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经冠状静脉系统消融治疗室性心律失常的研究进展

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中国循环杂志 2024年第2期39卷 204-208页

作者：米利杰张宏达唐闽中国医学科学院、北京协和医学院、国家心血管病中心阜外医院、心律失常中心北京100037

起源于心外膜面和心肌深层的室性心律失常消融一直是临床上的棘手难题,冠状静脉系统作为心脏血流的回流系统,其分支广泛覆盖于整个心脏表面及心肌组织之间,可能成为辅助标测和成功消融的替代途径,近年来出现多种依赖冠状静脉系统的新型... 详细信息

起源于心外膜面和心肌深层的室性心律失常消融一直是临床上的棘手难题,冠状静脉系统作为心脏血流的回流系统,其分支广泛覆盖于整个心脏表面及心肌组织之间,可能成为辅助标测和成功消融的替代途径,近年来出现多种依赖冠状静脉系统的新型消融方式,现对相关研究进展进行综述。

关键词：室性心律失常冠状静脉系统左心室summit区心外膜消融乙醇消融

Large eddy simulation of unconfined turbulent swirling flow

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Science China(Technological Sciences) 2015年第10期58卷 1731-1744页

作者： zhang hongda HAN Chao YE TaoHong zhang JiMin CHEN YiLiang Department of Thermal Science and Energy Engineering University of Science and Technology of China

Large eddy simulations(LES) were performed to study the non-reacting flow fields of a Cambridge swirl burner. The dynamic Smagorinsky eddy viscosity model is used as the sub-grid scale turbulence model. Comparisons of experimental data show that the LES results are capable of predicting mean and root-mean-square velocity profiles. The LES results show that the annular swirling flow has a minor impact on the formation of the bluff-body recirculation zone. The vortex structures near the shear layers, visualized by the iso-surface of Q-criterion, display ring structures in non-swirling flow and helical structures in swirling flow near the burner exit. Spectral analysis was employed to predict the occurrence of flow oscillations induced by vortex shedding and precessing vortex core(PVC). In order to extract accurately the unsteady large-scale structures in swirling flow, a three-dimensional proper orthogonal decomposition(POD) method was developed to reconstruct turbulent fluctuating velocity fields. POD analysis reveals that flow fields contain co-existing helical and toroidal shaped coherent structures. The helical structure associated with the PVC is the most energetic dynamic flow structure. The latter toroidal structure associated with vortex shedding has lower energy content which indicates that it is a secondary structure.

关键词： Cambridge swirl burner large eddy simulation proper orthogonal decomposition vortex shedding and breakdown,precessing vortex core

Large eddy simulation of turbulent premixed piloted flame using artificial thickened flame model coupled with tabulated chemistry

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Applied Mathematics and Mechanics(English Edition) 2018年第9期39卷 1277-1294页

作者： Zhou YU hongda zhang Taohong YE Minming ZHU Department of Thermal Science and Energy Engineering University of Science and Technology of China Shenyang Engine Research Institute Aero Engine (Group) Corporation of China

A sub-grid scale(SGS) combustion model, which combines the artificial thickened flame(ATF) model with the flamelet generated manifold(FGM) tabulation method, is proposed. Based on the analysis of laminar flame structures, two self-contained flame sensors are used to track the diffusion and reaction processes with different spatial scales in the flame front, respectively. The dynamic formulation for the proposed SGS combustion model is also performed. Large eddy simulations(LESs) of Bunsen flame F3 are used to evaluate the different SGS combustion models. The results show that the proposed SGS model has the ability in predicting the distributions of temperature and velocity reasonably, while the predictions for the distributions of some species need further improvement. The snapshots of instantaneous normalized progress variables reveal that the flame is more remarkably and severely wrinkled at the flame tip for flame *** satisfactory results obtained by the dynamic model indicate that it can preserve the premixed flame propagation characteristics better.

关键词： large eddy simulation(LES) artificial thickened flame model tabulation dynamic modeling flame sensor

Large eddy simulation of turbulent premixed and stratified combustion using flame surface density model coupled with tabulation method

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Applied Mathematics and Mechanics(English Edition) 2018年第12期39卷 1719-1736页

Large eddy simulations(LESs) are performed to investigate the Cambridge premixed and stratified flames, SwB1 and SwB5, respectively. The flame surface density(FSD) model incorporated with two different wrinkling factor models, i.e., the Muppala and Charlette2 wrinkling factor models, is used to describe combustion/turbulence interaction, and the flamelet generated manifolds(FGM) method is employed to determine major scalars. This coupled sub-grid scale(SGS) combustion model is named as the FSD-FGM model. The FGM method can provide the detailed species in the flame which cannot be obtained from the origin FSD model. The LES results show that the FSD-FGM model has the ability of describing flame propagation, especially for stratified flames. The Charlette2 wrinkling factor model performs better than the Muppala wrinkling factor model in predicting the flame surface area change by the *** combustion characteristics are analyzed in detail by the flame index and probability distributions of the equivalence ratio and the orientation angle, which confirms that for the investigated stratified flame, the dominant combustion modes in the upstream and downstream regions are the premixed mode and the back-supported mode, respectively.

关键词： large eddy simulation(LES) flame surface density(FSD) model tabulation premixed combustion stratified combustion

大型危岩体崩塌灾害早期监测预警技术研究综述

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工程科学与技术 2024年第5期56卷 10-23页

作者：杜岩张洪达谢谟文蒋宇静李双全刘敬楠北京科技大学城市地下空间工程北京市重点实验室北京100083 山东科技大学矿山灾害预防控制省部共建国家重点实验室培育基地山东青岛266590 中关村智连安全科学研究院北京102100

作为中国常见的一种地质灾害,大型危岩崩塌成因复杂、分布范围广、隐蔽性和突发性强、危害性大,其早期预警一直难以实现。通过总结岩体崩塌灾害失稳机理与预警模型可知,开展岩桥结构面损伤识别及静力学-动力学-环境量参量(SDEI)的综合... 详细信息

作为中国常见的一种地质灾害,大型危岩崩塌成因复杂、分布范围广、隐蔽性和突发性强、危害性大,其早期预警一直难以实现。通过总结岩体崩塌灾害失稳机理与预警模型可知,开展岩桥结构面损伤识别及静力学-动力学-环境量参量(SDEI)的综合性监测技术研究是实现大型危岩体崩塌灾害早期监测预警的关键所在,而基于分离破坏前兆识别的早期预警机制研究是提高崩塌灾害预警时效性的有效手段之一。随着微机电系统与云边融合技术的发展,在未来有望形成一套稳定性动态评价、失稳工况预测与失稳时间预测模型实时联动的多元预警新范式。与此同时,还需通过不断丰富大型危岩崩塌等脆性破坏灾害预警技术体系,实现危岩体预警等级、稳定性状态、失稳工况、失稳时间的实时分析,进而有效解决大型危岩体崩塌灾害科学精准防控与智慧化应急决策的双重难题。最后,针对目前崩塌灾害早期监测预警研究中存在的技术瓶颈问题,提出具体的发展策略与应对措施,以期为中国地质灾害高风险区更好地应对大型危岩体崩塌灾害提供一些参考。

关键词：崩塌早期预警大型危岩体脆性破坏灾害监测指标体系

A novel method for chemistry tabulation of strained premixed/stratified flames based on principal component analysis

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Applied Mathematics and Mechanics(English Edition) 2018年第6期39卷 855-866页

作者： Peng TANG hongda zhang Taohong YE Zhou YU Zhaoyang XIA Department of Thermal Science and Energy Engineering University of Science and Technology of China School of Mechatronics Engineering Chizhou University Shenyang Engine Research Institute Aero Engine(Group) Corporation of China

The principal component analysis （PCA） is used to analyze the high dimen- sional chemistry data of laminar premixed/stratified flames under strain effects. The first few principal components （PCs） with larger contribution ratios axe chosen as the tabu- lated scalars to build the look-up chemistry table. Prior tests show that strained premixed flame structure can be well reconstructed. To highlight the physical meanings of the tabu- lated scalars in stratified flames, a modified PCA method is developed, where the mixture fraction is used to replace one of the PCs with the highest correlation coefficient. The other two tabulated scalars are then modified with the Schmidt orthogonalization. The modified tabulated scalars not only have clear physical meanings, but also contain passive scalars. The PCA method has good commonality, and can be extended for building the thermo-chemistry table including strain rate effects when different fuels are used.

关键词： premixed flame stratified flame strain rate principal component analysis(PCA) chemistry table

北京市苯/酮类相关企业工作人员职业健康检测结果分析

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华南预防医学 2024年第7期50卷 642-644,648页

作者：贾琰张洪达靳俊梅北京市化工职业病防治院北京100093

目的分析北京市海淀区苯/酮类相关企业工作人员健康状况,并探讨苯/酮暴露程度与工作人员健康状况的相关性,对职业人员职业健康监护措施提出建议。方法选取北京市海淀区2022年苯/酮类相关企业工作人员为研究对象进行职业健康检查,并根... 详细信息

目的分析北京市海淀区苯/酮类相关企业工作人员健康状况,并探讨苯/酮暴露程度与工作人员健康状况的相关性,对职业人员职业健康监护措施提出建议。方法选取北京市海淀区2022年苯/酮类相关企业工作人员为研究对象进行职业健康检查,并根据检查结果进行综合评价。结果对照组的243名员工中138名为男性,105名为女性,平均年龄(32.33±5.93)岁;苯暴露组的222名员工中,137名为男性,85名为女性,平均年龄为(32.14±5.79)岁;苯及酮暴露组的63名员工中,35名为男性,28名为女性,平均年龄为(32.81±6.41)岁。性别和年龄分布在3组间差异均无统计学意义(均P>0.05)。收缩压、舒张压、蛋白质、红细胞、比重的分布差异在3组从业人员中均有统计学意义(P0.05),中间细胞数量(Mid)及其所占比例(Mid%)、平均红细胞血红蛋白浓度(MCHC)在3组间的差异均有统计学意义(均P<0.01)。结论长期职业性接触苯和酮类化学物质对工作人员的血压、血检和尿检指标产生了影响,应加大对相关由业人员职业健康的监护力度,降低职业病危害。

关键词：苯/酮类相关企业职业性接触苯酮类物质职业健康监护

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地震荷载对油气化工码头工艺管道的影响分析

港口航道与近海工程 2024年第2期61卷 56-60页

作者：南欢刘轩章张宏达中交第二航务工程勘察设计院有限公司湖北武汉430071 武汉炼化工程设计有限责任公司湖北武汉430071

随着GB/T 20801-2020压力管道规范的更新,对于压力管道地震荷载的计算条件提出了更高的要求,本文在此基础上,总结分析油气化工码头所在地地震情况,发现大部分的码头工艺管道需要考虑地震荷载。结合工程实例,使用CAESARⅡ应力分析软件进... 详细信息

随着GB/T 20801-2020压力管道规范的更新,对于压力管道地震荷载的计算条件提出了更高的要求,本文在此基础上,总结分析油气化工码头所在地地震情况,发现大部分的码头工艺管道需要考虑地震荷载。结合工程实例,使用CAESARⅡ应力分析软件进行分析计算,并针对码头工程特殊情况,在考虑地震荷载下,详细分析了不同因素对管道应力的影响,并针对性的提出了一定的管道抗震措施。

关键词：地震荷载油气化工码头工艺管道应力分析 CAESARⅡ

同方期刊数据库博看期刊评论

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盾构渣土制浆装备技术研究及应用

建筑机械化 2024年第6期45卷 60-63页

作者：杨露伟刘作威张宏达石富明中铁隧道局集团有限公司广东广州511400 中铁隧道局集团有限公司设备分公司广东广州511400

为解决基础建设过程中资源浪费和环境破坏问题,提出了利用盾构渣土进行制浆的技术方案。通过试验验证了这种制浆技术在不同土质条件下的性能表现,发现盾构渣土制备的同步注浆材料在强度、耐久性等方面满足设计要求。还探讨了制浆工艺流... 详细信息

为解决基础建设过程中资源浪费和环境破坏问题,提出了利用盾构渣土进行制浆的技术方案。通过试验验证了这种制浆技术在不同土质条件下的性能表现,发现盾构渣土制备的同步注浆材料在强度、耐久性等方面满足设计要求。还探讨了制浆工艺流程以及实际应用场景下的性能对比,强调了该技术在工程中的可行性和优势。总结指出,这种技术能降低成本、减少资源浪费,对环境友好,对基建行业发展和生态文明建设具有积极意义。

关键词：盾构渣土设备原状土同步制浆