Mining-induced fracture zone will be produced in the overlying strata after the coal was mined.In this article,the mining-induced deformation of overlying strata and the time-space evolution law of fissure were studie...Mining-induced fracture zone will be produced in the overlying strata after the coal was mined.In this article,the mining-induced deformation of overlying strata and the time-space evolution law of fissure were studied by the methods of physical simulation and field measurement.The results show that bed separation fissure and vertical fissure will appear in the overlying strata above mining face,which form the wedge-shaped fissure zone.The open degree of fissure depends on the size of uncoordinated deformation between neighbor layers,and the absolute strata sinking controls both the width of bed separation zone and the open degree of vertical breakage fissure.At last,the calculating formula was deducted based on theoretical analysis.展开更多
Developing hydrothermal resources in highly conductive karst aquifers at deep mine floors is regarded as a potential approach to achieving the co-development of coal and geothermal resources.However,the heat transfer ...Developing hydrothermal resources in highly conductive karst aquifers at deep mine floors is regarded as a potential approach to achieving the co-development of coal and geothermal resources.However,the heat transfer potential of the fracture system in the target reservoir under mining activities remains in suspense.Hence,a coupled thermal-hydraulic-mechanical model was developed for the karst reservoir of Anju coal mine in China,considering non-isothermal convective heat transfer in fractures.This model examined the influence of stress redistribution due to different mining distances(MD)on the effective flow channel length/density and the high/low-aperture fracture distribution.The dynamic heat generation characteristics of the geothermal reservoir were evaluated.Key findings include:Mining-induced stress creates interlaced high-aperture and low-aperture fracture zones below the goaf.Within these interlaced zones,the combined effect of high-and low-aperture fractures restricts the effective flow channel length/density of the fracture network.This contraction of the flow field leads to a significant decline in production flow rate,which consequently reduces both the production flow rate and power as MD increases.This work represents the study of mining disturbances on geothermal production,providing a theoretical foundation for the co-development of coal and geothermal resources.展开更多
As the mine depth around the world increases,the temperature of the surrounding rock of the mining workface increases significantly.To control the heat hazards,the hot water in the mining floor is developed during min...As the mine depth around the world increases,the temperature of the surrounding rock of the mining workface increases significantly.To control the heat hazards,the hot water in the mining floor is developed during mining to decrease the min-ing workface temperature while also developing geothermal energy.This method is called the co-exploitation of mine and geothermal energy(CMGE).The geothermal development may precipitate the large-scale failure of the nearby fault zone during the mining process.However,the evolution of shear slide and shear failure of fault under geothermal production/rein-jection during mining is missing.Therefore,a fully-coupled hydraulic mechanism(HM)double-medium model for CMGE was developed based on the measured data of the Chensilou mine.A comparative analysis of the mechanical response of fault between CMGE and single mining was conducted.The disturbance of geothermal production pressure and reinjection pressure under mining on fault stability were respectively expounded.The results indicate that:(1)The disturbance of geo-thermal reinjection amplifies the disturbance of mining on fault stability.The amplified effect resulted in a normal stress drop of the fault,further leading to a substantial increase in shear slide distance,failure area,and cumulative seismic moment of fault compared with the single mining process.(2)As the distance of reinjection well to the fault decreases,the fault failure intensity increases.Setting the production well within the fault is advantageous for controlling fault stability under CMGE.(3)The essence of the combined disturbance of CMGE on the nearby fault is the overlay of tensile stress disturbance on the fault rock mass of the mining and geothermal reinjection.Though the geothermal reinjection causes a minor normal stress drop of fault,it can result in a more serious fault failure under CMGE.This paper supplies a significant gap in understanding thenearby faults failure under CMGE.展开更多
文章基于CNKI、Web of Science两大数据库2005—2024年收录的图书馆学习空间研究文献,运用CiteSpace、Bicomb、SPSS软件进行可视化分析。结果显示,国外研究以技术驱动创新为主导,聚焦智能化技术与跨学科应用;而国内研究呈现理论创新与...文章基于CNKI、Web of Science两大数据库2005—2024年收录的图书馆学习空间研究文献,运用CiteSpace、Bicomb、SPSS软件进行可视化分析。结果显示,国外研究以技术驱动创新为主导,聚焦智能化技术与跨学科应用;而国内研究呈现理论创新与实践探索并重,通过大数据、AI等技术形成本土化解决方案。文章提出通过数字技术与人文关怀的平衡发展、国际化视野与本土化创新的有机结合、理论研究与实践应用的深度融合,为我国图书馆学习空间的研究提供借鉴与参考。展开更多
Understanding dynamic visualization of mining-induced stress is of great significance to disaster prevention and control in coal mining activities.In this study,three theoretical models,including linear,polynomial,and...Understanding dynamic visualization of mining-induced stress is of great significance to disaster prevention and control in coal mining activities.In this study,three theoretical models,including linear,polynomial,and exponential models,are proposed to inverse the mining-induced stress through the acquisition and analysis of hydraulic support stress and micro-seismicity in the coal mining face.The distribution of mining-induced stress in the coal seam are graphed by fitting two key stress parameters including hydraulic support stress and peak stress,and two key zones including goaf zone and in situ stress zone.These key stress parameters and zones are defined based on the critical nodes of the model curve.According to the geological background of Mataihao coal mine in Erdos,Inner Mongolia Autonomous Region,China,the contours of mining-induced stress are graphed through the stress calculation of these three inversion theoretical models.The multi-monitoring data of micro-seismicity,drilling chips,advanced borehole stress and bolts axial force are used to verify the key stress parameters and zones of the theoretical models.It shows that the monitoring data are in good agreement with the distribution of inversed results.It should be emphasized that,if the fault structure exists around the mining face,the mining-induced stress decreases obviously when the mining face is passing through the faults,and the location of the peak stress will be closer to the mining face.The results in this study could provide methods for early prevention of extreme mining-induced stress and disaster control in the mining activities.展开更多
High-intensive underground mining has caused severe ground fissures,resulting in environmental degradation.Consequently,prompt detection is crucial to mitigate their environmental impact.However,the accurate segmentat...High-intensive underground mining has caused severe ground fissures,resulting in environmental degradation.Consequently,prompt detection is crucial to mitigate their environmental impact.However,the accurate segmentation of fissuresin complex and variable scenes of visible imagery is a challenging issue.Our method,DeepFissureNets-Infrared-Visible(DFN-IV),highlights the potential of incorporating visible images with infrared information for improved ground fissuresegmentation.DFNIV adopts a two-step process.First,a fusion network is trained with the dual adversarial learning strategy fuses infrared and visible imaging,providing an integrated representation of fissuretargets that combines the structural information with the textual details.Second,the fused images are processed by a fine-tunedsegmentation network,which lever-ages knowledge injection to learn the distinctive characteristics of fissuretargets effectively.Furthermore,an infrared-visible ground fissuredataset(IVGF)is built from an aerial investigation of the Daliuta Coal Mine.Extensive experiments reveal that our approach provides superior accuracy over single-modality image strategies employed in fivesegmentation models.Notably,DeeplabV3+tested with DFN-IV improves by 9.7%and 11.13%in pixel accuracy and Intersection over Union(IoU),respectively,compared to solely visible images.Moreover,our method surpasses six state-of-the-art image fusion methods,achieving a 5.28%improvement in pixel accuracy and a 1.57%increase in IoU,respectively,compared to the second-best effective method.In addition,ablation studies further validate the significanceof the dual adversarial learning module and the integrated knowledge injection strategy.By leveraging DFN-IV,we aim to quantify the impacts of mining-induced ground fissures,facilitating the implementation of intelligent safety measures.展开更多
In this paper,we present a necessary and sufficient condition for hyponormal block Toeplitz operators T on the vector-valued weighted Bergman space with symbolsΦ(z)=G^(*)(z)+F(z),where F(z)=∑^(N)_(i)=1 A_(i)z^(i)and...In this paper,we present a necessary and sufficient condition for hyponormal block Toeplitz operators T on the vector-valued weighted Bergman space with symbolsΦ(z)=G^(*)(z)+F(z),where F(z)=∑^(N)_(i)=1 A_(i)z^(i)and G(z)=∑^(N)_(i)=1 A_(−i)z^(i),A_(i)ae culants.展开更多
In this article,we conduct a study on mixed quasi-martingale Hardy spaces that are defined by means of the mixed L_(p)-norm.By utilizing Doob’s inequalities,we explore the atomic decomposition and quasi-martingale in...In this article,we conduct a study on mixed quasi-martingale Hardy spaces that are defined by means of the mixed L_(p)-norm.By utilizing Doob’s inequalities,we explore the atomic decomposition and quasi-martingale inequalities of mixed quasi-martingale Hardy spaces.Moreover,we furnish sufficient conditions for the boundedness ofσ-sublinear operators in these spaces.These findings extend the existing conclusions regarding mixed quasi-martingale Hardy spaces defined with the help of the mixed L_(p)-norm.展开更多
Space exploration is significant for scientific innovation,resource utilization,and planetary security.Space exploration involves several systems including satellites,space suits,communication systems,and robotics,whi...Space exploration is significant for scientific innovation,resource utilization,and planetary security.Space exploration involves several systems including satellites,space suits,communication systems,and robotics,which have to function under harsh space conditions such as extreme temperatures(−270 to 1650℃),microgravity(10^(-6)g),unhealthy humidity(<20%RH or>60%RH),high atmospheric pressure(~1450 psi),and radiation(4000–5000 mSv).Conventional energy-harvesting technologies(solar cells,fuel cells,and nuclear energy),that are normally used to power these space systems have certain limitations(e.g.,sunlight dependence,weight,degradation,big size,high cost,low capacity,radioactivity,complexity,and low efficiency).The constraints in conventional energy resources have made it imperative to look for non-conventional yet efficient alternatives.A great potential for enhancing efficiency,sustainability,and mission duration in space exploration can be offered by integrating triboelectric nanogenerators(TENGs)with existing energy sources.Recently,the potential of TENG including energy harvesting(from vibrations/movements in satellites and spacecraft),self-powered sensing,and microgravity,for multiple applications in different space missions has been discussed.This review comprehensively covers the use of TENGs for various space applications,such as planetary exploration missions(Mars environment monitoring),manned space equipment,In-orbit robotic operations/collision monitoring,spacecraft’s design and structural health monitoring,Aeronautical systems,and conventional energy harvesting(solar and nuclear).This review also discusses the use of self-powered TENG sensors for deep space object perception.At the same time,this review compares TENGs with conventional energy harvesting technologies for space systems.Lastly,this review talks about energy harvesting in satellites,TENG-based satellite communication systems,and future practical implementation challenges(with possible solutions).展开更多
It is well known that the inhomogeneous Calderón-Zygmund convolution operators are bounded on the local Hardy spaces.In this paper,we prove that these operators are bounded on the local product Hardy spaces and t...It is well known that the inhomogeneous Calderón-Zygmund convolution operators are bounded on the local Hardy spaces.In this paper,we prove that these operators are bounded on the local product Hardy spaces and the Lipschitz spaces.The key ideas used here are the discrete local Calderón identity and a density argument for the inhomogeneous product Lipschitz spaces in the weak sense.展开更多
Letα>0 and letμbe a positive Borel measure on the interval[0,1).The Hankel matrix■with entries■induces,formally,the generalized-Hilbert operator■where f(z)■is an analytic function in D.This article is devoted...Letα>0 and letμbe a positive Borel measure on the interval[0,1).The Hankel matrix■with entries■induces,formally,the generalized-Hilbert operator■where f(z)■is an analytic function in D.This article is devoted to study the measuresμfor which Hμ,αis a bounded(resp.,compact)operator from Hp(0<p≤1)into H^(p)(1≤q<∞).We also study the analogous problem in the Hardy spaces H^(p)(1≤p≤2).Finally,we obtain the essential norm of H_(μ,α)from H^(p)(0<p≤1)into H^(p)(1≤q<∞).展开更多
The Pantone Color of the Year 2026,PANTONE 11-4201 Cloud Dancer,has been introduced as a soft,lofty white symbolizing calm and clarity in an increasingly noisy world.This gentle shade invites a sense of peace and spac...The Pantone Color of the Year 2026,PANTONE 11-4201 Cloud Dancer,has been introduced as a soft,lofty white symbolizing calm and clarity in an increasingly noisy world.This gentle shade invites a sense of peace and spaciousness,encouraging focus and creating room for creativity and reflection.Cloud Dancer embodies a desire for simplicity and renewal-a blank canvas that allows our minds to wander and new ideas to take shape.Its expansive presence fosters environments where tranquility meets inspiration,offering visual calm that supports wellbeing and mental lightness.展开更多
The neutral surface of a concave thin mirror is too close to the mirror surface,which makes it difficult to effectively mount the flexible structure and increases the mirror surface shape error.To address this problem...The neutral surface of a concave thin mirror is too close to the mirror surface,which makes it difficult to effectively mount the flexible structure and increases the mirror surface shape error.To address this problem,we design a flexible support structure including connectors,a support plate,and flexible structures,and construct an equivalent mirror by installing connectors and a support plate on the back of the mirror.While ensuring that the neutral surface of the equivalent mirror is moved away from the mirror surface,we optimize the support structure so that the rotary center of the flexible structure is located on the neutral surface of the equivalent mirror,avoiding the tilting moment.Following design and modeling of the structure,we analyze the static and dynamic characteristics using a finite element simulation,finding a root-mean-square(RMS)value for the surface shape error of 9.28 nm under the coupled effects of 1g gravity load,4℃ temperature rise,and 0.005 mm unevenness assembly error,with a fundamental frequency of 170.75 Hz,which all meet the design requirements.Finally,we carry out a surface shape error test of the mirror assembly,confirming it to meet the design index requirement of the mirror assembly.Simulation and test results verify the reliability and effectiveness of our proposed support structure.展开更多
In this paper,we studyλ-biharmonic hypersurfaces M_(r)^(5) of 6-dimensional pseudo Riemannian space form N_(p)^(6)(c)with the indexs 0≤p≤6,r=p−1 or p,and constant curvature c.It was proved that if the shape operato...In this paper,we studyλ-biharmonic hypersurfaces M_(r)^(5) of 6-dimensional pseudo Riemannian space form N_(p)^(6)(c)with the indexs 0≤p≤6,r=p−1 or p,and constant curvature c.It was proved that if the shape operator of M_(r)^(5) is diagonalizable,then the mean curvature is a constant.As an application,we find some types of biharmonic hypersurfaces of N_(p)^(6)(c)are minimal.展开更多
数字化赋能教学已成为当前教学的新趋势,本文借助Earth Space Lab程序赋能“地球的运动”教学,帮助学生从本质上理解较为抽象的地理概念,同时,基于Earth Space Lab的教学不仅能实现学生对抽象概念的熟练掌握与灵活应用,促进作业质量与...数字化赋能教学已成为当前教学的新趋势,本文借助Earth Space Lab程序赋能“地球的运动”教学,帮助学生从本质上理解较为抽象的地理概念,同时,基于Earth Space Lab的教学不仅能实现学生对抽象概念的熟练掌握与灵活应用,促进作业质量与学习效果显著提升,还能进一步提升学生学习兴趣、地理实践力与综合思维,促进其地理核心素养的培育。展开更多
Strategically coupling nanoparticle hybrids and internal thermosensitive molecular switches establishes an innovative paradigm for constructing micro/nanoscale-reconfigurable robots,facilitating energyefficient CO_(2)...Strategically coupling nanoparticle hybrids and internal thermosensitive molecular switches establishes an innovative paradigm for constructing micro/nanoscale-reconfigurable robots,facilitating energyefficient CO_(2) management in life-support systems of confined space.Here,a micro/nano-reconfigurable robot is constructed from the CO_(2) molecular hunters,temperature-sensitive molecular switch,solar photothermal conversion,and magnetically-driven function engines.The molecular hunters within the molecular extension state can capture 6.19 mmol g^(−1) of CO_(2) to form carbamic acid and ammonium bicarbonate.Interestingly,the molecular switch of the robot activates a molecular curling state that facilitates CO_(2) release through nano-reconfiguration,which is mediated by the temperature-sensitive curling of Pluronic F127 molecular chains during the photothermal desorption.Nano-reconfiguration of robot alters the amino microenvironment,including increasing surface electrostatic potential of the amino group and decreasing overall lowest unoccupied molecular orbital energy level.This weakened the nucleophilic attack ability of the amino group toward the adsorption product derivatives,thereby inhibiting the side reactions that generate hard-to-decompose urea structures,achieving the lowest regeneration temperature of 55℃ reported to date.The engine of the robot possesses non-contact magnetically-driven micro-reconfiguration capability to achieve efficient photothermal regeneration while avoiding local overheating.Notably,the robot successfully prolonged the survival time of mice in the sealed container by up to 54.61%,effectively addressing the issue of carbon suffocation in confined spaces.This work significantly enhances life-support systems for deep-space exploration,while stimulating innovations in sustainable carbon management technologies for terrestrial extreme environments.展开更多
In the construction and maintenance for large space equipment,it is essential to ensure the control accuracy and improve the dexterity of the space manipulator.In this paper,a FiniteTime Convergence Kinematic Control(...In the construction and maintenance for large space equipment,it is essential to ensure the control accuracy and improve the dexterity of the space manipulator.In this paper,a FiniteTime Convergence Kinematic Control(FTCKC)added with Acceleration Level Dexterity Optimization(ALDO)scheme is proposed to solve the kinematic uncertainty and dexterity optimization problems of redundant space manipulators.Concretely,distinguishing from the asymptotic convergence property of traditional adaptive Jacobian methods,the FTCKC scheme is adopted to construct the equality constraint to address the model uncertainty problem,and its error can converge within a finite time.Subsequently,the dexterity index is reconstructed at acceleration level by a multi-level target handling method.Then,the equality constraint,optimization task,and limit constraints are reformulated as a quadratic programming problem.Moreover,a Recurrent Neural Network(RNN)is engineered for the constructed FTCKC-ALDO scheme.Finally,the superiority of the FTCKC-ALDO-RNN scheme is verified by experiments.展开更多
文摘Mining-induced fracture zone will be produced in the overlying strata after the coal was mined.In this article,the mining-induced deformation of overlying strata and the time-space evolution law of fissure were studied by the methods of physical simulation and field measurement.The results show that bed separation fissure and vertical fissure will appear in the overlying strata above mining face,which form the wedge-shaped fissure zone.The open degree of fissure depends on the size of uncoordinated deformation between neighbor layers,and the absolute strata sinking controls both the width of bed separation zone and the open degree of vertical breakage fissure.At last,the calculating formula was deducted based on theoretical analysis.
基金supported by the National Natural Science Foundation of China(Nos.U23B2091,52304104,and 52404157)the National Key R&D Program of China(No.2022YFC2905600)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(No.GZB20240825).
文摘Developing hydrothermal resources in highly conductive karst aquifers at deep mine floors is regarded as a potential approach to achieving the co-development of coal and geothermal resources.However,the heat transfer potential of the fracture system in the target reservoir under mining activities remains in suspense.Hence,a coupled thermal-hydraulic-mechanical model was developed for the karst reservoir of Anju coal mine in China,considering non-isothermal convective heat transfer in fractures.This model examined the influence of stress redistribution due to different mining distances(MD)on the effective flow channel length/density and the high/low-aperture fracture distribution.The dynamic heat generation characteristics of the geothermal reservoir were evaluated.Key findings include:Mining-induced stress creates interlaced high-aperture and low-aperture fracture zones below the goaf.Within these interlaced zones,the combined effect of high-and low-aperture fractures restricts the effective flow channel length/density of the fracture network.This contraction of the flow field leads to a significant decline in production flow rate,which consequently reduces both the production flow rate and power as MD increases.This work represents the study of mining disturbances on geothermal production,providing a theoretical foundation for the co-development of coal and geothermal resources.
基金supported by the Key Project of the National Natural Science Foundation of China(U23B2091)the National Key R&D Program of China(2022YFC2905600)+1 种基金the Youth Project of the National Natural Science Foundation of China(52304104 and 52404157)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZB20240825).
文摘As the mine depth around the world increases,the temperature of the surrounding rock of the mining workface increases significantly.To control the heat hazards,the hot water in the mining floor is developed during mining to decrease the min-ing workface temperature while also developing geothermal energy.This method is called the co-exploitation of mine and geothermal energy(CMGE).The geothermal development may precipitate the large-scale failure of the nearby fault zone during the mining process.However,the evolution of shear slide and shear failure of fault under geothermal production/rein-jection during mining is missing.Therefore,a fully-coupled hydraulic mechanism(HM)double-medium model for CMGE was developed based on the measured data of the Chensilou mine.A comparative analysis of the mechanical response of fault between CMGE and single mining was conducted.The disturbance of geothermal production pressure and reinjection pressure under mining on fault stability were respectively expounded.The results indicate that:(1)The disturbance of geo-thermal reinjection amplifies the disturbance of mining on fault stability.The amplified effect resulted in a normal stress drop of the fault,further leading to a substantial increase in shear slide distance,failure area,and cumulative seismic moment of fault compared with the single mining process.(2)As the distance of reinjection well to the fault decreases,the fault failure intensity increases.Setting the production well within the fault is advantageous for controlling fault stability under CMGE.(3)The essence of the combined disturbance of CMGE on the nearby fault is the overlay of tensile stress disturbance on the fault rock mass of the mining and geothermal reinjection.Though the geothermal reinjection causes a minor normal stress drop of fault,it can result in a more serious fault failure under CMGE.This paper supplies a significant gap in understanding thenearby faults failure under CMGE.
文摘文章基于CNKI、Web of Science两大数据库2005—2024年收录的图书馆学习空间研究文献,运用CiteSpace、Bicomb、SPSS软件进行可视化分析。结果显示,国外研究以技术驱动创新为主导,聚焦智能化技术与跨学科应用;而国内研究呈现理论创新与实践探索并重,通过大数据、AI等技术形成本土化解决方案。文章提出通过数字技术与人文关怀的平衡发展、国际化视野与本土化创新的有机结合、理论研究与实践应用的深度融合,为我国图书馆学习空间的研究提供借鉴与参考。
基金financially supported by the Independent Research fund of Joint National Local Engineering Research Centre for Safe and Precise Coal Mining(Anhui University of Science and Technology)(Grant No.EC2022001)State Key Research Development Program of China(Grant No.2022YFC3004602)the Fundamental Research Funds for the Central Universities(Grant No.2022YJSLJ08).
文摘Understanding dynamic visualization of mining-induced stress is of great significance to disaster prevention and control in coal mining activities.In this study,three theoretical models,including linear,polynomial,and exponential models,are proposed to inverse the mining-induced stress through the acquisition and analysis of hydraulic support stress and micro-seismicity in the coal mining face.The distribution of mining-induced stress in the coal seam are graphed by fitting two key stress parameters including hydraulic support stress and peak stress,and two key zones including goaf zone and in situ stress zone.These key stress parameters and zones are defined based on the critical nodes of the model curve.According to the geological background of Mataihao coal mine in Erdos,Inner Mongolia Autonomous Region,China,the contours of mining-induced stress are graphed through the stress calculation of these three inversion theoretical models.The multi-monitoring data of micro-seismicity,drilling chips,advanced borehole stress and bolts axial force are used to verify the key stress parameters and zones of the theoretical models.It shows that the monitoring data are in good agreement with the distribution of inversed results.It should be emphasized that,if the fault structure exists around the mining face,the mining-induced stress decreases obviously when the mining face is passing through the faults,and the location of the peak stress will be closer to the mining face.The results in this study could provide methods for early prevention of extreme mining-induced stress and disaster control in the mining activities.
基金supported by the National Science Fund of China(Grant No.52225402)Fund of Inner Mongolia Research Institute,China University of Mining and Technology(Beijing)(Grant No.IMRI23003).
文摘High-intensive underground mining has caused severe ground fissures,resulting in environmental degradation.Consequently,prompt detection is crucial to mitigate their environmental impact.However,the accurate segmentation of fissuresin complex and variable scenes of visible imagery is a challenging issue.Our method,DeepFissureNets-Infrared-Visible(DFN-IV),highlights the potential of incorporating visible images with infrared information for improved ground fissuresegmentation.DFNIV adopts a two-step process.First,a fusion network is trained with the dual adversarial learning strategy fuses infrared and visible imaging,providing an integrated representation of fissuretargets that combines the structural information with the textual details.Second,the fused images are processed by a fine-tunedsegmentation network,which lever-ages knowledge injection to learn the distinctive characteristics of fissuretargets effectively.Furthermore,an infrared-visible ground fissuredataset(IVGF)is built from an aerial investigation of the Daliuta Coal Mine.Extensive experiments reveal that our approach provides superior accuracy over single-modality image strategies employed in fivesegmentation models.Notably,DeeplabV3+tested with DFN-IV improves by 9.7%and 11.13%in pixel accuracy and Intersection over Union(IoU),respectively,compared to solely visible images.Moreover,our method surpasses six state-of-the-art image fusion methods,achieving a 5.28%improvement in pixel accuracy and a 1.57%increase in IoU,respectively,compared to the second-best effective method.In addition,ablation studies further validate the significanceof the dual adversarial learning module and the integrated knowledge injection strategy.By leveraging DFN-IV,we aim to quantify the impacts of mining-induced ground fissures,facilitating the implementation of intelligent safety measures.
文摘In this paper,we present a necessary and sufficient condition for hyponormal block Toeplitz operators T on the vector-valued weighted Bergman space with symbolsΦ(z)=G^(*)(z)+F(z),where F(z)=∑^(N)_(i)=1 A_(i)z^(i)and G(z)=∑^(N)_(i)=1 A_(−i)z^(i),A_(i)ae culants.
基金Supported by the National Natural Science Foundation of China(11871195)。
文摘In this article,we conduct a study on mixed quasi-martingale Hardy spaces that are defined by means of the mixed L_(p)-norm.By utilizing Doob’s inequalities,we explore the atomic decomposition and quasi-martingale inequalities of mixed quasi-martingale Hardy spaces.Moreover,we furnish sufficient conditions for the boundedness ofσ-sublinear operators in these spaces.These findings extend the existing conclusions regarding mixed quasi-martingale Hardy spaces defined with the help of the mixed L_(p)-norm.
基金supported by Swedish Research Council(Vetenskapsradet,2023-04962).
文摘Space exploration is significant for scientific innovation,resource utilization,and planetary security.Space exploration involves several systems including satellites,space suits,communication systems,and robotics,which have to function under harsh space conditions such as extreme temperatures(−270 to 1650℃),microgravity(10^(-6)g),unhealthy humidity(<20%RH or>60%RH),high atmospheric pressure(~1450 psi),and radiation(4000–5000 mSv).Conventional energy-harvesting technologies(solar cells,fuel cells,and nuclear energy),that are normally used to power these space systems have certain limitations(e.g.,sunlight dependence,weight,degradation,big size,high cost,low capacity,radioactivity,complexity,and low efficiency).The constraints in conventional energy resources have made it imperative to look for non-conventional yet efficient alternatives.A great potential for enhancing efficiency,sustainability,and mission duration in space exploration can be offered by integrating triboelectric nanogenerators(TENGs)with existing energy sources.Recently,the potential of TENG including energy harvesting(from vibrations/movements in satellites and spacecraft),self-powered sensing,and microgravity,for multiple applications in different space missions has been discussed.This review comprehensively covers the use of TENGs for various space applications,such as planetary exploration missions(Mars environment monitoring),manned space equipment,In-orbit robotic operations/collision monitoring,spacecraft’s design and structural health monitoring,Aeronautical systems,and conventional energy harvesting(solar and nuclear).This review also discusses the use of self-powered TENG sensors for deep space object perception.At the same time,this review compares TENGs with conventional energy harvesting technologies for space systems.Lastly,this review talks about energy harvesting in satellites,TENG-based satellite communication systems,and future practical implementation challenges(with possible solutions).
基金supported by the NSFC(12301115)the Natural Science Foundation of Huzhou(2023YZ11,2024YZ37)the second author was supported by the NSFC(12071437).
文摘It is well known that the inhomogeneous Calderón-Zygmund convolution operators are bounded on the local Hardy spaces.In this paper,we prove that these operators are bounded on the local product Hardy spaces and the Lipschitz spaces.The key ideas used here are the discrete local Calderón identity and a density argument for the inhomogeneous product Lipschitz spaces in the weak sense.
基金supported by the Zhejiang Province Natural Science Foundation of China(LY23A010003).
文摘Letα>0 and letμbe a positive Borel measure on the interval[0,1).The Hankel matrix■with entries■induces,formally,the generalized-Hilbert operator■where f(z)■is an analytic function in D.This article is devoted to study the measuresμfor which Hμ,αis a bounded(resp.,compact)operator from Hp(0<p≤1)into H^(p)(1≤q<∞).We also study the analogous problem in the Hardy spaces H^(p)(1≤p≤2).Finally,we obtain the essential norm of H_(μ,α)from H^(p)(0<p≤1)into H^(p)(1≤q<∞).
文摘The Pantone Color of the Year 2026,PANTONE 11-4201 Cloud Dancer,has been introduced as a soft,lofty white symbolizing calm and clarity in an increasingly noisy world.This gentle shade invites a sense of peace and spaciousness,encouraging focus and creating room for creativity and reflection.Cloud Dancer embodies a desire for simplicity and renewal-a blank canvas that allows our minds to wander and new ideas to take shape.Its expansive presence fosters environments where tranquility meets inspiration,offering visual calm that supports wellbeing and mental lightness.
基金supported by the National Natural Science Foundation of China(12473085).
文摘The neutral surface of a concave thin mirror is too close to the mirror surface,which makes it difficult to effectively mount the flexible structure and increases the mirror surface shape error.To address this problem,we design a flexible support structure including connectors,a support plate,and flexible structures,and construct an equivalent mirror by installing connectors and a support plate on the back of the mirror.While ensuring that the neutral surface of the equivalent mirror is moved away from the mirror surface,we optimize the support structure so that the rotary center of the flexible structure is located on the neutral surface of the equivalent mirror,avoiding the tilting moment.Following design and modeling of the structure,we analyze the static and dynamic characteristics using a finite element simulation,finding a root-mean-square(RMS)value for the surface shape error of 9.28 nm under the coupled effects of 1g gravity load,4℃ temperature rise,and 0.005 mm unevenness assembly error,with a fundamental frequency of 170.75 Hz,which all meet the design requirements.Finally,we carry out a surface shape error test of the mirror assembly,confirming it to meet the design index requirement of the mirror assembly.Simulation and test results verify the reliability and effectiveness of our proposed support structure.
基金Supported by National Natural Science Foundation of China(12161078)Foundation for Innovative Fundamental Research Group Project of Gansu Province(24JRRA778)Project of Northwest Normal University(20240010)。
文摘In this paper,we studyλ-biharmonic hypersurfaces M_(r)^(5) of 6-dimensional pseudo Riemannian space form N_(p)^(6)(c)with the indexs 0≤p≤6,r=p−1 or p,and constant curvature c.It was proved that if the shape operator of M_(r)^(5) is diagonalizable,then the mean curvature is a constant.As an application,we find some types of biharmonic hypersurfaces of N_(p)^(6)(c)are minimal.
文摘数字化赋能教学已成为当前教学的新趋势,本文借助Earth Space Lab程序赋能“地球的运动”教学,帮助学生从本质上理解较为抽象的地理概念,同时,基于Earth Space Lab的教学不仅能实现学生对抽象概念的熟练掌握与灵活应用,促进作业质量与学习效果显著提升,还能进一步提升学生学习兴趣、地理实践力与综合思维,促进其地理核心素养的培育。
基金supported by the National Natural Science Foundation of China(22168008,22378085)the Guangxi Natural Science Foundation(2024GXNSFDA010053)+1 种基金the Technology Development Project of Guangxi Bossco Environmental Protection Technology Co.,Ltd(202100039)Innovation Project of Guangxi Graduate Education(YCBZ2024065).
文摘Strategically coupling nanoparticle hybrids and internal thermosensitive molecular switches establishes an innovative paradigm for constructing micro/nanoscale-reconfigurable robots,facilitating energyefficient CO_(2) management in life-support systems of confined space.Here,a micro/nano-reconfigurable robot is constructed from the CO_(2) molecular hunters,temperature-sensitive molecular switch,solar photothermal conversion,and magnetically-driven function engines.The molecular hunters within the molecular extension state can capture 6.19 mmol g^(−1) of CO_(2) to form carbamic acid and ammonium bicarbonate.Interestingly,the molecular switch of the robot activates a molecular curling state that facilitates CO_(2) release through nano-reconfiguration,which is mediated by the temperature-sensitive curling of Pluronic F127 molecular chains during the photothermal desorption.Nano-reconfiguration of robot alters the amino microenvironment,including increasing surface electrostatic potential of the amino group and decreasing overall lowest unoccupied molecular orbital energy level.This weakened the nucleophilic attack ability of the amino group toward the adsorption product derivatives,thereby inhibiting the side reactions that generate hard-to-decompose urea structures,achieving the lowest regeneration temperature of 55℃ reported to date.The engine of the robot possesses non-contact magnetically-driven micro-reconfiguration capability to achieve efficient photothermal regeneration while avoiding local overheating.Notably,the robot successfully prolonged the survival time of mice in the sealed container by up to 54.61%,effectively addressing the issue of carbon suffocation in confined spaces.This work significantly enhances life-support systems for deep-space exploration,while stimulating innovations in sustainable carbon management technologies for terrestrial extreme environments.
基金supported by the National Natural Science Foundation of China(Nos.92148203 and T2388101)。
文摘In the construction and maintenance for large space equipment,it is essential to ensure the control accuracy and improve the dexterity of the space manipulator.In this paper,a FiniteTime Convergence Kinematic Control(FTCKC)added with Acceleration Level Dexterity Optimization(ALDO)scheme is proposed to solve the kinematic uncertainty and dexterity optimization problems of redundant space manipulators.Concretely,distinguishing from the asymptotic convergence property of traditional adaptive Jacobian methods,the FTCKC scheme is adopted to construct the equality constraint to address the model uncertainty problem,and its error can converge within a finite time.Subsequently,the dexterity index is reconstructed at acceleration level by a multi-level target handling method.Then,the equality constraint,optimization task,and limit constraints are reformulated as a quadratic programming problem.Moreover,a Recurrent Neural Network(RNN)is engineered for the constructed FTCKC-ALDO scheme.Finally,the superiority of the FTCKC-ALDO-RNN scheme is verified by experiments.
