The concurrent processing and load capacity of a single server cannot meet the growing demand of users for a variety of services in a campus network system. This document put forward to solve this problem using load b...The concurrent processing and load capacity of a single server cannot meet the growing demand of users for a variety of services in a campus network system. This document put forward to solve this problem using load balancing techniques based on LVS-NAT, discussed the key technologies of LVS-NAT, designed and implemented campus network service system with LVS-NAT load balancing technology and tested. The results showed that this system improved the processing and load capacity of the concurrent server effectively and provided a good reference to building the efficient and stable digital campus network system.展开更多
ELM （edge localized mode） coils are key components of ITER that suppress the edge localized mode phenomenon. A giant electromagnetic force is generated during normal operations by the current flowing in the ELM coil...ELM （edge localized mode） coils are key components of ITER that suppress the edge localized mode phenomenon. A giant electromagnetic force is generated during normal operations by the current flowing in the ELM coils interacting with the external background field. The Lorentz force will induce Tresca stress in the ELM coils. If the load goes beyond the allowable threshold, the coils can hardly satisfy the safety requirements. The right-hand bottom corner was chosen to perform our electromagnetic analyses. Based on the Maxwell equation, the detailed magnetic field and Lorentz force were calculated. By use of the finite element software ANSYS, the Tresca stress was extracted and evaluated based on our analytical design. The present analysis aims to verify the feasibility of the current design. It can also serve as guidance for fabrication and structural optimization.展开更多
Recent developments in acceptor–donor–acceptor(A–D–A) type non-fullerene acceptors have led to substantial improvements in bulk-heterojunction polymer solar cells efficiency. The device performance strongly depend...Recent developments in acceptor–donor–acceptor(A–D–A) type non-fullerene acceptors have led to substantial improvements in bulk-heterojunction polymer solar cells efficiency. The device performance strongly depends on photoactive layer morphology, as the molecular packing, donor–acceptor interface and phase separation significantly affect the charge-transfer states and charge carrier dynamics. In this review, we start with a brief introduction of the techniques most effectively utilized to characterize multiphase morphology. Then, we summarize recent progress in A–D–A type acceptors, with the emphasis on understanding the molecular structure–morphology–performance relationships. Finally, an outlook on correlating morphological characteristics with photovoltage losses is presented for further improving device performance.展开更多
In a sensor network with a large number of densely populated sensor nodes, a single target of interest may be detected by multiple sensor nodes simultaneously. Data collected from the sensor nodes are usually highly c...In a sensor network with a large number of densely populated sensor nodes, a single target of interest may be detected by multiple sensor nodes simultaneously. Data collected from the sensor nodes are usually highly correlated, and hence energy saving using in-network data fusion becomes possible. A traditional data fusion scheme starts with dividing the network into clusters, followed by electing a sensor node as cluster head in each cluster. A cluster head is responsible for collecting data from all its cluster members, performing data fusion on these data and transmitting the fused data to the base station. Assuming that a sensor node is only capable of handling a single node-to-node transmission at a time and each transmission takes T time-slots, a cluster head with n cluster members will take at least nT time-slots to collect data from all its cluster members. In this paper, a tree-based network structure and its formation algorithms are proposed. Simulation results show that the proposed network structure can greatly reduce the delay in data collection.展开更多
This article considers the problem of directing a family of fully actuated surface vessels to cooperatively follow a set of convex and closed orbits with a time-invariant reference orbital velocity and maintain attitu...This article considers the problem of directing a family of fully actuated surface vessels to cooperatively follow a set of convex and closed orbits with a time-invariant reference orbital velocity and maintain attitude synchronization. A consensusbased adaptive control law under a bidirectional communication topology is proposed to estimate the reference orbital velocity so that the restriction that every vessel in the family must have access to the reference in the previous literature can be removed.The assumption of nonzero total linear speed of each vessel is removed by the use of potential function. Simulation results demonstrate the effectiveness of the proposed approach.展开更多
CONSPECTUS:Nonfullerene acceptors(NFAs)represent the latest breakthrough in organic solar cells(OSCs),which significantly outperform the long benchmark OSCs with fullerene derivative acceptors.In addition to binary bu...CONSPECTUS:Nonfullerene acceptors(NFAs)represent the latest breakthrough in organic solar cells(OSCs),which significantly outperform the long benchmark OSCs with fullerene derivative acceptors.In addition to binary bulk heterojunction(BHJ)OSCs,multicomponent,in particular ternary BHJ strategy has attracted tremendous interests due to the realization of broadened coverage of solar spectrum while maintaining easy processing compared to tandem OSCs.Subsequently,ternary OSCs containing NFA(s)have provided exciting opportunities to the promising field and achieved great progress in power conversion efficiencies(PCEs)over 17%.Inspired by the recent progress,in this account,we focus on the ternary OSCs containing NFA(s),share our view of the topic and aim to provide guidelines for material selections in designing successful ternary OSCstoward the cornerstone of 20%PCE in the near future.In this Account,we first discuss the principle of OSCsworking mechanisms,including charge transfer and energy transfer that govern the charge dynamics.Moreover,the promising functional roles of the third components in NFA OSCs are highlighted at the following the sequence:(1)Absorption sensitizingthe additional component plays a key role in broadening the solar cell absorption window and thus promising in improving the photocurrent in the ternary active layer,especially when employing a nearinfrared material NFA as the third component.(2)Morphology manipulation approaches and modelsthe ternary blend nanostructure is complex and not trivial to understand.Parallel and alloy nanomorphology models are discussed on the basis of the simultaneous consideration of the intrinsic properties among the involved materials,such as electronic properties and interplay(miscibility)among the host−vip materials.(3)Energy loss managementthe addition of donor or acceptor with small energy loss,especially low bandgap material,as the third component holds the promises to reduce the energy loss in ternary OSCs.On the other hand,due to the advantage of the alloyed microstructure in precisely tuning VOC,applying a second donor with deeper HOMO level or a second acceptor with shallower LUMO level is expected to increase VOC and thus reduce the energy loss in ternary OSCs.(4)Stability boosting agentfrom the thermodynamic point of view,the stable BHJ microstructure is beneficial and critical in enhancing the OSCs’long-term thermal and light stability.However,most material combinations suffer from the poor miscibility between the donor phase and acceptor phase,leading to demixing of two phases and thus the performance degradation.On the basis of this concept,rational selection of the third component could facilitate the formation of glassy nanostructure by vitrifying the pure donor phase or acceptor phase.Also it worth noting that suppressed crystallization of the small molecular acceptors by mixing a miscible component is effective to achieve a stable morphology.At the end of the Account,we share our view on the issues that limit the performance of ternary OSCs and outline their perspectives.展开更多
文摘The concurrent processing and load capacity of a single server cannot meet the growing demand of users for a variety of services in a campus network system. This document put forward to solve this problem using load balancing techniques based on LVS-NAT, discussed the key technologies of LVS-NAT, designed and implemented campus network service system with LVS-NAT load balancing technology and tested. The results showed that this system improved the processing and load capacity of the concurrent server effectively and provided a good reference to building the efficient and stable digital campus network system.
文摘ELM （edge localized mode） coils are key components of ITER that suppress the edge localized mode phenomenon. A giant electromagnetic force is generated during normal operations by the current flowing in the ELM coils interacting with the external background field. The Lorentz force will induce Tresca stress in the ELM coils. If the load goes beyond the allowable threshold, the coils can hardly satisfy the safety requirements. The right-hand bottom corner was chosen to perform our electromagnetic analyses. Based on the Maxwell equation, the detailed magnetic field and Lorentz force were calculated. By use of the finite element software ANSYS, the Tresca stress was extracted and evaluated based on our analytical design. The present analysis aims to verify the feasibility of the current design. It can also serve as guidance for fabrication and structural optimization.
基金support by Research Grants Council of Hong Kong(Grant Nos.15246816 and 15218517)the funding for Project of Strategic Importance provided by the Hong Kong Polytechnic University(Project Code:1-ZE29)the Shenzhen Science and Technology Innovation Commission(Project no.JCYJ20170413154602102)
文摘Recent developments in acceptor–donor–acceptor(A–D–A) type non-fullerene acceptors have led to substantial improvements in bulk-heterojunction polymer solar cells efficiency. The device performance strongly depends on photoactive layer morphology, as the molecular packing, donor–acceptor interface and phase separation significantly affect the charge-transfer states and charge carrier dynamics. In this review, we start with a brief introduction of the techniques most effectively utilized to characterize multiphase morphology. Then, we summarize recent progress in A–D–A type acceptors, with the emphasis on understanding the molecular structure–morphology–performance relationships. Finally, an outlook on correlating morphological characteristics with photovoltage losses is presented for further improving device performance.
基金The Hong Kong Polytechnic University under internal Grant No. G-YF51.
文摘In a sensor network with a large number of densely populated sensor nodes, a single target of interest may be detected by multiple sensor nodes simultaneously. Data collected from the sensor nodes are usually highly correlated, and hence energy saving using in-network data fusion becomes possible. A traditional data fusion scheme starts with dividing the network into clusters, followed by electing a sensor node as cluster head in each cluster. A cluster head is responsible for collecting data from all its cluster members, performing data fusion on these data and transmitting the fused data to the base station. Assuming that a sensor node is only capable of handling a single node-to-node transmission at a time and each transmission takes T time-slots, a cluster head with n cluster members will take at least nT time-slots to collect data from all its cluster members. In this paper, a tree-based network structure and its formation algorithms are proposed. Simulation results show that the proposed network structure can greatly reduce the delay in data collection.
文摘This article considers the problem of directing a family of fully actuated surface vessels to cooperatively follow a set of convex and closed orbits with a time-invariant reference orbital velocity and maintain attitude synchronization. A consensusbased adaptive control law under a bidirectional communication topology is proposed to estimate the reference orbital velocity so that the restriction that every vessel in the family must have access to the reference in the previous literature can be removed.The assumption of nonzero total linear speed of each vessel is removed by the use of potential function. Simulation results demonstrate the effectiveness of the proposed approach.
基金G.L.thanks the funding supports from the Research Grants Council of Hong Kong(CRF No.C5037-18G,GRF No.15218517)National Natural Science Foundation of China(No.51961165102)+2 种基金Shenzhen Science and Technology Innovation Commission(Project No.JCYJ20170413154602102)the Hong Kong Polytechnic University(Project Code:1-ZE29,8-8480)the State Key Laboratory of Luminescent Materials and Devices,South China University of Technology.
文摘CONSPECTUS:Nonfullerene acceptors(NFAs)represent the latest breakthrough in organic solar cells(OSCs),which significantly outperform the long benchmark OSCs with fullerene derivative acceptors.In addition to binary bulk heterojunction(BHJ)OSCs,multicomponent,in particular ternary BHJ strategy has attracted tremendous interests due to the realization of broadened coverage of solar spectrum while maintaining easy processing compared to tandem OSCs.Subsequently,ternary OSCs containing NFA(s)have provided exciting opportunities to the promising field and achieved great progress in power conversion efficiencies(PCEs)over 17%.Inspired by the recent progress,in this account,we focus on the ternary OSCs containing NFA(s),share our view of the topic and aim to provide guidelines for material selections in designing successful ternary OSCstoward the cornerstone of 20%PCE in the near future.In this Account,we first discuss the principle of OSCsworking mechanisms,including charge transfer and energy transfer that govern the charge dynamics.Moreover,the promising functional roles of the third components in NFA OSCs are highlighted at the following the sequence:(1)Absorption sensitizingthe additional component plays a key role in broadening the solar cell absorption window and thus promising in improving the photocurrent in the ternary active layer,especially when employing a nearinfrared material NFA as the third component.(2)Morphology manipulation approaches and modelsthe ternary blend nanostructure is complex and not trivial to understand.Parallel and alloy nanomorphology models are discussed on the basis of the simultaneous consideration of the intrinsic properties among the involved materials,such as electronic properties and interplay(miscibility)among the host−vip materials.(3)Energy loss managementthe addition of donor or acceptor with small energy loss,especially low bandgap material,as the third component holds the promises to reduce the energy loss in ternary OSCs.On the other hand,due to the advantage of the alloyed microstructure in precisely tuning VOC,applying a second donor with deeper HOMO level or a second acceptor with shallower LUMO level is expected to increase VOC and thus reduce the energy loss in ternary OSCs.(4)Stability boosting agentfrom the thermodynamic point of view,the stable BHJ microstructure is beneficial and critical in enhancing the OSCs’long-term thermal and light stability.However,most material combinations suffer from the poor miscibility between the donor phase and acceptor phase,leading to demixing of two phases and thus the performance degradation.On the basis of this concept,rational selection of the third component could facilitate the formation of glassy nanostructure by vitrifying the pure donor phase or acceptor phase.Also it worth noting that suppressed crystallization of the small molecular acceptors by mixing a miscible component is effective to achieve a stable morphology.At the end of the Account,we share our view on the issues that limit the performance of ternary OSCs and outline their perspectives.
