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Influence of soil texture on the process of subsurface drainage in saturated-unsaturated zones

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International Journal of Agricultural and Biological Engineering 2021年第1期14卷 82-89页

作者： yufang li Mingsi li Hongguang liu Wenbao Qin College of Water Resources and Architectural Engineering Shihezi UniversityShihezi 832000XinjiangChina Santunhe River Basin Management Section Changji Water Resources BureauChangji 831100XinjiangChina

This study addressed the problem of low drainage efficiency or even no drainage in subsurface drainage systems buried in saturated-unsaturated zones above the water *** indoor experiment on infiltration under ponded conditions in a homogeneous soil column was performed to study the effects of soil texture on the soil wetting front morphology,soil infiltration rate,drainage efficiency of the subsurface drainage pipe,vertical distribution of soil water content and salinity along the soil *** results showed that the drainage process of subsurface drainage pipes above the water table was quite different from that of subsurface drainage pipes below the water *** a subsurface drainage pipe was located in sandy soil,the migration of soil water toward the bottom of the drainage pipe was significant,and the water could not be discharged into the *** the drainage pipe was located in loamy clay,the movement of soil water towards the bottom of the pipe was retarded,and the water could be discharged into the *** the drainage process,the drainage of the pipe can produce nonequilibrium flow in the soil,and the continuity of the nonequilibrium flow can be affected by the hydraulic conductivity of the soil above the pipe,which can result in discontinuous drainage and low drainage *** water holding capacity,permeability and aeration of soil are important factors that affect the drainage under unsaturated *** the hysteresis effect and capillary barrier around the drainage pipe and adjusting water holding capacity,the permeability and aeration of soil structure through a new subsurface drainage structure may enhance the drainage efficiency of subsurface drainage pipes in saturated-unsaturated zones.

关键词： saturated-unsaturated zone soil texture subsurface drainage pipe groundwater level

Car-following behavior modeling driven by small data sets based on mnemonic extreme gradient boosting framework

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Science China(Information Sciences) 2022年第6期65卷 271-272页

作者： Baichuan LOU yufang li Xiaoding LU Zhe XU Department of Vehicle Engineering Nanjing University of Aeronautics and Astronautics Key Laboratory of Advanced Manufacture Technology for Automobile Parts (Chongqing University of Technology) Ministry of Education

Dear editor,In recent years, data-driven car-following models have been developed based on their ability to drill down to information in driving data and their flexibility. According to a study by Fleming et al. [1], the main limitation of existing methods is an insufficient amount of natural driving data. In addition,there are many situations during actual driving processes,such as those under extreme conditions [2] and in the early stages of car-following behavior modeling. In these cases,sparse data learning algorithms are indispensable.

关键词： car-following model sparse data learning XGBoost LSTM dynamic constraints

Investigating long-term vehicle speed prediction based on GA-BP algorithms and the road-traffic environment

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Science China(Information Sciences) 2020年第9期63卷 121-123页

作者： yufang li Chen REN Hongwei ZHAO Guoping CHEN Department of Vehicle Engineering College of Energy & Power Engineering Nanjing University of Aeronautics and Astronautics Key Laboratory of Advanced Manufacture Technology for Automobile Parts (Chongqing University of Technology) Ministry of Education Foton Motor Group

Dear editor,Effective and accurate long-term speed prediction is crucial for intelligent transportation and automobile intelligent energy management systems of intelligent connected vehicles. These predictions have important research value and broad application prospects including widespread use in improving traffic efficiency and safety, fuel economy, remaining driving range estimation [1], and electric

关键词： long-term speed prediction road-traffic environment characteristic parameters description GA-BP network modeling

Multi-objective robust design optimization of a novel negative Poisson's ratio bumper system

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Science China(Technological Sciences) 2017年第7期60卷 1103-1110页

作者： ZHOU Guan ZHAO WanZhong MA ZhengDong WANG ChunYan li yufang College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics State Key Laboratory of Mechanical Transmission Chongqing University Department of Mechanical Engineering and Applied Mechanics University of Michigan

Negative Poisson's ratio(NPR) structure has outstanding performances in lightweight and energy absorption, and it can be widely applied in automotive industries. By combining the front anti-collision beam, crash box and NPR structure, a novel NPR bumper system for improving the crashworthiness is first proposed in the work. The performances of the NPR bumper system are detailed studied by comparing to traditional bumper system and aluminum foam filled bumper system. To achieve the rapid design while considering perturbation induced by parameter uncertainties, a multi-objective robust design optimization method of the NPR bumper system is also proposed. The parametric model of the bumper system is constructed by combining the full parametric model of the traditional bumper system and the parametric model of the NPR structure. Optimal Latin hypercube sampling technique and dual response surface method are combined to construct the surrogate models. The multi-objective robust optimization results of the NPR bumper system are then obtained by applying the multi-objective particle swarm optimization algorithm and six sigma criteria. The results yielded from the optimizations indicate that the energy absorption capacity is improved significantly by the NPR bumper system and its performances are further optimized efficiently by the multi-objective robust design optimization method.

关键词： negative Poisson's ratio structure bumper system multi-objective robust design optimization parameterized model crashworthiness

Microinvasive analysis of textile relics from an ancient Silk Road turquoise mining site

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Science China(Technological Sciences) 2023年第8期66卷 2286-2296页

作者： XIAO Wei XIAN YiHeng YU Chun WANG Yan SUN liJuan li yufang Key Laboratory for Cultural Heritage Study&Conservation Ministry of EducationNorthwest UniversityXi’an 710127China School of Cultural Heritage Northwest UniversityXi’an 710127China

The Xinjiang region,with its unique location and climate,exhibits well-preserved relics of great academic *** paper focuses on the microinvasive analysis of textile samples obtained from an ancient turquoise mining site in the Heishanling region of Xinjiang,active between 820 and 400 *** analytical techniques,including optical microscopy,scanning electron microscopy,Fourier-transform infrared spectroscopy with attenuated total reflection,and liquid chromatography-mass spectrometry,were employed to investigate these *** results revealed that the textiles were composed of wool and dyed using indigo and *** bluegrass and madder-derived dyes were likely sourced locally or imported from wetter regions such as the Chinese Central *** infrared deconvolution spectra and the results demonstrated that red and blue dyes considerably influenced the movement of wool fiber chains,leading to a more rapid decay of dyed fibers compared to those that were *** addition,the medium dyeing process and Ke techniques were employed to create unique color shades and special *** scientific and technological analysis of the textiles provides essential data for elucidating the materials available to ancient ***,it offers scientific evidence supporting the cultural exchange between the western regions and the Central Plains and integration along the Silk Road.

关键词： microinvasive analysis textile relics turquoise mining site weave

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Relative Property A for Discrete Metric Space

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Journal of Mathematical Research with Applications 2019年第1期39卷 51-60页

作者： yufang li Zhe DONG Yuanyi WANG Department of Mathematics Zhejiang University Department of Mathematics and Statistics Guizhou University School of Information Engineering College of Science and Technology Ningbo University

Yu introduced Property A on discrete metric spaces. In this paper, a relative Property A for a discrete metric space X with respect to a set Y and a map ρ;is defined. Some characterizations for relative Property A are given. In particular, a discrete metric space with relative Property A can be coarse embedding into a Hilbert space under certain condition.

关键词： relative Property A coarse embedding mazur map

Zirconium-Induced Softening in Hyperstoichiometric Ni_3Al

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Journal of Materials Science & Technology 2005年第2期21卷 207-210页

作者： yufang li, Jianting GUO and Hengqiang YE Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China Inst. of Metal Res. Chinese Acad. of Sci. Shenyang 110016 China

The room temperature compressive properties and microhardness of Ni3AI alloys doped with Zr were studied. For the hypostoichiometric Ni3AI alloys, the compressive strength and microhardness increased with an increase in Zr content, while softening behavior induced by doping with a certain amount of Zr was observed in hyperstoichiometric Ni3AI alloy. Possible mechanisms for the softening effect were suggested.

关键词： Ni3Al Compressive properties Microhardness Softening

Effects of Hot Wire Temperature on Properties of GeSi:H Films with High Hydrogen Dilution by Hot-Wire Chemical Vapor Deposition

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Wuhan University Journal of Natural Sciences 2019年第5期24卷 405-408页

作者： TAI Xin li Xingbing ZHEN Huang SHEN Honglie li yufang HUANG Haibin Institute of Photovoltaics Nanchang University Nanchang 330031 Jiangxi China China China Intellectual Electric Power Technology(Taixing)Co.Ltd. Taixing 225400 Jiangsu China Jiangsu Key Laboratory of Materials and Technology for Energy Conversion Nanjing 211100 Jiangsu China

GeSi:H films are prepared by hot-wire chemical vapor deposition(CVD) with high hydrogen dilution, DH=98%. Effects of hot wire temperature(Tw) on deposition rate, structural properties and bandgap of GeSi:H films are studied with surface profilemeter, Raman spectroscopy, Fourier transformed infrared spectroscopy, and UV-VIS-NIR spectrophotometer. It is found that the deposition rate(Rd) goes up with increasing of Tw, but increasing rate of Rd declines when Tw≥1 550 ℃. High Tw is beneficial to the formation of Ge-Si, but it has little effect on relative contents of the hydrogen bonds(Ge-H, Si-H, etc.) in the films. In the Tw range of 1 400-1 850 ℃, the maximum bandgap of the GeSi:H films is 1.39 eV at Tw =1 450 ℃ and the band gap decreases with Tw increasing when Tw≥1 450 ℃.

关键词： GeSi:H films hot-wire chemical vapor deposition(CVD) deposition rate structural properties band gap hot wire temperature

Stable Growth of the Adipic Acid Demand

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China Chemical Reporter 2009年第33期20卷 20-20页

作者： li yufang

Evident reduction of importvolume in 2008Adipic acid production in China started ratherlate, but development has been rapid. TodayChina has 605 000 t/a of adipic acid *** producers include PetroChinaliaoyang Petrochemical Co., Ltd., ChinaShenma Group Co., Ltd. and ShandongHongye Chemical Industry Group Co., *** was 250 000 tons in 2008, an increaseof 19% over 2007.

关键词： Stable Major nylon downstream sector today reasons