Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)mutations are influenced by random and uncontrollable factors,and the risk of the next widespread epidemic remains.Dual-target drugs that synergistically act ...Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)mutations are influenced by random and uncontrollable factors,and the risk of the next widespread epidemic remains.Dual-target drugs that synergistically act on two targets exhibit strong therapeutic effects and advantages against mutations.In this study,a novel computational workflow was developed to design dual-target SARS-CoV-2 candidate inhibitors with the Envelope protein and Main protease selected as the two target proteins.The drug-like molecules of our self-constructed 3D scaffold database were used as high-throughput molecular docking probes for feature extraction of two target protein pockets.A multi-layer perceptron(MLP)was employed to embed the binding affinities into a latent space as conditional vectors to control conditional distribution.Utilizing a conditional generative neural network,cG-SchNet,with 3D Euclidean group(E3)symmetries,the conditional probability distributions of molecular 3D structures were acquired and a set of novel SARS-CoV-2 dual-target candidate inhibitors were generated.The 1D probability,2D joint probability,and 2D cumulative probability distribution results indicate that the generated sets are significantly enhanced compared to the training set in the high binding affinity area.Among the 201 generated molecules,42 molecules exhibited a sum binding affinity exceeding 17.0 kcal/mol while 9 of them having a sum binding affinity exceeding 19.0 kcal/mol,demonstrating structure diversity along with strong dual-target affinities,good absorption,distribution,metabolism,excretion,and toxicity(ADMET)properties,and ease of synthesis.Dual-target drugs are rare and difficult to find,and our“high-throughput docking-multi-conditional generation”workflow offers a wide range of options for designing or optimizing potent dual-target SARS-CoV-2 inhibitors.展开更多
Solid polymer electrolytes(SPEs)have attracted much attention for their safety,ease of packaging,costeffectiveness,excellent flexibility and stability.Poly-dioxolane(PDOL)is one of the most promising matrix materials ...Solid polymer electrolytes(SPEs)have attracted much attention for their safety,ease of packaging,costeffectiveness,excellent flexibility and stability.Poly-dioxolane(PDOL)is one of the most promising matrix materials of SPEs due to its remarkable compatibility with lithium metal anodes(LMAs)and suitability for in-situ polymerization.However,poor thermal stability,insufficient ionic conductivity and narrow electrochemical stability window(ESW)hinder its further application in lithium metal batteries(LMBs).To ameliorate these problems,we have successfully synthesized a polymerized-ionic-liquid(PIL)monomer named DIMTFSI by modifying DOL with imidazolium cation coupled with TFSI^(-)anion,which simultaneously inherits the lipophilicity of DOL,high ionic conductivity of imidazole,and excellent stability of PILs.Then the tridentate crosslinker trimethylolpropane tris[3-(2-methyl-1-aziridine)propionate](TTMAP)was introduced to regulate the excessive Li^(+)-O coordination and prepare a flame-retardant SPE(DT-SPE)with prominent thermal stability,wide ESW,high ionic conductivity and abundant Lit transference numbers(t_(Li+)).As a result,the LiFePO_(4)|DT-SPE|Li cell exhibits a high initial discharge specific capacity of 149.60 mAh g^(-1)at 0.2C and 30℃with a capacity retention rate of 98.68%after 500 cycles.This work provides new insights into the structural design of PIL-based electrolytes for long-cycling LMBs with high safety and stability.展开更多
In this work,we have developed a lignin-derived polymer electrolyte(LSELi),which demonstrates exceptional ionic conductivity of 1.6×10^(-3)S cm^(−1)and a high cation transference number of 0.57 at 25°C.Time ...In this work,we have developed a lignin-derived polymer electrolyte(LSELi),which demonstrates exceptional ionic conductivity of 1.6×10^(-3)S cm^(−1)and a high cation transference number of 0.57 at 25°C.Time of flight secondary ion mass spectrometry(TOF-SIMS)analysis shows that the large-size 1-ethyl-3-methylimidazolium cations(EMIM^(+))can induce the aggregation of the anionic segments in lignosulfonate to reconstruct the three-dimensional(3D)spatial structure of polyelectrolyte,thereby forming a fluent Li^(+)transport 3D network.Dielectric loss spectroscopy further reveals that within this transport network,Li^(+)transport is decoupled from the relaxation of lignosulfonate chain segments,exhibiting characteristics of rapid Li^(+)transport.Furthermore,in-situ distribution of relaxation times analysis indicates that a stable solid electrolyte interface layer is formed at the Li plating interface with LSELi,optimizing the Li plating interface and exhibiting low charge transfer impedance and stable Li plating and stripping.Thus,a substantially prolonged cycling stability and reversibility are obtained in the Li||LSELi||Li battery at 25°C(1800 h at 0.1 mA cm^(−2),0.1 mAh cm^(−2)).At 25°C,the Li||LSELi||LiFePO_(4)cell shows 132 mAh g^(−1)of capacity with 92.7%of retention over 120 cycles at 0.1 mA cm^(−2).展开更多
The advent of the 5G era has stimulated the rapid development of high power electronics with dense integration.Three-dimensional(3D)thermally conductive networks,possessing high thermal and electrical conductivities a...The advent of the 5G era has stimulated the rapid development of high power electronics with dense integration.Three-dimensional(3D)thermally conductive networks,possessing high thermal and electrical conductivities and many different structures,are regarded as key materials to improve the performance of electronic devices.We provide a critical overview of carbonbased 3D thermally conductive networks,emphasizing their preparation-structure-property relationships and their applications in different scenarios.A detailed discussion of the microscopic principles of thermal conductivity is provided,which is crucial for increasing it.This is followed by an in-depth account of the construction of 3D networks using different carbon materials,such as graphene,carbon foam,and carbon nanotubes.Techniques for the assembly of two-dimensional graphene into 3D networks and their effects on thermal conductivity are emphasized.Finally,the existing challenges and future prospects for 3D carbon-based thermally conductive networks are discussed.展开更多
With the increasing power density and integration of electronic devices,polymeric composites with high thermal conductivity(TC)are in urgent demand for solving heat accumulation issues.However,the direct introduction ...With the increasing power density and integration of electronic devices,polymeric composites with high thermal conductivity(TC)are in urgent demand for solving heat accumulation issues.However,the direct introduction of inorganic fillers into a polymer matrix at low filler content usually leads to low TC enhancement.In this work,an interconnected three-dimensional(3D)polysulfone/hexagonal boron nitride-carbon nanofiber(PSF/BN-CNF)skeleton was prepared via the salt templated method to address this issue.After embedding into the epoxy(EP),the EP/PSF/BN-CNF composite presents a high TC of 2.18 W m^(−1) K^(−1) at a low filler loading of 28.61 wt%,corresponding to a TC enhancement of 990%compared to the neat epoxy.The enhanced TC is mainly attributed to the fabricated 3D interconnected structure and the efficient synergistic effect of BN and CNF.In addition,the TC of the epoxy composites can be further increased to 2.85 W m^(−1) K^(−1) at the same filler loading through a post-heat treatment of the PSF/BN-CNF skeletons.After carbonization at 1500°C,the adhesive PSF was converted into carbonaceous layers,which could serve as a thermally conductive glue to connect the filler network,further decreasing the interfacial thermal resistance and promoting phonon transport.Besides,the good heat dissipation performance of the EP/C/BN-CNF composites was directly confirmed by thermal infrared imaging,indicating a bright and broad application in the thermal management of modern electronics and energy fields.展开更多
Room temperature phosphorescence(RTP) is important in both organic electronics and encryption. Despite rapid advances, a universal approach to robust and tunable RTP materials based on amorphous polymers remains a for...Room temperature phosphorescence(RTP) is important in both organic electronics and encryption. Despite rapid advances, a universal approach to robust and tunable RTP materials based on amorphous polymers remains a formidable challenge. Here, we present a strategy that uses three-dimensional(3 D)confinement of carbon dots in a polymer network to achieve ultra-long lifetime phosphorescence. The RTP of the as-obtained materials was not quenched in different polar organic solvents and the lifetime of the RTP was easily tuned by adjusting the amount of crosslinking or varying the drying temperature of the 3 D molecular network. As a demonstration of potential application, as-obtained RTP materials were successfully used to prepare RTP fibres for flexible textiles. As well as bringing to light a fundamental principle for the construction of polymer materials with RTP, we have endowed traditional carbon dots and polymers with fresh features that will expand potential applications.展开更多
The inferior conductivity and drastic volume expansion of silicon still remain the bottleneck in achieving high energy density Lithium-ion Batteries(LIBs).The design of the three-dimensional structure of electrodes by...The inferior conductivity and drastic volume expansion of silicon still remain the bottleneck in achieving high energy density Lithium-ion Batteries(LIBs).The design of the three-dimensional structure of electrodes by compositing silicon and carbon materials has been employed to tackle the above challenges,however,the exorbitant costs and the uncertainty of the conductive structure persist,leaving ample room for improvement.Herein,silicon nanoparticles were innovatively composited with eco-friendly biochar sourced from cotton to fabricate a 3D globally consecutive conductive network.The network serves a dual purpose:enhancing overall electrode conductivity and serving as a scaffold to maintain electrode integrity.The conductivity of the network was further augmented by introducing P-doping at the optimum doping temperature of 350℃.Unlike the local conductive sites formed by the mere mixing of silicon and conductive agents,the consecutive network can affirm the improvement of the conductivity at a macro level.Moreover,first-principle calculations further validated that the rapid diffusion of Li^(+)is attributed to the tailored electronic microstructure and charge rearrangement of the fiber.The prepared consecutive conductive Si@P-doped carbonized cotton fiber anode outperforms the inconsecutive Si@Graphite anode in both cycling performance(capacity retention of 1777.15 mAh g^(-1) vs.682.56 mAh g^(-1) after 150 cycles at 0.3 C)and rate performance(1244.24 mAh g^(-1) vs.370.28 mAh g^(-1) at 2.0 C).The findings of this study may open up new avenues for the development of globally interconnected conductive networks in Si-based anodes,thereby enabling the fabrication of high-performance LIBs.展开更多
Three-dimensional(3D)graphene monoliths are a new carbon material,that has tremendous potential in the fields of energy conversion and storage.They can solve the limitations of two-dimensional(2D)graphene sheets,inclu...Three-dimensional(3D)graphene monoliths are a new carbon material,that has tremendous potential in the fields of energy conversion and storage.They can solve the limitations of two-dimensional(2D)graphene sheets,including interlayer restacking,high contact resistance,and insufficient pore accessibility.By constructing interconnected porous networks,3D graphenes not only retain the intrinsic advantages of 2D graphene sheets,such as high specific surface area,excellent electrical and thermal conductivities,good mechanical properties,and outstanding chemical stability,but also enable efficient mass transport of external fluid species.We summarize the fabrication methods for 3D graphenes,with a particular focus on their applications in energy-related systems.Techniques including chemical reduction assembly,chemical vapor deposition,3D printing,chemical blowing,and zinc-tiered pyrolysis have been developed to change their pore structure and elemental composition,and ways in which they can be integrated with functional components.In terms of energy conversion and storage,they have found broad use in buffering mechanical impacts,suppressing noise,photothermal conversion,electromagnetic shielding and absorption.They have also been used in electrochemical energy systems such as supercapacitors,secondary batteries,and electrocatalysis.By reviewing recent progress in structural design and new applications,we also discuss the problems these materials face,including scalable fabrication and precise pore structure control,and possible new applications.展开更多
The three dimensional （3D） geometry of soil macropores largely controls preferential flow, which is a significant infiltrating mechanism for rainfall in forest soils and affects slope stability. However, detailed st...The three dimensional （3D） geometry of soil macropores largely controls preferential flow, which is a significant infiltrating mechanism for rainfall in forest soils and affects slope stability. However, detailed studies on the 3D geometry of macropore networks in forest soils are rare. The intense rainfall-triggered potentially unstable slopes were threatening the villages at the downstream of Touzhai valley （Yunnan, China）. We visualized and quantified the 3D macropore networks in undisturbed soil columns （Histosols） taken from a forest hillslope in Touzhai valley, and compared them with those in agricultural soils （corn and soybean in USA; barley, fodder beet and red fescue in Denmark） and grassland soils in USA. We took two large undisturbed soil columns （250 mm^25o mmxsoo mm）, and scanned the soil columns at in-situ soil water content conditions using X-ray computed tomography at a voxel resolution of 0.945 × 0.945 × 1.500o mm^3. After reconstruction and visualization, we quantified the characteristics of macropore networks. In the studied forest soils, the main types of maeropores were root channels, inter-aggregate voids, maeropores without knowing origin, root-soil interfaee and stone-soil interface. While maeropore networks tend to be more eomplex, larger, deeper and longer. The forest soils have high maeroporosity, total maeropore wall area density, node density, and large maeropore volume, hydraulie radius, mean maeropore length, angle, and low tortuosity. The findings suggest that maeropore networks in the forest soils have high inter- connectivity, vertical continuity, linearity and less vertically oriented.展开更多
Osteocytes reside as three-dimensionally（3D） networked cells in the lacunocanalicular structure of bones and regulate bone and mineral homeostasis. Despite of their important regulatory roles, in vitro studies of os...Osteocytes reside as three-dimensionally（3D） networked cells in the lacunocanalicular structure of bones and regulate bone and mineral homeostasis. Despite of their important regulatory roles, in vitro studies of osteocytes have been challenging because：（1） current cell lines do not sufficiently represent the phenotypic features of mature osteocytes and（2） primary cells rapidly differentiate to osteoblasts upon isolation. In this study, we used a 3D perfusion culture approach to：（1） construct the 3D cellular network of primary murine osteocytes by biomimetic assembly with microbeads and（2） reproduce ex vivo the phenotype of primary murine osteocytes, for the first time to our best knowledge. In order to enable 3D construction with a sufficient number of viable cells, we used a proliferated osteoblastic population of healthy cells outgrown from digested bone chips. The diameter of microbeads was controlled to：（1） distribute and entrap cells within the interstitial spaces between the microbeads and（2） maintain average cell-to-cell distance to be about 19 mm. The entrapped cells formed a 3D cellular network by extending and connecting their processes through openings between the microbeads. Also, with increasing culture time, the entrapped cells exhibited the characteristic gene expressions（SOST and FGF23） and nonproliferative behavior of mature osteocytes. In contrast, 2D-cultured cells continued their osteoblastic differentiation and proliferation. This 3D biomimetic approach is expected to provide a new means of：（1） studying flow-induced shear stress on the mechanotransduction function of primary osteocytes,（2） studying physiological functions of 3D-networked osteocytes with in vitro convenience,and（3） developing clinically relevant human bone disease models.展开更多
3D navigation within a 3D-GIS environment is increasingly getting more popular and spreading to various fields.In thelast decade,especially after the 9/11 disaster,evacuating the complex and tall buildings of today in...3D navigation within a 3D-GIS environment is increasingly getting more popular and spreading to various fields.In thelast decade,especially after the 9/11 disaster,evacuating the complex and tall buildings of today in case of emergencyhas been an important research area for scientists.Most of the current navigation systems are still in the 2D environmentand that is insufficient to visualize 3D objects and to obtain satisfactory solutions for the 3D environment.Therefore,there is currently still a lack of implementation of 3D network analysis and navigation for indoor spaces in respect toevacuation.The objective of this paper is to investigate and implement 3D visualization and navigation techniques andsolutions for indoor spaces within 3D-GIS.For realizing this,we have proposed a GIS implementation that is capable ofcarrying out 3D visualization of a building model stored in the CityGML format and perform analysis on a networkmodel stored in Oracle Spatial.The proposed GUI also provides routing simulation on the calculated shortest paths withvoice commands and visual instructions.展开更多
With an extension of the geological entropy concept in porous media,the approach called directional entrogram is applied to link hydraulic behavior to the anisotropy of the 3D fracture networks.A metric called directi...With an extension of the geological entropy concept in porous media,the approach called directional entrogram is applied to link hydraulic behavior to the anisotropy of the 3D fracture networks.A metric called directional entropic scale is used to measure the anisotropy of spatial order in different directions.Compared with the traditional connectivity indexes based on the statistics of fracture geometry,the directional entropic scale is capable to quantify the anisotropy of connectivity and hydraulic conductivity in heterogeneous 3D fracture networks.According to the numerical analysis of directional entrogram and fluid flow in a number of the 3D fracture networks,the hydraulic conductivities and entropic scales in different directions both increase with spatial order(i.e.,trace length decreasing and spacing increasing)and are independent of the dip angle.As a result,the nonlinear correlation between the hydraulic conductivities and entropic scales from different directions can be unified as quadratic polynomial function,which can shed light on the anisotropic effect of spatial order and global entropy on the heterogeneous hydraulic behaviors.展开更多
Three-dimensional(3D)carbon networks have been explored as promising capacitive materials thanks to their unique structural features such as large ion-accessible surface area and interconnected porous networks,thus en...Three-dimensional(3D)carbon networks have been explored as promising capacitive materials thanks to their unique structural features such as large ion-accessible surface area and interconnected porous networks,thus enhancing both ions and electrons transport.Here,sustainable bacterial cellulose(BC)is used both precursor and template for facile synthesis of free-standing N,S-codoped 3Dcarbon networks(a-NSC)by the pyrolysis and activation of polyrhodanine coated BC.The synthesized a-NSC shows highly conductive interconnected porous networks(24S·cm^(-1)),large surface area(1 420m^2·g^(-1))with hierarchical meso-microporosity,and high-level heteroatoms codoping(N:3.1%in atom,S:3.2%in atom).Benefitting from these,a-NSC as binder-free electrode exhibits an ultrahigh specific capacitance of 340F·g^(-1)(24μF·cm^(-2))at the current density of 0.5A·g^(-1)in 6MKOH electrolyte,high-rate capability(71%at 20A·g^(-1))and excellent cycle stability.Furthermore,the assembled symmetrical supercapacitor displays a much short time constant of 0.35sin 1MTEABF4/AN electrolyte,obtaining a maximum energy density of 32.1W·h·kg^(-1 )at power density of 637W·kg^(-1).The in situ multi-heteroatoms doping enables biocellulose-derived carbon networks to exploit its full potentials in energy storage applications,which can be extended to other dimensional carbon nanostructures.展开更多
In the construction and maintenance of particle accelerators,all the accelerator elements should be installed in the same coordinate system,only in this way could the devices in the actual world be consistent with the...In the construction and maintenance of particle accelerators,all the accelerator elements should be installed in the same coordinate system,only in this way could the devices in the actual world be consistent with the design drawings.However,with the occurrence of the movements of the reinforced concrete cover plates at short notice or building deformations in the long term,the control points upon the engineering structure will be displaced,and the fitness between the subnetwork and the global control network may be irresponsible.Therefore,it is necessary to evaluate the deformations of the 3D alignment control network.Different from the extant investigations,in this paper,to characterize the deformations of the control network,all of the congruent models between the points measured in different epochs have been identified,and the congruence model with the most control points is considered as the primary or fundamental model,the remaining models are recognized as the additional ones.Furthermore,the discrepancies between the primary S-transformation parameters and the additional S-transformation parameters can reflect the relative movements of the additional congruence models.Both the iterative GCT method and the iterative combinatorial theory are proposed to detect multiple congruence models in the control network.Considering the actual work of the alignment,it is essential to identify the competitive models in the monitoring network,which can provide us a hint that,even the fitness between the subnetwork and the global control network is good,there are still deformations which may be ignored.The numerical experiments show that the suggested approaches can describe the deformation of the 3D alignment control network roundly.展开更多
The syntheses and structures of eleven novel polymeric transition metal complexes having one dimensional chain structures or three dimensional networks are summarized. They are prepared from the controlled assemblin...The syntheses and structures of eleven novel polymeric transition metal complexes having one dimensional chain structures or three dimensional networks are summarized. They are prepared from the controlled assembling reactions in organic solvents and characterized by X ray diffraction analyses. The spectroscopic or magnetic properties of some complexes are studied.展开更多
The title complex, {[Cu2（4,4＇-bipyridine）2（μ-O2CMe）2（O2CMe）2],H2O}n 1, was synthesized and structurally characterized by X-ray crystallography. It crystallizes in monoclinic, space group C2/c with a = 13.4474...The title complex, {[Cu2（4,4＇-bipyridine）2（μ-O2CMe）2（O2CMe）2],H2O}n 1, was synthesized and structurally characterized by X-ray crystallography. It crystallizes in monoclinic, space group C2/c with a = 13.4474（5）, b = 11.7566（2）, c = 19.5380（6）A, β = 92.930（2）°, V = 3084.84（16） A^3, Z = 4, Cu2C28N409H30, Mr = 693.64, Dc = 1.494 g/cm^3, F（000） = 1424 and μ（MoKα） = 1.436 mm^-1. With the use of 2062 observed reflections （I 〉 2σ（I））, the structure was refined to R = 0.0769 and wR = 0.2154. In complex 1, the dimeric copper acetate units are linked through 4,4’-bipyridine to yield ID molecular ladders. These ladders are connected via O-H…O hydrogen bonds to generate 2D layers, which are further linked through C-H…O hydrogen bonds to give a 3D supramolecular network.展开更多
Because behavior recognition is based on video frame sequences,this paper proposes a behavior recognition algorithm that combines 3D residual convolutional neural network(R3D)and long short-term memory(LSTM).First,the...Because behavior recognition is based on video frame sequences,this paper proposes a behavior recognition algorithm that combines 3D residual convolutional neural network(R3D)and long short-term memory(LSTM).First,the residual module is extended to three dimensions,which can extract features in the time and space domain at the same time.Second,by changing the size of the pooling layer window the integrity of the time domain features is preserved,at the same time,in order to overcome the difficulty of network training and over-fitting problems,the batch normalization(BN)layer and the dropout layer are added.After that,because the global average pooling layer(GAP)is affected by the size of the feature map,the network cannot be further deepened,so the convolution layer and maxpool layer are added to the R3D network.Finally,because LSTM has the ability to memorize information and can extract more abstract timing features,the LSTM network is introduced into the R3D network.Experimental results show that the R3D+LSTM network achieves 91%recognition rate on the UCF-101 dataset.展开更多
A new compound [Zn3（C7NO4H3）3Cl4]·[C6NO2H6]4·4H2O （I） has been synthesized and structurally characterized by X-ray crystallography.It crystallizes in monoclinic,space group C2/c with a=16.9018（14）,b=12...A new compound [Zn3（C7NO4H3）3Cl4]·[C6NO2H6]4·4H2O （I） has been synthesized and structurally characterized by X-ray crystallography.It crystallizes in monoclinic,space group C2/c with a=16.9018（14）,b=12.6902（10）,c=25.1170（2）,β=90.54°,V=5387.0（8）3,Z=4,Zn3C45H41Cl4N7O24,Mr=1401.76,Dc=1.728 g/cm3,F（000）=2840,μ（MoKa）=1.615 mm-1,the R= 0.0758 and wR=0.2060 for 3468 observed reflections （I 〉 2σ（I））.Analysis of single-crystal X-ray diffraction data shows that compound I displays an interesting example of 3D supramolecular networks with perfect neutral and ionic hydrogen bonding array.展开更多
In this work,a three dimensional(3D)convolutional neural network(CNN)model based on image slices of various normal and pathological vocal folds is proposed for accurate and efficient prediction of glottal flows.The 3D...In this work,a three dimensional(3D)convolutional neural network(CNN)model based on image slices of various normal and pathological vocal folds is proposed for accurate and efficient prediction of glottal flows.The 3D CNN model is composed of the feature extraction block and regression block.The feature extraction block is capable of learning low dimensional features from the high dimensional image data of the glottal shape,and the regression block is employed to flatten the output from the feature extraction block and obtain the desired glottal flow data.The input image data is the condensed set of 2D image slices captured in the axial plane of the 3D vocal folds,where these glottal shapes are synthesized based on the equations of normal vibration modes.The output flow data is the corresponding flow rate,averaged glottal pressure and nodal pressure distributions over the glottal surface.The 3D CNN model is built to establish the mapping between the input image data and output flow data.The ground-truth flow variables of each glottal shape in the training and test datasets are obtained by a high-fidelity sharp-interface immersed-boundary solver.The proposed model is trained to predict the concerned flow variables for glottal shapes in the test set.The present 3D CNN model is more efficient than traditional Computational Fluid Dynamics(CFD)models while the accuracy can still be retained,and more powerful than previous data-driven prediction models because more details of the glottal flow can be provided.The prediction performance of the trained 3D CNN model in accuracy and efficiency indicates that this model could be promising for future clinical applications.展开更多
Low Earth Orbit(LEO)mega-constellation networks,exemplified by Starlink,are poised to play a pivotal role in future mobile communication networks,due to their low latency and high capacity.With the massively deployed ...Low Earth Orbit(LEO)mega-constellation networks,exemplified by Starlink,are poised to play a pivotal role in future mobile communication networks,due to their low latency and high capacity.With the massively deployed satellites,ground users now can be covered by multiple visible satellites,but also face complex handover issues with such massive high-mobility satellites in multi-layer.The end-to-end routing is also affected by the handover behavior.In this paper,we propose an intelligent handover strategy dedicated to multi-layer LEO mega-constellation networks.Firstly,an analytic model is utilized to rapidly estimate the end-to-end propagation latency as a key handover factor to construct a multi-objective optimization model.Subsequently,an intelligent handover strategy is proposed by employing the Dueling Double Deep Q Network(D3QN)-based deep reinforcement learning algorithm for single-layer constellations.Moreover,an optimal crosslayer handover scheme is proposed by predicting the latency-jitter and minimizing the cross-layer overhead.Simulation results demonstrate the superior performance of the proposed method in the multi-layer LEO mega-constellation,showcasing reductions of up to 8.2%and 59.5%in end-to-end latency and jitter respectively,when compared to the existing handover strategies.展开更多
基金supported by Interdisciplinary Innova-tion Project of“Bioarchaeology Laboratory”of Jilin University,China,and“MedicineþX”Interdisciplinary Innovation Team of Norman Bethune Health Science Center of Jilin University,China(Grant No.:2022JBGS05).
文摘Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)mutations are influenced by random and uncontrollable factors,and the risk of the next widespread epidemic remains.Dual-target drugs that synergistically act on two targets exhibit strong therapeutic effects and advantages against mutations.In this study,a novel computational workflow was developed to design dual-target SARS-CoV-2 candidate inhibitors with the Envelope protein and Main protease selected as the two target proteins.The drug-like molecules of our self-constructed 3D scaffold database were used as high-throughput molecular docking probes for feature extraction of two target protein pockets.A multi-layer perceptron(MLP)was employed to embed the binding affinities into a latent space as conditional vectors to control conditional distribution.Utilizing a conditional generative neural network,cG-SchNet,with 3D Euclidean group(E3)symmetries,the conditional probability distributions of molecular 3D structures were acquired and a set of novel SARS-CoV-2 dual-target candidate inhibitors were generated.The 1D probability,2D joint probability,and 2D cumulative probability distribution results indicate that the generated sets are significantly enhanced compared to the training set in the high binding affinity area.Among the 201 generated molecules,42 molecules exhibited a sum binding affinity exceeding 17.0 kcal/mol while 9 of them having a sum binding affinity exceeding 19.0 kcal/mol,demonstrating structure diversity along with strong dual-target affinities,good absorption,distribution,metabolism,excretion,and toxicity(ADMET)properties,and ease of synthesis.Dual-target drugs are rare and difficult to find,and our“high-throughput docking-multi-conditional generation”workflow offers a wide range of options for designing or optimizing potent dual-target SARS-CoV-2 inhibitors.
基金financially supported by the National Key R&D Program of China(Grant No.2022YFE0207300)National Natural Science Foundation of China(Grant Nos.22179142 and 22075314)+1 种基金Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant No.2024ZB051 and 2023ZB836)the technical support for Nano-X from Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences(SINANO).
文摘Solid polymer electrolytes(SPEs)have attracted much attention for their safety,ease of packaging,costeffectiveness,excellent flexibility and stability.Poly-dioxolane(PDOL)is one of the most promising matrix materials of SPEs due to its remarkable compatibility with lithium metal anodes(LMAs)and suitability for in-situ polymerization.However,poor thermal stability,insufficient ionic conductivity and narrow electrochemical stability window(ESW)hinder its further application in lithium metal batteries(LMBs).To ameliorate these problems,we have successfully synthesized a polymerized-ionic-liquid(PIL)monomer named DIMTFSI by modifying DOL with imidazolium cation coupled with TFSI^(-)anion,which simultaneously inherits the lipophilicity of DOL,high ionic conductivity of imidazole,and excellent stability of PILs.Then the tridentate crosslinker trimethylolpropane tris[3-(2-methyl-1-aziridine)propionate](TTMAP)was introduced to regulate the excessive Li^(+)-O coordination and prepare a flame-retardant SPE(DT-SPE)with prominent thermal stability,wide ESW,high ionic conductivity and abundant Lit transference numbers(t_(Li+)).As a result,the LiFePO_(4)|DT-SPE|Li cell exhibits a high initial discharge specific capacity of 149.60 mAh g^(-1)at 0.2C and 30℃with a capacity retention rate of 98.68%after 500 cycles.This work provides new insights into the structural design of PIL-based electrolytes for long-cycling LMBs with high safety and stability.
基金support from the National Natural Science Foundation of China(NSFC,22393901,22021001,22272143,22441030)the National Key Research and Development Program(2021YFA1502300)+1 种基金the Fundamental Research Funds for the Central Universities(20720220009)the Natural Science Foundation of Fujian Province,China(Grant No.2024J01213135)。
文摘In this work,we have developed a lignin-derived polymer electrolyte(LSELi),which demonstrates exceptional ionic conductivity of 1.6×10^(-3)S cm^(−1)and a high cation transference number of 0.57 at 25°C.Time of flight secondary ion mass spectrometry(TOF-SIMS)analysis shows that the large-size 1-ethyl-3-methylimidazolium cations(EMIM^(+))can induce the aggregation of the anionic segments in lignosulfonate to reconstruct the three-dimensional(3D)spatial structure of polyelectrolyte,thereby forming a fluent Li^(+)transport 3D network.Dielectric loss spectroscopy further reveals that within this transport network,Li^(+)transport is decoupled from the relaxation of lignosulfonate chain segments,exhibiting characteristics of rapid Li^(+)transport.Furthermore,in-situ distribution of relaxation times analysis indicates that a stable solid electrolyte interface layer is formed at the Li plating interface with LSELi,optimizing the Li plating interface and exhibiting low charge transfer impedance and stable Li plating and stripping.Thus,a substantially prolonged cycling stability and reversibility are obtained in the Li||LSELi||Li battery at 25°C(1800 h at 0.1 mA cm^(−2),0.1 mAh cm^(−2)).At 25°C,the Li||LSELi||LiFePO_(4)cell shows 132 mAh g^(−1)of capacity with 92.7%of retention over 120 cycles at 0.1 mA cm^(−2).
文摘The advent of the 5G era has stimulated the rapid development of high power electronics with dense integration.Three-dimensional(3D)thermally conductive networks,possessing high thermal and electrical conductivities and many different structures,are regarded as key materials to improve the performance of electronic devices.We provide a critical overview of carbonbased 3D thermally conductive networks,emphasizing their preparation-structure-property relationships and their applications in different scenarios.A detailed discussion of the microscopic principles of thermal conductivity is provided,which is crucial for increasing it.This is followed by an in-depth account of the construction of 3D networks using different carbon materials,such as graphene,carbon foam,and carbon nanotubes.Techniques for the assembly of two-dimensional graphene into 3D networks and their effects on thermal conductivity are emphasized.Finally,the existing challenges and future prospects for 3D carbon-based thermally conductive networks are discussed.
基金supported by the National Science Foundation for Distinguished Young Scholars of China(No.51925403)the Major Research Plan of the National Natural Science Foundation of China(No.91934302)+1 种基金the National Natural Science Foundation of China(Nos.21676052,21606042)the Funding for Exploratory Projects of the National Key Laboratory of Chemical Engineering(SKL-ChE-20T07).
文摘With the increasing power density and integration of electronic devices,polymeric composites with high thermal conductivity(TC)are in urgent demand for solving heat accumulation issues.However,the direct introduction of inorganic fillers into a polymer matrix at low filler content usually leads to low TC enhancement.In this work,an interconnected three-dimensional(3D)polysulfone/hexagonal boron nitride-carbon nanofiber(PSF/BN-CNF)skeleton was prepared via the salt templated method to address this issue.After embedding into the epoxy(EP),the EP/PSF/BN-CNF composite presents a high TC of 2.18 W m^(−1) K^(−1) at a low filler loading of 28.61 wt%,corresponding to a TC enhancement of 990%compared to the neat epoxy.The enhanced TC is mainly attributed to the fabricated 3D interconnected structure and the efficient synergistic effect of BN and CNF.In addition,the TC of the epoxy composites can be further increased to 2.85 W m^(−1) K^(−1) at the same filler loading through a post-heat treatment of the PSF/BN-CNF skeletons.After carbonization at 1500°C,the adhesive PSF was converted into carbonaceous layers,which could serve as a thermally conductive glue to connect the filler network,further decreasing the interfacial thermal resistance and promoting phonon transport.Besides,the good heat dissipation performance of the EP/C/BN-CNF composites was directly confirmed by thermal infrared imaging,indicating a bright and broad application in the thermal management of modern electronics and energy fields.
基金supported by the National Natural Science Foundation of China (No.31890774)Excellent Young Scholar Sponsorship Program by National Forestry and Grassland Administration of China Funding (No.2019132611)+1 种基金Heilong Jiang Postdoctoral Science Foundation (No.LBH-Z18005)Young Elite Scientists Sponsorship Program by CAST (No.2018QNRC001)。
文摘Room temperature phosphorescence(RTP) is important in both organic electronics and encryption. Despite rapid advances, a universal approach to robust and tunable RTP materials based on amorphous polymers remains a formidable challenge. Here, we present a strategy that uses three-dimensional(3 D)confinement of carbon dots in a polymer network to achieve ultra-long lifetime phosphorescence. The RTP of the as-obtained materials was not quenched in different polar organic solvents and the lifetime of the RTP was easily tuned by adjusting the amount of crosslinking or varying the drying temperature of the 3 D molecular network. As a demonstration of potential application, as-obtained RTP materials were successfully used to prepare RTP fibres for flexible textiles. As well as bringing to light a fundamental principle for the construction of polymer materials with RTP, we have endowed traditional carbon dots and polymers with fresh features that will expand potential applications.
基金supported by the National Natural Science Foundation of China(No.12205252)the Basic Public Welfare Re-search Special Project of Zhejiang Province(No.LZY22B040001)+4 种基金the Quzhou Science and Technology Plan Project(No.2022K39)Science and Technology Project of Quzhou Research Institute,Zhejiang University(Nos.IZQ2021KJ2032,IZQ2022KJ3014,and IZQ2022KJ3002)Independent scientific Research Project of Quzhou Research Institute,Zhejiang University(No.IZQ2021RCZX007)New“115 talents”Project ofQuzhou,National Nature Science Foundation of China(No.52172244)Fundamental Research Funds for the Central University(No.226202200053).
文摘The inferior conductivity and drastic volume expansion of silicon still remain the bottleneck in achieving high energy density Lithium-ion Batteries(LIBs).The design of the three-dimensional structure of electrodes by compositing silicon and carbon materials has been employed to tackle the above challenges,however,the exorbitant costs and the uncertainty of the conductive structure persist,leaving ample room for improvement.Herein,silicon nanoparticles were innovatively composited with eco-friendly biochar sourced from cotton to fabricate a 3D globally consecutive conductive network.The network serves a dual purpose:enhancing overall electrode conductivity and serving as a scaffold to maintain electrode integrity.The conductivity of the network was further augmented by introducing P-doping at the optimum doping temperature of 350℃.Unlike the local conductive sites formed by the mere mixing of silicon and conductive agents,the consecutive network can affirm the improvement of the conductivity at a macro level.Moreover,first-principle calculations further validated that the rapid diffusion of Li^(+)is attributed to the tailored electronic microstructure and charge rearrangement of the fiber.The prepared consecutive conductive Si@P-doped carbonized cotton fiber anode outperforms the inconsecutive Si@Graphite anode in both cycling performance(capacity retention of 1777.15 mAh g^(-1) vs.682.56 mAh g^(-1) after 150 cycles at 0.3 C)and rate performance(1244.24 mAh g^(-1) vs.370.28 mAh g^(-1) at 2.0 C).The findings of this study may open up new avenues for the development of globally interconnected conductive networks in Si-based anodes,thereby enabling the fabrication of high-performance LIBs.
基金supported by National Natural Science Foundation of China(52272039,U23B2075,51972168)Key Research and Development Program in Jiangsu Province(BE2023085)Natural Science Foundation of Jiangsu Province of China(BK20231406)。
文摘Three-dimensional(3D)graphene monoliths are a new carbon material,that has tremendous potential in the fields of energy conversion and storage.They can solve the limitations of two-dimensional(2D)graphene sheets,including interlayer restacking,high contact resistance,and insufficient pore accessibility.By constructing interconnected porous networks,3D graphenes not only retain the intrinsic advantages of 2D graphene sheets,such as high specific surface area,excellent electrical and thermal conductivities,good mechanical properties,and outstanding chemical stability,but also enable efficient mass transport of external fluid species.We summarize the fabrication methods for 3D graphenes,with a particular focus on their applications in energy-related systems.Techniques including chemical reduction assembly,chemical vapor deposition,3D printing,chemical blowing,and zinc-tiered pyrolysis have been developed to change their pore structure and elemental composition,and ways in which they can be integrated with functional components.In terms of energy conversion and storage,they have found broad use in buffering mechanical impacts,suppressing noise,photothermal conversion,electromagnetic shielding and absorption.They have also been used in electrochemical energy systems such as supercapacitors,secondary batteries,and electrocatalysis.By reviewing recent progress in structural design and new applications,we also discuss the problems these materials face,including scalable fabrication and precise pore structure control,and possible new applications.
基金financially supported by the National Science Foundation of China-Yunnan Joint Fund(U1502232)the Natural Science Foundation of Yunnan Province(2014FD007)the Natural Science Foundation of Kunming University of Science and Technology(KKSY201406009)
文摘The three dimensional （3D） geometry of soil macropores largely controls preferential flow, which is a significant infiltrating mechanism for rainfall in forest soils and affects slope stability. However, detailed studies on the 3D geometry of macropore networks in forest soils are rare. The intense rainfall-triggered potentially unstable slopes were threatening the villages at the downstream of Touzhai valley （Yunnan, China）. We visualized and quantified the 3D macropore networks in undisturbed soil columns （Histosols） taken from a forest hillslope in Touzhai valley, and compared them with those in agricultural soils （corn and soybean in USA; barley, fodder beet and red fescue in Denmark） and grassland soils in USA. We took two large undisturbed soil columns （250 mm^25o mmxsoo mm）, and scanned the soil columns at in-situ soil water content conditions using X-ray computed tomography at a voxel resolution of 0.945 × 0.945 × 1.500o mm^3. After reconstruction and visualization, we quantified the characteristics of macropore networks. In the studied forest soils, the main types of maeropores were root channels, inter-aggregate voids, maeropores without knowing origin, root-soil interfaee and stone-soil interface. While maeropore networks tend to be more eomplex, larger, deeper and longer. The forest soils have high maeroporosity, total maeropore wall area density, node density, and large maeropore volume, hydraulie radius, mean maeropore length, angle, and low tortuosity. The findings suggest that maeropore networks in the forest soils have high inter- connectivity, vertical continuity, linearity and less vertically oriented.
基金the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health (1R21AR065032 to W.Y.L and J.Z.)the National Science Foundation (DMR 1409779 to W.Y.L and J.Z.)
文摘Osteocytes reside as three-dimensionally（3D） networked cells in the lacunocanalicular structure of bones and regulate bone and mineral homeostasis. Despite of their important regulatory roles, in vitro studies of osteocytes have been challenging because：（1） current cell lines do not sufficiently represent the phenotypic features of mature osteocytes and（2） primary cells rapidly differentiate to osteoblasts upon isolation. In this study, we used a 3D perfusion culture approach to：（1） construct the 3D cellular network of primary murine osteocytes by biomimetic assembly with microbeads and（2） reproduce ex vivo the phenotype of primary murine osteocytes, for the first time to our best knowledge. In order to enable 3D construction with a sufficient number of viable cells, we used a proliferated osteoblastic population of healthy cells outgrown from digested bone chips. The diameter of microbeads was controlled to：（1） distribute and entrap cells within the interstitial spaces between the microbeads and（2） maintain average cell-to-cell distance to be about 19 mm. The entrapped cells formed a 3D cellular network by extending and connecting their processes through openings between the microbeads. Also, with increasing culture time, the entrapped cells exhibited the characteristic gene expressions（SOST and FGF23） and nonproliferative behavior of mature osteocytes. In contrast, 2D-cultured cells continued their osteoblastic differentiation and proliferation. This 3D biomimetic approach is expected to provide a new means of：（1） studying flow-induced shear stress on the mechanotransduction function of primary osteocytes,（2） studying physiological functions of 3D-networked osteocytes with in vitro convenience,and（3） developing clinically relevant human bone disease models.
基金This study was supported by TUBITAK–The Scientific and Technological Research Council of Turkey(Project No.112Y050)research grant.We are indebted for its financial support.
文摘3D navigation within a 3D-GIS environment is increasingly getting more popular and spreading to various fields.In thelast decade,especially after the 9/11 disaster,evacuating the complex and tall buildings of today in case of emergencyhas been an important research area for scientists.Most of the current navigation systems are still in the 2D environmentand that is insufficient to visualize 3D objects and to obtain satisfactory solutions for the 3D environment.Therefore,there is currently still a lack of implementation of 3D network analysis and navigation for indoor spaces in respect toevacuation.The objective of this paper is to investigate and implement 3D visualization and navigation techniques andsolutions for indoor spaces within 3D-GIS.For realizing this,we have proposed a GIS implementation that is capable ofcarrying out 3D visualization of a building model stored in the CityGML format and perform analysis on a networkmodel stored in Oracle Spatial.The proposed GUI also provides routing simulation on the calculated shortest paths withvoice commands and visual instructions.
基金supported by the National Natural Science Foundation of China(Nos.42077243,52209148,and 52079062).
文摘With an extension of the geological entropy concept in porous media,the approach called directional entrogram is applied to link hydraulic behavior to the anisotropy of the 3D fracture networks.A metric called directional entropic scale is used to measure the anisotropy of spatial order in different directions.Compared with the traditional connectivity indexes based on the statistics of fracture geometry,the directional entropic scale is capable to quantify the anisotropy of connectivity and hydraulic conductivity in heterogeneous 3D fracture networks.According to the numerical analysis of directional entrogram and fluid flow in a number of the 3D fracture networks,the hydraulic conductivities and entropic scales in different directions both increase with spatial order(i.e.,trace length decreasing and spacing increasing)and are independent of the dip angle.As a result,the nonlinear correlation between the hydraulic conductivities and entropic scales from different directions can be unified as quadratic polynomial function,which can shed light on the anisotropic effect of spatial order and global entropy on the heterogeneous hydraulic behaviors.
基金supported by the National Basic Research Program of China(973 Program)(No.2014CB239701)the National Natural Science Foundation of China(Nos.51672128,51372116,21773118)+2 种基金the Natural Science Foundation of Jiangsu Province(Nos.BK20150739,BK20151468)the Prospective Joint Research Project of Cooperative Innovation Fund of Jiangsu Province(No.BY2015003-7)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Three-dimensional(3D)carbon networks have been explored as promising capacitive materials thanks to their unique structural features such as large ion-accessible surface area and interconnected porous networks,thus enhancing both ions and electrons transport.Here,sustainable bacterial cellulose(BC)is used both precursor and template for facile synthesis of free-standing N,S-codoped 3Dcarbon networks(a-NSC)by the pyrolysis and activation of polyrhodanine coated BC.The synthesized a-NSC shows highly conductive interconnected porous networks(24S·cm^(-1)),large surface area(1 420m^2·g^(-1))with hierarchical meso-microporosity,and high-level heteroatoms codoping(N:3.1%in atom,S:3.2%in atom).Benefitting from these,a-NSC as binder-free electrode exhibits an ultrahigh specific capacitance of 340F·g^(-1)(24μF·cm^(-2))at the current density of 0.5A·g^(-1)in 6MKOH electrolyte,high-rate capability(71%at 20A·g^(-1))and excellent cycle stability.Furthermore,the assembled symmetrical supercapacitor displays a much short time constant of 0.35sin 1MTEABF4/AN electrolyte,obtaining a maximum energy density of 32.1W·h·kg^(-1 )at power density of 637W·kg^(-1).The in situ multi-heteroatoms doping enables biocellulose-derived carbon networks to exploit its full potentials in energy storage applications,which can be extended to other dimensional carbon nanostructures.
文摘In the construction and maintenance of particle accelerators,all the accelerator elements should be installed in the same coordinate system,only in this way could the devices in the actual world be consistent with the design drawings.However,with the occurrence of the movements of the reinforced concrete cover plates at short notice or building deformations in the long term,the control points upon the engineering structure will be displaced,and the fitness between the subnetwork and the global control network may be irresponsible.Therefore,it is necessary to evaluate the deformations of the 3D alignment control network.Different from the extant investigations,in this paper,to characterize the deformations of the control network,all of the congruent models between the points measured in different epochs have been identified,and the congruence model with the most control points is considered as the primary or fundamental model,the remaining models are recognized as the additional ones.Furthermore,the discrepancies between the primary S-transformation parameters and the additional S-transformation parameters can reflect the relative movements of the additional congruence models.Both the iterative GCT method and the iterative combinatorial theory are proposed to detect multiple congruence models in the control network.Considering the actual work of the alignment,it is essential to identify the competitive models in the monitoring network,which can provide us a hint that,even the fitness between the subnetwork and the global control network is good,there are still deformations which may be ignored.The numerical experiments show that the suggested approaches can describe the deformation of the 3D alignment control network roundly.
文摘The syntheses and structures of eleven novel polymeric transition metal complexes having one dimensional chain structures or three dimensional networks are summarized. They are prepared from the controlled assembling reactions in organic solvents and characterized by X ray diffraction analyses. The spectroscopic or magnetic properties of some complexes are studied.
基金This work was supported by the Science Foundation of Fujian Provincial Key Laboratory of Polymer Materials
文摘The title complex, {[Cu2（4,4＇-bipyridine）2（μ-O2CMe）2（O2CMe）2],H2O}n 1, was synthesized and structurally characterized by X-ray crystallography. It crystallizes in monoclinic, space group C2/c with a = 13.4474（5）, b = 11.7566（2）, c = 19.5380（6）A, β = 92.930（2）°, V = 3084.84（16） A^3, Z = 4, Cu2C28N409H30, Mr = 693.64, Dc = 1.494 g/cm^3, F（000） = 1424 and μ（MoKα） = 1.436 mm^-1. With the use of 2062 observed reflections （I 〉 2σ（I））, the structure was refined to R = 0.0769 and wR = 0.2154. In complex 1, the dimeric copper acetate units are linked through 4,4’-bipyridine to yield ID molecular ladders. These ladders are connected via O-H…O hydrogen bonds to generate 2D layers, which are further linked through C-H…O hydrogen bonds to give a 3D supramolecular network.
基金Supported by the Shaanxi Province Key Research and Development Project (No. 2021GY-280)Shaanxi Province Natural Science Basic Research Program (No. 2021JM-459)the National Natural Science Foundation of China (No. 61772417)
文摘Because behavior recognition is based on video frame sequences,this paper proposes a behavior recognition algorithm that combines 3D residual convolutional neural network(R3D)and long short-term memory(LSTM).First,the residual module is extended to three dimensions,which can extract features in the time and space domain at the same time.Second,by changing the size of the pooling layer window the integrity of the time domain features is preserved,at the same time,in order to overcome the difficulty of network training and over-fitting problems,the batch normalization(BN)layer and the dropout layer are added.After that,because the global average pooling layer(GAP)is affected by the size of the feature map,the network cannot be further deepened,so the convolution layer and maxpool layer are added to the R3D network.Finally,because LSTM has the ability to memorize information and can extract more abstract timing features,the LSTM network is introduced into the R3D network.Experimental results show that the R3D+LSTM network achieves 91%recognition rate on the UCF-101 dataset.
基金supported by the Natural Science Foundation of Fujian Province (2006F3042)
文摘A new compound [Zn3（C7NO4H3）3Cl4]·[C6NO2H6]4·4H2O （I） has been synthesized and structurally characterized by X-ray crystallography.It crystallizes in monoclinic,space group C2/c with a=16.9018（14）,b=12.6902（10）,c=25.1170（2）,β=90.54°,V=5387.0（8）3,Z=4,Zn3C45H41Cl4N7O24,Mr=1401.76,Dc=1.728 g/cm3,F（000）=2840,μ（MoKa）=1.615 mm-1,the R= 0.0758 and wR=0.2060 for 3468 observed reflections （I 〉 2σ（I））.Analysis of single-crystal X-ray diffraction data shows that compound I displays an interesting example of 3D supramolecular networks with perfect neutral and ionic hydrogen bonding array.
基金supported by the Open Project of Key Laboratory of Computational Aerodynamics,AVIC Aerodynamics Research Institute(Grant No.YL2022XFX0409).
文摘In this work,a three dimensional(3D)convolutional neural network(CNN)model based on image slices of various normal and pathological vocal folds is proposed for accurate and efficient prediction of glottal flows.The 3D CNN model is composed of the feature extraction block and regression block.The feature extraction block is capable of learning low dimensional features from the high dimensional image data of the glottal shape,and the regression block is employed to flatten the output from the feature extraction block and obtain the desired glottal flow data.The input image data is the condensed set of 2D image slices captured in the axial plane of the 3D vocal folds,where these glottal shapes are synthesized based on the equations of normal vibration modes.The output flow data is the corresponding flow rate,averaged glottal pressure and nodal pressure distributions over the glottal surface.The 3D CNN model is built to establish the mapping between the input image data and output flow data.The ground-truth flow variables of each glottal shape in the training and test datasets are obtained by a high-fidelity sharp-interface immersed-boundary solver.The proposed model is trained to predict the concerned flow variables for glottal shapes in the test set.The present 3D CNN model is more efficient than traditional Computational Fluid Dynamics(CFD)models while the accuracy can still be retained,and more powerful than previous data-driven prediction models because more details of the glottal flow can be provided.The prediction performance of the trained 3D CNN model in accuracy and efficiency indicates that this model could be promising for future clinical applications.
基金supported by the National Natural Science Foundation of China(No.62401597)Natural Science Foundation of Hunan Province,China(No.2024JJ6469)the Research Project of National University of Defense Technology,China(No.ZK22-02).
文摘Low Earth Orbit(LEO)mega-constellation networks,exemplified by Starlink,are poised to play a pivotal role in future mobile communication networks,due to their low latency and high capacity.With the massively deployed satellites,ground users now can be covered by multiple visible satellites,but also face complex handover issues with such massive high-mobility satellites in multi-layer.The end-to-end routing is also affected by the handover behavior.In this paper,we propose an intelligent handover strategy dedicated to multi-layer LEO mega-constellation networks.Firstly,an analytic model is utilized to rapidly estimate the end-to-end propagation latency as a key handover factor to construct a multi-objective optimization model.Subsequently,an intelligent handover strategy is proposed by employing the Dueling Double Deep Q Network(D3QN)-based deep reinforcement learning algorithm for single-layer constellations.Moreover,an optimal crosslayer handover scheme is proposed by predicting the latency-jitter and minimizing the cross-layer overhead.Simulation results demonstrate the superior performance of the proposed method in the multi-layer LEO mega-constellation,showcasing reductions of up to 8.2%and 59.5%in end-to-end latency and jitter respectively,when compared to the existing handover strategies.
