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Stability Study on Hydroelectric Production Site Using Eigenvalues Analysis Method

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Journal of Energy and Power Engineering 2012年第6期6卷 940-948页

作者： Pedro Camilo de Oliveira e Silva Basile Kawkabani Sébastien Alligné christophe nicolet Jean-Jacques Simond Francois Avellan Electrical Machinery Laboratory Ecole Polytechnique Fédérale de Lausanne EPFL Lausanne CH-1015 Switzerland Laboratory for Hydraulic Machines Ecole Polytechnique Fédérale de Lausanne EPFL Lausanne CH-1015 Switzerland Power Vision Engineering Sàrl Eeublens CH-1024 Switzerland

The eigenvalues analysis method is generally applied to synchronous machines by using d, q-components. This paper presents the application of this method on an equivalent model for the synchronous machine based on phase variables a, b, c instead of d, q-components. The advantages of this approach, essential for programs using phase variables as state variables, are presented. The application of this method to a complete hydroelectric production site including hydraulic components （pump-turbine, penstock, gallery, reservoir...） permits the study and analysis of the interactions between the hydraulic, electric and regulation parts of the system. Results coming from the proposed eigenvalues analysis method and the numerical simulations confirm the interest of the presented approach.

关键词： Hydraulic systems eigenvalues and eigenfunctions power systems transient analysis.

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混流式水泵水轮机动静干涉的一维模型

国外大电机 2008年第4期 57-65页

作者： christophe nicolet[瑞士] 王焕茂（译）吴新润（校）不详华中科技大学

为实现混流式水泵水轮机模型动静干涉的数值模拟建立了一维水声模型。数值结果能够辨别出转轮9个叶片与20个活动导叶相互作用无叶区中的旋转径向模式和蜗壳内的驻波。另外，这种数值模拟能够揭示出这些旋转径向模式和驻波之间的相互作... 详细信息

为实现混流式水泵水轮机模型动静干涉的数值模拟建立了一维水声模型。数值结果能够辨别出转轮9个叶片与20个活动导叶相互作用无叶区中的旋转径向模式和蜗壳内的驻波。另外，这种数值模拟能够揭示出这些旋转径向模式和驻波之间的相互作用。最后，对活动导叶厚度影响以及波速和旋转速度的参量研究还说明了水力系统本征频率的重要作用。

关键词：水声模型动静干涉水泵水轮机

混流式模型水轮机部分负荷压力脉动的识别和模拟

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国外大电机 2006年第2期 56-63页

作者： christophe nicolet[瑞士] 李军（译）王正伟（校）不详清华大学

在低空化系数、高部分负荷运行工况下，高比转速混流式水轮机模型机组会出现2～4倍转频t的压力脉动。在FLINDT研究项目中，测量了混流式模型水轮机尾水管壁面104个测点位置的压力数据，表明压力脉动的主要频率是25．7fn。分析尾水管压... 详细信息

在低空化系数、高部分负荷运行工况下，高比转速混流式水轮机模型机组会出现2～4倍转频t的压力脉动。在FLINDT研究项目中，测量了混流式模型水轮机尾水管壁面104个测点位置的压力数据，表明压力脉动的主要频率是25．7fn。分析尾水管压力脉动在2．5fn频率处的相位差，表明在尾水管肘管人口部分存在压力扰动源。该位置压力信号的频谱分析表明，能量均匀地分布在0-7fn频率范围内。出现均匀分布的原因是涡带在尾水管内运动过程中与壁面发生碰撞。根据试验测得的相位差结果可以计算沿着尾水管传播的波速，有了波速数据就可以用SIMSEN工具模拟整个试验装置。考虑在压力扰动源位置出现白噪声干扰后，对整个试验装置（包括模型水轮机、管道系统）的水力声学特性的模拟结果，给出整个水力系统的吲有频率：模拟结果中出现2．46L的特征频率．相应的振型和试验结果很吻合：对受迫扰动问题也进行了模拟，它包括两部分，一部分是直锥管段测得的同步压力波动，另一部分是频率为涡带运动频率的压力脉冲。模拟的扰动信号反映了涡带的同步扰动，扰动信号的能量来自于涡带与尾水管壁而的碰撞：整个试验装置的压力脉动分析表明2．46fn频率处的幅值最明显，这一结果揭示了激励机理。

关键词：混流式水轮机模型压力脉动识别模拟

Supply and quality of colonoscopy according to the characteristics of gastroenterologists in the French population-based colorectalcancer screening program

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World Journal of Gastroenterology 2023年第9期29卷 1492-1508页

作者： AkoïKoïvogui Catherine Vincelet Gaëlle Abihsera Hamou Ait-Hadad Hélène Delattre Tu Le Trung Agnès Bernoux Rachel Carroll Jérôme nicolet Site de Seine-Saint-Denis Centre Régional de Coordination des Dépistages des Cancers en Ile-de-France(CRCDC-IDF)Bondy 93146France Site des Yvelines Centre Régional de Coordination des Dépistages des Cancers en Ile-de-France(CRCDC-IDF)Le Chesnay Cedex 78153France Site du Val-de-Marne Centre Régional de Coordination des Dépistages des Cancers en Ile-de-France(CRCDC-IDF)Joinville-le-Pont 94340France Site de Seine-et-Marne Centre Régional de Coordination des Dépistages des Cancers en Ile-de-France(CRCDC-IDF)Lieusaint 77763France Site des Hauts-de-Seine Centre Régional de Coordination des Dépistages des Cancers en Ile-de-France(CRCDC-IDF)Nanterre 92000France site du Val-d’Oise Centre Régional de Coordination des Dépistages des Cancers en Ile-de-France(CRCDC-IDF)Cergy Saint-Christophe 95800France Site de l’Essonne Centre Régional de Coordination des Dépistages des Cancers en Ile-de-France(CRCDC-IDF)Fontenay-Les-Briis 91640France Siège Paris Centre Régional de Coordination des Dépistages des Cancers en Ile-de-France(CRCDC-IDF)Paris 75015France

BACKGROUND Since its complete roll-out in 2009,the French colorectal cancer screening program(CRCSP)experienced 3 major constraints[use of a less efficient Guaiac-test(gFOBT),stopping the supply of Fecal-Immunochemical-Test kits(FIT),and suspension of the program due to the coronavirus disease 2019(COVID-19)]affecting its *** To describe the impact of the constraints in terms of changes in the quality of screeningcolonoscopy(Quali-Colo).METHODS This retrospective cohort study included screening-colonoscopies performed by gastroenterologists between Jan-2010 and Dec-2020 in people aged 50-74 living in Ile-de-France(France).The changes in Quali-colo(Proportion of colonoscopies performed beyond 7 mo(Colo_7 mo),Frequency of serious adverse events(SAE)and Colonoscopy detection rate)were described in a cohort of Gastroenterologists who performed at least one colonoscopy over each of the four periods defined according to the chronology of the constraints[gFOBT:Normal progress of the CRCSP using gFOBT(2010-2014);FIT:Normal progress of the CRCSP using FIT(2015-2018);STOP-FIT:Year(2019)during which the CRCSP experienced the cessation of the supply of test kits;COVID:Program suspension due to the COVID-19 health crisis(2020)].The link between each dependent variable(Colo_7 mo;SAE occurrence,neoplasm detection rate)and the predictive factors was analyzed in a two-level multivariate hierarchical *** The 533 gastroenterologists(cohort)achieved 21509 screening colonoscopies over gFOBT period,38352 over FIT,7342 over STOP-FIT and 7995 over COVID *** frequency of SAE did not change between periods(gFOBT:0.3%;FIT:0.3%;STOP-FIT:0.3%;and COVID:0.2%;P=0.10).The risk of Colo_7 mo doubled between FIT[adjusted odds ratio(aOR):1.2(1.1;1.2)]and STOPFIT[aOR:2.4(2.1;2.6)];then,decreased by 40%between STOP-FIT and COVID[aOR:2.0(1.8;2.2)].Regardless of the period,this Colo_7 mo’s risk was twice as high for screening colonoscopy performed in a public hospital[aOR:2.

关键词： Colorectal cancer screening Screening colonoscopy Faecal immunochemical test Guaiac faecal occult blood test Quality of colonoscopy Severity of tumor lesions