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The first internal-tide deposits found in China

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Chinese Science Bulletin 1997年第13期42卷 1113-1117页

作者： Gao, ZZ He, YB li, jm li, WF Luo, SS Wang, ZZ Department of Geology Jianghan Petroleum Institute Jingzhou 434102 China

NOT until Gao Zhenzhong and Eriksson studied the Ordovician of Fincastle area, Appalachi-ans, the USA in 1990, did sedimentologist recognize internal-tide deposits in the ancientrecord and begin to use the term of 'internal-tide deposit'. In the Ordovician of Fincastlearea, two facies are recognized: (i) bidirectional cross-laminated very fine grained

关键词： sedimentary facies internal-tide deposits bidirectional cross-laminations couplet bidirectional graded sequences

Plant regeneration from dry mature endosperm cultures of Eucommia ulmoides Oliv.

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Chinese Science Bulletin 1997年第8期42卷 703-704页

作者： Zhu, DY Jiang, JH Pei, DQ Tian, HQ Wang, M Zhu, M Mi, JJ li, jm College of Biological Sciences China Agricultural University Beijing China

EUCOMMIA ulmoides is not only a famous medicinal plant,but also a most promising rubber-source plant in the temperate *** the individuals present in this species are diploid(2n=2x=34),and the objective of this work is to establish a novel triploid type of it so as to im-prove its overall biomass output or rubber content in the leaf cells by the characteristic cell en-

关键词： Plant regeneration from dry mature endosperm cultures of Eucommia ulmoides Oliv

Semi-automated detection of rangeland runoff and erosion control berms using high-resolution topography data

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International Soil and Water Conservation Research 2024年第1期12卷 217-226页

作者： li li Changjiang River Scientific Research Institute of Changjiang Water Resources Commission Wuhan430010China Research Center on Mountain Torrent&Geologic Disaster Prevention Ministry of Water ResourcesWuhan430010China University of Arizona School of Natural Resources and the EnvironmentTucsonAZ85719USA

An inventory of topographic modifications is essential to addressing their impacts on hydrological and morphological processes in human-altered ***,such inventories are generally *** study presents two workflows for semi-automatic detection of linear earthen runoff and erosion control berms in rangelands using high-resolution topographic *** workflows consist of initial object identification by applying either morphological grayscale reconstruction(MGR)or the Geomorphon(GEO)method,followed by identification refinements through filters based on objects’horizontal and vertical *** sites were selected within the Altar Valley,Arizona,in the southwestern United *** site was used for developing workflows and optimizing filter thresholds,and the other two sites were used to validate *** results showed that:1)The MGR-based workflow methodology could produce final precision and detection rates of up to 92%and 75%,respectively,and take less than 5 s for a 10.1 km^(2) site;2)The workflow based on the MGR method yielded greater identification accuracy than did the GEO workflow;3)Object length,orientation,and eccentricity were important characteristics for identifying earthen berms,and are sensitive to general channel flow direction and berm shape;4)Manual interrogation of topographic data and imagery can significantly improve identification precision *** proposed workflows will be useful for developing inventories of runoff and erosion control structures in support of sustainable rangeland management.

关键词： Earthen berm Rangeland Grayscale morphological reconstruction Geomorphon liDAR

Effects of mid-passage gap with a variable surface angle on a turbine vane endwall’s aerothermal and film cooling performances

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Chinese Journal of Aeronautics 2024年第6期37卷 20-37页

作者： Zhiyu li Kaiyuan ZHANG Zhigang li Jun li Institute of Turbomachinery Xi’an Jiaotong UniversityXi’an 710049China

The mid-passage gap is an inevitable structure in a vane passage due to turbine vanes being manufactured *** coolant from this gap is able to prevent hot mainstream ingression and provide cooling protection for the endwall.A novel idea of enlarging the endwall’s coverage area and reducing the endwall’s thermal load by applying the mid-passage gap with variable surface angles is carried out in this *** endwall’s aerothermal and film cooling performances under four mid-passage gap modes at three typical mass flow ratio conditions are numerically *** indicate that under the traditional mid-passage mode,the coolant flows into the mainstream with a perpendicular incidence angle and can’t stick to the ***,cooling failure occurs,and the endwall’s thermal load is badly *** film cooling level at the suction-side endwall is improved when applying the mid-passage gap of a 45surface angle due to the secondary vortex being *** addition,when applying the mid-passage gap of a 135surface angle,the horseshoe vortex is pushed away,and the coverage area at the pressure-side endwall is enlarged *** best film cooling performance is achieved when the upstream surface angle is 135and the downstream surface angle is 45due to the adiabatic film cooling effectiveness being increased at both the pressure-and suction-side *** the mass flow ratio is 1.5%,the coverage area is enlarged by 43%,and the area-averaged adiabatic film cooling effectiveness is increased by 37%,when compared with those under the traditional mid-passage mode.

关键词： Film cooling Heat transfer Surface angle Mid-passagegap Turbinevane endwall

Perturbed low-thrust geostationary orbit transfer guidance via polynomial costate estimation

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Chinese Journal of Aeronautics 2024年第3期37卷 181-193页

作者： Zhao li Hengnian li Fanghua JIANG Junfeng li State Key Laboratory of Astronautic Dynamics Xi’an Satellite Control CenterXi’an 710043China School of Aerospace Engineering Tsinghua UniversityBeijing 100084China

This paper proposes an optimal,robust,and efficient guidance scheme for the perturbed minimum-time low-thrust transfer toward the geostationary *** Earth’s oblateness perturbation and shadow are taken into *** is difficult for a Lyapunov-based or trajectory-tracking guidance method to possess multiple characteristics at the same time,including high guidance optimality,robustness,and onboard computational *** this work,a concise relationship between the minimum-time transfer problem with orbital averaging and its optimal solution is identified,which reveals that the five averaged initial costates that dominate the optimal thrust direction can be approximately determined by only four initial modified equinoctial orbit elements after a coordinate *** on this relationship,the optimal averaged trajectories constituting the training dataset are randomly generated around a nominal averaged *** polynomial regression models are trained on the training dataset and are regarded as the costate *** the transfer,the spacecraft can obtain the real-time approximate optimal thrust direction by combining the costate estimations provided by the estimators with the current state at any ***,all these computations onboard are *** simulation results show that the proposed guidance scheme possesses extremely high guidance optimality,robustness,and onboard computational efficiency.

关键词： Low thrust Orbital transfer Trajectory optimization Guidance Indirect method Orbital averaging Machine learning Geostationary satellites

Theoretical Analysis of Cooperative Driving at Idealized Unsignalized Intersections

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Tsinghua Science and Technology 2024年第1期29卷 257-270页

作者： Shen li Jiawei Zhang Zhenwu Chen li li Department of Civil Engineering Tsinghua UniversityBeijing 100084China Department of Automation Tsinghua UniversityBeijing 100084China Shenzhen Urban Transport Planning Center Co. Ltd.Shenzhen 518000China

Cooperative driving is widely viewed as a promising method to better utilize limited road resources and alleviate traffic *** recent years,several cooperative driving approaches for idealized traffic scenarios(i.e.,uniform vehicle arrivals,lengths,and speeds)have been ***,theoretical analyses and comparisons of these approaches are *** this study,we propose a unified group-by-group zipper-style movement model to describe different approaches synthetically and evaluate their *** derive the maximum throughput for cooperative driving plans of idealized unsignalized intersections and discuss how to minimize the delay of *** obtained conclusions shed light on future cooperative driving studies.

关键词： cooperative driving connected and automated vehicles unsignalized intersection

急性病毒性肝炎的全球负担及其与社会经济发展状态的关系(1990—2019)

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临床肝胆病杂志 2021年第6期37卷 1424-1424页

作者： ZENG DY li jm liN S Department of Hepatology The First Affiliated Hospital of Fujian Medical University Fuzhou Fujian China Hepatology Research Institute Fujian Medical University Fuzhou Fujian China School of Medicine Xiamen University Xiamen Fujian China Department of Statistics School of Economics Xiamen University Xiamen Fujian China Department of Gastroenterology Zhongshan Hospital Xiamen University Xiamen Fujian China School of Clinical Medicine Fujian Medical University Fuzhou Fujian China Department of Traditional Chinese Medicine Mengchao Hepatobiliary Hospital of Fujian Medical University Fuzhou Fujian China

【据Journal of Hepatology 2021年5月报道】题:急性病毒性肝炎的全球负担及其与社会经济发展状态的关系(1990—2019)(作者Zeng DY等)急性病毒性肝炎(AVH)是全球重要的公共卫生健康问题,但由于全球病毒性肝炎防治重心在于后果严重的慢... 详细信息

【据Journal of Hepatology 2021年5月报道】题:急性病毒性肝炎的全球负担及其与社会经济发展状态的关系(1990—2019)(作者Zeng DY等)急性病毒性肝炎(AVH)是全球重要的公共卫生健康问题,但由于全球病毒性肝炎防治重心在于后果严重的慢性乙型肝炎(CHB)以及慢性丙型肝炎(CHC),而关于AVH的研究进展有限。随着最近针对病毒性肝炎的疫苗和治疗方法的进展,需要对AVH的负担进行更深入的了解,从而为全球干预策略提供依据。来自福建医科大学第一附属医院肝病科的Zeng等通过全球疾病负担2019数据库(Global Burden of Disease Study 2019)收集4种主要AVH类型的年龄标准化发病率和伤残调整生命年(DALY)率数据,包括A、B、C和E型急性肝炎,并将数据以性别、社会人口指数(SDI)水平、国家和地区进行分层,描述社会经济发展状态(以SDI为代表)与AVH负担的关联性。

关键词：急性病毒性肝炎经济发展状态全球疾病负担急性肝炎肝病科福建医科大学人口指数

Failure mechanisms and surface treatment processes of thermal barrier coatings: Review

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CHINESE JOURNAL OF AERONAUTICS 2024年第9期37卷 20-40页

作者： li, Hao Yang, Shengqiang li, Xiuhong li, Wenhui Taiyuan Univ Technol Coll Mech & Vehicle Engn Taiyuan 030024 Peoples R China Taiyuan Univ Technol Shanxi Prov Key Lab Precise Machining Taiyuan 030024 Peoples R China Taiyuan Univ Technol Coll Aeronaut & Astronaut Taiyuan 030024 Peoples R China

Thermal Barrier Coatings (TBCs) technology is key to improving the service temperature and the productivity of aircraft engines. The performance and failure life of TBCs are strongly influenced by surface integrity and microstructure. Therefore, recognizing failure mechanisms and developing effective surface treatment processes are crucial for further improving the reliability and durability of TBCs. This paper explains the primary reasons for TBC failure, emphasizing on how integrity of surface and interface influences interfacial oxidation, high-temperature erosion, and Calcium-Magnesium-Alumina-Silicate (CMAS) corrosion. Furthermore, this paper completely and rigorously evaluates the research status of TBCs surface treatment processes, including the characteristics and effects of various processes, and describes the requirements and goals of pretreatment and post-treatment. In addition, a potential direction for the development and application of TBCs surface treatment is suggested. (c) 2024 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics. This is an open access article under the CC BY-NC-ND license (http://***/ licenses/by-nc-nd/4.0/).

关键词： Thermal Barrier Coatings (TBCs) Failure Surface treatment processes Processing goals Mass finishing HOT CORROSION BEHAVIOR YTTRIA-STABIliZED ZIRCONIA HIGH-TEMPERATURE OXIDATION ELECTRON-BEAM CMAS CORROSION EROSION BEHAVIOR HEAT-TREATMENT GROWN OXIDE STRESS-DISTRIBUTION ADHESION STRENGTH

Ultrathin organic solvent nanofiltration membrane with polydopamine-HKUST-1 interlayer for organic solvent separation

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Journal of Environmental Sciences 2024年第7期141卷 182-193页

作者： Haike li Xindong li Guozai Ouyang lijinhong Huang Lang li Wenhao li Wanfu Huang Duokun li Ganzhou Key Laboratory of Basin Pollution Simulation and Control Jiangxi University of Science and TechnologyGanzhou 341000China Innovation Center for Water Quality Security Technology at Ganjiang River Basin Jiangxi University of Science and TechnologyGanzhou 341000China School of Architecture and Design Jiangxi University of Science and TechnologyGanzhou 341000China WA School of Mines:Minerals Energy and Chemical EngineeringCurtin UniversityWA 6845Australia School of Materials Science and Engineering Tiangong UniversityTianjin 300387China

Polydopamine(PDA)and metal-organic skeleton HKUST-1 were co-deposited on the base membrane of hexamethylenediamine(HDA)-crosslinked polyetherimide(PEI)ultrafiltration membrane as the interlayer,and high-throughput organic solvent nanofiltration membrane(OSN)was prepared by interfacial polymerization and solvent activation *** polyamide(PA)layer surface roughness from 28.4 nm in PA/PEI to 78.3 nm in PA/PDA-HKUST-10.6/PEI membrane,reduced the thickness of the separation layer from 79 to 14 nm,and significantly improved the hydrophilic,thermal and mechanical *** flux of the PA/PDA-HKUST-10.6/PEI membrane in a 0.1 g/L Congo Red(CR)ethanol solution at 0.6 MPa test pressure reached 21.8 L/(m^(2)·hr)and the rejection of CR was 92.8%.Solvent adsorption test,N,N-dimethylformamide(DMF)immersion experiment,and long-term operation test in ethanol showed that the membranes had high solvent *** solvent flux test demonstrated that,under the test pressure of 0.6 MPa,the flux of different solvents ranked as follows:methanol(56.9 L/(m^(2)·hr))>DMF(39.6 L/(m^(2)·hr))>ethanol(31.2 L/(m^(2)·hr))>IPA(4.5 L/(m^(2)·hr))>N-hexane(1.9 L/(m^(2)·hr)).The ability of the membranes to retain dyes in IPA/water dyes solution was also *** flux of the membrane was 30.4 L/(m^(2)·hr)and the rejection of CR was 91.6%when the IPA concentration reached 50%.This OSN membrane-making strategy is economical,environment-friendly and efficient,and has a great application prospect in organic solvent separation systems.

关键词： Interfacial polymerization Organic solvent nanofiltration Interlayer Metal-organic frameworks Polydopamine