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Plasma density measurement and downstream etching of silicon and silicon oxide in Ar/NF3 mixture remote plasma source

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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

cerebral ischemia and neuroregeneration

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Neural Regeneration Research 2018年第3期13卷 373-385页

作者： Reggie h.c.lee Michelle h.h.lee celeste Y.c.Wu Alexandre couto e Silva harlee E.Possoit Tsung-han hsieh Alireza Minagar hung Wen Lin Department of Neurology Louisiana State University Health Science Center center for Brain health Louisiana State University Health Science Center Institute of cellular and System Medicine National Health Research Institutes Department of cellular Biology and Anatomy Louisiana State University Health Science Center cardiovascular and Metabolomics Research center Hualien Tzu Chi Hospital

cerebral ischemia is one of the leading causes of morbidity and mortality worldwide. Although stroke （a form of cerebral ischemia）-related costs are expected to reach 240.67 billion dollars by 2030, options for treatment against cerebral ischemia/stroke are limited. All therapies except anti-thrombolytics （i.e., tissue plasminogen activator） and hypothermia have failed to reduce neuronal injury, neurological deficits, and mortality rates following cerebral ischemia, which suggests that development of novel therapies again st stroke/cerebral ischemia are urgently needed. here, we discuss the possible mechanism（s） underlying cerebral ischemia-induced brain injury, as well as current and future novel therapies （i.e., growth factors, nicotinamide adenine dinucleotide, melatonin, resveratrol, protein kinase c isozymes, pifithrin, hypothermia, fatty acids, sympathoplegic drugs, and stem cells） as it relates to cerebral ischemia.

关键词： cerebral ischemia melatonin resveratrol protein kinase c pifithrin-α fatty acids sympathetic nervous system neuromodulation therapy traditional chinese therapies stem cel

采用Ag-cu-Zn-cd焊料焊接烧结刀头与低碳钢的焊接特性

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金刚石与磨料磨具工程 2001年第3期21卷 30-33,36页

作者： J.h.lee c.h.lee 郑鲁勋姜荣超韩国汉阳大学钢铁加工与应用研究院冶金工程部韩国迪爱克斯公司长沙矿院

该项研究中采用三种不同焊料 (W 4 0 ,BAg - 1,BAg3S)对低碳钢锯片基体和青铜基烧结刀头进行焊接。使用DIEXcorp(迪爱克斯公司 )SAB7型高频感应焊接机进行焊接实验。利用OLM(金相分析 ) ,SEM(扫描电子显微镜 ) ,EDS(能谱分析 )和XRD(X... 详细信息

该项研究中采用三种不同焊料 (W 4 0 ,BAg - 1,BAg3S)对低碳钢锯片基体和青铜基烧结刀头进行焊接。使用DIEXcorp(迪爱克斯公司 )SAB7型高频感应焊接机进行焊接实验。利用OLM(金相分析 ) ,SEM(扫描电子显微镜 ) ,EDS(能谱分析 )和XRD(X射线衍射分析 )等手段对不同焊接温度与时间条件下焊接区的焊缝宽度、气孔率和显微结构进行了评价。为了评价焊接强度 ,还进行了抗弯强度 (扭矩 )测试。焊接温度对焊缝强度有较大影响。对于青铜基刀头和锯片钢基体的匹配焊接 ,其合理的焊接温度为 70 0～ 850℃。焊接区的反应程度 ,气孔含量和焊缝宽度三个因素影响焊接强度。在青铜基刀头靠近接面处形成反应区 ,由于在该区形成富cu相 ,cu5.6Sn ,cuZn4 ,β(cuZn)和cdAg相 ,而对焊接强度产生有害影响。当焊接温度提高 ,焊接时间增加 ,则气孔率将增大。当焊缝区气孔率小于 3～ 5%时 ,则青铜基刀头将获得最佳强度。焊缝宽度大于 30

关键词：金刚石锯片低碳钢烧法刀头焊接银基焊料

circulation Pattern controls of Summer Temperature Anomalies in Southern Africa

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Advances in Atmospheric Sciences 2024年第2期41卷 341-354页

作者： chibuike chiedozie IBEBUchI cameron c.lee Department of Geography Kent State UniversityKentOhio 44242USA climRISE Lab Kent State UniversityKentOhio 44242USA

This study investigates the relationship between circulation patterns and austral summer temperature anomalies in southern Africa. The results show that the formation of continental lows tends to increase the thickness of the lower atmosphere. Further, the distinct variabilities of high and low pressure under the circulation types, influence air mass advection from the adjacent oceans, as well as atmospheric stability over land. Stronger anticyclonic circulation at the western branch of the Mascarene high-pressure system enhances the low-level cold air advection by southeast winds,decreases the thickness, and lowers the temperature over a majority of the land in southern Africa. conversely, a weaker Mascarene high, coupled with enhanced cyclonic activity in the southwest Indian Ocean increases low-level warm air advection and increases temperature anomalies over vast regions in southern Africa. The ridging of a closed South Atlantic anticyclone at the southern coast of southern Africa results in colder temperatures near the tip of southern Africa due to enhanced low-level cold air advection by southeast winds. however, when the ridge is weak and westerly winds dominate the southern coast of southern Africa, these areas experience temperature increases. The northward track of the Southern hemisphere mid-latitude cyclone, which can be linked to the negative Southern Annular Mode, reduces the temperature in the southwestern part of southern Africa. Also, during the analysis period, El Ni?o was associated with temperature increases over the central parts of southern Africa;while the positive Indian Ocean dipole was linked to a temperature increase over the northeastern, northwestern, and southwestern parts of southern Africa.

关键词： temperature circulation types Subtropical Indian Ocean dipole Southern Annular Mode El Ni?o Indian Ocean dipole Mascarene high South Atlantic anticyclone

Anti-obesity effects of fucoidan from Sargassum thunbergii in adipocytes and high fat diet induced obese mice through inhibiting adipogenic specific transcription factor

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Food Science and human Wellness 2024年第3期13卷 1608-1616页

作者： hyo-Geun lee h.h.A.c.K.Jayawardhana Fengqi Yang D.P.Nagahawaththa N.M.Liyanage Kyung-Mo Song Yun-Sang choi Seung-hong lee You-Jin Jeon Min-cheol Kang Department of Marine Life Sciences Jeju National UniversityJeju 63243Republic of Korea Marine Science Institute Jeju National UniversityJeju 63333Republic of Korea Research Group of Food Processing Korea Food Research InstituteWanju 55365Republic of Korea Department of Pharmoceutical Engineering Soonchunhyang UniversityAsan 31538Republic of Korea

The prevalence of obesity has increased and is a health concern *** to the concerns regarding synthetic anti-obesity treatments,nowadays natural products become a *** studies proved that there is a potential to use marine algae as anti-obesity ***,in this study,the lipid inhibitory effect of crude polysaccharide of amyloglucosidase-assisted hydrolysate from Sargassum thunbergii(STAc)and its fucoidan fractions(STAFs)on 3T3-L1 cells and high-fat diet(hFD)-induced obese mice were *** to the results,the STAF3,showed the highest xylose content and exhibited significant inhibitory effects on lipid accumulation by downregulating adipogenic and lipogenic proteins in 3T3-L1 ***,oral supplementation with STAc significantly declined gain in body weight and fat weight,and serum lipid contents in an hFD-induced obesity mouse *** and chemical characterizations demonstrated that puritied STAF3 has consistent surface morphology and small particle size,with similar structural characteristics as commercial ***,these results indicate that STAc and purified STAF3 from Sargassum thunbergia is a potent source to develop as ananti-obesity agents or functional food products to counter obesity.

关键词： Sargassum thunbergii Fucoidan Anti-obesity Anti-steatosis

Mathematical modeling and simulations of stress mitigation by coating polycrystalline particles in lithium-ion batteries

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 947-962页

作者： N.IQBAL J.chOI S.F.ShAh c.lee S.lee Department of Mechanical Roboticsand Energy EngineeringDongguk University-SeoulSeoul 04620Republic of Korea

A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyco_(z)O_(2)(x≥0.8)(NMc)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary NMc particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more ***,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress *** paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMc active particles mitigates stress levels.

关键词： lithium-ion battery(LIB) polycrystalline particle coating finite element simulation Ni-rich LiNixMnyco_(z)O_(2)(x>0.8)(NMc)

Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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Journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： h.T.Jeong S.W.lee W.J.Kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the Bccβphase and a small amount of the hcPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

Rationale and design of Tenecteplase Reperfusion Therapy in Acute Ischaemic cerebrovascular Events III (TRAcE III): a randomised, phase III, open- label, controlled trial

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Stroke & Vascular Neurology 2024年第1期9卷 82-89页

作者： Yunyun Xiong Bruce c V campbell Marc Fisher lee h Schwamm Mark Parsons hao Li Yuesong Pan Xia Meng Xingquan Zhao Yongjun Wang Neurology Beijing Tiantan HospitalBeijingChina china National clinical Research center for Neurological Diseases BeijingChina Department of Medicine and Neurology The University of MelbourneMelbourneVictoriaAustralia Neurology Beth Israel Deaconess Medical CenterBostonMassachusettsUSA Department of Neurology and comprehensive Stroke center Massachusetts General HospitalBostonMassachusettsUSA Department of Neurology University of New South Wales South Western Sydney Clinical SchoolLiverpoolNew South WalesAustralia

Background and purpose Recombinant human TNK tissue-type plasminogen activator(rhTNK-tPA)was not inferior to alteplase for ischaemic stroke within *** study aimed to investigate the efficacy and safety of rhTNK-tPA in patients who had an ischaemic stroke due to large vessel occlusion(LVO)of anterior circulation beyond *** and design Tenecteplase Reperfusion Therapy in Acute Ischaemic cerebrovascular Events-III(TRAcE III)is a multicentre,prospective,randomised,open-label,blind endpoint,controlled clinical *** who had an ischaemic stroke due to anterior circulation LVO(internal carotid artery,middle cerebral artery M1 and M2 segments)within 4.5–24hours from last known well(including wake-up stroke and no witness stroke)and with salvageable tissue(ischaemic core volumech ratio≥1.8 and mismatch volume≥15mL)based on cT perfusion or MRI perfusion-weighted imaging(PWI)were included and randomised to rhTNK-tPA 0.25mg/kg(single bolus)to a maximum of 25mg or standard medical ***,we will exclude patients who are intended for direct *** will be followed up for 90 *** outcomes Primary efficacy outcome is modified Rankin Scale(mRS)score≤1 at 90 *** efficacy outcomes include ordinal distribution of mRS at 90 days,major neurological improvement defined by a decrease≥8 points compared with the initial deficit or a score≤1 on the National Institutes of health Stroke Scale(NIhSS)at 72 hours,mRS score≤2 at 90 days,the rate of improvement on Tmax>6s at 24 hours and NIhSS score change from baseline at *** outcomes are symptomatic intracerebral haemorrhage within 36 hours and mortality at 90 *** TRAcE III will provide evidence for the efficacy and safety of rhTNK-tPA in patients who had an ischaemic strokes due to anterior circulation LVO beyond *** registration number NcT05141305.

关键词： Therapy random Rational

comparing the Effectiveness of coatings on carbide andcermet cutting Tool Inserts

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Journal of Materials Science & Technology 1995年第4期11卷 269-275页

作者： K.h. W.Seah M.Rahman and c.h.lee (Dept. of Mech. & Prod. Eng., National University of Singapore, 10 Kent Ridge crescent, Singapore 0511 T.N.Goh (Dept. of Ind. & Sys. Eng., National University of Singapore, 10 Kent Ridge crescent, Singapore 0511) National Univ of Singapore Singapore

A series of metal cutting experiments was performed on a cNc lathe to evaluate the performance of various coatings on different tool substrates. The workpiece material was plain medium carbon steel and the cutting tool materials were carbide and cermet inserts coated with various single as well as multilayer coatings. Machining was done under various cutting conditions of speed and feed-rate, and for various durations of cutting. The output parameters studied were the cutting forces (axial, radial and tangential), the surface roughness of the workpiece, as well as the tool wear (crater and flank wear). From these results, the performances of the various cutting inserts are evaluated and compared. Results show that cutting forces are significantly lower when using coated cermets than when using coated carbides although different coatings on the same substrate also result in different cutting forces. however, there is less difference in the surface roughness of the finished workpiece for the various coatings and substrates.

关键词： Tool comparing the Effectiveness of coatings on carbide andcermet cutting Tool Inserts