In daily life,keyword spotting plays an important role in human-computer interaction.However,noise often interferes with the extraction of time-frequency information,and achieving both computational efficiency and rec...In daily life,keyword spotting plays an important role in human-computer interaction.However,noise often interferes with the extraction of time-frequency information,and achieving both computational efficiency and recognition accuracy on resource-constrained devices such as mobile terminals remains a major challenge.To address this,we propose a novel time-frequency dual-branch parallel residual network,which integrates a Dual-Branch Broadcast Residual module and a Time-Frequency Coordinate Attention module.The time-domain and frequency-domain branches are designed in parallel to independently extract temporal and spectral features,effectively avoiding the potential information loss caused by serial stacking,while enhancing information flow and multi-scale feature fusion.In terms of training strategy,a curriculum learning approach is introduced to progressively improve model robustness fromeasy to difficult tasks.Experimental results demonstrate that the proposed method consistently outperforms existing lightweight models under various signal-to-noise ratio(SNR)conditions,achieving superior far-field recognition performance on the Google Speech Commands V2 dataset.Notably,the model maintains stable performance even in low-SNR environments such as–10 dB,and generalizes well to unseen SNR conditions during training,validating its robustness to novel noise scenarios.Furthermore,the proposed model exhibits significantly fewer parameters,making it highly suitable for deployment on resource-limited devices.Overall,the model achieves a favorable balance between performance and parameter efficiency,demonstrating strong potential for practical applications.展开更多
The construction of spot electricity markets plays a pivotal role in power system reforms,where market clearing systems profoundly influence market efficiency and security.Current clearing systems predominantly adopt ...The construction of spot electricity markets plays a pivotal role in power system reforms,where market clearing systems profoundly influence market efficiency and security.Current clearing systems predominantly adopt a single-system architecture,with research focusing primarily on accelerating solution algorithms through techniques such as high-efficiency parallel solvers and staggered decomposition of mixed-integer programming models.Notably absent are systematic studies evaluating the adaptability of primary-backup clearing systems incontingency scenarios—a critical gap given redundant systems’expanding applications in operational environments.This paper proposes a comprehensive evaluation framework for analyzing dual-system adaptability,demonstrated through an in-depth case study of the Inner Mongolia power market.First,we establish the innovative“Dual-Active Heterogeneous”architecture that enables independent parallelized operation and fault-isolated redundancy.Subsequently,key performance indices are quantitatively evaluated across four critical dimensions:unit commitment decisions,generator output constraints,transmission section congestion patterns,and clearing price formation mechanisms.An integrated fuzzy evaluation methodology incorporating grey relational analysis is employed for objective indicator weighting,enabling systematic quantification of system superiority under specific grid operating states.Empirical results based on actual operational data from 200 generation units demonstrate the framework’s efficacy in guiding optimal system selection,with particularly strong performance observed during peak load periods.The proposed approach shows high generalization potential for other regional markets employing redundant clearing mechanisms—particularly those with increasing renewable penetration and associated uncertainty.展开更多
The dissimilar 2B06 and 7B04 Al alloy joints were prepared by refill friction stir spot welding(RFSSW),and the microstructural evolution and corrosion behavior of the joints were investigated.Based on microstructural ...The dissimilar 2B06 and 7B04 Al alloy joints were prepared by refill friction stir spot welding(RFSSW),and the microstructural evolution and corrosion behavior of the joints were investigated.Based on microstructural analysis,the welded joints exhibit distinct microstructural zones,including the stir zone(SZ),thermomechanically affected zone(TMAZ),and heat-affected zone(HAZ).The grain size of each zone is in the order of HAZ>TMAZ>SZ.Notably,the TMAZ and HAZ contain significantly larger secondary-phase particles compared to the SZ,with particle size in the HAZ increasing at higher rotational speeds.Electrochemical tests indicate that corrosion susceptibility follows the sequence of HAZ>TMAZ>SZ>BM,with greater sensitivity observed at increased rotational speeds.Post-corrosion mechanical performance degradation primarily arises from crevice corrosion at joint overlaps,but not from the changes in the microstructure.展开更多
Accurate time delay estimation of target echo signals is a critical component of underwater target localization.In active sonar systems,echo signal processing is vulnerable to the effects of reverberation and noise in...Accurate time delay estimation of target echo signals is a critical component of underwater target localization.In active sonar systems,echo signal processing is vulnerable to the effects of reverberation and noise in the maritime environment.This paper proposes a novel method for estimating target time delay using multi-bright spot echoes,assuming the target’s size and depth are known.Aiming to effectively enhance the extraction of geometric features from the target echoes and mitigate the impact of reverberation and noise,the proposed approach employs the fractional order Fourier transform-frequency sliced wavelet transform to extract multi-bright spot echoes.Using the highlighting model theory and the target size information,an observation matrix is constructed to represent multi-angle incident signals and obtain the theoretical scattered echo signals from different angles.Aiming to accurately estimate the target’s time delay,waveform similarity coefficients and mean square error values between the theoretical return signals and received signals are computed across various incident angles and time delays.Simulation results show that,compared to the conventional matched filter,the proposed algorithm reduces the relative error by 65.9%-91.5%at a signal-to noise ratio of-25 dB,and by 66.7%-88.9%at a signal-to-reverberation ratio of−10 dB.This algorithm provides a new approach for the precise localization of submerged targets in shallow water environments.展开更多
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
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
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
Pigmented skin spots,a visible sign of aging,can significantly affect the appearance of facial skin.To elucidate their pathogenesis and support the development of novel cosmetic ingredients,this review summarizes the ...Pigmented skin spots,a visible sign of aging,can significantly affect the appearance of facial skin.To elucidate their pathogenesis and support the development of novel cosmetic ingredients,this review summarizes the morphological characteristics of pigmented skin spots and the extrinsic and intrinsic factors contributing to their development.Additionally,it highlights the common cosmetic ingredients currently used for reducing hyperpigmentation.The relevant literature was collected by searching PubMed and Wanfang Data for studies focusing on pigmented spots and facial spots.Overall,the literature indicates that pigmented spots display distinct morphological characteristics,including specialized melanocyte dendrites,altered vascular architecture,abnormal keratinization,and immune cell infiltration.Mechanistically,their formation is driven by both extrinsic factors(e.g.,sun exposure,skin microbiota,and particulate matter)as well as intrinsic factors(e.g.,vascular abnormalities,chronic inflammation,and hormonal fluctuations).Thus,pigmented skin spots represent a complex biological system encompassing multiple types of cells and molecular mediators,regulated by diverse environmental and physiological factors.Given their intricate microenvironment conditions and multifactorial etiology,a systematic and comprehensive investigation of pigmented spots is warranted.Such research could inform the development of cosmetic ingredients with targeted and multitargeted actions,enabling the more effective reduction of pigmented skin spots.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
文摘In daily life,keyword spotting plays an important role in human-computer interaction.However,noise often interferes with the extraction of time-frequency information,and achieving both computational efficiency and recognition accuracy on resource-constrained devices such as mobile terminals remains a major challenge.To address this,we propose a novel time-frequency dual-branch parallel residual network,which integrates a Dual-Branch Broadcast Residual module and a Time-Frequency Coordinate Attention module.The time-domain and frequency-domain branches are designed in parallel to independently extract temporal and spectral features,effectively avoiding the potential information loss caused by serial stacking,while enhancing information flow and multi-scale feature fusion.In terms of training strategy,a curriculum learning approach is introduced to progressively improve model robustness fromeasy to difficult tasks.Experimental results demonstrate that the proposed method consistently outperforms existing lightweight models under various signal-to-noise ratio(SNR)conditions,achieving superior far-field recognition performance on the Google Speech Commands V2 dataset.Notably,the model maintains stable performance even in low-SNR environments such as–10 dB,and generalizes well to unseen SNR conditions during training,validating its robustness to novel noise scenarios.Furthermore,the proposed model exhibits significantly fewer parameters,making it highly suitable for deployment on resource-limited devices.Overall,the model achieves a favorable balance between performance and parameter efficiency,demonstrating strong potential for practical applications.
基金supported by NARI Relays Electric Co.,Ltd.under the Project“Research on Evaluation of Clearing Results and Switching Criteria for Primary-Backup Systems in Electricity SpotMarkets”(Project No.CGSQ240800443).
文摘The construction of spot electricity markets plays a pivotal role in power system reforms,where market clearing systems profoundly influence market efficiency and security.Current clearing systems predominantly adopt a single-system architecture,with research focusing primarily on accelerating solution algorithms through techniques such as high-efficiency parallel solvers and staggered decomposition of mixed-integer programming models.Notably absent are systematic studies evaluating the adaptability of primary-backup clearing systems incontingency scenarios—a critical gap given redundant systems’expanding applications in operational environments.This paper proposes a comprehensive evaluation framework for analyzing dual-system adaptability,demonstrated through an in-depth case study of the Inner Mongolia power market.First,we establish the innovative“Dual-Active Heterogeneous”architecture that enables independent parallelized operation and fault-isolated redundancy.Subsequently,key performance indices are quantitatively evaluated across four critical dimensions:unit commitment decisions,generator output constraints,transmission section congestion patterns,and clearing price formation mechanisms.An integrated fuzzy evaluation methodology incorporating grey relational analysis is employed for objective indicator weighting,enabling systematic quantification of system superiority under specific grid operating states.Empirical results based on actual operational data from 200 generation units demonstrate the framework’s efficacy in guiding optimal system selection,with particularly strong performance observed during peak load periods.The proposed approach shows high generalization potential for other regional markets employing redundant clearing mechanisms—particularly those with increasing renewable penetration and associated uncertainty.
基金supported by the National Natural Science Foundation of China (Nos. 52075449, 51975480)。
文摘The dissimilar 2B06 and 7B04 Al alloy joints were prepared by refill friction stir spot welding(RFSSW),and the microstructural evolution and corrosion behavior of the joints were investigated.Based on microstructural analysis,the welded joints exhibit distinct microstructural zones,including the stir zone(SZ),thermomechanically affected zone(TMAZ),and heat-affected zone(HAZ).The grain size of each zone is in the order of HAZ>TMAZ>SZ.Notably,the TMAZ and HAZ contain significantly larger secondary-phase particles compared to the SZ,with particle size in the HAZ increasing at higher rotational speeds.Electrochemical tests indicate that corrosion susceptibility follows the sequence of HAZ>TMAZ>SZ>BM,with greater sensitivity observed at increased rotational speeds.Post-corrosion mechanical performance degradation primarily arises from crevice corrosion at joint overlaps,but not from the changes in the microstructure.
基金Supported by the State Key Laboratory of Acoustics and Marine Information Chinese Academy of Sciences(SKL A202507).
文摘Accurate time delay estimation of target echo signals is a critical component of underwater target localization.In active sonar systems,echo signal processing is vulnerable to the effects of reverberation and noise in the maritime environment.This paper proposes a novel method for estimating target time delay using multi-bright spot echoes,assuming the target’s size and depth are known.Aiming to effectively enhance the extraction of geometric features from the target echoes and mitigate the impact of reverberation and noise,the proposed approach employs the fractional order Fourier transform-frequency sliced wavelet transform to extract multi-bright spot echoes.Using the highlighting model theory and the target size information,an observation matrix is constructed to represent multi-angle incident signals and obtain the theoretical scattered echo signals from different angles.Aiming to accurately estimate the target’s time delay,waveform similarity coefficients and mean square error values between the theoretical return signals and received signals are computed across various incident angles and time delays.Simulation results show that,compared to the conventional matched filter,the proposed algorithm reduces the relative error by 65.9%-91.5%at a signal-to noise ratio of-25 dB,and by 66.7%-88.9%at a signal-to-reverberation ratio of−10 dB.This algorithm provides a new approach for the precise localization of submerged targets in shallow water environments.
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.
文摘Pigmented skin spots,a visible sign of aging,can significantly affect the appearance of facial skin.To elucidate their pathogenesis and support the development of novel cosmetic ingredients,this review summarizes the morphological characteristics of pigmented skin spots and the extrinsic and intrinsic factors contributing to their development.Additionally,it highlights the common cosmetic ingredients currently used for reducing hyperpigmentation.The relevant literature was collected by searching PubMed and Wanfang Data for studies focusing on pigmented spots and facial spots.Overall,the literature indicates that pigmented spots display distinct morphological characteristics,including specialized melanocyte dendrites,altered vascular architecture,abnormal keratinization,and immune cell infiltration.Mechanistically,their formation is driven by both extrinsic factors(e.g.,sun exposure,skin microbiota,and particulate matter)as well as intrinsic factors(e.g.,vascular abnormalities,chronic inflammation,and hormonal fluctuations).Thus,pigmented skin spots represent a complex biological system encompassing multiple types of cells and molecular mediators,regulated by diverse environmental and physiological factors.Given their intricate microenvironment conditions and multifactorial etiology,a systematic and comprehensive investigation of pigmented spots is warranted.Such research could inform the development of cosmetic ingredients with targeted and multitargeted actions,enabling the more effective reduction of pigmented skin spots.
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.
