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Modifying Poly(propylene carbonate) with Furan-based Non-Isocyanate Polyurethanes

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Chinese Journal of Polymer Science 2023年第7期41卷 1069-1077页

作者： xiao-Jing Li Ying-Feng Wen Yong Wang Xing-Ping Zhou xiao-lin xie Key Laboratory for Material Chemistry of Energy Conversion and Storage Ministry of EducationSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan430074China

Poly(propylene carbonate) (PPC) is gaining significant momentum as a biodegradable polymer using CO_(2) as an abundant, low-cost and renewable feedstock. Yet, PPC suffers from unsatisfactory thermal and mechanical properties, and its blends with other synthetic polymers as the second component typically exhibit poor compatibility. Herein, novel furan-based non-isocyanate polyurethanes (NIPUs) with high molecular weights and narrow distributions have been synthesized starting from 5-hydroxymethylfurfural (HMF) via a four-step procedure including reduction, glycidylation, carbonation of CO_(2) and step-growth polymerization with diamines. Owing to the structural similarity and intermolecular hydrogen bonding interactions, furan-based NIPUs display good compatibility with PPC. A sea-island morphology can be observed in SEM images of PPC/NIPU blends, where the NIPU phases are randomly dispersed in the PPC matrix. Moreover, the blends exhibit only one Tg (higher than both that of PPC and the corresponding NIPU) on the DSC curves, which first increase and then decrease when increasing the content of NIPUs from 0 wt% to 15 wt%. Notably, the physical crosslinking formed by hydrogen bonding interactions, coupled with the rigidity of furan rings, confer simultaneous improvements of elongation at the break and tensile strength, affording high-performance CO_(2)-based biodegradable polymeric materials with low carbon footprint, good sustainability, and ideal biocompatibility.

关键词： PPC CO_(2) NIPU HMF Blends

PARTIAL CARBAMOYLATION OF CELLULOSE MICROSPHERES: A NEW METHOD TO PREPARE ADSORBENTS FOR LIQUID CHROMATOGRAPHY

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Chinese Journal of Polymer Science 2013年第12期31卷 1725-1732页

作者： Wei Chen Qin Bin 柏正武周兴平 xiao-lin xie Key Lab for Large-Format Battery Materials and Systems Ministry of EducationSchool of Chemistry and Chemical EngineeringHuazhong University of Science and Technology Key Lab of Green Chemical Process Ministry of EducationHubei Key Laboratory of Novel Chemical Reactor and Green Chemical TechnologyWuhan Institute of Technology

Micron-sized cellulose microspheres were prepared through sol-gel method using NaOH/urea solution to dissolve cellulose, then cross-linked by 1,6-hexanylene diisocyanate （HDI）, toluene 2,4-diisocyanate （TDI） and 1,4-phenylene diisocyanate （PDI）, respectively. The reaction conditions for partial modification of the microspheres were studied. The degree of substitution （DS） in cellulose was controlled by adjusting the reaction conditions. HDI-crosslinked microspheres were partially modified with phenyl isocyanate to obtain chiral stationary phases （CSPs）. The CSPs of a lower degree of crosslinking （DC） showed better chiral recognition ability than those of a higher DC. Meanwhile the CSPs prepared by pre- modification exhibited better chiral recognition ability than those prepared by pre-crosslinking.

关键词： Cellulose Microspheres Functionalization Chiral stationary phase Chiral recognition.

Improving amplify-and-forward relay selection algorithm based on partial relay link

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The Journal of China Universities of Posts and Telecommunications 2010年第1期17卷 56-61页

作者： WANG Fei-fei LIU Yuan-an lin xiao-feng xie Gang Key Labomty of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

This article addresses the design problem of selecting an appropriate relay in amplify-and-forward （AF） cooperative diversity systems. In this regard, this article focuses on relay selection based on partial channel knowledge only across the source and relay links. In particular, the two fundamental questions will be answered, that is, whether to cooperate and whom to cooperate with. Through answering these two questions, an improved relay selection strategy based on partial relay link, which emphasizes that cooperation happens when necessary, is proposed to aim at maximizing the average mutual information. Then a joint optimization, in terms of power allocation and relay selection, is employed to guarantee a robust performance for relay selection based on partial relay link. Optimum power is allocated between the source and the selected relay to maximize the output signal-to-noise （SNR） at the destination. Simulation results turn out that the improved scheme can achieve better performance than previous work and the robust performance can be guaranteed by employing joint optimization.

关键词： cooperative diversity amplify-and-forward relay relay selection average mutual information

CO_(2)-based Biodegradable Supramolecular Polymers with Well-tunable Adhesive Properties

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Chinese Journal of Polymer Science 2022年第1期40卷 47-55页

作者： xiao-Jing Li Ying-Feng Wen Yong Wang Hai-Yan Peng Xing-Ping Zhou xiao-lin xie Key Laboratory for Material Chemistry of Energy Conversion and Storage Ministry of EducationSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Supramolecular adhesives that enable debonding on-demand are of significant research interest for the development of adaptive and smart materials,yet,biodegrable supramolecular adhesives have been rarely ***,telechelic,three-armed and four-armed CO_(2)-based polyols with close molecular weights and various content(or carbonate unite content)have been synthesized via a zinc-cobalt double metal cyanide complex catalyzed ring-opening copolymerization of CO_(2) and propylene oxide,and further exploited as sustainable and biodegradable building blocks for supramolecular polymers(SMPs)with 2-ureido-4[1H]-pyrimidinone(UPy)***,the orthogonal modulation of the CO_(2) content and the topology of CO_(2)-based polyols provide a unique opportunity to fine-tune the surface energy as well as the cohesive strength of the resulting CO_(2)-based ***,a three-armed SMP with 44%CO_(2)(3UPy-CO_(2)-44%)can well balance the trade-off between surface energy and cohesive strength,therefore bestowing a high adhesive strength of 7.5 and 9.7 MPa towards stainless steel and wood substrates respectively by testing the corresponding single lap ***,the light-responsive adhesion property of 3UPy-CO_(2)-44%has been demonstrated exemplarily by blending with a UV sensitizer.

关键词： Biodegradable polymer Adhesive CO_(2)-based polyol ROCOP Supramolecular polymer

Visible Light and Temperature Regulated Reflection Colors in Self-supporting Cholesteric Liquid Crystal Physical Gels

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Chinese Journal of Polymer Science 2021年第12期39卷 1617-1625页

作者： Dong-Xu Zhao Qian Jiang Jing Wang Yuan Qiu Yong-Gui Liao xiao-lin xie Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of EducationHubei Engineering Research Center for Biomaterials and Medical Protective MaterialsHubei Key Laboratory of Materials Chemistry and Service FailureSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Material Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan 430074China

Photo-responsive cholesteric liquid crystals(CLCs)have attracted much attention in recent years due to their wide applications in filters,tun able optical lasers,dyn amic display devices,***,UV light is usually used as the exter nal stimulus source,which is not envir on ment-frie ndly *** the other hand,the mecha nical properties of CLCs are not strong eno ugh for these practical ***,it still remains a challenge to endow the CLCs with visible light response and high mechanical properties at the same ***,an axially chiral tetra-fluorinated binaphthyl azobenzene gelator(S-4F-AG)is *** 550 and 450 nm light irradiations,S-4F-AG exhibits excellent photo-switchable ***,the maximum con tent of c/s-isomer and its half-life are as high as 35%and 89 h in acet on itrile,respectively.A self-supporting CLC physical gel with a storage modulus around 104 Pa can be obtained when 3wt%S-4F-AG and 12wt%binaphthyl azobenzene derivative(dopant 2)are co-doped into a nematic LC host *** CLC physical gel exhibits a temperature-driven blue,green,and red reflection colors ***,such three primary RGB colors can also be realized by adjusting the exposure time of 550 nm green *** work lays a solid foundation for the applications ranging from information storage to high-tech anticounterfeit.

关键词： Cholesteric liquid crystal Gel Visible light response Reflect!on color Self-supporting ability

Gas-based reduction of vanadium titano-magnetite concentrate:behavior and mechanisms

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International Journal of Minerals,Metallurgy and Materials 2017年第1期24卷 10-17页

作者： Yu-lei Sui Yu-feng Guo Tao Jiang xiao-lin xie Shuai Wang Fu-qiang Zheng School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China

The reduction of vanadium titano-magnetite pellets by H_2-CO at temperatures from 850 to 1050°C was investigated in this paper. The influences of pre-oxidation treatment, reduction temperature, and V_（H_2）/（V_（H_2）＋ VCO） on the metallization degree were studied. The results showed that pre-oxidation played a substantial role in the reduction of vanadium titano-magnetite pellets. During the reduction process, the metallization degree increased with increasing temperature and increasing V_（H_2） /（V_（H_2）＋ VCO）. The phase transformation of pre-oxidized vanadium titano-magnetite pellets during the reduction process under an H_2 atmosphere and a CO atmosphere was discussed, and the reduced samples were analyzed by scanning electron microscopy（SEM） in conjunction with back scatter electron（BSE） imaging. The results show that the difference in thermodynamic reducing ability between H_2 and CO is not the only factor that leads to differences in the reduction results obtained using different atmospheres. Some of Fe_（3-x）Ti_xO_4 cannot be reduced under a CO atmosphere because of the densification of particles＇ structure and because of the enrichment of Mg in unreacted cores. By contrast, a loose structure of particles was obtained when the pellets were reduced under an H_2 atmosphere and this structure decreased the resistance to gas diffusion. Moreover, the phenomenon of Mg enrichment in unreacted cores disappeared during H_2 reduction. Both the lower resistance to gas diffusion and the lack of Mg enrichment facilitated the reduction of vanadium titano-magnetite.

关键词： titano-magnetite ore reduction behavior mechanisms

Intake of tobacco nitrosamines of smokers in various provinces of China and their cancer risk:A meta-analysis

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Journal of Environmental Sciences 2024年第7期141卷 249-260页

作者： xiao Li Zhiwei Ye Jun Wang Pengfei lin xiaojin Zhang Shuguang xie Chao Chen Research Institute for Environmental Innovation(Suzhou) TsinghuaSuzhouJiangsu 215163China State Key Joint Laboratory of Environmental Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China Shenzhen Key Laboratory of Organic Pollution Prevention and Control State Key Laboratory of Urban Water Resource and EnvironmentHarbin Institute of TechnologyShenzhen 518055China State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Science and EngineeringPeking UniversityBeijing 100871China

Nitrosamines are a class of carcinogens which have been detected widely in food,water,some pharmaceuticals as well as *** objectives of this paper include reviewing the basic information on tobacco consumption and nitrosamine contents,and assessing the health risks of tobacco nitrosamines exposure to Chinese *** searched the publications in English from“Web of Science”and those in Chinese from the“China National Knowledge Infrastructure”in 2022 and collected 151 literatures with valid *** content of main nitrosamines in tobacco,including 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone(NNK),N-nitrosonornicotine(NNN),N-nitrosoanatabine(NAT),N-nitrosoanabasine(NAB),total tobacco-specific nitrosamines(TSNA),and N-nitrosodimethylamine(NDMA)were *** information of daily tobacco consumption of smokers in 30 provinces of China was also ***,the intakes of NNN,NNK,NAT,NAB,TSNAs,and NDMA via tobacco smoke were estimated as 1534ng/day,591 ng/day,685 ng/day,81 ng/day,2543 ng/day,and 484 ng/day by adult smokers in30 provinces,*** cancer risk(CR)values for NNN and NNK inhalation intake were further calculated as 1.44×10^(-5)and 1.95×10^(-4).The CR value for NDMA intake via tobacco smoke(inhalation:1.66×10^(-4))indicates that NDMA is similarly dangerous in tobacco smoke when compared with the *** China,the CR values caused by average nitrosamines intake via various exposures and their order can be estimated as the following:smoke(3.75×10^(-4))>food(1.74×10^(-4))>drinking water(1.38×10^(-5)).Smokers in China averagely suffer 200%of extra cancer risk caused by nitrosamines in tobacco when compared with non-smokers.

关键词： N-nitrosamine Tobacco Cancer risk Tobacco specific nitrosamines(TSNAs) N-nitrosodimethylamine(NDMA)

Cross section determination of^(27)Al(n,2n)^(26)Al reaction induced by 14-MeV neutrons uniting with D-T neutron activation and AMS techniques

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Nuclear Science and Techniques 2024年第6期35卷 78-89页

作者： Xian-lin Yang Chang-lin Lan Yu-Ting Wei Yi Zhang Gong Jiang Bo xie Yu Liu Hong-Tao Shen xiao-Jun Sun School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China MOE Frontiers Science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology Guangxi Normal UniversityGuilin 541004China

Aluminum is the primary structural material in nuclear engineering,and its cross section induced by 14-MeV neutrons is of great *** address the issue of insufficient accuracy for the^(27)Al(n,2n)^(26)Al reaction cross section,the activation method and accelerator mass spectrometry(AMS)technique were used to determine the^(27)Al(n,2n)^(26)Al cross section,which could be used as a D-T plasma ion temperature monitor in fusion *** the China Academy of Engineering Physics,neutron activation was performed using a K-400 neutron generator produced by the T(d,n)4He ***^(26)Al∕^(27)Al isotope ratios were measured using the newly installed GYIG 1 MV AMS at the Institute of Geochemistry,Chinese Academy of *** neutron flux was monitored by measuring the activity of 92mNb produced by the 93Nb(n,2n)92mNb *** measured results were compared with available data in the experimental nuclear reaction database,and the measured values showed a reasonable degree of consistency with partially available literature *** newly acquired cross-sectional data at 12 neutron energy points through systematic measurements clarified the divergence,which has two different growth trends from the existing experimental *** obtained results are also compared with the corresponding evaluated database,and the newly calculated excitation functions with TALYS−1.95 and EMPIRE−3.2 codes,the agreement with CENDL−3.2,TENDL-2021 and EMPIRE−3.2 results are generally acceptable.A substantial improvement in the knowledge of the^(27)Al(n,2n)^(26)Al reaction excitation function was obtained in the present work,which will lay the foundation for the diagnosis of the fusion ion temperature,testing of the nuclear physics model,evaluation of nuclear data,etc.

关键词： 14-MeV neutron ^(27)Al(n,2n)^(26)Al Cross section AMS

shinyTempSignal:an R shiny application for exploring temporal and other phylogenetic signals

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Journal of Genetics and Genomics 2024年第7期51卷 762-768页

作者： Li Zhan xiao Luo Wenqin xie Xuan-An Zhu Zijing xie Jianfeng lin lin Li Wenli Tang Rui Wang lin Deng Yufan Liao Bingdong Liu Yantong Cai Qianwen Wang Shuangbin Xu Guangchuang Yu Department of Bioinformatics School of Basic Medical SciencesSouthern Medical UniversityGuangzhouGuangdong 510515China Faculty of Computers Guangdong University of TechnologyGuangzhouGuangdong 510006China Ubigene Biosciences Co. Ltd.GuangzhouGuangdong 510530China State Key Laboratory of Applied Microbiology Southern China Guangdong Provincial Key Laboratory of Microbial Culture Collection and ApplicationGuangdong Open Laboratory of Applied MicrobiologyGuangdong Institute of MicrobiologyGuangdong Academy of SciencesGuangzhouGuangdong 510070China

The molecular clock model is fundamental for inferring species divergence times from molecular ***,its direct application may introduce significant biases due to sequencing errors,recombination events,and inaccurately labeled sampling *** accuracy necessitates rigorous quality control measures to identify and remove potentially erroneous ***,while not all branches of a phylogenetic tree may exhibit a clear temporal signal,specific branches may still adhere to the assumptions,with varying evolutionary *** a relaxed molecular clock model better aligns with the complexities of *** root-to-tip regression method has been widely used to analyze the temporal signal in phylogenetic studies and can be generalized for detecting other phylogenetic *** its utility,there remains a lack of corresponding software implementations for broader *** address this gap,we present shinyTempSignal,an interactive web application implemented with the shiny framework,available as an R package and publicly accessible at https://***/YuLab-SMU/*** tool facilitates the analysis of temporal and other phylogenetic signals under both strict and relaxed *** extending the root-to-tip regression method to diverse signals,shinyTempSignal helps in the detection of evolving features or traits,thereby laying the foundation for deeper insights and subsequent analyses.

关键词： Molecular clock Root-to-tip regression Temporal signal Phylogenetic signal