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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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货币社会学

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世界社会科学 1992年第11期 23-27页

作者： W.E.贝克 ,j.b.吉默森 ,晓良

货币是社会学中一直存在但又不居主要地位的课题。书伯、齐美尔和马克思等古典社会学理论家在观察工业革命和民族国家统一市场的迅速形成过程时,为货币这种社会变迁动因所吸引。社会学界对货币的兴趣的线索,曾由帕森斯等人拾起,并在最... 详细信息

货币是社会学中一直存在但又不居主要地位的课题。书伯、齐美尔和马克思等古典社会学理论家在观察工业革命和民族国家统一市场的迅速形成过程时,为货币这种社会变迁动因所吸引。社会学界对货币的兴趣的线索,曾由帕森斯等人拾起,并在最近由贝克(***)、科曼(***)和齐里泽(***)等人所复兴。不过,现在还没有系统的货币社会学。本文叙述关于货币的社会学研究中的主要问题,并指出走上新的研究大道的途径。作为出发点,我们先将社会学家关于货币的谈论与另外两个群体——经济学家和人类学家的专业兴趣相比较。这一比较为我们考察货币社会学作出广义的限定。

关键词：社会学研究文化视角自变量定义通货社会学家

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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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管道内的应力腐蚀开裂

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油气储运 1997年第8期16卷 58-59页

作者： bubenik T.A. Nestleroth j.b. 谢恒孙伯英胜利石油管理局勘察设计院

应力腐蚀开裂是应力和电化学环境的协同作用的结果。应力腐蚀开裂分两种形式,一种是高pH值应力腐蚀开裂,环境pH值接近9;另一种是低pH值应力腐蚀开裂,环境pH值在5.5至7之间。管道的高pH值应力腐蚀开裂电化学反应形成氧化铁膜粘附在钢表面... 详细信息

应力腐蚀开裂是应力和电化学环境的协同作用的结果。应力腐蚀开裂分两种形式,一种是高pH值应力腐蚀开裂,环境pH值接近9;另一种是低pH值应力腐蚀开裂,环境pH值在5.5至7之间。管道的高pH值应力腐蚀开裂电化学反应形成氧化铁膜粘附在钢表面,可保护管子不受裂纹环境影响,但氧化铁膜破裂将促使裂纹形成或增大。对腐蚀开裂的检测应集中在裂纹密集区,或异形和分支裂纹区。

关键词：管道应力腐蚀裂缝检测油气管

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保护自然:抵制地球的金融化

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世界哲学 2023年第2期 39-50页

作者： [美]j.b.福斯特赵卯生(译) 范明洋(译) 姜楷文(译) 美国俄勒冈大学社会学系中国政法大学马克思主义学院

马克思和索迪等思想家曾对资本拜物教进行了尖锐批判。马克思指出,资本主义只关注交换价值而非使用价值的生产,并把自然视为一种免费礼物,导致对作为生产基本要素的自然的剥削,造成自然和社会之间新陈代谢的断裂。索迪指出,对资本、货... 详细信息

马克思和索迪等思想家曾对资本拜物教进行了尖锐批判。马克思指出,资本主义只关注交换价值而非使用价值的生产,并把自然视为一种免费礼物,导致对作为生产基本要素的自然的剥削,造成自然和社会之间新陈代谢的断裂。索迪指出,对资本、货币和金融的极端幻想,正在把世界引向最终的灾难。然而,资本主义的当下现实却是,资本主义借着拯救自然的名义,对自然进行定价、估值、货币化和金融化,在全球范围内进行着地球金融化的土地掠夺和债务积累行径,在剥夺地球资源和毁灭地球生态的同时,亦产生了被剥夺的全球环境后备军。抵制当前的地球金融化,必要条件就是努力实现工人阶级、人民群众和人类历史上各种运动的最大联盟。

关键词：自然金融化生态系统服务自然资本新陈代谢断裂

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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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企业应付变化的战略

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作者： j.b.·奎因(j.b. Quin)

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