[Objective] The paper was to study the structure and performance of starch and styrene graft copolymer. [Method] The microscopic structure of corn starch and styrene graft copolymer was analyzed by using infrared spec...[Objective] The paper was to study the structure and performance of starch and styrene graft copolymer. [Method] The microscopic structure of corn starch and styrene graft copolymer was analyzed by using infrared spectrum and scanning electron microscope, and the property of starch and styrene graft copoly- mer was confirmed through grinding experiment, tensile strength, water absorption rate, hot water resistance properties and enzymatic properties analysis. [Result] The starch and styrene graft copolymer had the properties of thermoplastic and microbial degradation. IConclusion] The starch and styrene graft copolymer is expected to be developed as a biodegradable material.展开更多
A new multifunctional mPEG-b-PAA-grafted chitosan copolymer possessing amino and carboxyl groups,mPEG-b-PAA-g-CHI(compound 6) ,was designed for a potential application in gene/drug delivery and synthesized by the meth...A new multifunctional mPEG-b-PAA-grafted chitosan copolymer possessing amino and carboxyl groups,mPEG-b-PAA-g-CHI(compound 6) ,was designed for a potential application in gene/drug delivery and synthesized by the methods of reversible addition-fragmentation chain transfer(RAFT) polymerization of acrylic acid(AA) and grafting reaction of a biodegradable chitosan(CHI) derivative.Completion of the reactions and characterization of the resulting compounds were demonstrated by 1 H NMR,FTIR and gel permeation chtomatography(GPC) studies.The results show that the molar ratio of amino groups to carboxyl groups in the copolymer(compound 6) is 0.41-0.59.展开更多
Aims Projections of invasive species expansion under a warmer world often do not explicitly consider the concurring nitrogen(N)deposition.It remains largely unknown how the convoluted effect of climate warming and N d...Aims Projections of invasive species expansion under a warmer world often do not explicitly consider the concurring nitrogen(N)deposition.It remains largely unknown how the convoluted effect of climate warming and N deposition will shift the native and invasive species dynamics.Here,we hypothesize that the concurring in creases in N and temperature would promote growth of invasive species greater than that of native species.Methods A controlled greenhouse experiment was conducted to quantify the growth response of an invasive species(Solidago canadensis L.)and a co-existing native species(Artemisia argyi Levi,et Van)under the effects of climate warming,N deposition and their interactions.Important Findings Due to the strong positive effect of N addition,the interactive effect of temperature increase and N addition resulted in an overall significant increase in growth of both in vasive and native species,demonstrating that these manipulations may make microhabitats more favorable to plant growth.However,the relative increases in biomass,height and diameter of invasive S.canadensis were signifiesntly lower than those of native A.argyi.This suggests that the vegetative growth superiority of invasive S.canadensis over the native species A.argyi is reduced by the enhanced N availability in the warmer world.Therefore,the inclusion of N deposition may mitigate the projection of invasive species S.canadensis expansion under climate warming.展开更多
文摘[Objective] The paper was to study the structure and performance of starch and styrene graft copolymer. [Method] The microscopic structure of corn starch and styrene graft copolymer was analyzed by using infrared spectrum and scanning electron microscope, and the property of starch and styrene graft copoly- mer was confirmed through grinding experiment, tensile strength, water absorption rate, hot water resistance properties and enzymatic properties analysis. [Result] The starch and styrene graft copolymer had the properties of thermoplastic and microbial degradation. IConclusion] The starch and styrene graft copolymer is expected to be developed as a biodegradable material.
基金Project(20704011) supported by the National Natural Science Foundation of ChinaProject(09JJ3027) supported by the Natural Science Foundation of Hunan Province,ChinaProject(50725825) supported by the National Science Foundation for Distinguished Young Scholars
文摘A new multifunctional mPEG-b-PAA-grafted chitosan copolymer possessing amino and carboxyl groups,mPEG-b-PAA-g-CHI(compound 6) ,was designed for a potential application in gene/drug delivery and synthesized by the methods of reversible addition-fragmentation chain transfer(RAFT) polymerization of acrylic acid(AA) and grafting reaction of a biodegradable chitosan(CHI) derivative.Completion of the reactions and characterization of the resulting compounds were demonstrated by 1 H NMR,FTIR and gel permeation chtomatography(GPC) studies.The results show that the molar ratio of amino groups to carboxyl groups in the copolymer(compound 6) is 0.41-0.59.
基金supported by the State Key Research Development Program of China(2017YFC1200100)National Natural Science Foundation of China(31770446,31600326,31800429,31700342,31800342,31971427,31700108,31570414)+4 种基金Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Natural Science Foundation of Jiangsu Province(BK20170540)China Postdoctoral Science Foundation(2019M651720)Jiangsu Province Postdoctoral Science Foundation(1501014B)Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment.
文摘Aims Projections of invasive species expansion under a warmer world often do not explicitly consider the concurring nitrogen(N)deposition.It remains largely unknown how the convoluted effect of climate warming and N deposition will shift the native and invasive species dynamics.Here,we hypothesize that the concurring in creases in N and temperature would promote growth of invasive species greater than that of native species.Methods A controlled greenhouse experiment was conducted to quantify the growth response of an invasive species(Solidago canadensis L.)and a co-existing native species(Artemisia argyi Levi,et Van)under the effects of climate warming,N deposition and their interactions.Important Findings Due to the strong positive effect of N addition,the interactive effect of temperature increase and N addition resulted in an overall significant increase in growth of both in vasive and native species,demonstrating that these manipulations may make microhabitats more favorable to plant growth.However,the relative increases in biomass,height and diameter of invasive S.canadensis were signifiesntly lower than those of native A.argyi.This suggests that the vegetative growth superiority of invasive S.canadensis over the native species A.argyi is reduced by the enhanced N availability in the warmer world.Therefore,the inclusion of N deposition may mitigate the projection of invasive species S.canadensis expansion under climate warming.
