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Plasma Science and Technology 2019年第6期21卷 52-57页

作者： h J YEOM d h ChOI Y S LEE J h KIM d J SEONG S J YOU h C LEE Korea Research Institute of Standards and Science(KRISS) Daejeon 34113 Republic of Korea department of Physics Chungnam National University Daejeon 34134 Republic of Korea

In this study,plasma density measurements were performed near the plume region of the remote plasma source (RPS) in Ar/NF3 gas mixtures using a microwave cutoff *** measured plasma density is in the range of 1010-1011 cm-3 in the discharge conditions with RPS powers of 2-4 kW and gas pressures of 0.87-4 *** plasma density decreased with increasing gas pressures and RPS powers under various Ar/NF3 mixing *** decrease in the plasma density measured at the fixed measurement position (plume region) can be understood by the reduction of the electron energy relaxation length with increases in the gas pressures and mixing ratio of NF3/(Ar/NF3).We also performed downstream etching of silicon and silicon oxide films in this *** etch rate of the silicon films significantly increases while the silicon oxide is slightly etched with the gas pressures and *** was also found that the etch rate strongly depends on the wafer position on the processing chamber electrode,and that the etch selectivity reached 96-131 in the discharge conditions of RF powers (3730-4180 W) and gas pressures (3.6-4 Torr).

关键词： remote plasma source electron density cutoff probe downstream etch

Connections Between Induction Generator Effect and Open-loop Modal Proximity to Cause Sub-synchronous Oscillations in Series-compensated Power System

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 963-973页

作者： Wenjuan du Yang Wang h.F.Wang Tao zhao Tim Littler College of Electrical Engineering Sichuan UniversityChengduChina School of Electrical Engineering the Queen’s University of BelfastBelfastUK IEEE

The induction generator effect(IGE)and the openloop modal proximity(OLMP)are two different reasons why subsynchronous oscillations(SSOs)in a series-compensated power system(SCPS)may *** IGE attributes the growing SSOs to negative resistance,while the OLMP explains the SSO mechanism from the standpoint of modal *** this paper,we investigate the connections between the IGE and the OLMP through equivalent RLC circuit and open-loop modal *** investigation is conducted for two types of seriescompensated power systems where either a synchronous generator or a dFIG is connected at the sending *** investigation reveals the conditions,in which the IGE and the OLMP may jointly cause the growing SSOs,i.e.,both the IGE and the OLMP can explain why the growing SSOs ***,the investigation indicates that the IGE and the OLMP may be totally irrelevant and lead to growing SSOs *** implies that it is possible that in a SCPS,the growing SSOs are only due to the IGE,and the OLMP is non-existent,and vice ***,when the growing SSOs occurs in a SCPS,examination based on both the IGE and the OLMP should be carefully conducted in order to find if the oscillatory instability is due to the IGE,or the OLMP,or both of them.

关键词： Induction generator effect open-loop modal proximity series compensation sub-synchronous oscillations

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五味子甲素改善氧化应激引起的内皮功能障碍

中国药理学通报 2025年第1期41卷 122-130页

作者：侯惠民张文文赵卫萍赵鑫朴贤美寒地心血管疾病国家重点实验室哈尔滨医科大学药学院药理学教研室黑龙江省生物医药工程重点实验室—省部共建国家重点实验室培育基地心血管药物研究教育部重点实验室黑龙江哈尔滨150086

目的探究五味子甲素(schizandrin A,SchA)对氧化应激引起内皮功能障碍的拮抗作用及其作用机制。方法选用人脐静脉内皮细胞(human umbilical vein endothelial cells,hUVECs)作为研究对象,采用MTT实验检测SchA对hUVECs活力的影响;通过流... 详细信息

目的探究五味子甲素(schizandrin A,SchA)对氧化应激引起内皮功能障碍的拮抗作用及其作用机制。方法选用人脐静脉内皮细胞(human umbilical vein endothelial cells,hUVECs)作为研究对象,采用MTT实验检测SchA对hUVECs活力的影响;通过流式细胞技术检测细胞中ROS的含量;试剂盒检测hUVECs中MdA、CAT的含量以及细胞上清液中NO、ET-1的含量;Western blot实验检测细胞中SOd1、p-eNOS/eNOS蛋白以及Nrf2/Keap1/hO-1通路蛋白的表达情况;免疫荧光实验检测细胞Nrf2的入核情况。结果SchA通过激活Nrf2/Keap1/hO-1信号通路逆转LPS或缺氧诱导的hUVECs内ROS和MdA含量的升高及SOd1和CAT含量的下降;SchA逆转LPS诱导的hUVECs中p-eNOS和eNOS蛋白表达的降低及逆转细胞培养液中NO含量的下降和ET-1含量的升高;Nrf2抑制剂ML385逆转SchA对氧化应激及内皮功能障碍的拮抗作用。结论SchA拮抗LPS及缺氧诱导的氧化应激,SchA通过上调Nrf2/Keap1/hO-1信号通路改善氧化应激引起的内皮功能障碍。

关键词： SchA 氧化应激内皮功能障碍 Nrf2/Keap1/hO-1信号通路 hUVECs LPS

Flexural-wave-generation using a phononic crystal with a piezoelectric defect

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Applied Mathematics and Mechanics(English Edition) 2023年第8期44卷 1241-1262页

作者： S.h.JO d.LEE department of Mechanical Roboticsand Energy EngineeringDongguk UniversitySeoul 04620Republic of Korea department of Mechanical Engineering Seoul National UniversitySeoul 08826Republic of Korea

This paper proposes a method to amplify the performance of a flexural-wave-generation system by utilizing the energy-localization characteristics of a phononic crystal(PnC)with a piezoelectric defect and an analytical approach that accelerates the predictions of such wave-generation *** proposed analytical model is based on the Euler-Bernoulli beam *** proposed analytical approach,inspired by the transfer matrix and S-parameter methods,is used to perform band-structure and time-harmonic analyses.A comparison of the results of the proposed approach with those of the finite element method validates the high predictive capability and time efficiency of the proposed model.A case study is explored;the results demonstrate an almost ten-fold amplification of the velocity amplitudes of flexural waves leaving at a defect-band frequency,compared with a system without the ***,design guidelines for piezoelectric-defect-introduced PnCs are provided by analyzing the changes in wave-generation performance that arise depending on the defect location.

关键词： phononic crystal(PnC) defect wave-generation fexural wave analytical model

Mid-infrared hyperchaos of interband cascade lasers

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Light(Science & Applications) 2022年第1期11卷 69-78页

作者： Yu deng Zhuo-Fei Fan Bin-Bin zhao Xing-Guang Wang Shiyuan zhao Jiagui Wu Frédéric Grillot Cheng Wang School of Information Science and Technology ShanghaiTech UniversityShanghai 201210China LTCI Institut Polytechnique de ParisTélécom Paris19 place Marguerite Perey91120 PalaiseauFrance School of Physical Science and Technology Southwest UniversityChongqing 400715China Center for high Technology Materials University of New-Mexico1313 Goddard St SEAlbuquerqueNM 87106USA Shanghai Engineering Research Center of Energy Efficient and Custom AI IC ShanghaiTech UniversityShanghai 201210China

Chaos in nonlinear dynamical systems is featured with irregular appearance and with high sensitivity to initial ***-infrared light chaos based on semiconductor lasers has been extensively studied and has enabled various ***,we report a fully-developed hyperchaos in the mid-infrared regime,which is produced from interband cascade lasers subject to the external optical *** spectrum analysis demonstrates that the chaos exhibits three positive Lyapunov ***,the chaotic signal covers a broad frequency range up to the Ghz level,which is two to three orders of magnitude broader than existed mid-infrared chaos *** interband cascade lasers produce either periodic oscillations or low-frequency fluctuations before bifurcating to *** hyperchaos source is valuable for developing long-reach secure optical communication links and remote chaotic Lidar systems,taking advantage of the high-transmission windows of the atmosphere in the mid-infrared regime.

关键词： chaos chaotic hyperchaos

ON FATIGUE CRACK PATh dEVIATION AT ELEVATEd TEMPERATURE IN ELECTRON BEAM REPAIREd WELdMENTS OF TURBINE dISK

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 584-590页

作者： h.Q.Zhang h.Y.zhao Y.h.Zhang L.h.Li X.A.Zhang department of Mechanical Engineering Tsinghua University Beijing 100084 ChinaDepartment of Mechanical Engineering Tsinghua University Beijing 100084 ChinaSchool of Mechanical Engineering and Automation Beijing University of Aeronautics and AstronauticsBeijing 100083 ChinaSchool of Mechanical Engineering and Automation Beijing University of Aeronautics and AstronauticsBeijing 100083 ChinaBeijing Institute of Aeronautical Materials Beijing 100095 China

Fatigue crack growth behaviors in electron beam weldments of a nickel-base superalloy are studied. The objective of this paper is to discuss effects of the inhomogeneity of mechanical performance on fatigue crack growth (FCG) rate and crack path deviation (CPd). The base metal served in a turbine disk of aerospace engine was selected to fabricate bead-on-plate weldments by using electron beam welding. Some wedge-type opening loading specimens, notched in three different zone of weld metal, hAZ and base metal, were employed and performed fatigue crack growth tests at 650℃. The results show that the fatigue crack growth of electron beam welded joints is instable due to the influence of mechanical heterogeneities. Owing to the crack deviation at the weld metal and heat-affected-zone (hAZ), the effective growth driving force at the tip of fatigue crack was reduced with the reduction of the effective stress intensity factor (SIF) which finally causes fatigue crack rate decrease. Fatigue crack was strongly affected by size and the symmetrical characteristics of the plastic zone at the crack tip, which means that the integrity of the welded structure containing the fatigue crack mainly depended on the toughness of the low strength zone.

关键词： fatigue crack growth crack path deviation electron beam welding inhomogeneity of mechanical performance

STRUCTURAL PROPERTIES INVESTIGATION ON MICROCRYSTALLINE SILICON FILMS dEPOSITEd WITh VhF-PECVd TEChNIQUE

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 223-227页

作者： h.d.Yang departmentofElectronicEngineering JinanUniversityGuangzhou510632China

Raman scattering spectroscopy and scanning electron microscopy (SEM) techniques were used to determine the structural properties of two typical series of microc rystalline silicon (μc-Si:h) films deposited at different VhF plasma power and different working gas pressure by very high frequency plasma enhanced chemical v apor deposition (VhF-PECVd) technique. Raman spectra measurements show that both crystalline volume fraction Xc and average grain size d of μc-Si : h films ar e strongly affected by the two deposition conditions and are more sensitive to w orking gas pressure than VhF plasma power. SEM characterizations have further co nfirmed that VhF plasma power and working gas pressure could clearly enhance the surface roughness of μc-Si : h films ascribing to polymerization reactions, w hich is also more sensitive to working gas pressure than VhF plasma power.

关键词： VhF-PECVd microcrystalline silicon film structural property

OPTION PRIORITIZATION FOR UNKNOWN PREFERENCE

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Journal of Systems Science and Systems Engineering 2016年第1期25卷 39-61页

作者： Jing Yu Keith W. hipel d. Marc Kilgour Min zhao Business School hohai University Nanjing Jiangsu 211100 China department of Systems design Engineering University of Waterloo Waterloo N2L 3G1 Canada department of Mathematics Wt'lfrid Laurier University Waterloo N2L 3C5 Canada Centre for International Governance Innovation Waterloo Ontario Canada Water Resources and Sustainable development Research Centre of Jiangsu Province Nanjing 210098 China

An option prioritization technique is developed to efficiently elicit the preferences, both unknown and crisp, of decision makers （dMs） in strategic conflicts. In the Graph Model for Conflict Resolution, each dM has one or more options, each of which may be selected or not. A state, or possible scenario, is formed when all dMs make an option selection. The software GMCR II contains an option prioritization procedure that makes it easy for a modeUer to enter a dM＇s crisp preference ordering over the states using prioritized statements describing the dM＇s preferred option combinations. This procedure is extended by adding two new logical connectives that describe uncertainty of preference. For each dM, a range of possible scores for each feasible state can then be calculated, facilitating the determination of a preference ordering containing uncertainty by comparing and ranking scores. To demonstrate how this new methodology can be used to represent tmknown preferences in a real-world decision problem, it is applied to a Canadian dispute over proposed water exports.

关键词： Graph model for conflict resolution option prioritization unknown preference logical connectives

Improving the hard magnetic properties by intragrain pinning for Ta doped nanocrystalline Ce-Fe-B alloys

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Journal of Materials Science & Technology 2019年第9期35卷 1877-1885页

作者： J.S.Zhang W. Li X.F. Liao h.Y. Yu L.Z. zhao h.X. Zeng d.R. Peng Z.W. Liu School of Materials Science and Engineering South China University of TechnologyGuangzhou510640China Innovative Center for Advanced Materials (ICAM) Hangzhou Dianzi UniversityHangzhou310012China

To develop Ce based permanent magnets with high performance/cost ratio, Ta doping is was employed to enhance the magnetic performance of Ce-Fe-B alloys. For melt spun Cei7Fe78-xTaxB6 (x = 0-1) alloys, the coercivity hc increases from 439 to 553 kA/m with increasing x value from 0 to 0.75. Microstructure characterizations indicate that Ta doping is helpful for grain refinement. A second phase of TaB2 is observed in Ce17Fe77.25Tao.75B6 alloy, which acts as the pinning center of the magnetic domains, resulting in the change of coercivity mechanism from nucleation type to nucleation +pinning type. The micromagnetic simulation confirms that non-magnetic particles within hard magnetic phase can increase the demagnetization field around them and it is crucial for preventing the further magnetization reverse by pinning effect. Take the advantage of Ta doping for enhancing the coercivity, Ce content of Ce-Fe-B alloy can be further cut down to increase the remanence Jr due to the reduced volume fraction of CeFe2 phase and increased Fe/Ce ratio. As a result, a good combination of magnetic properties with hc = 514 kA/m, Jr = 0.49 T, and the maximum energy product (Bh)max = 36 kJ/m^3 have been obtained in Ce15Fe79.25Tao.75B6 alloy. It is expected that the present work can serve as a useful reference for designing new permanent magnetic materials with low-cost.

关键词： Melt-spinning Permanent magnets Second phase Coercivity mechanism Thermal stability

Spatial and seasonal variation in soil respiration along a slope in a rubber plantation and a natural forest in Xishuangbanna, Southwest China

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Journal of Mountain Science 2018年第4期15卷 695-707页

作者： zhao Yong-li Stefanie d.GOLdBERG XU Jian-chu Rhett d.hARRISON Center for Mountain Ecosystem Studies Kunming Institute of Botany Chinese Academy of Sciences Kunming 650201 China University of Chinese Academy of Sciences Beijing 100039 China World Agroforestry Centre East and Central Asia Kunming 650201 China World Agroforestry Centre East & Southern Africa Region 13 Elm Road Woodlands Lusaka Zambia

Soil respiration is a key component of the global carbon cycle, and even small changes in soil respiration rates could result in significant changes in atmospheric CO_2 levels. The conversion of tropical forests to rubber plantations in SE Asia is increasingly common, and there is a need to understand the impacts of this land-use change on soil respiration in order to revise CO_2 budget calculations. This study focused on the spatial variability of soil respiration along a slope in a natural tropical rainforest and a terraced rubber plantation in Xishuangbanna, Southwest(SW) China. In each land-use type, we inserted 105 collars for soil respiration *** was conducted over one year in Xishuangbanna during May, June, July and October 2015(wet season) and January and March 2016(dry season). The mean annual soil respiration rate was 30% higher in natural forest than in rubber plantation and mean fluxes in the wet and dry season were 15.1 and 9.5 Mg C ha^(-1) yr^(-1) in natural forest and 11.7 and 5.7 Mg C ha^(-1) yr^(-1) in rubber plantation. Using a linear mixedeffects model to assess the effect of changes in soil temperature and moisture on soil respiration, we found that soil temperature was the main driver of variation in soil respiration, explaining 48% of its seasonal variation in rubber plantation and 30% in natural forest. After including soil moisture, the model explained 70% of the variation in soil respiration in natural forest and 76% in rubber plantation. In the natural forest slope position had a significant effect on soil respiration, and soil temperature and soil moisture gradients only partly explained this correlation. In contrast, soil respiration in rubber plantation was not affected by slope position, which may be due to the terrace structure that resulted in more homogeneous environmental conditions along the slope. Further research is needed to determine whether or not these findings hold true at a landscape level.

关键词： Soil respiration Tropical rain forest Rubber plantation Land-use change Carbon cycle Transect