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Effect of Supersonic Fine Particles Bombarding on the Service Life of Thermal Barrier Coating

Chinese Journal of Mechanical Engineering 2011年第5期24卷 911-916页

作者： LIN Xiaoping DONG yun wang Zhiping LIU Shiqiang ren Zhimin DING Kunying Department of Materials Science and Engineering Northeastern Universi（y at Qinhuangdao Qinhuangdao 066004 China College of Science Civil Aviation University of China Tianjin 300300 China School of Material Science and Engineering Hebei University of Technology Tianjin 300130 China

Thermally Grown Oxide（TGO） is a dominating component in controlling the effectiveness of thermal barrier *** the growth of TGO,whether we could homogeneously distribute Al atom on the TGO and the intermediate metal layer will be the key factor in forming TGO with continuous,uniform and single-ingredient（Al2O3）.In this experiment,we bombarded particles on to the metallic bound *** studied the influence of supersonic particle bombardment on the diffusion of *** hope to control the growth of TGO by monitoring the diffusion of *** barrier coating（TBC）,which consists of a NiCoCrAlY bond coat and a ZrO2-8Y2O3（wt.%） topcoat（TC）,is fabricated on the nickel-base superalloy by air plasma spray（APS）.NiCoCrAlY bond coat is treated by supersonic fine particles bombarding（SFPB）.The morphology,oxidation behavior of TBC and phase are characterized by scanning electron microscope（SEM） equipped with an energy dispersive spectromrter（EDS） and X-ray diffractometer（XRD）.The influence of supersonic fine particles bombarding technique on the service life of thermal barrier coating is *** results show that SFPB technique improves the flaw of excessive surface undulation in the as-sprayed bond coat.A continuous,uniform and single-ingredient（Al2O3） TGO can quickly form in the SFPB TBC during high temperature oxidation *** thickening of TGO is relatively *** will effectively suppress the formation of other non-protective ***,SFPB technique reduces the growth stress level generated by the continuous growth of TGO,and also avoids the stress concentration induced by formation of the large particle spinal *** barrier coating still remains well after 350 thermal *** service life of TBC is *** proposed research provides theoretical basis and technical references to further improve and enhance the SFPB technique.

关键词： thermal barrier coating stress concentration supersonic fine particles bombarding thermally grown oxide

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Stability and a fast calculation method of travel speed of pulse peak in convergence zone

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Science China(Physics,Mechanics & Astronomy) 2014年第7期57卷 1274-1282页

作者： ren yun ZHANG renHe wang Jun GUO YongGang Luo WenYu State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences

A long-range sound propagation experiment was conducted in the West Pacific Ocean in summer *** signals received by a towed array indicate that the travel speed of pulse peak(TSPP)in the convergence zones is ***,an equivalent sound speed can be used at all ranges in the convergence zones.A fast calculation method based on the beam-displace-ment ray-mode(BDRM)theory and convergence zone theory is proposed to calculate this equivalent sound *** computation speed of this proposed method is over 1000 times faster than that of the conventional calculation method based on the normal mode theory,with the computation error less than 0.4%compared with the experimental ***,the effect of frequency and sound speed profile on the TSPP is studied with the conventional and fast calculation methods,showing that the TSPP is almost independent of the frequency and sound speed profile in the ocean surface layer.

关键词： travel speed pulse peak pulse propagation BDRM theory turning point convergence zone

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Experimental investigation of combined vibrations for a hydrofoil-rod system at low Reynold numbers

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Journal of Hydrodynamics 2019年第3期31卷 512-521页

作者： ren-feng wang Ke Chen Francis Nobelesse yun-xiang You Wei Li State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Shanghai 200240 China Collaborative Innovation Center far Advanced Ship and Deep-Sea Exploration Shanghai 200240 China

A hydrodynamic tunnel experimental investigation and analysis of vibration characteristics for a hydrofoil in a transient regime is considered. Tests are performed for NACA 0017 models with a non-uniform section at an angle of attack AOA = 5° and Reynolds numbers up to Re = 7.0 x 106. This study is related to a project design of experiments in a complex facility that involves several parameters. The analysis focuses on the vibrations of a hydrofoil for different values of the bracing stiffness kh, the torsional stiffness ka, and the locations of the elastic axis a and of the center of gravity xa . The structural bracing response is investigated via measurements of the displacement of the free tip section of the hydrofoil using a three-axis acceleration sensor, and the torsional response of the structure is analyzed via measurements of displacements with single-axis acceleration sensors. The hydrofoil is made of reinforced plastics without flexibility, and elastic functions are performed by a spring support mechanism combined with a torsional structure. The study shows that an increase of the velocity results in different behaviors of the bracing and torsional amplitudes. Another notable result of the study is that the emergence of transition occurs simultaneously with additional peaks and changes of vibration amplitudes.

关键词： Vibrations lifting bodies transition laminar separation bubbles

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On exponential stability for systems with state delays

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第8期8卷 1296-1303页

作者： CHEN yun XUE An-ke GE Ming wang Jian-zhong LU ren-quan Institute of Operational Research and Cybernetics Hangzhou Dianzi University Hangzhou 310018 China National Laboratory of Industrial Control Technology. Zhejiang University Hangzhou 310027 China Institute of Information and Control Hangzhou Dianzi University. Hangzhou 310018 China

This paper considers the issue of delay-dependent exponential stability for time-delay systems. Both nominal and uncertain systems are investigated. New sufficient conditions in terms of linear matrix inequalities(LMIs) are obtained. These criteria are simple owing to the use of an integral inequality. The model transformation approaches,bounding techniques for cross terms and slack matrices are all avoided in the derivation. Rigorous proof and numerical examples showed that the proposed criteria and those based on introducing slack matrices are equivalent.

关键词： Exponential stability Uncertain time-delay systems Integral inequality Slack matrix Linear matrix inequality (LMI)

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Desorption–recombination behavior of as-disproportionated NdFeCoB compacts by reactive deformation

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Rare Metals 2015年第2期34卷 89-94页

作者： yun-Ping Yu Ying Liu Jun Li Qing Zheng ren-Quan wang School of Materials Science and Engineering Sichuan University

The disproportionated phases of Nd Hx, Fe2B,and a-Fe from Nd2Fe14B were applied to prepare Nd Fe B magnets by two different routes. The results show that the route of annealing in horizontal vacuum sintering furnace cannot reach the purpose of complete recombination after the hot pressing and hot deformation process due to the lack of dehydrogenation channel. The route of applying low pressure of 4–25 MPa on the as-disproportionated green compact during the desorption recombination process in situ hot deformation in a spark plasma sintering（SPS）system can obtain completely recombined Nd Fe B magnet with good anisotropy and magnetic properties. The maximum magnetic properties,（BH）max= 201 kJ m^-3,Br= 1.142 T and Hcj= 469 k A m^-1, are obtained after being treated for 15 min at 750 ℃ under low pressure.

关键词： NdFeB magnets Hydrogenation-disproportionation-desorption-recombination Hotdeformation Anisotropy

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Inhibitory effect of Houttuynia cordata Thunb on LPS-induced retinal microglial activation

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International Journal of Ophthalmology(English edition) 2019年第7期12卷 1095-1100页

作者： Ying-Hui Zhang Le-Meng ren Xiao-yun wang The Second Hospital of Shandong University Shandong UniversityJinan 250033 Shandong ProvinceChina The First Clinical Medical College Lanzhou UniversityLanzhou 730000 Gansu ProvinceChina

AIM: To identify the effect of Houttuynia cordata Thunb(HCT) on lipopolysaccharide(LPS)-induced microglial activation and investigate its possible molecular mechanisms. METHODS: The primary retinal microglial cells were cultured from the retinas of newborn Sprague-Dawley rats and exposed to LPS, and/or HCT with different concentrations. The survival ability of retinal microglia cells was tested by standard MTT method. BrdU cell proliferation assay was used to evaluate the proliferation of retinal microglia. Inflammatory factors in the culture supernatants, including TNF-α, iNOS and IL-1β, were measured using ELISA. Microglia cells’ migration was determined with Transwell migration assay. The total p38-MAPK and phosphorylation of p38-MAPK(p-p38-MAPK) were detected with Western ***: Primary retinal microglia in culture exposed to LPS to induce microglia activation. Pretreatment with HCT significantly inhibited the LPS-induced cell proliferation, but not the cell viability. LPS induced inflammatory reaction in microglia and cell migration. HCT significantly reduced LPS-stimulated release of pro-inflammatory factors and decreased the number of migrating cells substantially in a concentration-dependent manner. Moreover, the protein levels of p-p38 MAPK were identified as the up regulation and co-treatment with HCT obviously inhibited the upregulation of p-p38 MAPK, but had no effect on the levels of total ***: The data suggest that HCT inhibits LPSinduced retinal microglial activation via suppression of the p-p38-MAPK. HCT may be used for the treatment of ocular diseases characterized by over-activated microglia.

关键词： Houttuynia cordata Thunb microglia activation retina inhibitory effect

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Recent progress in upgrading metallurgical-grade silicon to solar-grade silicon via pyrometallurgical routes

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International Journal of Minerals,Metallurgy and Materials 2022年第4期29卷 767-782页

作者： yun Lei Xiaodong Ma Ye wang Zhiyuan Chen Yongsheng ren Wenhui Ma Kazuki Morita Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093China Sustainable Minerals Institute The University of QueenslandSt Lucia 4072QLDAustralia School of Chemical Engineering Sichuan UniversityChengdu 610065China Separation and Conversion Technology Flemish Institute for Technological ResearchMol 2400Belgium Department of Materials Engineering Graduate School of EngineeringThe University of TokyoTokyo 113-8656Japan

Si-based photovoltaic solar power has been rapidly developed as a renewable and green energy *** widespread use of Sibased solar cells requires large amounts of solar-grade Si(SoG-Si)to manufacture Si *** routes,mainly the modified Siemens process,have dominated the preparation of polycrystalline SoG-Si;however,traditional chemical techniques employ a series of complex chemical reactions involving various corrosive and hazardous *** addition,large amounts of complex waste solar cells and Si kerf slurry waste gradually accumulate and are difficult to recycle using these *** methods are required to meet the demand for SoGSi preparation and Si waste *** metallurgical route shows promise but is hindered by the problem of eliminating B and P from metallurgical-grade Si(MG-Si).Various pyrometallurgical treatments have been proposed to enhance the removal of B and P from *** article reviews Si refining with slag treatment,chlorination,vacuum evaporation,and solvent refining,and summarizes and discusses the basic principles and recent representative studies of the four *** these,solvent refining is the most promising and environmentally friendly approach for obtaining low-cost SoG-Si and is a popular research ***,a simple and green approach,i.e.,a combination of solvent refining,slag treatment,or vacuum directional solidification,is proposed for low-cost SoG-Si preparation using MG-Si or Si wastes as raw materials.

关键词： silicon refining solar-grade silicon solvent refining vacuum evaporation slag treatment Si kerf slurry waste

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Realization approach of Pd-only three-way catalysts with high catalytic performance and thermal stability

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Science China Chemistry 2015年第1期58卷 123-130页

作者： Yutao ren Qun Shen yun Guo Yanqin wang Yanglong Guo Xueqing Gong Guanzhong Lu Key Laboratory for Advanced Materials and Research Institute of Industrial Catalysis East China University of Science and Technology

Pd-only three-way catalyst （TWC）, Pd supported on washcoating （the mixture of alumina and Ce-Zr solid solution）/cordierite, was prepared and its catalytic performance and the operation window （2-value） at 450 ℃ were evaluated with the simulated automotive exhaust feed gas. Surfactants such as Tween-80 and Span-20 were added in the process of preparing the catalyst in order to improve the thermal stability and catalytic performance of Pd-only TWC. The fresh and aged catalysts at 1000 ℃ for 4 h were characterized by low-temperature N2 adsorption, XRD, XPS, and H2-TPR techniques. The results show that the presence of surfactants in the synthesis slurry could influence the physicochemical properties of the final Pd-only TWC. The FTS catalyst prepared with the mixed surfactant of Tween-80 and Span-20 exhibited excellent three-way catalytic performance. After being aged at 1000℃ for 4 h, the catalytic performances of Pd-only TWCs slightly decreased, but the FTS catalyst still demonstrated higher catalytic performance and better thermal stability compared with the Pd-only catalysts prepared with single surfactant or without any surfactant. And the FTS catalyst has a wider 2 value （operation window） than other catalysts, even after being aged at 1000℃.

关键词： three-way catalyst Pd-only catalyst catalyst preparation mixed surfactants high thermal stability

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Isometries on the Quasi-Banach Spaces L^p (0 < p <1)

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Acta Mathematica Sinica,English Series 2010年第8期26卷 1519-1524页

作者： Lei LI Wei yun ren School of Mathematical Sciences and LPMC Nankai University Tianjin 300071 P. R. China Department of Mathematics School of Sciences Tianjin University Tianjin 300072 P. R. China

We study the extension of isometries between the unit spheres of quasi-Banach spaces Lp for 0〈p〈1. We give some sufficient conditions such that an isometric mapping from the the unit sphere of Lp（μ） into that of ... 详细信息

关键词： Quasi-Banach spaces isometric mappings unit spheres

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Investigation of L/D-threonine substituted L-serine octamer ions by mass spectrometry and infrared photodissociation spectroscopy

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Chinese Chemical Letters 2017年第3期28卷 537-540页

作者： Juan ren Yi-yun wang Ru-Xia Fenga Xiang-Lei Kong The State Key Laboratory of Elemento-Organic Chemistry Nankai University Tianjin 300071 China Collaborative Innovation Center of Chemical Science and Engineering Nankai University Tianjin 300071 China

Threonine-substituted serine octamer ions were generated by electrospray ionization（ESI） and investigated by mass spectrometry and infrared photodissociation（IRPD） spectroscopy. IRPD spectra of[L-Ser_7＋ L/D-Thr_1]H~＋and [L-Ser_6＋ L/D-Thr_2]H~＋were obtained in the range of 2700–3600 cm^（-1）. Chiral differentiation was achieved by comparing their IRPD spectra. The main difference located in the range of 3300–3500 cm^（-1）. And the results indicate the substitution of L-Ser by D-Thr could weaken the intermolecular H-bonds and loosen the original structures of serine octamers.

关键词： IRPD spectroscopy Threonine Serine octamer Chiral differentiation Mass spectrometry

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