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新时代材料科学基础课程教学改革与实践探索

中国现代教育装备 2024年第11期 127-129页

作者：陈贝贝严学华江苏大学材料科学与工程学院江苏镇江212013

材料科学基础是一门理论性和应用实践性都很强的专业基础课程,其特点为概念抽象、内容多且理论性强,存在教师难教、学生难学等问题。结合新时代对创新复合型“材料人”的需求及课程特点,从教学方法、教材内容、教学实践及考核方式等方... 详细信息

材料科学基础是一门理论性和应用实践性都很强的专业基础课程,其特点为概念抽象、内容多且理论性强,存在教师难教、学生难学等问题。结合新时代对创新复合型“材料人”的需求及课程特点,从教学方法、教材内容、教学实践及考核方式等方面对该课程进行教学改革与实践探索,以提高教学成效,提升学生的创新实践能力,促进新时代高质量“材料人”培养。

关键词：材料科学基础课程改革教学模式创新实践

响应面法优化肉桂子总有机酸提取工艺及其抗氧化活性研究

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饲料工业 2024年第16期45卷 132-139页

作者：黄梦刘宏炳杨珍王彦顺燕雪花新疆医科大学中医学院新疆乌鲁木齐830017 新疆维吾尔自治区新疆名医名方与特色方剂学重点实验室新疆乌鲁木齐830017

采用响应面法优化肉桂子中总有机酸的提取工艺并研究其体外抗氧化活性。根据Box-Behnken Design设计原理,分别考察乙醇浓度、料液比、超声功率、超声时长对肉桂子总有机酸得率的影响。以肉桂子总有机酸得率为响应值,通过响应面法确定肉... 详细信息

采用响应面法优化肉桂子中总有机酸的提取工艺并研究其体外抗氧化活性。根据Box-Behnken Design设计原理,分别考察乙醇浓度、料液比、超声功率、超声时长对肉桂子总有机酸得率的影响。以肉桂子总有机酸得率为响应值,通过响应面法确定肉桂子总有机酸的最佳提取工艺。采用DPPH法、铁离子还原能力评价肉桂子总有机酸抗氧化能力。结果表明,单因素影响顺序依次为料液比>乙醇浓度>超声时长。肉桂子中总有机酸的最优提取工艺为:乙醇浓度59%、料液比1:60(g/mL)、超声功率350 W,超声时长49 min,得到的总有机酸的平均得率9.77%。VC及S-1肉桂子的IC50分别为0.01119、0.01437 mg/mL。说明该提取工艺稳定、可行、可靠;肉桂子具有一定抗氧化能力。

关键词：肉桂子响应曲面法总有机酸含量测定抗氧化

Tripotassium citrate monohydrate derived carbon nanosheets as a competent assistant to manganese dioxide with remarkable performance in the supercapacitor

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Frontiers of Chemical Science and Engineering 2022年第3期16卷 420-432页

作者： Wenjing Zhang Xiaoxue Yuan xuehua yan Mingyu You Hui Jiang Jieyu Miao yanli Li Wending Zhou Yihan Zhu Xiaonong Cheng School of Materials Science and Engineering Jiangsu UniversityZhenjiang212013China Institute for Advanced Materials Jiangsu UniversityZhenjiang212013China

Production cost,capacitance,and electrode materials safety are the key factors to be concerned about for *** this work,a type of carbon nanosheets was produced through the carbonization of tripotassium citrate monohydrate and nitric ***,a well-designed manganese dioxide/carbon nanosheets composite was synthesized through hydrothermal *** carbon nanosheets served as the substrate for growing the manganese dioxide,regulating its distribution,and preventing it from inhomogeneous dimensions and severe *** manganese dioxide nanosheets grew vertically on the numerous functional groups generated on the surface of the carbon nanosheets during *** synergistic combination of carbon nanosheets and manganese dioxide tailors the electrochemical performance of the composite,which benefits from the excellent conductivity and stability of carbon *** carbon nanosheets derived from tripotassium citrate monohydrate are conducive to the remarkable performance of manganese dioxide/carbon nanosheets ***,an asymmetric supercapacitor with active carbon as the cathode and manganese dioxide/carbon nanosheets as the anode was assembled,achieving an outstanding energy density of 54.68 Wh·kg^(−1) and remarkable power density of 6399.2 W·kg^(−1) superior to conventional lead-acid *** 10000 charge-discharge cycles,the device retained 75.3%of the initial capacitance,showing good cycle *** assembled asymmetric supercapacitors in series charged for 3 min could power a yellow light emitting diode with an operating voltage of 2 V for 2 *** study may provide valuable insights for applying carbon materials and manganese dioxide in the energy storage field.

关键词： carbon nanosheets manganese dioxide asymmetric supercapacitors energy density power density

THE FURTHER RESULT ON GLOBAL PRACTICAL TRACKING FOR HIGH-ORDER UNCERTAIN NONLINEAR SYSTEMS

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Journal of Systems Science & Complexity 2012年第2期25卷 227-237页

作者： xuehua yan Yungang LIU School of Control Science and Engineering Shandong University

This paper extends the unknown control coefficients with lower and upper constant bounds to the ones which may take arbitrarily large and /or small *** the existing methods are no longer applicable and the technical obstacles caused by the extensions are essential,new control design scheme should be exploited to the global practical *** the approaches of Nussbaum-gain and adding a power integrator,the authors successfully propose the design scheme of the adaptive practical tracking controller for the *** is shown that the designed controller guarantees that all the closed-loop system states are bounded and the tracking error becomes prescribed arbitrarily small after a finite time.

关键词：不确定非线性系统跟踪系统自适应控制器高阶控制设计控制系数闭环系统跟踪误差

New results on global output-feedback stabilization for nonlinear systems with unknown growth rate

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控制理论与应用（英文版） 2013年第3期11卷 401-408页

作者： xuehua yan Yungang LIU School of Control Science and Engineering Shandong University

In this paper, the global asymptotic stabilization by output feedback is investigated for a class of uncertain nonlinear systems with unmeasured states dependent growth. Compared with the closely related works, the remarkableness of the paper is that either the growth rate is an unknown constant or the dimension of the closed-loop system is significantly reduced, mainly due to the introduction of a distinct dynamic high-gain observer based on a new updating law. Motivated by the related stabilization results, and by skillfully using the methods of universal control and backstepping, we obtain the design scheme to an adaptive output-feedback stabilizing controller to guarantee the global asymptotic stability of the resulting closed-loop system. Additionally, a numerical example is considered to demonstrate the effectiveness of the proposed method.

关键词： Uncertain nonlinear systems Global asymptotic stabilization Adaptive control Output feedback Dynamic high gain

Global Output-Feedback Tracking for Nonlinear Cascade Systems with Unknown Growth Rate and Control Coefficients

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Journal of Systems Science & Complexity 2015年第1期28卷 30-46页

作者： yan xuehua LIU Yungang WANG Qingguo School of Electrical Engineering University of Jinan School of Control Science and Engineering Shandong University Department of Electrical and Computer Engineering National University of Singapore

This paper deals with the global practical tracking problem by output-feedback for a class of uncertain cascade systems with zero-dynamics and unmeasured states dependent *** systems investigated are substantially different from the closely related works,and have zero-dynamics,unknown growth rate,and unknown time-varying control *** makes the problem much more difficult to *** by the authors' recent works,this paper proposes a new adaptive control scheme to achieve the global practical *** is shown that the designed controller guarantees that the state of the resulting closed-loop system is globally bounded and the tracking error converges to a prescribed arbitrarily small neighborhood of the origin after a finite *** is achieved by combining the methods of universal control and dead zone with backstepping technique,and using the framework of performance analysis in the closely related works.A numerical example demonstrates the effectiveness of the theoretical results.

关键词：级联系统跟踪问题控制系数生长速率输出反馈非线性控制方案有限时间

Preparation and Characterization of Nucleus/Shell TiO_2/HAP Complex Nanophotocatalyst

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Journal of Materials Science & Technology 2007年第1期23卷 123-126页

作者： Hongfei LIU Xiaonong CHENG Juan yanG xuehua yan Hebin SHI School of Materials Science and Engineering Jiangsu University Zhenjiang 212013 China School of Materials Science and Engineering Wuhan Institute of Chemical Technology Wuhan 430074 China

A rapid and more efficient method was developed to prepare nucleus/shell titania/hydroxyapatite （TiO2/HAP） complex nanophotocatalyst. Hydroxyapatite （5 μm） which had been dissolved with 0.1 mol/L HCI was formed on the surface of the nanosized anatase titania powders by increasing the pH value of the solution at 90℃ in the water bath for only several hours .The microstructure and morphology of the resulting sample were investigated by X-ray diffraction （XRD）, Fourier-transform infrared spectroscopy （FT-IR）, scanning electron microscopy （SEM）, energy dispersive spectrum （EDS） and atomic force microscope （AFM）. The results indicated that nucleus/shell structural TiO2/HAP was formed in our experiments, and the thickness of the coating layer was about 5 nm. Photocatalytic decomposition of methyl orange was utilized to test the photocatalysis of the resulting samples and the result was compared with that of pure anatase titania powders （about 20 nm）. It was shown that the photocatalytic activity of the sample was not decreased due to the coating of HAP.

关键词： TiO2/HAP Nucleus/Shell structure Photocatalysis

Global practical tracking by output-feedback for nonlinear systems with unknown growth rate

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Science China(Information Sciences) 2011年第10期54卷 2079-2090页

作者： yan xuehua & LIU YunGang School of Control Science and Engineering,Shandong University,Jinan 250061,China School of Control Science and Engineering Shandong University

This paper is devoted to the global practical tracking by output-feedback for a class of uncertain nonlinear systems with only the tracking error *** from the closely related works,the systems have unmeasured states dependent growth with unknown constant rate,and the reference signal,as well as its first order derivative,has unknown *** because of these,the tracking problem can hardly be solved by straightforwardly extending the existing *** the paper,motivated by the related stabilization results,and flexibly using the ideas of universal control and dead zone,an adaptive output-feedback controller is designed to make the tracking error prescribed arbitrarily small after a finite time while keeping all the states of the closed-loop system bounded.A numerical example demonstrates the effectiveness of the theoretical results.

关键词： uncertain nonlinear systems global practical tracking adaptive control output-feedback dynamic high-gain

Super-conductive silver nanoparticles functioned three-dimensional CuxO foams as a high-pseudocapacitive electrode for flexible asymmetric supercapacitors

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Journal of Materiomics 2021年第1期7卷 156-165页

作者： Hui Jiang xuehua yan Le Wang Xiaonong Cheng Jieyu Miao Mingyu You Yihan Zhu Jianmei Pan School of Materials Science and Engineering Jiangsu UniversityZhenjiang212013JiangsuChina Institute for Advanced Materials Jiangsu UniversityZhenjiang212013JiangsuChina Institute of Green Materials and Metallurgy Jiangsu UniversityZhenjiang212013JiangsuChina

Copper oxide has aroused great concern in energy storage fields due to its properties of high theoretical capacitance,low cost and mild ***,its wide application still remains challenges owing to its poor electrical conductivity and unstable cycling ***-free foam electrodes possess abundant porous structures and high specific surface area,which could get good contact with ***,we demonstrate Ag nanoparticles decorated CuxO nanowires grown spontaneously on copper foam(CF)electrode for asymmetric *** skeleton structure of CF provides large amounts of active sites for the growth of CuxO ***,Ag nanoparticles further decrease the internal resistance and enhance the electrochemical ***/CuxO/CF-40 electrode presents a high area specific capacitance of 1192 mF cm^(-2)at 2 mA cm^(-2)and the influence of surface capacitance-dominated process and diffusion-controlled process are discussed in ***,the energy density of the as-prepared asymmetric supercapacitor(ASC)reaches 46.32 mWh cm^(-2)at a power density of 3.00 mW cm^(-2).A 2V LED is lighted successfully by two ASC in *** work provides a new strategy to prepare low internal resistance and binder-free flexible Ag/CuxO/CF electrode,which demonstrates a good potential application in flexible supercapacitors or other wearable electronic devices.

关键词： Binder-free electrode CuxO nanowire arrays Cu foam Pseudocapacitance contribution Asymmetric supercapacitor