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Chinese Journal of Structural Chemistry 2020年第10期39卷 1763-1769,1741页

作者： GAO quan-dang YANG E College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350007China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China

Using density functional theory(DFT)combined with nonequilibrium Green?s function investigates the electron-transport properties of several molecular junctions based on the[2,5?]bipyrimidinyl(biphenyl isocyanide)gold(Ⅰ)molecule(BPM-Au(Ⅰ)CN-BP),which is modified by one to three alkyl groups forming BPM-Au(Ⅰ)CN-BP(CH2)*** asymmetric current-voltage characteristics have been obtained for the molecular *** performance of Au/S-BPM-Au(I)CN-BP-S/Au molecular junction can be regulated by introducing alkyl *** M1 molecular junction exhibits the best rectifying *** maximum rectifying ratio is 2109,which is about 150 times more than that of the molecular junction based on the original ***,all the systems modified by alkyl group have obvious negative differential resistance behavior(NDR).The current-voltage(Ⅰ-Ⅴ)curves of all the systems in this work are illustrated by transmission spectra.

关键词： the first-principles isocyanide gold(Ⅰ)compound alkyl chain rectifying ratio

Formation of Fe-19 wt%Cr-9 wt%Ni Nanocrystalline Alloy with Excellent Corrosion Resistance: Phase Transition and Microstructure

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Acta Metallurgica Sinica(English Letters) 2021年第6期34卷 825-833页

作者： Chongfeng Sun Shengqi Xi xiaofeng dang Jianping Li Yongchun Guo Zhong Yang Yaping Bai School of Materials and Chemical Engineering Xi'an Technological UniversityXi'an 710021China State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China

In this paper,microstructure characteristics and phase transitions of Fe-19 wt%Cr-9 wt%Ni nanocrystalline alloy are comprehensively studied during the mechanical alloying and hot pressing sintering *** resistance of the sintered Fe-19 wt%Cr-9 wt%Ni nanocrystalline alloy samples is further *** the mechanical alloying process,Fe-19 wt%Cr-9 wt%Ni nanocrystalline alloy powders mainly composed of metastable ferrite phase are obtained after mechanical alloying for 8,16 and 24 h,*** the subsequent hot pressing sintering process,the phase transitions(from ferrite to austenite)occur from 650 to 750°C for Fe-19 wt%Cr-9 wt%Ni alloy powders milled for 24 *** the sintering temperature is raised to 1050°C for 1 h,the ferrite phase has transformed into austenite phase completely,and the obtained grain size of sintered Fe-19 wt%Cr-9 wt%Ni alloy is around 40 *** test of the sintered Fe-19 wt%Cr-9 wt%Ni alloy has been operated in 0.5 mol L^(-1) H_(2)SO_(4) solution to show the corrosion resistance *** show that the sintered Fe-19 wt%Cr-9 wt%Ni alloy exhibits excellent corrosion resistance,which is proved by higher self-corrosion potential,lower self-corrosion current density and larger capacitive reactance,compared with that of commercial 304 stainless steel.

关键词： Mechanical alloying Hot pressing sintering Nanocrystalline alloy Phase transition Corrosion resistance

Experimental Research on Structural Behaviors of Glulam I-Beam with a Special-Shaped Section

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Journal of Renewable Materials 2020年第2期8卷 113-132页

作者： Ruyuan Yang Chaokun Hong xiaofeng Zhang quan Yuan Youfu Sun College of Materials Science and Engineering Nanjing Forestry UniversityNanjingChina College of Civil Engineering Nanjing Forestry UniversityNanjingChina College of Media and Art Nanjing University of Information Science&TechnologyNanjingChina

In order to enhance the bearing capacity of structural components,save materials,and reduce cost,a glued laminated timber(glulam)I-beam that is theoretically suitable for engineering application was *** this study,18 glulam specimens were fabricated using larch dimension lumber and resorcinol-formaldehyde ***-point bending tests were carried out to compare the ultimate bearing capacity,strain,and deflection of various *** results showed that:(1)The typical failure mode at bending is the web shear failure parallel to *** the failure,cracks and sounds appear at the beam web,which represent the sudden brittle failure.(2)The cross-sectional strain of glulam beam changed linearly with the beam height,indicating that the plane section assumption was basically established.(3)Stiffener could improve the initial flexural stiffness of glulam beam,which experiences an increase of 28.21%.Larger the shear span ratio,smaller the initial flexural *** initial flexural stiffness improves by 10-23.5%with the increase in the thickness of the lower flange.(4)The effects of stiffener and shear-span ratio on shear strength are relatively *** the stiffeners are set at the support and the loading point in pairs,the shear strength of the glulam beam increases by 15.05%*** the increase in the shear-span ratio,the shearing strength of the glulam I-beam gradually *** equation of the shearing strength with the shear span ratio is obtained,which is shown by high fitting precision.(5)The shear strength correlation,as proposed by Soltis and Rammer,is suitable not only for rectangular beams,but also for glulam I-beams.

关键词： Glulam I-beam stiffener shear span ratio flange thickness

Path Planning Approach in Unknown Environment

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International Journal of Automation and computing 2010年第3期7卷 310-316页

作者： Ting-Kai Wang quan dang Pei-Yuan Pan Faculty of Computing London Metropolitan University London N7 8DB UK

This paper presents a new algorithm of path planning for mobile robots, which utilises the characteristics of the obstacle border and fuzzy logical reasoning. The environment topology or working space is described by the time-variable grid method that can be further described by the moving obstacles and the variation of path safety. Based on the algorithm, a new path planning approach for mobile robots in an unknown environment has been developed. The path planning approach can let a mobile robot find a safe path from the current position to the goal based on a sensor system. The two types of machine learning： advancing learning and exploitation learning or trial learning are explored, and both are applied to the learning of mobile robot path planning algorithm. Comparison with A＊ path planning approach and various simulation results are given to demonstrate the efficiency of the algorithm. This path planning approach can also be applied to computer games.

关键词： Path planning fuzzy reasoning unknown environment mobile robot learning algorithm.

Spatiotemporal Trend Analysis of Precipitation Extremes in Ho Chi Minh City, Vietnam During 1980–2017

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International Journal of Disaster Risk Science 2021年第1期12卷 131-146页

作者： Nguyen Trong quan Dao Nguyen Khoi Nguyen Xuan Hoan Nguyen Ky Phung Thanh Duc dang Faculty of Environmental and Food Engineering Nguyen Tat Thanh UniversityHo Chi Minh City 700000Vietnam Faculty of Environment University of ScienceHo Chi Minh City 700000Vietnam Vietnam National University Ho Chi Minh City 700000Vietnam Ho Chi Minh City University of Food Industry Ho Chi Minh City 700000Vietnam Institute for Computational Science and Technology Ho Chi Minh City 700000Vietnam Engineering Systems and Design Pillar Singapore University of Technology and DesignTampines 487372Singapore

In this study,the spatiotemporal variability of trends in extreme precipitation events in Ho Chi Minh City during the period 1980–2017 was analyzed based on several core extreme precipitation indices(Rx1 day,Rx5 day,CDD,CWD,R20 mm,R25 mm,R95 p,and SDII).The nonparametric Mann–Kendall and Sen’s slope methods were used to compute the statistical strength,stability,and magnitude of trends in annual rainfall,as well as the extreme precipitation *** found that 64%of the stations had statistically significant upward trends in yearly rainfall,with high magnitudes frequently observed in the northern and southern regions of the *** the extreme precipitation indices,only SDII and R25 mm showed dominantly significant ***,there were increasing trends in the frequency and duration at the southern and central regions of the city during the study ***,El Ni?o-Southern Oscillation and Pacific Decadal Oscillation positively correlated with the duration and negatively correlated with the intensity and frequency of extreme ***,water management plans should be adjusted appropriately to reduce the severe impacts of precipitation extremes on communities and ecosystems.

关键词： Spatiotemporal trend Extreme precipitation Extreme precipitation indices Ho Chi Minh City

Habitat heterogeneity and biotic interactions mediate climate influences on seedling survival in a temperate forest

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Forest Ecosystems 2023年第5期10卷 579-588页

作者： Haikun Liu Hang Shi quan Zhou Man Hu Xiao Shu Kerong Zhang quanfa Zhang Haishan dang Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of SciencesWuhan430074China University of Chinese Academy of Sciences Beijing100049China

Seedling stage has long been recognized as the bottleneck of forest regeneration,and the biotic and abiotic processes that dominate at seedling stage largely affect the dynamics of *** might be particularly vulnerable to climate stress,so elucidating the role of interannual climate variation in fostering community dynamics is crucial to understanding the response of forest to climate *** seedling survival data of 69 woody species collected for five consecutive years from a 25-ha permanent plot in a temperate deciduous forest,we identified the effects of biotic interactions and habitat factors on seedling survival,and examined how those effects changed over *** found that interannual climate variations,followed by biotic interactions and habitat conditions,were the most significant predictors of seedling *** light showed a positive impact on seedling mortality,and seedling survival responded differently to soil and air *** of conspecific neighbor density were significantly strengthened with the increase of maximum air temperature and vapor pressure deficits in the growing season,but were weakened by increased maximum soil temperature and precipitation in the non-growing ***,seedling survival was strongly correlated with interannual climate variability at all life stages,and the strength of the correlation increased with seedling *** addition,the importance of biotic and abiotic factors on seedling survival differed significantly among species-trait ***,the neighborhood-mediated effects on mortality might be significantly contributing or even inverting the direct effects of varying abiotic conditions on seedling survival,and density-dependent effects could not be the only important factor influencing seedling survival at an early stage.

关键词： Seedling survival Extreme interannual climate Negative density-dependence Species coexistence

Patterns of species diversity and its determinants in a temperate deciduous broad-leaved forest

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Forest Ecosystems 2022年第5期9卷 647-656页

作者： Rui He Man Hu Hang Shi quan Zhou Xiao Shu Kerong Zhang quanfa Zhang Haishan dang Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of SciencesWuhan430074China University of Chinese Academy of Sciences Beijing100049China

Biodiversity conservation has long been a subject of extreme interest to community ecologists,with a particular focus on exploring the underlying causes of species diversity based on niche and neutral *** study aims to identify the potential determinants of species diversity in a deciduous broad-leaved forest in the transitional region from subtropical to temperate climate in *** collected woody plant data and environmental variables in a fully mapped 25-ha permanent forest plot,partitioned the beta-diversity into local contributions(LCBD)and species contributions(SCBD),and then applied multivariate linear regression analysis to test the effects of biotic and abiotic factors on alpha-diversity,LCBD,and *** used variation partitioning in combination with environmental variables and spatial distance to determine the contribution of environment-related variations versus spatial *** results showed that the indices of alpha-diversity(i.e.,species abundance and richness)were positively correlated with soil available phosphorus(P)and negatively with *** the betadiversity,environment and space together explained nearly half of the variations in community *** 60%of the variation of LCBD in the understory layer,40%in the substory layer,and 29%in the canopy layer were jointly explained by topographic,soil and biological variables,with biotic factors playing a dominant role in determining the *** abundance accounted for a large proportion of the variations in SCBD in each vertical stratum,and niche position(NP)was the ecological trait that significantly affected the variations in SCBD in the substory and canopy *** findings help to gain better understanding on how species diversity in forest ecosystem responds to environmental conditions and how it is influenced by biotic factors and ecological traits of species.

关键词： Alpha-diversity Beta-diversity Vertical strata Multivariate linear regression

Effect of rare-earth element Sm on the corrosion behavior of Mg-6Al-1.2Y-0.9Nd alloy

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Rare Metals 2010年第6期29卷 557-560页

作者： LI quan’an,LI xiaofeng,ZHANG Qing,and CHEN Jun School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471003,China School of Materials Science and Engineering Henan University of Science and Technology Luoyang China

The effect of Sm（0 wt.%-2 wt.%） addition on the corrosion behavior of Mg-6Al-1.2Y-0.9Nd alloy in 3.5 wt.% NaCl solution has been studied by static corrosion tests,corrosion morphology observation,corrosion scale and microstructure *** results show that,with the increasing of Sm content,the corrosion rate of the alloy decreases at first,then increases and reaches the valley at 0.5 wt.% *** reason is that the proper content of Sm addition can refine the precipitates and make the component and microstructure uniform,and therefore,it remarkably improves the corrosion resistance of the alloy.

关键词： magnesium alloys samarium corrosion behavior microstructure

Computed tomography and photoacoustic imaging guided photodynamic therapy against breast cancer based on mesoporous platinum with insitu oxygen generation ability

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Acta Pharmaceutica Sinica B 2020年第9期10卷 1719-1729页

作者： Lingyan Zhang Mifang Li quan Zhou Meng dang Yuxia Tang Shouju Wang Jijun Fu Zhaogang Teng Guangming Lu Department of Medical Imaging Jinling HospitalThe First School of Clinical MedicineSouthern Medical UniversityNanjing 210002China Department of Medical Imaging The Third Affiliated HospitalSouthern Medical UniversityGuangzhou 510630China Key Laboratory for Organic Electronics&Information Displays and Institute of Advanced Materials Jiangsu Key Laboratory for BiosensorsJiangsu National Synergetic Innovation Centre for Advanced MaterialsNanjing University of Posts and TelecommunicationsNanjing 210046China Departm ent of Medical Imaging Jiangsu Province HospitalNanjing 210029China Key Laboratory of Molecular Target&Clinical Pharmacology School of Pharmaceutical SciencesGuangzhou Medical UniversityGuangzhou 511436China

Photodynamic therapy(PDT)has been widely used in cancer ***,hypoxia in most solid tumors seriously restricts the efficacy of *** improve the hypoxic microenvironment,we designed a novel mesoporous platinum(mPt)nanoplatform to catalyze hydrogen peroxide(H2 O2)within the tumor cells in situ without an extra *** the fabrication,the carboxy terminus of the photosensitizer chlorin e6(Ce6)was connected to the amino terminus of the bifunctional mercaptoaminopolyglycol(SH-PEG-NH2)by a condensation reaction,and then PEG-Ce6 was modified onto the mPt moiety via the mercapto terminal of ***,cellular and animal experiments demonstrated that Pt@PEG-Ce6 catalyzed H2 O2 to produce oxygen(O2)and that Ce6 transformed O2 to generate reactive oxygen species(ROS)upon laser *** Pt@PEG-Ce6 nanoplatform with uniform diameter presented good biocompatibility and efficient tumor *** to the high atomic number and good near-infrared absorption for Pt,this Pt@PEG-Ce6 nanoplatform showed computed tomography(CT)and photoacoustic(PA)dual-mode imaging ability,thus providing an important tool for monitoring the tumor hypoxic ***,the Pt@PEG-Ce6 nanoplatform reduced the expression of hypoxia-inducible factor-la(HIF-1α)and programmed death-1(PD-1)in tumors,discussing the relationship between hypoxia,PD-1,and PDT for the first time.

关键词： Mesoporous platinum Photodynamic therapy Tumor hypoxia Photoacoustic imaging Computed tomography imaging