs on the total *** work helps in identifying the most suitable heat recovery technologies for marine engine.

关键词： Waste heat recovery Marine engine Grey relational analysis Analytic hierarchy process Comprehensive evaluation

A Novel Dynamic Quadrature Scheme for Solving Boltzmann Equation with Discrete Ordinate and Lattice Boltzmann Methods

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Communications in Computational Physics 2012年第4期11卷 1397-1414页

作者： C.T.Hsu S.W.Chiang K.F.sin Department of Mechanical Engineering Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong

The Boltzmann equation(BE)for gas flows is a time-dependent nonlinear differential-integral equation in 6 *** current simplified practice is to linearize the collision integral in BE by the BGK model using Maxwellian equilibrium distribution and to approximate the moment integrals by the discrete ordinatemethod(DOM)using a finite set of velocity quadrature *** simplification reduces the dimensions from 6 to 3,and leads to a set of linearized discrete *** main difficulty of the currently used(conventional)numerical procedures occurs when the mean velocity and the variation of temperature are large that requires an extremely large number of quadrature *** this paper,a novel dynamic scheme that requires only a small number of quadrature points is *** is achieved by a velocity-coordinate transformation consisting of Galilean translation and thermal normalization so that the transformed velocity space is independent of mean velocity and *** enables the efficient implementation of Gaussian-Hermite *** velocity quadrature points in the new velocity space are fixed while the correspondent quadrature points in the physical space change from time to time and from position to *** this dynamic nature in the physical space,this new quadrature scheme is termed as the dynamic quadrature scheme(DQS).The DQS was implemented to the DOM and the lattice Boltzmann method(LBM).These new methods with DQS are therefore termed as the dynamic discrete ordinate method(DDOM)and the dynamic lattice Boltzmann method(DLBM),*** new DDOM and DLBMhave been tested and validated with several testing *** the same accuracy in numerical results,the proposed schemes are much faster than the conventional ***,the new DLBM have effectively removed the incompressible and isothermal restrictions encountered by the conventional LBM.

关键词： Dynamics quadrature dynamic discrete ordinatemethod dynamic lattice Boltzmann method thermal lattice Boltzmann method

Cross-Linguistic Influence in Hong Kong ESL Learners' Acquisition of Conjunctions

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Fudan Journal of the Humanities and Social Sciences 2023年第4期16卷 515-539页

作者： Ming Sum Kong Mary Carr sin Wang Chong International Education Institute University of St.AndrewsKinessburn Kennedy GardensSt Andrews KY169DJUK Student Services University of DundeeDundee DD14HNUK

Language transfer is one of the most significant aspects of cross-linguistic *** can be divided into two types:positive and negative,the beneficial and det-rimental use of one language's acquired characteristics in *** study aims to investigate the L1(Chinese)influence on Hong Kong ESL learners'acquisition of conjunctions and whether the use of L1 has an impact on this *** online questionnaire combining questions about students'English learning experience and a grammatical judgement task was sent to a government-funded secondary school in Hong Kong and completed by 79 *** of both positive and negative transfer from Chinese to English was found by testing six conjunctions or conjunc-tion pairs:although...but,because...so,not only...but also,either...or,neither...nor,.and *** results suggest that Chinese is likely to have an impact on students'acquisition of conjunctions,and the use of Chinese in English classes can worsen negative transfer and boost positive *** degree of transfer might increase when more Chinese is used in *** alleviate the impact of Chinese transfer and to provide more effective L2 teaching,monitoring the use of L1 and regular evalua-tion might be *** can also adjust the amount of Chinese used according to the students'English proficiency level.

关键词： Cross-linguistic influence Language transfer Conjunctions Hong Kong ESL learners

Comparative transcriptome analysis reveals molecular adaptations underlying distinct immunity and inverted resting posture in bats

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Integrative Zoology 2023年第3期18卷 493-505页

作者： Jinwei WU Libiao ZHANG Chao SHEN Simon Yung Wa sin Caoqi LEI Huabin ZHAO Engineering Research Center of Eco-environment in Three Gorges Reservoir Region of Ministry of Education China Three Gorges UniversityYichangChina Guangdong Key Laboratory of Animal Conservation and Resource Utilization Guangdong Public Laboratory of Wild Animal Conservation and UtilizationInstitute of ZoologyGuangdong Academy of SciencesGuangzhouChina College of Life Sciences Wuhan UniversityWuhanChina School of Biological Sciences The University of Hong KongHong Kong SARChina

Understanding how natural selection shapes unique traits in mammals is a central topic in evolutionary *** mammalian order Chiroptera(bats)is attractive for biologists as well as the general public due to their speciﬁc traits of extraordinary immunity and inverted resting ***,genomic resources for bats that occupy key phylogenetic positions are not sufﬁcient,which hinders comprehensive investigation of the molecular mechanisms underpinning the origin of speciﬁc traits in ***,we sequenced the transcriptomes of 5 bats that are phylo-genetically divergent and occupy key positions in the phylogenetic tree of *** combination with the available genomes of 19 bats and 21 other mammals,we built a database consisting of 10918 one-to-one ortholog genes and reconstructed phylogenetic relationships of these *** found that genes related to immunity,bone remodeling,and cardiovascular system are targets of natural selection along the ancestral branch of *** analyses revealed that the T cell receptor signaling pathway involved in immune adaptation is speciﬁcally enriched in ***,molecular adaptations of bone remodeling,cardiovascular system,and balance sensing may help to explain the reverted resting posture in *** study provides valuable transcriptome resources,enabling us to tentatively identify genetic changes associated with bat-speciﬁc *** work is among theﬁrst to advance our understanding of the molecular underpinnings of inverted resting posture in bats,which could provide insight into healthcare applications such as hypertension in humans.

关键词： adaptation bats immunity resting posture transcriptome

The Edge-Balanced Properties of Product Graphs of Paths

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Journal of Mathematical Research with Applications 2023年第1期43卷 25-39页

作者： Zhenbin GAO Wei QIU sin-Min LEE College of Mathematical Sciences Harbin Engineering University 1786 Plan Tree Drive

In 2009, Kwong and Lee considered a new labeling problem of graph theory–the edge-balance index set of graph. In this paper, we investigated the edge-balanced properties of product of paths by using a method known as... 详细信息

关键词： vertex labeling edge labeling embedding graph boundary vertex inner vertex P_m × P_n

Quality Input and Sustainability in Early Immersion Classrooms:A Case Study of an Experimental School in Macao

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Frontiers of Education in China 2011年第1期6卷 92-105页

作者： Sylvia S.L.IEONG LAU sin Peng Faculty of Education University of MacaoMacaoChina Macao Chinese Educators’Association MacaoChina

This paper looks into the case of a school in Macao nominated as the first(and so far the only)China-Canada-United States English Immersion(CCUEI)centre in the Macao Special Administrative Region(Macao SAR)China for the experimentation and application of English immersion instruction(EI)in the K1-3 and Primary 1-2 *** on Krashen’s Input Hypothesis(1982)and Cummins’(2000)framework of instruction for language learning and academic achievement in the formal school context,the authors report their observations by analyzing the data collected from school teachers and participation in classes and by reflecting on their experiences,and suggest improvement that can be made to teachers’linguistic and communicative competence,in terms of quantity and quality of comprehensible input and expected output,and thus the sustainability of English immersion classrooms in a Chinese context.

关键词： English immersion instruction(EI) Input Hypothesis teacher development and quality input continuity and sustainability in school context