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Compressive property and energy absorption characteristic of interconnected porous Mg-Zn-Y alloys with adjusting Y addition

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journal of Magnesium and Alloys 2024年第1期12卷 171-185页

作者： j.A.Liu S.j.Liu b.Wang W.b.Sun X.j.Liu Z.W.Han College of Materials Science and Engineering Key Laboratory of Automobile Materials(Ministry of Education)Jilin UniversityChangchun 130022PR China Key Laboratory of bionic Engineering(Ministry of Education) College of Biological and Agricultural EngineeringJilin UniversityChangchun130022PR China Weihai Institute for bionics-jilin University Weihai 264205PR China

In this study,interconnected porous Mg-2Zn-xY alloys with different phase compositions were prepared by various Y additions(x=0.4,3,and 6 wt.%)to adjust the compressive properties and energy absorption *** characterization methods were then applied to identify the microstructure of the porous Mg-Zn-Y and describe the details of the second *** tests were performed at room temperature(RT),200℃,and 300℃to study the impact of the Y addition and testing temperature on the compressive properties of the porous *** experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second *** the Y content increases,different Mg-Zn-Y ternary phases appear:I-phase(Mg_(3)Zn_(6)Y),W-phase(Mg_(3)Zn_(3)Y_(2)),and LPSO phase(Mg_(12)ZnY).When the Y content ranges between 0.4%and 6%,the compressive strength increases from 6.30MPa to 9.23 MPa,and the energy absorption capacity increases from 7.33 Mj/m^(3)to 10.97 Mj/m^(3)at RT,which is mainly attributed to the phase composition and volume fraction of the second ***,the average energy absorption efficiency is independent of the Y *** addition,the compressive deformation behaviors of the porous Mg-Zn-Y are altered by the testing *** compressive strength and energy absorption capacity of the porous Mg-Zn-Y decrease due to the softening effect of the high temperature on the *** deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts.

关键词： Porous magnesium Rare earth elements Microstructure Compressive behavior Energy absorption characteristic

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Design of synthetic materials for intracellular delivery of RNAs： From siRNA-mediated gene silencing to CRISPR/Cas gene editing

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Nano Research 2018年第10期11卷 5310-5337页

作者： jason b. Miller Daniel j. Siegwart Simmons Comprehensive Cancer Center University of Texas Southwestern Medical Center Dallas TX 75390 USA Department of biochemistry University of Texas Southwestern Medical Center Dallas TX 75390 USA

Ribonucleic acids （RNAs） possess great therapeutic potential and can be used to treat a variety of diseases. The unique biophysical properties of RNAs, such as high molecular weight, negative charge, hydrophilicity, low stability, and potential immunogenicity, require chemical modification and development of carriers to enable intracellular delivery of RNAs for clinical use. A variety of nanornaterials have been developed for the effective in vivo delivery of short/ small RNAs, messenger RNAs, and RNAs required for gene editing technologies including clustered regularly interspaced palindromic repeat （CRISPR）/Cas. This review outlines the challenges of delivering RNA therapeutics, explores the chemical synthesis of RNA modifications and carriers, and describes the efforts to design nanomaterials that can be used for a variety of clinical indications.

关键词： nucleic acid therapeutics nanoparticles synthetic nanomaterials RNA interference (RNAi) messenger RNA (mRNA) clustered regularly inter-spaced palindromic repeat(CRISPR)/Cas

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A COMPARATIVE STUDY OF THE INVENTORY SYSTEM WITH SERVICE FACILITY AND POSTPONED DEMANDS

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journal of Systems Science and Systems Engineering 2014年第2期23卷 176-195页

作者： j.Sebastian Arockia jenifer b.Sivakumar School of Mathematics Madurai Kamaraj University

In this article, we present a continuous review （s,S） inventory system with a service facility consisting of finite buffer （capacity N ） and a single server. The customers arrive according to a Poisson process. The individual customer＇s unit demand is satisfied after a random time of service, which is assumed to be exponential. When the inventory level drops to s＇an order for Q（= S-s） items is placed. The lead time of reorder is assumed to be exponential distribution. An arriving customer, who finds the buffer is full, enters into the pool of infinite size or leaves the system according to a bernolli trial. At the time of service completion, if the buffer size drops to a preassigned level L （1 〈 L 〈 N） or below and the inventory level is above s, we select the customers from the pool according to two different policy ： in first policy, with probability p （0 〈 p 〈 1） we select the customer from the head of the pool and we place the customer at the end of the buffer; in the second policy, with p （0 〈 p 〈 1） the customer from the pool is transferred to the buffer for immediate service and after completion of his service we provide service to the customer who is in the buffer with probability one. If at a service completion epoch the buffer turns out to be empty, there is at least one customer in the pool and the inventory level is positive, then the one ahead of all waiting in the pool gets transferred to the buffer, and his service starts immediately. The joint probability distribution of the number of customers in the pool, number of customers in the buffer and the inventory level is obtained in the steady-state case. Various stationary system performance measures are computed and total expected cost rate is calculated. A comparative result of two models is illustrate numerically.

关键词： Continuous review inventory system postponed demands service facility finite waiting hall pool with infinite size

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Magnetically propelled Carreau fluid flow over penetrable sensor surface influenced by thermal radiation,joule heating and heat generation

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Communications in Theoretical Physics 2022年第2期74卷 9-18页

作者： b j Gireesha b Nagaraja N Srikantha N G Rudraswamy A Felicita Department of Studies and Research in Mathematics Kuvempu UniversityShankaraghattaShivamoggaKarnatakaIndia Department of Mathematics MS Ramaiah Institute of TechnologyBangaloreIndia Department of Mathematics P.C.Jabin Science College(Autonomous)HubballiIndia

This examination emphasizes the analysis of thermal transmission of Carreau fluid flow on a permeable sensor surface equipped with radiation,joule heating,an internal heat source,and a magnetic *** the above effects and assumptions,the equations that administer the flow are formulated.A configured system of equations is productively reduced to a system of ordinary differential *** reduced system is then dealt with using the Runge–Kutta-Fehlberg fourth–fifth order tool equipped by the shooting *** numerical solutions are utilized to plot graphs and *** conclusion of the study outlines some important findings such as the power law index,the thermal radiation parameter and the heat source parameter enhance the thermal panel whereas the Weissenberg number deescalates the *** power law index and permeable velocity decrease the velocity panel *** representation of streamlines of the flow has been given to strengthen the study.A detailed description has been produced about the results obtained in the study.

关键词： sensor surface Carreau fluid squeezed flow thermal radiation heat generation

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An analytical model for electrode-ceramic interaction in multilayer piezoelectric actuators

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Acta Mechanica Sinica 2007年第2期23卷 199-208页

作者： b.L.Wang j.C.Han Center for Composite Materials Harbin Institute of TechnologyHarbin 150001China

The present paper develops an analytical model for multi-electrodes in multi-layered piezoelectric actuators, in which the electrodes are vertical to and terminated at the edges of the medium and electroelastic field concentrations ahead of the electrodes in the multilayer piezoelectric actuators are examined. by considering a representative unit in realistic multilayers, the problem is formulated in terms of electric potential between the electrode tips and results in a system of singular integral equations in which the electric potential is taken as unknown function. Effects are investigated of electrode spacing and piezoelectric coupling on the singular electroelastic fields at the electrode tips, and closed-form expressions are given for the electromechanical field near the electrode tips. Exact solution for un-coupled dielectrics is provided, where no piezoelectric coupling is present.

关键词： Actuators . Piezoelectric materials . Electrodes. Multilayer. Fracture mechanics

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Plasticity and Interfacial Dislocation Mechanisms in Epitaxial and Polycrystalline Al Films Constrained by Substrates

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journal of Materials Science & Technology 2002年第2期18卷 113-117页

作者： G.Dehm b.j.Inkson 等 Max-Planck-InstitutfirtMetallforschung Seestr9270174StuttgartGermany DepartmentofMaterials UniversityofOxfordParksRoadOxfordOX13PHU.K.

Stresses in epitaxial and textured Al films were determined by substrate-curvature measurements. It was found that in both cases the flow stresses increase with decreasing film thickness. The flow stresses in the epitaxial Al films are in agreement with a dislocation-based model, while the same model strongly underestimates the flow stresses of textured Al films. In-situ transmission electron microscopy studies indicate that dislocations channeling through epitaxial Al films on single-crystalline (0001) α-AI2O3 substrates frequently deposit dislocation segments adjacent to the interface. Furthermore, the AI/α-AI2O3 interface acted as a dislocation source. In this case, the interface is between two crystalline lattices. In contrast, the interface of textured Al films on oxidized silicon substrates is between the crystalline Al and the amorphous SiOx interlayer. It is speculated that the different nature of the interfaces changes dislocation mechanisms and thus influences the flow stresses.

关键词： Thin film Plasticity Dislocation Interface

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ELASTICITY OF MONOLAYER OF LINOLEIC ACID AND ITS POLYMER

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Chinese journal of Polymer Science 1998年第2期16卷 147-154页

作者：何平笙 PELTONEN j.P.K. ROSENHOLM j.b. Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230026 China Department of Physical Chemistry Abo Akademi University Abo Finland

The dynamic elasticity of linoleic acid monolayer on a subphase of 10** minus **4mol/L TbCl//3 at various surface pressure has been measured by means of dynamic oscillation method in measuring the change of surface pressure caused by periodic compression-expansion cycles of the barrier. The elasticity of monolayer increases with increasing of surface pressure linearly. The linoleic acid polymer monolayer has been obtained under UV-irradiation in situ when keeping a constant surface pressure. but the elasticity of the resulting polymerized monolayer is even smaller than that of its corresponding monomer monolayer. The elasticity of the polymerized linoleic acid monolayer decreases with increasing polymerization time. The explanation based on entropy has been presented. (Author abstract) 10 Refs.

关键词： elasticity monolayer linoleic acid

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Heavy Metals in brown Rice(Oryza sativa L.) and Soil After Long-Term Irrigation of Wastewater Discharged from Domestic Sewage Treatment Plants

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Pedosphere 2011年第5期21卷 621-627页

作者： b.Y.CHUNG C.H.SONG b.j.PARK j.Y.CHO Advanced Radiation Technology Institute Korea Atomic Energy Research Institute(KAERI) Korea Testing & Research Institute(KTR) Department of Horticultural Science Chungbuk National University Department of bio-environmental Chemistry Chonbuk National University

A pot experiment was conducted in a plastic film house to evaluate the translocation and uptake of heavy metals(Pb,Cd,Cu,and Zn) into brown rice(Oryza sativa L.) and the heavy metals residues in soils which had previously been irrigated with domestic wastewater for a long time(3 years).The range of Pb,Cd,Cu,and Zn was 5.10 ± 0.01,0.105 ± 0.017,5.76 ± 0.42,and 23.56 ± 1.40 mg kg-1,respectively in the domestic wastewater-irrigated soil,and 0.370 ± 0.006,0.011 ± 0.001,0.340 ± 0.04,and 2.05 ± 0.18 mg kg-1,respectively,in the domestic wastewater-irrigated brown *** results indicated that application of domestic wastewater to arable land slightly increased the levels of Pb,Cd,Cu,and Zn in soil and brown rice(P brown rice were lower than the recommended tolerable levels proposed by the joint FAO/WHO Expert Committee on Food ***,the continuous monitoring and pollution control of hazardous materials from domestic wastewater are needed in order to prevent excessive build-up of heavy metals in the food chain.

关键词： accumulation domestic wastewater ground water irrigation P2O5 total N

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Enhancements to Modified Chebyshev-Picard Iteration Efficiency for Perturbed Orbit Propagation

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Computer Modeling in Engineering & Sciences 2016年第1期111卷 29-64页

作者： b.Macomber A.b.Probe R.Woollands j.Read j.L.junkins Texas A&M University College StationTXUSA.

Modified Chebyshev Picard Iteration is an iterative numerical method for solving linear or non-linear ordinary differential *** a serial computational environment the method has been shown to compete with,or outperform,current state of practice numerical *** paper presents several improvements to the basic method,designed to further increase the computational efficiency of solving the equations of perturbed orbit propagation.

关键词： Astrodynamics Orbit Propagation Cheybshev Polynomials Picard Iteration.

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APPLICATION OF Ct-PARAMETER FOR CREEP-FATIGUE CRACK GROWTH WITH SLOW LOAD RISING CONDITION

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Acta Metallurgica Sinica(English Letters) 1999年第1期12卷 22-30页

作者： Lee, j.H. Yoon, K.b. Kim, Y.j. back, U.b. Korea Inst of Nuclear Safety Taejon South Korea

Most of the assessment equations for Ct which is a wellknown fracture parameter characterizing high temperature crack growth rates, have limited applicability to constant load conditions after sudden loading. However, crack growth due to creep can also occur under load varying conditions when load rising time is so long that accumulated creep deformation near the crack tip is not *** this paper, the estimation equation of the Ctparameter which can be applied to the case of slow load rising, i.e., (Ct)r, is explained. And the correlation between (Ct)r at the end of the load increasing period and Ct at the beginning of the succeeding load hold period is discussed. Finite element analyses of several cases with various loading conditions were performed and results were presented to show the effectiveness of the proposed Ct estimation scheme. The general applicability of the equation is also discussed.

关键词： creep fatigue crack time dependent fracture mechanics Ctparameter,C*integral

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