Higher Himalayan Crystalline (HHC) rocks often show metamorphic zonations from lower greenschist facies to migmatites associated with leucogranite intrusions that are classically described as examples of Tertiary inve...Higher Himalayan Crystalline (HHC) rocks often show metamorphic zonations from lower greenschist facies to migmatites associated with leucogranite intrusions that are classically described as examples of Tertiary inverted metamorphism. The present study, based on structural, petrological and geochronological investigations in the Kinnar Kailas Granite (KKG) and surrounding HHC sequence, evidences a discordant intrusive contact of the Ordovician KKG with respect to Pre\|Alpine high grade deformed HHC sequence in the Sutlej valley.Four main phases of deformation are recorded in this HHC sequence and pre\|Ordovician sediments. The first three phases of deformation occurred under high\|grade metamorphic conditions, before the intrusion of the KKG. The geometry of the main progressive ductile deformation (D2—D3) results from SW vergent doming and migmatisation. The latest deformation is expressed by local shearing under greenschist facies conditions. This late D4 deformation corresponds to N—S oriented ductile normal faults lowering the eastern blocks. The KKG is a shallow depth intrusion, showing discordant contacts with the surrounding basement rocks and large scale magmatic stoping. The KKG crosscuts the high\|grade deformation structures (D2—D3) but is locally affected by the local late D4 extensional deformation. The granite textures reflect only slight orientation related to magmatic deformation and even at few centimetres from the intrusion contact, the granite appears undeformed in contrast to the surrounding highly foliated rocks. Furthermore, xenoliths of Kyanite\|Sillimanite bearing basement rocks are present within the KKG.展开更多
The Shenshan Group provides important geological information which is vital in unraveling the amalgamation and subsequent rifting processes of South China.While conventional studies have asserted its formation in a su...The Shenshan Group provides important geological information which is vital in unraveling the amalgamation and subsequent rifting processes of South China.While conventional studies have asserted its formation in a subduction setting,the distinct investigation reveals the necessity for reassessment.To address this,the authors employ integrated methods encompassing petrological,zircon U-Pb geochronological,Lu-Hf isotopic and geochemical methods for sedimentary rocks from the upper Shenshan subgroup and Banxi Group.The geochemical results indicate that they were formed through the recycling deposition of intermediate-acidic igneous source material and experienced moderate chemical weathering.Additionally,both sedimentary sequences exhibit characteristics consistent with those formed in an intracontinental extensional rift setting since ca.810 Ma.The provenance analysis indicates that the upper Shenshan subgroup primarily originates from the Yangtze Domain,while the Banxi Group from both the Yangtze and Cathaysia domains.Synthesizing with previous studies,the Shenshan Group should be subdivided into the lower and upper subgroups which represent distinct tectonic backgrounds.The lower subgroup is inferred to have formed in an Early Neoproterozoic fore-arc setting,akin to the Zhoutan group.The upper subgroup corresponds to the Banxi Group,representing the Middle Neoproterozoic postorogenic rift setting,responding to the breakup of Rodinia.展开更多
This work studies new petrological and geochemical data and zircon U-Pb ages for bimodal intrusive rocks from Xinglong re- gion, Hainan Island. Zircon U-Pb dating yields mean 238U/26pb ages of 238 ± 2 Ma and 234&...This work studies new petrological and geochemical data and zircon U-Pb ages for bimodal intrusive rocks from Xinglong re- gion, Hainan Island. Zircon U-Pb dating yields mean 238U/26pb ages of 238 ± 2 Ma and 234±2 Ma for diabasic and granitic phases, respectively, representing the Middle Triassic emplacement. The diabase and granite bodies were formed from discrete mafic and acidic magma sources that experienced local mechanical mixing at their mutual contacts. Although SiO2 content of intrusions is bimodal, trace element ratios indicate that both were formed in a post-orogenic extensional setting. Sr-Nd isotopic composition reflects a shared EMII type enriched mantle source component, possibly influenced by subduction-fluid metaso- matism.展开更多
The Xikuangshan antimony deposit in central Hunan, South China, is the largest antimony deposit ever known in the world. The ore bodies are strictly confined to the footwalls of mafor high-angle normal faults which tr...The Xikuangshan antimony deposit in central Hunan, South China, is the largest antimony deposit ever known in the world. The ore bodies are strictly confined to the footwalls of mafor high-angle normal faults which transect the inclined folds in the flank;away from the fault planes,both the homogenization temperatures of inclusions in gangue minerals and the intensity of antimony mineralization decrease.These characteristics strongly demonstrate that the faults are used as the conduit for the metal-bearing fluid in mineralization.The normal faults,striking the NE to NNE,are interpreted to be generated by the postmgenic extension in the time from Cretaceous to Paleogene.Crustal or lithospheric thinning, directly resulting from regional extension inevitably increase the geothermal gradient, Which is likely to cause large-scale convection of underground water that may leach out and transport valuablemetals such as Sb from source rocks.Focussed discharge along the fault zones contributes to the formation of the supergiant antimony deposit in Xikuangshan under the appropriate sedimentary barrier.展开更多
This paper introduced the concept of generalized quasidiagonal extension of C^(*)-algebras and gave some basic properties.We show that the extension algebra preserves quasidiagonality and finitary in generalized quasi...This paper introduced the concept of generalized quasidiagonal extension of C^(*)-algebras and gave some basic properties.We show that the extension algebra preserves quasidiagonality and finitary in generalized quasidiagonal extension.We give also an example of generalized quasidiagonal extension,which is not quasidiagonal extension.展开更多
How the subduction direction of the Paleo-Pacific plate beneath the Eurasian plate changes in the Early Cretaceous remains highly controversial due to the disappearance of the subducted oceanic plate.Intraplate deform...How the subduction direction of the Paleo-Pacific plate beneath the Eurasian plate changes in the Early Cretaceous remains highly controversial due to the disappearance of the subducted oceanic plate.Intraplate deformation structures in the east Asian continent,however,provide excellent opportunities for reconstructing paleostress fields in continental interior in relation to the Paleo-Pacific/Eurasian plate interaction.Anisotropy of magnetic susceptibility(AMS),geological,and geochronological analyses of post-kinematic mafic dykes intruding the detachment fault zone of the Wulian metamorphic core complex(WL MCC)in Jiaodong Peninsula exemplify emplacement of mantle-sourced dykes in a WNW-ESE(301°-121°)oriented tectonic extensional setting at ca.120 Ma.In combination with the results from our previous kinematic analysis of the MCC,a ca.21°clockwise change in the direction of intraplate extension is obtained for early(135-122 Ma)extensional exhumation of the MCC to late(122-108 Ma)emplacement of the dykes.Such a change is suggested to be related to the variation in subduction direction of the Paleo-Pacific plate beneath the Eurasian plate,from westward(pre-122 Ma)to west-northwestward(post-122 Ma).展开更多
The modifiedλ-differential Lie-Yamaguti algebras are considered,in which a modifiedλ-differential Lie-Yamaguti algebra consisting of a Lie-Yamaguti algebra and a modifiedλ-differential operator.First we introduce t...The modifiedλ-differential Lie-Yamaguti algebras are considered,in which a modifiedλ-differential Lie-Yamaguti algebra consisting of a Lie-Yamaguti algebra and a modifiedλ-differential operator.First we introduce the representation of modifiedλ-differential Lie-Yamaguti algebras.Furthermore,we establish the cohomology of a modifiedλ-differential Lie-Yamaguti algebra with coefficients in a representation.Finally,we investigate the one-parameter formal deformations and Abelian extensions of modifiedλ-differential Lie-Yamaguti algebras using the second cohomology group.展开更多
The Ross Sea basins,shaped by Late Cretaceous and Cenozoic extension within the crust of the Ross Sea,represent key regions for understanding continental rifting processes.However,the dynamic mechanisms driving the tr...The Ross Sea basins,shaped by Late Cretaceous and Cenozoic extension within the crust of the Ross Sea,represent key regions for understanding continental rifting processes.However,the dynamic mechanisms driving the transition from diffuse extension to focused extension in these basins remain poorly understood.Here,we provide a comprehensive model of crustal extension in the Ross Sea basins,detailing the kinematic and dynamic evolution from 100 Ma to the present on the basis of published finite rotation poles.Our model illuminates the complex relative motions between the West Antarctic and East Antarctic Plates and quantifies the crustal strain rates associated with their relative movements.We show that West Antarctica began to move away slowly from the East Antarctic and rotated clockwise at approximately 53 Ma,and the motion progressively decreased until it ceased at approximately 11 Ma.This kinematic shift temporally coincided with the onset of focused rifting,indicating a transition from broadly distributed extension in the eastern Ross Sea to localized deformation in the western basin.Time-resolved strain rate fields further reveal several hundred kilometers of total crustal extension,suggesting a primary influence of evolving plate motions over passive lithospheric weakening.These findings refine the tectonic history of the Ross Sea and provide a reproducible framework linking rift basin evolution to global plate motion.展开更多
Optical-resolution photoacoustic microscopy is a novel imaging technique that combines the advantages of optical and ultrasound imaging,enabling high-resolution visualization of biological tissues at the micrometer sc...Optical-resolution photoacoustic microscopy is a novel imaging technique that combines the advantages of optical and ultrasound imaging,enabling high-resolution visualization of biological tissues at the micrometer scale.However,the divergence of the excited Gaussian beam limits the depth-of-field of the system to less than 100μm,which hinders accurate three-dimensional imaging of living tissues and restrictsits applicability in biological research.Therefore,there is an urgent need for an effective method to enhance the depth-of-field without altering the hardware configuration.This paper presents a photoacoustic microscopy depth-of-field extension method and system based on three-dimensional continuity and sparsity deconvolution.This method utilizes a depth-varying point spread function and incorporates continuity and sparsity con-straints into the deconvolution process to mitigate the effect of background noise,enhancing the stability and accuracy of the depth-of-field extension.Experimental results using tungsten wire phantoms suggest that the depth-of-field of system can be extended to 650 pm,which is 7.2 times greater than conventional system,while improving the resolution of the defocused region by an average factor of 3.5.Furthermore,experiments on zebrafish and nude mouse ears with irregular topologies demonstrate that the proposed method successfully overcomes image blurring and the loss of structural information due to limited depth-of-field.All the results suggest that the system with higher lateral resolution and enhanced depth-of-field has significant potential for a wide range of practical biomedical applications.展开更多
The tectonic setting of the Himalaya during the Early Paleozoic has been a subject of enduring debate within the scientific community.Newly discovered bimodal intrusive rocks from comprehensive field geological invest...The tectonic setting of the Himalaya during the Early Paleozoic has been a subject of enduring debate within the scientific community.Newly discovered bimodal intrusive rocks from comprehensive field geological investigation in the central mountain range were subjected to petrology,zircon U-Pb geochronology,zircon Hf isotopes and whole-rock geochemistry analyses.The Palie bimodal intrusive rocks,comprising amphibolite and granitic gneiss,were formed at~489 Ma.The amphibolite exhibits geochemical characteristics consistent with N-MORB,while the granitic gneiss is classified as high potassium calc-alkaline peraluminous S-type granite.Both igneous rocks exhibit negative zirconε_(Hf)(t)values and display ancient T_(DM)^(C)ages.In conjunction with regional geological survey findings,it can be inferred that the formation of the Palie bimodal intrusive rocks occurred within a post-collision extensional tectonic setting.The amphibolite genesis involved partial melting of an enriched lithospheric mantle with some crustal assimilation,whereas the origin of the granitic gneiss can be attributed to partial melting of pre-existing felsic crust.Our data indicate that during the Early Paleozoic,the Himalaya underwent a transition from a pan-African collisional setting to post-collisional extensional tectonics.展开更多
In this paper,we call a tuple consisting of 3-Lie algebra and a higher derivation on it a 3-LieHDer pair.We introduce a cohomology theory of 3-LieHDer pairs.Next,we interpret the second cohomology group as the space o...In this paper,we call a tuple consisting of 3-Lie algebra and a higher derivation on it a 3-LieHDer pair.We introduce a cohomology theory of 3-LieHDer pairs.Next,we interpret the second cohomology group as the space of all isomorphism classes of abelian extensions.Finally,we consider formal deformations of 3-LieHDer pairs that are governed by the cohomology with self-coefficient.展开更多
This study aimed to examine the influence of farmer characteristics and extension services on the sustainability of seaweed cultivation in three districts of Polewali Mandar Regency,West Sulawesi,namely Polewali,Binua...This study aimed to examine the influence of farmer characteristics and extension services on the sustainability of seaweed cultivation in three districts of Polewali Mandar Regency,West Sulawesi,namely Polewali,Binuang,and Wonomulyo.A total of 267 seaweed farmers were surveyed using a questionnaire,and the data were analyzed through multiple linear regression.Informed consent was obtained in writing from all participants before data collection.The results showed that farmer characteristics and extension services had a positive and significant effect on seaweed farming sustainability.These findings highlight the importance of strengthening both human capital and institutional support.Key farmer characteristics,such as education level,farming experience,motivation,and openness to innovation,play a vital role in sustaining seaweed businesses.Enhancing these competencies through training,formal and non-formal education,and capacity-building programs will improve farmers’ability to adopt sustainable practices,adapt to environmental changes,and increase productivity.Similarly,the significant role of extension services demonstrates the need for continuous technical assistance,knowledge transfer,and institutional backing.Improving extension systems by deploying more qualified field officers,conducting regular farm visits,and tailoring content to local contexts can bridge the gap between innovation and practice.Participatory extension models that engage farmers directly can further promote peer learning and community cohesion.At the policy level,this study supports integrating farmer capacity development and extension strengthening into regional agricultural and fisheries strategies to ensure long-term sustainability of seaweed farming.展开更多
In this paper,we introduce non-abelian cohomology groups and classify the nonabelian extensions of Rota-Baxter pre-Lie algebras in terms of non-abelian cohomology groups.Next,we explore the inducibility of pairs of au...In this paper,we introduce non-abelian cohomology groups and classify the nonabelian extensions of Rota-Baxter pre-Lie algebras in terms of non-abelian cohomology groups.Next,we explore the inducibility of pairs of automorphisms and derive the analog Wells exact sequences under the circumstance of Rota-Baxter pre-Lie algebras.Finally,we discuss the inducibility problem of pairs of automorphisms about an abelian extensions of Rota-Baxter pre-Lie algebras.展开更多
After excavation,some of the surrounding rock mass is in a state of triaxial extension,exhibiting tensile or shear fracture modes.To study the energy mechanism of tensile fracture turning to shear fracture,a series of...After excavation,some of the surrounding rock mass is in a state of triaxial extension,exhibiting tensile or shear fracture modes.To study the energy mechanism of tensile fracture turning to shear fracture,a series of triaxial extension tests were conducted on sandstone under confining pressures of 10,30,50 and 70 MPa.Elastic energy and dissipated energy were separated by single unloading,the input energy u_(t),elastic energy u_(e),and dissipated energy u_(d)at different unloading stress levels were calculated by the integrating stress−strain curves.The results show that tensile cracks dominate fracture under lower confining pressure(10 MPa),and shear cracks play an increasingly important role in fracture as confining pressure increases(30,50 and 70 MPa).Based on the phenomenon that u_(e)and u_(d)increase linearly with increasing u_(t),a possible energy distribution mechanism of fracture mode transition under triaxial extension was proposed.In addition,it was found that peak energy storage capacity is more sensitive to confining pressure compared to elastic energy conversion capacity.展开更多
In this study,convolutional long short-term memory(ConvLSTM)model is used to predict sea level anomaly(SLA)in the Kuroshio Extension(KE)region,utilizing daily satellite altimetry data(1993-2016).The model captures reg...In this study,convolutional long short-term memory(ConvLSTM)model is used to predict sea level anomaly(SLA)in the Kuroshio Extension(KE)region,utilizing daily satellite altimetry data(1993-2016).The model captures regional averaged SLA variability,achieving a correlation coefficient of 0.98 for prediction horizon up to 23 d.Propagating features of Rossby waves are also reproduced in the prediction model.While in spatial,discrepancies between predicted SLA and observed SLA are quite large,especially in regions with strong eddy activities.Incorporating equation of motion for the 11/2-layer reduced-gravity model,the performance of the model has a significant improvement spatially and temporally.Challenges persist in high-variability regions,underscoring the need for advanced models.This study highlights ConvLSTM’s potential for SLA forecasting with wind driven physical constraints,offering insights into wind-driven and eddy-influenced processes in the KE region.展开更多
Sponge city(SPC)is proposed to solve the issues such as the degradation of urban water ecosystem environment,imbalanced water resource allocation,urban water logging,and water contamination.The PPP(Public Private Part...Sponge city(SPC)is proposed to solve the issues such as the degradation of urban water ecosystem environment,imbalanced water resource allocation,urban water logging,and water contamination.The PPP(Public Private Partnership)model is combined to release the government pressure of SPC project construction.The development of the SPC-PPP model makes significant contributions to the sustainable development and the enhancement of urban resilience against water-related disasters.However,there is no scientific performance evaluation system on its operation period has been conducted.Therefore,the SPC-PPP Evaluation model aims to objectively and reasonably assess project effectiveness,promote its development and refine the evaluation framework.This paper has set up the MEE model for performance evaluation,with improved Matter-Element Extension method to assign values to the evaluation indices.The research results show that:(1)The MEE model is more accurate in the performance evaluation and its effectiveness is reflected in its ability to capture the correlation among different indices in the same membership,rather than merely focusing on individual indices.(2)The proposed approach provided a new aspect for performance evaluation,improving the accuracy of evaluation and promoting the development of SPC-PPP project.展开更多
This paper proposes a universal impulse-function-based method for extending discrete chaotic maps,enabling flexible construction of multicavity chaotic attractors.The proposed method achieves one-directional(1D)/two-d...This paper proposes a universal impulse-function-based method for extending discrete chaotic maps,enabling flexible construction of multicavity chaotic attractors.The proposed method achieves one-directional(1D)/two-directional(2D)extensions without introducing additional nonlinear terms or altering system stability.Theoretically,the cavity quantity in arbitrary directions is controlled by adjusting impulse levels N,while the amplitude regulation is implemented through modifications to the proportionality parameter r.Theoretical analyses,including Lyapunov exponents(LEs)and bifurcation diagrams,are conducted,confirming that the extended maps retain the intrinsic dynamics of five rational map classes.The field-programmable gate array(FPGA)implementation results are consistent with the numerical simulation results,verifying the correctness of the theoretical analysis.The method enables the expansion of unipolar attractors and enhances entropy metrics,offering a robust framework for applications in secure communication,encryption,and chaos-based technologies.展开更多
This paper introduce the concept of locally quasidiagonal extension of C^(*)-algebras and give some basic properties.We use the method of analogy,based on some properties possessed by quasidiagonal extensions,we inves...This paper introduce the concept of locally quasidiagonal extension of C^(*)-algebras and give some basic properties.We use the method of analogy,based on some properties possessed by quasidiagonal extensions,we investigate whether local quasidiagonal extensions still retain these properties.We then show that an extension of a locally AF algebra by a locally AF algebra is a locally quasidiagonal extension.展开更多
Mesoscale air-sea interactions play a critical role in damping eddy activities.However,how mesoscale heat flux influences the distribution of eddy kinetic energy(EKE)in the wavenumber space remains unclear.In this stu...Mesoscale air-sea interactions play a critical role in damping eddy activities.However,how mesoscale heat flux influences the distribution of eddy kinetic energy(EKE)in the wavenumber space remains unclear.In this study,we investigate the EKE and temperature variance(T_(var))budgets in the Kuroshio Extension(KE)region using wavenumber spectral analysis based on 1/10°coupled climate simulations.These simulations include a standard high-resolution simulation and a smoothed simulation that overlooks mesoscale heat flux.By comparing the differences between these models,we confirm that air-sea heat exchange significantly dissipates Tvar.Neglecting mesoscale heat flux results in a 60% underestimation of the Tvar damping rate,which in turn increases energy transfer to EKE through the vertical buoyancy flux by 22%.This enhanced vertical buoyancy flux leads to a 20% higher EKE level and larger energy budget terms,particularly in the diffusion term,which is closely related to wind power.Furthermore,underestimating air-sea heat exchange could lead to an overestimation of the inverse kinetic energy cascade,thereby distorting the overall energy budget in the KE region.展开更多
文摘Higher Himalayan Crystalline (HHC) rocks often show metamorphic zonations from lower greenschist facies to migmatites associated with leucogranite intrusions that are classically described as examples of Tertiary inverted metamorphism. The present study, based on structural, petrological and geochronological investigations in the Kinnar Kailas Granite (KKG) and surrounding HHC sequence, evidences a discordant intrusive contact of the Ordovician KKG with respect to Pre\|Alpine high grade deformed HHC sequence in the Sutlej valley.Four main phases of deformation are recorded in this HHC sequence and pre\|Ordovician sediments. The first three phases of deformation occurred under high\|grade metamorphic conditions, before the intrusion of the KKG. The geometry of the main progressive ductile deformation (D2—D3) results from SW vergent doming and migmatisation. The latest deformation is expressed by local shearing under greenschist facies conditions. This late D4 deformation corresponds to N—S oriented ductile normal faults lowering the eastern blocks. The KKG is a shallow depth intrusion, showing discordant contacts with the surrounding basement rocks and large scale magmatic stoping. The KKG crosscuts the high\|grade deformation structures (D2—D3) but is locally affected by the local late D4 extensional deformation. The granite textures reflect only slight orientation related to magmatic deformation and even at few centimetres from the intrusion contact, the granite appears undeformed in contrast to the surrounding highly foliated rocks. Furthermore, xenoliths of Kyanite\|Sillimanite bearing basement rocks are present within the KKG.
基金supported by the National Natural Science Foundation of China(42372250,42102262 and 41972235)National Key Research and Development Program Project(2023YFF0803701)+1 种基金Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(SML2023SP206)the program of China Scholarship Council。
文摘The Shenshan Group provides important geological information which is vital in unraveling the amalgamation and subsequent rifting processes of South China.While conventional studies have asserted its formation in a subduction setting,the distinct investigation reveals the necessity for reassessment.To address this,the authors employ integrated methods encompassing petrological,zircon U-Pb geochronological,Lu-Hf isotopic and geochemical methods for sedimentary rocks from the upper Shenshan subgroup and Banxi Group.The geochemical results indicate that they were formed through the recycling deposition of intermediate-acidic igneous source material and experienced moderate chemical weathering.Additionally,both sedimentary sequences exhibit characteristics consistent with those formed in an intracontinental extensional rift setting since ca.810 Ma.The provenance analysis indicates that the upper Shenshan subgroup primarily originates from the Yangtze Domain,while the Banxi Group from both the Yangtze and Cathaysia domains.Synthesizing with previous studies,the Shenshan Group should be subdivided into the lower and upper subgroups which represent distinct tectonic backgrounds.The lower subgroup is inferred to have formed in an Early Neoproterozoic fore-arc setting,akin to the Zhoutan group.The upper subgroup corresponds to the Banxi Group,representing the Middle Neoproterozoic postorogenic rift setting,responding to the breakup of Rodinia.
基金supported China Postdoctoral Science Foundation (Grant No. 2011M500991)Basic Scientific Research Specific Foundation of Second Insitute of Oceanography, SIO (Grant No. JT1104)
文摘This work studies new petrological and geochemical data and zircon U-Pb ages for bimodal intrusive rocks from Xinglong re- gion, Hainan Island. Zircon U-Pb dating yields mean 238U/26pb ages of 238 ± 2 Ma and 234±2 Ma for diabasic and granitic phases, respectively, representing the Middle Triassic emplacement. The diabase and granite bodies were formed from discrete mafic and acidic magma sources that experienced local mechanical mixing at their mutual contacts. Although SiO2 content of intrusions is bimodal, trace element ratios indicate that both were formed in a post-orogenic extensional setting. Sr-Nd isotopic composition reflects a shared EMII type enriched mantle source component, possibly influenced by subduction-fluid metaso- matism.
文摘The Xikuangshan antimony deposit in central Hunan, South China, is the largest antimony deposit ever known in the world. The ore bodies are strictly confined to the footwalls of mafor high-angle normal faults which transect the inclined folds in the flank;away from the fault planes,both the homogenization temperatures of inclusions in gangue minerals and the intensity of antimony mineralization decrease.These characteristics strongly demonstrate that the faults are used as the conduit for the metal-bearing fluid in mineralization.The normal faults,striking the NE to NNE,are interpreted to be generated by the postmgenic extension in the time from Cretaceous to Paleogene.Crustal or lithospheric thinning, directly resulting from regional extension inevitably increase the geothermal gradient, Which is likely to cause large-scale convection of underground water that may leach out and transport valuablemetals such as Sb from source rocks.Focussed discharge along the fault zones contributes to the formation of the supergiant antimony deposit in Xikuangshan under the appropriate sedimentary barrier.
基金Supported by NSF of Jiangsu Province(No.BK20171421)。
文摘This paper introduced the concept of generalized quasidiagonal extension of C^(*)-algebras and gave some basic properties.We show that the extension algebra preserves quasidiagonality and finitary in generalized quasidiagonal extension.We give also an example of generalized quasidiagonal extension,which is not quasidiagonal extension.
基金supported by the National Natural Science Foundation of China(Grant Nos:42130801,41430211,90814006,and 42072226)the“Deep-time Digital Earth”Science and Technology Leading Talents Team Funds for the Central Universities for the Frontiers Science Center for Deep-time Digital Earth,CUGB(Fundamental Research Funds for the Central UniversitiesGrant No:2652023001).
文摘How the subduction direction of the Paleo-Pacific plate beneath the Eurasian plate changes in the Early Cretaceous remains highly controversial due to the disappearance of the subducted oceanic plate.Intraplate deformation structures in the east Asian continent,however,provide excellent opportunities for reconstructing paleostress fields in continental interior in relation to the Paleo-Pacific/Eurasian plate interaction.Anisotropy of magnetic susceptibility(AMS),geological,and geochronological analyses of post-kinematic mafic dykes intruding the detachment fault zone of the Wulian metamorphic core complex(WL MCC)in Jiaodong Peninsula exemplify emplacement of mantle-sourced dykes in a WNW-ESE(301°-121°)oriented tectonic extensional setting at ca.120 Ma.In combination with the results from our previous kinematic analysis of the MCC,a ca.21°clockwise change in the direction of intraplate extension is obtained for early(135-122 Ma)extensional exhumation of the MCC to late(122-108 Ma)emplacement of the dykes.Such a change is suggested to be related to the variation in subduction direction of the Paleo-Pacific plate beneath the Eurasian plate,from westward(pre-122 Ma)to west-northwestward(post-122 Ma).
基金National Natural Science Foundation of China(12161013)Research Projects of Guizhou University of Commerce in 2024。
文摘The modifiedλ-differential Lie-Yamaguti algebras are considered,in which a modifiedλ-differential Lie-Yamaguti algebra consisting of a Lie-Yamaguti algebra and a modifiedλ-differential operator.First we introduce the representation of modifiedλ-differential Lie-Yamaguti algebras.Furthermore,we establish the cohomology of a modifiedλ-differential Lie-Yamaguti algebra with coefficients in a representation.Finally,we investigate the one-parameter formal deformations and Abelian extensions of modifiedλ-differential Lie-Yamaguti algebras using the second cohomology group.
基金The National Natural Science Foundation of China under contract Nos 42176067,41576069,47906197 and 42206066the National Key R&D Program of China under contract No.2024YFF0506701the Project of Impact and Response of Antarctic Seas to Climate Change under contract No.IRASCC01-03-01.
文摘The Ross Sea basins,shaped by Late Cretaceous and Cenozoic extension within the crust of the Ross Sea,represent key regions for understanding continental rifting processes.However,the dynamic mechanisms driving the transition from diffuse extension to focused extension in these basins remain poorly understood.Here,we provide a comprehensive model of crustal extension in the Ross Sea basins,detailing the kinematic and dynamic evolution from 100 Ma to the present on the basis of published finite rotation poles.Our model illuminates the complex relative motions between the West Antarctic and East Antarctic Plates and quantifies the crustal strain rates associated with their relative movements.We show that West Antarctica began to move away slowly from the East Antarctic and rotated clockwise at approximately 53 Ma,and the motion progressively decreased until it ceased at approximately 11 Ma.This kinematic shift temporally coincided with the onset of focused rifting,indicating a transition from broadly distributed extension in the eastern Ross Sea to localized deformation in the western basin.Time-resolved strain rate fields further reveal several hundred kilometers of total crustal extension,suggesting a primary influence of evolving plate motions over passive lithospheric weakening.These findings refine the tectonic history of the Ross Sea and provide a reproducible framework linking rift basin evolution to global plate motion.
基金supported by the National Key R&D Program of China[Grant No.2022YFC2402400]the National Natural Science Foundation of China[Grant No.62275062]+2 种基金Project of Shandong Innovation and Startup Community of High-end Medical Apparatus and Instruments[Grant Nos.2023-SGTTXM-002 and 2024-SGTTXM-005]the Shandong Province Technology Innovation Guidance Plan(Central Leading Local Science and Technology Development Fund)[Grant No.YDZX2023115]the Taishan Scholar Special Funding Project of Shandong Province,and the Shandong Laboratory of Advanced Biomaterials and Medical Devices in Weihai[Grant No.ZL202402].
文摘Optical-resolution photoacoustic microscopy is a novel imaging technique that combines the advantages of optical and ultrasound imaging,enabling high-resolution visualization of biological tissues at the micrometer scale.However,the divergence of the excited Gaussian beam limits the depth-of-field of the system to less than 100μm,which hinders accurate three-dimensional imaging of living tissues and restrictsits applicability in biological research.Therefore,there is an urgent need for an effective method to enhance the depth-of-field without altering the hardware configuration.This paper presents a photoacoustic microscopy depth-of-field extension method and system based on three-dimensional continuity and sparsity deconvolution.This method utilizes a depth-varying point spread function and incorporates continuity and sparsity con-straints into the deconvolution process to mitigate the effect of background noise,enhancing the stability and accuracy of the depth-of-field extension.Experimental results using tungsten wire phantoms suggest that the depth-of-field of system can be extended to 650 pm,which is 7.2 times greater than conventional system,while improving the resolution of the defocused region by an average factor of 3.5.Furthermore,experiments on zebrafish and nude mouse ears with irregular topologies demonstrate that the proposed method successfully overcomes image blurring and the loss of structural information due to limited depth-of-field.All the results suggest that the system with higher lateral resolution and enhanced depth-of-field has significant potential for a wide range of practical biomedical applications.
基金supported by the China Geological Survey Program(Grant No.DD20220989)the National Natural Science Foundation of China(Grant No.41972118)。
文摘The tectonic setting of the Himalaya during the Early Paleozoic has been a subject of enduring debate within the scientific community.Newly discovered bimodal intrusive rocks from comprehensive field geological investigation in the central mountain range were subjected to petrology,zircon U-Pb geochronology,zircon Hf isotopes and whole-rock geochemistry analyses.The Palie bimodal intrusive rocks,comprising amphibolite and granitic gneiss,were formed at~489 Ma.The amphibolite exhibits geochemical characteristics consistent with N-MORB,while the granitic gneiss is classified as high potassium calc-alkaline peraluminous S-type granite.Both igneous rocks exhibit negative zirconε_(Hf)(t)values and display ancient T_(DM)^(C)ages.In conjunction with regional geological survey findings,it can be inferred that the formation of the Palie bimodal intrusive rocks occurred within a post-collision extensional tectonic setting.The amphibolite genesis involved partial melting of an enriched lithospheric mantle with some crustal assimilation,whereas the origin of the granitic gneiss can be attributed to partial melting of pre-existing felsic crust.Our data indicate that during the Early Paleozoic,the Himalaya underwent a transition from a pan-African collisional setting to post-collisional extensional tectonics.
基金Supported by the National Natural Science Foundation of China(Grant No.12161013)the Basic Research Program(Natural Science)of Guizhou Province(Grant No.ZK[2023]025).
文摘In this paper,we call a tuple consisting of 3-Lie algebra and a higher derivation on it a 3-LieHDer pair.We introduce a cohomology theory of 3-LieHDer pairs.Next,we interpret the second cohomology group as the space of all isomorphism classes of abelian extensions.Finally,we consider formal deformations of 3-LieHDer pairs that are governed by the cohomology with self-coefficient.
基金funded by Beasiswa Pendidikan Pascasarjana Dalam Negeri(BPPDN),Ministry of Education,Culture,Research,and Technology of the Republic of Indonesia。
文摘This study aimed to examine the influence of farmer characteristics and extension services on the sustainability of seaweed cultivation in three districts of Polewali Mandar Regency,West Sulawesi,namely Polewali,Binuang,and Wonomulyo.A total of 267 seaweed farmers were surveyed using a questionnaire,and the data were analyzed through multiple linear regression.Informed consent was obtained in writing from all participants before data collection.The results showed that farmer characteristics and extension services had a positive and significant effect on seaweed farming sustainability.These findings highlight the importance of strengthening both human capital and institutional support.Key farmer characteristics,such as education level,farming experience,motivation,and openness to innovation,play a vital role in sustaining seaweed businesses.Enhancing these competencies through training,formal and non-formal education,and capacity-building programs will improve farmers’ability to adopt sustainable practices,adapt to environmental changes,and increase productivity.Similarly,the significant role of extension services demonstrates the need for continuous technical assistance,knowledge transfer,and institutional backing.Improving extension systems by deploying more qualified field officers,conducting regular farm visits,and tailoring content to local contexts can bridge the gap between innovation and practice.Participatory extension models that engage farmers directly can further promote peer learning and community cohesion.At the policy level,this study supports integrating farmer capacity development and extension strengthening into regional agricultural and fisheries strategies to ensure long-term sustainability of seaweed farming.
基金Supported by the National Natural Science Foundation of China(Grant No.12161013)the School-Level Student Research Project of Guizhou University of Finance and Economics(Grant No.2024ZXSY239).
文摘In this paper,we introduce non-abelian cohomology groups and classify the nonabelian extensions of Rota-Baxter pre-Lie algebras in terms of non-abelian cohomology groups.Next,we explore the inducibility of pairs of automorphisms and derive the analog Wells exact sequences under the circumstance of Rota-Baxter pre-Lie algebras.Finally,we discuss the inducibility problem of pairs of automorphisms about an abelian extensions of Rota-Baxter pre-Lie algebras.
基金Project(52074352)supported by the National Natural Science Foundation of ChinaProject(2023JJ30680)supported by the National Science and Technology Major Project of China。
文摘After excavation,some of the surrounding rock mass is in a state of triaxial extension,exhibiting tensile or shear fracture modes.To study the energy mechanism of tensile fracture turning to shear fracture,a series of triaxial extension tests were conducted on sandstone under confining pressures of 10,30,50 and 70 MPa.Elastic energy and dissipated energy were separated by single unloading,the input energy u_(t),elastic energy u_(e),and dissipated energy u_(d)at different unloading stress levels were calculated by the integrating stress−strain curves.The results show that tensile cracks dominate fracture under lower confining pressure(10 MPa),and shear cracks play an increasingly important role in fracture as confining pressure increases(30,50 and 70 MPa).Based on the phenomenon that u_(e)and u_(d)increase linearly with increasing u_(t),a possible energy distribution mechanism of fracture mode transition under triaxial extension was proposed.In addition,it was found that peak energy storage capacity is more sensitive to confining pressure compared to elastic energy conversion capacity.
基金The National Natural Science Foundation of China under contract No.42276014Jiangsu Natural Resources Development Special Fund(Marine Science and Technology Innovation)under contract No.JSZRKJ202403.
文摘In this study,convolutional long short-term memory(ConvLSTM)model is used to predict sea level anomaly(SLA)in the Kuroshio Extension(KE)region,utilizing daily satellite altimetry data(1993-2016).The model captures regional averaged SLA variability,achieving a correlation coefficient of 0.98 for prediction horizon up to 23 d.Propagating features of Rossby waves are also reproduced in the prediction model.While in spatial,discrepancies between predicted SLA and observed SLA are quite large,especially in regions with strong eddy activities.Incorporating equation of motion for the 11/2-layer reduced-gravity model,the performance of the model has a significant improvement spatially and temporally.Challenges persist in high-variability regions,underscoring the need for advanced models.This study highlights ConvLSTM’s potential for SLA forecasting with wind driven physical constraints,offering insights into wind-driven and eddy-influenced processes in the KE region.
基金supported by the Open Fund of Hubei Key Laboratory of Construction Management in Hydropower Engineering(Grant No.2016KSD04)the Open Fund of Engineering Research Center of Eco-environment in Three Gorges Reservoir Region,Ministry of Education(Grant No.KF2016-11).
文摘Sponge city(SPC)is proposed to solve the issues such as the degradation of urban water ecosystem environment,imbalanced water resource allocation,urban water logging,and water contamination.The PPP(Public Private Partnership)model is combined to release the government pressure of SPC project construction.The development of the SPC-PPP model makes significant contributions to the sustainable development and the enhancement of urban resilience against water-related disasters.However,there is no scientific performance evaluation system on its operation period has been conducted.Therefore,the SPC-PPP Evaluation model aims to objectively and reasonably assess project effectiveness,promote its development and refine the evaluation framework.This paper has set up the MEE model for performance evaluation,with improved Matter-Element Extension method to assign values to the evaluation indices.The research results show that:(1)The MEE model is more accurate in the performance evaluation and its effectiveness is reflected in its ability to capture the correlation among different indices in the same membership,rather than merely focusing on individual indices.(2)The proposed approach provided a new aspect for performance evaluation,improving the accuracy of evaluation and promoting the development of SPC-PPP project.
基金supported by the National Natural Science Foundation of China(Grant No.62001391)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2024A1515010308)+1 种基金the Natural Science Basic Research Program of Shaanxi(Grant No.2024JC-YBQN-0464)the Scientific Research Program Funded by Education Department of Shaanxi Provincial Government(Grant No.24JK0559).
文摘This paper proposes a universal impulse-function-based method for extending discrete chaotic maps,enabling flexible construction of multicavity chaotic attractors.The proposed method achieves one-directional(1D)/two-directional(2D)extensions without introducing additional nonlinear terms or altering system stability.Theoretically,the cavity quantity in arbitrary directions is controlled by adjusting impulse levels N,while the amplitude regulation is implemented through modifications to the proportionality parameter r.Theoretical analyses,including Lyapunov exponents(LEs)and bifurcation diagrams,are conducted,confirming that the extended maps retain the intrinsic dynamics of five rational map classes.The field-programmable gate array(FPGA)implementation results are consistent with the numerical simulation results,verifying the correctness of the theoretical analysis.The method enables the expansion of unipolar attractors and enhances entropy metrics,offering a robust framework for applications in secure communication,encryption,and chaos-based technologies.
文摘This paper introduce the concept of locally quasidiagonal extension of C^(*)-algebras and give some basic properties.We use the method of analogy,based on some properties possessed by quasidiagonal extensions,we investigate whether local quasidiagonal extensions still retain these properties.We then show that an extension of a locally AF algebra by a locally AF algebra is a locally quasidiagonal extension.
基金supported by the Natu-ral Science Foundation of China and Fundamental Research Funds for the Central Universities(Grant Nos.42176006,42422601,202241006 to H.Y.)the Natural Science Foundation of China(Grant No.42225601 to Z.C.).
文摘Mesoscale air-sea interactions play a critical role in damping eddy activities.However,how mesoscale heat flux influences the distribution of eddy kinetic energy(EKE)in the wavenumber space remains unclear.In this study,we investigate the EKE and temperature variance(T_(var))budgets in the Kuroshio Extension(KE)region using wavenumber spectral analysis based on 1/10°coupled climate simulations.These simulations include a standard high-resolution simulation and a smoothed simulation that overlooks mesoscale heat flux.By comparing the differences between these models,we confirm that air-sea heat exchange significantly dissipates Tvar.Neglecting mesoscale heat flux results in a 60% underestimation of the Tvar damping rate,which in turn increases energy transfer to EKE through the vertical buoyancy flux by 22%.This enhanced vertical buoyancy flux leads to a 20% higher EKE level and larger energy budget terms,particularly in the diffusion term,which is closely related to wind power.Furthermore,underestimating air-sea heat exchange could lead to an overestimation of the inverse kinetic energy cascade,thereby distorting the overall energy budget in the KE region.
