Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challe...Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challenges.In this work,we demonstrate for the firs time that the coherent radiation farfiel patterns from laser–foil interactions can serve as an in situ,real-time,and easy-to-implement diagnostic for an ultraintense laser focus.The laser-driven electron sheets,curved by the spatially varying laser fiel and leaving the targets at nearly the speed of light,produce doughnut-shaped patterns depending on the shapes of the focal spot and the absolute laser intensities.Assisted by particle-in-cell simulations,we can achieve measurements of the intensity and the focal spot,and provide immediate feedback to optimize the focal spots for extremely high intensity.展开更多
Gas-bearing shales have become a major source of future natural gas production worldwide.It has become increasingly urgent to develop a reliable prediction model and corresponding workflow for identifying shale gas sw...Gas-bearing shales have become a major source of future natural gas production worldwide.It has become increasingly urgent to develop a reliable prediction model and corresponding workflow for identifying shale gas sweet spots.The formation of gas-bearing shales is closely linked to relative sealevel changes,providing an important approach to predicting sweet spots in the Wufeng-Longmaxi shale in the southern Sichuan Basin,China.Three types of marine shale gas sweet spots are identified in the shale based on their formation stages combined with relative sea-level changes:early,middle,and late transgression types.This study develops a prediction model and workflow for identifying shale gas sweet spots by analyzing relative sea-level changes and facies sequences.Predicting shale gas sweet spots in an explored block using this model and workflow can provide a valuable guide for well design and hydraulic fracturing,significantly enhancing the efficiency of shale gas exploration and development.Notably,the new prediction model and workflow can be utilized for the rapid evaluation of the potential for shale gas development in new shale gas blocks or those with low exploratory maturity.展开更多
A low rare-earth containing ZEK100-O magnesium alloy was welded to AA1230-clad high-strength AA2024-T3 aluminum alloy via solidstate ultrasonic spot welding(USW)to evaluate the microstructure,tensile lap shear strengt...A low rare-earth containing ZEK100-O magnesium alloy was welded to AA1230-clad high-strength AA2024-T3 aluminum alloy via solidstate ultrasonic spot welding(USW)to evaluate the microstructure,tensile lap shear strength,and fatigue properties.The tensile strength increased with increasing welding energy,peaked at a welding energy of 1000 J,and then decreased due to the formation of an increasingly thick diffusion layer mainly containing Al12Mg17intermetallic compound at higher energy levels.The peak tensile lap shear strength attained at 1000 J was attributed to the optimal inter-diffusion between the magnesium alloy and softer AA1230-clad Al layer along with the presence of‘fishhook'-like mechanical interlocks at the weld interface and the formation of an indistinguishable intermetallic layer.The dissimilar joints welded at 1000 J also exhibited a longer fatigue life than other Mg-Al dissimilar joints,suggesting the beneficial role of the softer clad layer with a better intermingling capacity during USW.While the transverse-through-thickness(TTT)failure mode prevailed at lower cyclic loading levels,interfacial failure was the predominant mode of fatigue failure at higher cyclic loads,where distinctive fatigue striations were also observed on the fracture surface of the softer clad Al layer.This was associated with the presence of opening stress and bending moment near the nugget edge despite the tension-tension lap shear cyclic loading applied.展开更多
The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave...The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave infrared wavelengths as beacon light can reduce atmospheric absorption and signal attenuation.However,there are strong non-uniformity and blind pixels in the short-wave infrared image,which makes the image distorted and leads to the decrease of spot centroid positioning accuracy.Therefore,the high-precision localization of the spot centroid of the short-wave infrared images is of great research significance.A high-precision spot centroid positioning model for short-wave infrared is proposed to correct for non-uniformity and blind pixels in short-wave infrared images and quantify the localization errors caused by the two,further model-based localization error simulations are performed,and a novel spot centroid positioning payload for satellite laser communications has been designed using the latest 640×512 planar array InGaAs shortwave infrared detector.The experimental results show that the non-uniformity of the corrected image is reduced from 7%to 0.6%,the blind pixels rejection rate reaches 100%,the frame rate can be up to 2000 Hz,and the spot centroid localization accuracy is as high as 0.1 pixel point,which realizes high-precision spot centroid localization of high-frame-frequency short-wave infrared images.展开更多
This paper provide a comprehensive overview of research findings regarding the pathogen responsible for tobacco brown spot,its occurrence regularity,and integrated control strategies.Additionally,this study provide a ...This paper provide a comprehensive overview of research findings regarding the pathogen responsible for tobacco brown spot,its occurrence regularity,and integrated control strategies.Additionally,this study provide a brief analysis of the challenges encountered in the study of tobacco brown spot,which include the study of pathogenesis and virulence,the breeding of disease-resistant varieties,the screening of low-toxicity and high-efficiency agents,the development of biological control methods with more stable efficacy,and the necessity for accurate prediction and forecasting techniques.展开更多
Deep-sea aquaculture is an emerging trend due to the contamination and overexploitation of nearshore mariculture areas.However,the complex water conditions in the deep sea impose higher demands on the swimming perform...Deep-sea aquaculture is an emerging trend due to the contamination and overexploitation of nearshore mariculture areas.However,the complex water conditions in the deep sea impose higher demands on the swimming performance of farmed animals.Spotted sea bass(Lateolabrax maculatus)is one of the most economically important fish species in China.To investigate the mechanisms underlying the individual variations in swimming performance among spotted sea bass,we measured their critical swimming speed(U_(crit))and morphological phenotypes.Total length,body length,body weight,caudal region length,and condition factor showed significant positive correlations with absolute Ucrit.In contrast,caudal fin length and pectoral fin length tended to hinder the swimming performance of individual spotted sea bass.Additionally,white muscle tissues from fish exhibiting good swimming performance(relative U_(crit)>8.20 BL/s)and poor swimming performance(relative U_(crit)<7.31 BL/s)were sampled for RNA-seq.A total of 694 differential expression genes(DEGs)were identified through gene expression analysis,with significant enrichment in GO terms such as mitochondrial protein complex,ribosomal subunit,structural constituent of ribosome,and oxidative phosphorylation,as well as genes in KEGG pathways including ribosome and metabolic pathways.In conclusion,our study for the first time comprehensively elucidated the impact of morphology of spotted sea bass on its individual differences in swimming ability,and analyzed the genetic basis underlying swimming ability using transcriptomic methods.This study provides a theoretical basis for the potential breeding varieties of spotted sea bass suitable for deep-sea aquaculture.展开更多
Urea is a major end product of nitrogen catabolism,serving as an osmolyte to regulate osmotic stress in fish exposed to varying water environments.It has been well known that urea transporters(UTs)facilitate the rapid...Urea is a major end product of nitrogen catabolism,serving as an osmolyte to regulate osmotic stress in fish exposed to varying water environments.It has been well known that urea transporters(UTs)facilitate the rapid movement of urea across cell membranes.However,researches on ut genes were predominantly focused on elasmobranchs and early developmental stages of fish.In this investigation,a total of three ut genes were identified in spotted sea bass.Phylogenetic,homology,and syntenic analyses were conducted to validate the annotation and assess the evolutionary relationships among ut genes.Both ut-a and ut-b genes have retained their evolutionary stability,demonstrating a significant level of homology between them.To gain deeper insights into the evolution of ut genes in spotted sea bass,we performed selective pressure analysis using site,branch,and branch-site models.The results suggested that positive selection likely played a significant role in shaping the evolution of the ut gene family.Furthermore,tissue-specific expression analyses revealed high expression levels of ut genes in osmoregulatory tissues such as the gill and kidney.Additionally,all three ut genes exhibited salinity-related expression patterns in gill and kidney tissues during both seawater-to-freshwater(SF)and freshwater-to-seawater(FS)adaptation.In situ hybridization results demonstrated the localization of both ut-a and ut-c mRNAs on the gill lamellae and adjacent gill filament epithelium.In summary,our study establishes a solid foundation for future research elucidating the evolutionary relationships and functional significance of ut genes during salinity acclimation in spotted sea bass and other teleost species.展开更多
The crankshaft is subjected to complex rotational centrifugal force,periodic gas inertia force,and reciprocating inertia force during its working process.Consequently,the homogeneity requirement for crankshaft steel i...The crankshaft is subjected to complex rotational centrifugal force,periodic gas inertia force,and reciprocating inertia force during its working process.Consequently,the homogeneity requirement for crankshaft steel is exceptionally high.The distribution characteristics of center segregation and spot segregation of continuous casting bloom 42CrMoA crankshaft steel were analyzed by experiments,and the control mechanism of spot segregation by soft reduction zone and reduction amount was discussed.When the center solid fraction is between 0.61 and 1.00,an 8-mm soft reduction has a negligible impact on the flow of liquid steel at the end of solidification.Although it effectively improves center segregation,the improvement of spot segregation is limited.On the other hand,when the center solid fraction is between 0.31 and 1.00,a reduction of 10–12 mm,along with an expanded reduction zone and increased reduction amount,significantly promotes the flow of liquid steel at the end of solidification,reduces the size of equiaxed grains,mitigates the center negative segregation,and decreases the maximum size of spot segregation from 2954.29 to 1354.07μm.The number of spot segregations and the solutes enrichment degree of C,Cr,and Mn have also been significantly improved.An appropriate soft reduction zone and reduction amount can markedly ameliorate the semi-macro spot segregation of crankshaft steel blooms,thereby providing high-quality raw materials for subsequent products and enhancing the competitiveness of crankshaft products.展开更多
As NPC performances surge in popularity,destinations are recruiting actors and building story-driven scenes to reinvent traditional tourism Eight days,seven cities-a whirlwind tour that defined actor Zheng Guolin’s w...As NPC performances surge in popularity,destinations are recruiting actors and building story-driven scenes to reinvent traditional tourism Eight days,seven cities-a whirlwind tour that defined actor Zheng Guolin’s work schedule during the National Day holiday a month ago.From 1 to 8 October,he maintained a relentless pace,not just logging miles but also switching between roles.展开更多
Position-sensitive detector(PSD)is widely used in precision measurement fields such as flatness detection,auto-collimator systems,and degrees of freedom testing.However,due to factors such as uneven surface resistance...Position-sensitive detector(PSD)is widely used in precision measurement fields such as flatness detection,auto-collimator systems,and degrees of freedom testing.However,due to factors such as uneven surface resistance and differences in electrode structures,the nonlinearity of PSD becomes increasingly severe as the photosensitive surface moves from the center toward the edges of the four electrodes.To address this issue,a PSD nonlinearity correction algorithm is proposed.The algorithm utilizes the particle swarm optimization(PSO)algorithm to determine the optimal weights and thresholds,providing better initial parameters for the back propagation(BP)neural network.The BP neural network then iterates continuously until the error conditions are met,completing the correction process.Furthermore,a PSD nonlinearity correction system was developed,and the influence of different spot sizes on PSD positioning accuracy was simulated based on the current equation under the Gaussian spot model.This validated the robustness of the correction algorithm under varying spot sizes.The results demonstrate that the overall optimized error is reduced by 84.51%,and for spot sizes smaller than 1 mm,the error reduction exceeds 93.89%.This method not only meets the measurement accuracy requirements but also extends the measurement range of PSD.展开更多
Danxia Mountain scenic area is a famous world natural heritage site and national 5A tourist attraction in China.It is renowned for its unique Danxia landform and rich biodiversity,and it has high ecological,scientific...Danxia Mountain scenic area is a famous world natural heritage site and national 5A tourist attraction in China.It is renowned for its unique Danxia landform and rich biodiversity,and it has high ecological,scientific research,and tourism value.In recent years,the upgrading of consumption,the promotion of personalized and in-depth tourism,and the wide application of digital technology in culture and tourism have presented many challenges to the current marketing strategy of scenic spots.Based on the 7P marketing mix theory,this paper systematically analyzes the marketing strategy of the Danxia Mountain scenic area in seven dimensions:product,price,channel,promotion,personnel,tangible display,and service process.The analysis reveals several issues,including a limited product selection and a significant tendency toward homogenization.There is insufficient diversity in online and offline marketing channels,a lack of emotional resonance and international vision in promotional content,an imperfect professional talent echelon,traditional and interactive tangible displays,and an unbalanced service process system.These issues make it difficult to fully meet the needs of different customer groups.Based on this analysis,and considering the characteristics of the scenic spot’s resources and the tourism market’s trends,the paper offers targeted optimization suggestions.These include innovating experience projects,expanding marketing channels,strengthening talent cultivation,enriching tangible displays,and improving the service system.The aim is to enhance the market competitiveness and tourist satisfaction of scenic spots,promote the integration of culture and tourism while protecting natural heritage,and provide a reference for optimizing the marketing strategies of similar natural heritage sites.展开更多
Soybean frogeye leaf spot(FLS)disease is a worldwide disease caused by Cercospora sojina Hara.It is one of the major diseases suffered by soybean during the growth cycle,which seriously damages the yield and seed qual...Soybean frogeye leaf spot(FLS)disease is a worldwide disease caused by Cercospora sojina Hara.It is one of the major diseases suffered by soybean during the growth cycle,which seriously damages the yield and seed quality of soybean.The current resistant varieties are difficult to meet the production demand.The breeders have identified 50 different physiological small species and discussed the physiological and biochemical characteristics of soybean resistance to FLS.In soybean disease resistance breeding,resistance resources are screened for the main physiological races in different countries,resistance materials are created,more than 100 genome regions associated with resistance are located,and 12 resistance-related genes are identified.In order to promote the research of soybean disease resistance breeding,this paper expounded and analyzed the pathogenesis characteristics of soybean FLS,the division of races,the physiological and biochemical mechanism of soybean resistance to FLS disease,quantitative trait locus(QTL),quantitative trait nucleotides(QTN),genes of resistance sites,the screening of resistant germplasm resources,and the breeding of new varieties,so as to gain an in-depth understanding of the pathogenesis principle of soybean FLS disease.In order to provide a theoretical basis and technical support for the breeding of soybean FLS disease,the resistance mechanism of soybean FLS disease was analyzed from the molecular level.展开更多
As the power system transitions to a new green and low-carbon paradigm,the penetration of renewable energy in China’s power system is gradually increasing.However,the variability and uncertainty of renewable energy o...As the power system transitions to a new green and low-carbon paradigm,the penetration of renewable energy in China’s power system is gradually increasing.However,the variability and uncertainty of renewable energy output limit its profitability in the electricity market and hinder its market-based integration.This paper first constructs a wind-solar-thermalmulti-energy complementary system,analyzes its external game relationships,and develops a bi-level market optimization model.Then,it considers the contribution levels of internal participants to establish a comprehensive internal distribution evaluation index system.Finally,simulation studies using the IEEE 30-bus system demonstrate that the multi-energy complementary system stabilizes nodal outputs,enhances the profitability of market participants,and promotes the market-based integration of renewable energy.展开更多
Pinless friction stir spot welding(P-FSSW)was performed to manufacture Mg/steel lap joints.Orthogonal tests for P-FSSW of Mg/steel were investigated,and the main factors affecting the properties of Mg/steel lap joints...Pinless friction stir spot welding(P-FSSW)was performed to manufacture Mg/steel lap joints.Orthogonal tests for P-FSSW of Mg/steel were investigated,and the main factors affecting the properties of Mg/steel lap joints were derived.The shear force of the Mg/steel lap joints gradually increased and then decreased as the welding time increased.Maximum shear force was 5.3 kN.Fe-Al intermetallic compound(IMC)was formed at the Mg/steel interface near the steel side,and Mg-Al IMCs were formed at the Mg/steel interface near the Mg alloy side.Mg/steel lap joint was transformed from an initial solid-state welding to fusion-brazing welding as the welding time increased.No hole defects were formed in Mg/steel solid-state welding joints,whereas hole defects appeared in Mg/steel fusion-brazing welding joints.The temperature field of Mg/steel lap joints was simulated to analyze hole defects generated during the welding process.Hole defects can be eliminated by changing the spindle deflection angle,and the shear force decreased.Excessive spindle deflection can also lead to failure to form a stable joint.Hole defects were removed because the spindle deflection angle reduced the interfacial reaction temperature,and a solid-state welding joint was formed,which resulted in an absence of fusion-brazing welding hole formation.展开更多
Refill friction stir spot welding process is difficultly optimized by accurate modeling because of the high-order functional relationship between welding parameters and joint strength.A database of the welding process...Refill friction stir spot welding process is difficultly optimized by accurate modeling because of the high-order functional relationship between welding parameters and joint strength.A database of the welding process was first established with 6061-T6 aluminum alloy and DP780 galvanized steel as base materials.This dataset was then optimized using a backpropagation neural network.Analyses and mining of the experimental data confirmed the multidimensional mapping relationship between welding parameters and joint strength.Subsequently,intelligent optimization of the welding process and prediction of joint strength were achieved.At the predicted welding parameter(plunging rotation speedω1=1733 r/min,refilling rotation speedω_(2)=1266 r/min,plunging depth p=1.9 mm,and welding speed v=0.5 mm/s),the tensile shear fracture load of the joint reached a maximum value of 10,172 N,while the experimental result was 9980 N,with an error of 1.92%.Furthermore,the correlation of welding parameters-microstructure-joint strength was established.展开更多
Late leaf spot disease(LLS)is one of the most important diseases that cause severe yield losses in peanut.Peanut has various sources of resistance to LLS,so the identification of resistant quantitative trait loci(QTLs...Late leaf spot disease(LLS)is one of the most important diseases that cause severe yield losses in peanut.Peanut has various sources of resistance to LLS,so the identification of resistant quantitative trait loci(QTLs)and the development of related molecular markers are of great importance for the breeding of LLS-resistant peanut.In this study,173 individual lines of a recombinant inbred line(RIL)population and the 48K SNP array for genotyping were used to construct a high-density genetic map with 1,475 bin markers and 20 linkage groups.A total of 11 QTLs were obtained through QTL analysis using the constructed genetic map.Among them,the stable major QTL qLLS.LG02 was identified on linkage group 2 in all six environments,with the phenotypic variation explained(PVE)ranging from 15.57 to 31.09%.QTL-seq technology was also employed for a QTL analysis of LLS resistance.As a result,14 QTL loci related to LLS resistance were identified using the G prime algorithm.Notably,the physical positions of qLLS02 and qLLS03 coincided with those of qLLS.LG02 and qLLS.LG03,respectively.Gene annotation analysis within the 14 QTL intervals from QTL-seq revealed a total of 163 nucleotide-binding site-leucine-rich repeat(NBS-LRR)disease resistance genes,accounting for 22.86%of all resistance(R)genes in the peanut genome and showing a 4.26-fold enrichment with a P-value of 5.19e-57.Within the QTL region qLLS02 of the resistant parent Mi-2,there was a 5 Mb structural variation(SV)interval containing 81 NBS-LRR genes.A PCR diagnostic marker was developed,and validation data suggested that this SV might lead to gene deletion or replacement with other genes.This SV has the potential to enhance peanut resistance to LLS.The results of this study have significant implications for improving peanut breeding for LLS resistance through the development of associated molecular markers.展开更多
The uncertain nature of mapping user tasks to Virtual Machines(VMs) causes system failure or execution delay in Cloud Computing.To maximize cloud resource throughput and decrease user response time,load balancing is n...The uncertain nature of mapping user tasks to Virtual Machines(VMs) causes system failure or execution delay in Cloud Computing.To maximize cloud resource throughput and decrease user response time,load balancing is needed.Possible load balancing is needed to overcome user task execution delay and system failure.Most swarm intelligent dynamic load balancing solutions that used hybrid metaheuristic algorithms failed to balance exploitation and exploration.Most load balancing methods were insufficient to handle the growing uncertainty in job distribution to VMs.Thus,the Hybrid Spotted Hyena and Whale Optimization Algorithm-based Dynamic Load Balancing Mechanism(HSHWOA) partitions traffic among numerous VMs or servers to guarantee user chores are completed quickly.This load balancing approach improved performance by considering average network latency,dependability,and throughput.This hybridization of SHOA and WOA aims to improve the trade-off between exploration and exploitation,assign jobs to VMs with more solution diversity,and prevent the solution from reaching a local optimality.Pysim-based experimental verification and testing for the proposed HSHWOA showed a 12.38% improvement in minimized makespan,16.21% increase in mean throughput,and 14.84% increase in network stability compared to baseline load balancing strategies like Fractional Improved Whale Social Optimization Based VM Migration Strategy FIWSOA,HDWOA,and Binary Bird Swap.展开更多
基金supported by the Guangdong High Level Innovation Research Institute(Grant No.2021B0909050006)the National Grand Instrument Project(Grant No.2019YFF01014402)+1 种基金the National Natural Science Foundation of China(Grant No.12205008)support from the National Science Fund for Distinguished Young Scholars(Grant No.12225501)。
文摘Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challenges.In this work,we demonstrate for the firs time that the coherent radiation farfiel patterns from laser–foil interactions can serve as an in situ,real-time,and easy-to-implement diagnostic for an ultraintense laser focus.The laser-driven electron sheets,curved by the spatially varying laser fiel and leaving the targets at nearly the speed of light,produce doughnut-shaped patterns depending on the shapes of the focal spot and the absolute laser intensities.Assisted by particle-in-cell simulations,we can achieve measurements of the intensity and the focal spot,and provide immediate feedback to optimize the focal spots for extremely high intensity.
文摘Gas-bearing shales have become a major source of future natural gas production worldwide.It has become increasingly urgent to develop a reliable prediction model and corresponding workflow for identifying shale gas sweet spots.The formation of gas-bearing shales is closely linked to relative sealevel changes,providing an important approach to predicting sweet spots in the Wufeng-Longmaxi shale in the southern Sichuan Basin,China.Three types of marine shale gas sweet spots are identified in the shale based on their formation stages combined with relative sea-level changes:early,middle,and late transgression types.This study develops a prediction model and workflow for identifying shale gas sweet spots by analyzing relative sea-level changes and facies sequences.Predicting shale gas sweet spots in an explored block using this model and workflow can provide a valuable guide for well design and hydraulic fracturing,significantly enhancing the efficiency of shale gas exploration and development.Notably,the new prediction model and workflow can be utilized for the rapid evaluation of the potential for shale gas development in new shale gas blocks or those with low exploratory maturity.
基金the National Natural Science Foundation of China(Grant No.51971183)supported by OU(Osaka University,Japan)program for multilateral international collaboration research in joining and welding。
文摘A low rare-earth containing ZEK100-O magnesium alloy was welded to AA1230-clad high-strength AA2024-T3 aluminum alloy via solidstate ultrasonic spot welding(USW)to evaluate the microstructure,tensile lap shear strength,and fatigue properties.The tensile strength increased with increasing welding energy,peaked at a welding energy of 1000 J,and then decreased due to the formation of an increasingly thick diffusion layer mainly containing Al12Mg17intermetallic compound at higher energy levels.The peak tensile lap shear strength attained at 1000 J was attributed to the optimal inter-diffusion between the magnesium alloy and softer AA1230-clad Al layer along with the presence of‘fishhook'-like mechanical interlocks at the weld interface and the formation of an indistinguishable intermetallic layer.The dissimilar joints welded at 1000 J also exhibited a longer fatigue life than other Mg-Al dissimilar joints,suggesting the beneficial role of the softer clad layer with a better intermingling capacity during USW.While the transverse-through-thickness(TTT)failure mode prevailed at lower cyclic loading levels,interfacial failure was the predominant mode of fatigue failure at higher cyclic loads,where distinctive fatigue striations were also observed on the fracture surface of the softer clad Al layer.This was associated with the presence of opening stress and bending moment near the nugget edge despite the tension-tension lap shear cyclic loading applied.
基金Supported by the Short-wave Infrared Camera Systems(B025F40622024)。
文摘The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave infrared wavelengths as beacon light can reduce atmospheric absorption and signal attenuation.However,there are strong non-uniformity and blind pixels in the short-wave infrared image,which makes the image distorted and leads to the decrease of spot centroid positioning accuracy.Therefore,the high-precision localization of the spot centroid of the short-wave infrared images is of great research significance.A high-precision spot centroid positioning model for short-wave infrared is proposed to correct for non-uniformity and blind pixels in short-wave infrared images and quantify the localization errors caused by the two,further model-based localization error simulations are performed,and a novel spot centroid positioning payload for satellite laser communications has been designed using the latest 640×512 planar array InGaAs shortwave infrared detector.The experimental results show that the non-uniformity of the corrected image is reduced from 7%to 0.6%,the blind pixels rejection rate reaches 100%,the frame rate can be up to 2000 Hz,and the spot centroid localization accuracy is as high as 0.1 pixel point,which realizes high-precision spot centroid localization of high-frame-frequency short-wave infrared images.
文摘This paper provide a comprehensive overview of research findings regarding the pathogen responsible for tobacco brown spot,its occurrence regularity,and integrated control strategies.Additionally,this study provide a brief analysis of the challenges encountered in the study of tobacco brown spot,which include the study of pathogenesis and virulence,the breeding of disease-resistant varieties,the screening of low-toxicity and high-efficiency agents,the development of biological control methods with more stable efficacy,and the necessity for accurate prediction and forecasting techniques.
基金National Key R&D Program of China(No.2022YFD2400103).
文摘Deep-sea aquaculture is an emerging trend due to the contamination and overexploitation of nearshore mariculture areas.However,the complex water conditions in the deep sea impose higher demands on the swimming performance of farmed animals.Spotted sea bass(Lateolabrax maculatus)is one of the most economically important fish species in China.To investigate the mechanisms underlying the individual variations in swimming performance among spotted sea bass,we measured their critical swimming speed(U_(crit))and morphological phenotypes.Total length,body length,body weight,caudal region length,and condition factor showed significant positive correlations with absolute Ucrit.In contrast,caudal fin length and pectoral fin length tended to hinder the swimming performance of individual spotted sea bass.Additionally,white muscle tissues from fish exhibiting good swimming performance(relative U_(crit)>8.20 BL/s)and poor swimming performance(relative U_(crit)<7.31 BL/s)were sampled for RNA-seq.A total of 694 differential expression genes(DEGs)were identified through gene expression analysis,with significant enrichment in GO terms such as mitochondrial protein complex,ribosomal subunit,structural constituent of ribosome,and oxidative phosphorylation,as well as genes in KEGG pathways including ribosome and metabolic pathways.In conclusion,our study for the first time comprehensively elucidated the impact of morphology of spotted sea bass on its individual differences in swimming ability,and analyzed the genetic basis underlying swimming ability using transcriptomic methods.This study provides a theoretical basis for the potential breeding varieties of spotted sea bass suitable for deep-sea aquaculture.
基金supported by the National Natural Science Foundation of China(No.32072947)the China Agriculture Research System(No.CARS-47)。
文摘Urea is a major end product of nitrogen catabolism,serving as an osmolyte to regulate osmotic stress in fish exposed to varying water environments.It has been well known that urea transporters(UTs)facilitate the rapid movement of urea across cell membranes.However,researches on ut genes were predominantly focused on elasmobranchs and early developmental stages of fish.In this investigation,a total of three ut genes were identified in spotted sea bass.Phylogenetic,homology,and syntenic analyses were conducted to validate the annotation and assess the evolutionary relationships among ut genes.Both ut-a and ut-b genes have retained their evolutionary stability,demonstrating a significant level of homology between them.To gain deeper insights into the evolution of ut genes in spotted sea bass,we performed selective pressure analysis using site,branch,and branch-site models.The results suggested that positive selection likely played a significant role in shaping the evolution of the ut gene family.Furthermore,tissue-specific expression analyses revealed high expression levels of ut genes in osmoregulatory tissues such as the gill and kidney.Additionally,all three ut genes exhibited salinity-related expression patterns in gill and kidney tissues during both seawater-to-freshwater(SF)and freshwater-to-seawater(FS)adaptation.In situ hybridization results demonstrated the localization of both ut-a and ut-c mRNAs on the gill lamellae and adjacent gill filament epithelium.In summary,our study establishes a solid foundation for future research elucidating the evolutionary relationships and functional significance of ut genes during salinity acclimation in spotted sea bass and other teleost species.
基金funded by the National Natural Science Foundation of China(NSFC)(Grant No.U1860111)Weifang Science and Technology Development Plan Project(Project No.2023ZJ1166).
文摘The crankshaft is subjected to complex rotational centrifugal force,periodic gas inertia force,and reciprocating inertia force during its working process.Consequently,the homogeneity requirement for crankshaft steel is exceptionally high.The distribution characteristics of center segregation and spot segregation of continuous casting bloom 42CrMoA crankshaft steel were analyzed by experiments,and the control mechanism of spot segregation by soft reduction zone and reduction amount was discussed.When the center solid fraction is between 0.61 and 1.00,an 8-mm soft reduction has a negligible impact on the flow of liquid steel at the end of solidification.Although it effectively improves center segregation,the improvement of spot segregation is limited.On the other hand,when the center solid fraction is between 0.31 and 1.00,a reduction of 10–12 mm,along with an expanded reduction zone and increased reduction amount,significantly promotes the flow of liquid steel at the end of solidification,reduces the size of equiaxed grains,mitigates the center negative segregation,and decreases the maximum size of spot segregation from 2954.29 to 1354.07μm.The number of spot segregations and the solutes enrichment degree of C,Cr,and Mn have also been significantly improved.An appropriate soft reduction zone and reduction amount can markedly ameliorate the semi-macro spot segregation of crankshaft steel blooms,thereby providing high-quality raw materials for subsequent products and enhancing the competitiveness of crankshaft products.
文摘As NPC performances surge in popularity,destinations are recruiting actors and building story-driven scenes to reinvent traditional tourism Eight days,seven cities-a whirlwind tour that defined actor Zheng Guolin’s work schedule during the National Day holiday a month ago.From 1 to 8 October,he maintained a relentless pace,not just logging miles but also switching between roles.
基金Supported by the National Natural Science Foundation of China(U1831133)Open Fund of Key Laboratory of Space Active Optoelectronics Technology,Chinese Academy of Sciences(2021ZDKF4)。
文摘Position-sensitive detector(PSD)is widely used in precision measurement fields such as flatness detection,auto-collimator systems,and degrees of freedom testing.However,due to factors such as uneven surface resistance and differences in electrode structures,the nonlinearity of PSD becomes increasingly severe as the photosensitive surface moves from the center toward the edges of the four electrodes.To address this issue,a PSD nonlinearity correction algorithm is proposed.The algorithm utilizes the particle swarm optimization(PSO)algorithm to determine the optimal weights and thresholds,providing better initial parameters for the back propagation(BP)neural network.The BP neural network then iterates continuously until the error conditions are met,completing the correction process.Furthermore,a PSD nonlinearity correction system was developed,and the influence of different spot sizes on PSD positioning accuracy was simulated based on the current equation under the Gaussian spot model.This validated the robustness of the correction algorithm under varying spot sizes.The results demonstrate that the overall optimized error is reduced by 84.51%,and for spot sizes smaller than 1 mm,the error reduction exceeds 93.89%.This method not only meets the measurement accuracy requirements but also extends the measurement range of PSD.
基金2024 Guangdong University of Science and Technology Institutional Quality Engineering Project:Integrated Marketing Course Development Combining Teaching,Learning,Practice,and Competition(Project No.:GKZLGC2024430)。
文摘Danxia Mountain scenic area is a famous world natural heritage site and national 5A tourist attraction in China.It is renowned for its unique Danxia landform and rich biodiversity,and it has high ecological,scientific research,and tourism value.In recent years,the upgrading of consumption,the promotion of personalized and in-depth tourism,and the wide application of digital technology in culture and tourism have presented many challenges to the current marketing strategy of scenic spots.Based on the 7P marketing mix theory,this paper systematically analyzes the marketing strategy of the Danxia Mountain scenic area in seven dimensions:product,price,channel,promotion,personnel,tangible display,and service process.The analysis reveals several issues,including a limited product selection and a significant tendency toward homogenization.There is insufficient diversity in online and offline marketing channels,a lack of emotional resonance and international vision in promotional content,an imperfect professional talent echelon,traditional and interactive tangible displays,and an unbalanced service process system.These issues make it difficult to fully meet the needs of different customer groups.Based on this analysis,and considering the characteristics of the scenic spot’s resources and the tourism market’s trends,the paper offers targeted optimization suggestions.These include innovating experience projects,expanding marketing channels,strengthening talent cultivation,enriching tangible displays,and improving the service system.The aim is to enhance the market competitiveness and tourist satisfaction of scenic spots,promote the integration of culture and tourism while protecting natural heritage,and provide a reference for optimizing the marketing strategies of similar natural heritage sites.
基金Supported by the 14th Five-Year National Key Research and Development Program(2021YFD1201103–01–05)the National Natural Science Foundation of China(32301819)the Cooperation Project of Research and Development Center between Wudalianchi Government and Northeast Agricultural University.
文摘Soybean frogeye leaf spot(FLS)disease is a worldwide disease caused by Cercospora sojina Hara.It is one of the major diseases suffered by soybean during the growth cycle,which seriously damages the yield and seed quality of soybean.The current resistant varieties are difficult to meet the production demand.The breeders have identified 50 different physiological small species and discussed the physiological and biochemical characteristics of soybean resistance to FLS.In soybean disease resistance breeding,resistance resources are screened for the main physiological races in different countries,resistance materials are created,more than 100 genome regions associated with resistance are located,and 12 resistance-related genes are identified.In order to promote the research of soybean disease resistance breeding,this paper expounded and analyzed the pathogenesis characteristics of soybean FLS,the division of races,the physiological and biochemical mechanism of soybean resistance to FLS disease,quantitative trait locus(QTL),quantitative trait nucleotides(QTN),genes of resistance sites,the screening of resistant germplasm resources,and the breeding of new varieties,so as to gain an in-depth understanding of the pathogenesis principle of soybean FLS disease.In order to provide a theoretical basis and technical support for the breeding of soybean FLS disease,the resistance mechanism of soybean FLS disease was analyzed from the molecular level.
基金funded by the National Key R&D Program of China,grant number 2019YFB1505400.
文摘As the power system transitions to a new green and low-carbon paradigm,the penetration of renewable energy in China’s power system is gradually increasing.However,the variability and uncertainty of renewable energy output limit its profitability in the electricity market and hinder its market-based integration.This paper first constructs a wind-solar-thermalmulti-energy complementary system,analyzes its external game relationships,and develops a bi-level market optimization model.Then,it considers the contribution levels of internal participants to establish a comprehensive internal distribution evaluation index system.Finally,simulation studies using the IEEE 30-bus system demonstrate that the multi-energy complementary system stabilizes nodal outputs,enhances the profitability of market participants,and promotes the market-based integration of renewable energy.
基金supported by the National Natural Science Foundation of China(Grant Number 52001141).
文摘Pinless friction stir spot welding(P-FSSW)was performed to manufacture Mg/steel lap joints.Orthogonal tests for P-FSSW of Mg/steel were investigated,and the main factors affecting the properties of Mg/steel lap joints were derived.The shear force of the Mg/steel lap joints gradually increased and then decreased as the welding time increased.Maximum shear force was 5.3 kN.Fe-Al intermetallic compound(IMC)was formed at the Mg/steel interface near the steel side,and Mg-Al IMCs were formed at the Mg/steel interface near the Mg alloy side.Mg/steel lap joint was transformed from an initial solid-state welding to fusion-brazing welding as the welding time increased.No hole defects were formed in Mg/steel solid-state welding joints,whereas hole defects appeared in Mg/steel fusion-brazing welding joints.The temperature field of Mg/steel lap joints was simulated to analyze hole defects generated during the welding process.Hole defects can be eliminated by changing the spindle deflection angle,and the shear force decreased.Excessive spindle deflection can also lead to failure to form a stable joint.Hole defects were removed because the spindle deflection angle reduced the interfacial reaction temperature,and a solid-state welding joint was formed,which resulted in an absence of fusion-brazing welding hole formation.
基金the financial supports provided by the National Key Research and Development Program of China(2023YFE0201500)the National Natural Science Foundation of China(52375315)+2 种基金the Key Talent Plan Project of Guangdong Province(2023TQ07C702)the Research and Development Program in Key Areas of Dongguan(20201200300122)the GDAS’Project of Science and Technology Development(2022GDASZH-2022010203).
文摘Refill friction stir spot welding process is difficultly optimized by accurate modeling because of the high-order functional relationship between welding parameters and joint strength.A database of the welding process was first established with 6061-T6 aluminum alloy and DP780 galvanized steel as base materials.This dataset was then optimized using a backpropagation neural network.Analyses and mining of the experimental data confirmed the multidimensional mapping relationship between welding parameters and joint strength.Subsequently,intelligent optimization of the welding process and prediction of joint strength were achieved.At the predicted welding parameter(plunging rotation speedω1=1733 r/min,refilling rotation speedω_(2)=1266 r/min,plunging depth p=1.9 mm,and welding speed v=0.5 mm/s),the tensile shear fracture load of the joint reached a maximum value of 10,172 N,while the experimental result was 9980 N,with an error of 1.92%.Furthermore,the correlation of welding parameters-microstructure-joint strength was established.
基金funded by the Key Research and Development Program of Shandong Province,China(2022LZGC007 and 2018GNC110036)the Natural Science Foundation of Shandong Province,China(ZR2024MC038 and ZR2020QC121)+5 种基金the Taishan Scholar Project Funding,China(tsqn201812121)the Agricultural Scientific and Technological Innovation Project of Shandong Academy of Agricultural Sciences,China(CXGC2024G20,CXGC2023A06,CXGC2022A03,and CXGC2022F33)the Science and Technology for People’s Livelihood Project of Qingdao,China(20-3-4-26-nsh)the China Agriculture Research System(CARS-13)the National Natural Science Foundation of China(32072107)the Major Scientific and Technological Project in Xinjiang,China(2022A02008-3).
文摘Late leaf spot disease(LLS)is one of the most important diseases that cause severe yield losses in peanut.Peanut has various sources of resistance to LLS,so the identification of resistant quantitative trait loci(QTLs)and the development of related molecular markers are of great importance for the breeding of LLS-resistant peanut.In this study,173 individual lines of a recombinant inbred line(RIL)population and the 48K SNP array for genotyping were used to construct a high-density genetic map with 1,475 bin markers and 20 linkage groups.A total of 11 QTLs were obtained through QTL analysis using the constructed genetic map.Among them,the stable major QTL qLLS.LG02 was identified on linkage group 2 in all six environments,with the phenotypic variation explained(PVE)ranging from 15.57 to 31.09%.QTL-seq technology was also employed for a QTL analysis of LLS resistance.As a result,14 QTL loci related to LLS resistance were identified using the G prime algorithm.Notably,the physical positions of qLLS02 and qLLS03 coincided with those of qLLS.LG02 and qLLS.LG03,respectively.Gene annotation analysis within the 14 QTL intervals from QTL-seq revealed a total of 163 nucleotide-binding site-leucine-rich repeat(NBS-LRR)disease resistance genes,accounting for 22.86%of all resistance(R)genes in the peanut genome and showing a 4.26-fold enrichment with a P-value of 5.19e-57.Within the QTL region qLLS02 of the resistant parent Mi-2,there was a 5 Mb structural variation(SV)interval containing 81 NBS-LRR genes.A PCR diagnostic marker was developed,and validation data suggested that this SV might lead to gene deletion or replacement with other genes.This SV has the potential to enhance peanut resistance to LLS.The results of this study have significant implications for improving peanut breeding for LLS resistance through the development of associated molecular markers.
文摘The uncertain nature of mapping user tasks to Virtual Machines(VMs) causes system failure or execution delay in Cloud Computing.To maximize cloud resource throughput and decrease user response time,load balancing is needed.Possible load balancing is needed to overcome user task execution delay and system failure.Most swarm intelligent dynamic load balancing solutions that used hybrid metaheuristic algorithms failed to balance exploitation and exploration.Most load balancing methods were insufficient to handle the growing uncertainty in job distribution to VMs.Thus,the Hybrid Spotted Hyena and Whale Optimization Algorithm-based Dynamic Load Balancing Mechanism(HSHWOA) partitions traffic among numerous VMs or servers to guarantee user chores are completed quickly.This load balancing approach improved performance by considering average network latency,dependability,and throughput.This hybridization of SHOA and WOA aims to improve the trade-off between exploration and exploitation,assign jobs to VMs with more solution diversity,and prevent the solution from reaching a local optimality.Pysim-based experimental verification and testing for the proposed HSHWOA showed a 12.38% improvement in minimized makespan,16.21% increase in mean throughput,and 14.84% increase in network stability compared to baseline load balancing strategies like Fractional Improved Whale Social Optimization Based VM Migration Strategy FIWSOA,HDWOA,and Binary Bird Swap.
