Carbon resources play an important role in affecting the benthic bacterial community in shallow lakes. In this study, pyrosequencing was applied to compare bacteria phylogenic profile in incubated sediments with norma...Carbon resources play an important role in affecting the benthic bacterial community in shallow lakes. In this study, pyrosequencing was applied to compare bacteria phylogenic profile in incubated sediments with normal and exchanged organic detritus in macrophyte-dominated East Lake Taihu and algal-dominated Meiliang Bay. We observed significant bacteria species variations in sediments from two bays, regardless of treatments. RDA (Redundancy Analysis) analysis showed that sediment characteristics, especially concentrations of total nitrogen might account for this differentiation. Besides, algal-dominated Meiliang Bay sediment with addition of Vallisneria detritus exhibited higher bacterial species variations than the sediment amended with Microcystis detritus. To the contrary, sediments from macrophyte-dominated East Lake Taihu shared similar bacteria profile at all taxonomic levels and grouped together in MDS (multidimensional scaling) plots over the treatments with Vallisneria or Microcystis detritus addition into the sediment. We speculated that the different degradability of macrophyte detritus and algal detritus led to varied bacterial responses to exchanged organic resources and ultimately, the amounts, nutrient availability and degradability of organic resources may be main reasons for benthic bacteria community structure differentiation between the two states in shallow lakes.展开更多
The primary purpose of underground gas storages is to provide gas for seasonal consumptions or strategic reserve.The periodical operations of gas injection and extraction lead to cyclic loading on the walls and surrou...The primary purpose of underground gas storages is to provide gas for seasonal consumptions or strategic reserve.The periodical operations of gas injection and extraction lead to cyclic loading on the walls and surrounding rocks of gas storages.To investigate the mechanical behaviors of different host rocks in bedded salt deposit,laboratory experiments were conducted on the samples of rock salt,thenardite,glauberite and gypsum.The mechanical properties of rock samples under monotonic and cyclic loadings were studied.Testing results show that,under monotonic loading,the uniaxial compressive stress（UCS） of glauberite is the largest（17.3 MPa）,while that of rock salt is the smallest（14.0 MPa）.The UCSs of thenardite and gypsum are 16.3 and 14.6 MPa,respectively.The maximum strain at the peak strength of rock salt（halite） is much greater than those of the other three rocks.The elastic moduli of halite,thenardite,glauberite and gypsum are 3.0,4.2,5.1 and 6.8 GPa,respectively.Under cyclic loading,the peak strengths of the rock specimens are deteriorated except for rock salt.The peak strengths of thenardite,glauberite and gypsum decrease by 33.7%,19.1% and 35.5%,respectively;and the strains of the three rocks at the peak strengths are almost the same.However,the strain of rock salt at the peak strength increases by 1.98%,twice more than that under monotonic loading.Under monotonic loading,deformation of the tested rock salt,thenardite and glauberite shows in an elastoplastic style.However,it changes to a ductile style under cyclic loading.Brittle deformation and failure are only observed for gypsum.The results should be helpful for engineering design and operation of gas storage in bedded salt deposit.展开更多
Repair and reconstruction of large bone defect were often difficult,and bone substitute materials,including autogenous bone,allogenic bone and artificial bone,were common treatment strategies.The key to elucidate the ...Repair and reconstruction of large bone defect were often difficult,and bone substitute materials,including autogenous bone,allogenic bone and artificial bone,were common treatment strategies.The key to elucidate the clinical effect of these bone repair materials was to study their osteogenic capacity and immunotoxicological compatibility.In this paper,the mechanical properties,micro-CT imaging analysis,digital image analysis and histological slice analysis of the three bone grafts were investigated and compared after different time points of implantation in rat femur defect model.Autogenous bone and biphasic calcium phosphate particular artificial bone containing 61.4% HA and 38.6%β-tricalcium phosphate with 61.64%porosity and 0.8617±0.0068 g/cm^(3) den-sity(d≤2 mm)had similar and strong bone repair ability,but autogenous bone implant materials caused greater secondary damage to experimental animals;allogenic bone exhibited poor bone defect repair ability.At the early stage of implantation,the immunological indexes such as Immunoglobulin G,Immunoglobulin M concentration and CD4 cells'population of allogenic bone significantly increased in compared with those of autologous bone and artificial bone.Although the repair process of artificial bone was relatively inefficient than autologous bone graft,the low immunotoxicological indexes and acceptable therapeutic effects endowed it as an excellent alter-native material to solve the problems with insufficient source and secondary trauma of autogenous bone.展开更多
Graphene is a material with unique properties that can be exploited in electronics, catalysis, energy, and bio-related fields. Although, for maximal utilization of this material, high-quality graphene is required at b...Graphene is a material with unique properties that can be exploited in electronics, catalysis, energy, and bio-related fields. Although, for maximal utilization of this material, high-quality graphene is required at both the growth process and after transfer of the graphene film to the application-compatible substrate. Chemical vapor deposition (CVD) is an important method for growing high-quality graphene on non-technological substrates (as, metal substrates, e.g., copper foil). Thus, there are also considerable efforts toward the efficient and non-damaging transfer of quality of graphene on to technologically relevant materials and systems. In this review article, a range of graphene current transfer techniques are reviewed from the standpoint of their impact on contamination control and structural integrity preservation of the as-produced graphene. In addition, their scalability, cost- and time-effectiveness are discussed. We summarize with a perspective on the transfer challenges, alternative options and future developments toward graphene technology.展开更多
Graphene doping continues to gather momentum because it enables graphene properties to be tuned,thereby affording new properties to,improve the performance of,and expand the application potential of graphene.Graphene ...Graphene doping continues to gather momentum because it enables graphene properties to be tuned,thereby affording new properties to,improve the performance of,and expand the application potential of graphene.Graphene can be chemically doped using various methods such as surface functionalization,hybrid composites(e.g.,nanoparticle decoration),and substitution doping,wherein C atoms are replaced by foreign ones in the graphene lattice.Theoretical works have predicted that graphene could be substitutionally doped by aluminum(Al)atoms,which could hold promise for exciting applications,including hydrogen storage and evolution,and supercapacitors.Other theoretical predictions suggest that Al substitutionally doped graphene(AIG)could serve as a material for gas sensors and the catalytic decomposition of undesirable materials.However,fabricating Al substitutionally doped graphene has proven challenging until now.Herein,we demonstrate how controlled-flow chemical vapor deposition(CVD)implementing a simple solid precursor can yield high-quality and large-area monolayer AIG,and this synthesis is unequivocally confirmed using various characterization methods including local electron energy-loss spectroscopy(EELS).Detailed high-resolution transmission electron microscopy(HRTEM)shows numerous bonding configurations between the Al atoms and the graphene lattice,some of which are not theoretically predicted.Furthermore,the produced AIG shows a CO_(2) capturability superior to those of other substitutionally doped graphenes.展开更多
Water color is a crucial optical indicator of water quality,polluted water bodies often show water color anomalies.To comprehensively understand the occurrence of water color anomalies in inland lakes,an integrated me...Water color is a crucial optical indicator of water quality,polluted water bodies often show water color anomalies.To comprehensively understand the occurrence of water color anomalies in inland lakes,an integrated method was designed using the hue angle based on the Forel-Ule Index(FUI)model,and other remote sensing indices,including the Turbid Water Index(TWI),Floating Algae Index(FAI),and Cyanobacteria and Macrophytes Index(CMI).Based on all available Landsat-8 OLI images from 2013 to 2020,continuous monitoring was conducted in three different lakes in the middle of the Yangtze River,China.The results demonstrated that:(1)The proposed method can accurately identify algal blooms,high sediment loads,and eutrophication from the abnormal water color areas;(2)The calculated hue angles of sediment-dominated water were significantly higher than those of algal blooms and aquatic vegetation,providing a noticeable visual discoloration of water;(3)These water color anomalies exhibited significant correlations with the water quality and environmental conditions.This study serves as an example for accurate and spatially continuous assessment of water color anomaly and supports practical information to facilitate local water environment conservation.展开更多
There is ongoing research in freestanding single-atom thick elemental metal patches,including those suspended in a two-dimensional(2D)material,due to their utility in providing new structural and energetic insight int...There is ongoing research in freestanding single-atom thick elemental metal patches,including those suspended in a two-dimensional(2D)material,due to their utility in providing new structural and energetic insight into novel metallic 2D systems.Graphene pores have shown promise as support systems for suspending such patches.This study explores the potential of Sn atoms to form freestanding stanene and/or Sn patches in graphene pores.Sn atoms were deposited on graphene,where they formed novel single-atom thick 2D planar clusters/patches(or membranes)ranging from 1 to 8 atoms within the graphene pores.Patches of three or more atoms adopted either a star-like or close-packed structural configuration.Density functional theory(DFT)calculations were conducted to look at the cluster configurations and energetics(without the graphene matrix)and were found to deviate from experimental observations for 2D patches larger than five atoms.This was attributed to interfacial interactions between the graphene pore edges and Sn atoms.The presented findings help advance the development of single-atom thick 2D elemental metal membranes.展开更多
Autographa californica multiple nucleopolyhedrovirus(Ac MNPV)orf13(ac13)is a conserved gene in all sequenced alphabaculoviruses.However,its function in the viral life cycle remains unknown.In this study,we found that ...Autographa californica multiple nucleopolyhedrovirus(Ac MNPV)orf13(ac13)is a conserved gene in all sequenced alphabaculoviruses.However,its function in the viral life cycle remains unknown.In this study,we found that ac13 was a late gene and that the encoded protein,bearing a putative nuclear localization signal motif,colocalized with the nuclear lamina.Deletion of ac13 did not affect viral genome replication,nucleocapsid assembly or occlusion body(OB)formation,but reduced virion budding from infected cells by approximately 400-fold compared with the wild-type virus.Deletion of ac13 substantially impaired the egress of nucleocapsids from the nucleus to the cytoplasm,while the OB morphogenesis was unaffected.Taken together,our results indicated that ac13 was required for efficient nuclear egress of nucleocapsids during virion budding,but was dispensable for OB formation.展开更多
Silicon(Si)is a promising anode material for next-generation Li-ion batteries.The nanometer-sized Si could alleviate the pulverization caused by large volume changes during deep cycling.However,compression between agg...Silicon(Si)is a promising anode material for next-generation Li-ion batteries.The nanometer-sized Si could alleviate the pulverization caused by large volume changes during deep cycling.However,compression between agglomerated Si particles causes Si cracking and electrode failure.Considering this,we engineered a mechanical cushioning space between Si particles via elastic hollow graphene shells(GSs)to flexibly buffer volume changes and maintain the stability of the electrode structure.The stress generated from the Si volume expansion during lithiation was mechanically buffered and gently released by compression of the hollow space of the GS.In this Si/GS composite electrode,GS also reduced the local agglomeration of Si particles and effectively improved the overall conductivity.Considering these advantages,the designed Si/GS electrode showed an enhanced cycling performance with more than 1200 mA h g^(-1) at 0.8 A g^(-1) and an excellent rate capability of 1025 mA h g^(-1) at 4 A g^(-1) after 200 cycles.展开更多
文摘Carbon resources play an important role in affecting the benthic bacterial community in shallow lakes. In this study, pyrosequencing was applied to compare bacteria phylogenic profile in incubated sediments with normal and exchanged organic detritus in macrophyte-dominated East Lake Taihu and algal-dominated Meiliang Bay. We observed significant bacteria species variations in sediments from two bays, regardless of treatments. RDA (Redundancy Analysis) analysis showed that sediment characteristics, especially concentrations of total nitrogen might account for this differentiation. Besides, algal-dominated Meiliang Bay sediment with addition of Vallisneria detritus exhibited higher bacterial species variations than the sediment amended with Microcystis detritus. To the contrary, sediments from macrophyte-dominated East Lake Taihu shared similar bacteria profile at all taxonomic levels and grouped together in MDS (multidimensional scaling) plots over the treatments with Vallisneria or Microcystis detritus addition into the sediment. We speculated that the different degradability of macrophyte detritus and algal detritus led to varied bacterial responses to exchanged organic resources and ultimately, the amounts, nutrient availability and degradability of organic resources may be main reasons for benthic bacteria community structure differentiation between the two states in shallow lakes.
基金Supported by the Program for New Century Excellent Talents in University of China (NCET-07-0594)the National Natural Science Foundation of China (50874078 and 50804033)the Special Support for National Excellent Ph.D.Thesis (200959)
文摘The primary purpose of underground gas storages is to provide gas for seasonal consumptions or strategic reserve.The periodical operations of gas injection and extraction lead to cyclic loading on the walls and surrounding rocks of gas storages.To investigate the mechanical behaviors of different host rocks in bedded salt deposit,laboratory experiments were conducted on the samples of rock salt,thenardite,glauberite and gypsum.The mechanical properties of rock samples under monotonic and cyclic loadings were studied.Testing results show that,under monotonic loading,the uniaxial compressive stress（UCS） of glauberite is the largest（17.3 MPa）,while that of rock salt is the smallest（14.0 MPa）.The UCSs of thenardite and gypsum are 16.3 and 14.6 MPa,respectively.The maximum strain at the peak strength of rock salt（halite） is much greater than those of the other three rocks.The elastic moduli of halite,thenardite,glauberite and gypsum are 3.0,4.2,5.1 and 6.8 GPa,respectively.Under cyclic loading,the peak strengths of the rock specimens are deteriorated except for rock salt.The peak strengths of thenardite,glauberite and gypsum decrease by 33.7%,19.1% and 35.5%,respectively;and the strains of the three rocks at the peak strengths are almost the same.However,the strain of rock salt at the peak strength increases by 1.98%,twice more than that under monotonic loading.Under monotonic loading,deformation of the tested rock salt,thenardite and glauberite shows in an elastoplastic style.However,it changes to a ductile style under cyclic loading.Brittle deformation and failure are only observed for gypsum.The results should be helpful for engineering design and operation of gas storage in bedded salt deposit.
基金This work was supported by National Key Research and Development Program of China(2018YFC1106800)Sichuan province key research and development project(20ZDYF0191).
文摘Repair and reconstruction of large bone defect were often difficult,and bone substitute materials,including autogenous bone,allogenic bone and artificial bone,were common treatment strategies.The key to elucidate the clinical effect of these bone repair materials was to study their osteogenic capacity and immunotoxicological compatibility.In this paper,the mechanical properties,micro-CT imaging analysis,digital image analysis and histological slice analysis of the three bone grafts were investigated and compared after different time points of implantation in rat femur defect model.Autogenous bone and biphasic calcium phosphate particular artificial bone containing 61.4% HA and 38.6%β-tricalcium phosphate with 61.64%porosity and 0.8617±0.0068 g/cm^(3) den-sity(d≤2 mm)had similar and strong bone repair ability,but autogenous bone implant materials caused greater secondary damage to experimental animals;allogenic bone exhibited poor bone defect repair ability.At the early stage of implantation,the immunological indexes such as Immunoglobulin G,Immunoglobulin M concentration and CD4 cells'population of allogenic bone significantly increased in compared with those of autologous bone and artificial bone.Although the repair process of artificial bone was relatively inefficient than autologous bone graft,the low immunotoxicological indexes and acceptable therapeutic effects endowed it as an excellent alter-native material to solve the problems with insufficient source and secondary trauma of autogenous bone.
基金This work was supported by the National Natural Science Foundation of China(No.52071225)the Czech Republic from ERDF“Institute of Environmental Technology-Excellent Research”(No.CZ.02.1.01/0.0/0.0/16_019/0000853)M.H.R.and L.F.thank the Sino-German Research Institute for support(project:GZ 1400).X.Q.Y.thanks Suzhou University.H.Q.T.thanks the Alexander Von Humboldt Foundation for support through a fellowship.
文摘Graphene is a material with unique properties that can be exploited in electronics, catalysis, energy, and bio-related fields. Although, for maximal utilization of this material, high-quality graphene is required at both the growth process and after transfer of the graphene film to the application-compatible substrate. Chemical vapor deposition (CVD) is an important method for growing high-quality graphene on non-technological substrates (as, metal substrates, e.g., copper foil). Thus, there are also considerable efforts toward the efficient and non-damaging transfer of quality of graphene on to technologically relevant materials and systems. In this review article, a range of graphene current transfer techniques are reviewed from the standpoint of their impact on contamination control and structural integrity preservation of the as-produced graphene. In addition, their scalability, cost- and time-effectiveness are discussed. We summarize with a perspective on the transfer challenges, alternative options and future developments toward graphene technology.
基金supported by the National Natural Science Foundation of China(NSFC,No.52071225)the National Science Center,and the Czech Republic under the ERDF program“Institute of Environmental Technology-Excellent Research”(No.CZ.02.1.01/0.0/0.0/16-019/0000853)M.H.R.and L.F.thank the Sino-German Research Institute for support(No.GZ 1400).
文摘Graphene doping continues to gather momentum because it enables graphene properties to be tuned,thereby affording new properties to,improve the performance of,and expand the application potential of graphene.Graphene can be chemically doped using various methods such as surface functionalization,hybrid composites(e.g.,nanoparticle decoration),and substitution doping,wherein C atoms are replaced by foreign ones in the graphene lattice.Theoretical works have predicted that graphene could be substitutionally doped by aluminum(Al)atoms,which could hold promise for exciting applications,including hydrogen storage and evolution,and supercapacitors.Other theoretical predictions suggest that Al substitutionally doped graphene(AIG)could serve as a material for gas sensors and the catalytic decomposition of undesirable materials.However,fabricating Al substitutionally doped graphene has proven challenging until now.Herein,we demonstrate how controlled-flow chemical vapor deposition(CVD)implementing a simple solid precursor can yield high-quality and large-area monolayer AIG,and this synthesis is unequivocally confirmed using various characterization methods including local electron energy-loss spectroscopy(EELS).Detailed high-resolution transmission electron microscopy(HRTEM)shows numerous bonding configurations between the Al atoms and the graphene lattice,some of which are not theoretically predicted.Furthermore,the produced AIG shows a CO_(2) capturability superior to those of other substitutionally doped graphenes.
基金jointly supported by the National Key Research and Development Program of China[grant numbers 2018YFB0504900 and 2018YFB0504904]the National Natural Science Foundation of China[grant numbers 42071325,42171346,and 42176183]LIESMARS Special Research Funding,the‘985 Project’of Wuhan University,and Special funds of State Key Laboratory for equipment.
文摘Water color is a crucial optical indicator of water quality,polluted water bodies often show water color anomalies.To comprehensively understand the occurrence of water color anomalies in inland lakes,an integrated method was designed using the hue angle based on the Forel-Ule Index(FUI)model,and other remote sensing indices,including the Turbid Water Index(TWI),Floating Algae Index(FAI),and Cyanobacteria and Macrophytes Index(CMI).Based on all available Landsat-8 OLI images from 2013 to 2020,continuous monitoring was conducted in three different lakes in the middle of the Yangtze River,China.The results demonstrated that:(1)The proposed method can accurately identify algal blooms,high sediment loads,and eutrophication from the abnormal water color areas;(2)The calculated hue angles of sediment-dominated water were significantly higher than those of algal blooms and aquatic vegetation,providing a noticeable visual discoloration of water;(3)These water color anomalies exhibited significant correlations with the water quality and environmental conditions.This study serves as an example for accurate and spatially continuous assessment of water color anomaly and supports practical information to facilitate local water environment conservation.
基金This work was supported by the National Natural Science Foundation of China(Nos.11874044,51676154,and 51672181)the Czech Republic from ERDF“Institute of Environmental Technology-Excellent Research”(No.CZ.02.1.01/0.0/0.0/16_019/0000853)M.H.R.thanks the Sino-German Research Institute for its support(project:GZ 1400).
文摘There is ongoing research in freestanding single-atom thick elemental metal patches,including those suspended in a two-dimensional(2D)material,due to their utility in providing new structural and energetic insight into novel metallic 2D systems.Graphene pores have shown promise as support systems for suspending such patches.This study explores the potential of Sn atoms to form freestanding stanene and/or Sn patches in graphene pores.Sn atoms were deposited on graphene,where they formed novel single-atom thick 2D planar clusters/patches(or membranes)ranging from 1 to 8 atoms within the graphene pores.Patches of three or more atoms adopted either a star-like or close-packed structural configuration.Density functional theory(DFT)calculations were conducted to look at the cluster configurations and energetics(without the graphene matrix)and were found to deviate from experimental observations for 2D patches larger than five atoms.This was attributed to interfacial interactions between the graphene pore edges and Sn atoms.The presented findings help advance the development of single-atom thick 2D elemental metal membranes.
基金supported by the National Key Research and Development Program of China(2017YFD0201206)the WIV “One-Three-Five”strategic program(Y602111SA1 to XS)。
文摘Autographa californica multiple nucleopolyhedrovirus(Ac MNPV)orf13(ac13)is a conserved gene in all sequenced alphabaculoviruses.However,its function in the viral life cycle remains unknown.In this study,we found that ac13 was a late gene and that the encoded protein,bearing a putative nuclear localization signal motif,colocalized with the nuclear lamina.Deletion of ac13 did not affect viral genome replication,nucleocapsid assembly or occlusion body(OB)formation,but reduced virion budding from infected cells by approximately 400-fold compared with the wild-type virus.Deletion of ac13 substantially impaired the egress of nucleocapsids from the nucleus to the cytoplasm,while the OB morphogenesis was unaffected.Taken together,our results indicated that ac13 was required for efficient nuclear egress of nucleocapsids during virion budding,but was dispensable for OB formation.
基金supported by the National Natural Science Foundation of China(52071225,52172240,51702225 and 51672181)Czech Republic through the ERDF“Institute of Environmental TechnologyExcellent Research”grant(CZ.02.1.01/0.0/0.0/16_019/0000853)+3 种基金the SinoGerman Research Institute for their support(Project GZ 1400)the Fundamental Research Funds for the Central Universities(20720200075)Beijing Municipal Science and Technology Commission(Z161100002116020)the Natural Science Foundation of Jiangsu Province(BK20170336)。
文摘Silicon(Si)is a promising anode material for next-generation Li-ion batteries.The nanometer-sized Si could alleviate the pulverization caused by large volume changes during deep cycling.However,compression between agglomerated Si particles causes Si cracking and electrode failure.Considering this,we engineered a mechanical cushioning space between Si particles via elastic hollow graphene shells(GSs)to flexibly buffer volume changes and maintain the stability of the electrode structure.The stress generated from the Si volume expansion during lithiation was mechanically buffered and gently released by compression of the hollow space of the GS.In this Si/GS composite electrode,GS also reduced the local agglomeration of Si particles and effectively improved the overall conductivity.Considering these advantages,the designed Si/GS electrode showed an enhanced cycling performance with more than 1200 mA h g^(-1) at 0.8 A g^(-1) and an excellent rate capability of 1025 mA h g^(-1) at 4 A g^(-1) after 200 cycles.
