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Investigation on subsurface vortices within a closed pump intake under different pressure conditions

Journal of Hydrodynamics 2020年第5期32卷 914-928页

作者： miao Guo Xue-lin Tang Xiao-qin.Li Fu-jun Wang Xiao-yan Shi College of Water Resources and Civil Engineering China Agricultural UniversityBeijing 100083China Beijing Engineering Research Centre of Safety and Energy Saving Technology for Water Supply Network System China Agricultural UniversityBeijing 100083China

An experimental study to investigate various features of subsurface vortices and their evolutions inside a closed pump intake under different pressure conditions at free surface,and to analyze the influence of a pipe bell with different mean axial velocities at the same water level on flow patterns is *** all cases,three different flow regimes are closely observed:various side-wall attached,back-wall attached and submerged vortices structures,and their evolutions are subject to the free-surface pressure for a critical flow rate,the number and strength of all these vortex rise as the absolute value of the pressure increases for a higher flow rate,for a lower flow rate,whether the side-wall vortices occur or not is related closely to the pressure magnitude,and there are no vortices for lower absolute pressure values,the number and the strength of the side-wall vortices increase as the absolute pressure values ***,based on statistical analyses,the side-wall vortex probability on the right side along the stream-wise direction is much higher than that on the opposite side for all operation cases,particularly single vortex probability,and the back-wall vortex probabilities are quite higher with values of more than 90%,meanwhile,the multi-vortices probability is much higher than that of the *** captured vortices have been qualitatively classified into different“vortex zones”:no vortex zones and vortex zones including transition,single-and *** Reynolds number and the absolute value pressure are the most important parameters which influence the existence and the number of these vortices,and the increase of the two parameters reduces the no vortex transition zone and causes bigger difference in the back-wall and side-wall vortex zones.

关键词： Evolution of subsurface vortices particle-image velocimetry(PIV) vortex probability closed pump intake

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THE OPTIMAL MOTION OF TWO-DIMENSIONAL UNDULATING PLATE SWIMMING IN FLUID FLOW

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Journal of Hydrodynamics 2011年第1期23卷 12-20页

作者： QIAN qin.jian LIU miao-qin.SUN Liang SUN De-jun Department of Modern Mechanics University of Science and Technology of China Hefei 230026 China School of Earth Sciences University of Science and Technology of China Hefei 230026 China

The optimum shape of a two-dimensional undulatory plate in its motion in fluid flow is analyzed and the physical parameters（the thrust and the power）are calculated by the boundary element *** the commonly used Lagrange multiplier method,only a saddle point of the optimum solution can be obtained,but not the solution itself due to the singularity of the *** eliminate the singularity,a method is proposed by adding an amplitude *** new method is a generalization of that proposed by Wu,and it can be applied to more complex *** optimum shape of the linearly varying amplitude motion is studied in *** is shown that both the maximum and the minimum solutions exist when the frequency is higher than a critical *** a high frequency,the maximum efficient motion with a large amplitude at the leading edge and a small amplitude at the trailing edge induces a large leading edge suction *** the frequency decreases,the leading edge suction force decreases to a minimum and then *** high wavenumbers,there exists an optimum frequency with the maximum *** efficiency holds over a large range of *** optimum efficiency increases as the wavenumber *** increase of the wavenumber can also reduce the leading edge suction *** optimization method can also be applied to a quadratically varying amplitude *** is found that the optimum efficiency is larger than that for the linearly varying amplitude ***,the additional efficiency is relatively small,especially as the original efficiency is already high enough.

关键词： two-dimensional undulating plate boundary element method optimization

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Effect of Ni on the corrosion resistance of bridge steel in a simulated hot and humid coastal-industrial atmosphere

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International Journal of Minerals,Metallurgy and Materials 2018年第3期25卷 325-338页

作者： Dong-liang Li Gui-qin.Fu miao-yong Zhu qin. Li Cheng-xiang Yin School of Metallurgy Northeastern University

The corrosion resistance of weathering bridge steels containing conventional contents of Ni(0.20 wt%, 0.42 wt%, 1.50 wt%) and a higher content of Ni(3.55 wt%) in a simulated hot and humid coastal-industrial atmosphere was investigated by corrosion depth loss, scanning electron microscopy–energy-dispersive X-ray spectroscopy, Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical methods. The results showed that, with increasing Ni content, the mechanical properties of the bridge steel were markedly improved, the welding parameters were satisfactory at room temperature, and the corrosion resistance was enhanced. When the Ni content was low(≤0.42 wt%), the crystallization process of the corrosion products was substantially promoted, enhancing the stability of the rust layer. When the Ni content was higher(~3.55 wt%), the corrosion reaction of the steel quickly reached a balance, because the initial rapid corrosion induced the formation of a protective rust layer in the early stage. Simultaneously, NiO and NiFe_2O_4 were generated in large quantities; they not only formed a stable, compact, and continuous oxide protective layer, but also strongly inhibited the transformation process of the corrosion products. This inhibition reduced the structural changes in the rust layer, thereby enhancing the protection. However, when the Ni content ranged from 0.42 wt% to 1.50 wt%, the corrosion resistance of the bridge steel increased only slightly.

关键词： bridge steel atmospheric corrosion corrosion resistance nickel rust anti-corrosion mechanism

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Lubrication Performance of Connecting-Rod and Main Bearing in Di erent Engine Operating Conditions

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Chinese Journal of Mechanical Engineering 2019年第2期32卷 81-92页

作者： Jun Sun Biao Li Shaoyu Zhu Enming miao Hu Wang Xiaoyong Zhao qin.Teng School of Automotive and Transportation Engineering Hefei University of Technology School of Mechanical Engineering Hefei University of Technology School of Instrument Science and Opto-electronics Engineering Hefei University of Technology

Only the lubrication performance at rated engine operating condition was generally analyzed in current design and research of engine connecting-rod and main bearing. However, the actual engine(especially vehicle engine) does not always operate in rated operating condition and its operating condition changes constantly. In this paper, a fourstroke four-cylinder engine is taken as the studying object, the load and lubrication of connecting-rod and main bearing in di erent operating conditions are analyzed. The load of connecting-rod bearing is calculated by the dynamic calculation method, the loads of all main bearings are calculated by the whole crankshaft beam-element finite element method, and the lubrication performance of connecting-rod and main bearings are analyzed by the dynamic method. The results show that there are major di erences in the changes and numerical value at corresponding moment of the loads and lubrication performance of connecting-rod and main bearings in an engine operating cycle in di erent engine operating conditions; the most unfavorable case of the lubrication performance of connectingrod and main bearings may not take place in the rated engine operating condition. There are also major di erences between the lubrication performance of connecting-rod bearing and that of main bearing and between the lubrication performances of main bearings one another. Therefore, it will not be reasonable that the lubrication performance of a certain connecting-rod bearing or main bearing is analyzed in the design of the engine bearing. It is necessary to analyze simultaneously the lubrication performances of all bearings in di erent engine operating conditions.

关键词： Lubrication Connecting-rod bearing Main bearing Engine Operating condition

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Factors influencing oil recovery by surfactant-polymer flooding in conglomerate reservoirs and its quantitative calculation method

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Petroleum Science 2022年第3期19卷 1198-1210页

作者： Feng-Qi Tan Chun-miao Ma Jian-Hua qin.Xian-Kun Li Wen-Tao Liu College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing100049China Key Laboratory Computational Geodynamics Chinese Academy of SciencesBeijing100049China Xinjiang Oilfield Company PetroChinaKaramayXinjiang834000China

This study aims to clarify the factors influencing oil recovery of surfactant-polymer(SP)flooding and to establish a quantitative calculation model of oil recovery during different displacement stages from water flooding to SP *** conglomerate reservoir of the Badaowan Formation in the seventh block of the Karamay Oilfield is selected as the research object to reveal the start-up mechanism of residual oil and determine the controlling factors of oil recovery through SP flooding experiments of natural cores and microetching *** experimental results are used to identify four types of residual oil after water flooding in this conglomerate reservoir with a complex pore structure:oil droplets retained in pore throats by capillary forces,oil cluster trapped at the junction of pores and throats,oil film on the rock surface,isolated oil in dead-ends of flow *** the four types of residual oil identified,the SP solution can enhance oil recovery by enlarging the sweep volume and improving the oil displacement ***,the viscosity-increasing effect of the polymer can effectively reduce the permeability of the displacement liquid phase,change the oil-water mobility ratio,and increase the water ***,the stronger the shear drag force of the SP solution,the more the crude oil in a porous medium is ***,the surfactant can change the rock wettability and reduce the absorption capacity of residual oil by lowering interfacial *** the same time,the emulsification further increases the viscosity of the SP solution,and the residual oil is recovered effectively under the combined effect of the above two *** the four start-up mechanisms of residual oil identified after water flooding,enlarging the sweep volume and improving the oil displacement efficiency are interdependent,but their contribution to enhanced oil recovery are *** SP flooding system primarily enlarges the sweep volume by increasing viscos

关键词： Conglomerate reservoir Water flooding Surfactant-polymer flooding Residual oil type Influencing factor Enhanced oil recovery Computational model

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Evolution of the Rust Layers Formed on Carbon and Weathering Steels in Environment Containing Chloride Ions

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Acta Metallurgica Sinica(English Letters) 2016年第11期29卷 1025-1036页

作者： Xin-Liang Gao Yi Han Gui-qin.Fu miao-Yong Zhu Xing-Zhong Zhang National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan University School of Metallurgy Northeastern University

To clarify the correlation between alloy elements and growth pattern of the rust layers, the rusting evolution of the carbon and weathering steels was investigated by using the gold markers method. The corrosion experiments were carried out in a simulated environment containing chloride ions. The results indicate that Ni, Cu, Cr and Mo elements in the weathering steel suppress the rust crystallization and impede the rust layer growth to an internal development, and the suppression function benefits the formation of a protective rust layer. Moreover, c-FeOOH is mainly located in the outer rust layer, while b-FeOOH is mainly located in the inner rust layer, and the distribution of the rust compounds in the rust layer is closely related to the growth pattern of the rust layer.

关键词： Atmospheric corrosion Steel Rust layer SEM Chloride ions

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Molecular Characterization and Expression Analysis of S1 self-incompatibility Locus-linked Pollen 3.15 Gene in Citrus reticulata

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Journal of Integrative Plant Biology 2013年第5期55卷 443-452页

作者： Hong Xia miao Zi Xing Ye Yong Hua qin.Gui Bing Hu College of Horticulture South China Agricultural University State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources South China Agricultural University Key Laboratory of Biology and Genetic Improvement of Horticultural Crops-South China Ministry of Agriculture

Gametophytic self-incompatibility （GSI） is controlled by a highly polymorphic locus called the S-locus, which is an important factor that can result in seedless fruit in Citrus. The S 1 self-incompatibility locus-linked pollen 3.15 gene （S1-3.15） belongs to a type of S locus gene. The role of S1-3.15 in the SI reaction of Citrus has not yet been reported. In this study, full-length sequences of cDNA and DNA encoding the S1-3.15 gene, referred to as CrS1-3.15 , were isolated from ‘Wuzishatangju’ （Self-incompatibility, SI） and ‘Shatangju’ （Self-compatibility, SC） . The predicted amino acid sequences of CrS1-3.15 between ‘Wuzishatangju’ and ‘Shatangju’ differ by only three amino acids. Compared to ‘Wuzishatangju’, three bases were substituted in the genomic DNA of CrS1-3.15 from ‘Shatangju’. Southern blot results showed that one copy of CrS1-3.15 existed in the genomic DNA of both ‘Wuzishatangju’ and ‘Shatangju’. The expression level of the CrS1-3.15 gene in the ovaries of ‘Shatangju’ was approximately 60-fold higher than that in the ovaries of ‘Wuzishatangju’. When ‘Wuzishatangju’ was cross-pollinated, the expression of CrS1-3.15 was upregulated in the ovaries at 3d, and the highest expression levels were detected in the ovaries at 6d after cross-pollination of ‘Wuzishatangju’ × ‘Shatangju’. To obtain the CrS1-3.15 protein, the full-length cDNA of CrS1-3.15 genes from ‘Wuzishatangju’ and ‘Shatangju’ was successfully expressed in Pichia pastoris. Pollen germination frequency of ‘Wuzishatangju’ was inhibited significantly with increasing CrS1-3.15 protein concentrations from SI ‘Wuzishatangju’.

关键词： Citrus reticulata expression analysis pollen germination S1 self-incompatibility locus-linked pollen 3.15 gene self-compatibility self-incompatibility.

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pH Readout enhanced ELISA for point-of-care testing of cardiac troponin I

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Chinese Chemical Letters 2017年第9期28卷 1878-1880页

作者： Luyang miao Lianhua Zhang Lei Jiao Xiaofeng Tan qin.Wei He Li School of Chemistry and Chemical Engineering University of Jinan Department of Urology Renji HospitalSchool of MedicineShanghai Jiao Tong University

Enzyme-linked immunosorbent assay（ELISA） as a conventional method for protein quantification has its characteristic properties,however,it is challenging to implement excellent portability and sensitivity at the same *** this study,we described a pH ELISA using synthetic melanin nanoparticles（SMNPs） for the co-immobilization of glucose oxidase（GOx） and second antibody（Ab_2） as signal labels,portable pH meter as signal readout device for point-of-care testing（POCT） of cardiac troponin I（cTnI）.In accordance with the varying amount of cTnI,following sandwich type immunoassay,proportional SMNPs-GOx-Ab_2 were immobilized specifically resulting in corresponding decrease of pH values owing to GOx loaded on SMNPs can high-efficiency convert glucose into gluconic *** assay is easy-to-use,portable,sensitive and able to realize POCT,affording a linear range from 0.5 pg/m L to 10 ng/m L and low limit of detection（LOD） of 0.15 pg/m L towards cTnI,which was demonstrated the significant promising in the early diagnosis and screening of acute myocardial infarction.

关键词： pH meter Synthetic melanin nanoparticles Polydopamine nanospheres Biomarker Immunosensor

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Prediction on Phase Stabilities of the Zr-H System from the First-Principles

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Acta Metallurgica Sinica(English Letters) 2021年第4期34卷 514-522页

作者： miao Chen Wu qin.Yixuan Hu Yiren Wang Yong Jiang Xiaosong Zhou Shuming Peng Yibei Fu Institute of Nuclear Physics and Chemistry China Academy of Engineering PhysicsMianyang621999China State Key Laboratory for Powder Metallurgy School of Materials Science and EngineeringCentral South UniversityChangsha410083China

Basic fundamentals governing the hydrogenation of Zr and its alloys have both theoretical and practical *** this work,first-principles calculations have been performed to evaluate the relative stabilities of various possible phases in ZrH_(x)(x=1-2)under different temperatures and *** was predicted that fct-γandεphases with various different H-atom configurations can be energetically favorable for ZrH_(x)(x=1,1.25 and 1.5),while ZrH_(1.75) and ZrH_(2) prefer fct-ε phase ***-δ phase is less favored in energy at any H concentrations,but can be mechanically stable in some *** thermodynamically stable and metastable phase stability diagrams were then constructed for a wide temperature and H concentration range,to predict the environment-dependent formation of ZrH_(x) during hydrogenation.

关键词： Zr-H Hydrogenation Hydride Phase stability First-principles

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Enhanced stability and efficacy of GEM-TOS prodrug by co-assembly with antimetastatic shell LMWH-TOS

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Acta Pharmaceutica Sinica B 2020年第10期10卷 1977-1988页

作者： Rong Guoy Yang Longy Zhengze Lu miao Deng Penghui He Man Li qin.He Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry West China School of PharmacySichuan UniversityChengdu 610064China

Chemotherapy agents have been widely used for cancer treatment,while the insolubility,instability and toxicity seriously restrict their ***,prodrug strategy was *** some prodrugs are still with poor solubility or stability,a synergy strategy is needed to enhance their ***(GEM)is a prescribed anticancer drug,however,the rapid clearance,growing resistance and serious side effects limit its clinical *** GEM with D-a-tocopherol succinate(TOS)is an effective solution,while the GEM-TOS(GT)is unstable in aqueous solution.D-a-Tocopherol polyethylene glycol succinate(TPGS)has been used to enhance the stability,but GT stabilized by TPGS(GTT)has limited effect on tumor *** metastases lead to high mortality in patients suffering from *** order to further achieve antimetastatic effect,an amphiphilic polymer(LT)was synthesized by connecting low-molecular-weight heparin(LMWH)with TOS,and eventually obtained desired selfdelivery micellar NPs(GLT)by co-assembly GT with *** GLT not only possessed excellent stability,but also inhibited the metastases by acting on different phases of the metastatic *** hydrophobic TOS inhibited the secretion of matrix metalloproteinase-9(MMP-9),the hydrophilic LMWH inhibited the interaction between tumor cells and *** a result,GLT reduced tumor cells entering the blood and implanting at the distant organs,leading to a much more excellent inhibitory effect on the lung metastasis than GEM and GTT.

关键词： Gemcitabine TOS LMWH Tumor metastasis MMP-9

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