Background:Invasive species can threaten native diversity and alter ecosystem processes while interacting with other components of global environmental change.Invasive plants are becoming increasingly problematic and ...Background:Invasive species can threaten native diversity and alter ecosystem processes while interacting with other components of global environmental change.Invasive plants are becoming increasingly problematic and this can be stimulated by changes in the environment.However,existing studies have primarily investigated the effects of environmental change on a specific stage of plant invasion rather than the continuous invasion process.Methods:A space-for-time substitution experiment was performed to investigate how warming and nitrogen deposition affects the invasion process of a plant.Specifically,different ratios of invasive Solidago canadensis L.to native Artemisia argyi Levl.et Van were employed as a proxy to represent successive levels of invasion.A total of seven treatments were applied in the experiment:ambient(CK),N addition(+5,+12 g m^(−2)year^(−1)),warming(+1.15,+1.86℃)and their interaction(5 g N m^(−2)year^(−1)+1.15℃,12 g N m^(−2)year^(−1)+1.86℃).The growth performance and competitiveness of S.canadensis were investigated.Results:The competitiveness of Solidago canadensis decreased linearly with its invasion degree(p<0.05).Non-linear regression showed that S.canadensis invasion levels of 53%,53%,68%,55%and 58%were the critical thresholds for shifting the direction or magnitude of chlorophyll,leaf nitrogen,leaf shape index,diameter,and root/shoot ratio,respectively.Compared with the ambient treatment(CK,no warming and no N addition),the diameter,height,bio-mass and relative competitiveness of S.canadensis were each limited by warming,to a certain extent,whereas these and the above parameters were significantly increased by nitrogen deposition.The interaction of increased temperature and nitrogen deposition led to significant increases in the growth and competitiveness of S.canadensis,and this effect was detected in every stage of the invasion,throughout the invasion process.Conclusions:Environmental change might have a continuous,progressive,and augmentative effect on the phenotypic traits of S.canadensis.This study provides fairly robust evidence that environmental change promotes the invasion process of S.canadensis in general,not simply in specific stages.In the future,rather than focusing on specific stages,experimental studies should consider examining invasion on a broader scale.展开更多
Extensive work have been done to harvest untapped water energy in formats of raindrops,flows,waves,and others.However,attaining stable and efficient electricity generation from these low-frequency water kinetic energi...Extensive work have been done to harvest untapped water energy in formats of raindrops,flows,waves,and others.However,attaining stable and efficient electricity generation from these low-frequency water kinetic energies at both individual device and large-scale system level remains challenging,partially owing to the difficulty in designing a unit that possesses stable liquid and charge transfer properties,and also can be seamlessly integrated to achieve preferential collective performances without the introduction of tortuous wiring and redundant node connection with external circuit.Here,we report the design of water electricity generators featuring the combination of lubricant layer and transistor-like electrode architecture that endows enhanced electrical performances in different working environments.Such a design is scalable in manufacturing and suitable for facile integration,characterized by significant reduction in the numbers of wiring and nodes and elimination of complex interfacing problems,and represents a significant step toward large-scale,real-life applications.展开更多
Engineering materials serving in marine surroundings are inevitably corroded.The corrosive marine conditions can also be utilized to harvest kinetic ocean wave energy to solve this problem.Leveraging water–solid trib...Engineering materials serving in marine surroundings are inevitably corroded.The corrosive marine conditions can also be utilized to harvest kinetic ocean wave energy to solve this problem.Leveraging water–solid triboelectrification to harvest lowfrequency wave energy for active anticorrosion is promising.Existing techniques are efficient in harnessing environmental energy with frequencies higher than 3 Hz,whereas the dominated ocean waves with optimal wave spectral density fluctuate from 0.45 to 1.5 Hz.Herein,we proposed a highly efficient and sustainable blue energy-powered cathodic protection(BECP)strategy by fusing water–solid triboelectric nanogenerators and cathodic protection technology.Leveraging the highly efficient triboelectrification between the moving water and hydrophobic fluorinated ethylene propylene tube,we developed the built-in power module,enabling the harvest of ocean wave energy lower than 1.5 Hz.The generated volumetric current density is 28.9 mA·m^(-3),5–20 times higher than the values of the reported devices.Moreover,the proposed BECP performs comparably to conventional cathodic protection in corrosion inhibition.Significantly,the proposed approach can be easily applied to ships,buoys,and other offshore platforms to simultaneously realize blue energy harvesting and engineering material protection,providing an alternative to traditional active protection technology.展开更多
Let H be a Hilbert space and A ■ B(H) be a C~*-subalgebra. This paper is devoted to studying the set gP of generalized projections in A from a differential geometric point of view, and mainly focuses on geodesic curv...Let H be a Hilbert space and A ■ B(H) be a C~*-subalgebra. This paper is devoted to studying the set gP of generalized projections in A from a differential geometric point of view, and mainly focuses on geodesic curves. We prove that the space gP is a C~∞ Banach submanifold of A, and a homogeneous reductive space under the action of Banach Lie group U_A of A. Moreover, we compute the geodesics of gP in a standard fashion, and prove that any generalized projection in a prescribed neighbourhood of p∈gP can be joined with p by a unique geodesic curve in gP.展开更多
This article employed a layer-by-layer approach to modify the interfacial boundary of halloysite clay nanotubes(HNTs)using(poly(diallyldimethylammonium chloride))(PDDA)and poly(styrene sulfonate)(PSS)polyelectrolytes ...This article employed a layer-by-layer approach to modify the interfacial boundary of halloysite clay nanotubes(HNTs)using(poly(diallyldimethylammonium chloride))(PDDA)and poly(styrene sulfonate)(PSS)polyelectrolytes to form core(inhibitor-loaded HNTs)-shell(polyelectrolytes layers(PDDA/PSS))structured smart microcapsules or micro-containers.Responses of the smart microcapsules to changes in pH(H^(+)),Cl^(-),OH^(-)and H_(2)O during the release of the loaded inhibitor(2-mecaptobenzothiazole inhibitor(2-MBT))coupled with the number of PDDA/PSS polyelectrolytes layers(n)required to obtain optimal response were characterized.The anticorrosion efficacies of several organic compounds were screened to identify the most suitable inhibitor for the protection of Al alloy 2024 in 3.5 wt.%NaCl.2-MBT which exhibits the best inhibition efficiency was successfully loaded into the HNTs lumen as demonstrated by TGA and DSC results.The release profiles of 2-MBT reveal that the sensitivity of the smart microcapsules to the various external stimuli decreased in the following order:pH>Cl^(-)>H_(2)O>OH^(-);and three-layered polyelectrolyte(3n)displays the highest sensitivity amongst the studied layer numbers(n).The release profiles were fitted to the Pappas and Weibull’s models which describe the release mechanisms.Compatibility of the smart microcapsules with epoxy coating coupled with the anticorrosion effect on Al alloy 2024 substrate were evaluated by means of long-term salt spray and immersion tests.展开更多
基金supported by the National Natural Science Foundation of China(32071521,32271587,32201297,31770446)the Carbon Peak and Carbon Neutrality Technology Innovation Foundation of Jiangsu Province(BK20220030)+2 种基金the Natural Science Foundation of Jiangsu Province(BK20211321)the Jiangsu Planned Projects for Postdoctoral Research Funds(2021K384C)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)and the Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment。
文摘Background:Invasive species can threaten native diversity and alter ecosystem processes while interacting with other components of global environmental change.Invasive plants are becoming increasingly problematic and this can be stimulated by changes in the environment.However,existing studies have primarily investigated the effects of environmental change on a specific stage of plant invasion rather than the continuous invasion process.Methods:A space-for-time substitution experiment was performed to investigate how warming and nitrogen deposition affects the invasion process of a plant.Specifically,different ratios of invasive Solidago canadensis L.to native Artemisia argyi Levl.et Van were employed as a proxy to represent successive levels of invasion.A total of seven treatments were applied in the experiment:ambient(CK),N addition(+5,+12 g m^(−2)year^(−1)),warming(+1.15,+1.86℃)and their interaction(5 g N m^(−2)year^(−1)+1.15℃,12 g N m^(−2)year^(−1)+1.86℃).The growth performance and competitiveness of S.canadensis were investigated.Results:The competitiveness of Solidago canadensis decreased linearly with its invasion degree(p<0.05).Non-linear regression showed that S.canadensis invasion levels of 53%,53%,68%,55%and 58%were the critical thresholds for shifting the direction or magnitude of chlorophyll,leaf nitrogen,leaf shape index,diameter,and root/shoot ratio,respectively.Compared with the ambient treatment(CK,no warming and no N addition),the diameter,height,bio-mass and relative competitiveness of S.canadensis were each limited by warming,to a certain extent,whereas these and the above parameters were significantly increased by nitrogen deposition.The interaction of increased temperature and nitrogen deposition led to significant increases in the growth and competitiveness of S.canadensis,and this effect was detected in every stage of the invasion,throughout the invasion process.Conclusions:Environmental change might have a continuous,progressive,and augmentative effect on the phenotypic traits of S.canadensis.This study provides fairly robust evidence that environmental change promotes the invasion process of S.canadensis in general,not simply in specific stages.In the future,rather than focusing on specific stages,experimental studies should consider examining invasion on a broader scale.
基金support of the Research Grants Council of Hong Kong(nos.C1006-20WF and 11213320)the Tencent Foundation through the XPLORER PRIZE,the Innovation and Technology Council(no.9440248)+1 种基金the National Natural Science Foundation of China(grant nos.51975502 and 21621001)the 111 Project(B17020).
文摘Extensive work have been done to harvest untapped water energy in formats of raindrops,flows,waves,and others.However,attaining stable and efficient electricity generation from these low-frequency water kinetic energies at both individual device and large-scale system level remains challenging,partially owing to the difficulty in designing a unit that possesses stable liquid and charge transfer properties,and also can be seamlessly integrated to achieve preferential collective performances without the introduction of tortuous wiring and redundant node connection with external circuit.Here,we report the design of water electricity generators featuring the combination of lubricant layer and transistor-like electrode architecture that endows enhanced electrical performances in different working environments.Such a design is scalable in manufacturing and suitable for facile integration,characterized by significant reduction in the numbers of wiring and nodes and elimination of complex interfacing problems,and represents a significant step toward large-scale,real-life applications.
基金We acknowledge the financial support from the National Natural Science Foundation of China(No.51975502)the Research Grants Council of Hong Kong(Nos.SRFS2223-1S01,C1006-20W,11213320,and 11219219)+3 种基金the Shenzhen Science and Technology Innovation Council(No.SGDX20201103093005028)the Innovation and Technology Commission of HongKong(Nos.GHP/021/19SZ and GHP/092/20GD)the Science and Technology Planning Project of Guangdong Province(No.2021A0505110002)the Tencent Foundation through the XPLORER PRIZE.
文摘Engineering materials serving in marine surroundings are inevitably corroded.The corrosive marine conditions can also be utilized to harvest kinetic ocean wave energy to solve this problem.Leveraging water–solid triboelectrification to harvest lowfrequency wave energy for active anticorrosion is promising.Existing techniques are efficient in harnessing environmental energy with frequencies higher than 3 Hz,whereas the dominated ocean waves with optimal wave spectral density fluctuate from 0.45 to 1.5 Hz.Herein,we proposed a highly efficient and sustainable blue energy-powered cathodic protection(BECP)strategy by fusing water–solid triboelectric nanogenerators and cathodic protection technology.Leveraging the highly efficient triboelectrification between the moving water and hydrophobic fluorinated ethylene propylene tube,we developed the built-in power module,enabling the harvest of ocean wave energy lower than 1.5 Hz.The generated volumetric current density is 28.9 mA·m^(-3),5–20 times higher than the values of the reported devices.Moreover,the proposed BECP performs comparably to conventional cathodic protection in corrosion inhibition.Significantly,the proposed approach can be easily applied to ships,buoys,and other offshore platforms to simultaneously realize blue energy harvesting and engineering material protection,providing an alternative to traditional active protection technology.
基金supported by National Natural Science Foundation of China(Grant No.11371233)
文摘Let H be a Hilbert space and A ■ B(H) be a C~*-subalgebra. This paper is devoted to studying the set gP of generalized projections in A from a differential geometric point of view, and mainly focuses on geodesic curves. We prove that the space gP is a C~∞ Banach submanifold of A, and a homogeneous reductive space under the action of Banach Lie group U_A of A. Moreover, we compute the geodesics of gP in a standard fashion, and prove that any generalized projection in a prescribed neighbourhood of p∈gP can be joined with p by a unique geodesic curve in gP.
基金the financial supports from the National Natural Science Foundation of China(Nos.51871227 and 51671198)financial support from the Shenzhen Science and Technology Innovation Council(No.JCYJ20170413141208098)+2 种基金the Innovation Technology Fund(No.9440175)the Research Grants Council of Hong Kong(Nos.C1018-17G and 11275216)the City University of Hong Kong(Nos.9360140 and 9667139)
文摘This article employed a layer-by-layer approach to modify the interfacial boundary of halloysite clay nanotubes(HNTs)using(poly(diallyldimethylammonium chloride))(PDDA)and poly(styrene sulfonate)(PSS)polyelectrolytes to form core(inhibitor-loaded HNTs)-shell(polyelectrolytes layers(PDDA/PSS))structured smart microcapsules or micro-containers.Responses of the smart microcapsules to changes in pH(H^(+)),Cl^(-),OH^(-)and H_(2)O during the release of the loaded inhibitor(2-mecaptobenzothiazole inhibitor(2-MBT))coupled with the number of PDDA/PSS polyelectrolytes layers(n)required to obtain optimal response were characterized.The anticorrosion efficacies of several organic compounds were screened to identify the most suitable inhibitor for the protection of Al alloy 2024 in 3.5 wt.%NaCl.2-MBT which exhibits the best inhibition efficiency was successfully loaded into the HNTs lumen as demonstrated by TGA and DSC results.The release profiles of 2-MBT reveal that the sensitivity of the smart microcapsules to the various external stimuli decreased in the following order:pH>Cl^(-)>H_(2)O>OH^(-);and three-layered polyelectrolyte(3n)displays the highest sensitivity amongst the studied layer numbers(n).The release profiles were fitted to the Pappas and Weibull’s models which describe the release mechanisms.Compatibility of the smart microcapsules with epoxy coating coupled with the anticorrosion effect on Al alloy 2024 substrate were evaluated by means of long-term salt spray and immersion tests.
