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随机激励下连续时间马尔科夫跳变非线性系统的平稳响应研究（英文）

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2017年第2期18卷 83-91页

作者： shan-shan pan Wei-qiu ZHU Rong-chun HU Rong-hua HUAN Department of Mechanics Zhejiang University Hangzhou 310027 China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang University Hangzhou 310027 China Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Zhejiang University Hangzhou 310027 China

目的:提出一种预测随机激励下连续时间马尔科夫跳变非线性系统的平稳响应的近似方法。创新点:1.得到了含有马尔科夫跳变参数的关于能量的平均It?方程;2.建立了含有马尔科夫跳变参数的平均It?方程相应的FPK方程。方法:1.将一个随机激励... 详细信息

目的:提出一种预测随机激励下连续时间马尔科夫跳变非线性系统的平稳响应的近似方法。创新点:1.得到了含有马尔科夫跳变参数的关于能量的平均It?方程;2.建立了含有马尔科夫跳变参数的平均It?方程相应的FPK方程。方法:1.将一个随机激励的马尔科夫跳变非线性系统由状态方程转化为等价的It?方程,并根据It?微分法则给出哈密顿量(系统总能量)的It?方程;2.通过随机平均法,得到关于系统能量的平均It?方程;3.推导并求解相应的FPK方程。结论:1.跳变规律对马尔科夫跳变非线性系统随机响应具有重要影响;2.理论结果与数字模拟结果吻合验证了理论方法的准确性。

关键词：非线性系统连续时间马尔科夫跳变随机激励随机平均

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空间结构对捕食关系影响研究进展

应用生态学报 2017年第2期28卷 712-720页

作者：董红娟吴新卫王洪娇夏珊珊潘瑛云南大学生态学与环境学院昆明650091 云南大学科技咨询中心昆明650091 云南协同环保工程有限公司昆明650000 南京大学生命科学学院南京210093

随着人类对环境影响的加剧(如空间破碎化),生态系统的空间结构发生了剧烈变化,极大地改变了生态系统的结构和功能.空间结构对生态系统的影响与捕食关系的改变密切相关,探讨两者之间的联系对于了解破碎生境生态变化的机制至关重要.基于此... 详细信息

随着人类对环境影响的加剧(如空间破碎化),生态系统的空间结构发生了剧烈变化,极大地改变了生态系统的结构和功能.空间结构对生态系统的影响与捕食关系的改变密切相关,探讨两者之间的联系对于了解破碎生境生态变化的机制至关重要.基于此,本文就典型空间结构对捕食关系的影响进行了论述,包括空间大小、形状、方向、布局和连通性等.资料表明,空间变小、连通性降低、空间及集合群落过度破碎化、空间方向和形状变化等导致捕食成功率过度增长,都不利于猎物-捕食者系统的稳定和持续.关于简单空间构型耦合形成的复杂空间结构对捕食关系,尤其是对多物种共存的复杂捕食关系的影响有待在今后的研究中进一步加强.

关键词：空间大小空间形状空间方向空间布局空间连通性营养级联效应生态过程

木鳖果假种皮中β-胡萝卜素的提取工艺优化及稳定性研究

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食品工业科技 2018年第21期39卷 191-195,201页

作者：向珊珊张楠潘晴李雨浩吴傲孙爱东北京林业大学生物科学与技术学院食品加工与安全北京市重点实验室北京10083

为探究超声辅助乙醇法提取木鳖果假种皮中β-胡萝卜素的最优工艺条件,本文考察了超声功率、超声时间、超声温度以及料液比对β-胡萝卜素提取量的影响,并在单因素实验基础上进行4因素3水平正交优化试验。同时根据β-胡萝卜素的保留率大小... 详细信息

为探究超声辅助乙醇法提取木鳖果假种皮中β-胡萝卜素的最优工艺条件,本文考察了超声功率、超声时间、超声温度以及料液比对β-胡萝卜素提取量的影响,并在单因素实验基础上进行4因素3水平正交优化试验。同时根据β-胡萝卜素的保留率大小,研究了光照、温度、pH以及金属离子对其稳定性的影响。结果表明,木鳖果假种皮中β-胡萝卜素的最佳提取条件为:超声功率60 W,超声时间60 min,超声温度65℃,料液比1∶20 g/mL。在此条件下提取的木鳖果假种皮中β-胡萝卜素含量为2.212 mg/g。稳定性实验表明:木鳖果假种皮中β-胡萝卜素在光照、高温(100℃)条件下不稳定,容易分解;酸性条件对β-胡萝卜素有增色作用,而碱性及中性条件对其有减色作用,保留率降低;Na^+、K^+、Fe^(2+)、Fe^(3+)、Cu^(2+)、Zn^(2+)对β-胡萝卜素有不同的作用,其中,Fe^(3+)对其有较强的增色作用,而Fe^(2+)、Cu^(2+)、Zn^(2+)对其有减色作用。该研究结果对于高效利用木鳖果假种皮中的β-胡萝卜素以及假种皮深加工具有重要意义。

关键词：木鳖果假种皮 β-胡萝卜素超声辅助稳定性

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ICU多重耐药菌目标性监测与干预效果分析

中国感染控制杂志 2017年第1期16卷 58-61,65页

作者：陈亚男刘菁田丽梅刘善善潘立业刘婷吴惠毅连云港市第一人民医院江苏连云港222000

目的了解重症监护病房(ICU)多重耐药菌(MDRO)的感染现状,评价目标性监测的干预效果。方法采用前瞻性研究方法,选取2014—2015年入住ICU的患者,2014年1—12月为干预前阶段,2015年1—12月为干预阶段,对比分析干预前后MDRO感染趋势。结果... 详细信息

目的了解重症监护病房(ICU)多重耐药菌(MDRO)的感染现状,评价目标性监测的干预效果。方法采用前瞻性研究方法,选取2014—2015年入住ICU的患者,2014年1—12月为干预前阶段,2015年1—12月为干预阶段,对比分析干预前后MDRO感染趋势。结果干预前检出MDRO297株,干预后检出217株,除CRPA外,干预后耐碳青霉烯类鲍曼不动杆菌(CRAB)、耐碳青霉烯类肠杆菌科细菌(CRE)、耐甲氧西林金黄色葡萄球菌(MRSA)、耐万古霉素肠球菌(VRE)检出株数均较干预前减少。ICU MDRO感染率由干预前的7.17‰降至3.88‰,其中CRAB、CRE干预后感染率低于干预前,差异有统计学意义(均P<0.05);综合、内科ICU MDRO感染率分别由干预前的8.75‰、7.84‰,降至干预后的4.39‰、2.28‰,两组比较差异均有统计学意义(均P<0.05)。采取干预措施后,接触隔离医嘱24 h下达率、手卫生依从率、医护人员知晓率等防控措施的依从性较干预前显著提高(均P<0.05)。结论采取目标性监测和干预措施,可降低ICU MDRO检出率。

关键词：重症监护病房多重耐药菌目标性监测干预

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锶的分析方法研究进展

盐科学与化工 2017年第10期46卷 9-12页

作者：李姗姗潘雨王悦邓彪孟令宗临沂大学化学化工学院山东临沂276000

锶的分析方法对于锶资源的开发具有重要意义。文章从化学分析法和仪器分析法两方面,归纳总结了单组分锶和当与锂(钙)锶共存时,锶的分析方法研究现状,指出了各种分析方法存在的主要问题,提出了新的发展方向。

关键词：锶化学分析法仪器分析法

Progress in helicopter infrared signature suppression

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Chinese Journal of Aeronautics 2014年第2期27卷 189-199页

作者： Zhang Jingzhou pan Chengxiong shan Yong Jiangsu Province Key Laboratory of Aerospace Power System College of Energy & Power Engineering Nanjing University of Aeronautics and Astronautics

Due to their low-attitude and relatively low-speed fight profiles, helicopters are subjected to serious threats from radio, infrared （IR）, visual, and aural detection and tracking. Among these threats, infrared detection and tracking are regarded as more crucial for the survivability of helicop- ters. In order to meet the requirements of infrared stealth, several different types of infrared sup- pressor （IRS） for helicopters have been developed. This paper reviews contemporary developments in this discipline, with particular emphasis on infrared signature suppression, advances in mixer-ejectors and prediction for helicopters. In addition, several remaining challenges, such as advanced IRS, emissivity optimization technique, helicopter infrared characterization, etc., are proposed, as an initial guide and stimulation for future research. In the future, the comprehen- sive infrared suppression in the 3-5 μm and 8-14 μm bands will doubtfully become the emphasis of helicopter stealth. Multidisciplinary optimization of a complete infrared suppression system deserves further investigation.

关键词： Helicopter Infrared radiation Infrared suppression Internal aerodynamics Mixer-ejector

Failure mechanism of full-size concrete filled steel circle and square tubes under uniaxial compression

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Science China(Technological Sciences) 2015年第10期58卷 1638-1647页

作者： CAI JingMing pan JinLong shan QiFeng Key Laboratory of Concrete and Pre-stressed Concrete Structures of Ministry of Education Southeast University

In this paper, the failure mechanisms of full-size concrete filled steel tubes(CFST) under uniaxial compression were investigated with nonlinear finite element method. Existing experimental results were employed to verify the validity of the finite element models of CFST specimens. Then, the numerical analysis was further conducted to study the mechanical behaviors of full-size CFST columns with circular and square cross sections under uniaxial compression. The simulation results indicate that the distribution of the contact pressure between circular steel tube and core concrete is much more uniform than that between square steel tube and concrete, resulting in much higher confinement and more efficient interaction between steel tube and core concrete in circular CFST columns, as well as ultimate load capacity and ultimate displacement. Extensive parametric analysis was also conducted to examine the effect of various parameters on the uniaxial compression behaviors of circular and square CFST columns.

关键词： CFST uniaxial compression finite element analysis interaction mechanism

Mechanism of magnetic field-modulated luminescence from lanthanide ions in inorganic crystal:a review

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Rare Metals 2020年第10期39卷 1113-1126页

作者： shan-Ling Zuo Ping Chen Cao-Feng pan Guangxi Key Laboratory for Relativistic Astrophysics Center On Nanoenergy ResearchSchool of Physical Science and TechnologyGuangxi UniversityNanning 530004China Beijing Institute of Nanoenergy and Nanosystems National Center for Nanoscience and TechnologyChinese Academy of SciencesBeijing 100083China

The luminescence from lanthanide ions has potential applications in light emitting diodes,biomedical,solar cells,sensors,display,***,the luminescence is suffered from the various problems,such as low luminescence efficiency and inharmonious wavelength for energy *** field is an efficient method to modulate the wavelength and intensity of luminescence from lanthanide *** field redistributes the populated electrons in the excited states to tune the wavelength of lanthanide ions by Zeeman effect,mixing effect,and quantum confinement *** field enhances or suppresses the luminescence intensity by the administration of cross-relaxation,energy transfer,and Boltzmann *** this review,we first introduce the various phenomena and mechanisms of magnetic field modulated downshift luminescence from lanthanide ions,including Zeeman effect,cross-relaxation,crystal structure,absorption,quantum confinement effect,and magneticoptical ***,we explain the regulation of upconversion luminescence by magnetic field,containing energy transfer and mixing ***,different options regarding how to understand the mechanism of magnetic field-modulated luminescence from lanthanide ions in the future are outlined.

关键词： Magnetic field Lanthanide ions Luminescence Microscopic mechanism

Impedance Analysis of Grid Forming Control Based Modular Multilevel Converters

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Journal of Modern Power Systems and Clean Energy 2023年第3期11卷 967-979页

作者： Rongcai pan Guangfu Tang shan Liu Zhiyuan He China Electric Power Research Institute Beijing 100192China State Grid Smart Grid Research Institute Beijing 102209China

Grid-forming control(GFC)is promising for power electronics based power systems with high renewable energy ***,the impedance modeling for GFC is necessary and has gained significant attention ***,most of the impedance analyses for GFC are based on a twolevel converter(TLC)rather than a modular multilevel converter(MMC).MMC differs from TLC with respect to its dominant multi-frequency *** is necessary to analyze the impedance of GFC-based MMC owing to its superiority in highvoltage direct current(HVDC)transmission to interlink two weak AC systems with high renewable energy *** the main contribution,this paper presents the AC-and DC-side impedance analyses for the GFC-based MMC with both power and DC voltage control using the harmonic transfer function(HTF),and compares the impedances of GFC-based MMC and *** is inferred that although the impedance is mainly influenced within 200 Hz,the instability still could occur owing to negative resistance triggered by relatively larger *** difference in AC-side impedance with power and DC voltage control is not apparent with proper parameters,while the DC-side impedance differs *** generalized Nyquist criterion is necessary for AC-side stability owing to the relatively large coupling terms under ***,the coupling between AC-and DC-side impedances is noneligible,especially considering the DC-side resonance around the system resonant *** effects of parameters,system strength,and virtual impedance on the impedance shaping are analyzed and verified through simulations.

关键词： Sequence impedance modular multilevel converter(MMC) grid-forming control(GFC) harmonic transfer function generalized Nyquist criterion