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Preparation Process and Mechanical Properties of PLA/PCL Intravascular Stent

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Journal of Donghua University(English Edition) 2014年第5期31卷 640-642页

作者： WANG Cong-er key Laboratory of Textile Science & Technology Ministry of Education Donghua University Shanghai 201620 China College of Textiles Donghua University Shanghai 201620 China

A hand-made biodegradable intravascular stent with zig- zag structure has been developed, which made from polylactic acid （ PLA ） braided thread and poly-eaprolactone （ PCL ） tube. This paper showed the preparation process of the PLA braded thread and stent, and discussed the heat setting process of the stents. The sixteen groups of stents were made for the heat setting experiments, discussing two factors on four levels. Radial compression behavior of stents was tested by plate compression method. The result showed that both the heat setting temperature and time had significant effects on stent compression strength. The compression recovery rate was mainly affected by heat setting temperature. The optimized heat setting condition should be 90-100℃ for 45 rain.

关键词： biodegradable intravascular stents polylactic acid(PLA) heat setting process compression properties

Meiofaunal Community Spatial Distribution and Diversity as Indicators of Ecological Quality in the Bohai Sea, China

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Journal of Ocean University of China 2021年第2期20卷 409-420页

作者： CUI Chunyan ZHANG Zhinan HUA er College of Marine Life Sciences Ocean University of ChinaQingdao 266100China

The Bohai Sea is a semi-enclosed marginal sea in the North West Pacific. Meiofauna samples were collected from 22 stations in the Bohai Sea to document the spatial distribution, structure, and diversity of the meiofaunal community and investigate the major factors influencing the community features. A total of 20 higher taxa of meiofauna were identified. The dominant group was Nematoda, accounting for 90.8% of the total meiofaunal abundance on average, followed by Copepoda, Bivalvia, Polychaeta, kinorhyncha, and Ostracoda. Meiofaunal abundance ranged from 121 ± 89 ind(10 cm2)-1 to 3042 ± 1054 ind(10 cm2)-1. Diversity indices also varied among different stations, with a Margalef's richness index(d) of 1.1–3.1, Shannon-Wiener diversity index(H′) of 0.7–1.8, and Pielou's evenness index(J′) of 0.4– 0.8. Meiofaunal abundance and diversity indices were significantly lower in the areas of Bohai Bay and adjacent to Laizhou Bay. The correlation analysis showed that meiofaunal abundance and diversity indices are closely linked to variations in sediment silt-clay content, medium grain size(MDΦ), and chlorophyll-a concentrations. The ecological quality status of most stations can be ranked from poor to moderate based on meiofaunal richness. According to the value of nematode to copepod ratio(Ne:Co ratio), most stations are uncontaminated, except seven stations are slightly or moderately contaminated. Both meiofaunal richness and Ne:Co ratio indicate the poor ecological quality of three stations adjacent to Laizhou Bay. The efficiency of the meiofauna communities as environmental indicators will be tested in a greater area in the future studies.

关键词： meiofauna spatial distribution biodiversity ecological quality the Bohai Sea

Recent innovation in benchmark rates (BMR):evidence from influential factors on Turkish Lira Overnight Reference Interest Rate with machine learning algorithms

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financial Innovation 2021年第1期7卷 942-961页

作者： Öer Depren Mustafa Tevfik kartal Serpil kılıçDepren Yapıkredi Bank IstanbulTurkey Borsaİstanbul financial Reporting and Subsidiaries Directorate Reşitpaşa Mahallesi Borsaİstanbul CaddesiNo:434467 IstanbulTurkey Department of Statistics Yildiz Technical UniversityIstanbulTurkey

Some countries have announced national benchmark rates,while others have been working on the recent trend in which the London Interbank Offered Rate will be retired at the end of *** that Turkey announced the Turkish Lira Overnight Reference Interest Rate(TLREf),this study examines the determinants of *** this context,three global determinants,five country-level macroeconomic determinants,and the COVID-19 pandemic are considered by using daily data between December 28,2018,and December 31,2020,by performing machine learning algorithms and Ordinary Least *** empirical results show that(1)the most significant determinant is the amount of securities bought by Central Banks;(2)country-level macroeconomic factors have a higher impact whereas global factors are less important,and the pandemic does not have a significant effect;(3)Random forest is the most accurate prediction *** action by considering the study’s findings can help support economic growth by achieving low-level benchmark rates.

关键词： Benchmark rate Determinants Machine learning algorithms Turkey

An analytical model to estimate the time delay to reach spontaneous ignition considering heat loss in oil reservoirs

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Petroleum Science 2024年第4期21卷 2469-2474页

作者： James J.Sheng er-Long Yang College of Petroleum Engineering Northeast Petroleum UniversityDaqing163318HeilongjiangChina

During air injection into an oil reservoir,an oxidation reaction generates some heat to raise the reservoir *** the reservoir temperature reaches an ignition temperature,spontaneous ignition *** is a time delay from the injection to *** are mixed results regarding the feasibility of spontaneous ignition in real-field projects and in laboratory *** analytical model is available in the literature to estimate the oxidation time required to reach spontaneous ignition with heat *** paper discusses the feasibility of spontaneous ignition from theoretical points and experimental and field project *** analytical model considering heat loss is *** models with and without heat loss investigate the factors that affect spontaneous *** on the discussion and investigations,we find that it is more difficult for spontaneous ignition to occur in laboratory experiments than in oil reservoirs;spontaneous ignition is strongly affected by the initial reservoir temperature,oil activity,and heat loss;spontaneous ignition is only possible when the initial reservoir temperature is high,the oil oxidation rate is high,and the heat loss is low.

关键词： Spontaneous ignition Time delay Air injection Heat loss Low temperature oxidation Combustion

Performance assessment of a power-to-gas process based on reversible solid oxide cell

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frontiers of Chemical Science and Engineering 2018年第4期12卷 697-707页

作者： Hanaa er-rbib Nouaamane kezibri Chakib Bouallou Centre for Energy Efficiency of Systems MINES ParisTechPSL Research UniversityParis 75006France

Due to the foreseen growth of sustainable energy utilization in the upcoming years, storage of the excess production is becoming a rather serious matter. In this work, a promising solution to this issue is investigated using one of the most emerging technologies of electricity conversion: reversible solid oxide cells (RSOC). A detailed model was created so as to study the RSOC performance before implementing it in the global co-electrolysis Aspen Plus(TM) model. The model was compared to experimental results and showed good agreement with the available data under steady state conditions. The system was then scaled up to a 10MWco-electrolysis unit operating at 1073 k and 3 bar. The produced syngas is subsequently directed to a methanation unit to produce a synthetic natural gas (SNG) with an equivalent chemical power of 8.3 MWth. Additionally, as a result of a heat integration analysis, the methanation process provides steam and electricity to operate the rest of the units in the process. A final CO2 capture step is added to ensure the required specifications of the produced SNG for gas network injection. Lastly, the overall performance of the power-to-gas process was evaluated taking into account the energy consumption of each unit.

关键词： renewable electricity storage co-electrolysis methanation carbone capture

Teleportation of unknown states of a qubit and a single-mode field in strong coupling regime without Bell-state measurement

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Communications in Theoretical Physics 2023年第2期75卷 73-79页

作者： f Jahanbakhsh M k Tavassoly Optics and Laser Group Faculty of PhysicsYazd UniversityYazd 89195-741Iran

In this paper,we develop the teleportation scheme in[Zheng in Phys Rev A 69,064302,2004],in the sense that,we work in the strong atom-field coupling regime wherein the rotating wave approximation(RWA)is no longer *** achieve the purpose,a scheme consisting of a qubit interacting with a single-mode quantized field is described via the Rabi model(counter rotation terms are taken into account).Our first aim is to teleport an unknown atomic state of a qubit(which interacts with the quantized field in a cavity)to a second qubit(exists in another distant cavity field),beyond the RWA and without the Bell-state measurement *** the continuation,in a similar way,we teleport an unknown state of a single-mode field *** fact,it is shown that,in this regime,after applying some particular conditions,containing the interaction time of atom-field in the cavities,adjusting the involved frequencies,as well as the atom-field coupling in the model,if a proper measurement is performed on the state of the first qubit(the related field in the cavity),the unknown states of the qubit(field)can be teleported from the first qubit(cavity field)to the second qubit(cavity field),*** show that in both considered cases,the teleportation protocol is successfully performed with the maximum possible fidelity,1,and the acceptable success probability,0.25.

关键词： strong atom-field coupling Rabi model quantum teleportation success probability fidelity

Synthesis and Crystal Structure of a New Potassium Yttrium Diphosphate Dihydrate kYP_2O_7·2H_2O

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Chinese Journal of Structural Chemistry 2008年第10期27卷 1199-1204页

作者： férid M Horchani-Naifer k Unité de Recherches de Matériaux de Terres Rares Centre National de Recherches en Sciences des MatériauxB.P.95 Hammam-Lif 2050Tunisie

The dihydrated potassium yttrium diphosphate, kYP2O7·2H2O, has been synthesized for the first time. Single-crystal XRD study has allowed the determination of its structure and correct formula. It crystallizes in the monoclinic system, space group P21/c, with the cell parameters a = 7.7069（3）, b = 10.5801（4）, c = 10.0204（5）A,β = 93.24（3）A, V= 815.76（6）A^3, Z= 4, Mr = 337.98, f（000） = 656, Dc = 2.752 g/cm^3 and/t = 8.073 mm^-1. The single-crystal structure was solved from 1856 unique reflections with the final R = 0.0365 and wR = 0.0772, refined with 119 parameters. The atomic arrangement of kYP2O7·2H2O is built by the P2O7 groups, the YO7 and the kO10 polyhedrons which are connected by corner and edge-sharing to form a three-dimensional framework. Water molecules are directly bonded to the Y and k atoms, and they are located in channels running along the a direction.

关键词： crystal structure yttrium diphosphate infrared spectrum TGA-DTA analysis

The fine Structures of Three Symmetric Latin Squares with Even Orders

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Acta Mathematica Sinica,English Series 2011年第6期27卷 1137-1148页

作者： er Qiang fENG Yan Xun CHANG Institute of Mathematics Beijing Jiaotong University Beijing 100044 P. R. China

Denote by Sfin（v） the set of all integer pairs （t, s） for which there exist three symmetric Latin squares of order v on the same set having fine structure （t, s）. We completely determine the set Sfin（2n） for a... 详细信息

关键词： Symmetric Latin square symmetric Latin trade fine structure

Clique-Transversal Sets in 4-Regular Claw-free Graphs

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Acta Mathematica Sinica,English Series 2011年第5期27卷 883-890页

作者： er fang SHAN Li Ying kANG Department of Mathematics Shanghai University Shanghai 200444 P. R. China

A clique-transversal set D of a graph C is a set of vertices of G such that D meets all cliques of G. The clique-transversal number, denoted by To（G）, is the minimum cardinality of a clique- transversal set in G. In this paper we give the exact value of the clique-transversal number for the line graph of a complete graph. Also, we give a lower bound on the clique-transversal number for 4-regular claw-free graphs and characterize the extremal graphs achieving the lower bound.

关键词： Clique-transversal set claw-free graph line graph regular graph