The existing graph convolution methods usually suffer high computational burdens,large memory requirements,and intractable batch-processing.In this paper,we propose a high-efficient variational gridded graph convoluti...The existing graph convolution methods usually suffer high computational burdens,large memory requirements,and intractable batch-processing.In this paper,we propose a high-efficient variational gridded graph convolution network(VG-GCN)to encode non-regular graph data,which overcomes all these aforementioned problems.To capture graph topology structures efficiently,in the proposed framework,we propose a hierarchically-coarsened random walk(hcr-walk)by taking advantage of the classic random walk and node/edge encapsulation.The hcr-walk greatly mitigates the problem of exponentially explosive sampling times which occur in the classic version,while preserving graph structures well.To efficiently encode local hcr-walk around one reference node,we project hcrwalk into an ordered space to form image-like grid data,which favors those conventional convolution networks.Instead of the direct 2-D convolution filtering,a variational convolution block(VCB)is designed to model the distribution of the randomsampling hcr-walk inspired by the well-formulated variational inference.We experimentally validate the efficiency and effectiveness of our proposed VG-GCN,which has high computation speed,and the comparable or even better performance when compared with baseline GCNs.展开更多
介绍了基于船舶产品数据管理PDM(Product Data Management)船体分系统的船体搭载焊缝可视化派工模块程序设计及应用的研究,通过完整的焊缝派工管理体系和数字化管理平台,实现了船体焊缝可视化派工,大大提升了派工的效率,对劳动力的平衡...介绍了基于船舶产品数据管理PDM(Product Data Management)船体分系统的船体搭载焊缝可视化派工模块程序设计及应用的研究,通过完整的焊缝派工管理体系和数字化管理平台,实现了船体焊缝可视化派工,大大提升了派工的效率,对劳动力的平衡和生产管理起到了很大的作用。展开更多
Lithium sulfur(Li-S)batteries with high specific capacity and energy density can bring enormous opportunities for the nextgeneration energy storage systems.However,the severe dissolution and shuttle effect of lithium ...Lithium sulfur(Li-S)batteries with high specific capacity and energy density can bring enormous opportunities for the nextgeneration energy storage systems.However,the severe dissolution and shuttle effect of lithium polysulfides(LiPSs)is still the key issue that seriously impedes the development of practical Li-S batteries.Here,polar Co9S8 inlaid carbon nanoboxes(Co9S8@C NBs)have been investigated as cathode host for high-performance Li-S batteries.In this integrated structure,Co9S8 nanocrystals not only provide strong chemisorptive capability for polar LiPSs,but also act as a catalyst to accelerate polysulfide redox reactions;while carbon nanobox with large inner space can offer enough space to relieve the volume expansion and physically confine LiPSs’dissolution.As a result,the S/Co9S8@C NBs cathode exhibits high specific capacity at 1C and the capacity retention was^83%after 400 cycles,corresponding to an average decay rate of only^0.043%per cycle.展开更多
Despite great progress of lithium-sulfur(Li-S)battery performance at the laboratory-level,both key parameters and challenges at cell scales to achieve practical high energy density require high-sulfur-loading cathodes...Despite great progress of lithium-sulfur(Li-S)battery performance at the laboratory-level,both key parameters and challenges at cell scales to achieve practical high energy density require high-sulfur-loading cathodes and lean electrolytes.Herein,a novel carbon foam integrated by hollow carbon bubble nanoreactors with ultrahigh pore volume of 6.9 cm3·g−1 is meticulously designed for ultrahigh sulfur content up to 96 wt.%.Tailoring polysulfide trapping and ion/electron transport kinetics during the charge-discharge process can be achieved by adjusting the wall thickness of hollow carbon bubbles.And a further in-depth understanding of electrochemical reaction mechanism for the cathode is impelled by the in-situ Raman spectroscopy.As a result,the as-prepared cathode delivers high specific capacitances of 1,269 and 695 mAh·g−1 at 0.1 and 5 C,respectively.Furthermore,Li-S pouch cells with high areal sulfur loading of 6.9 mg·cm−2 yield exceptional practical energy density of 382 Wh·kg−1 under lean electrolyte of 3.5µL·mg−1,which demonstrates the great potential for realistic high-energy Li-S batteries.展开更多
We propose a linear mapping relationship between the polarization of the fundamental mode and the cylindrical vector(CV)modes on the first-order Poincaresphere(FOPS)in fiber.The new method is based on the fourdimensio...We propose a linear mapping relationship between the polarization of the fundamental mode and the cylindrical vector(CV)modes on the first-order Poincaresphere(FOPS)in fiber.The new method is based on the fourdimensional complex Jones matrices in terms of the linearly polarized mode bases.With our theoretical model,an all-fiber approach to generate arbitrary CV beams on the FOPS is proposed theoretically and verified experimentally.In the experiment,through the combination of a mode converter and a two-segment cascaded few-mode fiber with fixed stresses,it is possible to generate all CV modes on the FOPS by only adjusting the polarization of the fundamental mode.The Stokes parameters of the output light are measured to verify our scheme,which shows good agreement with the theoretical prediction.The method may provide a convenient way to generate CV beams and evolve the polarization states in any path on the FOPS,which is expected to have potential applications in encoding information and quantum computation.展开更多
基金supported by the Natural Science Foundation of Jiangsu Province(BK20190019,BK20190452)the National Natural Science Foundation of China(62072244,61906094)the Natural Science Foundation of Shandong Province(ZR2020LZH008)。
文摘The existing graph convolution methods usually suffer high computational burdens,large memory requirements,and intractable batch-processing.In this paper,we propose a high-efficient variational gridded graph convolution network(VG-GCN)to encode non-regular graph data,which overcomes all these aforementioned problems.To capture graph topology structures efficiently,in the proposed framework,we propose a hierarchically-coarsened random walk(hcr-walk)by taking advantage of the classic random walk and node/edge encapsulation.The hcr-walk greatly mitigates the problem of exponentially explosive sampling times which occur in the classic version,while preserving graph structures well.To efficiently encode local hcr-walk around one reference node,we project hcrwalk into an ordered space to form image-like grid data,which favors those conventional convolution networks.Instead of the direct 2-D convolution filtering,a variational convolution block(VCB)is designed to model the distribution of the randomsampling hcr-walk inspired by the well-formulated variational inference.We experimentally validate the efficiency and effectiveness of our proposed VG-GCN,which has high computation speed,and the comparable or even better performance when compared with baseline GCNs.
基金The authors acknowledge the financial support from the National Postdoctoral Program for Innovation Talents(No.BX201700103)China Postdoctoral Science Foundation funded project(No.2018M633664).
文摘Lithium sulfur(Li-S)batteries with high specific capacity and energy density can bring enormous opportunities for the nextgeneration energy storage systems.However,the severe dissolution and shuttle effect of lithium polysulfides(LiPSs)is still the key issue that seriously impedes the development of practical Li-S batteries.Here,polar Co9S8 inlaid carbon nanoboxes(Co9S8@C NBs)have been investigated as cathode host for high-performance Li-S batteries.In this integrated structure,Co9S8 nanocrystals not only provide strong chemisorptive capability for polar LiPSs,but also act as a catalyst to accelerate polysulfide redox reactions;while carbon nanobox with large inner space can offer enough space to relieve the volume expansion and physically confine LiPSs’dissolution.As a result,the S/Co9S8@C NBs cathode exhibits high specific capacity at 1C and the capacity retention was^83%after 400 cycles,corresponding to an average decay rate of only^0.043%per cycle.
基金This work was financially supported by National Natural Science Foundation of China(Grant Nos.51702095,51702362,51722503,and 51621004)Natural Science Foundation of Hunan Province,China(Grant No.2018JJ3041)the scientific research project of National University of Defense Technology(Grant Nos.ZK19-27 and ZK17-03-61).
文摘Despite great progress of lithium-sulfur(Li-S)battery performance at the laboratory-level,both key parameters and challenges at cell scales to achieve practical high energy density require high-sulfur-loading cathodes and lean electrolytes.Herein,a novel carbon foam integrated by hollow carbon bubble nanoreactors with ultrahigh pore volume of 6.9 cm3·g−1 is meticulously designed for ultrahigh sulfur content up to 96 wt.%.Tailoring polysulfide trapping and ion/electron transport kinetics during the charge-discharge process can be achieved by adjusting the wall thickness of hollow carbon bubbles.And a further in-depth understanding of electrochemical reaction mechanism for the cathode is impelled by the in-situ Raman spectroscopy.As a result,the as-prepared cathode delivers high specific capacitances of 1,269 and 695 mAh·g−1 at 0.1 and 5 C,respectively.Furthermore,Li-S pouch cells with high areal sulfur loading of 6.9 mg·cm−2 yield exceptional practical energy density of 382 Wh·kg−1 under lean electrolyte of 3.5µL·mg−1,which demonstrates the great potential for realistic high-energy Li-S batteries.
基金National Natural Science Foundation of China(61875019,61675034,61875020,61571067)Fund of State Key Laboratory of IPOC(BUPT)Fundamental Research Funds for the Central Universities.
文摘We propose a linear mapping relationship between the polarization of the fundamental mode and the cylindrical vector(CV)modes on the first-order Poincaresphere(FOPS)in fiber.The new method is based on the fourdimensional complex Jones matrices in terms of the linearly polarized mode bases.With our theoretical model,an all-fiber approach to generate arbitrary CV beams on the FOPS is proposed theoretically and verified experimentally.In the experiment,through the combination of a mode converter and a two-segment cascaded few-mode fiber with fixed stresses,it is possible to generate all CV modes on the FOPS by only adjusting the polarization of the fundamental mode.The Stokes parameters of the output light are measured to verify our scheme,which shows good agreement with the theoretical prediction.The method may provide a convenient way to generate CV beams and evolve the polarization states in any path on the FOPS,which is expected to have potential applications in encoding information and quantum computation.
