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冠状动脉钙化调控机制及评估技术的研究进展

中华心血管病杂志 2024年第3期52卷 303-310页

作者：陈雪宁金晓雪崔术刘德敏河北医科大学第二医院心内一科石家庄050000 河北省医学考试中心石家庄050000

血管钙化广泛存在于心血管疾病、糖尿病等疾病中,是导致心血管并发症的重要因素。随着钙化评估和诊断技术的发展,钙化过程为主动炎症过程的观点逐渐被接受,而调控冠状动脉钙化(CAC)的信号通路也被进一步探索。CAC的评估技术在不断革新,... 详细信息

血管钙化广泛存在于心血管疾病、糖尿病等疾病中,是导致心血管并发症的重要因素。随着钙化评估和诊断技术的发展,钙化过程为主动炎症过程的观点逐渐被接受,而调控冠状动脉钙化(CAC)的信号通路也被进一步探索。CAC的评估技术在不断革新,以期更清晰地显示斑块结构,评估斑块的钙化程度及预测术后并发症的风险。该文主要对CAC的分子调控机制及相关评估技术的研究进展作一综述,旨在结合目前的检测技术更好地识别病变,全面了解CAC的发生发展过程。

关键词：冠状动脉成骨样细胞转化平滑肌细胞内皮细胞光学相干断层成像

Mixed finite element for two-dimensional incompressible convective Brinkman-Forchheimer equations

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Applied Mathematics and Mechanics(English Edition) 2019年第6期40卷 889-910页

作者： demin liu Kaitai LI College of Mathematics and System Sciences Xinjiang UniversityUrumqi 830046China School of Mathematics and Statistics Xi’an Jiaotong UniversityXi’an 710049China

In this work, the two-dimensional convective Brinkman-Forchheimer equa- tions are considered. The well-posedness for the variational problem and its mixed finite element approximation is established, and the error estimates based on the conforming approximation are obtained. For the computation, a one-step Newton (or semi-Newton) iteration algorithm initialized using a fixed-point iteration is proposed. Finally, numerical experiments using a Taylor-Hood mixed element built on a structured or unstructured triangular mesh are implemented. The numerical results obtained using the algorithm are compared with the analytic data, and are shown to be in very good agreement. Moreover, the lid-driven problem at Reynolds numbers of 100 and 400 is considered and analyzed.

关键词： Brinkman-Forchheimer equations finite element method Newton iteration

VIBRATION ANALYSIS OF TURBINE BASED ON FLUID-STRUCTURE COUPLING

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Chinese Journal of Mechanical Engineering 2008年第4期21卷 40-43页

作者： liu demin liu Xiaobing School of Energy and Environment Xihua University Chengdu 610039 China Department of Thermal Engineering Tsinghua University Beijing 100084 China

The vibration of a Francis turbine is analyzed with the additional quality matrix method based on fluid-structure coupling （FSC）. Firstly, the vibration frequency and mode of blade and runner in air and water are calculated. Secondly, the influences to runner frequency domain by large flow, small flow and design flow working conditions are compared. Finally the influences to runner modes by centrifugal forces under three rotating speeds of 400 r/rain, 500 r/min and 600 r/rain are compared. The centrifugal force and small flow working condition have greatly influence on the vibration of small runner. With the increase of centrifugal force, the vibration frequency of the runner is sharply increased. Some order frequencies are even close to the runner natural frequency in the air. Because the low frequency vibration will severely damage the stability of the turbine, low frequency vibration of units should be avoided as soon as possible.

关键词： Fluid-structure coupling Additional quality matrix Vibration Mode

Experimental Investigation of Inter-Blade Vortices in a Model Francis Turbine

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Chinese Journal of Mechanical Engineering 2017年第4期30卷 854-865页

作者： demin liu Xiaobing liu Yongzhi ZHAO Key Laboratory of Fluid and Power Machinery of Ministry of Education Xihua University Dongfang Electric Machinery Co. Ltd

The inter-blade vortex in a Francis turbine becomes one of the main hydraulic factors that are likely to cause blade erosion at deep part load operating con- ditions. However, the causes and the mechanism of inter- blade vortex are still under investigation according to present researches. Thus the causes of inter-blade vortex and the effect of different hydraulic parameters on the inter-blade vortex are investigated experimentally. The whole life cycle of the inter-blade vortex is observed by a high speed camera. The test results illustrate the whole life cycle of the inter-blade vortex from generation to separation and even to fading. It is observed that the inter- blade vortex becomes stronger with the decreasing of flow and head, which leads to pressure fluctuation. Meanwhile, the pressure fluctuations in the vane-less area and the draft tube section become stronger when inter-blade vortices exist in the blade channel. The turbine will be damaged if operating in the inter-blade vortex zone, so its operating range must be far away from that zone. This paper reveals the main cause of the inter-blade vortex which is the larger incidence angle between the inflow angle and theblade angle on the leading edge of the runner at deep part load operating conditions.

关键词： Inter-blade vortex Francis turbine Highspeed photography

三门峡断陷盆地及邻区深部结构及成因——来自深地震反射与大地电磁测深的证据

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地质学报 2024年第4期98卷 1088-1100页

作者：何发岐於文辉马超张世晖黎小伟刘德民中石化华北油气分公司河南郑州450006 中国地质大学(武汉) 湖北武汉430074

近年来,围绕三门峡断陷盆地中的油气、地热资源做了大量的工作,成因机制研究较少,严重制约了矿产资源的勘探开发。本文在前人研究工作基础上,结合野外地质调查并利用高精度深反射地震剖面、大地电磁(MT)、重磁等地球物理探测技术,对三... 详细信息

近年来,围绕三门峡断陷盆地中的油气、地热资源做了大量的工作,成因机制研究较少,严重制约了矿产资源的勘探开发。本文在前人研究工作基础上,结合野外地质调查并利用高精度深反射地震剖面、大地电磁(MT)、重磁等地球物理探测技术,对三门峡盆地进行综合研究。发现三门峡盆地主要由东、西2个负花状构造构成,西花状构造体大于东花状构造体;盆地东部边缘以观音堂隆起与洛阳凹陷相邻,观音堂隆起发育有壳内透镜状低速体,其东、西两侧均发育有规模较大的隐伏逆断层。研究区内莫霍面为大约5 km厚度滑脱层,在深反射地震剖面上表现为蚯蚓状反射特征,指示滑脱层为西向运动。莫霍面滑脱层上部与下部新发现多条弧形断层。地质与地球物理资料综合研究表明,莫霍面滑脱层的解耦作用是三门峡断陷盆地花状构造形成的主因;在不同时空构造力系作用下,形成研究区新生代全地壳旋转花状构造盆地。

关键词：三门峡断陷盆地高精度深反射地震剖面大地电磁负花状构造莫霍面滑脱层弧形断层

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新型电力系统下的氢储能研究

水电与抽水蓄能 2024年第2期10卷 34-41页

作者：刘德民刘志刚东方电气集团东方电机有限公司四川省德阳市618000

在“双碳”目标的指引下,新能源将逐步代替化石能源,而新能源主要为风电和太阳能发电,存在不稳定和间歇性,需要用储能的方式来提高新能源的稳定性。同时,全球的能源利用一直朝着低碳的方向在发展,从生物质到煤炭、石油、天然气再到氢能... 详细信息

在“双碳”目标的指引下,新能源将逐步代替化石能源,而新能源主要为风电和太阳能发电,存在不稳定和间歇性,需要用储能的方式来提高新能源的稳定性。同时,全球的能源利用一直朝着低碳的方向在发展,从生物质到煤炭、石油、天然气再到氢能,碳氢比一直在减少。在新型电力系统下,氢储能对比传统电化学储能、热化学储能、热能储能、压缩空气储能、飞轮储能、抽水蓄能储能、超导储能等方面有着超高能量密度的独特优势。截至目前,美国、德国、日本、中国等多个国家都发布了国家级氢能发展战略,氢储能可以说是终端实现绿色低碳转型的重要载体。虽然优势明显,但氢储能产业发展形态和发展路径尚需进一步探索。本文结合国内外储能现状、氢能产业发展情况以及氢能关键技术,探讨氢储能特征优势和关键技术,为氢能产业发展提供价值方向。

关键词：双碳新型电力系统储能氢储能氢产业

国内外相变储能材料技术现状及应用情况研究综述

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水电与抽水蓄能 2024年第2期10卷 42-58页

作者：王智超刘德民东方电气集团东方电机有限公司四川省德阳市618000

在全球生产力指数进一步增长的大背景下,能源供给侧面临化石燃料能源枯竭风险而消费端需求旺盛,供给消费两侧剪刀差日益扩大,有必要大力开发可再生能源技术。热能的储存与利用是可再生能源利用技术的重要一环,作为高效储热介质的相变材... 详细信息

在全球生产力指数进一步增长的大背景下,能源供给侧面临化石燃料能源枯竭风险而消费端需求旺盛,供给消费两侧剪刀差日益扩大,有必要大力开发可再生能源技术。热能的储存与利用是可再生能源利用技术的重要一环,作为高效储热介质的相变材料开发是当下最为活跃的研究方向之一。从包括相变材料的各种储热材料物理特性出发,结合当下国内外该领域研究进展,重点介绍各类相变材料在储热领域的应用情况。

关键词：相变材料储热可再生能源

维普期刊数据库博看期刊

鄂北耿集-板桥地区新元古代变火山岩系地层归属——来自锆石U-Pb测年、Hf同位素的证据

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吉林大学学报（地球科学版） 2024年第2期54卷 516-530页

作者：苑东洋石威刘德民黄天统徐龙生陈超孔令耀核工业二三〇研究所长沙410007 湖南省伴生放射性矿产资源评价与综合利用工程技术研究中心长沙410007 湖北省地质局第三地质大队湖北黄冈438000 中国地质大学地球科学学院武汉430074 湖北省地质调查院武汉430034

扬子克拉通北缘、鄂北枣阳市耿集-板桥地区震旦系—奥陶系中相间出露两套变火山岩系,其地层归属存在武当群和花山群的争议且长期缺乏深入研究。耿集-板桥地区野外调查、变火山岩系LA-ICPMS锆石U-Pb测年、Lu-Hf同位素分析结果表明:耿集... 详细信息

扬子克拉通北缘、鄂北枣阳市耿集-板桥地区震旦系—奥陶系中相间出露两套变火山岩系,其地层归属存在武当群和花山群的争议且长期缺乏深入研究。耿集-板桥地区野外调查、变火山岩系LA-ICPMS锆石U-Pb测年、Lu-Hf同位素分析结果表明:耿集地区变火山岩系主要为浅灰色、灰白色变酸性含砾晶屑岩屑凝灰岩、晶屑凝灰岩、玻屑凝灰岩、粉砂岩,与打鼓石群硅质条带叠层石白云岩共生,其中变酸性晶屑凝灰岩锆石年龄为821.7 Ma、ε_(Hf)(t)值为-2.44~9.70,其可能是扬子克拉通前南华纪基底青白口系花山群组成部分;板桥地区变火山岩系主要由灰白色变酸性晶屑岩屑凝灰岩、火山凝灰岩、酸性火山岩、粉砂岩组成,内部发育大量基性侵入岩,其中变酸性火山岩锆石年龄为741.2 Ma,ε_(Hf)(t)值为4.62~9.56,其应归属为南秦岭造山带南华系武当群,可能是印支期逆冲到扬子克拉通盖层上的残块。

关键词：扬子克拉通新元古代花山群武当群锆石U-Pb测年 Lu-Hf同位素

Numerical predictions and stability analysis of cavitating draft tube vortices at high head in a model Francis turbine

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Science China(Technological Sciences) 2014年第11期57卷 2106-2114页

作者： ZUO ZhiGang liu ShuHong liu demin QIN DaQing State Key Laboratory of Hydro Science and Engineering Department of Thermal Engineering Tsinghua University Research & Test Center Dongfang Electric Machinery Co. Ltd State Key Laboratory of Hydro-Power Equipment

Draft tube vortex is one of the main causes of hydraulic instability in hydraulic reaction turbines,in particular Francis turbines.A method of cavitation calculations was proposed to predict the pressure fluctuations induced by draft tube vortices in a model Francis turbine,by solving RANS equations with RNG k-turbulence model and ZGB cavitation model,with modified turbulence *** cases with different flow rates at high head were *** the study case of part load,two modes of revolutions with the same rotating direction,revolution around the axis of the draft tube cone,and revolution around the core of the vortex rope,can be *** elliptical shaped vortex rope causes anisotropic characteristics of pressure fluctuations around the centerline of the draft tube *** analyzing the phase angles of the pressure fluctuations,the role of the vortex rope as an exciter in the oscillating case can be *** analysis of Batchelor instability,*** in q-vortex like flow structure,has been carried out on the draft tube vortices in these three *** can be concluded that the trajectory for study case with part load lies in the region of absolute instability(AI),and it lies in the region of convective instability(CI)for study case with design flow *** for study case with over load lies in the AI region at the inlet of the draft tube,and enters CI region near the end of the elbow.

关键词： draft tube vortices pressure fluctuations Francis turbine cavitation Batchelor instability