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Active disturbance rejected predictive functional control for space vehicles with RCS

Journal of Systems Engineering and Electronics 2018年第5期29卷 1022-1035页

作者： tian jiayi ZHANG Shifeng College of Aerospace Science and Engineering National University of Defense Technology

Reaction control system(RCS) is a powerful and efficient actuator for space vehicles attitude control, which is typically characterized as a pulsed unilateral effector only with two states(off/on). Along with inevitable internal uncertainties and external disturbances in practice, this inherent nonlinear character always hinders space vehicles autopilot from pursuing precise tracking performance. Compared to most of pre-existing methodologies that passively suppress the uncertainties and disturbances, a design based on predictive functional control(PFC) and generalized extended state observer(GESO) is firstly proposed for three-axis RCS control system to actively reject that with no requirement for additional fuel consumption. To obtain a high fidelity predictive model on which the performance of PFC greatly depends, the nonlinear coupling multiple-input multiple-output(MIMO) flight dynamics model is parameterized as a state-dependent coefficient form. And based on that, a MIMO PFC algorithm in state space domain for a plant of arbitrary orders is deduced in this *** internal uncertainties and external disturbances are lumped as a total disturbance, which is estimated and cancelled timely to further enhance the robustness. The continuous control command synthesised by above controller-rejector tandem is finally modulated by pulse width pulse frequency modulator(PWPF) to on-off signals to meet RCS requirement. The robustness and feasibility of the proposed design are validated by a series of performance comparison simulations with some prominent methods in the presence of significant perturbations and disturbances, as well as measurement noise.

关键词： reaction control system(RCS) predictive functional control(PFC) generalized extended state observer(GESO) pulse width pulse frequency(PWPF) multiple-input multiple-output(MIMO)

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Flow field control for 2-meter high-speed free-jet wind tunnel

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Chinese Journal of Aeronautics 2023年第10期36卷 77-89页

作者： jiayi tian Zhongwei LING Weijie LIU Jianhua Qin Neng XIONG China Aerodynamics Research and Development Center Mianyang 621000China

The 2-meter High-speed Free-jet Wind Tunnel(2 m HFWT)is China’s first large-scale open-jet trisonic wind *** to traditional closed high-speed wind tunnels,this wind tunnel is endowed with remarkable advantages of ample test chamber space,less interference from the tunnel wall,flexible model support mode,and adjustable continuous variation of the Mach ***,its unique structure makes traditional wind tunnel control methods difficult to apply and brings significant challenges to wind tunnel flow field *** this paper,a flow field control system is designed for the 2 m HFWT by comprehensively using advanced control technologies such as neural network,gain scheduling,feedforward control,and adaptive *** practical application tests,it is proved that the proposed control system successfully solves the problem of high-precision flow field control under continual depletion of storage tank pressure,and realizes distinctive functions of adaptive static pressure matching and continuously varying Mach number at supersonic *** addition,due to the application of workflow technology,the flow field control system can flexibly adapt to the implementation of tests of different types and operation conditions,thus fully satisfying the needs of conducting various conventional and special tests in the 2 m HFWT.

关键词： Continuously varying Mach number Wind tunnel Flow field control Neural network Static pressure matching Feedforward control

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Vegetation pattern in Shell Ridge Island in China＇s Yellow River Delta

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Frontiers of Earth Science 2015年第3期9卷 567-577页

作者： Yanyun ZHAO Xiangming HU Jingtao LIU Zhaohua LU Jiangbao XIA jiayi tian JunshengMA Institute of Restoration Ecology School of Chemical & Environmental Engineering China University of Mining & Technology (Beijing) Beijing 100083 China Shandong Provincial Key Laboratory of Eco-Environmental Science for Yellow River Delta Binzhou University Binzhou 256603 China Department of Resources & Environmental Engineering Binzhou University Binzhou 256603 China Administrative Bureau of Binzhou Shell Dyke Island and Wetland National Reserve Binzhou 251900 China

In general, coastal habitat conditions are extremely harsh, with the ecological equilibrium inextric- ably related to the plant community. Understanding the natural vegetation features of a coastal zone with little human disturbance could provide a reference for future vegetation restoration and ecosystem maintenance ser- vices. In this study, the vegetation patterns of Wangzi Shell Ridge Island in the Yellow River Delta were investigated. A total of 35 taxa of vascular plants were documented, representing 15 families and 33 genera （of which most were mono-specific）. Surveys identified only one to eight taxa in each plot. From sea to land, the vegetation showed a typical zonal distribution pattern. There was a correlation between the landform and important factors that influenced the plants including soil factors and distance from the sea. Thus, the taxa distribution and vegetation had a significant correlation with landform. The dune crest, backdune and interdune lowlands were areas with weak storm surges and were the important locations for the taxa to be become established. Plants along the high-tide line formed important defenses from large waves and high winds. The significant protection provided a suitable living environment for many organisms with high medicinal value. Special attention and protection could be provided to this area by reducing the use of the beach road and enclosing the complete section from sea to land with a protective fence. In addition, vegetation protection and restoration on Shell Ridge Island would aid in the formulation and implementation of reintroduction strate- gies for similar vegetation in similar habitats.

关键词： wetland vegetation diversity landform zonaldistribution conservation value

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Temporal dynamic changes of connexin 43 expression in C6 cells following lipopolysaccharide stimulation

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Neural Regeneration Research 2012年第25期7卷 1947-1953页

作者： Ling Liu Zhenping Gao Linbo Zhang Lue Su Guojun Dong Haiyang Yu jiayi tian Hang Zhao Yanyan Xu Haiyan Liu Department of Human Anatomy Norman Bethune College of Medicine Jflin University Changchun 130021 Jilin Province China Department of Pharmaceutical Engineering College of Life Sciences Jilin Agricultural University Changchun 130118 Jilin Province China

Connexin 43, a gap junction protein, is expressed mainly in glia in the central nervous system. Neuroinflammation plays an important role in central nervous system injury. Changes to glial connexin 43 levels and neuroinflammation may trigger brain injury and neurodegenerative diseases To illustrate the relationship between connexin 43 and neuroinflammation, this study investigated how connexin 43 expression levels change in lipopolysaccharide-stimulated rat C6 glioma cells. C6 cells were treated with 0.05, 0.25, 0.5, 1,2.5 and 5 IJg/mL lipopolysaccharide for 24 hours. The nitrite estimation-detected nitric oxide release level was elevated substantially after lipopolysaccharide stimulation. To test the transcriptional level changes of inducible nitric oxide synthase, tumor necrosis factor-a and connexin 43 mRNA, C6 cells were treated with 5 pg/mL lipopolysaccharide for 3 48 hours. Reverse transcription-PCR showed that the expression of inducible nitric oxide synthase and tumor necrosis factor-a mRNA increased over time, but connexin 43 mRNA levels increased in lipopolysaccharide-stimulated C6 cells at 3 and 6 hours, and then decreased from 12 to 48 hours. Connexin 43 protein expression was detected by immunofluorescence staining, and the protein levels matched the mRNA expression levels. These results suggest that connexin 43 expression is biphasic in lipopo^ysacchadde-induced neuroinflammation in C6 cells, which may be correlated with the connexin 43 compensatory mechanism.

关键词： connexin lipopolysaccharide C6 cells neuroinflammation central nervous system inducible nitricoxide synthase tumor necrosis factor-a neural regeneration

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New College Entrance Examination Reform in the Zhejiang Province of China

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Psychology Research 2023年第1期13卷 43-50页

作者： CHEN Yaowu LI Yujie tian jiayi School of Art and Social Science Hong Kong Metropolitan UniversityHong KongChina School of International Studies Jiangxi Normal UniversityNanchangChina School of Japanese Language Shanxi UniversityTaiyuanChina

This paper reviews the situation,challenge,and consequence of the new college entrance examination(NEMT)reform in the Zhejiang Province of *** analyzing the issues arising from the new NEMT reform,the researchers analyze the effectiveness of the new college entrance examination reform in Zhejiang *** main issues could be found in the new college entrance examination reform,which are difficult in class arrangements,increasing costs,and confusion for students in choosing future *** researchers compare the influence of these issues from the new college entrance examination reform with that of the labor *** review also indicates that the influence of the labor market exceeds that of issues from NEMT *** the way career planning education under the new college entrance reform is discussed.

关键词： the new NEMT reform career planning education labor market

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The Relationships between Obstructive Sleep Apnea and Depressive Disorder

The Relationships between Obstructive Sleep Apnea and Depres...

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2015年全国睡眠呼吸学术年会

作者： Mingxian Li Pingping He Lili Han jiayi tian Chaoying Yan The First Affiliated Hospital of Jilin University Changchun P.R.China Jiangning Hospital The Affiliated Hospital of Nanjing Medical UniversityNanjing P.R.China Daxing Hospital The Affiliated Hospital of Capital Medical University BeijingP.R.China

Object:We explored the relationship between obstructive sleep apnea（OSA）and depressive ***:88 patients suffered from OSA were divided into mild,moderate and severe according to the apnea-hypopnea index（AHI）and the lowest oxygen saturation at *** the patients accepted the Zung self rating depression scale（SDS）test,including 20 subjects to analysis the situation of the depressive *** standard score is that the SDS score multiplied by *** the standard scores≥50 the patients should have the depressive *** compared the morbidity of depressive disorder in every group,then discussed the relationship between OSA and depressive disorder,moreover,we discussed the relevant ***:47.73%OSA patients developed the depressive disorder,significantly higher than the control *** morbidity of depressive disorder in mild,moderate and severe group respectively are 11.9%、38.1%、50.0%.42 patients who have OSA and depressive disorder,the SDS scores are higher with the increasing of BIM,AHI,and Sa02min at ***:*** is relationship between OSA and depressive *** the OSA patients,the incidence rate of depressive disorder is increasing with the severe degree of *** the patients have the OSA and depressive disorder,the degree of the depressive disorder is positive correlative with BMI,AHI,ESS and is negative correlative with SaO2min at *** OSA patients should pay attention to develop the depressive disorder,and the survey of depressive disorder should be carried out in the OSA patients regularly,which is good for the clinical diagnosis and treatment.

关键词： sleep apnea obstructive depressive disorder correlation

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基于机器学习的地下溶洞空间形态对地面沉降影响的分析与预测

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中山大学学报（自然科学版）（中英文） 2023年第2期62卷 83-92页

作者：高燕吴晓东田嘉逸中山大学地球科学与工程学院广东珠海519082 南方海洋科学与工程广东省实验室(珠海) 广东珠海519082

为了解工程活动对含地下岩溶的地基造成的地面沉降规律,本文采用有限元数值模拟,分析荷载作用下含不同形式溶洞的地基的地面沉降响应。分析了溶洞的发育尺度、埋深、形状、荷载4个主要因素对地面沉降的影响。研究表明,溶洞发育尺度越大... 详细信息

为了解工程活动对含地下岩溶的地基造成的地面沉降规律,本文采用有限元数值模拟,分析荷载作用下含不同形式溶洞的地基的地面沉降响应。分析了溶洞的发育尺度、埋深、形状、荷载4个主要因素对地面沉降的影响。研究表明,溶洞发育尺度越大、埋深越浅、形状系数越小、荷载越大,产生的地面沉降越大,地面沉降曲线形状均为钟形,且符合高斯分布规律;通过灰色关联法计算分析表明溶洞的发育尺度与形状对最大地表沉降值的灵敏度较高,即溶洞的几何形状对地面沉降有重要影响。通过深度神经网络对有限元计算得到的地面沉降曲线进行训练,训练后的模型预测值与计算值误差在5%以内,深度神经网络可作为预测含溶洞地基在工程建设引发的地面沉降的一种有效方法。

关键词：地面沉降地下溶洞灰色关联法机器学习深度神经网络

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黄河三角洲淡水浮游植物名录

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海洋湖沼通报 2000年第3期 65-77页

作者：高霞田家怡博兴县环保监测站博兴256500 滨州师范专科学校滨州256604

１９９６年对黄河三角洲９条代表性河流和３座代表性水库进行了２－６次浮游植物调查，共鉴定出浮游植物２９１种（变种），隶属于８门４１科９７属。

关键词：黄河三角洲淡水浮游植物名录

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黄河三角洲潮间带动物多样性的研究

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海洋湖沼通报 2000年第4期 45-52页

作者：蔡学军田家怡山东省滨洲地区环境保护科学技术研究所 256614 滨洲师范专科学校 256604

以１９９６年黄河三角洲潮间带动物定性调查结果，分析了黄河三角洲潮间带动物物种多样性；以定量调查结果研究了潮间带动物多样度以及与均度、单纯度的关系。研究表明：该区共鉴出潮间带动物１９３种，隶属于１３个门１５个纲４０个目... 详细信息

以１９９６年黄河三角洲潮间带动物定性调查结果，分析了黄河三角洲潮间带动物物种多样性；以定量调查结果研究了潮间带动物多样度以及与均度、单纯度的关系。研究表明：该区共鉴出潮间带动物１９３种，隶属于１３个门１５个纲４０个目９４个科；潮间带动物多样度为０～１．７０，均度为０～１．００，单纯度为０．２２～１．００；多样度与均度呈正相关，与单纯度呈负相关关系。

关键词：黄河三角洲潮间带动物多样性均度单纯度

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黄河三角洲附近海域底栖动物多样性及其保护措施

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海洋环境科学 1999年第1期18卷 39-44页

作者：高六礼田家怡山东滨州教育学院滨州256605 山东滨州师范专科学校滨州256604

在对黄河王角洲附近海域３０个站点底栖动物调查基础上，辅以文献资料法，综合分析了底栖动物物种多样性，研究了生物多样度以及与均度、单纯度之间的关系，并提出了保护底栖动物多样性的措施。结果表明：该海域共记录底栖动物２２２种... 详细信息

在对黄河王角洲附近海域３０个站点底栖动物调查基础上，辅以文献资料法，综合分析了底栖动物物种多样性，研究了生物多样度以及与均度、单纯度之间的关系，并提出了保护底栖动物多样性的措施。结果表明：该海域共记录底栖动物２２２种，物种较为丰富；生物多样度为０～４．４２，均度为０～２．０１，单纯度为０．１１～１．００；多样度与均度呈显著的正相关，与单纯度呈显著的负相关。

关键词：黄河三角洲海域底栖动物多样性保护措施

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