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Deep learning to estimate ocean subsurface salinity structure in the Indian Ocean using satellite observations

Journal of Oceanology and Limnology 2024年第2期42卷 377-389页

作者： Jifeng qi Guimin SUN Bowen xie Delei LI Baoshu YIN CAS Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China School of Mathematics and Physics Qingdao University of Science and TechnologyQingdao 266061China CAS Engineering Laboratory for Marine Ranching Institute of OceanologyChinese Academy of SciencesQingdao 266071China

Accurately estimating the ocean subsurface salinity structure(OSSS)is crucial for understanding ocean dynamics and predicting climate variations.We present a convolutional neural network(CNN)model to estimate the OSSS in the Indian Ocean using satellite data and Argo observations.We evaluated the performance of the CNN model in terms of its vertical and spatial distribution,as well as seasonal variation of OSSS estimation.Results demonstrate that the CNN model accurately estimates the most significant salinity features in the Indian Ocean using sea surface data with no significant differences from Argo-derived OSSS.However,the estimation accuracy of the CNN model varies with depth,with the most challenging depth being approximately 70 m,corresponding to the halocline layer.Validations of the CNN model’s accuracy in estimating OSSS in the Indian Ocean are also conducted by comparing Argo observations and CNN model estimations along two selected sections and four selected boxes.The results show that the CNN model effectively captures the seasonal variability of salinity,demonstrating its high performance in salinity estimation using sea surface data.Our analysis reveals that sea surface salinity has the strongest correlation with OSSS in shallow layers,while sea surface height anomaly plays a more significant role in deeper layers.These preliminary results provide valuable insights into the feasibility of estimating OSSS using satellite observations and have implications for studying upper ocean dynamics using machine learning techniques.

关键词： machine learning convolutional neural network(CNN) ocean subsurface salinity structure(OSSS) Indian Ocean satellite observations

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Application of the Mathieu combined tunnel technique for repairing glans dehiscence after failed hypospadias repair

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Asian Journal of Andrology 2022年第3期24卷 311-316页

作者： qi-gen xie Kai Xia Xiang-Ping Li Peng Luo Zuo-qing Li Cheng Su Chun-Hua Deng Department of Pediatric Surgery First Affiliated HospitalSun Yat-Sen UniversityGuangzhou 510080China Department of Andrology First Affiliated HospitalSun Yat-Sen UniversityGuangzhou 510080China

Repairing glans dehiscence after failed hypospadias repair is challenging for pediatric surgeons.Here,we introduced and evaluated a newly modified Mathieu technique,Mathieu combined tunnel(MCT),which involves multiple custom-designed flaps for the shortage of flap source material after repeated operations;we also constructed a tunnel to avoid the glans incision that may carry new risks of dehiscence.This retrospective study included 26 patients who were consecutively admitted to the First Affiliated Hospital of Sun Yat-Sen University(Guangzhou,China)for glans dehiscence repair after failed hypospadias repair from October 2014 to October 2020;sixteen patients underwent surgery using the MCT(MCT group)and ten patients underwent surgery using the tubularized incised plate(TIP)technique(TIP group).The operative time,blood loss,postoperative complications,normal urethral meatus rate,success rate,and Hypospadias Objective Penile Evaluation(HOPE)score were compared between the two groups.The MCT group achieved an overall satisfactory penile appearance and voiding function,with a higher rate of normal urethral meatus(15/16,93.8%)and a lower rate of glans dehiscence(1/16,6.2%),compared with the TIP group(70.0%and 30.0%,respectively).However,these differences were not statistically significant,possibly because of the limited number of patients(all P>0.05).Mean postoperative HOPE scores were similar in the MCT group(mean±standard deviation:8.83±0.89)and TIP group(8.94±0.57)(P>0.05).No significant differences were found between the two groups in terms of blood loss and success rate,nor in the rates of various complications(e.g.,fistula,urethral stricture,and glans dehiscence).In conclusion,the MCT technique appears to be feasible and reliable for repairing glans dehiscence after failed hypospadias repair.

关键词： failed hypospadias glans dehiscence Mathieu tubularized incised plate(TIP) tunnel

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Fundamentals and progress of the manifold method based on independent covers

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Science China(Technological Sciences) 2024年第4期67卷 966-991页

作者： SU HaiDong LIN ShaoZhong xie Zhiqiang GONG Yaqi qi YongFeng Material and Engineering Structure Department Yangtze River Scientific Research InstituteWuhan 430010China Research Center of Water Engineering Safety and Disaster Prevention of Ministry of Water Resources Wuhan 430010China

Aiming to solve mesh generation,computational stability,accuracy control,and other problems encountered with existing numerical methods,such as the finite element method and the finite volume method,a new numerical computational method for continuum mechanics,namely the manifold method based on independent covers(MMIC),is proposed based on the concept of mathematical manifolds,to form partitioned series solutions of partial differential equations.As partitions,the cover meshes have the characteristics of arbitrary shape,arbitrary connection,and arbitrary refinement.They are expected to fundamentally solve the mesh generation problem and can also simulate the precise geometric boundaries of the CAD model and strictly impose boundary conditions.In the selection of series solutions,local analytical solutions(such as series solutions at crack tips and series solutions in infinite domains)or proper forms of complete series can be used to reflect the local or global characteristics of the physical field to accelerate convergence.Various applications are presented.A new method of beam,plate,and shell analysis is proposed.The deformation characteristics of beams,plates,and shells are simulated with polynomial series of suitable forms,and the analysis of curved beams and shells with accurate geometric representation is realized.For the static elastic analysis of two-dimensional structures,a mesh splitting algorithm is proposed,and h-p version adaptive analysis is carried out with error estimation.Thus,automatic computation integrated with CAD is attempted.Adaptive analysis is also attempted for the solution of differential equations of fluids.For the one-dimensional convection-diffusion equation and Burgers equation,calculation results with high precision are obtained in strong convection and shock wave simulations,avoiding nonphysical oscillations.And solving the two-dimensional incompressible Navier-Stokes equation is also attempted.The series solution formula is used to obtain the physical quantity of interest of the m

关键词： series solutions mesh generation adaptive analysis fixed meshes numerical manifold method

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In-situ formation of nitrogen doped microporous carbon nanospheres derived from polystyrene as lubricant additives for anti-wear and friction reduction

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Friction 2024年第3期12卷 439-451页

作者： Yixin WANG qi LU Huijie xie Shujuan LIU qian YE Feng ZHOU Weimin LIU State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'an 710072China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

This study presents a nitrogen-doped microporous carbon nanospheres(N@MCNs)prepared by a facile polymerization–carbonization process using low-cost styrene.The N element in situ introduces polystyrene(PS)nanospheres via emulsion polymerization of styrene with cyanuric chloride as crosslinking agent,and then carbonization obtains N@MCNs.The as-prepared carbon nanospheres possess the complete spherical structure and adjustable nitrogen amount by controlling the relative proportion of tetrachloromethane and cyanuric chloride.The friction performance of N@MCNs as lubricating oil additives was surveyed utilizing the friction experiment of ball-disc structure.The results showed that N@MCNs exhibit superb reduction performance of friction and wear.When the addition of N@MCNs was 0.06 wt%,the friction coefficient of PAO-10 decreased from 0.188 to 0.105,and the wear volume reduced by 94.4%.The width and depth of wear marks of N@MCNs decreased by 49.2% and 94.5%,respectively.The carrying capacity of load was rocketed from 100 to 400 N concurrently.Through the analysis of the lubrication mechanism,the result manifested that the prepared N@MCNs enter clearance of the friction pair,transform the sliding friction into the mixed friction of sliding and rolling,and repair the contact surface through the repair effect.Furthermore,the tribochemical reaction between nanoparticles and friction pairs forms a protective film containing nitride and metal oxides,which can avert direct contact with the matrix and improve the tribological properties.This experiment showed that nitrogen-doped polystyrene-based carbon nanospheres prepared by in-situ doping are the promising materials for wear resistance and reducing friction.This preparing method can be ulteriorly expanded to multi-element co-permeable materials.Nitrogen and boron co-doped carbon nanospheres(B,N@MCNs)were prepared by mixed carbonization of N-enriched PS and boric acid,and exhibited high load carrying capacity and good tribological properties.

关键词： lubricant additives hypercrosslinked polystyrene carbon nanospheres friction reduction anti-wear

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Adsorption limitation investigation on olefins for Cu–BTC

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Friction 2024年第4期12卷 606-617页

作者： Xiao YANG Yunbo WANG Weihua CAO Ruizheng JIANG Guoxin xie Yuying CAO Xiaowen qi School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China Key Laboratory of Self-Lubricating Spherical Plain Bearing Technology of Hebei Province Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China Aviation Key Laboratory of Science and Technology on generic Technology of Self-Lubricating Spherical Plain Bearing Yanshan UniversityQinhuangdao 066004China

To utilize Cu-benzene-1,3,5-tricarboxylate(Cu-BTC)adsorbed lubricant oils in the self-lubricating field,the adsorption properties of Cu-BTC on different 1-olefins must be clarified.In this work,1-hexene,1-octene,1-nonene,1-decene,1-undecene,and 1-dodecene were studied by the Monte Carlo method and experimentally.The adsorption limit of Cu-BTC for n-olefins was determined as 1-undecene by the adsorption isotherms.This suggested a limit for even straight-chain molecules to the adsorption of Cu-BTC.The maximum ratio of the olefin length of the largest pore diameter(L/D)of Cu-BTC was approximately 1.57.Furthermore,theoretical calculations(radial distribution function(RDF))and experiments(infrared(IR)spectra)confirmed the interaction of n-olefin adsorbates and the Cu-BTC framework occurred between the-CH=of olefins and the Cu and O atoms of the Cu-BTC framework.This work adds to the understanding and investigation of the adsorption of liquid lubricants using Cu-BTC as a metal-organic framework(MOF).

关键词： metal-organic framework(MOF) Cu-benzene-1,3,5-tricarboxylate(Cu-BTC) Monte Carlo method adsorption properties 1-olefins

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genome-wide identification and characterization of the PbrATG family in Pyrus bretschneideri and functional analysis of PbrATG1a in response to Botryosphaeria dothidea

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Horticultural Plant Journal 2024年第2期10卷 327-340页

作者： Yun Wang Xun Sun Zhenwu Zhang Zhihua xie Kaijie qi Shaoling Zhang Center of Pear Engineering Technology Research State Key Laboratory of Crop Genetics and Germplasm EnhancementCollege of HorticultureNanjing Agricultural UniversityNanjingJiangsu 210095China

The pear is an economic fruit that is widely planted around the world and is loved by people for its rich nutritional value. Autophagy is a self-protection mechanism in eukaryotes, and its occurrence often accompanied by the degradation of damaged substances in cells and the recycling of nutrients. Autophagy is one of the mechanisms through which plants respond to environmental stress and plays an important role in plant development and stress resistance. Functional studies of autophagy-related genes (ATGs) have been performed on a variety of plant species, but little information is available on the ATG family in pear (Pyrus bretschneideri Rehd). Therefore, we analyzed the evolutionary dynamics and performed a genome-wide characterization of the PbrATG gene family. A total of 28 PbrATG members were identified.Phylogenetic analysis showed that PbrATGs were more closely related to ATGs of European pear and apple. Evolutionary analysis revealed that whole-genome duplication (WGD) and dispersed duplication events were the main driving forces of PbrATG family expansion.Expression analysis of different pear tissues showed that all the genes were expressed in different pear tissues, and different PbrATGs are expressed at different times and in different locations. Moreover, all PbrATGs also responded to different abiotic stresses, especially salt and drought stress, which elicited the highest expression levels. Pear seedlings were subsequently infected with Botryosphaeria dothidea (B.dothidea). The results showed that different PbrATGs had different expression patterns at different infection stages. According to the gene expression data, PbrATG1a was selected as a key autophagy gene for further analysis. Silencing of PbrATG1a reduced the resistance of pear to B. dothidea, which resulted in increased lesions, reactive oxygen species (ROS) contents, antioxidant enzyme activity, and gene expression levels in the silenced pear seedlings after B. dothidea inoculation. In this study, a comprehensive bioinformatic analysis of

关键词： Autophagy Pear PbrATGs Abiotic stress Botryosphaeria dothidea PbrATG1a

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Revealing the Structure-Property Difference of Natural Rubber Prepared by Different Methods: Protein and Gel Content are Key Factors

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Chinese Journal of Polymer Science 2024年第4期42卷 457-467页

作者： Shao-qi Huang Jun-qi Zhang Yong Zhu Ling-Min Kong Lu-Sheng Liao Fu-Quan Zhang Zheng-Tian xie Jin-Rong Wu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China Hainan Provincial Key Laboratory of Natural Rubber Processing Agricultural Products Processing Research Institute of Chinese Academy of Tropical Agricultural SciencesZhanjiang524001China

Natural rubber (NR) is widely used in various fields including aerospace, military industry and transportation due to its superior elasticity and comprehensive mechanical properties. Nonetheless, the commercial NR prepared by different methods usually exhibits different mechanical properties, primarily due to variations in processing conditions during the conversion from latex to bulk rubber material. Consequently, this poses challenges in scientific research and industrial production of NR. In order to assess the properties of various commercially available NR and identify key structural and compositional components, this study systematically compares and analyzes four representative NR raw materials: air dried sheet (ADS), ribbed smoked sheets (RSS), constant viscidity NR (CV), and whole field latex rubber (WF). The investigation focuses on evaluating their static mechanical behavior, SIC behavior, wear resistance, and fatigue resistance. The findings indicate that protein and gel content exhibit a crucial influence on the NR properties. These constituents contribute to the formation of a high-crosslinking density region, generating a heterogeneous network structure within the rubber. This structure amplifies strains during deformation, leading to earlier and stronger strain-induced crystallization (SIC). Among the four commercial NR brands, RSS demonstrates superior overall mechanical and dynamic properties owing to its high protein and gel content. This study serves as a valuable reference for comprehending the differences in properties among various commercial NR, thereby offering guidance for the actual processing and selection of NR.

关键词： Natural rubber Processingmethod Protein Gel content Property

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Microstructural characterization and mechanical properties of(TiC+TiB)/TA15 composites prepared by an in-situ synthesis method

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China Foundry 2024年第2期21卷 168-174页

作者： Zhi-yong Zhang Jiao-jiao Cheng Jia-qi xie Shi-bing Liu Kun Shi Jun Zhao Shenyang Research Institute of Foundry Co. Ltd.CAMShenyang 110022China National Key Laboratory of Advanced Casting Technologies Shenyang 110022China

Titanium matrix composites reinforced with ceramic particles are considered a promising engineering material due to their combination of high specific strength,low density,and high modulus.In this study,the TA15-based composites reinforced with a volume fraction of 10% to 25%(TiB+TiC)were prepared using powder metallurgy and casting technique.Microstructural characterization and phase constitution were examined using optical microscopy(OM),scanning electron microscopy(SEM),and X-ray diffraction(XRD).In addition,the microhardness,room temperature(RT)and high temperature(HT)tensile properties of the composites were evaluated.Results revealed that the reinforcements are distributed uniformly even in the composites with a high volume of TiB and TiC.However,as the volume fraction exceeds 15%,TiB and TiC particles become coarsening and exhibit rod-like and dendritic-like morphology.Microhardness increases gradually from 321.2 HV for the base alloy to a maximum of 473.3 HV as the reinforcement increases to 25vol.%.Tensile test results indicate that a reinforcement volume fraction above 20% is beneficial for enhancing tensile strength and yield strength at high temperatures,but it has an adverse effect on room temperature elongation.Conversely,if the reinforcement volume fraction is below 20%,it can improve high-temperature elongation when the temperature exceeds 600℃.

关键词： titanium matrix composites microstucture microhardness tensile properties in-situ synthesis

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Hydrocarbon Charging and Accumulation Process of the Large Bozhong19-6 Condensate Gas Reservoirs in the Southwestern Bozhong Sub-Basin,Bohai Bay Basin,China

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Journal of Earth Science 2024年第2期35卷 613-630页

作者： Quanyun Miao Changgui Xu Fang Hao Minjunshi xie qi Wang Jie Yin Huayao Zou general Prospecting Institute of China National Administration of Coal Geology Beijing100039China State Key Laboratory of Petroleum Resource and Prospecting China University of PetroleumBeijing102249China Tianjin Branch of China National Offshore Oil Company Ltd. Tianjin300452China School of Geosciences China University of PetroleumQingdao266580China School of Geosciences Yangtze UniversityWuhan430100China

The Bozhong19-6(BZ19-6)condensate gas reservoirs,located in the southwestern Bozhong sub-basin,Bohai Bay Basin,China,were paleo-oil reservoirs in the geological past and have undergone at least three successive hydrocarbon charging events.The hydrocarbon migration and accumulation process of“early oil and late gas”has occurred in the current reservoirs.At the end of the sedimentation of the Guantao Formation(N_(1)g,∼12 Ma),the reservoirs began to fill with first stage low-moderate mature crude oil.At the late stage of the Lower Minghuazhen Formation(N_(1)ml)(∼6.7 Ma),the reservoirs were largely charged with second stage high mature crude oil.Since the deposition of the upper Minghuazhen Formation(N_(2)m^(u),∼5.1 Ma),the paleo-oil reservoirs were transformed into shallow Neogene reservoirs due to the reactivation of basement faults.From the late stage of the N_(2)m^(u)to the present day(∼2.8–0 Ma),the reservoirs were rapidly filled by natural gas within a short period.In addition,analysis of the formation of the reservoir bitumen and the conspicuous loss of the lower molecular weight n-alkanes in the crude oil reveal that the injection of a large amount of gas in the late stage caused gas flushing of the early charged oil.

关键词： Bohai Bay Basin BZ19-6 condensate gas reservoirs fluid inclusions hydrocarbon charging and accumulation petroleum geology

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Microbial Fertilizer: A Sustainable Strategy for Medicinal Plants Production

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Phyton-International Journal of Experimental Botany 2024年第6期93卷 1221-1236页

作者： Chuang Liu Jing xie Hao Liu Can Zhong gen Pan Shuihan Zhang Jian Jin Hunan Academy of Chinese Medicine Hunan University of Chinese MedicineChangsha410036China Institute of Chinese Medicine Resources Hunan Academy of Chinese MedicineChangsha410013China

Medicinal plants have aroused considerable interest as an alternative to chemical drugs due to the beneﬁcial effects of their active secondary metabolites.However,the extensive use of chemical fertilizers and pesticides in pursuit of yield has caused serious pollution to the environment,which is not conducive to sustainable devel-opment in theﬁeld of medicinal plants.Microbial fertilizers are a type of“green fertilizer”containing speciﬁc microorganisms that can improve the soil microbial structure,enhance plant resistance to biological and abiotic stresses,and increase the yield of medicinal plants.The root exudates of medicinal plants attract different micro-organisms to the rhizosphere,which then migrate further to the plant tissues.These microbes can increase the levels of soil nutrients,and improve the physical and chemical properties of soil through nitrogenﬁxation,and phosphorus and potassium solubilization.In addition,soil microbes can promote the synthesis of hormones that increase plant growth and the accumulation of active compounds,eventually improving the quality of med-icinal plants.In 2022,the total value of the global microbial fertilizer market was$4.6 billion and is estimated to reach$10.36 billion by 2030.In this review,we have summarized the types of microbial fertilizers,the coloniza-tion and migration of microorganisms to plant tissues,and the beneﬁcial effects of microbial fertilizers.In addi-tion,the prospects of developing microbial fertilizers and their application for medicinal plants have also been discussed.It aims to provide a reference for the rational application of microbial fertilizers in theﬁeld of med-icinal plants and the green and sustainable development of medicinal plant resources.

关键词： Microbial fertilizers market overview rhizosphere microorganisms endophytic bacteria beneﬁcial effects

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