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Persistent greening against drying in northeast Asian semiarid grasslands:Asymmetrical responses of direct and legacy effects to intensified drought

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Advances in Climate Change Research 2024年第1期15卷 9-20页

作者： Yu-Tong MA Hai-Shan CHEN Yao-Ming SONG Bo-Tao ZHOU Shan-Lei SUN xin-guan du Yue SUN Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing 210044China

Despite experiencing a decadal shift towards drought conditions at the end of the 2Oth century,semiarid grasslands in northeast Asia(NEA)exhibited an evident greening trend from 1982 to ***,the mechanism behind this phenomenon remains ***,we analysed the interdecadal changes in vegetation response to drought on the basis of the standardised precipitation evapotranspiration index(SPEI)and Global Inventory Modelling and Mapping Studies LAI4g datasets,with an emphasis on the differences between direct and legacy effects(as measured by resilience),to explore the mechanism of persistent grassland *** revealed that during the post-drought shift period(2000-2020),the sudden decrease in the water content of the intermediate soil layer triggered an intensified vegetation response to ***,although direct effects and resilience were amplified,they exhibited asymmetric *** was stronger than direct effects,and this difference increased with increasing drought(drought recovery)*** combined effects may account for persistent greening against intensified drying in the semiarid grasslands in *** the projected exacerbation of future droughts,this study holds notable importance for comprehending the long-term change dynamics of dryland ecosystems.

关键词： Semiarid grassland Drought decadal shift Direct effect Legacy effect(resilience) Northeast Asia

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A low-frequency and broadband wave-insulating vibration isolator based on plate-shaped metastructures

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1171-1188页

作者： Wei WEI Feng guan xin FANG College of Intelligent Science National University of Defense Technology Naval Research Academy

A metamaterial vibration isolator, termed as wave-insulating isolator, is proposed, which preserves enough load-bearing capability and offers ultra-low and broad bandgaps for greatly enhanced wave insulation. It consists of plate-shaped metacells,whose symmetric and antisymmetric local resonant modes offer several low and broad mode bandgaps although the complete bandgap remains high and narrow. The bandgap mechanisms, vibration isolation properties, effects of key parameters, and robustness to complex conditions are clarified. As experimentally demonstrated, the wave-insulating isolator can improve the vibration insulation in the ranges of [50 Hz, 180 Hz] and [260 Hz,400 Hz] by 15 dB and 25 dB, respectively, in contrast to the conventional isolator with the same first resonant frequency.

关键词： metamaterial and metastructure vibration isolation bandgap wave insulation plate O328 34A30 74K20

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Utilization of human excrement in pre-modern China,its theoretical interpretations and ecological significance

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Soil Ecology Letters 2024年第1期6卷 1-5页

作者： xin-Hao du Yuan-Ming Song Ji-An Cai Yong-guan Zhu Institute for the History of Natural Sciences Chinese Academy of SciencesBeijing 100190China Institute for Cultural Heritage and History of Science&Technology University of Science and Technology BeijingBeijing 100083China Faculty of History Nankai UniversityTianjin 300350China Research Center for Eco Environmental Sciences Chinese Academy of SciencesBeijing 100085China

The use of human excrement as fertilizer is a characteristic of traditional Chinese agriculture..The application of excrement from urban residents in agriculture since the Song Dynasty has ensured the cleanliness and hygiene of *** early as the Ming Dynasty,the Chinese people defined the principle of fertilizing fields with human excrement from the perspective of *** concept Peri-URban ecosystems(PURE)provides inspiration forurban-rural symbiosis regarding *** use of human excrement in fertilization is a major attribute differentiating the Chinese traditional agriculture from the agriculture in other regions around the *** the fact that the exact record showing that human excrement was used as fertilizer in China emerged in the Western Han Dynasty(B.C.202-A.D.8),such records did not become prevalent until the Southern Song Dynasty(A.D.1127-1279).In the Ming and Qing eras(A.D.1368-1912),human excrement was even considered"top-class fertilizerand servedas themost essential fertilizerin farmland *** importance of human excrement in the Ming and Qing was mainly reflected by farmers'purchase of human excrement from urban *** fertilization practices became increasingly popular during the period,men of letters built a localized theoretical system centering on human *** the use of human excrement had both positive and negative impacts on public health and the ecological environment,the positive overshadowed the negativeas a ***,it is worth pondering on how the utilization of human excrement as an agricultural resource can be improved so that a material cycle system can be rebuilt to re-connect the urban and rural areas.

关键词： excrement fertilizer theorization urban and rural ecology public health

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A GMDA clustering algorithm based on evidential reasoning architecture

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Chinese Journal of Aeronautics 2024年第1期37卷 300-311页

作者： Haibin WANG xin guan Xiao YI Shuangming LI Guidong SUN Naval Aviation University Yantai 264001China Unit 92941 of PLA Huludao 125001China Institute of Systems Engineering Beijing 100082China

The traditional clustering algorithm is difficult to deal with the identification and division of uncertain objects distributed in the overlapping region,and aimed at solving this problem,the Evidential Clustering based on General Mixture Decomposition Algorithm(GMDA-EC)is ***,the belief classification of target cluster is carried out,and the sample category of target distribution overlapping region is ***,on the basis of General Mixture Decomposition Algorithm(GMDA)clustering,the fusion model of evidence credibility and evidence relative entropy is constructed to generate the basic probability assignment of the target and achieve the belief division of the ***,the performance of the algorithm is verified by the synthetic dataset and the measured *** experimental results show that the algorithm can reflect the uncertainty of target clustering results more comprehensively than the traditional probabilistic partition clustering algorithm.

关键词： Evidential clustering Credal partition Evidential reasoning Mixed decomposition Gaussian mixture model

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Understanding the Mechanism for the In-Plane Yielding Anisotropy of a Hot-Rolled Zirconium Plate

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 1066-1076页

作者： Guodong Song Conghui Zhang Yunchang xin Nobuhiro Tsuji xinde Huang Bo guan Xiaomei He School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an710055China Key Laboratory for Light-Weight Materials Nanjing Tech UniversityNanjing210009China Department of Materials Science and Engineering Kyoto UniversityYoshida-honmachiSakyo-kuKyoto606-8501Japan Institute of Applied Physics Jiangxi Academy of ScienceNanchang330029China

Previously,the in-plane mechanical anisotropy of Zr hot-rolled plates is ascribed mainly to the different activities of the deformation modes activated when loading along different *** this work,a quantitative study on the deformation behavior of a pure Zr hot-rolled plate under tension along the rolling direction(RD)and transverse direction(TD)reveals that both the activities of deformation modes and the anisotropy of grain boundary strengthening account for a tensile yield strength anisotropy along the TD and *** plasticity simulations using viso-plastic self-consistent model show that prismatic slip is the predominant deformation mode for tension along the RD(RD-tension),while prismatic slip and basal slip are co-dominant deformation modes under tension along the TD(TD-tension).A low fraction of■under TD-tension,while hardly activated under *** activation of basal slip with a much higher critical resolve shear stress under TD-tension contributes to a higher yield strength along the TD than along the *** grain boundary strengthening effect under tension along the TD and RD were compared by calculating the activation stress difference(△Stress)and the geometric compatibility factor(m′)between neighboring *** results indicate a higher grain boundary strengthening for TD-tension than that for RD-tension,which will lead to a higher yield strength along the *** is,the anisotropy of grain boundary strengthening between TD-tension and RD-tension also plays an important role in the in-plane anisotropy along the RD and ***,the reasons for why there is a grain-boundary-strengthening anisotropy along the TD and RD were discussed.

关键词： Zirconium Strengthening Grain boundary Orientation

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Multi-scale data joint inversion of minerals and porosity in altered igneous reservoirs—A case study in the South China Sea

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Petroleum Science 2024年第1期21卷 206-220页

作者： xin-Ru Wang Bao-Zhi Pan Yu-Hang Guo Qing-Hui Wang Yao guan College of Geo-exploration Science and Technology Jilin UniversityChangchun130046JilinChina Research Institute CNOOC Ltd.-ShenzhenShenzhen518000GuangdongChina

There are abundant igneous gas reservoirs in the South China Sea with significant value of research,and lithology classification,mineral analysis and porosity inversion are important links in reservoir ***,affected by the diverse lithology,complicated mineral and widespread alteration,conventional logging lithology classification and mineral inversion become considerably *** the same time,owing to the limitation of the wireline log response equation,the quantity and accuracy of minerals can hardly meet the exploration requirements of igneous *** overcome those issues,this study takes the South China Sea as an example,and combines multi-scale data such as micro rock slices,petrophysical experiments,wireline log and element cutting log to establish a set of joint inversion methods for minerals and porosity of altered igneous ***,we define the lithology and mineral characteristics through core slices and mineral data,and establish an igneous multi-mineral volumetric *** we determine element cutting log correction method based on core element data,and combine wireline log and corrected element cutting log to perform the lithology classification and joint inversion of minerals and ***,it is always difficult to determine the elemental eigenvalues of different minerals in *** paper uses multiple linear regression methods to solve this ***,an integrated inversion technique for altered igneous formations was *** results show that the corrected element cutting log are in good agreement with the core element data,and the mineral and porosity results obtained from the joint inversion based on the wireline log and corrected element cutting log are also in good agreement with the core data from X-ray *** results demonstrate that the inversion technique is applicable and this study provides a new direction for the mineral inversion research of altered igneous formation

关键词： Joint inversion Altered igneous rock Element correction method Lithology identification Multi mineral volume model

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Volume-averaged modeling of multiphase solidification with equiaxed crystal sedimentation in a steel ingot

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China Foundry 2024年第3期21卷 229-238页

作者： Xiao-lei Zhu Shuang Cao Rui guan Ji Yang Zhe Ning xin-gang Ai Sheng-li Li xin-cheng Miao The key Laboratory of Material Forming and Structure Property Control Anshan 114051LiaoningChina State Key Laboratory of Metal Material for Marine Equipment and Application Anshan 114009LiaoningChina School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina

Macrosegregation is a critical factor that limits the mechanical properties of *** impact of equiaxed crystal sedimentation on macrosegregation has been extensively studied,as it plays a significant role in determining the distribution of alloying elements and impurities within a *** improve macrosegregation in steel connecting shafts,a multiphase solidification model that couples melt flow,heat transfer,microstructure evolution,and solute transport was established based on the volume-averaged Eulerian-Eulerian *** this model,the effects of liquid phase,equiaxed crystals,columnar dendrites,and columnar-to-equiaxed transition(CET)during solidification and evolution of microstructure can be considered *** sedimentation of equiaxed crystals contributes to negative macrosegregation,where regions between columnar dendrites and equiaxed crystals undergo significant A-type positive macrosegregation due to the ***,noticeable positive macrosegregation occurs in the area of final solidification in the *** improvement in macrosegregation is beneficial for enhancing the mechanical properties of connecting *** mitigate the thermal convection of molten steel resulting from excessive superheating,reducing the superheating during casting without employing external fields or altering the design of the ingot mold is indeed an effective approach to control macrosegregation.

关键词： ingot casting multiphase solidification model equiaxed crystal sedimentation microstructure macrosegregation

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Appendicitis combined with Meckel’s diverticulum obstruction, perforation, and inflammation in children: Three case reports

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World Journal of Clinical Cases 2024年第4期12卷 865-871页

作者： Yi-Meng Sun Wang xin Yu-Fang Liu Zhe-Ming guan Hao-Wen du Ning-Ning Sun Yong-Dong Liu School of Clinical Medicine Weifang Medical UniversityWeifang 261000Shandong ProvinceChina Department of Pediatric Surgery Weifang People’s HospitalWeifang 261000Shandong ProvinceChina Department of Burn Surgery Weifang People’s HospitalWeifang 261000Shandong ProvinceChina

BACKGROUND Meckel’s diverticulum is a common congenital malformation of the small intestine,with the three most common complications being obstruction,per-foration,and *** date,only a few cases have been reported *** children,the clinical symptoms are similar to *** most of the imaging features are nonspecific,the preoperative diagnosis is not *** addition,the clinical characteristics are highly similar to pediatric acute appendicitis,thus special attention is necessary to distinguish Meckel’s diver-ticulum from pediatric *** with poor disease control should undergo laparoscopic exploration to avoid serious complications,including intestinal necrosis,intestinal perforation and gastrointestinal *** SUMMARY This report presents three cases of appendicitis in children combined with intestinal obstruction,which was caused by fibrous bands(ligaments)arising from the top part of Meckel's diverticulum,diverticular perforation,and diver-ticular *** three patients,aged 11-12 years,had acute appendicitis as their initial clinical *** were treated by laparoscopic surgery with a favorable outcome.A complete dataset including clinical presentation,dia-gnostic imaging,surgical information,and histopathologic findings was also *** Preoperative diagnosis of Meckel’s diverticulum and its complications is challenging because its clinical signs and complications are similar to those of appendicitis in *** combined with laparotomy is useful for diagnosis and treatment.

关键词： Meckel’s diverticulum Complications Intestinal obstruction Perforation Appendicitis in children Mesodiverticular band Ligament Diverticular disease Case report

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Influence of Surface Ice Roughness on the Aerodynamic Performance of Wind Turbines

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Fluid Dynamics & Materials Processing 2024年第9期20卷 2029-2043页

作者： xin guan Mingyang Li Shiwei Wu Yuqi Xie Yongpeng Sun School of New Energy Shenyang Engineering CollegeShenyang110136China Shenyang Key Laboratory Clean Energy Fine Comprehensive Utilization and Scheduling Energy Storage Shenyang110136China

The focus of this research was on the equivalent particle roughness height correction required to account for the presence of ice when determining the performances of wind *** particular,two icing processes(frost ice and clear ice)were examined by combining the FENSAP-ICE and FLUENT analysis *** ice type on the blade surfaces was predicted by using a multi-time step ***,the influence of variations in icing shape and ice surface roughness on the aerodynamic performance of blades during frost ice formation or clear ice formation was *** results indicate that differences in blade surface roughness and heat flux lead to disparities in both ice formation rate and shape between frost ice and clear *** ice has a greater impact on aerodynamics compared to frost ice,while frost ice is significantly influenced by the roughness of its icy surface.

关键词： Wind turbine icing blade surface roughness aerodynamic characteristics airfoil

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Research on Leading Edge Erosion and Aerodynamic Characteristics of Wind Turbine Blade Airfoil

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Fluid Dynamics & Materials Processing 2024年第9期20卷 2045-2058页

作者： xin guan Yuqi Xie Shuaijie Wang Mingyang Li Shiwei Wu School of New Energy Shenyang Institute of EngineeringShenyang110136China

The effects of the erosion present on the leading edge of a wind turbine airfoil(du 96-W-180)on its aerodynamic performances have been investigated numerically in the framework of a SST k–ωturbulence model based on the Reynolds Averaged Navier-Stokes equations(RANS).The results indicate that when sand-induced holes and small pits are involved as leading edge wear features,they have a minimal influence on the lift and drag coefficients of the ***,if delamination occurs in the same airfoil region,it significantly impacts the lift and resistance characteristics of the ***,as the angle of attack grows,there is a significant decrease in the lift coefficient accompanied by a sharp increase in the drag *** wear intensifies,these effects gradually ***,the leading edge wear can exacerbate flow separation near the trailing edge suction surface of the airfoil and cause forward displacement of the separation point.

关键词： Wind energy wind turbine erosion airfoil leading edge erosion characteristics aerodynamic performance numerical simulation

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