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Optimized Mask-RCNN model for particle chain segmentation based on improved online ferrograph sensor

Friction 2024年第6期12卷 1194-1213页

作者： Shuo wanG Miao wan Tonghai WU Zichen BAI Kunpeng wanG Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi’an Jiaotong UniversityXi’an 710049China

Ferrograph-based wear debris analysis(WDA)provides significant information for wear fault analysis of mechanical equipment.After decades of offline application,this conventional technology is being driven by the online ferrograph sensor for real-time wear state monitoring.However,online ferrography has been greatly limited by the low imaging quality and segmentation accuracy of particle chains when analyzing degraded lubricant oils in practical applications.To address this issue,an integrated optimization method is developed that focuses on two aspects:the structural re-design of the online ferrograph sensor and the intelligent segmentation of particle chains.For enhancing the imaging quality of wear particles,the magnetic pole of the online ferrograph sensor is optimized to enable the imaging system directly observe wear particles without penetrating oils.Furthermore,a light source simulation model is established based on the light intensity distribution theory,and the LED installation parameters are determined for particle illumination uniformity in the online ferrograph sensor.On this basis,a Mask-RCNN-based segmentation model of particle chains is constructed by specifically establishing the region of interest(ROI)generation layer and the ROI align layer for the irregular particle morphology.With these measures,a new online ferrograph sensor is designed to enhance the image acquisition and information extraction of wear particles.For verification,the developed sensor is tested to collect particle images from different degraded oils,and the images are further handled with the Mask-RCNN-based model for particle feature extraction.Experimental results reveal that the optimized online ferrography can capture clear particle images even in highly-degraded lubricant oils,and the illumination uniformity reaches 90%in its imaging field.Most importantly,the statistical accuracy of wear particles has been improved from 67.2%to 94.1%.

关键词： wear particle analysis online ferrography particle image acquisition particle chain segmentation

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Finite barrier bound state

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Light(Science & Applications) 2024年第4期13卷 664-671页

作者： Tao Liu Kai Bai yicheng Zhang Duanduan wan Yun Lai C.T.Chan Meng Xiao Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education and School of Physics and Technology Wuhan University430072 WuhanChina. National Laboratory of Solid State Microstructures School of Physicsand Collaborative Innovation Center of Advanced MicrostructuresNanjing University210093 NanjingChina. Department of Physics The Hong Kong University of Science and TechnologyClear Water BayKowloon999077Hong KongChina. Wuhan Institute of Quantum Technology 430206 WuhanChina

A boundary mode localized on one side of a finite-size lattice can tunnel to the opposite side which results in unwanted couplings.Conventional wisdom tells that the tunneling probability decays exponentially with the size of the system which thus requires many lattice sites before eventually becoming negligibly small.Here we show that the tunneling probability for some boundary modes can apparently vanish at specific wavevectors.Thus,similar to bound states in the continuum,a boundary mode can be completely trapped within very few lattice sites where the bulk bandgap is not even well-defined.More intriguingly,the number of trapped states equals the number of lattice sites along the normal direction of the boundary.We provide two configurations and validate the existence of this peculiar finite barrier-bound state experimentally in a dielectric photonic crystal at microwave frequencies.Our work offers extreme flexibility in tuning the coupling between localized states and channels as well as a new mechanism that facilitates unprecedented manipulation of light.

关键词： boundary state eventually

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Enhancing leaching efficiency of ion adsorption rare earths by ameliorating mass transfer effect of rare earth ions by applying an electric field

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Journal of Rare Earths 2024年第1期42卷 172-180,I0006页

作者： Lingbo Zhou Jie Yang Shijie Kang Xiaojun wang Hongdong Yu yinhua wan Rare Earth Institute University of Science and Technology of ChinaHefei230000China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou341000China Jiangxi Institute of Rare Earths Chinese Academy of SciencesGanzhou341000China School of Resources and Environment Engineering Jiangxi University of Science and TechnologyGanzhou341000China

Improving the seepage of leaching solution in the ore body and strengthening the mass transfer process of rare earth ions during in-situ leaching are two critical methods to improve the leaching efficiency of rare earth.In this study,2 wt%MgSO_(4)solution was used for the indoor simulated column leaching experiment on rare earth samples and an electric field was applied at both ends of the samples.Then the effects of different intensities,initial application time and duration of the electric field on the rare earth leaching system and its mechanism were investigated.The results show that compared with the single MgSO_(4)solution leaching,applying an electric field with a strength of 6 V/cm can save the leaching time of 30 min and increase the flow velocity of the rare earth leachate by 26.98%.Under the optimal conditions of applying an electric field with a strength of 6 V/cm for 20 min to the leaching system after10 min of the rare earth leachate flowing out,the leaching efficiency of sample increases from 81.20% to 86.05% with the increase of 4.85%.The mechanism analysis shows that when a direct current electric field is applied to the rare earth leaching system,rare earth ions rapidly change from disorderly movement with the seepage into faster and directional movement.In addition,the seepage of the leaching solution is also improved due to the increase of the cross-sectional area of the seepage channel,the polarized water molecules migrate directionally by force from the negative pole,and the movement of the hydrogen is generated by the electrolytic water.More impo rtantly,based on the principle of in-situ leaching process,the layout of injection holes and deflector holes in this process provides a natural site for the electrode layout of the electric field.With the simple equipme nt and the ope ration,the rare earth leaching process with the applied electric field has high feasibility in industrial application.

关键词： Ion adsorption rare earths Leaching system Electric field Mass transfer process Seepage

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Role of Stokes Drift in Ocean Dynamics Under Typhoon Conditions in the Bohai Sea

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Journal of Ocean University of China 2024年第1期23卷 33-45页

作者： LI Haoqian wan Kai wanG Menghan DENG Zeng’an CAO Yu North China Sea Marine Forecasting Center Qingdao 266061China Shandong Provincial Key Laboratory of Marine Ecology and Environment&Disaster Prevention and Mitigation Qingdao 266061China North China Sea Offshore Engineering Survey Institute Qingdao 266061China School of Marine Science and Technology Tianjin UniversityTianjin 300072China South China Sea Marine Forecasting Center Guangzhou 510006China

The effect of Stokes drift production(SDP),which includes Coriolis-Stokes forcing,Langmuir circulation,and Craik-Lei-bovich vortexes,on the upper ocean during typhoon passage in the Bohai Sea(BS),China,is investigated by using a coupled wave-current model.The role of SDP in turbulent mixing and the further dynamics during the entire typhoon period are comprehensively stud-ied.Experimental results show that SDP greatly increases turbulent mixing at all depths under typhoon conditions by up to seven times that under normal weather conditions.SDP generally strengthens sea surface cooling by more than 0.4℃,with the maximum reduction in sea surface temperature(SST)at the during-typhoon stage exceeding 2℃,which is approximately seven times larger than that under normal weather conditions.The SDP-induced decrease in current speed can exceed 0.2ms^(-1),and the change in current direction is generally opposite the wind direction.These results suggest that Stokes drift depresses the effect of strong winds on currents by intensifying turbulent mixing.Mixed layer depth(MLD)is distinctly increased by O(1)during typhoons due to SDP and can deepen by more than 5m.In addition,the continuous effects of SDP on SST,current,and MLD at the after-typhoon stage indi-cate a hysteretic response between SDP and typhoon actions.

关键词： Stokes drift production Langmuir turbulence rurbulent mixing typhoon coupled model

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Numerical investigation of sinusoidal pulsating gas intake to intensify the gas-slag momentum transfer in the top-blown smelting furnace

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 301-314页

作者： Zhanghao wan Shiliang Yang Desong Kong Dongbo Li Jianhang Hu Hua wang State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and TechnologyKunming 650093China Southwest Copper Branch Yunnan Copper Co.Ltd.Kunming 650102China

The variation characteristics of bubble morphology and the thermal-physical properties of bubble boundary in the top-blown smelting furnace were explored by means of the computational fluid dynamics method.The essential aspects of the fluid phase(e.g.,splashing volume,dead zone of copper slag,and gas penetration depth)were explored together with the effect of sinusoidal pulsating gas intake on the momentum-transfer performance between phases.The results illustrated that two relatively larger vortices and two smaller vortices appear in the bubble waist and below the lance,respectively.The expansion of larger ones as well as the shrinking of smaller ones combine to cause the contraction of the bubble waist.Compared to the results of the case with a fixed gas injection velocity(V_(g)=58 m/s),the splashing volume and dead zone volume of the slag under the V_(g)=58+10sin(2πt)condition are reduced by 24.9%and 23.5%,respectively,where t represents the instant time.Gas penetration depth and slag motion velocity of the latter are 1.03 and 1.31 times high-er than those of the former,respectively.

关键词： top-blown smelting furnace pulsed flow volume of fluid penetration depth splashing volume

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Efficient and selective removal of Pb(Ⅱ) from landfill leachate using L-serine-modified polyethylene/polypropylene nonwoven fabric synthesized via radiation grafting technique

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Nuclear Science and Techniques 2024年第4期35卷 144-155页

作者： Xin-Xin Feng Cheng Li Xuan-Zhi Mao wan-Ning Ren Yang Gao Yu-Long He Zhe xing Rong Li Guo-Zhong Wu Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China

In this study,to efficiently remove Pb(Ⅱ) from aqueous environments,a novel L-serine-modified polyethylene/polypropylene nonwoven fabric sorbent(NWF-serine)was fabricated through the radiation grafting of glycidyl methacrylate and subsequent L-serine modification.The effect of the absorbed dose was investigated in the range of 5–50 kGy.NWF-serine was characterized by Fourier transform infrared spectroscopy,thermogravimetric analysis,and scanning electron microscopy.Batch adsorption tests were conducted to investigate the influences of pH,adsorption time,temperature,initial concentration,and sorbent dosage on the Pb(Ⅱ) adsorption performance of NWF-serine.The results indicated that Pb(Ⅱ) adsorption onto NWF-serine was an endothermic process,following the pseudo-second-order kinetic model and Langmuir isotherm model.The saturated adsorption capacity was 198.1 mg/g.NWF-serine exhibited Pb(Ⅱ) removal rates of 99.8% for aqueous solutions with initial concentrations of 100 mg/L and 82.1% for landfill leachate containing competitive metal ions such as Cd,Cu,Ni,Mn,and Zn.Furthermore,NWF-serine maintained 86% of its Pb(Ⅱ) uptake after five use cycles.The coordination of the carboxyl and amino groups with Pb(Ⅱ) was confirmed using X-ray photoelectron spectroscopy and extended X-ray absorption fine structure analysis.

关键词： Landfill leachate Radiation grafting Polyethylene/polypropylene nonwoven fabric Pb(Ⅱ)removal

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Predicting PM_(2.5) Concentration in the Yangtze River Delta Region Using Climate System Monitoring Indices and Machine Learning

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Journal of Meteorological Research 2024年第2期38卷 249-261页

作者： Jinghui MA Shiquan wan Shasha XU Chanjuan wanG Danni QIU Shanghai Typhoon Institute Shanghai Meteorological ServiceShanghai 200030 Key Laboratory of Polar Atmosphere-Ocean-Iice System for Weather and Climate Ministry of EducationDepartment of Atmospheric and Oceanic SciencesFudan UniversityShanghai 200438 Shanghai Key Laboratory of Meteorology and Health Shanghai Meteorological ServiceShanghai 200030 Yangzhou Meteorological Office Yangzhou 225001 Department of Physics Yangzhou UniversityYangzhou 225003

Changing meteorological conditions during autumn and winter have considerable impact on air quality in the Yangtze River Delta(YRD)region.External climatic factors,such as sea surface temperature and sea ice,together with the atmospheric circulation,directly affect meteorological conditions in the YRD region,thereby modulating the variation in atmospheric PM_(2.5) concentration.This study used the evolutionary modeling machine learning technique to investigate the lag relationship between 144 climate system monitoring indices and autumn/winter PM_(2.5) concentration over 0-12 months in the YRD region.After calculating the contribution ratios and lagged correlation coefficients of all indices over the previous 12 months,the top 36 indices were selected for model training.Then,the nine indices that contributed most to the PM_(2.5) concentration in the YRD region,including the decadal oscillation index of the Atlantic Ocean and the consistent warm ocean temperature index of the entire tropical Indian Ocean,were selected for physical mechanism analysis.An evolutionary model was developed to forecast the average PM_(2.5) concentration in major cities of the YRD in autumn and winter,with a correlation coefficient of 0.91.In model testing,the correlation coefficient between the predicted and observed PM_(2.5) concentrations was in the range of 0.73-0.83 and the root-mean-square error was in the range of 9.5-11.6μg m-3,indicating high predictive accuracy.The model performed exceptionally well in capturing abnormal changes in PM_(2.5) concentration in the YRD region up to 50 days in advance.

关键词： PM_(2.5)concentration machine learning evolutionary modeling seasonal prediction

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Atom substitution of the solid-state electrolyte Li_(10)GeP_(2)S_(12)for stabilized all-solid-state lithium metal batteries

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Journal of Energy Chemistry 2024年第1期88卷 28-38,I0002页

作者： Zijing wan Xiaozhen Chen Ziqi Zhou Xiaoliang Zhong Xiaobing Luo Dongwei Xu State Key Laboratory of Coal Combustion School of Energy and Power EngineeringHuazhong University of Science and TechnologyWuhan 430074HubeiChina

Solid-state electrolyte Li_(10)GeP_(2)S_(12)(LGPS)has a high lithium ion conductivity of 12 mS cm^(-1)at room temperature,but its inferior chemical stability against lithium metal anode impedes its practical application.Among all solutions,Ge atom substitution of the solid-state electrolyte LGPS stands out as the most promising solution to this interface problem.A systematic screening framework for Ge atom substitution including ionic conductivity,thermodynamic stability,electronic and mechanical properties is utilized to solve it.For fast screening,an enhanced model Dop Net FC using chemical formulas for the dataset is adopted to predict ionic conductivity.Finally,Li_(10)SrP_(2)S_(12)(LSrPS)is screened out,which has high lithium ion conductivity(12.58 mS cm^(-1)).In addition,an enhanced migration of lithium ion across the LSr PS/Li interface is found.Meanwhile,compared to the LGPS/Li interface,LSrPS/Li interface exhibits a larger Schottky barrier(0.134 eV),smaller electron transfer region(3.103?),and enhanced ability to block additional electrons,all of which contribute to the stabilized interface.The applied theoretical atom substitution screening framework with the aid of machine learning can be extended to rapid determination of modified specific material schemes.

关键词： Atom substitution Solid-state electrolyte Machine learning Stabilized interface

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Extracellular vesicles from human urine-derived stem cells delay aging through the transfer of PLAU and TIMP1

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Acta Pharmaceutica Sinica B 2024年第3期14卷 1166-1186页

作者： Shanshan Rao Zehui He Zun wang Hao yin Xiongke Hu yijuan Tan Tengfei wan Hao Zhu yi Luo Xin wang Hongming Li Zhenxing wang Xinyue Hu Chungu Hong yiyi wang Mingjie Luo Wei Du Yuxuan Qian Siyuan Tang Hui Xie Chunyuan Chen Department of Orthopedics Movement System Injury and Repair Research CenterXiangya HospitalCentral South UniversityChangsha 410008China Hunan Key Laboratory of Angmedicine Changsha 410008China Xiangya School of Nursing Central South UniversityChangsha 410013China Department of Pediatric Orthopedics Hunan Children’s HospitalUniversity of South ChinaChangsha 410007China Department of Respiratory Medicine Xiangya HospitalCentral South UniversityChangsha 410008China School of Nursing Xinjiang Medical UniversityUrumqiXinjiang 830000China Department of Rehabilitation Xiangya HospitalCentral South UniversityChangsha 410008China National Clinical Research Center for Geriatric Disorders Xiangya HospitalCentral South UniversityChangsha 410008China

Aging increases the risks of various diseases and the vulnerability to death.Cellular senescence is a hallmark of aging that contributes greatly to aging and aging-related diseases.This study demonstrates that extracellular vesicles from human urine-derived stem cells(USC-EVs)efficiently inhibit cellular senescence in vitro and in vivo.The intravenous injection of USC-EVs improves cognitive function,increases physical fitness and bone quality,and alleviates aging-related structural changes in different organs of senescence-accelerated mice and natural aging mice.The anti-aging effects of USC-EVs are not obviously affected by the USC donors’ages,genders,or health status.Proteomic analysis reveals that USC-EVs are enriched with plasminogen activator urokinase(PLAU)and tissue inhibitor of metalloproteinases 1(TIMP1).These two proteins contribute importantly to the anti-senescent effects of USC-EVs associated with the inhibition of matrix metalloproteinases,cyclin-dependent kinase inhibitor 2A(P16INK4a),and cyclin-dependent kinase inhibitor 1A(P21cip1).These findings suggest a great potential of autologous USC-EVs as a promising anti-aging agent by transferring PLAU and TIMP1 proteins.

关键词： Extracellular vesicles Urine-derived stem cells Cellular senescence Anti-aging PLAU TIMP1 Senescence-accelerated mice Natural aging mice

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成长叙事与政治美育:论红色经典电影中的少儿形象及其当代回响

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电影评介 2024年第1期 15-21页

作者：万兴中国人民大学文学院

在中国文艺界,“红色经典”一词具有专属内涵,据孟繁华考证,“红色经典,是指1942年以来,在《延安文艺座谈会上的讲话》指导下,文学艺术工作者创作的具有民族风格、民族作派、为工农兵喜闻乐见的作品。这些作品以革命历史题材为主,以歌... 详细信息

在中国文艺界,“红色经典”一词具有专属内涵,据孟繁华考证,“红色经典,是指1942年以来,在《延安文艺座谈会上的讲话》指导下,文学艺术工作者创作的具有民族风格、民族作派、为工农兵喜闻乐见的作品。这些作品以革命历史题材为主,以歌颂中国共产党领导下的人民民主革命和社会主义建设为主要内容”[1]。因此,红色经典不仅仅指革命文学这一单一体裁;新中国成立至今,有大量电影工作者不断以真实革命历史事件、革命英雄的感人事迹或文学工作者创作的革命小说为蓝本,改编、再创作并拍摄出一大批兼顾政治宣传导向和文艺审美气息的红色经典电影。

关键词：延安文艺座谈会文学工作者中国文艺界红色经典革命英雄成长叙事文艺审美人民民主革命

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