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spatial and environmental determinants of plant species diversity in a temperate desert

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Journal of Plant Ecology 2016年第2期9卷 124-131页

作者： Rong zhang Tong Liu Jin-long zhang Qin-ming Sun College of Life Sciences Shihezi University4 North RoadShiheziXinjiang 832003China Coastal Ecosystems Research Station of the Yangtze River Estuary Ministry of Education Key Laboratory for Biodiversity Science and Ecological EngineeringInstitute of Biodiversity ScienceFudan University2005 Songhu RoadShanghai 200438China Flora Conservation Department Kadoorie Farm and Botanic GardenLam Kam RoadTai PoNew TerritoriesHong Kong

Aims Deserts are one of the ecosystems most sensitive to global climate ***,there are few studies examining how changing abiotic and biotic factors under climate change will affect plant species diversity in the temperate deserts of *** study aimed to:(i)characterize species distributions and diversity patterns in an Asian temperate desert;and(ii)to quantify the effects of spatial and environment variables on plant species *** We surveyed 61 sites to examine the relationship between plant species diversity and several spatial/environmental variables in the Gurbantunggut *** and environmental variables were used to predict plant species diversity in separate multiple regression and ordination *** in species responses to spatial and environmental conditions was partitioned by combining these variables in a redundancy analysis(RDA)and by creating multivariate regression trees(MRT).Important Findings We found 92 plant species across the 61 *** and geographic location were the dominant environmental factors underlying variation in site species richness.A RDA indicated that 93%of the variance in the species–environment relationships was explained by altitude,latitude,longitude,precipitation and slope *** and topographic heterogeneity,through their effects on water availability,were more important than soil chemistry in determining the distribution of *** analyses categorized communities into four groups based on latitude,soil pH and elevation,explaining 42.3%of the standardized species *** pH strongly influenced community composition within homogeneous geographic *** findings suggest that precipitation and topographic heterogeneity,rather than edaphic heterogeneity,are more closely correlated to the number of species and their distributions in the temperate desert.

关键词： Gurbantunggut Desert ephemerals redundancy analysis species richness soil pH

Highly stable Eu-coordination polymer exhibiting the highest quantum yield

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Science China Chemistry 2023年第5期66卷 1400-1405页

作者： ming-Yu Ye ming-Xuan zhang Qiao-Fei Xu Han Xu La-Sheng long Lan-Sun Zheng State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry College of Chemistry and Chemical EngineeringXiamenUniversityXiamen361005China

Lanthanide luminescent materials with high quantum yield and thermal stability are of key importance for their practical *** we report crystal structures and luminescent properties of[Eu(pfbz)_(2)(phen)Cl](1)and[Tb(pfbz)2(phen)Cl](2)(pfbz=Pentafluorobenzoate).Single-crystal analysis reveals that both 1 and 2 crystallize in a polar space group of *** on their luminescent properties indicates that the solid-state quantum yields of 1 and 2 are 97.7%and 90.7%,respectively,while their efficiency of the sensitization process is as high as 100%,revealing that polar structures are more favorable to obtain high quantum *** analysis reveals that both 1 and 2 can be stable up to 240℃.More importantly,temperature-dependent luminescent spectra of 1 indicate its luminescent intensity at 612 nm only decreased by 5%from room temperature to 373 K,whereas at 373 K,its luminescent intensity remains almost constant for 36 *** that1 represents the highest quantum yield among known Eu-coordination polymers and its performance as the LED material is better than that of commercially widely used luminescent materials of(Sr,Ca)Al Si N3:Eu(630 nm)and(Sr,Ca)Al Si N3:Eu(640 nm),the present work provides an excellent substitute for commercial LED materials.

关键词： lanthanide coordination polymers luminescence LED materials

Enhanced Upconversion Emissions of TiO_(2):Yb^(3+)/Tm^(3+) Nanocrystals: Comparison with Different Effects of Li^(+),Mn^(2+) and Cu^(2+) Ions

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Chinese Journal of Structural Chemistry 2021年第10期40卷 1379-1384页

作者： JI He-ming XU ming-Guang zhang Hai-Yan LI Xiao-long QIAN Yan-Nan Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter School of Materials and EnergyGuangdong University of TechnologyGuangzhou 510006China School of Mechanical and Electrical Engineering Yunnan Agricultural UniversityKunming 650201China

Codoping with M^(n+) ions (M^(n+)=Li^(+),Mn^(2+) and Cu^(2+)) enhanced the blue and red upconversion (UC)emissions in TiO_(2):Yb^(3+)/Tm^(3+) nanocrystals under 980 nm *** different effects of Li^(+),Mn^(2+) and Cu^(2+) ions on the phase structures,morphologies and optical characteristics of TiO_(2):Yb^(3+)/Tm^(3+)were *** minor shifting in the diffraction peaks at 25.2°was observed for TiO_(2):Yb^(3+)/Tm^(3+)/Li^(+),and adding Mn^(2+) ions remained almost the same position of diffraction peaks,while the introduction of Cu^(2+) ions resulted in the shift of the diffraction peaks towards the larger ***_(2):Yb^(3+)/Tm^(3+)/Li^(+)and TiO_(2):Yb^(3+)/Tm^(3+)/Mn^(2+) nanosheets and the sphere-like TiO_(2):Yb^(3+)/Tm^(3+)/Cu^(2+) were *** mechanisms for increased UC emissions caused by adding Li^(+),Mn^(2+) and Cu^(2+) ions were attributed to the tailored local environment around Tm^(3+) ions,efficient energy transition between Mn^(2+) -Yb^(3+) dimer and Tm^(3+) ions,and the localized surface plasmon resonance (LSPR) of Cu^(2+) ions,respectively.

关键词： TiO_(2):Yb^(3+)/Tm^(3+) Li^(+) Mn^(2+)and Cu^(2+) optical characteristics

Characteristics of Early Cretaceous wildfires in peat-forming environment, NE China

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Journal of Palaeogeography 2019年第3期8卷 238-250页

作者： Shuai Wang long-Yi Shao Zhi-ming Yan ming-Jian Shi Yun-He zhang College of Geoscience and Surveying Engineering China University of Mining and Technology (Beijing)

Inertinite maceral compositions in coals from the Early Cretaceous Erlian, Hailar, and Sanjiang Basins in NE China are analyzed in order to reveal palaeowildfire events and palaeoclimate variations. Although huminite is the dominant maceral group in the studied basins, the inertinite group, as a byproduct of palaeowildfires, makes up a considerable proportion. Occurrence of inertinite macerals indicates that wildfires were widespread and frequent,and supports the opinion that the Early Cretaceous was a "high-fire" interval. Inertinite contents vary from 0.2% to 85.0%, mostly within the range of 10%–45%, and a model-based calculation suggests that the atmospheric oxygen levels during the Aptian and Albian(Early Cretaceous) were around 24.7% and 25.3% respectively. Frequent fire activity during Early Cretaceous has been previously related to higher atmospheric oxygen concentrations. The inertinite reflectance, ranging from 0.58%Ro to 2.00%Ro, indicates that the palaeowildfire in the Early Cretaceous was dominated by ground fires, partially reaching-surface fires. These results further support that the Cretaceous earliest angiosperms from NE China were growing in elevated O2 conditions compared to the present day.

关键词： Inertinite Coal Wildfire Palaeo-atmospheric oxygen level Angiosperm Early Cretaceous NE China

Characterization of the copper-containing amine oxidase from Trifolium pratense seedlings

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Nuclear Science and Techniques 2016年第3期27卷 138-144页

作者： Yong-ming zhang Guo-long Li Rui-Bo ZhongYu-Xing Ma Pei Gong Feng zhang College of Life Science and Technology Inner Mongolia Normal UniversityHohhot 010022China Sugar beet Physiological Institute Inner Mongolia Agricultural UniversityHohhot 010019China Agricultrual Nanocenter School of Life SciencesInner Mongolia Agricultural UniversityHohhot 010018China

We studied the kinetic characterizations of the Trifolium pratense seedlings copper-containing amine oxidase(TPAO) by using various amine-containing *** catalyzing rate for all of amine-containing substrates can be ordered as diamines > polyamines > aromatic monoamines,and it shows an apparent trend in each category of substrates such as the longer the carbon chain,the lower the V_(max) is,so does the V_(max)/K_m values but is opposite for the K_m value of *** distinct differences between the kinetic parameters for different amine-containing substrates indicated that the rate-determining step of the catalytic reaction strongly depends on the substrate's chemical *** is concluded that both pH and ionic strength can affect the catalytic activity of TPAO via influencing the coulomb interaction-mediated enzyme-substrate docking processes,which can be attributed to the potential of charged groups from both substrates and the activity sites of TPAO by the regulation of ionic strength.

关键词：胺氧化酶含铜幼苗红三叶表征库仑相互作用催化速率离子强度

Physical Properties of Polymers under Soft and Hard Nanoconfinement: A Review

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Chinese Journal of Polymer Science 2020年第6期38卷 565-578页

作者： ming-Chao Ma Yun-long Guo University o f Michigan-Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong UniversityShanghai 200240China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai200240China

Polymeric materials under nanoconfinements have substantially deviated physical properties with respect to the bulk,especially glass transition temperature,physical aging,and crystallization *** we highlight the leading methods for creating various confinement *** these systems,recent advances on hard and soft confinement effect for glass transition,physical aging,mechanical properties and crystallization of polymers are reviewed in ***,as nanoconfined systems in extreme conditions are experimentally inaccessible,simulation results describing confinement effect on such systems are also discussed.

关键词： Nanoconfinement Glass transition temperature Physical aging Mechanical properties Crystallization

骨骼肌血管合成蛋白VEGF的调控通路研究综述

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体育科学研究 2018年第4期22卷 62-68页

作者：杨小月陈建明刘小龙张娟林家仕集美大学体育学院福建厦门361021

目前国内外学者研究运动对线粒体生物合成的通路比较成熟,然而研究运动对骨骼肌血管内皮生长因子(vascular endothelial growth factor,VEGF)的具体通路较少。而骨骼肌中的血管因为线粒体生物合成提供氧气和能源物质,所以两者关系密切... 详细信息

目前国内外学者研究运动对线粒体生物合成的通路比较成熟,然而研究运动对骨骼肌血管内皮生长因子(vascular endothelial growth factor,VEGF)的具体通路较少。而骨骼肌中的血管因为线粒体生物合成提供氧气和能源物质,所以两者关系密切。遂针对此现状通过文献查阅法和逻辑分析法,综述以往国内外相关研究,拟出主要的四条通过VEGF调控骨骼肌血管合成的通路,为后来研究者提供理论依据和研究思路。

关键词：血管合成血管内皮生长因子过氧化物酶体增殖物受体γ共激活因子1a 信号转导通路心肺耐力

Numerical simulation and structure improvement of double throttling in a high parameter pressure reducing valve

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第2期14卷 137-146页

作者： Zhi-jiang JIN Lin WEI Li-long CHEN Jin-yuan QIAN ming zhang Institute of Chemical Machinery and Process Equipment Zhejiang University Hangzhou Worldwides Valve Co. Ltd.

In this paper, a new pressure reducing valve （PRV） with an orifice plate is proposed. The main objective is to explain the mechanisms of pressure reduction and energy conversion in the new PRV. A numerical simulation method was used to investigate the PRV internal flow field and to analyze the throttling effects of the orifice plate and the transform of thermal parameters as outlet pressure, outlet temperature, velocity, and superheat. A structure improvement method for the valve body and orifice plate is put forward to reduce energy loss. The governing equations for internal flow numerical simulation are composed of the continuity, momentum, energy and k-e transport equations, based on isotropic eddy viscosity theory. Different valve plug displacement models were built to describe the double throttling process. Our analysis shows that the steam pressure drops twice and the degree of superheat increases. There are also lots of eddies which clog the flow channel and disturb the steam flow in the valve cavity after the valve plug and the outlet cavity. After modifying the structure, the numerical results show a better performance of steam flow.

关键词： Numerical simulation Pressure and temperature reducing system Pressure reducing valve (PRV) Double throttling Structural improvement

Investigation of shale gas microflow with the Lattice Boltzmann method

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Petroleum Science 2015年第1期12卷 96-103页

作者： Xiao-Ling zhang Li-Zhi Xiao long Guo Qing-ming Xie State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum Key Laboratory of Shale Gas Exploration Ministry of Land and Resources Chongqing Institute of Geology and Mineral Resources

In contrast to conventional gas-bearing rocks, gas shale has extremely low permeability due to its nano- scale pore networks. Organic matter which is dispersed in the shale matrix makes gas flow characteristics more complex. The traditional Darcy＇s law is unable to estimate matrix permeability due to the particular flow mechanisms of shale gas. Transport mechanisms and influence factors are studied to describe gas transport in extremely tight shale. Then Lattice Boltzmann simulation is used to establish a way to estimate the matrix permeability numerically. The results show that net desorption, diffu- sion, and slip flow are very sensitive to the pore scale. Pore pressure also plays an important role in mass fluxes of gas. Temperature variations only cause small changes in mass fluxes. The Lattice Boltzmann method can be used to study the flow field in the micropore spaces and then provides numerical solutions even in complex pore structure models. Understanding the transport characteristics and establishing a way to estimate potential gas flow is very important to guide shale gas t＇eserve estimation and recovery schemes.

关键词： Shale gas Permeability Adsorption Desorption Diffusion Slip effect