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Static and dynamic stability responses of multilayer functionally graded carbon nanotubes reinforced composite nanoplates via quasi 3D nonlocal strain gradient theory

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Defence Technology（防务技术） 2022年第10期18卷 1778-1809页

作者： Ahmed Amine Daikh Mohamed sid Ahmed Houari Mohamed Ouejdi Belarbi Salwa A.Mohamed Mohamed A.Eltaher Laboratoire D'Etude des Structures et de Mecanique des Materiaux Departement de Genie CivilFacultedes Sciences et de La TechnologieUniversite Mustapha Stambouli B.P.305R.P.29000MascaraAlgeria Laboratoire de Genie Energetique et Materiaux LGEMUniversite de BiskraB.P.145R.P07000BiskraAlgeria Department of Engineering Mathematics Zagazig UniversityP.O.Box 44519ZagazigEgypt Faculty of Engineering Mechanical Engineering DepartmentKing Abdulaziz UniversityP.O.Box 80204JeddahSaudi Arabia Faculty of Engineering Mechanical Design and Production DepartmentZagazig UniversityP.O.Box 44519ZagazigEgypt

This manuscript presents the comprehensive study of thickness stretching effects on the free vibration,static stability and bending of multilayer functionally graded(FG)carbon nanotubes reinforced composite(CNTRC)*** nanoscale and microstructure influences are considered through a modified nonlocal strain gradient continuum *** on power-law functions,four different patterns of CNTs distribution are considered in this analysis,a uniform distribution UD,FG-V CNTRC,FG-X CNTRC,and FG-O CNTRC.A 3D kinematic shear deformation theory is proposed to include the stretching influence,which is neglected in classical ***'s principle is applied to derive the governing equations of motion and associated boundary *** solutions are developed based on Galerkin method to solve the governing equilibrium equations based on the generalized higher-order shear deformation theory and the nonlocal strain gradient theory and get the static bending,buckling loads,and natural frequencies of *** with previous works is presented.A detailed parametric analysis is carried out to highlight the impact of thickness stretching,length scale parameter(nonlocal),material scale parameter(gradient),CNTs distribution pattern,geometry of the plate,various boundary conditions and the total number of layers on the stresses,deformation,critical buckling loads and vibration *** new results are also reported in the current study,which will serve as a benchmark for future research.

关键词： 3D shear deformation theory Free vibration Buckling Bending Galerkin method Functionally graded nanotube Nonlocal strain gradient theory

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可防止深层钻井故障的BHPI技术

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国外石油动态 2002年第5期 10-13页

作者： sid.webb 谢力

总垂直深度超过15000ft(4575m)的深井在加利福尼亚并不常见，钻至这些深度的许多尝试都导致很高的故障成本，有些则由于不利的地层条件而未达到目标深度，井眼压力整体性（BHPI）技术有助于解决引起深层高温高压钻井故障的一个根本问题... 详细信息

总垂直深度超过15000ft(4575m)的深井在加利福尼亚并不常见，钻至这些深度的许多尝试都导致很高的故障成本，有些则由于不利的地层条件而未达到目标深度，井眼压力整体性（BHPI）技术有助于解决引起深层高温高压钻井故障的一个根本问题：可引起循环液严重漏失的岩石张性破裂，作业人员在设计BHPI处理前，应使用漏失测试（LOT）数据来帮助确定较低的井眼整体压力或破裂梯度条件。

关键词：石油钻井深层钻井故障 BHPI技术吸液压力地层压力

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Silibinin induces hepatic stellate cell cycle arrest via enhancing p53/p27 and inhibiting Akt downstream signaling protein expression

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Hepatobiliary & Pancreatic Diseases International 2017年第1期16卷 80-87页

作者： Devaraj Ezhilarasan Jonathan Evraerts Brice sid Pedro Buc Calderon Sivanesan Karthikeyan Etienne Sokal Mustapha Najimi institut de recherche expérimentale et clinique (irec) laboratory of pediatric hepatology and cell therapyuniversité catholique de louvain，1200，Brussels，Belgium louvain drug research institute toxicology and cancer biology research group pmnt unituniversité catholique de louvain，1200，Brussels，Belgium facultad de ciencias de la salud universidad arturo prat，Iquique，Chil department of pharmacology and environmental toxicology food and hepatotoxicology laboratory dr. alm post graduate institute of basic medical sciences university of madrastaramani campus，Chennai-600 l13，India

BACKGROUND： Proliferation of hepatic stellate cells （HSCs） plays a pivotal role in the progression of liver fibrosis conse- quent to chronic liver injury. Silibinin, a flavonoid compound, has been shown to possess anti-fibrogenic effects in animal models of liver fibrosis. This was attributed to an inhibition of cell proliferation of activated HSCs. The present study was to gain insight into the molecular pathways involved in silibinin anti-fibrogenic effect. METHODS： The study was conducted on LX-2 human stellate cells treated with three concentrations of silibinin （10, 50 and 100 μmol/L） for 24 and 96 hours. At the end of the treatment cell viability and proliferation were evaluated. Protein expression of p27, p21, p53, Akt and phosphorylated-Akt was evaluated by Western blotting analysis and Ki-67 protein expression was by immunocytochemistry. Sirtuin activity was evaluated by chemiluminescence based assay. RESULTS： Silibinin inhibits LX-2 cell proliferation in doseand time-dependent manner; we showed that silibinin upregulated the protein expressions of p27 and p53. Such regulation was correlated to an inhibition of both downstream Akt and phosphorylated-Akt protein signaling and Ki-67 protein expression. Sirtuin activity also was correlated to silibinin- inhibited proliferation of LX-2 cells. CONCLUSION： The anti-proliferative effect of silibinin on LX-2 human steUate cells is via the inhibition of the expres- sions of various cell cycle targets including p27, Akt and sir- tuin signaling.

关键词： silibinin hepatic stellate cells in vitro cell cycle arrest proliferation

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Prediction of Thermal Conductivity and Specific Heat of Native Maize Starch and Comparison with HMT Treated Starch

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Journal of Renewable Materials 2019年第6期7卷 535-546页

作者： Aklouche Leila Monteau Jean-Yves Rezzoug sid-Ahmed Maugard Thierry Guihard Luc Cohendoz Stephane Maache-Rezzoug Zoulikha LaSIE UMR CNRS 7356University of La RochelleAvenue Michel Crépeau17042 La RochelleFrance GEPEA UMR CNRS 6144ONIRISRue de la Géraudière44322 NantesFrance LIENSs UMR CNRS 7266 Universitéde La RochelleFrance

Specific heat(Cp)and effective thermal conductivity(λ)of native maize starch(NS)were measured by DSC and transient heat transfer method,respectively,at different moisture contents and *** dependency of temperature(T)and moisture content(W)on the two parameters were *** thermophysical properties of treated starch(TS)by four hydrothermal processes(RP-HMT,IV-HMT,DV-HMT and FV-HMT)were measured and compared to native *** treatments were performed at 3 bars(133°C)for 10 *** Cp andλmeasurements,moisture content varied for NS from 5 to 21.5%*** from 8.8 to 25%d.b.,respectively,and was fixed at 6%*** *** models were developed to specific heat and effective thermal conductivity,using a multiple regression algorithm with subsequent statistical *** proposed models for NS based on T and W predict Cp andλwith a mean absolute error of 3.5%and 1.3%,*** differences in specific heat were observed between TS and *** a temperature range of 40 to 160°C,Cp values varied from 1.964 to 2.699 for NS and 1.380 to 2.085(J.g-1.°C-1)for *** contrast,the conductivity of NS was almost identical to that of treated starch by FV-HMT,followed in an increasing order by those treated by DV-HMT,RP-HMT,and IV-HM processes.

关键词： Starch HMT treatment specific heat effective thermal conductivity

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Polymer Breakdown: Reaction Offers Possible Way to Recycle Nylon

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科技英语学习 2007年第8期 5-6页

作者： sid Perkins 李琳

化学聚合物及纤维的发明和使用大大丰富了人们的生活,从衣物到日常生活用品,堪称是无处不在,不可或缺。可如何处理其制品垃圾却成了难题,这些不易降解又不宜燃烧的石油衍生产品究竟能否回收再利用呢?科学家们做出了大胆尝试。

关键词： nylon 聚合物 Reaction Offers Possible Way to Recycle Nylon Polymer Breakdown

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Synthesis, crystal structure, magnetic properties and second harmonic generation of a new noncentrosymmetric coordination compound：Triaqua(4-amino-6-methoxypyrimidine) cuprate(Ⅱ)sulfate

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Chinese Chemical Letters 2016年第6期27卷 896-900页

作者： Mahjouba Ben Nasr Kamel Kaabi Matthias Zeller Wataru Fujita Pedro sidónio Pereira da Silva Cherif Ben Nasr Laboratoire de Chimie des Materiaux Universite de Carthage Facultedes Sciences de Bizerte 7021 Zarzouna Tunisia Department of Chemistry Youngstown State University One University Plaza Youngstown OH 44555-3663 USA Graduate School of Natural Science Nagoya City University Yamanohata Mizuho-cho Mizuho-ku Nagoya 467-8501 Japan CFisUC Department of Physics University of Coimbra 3004-516 Coimbra Portugal

The chemical preparation, crystal structure and infrared spectroscopic characterization of the triaqua（4-amino-6-methoxypyrimidine） cuprate（II） sulfate, [Cu（C5H7N3）（H2O）3]SO4, is reported. The compound crystallizes in the noncentrosymmetric orthorhombic space group P212121 with lattice parameters a = 7.9025（3）, b = 11.1189（4）, c = 12.9720（4） , V = 1139.81（7） ~3 and Z = 4. The Cu（II） cation is fivecoordinated, in an early half-way between square pyramidal and trigonal bipyramidal fashion, by two nitrogen atoms of the 4-amino-6-methoxypyrimidine ligand and three water oxygen atoms. In the atomic arrangement, the organic ligands and the 5-connected Cu centers are linked with each other to give a 1-D corrugated hybrid chain running along the b-axis direction. The chains are interconnected by the SO4^（2-） anions via O–H...O, O–H...S, C–H...O and N–H...O hydrogen bonds to form layers spreading parallel to the（011） plane. The vibrational absorption bands were identified by infrared spectroscopy. Quantitative measurements of the second harmonic generation（SHG） of a powdered sample at 1064 nm were performed and a relative efficiency of 5.2 times the KDP standard was observed. Magnetic properties were also defined to characterize the complex. Magnetic measurements revealed that this material had a onedimensional antiferromagnetic character. The magnetic parameters were g = 2.11 and 2J/k B = -36 K.

关键词： Square pyramid Cu(II) complex X-ray diffraction Magnetic properties Second harmonic generation

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Value-added Impact of Geostationary Hyperspectral Infrared Sounders on Local Severe Storm Forecasts——via a Quick Regional OSSE

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Advances in Atmospheric Sciences 2018年第10期35卷 1217-1230页

作者： Zhenglong LI Jun LI Pei WANG Agnes LIM Jinlong LI Timothy J.SCHMIT Robert ATLAS sid-Ahmed BOUKABARA Ross N.HOFFMAN Cooperative Institute for Meteorological Satellite Studies University of Wisconsin-Madison Center for Satellite Applications and Research NOAA Atlantic Oceanographic and Meteorological Laboratory OAR/NOAA Center for Satellite Applications and Research NOAA

Accurate atmospheric temperature and moisture information with high temporal/spatial resolutions are two of the key parameters needed in regional numerical weather prediction(NWP) models to reliably predict high-impact weather events such as local severe storms(LSSs). High spectral resolution or hyperspectral infrared(HIR) sounders from geostationary orbit(GEO) provide an unprecedented source of near time-continuous, three-dimensional information on the dynamic and thermodynamic atmospheric fields—an important benefit for nowcasting and NWP-based forecasting. In order to demonstrate the value of GEO HIR sounder radiances on LSS forecasts, a quick regional OSSE(Observing System Simulation Experiment)framework has been developed, including high-resolution nature run generation, synthetic observation simulation and validation, and impact study on LSS forecasts. Results show that, on top of the existing LEO(low earth orbit) sounders, a GEO HIR sounder may provide value-added impact [a reduction of 3.56% in normalized root-mean-square difference(RMSD)] on LSS forecasts due to large spatial coverage and high temporal resolution, even though the data are assimilated every 6 h with a thinning of 60 km. Additionally, more frequent assimilations and smaller thinning distances allow more observations to be assimilated, and may further increase the positive impact from a GEO HIR sounder. On the other hand, with denser and more frequent observations assimilated, it becomes more difficult to handle the spatial error correlation in observations and gravity waves due to the limitations of current assimilation and forecast systems(such as a static background error covariance). The peak reduction of 4.6% in normalized RMSD is found when observations are assimilated every 3 h with a thinning distance of 30 km.

关键词： OSSE hyperspectral sounder high-impact weather

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Toxic Tides:Another Reason to Worry about Hurricanes

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当代外语研究 2006年第11期 23-25页

作者： sid Perkins 颜木荣

赤潮严重威胁着海岸生态系统,也影响着渔业生产。究其原因,一是化工污染,如化肥和去垢剂的磷酸盐,均为藻类所需的营养素。二是沙暴中的富铁沙粒。美国海洋学家近期对佛罗里达近海域赤潮的研究报告却认为,飓风登陆时的过量降水,经地下吸... 详细信息

赤潮严重威胁着海岸生态系统,也影响着渔业生产。究其原因,一是化工污染,如化肥和去垢剂的磷酸盐,均为藻类所需的营养素。二是沙暴中的富铁沙粒。美国海洋学家近期对佛罗里达近海域赤潮的研究报告却认为,飓风登陆时的过量降水,经地下吸水层积蓄和渗入海里后,将大量污染物为赤潮的疯长助纣为虐。2003年我国全海域就发生过119次赤潮;2004年5月,仅浙江中南部海域赤潮总面积就达4,000余平方公里,颇令人堪忧!

关键词：赤潮生态系统佛罗里达藻类化工污染渔业生产营养素过量降水磷酸盐去垢剂

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On Leader Election in Multi-Agent Control Systems

On Leader Election in Multi-Agent Control Systems

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2010 Chinese Control and Decision Conference

作者： Theodor Borsche sid Ahmed Attia Control Systems Group Berlin Institute of TechnologyBerlinGermany

ISBN: (纸本)9781424451814

＜正＞In this contribution,we discuss the election of an optimal leader out of a network of agents described by first integrator dynamics and running a consensus *** network of agents may be a group of autonomous robots or more generally communicating vehicles,and the target is,for instance,to move the formation to a new location.A leader is said to be optimal if it leads to a controllable network,and minimizes a quadratic cost of reaching a target for all the other agents of the *** the first part,controllability conditions and a decentralized way of checking them are *** then study the correlation between the value of a quadratic cost function measuring the leader performance and the network *** correlation is found between closeness and degree centrality indices of the agents and the cost of achieving the assigned *** allows us to run the optimal leader election process without a central authority and without the nodes having full knowledge of the network topology.

关键词： Consensus algorithms controllability multi-agent control systems leader election networked control systems centrality indices

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The Role of High Precision Arithmetic in Calculating Numerical Laplace and Inverse Laplace Transforms

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Applied Mathematics 2017年第4期8卷 562-589页

作者： Zinovi Krougly Matt Davison sid Aiyar Department of Applied Mathematics Western University London Ontario Canada

In order to find stable, accurate, and computationally efficient methods for performing the inverse Laplace transform, a new double transformation approach is proposed. To validate and improve the inversion solution obtained using the Gaver-Stehfest algorithm, direct Laplace transforms are taken of the numerically inverted transforms to compare with the original function. The numerical direct Laplace transform is implemented with a composite Simpson’s rule. Challenging numerical examples involving periodic and oscillatory functions, are investigated. The numerical examples illustrate the computational accuracy and efficiency of the direct Laplace transform and its inverse due to increasing the precision level and the number of terms included in the expansion. It is found that the number of expansion terms and the precision level selected must be in a harmonious balance in order for correct and stable results to be obtained.

关键词： Numerical Laplace Transform Numerical Laplace Transform Inversion Composite Simpson’s Rule Gaver-Stehfest Algorithm High Precision Computation

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