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Design and characterisation of the high-current DC breaker driven by explosive

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High Voltage 2023年第3期8卷 466-476页

作者： Cunwen Tang Hua Li Zhiquan song Jifei Ye Meng Xu Xingguang Hu fu peng Institute of Plasma Physic s Hefei Institutes of Physical ScienceChinese Academy of SciencesHefeiChina 2University of Science and Technology of ChinaHefeiChina College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhenChina

The development of a high-current DC breaker is very important for the protection of the expensive superconducting magnet.A kind of an economic switch called pyrobreaker,which is driven by explosive detonation waves,has been used as the backup quench protection due to its inherent reliability and fast response.A prototype pyrobreaker with a special structure that can withstand and break 100 kA is *** numerical material model is taken to calculate the fracture demand of contact and the mass demand of ***,the detonation wave and contact breaking process are simulated by the ANSYS *** performance of the design and characterisation during dynamic breaking are compared with simulation and no-load experiment *** the end,the temperature rise test and the breaking test under 100 kA are completed *** results demonstrate that the design of 100 kA pyrobreaker is reliable.

关键词： breaking character high

Synergistically enhanced ORR and HER performance on Co-N-C coupled in-situ generated PtCo intermetallic

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Journal of Energy Chemistry 2025年第1期100卷 721-729页

作者： Guanyu Luo Min song Lulu An Xiao Huang Qian Zhang Chenhao Zhang Tao Shen Shuang Wang Deli Wang Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology) Ministry of Education School of Chemistry and Chemical Engineering Huazhong University of Science and Technology

Integrating multi-scale sites in a composite catalyst is vital to realize efficient ***,a synergistic composite catalyst consisting of Co atomic sites and in-situ generated PtCo intermetallic compounds （IMCs）(o-PtCo@CoNC) is proposed through Co pre-anchoring and subsequent impregnation-reduction *** loading of Co atoms provides a chance for in-situ generating PtCo ordered intermetallic *** remaining Co single atoms and PtCo IMCs construct synergistic electrocatalytic *** from the ordered structure,synergistic effect of Pt Co IMCs and Co single atoms,o-PtCo@CoNC exhibits excellent electrocatalytic performance for oxygen reduction reaction （ORR） and hydrogen evolution reaction （HER） with mass activity of 1.21 A mgPt-1（at 0.9 V） and5.70 A mgPt-1（at an overpotential of 100 mV）,***,o-PtCo@CoNC delivers negligible loss of half-wave potential and overpotential during long-term stability test in acid solutions,with 13 mV decay after 50,000 potential cycles for ORR and a 2.7 mV decay after 20,000 potential cycles for *** integration strategy of single-atomic sites coupled IMCs paves the way for enhancing the activity and durability of Pt-based electrocatalysts.

关键词： Electrolytic reduction

冠心病患者血浆中miR-210和miR-214及基质细胞衍生因子-1α变化与冠状动脉侧支循环形成的相关性研究

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中国心血管病研究 2019年第5期17卷 426-430页

作者：赵宁杨磊磊彭夫松贾博曾真张萍北京市垂杨柳医院急诊内科北京市100022 北京清华长庚医院心内科

目的探讨冠心病患者血浆中miR-210、miR-214及基质细胞衍生因子-1 α(stromal cell-derived factor,SDF-1α)的变化与冠状动脉侧支循环形成的相关性.方法选择2014年2月至2018年5月在我院诊治的冠心病患者140例,检测所有患者血浆中miR-... 详细信息

目的探讨冠心病患者血浆中miR-210、miR-214及基质细胞衍生因子-1 α(stromal cell-derived factor,SDF-1α)的变化与冠状动脉侧支循环形成的相关性.方法选择2014年2月至2018年5月在我院诊治的冠心病患者140例,检测所有患者血浆中miR-210、miR-214、SDF-1α的含量,检测患者心功能,判定患者的冠状动脉侧支循环形成状况并进行相关性分析.结果在140例患者中,冠状动脉侧支循环形成80例(观察组),冠状动脉侧支循环未形成60例(对照组),观察组中Ⅰ级45例,Ⅱ级25例,Ⅲ级10例.不同组别的性别、年龄、体重指数、收缩压、舒张压、TG、LDL等对比未见统计学差异(P>0.05).观察组的miR-210相对表达量高于对照组,miR-214相对表达量低于对照组,对比差异有统计学意义(P<0.05).观察组的血浆SDF-1α含量高于对照组[(2543.95±567.01)ng/ml比(2049.88±87.19)ng/ml,t=12.055,P<0.05].观察组的LVEF值高于对照组,Gensini积分低于对照组,对比差异有统计学意义(P<0.05).Spearman相关分析显示,冠心病患者冠状动脉侧支循环形成与血浆miR-210、miR-214和SDF-1α表达有显著相关性(r=0.544、-0.345、0.416,P<0.05).血浆miR-210、miR-214和SDF-1α对冠状动脉侧支循环形成预测的曲线下面积(AUC)分别为0.731、0.802和0.765,诊断的灵敏度分别为72%、81%和61%,特异度分别为64%、66%和75%.结论冠心病患者中冠状动脉侧支循环形成比较常见,患者血浆中miR-210、miR-214及SDF-1α水平的变化可预测冠状动脉侧支循环形成.

关键词：冠状动脉疾病 miR-210 基质细胞衍生因子-1α 侧支循环

Study of contact resistance in the design of a pyro-breaker applied in superconducting fusion facility

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Plasma Science and Technology 2019年第6期21卷 153-159页

作者： Jun HE Zhiquan song Cunwen TANG peng fu Jie ZHANG Institute of Plasma Physics Chinese Academy of Sciences Hefei 230031 People's Republic of China University of Science and Technology of China Hefei 230031 People's Republic of China

Pyro-breaker is a fast-responding and high-reliable explosive-driven circuit breaker,which has been applied in several quench protection systems,such as International Thermonuclear Experimental Reactor and Experimental Advanced Superconducting *** an indispensable back-up switch,Pyro-breaker guarantees the reliability and safety of the system and avoids tremendous loss when quench *** contact,a crucial part of an electrical device greatly determines the steady current capacity of a ***,due to the complexity of the model and the deficiency knowledge of the microstate of contact areas,an accurate calculation for contact resistance is difficult to acquire.A study of electrical contact in the design of a Pyro-breaker has been presented in this *** engineering calculation method is verified with *** are fitted for the presented model,which will be a significant theoretical basis for the future designing.

关键词： quench protection system pyro-breaker contact resistance four-point-method

A review of microwave-metal discharge interaction:Mechanism,regulation,and application for synthesis of nanomaterials

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Nano Research 2024年第10期17卷 9225-9254页

作者： Yixuan Xie Ruiqian Shi Benwei fu Chengyi song Wen Shang peng Tao Tao Deng State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China National Engineering Research Center of Special Equipment and Power System for Ship and Marine Engineering Shanghai 200030China

Placing metals within microwave ovens has been generally viewed as a dangerous practice because of occurrence of violent discharge,but in recent years such discharge phenomenon has attracted increasing attention and has enabled a variety of exciting *** this work,we provide a comprehensive review of fundamental understanding of microwave-metal discharge interaction and its state-of-the-art application for nanomaterials *** introduce the microscopic interaction between different categories of materials and the electric and magnetic field of *** microwave-metal interaction,we highlight its size-dependence and point out the influence of the oxide layer on the surface of *** discuss the required conditions for occurrence of discharge,microscopic formation mechanism,and characteristic features of microwave-metal discharge *** analyzing the influence from the microwave input,discharging metals,and surrounding discharging media,we discuss the strategy for systematical regulation of the discharge *** describe the applications of the microwave-metal discharge for facile synthesis of various functional nanomaterials including core-shell carbon/metal,metal oxides,metal chalcogenides,intermetallic compounds,metallic nanoparticles and metallic compounds,and organic ***,the challenges in precise characterization and dynamic regulation of the discharge process as well as exciting application opportunities are discussed.

关键词： microwave-metal interaction discharge microwave heating skin depth nanomaterial synthesis

Modelling of pressure-strain correlation in compressible turbulent flow

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Acta Mechanica Sinica 2008年第1期24卷 37-43页

作者： Siyuan Huang song fu Department of Engineering Mechanics Tsinghua University100084 Beijing China

Previous studies carried out in the early 1990s conjectured that the main compressible effects could be associated with the dilatational effects of velocity fluctuation. Later, it was shown that the main compressibility effect came from the reduced pressure-strain term due to reduced pressure fluctuations. Although better understanding of the compressible turbulence is generally achieved with the increased DNS and experimental research effort, there are still some discrepancies among these recent findings. Analysis of the DNS and experimental data suggests that some of the discrepancies are apparent if the compressible effect is related to the turbulent Mach number, Mt. From the comparison of two classes of compressible flow, homogenous shear flow and inhomogeneous shear flow （mixing layer）, we found that the effect of compressibility on both classes of shear flow can be characterized in three categories corresponding to three regions of turbulent Mach numbers： the low-Mr, the moderate-Mr and high-Mr regions. In these three regions the effect of compressibility on the growth rate of the turbulent mixing layer thickness is rather different. A simple approach to the reduced pressure-strain effect may not necessarily reduce the mixing-layer growth rate, and may even cause an increase in the growth rate. The present work develops a new second-moment model for the compressible turbulence through the introduction of some blending functions of Mt to account for the compressibility effects on the flow. The model has been successfully applied to the compressible mixing layers.

关键词： Compressible turbulence Reynolds stresses Second-moment closure Turbulent Mach number Mixing layer

Investigations of an enclosed annular rotor-stator system with LES method

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Science China(Physics,Mechanics & Astronomy) 2018年第11期61卷 50-60页

作者： Zhe Jiao song fu School of Aerospace Engineering Tsinghua University

In this study, the flows in an enclosed annular rotor-stator system with the Reynolds number ranging from 0.75×105 to 3.75×105 and an aspect ratio of 36.5 are investigated using the LES method. Few studies have explored such a rotor-stator system with this aspect ratio and the flow structure on the rotor side. The mean flow structure varies from a torsional Couette type to a Batchelor type as the Reynolds number increases. The onset of the instability in the B?dewadt layer adjacent to the stator is delayed,whereas it is promoted in the Ekman layer adjacent to the rotor. Both the layers demonstrate rich spiral structures. Turbulent spirals are observed to occur at the rotor disk side that also generates TS-wave-like(Tollmien-Schlichting) structures between adjacent spiral arms. further, the turbulence at the stator is complex and interesting. Statistically, the turbulence is highly anisotropic near both the rotating and nonrotating disks, which is depicted by the Reynolds stresses.

关键词： rotating flow rotor-stator system large eddy simulation anisotropic turbulence Ekman-B6dewadt layers

Forward-facing steps induced transition in a subsonic boundary layer

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Science China(Physics,Mechanics & Astronomy) 2017年第10期60卷 34-44页

作者： Hui Zhu song fu School of Aerospace Engineering Tsinghua University Beijing 100084 China

A forward-facing step (FFS) immersed in a subsonic boundary layer is studied through a high-order flux reconstruction (FR) method to highlight the flow transition induced by the step. The step height is a third of the local boundary-layer thickness. The Reynolds number based on the step height is 720. Inlet disturbances are introduced giving rise to streamwise vortices upstream of the step. It is observed that these small-scale streamwise structures interact with the step and hairpin vortices are quickly developed after the step leading to flow transition in the boundary layer.

关键词： forward-facing steps boundary layer transitional flow

Identification of similar transcriptional regulatory mechanisms in multiple cry genes in Bacillus thuringiensis HD12

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Journal of Integrative Agriculture 2017年第1期16卷 135-143页

作者： song Zhi-ru peng Qi SHU Chang-long ZHANG Jie SUN Dong-mei song fu-ping College of Life Science and Technology Heilongjiang Bayi Agricultural University State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural Sciences

Bacillus thuringiensis subspecies morrisoni strain HD12, whose genome harbors multiple insecticidal protein-encoding genes, includes eight cry genes, as indicated by genome sequencing. This strain produces crystals that are toxic to lepidopteran species. These crystal inclusions were purified by sucrose gradients and sodium dodecyl sulphate-polyacrylamide gel electrophoresis （SDS-PAGE）, followed by liquid chromatography-mass spectrometry, and found to contain five proteins （Cry1Da, Cry1Ae, Cry1Bb, Cry1Fb, and CrylJa）. The transcriptional activities of the cry1Da, cry1Ae, cry1Bb, cry1Fb, and cry11Ja promoters indicated that transcription of crylDa is controlled by SigE; however, the other four cry genes were found to be controlled by both SigE and SigK. The activities of the crylJa and crylFb promoters were the strongest among the five genes studied. These promoters were therefore used to direct the expression of the Cry1Ac- and Cry2Ab-encoding genes concurrently in a single strain. Our findings indicate that promoters with the same transcriptional profile may be used to direct the expression of different cry genes in one strain. Our results are expected to be valuable for the construction of strains with efficient expression of multiple cry genes in order to overcome current limitations associated with the application of B. thuringiensis-based insecticides.

关键词： Bacillus thuringiensis transcription cry genes insecticide