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Preparation and Structure-Property Regulation Mechanism of Reversible Thermochromic Polydiacetylene

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Chinese Journal of Polymer Science 2024年第8期42卷 1111-1121页

作者： Zhi-Qing Ge Shuo Yan Zu-Xiong Pan Shan Lei Xuan-Zhi Mao chu Zhao Mo-Zhen Wang Xue-wu Ge Key Laboratory of Precision and Intelligent Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China Marshall Laboratory of Biomedical Engineering International Cancer CenterLaboratory of Evolutionary Theranostics(LET)School of Biomedical EngineeringShenzhen University Medical SchoolShenzhen UniversityShenzhen 518055China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

The thermochromic mechanism and the structure-property regulation principle of reversible thermochromic polydiacetylene(PDA)materials have always been a challenging *** this work,a series of diacetylene monomers(m-PCDA)containing phenyl and amide or carboxyl groups were synthesized from 10,12-pentacosadiynoic acid(PCDA)through the esterification or amidation *** effects of the number and the distribution of the functional groups in m-PCDA molecules on their solid-state polymerization capability,and the thermochromic mechanism of their corresponding polymers(m-PDA)were investigated and discussed in *** results show that the m-PCDA monomers containing both benzene ring and groups that can form hydrogen bonding interactions have strong intermolecular interaction,and are easy to carry out the solid phase polymerization under 254-nm UV irradiation to obtain the corresponding new thermochromic m-PDA *** thermochromic behavior of m-PDA depends on its melting *** initial color-change temperature(blue to red)is determined by the onset melting tem perature,and the temperature range in which reversible color recovery can be achieved by repeat heating-cooling treatment is determined by its melting *** to the proposed thermochromic mechanism of PDA,various new PDA materials with precise thermochromic temperatu res and reversible thermochromic temperature ra nges can be designed and synthesized through the appropriate introduction of benzene ring and groups that can form hydrogen bonding interactions into the molecular structure of linear diacetylene *** work provides a perspective to the precise molecular structure design and the property regulation of the reversible thermochromic PDA materials.

关键词： Polydiacetylene Thermochromism Hydrogen bonding Chemical modification

Modulating the Electronic Structures of Single-walled Carbon Nanotubes by Filling with Electron Acceptors and the Effect on Their Reactivity with Aryl Diazonium Salts

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Chinese Journal of Structural Chemistry 2013年第12期32卷 1911-1915页

作者： WANG Hong-Tao wu chu-Xin GUAN Lun-Hui State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of Sciences University of Chinese Academy of Sciences

The electronic structures of single-walled carbon nanotubes （SWCNTs） were modulated by filling with tetracyanoquinodimethane （TCNQ）, a strong electron acceptor. The structures of TCNQ-filled SWCNTs were checked by X-ray diffraction analysis, high-resolution transmission electron microscopy and Raman spectroscopy. Optical absorption spectroscopy demonstrated an enhanced reactivity between aryl diazonium and semiconducting SWCNTs.

关键词： carbon nanotubes electronic structures chemical reactivity doping

Carbon unloading in roots in relation to root senescence in Cercis chinensis seedlings under drought stress

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Forestry Studies in China 2009年第2期11卷 77-84页

作者： GAN Cai-xia wu chu School of Horticulture and Gardening Yangtze University Hubei Province Jingzhou 434025 P. R. China Institute of Vegetables Hubei Academy of Agricultural Sciences Wuhan 430093 P. R. China

When Cercis chinensis seedlings suffered from drought treatment, net photosynthetic rates had been significantly reduced at the end of the drought treatment. Compared with the control, the activities of acid invertases in roots had increased 5 and 11 days after drought treatment. Seventeen days after drought treatment, the activities of acid invertases in roots were significantly decreased, while activities of alkaline invertases in roots had also been significantly reduced. As the moisture in culture media decreased, so the activities of sucrose synthases in leaves decreased slightly. In roots, their activities had significantly increased 5 and 11 days after drought treatment. The contents of fructose in roots reduced as the moisture in culture media decreased and 11 and 17 days after drought treatment the reduction was significant. The content of glucose in roots clearly did not change as drought stress occurred further, but was still less than that in the control seedlings. Similarly, the content of sucrose reduced as the moisture in culture media decreased. At the beginning of the drought stress, the content of sucrose was significantly higher than that in the control and afterwards there were no differences between drought-treated seedlings and the control. The gradient of the sucrose content between leaves and roots was 0.0982 mg.g^-1 FW 17 days after drought treatment, while the gradient of the seedlings under normal condition was 1.3832 mg.g^-1 FW. The sucrose concentration gradient reduced by 92.9%. The reduction in the sucrose content gradient under drought stress decreased the sucrose partitioning in roots. Therefore, our results support the hypothesis of‘shared control＇.

关键词： drought stress carbon unloading root senescence Cercis chinensis

Effects of nutrition spatial heterogeneity on root traits and carbon usage by roots of Cercis chinensis seedlings in split root rooms

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Forestry Studies in China 2008年第4期10卷 220-228页

作者： GAN Cai-xia wu chu School of Horticulture and Gardening Yangtze University Jingzhou 434025 P. R. China Institute of Vegetables Hubei Academy of Agricultural Sciences Wuhan 430093 P. R. China

In natural ecosystems, nutrition available for plants shows great spatial heterogeneity. Much is known about plant root responses to the spatial heterogeneity of nutrition, but little is known about carbon usage in roots in nutrition-deficient patches and its effect on root longevity. In this study, split-room boxes were used for culture of Cercis chinensis seedlings, and the small rooms were supplied with different nutrition levels. The number of the first-order roots in the rooms with nutrition supply was significantly higher than that in the rooms with deficient nutrition. Specific root length （SRL） of the first-order roots in the rooms with deficient nutrition reached its peak at day 64 after nutrition treatment. There was no significant SRL differences between the two order roots during the experiment. Biomass of the first-order roots in the rooms without nutrition supply was significantly less than that of the first-order roots in the rooms with nutrition supply from day 64 to 96. The total biomass of the lateral roots in the rooms without nutrition supply decreased from day 64 to 96. The activities of the enzymes in roots in the rooms without nutrition supply increased and the activities of alkaline invertases in roots in the two sides of split box did not change significantly. The activities of the enzymes in roots in the rooms without nutrition supply increased gradually. These results suggest that nutrition spatial heterogeneity induced the changes in root traits and plants actively controlled carbon usage in roots in nutrition-deficient patches by regulating the activities of invertases and sucrose synthases, resulting in the reduction in carbon usage in the roots in nutrition-deficient patches.

关键词： nutrition spatial heterogeneity root trait carbon usage Cercis chinensis

Molecular analyses display the increasing diversity of Podostemaceae in China

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Plant Diversity 2024年第3期46卷 421-424页

作者： Zhi-Zhong Li Zhun Xu Shuang wu Lang-Xing Yuan chun-Yu Zou Yan Liu Jian-Yong Lin Shi-chu Liang Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection(Guangxi Normal University) Ministry of EducationGuilin 541006China wuhan Botanical Garden Chinese Academy of SciencesWuhan 430074China Sino-Africa Joint Research Center Chinese Academy of SciencesWuhan 430074China Guangxi Association for Science and Technology Nanning 530023China Tropical Crops Genetic Resources Institute Chinese Academy of Tropical Agricultural SciencesHaikou 571101China Guangxi Institute of Botany Chinese Academy of SciencesGuilin 541006China Guangxi Forestry Research Institute Nanning 530028China

Podostemaceae(riverweed family),one of the largest aquatic plant families in the world,comprises about 350 species in 51 genera placed in three subfamilies,Podostemoideae,Weddellinoideae,and Tristichoideae(Koi et al.,2022).Most Podostemaceae genera(~38)are monotypic or oligotypic,with a high level of endemism(Koi et al.,2018,2022).Members of Podostemaceae adhere to rocks in fast-flowing rivers,streams,or waterfalls in the subtropics and tropics(Koi et al.,2018).As an adaptation to fastrunning currents,the morphological structure of river-weeds tends to be extremely reduced,including a loss or reduction of primary shoots or roots(Koi and Kato,2007).The vegetative mass of these plants resembles lichens or bryophytes,and are thus known commonly as“dream bryophytes”(Philbrick and Retana,1998).Podostemaceae plants flower when the water level drops during the dry *** recent years,anthropogenic factors and climate change have severely affected river weed habitats,decreasing populations of these plants.

关键词： roots season habitat

Winter extreme precipitation over the Tibetan Plateau influenced by Arctic sea ice on interdecadal timescale

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Advances in Climate Change Research 2024年第1期15卷 42-51页

作者： Qing-Quan LI Miao BI Song YANG Qing-Yuan wu Yi-Hui DING Xin-Yong SHEN Xiao-Ting SUN Meng-chu ZHAO China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CentreBeijing 100081China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China CMA Key Open Laboratory of Transforming Climate Resources to Economy Chongqing Institute of Meteorological SciencesChongqing 401147China School of Atmospheric Sciences and Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen University Zhuhai 519082China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China

The Tibetan Plateau(TP)and the Arctic are the most sensitive regions to global climate ***,the interdecadal varibility of winter extreme precipitation over the TP and its linkage with Arctic sea ice are still *** this study,the characteristics and mechisnems of the TP extreme precipitation(TPEP)influenced by Arctic sea ice on interdecadal timescale are studied based on the daily precipitation,monthly sea ice concentration and ERA5 reanalysis data from 1980 to *** found that the dominant mode of the TPEP in winter mostly exhibits a uniform spatial variation on the interdecadal timescale,with an opposite weak variation in the southeastern TP,and the Arctic sea ice concentration(SIC)before 2002 are larger than that after *** interdecadal variation of TPEP is affected by two teleconnection wave trains regulated by the Barents and Kara Sea *** the light ice years,a remarkable positive geopotential height(HGT)anomaly appears over the Barents-Kara Sea and a remarkable negative HGT anomaly is located over the Lake *** wave trains originating over the Barents-Kara Sea can be *** southern branch forms a wave train through the North Atlantic along the subtropical westerly jet stream,showing a‘+-+-+'pattern of HGT anomalies from Arctic to the *** HGT anomaly controls the western TP,which creates dynamic and water vapor conditions for the *** northern branch forms a wave train through the Lake Baikal and the southeast of the TP,showing a‘+-+'HGT anomaly *** HGT anomaly controls the southeastern TP,which is not conducive to precipitation in the *** the SIC in the Barents-Kara Sea increases,the situation is *** above analysis also reveals the reason for the difference in the east-west distribution of the TPEP.

关键词： Arctic sea ice Tibetan Plateau Winter extreme precipitation Rossby wave activity Interdecadal variation

Tunning the bandgap of MnO_(2)homojunction by building active high-index facet to achieve rapid electron transfer for enhanced photocatalytic sterilization

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Journal of Materials Science & Technology 2024年第1期168卷 265-275页

作者： Tao Zhang Bo Li Chaofeng Wang Shuilin wu Shengli Zhu Hui Jiang Yufeng Zheng Zhaoyang Li Zhenduo Cui Yu Zhang Paul K chu Xiangmei Liu Biomedical Materials Engineering Research Center Hubei Key Laboratory of Polymer MaterialsMinistry-of-Education Key Laboratory for the Green Preparation and Application of Functional MaterialsSchool of Materials Science and Engineering Hubei UniversityWuhan 430062China School of Health Science&Biomedical Engineering Hebei University of TechnologyTianjin 300401China School of Materials Science&Engineering Peking UniversityBeijing 100871China School of Materials Science&Engineering the Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of ChinaTianjin UniversityTianjin 300072China Department of Orthopedics Guangdong Provincial People’s HospitalGuangdong Academy of Medical SciencesGuangzhou 510080China Department of Physics Department of Materials Science and Engineering and Department of Biomedical EngineeringCity University of Hong KongHong Kong 999077China

Photocatalysis has been a research hotspot in recent years,and the design and modification of photocat-alysts have been the key *** methods for designing photocatalysts,including constructing heterojunctions and homojunctions,have been developed on the basis of *** this study,two homojunctions of manganese dioxide(MnO_(2)),including a high-index crystal plane homojunction and a general homojunction,are prepared using a stepwise hydrothermal *** a capping agent,the high-index crystal surface of the MnO_(2)is *** is found that the electron transport efficiency be-tween the two components of the homojunction with high-index planes is higher and the adsorption capacity of the oxygen is stronger,which leads to higher photocatalytic *** addition,the newly designed high-index homojunction is used for the treatment of bacterial infections,and it kills Staphy-lococcus aureus(***)and Escherichia coli(***)at rates of 99.95%±0.04%and 99.31%±0.25%,*** also has excellent therapeutic effects on mouse wounds,which implies superb practical application *** work provides a new strategy for the improved design of homojunctions and the application of photocatalytic materials.

关键词： Photocatalysis Homojunction Bandgap High-index facet Antibacterial

Corrosion Behavior of B_4C/6061Al Neutron Absorber Composite in Different H_3BO_3 Concentration Solutions

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Acta Metallurgica Sinica(English Letters) 2016年第11期29卷 1037-1046页

作者： Yu-Li Li Wen-Xian Wang Hong-Sheng Chen Jun Zhou Qiao-chu wu School of Materials Science and Engineering Taiyuan University of Technology Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of Education Taiyuan University of Technology Department of Mechanical Engineering Pennsylvania State University Erie The Behrend College

In this study, electrochemical corrosion tests, full-soak corrosion tests and associated microstructure analysis were conducted to investigate the corrosion behaviors of B4C/6061Al neutron absorber composites（NACs） manufactured by powder metallurgy method in solutions having different boric acid（H3BO3） concentrations（500, 2500 and 10,000 ppm）. In electrochemical corrosion tests, B4C/6061Al NACs demonstrate the highest（short-term） corrosion resistance in the 2500 ppm H3BO3 solution. While for full-soak corrosion tests, the B4C/6061Al NACs show the highest（long-term） corrosion resistance in the 500 ppm H3BO3 solution. This difference is found to be mainly due to the formation of different surface morphologies during these two different corrosion tests. As noticed, a layer of Al（OH）3was formed on the composite surface during full-soak corrosion tests, but it cannot be found in the electrochemical corrosion tests. The full-soak corrosion mechanism of the B4C/6061Al NACs in the H3BO3 solution is found to be primarily determined by the dynamic balance between the formation and dissolution rates of the oxide film, which is mainly controlled by the density of H~＋ ions in the solution.

关键词： B4C/6061Al NACs Powder metallurgy Electrochemical corrosion Full-soak corrosion

The corrosion of AA2037 aluminum alloy in alkaline aqueous solution studied using slow positron beam spectroscopy

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Nuclear Science and Techniques 2016年第2期27卷 6-13页

作者： Jiao-Jiao Wang Zhe-Jie Zhu Wei Yang Yi-chu wu Tong-Guang Zhai Hubei Key Laboratory of Nuclear Solid Physics School of Physics and Technology Wuhan University Chemical and Materials Engineering Department University of Kentucky

Corrosion behavior of AA2037 T8 Al alloy in a1 M Na OH aqueous solution was investigated using slow positron beam, together with microscopy techniques and electrochemical tests. The alloy was homogenized at 510℃ for 2 h and 30 s, respectively, before final peak aging, so that one Sample A had more dispersoids than Sample B after homogenization. It was found that S parameter of the Doppler-broadened annihilation was significantly decreased near the surface in both samples in the alkaline solution. With increasing the dissolution time,Sample A showed a slower decrease rate than Sample B,which might imply that the preexistence of more dispersoids might hinder the corrosion process in Sample *** electron microscopy and atomic force microscopy observations found that the surfaces of both samples were uniformly thinned due to intense chemical dissolution by the attack of OH-. With increasing the dissolution time,Sample B was corroded more substantially and produced more and larger pits in a short dissolution time than Sample A. Furthermore, polarization curves showed that Sample A had a lower corrosion current and corrosion rate than Sample B, which revealed that the presence of the dispersoids was responsible for the better corrosion resistance in the alloy.

关键词：慢正电子束碱性水溶液腐蚀行为铝合金扫描电子显微镜光谱溶解时间电化学测试