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mechanical properties of 65mn chiral structure with three ligaments

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Acta mechanica Sinica 2019年第1期35卷 88-98,I0003页

作者： X.W.Su D.m.Zhu c.Zheng m.m.Tomovic School of Technology Beijing Forestry UniversityBeijing 100083China School of mechanical Engineering University of Science and Technology BeijingBeijing 100083 China Batten college of Engineering and Technology Old Dominion University Norfolk VA 23529 USA

chiral honeycomb structures have been developed in recent years, showing excellent mechanical properties, including in-plane deformation and out-of-plane bearing and vibration isolation. In this study, the 65mn chiral structure with three ligaments was modeled and analyzed using the finite element (FE) method. The effects of the dimensionless ligament length and dimensionless ligament thickness on the in-plane equivalent elastic modulus, equivalent Poisson's ratio, and out-of-plane shear modulus were studied. The numerical results indicate that increase of the dimensionless ligament length leads to decrease of the equivalent elastic modulus and increase of the equivalePoisson's ratio, whereas the out-of-plane equivalent shear modulus decreases. The results also indicate that increase of the dimensionless ligament thickness leads to in crease of the equivalent elastic modulus, whereas the equivalent Poisson's ratio remains nearly unchanged and the out-of-plane equivalent shear modulus shows a linear in crease. The numerical results are verified by comparis on with published experime ntal data. These results will provide a reference for the application of chiral structures with three ligaments in the aerospace field.

关键词： chiral structure with three ligaments mechanical properties Finite elemern method

coupling textural and stable-isotope variations in fluvial stromatolites:comparison of Pleistocene and recent records in NE Spain

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Journal of Palaeogeography 2019年第2期8卷 150-169页

作者： c.Arenas m.c.Osácar L.Auqué c.Sancho Department of Earth Sciences University of Zaragoza Geotransfer Group and Institute for Research on Environmental Sciences of Aragón(IUcA)

Textural and stable isotopic features of two middle Pleistocene fluvial stromatolite profiles are compared to a recent stromatolite,both formed in the River Piedra system(NE Spain),to test the reliability of climatic,hydrologic and depositional information derived from ancient *** Pleistocene stromatolites formed in a multi-domed,highly-inclined *** recent stromatolite also formed in a highly-inclined cascade of the River Piedra,the sedimentary conditions of which were periodically examined between the years 2000 and *** Pleistocene stromatolites are formed of an alternation of 1) thin large-crystal laminae(type A),with elongated crystals up to 1 mm long,and 2) thick small-crystal laminae(type B),consisting of cyanobacterial fan-and bushshaped *** textural and isotopic comparison with the recent stromatolite shows that each A–B couplet corresponds to one *** type-A laminae are comparable to the macrocrystalline laminae that occur in the cool-period deposits of the recent stromatolite,and the type-B laminae are comparable to the warm-period deposits of the recent *** temperatures(Tw),calculated from δ^(18)O_(calcite) and present measures of δ^(18)O_(water),were similar in the Pleistocene and recent specimens,and close to the measured river ***,the Pleistocene stromatolites formed not far from isotopic equilibrium,as did the recent *** Pleistocene δ^(18) O_(calcite) biannual oscillation is wider in amplitude than in the recent stromatolite,which suggests larger differences in Tw through the year in the Pleistocene than at *** Pleistocene δ^(13)c_(calcite) does not show any pattern;and the values are slightly higher than the recent *** co-evolution of δ^(18)O and δ^(13)c is parallel in the Pleistocene stromatolites,matching the recent stromatolite *** results and their comparison with other ancient examples prove that textural and isotopic features in ancient stromatolites

关键词： Tufa Recent and ancient stromatolites Stable isotopes Biotic and abiotic laminae Intra-annual and inter-annual water temperature variations

Kaolin-based geopolymers with various NaOH concentrations

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International Journal of minerals,metallurgy and materials 2013年第3期20卷 313-322页

作者： c.Y. Heah H. Kamarudin A.m. mustafa Al Bakri m. Bnhussain m. Luqman I. Khairul Nizar c.m. Ruzaidi Y.m. Liew center of Excellence Geopolymer and Green Technology (cEGeoGTech) School of Materials Engineering Universiti Malaysia Perlis (UniMAP) King Abdulaziz city Science and Technology

Kaolin geopolymers were produced by the alkali-activation of kaolin with an activator solution （a mixture of NaOH and sodium silicate solutions）. The NaOH solution was prepared at a concentration of 6-14 mol/L and was mixed with the sodium silicate solution at a Na2SiO3/NaOH mass ratio of 0.24 to prepare an activator solution. The kaolin-to-activator solution mass ratio used was 0.80. This paper aimed to analyze the effect of NaOH concentration on the compressive strength of kaolin geopolymers at 80℃ for 1, 2, and 3 d. Kaolin geopolymers were stable in water, and strength results showed that the kaolin binder had adequate compressive strength with 12 mol/L of NaOH concentration. When the NaOH concentration increased, the SiO2/Na20 decreased. The increased Na20 content enhanced the dissolution of kaolin as shown in X-ray diffraction （XRD） and Fourier transform infrared spectroscopy （FTIR） analyses. However, excess in this content was not beneficial for the strength development of kaolin geopolymers. In addition, there was the formation of more geopolymeric gel in 12 mol/L samples. The XRD pattern of the samples showed a higher amorphous content and a more geopolymer bonding existed as proved by FTIR analysis.

关键词： geopolymers kaolin compressive strength sodium hydroxide

Artificial Intelligence Based Smart Routing in Software Defined Networks

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computer Systems Science & Engineering 2023年第2期44卷 1279-1293页

作者： c.Aswini m.L.Valarmathi Department of Information Technology Government College of TechnologyCoimbatore641013India Department of computer Science and Engineering Dr.Mahalingam College of Engineering and TechnologyPollachi642003India

In a non-static information exchange network,routing is an overly com-plex task to perform,which has to satisfy all the needs of the *** Deﬁned Network(SDN)is the latest and widely used technology in the future communication networks,which would provide smart routing that is visible *** various features of routing are supported by the information centric network,which minimizes the congestion in the dataﬂow in a network and pro-vides the content awareness through its mined *** to the advantages of the information centric network,the concepts of the information-centric net-work has been used in the paper to enable an optimal routing in the software-deﬁned *** there are many advantages in the information-centric network,there are some disadvantages due to the non-static communication prop-erties,which affects the routing in *** this regard,artiﬁcial intelligence meth-odology has been used in the proposed approach to solve these difﬁculties.A detailed analysis has been conducted to map the content awareness with deep learning and deep reinforcement learning with *** novel aligned internet investigation technique has been proposed to process the deep reinforcement *** performance evaluation of the proposed systems has been con-ducted among various existing approaches and results in optimal load balancing,usage of the bandwidth,and maximization in the throughput of the network.

关键词： content aware routing software deﬁned networks deep learning load balancing

Enhancing Heat Transfer and Energy Storage Performance of Shell-and-Tube Latent Heat Thermal Energy Storage Unit with Unequal-Length Fins

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Journal of Thermal Science 2023年第6期32卷 2018-2031页

作者： WU Yangyang LI Dong YANG Ruitong mÜSLÜm Arıcı LIU changyu School of Architecture and civil Engineering Northeast Petroleum UniversityDaqing163318China Engineering Faculty Mechanical Engineering DepartmentKocaeli UniversityUmuttepe CampusKocaeliİzmit41001Turkey

Previous studies in literatures adequately emphasized that inserting fins into phase change material is among the most promising techniques to augment thermal performance of shell-and-tube latent heat thermal energy storage *** this study,the novel unequal-length fins are designed from the perspective of synergistic benefits of heat transfer and energy storage performance,and the effects of arrangement,number and total length of unequal-length fins are numerically *** show that utilization of fins with ascending length,when short and long fins are located in the inlet and outlet of heat transfer fluid respectively,can further promote the heat transfer and energy storage performance compared with equal length fins,and a maximum 6.17%and 0.43%increment of heat transfer performance and stored energy is achieved in full melting time,*** number of unequal-length fins plays a major role in the energy storage,and 18.95%and 0.91%improvement of heat transfer performance and stored energy is realized when equipped with 2 unequal-length fins.A 21.17%improvement of the heat transfer performance is obtained when the total length of unequal-length fins is 18 *** present study is helpful to make further efforts to enhance heat transfer and energy storage of shell-and-tube latent heat thermal energy storage unit with unequal-length fins.

关键词： unequal-length fin enhanced heat transfer energy storage shell and tube heat exchanger Pcm

EmDEN-FOWLER TYPE SYSTEm:NOETHER SYmmETRIES AND FIRST INTEGRALS

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Acta mathematica Scientia 2012年第5期32卷 1959-1966页

作者： B.muatjetjeja c.m.Khalique International Institute for Symmetry Analysis and mathematical modelling Department of Mathematical SciencesNorth-West UniversityMafikeng CampusPrivate Bag X 2046Mmabatho 2735Republic of South Africa

We classify a generalized coupled singular Emden-Fowler type system ＋a（t）vn=0,v＋b（t）um=0 with respect to the standard first-order Lagrangian according to the Noether point symmetries which it *** integrals of the various cases which admit Noether point symmetries are then *** system was discussed in the literature from the view-point of existence and uniqueness of positive solutions.

关键词： Lagrangian Noether symmetry first integrals Emden-Fowler type system Gauge function

Visual observations of 1998 Leonids in Delingha and their preliminary analysis

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chinese Science Bulletin 2000年第23期45卷 2142-2147页

作者： m.c.de Lignie m.Langbroek Dutch meteor Society Jan Steenlaan 46NL-2251Jh Voorschotenthe NetherlandsDutch Meteor SocietyJan Steenlaan 46NL-2251Jh Voorschotenthe Netherlands

On the basis of the observational data obtained by the Sino-Dutch Joint Leonids Observation Team at Delingha Station of Purple mountain Observatory from Nov. 13 to 18, 1998, and those obtained in other places of china during the same period, the distribution characteristics of the 1998 Leonids are analyzed and a three-layer structure of the meteoric shower encountered by the Earth is proposed.

关键词： Leonids ZHR mass distribution.

Hole Burning in the Fock Space: from Single to Several Holes

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chinese Physics Letters 2001年第11期18卷 1467-1469页

作者： B.Baseia J.m.c.malbouisson Instituto de Fisica Universidade Federal de Goias74001-970GoianiaGOBrazil Instituto de Fisica Universidade Federal da Bahia40210-340SalvadorBABrazil

In our previous papers we have studied the production of a single hole in the photon number distribution of a field state [Phys. Lett. A 240 (1998) 277;253 (1999) 123]. In this letter we extend the procedure for the c... 详细信息

关键词： letter creation distribution

Analysis of Rheological Behavior of Some Aqueous PEO Gels under Thermal Treatment

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chinese Physics Letters 2009年第7期26卷 362-365页

作者： m. Todica and c. V. Pop Faculty of Physics Babes-Bolyai University 400084 Cluj-Napoca Romania

Evolution of viscosity of some aqueous poly （ethylene oxide） gels is observed as functions of polymeric concentration and temperature for samples subjected to thermal shock. The experimental data are analyzed following an appropriate algorithm, and reveal the transient effect from Newtonian to non-Newtonian flow as a function of the polymeric concentration.

关键词： Soft matter liquids and polymers Fluid dynamics