Along with decrease of fine particulate matter(PM_(2.5))concentration in recent years in China,secondary species become increasingly important.This work focuses on characterizing secondary components,and a few importa...Along with decrease of fine particulate matter(PM_(2.5))concentration in recent years in China,secondary species become increasingly important.This work focuses on characterizing secondary components,and a few important groups of organics including organic nitrogen(ON),organonitrates(OrgN),organosulfates(OS)and polycyclic aromatic hydrocarbons(PAHs),via online measurement of submicron aerosols(PM_(1))in Nanjing,China,during 2022 summer.The average PM_(1) concentration was 15.39μg/m^(3),dominated by secondary components(69.1%),which were even more important at higher PM_(1) levels.The primary organic aerosols(POA)were from traffic,industry and cooking;the two secondary OA factors were both closely linked with photochemistry,with one(OOA1)being relatively fresh and important in early afternoon and another(OOA2)being aged and important in late afternoon.Sulfate formation was also governed by photochemistry but resembled that of OOA2 not OOA1;nitrate formation was associated strongly with heterogeneous hydrolysis and thermodynamic equilibrium.Results also reveal a possible photochemical reaction channel from POA to OOA1,then to OOA2.Case studies show that formations of secondary components responded differently to different weather conditions and governed summer PM_(1) pollution.The average ON,OrgN,OS and PAHs concentrations were determined to be 122.8,84.4,45.6 and 3.3 ng/m^(3),respectively.ON was dominated by primary sources(53.8%).OrgN varied similarly to nitrate.OS formation was linked with aqueous-phase reactions,which were insignificant therefore its level was low.PAHs was mainly from traffic,and photochemical oxidation might be its important sink during afternoon.展开更多
Organic electrochemical transistor(OECT)devices demonstrate great promising potential for reservoir computing(RC)systems,but their lack of tunable dynamic characteristics limits their application in multi-temporal sca...Organic electrochemical transistor(OECT)devices demonstrate great promising potential for reservoir computing(RC)systems,but their lack of tunable dynamic characteristics limits their application in multi-temporal scale tasks.In this study,we report an OECT-based neuromorphic device with tunable relaxation time(τ)by introducing an additional vertical back-gate electrode into a planar structure.The dual-gate design enablesτreconfiguration from 93 to 541 ms.The tunable relaxation behaviors can be attributed to the combined effects of planar-gate induced electrochemical doping and back-gateinduced electrostatic coupling,as verified by electrochemical impedance spectroscopy analysis.Furthermore,we used theτ-tunable OECT devices as physical reservoirs in the RC system for intelligent driving trajectory prediction,achieving a significant improvement in prediction accuracy from below 69%to 99%.The results demonstrate that theτ-tunable OECT shows a promising candidate for multi-temporal scale neuromorphic computing applications.展开更多
Digital watermarking technology plays an important role in detecting malicious tampering and protecting image copyright.However,in practical applications,this technology faces various problems such as severe image dis...Digital watermarking technology plays an important role in detecting malicious tampering and protecting image copyright.However,in practical applications,this technology faces various problems such as severe image distortion,inaccurate localization of the tampered regions,and difficulty in recovering content.Given these shortcomings,a fragile image watermarking algorithm for tampering blind-detection and content self-recovery is proposed.The multi-feature watermarking authentication code(AC)is constructed using texture feature of local binary patterns(LBP),direct coefficient of discrete cosine transform(DCT)and contrast feature of gray level co-occurrence matrix(GLCM)for detecting the tampered region,and the recovery code(RC)is designed according to the average grayscale value of pixels in image blocks for recovering the tampered content.Optimal pixel adjustment process(OPAP)and least significant bit(LSB)algorithms are used to embed the recovery code and authentication code into the image in a staggered manner.When detecting the integrity of the image,the authentication code comparison method and threshold judgment method are used to perform two rounds of tampering detection on the image and blindly recover the tampered content.Experimental results show that this algorithm has good transparency,strong and blind detection,and self-recovery performance against four types of malicious attacks and some conventional signal processing operations.When resisting copy-paste,text addition,cropping and vector quantization under the tampering rate(TR)10%,the average tampering detection rate is up to 94.09%,and the peak signal-to-noise ratio(PSNR)of the watermarked image and the recovered image are both greater than 41.47 and 40.31 dB,which demonstrates its excellent advantages compared with other related algorithms in recent years.展开更多
The Macao Science Satellite-1(MSS-1)is the first space science satellite jointly developed on the Chinese mainland and in Macao region.It comprises two satellites,named MSS-1A and MSS-1B,and holds considerable importa...The Macao Science Satellite-1(MSS-1)is the first space science satellite jointly developed on the Chinese mainland and in Macao region.It comprises two satellites,named MSS-1A and MSS-1B,and holds considerable importance in China’s space exploration endeavors.Among these,MSS-1A is the world’s first high-precision scientific satellite dedicated to exploring the geomagnetic field and space environment at low latitudes.Equipped with two high-precision vector magnetometers and one scalar magnetometer,which are integrally installed on a highly stable nonmagnetic optical bench,the MSS-1A enables simultaneous high-precision measurements of both the Earth’s vector magnetic field and its scalar components.Its design integrates several state-of-the-art technologies,including arc-second-level thermal stability control,nonmagnetic thermal control for the optical bench,and ultra-high magnetic cleanliness control.These innovations effectively minimize magnetic interference originating from the satellite itself,thereby substantially improving the precision of geomagnetic field measurements and establishing a robust technical foundation for future magnetic survey satellite constellations.展开更多
In order to further promote the standardization of diagnosis and treatment of gastrointestinal stromal tumor （GIST） in China, the members of Chinese Society of Clinical Oncology （CSCO） Expert Committee on GIST tho...In order to further promote the standardization of diagnosis and treatment of gastrointestinal stromal tumor （GIST） in China, the members of Chinese Society of Clinical Oncology （CSCO） Expert Committee on GIST thoroughly discussed the key contents of the consensus guidelines, and voted on the controversial issue. In final, the Chinese consensus guidelines for the diagnosis and management of GIST （2017 edition） was formed on the basis of 2013 edition consensus guidelines, which is hereby announced. The consensus included the pathological diagnosis, recurrence risk classification evaluation, targeted agent therapy, surgery and principles of surveillance of GIST.展开更多
In complex water environments,search tasks often involve multiple Autonomous Underwater Vehicles(AUVs),and a single centralized control cannot handle the complexity and computational burden of large-scale systems.Targ...In complex water environments,search tasks often involve multiple Autonomous Underwater Vehicles(AUVs),and a single centralized control cannot handle the complexity and computational burden of large-scale systems.Target search in complex water environments has always been a major challenge in the field of underwater robots.To address this problem,this paper proposes a multi-biomimetic robot fish collaborative target search method based on Distributed Model Predictive Control(DMPC).First,we established a bionic robot fish kinematic model and a multi-biomimetic robot fish communication model;second,this paper proposed a distributed model predictive control algorithm based on the distributed search theory framework,so that the bionic robot fish can dynamically adjust their search path according to each other’s position information and search status,avoid repeated coverage or missing areas,and thus improve the search efficiency;third,we conducted simulation experiments based on DMPC,and the results showed that the proposed method has a target search success rate of more than 90%in static targets,dynamic targets,and obstacle environments.Finally,we compared this method with Centralized Model Predictive Control(CMPC)and Random Walk(RW)algorithms.The DMPC approach demonstrates significant advantages,achieving a remarkable target search success rate of 94.17%.These findings comprehensively validate the effectiveness and superiority of the proposed methodology.It can be seen that DMPC can effectively dispatch multiple bionic robot fish to work together to achieve efficient search of vast waters.It can significantly improve the flexibility,scalability,robustness and cooperation efficiency of the system and has broad application prospects.展开更多
Understanding vegetation water availability can be important for managing vegetation and combating climate change.Changes in vegetation water availability throughout China remains poorly understood,especially at a hig...Understanding vegetation water availability can be important for managing vegetation and combating climate change.Changes in vegetation water availability throughout China remains poorly understood,especially at a high spatial resolution.Standardized Precipitation Evapotranspiration Index(SPEI)is an ideal water availability index for assessing the spatiotemporal characteristics of drought and investigating the vegetation-water availability relationship.However,no high-resolution and long-term SPEI datasets over China are available.To fill this gap,we developed a new model based on machine learning to obtain high-resolution(1 km)SPEI data by combining climate variables with topographical and geographical features.Here,we analyzed the long-term drought over the past century(1901–2020)and vegetation-water availability relationship in the past two decades(2000–2020).The century-long drought trend analyses indicated an overall drying trend across China with increasing drought frequency,duration,and severity during the past century.We found that drought events in 1901–1961 showed a larger increase than that in 1961–2020,with the Qinghai-Xizang Plateau showing a significant drying trend during 1901–1960 but a wetting trend during 1961–2020.There were 13.90%and 28.21%of vegetation in China showing water deficit and water surplus respectively during 2000–2020.The water deficit area significantly shrank from 2000 to 2020 across China,which is dominated by the significant decrease in water deficit areas in South China.Among temperature,precipitation,and vegetation abundance,temperature is the most important factor for the vegetation-water availability dynamics in China over the past two decades,with high temperature contributing to water deficit.Our findings are important for water and vegetation management under a warming climate.展开更多
CO_(2) hydrate-based sequestration in submarine sediments shows great potential for carbon emission reduction.Considering the proportional relationship of CO_(2) and water for hydrates formation,their existing ratio l...CO_(2) hydrate-based sequestration in submarine sediments shows great potential for carbon emission reduction.Considering the proportional relationship of CO_(2) and water for hydrates formation,their existing ratio largely determines the CO_(2) sequestration density and phase state.Here,this work focuses on determining the optimal ratio of CO_(2) to seawater in sediments simulated with 20-40 mesh(0.42-0.85 mm) quartz sand,in order to maximize CO_(2) hydrate conversion in sediments.The results show that the conversion rate of CO_(2) hydrate increases with the initial water saturation,reaching 15.3%at 80% initial water saturation.The optimal CO_(2) hydrate formation occurs at 30% initial water saturation,with the corresponding CO_(2) storage density in hydrate form of 33.09 kg·m^(-3) and the hydrate saturation of 22.3%.However,CO_(2) hydrate conversion rate is <10%,which implies that most CO2 still exists in liquid state,despite the presence of free water.The total CO_(2) sequestration density is negatively correlated with the initial water saturation,and at 10% initial water saturation,398.73 kg·m^(-3) of CO_(2) is sequestered,of which only 18.02 kg·m^(-3) is hydrated.Additionally,the lower initial water saturation corresponds to the shorter time to achieve t_(90) of CO_(2) consumption,and the water conversion rate to hydrate reaches 90% at 10% initial water saturation.In summary,adjusting the volume ratio of liquid CO_(2) to seawater can effectively increase the sequestration amount of CO_(2) hydrates,but methods to increase CO_(2) conversion to hydrate still need to be established.展开更多
Objective:As an age-related neurodegenerative disease,the prevalence of mild cognitive impairment(MCI)increases with age.Within the framework of traditional Chinese medicine,spleen-kidney deficiency syndrome(SKDS)is r...Objective:As an age-related neurodegenerative disease,the prevalence of mild cognitive impairment(MCI)increases with age.Within the framework of traditional Chinese medicine,spleen-kidney deficiency syndrome(SKDS)is recognized as the most frequent MCI subtype.Due to the covert and gradual onset of MCI,in community settings it poses a significant challenge for patients and their families to discern between typical aging and pathological changes.There exists an urgent need to devise a preliminary diagnostic tool designed for community-residing older adults with MCI attributed to SKDS(MCI-SKDS).Methods:This investigation enrolled 312 elderly individuals diagnosed with MCI,who were randomly distributed into training and test datasets at a 3:1 ratio.Five machine learning methods,including logistic regression(LR),decision tree(DT),naive Bayes(NB),support vector machine(SVM),and gradient boosting(GB),were used to build a diagnostic prediction model for MCI-SKDS.Accuracy,sensitivity,specificity,precision,F1 score,and area under the curve were used to evaluate model performance.Furthermore,the clinical applicability of the model was evaluated through decision curve analysis(DCA).Results:The accuracy,precision,specificity and F1 score of the DT model performed best in the training set(test set),with scores of 0.904(0.845),0.875(0.795),0.973(0.875)and 0.973(0.875).The sensitivity of the training set(test set)of the SVM model performed best among the five models with a score of 0.865(0.821).The area under the curve of all five models was greater than 0.9 for the training dataset and greater than 0.8 for the test dataset.The DCA of all models showed good clinical application value.The study identified ten indicators that were significant predictors of MCI-SKDS.Conclusion:The risk prediction index derived from machine learning for the MCI-SKDS prediction model is simple and practical;the model demonstrates good predictive value and clinical applicability,and the DT model had the best performance.展开更多
AIM:To estimate if nanopore targeted sequencing(NTS)could identify pathogens causing postoperative endophthalmitis and further determine the feasibility of clinical application of NTS.METHODS:A total of 55 patients(55...AIM:To estimate if nanopore targeted sequencing(NTS)could identify pathogens causing postoperative endophthalmitis and further determine the feasibility of clinical application of NTS.METHODS:A total of 55 patients(55 eyes)with postoperative endophthalmitis were retrospectively included in this study with their medical records.Intraocular fluid samples were examined by NTS and microbial culture.All included patients had undergone examinations including measurement of best corrected visual acuity(BCVA)and intraocular pressure(IOP),slit-lamp biomicroscopy,and indirect ophthalmoscopy;additionally,they underwent B-ultrasound,anterior segment photography,and fundus photography if necessary.RESULTS:Among 55 patients with postoperative endophthalmitis,the age was 65.25±15.04y and there were 30 female(54.54%)patients.Forty-one(74.54%)vitreous humor samples and fourteen(25.45%)aqueous humor samples were sent for both NTS and microbial culture.NTS had a notable higher detection rate than microbial culture in detecting pathogens(90.91%vs 38.18%,χ^(2)=33.409,P<0.001).NTS exhibited high sensitivity of pathogen detection in both microbial culture positive and negative samples(100%and 85.29%,respectively).In 16 of 21(76.19%)patients who showed culture-positivity,their results corresponded with those of NTS.Moreover,in two patients(9.52%),NTS showed a better species resolution than microbial culture;in three patients(14.28%),NTS identified additional pathogens.As for fungus,the positive detection rate of NTS was significantly higher than that of microbial culture(20%vs 3.64%,χ^(2)=7.066,P=0.008).Also,NTS could detect multi-infection by bacteria and fungi than microbial culture(32.73%vs 0,χ^(2)=21.522,P<0.001).NTS could detect bacteria as well as fungi simultaneously within 48h in all patients.Meanwhile,NTS had a shorter detection time than microbial culture(1.13±0.34 vs 2.67±0.55d,Z=-9.218,P<0.001).After the NTS results were obtained,15 patients received additional intravitreal/intracameral anti-infection treatment.At follow-up,there was a statistically significant improvement in the visual acuity relative to the baseline(Z=−5.222,P<0.001).CONCLUSION:NTS can provide rapid identification and highly sensitive detection of pathogens among patients with postoperative endophthalmitis,which can guide anti-infection treatment and improve visual prognosis.展开更多
Plastic waste recycling is a focal point in today's sustainable development efforts.Improper disposal can lead to secondary pollution,posing threats to the environment and human health.In this study,we aim to recy...Plastic waste recycling is a focal point in today's sustainable development efforts.Improper disposal can lead to secondary pollution,posing threats to the environment and human health.In this study,we aim to recycle waste epoxy resin and glass fiber-reinforced epoxy resin composites via an electroless plating and a carbonization process,to design high-value-added carbon materials for microwave absorption.By pulverizing solid waste and introducing magnetic metal nanoparticles onto its surface,a composite carbon material capable of excellent microwave absorption performance was successfully developed.Specifically,doping nickel particles into carbon materials derived from glass fiber/epoxy resin achieved a wide effective absorption bandwidth(EAB)of 5.9 GHz with a matching thickness of 1.9 mm,covering nearly the entire Ku band,and achieving a minimum reflection loss(RLmin)of−36 dB simultaneously.The superior absorption performance is attributed to multiple reflections or scattering of electromagnetic waves within the material,as well as conduction and magnetic losses,dipole and interfacial polarization effects.These results demonstrate that through rational design and optimization,waste epoxy and waste glass fiber-reinforced epoxy resin-based composite materials can be effectively recycled into high-performance microwave absorbing materials,offering a straightforward and efficient pathway for waste resource utilization.展开更多
Promoting the development of deep-sea mineral exploration instrumentation can help alleviate the global resource shortage faced by mankind.X-ray fluorescence(XRF)spectrometry has been widely used in the in situ analys...Promoting the development of deep-sea mineral exploration instrumentation can help alleviate the global resource shortage faced by mankind.X-ray fluorescence(XRF)spectrometry has been widely used in the in situ analysis of deep-sea minerals owing to its fast analytical speed,nondestructive nature,and wide analytical range.This study focused on the structural safety and detection efficiency of X-ray fluorescence in situ measurement equipment under high pressure for deep-sea XRF analysis.This study first combined finite element analysis and experiments to design and optimize the structure of an X-ray probe tube required for deep-sea mineral exploration and to determine the Be window thickness to ensure stress safety.Subsequently,the Monte Carlo method was used to analyze and optimize the Be window thickness on the X-ray probe tube to improve the accuracy of the elemental analyses.Finally,the effect of seawater thickness between the transmitter outer tube and rock wall was also considered.The results show that based on ocean depth in different detection environments,Be windows with a thickness of 1.5 mm or 2.0 mm can be selected to improve the detection efficiency of the device while ensuring the structural safety of the instrument.According to the design features and detection requirements of the device,in deep-sea exploration of minerals with characteristic peak energies below 10 keV,the transmitter outer tube should be as close as possible to the rock wall inside the logging.When the characteristic peak energy of the minerals is more than 10 keV,the distance between the transmitter outer tube and rock wall inside the logging should be controlled to approximately 2 mm.This study provides feasible solutions for future deep-sea mineral resource development and a useful reference for elemental analysis of minerals in the deep-sea or other extreme working environments.展开更多
Lithium-ion batteries(LIBs)play a critical role in reducing carbon emissions in the automotive industry.However,they face challenges related to safety and performance failures.Smart technologies offer a promising solu...Lithium-ion batteries(LIBs)play a critical role in reducing carbon emissions in the automotive industry.However,they face challenges related to safety and performance failures.Smart technologies offer a promising solution to address these issues.Bioinspired microcapsules are a common approach to enhancing the performance and safety of smart LIBs.However,despite their potential,this area has not been thoroughly explored.This review provides an overview of the preparation methods for microcapsules,including physical,chemical,and physicochemical techniques.These microcapsules are categorized based on their mechanisms into electrode self-healing burst microcapsules,interphase-forming sustained-release microcapsules,live-lithium sustained-release microcapsules,and flame-retardant burst microcapsules.A comprehensive analysis of their bioinspired design concepts,mechanisms,and performance is presented,along with the design criteria for microcapsules suitable for LIBs.Finally,the review explores the potential applications of microcapsule technologies in LIBs and their future trends,such as enhancing existing technologies for novel applications like solid-state batteries and developing new types of microcapsules.This review aims to provide a foundation for the implementation of microcapsule technologies in LIBs and to highlight the latest advancements in smart batteries.展开更多
Indoxyl sulfate(IS),a protein-bound indole toxin,is currently a key research focus regarding uremic toxins and renal injury both in China and internationally.Studies have shown that IS can upregulate the expression of...Indoxyl sulfate(IS),a protein-bound indole toxin,is currently a key research focus regarding uremic toxins and renal injury both in China and internationally.Studies have shown that IS can upregulate the expression of TGF-β1,TIMP-1,and pro-α1(I),induce the production of free radicals,decrease superoxide scavenging activity,and promote the apoptosis of renal tubular epithelial cells,thereby exacerbating renal damage.As metabolomics research progresses,IS is emerging as a potential new biomarker for kidney injury.This paper reviews the progress of research on the application of IS in kidney injury over the past decade,drawing on resources from databases such as the CNKI and PubMed.The aim is to provide insights that can aid in clinical individualized treatment,enhancing the safety and effectiveness of patient care.展开更多
Haze (known as “Mai” 霾 in Chinese) threatens the health of billions of people across the globe. To begin solving this problem without severely slowing down the economy, one has to mechanistically and geographically...Haze (known as “Mai” 霾 in Chinese) threatens the health of billions of people across the globe. To begin solving this problem without severely slowing down the economy, one has to mechanistically and geographically pinpoint the sources of these pollutants, the key of which is to thoroughly characterize and fingerprint the particulates. Here we present a broad survey and classification of thousands of individual airborne particu-lates by using the Scanning Electron Microscope (SEM) to measure their diverse mor-phologies and chemistries, which could eventually be organized into a “haze finger-print database”. For instance, one collection in Xi’an City, China during March-April 2014 yielded 494 airborne particulates that settled on silicon wafers placed outside the window of a 3<sup>rd</sup> floor office. These 494 particulates were manually imaged with high resolution (down to 2 nm), elementally mapped using Energy-dispersive X-ray Spec-troscopy (EDS), and were identified and categorized into presumed source classes such as construction activities (Ca, Al, Si-O), coal burning (sulfates), biologic (pollen, bac-teria), automotive, mining, steel making, and etc. About 20% of the particulates have mysterious origins, as it is still unclear how they were formed, and a fraction of them contained clearly hazardous elements such as lead and chromium. For future work, we propose using unmanned aerial vehicles with a special “rolling film” substrate that can autonomously collect airborne particulates, a customized SEM auto-imaging system, and machine learning software to establish an online open-access database. The end goal would be to monitor and analyze the particulate pollutants that are pumped into our atmosphere every day, and precisely track down their sources so we can better model and police the quality of the air around us.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22361162668 and 42021004)the National Key Research and Development Program of China(No.2023YFC3706203).
文摘Along with decrease of fine particulate matter(PM_(2.5))concentration in recent years in China,secondary species become increasingly important.This work focuses on characterizing secondary components,and a few important groups of organics including organic nitrogen(ON),organonitrates(OrgN),organosulfates(OS)and polycyclic aromatic hydrocarbons(PAHs),via online measurement of submicron aerosols(PM_(1))in Nanjing,China,during 2022 summer.The average PM_(1) concentration was 15.39μg/m^(3),dominated by secondary components(69.1%),which were even more important at higher PM_(1) levels.The primary organic aerosols(POA)were from traffic,industry and cooking;the two secondary OA factors were both closely linked with photochemistry,with one(OOA1)being relatively fresh and important in early afternoon and another(OOA2)being aged and important in late afternoon.Sulfate formation was also governed by photochemistry but resembled that of OOA2 not OOA1;nitrate formation was associated strongly with heterogeneous hydrolysis and thermodynamic equilibrium.Results also reveal a possible photochemical reaction channel from POA to OOA1,then to OOA2.Case studies show that formations of secondary components responded differently to different weather conditions and governed summer PM_(1) pollution.The average ON,OrgN,OS and PAHs concentrations were determined to be 122.8,84.4,45.6 and 3.3 ng/m^(3),respectively.ON was dominated by primary sources(53.8%).OrgN varied similarly to nitrate.OS formation was linked with aqueous-phase reactions,which were insignificant therefore its level was low.PAHs was mainly from traffic,and photochemical oxidation might be its important sink during afternoon.
基金supported by the National Key Research and Development Program of China under Grant 2022YFB3608300in part by the National Nature Science Foundation of China(NSFC)under Grants 62404050,U2341218,62574056,62204052。
文摘Organic electrochemical transistor(OECT)devices demonstrate great promising potential for reservoir computing(RC)systems,but their lack of tunable dynamic characteristics limits their application in multi-temporal scale tasks.In this study,we report an OECT-based neuromorphic device with tunable relaxation time(τ)by introducing an additional vertical back-gate electrode into a planar structure.The dual-gate design enablesτreconfiguration from 93 to 541 ms.The tunable relaxation behaviors can be attributed to the combined effects of planar-gate induced electrochemical doping and back-gateinduced electrostatic coupling,as verified by electrochemical impedance spectroscopy analysis.Furthermore,we used theτ-tunable OECT devices as physical reservoirs in the RC system for intelligent driving trajectory prediction,achieving a significant improvement in prediction accuracy from below 69%to 99%.The results demonstrate that theτ-tunable OECT shows a promising candidate for multi-temporal scale neuromorphic computing applications.
基金supported by Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(Grant No.SJCX24_1332)Jiangsu Province Education Science Planning Project in 2024(Grant No.B-b/2024/01/122)High-Level Talent Scientific Research Foundation of Jinling Institute of Technology,China(Grant No.jit-b-201918).
文摘Digital watermarking technology plays an important role in detecting malicious tampering and protecting image copyright.However,in practical applications,this technology faces various problems such as severe image distortion,inaccurate localization of the tampered regions,and difficulty in recovering content.Given these shortcomings,a fragile image watermarking algorithm for tampering blind-detection and content self-recovery is proposed.The multi-feature watermarking authentication code(AC)is constructed using texture feature of local binary patterns(LBP),direct coefficient of discrete cosine transform(DCT)and contrast feature of gray level co-occurrence matrix(GLCM)for detecting the tampered region,and the recovery code(RC)is designed according to the average grayscale value of pixels in image blocks for recovering the tampered content.Optimal pixel adjustment process(OPAP)and least significant bit(LSB)algorithms are used to embed the recovery code and authentication code into the image in a staggered manner.When detecting the integrity of the image,the authentication code comparison method and threshold judgment method are used to perform two rounds of tampering detection on the image and blindly recover the tampered content.Experimental results show that this algorithm has good transparency,strong and blind detection,and self-recovery performance against four types of malicious attacks and some conventional signal processing operations.When resisting copy-paste,text addition,cropping and vector quantization under the tampering rate(TR)10%,the average tampering detection rate is up to 94.09%,and the peak signal-to-noise ratio(PSNR)of the watermarked image and the recovered image are both greater than 41.47 and 40.31 dB,which demonstrates its excellent advantages compared with other related algorithms in recent years.
文摘The Macao Science Satellite-1(MSS-1)is the first space science satellite jointly developed on the Chinese mainland and in Macao region.It comprises two satellites,named MSS-1A and MSS-1B,and holds considerable importance in China’s space exploration endeavors.Among these,MSS-1A is the world’s first high-precision scientific satellite dedicated to exploring the geomagnetic field and space environment at low latitudes.Equipped with two high-precision vector magnetometers and one scalar magnetometer,which are integrally installed on a highly stable nonmagnetic optical bench,the MSS-1A enables simultaneous high-precision measurements of both the Earth’s vector magnetic field and its scalar components.Its design integrates several state-of-the-art technologies,including arc-second-level thermal stability control,nonmagnetic thermal control for the optical bench,and ultra-high magnetic cleanliness control.These innovations effectively minimize magnetic interference originating from the satellite itself,thereby substantially improving the precision of geomagnetic field measurements and establishing a robust technical foundation for future magnetic survey satellite constellations.
文摘In order to further promote the standardization of diagnosis and treatment of gastrointestinal stromal tumor （GIST） in China, the members of Chinese Society of Clinical Oncology （CSCO） Expert Committee on GIST thoroughly discussed the key contents of the consensus guidelines, and voted on the controversial issue. In final, the Chinese consensus guidelines for the diagnosis and management of GIST （2017 edition） was formed on the basis of 2013 edition consensus guidelines, which is hereby announced. The consensus included the pathological diagnosis, recurrence risk classification evaluation, targeted agent therapy, surgery and principles of surveillance of GIST.
基金funded by National Natural Science Foundation of China(Nos.62473236,62073196).
文摘In complex water environments,search tasks often involve multiple Autonomous Underwater Vehicles(AUVs),and a single centralized control cannot handle the complexity and computational burden of large-scale systems.Target search in complex water environments has always been a major challenge in the field of underwater robots.To address this problem,this paper proposes a multi-biomimetic robot fish collaborative target search method based on Distributed Model Predictive Control(DMPC).First,we established a bionic robot fish kinematic model and a multi-biomimetic robot fish communication model;second,this paper proposed a distributed model predictive control algorithm based on the distributed search theory framework,so that the bionic robot fish can dynamically adjust their search path according to each other’s position information and search status,avoid repeated coverage or missing areas,and thus improve the search efficiency;third,we conducted simulation experiments based on DMPC,and the results showed that the proposed method has a target search success rate of more than 90%in static targets,dynamic targets,and obstacle environments.Finally,we compared this method with Centralized Model Predictive Control(CMPC)and Random Walk(RW)algorithms.The DMPC approach demonstrates significant advantages,achieving a remarkable target search success rate of 94.17%.These findings comprehensively validate the effectiveness and superiority of the proposed methodology.It can be seen that DMPC can effectively dispatch multiple bionic robot fish to work together to achieve efficient search of vast waters.It can significantly improve the flexibility,scalability,robustness and cooperation efficiency of the system and has broad application prospects.
基金funded by the General Program of National Natural Science Foundation of China(Grant No.42377467).
文摘Understanding vegetation water availability can be important for managing vegetation and combating climate change.Changes in vegetation water availability throughout China remains poorly understood,especially at a high spatial resolution.Standardized Precipitation Evapotranspiration Index(SPEI)is an ideal water availability index for assessing the spatiotemporal characteristics of drought and investigating the vegetation-water availability relationship.However,no high-resolution and long-term SPEI datasets over China are available.To fill this gap,we developed a new model based on machine learning to obtain high-resolution(1 km)SPEI data by combining climate variables with topographical and geographical features.Here,we analyzed the long-term drought over the past century(1901–2020)and vegetation-water availability relationship in the past two decades(2000–2020).The century-long drought trend analyses indicated an overall drying trend across China with increasing drought frequency,duration,and severity during the past century.We found that drought events in 1901–1961 showed a larger increase than that in 1961–2020,with the Qinghai-Xizang Plateau showing a significant drying trend during 1901–1960 but a wetting trend during 1961–2020.There were 13.90%and 28.21%of vegetation in China showing water deficit and water surplus respectively during 2000–2020.The water deficit area significantly shrank from 2000 to 2020 across China,which is dominated by the significant decrease in water deficit areas in South China.Among temperature,precipitation,and vegetation abundance,temperature is the most important factor for the vegetation-water availability dynamics in China over the past two decades,with high temperature contributing to water deficit.Our findings are important for water and vegetation management under a warming climate.
基金financially supported by the National Natural Science Foundation of China (22378424,22127812)the Science Foundation of China University of Petroleum Beijing,China (2462023BJRC017)。
文摘CO_(2) hydrate-based sequestration in submarine sediments shows great potential for carbon emission reduction.Considering the proportional relationship of CO_(2) and water for hydrates formation,their existing ratio largely determines the CO_(2) sequestration density and phase state.Here,this work focuses on determining the optimal ratio of CO_(2) to seawater in sediments simulated with 20-40 mesh(0.42-0.85 mm) quartz sand,in order to maximize CO_(2) hydrate conversion in sediments.The results show that the conversion rate of CO_(2) hydrate increases with the initial water saturation,reaching 15.3%at 80% initial water saturation.The optimal CO_(2) hydrate formation occurs at 30% initial water saturation,with the corresponding CO_(2) storage density in hydrate form of 33.09 kg·m^(-3) and the hydrate saturation of 22.3%.However,CO_(2) hydrate conversion rate is <10%,which implies that most CO2 still exists in liquid state,despite the presence of free water.The total CO_(2) sequestration density is negatively correlated with the initial water saturation,and at 10% initial water saturation,398.73 kg·m^(-3) of CO_(2) is sequestered,of which only 18.02 kg·m^(-3) is hydrated.Additionally,the lower initial water saturation corresponds to the shorter time to achieve t_(90) of CO_(2) consumption,and the water conversion rate to hydrate reaches 90% at 10% initial water saturation.In summary,adjusting the volume ratio of liquid CO_(2) to seawater can effectively increase the sequestration amount of CO_(2) hydrates,but methods to increase CO_(2) conversion to hydrate still need to be established.
基金funded by the National Natural Science Foundation of China(No.82405530,81973921 and 72374068)the Science and Technology Research Project of Hubei Provincial Department of Education(No.B2023098)。
文摘Objective:As an age-related neurodegenerative disease,the prevalence of mild cognitive impairment(MCI)increases with age.Within the framework of traditional Chinese medicine,spleen-kidney deficiency syndrome(SKDS)is recognized as the most frequent MCI subtype.Due to the covert and gradual onset of MCI,in community settings it poses a significant challenge for patients and their families to discern between typical aging and pathological changes.There exists an urgent need to devise a preliminary diagnostic tool designed for community-residing older adults with MCI attributed to SKDS(MCI-SKDS).Methods:This investigation enrolled 312 elderly individuals diagnosed with MCI,who were randomly distributed into training and test datasets at a 3:1 ratio.Five machine learning methods,including logistic regression(LR),decision tree(DT),naive Bayes(NB),support vector machine(SVM),and gradient boosting(GB),were used to build a diagnostic prediction model for MCI-SKDS.Accuracy,sensitivity,specificity,precision,F1 score,and area under the curve were used to evaluate model performance.Furthermore,the clinical applicability of the model was evaluated through decision curve analysis(DCA).Results:The accuracy,precision,specificity and F1 score of the DT model performed best in the training set(test set),with scores of 0.904(0.845),0.875(0.795),0.973(0.875)and 0.973(0.875).The sensitivity of the training set(test set)of the SVM model performed best among the five models with a score of 0.865(0.821).The area under the curve of all five models was greater than 0.9 for the training dataset and greater than 0.8 for the test dataset.The DCA of all models showed good clinical application value.The study identified ten indicators that were significant predictors of MCI-SKDS.Conclusion:The risk prediction index derived from machine learning for the MCI-SKDS prediction model is simple and practical;the model demonstrates good predictive value and clinical applicability,and the DT model had the best performance.
基金Supported by Open Project of Key Laboratory of Hubei Province(No.2023KFZZ026).
文摘AIM:To estimate if nanopore targeted sequencing(NTS)could identify pathogens causing postoperative endophthalmitis and further determine the feasibility of clinical application of NTS.METHODS:A total of 55 patients(55 eyes)with postoperative endophthalmitis were retrospectively included in this study with their medical records.Intraocular fluid samples were examined by NTS and microbial culture.All included patients had undergone examinations including measurement of best corrected visual acuity(BCVA)and intraocular pressure(IOP),slit-lamp biomicroscopy,and indirect ophthalmoscopy;additionally,they underwent B-ultrasound,anterior segment photography,and fundus photography if necessary.RESULTS:Among 55 patients with postoperative endophthalmitis,the age was 65.25±15.04y and there were 30 female(54.54%)patients.Forty-one(74.54%)vitreous humor samples and fourteen(25.45%)aqueous humor samples were sent for both NTS and microbial culture.NTS had a notable higher detection rate than microbial culture in detecting pathogens(90.91%vs 38.18%,χ^(2)=33.409,P<0.001).NTS exhibited high sensitivity of pathogen detection in both microbial culture positive and negative samples(100%and 85.29%,respectively).In 16 of 21(76.19%)patients who showed culture-positivity,their results corresponded with those of NTS.Moreover,in two patients(9.52%),NTS showed a better species resolution than microbial culture;in three patients(14.28%),NTS identified additional pathogens.As for fungus,the positive detection rate of NTS was significantly higher than that of microbial culture(20%vs 3.64%,χ^(2)=7.066,P=0.008).Also,NTS could detect multi-infection by bacteria and fungi than microbial culture(32.73%vs 0,χ^(2)=21.522,P<0.001).NTS could detect bacteria as well as fungi simultaneously within 48h in all patients.Meanwhile,NTS had a shorter detection time than microbial culture(1.13±0.34 vs 2.67±0.55d,Z=-9.218,P<0.001).After the NTS results were obtained,15 patients received additional intravitreal/intracameral anti-infection treatment.At follow-up,there was a statistically significant improvement in the visual acuity relative to the baseline(Z=−5.222,P<0.001).CONCLUSION:NTS can provide rapid identification and highly sensitive detection of pathogens among patients with postoperative endophthalmitis,which can guide anti-infection treatment and improve visual prognosis.
基金supported by the National Natural Science Foundation of China(No.52173264)the Natural Science Foundation Project of Chongqing(No.cstc2024ycjh-bgzxm0005)+1 种基金the Fundamental Research Funds for the Central Universities(No.SWU-XDJH202314)The authors thanks Dr.Xi Tang in Southwest University for the technical support in the use of the vector network analyzer.
文摘Plastic waste recycling is a focal point in today's sustainable development efforts.Improper disposal can lead to secondary pollution,posing threats to the environment and human health.In this study,we aim to recycle waste epoxy resin and glass fiber-reinforced epoxy resin composites via an electroless plating and a carbonization process,to design high-value-added carbon materials for microwave absorption.By pulverizing solid waste and introducing magnetic metal nanoparticles onto its surface,a composite carbon material capable of excellent microwave absorption performance was successfully developed.Specifically,doping nickel particles into carbon materials derived from glass fiber/epoxy resin achieved a wide effective absorption bandwidth(EAB)of 5.9 GHz with a matching thickness of 1.9 mm,covering nearly the entire Ku band,and achieving a minimum reflection loss(RLmin)of−36 dB simultaneously.The superior absorption performance is attributed to multiple reflections or scattering of electromagnetic waves within the material,as well as conduction and magnetic losses,dipole and interfacial polarization effects.These results demonstrate that through rational design and optimization,waste epoxy and waste glass fiber-reinforced epoxy resin-based composite materials can be effectively recycled into high-performance microwave absorbing materials,offering a straightforward and efficient pathway for waste resource utilization.
基金supported by the National Major Scientific Research Instrument Development Projects(No.42127807)the National Natural Science Foundation of China(No.12105030)。
文摘Promoting the development of deep-sea mineral exploration instrumentation can help alleviate the global resource shortage faced by mankind.X-ray fluorescence(XRF)spectrometry has been widely used in the in situ analysis of deep-sea minerals owing to its fast analytical speed,nondestructive nature,and wide analytical range.This study focused on the structural safety and detection efficiency of X-ray fluorescence in situ measurement equipment under high pressure for deep-sea XRF analysis.This study first combined finite element analysis and experiments to design and optimize the structure of an X-ray probe tube required for deep-sea mineral exploration and to determine the Be window thickness to ensure stress safety.Subsequently,the Monte Carlo method was used to analyze and optimize the Be window thickness on the X-ray probe tube to improve the accuracy of the elemental analyses.Finally,the effect of seawater thickness between the transmitter outer tube and rock wall was also considered.The results show that based on ocean depth in different detection environments,Be windows with a thickness of 1.5 mm or 2.0 mm can be selected to improve the detection efficiency of the device while ensuring the structural safety of the instrument.According to the design features and detection requirements of the device,in deep-sea exploration of minerals with characteristic peak energies below 10 keV,the transmitter outer tube should be as close as possible to the rock wall inside the logging.When the characteristic peak energy of the minerals is more than 10 keV,the distance between the transmitter outer tube and rock wall inside the logging should be controlled to approximately 2 mm.This study provides feasible solutions for future deep-sea mineral resource development and a useful reference for elemental analysis of minerals in the deep-sea or other extreme working environments.
基金supported by the Jilin Provincial Science and Technology Development Plan Project(No.20220508003RC)the National Natural Science Foundation of China(52202440,52003012)。
文摘Lithium-ion batteries(LIBs)play a critical role in reducing carbon emissions in the automotive industry.However,they face challenges related to safety and performance failures.Smart technologies offer a promising solution to address these issues.Bioinspired microcapsules are a common approach to enhancing the performance and safety of smart LIBs.However,despite their potential,this area has not been thoroughly explored.This review provides an overview of the preparation methods for microcapsules,including physical,chemical,and physicochemical techniques.These microcapsules are categorized based on their mechanisms into electrode self-healing burst microcapsules,interphase-forming sustained-release microcapsules,live-lithium sustained-release microcapsules,and flame-retardant burst microcapsules.A comprehensive analysis of their bioinspired design concepts,mechanisms,and performance is presented,along with the design criteria for microcapsules suitable for LIBs.Finally,the review explores the potential applications of microcapsule technologies in LIBs and their future trends,such as enhancing existing technologies for novel applications like solid-state batteries and developing new types of microcapsules.This review aims to provide a foundation for the implementation of microcapsule technologies in LIBs and to highlight the latest advancements in smart batteries.
文摘Indoxyl sulfate(IS),a protein-bound indole toxin,is currently a key research focus regarding uremic toxins and renal injury both in China and internationally.Studies have shown that IS can upregulate the expression of TGF-β1,TIMP-1,and pro-α1(I),induce the production of free radicals,decrease superoxide scavenging activity,and promote the apoptosis of renal tubular epithelial cells,thereby exacerbating renal damage.As metabolomics research progresses,IS is emerging as a potential new biomarker for kidney injury.This paper reviews the progress of research on the application of IS in kidney injury over the past decade,drawing on resources from databases such as the CNKI and PubMed.The aim is to provide insights that can aid in clinical individualized treatment,enhancing the safety and effectiveness of patient care.
文摘Haze (known as “Mai” 霾 in Chinese) threatens the health of billions of people across the globe. To begin solving this problem without severely slowing down the economy, one has to mechanistically and geographically pinpoint the sources of these pollutants, the key of which is to thoroughly characterize and fingerprint the particulates. Here we present a broad survey and classification of thousands of individual airborne particu-lates by using the Scanning Electron Microscope (SEM) to measure their diverse mor-phologies and chemistries, which could eventually be organized into a “haze finger-print database”. For instance, one collection in Xi’an City, China during March-April 2014 yielded 494 airborne particulates that settled on silicon wafers placed outside the window of a 3<sup>rd</sup> floor office. These 494 particulates were manually imaged with high resolution (down to 2 nm), elementally mapped using Energy-dispersive X-ray Spec-troscopy (EDS), and were identified and categorized into presumed source classes such as construction activities (Ca, Al, Si-O), coal burning (sulfates), biologic (pollen, bac-teria), automotive, mining, steel making, and etc. About 20% of the particulates have mysterious origins, as it is still unclear how they were formed, and a fraction of them contained clearly hazardous elements such as lead and chromium. For future work, we propose using unmanned aerial vehicles with a special “rolling film” substrate that can autonomously collect airborne particulates, a customized SEM auto-imaging system, and machine learning software to establish an online open-access database. The end goal would be to monitor and analyze the particulate pollutants that are pumped into our atmosphere every day, and precisely track down their sources so we can better model and police the quality of the air around us.
