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Sustainable shape memory polymers based on epoxidized natural rubber cured by zinc ferulate via oxa-Michael reaction

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International Journal of Smart and Nano Materials 2015年第4期6卷 195-210页

作者： Xuhui Zhang Tengfei Lin Zhenghai Tang kailun sun Baochun Guo Department of Polymer Materials and Engineering South China University of TechnologyGuangzhou 510640P.R.China

Although various shape memory polymers(SMPs)or diverse applications have been widely reported,the SMPs based on rubbers have been rarely realized due to the low triggering temperature of *** another aspect,the SMPs based on sustainable substances are highly desired for the growing shortage in fossil *** the present study,we accordingly developed the sustainable SMPs with tunable triggering temperature,based on natural rubber(NR)and ferulic acid(FA)as the raw ***,the SMPs are based on a crosslinked network of epoxidized natural rubber(ENR)crosslinked by in situ formed zinc ferulate(ZDF)via oxa-Michael *** excellent shape memory effect(SME)is found in these SMPs,as evidenced by the high fixity/recovery ratio and the tunable triggering *** the incorpora-tion of natural halloysite nanotubes(HNTs),the stress and recovery rate of the SMPs are found to be tunable,which widens the application of this kind of *** combination of adoption of sustainable raw materials,and the excellent and tunable SME makes these SMPs potentially useful in many applications,such as various actuators and heat-shrinkable package materials.

关键词： shape memory polymers epoxidized natural rubber ferulic acid oxa-Michael reaction sustainable

Effect of Troglitazone on Expression of Adhesion Molecules and eNOS in Human Saphenous Vein Gaft

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Journal of Huazhong University of Science and Technology(Medical Sciences) 2007年第6期27卷 657-659页

作者：陈澍胡志伟张凯伦苏伟孙宗全 Department of Cardiovascular Surgery Union Hospital Tongji Medical College Huazhong University of Science and Technology

To investigate whether peroxisome proliferators-activated receptor-γ （PPARγ） ligand Troglitazone can reduce endothelial injury and activation during storage of harvested saphenous vein grafts. Segments of human saphenous vein graft were collected from 9 patients undergoing coronary bypass surgery and then divided into two equal parts of control and test specimens, were stored in ei- ther heparinized blood （control group） or heparinized blood containing 20 μmol/L troglitazone （test group） for 1 h at room temperature. Tissue distribution and protein expression of VCAM-I, ICAM-I, and endothelial nitric oxide synthase （eNOS） were compared using immunohistochemistry and Western blot analysis. Myeloperoxidase （MPO） activity, a marker of neutrophil sequestration in human saphenous vein grafts, was also measured in each group. The expression of ICAM-1 （753±132 versus 7201±934; P〈0.01） , VCAM-1 （3731±294 versus 8292±793; P〈0.01）, and MPO activity （1.52±0.42 U/g, 5.04±1.26 U/g P〈0.01） were significantly lower in test group. In contract, eNOS expression （7983±834 versus 3989±1008; P〈0.01） was significantly higher in test group. PPARγ ligand troglitazone might reduce endothelial injury during the storage period of human saphenous vein grafts.

关键词： Troglitazone adhesion molecule endothelial nitric oxide synthase saphenous vein graft

Divergent responses of runoff to climate change in the upper basins of the Third Pole dominated by westerlies and monsoon

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Science China Earth Sciences 2024年第8期67卷 2592-2614页

作者： Qikai sun Fengge SU He sun State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100101China

The diverse climates,distribution of snow and glaciers,and geographic locations directly affect the runoff response to climate change in the upper basins of the Third *** present,a comprehensive analysis of runoff variations and their distinct responses to climate change in the westerlies-and monsoon-dominated upper basins is still *** study comprehensively analyzed annual runoff variations in westerlies-dominated basins(the upper basins of the Aksu(UAKS),Syr Darya(USRD),Yarkant(UYK),Hotan(UHT),Amu Darya(UAMD),and Indus(UI))and monsoon-dominated basins(the upper basins of the Yangtze(UYA),Yellow(UYE),Lancang(ULC),Nujiang(UNJ),and Yarlung Zangbo(UYZ))of the Third Pole from 1961 *** multi-source meteorological data and large-scale circulation factors,this study investigated the divergent responses of runoff in the upper basins to climate change,and explored the large-scale circulation mechanisms underlying runoff variations in these upper *** results showed that:(1)The annual runoff in the majority of upper basins(except for the UYE and UYZ)exhibited an increasing trend,and the annual runoff in the UAKS,UYK,and UI showed a significant increasing trend from1961 to *** annual runoff in the upper basins of the Third Pole changed abruptly from decreasing to increasing between the 1980s and 2000s,with the exception of the UYE.(2)The runoff in the monsoon-dominated upper basins has been controlled primarily by changes in precipitation over the past 55 *** contrast,the runoff in the westerlies-dominated upper basins exhibited three distinct long-term responses to climate change:temperature-dominated(UYK and UHT),precipitation-dominated(USRD and UAMD),and the combined influence of precipitation and temperature(UAKS and UI).Since the 1960s,the sensitivity of runoff to warm season temperature changes in the most westerlies-dominated upper basins has decreased,while the response of runoff to precipitation changes has intensified.(3)The stud

关键词： Upper basins of the Third Pole Climate change Westerlies and monsoon Runoff variations Large-scale circulation factors

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Fossil Equidae in the Linxia Basin with Biostratigraphic and Paleozoogeographic Significance

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 1-9页

作者： sun Boyang Key Laboratory of Vertebrate Evolution and Human Origins of the Chinese Academy of Sciences Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China

The Linxia Basin is characterized by an abundance of Cenozoic sediments,that contain exceptionally rich fossil *** are abundant in the Linxia Basin,the fossil record of equids in this region including 16 species that represent 10 *** comparison to other classic late Cenozoic areas in China,the Linxia Basin stands out,because the fauna and chronological data accompanying Linxia equids render them remarkably useful for *** anchitheriines in the region,such as Anchitherium and Sinohippus,represent early equids that appeared in the late stages of the middle and late Miocene,*** the equines,most species of Chinese hipparions have been identified in the Linxia Basin and some species of the genera Hipparion and Hippotherium have FAD records for ***,Equus eisenmannae is one of the earliest known species of Equus in the Old World and is well-represented at the Longdan *** species with precise geohistorical distributions can serve as standards for high-resolution chronological units within this *** at the eastern margin of the Tibetan Plateau and subject to considerable uplift,the Linxia Basin has served as a biogeographic transition area for equids throughout the late Cenozoic.

关键词： Equidae Cenozoic biostratigraphy paleozoogeography Linxia Basin

Achieving simultaneously high conversion and high selectivity for light olefins directly producing from syngas

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Science China Chemistry 2024年第3期67卷 753-754页

作者： Yuhan sun Shanxi Research Institute Huairou Research LaboratoryTaiyuan 030032China Institute of Carbon Neutrality ShanghaiTech UniversityShanghai 201210China

The activity and selectivity are two primary indexes of a successful catalyst for chemical reactions. However,achieving a high activity and a high selectivity simultaneously is a long-standing challenge in catalysis, the socalled activity-selectivity trade-off. In the article recently published in Science, a research team led by Prof.

关键词： selectivity simultaneous catalysis

ONE-PARAMETER FINITE DIFFERENCE METHODS AND THEIR ACCELERATED SCHEMES FOR SPACE-FRACTIONAL SINE-GORDON EQUATIONS WITH DISTRIBUTED DELAY

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Journal of Computational Mathematics 2024年第3期42卷 705-734页

作者： Tao sun Chengjian Zhang Haiwei sun School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory of Engineering Modeling and Scientific Computing Huazhong University of Science and TechnologyWuhan 430074China Department of Mathematics University of MacaoMacaoChina

This paper deals with numerical methods for solving one-dimensional(1D)and twodimensional(2D)initial-boundary value problems(IBVPs)of space-fractional sine-Gordon equations(SGEs)with distributed *** 1D problems,we construct a kind of oneparameter finite difference(OPFD)*** is shown that,under a suitable condition,the proposed method is convergent with second order accuracy both in time and *** implementation,the preconditioned conjugate gradient(PCG)method with the Strang circulant preconditioner is carried out to improve the computational efficiency of the OPFD *** 2D problems,we develop another kind of OPFD *** such a method,two classes of accelerated schemes are suggested,one is alternative direction implicit(ADI)scheme and the other is ADI-PCG *** particular,we prove that ADI scheme can arrive at second-order accuracy in time and *** some numerical experiments,the computational effectiveness and accuracy of the methods are further ***,for the suggested methods,a numerical comparison in computational efficiency is presented.

关键词： Fractional sine-Gordon equation with distributed delay One-parameter finite difference methods Convergence analysis ADI scheme PCG method

Dominant woody plant species recognition with a hierarchical model based on multimodal geospatial data for subtropical forests

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Journal of Forestry Research 2024年第3期35卷 111-130页

作者： Xin Chen Yujun sun State Forestry&Grassland Administration Key Laboratory of Forest Resources&Environmental Management Beijing Forestry UniversityBeijing 100083People's Republic of China

Since the launch of the Google Earth Engine(GEE)cloud platform in 2010,it has been widely used,leading to a wealth of valuable ***,the potential of GEE for forest resource management has not been fully *** extract dominant woody plant species,GEE combined Sen-tinel-1(S1)and Sentinel-2(S2)data with the addition of the National Forest Resources Inventory(NFRI)and topographic data,resulting in a 10 m resolution multimodal geospatial dataset for subtropical forests in southeast *** and texture features,red-edge bands,and vegetation indices of S1 and S2 data were computed.A hierarchical model obtained information on forest distribution and area and the dominant woody plant *** results suggest that combining data sources from the S1 winter and S2 yearly ranges enhances accuracy in forest distribution and area extraction compared to using either data source ***,for dominant woody species recognition,using S1 winter and S2 data across all four seasons was *** terrain factors and removing spatial correlation from NFRI sample points further improved the recognition *** optimal forest extraction achieved an overall accuracy(OA)of 97.4%and a maplevel image classification efficacy(MICE)of 96.7%.OA and MICE were 83.6%and 80.7%for dominant species extraction,*** high accuracy and efficacy values indicate that the hierarchical recognition model based on multimodal remote sensing data performed extremely well for extracting information about dominant woody plant *** the results using the GEE application allows for an intuitive display of forest and species distribution,offering significant convenience for forest resource monitoring.

关键词： Google Earth Engine Sentinel Forest resource inventory data Dominant woody plant species Subtropics Model performance

Complex adaptive system theory,agent-based modeling,and simulation in dominant technology formation

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Journal of Systems Engineering and Electronics 2024年第1期35卷 130-153页

作者： ZHANG Ruihan sun Bing Glorious sun School of Business and Management Donghua UniversityShanghai 200051China School of Economics and Management Harbin Engineering UniversityHarbin 150001China

Dominant technology formation is the key for the hightech industry to“cross the chasm”and gain an established foothold in the market(and hence disrupt the regime).Therefore,a stimulus-response model is proposed to investigate the dominant technology by exploring its formation process and ***,based on complex adaptive system theory and the basic stimulus-response model,we use a combination of agent-based modeling and system dynamics modeling to capture the interactions between dominant technology and the socio-technical *** results indicate the following:(i)The dynamic interaction is“stimulus-reaction-selection”,which promotes the dominant technology’s formation.(ii)The dominant technology’s formation can be described as a dynamic process in which the adaptation intensity of technology standards increases continuously until it becomes the leading technology under the dual action of internal and external mechanisms.(iii)The dominant technology’s formation in the high-tech industry is influenced by learning ability,the number of adopting users and ***,a“critical scale”of learning ability exists to promote the formation of leading technology:a large number of adopting users can promote the dominant technology’s formation by influencing the adaptive response of technology standards to the socio-technical landscape and the choice of technology standards by the socio-technical *** is a minimum threshold and a maximum threshold for the role of adaptability in the dominant technology’s formation.(iv)The socio-technical landscape can promote the leading technology’s shaping in the high-tech industry,and different elements have different *** study promotes research on the formation mechanism of dominant technology in the high-tech industry,presents new perspectives and methods for researchers,and provides essential enlightenment for managers to formulate technology strategies.

关键词： complex adaptive system theory agent-based modeling and simulation dominant technology socio-technical landscape adaptation-choice

Rational surface charge engineering of haloalkane dehalogenase for boosting the enzymatic performance in organic solvent solutions

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Chinese Journal of Chemical Engineering 2024年第1期65卷 276-285页

作者： Yin Wu Yan sun Department of Biochemical Engineering School of Chemical Engineering and Technology and Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology(Ministry of Education)Tianjin UniversityTianjin 300350China

Biocatalysis in organic solvents(OSs)has numerous important applications,but native enzymes in OSs often exhibit limited catalytic ***,we proposed a computation-aided surface charge engineering strategy to improve the catalytic performance of haloalkane dehalogenase DhaA in OSs based on the energetic analysis of substrate binding to the DhaA *** variants with enhanced OS resistance were obtained by replacing negative charged residues on the surface with positive charged residue(Arg).Particularly,a four-substitution variant E16R/E93R/E121R/E257R exhibited the best catalytic performance(five-fold improvement in OS resistance and seven-fold half-life increase in 40%(vol)dimethylsulfoxide).As a result,the overall catalytic performance of the variant could be at least 26 times higher than the wild-type *** spectroscopy and molecular dynamics simulation studies revealed that the residue substitution mainly enhanced OS resistance from four aspects:(a)improved the overall structural stability,(b)increased the hydrophobicity of the local microenvironment around the catalytic triad,(c)enriched the hydrophobic substrate around the enzyme molecule,and(d)lowered the contact frequency between OS molecules and the catalytic *** findings validate that computationaided surface charge engineering is an effective and ingenious rational strategy for tailoring enzyme performance in OSs.

关键词： Surface charge engineering Organic solvent resistance Molecular dynamics simulation Haloalkane dehalogenase