Weather forecasts from numerical weather prediction models play a central role in solar energy forecasting,where a cascade of physics-based models is used in a model chain approach to convert forecasts of solar irradi...Weather forecasts from numerical weather prediction models play a central role in solar energy forecasting,where a cascade of physics-based models is used in a model chain approach to convert forecasts of solar irradiance to solar power production.Ensemble simulations from such weather models aim to quantify uncertainty in the future development of the weather,and can be used to propagate this uncertainty through the model chain to generate probabilistic solar energy predictions.However,ensemble prediction systems are known to exhibit systematic errors,and thus require post-processing to obtain accurate and reliable probabilistic forecasts.The overarching aim of our study is to systematically evaluate different strategies to apply post-processing in model chain approaches with a specific focus on solar energy:not applying any post-processing at all;post-processing only the irradiance predictions before the conversion;post-processing only the solar power predictions obtained from the model chain;or applying post-processing in both steps.In a case study based on a benchmark dataset for the Jacumba solar plant in the U.S.,we develop statistical and machine learning methods for postprocessing ensemble predictions of global horizontal irradiance(GHI)and solar power generation.Further,we propose a neural-network-based model for direct solar power forecasting that bypasses the model chain.Our results indicate that postprocessing substantially improves the solar power generation forecasts,in particular when post-processing is applied to the power predictions.The machine learning methods for post-processing slightly outperform the statistical methods,and the direct forecasting approach performs comparably to the post-processing strategies.展开更多
This article focuses on the challenges of rural economic development under the strategy of rural revitalization,and deeply analyzes the current situation of rural economic development.Research has found that although ...This article focuses on the challenges of rural economic development under the strategy of rural revitalization,and deeply analyzes the current situation of rural economic development.Research has found that although the rural revitalization strategy has achieved significant results in improving residents’quality of life,promoting agricultural modernization,it still faces challenges such as severe loss of human resources,insufficient agricultural technological innovation,and backward infrastructure construction.In response to these challenges,this paper proposes optimization strategies from three aspects:strengthening rural education and talent team construction,promoting agricultural technology innovation and achievement transformation,and increasing investment in rural infrastructure construction.展开更多
Ischemic stroke is a major cause of neurological deficits and high disability rate.As the primary immune cells of the central nervous system,microglia play dual roles in neuroinflammation and tissue repair following a...Ischemic stroke is a major cause of neurological deficits and high disability rate.As the primary immune cells of the central nervous system,microglia play dual roles in neuroinflammation and tissue repair following a stroke.Their dynamic activation and polarization states are key factors that influence the disease process and treatment outcomes.This review article investigates the role of microglia in ischemic stroke and explores potential intervention strategies.Microglia exhibit a dynamic functional state,transitioning between pro-inflammatory(M1)and anti-inflammatory(M2)phenotypes.This duality is crucial in ischemic stroke,as it maintains a balance between neuroinflammation and tissue repair.Activated microglia contribute to neuroinflammation through cytokine release and disruption of the blood-brain barrier,while simultaneously promoting tissue repair through anti-inflammatory responses and regeneration.Key pathways influencing microglial activation include Toll-like receptor 4/nuclear factor kappa B,mitogen-activated protein kinases,Janus kinase/signal transducer and activator of transcription,and phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathways.These pathways are targets for various experimental therapies aimed at promoting M2 polarization and mitigating damage.Potential therapeutic agents include natural compounds found in drugs such as minocycline,as well as traditional Chinese medicines.Drugs that target these regulatory mechanisms,such as small molecule inhibitors and components of traditional Chinese medicines,along with emerging technologies such as single-cell RNA sequencing and spatial transcriptomics,offer new therapeutic strategies and clinical translational potential for ischemic stroke.展开更多
Dove’s 2017 advertising incident,which sparked widespread debate regarding perceived cultural insensitivity,highlighted a disconnect between the brand’s“Real Beauty”positioning and public reception.In response,thi...Dove’s 2017 advertising incident,which sparked widespread debate regarding perceived cultural insensitivity,highlighted a disconnect between the brand’s“Real Beauty”positioning and public reception.In response,this study proposes a strategic digital recovery framework,including revised campaign content,transparent communication through social media,and data-driven customer segmentation based on diverse skincare needs and cultural backgrounds.A PESTLE analysis underscores the importance of digital transformation and rising social consciousness in brand management.Findings suggest that inclusive messaging,precision targeting,and omnichannel digital engagement are key to restoring brand trust and reputation in the digital landscape.展开更多
Neural injuries can cause considerable functional impairments,and both central and peripheral nervous systems have limited regenerative capacity.The existing conventional pharmacological treatments in clinical practic...Neural injuries can cause considerable functional impairments,and both central and peripheral nervous systems have limited regenerative capacity.The existing conventional pharmacological treatments in clinical practice show poor targeting,rapid drug clearance from the circulatory system,and low therapeutic efficiency.Therefore,in this review,we have first described the mechanisms underlying nerve regeneration,characterized the biomaterials used for drug delivery to facilitate nerve regeneration,and highlighted the functionalization strategies used for such drug-delivery systems.These systems mainly use natural and synthetic polymers,inorganic materials,and hybrid systems with advanced drug-delivery abilities,including nanoparticles,hydrogels,and scaffoldbased systems.Then,we focused on comparing the types of drug-delivery systems for neural regeneration as well as the mechanisms and challenges associated with targeted delivery of drugs to facilitate neural regeneration.Finally,we have summarized the clinical application research and limitations of targeted delivery of these drugs.These biomaterials and drug-delivery systems can provide mechanical support,sustained release of bioactive molecules,and enhanced intercellular contact,ultimately reducing cell apoptosis and enhancing functional recovery.Nevertheless,immune reactions,degradation regulation,and clinical translations remain major unresolved challenges.Future studies should focus on optimizing biomaterial properties,refining delivery precision,and overcoming translational barriers to advance these technologies toward clinical applications.展开更多
Single-atom nanozymes(SAzymes)exhibit exceptional catalytic efficiency due to their maximized atom utilization and precisely modulated metalcarrier interactions,which have attracted significant attention in the biomed...Single-atom nanozymes(SAzymes)exhibit exceptional catalytic efficiency due to their maximized atom utilization and precisely modulated metalcarrier interactions,which have attracted significant attention in the biomedical field.However,stability issues may impede the clinical translation of SAzymes.This review provides a comprehensive overview of the applications of SAzymes in various biomedical fields,including disease diagnosis(e.g.,biosensors and diagnostic imaging),antitumor therapy(e.g.,photothermal therapy,photodynamic therapy,sonodynamic therapy,and immunotherapy),antimicrobial therapy,and anti-oxidative stress therapy.More importantly,the existing challenges of SAzymes are discussed,such as metal atom clustering and active site loss,ligand bond breakage at high temperature,insufficient environment tolerance,biosecurity risks,and limited catalytic long-term stability.Finally,several innovative strategies to address these stability concerns are proposed—synthesis process optimization(space-limited strategy,coordination site design,bimetallic synergistic strategy,defect engineering strategy,atom stripping-capture),surface modification,and dynamic responsive design—that collectively pave the way for robust,clinically viable SAzymes.展开更多
The discharge of micro-polluted water from sources such as agricultural runoff,urban stormwater,and treated effluents presents significant challenges to aquatic ecosystems.Constructed wetlands(CWs)have gained recog-ni...The discharge of micro-polluted water from sources such as agricultural runoff,urban stormwater,and treated effluents presents significant challenges to aquatic ecosystems.Constructed wetlands(CWs)have gained recog-nition as an eco-friendly solution for removing pollutants from various wastewater sources and are increasingly applied for micro-polluted water treatment.By reviewing 78 full-scale CW studies from Web of Science,it is summarized that the ranges of ammonium nitrogen(NH4+-N)concentrations in runoff,wastewater treatment plant effluent and polluted river were 0.1–6.6,0.3–12.3,and 0.2–41.1 mg/L,respectively.The ranges of ni-trate nitrogen concentrations were 0.2–14.2,0–5.7,and 0–2.6 mg/L,respectively.Removal efficiencies of CWs for micro-polluted water varied by CW types.The total nitrogen removal efficiencies for subsurface-flow CWs,free-water surface-flow CWs,and hybrid CWs ranged from 27.4%to 66.5%,16.8%to 89.8%,and 19.4%to 88.2%,respectively.The NH4+-N removal efficiencies ranged from 34.2%to 73.6%,38.4%to 89.4%and 13.5%to 94.2%,respectively.Additionally,other factors influencing contaminant removal efficiency such as hydraulic retention time,vegetation types,redox micro-environment and influent water quality were evaluated.Based on these findings,two strategies for improving the purification performance of CWs were proposed:the selection of incorporating electron donor substrates and the optimization of operation parameters.This paper serves as a synthesis of information to guide future research and full-scale CW applications in micro-polluted water treatment.展开更多
Conventional locking/release mechanisms often face challenges in aircraft wing separation processes,such as excessive impact loads and insufficient synchronization.These may cause structural damage to the airframe or ...Conventional locking/release mechanisms often face challenges in aircraft wing separation processes,such as excessive impact loads and insufficient synchronization.These may cause structural damage to the airframe or attitude instability,seriously compromising mission reliability.To address this engineering challenge,this paper proposes a multi-point low-impact locking/release mechanism based on the mobility model and energy conversion strategy.Through establishing a DOF constraint framework system,this paper systematically analyzes the energy transfer and conversion characteristics during the wing separation process,reveals the generation mechanism of impact loads,and conducts research on low-impact design based on energy conversion strategy.Building on this foundation,a single-point locking/release mechanism employing parallel trapezoidal key shaft structure was designed,which increases frictional contact time and reduces the energy release rate,thereby achieving low-impact characteristics.The mechanism's performance was validated through physical prototype development and systematic functional testing(including unlocking force,synchronization,and impact tests).Experimental results demonstrate:(1)Under 14 kN preload condition,the maximum unlocking force was only 92.54 N,showing a linear relationship with preload that satisfies the"strong-connection/weak-unlock"design requirement;(2)Wing separation was completed within 46 ms,with synchronization time difference among three separation mechanisms stably controlled within 12-14 ms,proving rapid and reliable operation;(3)The unlocking impact acceleration ranged between 26 and 73 g,below the 100 g design limit,confirming the effectiveness of the energy conversion strategy.The proposed low-impact locking/release mechanism design method based on energy conversion strategy resolves the traditional challenges of high impact and synchronization deficiencies.The synergistic optimization mechanism of"structural load reduction and performance improvement"provides a highly reliable technical solution for wing separable mechanisms while offering novel design insights for wing connection/separation systems engineering.展开更多
Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespr...Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespread attention for CO_(2)RR due to their high catalytic activity,selectivity,excellent stability,and low cost.However,they still need to be further improved to meet the needs of industrial applications.This review article comprehensively summarizes the recent advances in regulation strategies of Bi-based catalysts and can be divided into six categories:(1)defect engineering,(2)atomic doping engineering,(3)organic framework engineering,(4)inorganic heterojunction engineering,(5)crystal face engineering,and(6)alloying and polarization engineering.Meanwhile,the corresponding catalytic mechanisms of each regulation strategy will also be discussed in detail,aiming to enable researchers to understand the structure-property relationship of the improved Bibased catalysts fundamentally.Finally,the challenges and future opportunities of the Bi-based catalysts in the photoelectrocatalytic CO_(2)RR application field will also be featured from the perspectives of the(1)combination or synergy of multiple regulatory strategies,(2)revealing formation mechanism and realizing controllable synthesis,and(3)in situ multiscale investigation of activation pathways and uncovering the catalytic mechanisms.On the one hand,through the comparative analysis and mechanism explanation of the six major regulatory strategies,a multidimensional knowledge framework of the structure-activity relationship of Bi-based catalysts can be constructed for researchers,which not only deepens the atomic-level understanding of catalytic active sites,charge transport paths,and the adsorption behavior of intermediate products,but also provides theoretical guiding principles for the controllable design of new catalysts;on the other hand,the promising collaborative regulation strategies,controllable synthetic paths,and the in situ multiscale characterization techniques presented in this work provides a paradigm reference for shortening the research and development cycle of high-performance catalysts,conducive to facilitating the transition of photoelectrocatalytic CO_(2)RR technology from the laboratory routes to industrial application.展开更多
In the present computational fluid dynamics （CFD） community, post-processing is regarded as a procedure to view parameter distribution, detect characteristic structure and reveal physical mechanism of fluid flow bas...In the present computational fluid dynamics （CFD） community, post-processing is regarded as a procedure to view parameter distribution, detect characteristic structure and reveal physical mechanism of fluid flow based on computational or experimental results. Field plots by contours, iso-surfaces, streamlines, vectors and others are traditional post-processing techniques. While the shock wave, as one important and critical flow structure in many aerodynamic problems, can hardly be detected or distinguished in a direct way using these traditional methods, due to possible confusions with other similar discontinuous flow structures like slip line, contact discontinuity, etc. Therefore, method for automatic detection of shock wave in post-processing is of great importance for both academic research and engineering applications. In this paper, the current status of methodologies developed for shock wave detection and implementations in post-processing platform are reviewed, as well as discussions on advantages and limitations of the existing methods and proposals for further studies of shock wave detection method. We also develop an advanced post-processing software, with improved shock detection.展开更多
Quantum random number generators adopting single negligible dead time of avalanche photodiodes （APDs） photon detection have been restricted due to the non- We propose a new approach based on an APD array to improve...Quantum random number generators adopting single negligible dead time of avalanche photodiodes （APDs） photon detection have been restricted due to the non- We propose a new approach based on an APD array to improve the generation rate of random numbers significantly. This method compares the detectors＇ responses to consecutive optical pulses and generates the random sequence. We implement a demonstration experiment to show its simplicity, compactness and scalability. The generated numbers are proved to be unbiased, post-processing free, ready to use, and their randomness is verified by using the national institute of standard technology statistical test suite. The random bit generation efficiency is as high as 32.8% and the potential generation rate adopting the 32× 32 APD array is up to tens of Gbits/s.展开更多
In order to carry out numerical simulation using geologic structural data obtained from Landmark(seismic interpretation system), underground geological structures are abstracted into mechanical models which can reflec...In order to carry out numerical simulation using geologic structural data obtained from Landmark(seismic interpretation system), underground geological structures are abstracted into mechanical models which can reflect actual situations and facilitate their computation and analyses.Given the importance of model building, further processing methods about traditional seismic interpretation results from Landmark should be studied and the processed result can then be directly used in numerical simulation computations.Through this data conversion procedure, Landmark and FLAC(the international general stress software) are seamlessly connected.Thus, the format conversion between the two systems and the pre-and post-processing in simulation computation is realized.A practical application indicates that this method has many advantages such as simple operation, high accuracy of the element subdivision and high speed, which may definitely satisfy the actual needs of floor grid cutting.展开更多
The travel time data collection method is used to assist the congestion management. The use of traditional sensors (e.g. inductive loops, AVI sensors) or more recent Bluetooth sensors installed on major roads for coll...The travel time data collection method is used to assist the congestion management. The use of traditional sensors (e.g. inductive loops, AVI sensors) or more recent Bluetooth sensors installed on major roads for collecting data is not sufficient because of their limited coverage and expensive costs for installation and maintenance. Application of the Global Positioning Systems (GPS) in travel time and delay data collections is proven to be efficient in terms of accuracy, level of details for the data and required data collection of man-power. While data collection automation is improved by the GPS technique, human errors can easily find their way through the post-processing phase, and therefore data post-processing remains a challenge especially in case of big projects with high amount of data. This paper introduces a stand-alone post-processing tool called GPS Calculator, which provides an easy-to-use environment to carry out data post-processing. This is a Visual Basic application that processes the data files obtained in the field and integrates them into Geographic Information Systems (GIS) for analysis and representation. The results show that this tool obtains similar results to the currently used data post-processing method, reduces the post-processing effort, and also eliminates the need for the second person during the data collection.展开更多
When castings become complicated and the demands for precision of numerical simulation become higher,the numerical data of casting numerical simulation become more massive.On a general personal computer,these massive ...When castings become complicated and the demands for precision of numerical simulation become higher,the numerical data of casting numerical simulation become more massive.On a general personal computer,these massive numerical data may probably exceed the capacity of available memory,resulting in failure of rendering.Based on the out-of-core technique,this paper proposes a method to effectively utilize external storage and reduce memory usage dramatically,so as to solve the problem of insufficient memory for massive data rendering on general personal computers.Based on this method,a new postprocessor is developed.It is capable to illustrate filling and solidification processes of casting,as well as thermal stess.The new post-processor also provides fast interaction to simulation results.Theoretical analysis as well as several practical examples prove that the memory usage and loading time of the post-processor are independent of the size of the relevant files,but the proportion of the number of cells on surface.Meanwhile,the speed of rendering and fetching of value from the mouse is appreciable,and the demands of real-time and interaction are satisfied.展开更多
To improve the ability of detecting underwater targets under strong wideband interference environment,an efficient method of line spectrum extraction is proposed,which fully utilizes the feature of the target spectrum...To improve the ability of detecting underwater targets under strong wideband interference environment,an efficient method of line spectrum extraction is proposed,which fully utilizes the feature of the target spectrum that the high intense and stable line spectrum is superimposed on the wide continuous spectrum.This method modifies the traditional beam forming algorithm by calculating and fusing the beam forming results at multi-frequency band and multi-azimuth interval,showing an excellent way to extract the line spectrum when the interference and the target are not in the same azimuth interval simultaneously.Statistical efficiency of the estimated azimuth variance and corresponding power of the line spectrum band depends on the line spectra ratio(LSR)of the line spectrum.The change laws of the output signal to noise ratio(SNR)with the LSR,the input SNR,the integration time and the filtering bandwidth of different algorithms bring the selection principle of the critical LSR.As the basis,the detection gain of wideband energy integration and the narrowband line spectrum algorithm are theoretically analyzed.The simulation detection gain demonstrates a good match with the theoretical model.The application conditions of all methods are verified by the receiver operating characteristic(ROC)curve and experimental data from Qiandao Lake.In fact,combining the two methods for target detection reduces the missed detection rate.The proposed post-processing method in2-dimension with the Kalman filter in the time dimension and the background equalization algorithm in the azimuth dimension makes use of the strong correlation between adjacent frames,could further remove background fluctuation and improve the display effect.展开更多
Social capital in the form of social resources or social networks is one of the most important livelihood capital of farmers, which can increase the labor productivity of poor households and increase income. It is imp...Social capital in the form of social resources or social networks is one of the most important livelihood capital of farmers, which can increase the labor productivity of poor households and increase income. It is important to explore the reasons underlying the livelihood strategy choices of farmers from the perspective of social capital under China’s rural revitalization strategy. In this study, the Liangshan Yi Autonomous Prefecture, a povertystricken mountainous area in southwestern China, was selected as the case study area, and multivariable linear regression models were constructed to analyze the influence of social capital on livelihood strategies.The results are as follows:(1) Individual social capital had a positive effect on non-agricultural livelihood strategies. On average, with a one-unit increase in individual social capital, the ratio of farmers’ nonagricultural income to total productive income(Income_Rto) increased by 0.002% and 0.062%,respectively. Collective social capital, with the Peasant Economic Cooperation Organization(PECO) as the carrier, had a negative effect on the non-agricultural livelihood strategies of farmers;on average, with a oneunit increase in PECO, Income_Rto decreased by approximately 0.053%. However, this effect was only significant in the river valley area.(2) The income differences among the different livelihood strategy types were explained by the livelihood strategy choices of farmers. As non-agricultural work can bring more benefits, the labor force exhibited one-way migration from villages to cities, resulting in a lack of the subject of rural revitalization. It is necessary to implement effective measures to highlight the role of PECO in increasing agricultural income for farmers. Finally,based on the above conclusions,policy recommendations with respect to livelihood transformation of farmers and rural sustainable development are discussed.展开更多
This paper proposed improvements to the low bit rate parametric audio coder with sinusoid model as its kernel. Firstly, we propose a new method to effectively order and select the perceptually most important sinusoids...This paper proposed improvements to the low bit rate parametric audio coder with sinusoid model as its kernel. Firstly, we propose a new method to effectively order and select the perceptually most important sinusoids. The sinusoid which contributes most to the reduction of overall NMR is chosen. Combined with our improved parametric psychoacoustic model and advanced peak riddling techniques, the number of sinusoids required can be greatly reduced and the coding efficiency can be greatly enhanced. A lightweight version is also given to reduce the amount of computation with only little sacrifice of performance. Secondly, we propose two enhancement techniques for sinusoid synthesis: bandwidth enhancement and line enhancement. With little overhead, the effective bandwidth can be extended one more octave; the timbre tends to sound much brighter, thicker and more beautiful.展开更多
Since confidence is fading and anxiety is increasing in the US,America’s China policy has become more radical. In the short term, the US has the upper hand and China is in a relatively passive position. In the medium...Since confidence is fading and anxiety is increasing in the US,America’s China policy has become more radical. In the short term, the US has the upper hand and China is in a relatively passive position. In the medium-and long-term, there will be more balance between them. This current strategic gambling between China and the US will be the major issue of international politics in the first half of the 21 st century and the most prominent external challenge China faces. China needs to make strategic adjustments but the gamble may be worthwhile in correcting imbalance in the international order and in the co-evolution of the two countries.展开更多
Low contrast of Magnetic Resonance(MR)images limits the visibility of subtle structures and adversely affects the outcome of both subjective and automated diagnosis.State-of-the-art contrast boosting techniques intole...Low contrast of Magnetic Resonance(MR)images limits the visibility of subtle structures and adversely affects the outcome of both subjective and automated diagnosis.State-of-the-art contrast boosting techniques intolerably alter inherent features of MR images.Drastic changes in brightness features,induced by post-processing are not appreciated in medical imaging as the grey level values have certain diagnostic meanings.To overcome these issues this paper proposes an algorithm that enhance the contrast of MR images while preserving the underlying features as well.This method termed as Power-law and Logarithmic Modification-based Histogram Equalization(PLMHE)partitions the histogram of the image into two sub histograms after a power-law transformation and a log compression.After a modification intended for improving the dispersion of the sub-histograms and subsequent normalization,cumulative histograms are computed.Enhanced grey level values are computed from the resultant cumulative histograms.The performance of the PLMHE algorithm is comparedwith traditional histogram equalization based algorithms and it has been observed from the results that PLMHE can boost the image contrast without causing dynamic range compression,a significant change in mean brightness,and contrast-overshoot.展开更多
基金the Young Investigator Group“Artificial Intelligence for Probabilistic Weather Forecasting”funded by the Vector Stiftungfunding from the Federal Ministry of Education and Research(BMBF)and the Baden-Württemberg Ministry of Science as part of the Excellence Strategy of the German Federal and State Governments。
文摘Weather forecasts from numerical weather prediction models play a central role in solar energy forecasting,where a cascade of physics-based models is used in a model chain approach to convert forecasts of solar irradiance to solar power production.Ensemble simulations from such weather models aim to quantify uncertainty in the future development of the weather,and can be used to propagate this uncertainty through the model chain to generate probabilistic solar energy predictions.However,ensemble prediction systems are known to exhibit systematic errors,and thus require post-processing to obtain accurate and reliable probabilistic forecasts.The overarching aim of our study is to systematically evaluate different strategies to apply post-processing in model chain approaches with a specific focus on solar energy:not applying any post-processing at all;post-processing only the irradiance predictions before the conversion;post-processing only the solar power predictions obtained from the model chain;or applying post-processing in both steps.In a case study based on a benchmark dataset for the Jacumba solar plant in the U.S.,we develop statistical and machine learning methods for postprocessing ensemble predictions of global horizontal irradiance(GHI)and solar power generation.Further,we propose a neural-network-based model for direct solar power forecasting that bypasses the model chain.Our results indicate that postprocessing substantially improves the solar power generation forecasts,in particular when post-processing is applied to the power predictions.The machine learning methods for post-processing slightly outperform the statistical methods,and the direct forecasting approach performs comparably to the post-processing strategies.
文摘This article focuses on the challenges of rural economic development under the strategy of rural revitalization,and deeply analyzes the current situation of rural economic development.Research has found that although the rural revitalization strategy has achieved significant results in improving residents’quality of life,promoting agricultural modernization,it still faces challenges such as severe loss of human resources,insufficient agricultural technological innovation,and backward infrastructure construction.In response to these challenges,this paper proposes optimization strategies from three aspects:strengthening rural education and talent team construction,promoting agricultural technology innovation and achievement transformation,and increasing investment in rural infrastructure construction.
基金supported by the National Natural Science Foundation of China,82471345(to LC)the Key Research and Development Program for Social Development by the Jiangsu Provincial Department of Science and Technology.No.BE2022668(to LC).
文摘Ischemic stroke is a major cause of neurological deficits and high disability rate.As the primary immune cells of the central nervous system,microglia play dual roles in neuroinflammation and tissue repair following a stroke.Their dynamic activation and polarization states are key factors that influence the disease process and treatment outcomes.This review article investigates the role of microglia in ischemic stroke and explores potential intervention strategies.Microglia exhibit a dynamic functional state,transitioning between pro-inflammatory(M1)and anti-inflammatory(M2)phenotypes.This duality is crucial in ischemic stroke,as it maintains a balance between neuroinflammation and tissue repair.Activated microglia contribute to neuroinflammation through cytokine release and disruption of the blood-brain barrier,while simultaneously promoting tissue repair through anti-inflammatory responses and regeneration.Key pathways influencing microglial activation include Toll-like receptor 4/nuclear factor kappa B,mitogen-activated protein kinases,Janus kinase/signal transducer and activator of transcription,and phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathways.These pathways are targets for various experimental therapies aimed at promoting M2 polarization and mitigating damage.Potential therapeutic agents include natural compounds found in drugs such as minocycline,as well as traditional Chinese medicines.Drugs that target these regulatory mechanisms,such as small molecule inhibitors and components of traditional Chinese medicines,along with emerging technologies such as single-cell RNA sequencing and spatial transcriptomics,offer new therapeutic strategies and clinical translational potential for ischemic stroke.
文摘Dove’s 2017 advertising incident,which sparked widespread debate regarding perceived cultural insensitivity,highlighted a disconnect between the brand’s“Real Beauty”positioning and public reception.In response,this study proposes a strategic digital recovery framework,including revised campaign content,transparent communication through social media,and data-driven customer segmentation based on diverse skincare needs and cultural backgrounds.A PESTLE analysis underscores the importance of digital transformation and rising social consciousness in brand management.Findings suggest that inclusive messaging,precision targeting,and omnichannel digital engagement are key to restoring brand trust and reputation in the digital landscape.
基金the support from Base for Interdisciplinary Innovative Talent Training,Shanghai Jiao Tong UniversityYouth Science and Technology Innovation Studio of Shanghai Jiao Tong University School of Medicine。
文摘Neural injuries can cause considerable functional impairments,and both central and peripheral nervous systems have limited regenerative capacity.The existing conventional pharmacological treatments in clinical practice show poor targeting,rapid drug clearance from the circulatory system,and low therapeutic efficiency.Therefore,in this review,we have first described the mechanisms underlying nerve regeneration,characterized the biomaterials used for drug delivery to facilitate nerve regeneration,and highlighted the functionalization strategies used for such drug-delivery systems.These systems mainly use natural and synthetic polymers,inorganic materials,and hybrid systems with advanced drug-delivery abilities,including nanoparticles,hydrogels,and scaffoldbased systems.Then,we focused on comparing the types of drug-delivery systems for neural regeneration as well as the mechanisms and challenges associated with targeted delivery of drugs to facilitate neural regeneration.Finally,we have summarized the clinical application research and limitations of targeted delivery of these drugs.These biomaterials and drug-delivery systems can provide mechanical support,sustained release of bioactive molecules,and enhanced intercellular contact,ultimately reducing cell apoptosis and enhancing functional recovery.Nevertheless,immune reactions,degradation regulation,and clinical translations remain major unresolved challenges.Future studies should focus on optimizing biomaterial properties,refining delivery precision,and overcoming translational barriers to advance these technologies toward clinical applications.
基金supported by the National Natural Science Foundation of China[82003956]the National Key Research and Development Program of China[No.2022YFA1205802]+2 种基金financially supported by Henan Province Health Science and Technology Innovation Youth Talent Project(YQRC2023013 and YQRC2024013)the Key Project of Medical Science and Technology of Henan Province(SBGJ202302072)the Science and Technology Research Project of Henan Province(252102311236).
文摘Single-atom nanozymes(SAzymes)exhibit exceptional catalytic efficiency due to their maximized atom utilization and precisely modulated metalcarrier interactions,which have attracted significant attention in the biomedical field.However,stability issues may impede the clinical translation of SAzymes.This review provides a comprehensive overview of the applications of SAzymes in various biomedical fields,including disease diagnosis(e.g.,biosensors and diagnostic imaging),antitumor therapy(e.g.,photothermal therapy,photodynamic therapy,sonodynamic therapy,and immunotherapy),antimicrobial therapy,and anti-oxidative stress therapy.More importantly,the existing challenges of SAzymes are discussed,such as metal atom clustering and active site loss,ligand bond breakage at high temperature,insufficient environment tolerance,biosecurity risks,and limited catalytic long-term stability.Finally,several innovative strategies to address these stability concerns are proposed—synthesis process optimization(space-limited strategy,coordination site design,bimetallic synergistic strategy,defect engineering strategy,atom stripping-capture),surface modification,and dynamic responsive design—that collectively pave the way for robust,clinically viable SAzymes.
基金supported by the Natural Science Foundation of China(No.52470105)the Young Taishan Scholars Program of Shandong Province(No.358202103017).
文摘The discharge of micro-polluted water from sources such as agricultural runoff,urban stormwater,and treated effluents presents significant challenges to aquatic ecosystems.Constructed wetlands(CWs)have gained recog-nition as an eco-friendly solution for removing pollutants from various wastewater sources and are increasingly applied for micro-polluted water treatment.By reviewing 78 full-scale CW studies from Web of Science,it is summarized that the ranges of ammonium nitrogen(NH4+-N)concentrations in runoff,wastewater treatment plant effluent and polluted river were 0.1–6.6,0.3–12.3,and 0.2–41.1 mg/L,respectively.The ranges of ni-trate nitrogen concentrations were 0.2–14.2,0–5.7,and 0–2.6 mg/L,respectively.Removal efficiencies of CWs for micro-polluted water varied by CW types.The total nitrogen removal efficiencies for subsurface-flow CWs,free-water surface-flow CWs,and hybrid CWs ranged from 27.4%to 66.5%,16.8%to 89.8%,and 19.4%to 88.2%,respectively.The NH4+-N removal efficiencies ranged from 34.2%to 73.6%,38.4%to 89.4%and 13.5%to 94.2%,respectively.Additionally,other factors influencing contaminant removal efficiency such as hydraulic retention time,vegetation types,redox micro-environment and influent water quality were evaluated.Based on these findings,two strategies for improving the purification performance of CWs were proposed:the selection of incorporating electron donor substrates and the optimization of operation parameters.This paper serves as a synthesis of information to guide future research and full-scale CW applications in micro-polluted water treatment.
文摘Conventional locking/release mechanisms often face challenges in aircraft wing separation processes,such as excessive impact loads and insufficient synchronization.These may cause structural damage to the airframe or attitude instability,seriously compromising mission reliability.To address this engineering challenge,this paper proposes a multi-point low-impact locking/release mechanism based on the mobility model and energy conversion strategy.Through establishing a DOF constraint framework system,this paper systematically analyzes the energy transfer and conversion characteristics during the wing separation process,reveals the generation mechanism of impact loads,and conducts research on low-impact design based on energy conversion strategy.Building on this foundation,a single-point locking/release mechanism employing parallel trapezoidal key shaft structure was designed,which increases frictional contact time and reduces the energy release rate,thereby achieving low-impact characteristics.The mechanism's performance was validated through physical prototype development and systematic functional testing(including unlocking force,synchronization,and impact tests).Experimental results demonstrate:(1)Under 14 kN preload condition,the maximum unlocking force was only 92.54 N,showing a linear relationship with preload that satisfies the"strong-connection/weak-unlock"design requirement;(2)Wing separation was completed within 46 ms,with synchronization time difference among three separation mechanisms stably controlled within 12-14 ms,proving rapid and reliable operation;(3)The unlocking impact acceleration ranged between 26 and 73 g,below the 100 g design limit,confirming the effectiveness of the energy conversion strategy.The proposed low-impact locking/release mechanism design method based on energy conversion strategy resolves the traditional challenges of high impact and synchronization deficiencies.The synergistic optimization mechanism of"structural load reduction and performance improvement"provides a highly reliable technical solution for wing separable mechanisms while offering novel design insights for wing connection/separation systems engineering.
基金supports from the National Natural Science Foundation of China(Grant Nos.12305372 and 22376217)the National Key Research&Development Program of China(Grant Nos.2022YFA1603802 and 2022YFB3504100)+1 种基金the projects of the key laboratory of advanced energy materials chemistry,ministry of education(Nankai University)key laboratory of Jiangxi Province for persistent pollutants prevention control and resource reuse(2023SSY02061)are gratefully acknowledged.
文摘Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespread attention for CO_(2)RR due to their high catalytic activity,selectivity,excellent stability,and low cost.However,they still need to be further improved to meet the needs of industrial applications.This review article comprehensively summarizes the recent advances in regulation strategies of Bi-based catalysts and can be divided into six categories:(1)defect engineering,(2)atomic doping engineering,(3)organic framework engineering,(4)inorganic heterojunction engineering,(5)crystal face engineering,and(6)alloying and polarization engineering.Meanwhile,the corresponding catalytic mechanisms of each regulation strategy will also be discussed in detail,aiming to enable researchers to understand the structure-property relationship of the improved Bibased catalysts fundamentally.Finally,the challenges and future opportunities of the Bi-based catalysts in the photoelectrocatalytic CO_(2)RR application field will also be featured from the perspectives of the(1)combination or synergy of multiple regulatory strategies,(2)revealing formation mechanism and realizing controllable synthesis,and(3)in situ multiscale investigation of activation pathways and uncovering the catalytic mechanisms.On the one hand,through the comparative analysis and mechanism explanation of the six major regulatory strategies,a multidimensional knowledge framework of the structure-activity relationship of Bi-based catalysts can be constructed for researchers,which not only deepens the atomic-level understanding of catalytic active sites,charge transport paths,and the adsorption behavior of intermediate products,but also provides theoretical guiding principles for the controllable design of new catalysts;on the other hand,the promising collaborative regulation strategies,controllable synthetic paths,and the in situ multiscale characterization techniques presented in this work provides a paradigm reference for shortening the research and development cycle of high-performance catalysts,conducive to facilitating the transition of photoelectrocatalytic CO_(2)RR technology from the laboratory routes to industrial application.
文摘In the present computational fluid dynamics （CFD） community, post-processing is regarded as a procedure to view parameter distribution, detect characteristic structure and reveal physical mechanism of fluid flow based on computational or experimental results. Field plots by contours, iso-surfaces, streamlines, vectors and others are traditional post-processing techniques. While the shock wave, as one important and critical flow structure in many aerodynamic problems, can hardly be detected or distinguished in a direct way using these traditional methods, due to possible confusions with other similar discontinuous flow structures like slip line, contact discontinuity, etc. Therefore, method for automatic detection of shock wave in post-processing is of great importance for both academic research and engineering applications. In this paper, the current status of methodologies developed for shock wave detection and implementations in post-processing platform are reviewed, as well as discussions on advantages and limitations of the existing methods and proposals for further studies of shock wave detection method. We also develop an advanced post-processing software, with improved shock detection.
基金Supported by the Chinese Academy of Sciences Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics,Shanghai Branch,University of Science and Technology of Chinathe National Natural Science Foundation of China under Grant No 11405172
文摘Quantum random number generators adopting single negligible dead time of avalanche photodiodes （APDs） photon detection have been restricted due to the non- We propose a new approach based on an APD array to improve the generation rate of random numbers significantly. This method compares the detectors＇ responses to consecutive optical pulses and generates the random sequence. We implement a demonstration experiment to show its simplicity, compactness and scalability. The generated numbers are proved to be unbiased, post-processing free, ready to use, and their randomness is verified by using the national institute of standard technology statistical test suite. The random bit generation efficiency is as high as 32.8% and the potential generation rate adopting the 32× 32 APD array is up to tens of Gbits/s.
基金Projects 50221402, 50490271 and 50025413 supported by the National Natural Science Foundation of Chinathe National Basic Research Program of China (2009CB219603, 2009 CB724601, 2006CB202209 and 2005CB221500)+1 种基金the Key Project of the Ministry of Education (306002)the Program for Changjiang Scholars and Innovative Research Teams in Universities of MOE (IRT0408)
文摘In order to carry out numerical simulation using geologic structural data obtained from Landmark(seismic interpretation system), underground geological structures are abstracted into mechanical models which can reflect actual situations and facilitate their computation and analyses.Given the importance of model building, further processing methods about traditional seismic interpretation results from Landmark should be studied and the processed result can then be directly used in numerical simulation computations.Through this data conversion procedure, Landmark and FLAC(the international general stress software) are seamlessly connected.Thus, the format conversion between the two systems and the pre-and post-processing in simulation computation is realized.A practical application indicates that this method has many advantages such as simple operation, high accuracy of the element subdivision and high speed, which may definitely satisfy the actual needs of floor grid cutting.
文摘The travel time data collection method is used to assist the congestion management. The use of traditional sensors (e.g. inductive loops, AVI sensors) or more recent Bluetooth sensors installed on major roads for collecting data is not sufficient because of their limited coverage and expensive costs for installation and maintenance. Application of the Global Positioning Systems (GPS) in travel time and delay data collections is proven to be efficient in terms of accuracy, level of details for the data and required data collection of man-power. While data collection automation is improved by the GPS technique, human errors can easily find their way through the post-processing phase, and therefore data post-processing remains a challenge especially in case of big projects with high amount of data. This paper introduces a stand-alone post-processing tool called GPS Calculator, which provides an easy-to-use environment to carry out data post-processing. This is a Visual Basic application that processes the data files obtained in the field and integrates them into Geographic Information Systems (GIS) for analysis and representation. The results show that this tool obtains similar results to the currently used data post-processing method, reduces the post-processing effort, and also eliminates the need for the second person during the data collection.
基金supported by the New Century Excellent Talents in University(NCET-09-0396)the National Science&Technology Key Projects of Numerical Control(2012ZX04014-031)+1 种基金the Natural Science Foundation of Hubei Province(2011CDB279)the Foundation for Innovative Research Groups of the Natural Science Foundation of Hubei Province,China(2010CDA067)
文摘When castings become complicated and the demands for precision of numerical simulation become higher,the numerical data of casting numerical simulation become more massive.On a general personal computer,these massive numerical data may probably exceed the capacity of available memory,resulting in failure of rendering.Based on the out-of-core technique,this paper proposes a method to effectively utilize external storage and reduce memory usage dramatically,so as to solve the problem of insufficient memory for massive data rendering on general personal computers.Based on this method,a new postprocessor is developed.It is capable to illustrate filling and solidification processes of casting,as well as thermal stess.The new post-processor also provides fast interaction to simulation results.Theoretical analysis as well as several practical examples prove that the memory usage and loading time of the post-processor are independent of the size of the relevant files,but the proportion of the number of cells on surface.Meanwhile,the speed of rendering and fetching of value from the mouse is appreciable,and the demands of real-time and interaction are satisfied.
基金supported by the National Natural Science Foundation of China(51875535)the Natural Science Foundation for Young Scientists of Shanxi Province(201701D221017,201901D211242)。
文摘To improve the ability of detecting underwater targets under strong wideband interference environment,an efficient method of line spectrum extraction is proposed,which fully utilizes the feature of the target spectrum that the high intense and stable line spectrum is superimposed on the wide continuous spectrum.This method modifies the traditional beam forming algorithm by calculating and fusing the beam forming results at multi-frequency band and multi-azimuth interval,showing an excellent way to extract the line spectrum when the interference and the target are not in the same azimuth interval simultaneously.Statistical efficiency of the estimated azimuth variance and corresponding power of the line spectrum band depends on the line spectra ratio(LSR)of the line spectrum.The change laws of the output signal to noise ratio(SNR)with the LSR,the input SNR,the integration time and the filtering bandwidth of different algorithms bring the selection principle of the critical LSR.As the basis,the detection gain of wideband energy integration and the narrowband line spectrum algorithm are theoretically analyzed.The simulation detection gain demonstrates a good match with the theoretical model.The application conditions of all methods are verified by the receiver operating characteristic(ROC)curve and experimental data from Qiandao Lake.In fact,combining the two methods for target detection reduces the missed detection rate.The proposed post-processing method in2-dimension with the Kalman filter in the time dimension and the background equalization algorithm in the azimuth dimension makes use of the strong correlation between adjacent frames,could further remove background fluctuation and improve the display effect.
基金financial supports from the National Natural Science Foundation of China (Grant Nos. 41461040, 41601614, 41601176)the Fundamental Research Funds for the Central Universities (JBK2102018)the Sichuan Center for Rural Development Research (CR2107, Mechanism of Farmers’ Livelihoods on Ecological Security in Ethnic Regions in Sichuan Province)。
文摘Social capital in the form of social resources or social networks is one of the most important livelihood capital of farmers, which can increase the labor productivity of poor households and increase income. It is important to explore the reasons underlying the livelihood strategy choices of farmers from the perspective of social capital under China’s rural revitalization strategy. In this study, the Liangshan Yi Autonomous Prefecture, a povertystricken mountainous area in southwestern China, was selected as the case study area, and multivariable linear regression models were constructed to analyze the influence of social capital on livelihood strategies.The results are as follows:(1) Individual social capital had a positive effect on non-agricultural livelihood strategies. On average, with a one-unit increase in individual social capital, the ratio of farmers’ nonagricultural income to total productive income(Income_Rto) increased by 0.002% and 0.062%,respectively. Collective social capital, with the Peasant Economic Cooperation Organization(PECO) as the carrier, had a negative effect on the non-agricultural livelihood strategies of farmers;on average, with a oneunit increase in PECO, Income_Rto decreased by approximately 0.053%. However, this effect was only significant in the river valley area.(2) The income differences among the different livelihood strategy types were explained by the livelihood strategy choices of farmers. As non-agricultural work can bring more benefits, the labor force exhibited one-way migration from villages to cities, resulting in a lack of the subject of rural revitalization. It is necessary to implement effective measures to highlight the role of PECO in increasing agricultural income for farmers. Finally,based on the above conclusions,policy recommendations with respect to livelihood transformation of farmers and rural sustainable development are discussed.
文摘This paper proposed improvements to the low bit rate parametric audio coder with sinusoid model as its kernel. Firstly, we propose a new method to effectively order and select the perceptually most important sinusoids. The sinusoid which contributes most to the reduction of overall NMR is chosen. Combined with our improved parametric psychoacoustic model and advanced peak riddling techniques, the number of sinusoids required can be greatly reduced and the coding efficiency can be greatly enhanced. A lightweight version is also given to reduce the amount of computation with only little sacrifice of performance. Secondly, we propose two enhancement techniques for sinusoid synthesis: bandwidth enhancement and line enhancement. With little overhead, the effective bandwidth can be extended one more octave; the timbre tends to sound much brighter, thicker and more beautiful.
文摘Since confidence is fading and anxiety is increasing in the US,America’s China policy has become more radical. In the short term, the US has the upper hand and China is in a relatively passive position. In the medium-and long-term, there will be more balance between them. This current strategic gambling between China and the US will be the major issue of international politics in the first half of the 21 st century and the most prominent external challenge China faces. China needs to make strategic adjustments but the gamble may be worthwhile in correcting imbalance in the international order and in the co-evolution of the two countries.
基金This work was supported by Taif university Researchers Supporting Project Number(TURSP-2020/114),Taif University,Taif,Saudi Arabia.
文摘Low contrast of Magnetic Resonance(MR)images limits the visibility of subtle structures and adversely affects the outcome of both subjective and automated diagnosis.State-of-the-art contrast boosting techniques intolerably alter inherent features of MR images.Drastic changes in brightness features,induced by post-processing are not appreciated in medical imaging as the grey level values have certain diagnostic meanings.To overcome these issues this paper proposes an algorithm that enhance the contrast of MR images while preserving the underlying features as well.This method termed as Power-law and Logarithmic Modification-based Histogram Equalization(PLMHE)partitions the histogram of the image into two sub histograms after a power-law transformation and a log compression.After a modification intended for improving the dispersion of the sub-histograms and subsequent normalization,cumulative histograms are computed.Enhanced grey level values are computed from the resultant cumulative histograms.The performance of the PLMHE algorithm is comparedwith traditional histogram equalization based algorithms and it has been observed from the results that PLMHE can boost the image contrast without causing dynamic range compression,a significant change in mean brightness,and contrast-overshoot.
