[Objectives]This study was conducted to investigate the effects of Vitis heyneana cultivation on rocky hillsides on the variation of soil fertility,so as to provide theoretical support for economic development and the...[Objectives]This study was conducted to investigate the effects of Vitis heyneana cultivation on rocky hillsides on the variation of soil fertility,so as to provide theoretical support for economic development and the control of rocky desertification in the Dashi mountainous area.[Methods]Taking V.heyneana planting base in Luocheng County,Hechi City,Guangxi Province as the research object,the methods of field investigation,regular sampling and experimental analysis were used to analyze seasonal variations of soil urease,sucrase and soil alkaline phosphatase activity of 15 different sample plots surveyed,and their correlation with soil physical and chemical properties was analyzed.[Results]①In general,sucrase,urease and alkaline phosphatase were lower in summer and autumn,and higher in spring and winter,and the performance of the activity of the three enzymes was inconsistent.Among them,the activity of sucrase was in order of spring>autumn>summer>winter,and the activity of urease and alkaline phosphatase showed an order of winter>spring>summer>autumn.②The seasonal variations of soil fertility in different sample plots were affected by various factors such as human disturbance,climate change,vegetation coverage,topography and landforms,cultivation and management measures,and although the change laws in different sample plots were different,the seasonal differences in soil fertility in the same place were extremely significant.③If the influence of artificial fertilization factors is excluded,the planting of V.heyneana on rocky hillsides will cause a significant decrease in soil enzyme activity,that is,a significant decrease in soil fertility.[Conclusions]Related issues such as the effects of planting V.heyneana on the variation of soil fertility in rocky hillsides should arouse necessary attention of management departments and producers.展开更多
[Objectives]This study was conducted to investigate the effects of different heavy metal stresses on seed germination,in order to provide a theoretical basis for phytoremediation of soil heavy metal pollution.[Methods...[Objectives]This study was conducted to investigate the effects of different heavy metal stresses on seed germination,in order to provide a theoretical basis for phytoremediation of soil heavy metal pollution.[Methods]With the seeds of A.julibrissin as an experimental material,the germination test of A.julibrissin seeds under different concentrations of Cu^(2+),Zn^(2+) and Pb^(2+) was carried out.The germination potential,germination rate,germination index,radicle length,embryo length and other indexes were measured.[Results]①Different heavy metals had different effects on the germination of A.julibrissin seeds.Low concentrations of Cu^(2+),Zn^(2+) and Pb^(2+) stresses had certain promotion effects on the germination of A.julibrissin seeds,but high concentrations of Cu^(2+),Zn^(2+),Pb^(2+) stresses had obvious inhibitory effects on the germination of A.julibrissin seeds.②There were obvious differences in the tolerance of A.julibrissin seeds to different metal ion stresses.According to the comparison of the average values of membership functions,the order of their tolerance to different heavy metal ions was:Zn^(2+)>Cu^(2+)>Pb^(2+).[Conclusions]In the case of light pollution,the germination of A.julibrissin seeds was not inhibited,and the use of this plant for the remediation of lightly contaminated soil with heavy metals can also be considered.展开更多
Integration of phase-change materials(PCMs)created a unique opportunity to implement reconfigurable photonics devices that their performance can be tuned depending on the target application.Conventional PCMs such as G...Integration of phase-change materials(PCMs)created a unique opportunity to implement reconfigurable photonics devices that their performance can be tuned depending on the target application.Conventional PCMs such as Ge-Sb-Te(GST)and Ge-Sb-Se-Te(GSST)rely on melt-quench and high temperature annealing processes to change the organization of the molecules in the materials’crystal.Such a reorganization leads to different optical,electrical,and thermal properties which can be exploited to implement photonic memory cells that are able to store the data at different resistance or optical transmission levels.Despite the great promise of conventional PCMs for realizing reconfigurable photonic memories,their slow and extremely power-hungry thermal mechanisms make scaling the systems based on such devices challenging.In addition,such materials do not offer a stable multi-level response over a long period of time.To address these shortcomings,the research carried out in this study shows the proof of concept to implement next-generation photonic memory cells based on two-dimensional(2D)birefringence PCMs such as SnSe,which offer anisotropic optical properties that can be switched ferroelectrically.We demonstrate that by leveraging the ultrafast and low-power crystallographic direction change of the material,the optical polarization state of the input optical signal can be changed.This enables the implementation of next-generation high-speed polarization-encodable photonic memory cells for future photonic computing systems.Compared to the conventional PCMs,the proposed SnSe-based photonic memory cells offer an ultrafast switching and low-loss optical response relying on ferroelectric property of SnSe to encode the data on the polarization state of the input optical signal.Such a polarization encoding scheme also reduces memory read-out errors and alleviates the scalability limitations due to the optical insertion loss often seen in optical transmission encoding.展开更多
基金Natural Science Foundation of Guangxi(GKZ 0832273)Laboratory of Comprehensive Prevention and Control of Rocky Desertification in Karst Areas in Northwest Guangxi(XZF[2016]91)+1 种基金High-level Talent Research Startup Fund of Hechi University(XJ2018GKQ016)Undergraduate Innovation and Enterpreneurship Training Program of Guangxi(201810605086).
文摘[Objectives]This study was conducted to investigate the effects of Vitis heyneana cultivation on rocky hillsides on the variation of soil fertility,so as to provide theoretical support for economic development and the control of rocky desertification in the Dashi mountainous area.[Methods]Taking V.heyneana planting base in Luocheng County,Hechi City,Guangxi Province as the research object,the methods of field investigation,regular sampling and experimental analysis were used to analyze seasonal variations of soil urease,sucrase and soil alkaline phosphatase activity of 15 different sample plots surveyed,and their correlation with soil physical and chemical properties was analyzed.[Results]①In general,sucrase,urease and alkaline phosphatase were lower in summer and autumn,and higher in spring and winter,and the performance of the activity of the three enzymes was inconsistent.Among them,the activity of sucrase was in order of spring>autumn>summer>winter,and the activity of urease and alkaline phosphatase showed an order of winter>spring>summer>autumn.②The seasonal variations of soil fertility in different sample plots were affected by various factors such as human disturbance,climate change,vegetation coverage,topography and landforms,cultivation and management measures,and although the change laws in different sample plots were different,the seasonal differences in soil fertility in the same place were extremely significant.③If the influence of artificial fertilization factors is excluded,the planting of V.heyneana on rocky hillsides will cause a significant decrease in soil enzyme activity,that is,a significant decrease in soil fertility.[Conclusions]Related issues such as the effects of planting V.heyneana on the variation of soil fertility in rocky hillsides should arouse necessary attention of management departments and producers.
基金Guangxi Natural Science Foundation(GKZ 0832273)Laboratory for Comprehensive Prevention and Control of Rocky Desertification in Karst Areas in Northwest Guangxi(XZF[2016]91)Hechi University Master s Professional Degree Construction Fund(2016HJA007).
文摘[Objectives]This study was conducted to investigate the effects of different heavy metal stresses on seed germination,in order to provide a theoretical basis for phytoremediation of soil heavy metal pollution.[Methods]With the seeds of A.julibrissin as an experimental material,the germination test of A.julibrissin seeds under different concentrations of Cu^(2+),Zn^(2+) and Pb^(2+) was carried out.The germination potential,germination rate,germination index,radicle length,embryo length and other indexes were measured.[Results]①Different heavy metals had different effects on the germination of A.julibrissin seeds.Low concentrations of Cu^(2+),Zn^(2+) and Pb^(2+) stresses had certain promotion effects on the germination of A.julibrissin seeds,but high concentrations of Cu^(2+),Zn^(2+),Pb^(2+) stresses had obvious inhibitory effects on the germination of A.julibrissin seeds.②There were obvious differences in the tolerance of A.julibrissin seeds to different metal ion stresses.According to the comparison of the average values of membership functions,the order of their tolerance to different heavy metal ions was:Zn^(2+)>Cu^(2+)>Pb^(2+).[Conclusions]In the case of light pollution,the germination of A.julibrissin seeds was not inhibited,and the use of this plant for the remediation of lightly contaminated soil with heavy metals can also be considered.
基金supported by the National Science Foundation(NSF)(Nos.CCF-2006788 and CNS-2046226)L.H.C.and J.Y.thank the support of Heising-Simons Faculty Fellowship.
文摘Integration of phase-change materials(PCMs)created a unique opportunity to implement reconfigurable photonics devices that their performance can be tuned depending on the target application.Conventional PCMs such as Ge-Sb-Te(GST)and Ge-Sb-Se-Te(GSST)rely on melt-quench and high temperature annealing processes to change the organization of the molecules in the materials’crystal.Such a reorganization leads to different optical,electrical,and thermal properties which can be exploited to implement photonic memory cells that are able to store the data at different resistance or optical transmission levels.Despite the great promise of conventional PCMs for realizing reconfigurable photonic memories,their slow and extremely power-hungry thermal mechanisms make scaling the systems based on such devices challenging.In addition,such materials do not offer a stable multi-level response over a long period of time.To address these shortcomings,the research carried out in this study shows the proof of concept to implement next-generation photonic memory cells based on two-dimensional(2D)birefringence PCMs such as SnSe,which offer anisotropic optical properties that can be switched ferroelectrically.We demonstrate that by leveraging the ultrafast and low-power crystallographic direction change of the material,the optical polarization state of the input optical signal can be changed.This enables the implementation of next-generation high-speed polarization-encodable photonic memory cells for future photonic computing systems.Compared to the conventional PCMs,the proposed SnSe-based photonic memory cells offer an ultrafast switching and low-loss optical response relying on ferroelectric property of SnSe to encode the data on the polarization state of the input optical signal.Such a polarization encoding scheme also reduces memory read-out errors and alleviates the scalability limitations due to the optical insertion loss often seen in optical transmission encoding.
