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Journal of Computational Mathematics 2018年第3期36卷 441-458页

作者： ying cui Defeng Sun The Daniel J. Epstein Department of Industrial and Systems Engineering University of Southern California Los Angeles California USA Department of Applied Mathematics The Hong Kong Polytechnic University Hung Hom Hong Kong

In this paper, we provide a complete characterization of the robust isolated calmness of the Karush-Kuhn-Tucker （KKT） solution mapping for convex constrained optimization problems regularized by the nuclear norm function. This study is motivated by the recent work in [8], where the authors show that under the Robinson constraint qualification at a local optimal solution, the KKT solution mapping for a wide class of conic programming problems is robustly isolated calm if and only if both the second order sufficient condition （SOSC） and the strict Robinson constraint qualification （SRCQ） are satisfied. Based on the variational properties of the nuclear norm function and its conjugate, we establish the equivalence between the primal/dual SOSC and the dual/primal SRCQ. The derived results lead to several equivalent characterizations of the robust isolated calmness of the KKT solution mapping and add insights to the existing literature on the stability of nuclear norm regularized convex optimization problems.

关键词： Robust isolated calmness Nuclear norm Second order sufficient condition Strict Robinson constraint qualification

Carbon cycle variability in tropical Atlantic across two Early Eocene hyperthermals

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Geoscience Frontiers 2021年第2期12卷 521-530页

作者： Shijun Jiang ying cui Yasu Wang Institute of Groundwater and Earth Sciences Jinan UniversityGuangzhou510632China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai519082China Department of Earth and Environmental Studies Montclair State UniversityMontclairNJ07043USA

Early Eocene hyperthermals are geologically short-lived global warming events and represent fundamental perturbations to the global carbon cycle and the Earth’s ecosystem due to massive additions of isotopically light carbon to the ocean-atmosphere *** serve as ancient analogs for understanding how the oceanic carbonate system and surface-ocean ecosystem would respond to ongoing and future climate ***,we present a continuous carbonate record across the Eocene Thermal Maximum 2(ETM2 or H1,ca.54.1 Ma)and H2(ca.54 Ma)events from an expanded section at Ocean Drilling Program Site 1258 in tropical *** abundant calcareous nannofossils and moderate carbonate content throughout the studied interval suggest this record was deposited above the calcite compensation depth(CCD),but below the lysocline and under the influence of terrestrial *** Earth system model cGENIE is used to simulate the carbon cycle dynamics across the ETM2 and H2 to offer insights on the mechanism of the rapid warming and subsequent recovery in climate and *** model suggests moderate changes in ocean pH(0.1–0.2 unit)for the two scenarios,biogenic methane from a rechargeable methane capacitor and organic matter oxidation from thawing of the *** pH changes are consistent with a recent independent pH estimate across the ETM2 using boron *** carbon emission flux during the ETM2 is at least an order of magnitude smaller than that during the Paleocene–Eocene Thermal Maximum(PETM)(0.015–0.05 Pg C yr^(-1)vs.0.3–1.7 Pg C yr^(-1)).The comparable pre-and post-event carbonate contents suggest the lysocline did not over deepen following the ETM2 at this tropical Atlantic site,indicating spatial heterogeneity in the carbonate system due to strong dilution influence from terrestrial weathering and riverine discharge at Site 1258.

关键词： Early Eocene hyperthermals Oceanic carbonate system Stable carbon and oxygen isotopes Earth system modeling Tropical Atlantic cGENIE

Pneumatic Performance of Staggered Impulse Turbine for OWC Wave Energy Convertor

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Journal of Thermal Science 2015年第5期24卷 403-409页

作者： cui ying LIU Zhen Beom-Soo Hyun Department of Ocean Engineering College of Engineering Ocean University of China Division of Naval Architecture and Ocean Engineering Korea Maritime and Ocean University Shandong Provincial Key Laboratory of Ocean Engineering Ocean University of China Qingdao Municipal Key Laboratory of Ocean Renewable Energy Ocean University of China

A staggered impulse turbine is proposed for asymmetric air flows in Oscillating Water Column wave energy plants, which is expected to enhance the pneumatic power output in a wave cycle. The setting angle of rotor blades is set as 5°. The 3D numerical simulations were conducted under steady conditions using MRF and Mixing Plane model based on CFD software Fluent 12.0. Its mean efficiencies under different velocity amplitude ratios are studied using quasi-steady analysis, which derive corresponding data from the numerical simulation. It is found that the staggered turbine shows better performance than the conventional one under the asymmetrical air flows. Furthermore, its mean efficiency and output-work in a wave period are compared with another unsymmetrical twin impulse turbine system. The results show that the staggered turbine shows better output-work performance than the twin turbine system over the high flow coefficient domain(φ>0.7), which provides more choices to future research on turbine's optimization.

关键词： Wave Energy Oscillating Water Column Staggered Impulse Turbine Asymmetric Air Flows Nu-merical Simulation Quasi-steady Analysis

Numerical Study on Air Turbines with Enhanced Techniques for OWC Wave Energy Conversion

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China Ocean Engineering 2017年第5期31卷 517-527页

作者： cui ying HYUN Beom-Soo KIM Kilwon Department of Ocean Engineering College of EngineeringOcean University of China Division of Naval Architecture and Ocean Engineering Korea Maritime and Ocean University

In recent years,the oscillating water column(OWC) wave energy converter,which can capture wave energy from the ocean,has been widely applied all over the *** the essential part of the OWC system,the impulse and Wells turbines are capable of converting the low pressure pneumatic energy into the mechanical shaft *** an enhanced technique,the design of endplate or ring attached to the blade tip is investigated numerically in this paper.3 D numerical models based on a CFD-software FLUENT 12.0 are established and validated by the corresponding experimental results from the reports of Setoguchi et al.(2004) and Takao et al.(2001).Then the flow fields and non-dimensional evaluating coefficients are calculated and analyzed under steady *** show that the efficiency of impulse turbine with ring can reach up to 0.49 when Ф=1,which is 4% higher than that in the cases for the endplate-type and the original *** the ring-type Wells turbine with fixed guide vanes shows the best performance with the maximal efficiency of 0.55,which is 22% higher than that of the original *** addition,the quasi-steady analysis is used to calculate the mean efficiency and output-work of a wave cycle under sinusoidal flow *** all together,this study provides support for structural optimization of impulse turbine and Wells turbine in the future.

关键词： OWC impulse turbine Wells turbine CFD endplate ring quasi-steady analysis

Effects of Lead on the Initial Corrosion Behavior of 316LN Stainless Steel in High-Temperature Alkaline Solution

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Acta Metallurgica Sinica(English Letters) 2019年第1期32卷 89-97页

作者： Jia-Min Shao cui-Wei Du Xin Zhang Li-ying cui Corrosion and Protection Center University of Science and Technology Beijing Nuclear and Radiation Safety Center Ministry of Environmental Protection of P.R.China

The effect of lead on the initial corrosion behavior of 316 LN stainless steel has been investigated by U-bend immersion experiments in 4 wt% NaOH solutions at 300 °C. Follow-up studies after soaking were carried out by scanning electron microscope, energy dispersive X-ray spectrometer, X-ray photoelectron spectrometer, Auger electron spectroscopy and Raman spectroscopy. The results show that lead affects the properties of the oxide film by changing the thickness and composition, which leads to an increase in the sensitivity of stress corrosion cracking of 316 LN stainless steel. Pits and cracks appeared on the surface of 316 LN stainless steel under both lead-free and lead-containing conditions. The corrosion products were oxides of Fe, Cr and Ni, and the main spinel structure on the surface of the film was NiCr_2O_4 under both conditions. However, in the presence of lead, the cracks and pits were more obvious, the thickness of the film increased from 50 to 200 nm, and the amount of protective NiCr_2O_4 decreased. Lead was concluded to be involved in the dehydration reactions in the form of Pb(OH)_2, which affected the normal dehydration process of the hydroxides and inhibited the formation of spinel structures. Because of the above characteristics of lead, the stability of the oxide film and its protection of 316 LN stainless steel were reduced.

关键词： PbSCC Oxide film 316LN High temperature

Dynamic Modeling and Analysis of 9-DOF Omnidirectional Legged Vehicle

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Chinese Journal of Mechanical Engineering 2011年第4期24卷 515-521页

作者： GAO Feng WANG Guofu cui ying YANG Xinhong School of Transportation Science ＆ Engineering Beihang University Beijing 100191 China

The omnidirectional legged vehicle with steering-rails has a specific mechanism feature, and it can be controlled flexibly and accurately in omnidirectional motion. Currently there lacks further research in this area. In this paper, the mechanical characteristics of independent walking control and steering control and its kinematics principle are introduced, and a vehicle has a composite motion mode of parallel link mechanism and steering mechanism is presented. The motion direction control of the proposed vehicle is only dependant on its steering rails, so its motion is simple and effective to control. When the relative motion between the walking and steering is controlled cooperatively, the vehicle can walk perfectly. By controlling the steering rails, the vehicle can walk along arbitrary trajectory on the ground. To achieve a good result of motion control, an equivalent manipulator model needs to be built. In terms of the mechanism feature and the kinematic principle, the simplified manipulator model consists of a rail in stance phase, a rail in swing phase, and an equivalent leg. Considering the ground surface slope during walking, a parameter of inclination angle is added. Based on such a RPP manipulator model, the equations of motion are derived by means of Lagrangian dynamic approach. To verify the dynamic equations, the motion of the manipulator model is simulated based on linear and nonlinear motion planning. With the same model and motion parameters, the dynamic equations can be solved by Matlab and the calculation data can be gained. Compared with the simulation data, the result confirms the manipulator dynamic equations are correct. As a result of such special characteristics of the legged mechanism with steering rails, it has a potential broad application prospects. The derivation of dynamics equation could benefit the motion control of the mechanism.

关键词： legged vehicle omnidirectional motion steering rails dynamic modeling dynamic simulation

Lung Nodules Detection in CT Images Using Gestalt-Based Algorithm

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Chinese Journal of Electronics 2016年第4期25卷 711-718页

作者： QIU Shi WEN Desheng cui ying FENG Jun Xi'an Institute of Optics and Precision Mechanics of CAS University of Chinese Academy of Sciences College of Equipment Engineering Engineering University of Chinese Armed Police Force School of Information Science and Technology Northwest University

To overcome low accuracy and high false positive of existing computer-aided lung nodules *** propose a novel lung nodule detection scheme based on the Gestalt visual cognition *** proposed scheme involves two parts which simulate human eyes cognition features such as simplicity,integrity and ***,lung region was segmented from lung Computed tomography(CT) *** local threedimensional information was integrated into the Maximum intensity pro jection(MIP) images from axial,coronal and sagittal *** this way,lung nodules and vascular are strengthened and discriminated based on pathologic image characteristics of lung *** experimental database includes fifty-three high resolution CT images contained lung nodules,which had been confirmed by *** experimental results show that,the accuracy rate of the proposed algorithm achieves 91.29%.The proposed framework improves performance and computation speed for computer aided nodules detection.

关键词： Computer-aided detection(CAD) Lung nodules Maximum intensity pro jection(MIP)

Effects of Power Density and Post Annealing Process on the Microstructure and Wettability of TiO_2 Films Deposited by Mid-frequency Magnetron Reactive Sputtering

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Journal of Materials Science & Technology 2008年第2期24卷 172-178页

作者： ying cui Hao DU Jinquan XIAO Lishi WEN Division of Surface Engineering of Materials Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Graduate School of Chinese Academy of Sciences Beijing 100039 China

The relationship of ＂preparation parameters-microstructures-wettability＂ of TiO2 films was reported. In this work, TiO2 films were deposited onto glass and silicon substrates by using mid-frequency dual magnetron sputtering technique at ambient temperature with various power densities and deposition time. After deposition, the films were heat treated at different annealing temperatures. X-ray diffraction （XRD）, Raman spectroscopy, and field-emission scanning electron microscopy （FE-SEM） were utilized to characterize TiO2 films. The wettability of the films was evaluated by water contact angle measurement. The phase transition temperature of TiO2 films depended on the power density. It was demonstrated that wettability was strongly structure dependent and the film with the thickness of 610 nm （the power density was 2.22 W/cm^2） showed the lowest contact angle （8°）. It can be concluded that smaller crystallite size, the rutile phase with （110） face being parallel to the surface, and tensile stress favored the hydrophilicity of the TiO2 films.

关键词： Titanium dioxide Reactive magnetron sputtering Phase composition Microstructure Hydrophilicity

Modifying agent selection for Al-7Si alloy by Miedema model

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International Journal of Minerals,Metallurgy and Materials 2012年第2期19卷 131-135页

作者： Zhong-wei Chen cui-ying Ma Pei Chen State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China

To determine the modifying agents for Al-7Si alloys, microstructure observation and mixing enthalpy analysis using Miedema model for Al-7Si alloy with additions of different rare earth elements were performed, and the effects of rare earth elements on the modifica-tion of eutectic silicon morphology were investigated. The results of mixing enthalpy analysis show that these four rare earth elements, La, Sm, Pr, and Ce, which have the large negative mixing enthalpies with Si, can be selected as modifying agents for eutectic silicon morphology. The element with the largest negative mixing enthalpy is Ce. Furthermore, the microstructures indicate that these four elements can effec-tively modify the eutectic （α）Al-Si crystals in Al-7Si alloy, and the most effective one is also Ce. Differential scanning calorimetry （DSC） results show that the eutectic temperature depressions due to the additions of modifying agents are the important reasons for the modification of eutectic （α）Al-Si crystals.

关键词： aluminum alloys silicon alloys modifying agents rare earth elements microstructure enthalpy

Enhanced photocataly tic activity of TiO_2 by surface fluorination in degradation of organic cationic compound

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Journal of Environmental Sciences 2007年第1期19卷 86-89页

作者： YANG Shi-ying CHEN You-yuan ZHENG Jian-guo cui ying-jie Key Lab of Maline Environmental Science and Ecology Ministry of Education Ocean University of China Qingdao 266100 China College of Environmental Science and Engineering Ocean University of China Qingdao 266100 China

Experiments were carried out to investigate the influence of TiO2 surface fluorination on the photodegradation of a representative organic cationic compound, Methylene Blue （MB）. The eleetropositive MB shows poor adsorption on TiO2 surface; its degradation performs a HO. radical-mediated mechanism. In the F-modified system, the kinetic reaction rate enlarged more than 2.5 fold that was attributed mainly to the accumulating adsorption of MB and the increased photogenerated hole available on the F-modified TiO2 surface.

关键词： photocatalysis mechanism adsorption surface fluorination photogenerated hole Methylene Blue(MB)