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Spontaneous dissection of proximal left main coronary artery in a healthy adolescent presenting with syncope:A case report

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World Journal of Clinical Cases 2022年第7期10卷 2341-2350页

作者： Sui-Feng Liu Ya-Nan Zhao Chun-Wen Jia tian-yi ma Shi-Da Cai Feng Gao Department of Cardiology Zhongshan HospitalXiamen UniversityXiamen 361000Fujian ProvinceChina

BACKGROUND Spontaneous coronary artery dissection(SCAD)is a frequent cause of acute coronary syndrome in young to middle-aged women with few or no traditional cardiovascular risk *** pain is the most frequently described presenting symptom,but syncope is extremely ***,we report on a 16-year-old girl who presented with an episode of syncope occurring during a *** significantly elevated troponin level,the diagnosis of the left main coronary artery SCAD with cardiogenic shock was *** SUMmaRY A 16-year-old girl presented with an episode of *** injury markers were *** showed a mildly reduced left ventricular ejection fraction(50%).Although initially stable,she later experienced recurrent chest pain accompanying precordial ST segment elevation with dynamic changes and developed cardiogenic shock,necessitating emergent *** angiography demonstrated almost total occlusion at the ostium and proximal segment of the left main trunk coronary artery(LMT).Intravascular ultrasound confirmed a false lumen with prominent dissection in the *** coronary intervention assisted by intra-aortic balloon pump was conducted in the LMT.A 3.5 mm×24 mm everolimus-eluting stent was deployed to the focal lesions of the LMT.A postprocedural electrocardiogram showed alleviation of the precordial ST-segment *** diagnosis of SCAD was *** echocardiography showed an improved left ventricular ejection fraction(57%).The patient was asymptomatic during the ***-up *** SCAD should always be considered in the differential diagnosis of acute coronary syndrome presentations in low-risk patients,regardless of age.

关键词： Spontaneous coronary artery dissection Intravascular ultrasound percutaneous coronary intervention Case report

Capturing metal clusters at the strong-interaction region to reverse Ostwald ripening

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Science China materials 2024年第4期67卷 1363-1364页

作者： Shuheng tian Ding ma Beijing National Laboratory for Molecular Sciences New Cornerstone Science LaboratoryCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

High-temperature interactions induce sintering of metal nanoparticles(NPs) on heterogeneous catalyst surfaces, leading to reduced surface area and active site loss through Ostwald ripening [1]. This irreversible deactivation necessitates costly catalyst replacement, notably impacting metals like copper in hydrogenation and reforming reactions [2].

关键词： catalyst reforming irreversible

Numerical investigation on characteristics of interfacial wave of liquid film in gas-liquid two-phase flow using OpenFOAM

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Chinese Journal of Aeronautics 2024年第2期37卷 233-248页

作者： Xiaoqi ma Yueshe WANG Jiaming tian State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049China

Liquid film cooling as an advanced cooling technology is widely used in space *** operation of liquid film along the rocket combustion inner wall is crucial for thermal protection of rocket *** stability of liquid film is mainly determined by the characteristics of interfacial wave,which is rarely investigated right *** to improve the stability of thin film has become a hot *** view of this,an advanced model based on the conventional Volume of Fluid(VOF)model is adopted to investigate the characteristics of interfacial wave in gas-liquid flow by using OpenFOAM,and the mechanism of formation and development of wave is revealed intuitively through numerical *** effects from gas velocity,surface tension and dynamic viscosity of liquid(three factors)on the wave are studied *** can be found that the gas velocity is critical to the formation and development of wave,and four modes of droplets generation are illustrated in this ***,a gas vortex near the gas-liquid interface can induce formation of wave easily,so changing the gas vortex state can regulate formation and development of ***’s more,the change rules of three factors influencing on the interfacial wave are obtained,and the surface tension has a negative effect on the formation and development of wave only when the surface tension coefficient is above the critical value,whereas the dynamic viscosity has a positive effect in this ***,the maximum height and maximum slope angle of wave will level off as the gas velocity ***,the maximum slope angle of wave is usually no more than 38°,no matter what happens to the three factors.

关键词： Interfacial wave Gas-liquid Two-phase flow VOF model OpenFOAM

An Experimental Study on the Effect of a Nanofluid on Oil-Water Relative Permeability

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Fluid Dynamics & materials Processing 2024年第6期20卷 1265-1277页

作者： Hui tian Dandan Zhao Yannan Wu Xingyu yi Jun ma Xiang Zhou Baikouquan Oil Production Plant PetroChina Xinjiang Oilfield CompanyKaramay834000China Research Institute of Petroleum Exploration Development PetroChina Liaohe OilfieldPanjin124010China Petroleum Engineering School Southwest Petroleum UniversityChengdu610500China Oil and Gas Development Haosheng Xincheng Energy TechnologyLtd.of SicuanChengdu610213China

The low porosity and low permeability of tight oil reservoirs call for improvements in the current technologies for oil *** chemical solutions with large molecular size cannot effectively flow through the nanopores of the *** this study,the feasibility of Nanofluids has been investigated using a high pressure high temperature core-holder and nuclear magnetic resonance(NMR).The results of the experiments indicate that the specified Nanofluids can enhance the tight oil recovery *** water and oil relative permeability curve shifts to the high water saturation side after Nanofluid flooding,thereby demonstrating an increase in the water wettability of the *** the Nanofluid flooding process the oil recovery was enhanced by 15.1%,compared to waterflooding *** T2 spectra using the NMR show that after Nanofluid flooding,a 7.18%increment in oil recovery factor was gained in the small pores,a 4.9%increase in the middle pores,and a 0.29%increase in the large *** results confirm that the Nanofluids can improve the flow state in micro-sized pores inside the core and increase the ultimate oil recovery factor.

关键词： Tight oil reservoir nanofluid relative permeability nuclear magnetic resonance T2 spectrum

Hydration lubrication modulated by water structure at TiO2–aqueous interfaces

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Friction 2024年第4期12卷 591-605页

作者： Pingsu ma Yuan LIU Ke HAN Yu tian Liran ma State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China

The nature of solid-liquid interfaces is of great significance in *** advances have been made in lubrication based on hydration ***,a detailed molecular-level understanding is still ***,we investigated water molecule behaviors at the TiO2-aqueous interfaces by the sum-frequency generation vibrational spectroscopy(SFG-VS)and atomic force microscope(AFM)to elucidate the fundamental role of solid-liquid interfaces in *** contributions of water structures and hydration effects were revealed,where water structures played the dominant role in lubrication for TiO2 surfaces of varying hydrophilicity,while hydration effects dominated with the increasing of ion *** lubrication is observed on the initial TiO2 surfaces with strongly H-bonded water molecules compared to the hydrophilic TiO2 surfaces with more disordered *** stable ordered water arrangement with strong hydrogen bonds and the shear plane occurring between the ordered water layer and subsequent water layer may play a significant role in achieving lower *** adsorbed hydrated molecules with the increasing ionic concentration perturb ordered water but lead to the enhancement of hydration effects,which is the main reason for the improved lubrication for both *** work provides more insights into the detailed molecular-level understanding of the mechanism of hydration lubrication.

关键词： hydration lubrication interfacial water structures hydration effects titanium dioxide(TiO2)

Ore Geology,H-O-C Isotopes and 40Ar-39Ar Dating of the Wutonggou Iron Deposit,Eastern tianshan,NW China:Implications for the Source,Timing,and Genesis of Hydrothermal Mineralization in a Sedimentary Iron Deposit

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Journal of Earth Science 2024年第4期35卷 1170-1185页

作者： Chun-Long Wang yi-tian Wang State Key Laboratory of Geological Processes and Mineral Resources Collaborative Innovation Center for Exploration of Strategic Mineral ResourcesSchool of Earth ResourcesChina University of GeosciencesWuhan430074China MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing100037China

The Wutonggou iron deposit is located in the well-known iron metallogenic belt in the eastern tianshan,NW China,and has been regarded as a sedimentary iron *** hydrothermal overprinting could play indispensable roles in the formation of high-grade iron ores in sedimentary iron deposits,previous studies mainly focused on sedimentary-related iron mineralization,while the nature and contribution of hydrothermal fluids are poorly ***,an integrated study of ore geology,H-O-C isotopes and^(40)Ar-^(39)Ar dating,is conducted on the Wutonggou deposit,in order to reveal the features,source,and timing of hydrothermal *** studied deposit includes two mining sections namely the Jianshan and ***δ^(18)O values of early magnetite from the Jianshan section range from+3.0‰to+5.8‰that nearly consistent with classic magmatic magnetite,while increase to 6.3‰-8.0‰in the late *** from the two sections shows comparable H-O isotopic compositions and identical fractionation trends,and is plotted in or periphery to the primary magmatic water *** from the two sections are broadly similar in carbon and oxygen isotopic compositions,and siderite from the Wutonggou section is plotted in the same ***,comparable stable isotopic compositions and evolution trends indicate similar magmatic fluids contributed hydrothermal iron mineralization in the two mining ***,water-rock interactions of varying degrees generated distinct mineralization styles in the Jianshan and Wutonggou sections,and caused the isotopic fractionation in late *** extracted from a hydrothermal siderite ore yielded a^(40)Ar-^(39)Ar plateau age of 299.5±2.0 ma,indicates the timing of hydrothermal iron mineralization is corresponding to the emplacement of vicinity *** together,the hydrothermal mineralization in the Wutonggou iron deposit was the product of remobilization and upgrading of early sedimentary iron ores,a

关键词： iron deposits H-O-C isotopes 40Ar-39Ar dating sedimentary iron deposits Wutonggou iron deposit eastern tianshan

Photoinduced superlubricity on TiO_(2) surfaces

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Friction 2024年第3期12卷 428-438页

作者： Ke HAN Liran ma Yu tian Jianbin LUO State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China Received:16 September 2022/Revised:28 October 2022/Accepted:27 December 2022The author(s)2022.

Superlubricity control is of great interest in both industry and scientific research,and several methods have been proposed to achieve this *** this work,ultraviolet(UV)light was introduced into titanium dioxide(TiO_(2))and silicon nitride(Si_(3)N_(4))tribosystems to accomplish photoinduced *** friction coefficients(COFs)between Si_(3)N_(4) balls and TiO_(2) plates in the mixtures of sulfuric acid(H^(2)SO_(4))solution and glycerol solution were obviously reduced,and the system entered the superlubricity region(COFmation of silica(SiO_(2))layers on the surfaces of Si_(3)N_(4) balls and the elastohydrodynamic effects were determined to be fundamental to the low friction in this experiment,and the enhancement of the combination between the TiO_(2) surface and the hydroxy group of glycerol by UV illumination was the key to the photoinduced superlubricity in this *** findings showed one method for achieving superlubricity by introducing a light field that could be further applied to special working conditions.

关键词： light control friction superlubricity glycerol titanium dioxide(TiO_(2))

Photo-induced grease/oil switched lubricant for friction regulation

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Friction 2024年第8期12卷 1696-1706页

作者： Zheng ZHANG Shuangxi TANG Liran ma Yu tian State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China

Controllable friction regulation has drawn much interest in both scientific and industrial *** there have been many researches on friction regulation by many physical fields and chemical ***-sensitive materials are promising because it is relatively easy to change their properties compared with ***,a new kind of photo-induced grease/oil switched lubricant is designed and shows great reversibility under ultraviolet(UV)and visible(Vis)*** viscosity can change more than 50 times under different irradiation,and the coefficients of friction(COFs)obviously increase under Vis irradiation and decrease under UV irradiation,which performs better than those of the common *** to the experimental results,the phenomena are contributed to the break and reconstruction of the three-dimensional network inside the *** a switchable grease/oil state under different irradiation,this work provides a new principle for designing a smart lubricant with controllable friction regulation.

关键词： photo-induced spiropyran switched lubricant friction regulation

Growth,optical dispersion and magnetic behavior of Dy^(3+) doped yttrium iron garnet crystals

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Journal of Rare Earths 2024年第6期42卷 1110-1117,I0004页

作者： Yating Fang Hui Shen Yudie ma Shijie Liao Shuang Xia tian tian Ding Zhou Yunfeng ma Jiayue Xu Institute of Crystal Growth School of Materials Science and EngineeringShanghai Institute of Technology National Engineering Center of Electromagnetic Radiation Control materials School of Electronic Science and EngineeringUniversity of Electronic Science and Technology of China

Y_(3)Fe_(5)O_(12)(yiG)crystals are highly desirable for the fabrication of mid-infrared isolators with the rapid growth of optical communications,although it is rather challenging to grow large size and high-quality single ***^(3+)doping is expected to improve the optical and magneto-optical prope ***,high quality Dy:yiG crystals and the adjustment of Dy^(3+)on the structure and optical behavior of yiG crystal remain unclear,impeding its practical ***,a series of Y_(3-x)Dy_(x)Fe_(5)O_(12)(x=0,0.5,1.0,1.5,3)solid solution crystals was grown by the flux-Bridgman method and single crystals up to 25 mm were *** the introduction of Dy^(3+),lattice parameters are gradually enlarged from 1.2379 nm(yiG)to 1.2420 nm(DyiG).Typical Dy^(3+)absorption peaks are observed around 1070,1265 and 1670 *** refractive index decreases from 2.37(500 nm)to 2.10(2500 nm)for yiG crystal,and it reduces from 2.47(500 nm)to 2.16(2500 nm)for DyiG *** optical bandgaps remain almost unchanged for Dy:yiG *** optical dispersion of the refractive indices was finely fitted by the Wemple and DiDomenico(WDD)and the Sellmeier models,*** the increase of Dy^(3+)content,the saturation magnetization(Ms)decreases significantly from 23.62 emu/g(yiG)to 5.33 emu/g(DyiG).Small coercive field is persisted for this system,endowing small external magnetic *** results provide valuable references for the manipulation of rare earths on the properties of magnetooptical crystals,which is beneficial to the design of high-performance garnet crystals for the application of optical switching and non-reciprocal related devices.

关键词： magneto-optical crystal Yttrium iron garnet Dy^(3+)doping Crystal growth Optical dispersion Rare earths