A glasshouse experiment using a rhizobox technique was conducted to examine salt dynamics in the rhizosphere of a salt-tolerant grass, Puccinellia ciliata Bor. ’Irwin Hunter’, grown in a loamy soil, and to study the...A glasshouse experiment using a rhizobox technique was conducted to examine salt dynamics in the rhizosphere of a salt-tolerant grass, Puccinellia ciliata Bor. ’Irwin Hunter’, grown in a loamy soil, and to study the effect of rainfall flush on salt accumulation in the rhizosphere. The rhizobox (10 × 5.5 × 50 cm) had a nylon mesh (1 μm) positioned vertically in the middle to create two compartments filled with soil amended with 1 g NaCl kg-1. The plants were grown in one compartment only. Flushed treatments received 275 mL of deionized water two days before harvest. In the plant-growing compartment, soils were sectioned vertically at 5 cm intervals. Significant differences in soil electrical conductivity (EC) (P < 0.05) and pH (P < 0.05) were observed for depths, but not between flushed and non-flushed treatments. In the no-plant compartment (rhizosphere), soil cores were taken horizontally at depths of 5, 20 and 40 cm and sliced at 1, 2, 3, 4, 5, 7, 10, 15 and 20 mm away from the roots. Soil EC and Cl- concentration at the 5 and 20 cm depths, and Na+ concentration at the 5 cm depth significantly decreased (P < 0.05) with the distance away from the root, but no significant differences were observed in soil pH and concentrations of the K+ and Ca2+. The flush treatment only had significant influence on soil EC, pH, and Cl- concentration at the 20 cm depth. Thus, salt accumulation could occur in the rhizosphere of salt-tolerant species on saline soils, and the periodic low rainfall might not have a strong influence on salt distribution in the rhizosphere and/or root zone.展开更多
A new synchronization technique of inner and outer couplings is proposed in this work to investigate the synchro- nization of network group. Some Haken-Lorenz lasers with chaos behaviors are taken as the nodes to cons...A new synchronization technique of inner and outer couplings is proposed in this work to investigate the synchro- nization of network group. Some Haken-Lorenz lasers with chaos behaviors are taken as the nodes to construct a few nearest neighbor complex networks and those sub-networks are also connected to form a network group. The effective node controllers are designed based on Lyapunov function and the complete synchronization among the sub-networks is realized perfectly under inner and outer couplings. The work is of potential applications in the cooperation output of lasers and the communication network.展开更多
Monoelemental two-dimensional(2D)materials(Xenes)aroused a tremendous attention in 2D science owing to their unique properties and extensive applications.Borophene,one emerging and typical Xene,has been regarded as a ...Monoelemental two-dimensional(2D)materials(Xenes)aroused a tremendous attention in 2D science owing to their unique properties and extensive applications.Borophene,one emerging and typical Xene,has been regarded as a promising agent for energy,sensor,and biomedical applications.However,the production of borophene is still a challenge because bulk boron has rather intricate spatial structures and multiple chemical properties.In this review,we describe its excellent properties including the optical,electronic,metallic,semiconducting,photoacoustic,and photothermal properties.The fabrication methods of borophene are also presented including the bottom-up fabrication and the top-down fabrication.In the end,the challenges of borophene in the latest applications are presented and perspectives are discussed.展开更多
Performing mobile k nearest neighbor （MkNN） queries whilst also being mobile is a challenging problem. All the mobile objects issuing queries and/or being queried are mobile. The performance of this kind of query re...Performing mobile k nearest neighbor （MkNN） queries whilst also being mobile is a challenging problem. All the mobile objects issuing queries and/or being queried are mobile. The performance of this kind of query relies heav- ily on the maintenance of the current locations of the objects. The index used for mobile objects must support efficient up- date operations and efficient query handling. This study aims to improve the performance of the MkNN queries while re- ducing update costs. Our approach is based on an observa- tion that the frequency of one region changing between being occupied or not by mobile objects is much lower than the frequency of the position changes reported by the mobile ob- jects. We first propose an virtual grid quadtree with Voronoi diagram （VGQ-Vor）, which is a two-layer index structure that indexes regions occupied by mobile objects in a quadtree and builds a Voronoi diagram of the regions. Then we propose a moving k nearest neighbor （kNN） query algorithm on the VGQ-Vor and prove the correctness of the algorithm. The ex- perimental results show that the VGQ-Vor outperforms the existing techniques （Bx-tree, Bdual-tree） by one to three or- ders of magnitude in most cases.展开更多
Large calculation error can be formed by directly employing the conventional Yee’s grid to curve surfaces.In order to alleviate such condition,unconditionally stable CrankNicolson Douglas-Gunn(CNDG)algorithm with is ...Large calculation error can be formed by directly employing the conventional Yee’s grid to curve surfaces.In order to alleviate such condition,unconditionally stable CrankNicolson Douglas-Gunn(CNDG)algorithm with is proposed for rotationally symmetric multi-scale problems in anisotropic magnetized plasma.Within the CNDG algorithm,an alternative scheme for the simulation of anisotropic plasma is proposed in body-of-revolution domains.Convolutional perfectly matched layer(CPML)formulation is proposed to efficiently solve the open region problems.Numerical example is carried out for the illustration of effectiveness including the efficiency,resources,and absorption.Through the results,it can be concluded that the proposed scheme shows considerable performance during the simulation.展开更多
随着线上线下融合的全渠道模式蓬勃发展,厂商相继退出线上购买线下退货的全渠道退货服务(Buy Online and Return in Store,BORS)。考虑了服务差异化与消费者异质双重影响下的全渠道退货的问题,构建同渠道退货和全渠道退货两种退货策略模...随着线上线下融合的全渠道模式蓬勃发展,厂商相继退出线上购买线下退货的全渠道退货服务(Buy Online and Return in Store,BORS)。考虑了服务差异化与消费者异质双重影响下的全渠道退货的问题,构建同渠道退货和全渠道退货两种退货策略模型,研究产品定价决策与退货策略选择,并分析服务与消费者差异性对供应链定价及退货策略的影响。研究表明,当服务水平达到一定阈值后,消费者会为全渠道退货服务承担一定溢价;供应链提供合理的差异化服务实施差异化竞争,能凸显全渠道退货优势,提升供应链利润。当服务成本低且消费者服务感知较高时,更适合采用全渠道退货策略。展开更多
文摘A glasshouse experiment using a rhizobox technique was conducted to examine salt dynamics in the rhizosphere of a salt-tolerant grass, Puccinellia ciliata Bor. ’Irwin Hunter’, grown in a loamy soil, and to study the effect of rainfall flush on salt accumulation in the rhizosphere. The rhizobox (10 × 5.5 × 50 cm) had a nylon mesh (1 μm) positioned vertically in the middle to create two compartments filled with soil amended with 1 g NaCl kg-1. The plants were grown in one compartment only. Flushed treatments received 275 mL of deionized water two days before harvest. In the plant-growing compartment, soils were sectioned vertically at 5 cm intervals. Significant differences in soil electrical conductivity (EC) (P < 0.05) and pH (P < 0.05) were observed for depths, but not between flushed and non-flushed treatments. In the no-plant compartment (rhizosphere), soil cores were taken horizontally at depths of 5, 20 and 40 cm and sliced at 1, 2, 3, 4, 5, 7, 10, 15 and 20 mm away from the roots. Soil EC and Cl- concentration at the 5 and 20 cm depths, and Na+ concentration at the 5 cm depth significantly decreased (P < 0.05) with the distance away from the root, but no significant differences were observed in soil pH and concentrations of the K+ and Ca2+. The flush treatment only had significant influence on soil EC, pH, and Cl- concentration at the 20 cm depth. Thus, salt accumulation could occur in the rhizosphere of salt-tolerant species on saline soils, and the periodic low rainfall might not have a strong influence on salt distribution in the rhizosphere and/or root zone.
基金Project supported by the National Natural Science Foundation of China(Grant No.11004092)the Natural Science Foundation of Liaoning Province,China(Grant Nos.2015020079 and 201602455)the Foundation of Education Department of Liaoning Province,China(Grant No.L201683665)
文摘A new synchronization technique of inner and outer couplings is proposed in this work to investigate the synchro- nization of network group. Some Haken-Lorenz lasers with chaos behaviors are taken as the nodes to construct a few nearest neighbor complex networks and those sub-networks are also connected to form a network group. The effective node controllers are designed based on Lyapunov function and the complete synchronization among the sub-networks is realized perfectly under inner and outer couplings. The work is of potential applications in the cooperation output of lasers and the communication network.
基金This work is supported by the State Key Research Development Program of China(Grant No.2019YFB2203503)the National Natural Science Fund(Grant Nos.61875138,61435010,and 61961136001)+1 种基金the Natural Science Foundation of Guangdong Province(Grant No.2020A1515010612)the Longhua District Science and Innovation Commission Project Grants(JCYJ201904)to Shenzhen International Institute for Biomedical Research.
文摘Monoelemental two-dimensional(2D)materials(Xenes)aroused a tremendous attention in 2D science owing to their unique properties and extensive applications.Borophene,one emerging and typical Xene,has been regarded as a promising agent for energy,sensor,and biomedical applications.However,the production of borophene is still a challenge because bulk boron has rather intricate spatial structures and multiple chemical properties.In this review,we describe its excellent properties including the optical,electronic,metallic,semiconducting,photoacoustic,and photothermal properties.The fabrication methods of borophene are also presented including the bottom-up fabrication and the top-down fabrication.In the end,the challenges of borophene in the latest applications are presented and perspectives are discussed.
文摘Performing mobile k nearest neighbor （MkNN） queries whilst also being mobile is a challenging problem. All the mobile objects issuing queries and/or being queried are mobile. The performance of this kind of query relies heav- ily on the maintenance of the current locations of the objects. The index used for mobile objects must support efficient up- date operations and efficient query handling. This study aims to improve the performance of the MkNN queries while re- ducing update costs. Our approach is based on an observa- tion that the frequency of one region changing between being occupied or not by mobile objects is much lower than the frequency of the position changes reported by the mobile ob- jects. We first propose an virtual grid quadtree with Voronoi diagram （VGQ-Vor）, which is a two-layer index structure that indexes regions occupied by mobile objects in a quadtree and builds a Voronoi diagram of the regions. Then we propose a moving k nearest neighbor （kNN） query algorithm on the VGQ-Vor and prove the correctness of the algorithm. The ex- perimental results show that the VGQ-Vor outperforms the existing techniques （Bx-tree, Bdual-tree） by one to three or- ders of magnitude in most cases.
文摘Large calculation error can be formed by directly employing the conventional Yee’s grid to curve surfaces.In order to alleviate such condition,unconditionally stable CrankNicolson Douglas-Gunn(CNDG)algorithm with is proposed for rotationally symmetric multi-scale problems in anisotropic magnetized plasma.Within the CNDG algorithm,an alternative scheme for the simulation of anisotropic plasma is proposed in body-of-revolution domains.Convolutional perfectly matched layer(CPML)formulation is proposed to efficiently solve the open region problems.Numerical example is carried out for the illustration of effectiveness including the efficiency,resources,and absorption.Through the results,it can be concluded that the proposed scheme shows considerable performance during the simulation.
文摘随着线上线下融合的全渠道模式蓬勃发展,厂商相继退出线上购买线下退货的全渠道退货服务(Buy Online and Return in Store,BORS)。考虑了服务差异化与消费者异质双重影响下的全渠道退货的问题,构建同渠道退货和全渠道退货两种退货策略模型,研究产品定价决策与退货策略选择,并分析服务与消费者差异性对供应链定价及退货策略的影响。研究表明,当服务水平达到一定阈值后,消费者会为全渠道退货服务承担一定溢价;供应链提供合理的差异化服务实施差异化竞争,能凸显全渠道退货优势,提升供应链利润。当服务成本低且消费者服务感知较高时,更适合采用全渠道退货策略。
