Nonhuman primates are increasingly being used as animal models in neuroscience research.However,efficient neuronal tracing techniques for labeling motor neurons and primary sensory afferents in the monkey spinal cord ...Nonhuman primates are increasingly being used as animal models in neuroscience research.However,efficient neuronal tracing techniques for labeling motor neurons and primary sensory afferents in the monkey spinal cord are lacking.Here,by injecting the cholera toxin B subunit into the sciatic nerve of a rhesus monkey,we successfully labeled the motor neurons and primary sensory afferents in the lumbar and sacralspinal cord.Labeled alpha motor neurons were located in lamina IX of the L6–S1 segments,which innervate both flexors and extensors.The labeled primary sensory afferents were mainly myelinated Aβfibers that terminated mostly in laminae I and II of the L4–L7 segments.Together with the labeled proprioceptive afferents,the primary sensory afferents formed excitatory synapses with multiple types of spinal neurons.In summary,our methods successfully traced neuronal connections in the monkey spinal cord and can be used in spinal cord studies when nonhuman primates are used.展开更多
In the field of intelligent education,the integration of artificial intelligence,especially deep learning technologies,has garnered significant attention.Knowledge tracing(KT)plays a pivotal role in this field by pred...In the field of intelligent education,the integration of artificial intelligence,especially deep learning technologies,has garnered significant attention.Knowledge tracing(KT)plays a pivotal role in this field by predicting students’future performance through the analysis of historical interaction data,thereby assisting educators in evaluating knowledgemastery and tailoring instructional strategies.Traditional knowledge tracingmethods,largely based on Recurrent Neural Networks(RNNs)and Transformer models,primarily focus on capturing long-term interaction patterns in sequential data.However,these models may neglect crucial short-term dynamics and other relevant features.This paper introduces a novel approach to knowledge tracing by leveraging a pure Multilayer Perceptron(MLP)architecture.We proposeMixerKT,a knowledge tracing model based on theHyperMixer framework,which uniquely integrates global and localMixer feature extractors.This architecture enables more effective extraction of both long-terminteraction trends and recent learning behaviors,addressing limitations in currentmodels thatmay overlook these key aspects.Empirical evaluations on twowidely-used datasets,ASSIS Tments2009 and Algebra2005,demonstrate that MixerKT consistently outperforms several state-of-the-art models,including DKT,SAKT,and Separated Self-Attentive Neural Knowledge Tracing(SAINT).Specifically,MixerKT achieves higher prediction accuracy,highlighting its effectiveness in capturing the nuances of learners’knowledge states.These results indicate that our model provides a more comprehensive representation of student learning patterns,enhancing the ability to predict future performance with greater precision.展开更多
The present study focuses on the flow of a yield-stress(Bingham)nanofluid,consisting of suspended Fe3O4 nanoparticles,subjected to a magnetic field in a backward-facing step duct(BFS)configuration.The duct is equipped...The present study focuses on the flow of a yield-stress(Bingham)nanofluid,consisting of suspended Fe3O4 nanoparticles,subjected to a magnetic field in a backward-facing step duct(BFS)configuration.The duct is equipped with a cylindrical obstacle,where the lower wall is kept at a constant temperature.The yield-stress nanofluid enters this duct at a cold temperature with fully developed velocity.The aim of the present investigation is to explore the influence of flow velocity(Re=10 to 200),nanoparticle concentration(ϕ=0 to 0.1),magnetic field intensity(Ha=0 to 100),and its inclination angle(γ=0 to 90)and nanofluid yield stress(Bn=0 to 20)on the thermal and hydrodynamic efficiency inside the backward-facing step.The numerical results have been obtained by resolving the momentum and energy balance equations using the Galerkin finite element method.The obtained results have indicated that an increase in Reynolds number and nanoparticle volume fraction enhances heat transfer.In contrast,a significant reduction is observed with an increase in Hartmann and Bingham numbers,resulting in quasi-immobilization of the fluid under the magnetic influence and radical solidification of this type of fluid,accompanied by the suppression of the vortex zone downstream of the cylindrical obstacle.This study sheds light on the complexity of this magnetically influenced fluid,with potential implications in various engineering and materials science fields.展开更多
The opening of the Central South Atlantic and the consequent formation of the eastern Brazilian continental margin was marked by a complex history of mafic magmatism,carbonate sedimentation,and deposition of a thick s...The opening of the Central South Atlantic and the consequent formation of the eastern Brazilian continental margin was marked by a complex history of mafic magmatism,carbonate sedimentation,and deposition of a thick salt layer.The carbonates underlying the salt layer(pre-salt carbonates)were formed in restricted lacustrine basins.Here,the timing and fluid sources of deposition,diagenetic,and hydrothermal alterations of the pre-salt carbonate rocks are defined through in-situ U-Pb dating,87Sr/86Sr,and trace element analyses of samples from the Santos Basin.The very alkaline nature of the Aptian lake(s)produced characteristically unique and widely distributed carbonate rocks such as Mg-clays with calcite spherulite and calcite crystal shrub limestones transitioning laterally and vertically into travertines formed by hydrothermal pulses during basin evolution.Hydrothermalism caused extensive replacement,dissolution,and calcite cementation.REE+Y PAAS-normalised patterns and 87Sr/86Sr ratios indicate that deposition/eo-diagenesis of the primary carbonates occurred in a lacustrine environment primarily controlled by evaporation,pH,and continental water source,with 2%–10%hydrothermal fluid input.Trace elements and Sr-isotope of travertines and burial diagenetic phases show that they are produced from a hot mixture of mafic/mantle-derived fluids and dissolution/alteration of older carbonate formations.U-Pb dating indicates that carbonate deposition occurred between 124.8±2.6 Ma and 120.0±1.6 Ma,earlier than previously proposed,followed closely by the circulation of hydrothermal fluids.Replacement and cementation ages range from 120.5±2.4 Ma to 80.4±2.4 Ma.展开更多
Although ray tracing produces high-fidelity, realistic images, it is considered computationally burdensome when implemented on a high rendering rate system. Perception-driven rendering techniques generate images with ...Although ray tracing produces high-fidelity, realistic images, it is considered computationally burdensome when implemented on a high rendering rate system. Perception-driven rendering techniques generate images with minimal noise and distortion that are generally acceptable to the human visual system, thereby reducing rendering costs. In this paper, we introduce a perception-entropy-driven temporal reusing method to accelerate real-time ray tracing. We first build a just noticeable difference(JND) model to represent the uncertainty of ray samples and image space masking effects. Then, we expand the shading gradient through gradient max-pooling and gradient filtering to enlarge the visual receipt field. Finally, we dynamically optimize reusable time segments to improve the accuracy of temporal reusing. Compared with Monte Carlo ray tracing, our algorithm enhances frames per second(fps) by 1.93× to 2.96× at 8 to 16 samples per pixel, significantly accelerating the Monte Carlo ray tracing process while maintaining visual quality.展开更多
Upgrading of abundant cellulosic biomass to isosorbide can reduce the dependence on limited fossil resources and provide a sustainable way to produce isosorbide,utilized for polymers,medicine and health care product s...Upgrading of abundant cellulosic biomass to isosorbide can reduce the dependence on limited fossil resources and provide a sustainable way to produce isosorbide,utilized for polymers,medicine and health care product synth-esis.This review comprehensively examines the key steps and catalytic systems involved in the conversion of cel-lulose to isosorbide.Initially,the reaction pathway from cellulose to isosorbide is elucidated,emphasizing three critical steps:cellulose hydrolysis,glucose hydrogenation,and the two-step dehydration of sorbitol to produce isosorbide.Additionally,the activation energy and acidic sites during cellulose hydrolysis,the impact of metal particle size and catalyst support on hydrogenation,and the effects of catalyst acidity,pore structure,and reaction conditions on sorbitol dehydration have been thoroughly examined.Finally,the progress made in cellulose con-version to isosorbide is summarized,current challenges are highlighted,and future development trends are pro-jected in this review.展开更多
Background:Rabies virus(RABV)-derived neuronal tracing tools are extensively applied in retrograde tracing due to their strict retrograde transsynaptic transfer property and low neurotoxicity.However,the RABV infectio...Background:Rabies virus(RABV)-derived neuronal tracing tools are extensively applied in retrograde tracing due to their strict retrograde transsynaptic transfer property and low neurotoxicity.However,the RABV infection and expression of fluorescence products would be gradually cleared while the infected neurons still survive,a phenomenon known as non-cytolytic immune clearance(NCLIC).This phenomenon introduced the risk of fluorescence loss and led to the omission of a subset of neurons that should be labeled,thereby interfering in the analysis of tracing results.Methods:To compensate for the fluorescence loss problem,in this study,we developed a novel marker footprints(MF)mouse,involving a Cre recombinase-dependent red fluorescent reporter system and systemic expression of glycoprotein(G)and ASLV-A receptor(TVA).Using this mouse model combined with the well-developed RABV-EnvA-ΔG-GFP-Cre viral tool,we developed a novel green-to-red spectral labeling strategy.Results:Neurons in the MF mouse could be co-labeled with green fluorescence from the very quick expression of the viral tool and with red fluorescence from the relatively slow expression of the neuron itself,so neurons undergoing NCLIC with green fluorescence loss could be relabeled red.Furthermore,newly infected neurons could be labeled green and other neurons could be labeled yellow due to the temporal expression difference between the two fluorescent proteins.Conclusions:This is the first polysynaptic retrograde tracing labeling strategy that could label neurons using spectral fluorescence colors with only one injection of the viral tool,enabling its application in recognizing the labeling sequence of neurons in brain regions and enhancing the spatiotemporal resolution of neuronal tracing.展开更多
Advancements in artificial intelligence and big data technologies have led to the gradual emergence of intelligent ships,which are expected to dominate the future of maritime transportation.Supporting the navigation o...Advancements in artificial intelligence and big data technologies have led to the gradual emergence of intelligent ships,which are expected to dominate the future of maritime transportation.Supporting the navigation of intelligent ships,route planning technologies have developed many route planning algorithms that prioritize economy and safety.This paper conducts an in-depth study of algorithm efficiency for a route planning problem,proposing an intelligent ship route planning algorithm based on the adaptive step size Informed-RRT^(*).This algorithm can quickly plan a short route according to automatic obstacle avoidance and is suitable for planning the routes of intelligent ships.Results show that the adaptive step size Informed-RRT^(*) algorithm can shorten the optimal route length by approximately 13.05%while ensuring the running time of the planning algorithm and avoiding approximately 23.64%of redundant sampling nodes.The improved algorithm effectively circumvents unnecessary calculations and reduces a large amount of redundant sampling data,thus improving the efficiency of route planning.In a complex water environment,the unique adaptive step size mechanism enables this algorithm to prevent restricted search tree expansion,showing strong search ability and robustness,which is of practical significance for the development of intelligent ships.展开更多
Bionic microfluidics is garnering increasing attention due to the superior fluidic performance enabled by biomimetic microstructures.Inspired by the unique structures of young pumpkin stems,we fabricate helicoidally p...Bionic microfluidics is garnering increasing attention due to the superior fluidic performance enabled by biomimetic microstructures.Inspired by the unique structures of young pumpkin stems,we fabricate helicoidally patterned microchannels with precisely controlled morphologies using the projection micro-stereolithography(PμSL)-based 3D printing technique.Our helicoidally patterned microchannels achieve approximately twice the liquid lifting height compared to similarly sized smooth microchannels.This improvement is attributed to the enhanced capillary force.The additional meniscus formed between the helicoidally patterned microstructures significantly contributes to the increased capillary effects.Furthermore,the underlying mechanisms of fluidic performance in helicoidally patterned microchannels are theorized using a newly developed equation,which is also employed to optimize the geometric parameters and fluidic performance of the biomimetic helicoidal microchannels.Additionally,our biomimetic helicoidally patterned microchannels facilitate a significant step-lifting phenomenon,mimicking tall trees'transpiration.The fluidic performance of our biomimetic helicoidally patterned microchannels show promise for applications in enhanced liquid lifting,step-lifting,clean-water production,and others.展开更多
Cell lineage tracing is a key technology for describing the developmental history of individual progenitor cells and assembling them to form a lineage development tree.However,traditional methods have limitations of p...Cell lineage tracing is a key technology for describing the developmental history of individual progenitor cells and assembling them to form a lineage development tree.However,traditional methods have limitations of poor stability and insufficient reso-lution.As an efficient and flexible gene editing tool,CRISPR-Cas9 system has been widely used in biological research.Furthermore,CRISPR-Cas9 gene editing-based tracing methods can introduce fluorescent proteins,reporter genes,or DNA barcodes for high-throughput sequencing,enabling precise lineage analysis,significantly im-proving precision and resolution,and expanding its application range.In this review,we summarize applications of CRISPR-Cas9 system in cell lineage tracing,with special emphasis on its successful applications in traditional model animals(e.g.,zebrafish and mice),large animal models(pigs),and human cells or organoids.We also discussed its potential prospects and challenges in xenotransplantation and regenerative medicine.展开更多
Step heterostructures are predicted to hold a profound catalytic performance because of the rearranged electronic structure at their interface.However,limitations in the morphology of heterostructures prepared by hydr...Step heterostructures are predicted to hold a profound catalytic performance because of the rearranged electronic structure at their interface.However,limitations in the morphology of heterostructures prepared by hydrothermal reactions or molten salt-assisted strategies make it challenging to directly assess charge distribution and evaluate a single interface's hydrogen evolution reaction(HER)performance.Here,we prepared two-dimensional MoO_(2)/MoS_(2) step heterostructures with a large specific surface area by the chemical vapor deposition method.Surface Kelvin probe force microscopy and electrical transport measurement verified the asymmetric charge distribution at a single interface.By fabricating a series of micro on-chip electrocatalytic devices,we investigate the HER performance for a single interface and confirm that the interface is essential for superior catalytic performance.We experimentally confirmed that the enhancement of the HER performance of step heterostructure is attributed to the asymmetric charge distribution at the interface.This work lays a foundation for designing highly efficient catalytic systems based on step heterostructures.展开更多
The motivation of this paper is to explore the application of Step-Heating Thermography(SHT)as a technique capable of inspecting new composite rail carbodies using demanding requirements set by the rail manufacturing ...The motivation of this paper is to explore the application of Step-Heating Thermography(SHT)as a technique capable of inspecting new composite rail carbodies using demanding requirements set by the rail manufacturing industry.A large composite sample,with Polytetrafluoroethylene(PTFE)artificial defects,replicating a side-wall section of a new rail carbody,was manufactured and inspected for surface and subsurface defects in this research.The sample,characterized by its large thickness,consists of a monolithic Carbon Fibre Reinforced Polymers(CFRP)component(20mm thickness)and a CFRP-PET foam-CFRP sandwich(40mm total thickness)component fused together.The main challenge of the inspection procedure was to apply reflection mode thermography and detect defects in the entire thickness of the sample that exhibits both low emissivity and thermal insulating properties,especially at the sandwich sections of the sample.The paper explored thermography procedures that would be able to detect large numbers of defects under one single acquisition and would be applied under an automated inspection process leading to the detection of defects only up to 5mm in the CFRP sections of the sample while no defects were able to be detected at the back skin of the sample.展开更多
demand for faster vessels continues to grow,various high speed vessels have been designed and constructed for military,recreational,and passenger use.Planing vessels,specifically engineered for high-speed travel,requi...demand for faster vessels continues to grow,various high speed vessels have been designed and constructed for military,recreational,and passenger use.Planing vessels,specifically engineered for high-speed travel,require optimization to improve their hydrodynamic performance and stability during design.Reducing resistance and improving longitudinal stability are key challenges in the design of high-speed vessels.Various methods are employed to overcome these challenges,with the use of a transverse step being one of the most common approaches.This study explores the effect of changing the angle of the aft-wise step and incorporates these changes into existing analytical formulas,resulting in new formulas specifically for high-speed vessels equipped with aft-wise steps.This research investigates how the angle of the transverse step affects the hydrodynamic performance and longitudinal stability of high-speed vessels.Based on the results,analytical formulas have been developed to calculate the wetted surface parameters of vessels equipped with an aft-wise transverse step.The study used experimental methods to analyze the vessel's behavior with six different aft-wise transverse step angles of 0°,9°,11°,13°,15°,and 17°at three speeds of 8,10,and 12 m/s.In the experimental tests,the hydrodynamic components of resistance,trim angle,and wetted surface of the vessel were measured.Results indicate that creating an angle in the transverse step substantially improves the hydrodynamic components and longitudinal stability of the vessel.At the optimal angle,the resistance and trim angle of the vessel were reduced by 7.8%and 12.8%,respectively,compared to the base vessel.Additionally,the existing analytical methods for calculating the wetted surface area are more accurate than similar methods.展开更多
The art of polychrome lacquer painting with gold tracing and inlay represents the culmination of traditional Chinese lacquer craftsmanship.It integrates four core techniques-lacquer application,polychrome painting,gol...The art of polychrome lacquer painting with gold tracing and inlay represents the culmination of traditional Chinese lacquer craftsmanship.It integrates four core techniques-lacquer application,polychrome painting,gold tracing,and inlay-embodying the pinnacle of ancient artisan ingenuity.This paper begins by outlining the historical origins,technical characteristics,and cultural significance of this art form.Subsequently,using a Qing Dynasty“Hanging Screen Inlaid with Boxwood and Coral Depicting the Scene of Sudhana Paying Homage to Guanyin,with Polychrome Lacquer Painting and Gold Tracing”as a case study,it offers an in-depth analysis of its craftsmanship,visual elements,thematic narrative,and cultural connotations.The study aims to unveil its artistic value and contemporary relevance as a form of“living cultural heritage.”展开更多
Dear Editor,Sleep plays a vital role in physical health,influencing chronic diseases,memory,and overall quality of life[1,2].In recent years,the relationship between sleep health and physical activity has gained atten...Dear Editor,Sleep plays a vital role in physical health,influencing chronic diseases,memory,and overall quality of life[1,2].In recent years,the relationship between sleep health and physical activity has gained attention,with a particular focus on how daily step count affects various sleep metrics.展开更多
In this paper,a fu-Newton step interior-point algorithm is proposed for solving P_(*)(k)-linear complementarity problem based on a new search direction,which is an extension of Grimes'algorithm.It is proved that t...In this paper,a fu-Newton step interior-point algorithm is proposed for solving P_(*)(k)-linear complementarity problem based on a new search direction,which is an extension of Grimes'algorithm.It is proved that the number of iterations of the algorithm is O(n^(1/2)(1+4κ)logn/ε),which matches the best known iteration bound of the interior-point method for P_(*)(k)-linear complementarity problem.Some numerical results have proved the feasibility and efficiency of the proposed algorithm.展开更多
In the practical slope engineering,the stability of lower sliding mass(region A)with back tensile cracks of the jointed rock slope attracts more attentions,but the upper rock mass(region B)may also be unstable.Therefo...In the practical slope engineering,the stability of lower sliding mass(region A)with back tensile cracks of the jointed rock slope attracts more attentions,but the upper rock mass(region B)may also be unstable.Therefore,in this study,based on the stepped failure mode of bedding jointed rock slopes,considering the influence of the upper rock mass on the lower stepped sliding mass,the improved failure model for analyzing the interaction force(F_(AB))between two regions is constructed,and the safety factors(F_(S))of two regions and whole region are derived.In addition,this paper proposes a method to determine the existence of F_(AB) using their respective acceleration values(a_(A) and a_(B))when regions A and B are unstable.The influences of key parameters on two regions and the whole region are analyzed.The results show that the variation of the F_(AB) and F_(S) of two regions can be obtained accurately based on the improved failure model.The accuracy of the improved failure model is verified by comparative analysis.The research results can explain the interaction mechanism of two regions and the natural phenomenon of slope failure caused by the development of cracks.展开更多
基金supported by a grant from Ministry of Science and Technology China,No.2022ZD0204704(to WW)the National Natural Science Foundation of China,No.82301572(to XZ)the China Postdoctoral Science Foundation,No.2023M731202(to XZ)。
文摘Nonhuman primates are increasingly being used as animal models in neuroscience research.However,efficient neuronal tracing techniques for labeling motor neurons and primary sensory afferents in the monkey spinal cord are lacking.Here,by injecting the cholera toxin B subunit into the sciatic nerve of a rhesus monkey,we successfully labeled the motor neurons and primary sensory afferents in the lumbar and sacralspinal cord.Labeled alpha motor neurons were located in lamina IX of the L6–S1 segments,which innervate both flexors and extensors.The labeled primary sensory afferents were mainly myelinated Aβfibers that terminated mostly in laminae I and II of the L4–L7 segments.Together with the labeled proprioceptive afferents,the primary sensory afferents formed excitatory synapses with multiple types of spinal neurons.In summary,our methods successfully traced neuronal connections in the monkey spinal cord and can be used in spinal cord studies when nonhuman primates are used.
基金supported by National Natural Science Foundation of China(Nos.62266054 and 62166050)Key Program of Fundamental Research Project of Yunnan Science and Technology Plan(No.202201AS070021)+2 种基金Yunnan Fundamental Research Projects(No.202401AT070122)Yunnan International Joint Research and Development Center of China-Laos-Thailand Educational Digitalization(No.202203AP140006)Scientific Research Foundation of Yunnan Provincial Department of Education(No.2024Y159).
文摘In the field of intelligent education,the integration of artificial intelligence,especially deep learning technologies,has garnered significant attention.Knowledge tracing(KT)plays a pivotal role in this field by predicting students’future performance through the analysis of historical interaction data,thereby assisting educators in evaluating knowledgemastery and tailoring instructional strategies.Traditional knowledge tracingmethods,largely based on Recurrent Neural Networks(RNNs)and Transformer models,primarily focus on capturing long-term interaction patterns in sequential data.However,these models may neglect crucial short-term dynamics and other relevant features.This paper introduces a novel approach to knowledge tracing by leveraging a pure Multilayer Perceptron(MLP)architecture.We proposeMixerKT,a knowledge tracing model based on theHyperMixer framework,which uniquely integrates global and localMixer feature extractors.This architecture enables more effective extraction of both long-terminteraction trends and recent learning behaviors,addressing limitations in currentmodels thatmay overlook these key aspects.Empirical evaluations on twowidely-used datasets,ASSIS Tments2009 and Algebra2005,demonstrate that MixerKT consistently outperforms several state-of-the-art models,including DKT,SAKT,and Separated Self-Attentive Neural Knowledge Tracing(SAINT).Specifically,MixerKT achieves higher prediction accuracy,highlighting its effectiveness in capturing the nuances of learners’knowledge states.These results indicate that our model provides a more comprehensive representation of student learning patterns,enhancing the ability to predict future performance with greater precision.
文摘The present study focuses on the flow of a yield-stress(Bingham)nanofluid,consisting of suspended Fe3O4 nanoparticles,subjected to a magnetic field in a backward-facing step duct(BFS)configuration.The duct is equipped with a cylindrical obstacle,where the lower wall is kept at a constant temperature.The yield-stress nanofluid enters this duct at a cold temperature with fully developed velocity.The aim of the present investigation is to explore the influence of flow velocity(Re=10 to 200),nanoparticle concentration(ϕ=0 to 0.1),magnetic field intensity(Ha=0 to 100),and its inclination angle(γ=0 to 90)and nanofluid yield stress(Bn=0 to 20)on the thermal and hydrodynamic efficiency inside the backward-facing step.The numerical results have been obtained by resolving the momentum and energy balance equations using the Galerkin finite element method.The obtained results have indicated that an increase in Reynolds number and nanoparticle volume fraction enhances heat transfer.In contrast,a significant reduction is observed with an increase in Hartmann and Bingham numbers,resulting in quasi-immobilization of the fluid under the magnetic influence and radical solidification of this type of fluid,accompanied by the suppression of the vortex zone downstream of the cylindrical obstacle.This study sheds light on the complexity of this magnetically influenced fluid,with potential implications in various engineering and materials science fields.
基金C.Lana and F.F.Alkmim benefit from the Brazilian National Research Council(CNPq)research grants 3073353/2019-2 and 311543/2020-0.C.Lana,F.F.Alkmim,and Maria Eugênia Souza are part of the Instituto GeoAtlântico,a National Institute of Science and Technology,CNPq-Brazil process 405653/2022-0We acknowledge Petrobras’s support during the investigation and permission to publish this study.I.Figueiredo acknowledged the Brazilian Federal Agency for Support and Evaluation of Graduate Education(CAPES)for Master's scholarship 88887.816343/2023-00.
文摘The opening of the Central South Atlantic and the consequent formation of the eastern Brazilian continental margin was marked by a complex history of mafic magmatism,carbonate sedimentation,and deposition of a thick salt layer.The carbonates underlying the salt layer(pre-salt carbonates)were formed in restricted lacustrine basins.Here,the timing and fluid sources of deposition,diagenetic,and hydrothermal alterations of the pre-salt carbonate rocks are defined through in-situ U-Pb dating,87Sr/86Sr,and trace element analyses of samples from the Santos Basin.The very alkaline nature of the Aptian lake(s)produced characteristically unique and widely distributed carbonate rocks such as Mg-clays with calcite spherulite and calcite crystal shrub limestones transitioning laterally and vertically into travertines formed by hydrothermal pulses during basin evolution.Hydrothermalism caused extensive replacement,dissolution,and calcite cementation.REE+Y PAAS-normalised patterns and 87Sr/86Sr ratios indicate that deposition/eo-diagenesis of the primary carbonates occurred in a lacustrine environment primarily controlled by evaporation,pH,and continental water source,with 2%–10%hydrothermal fluid input.Trace elements and Sr-isotope of travertines and burial diagenetic phases show that they are produced from a hot mixture of mafic/mantle-derived fluids and dissolution/alteration of older carbonate formations.U-Pb dating indicates that carbonate deposition occurred between 124.8±2.6 Ma and 120.0±1.6 Ma,earlier than previously proposed,followed closely by the circulation of hydrothermal fluids.Replacement and cementation ages range from 120.5±2.4 Ma to 80.4±2.4 Ma.
基金supported by the National Natural Science Foundation of China (No.U19A2063)the Jilin Provincial Science&Technology Development Program of China (No.20230201080GX)。
文摘Although ray tracing produces high-fidelity, realistic images, it is considered computationally burdensome when implemented on a high rendering rate system. Perception-driven rendering techniques generate images with minimal noise and distortion that are generally acceptable to the human visual system, thereby reducing rendering costs. In this paper, we introduce a perception-entropy-driven temporal reusing method to accelerate real-time ray tracing. We first build a just noticeable difference(JND) model to represent the uncertainty of ray samples and image space masking effects. Then, we expand the shading gradient through gradient max-pooling and gradient filtering to enlarge the visual receipt field. Finally, we dynamically optimize reusable time segments to improve the accuracy of temporal reusing. Compared with Monte Carlo ray tracing, our algorithm enhances frames per second(fps) by 1.93× to 2.96× at 8 to 16 samples per pixel, significantly accelerating the Monte Carlo ray tracing process while maintaining visual quality.
文摘Upgrading of abundant cellulosic biomass to isosorbide can reduce the dependence on limited fossil resources and provide a sustainable way to produce isosorbide,utilized for polymers,medicine and health care product synth-esis.This review comprehensively examines the key steps and catalytic systems involved in the conversion of cel-lulose to isosorbide.Initially,the reaction pathway from cellulose to isosorbide is elucidated,emphasizing three critical steps:cellulose hydrolysis,glucose hydrogenation,and the two-step dehydration of sorbitol to produce isosorbide.Additionally,the activation energy and acidic sites during cellulose hydrolysis,the impact of metal particle size and catalyst support on hydrogenation,and the effects of catalyst acidity,pore structure,and reaction conditions on sorbitol dehydration have been thoroughly examined.Finally,the progress made in cellulose con-version to isosorbide is summarized,current challenges are highlighted,and future development trends are pro-jected in this review.
基金Hubei Natural Science Foundation of China,Grant/Award Number:2024AFB593。
文摘Background:Rabies virus(RABV)-derived neuronal tracing tools are extensively applied in retrograde tracing due to their strict retrograde transsynaptic transfer property and low neurotoxicity.However,the RABV infection and expression of fluorescence products would be gradually cleared while the infected neurons still survive,a phenomenon known as non-cytolytic immune clearance(NCLIC).This phenomenon introduced the risk of fluorescence loss and led to the omission of a subset of neurons that should be labeled,thereby interfering in the analysis of tracing results.Methods:To compensate for the fluorescence loss problem,in this study,we developed a novel marker footprints(MF)mouse,involving a Cre recombinase-dependent red fluorescent reporter system and systemic expression of glycoprotein(G)and ASLV-A receptor(TVA).Using this mouse model combined with the well-developed RABV-EnvA-ΔG-GFP-Cre viral tool,we developed a novel green-to-red spectral labeling strategy.Results:Neurons in the MF mouse could be co-labeled with green fluorescence from the very quick expression of the viral tool and with red fluorescence from the relatively slow expression of the neuron itself,so neurons undergoing NCLIC with green fluorescence loss could be relabeled red.Furthermore,newly infected neurons could be labeled green and other neurons could be labeled yellow due to the temporal expression difference between the two fluorescent proteins.Conclusions:This is the first polysynaptic retrograde tracing labeling strategy that could label neurons using spectral fluorescence colors with only one injection of the viral tool,enabling its application in recognizing the labeling sequence of neurons in brain regions and enhancing the spatiotemporal resolution of neuronal tracing.
文摘Advancements in artificial intelligence and big data technologies have led to the gradual emergence of intelligent ships,which are expected to dominate the future of maritime transportation.Supporting the navigation of intelligent ships,route planning technologies have developed many route planning algorithms that prioritize economy and safety.This paper conducts an in-depth study of algorithm efficiency for a route planning problem,proposing an intelligent ship route planning algorithm based on the adaptive step size Informed-RRT^(*).This algorithm can quickly plan a short route according to automatic obstacle avoidance and is suitable for planning the routes of intelligent ships.Results show that the adaptive step size Informed-RRT^(*) algorithm can shorten the optimal route length by approximately 13.05%while ensuring the running time of the planning algorithm and avoiding approximately 23.64%of redundant sampling nodes.The improved algorithm effectively circumvents unnecessary calculations and reduces a large amount of redundant sampling data,thus improving the efficiency of route planning.In a complex water environment,the unique adaptive step size mechanism enables this algorithm to prevent restricted search tree expansion,showing strong search ability and robustness,which is of practical significance for the development of intelligent ships.
基金supported by National Natural Science Foundation of China through Grant Nos.52495000,52332012 and 52176093partially supported by Beijing Huiyangdao Health Technology Co.,Ltd。
文摘Bionic microfluidics is garnering increasing attention due to the superior fluidic performance enabled by biomimetic microstructures.Inspired by the unique structures of young pumpkin stems,we fabricate helicoidally patterned microchannels with precisely controlled morphologies using the projection micro-stereolithography(PμSL)-based 3D printing technique.Our helicoidally patterned microchannels achieve approximately twice the liquid lifting height compared to similarly sized smooth microchannels.This improvement is attributed to the enhanced capillary force.The additional meniscus formed between the helicoidally patterned microstructures significantly contributes to the increased capillary effects.Furthermore,the underlying mechanisms of fluidic performance in helicoidally patterned microchannels are theorized using a newly developed equation,which is also employed to optimize the geometric parameters and fluidic performance of the biomimetic helicoidal microchannels.Additionally,our biomimetic helicoidally patterned microchannels facilitate a significant step-lifting phenomenon,mimicking tall trees'transpiration.The fluidic performance of our biomimetic helicoidally patterned microchannels show promise for applications in enhanced liquid lifting,step-lifting,clean-water production,and others.
基金supported by Institute of Laboratory Animal Sciences,Chinese Academy of Medical Sciences and Comparative Medicine Center,Peking Union Medical College,Collaborative Innovation Program of the Chinese Academy of Sciences(22SH19)Nonprofit Central Research Institute Fund of Chinese Academy of Medical Sciences(2023-PT180-01).
文摘Cell lineage tracing is a key technology for describing the developmental history of individual progenitor cells and assembling them to form a lineage development tree.However,traditional methods have limitations of poor stability and insufficient reso-lution.As an efficient and flexible gene editing tool,CRISPR-Cas9 system has been widely used in biological research.Furthermore,CRISPR-Cas9 gene editing-based tracing methods can introduce fluorescent proteins,reporter genes,or DNA barcodes for high-throughput sequencing,enabling precise lineage analysis,significantly im-proving precision and resolution,and expanding its application range.In this review,we summarize applications of CRISPR-Cas9 system in cell lineage tracing,with special emphasis on its successful applications in traditional model animals(e.g.,zebrafish and mice),large animal models(pigs),and human cells or organoids.We also discussed its potential prospects and challenges in xenotransplantation and regenerative medicine.
基金National Natural Science Foundation of China,Grant/Award Numbers:52288102,52090022,62274087,52472306Science Research Project of Hebei Education Department,Grant/Award Number:BJ2021040Natural Science Foundation of Hebei Province of China,Grant/Award Numbers:E2024203054,E2022203109。
文摘Step heterostructures are predicted to hold a profound catalytic performance because of the rearranged electronic structure at their interface.However,limitations in the morphology of heterostructures prepared by hydrothermal reactions or molten salt-assisted strategies make it challenging to directly assess charge distribution and evaluate a single interface's hydrogen evolution reaction(HER)performance.Here,we prepared two-dimensional MoO_(2)/MoS_(2) step heterostructures with a large specific surface area by the chemical vapor deposition method.Surface Kelvin probe force microscopy and electrical transport measurement verified the asymmetric charge distribution at a single interface.By fabricating a series of micro on-chip electrocatalytic devices,we investigate the HER performance for a single interface and confirm that the interface is essential for superior catalytic performance.We experimentally confirmed that the enhancement of the HER performance of step heterostructure is attributed to the asymmetric charge distribution at the interface.This work lays a foundation for designing highly efficient catalytic systems based on step heterostructures.
文摘The motivation of this paper is to explore the application of Step-Heating Thermography(SHT)as a technique capable of inspecting new composite rail carbodies using demanding requirements set by the rail manufacturing industry.A large composite sample,with Polytetrafluoroethylene(PTFE)artificial defects,replicating a side-wall section of a new rail carbody,was manufactured and inspected for surface and subsurface defects in this research.The sample,characterized by its large thickness,consists of a monolithic Carbon Fibre Reinforced Polymers(CFRP)component(20mm thickness)and a CFRP-PET foam-CFRP sandwich(40mm total thickness)component fused together.The main challenge of the inspection procedure was to apply reflection mode thermography and detect defects in the entire thickness of the sample that exhibits both low emissivity and thermal insulating properties,especially at the sandwich sections of the sample.The paper explored thermography procedures that would be able to detect large numbers of defects under one single acquisition and would be applied under an automated inspection process leading to the detection of defects only up to 5mm in the CFRP sections of the sample while no defects were able to be detected at the back skin of the sample.
文摘demand for faster vessels continues to grow,various high speed vessels have been designed and constructed for military,recreational,and passenger use.Planing vessels,specifically engineered for high-speed travel,require optimization to improve their hydrodynamic performance and stability during design.Reducing resistance and improving longitudinal stability are key challenges in the design of high-speed vessels.Various methods are employed to overcome these challenges,with the use of a transverse step being one of the most common approaches.This study explores the effect of changing the angle of the aft-wise step and incorporates these changes into existing analytical formulas,resulting in new formulas specifically for high-speed vessels equipped with aft-wise steps.This research investigates how the angle of the transverse step affects the hydrodynamic performance and longitudinal stability of high-speed vessels.Based on the results,analytical formulas have been developed to calculate the wetted surface parameters of vessels equipped with an aft-wise transverse step.The study used experimental methods to analyze the vessel's behavior with six different aft-wise transverse step angles of 0°,9°,11°,13°,15°,and 17°at three speeds of 8,10,and 12 m/s.In the experimental tests,the hydrodynamic components of resistance,trim angle,and wetted surface of the vessel were measured.Results indicate that creating an angle in the transverse step substantially improves the hydrodynamic components and longitudinal stability of the vessel.At the optimal angle,the resistance and trim angle of the vessel were reduced by 7.8%and 12.8%,respectively,compared to the base vessel.Additionally,the existing analytical methods for calculating the wetted surface area are more accurate than similar methods.
文摘The art of polychrome lacquer painting with gold tracing and inlay represents the culmination of traditional Chinese lacquer craftsmanship.It integrates four core techniques-lacquer application,polychrome painting,gold tracing,and inlay-embodying the pinnacle of ancient artisan ingenuity.This paper begins by outlining the historical origins,technical characteristics,and cultural significance of this art form.Subsequently,using a Qing Dynasty“Hanging Screen Inlaid with Boxwood and Coral Depicting the Scene of Sudhana Paying Homage to Guanyin,with Polychrome Lacquer Painting and Gold Tracing”as a case study,it offers an in-depth analysis of its craftsmanship,visual elements,thematic narrative,and cultural connotations.The study aims to unveil its artistic value and contemporary relevance as a form of“living cultural heritage.”
文摘Dear Editor,Sleep plays a vital role in physical health,influencing chronic diseases,memory,and overall quality of life[1,2].In recent years,the relationship between sleep health and physical activity has gained attention,with a particular focus on how daily step count affects various sleep metrics.
基金Supported by the Optimization Theory and Algorithm Research Team(23kytdzd004)the General Programs for Young Teacher Cultivation of Educational Commission of Anhui Province of China(YQYB2023090)the University Science Research Project of Anhui Province(2024AH050631)。
文摘In this paper,a fu-Newton step interior-point algorithm is proposed for solving P_(*)(k)-linear complementarity problem based on a new search direction,which is an extension of Grimes'algorithm.It is proved that the number of iterations of the algorithm is O(n^(1/2)(1+4κ)logn/ε),which matches the best known iteration bound of the interior-point method for P_(*)(k)-linear complementarity problem.Some numerical results have proved the feasibility and efficiency of the proposed algorithm.
基金Projects(52208369,52309138,52108320)supported by the National Natural Science Foundation of ChinaProjects(2023NSFSC0284,2025ZNSFSC0409)supported by the Sichuan Science and Technology Program,ChinaProject(U22468214)supported by the Joint Fund Project for Railway Basic Research by the National Natural Science Foundation of China and China State Railway Group Co.,Ltd.
文摘In the practical slope engineering,the stability of lower sliding mass(region A)with back tensile cracks of the jointed rock slope attracts more attentions,but the upper rock mass(region B)may also be unstable.Therefore,in this study,based on the stepped failure mode of bedding jointed rock slopes,considering the influence of the upper rock mass on the lower stepped sliding mass,the improved failure model for analyzing the interaction force(F_(AB))between two regions is constructed,and the safety factors(F_(S))of two regions and whole region are derived.In addition,this paper proposes a method to determine the existence of F_(AB) using their respective acceleration values(a_(A) and a_(B))when regions A and B are unstable.The influences of key parameters on two regions and the whole region are analyzed.The results show that the variation of the F_(AB) and F_(S) of two regions can be obtained accurately based on the improved failure model.The accuracy of the improved failure model is verified by comparative analysis.The research results can explain the interaction mechanism of two regions and the natural phenomenon of slope failure caused by the development of cracks.
