By qualitative analysis method, a sufficient condition for the existence of peaked periodic wave solutions to the Broer–Kaup equation is given. Some exact explicit expressions of peaked periodic wave solutions are al...By qualitative analysis method, a sufficient condition for the existence of peaked periodic wave solutions to the Broer–Kaup equation is given. Some exact explicit expressions of peaked periodic wave solutions are also presented.展开更多
This paper introduces a method for modeling the entire aggregated electric vehicle(EV)charging process and analyzing its dispatchable capabilities.The methodology involves developing a model for aggregated EV charging...This paper introduces a method for modeling the entire aggregated electric vehicle(EV)charging process and analyzing its dispatchable capabilities.The methodology involves developing a model for aggregated EV charging at the charging station level,estimating its physical dispatchable capability,determining its economic dispatchable capability under economic incentives,modeling its participation in the grid,and investigating the effects of different scenarios and EV penetration on the aggregated load dispatch and dispatchable capability.The results indicate that using economic dispatchable capability reduces charging prices by 9.7%compared to physical dispatchable capability and 9.3%compared to disorderly charging.Additionally,the peak-to-valley difference is reduced by 64.6%when applying economic dispatchable capability with 20%EV penetration and residential base load,compared to disorderly charging.展开更多
We use qualitative analysis and numerical simulation to study peaked traveling wave solutions of CH-γ and CH equations. General expressions of peakon and periodic cusp wave solutions are obtained. Some previous resul...We use qualitative analysis and numerical simulation to study peaked traveling wave solutions of CH-γ and CH equations. General expressions of peakon and periodic cusp wave solutions are obtained. Some previous results become our special cases.展开更多
This paper proposes a novel modified uni-traveling-carrier photodiode(MUTC-PD)featuring an electric field regulation layer:a p-type doped thin layer inserted behind the PD’s n-doped cliff layer.This electric field re...This paper proposes a novel modified uni-traveling-carrier photodiode(MUTC-PD)featuring an electric field regulation layer:a p-type doped thin layer inserted behind the PD’s n-doped cliff layer.This electric field regulation layer enhances the PD’s performance by not only reducing and smoothing the electric field intensity in the collector layer,allowing photo-generated electrons to transit at peak drift velocity,but also improving the electric field intensity in the depleted absorber layer and optimizing the photo-generated carriers’saturated transit performance.Additionally,the transport characteristics of the peak drift velocity of photogenerated electrons in the device’s collection layer can be used to optimize its parasitic characteristics.The electron’s peak drift velocity compensates for the lost transit time.Thus improving the 3 dB bandwidth of the PD’s photo response.Finally obtains a MUTC-PD with a 3 dB bandwidth of 68 GHz at a responsivity of 0.502 A/W,making it suitable for 100 Gbit/s optical receivers.展开更多
It is well-known that the celebrated Camassa-Holm equation has the peaked solitary waves,which have been not reported for other mainstream models of shallow water waves.In this letter,the closed-form solutions of peak...It is well-known that the celebrated Camassa-Holm equation has the peaked solitary waves,which have been not reported for other mainstream models of shallow water waves.In this letter,the closed-form solutions of peaked solitary waves of the KdV equation,the BBM equation and the Boussinesq equation are given for the first time.All of them have either a peakon or an anti-peakon.Each of them exactly satisfies the corresponding Rankine-Hogoniot jump condition and could be understood as weak solution.Therefore,the peaked solitary waves might be common for most of shallow water wave models,no matter whether or not they are integrable and/or admit breaking-wave solutions.展开更多
In this paper the qualitative analysis methods of planar autonomous systems and numerical simu-lation are used to investigate the peaked wave solutions of CH-r equation. Some explicit expressions of peakedsolitary wav...In this paper the qualitative analysis methods of planar autonomous systems and numerical simu-lation are used to investigate the peaked wave solutions of CH-r equation. Some explicit expressions of peakedsolitary wave solutions and peaked periodic wave solutions are obtained, and some of their relationships arerevealed. Why peaked points are generated is discussed.展开更多
By constructing auxiliary differential equations, we obtain peaked solitary wave solutions of the generalized Camassa-Holm equation, including periodic cusp waves expressed in terms of elliptic functions.
To investigate the effect of saturation on the storage-dissipation properties and failure characteristics of red sandstone,as well as the energy mechanism of rockburst prevention by water,a series of uniaxial compress...To investigate the effect of saturation on the storage-dissipation properties and failure characteristics of red sandstone,as well as the energy mechanism of rockburst prevention by water,a series of uniaxial compression and uniaxial loading–unloading tests were conducted under five saturation levels.The effect of saturation on the mechanical properties and elastic energy density was analyzed,and a method for obtaining peak energy density was proposed.The effect of saturation on the energy evolution was examined,and the energy mechanism of water in preventing rockburst was revealed.The results indicate that an increase in saturation of red sandstone decreases the input energy density,elastic energy density,dissipated energy density,peak strength and peak strain;the compaction phase of the stress–strain curve becomes shorter;the failure mode transitions from X-conjugate oblique shear to single oblique shear;the variation in the debris ejection trajectory is as follows:radiation→X-ray→oblique upward parabola→horizontal parabola→oblique downward parabola;the degree of failure intensity and fragmentation is decreased gradually.Elastic energy density is interconnected with both saturation and stress but independent of the loading path.Saturation exhibits a dual effect on the energy storage property,i.e.,increasing saturation increases the energy storage efficiency and reduces the energy storage capacity.The ratio of peak elastic energy density to peak input energy density remains constant irrespective of saturation levels.Water prevents rockburst by decreasing the energy storage capacity of surrounding rock,alleviating the stress of surrounding rock to reduce energy storage,and elevating the energy release threshold of high-energy surrounding rock.The findings of this study contribute to understanding the effect of water on rock failure from an energy perspective,as well as provide theoretical guidance for rockburst prevention by water in deep tunnels.展开更多
Traffic engineering such as tunnels in various altitudinal gradient zone are at risk of accidental explosion,which can damage personnel and equipment.Accurate prediction of the distribution pattern of explosive loads ...Traffic engineering such as tunnels in various altitudinal gradient zone are at risk of accidental explosion,which can damage personnel and equipment.Accurate prediction of the distribution pattern of explosive loads and shock wave propagation process in semi-enclosed structures at various altitude environment is key research focus in the fields of explosion shock and fluid dynamics.The effect of altitude on the propagation of shock waves in tunnels was investigated by conducting explosion test and numerical simulation.Based on the experimental and numerical simulation results,a prediction model for the attenuation of the peak overpressure of tunnel shock waves at different altitudes was established.The results showed that the peak overpressure decreased at the same measurement points in the tunnel entrance under the high altitude condition.In contrast,an increase in altitude accelerated the propagation speed of the shock wave in the tunnel.The average error between the peak shock wave overpressure obtained using the overpressure prediction formula and the measured test data was less than15%,the average error between the propagation velocity of shock waves predicted values and the test data is less than 10%.The method can effectively predict the overpressure attenuation of blast wave in tunnel at various altitudes.展开更多
Solar energy, as a renewable resource, is an effective solution to the current global energy shortage problem. To actively respond to the call for "carbon peak" and "carbon neutrality", solar cell ...Solar energy, as a renewable resource, is an effective solution to the current global energy shortage problem. To actively respond to the call for "carbon peak" and "carbon neutrality", solar cell industry has experienced unprecedented development. The full utilization of solar energy resources remains an urgent issue to be addressed.展开更多
The level of ground shaking,as determined by the peak ground acceleration(PGA),can be used to analyze seismic hazard at a certain location and is crucial for constructing earthquake-resistant structures.Predicting the...The level of ground shaking,as determined by the peak ground acceleration(PGA),can be used to analyze seismic hazard at a certain location and is crucial for constructing earthquake-resistant structures.Predicting the PGA immediately after an earthquake occurs allows for the issuing of a warning by an earthquake early warning system.In this study,we propose a deep learning model,ConvMixer,to predict the PGA recorded by weak-motion velocity seismometers in Japan.We use 5-s threecomponent seismograms,from 2 s before until 3 s after the P-wave arrival time of the earthquake.Our dataset comprised more than 50,000 single-station waveforms recorded by 10 seismic stations in the K-NET,Kiki-NET,and Hi-Net networks between 2004 and 2023.The proposed ConvMixer is a patch-based model that extracts global features from input seismic data and predicts the PGA of an earthquake by combining depth and pointwise convolutions.The proposed ConvMixer network had a mean absolute error of 2.143 when applied to the test set and outperformed benchmark deep learning models.In addition,the proposed ConvMixer demonstrated the ability to predict the PGA at the corresponding station site based on 1-second waveforms obtained immediately after the arrival time of the P-wave.展开更多
Tectonic reconstructions of Proterozoic Australia commonly place the Peake and Denison Domain of the northeastern Gawler Craton at the interface between the North and South Australian cratons prior to the reconfigurat...Tectonic reconstructions of Proterozoic Australia commonly place the Peake and Denison Domain of the northeastern Gawler Craton at the interface between the North and South Australian cratons prior to the reconfiguration of Australia’s main tectonic components in the Mesoproterozoic.However,this reconstruction is largely based on palaeomagnetic data as the geological correlations between these regions are currently limited,particularly during the Mesoproterozoic.The early Mesoproterozoic period is significant as it corresponds to major IOCG mineralization in the eastern Gawler Craton between 1600 Ma and 1575 Ma,and IOCG mineralization in the Mount Isa Province largely between 1550 Ma and 1490 Ma.Therefore,determining the relationship of the Peake and Denison Domain to the Gawler Craton and Mount Isa Province during this period is essential to evaluating mineral prospectivity in the northeastern Gawler Craton.New U–Pb LA-ICP-MS geochronology on zircon and titanite improves our understanding of the tectonothermal and hydrothermal history the Peake and Denison Domain during the latePalaeoproterozoic,early-Mesoproterozoic and the Cambrian–Ordovician periods.Titanite formed within largely calc-silicate alteration assemblages indicates the Peake and Denison Domain has a protracted history of hydrothermal activity,recording events at c.1565 Ma,1530–1515 Ma,c.1500 Ma,c.1465 Ma and c.490 Ma.The highly calcic nature of the c.1565–1500 Ma alteration in the Peake and Denison Domain shares strong similarities in age and character to the regional calcic-sodic alteration recorded in the Mount Isa Province.We suggest the two regions were influenced by similar hydrothermal systems during the early Mesoproterozoic,supporting reconstruction models that place the Peake and Denison Domain near the Mount Isa Province during the early-Mesoproterozoic.This highlights the prospectivity of the Peake and Denison Domain for Isan-style IOCG mineralization,but requires consideration of the post-1500 Ma rotation of prospective structures.展开更多
The present paper investigates the methods for estimating the maximum(positive)and the minimum(negative)peak wind force coefficients on domed free roofs based on the quasi-steady theory and the peak factor method,in w...The present paper investigates the methods for estimating the maximum(positive)and the minimum(negative)peak wind force coefficients on domed free roofs based on the quasi-steady theory and the peak factor method,in which the experimental results obtained from our previous studies(2019,2025)are used.Focus is on the distributions of the peak wind force coefficients along the centerline parallel to the wind direction considering that domed free roof is an axisymmetric body.Empirical formulas are provided to the distributions of mean wind force coefficient,RMS(root mean square)fluctuating wind force coefficient and peak factors as a function of the rise/span ratio of the roof and the turbulence intensity of the approach flow in the along-wind direction at the mean roof height.The proposed methods are validated by the experimental results for the peak wind force coefficients.The methods would provide useful information to structural engineers when estimating the design wind loads on cladding/components of domed free roofs.展开更多
On April 30,the 22nd China Xiza ng Mountai neering Conventi on in 2025 comme need.As its flagship eve nt,the Luodui Peak Mountaineering Expedition took place from May 2 to 3 in Yangbajain Town of Lhasa,attracting more...On April 30,the 22nd China Xiza ng Mountai neering Conventi on in 2025 comme need.As its flagship eve nt,the Luodui Peak Mountaineering Expedition took place from May 2 to 3 in Yangbajain Town of Lhasa,attracting more than 160 mountain climbing enthusiasts from all over the country.展开更多
To address the issues of unknown target size,blurred edges,background interference and low contrast in infrared small target detection,this paper proposes a method based on density peaks searching and weighted multi-f...To address the issues of unknown target size,blurred edges,background interference and low contrast in infrared small target detection,this paper proposes a method based on density peaks searching and weighted multi-feature local difference.Firstly,an improved high-boost filter is used for preprocessing to eliminate background clutter and high-brightness interference,thereby increasing the probability of capturing real targets in the density peak search.Secondly,a triple-layer window is used to extract features from the area surrounding candidate targets,addressing the uncertainty of small target sizes.By calculating multi-feature local differences between the triple-layer windows,the problems of blurred target edges and low contrast are resolved.To balance the contribution of different features,intra-class distance is used to calculate weights,achieving weighted fusion of multi-feature local differences to obtain the weighted multi-feature local differences of candidate targets.The real targets are then extracted using the interquartile range.Experiments on datasets such as SIRST and IRSTD-IK show that the proposed method is suitable for various complex types and demonstrates good robustness and detection performance.展开更多
The Degasperis-Procesi （DP） equation describing the propagation of shallow water waves contains a physical parameter co, and it is well-known that the DP equation admits solitary waves with a peaked crest when ω = ...The Degasperis-Procesi （DP） equation describing the propagation of shallow water waves contains a physical parameter co, and it is well-known that the DP equation admits solitary waves with a peaked crest when ω = 0. In this article, we illustrate, for the first time, that the DP equation admits peaked solitary waves even when ω≠ 0. This is helpful to enrich our knowledge and deepen our understandings about peaked solitary waves of the DP equation.展开更多
Urban environments have challenging characteristics for bird acoustic communication.High levels of anthropogenic noise,as well as vegetation structure(e.g.,in urban parks),can potentially affect the song frequency cha...Urban environments have challenging characteristics for bird acoustic communication.High levels of anthropogenic noise,as well as vegetation structure(e.g.,in urban parks),can potentially affect the song frequency characteristics of several bird species.An additional factor such as the abundance of conspecific and heterospecific vocalizing birds may play an important role in determining the structure of bird songs.In this study,we analyzed whether noise levels,vegetation percentage,and abundance of conspecifics and heterospecifics influence the song characteristics of three syntopic songbird species:House Finch(Haemorhous mexicanus),Rufouscollared Sparrow(Zonotrichia capensis),and House Sparrow(Passer domesticus)living in urban sites.We recorded songs of these species and measured the peak frequency and entropy of their songs at 14 sites in the city of San Cristobal de Las Casas,Chiapas,Mexico.We found that the song peak frequency of House Finch and House Sparrow's songs was negatively related to the vegetation.The peak frequency of neither of the three species correlated with the average noise level.However,the abundances of conspecific and heterospecific were related to the peak frequency of the three species'songs.The entropy of the House Finch and House Sparrow songs was positively and negatively related,respectively,to noise levels.House Sparrow song entropy was negatively related to the percentage of vegetation.Song entropy of House Finches was negatively associated to conspecific and House Sparrow abundance.Song entropy of Rufous-collared Sparrows was positively related to conspecific abundance.In conclusion,the song peak frequency and song entropy of the three songbird species were differentially related to urban noise,vegetation,and conspecific and heterospecific abundance,suggesting these factors influence bird song characteristics.展开更多
The primary objective of this work is to improve our understanding of the mechanical involvements of two-order roughness in shear.First,wavelet analysis is used to separate the waviness(first-order)and unevenness(seco...The primary objective of this work is to improve our understanding of the mechanical involvements of two-order roughness in shear.First,wavelet analysis is used to separate the waviness(first-order)and unevenness(second-order)from four granite joint surfaces,with roughness characterized using Grasselli’s 3D morphology parameters.The results reveal that first-order roughness is more pronounced than second-order roughness,highlighting the dominant role of waviness in joint surface roughness.Additionally,the variation in first-order roughness with strike direction corresponds to the total roughness,while second-order roughness remains largely constant,indicating that roughness anisotropy is primarily driven by waviness.Then,direct shear tests on joint replicas are performed to investigate the contributions of both roughness orders to peak shear strength.The results show that the peak dilation angle is closely related to first-order roughness,while the shear component angle is closely associated with second-order roughness,both exhibiting a linear correlation.Based on these findings,relationships are established between the angles and their respective roughness orders.Finally,a joint shear strength criterion based on two-order roughness is proposed.A comparative analysis of prediction accuracy reveals that the average relative error for the proposed criterion is 13.79%,while the errors for Xia's,Yang's,and Ban's criteria are 15.19%,16.29%,and 13.87%,respectively.It demonstrates the proposed criterion can predict the peak shear strength of rock joints.展开更多
Atomic-scale strain mapping has become increasingly vital for investigating deformation mechanisms and the governing principles of solid materials.This is due to the significant impact of atomic-scale strain on the ph...Atomic-scale strain mapping has become increasingly vital for investigating deformation mechanisms and the governing principles of solid materials.This is due to the significant impact of atomic-scale strain on the physical,chemical,and mechanical properties of nanomaterials that comprise functional devices such as nanoelectronics,communication devices,electromechanical systems,and sensors.The advent of advanced electron microscopes has enabled the acquisition of high-magnification images with atomic resolution,providing an exceptional platform for measuring the atomic-scale strain of solid materials.However,accurate and unified strain mapping methods and standards for evaluating atomic-scale strain distribution remain scarce.Consequently,a unified strain mapping framework is proposed for atomic-scale strain measurement.Utilizing finite deformation analysis and the least-squares mathematical method,two types of atomic-scale strain field mapping methods have been developed,including the phase analysis-based methods(PAD and PAS)and the peak matching-based strain mapping method(PMS)for high-resolution scanning transmission electron microscope images.The prototypical 2D materials,graphene and molybdenum disulfide,serve as the subjects for the strain field mapping research,conducted through both simulation and experimentation.Upon comparing the theoretical strain mapping results of single-layer graphene and molybdenum disulfide with and without defects,it is demonstrated that the proposed strain mapping methods,particularly the PMS method,can accurately describe the large deformation surrounding a significant strain gradient.展开更多
基金Supported by National Nature Science Foundation of China under Grant No.11102076Natural Science Fund for Colleges and Universities in Jiangsu Province under Grant No.15KJB110005
文摘By qualitative analysis method, a sufficient condition for the existence of peaked periodic wave solutions to the Broer–Kaup equation is given. Some exact explicit expressions of peaked periodic wave solutions are also presented.
基金State Grid Henan Power Company Science and Technology Project‘Key Technology and Demonstration Application of Multi-Domain Electric Vehicle Aggregated Charging Load Dispatch’(5217L0240003).
文摘This paper introduces a method for modeling the entire aggregated electric vehicle(EV)charging process and analyzing its dispatchable capabilities.The methodology involves developing a model for aggregated EV charging at the charging station level,estimating its physical dispatchable capability,determining its economic dispatchable capability under economic incentives,modeling its participation in the grid,and investigating the effects of different scenarios and EV penetration on the aggregated load dispatch and dispatchable capability.The results indicate that using economic dispatchable capability reduces charging prices by 9.7%compared to physical dispatchable capability and 9.3%compared to disorderly charging.Additionally,the peak-to-valley difference is reduced by 64.6%when applying economic dispatchable capability with 20%EV penetration and residential base load,compared to disorderly charging.
文摘We use qualitative analysis and numerical simulation to study peaked traveling wave solutions of CH-γ and CH equations. General expressions of peakon and periodic cusp wave solutions are obtained. Some previous results become our special cases.
文摘This paper proposes a novel modified uni-traveling-carrier photodiode(MUTC-PD)featuring an electric field regulation layer:a p-type doped thin layer inserted behind the PD’s n-doped cliff layer.This electric field regulation layer enhances the PD’s performance by not only reducing and smoothing the electric field intensity in the collector layer,allowing photo-generated electrons to transit at peak drift velocity,but also improving the electric field intensity in the depleted absorber layer and optimizing the photo-generated carriers’saturated transit performance.Additionally,the transport characteristics of the peak drift velocity of photogenerated electrons in the device’s collection layer can be used to optimize its parasitic characteristics.The electron’s peak drift velocity compensates for the lost transit time.Thus improving the 3 dB bandwidth of the PD’s photo response.Finally obtains a MUTC-PD with a 3 dB bandwidth of 68 GHz at a responsivity of 0.502 A/W,making it suitable for 100 Gbit/s optical receivers.
基金supported by the State Key Lab of Ocean Engineering(Grant No.GKZD010056-6)the National Natural Science Foundation of China(Grant Nos.10872129 and 11272209
文摘It is well-known that the celebrated Camassa-Holm equation has the peaked solitary waves,which have been not reported for other mainstream models of shallow water waves.In this letter,the closed-form solutions of peaked solitary waves of the KdV equation,the BBM equation and the Boussinesq equation are given for the first time.All of them have either a peakon or an anti-peakon.Each of them exactly satisfies the corresponding Rankine-Hogoniot jump condition and could be understood as weak solution.Therefore,the peaked solitary waves might be common for most of shallow water wave models,no matter whether or not they are integrable and/or admit breaking-wave solutions.
基金This work was supported by the National Natural Science Foundation of China(Grant No.10261008)the Natural Science Foundation of Yunnan Province(Grant No,2002A0002M).
文摘In this paper the qualitative analysis methods of planar autonomous systems and numerical simu-lation are used to investigate the peaked wave solutions of CH-r equation. Some explicit expressions of peakedsolitary wave solutions and peaked periodic wave solutions are obtained, and some of their relationships arerevealed. Why peaked points are generated is discussed.
基金Supported by the Nature Science Foundation of Shandong (No. 2004zx16,Q2005A01)
文摘By constructing auxiliary differential equations, we obtain peaked solitary wave solutions of the generalized Camassa-Holm equation, including periodic cusp waves expressed in terms of elliptic functions.
基金supported by the National Natural Science Foundation of China(52104133,52304227)the Natural Science Foundation of Hunan Province(2021JJ40465,2023JJ40548)the Opening Foundation of the State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines(SKLMRDPC20KF03).
文摘To investigate the effect of saturation on the storage-dissipation properties and failure characteristics of red sandstone,as well as the energy mechanism of rockburst prevention by water,a series of uniaxial compression and uniaxial loading–unloading tests were conducted under five saturation levels.The effect of saturation on the mechanical properties and elastic energy density was analyzed,and a method for obtaining peak energy density was proposed.The effect of saturation on the energy evolution was examined,and the energy mechanism of water in preventing rockburst was revealed.The results indicate that an increase in saturation of red sandstone decreases the input energy density,elastic energy density,dissipated energy density,peak strength and peak strain;the compaction phase of the stress–strain curve becomes shorter;the failure mode transitions from X-conjugate oblique shear to single oblique shear;the variation in the debris ejection trajectory is as follows:radiation→X-ray→oblique upward parabola→horizontal parabola→oblique downward parabola;the degree of failure intensity and fragmentation is decreased gradually.Elastic energy density is interconnected with both saturation and stress but independent of the loading path.Saturation exhibits a dual effect on the energy storage property,i.e.,increasing saturation increases the energy storage efficiency and reduces the energy storage capacity.The ratio of peak elastic energy density to peak input energy density remains constant irrespective of saturation levels.Water prevents rockburst by decreasing the energy storage capacity of surrounding rock,alleviating the stress of surrounding rock to reduce energy storage,and elevating the energy release threshold of high-energy surrounding rock.The findings of this study contribute to understanding the effect of water on rock failure from an energy perspective,as well as provide theoretical guidance for rockburst prevention by water in deep tunnels.
基金financially supported by National Natural Science Foundation of China(Grant Nos.52378401,52278504)the Fundamental Research Funds for the Central Universities(Grant No.30922010918)。
文摘Traffic engineering such as tunnels in various altitudinal gradient zone are at risk of accidental explosion,which can damage personnel and equipment.Accurate prediction of the distribution pattern of explosive loads and shock wave propagation process in semi-enclosed structures at various altitude environment is key research focus in the fields of explosion shock and fluid dynamics.The effect of altitude on the propagation of shock waves in tunnels was investigated by conducting explosion test and numerical simulation.Based on the experimental and numerical simulation results,a prediction model for the attenuation of the peak overpressure of tunnel shock waves at different altitudes was established.The results showed that the peak overpressure decreased at the same measurement points in the tunnel entrance under the high altitude condition.In contrast,an increase in altitude accelerated the propagation speed of the shock wave in the tunnel.The average error between the peak shock wave overpressure obtained using the overpressure prediction formula and the measured test data was less than15%,the average error between the propagation velocity of shock waves predicted values and the test data is less than 10%.The method can effectively predict the overpressure attenuation of blast wave in tunnel at various altitudes.
文摘Solar energy, as a renewable resource, is an effective solution to the current global energy shortage problem. To actively respond to the call for "carbon peak" and "carbon neutrality", solar cell industry has experienced unprecedented development. The full utilization of solar energy resources remains an urgent issue to be addressed.
基金the National Research Institute of Astronomy and Geophysics (NRIAG) for supporting this work
文摘The level of ground shaking,as determined by the peak ground acceleration(PGA),can be used to analyze seismic hazard at a certain location and is crucial for constructing earthquake-resistant structures.Predicting the PGA immediately after an earthquake occurs allows for the issuing of a warning by an earthquake early warning system.In this study,we propose a deep learning model,ConvMixer,to predict the PGA recorded by weak-motion velocity seismometers in Japan.We use 5-s threecomponent seismograms,from 2 s before until 3 s after the P-wave arrival time of the earthquake.Our dataset comprised more than 50,000 single-station waveforms recorded by 10 seismic stations in the K-NET,Kiki-NET,and Hi-Net networks between 2004 and 2023.The proposed ConvMixer is a patch-based model that extracts global features from input seismic data and predicts the PGA of an earthquake by combining depth and pointwise convolutions.The proposed ConvMixer network had a mean absolute error of 2.143 when applied to the test set and outperformed benchmark deep learning models.In addition,the proposed ConvMixer demonstrated the ability to predict the PGA at the corresponding station site based on 1-second waveforms obtained immediately after the arrival time of the P-wave.
基金supported by ARC Linkage Project LP160100578(JLP and MH)the Mineral Exploration Cooperative Research Centre whose activities are funded by the Australian Government’s Cooperative Research Centre Programsupport of an Australian Government Research Training Program Stipend and LJM acknowledges the support of ARC DECRA Fellowship DE210101126.
文摘Tectonic reconstructions of Proterozoic Australia commonly place the Peake and Denison Domain of the northeastern Gawler Craton at the interface between the North and South Australian cratons prior to the reconfiguration of Australia’s main tectonic components in the Mesoproterozoic.However,this reconstruction is largely based on palaeomagnetic data as the geological correlations between these regions are currently limited,particularly during the Mesoproterozoic.The early Mesoproterozoic period is significant as it corresponds to major IOCG mineralization in the eastern Gawler Craton between 1600 Ma and 1575 Ma,and IOCG mineralization in the Mount Isa Province largely between 1550 Ma and 1490 Ma.Therefore,determining the relationship of the Peake and Denison Domain to the Gawler Craton and Mount Isa Province during this period is essential to evaluating mineral prospectivity in the northeastern Gawler Craton.New U–Pb LA-ICP-MS geochronology on zircon and titanite improves our understanding of the tectonothermal and hydrothermal history the Peake and Denison Domain during the latePalaeoproterozoic,early-Mesoproterozoic and the Cambrian–Ordovician periods.Titanite formed within largely calc-silicate alteration assemblages indicates the Peake and Denison Domain has a protracted history of hydrothermal activity,recording events at c.1565 Ma,1530–1515 Ma,c.1500 Ma,c.1465 Ma and c.490 Ma.The highly calcic nature of the c.1565–1500 Ma alteration in the Peake and Denison Domain shares strong similarities in age and character to the regional calcic-sodic alteration recorded in the Mount Isa Province.We suggest the two regions were influenced by similar hydrothermal systems during the early Mesoproterozoic,supporting reconstruction models that place the Peake and Denison Domain near the Mount Isa Province during the early-Mesoproterozoic.This highlights the prospectivity of the Peake and Denison Domain for Isan-style IOCG mineralization,but requires consideration of the post-1500 Ma rotation of prospective structures.
文摘The present paper investigates the methods for estimating the maximum(positive)and the minimum(negative)peak wind force coefficients on domed free roofs based on the quasi-steady theory and the peak factor method,in which the experimental results obtained from our previous studies(2019,2025)are used.Focus is on the distributions of the peak wind force coefficients along the centerline parallel to the wind direction considering that domed free roof is an axisymmetric body.Empirical formulas are provided to the distributions of mean wind force coefficient,RMS(root mean square)fluctuating wind force coefficient and peak factors as a function of the rise/span ratio of the roof and the turbulence intensity of the approach flow in the along-wind direction at the mean roof height.The proposed methods are validated by the experimental results for the peak wind force coefficients.The methods would provide useful information to structural engineers when estimating the design wind loads on cladding/components of domed free roofs.
文摘On April 30,the 22nd China Xiza ng Mountai neering Conventi on in 2025 comme need.As its flagship eve nt,the Luodui Peak Mountaineering Expedition took place from May 2 to 3 in Yangbajain Town of Lhasa,attracting more than 160 mountain climbing enthusiasts from all over the country.
基金supported by the National Natural Science Foundation of China (No.52205548)。
文摘To address the issues of unknown target size,blurred edges,background interference and low contrast in infrared small target detection,this paper proposes a method based on density peaks searching and weighted multi-feature local difference.Firstly,an improved high-boost filter is used for preprocessing to eliminate background clutter and high-brightness interference,thereby increasing the probability of capturing real targets in the density peak search.Secondly,a triple-layer window is used to extract features from the area surrounding candidate targets,addressing the uncertainty of small target sizes.By calculating multi-feature local differences between the triple-layer windows,the problems of blurred target edges and low contrast are resolved.To balance the contribution of different features,intra-class distance is used to calculate weights,achieving weighted fusion of multi-feature local differences to obtain the weighted multi-feature local differences of candidate targets.The real targets are then extracted using the interquartile range.Experiments on datasets such as SIRST and IRSTD-IK show that the proposed method is suitable for various complex types and demonstrates good robustness and detection performance.
基金supported by the State Key Lab of Ocean Engineering(Grant No. GKZD010056-6)the National Natural Science Foundation of China (Grant No. 11272209)
文摘The Degasperis-Procesi （DP） equation describing the propagation of shallow water waves contains a physical parameter co, and it is well-known that the DP equation admits solitary waves with a peaked crest when ω = 0. In this article, we illustrate, for the first time, that the DP equation admits peaked solitary waves even when ω≠ 0. This is helpful to enrich our knowledge and deepen our understandings about peaked solitary waves of the DP equation.
基金the Consejo Nacional de Humanidades,Ciencias y Tecnologías (CONAHCYT)of Mexico for providing funding for graduate studies of X.D.L. (No.001283)El Colegio de la Frontera Sur for PATM graduate fellowship for fieldwork。
文摘Urban environments have challenging characteristics for bird acoustic communication.High levels of anthropogenic noise,as well as vegetation structure(e.g.,in urban parks),can potentially affect the song frequency characteristics of several bird species.An additional factor such as the abundance of conspecific and heterospecific vocalizing birds may play an important role in determining the structure of bird songs.In this study,we analyzed whether noise levels,vegetation percentage,and abundance of conspecifics and heterospecifics influence the song characteristics of three syntopic songbird species:House Finch(Haemorhous mexicanus),Rufouscollared Sparrow(Zonotrichia capensis),and House Sparrow(Passer domesticus)living in urban sites.We recorded songs of these species and measured the peak frequency and entropy of their songs at 14 sites in the city of San Cristobal de Las Casas,Chiapas,Mexico.We found that the song peak frequency of House Finch and House Sparrow's songs was negatively related to the vegetation.The peak frequency of neither of the three species correlated with the average noise level.However,the abundances of conspecific and heterospecific were related to the peak frequency of the three species'songs.The entropy of the House Finch and House Sparrow songs was positively and negatively related,respectively,to noise levels.House Sparrow song entropy was negatively related to the percentage of vegetation.Song entropy of House Finches was negatively associated to conspecific and House Sparrow abundance.Song entropy of Rufous-collared Sparrows was positively related to conspecific abundance.In conclusion,the song peak frequency and song entropy of the three songbird species were differentially related to urban noise,vegetation,and conspecific and heterospecific abundance,suggesting these factors influence bird song characteristics.
基金funded by the National Natural Science Foundation of China (Grant nos. 42272333 and 42377154)the China Association for Science and Technology Youth Talent Support Program for PhD Students.
文摘The primary objective of this work is to improve our understanding of the mechanical involvements of two-order roughness in shear.First,wavelet analysis is used to separate the waviness(first-order)and unevenness(second-order)from four granite joint surfaces,with roughness characterized using Grasselli’s 3D morphology parameters.The results reveal that first-order roughness is more pronounced than second-order roughness,highlighting the dominant role of waviness in joint surface roughness.Additionally,the variation in first-order roughness with strike direction corresponds to the total roughness,while second-order roughness remains largely constant,indicating that roughness anisotropy is primarily driven by waviness.Then,direct shear tests on joint replicas are performed to investigate the contributions of both roughness orders to peak shear strength.The results show that the peak dilation angle is closely related to first-order roughness,while the shear component angle is closely associated with second-order roughness,both exhibiting a linear correlation.Based on these findings,relationships are established between the angles and their respective roughness orders.Finally,a joint shear strength criterion based on two-order roughness is proposed.A comparative analysis of prediction accuracy reveals that the average relative error for the proposed criterion is 13.79%,while the errors for Xia's,Yang's,and Ban's criteria are 15.19%,16.29%,and 13.87%,respectively.It demonstrates the proposed criterion can predict the peak shear strength of rock joints.
基金support from the National Natural Science Foundation of China through Grants 12172190,11872035,11632010,and 12302236。
文摘Atomic-scale strain mapping has become increasingly vital for investigating deformation mechanisms and the governing principles of solid materials.This is due to the significant impact of atomic-scale strain on the physical,chemical,and mechanical properties of nanomaterials that comprise functional devices such as nanoelectronics,communication devices,electromechanical systems,and sensors.The advent of advanced electron microscopes has enabled the acquisition of high-magnification images with atomic resolution,providing an exceptional platform for measuring the atomic-scale strain of solid materials.However,accurate and unified strain mapping methods and standards for evaluating atomic-scale strain distribution remain scarce.Consequently,a unified strain mapping framework is proposed for atomic-scale strain measurement.Utilizing finite deformation analysis and the least-squares mathematical method,two types of atomic-scale strain field mapping methods have been developed,including the phase analysis-based methods(PAD and PAS)and the peak matching-based strain mapping method(PMS)for high-resolution scanning transmission electron microscope images.The prototypical 2D materials,graphene and molybdenum disulfide,serve as the subjects for the strain field mapping research,conducted through both simulation and experimentation.Upon comparing the theoretical strain mapping results of single-layer graphene and molybdenum disulfide with and without defects,it is demonstrated that the proposed strain mapping methods,particularly the PMS method,can accurately describe the large deformation surrounding a significant strain gradient.
