Nonlinear phenomena in vibrations of embedded carbon nanotubes conveying viscous fluid

Various nonlinear phenomena such as bifurcations and chaos in the responses of carbon nanotubes(CNTs)are recognized as being major contributors to the inaccuracy and instability of nanoscale mechanical systems.Therefore,the main purpose of this paper is to predict the nonlinear dynamic behavior of a CNT conveying viscousfluid and supported on a nonlinear elastic foundation.The proposed model is based on nonlocal Euler–Bernoulli beam theory.The Galerkin method and perturbation analysis are used to discretize the partial differential equation of motion and obtain the frequency-response equation,respectively.A detailed parametric study is reported into how the nonlocal parameter,foundation coefficients,fluid viscosity,and amplitude and frequency of the external force influence the nonlinear dynamics of the system.Subharmonic,quasi-periodic,and chaotic behaviors and hardening nonlinearity are revealed by means of the vibration time histories,frequency-response curves,bifurcation diagrams,phase portraits,power spectra,and Poincarémaps.Also,the results show that it is possible to eliminate irregular motion in the whole range of external force amplitude by selecting appropriate parameters.

Geochemistry, mineral paragenesis and geothermal conditions of oreforming fluids from the Ain El Bey Cu–Fe deposit: potential occurrence of native gold and precious metal traces (North African orogenic belt, Northern Tunisia)

The Ain El Bey abandoned mine, in North-West Tunisia, fits into the geodynamic context of the European and African plate boundary. Ore deposit corresponds to veins and breccia of multiphase Cu–Fe-rich mineralization related to various hydrothermal fluid circulations. Petromineralogical studies indicate a rich mineral paragenesis with a minimum of seven mineralization phases and, at least, six pyrite generations. As is also the case for galena and native silver, native gold is observed for the first time as inclusion in quartz which opens up, thus, new perspectives for prospecting and evaluating the potential for noble metals associated with the mineralization. Scanning Electron Microscope--Energy Dispersive Spectroscopy and Transmission electron microscopy analyses show, in addition, a large incorporation of trace elements, including Ag and Au, in mineral structures such as fahlores(tetrahedrite-tennantite) and chalcopyrite ones. The mineral/mineral associations, used as geothermometers, gave estimated temperatures for the mineralizing fluids varying from 254 to 330 ℃ for phase Ⅲ, from 254 to 350 ℃ for phase Ⅳ, and from 200 to 300 ℃ for phases Ⅴ and Ⅵ. The seventh and last identified mineralization phase, marked by a deposit of native gold, reflects a drop in the mineralizing fluid’s temperature(< 200 ℃) compatible with boiling conditions. Such results open up perspectives for the development of precious metal research and the revaluation of the Cu–Fe ore deposit at the Ain El Bey abandoned mine, as well as at the surrounding areas fitting in the geodynamic framework of the Africa-Europe plate boundary.

Insight into the dynamics of non-Newtonian Carreau fluid when viscous dissipation,entropy generation,convective heating and diffusion are significant

The investigation endorsed the convective flow of Carreau nanofluid over a stretched surface in presence of entropy generation optimization.The novel dynamic of viscous dissipation is utilized to analyze the thermal mechanism of magnetized flow.The convective boundary assumptions are directed in order to examine the heat and mass transportation of nanofluid.The thermal concept of thermophoresis and Brownian movements has been re-called with the help of Buongiorno model.The problem formulated in dimensionless form is solved by NDSolve MATHEMATICA.The graphical analysis for parameters governed by the problem is performed with physical applications.The affiliation of entropy generation and Bejan number for different parameters is inspected in detail.The numerical data for illustrating skin friction,heat and mass transfer rate is also reported.The motion of the fluid is highest for the viscosity ratio parameter.The temperature of the fluid rises via thermal Biot number.Entropy generation rises for greater Brinkman number and diffusion parameter.

图书馆行业RFID-UID编码标准化方案问题探讨

通过对现行图书馆RFID-UID应用模式和商业物流RFID-UID标准的对比分析及与ISBN的关系,提出了书馆行业RFID-UID的编码方案。

GeoUIDS的研制及其在地震模拟软件开发中的应用

论述了基于UIDS开发用户界面的优势 ,介绍了用户接口开发系统 (GeoUIDS)所使用的一些关键技术 ,其中包括目标用户接口模型、基于对话树控制的事件驱动机制、面向对象技术、交互技术等 ,重点阐述了GeoUIDS描述器的组成和如何利用该描述器生成图形用户界面 ,并对GeoUIDS的特点进行了总结。最后 ,以地震模拟软件的开发为例 。

泛在ID(UID)中心的RFID标准化进展

介绍了泛在识别(UID)中心的机构组成、成立宗旨和标准化现状,研究了泛在识别中心RFID标准体系结构,对泛在识别码、泛在通信器、信息系统服务器和ucode解析服务器的功能及原理进行了分析,最后给出了ucode标签分级标准。

Transient thermo-mechanical analysis for bimorph soft robot based on thermally responsive liquid crystal elastomers

Thermally responsive liquid crystal elastomers (LCEs) hold great promise in applications of soft robots and actuators because of the induced size and shape change with temperature. Experiments have successfully demonstrated that the LCE based bimorphs can be effective soft robots once integrated with soft sensors and thermal actuators. Here, we present an analytical transient thermo-mechanical model for a bimorph structure based soft robot, which consists of a strip of LCE and a thermal inert polymer actuated by an ultra-thin stretchable open-mesh shaped heater to mimic the unique locomotion behaviors of an inchworm. The coupled mechanical and thermal analysis based on the thermo-mechanical theory is carried out to underpin the transient bending behavior, and a systematic understanding is therefore achieved. The key analytical results reveal that the thickness and the modulus ratio of the LCE and the inert polymer layer dominate the transient bending deformation. The analytical results will not only render fundamental understanding of the actuation of bimorph structures, but also facilitate the rational design of soft robotics.

美国国防部物品唯一标识(UID)初探

唯一标识(UID)技术,其基本思路是对超过一定价值或比较关键的资产进行唯一性编号,包括应用标识符或数据标识符、授权机构代码、企业代码、批次号、序列号等;使用一定的编码技术使之成为机器可读标识符;使用粘贴标签、DPM、激光雕刻、化学蚀刻、喷墨等方式,在不影响设备功能的前提下,制作永久标识。UID技术对于我国军队的现代化建设有一定借鉴意义。

V-uniform ergodicity for fluid queues

In this paper, we show that a positive recurrent ?uid queue is automatically V-uniformly ergodic for some function V ≥ 1 but never uniformly ergodic. This reveals a similarity of ergodicity between a ?uid queue and a quasi-birth-and-death process. As a byproduct of V-uniform ergodicity, we derive computable bounds on the exponential moments of the busy period.

UID的浮沉录

一、背景简介 在日本，射频的发展始于20世纪80年代中期的实时操作系统（TRON），T—Engine是TRON核心的体系构架。2003年3月，T-Entgine论坛领导成立了U—biquitous ID中心（简称UID，目前中文普遍翻译成“泛在技术”），并得到了日本政府经产省、总务省以及包括索尼、三菱、日立等大企业在内的ETRON联盟的支持，其目的是创造一个泛在环境，能够支持物品自动识别和随时随地的通信，满足人们日益增长的信息化需求。

Electroviscous effect on electromagnetohydrodynamic flows of Maxwell fluids in parallel plate microchannels

Considering the influence of the streaming potential and electroviscous effects, the analytical solutions for electromagnetohydrodynamic (EMHD) flows in parallel plate microchannels are obtained. The electrolyte solutions in the microchannels are taken as generalized Maxwell fluids, and slip boundary conditions are adopted. To accurately analyze the EMHD flow characteristics, the variation trends of the electroviscous effects with the corresponding parameters must be understood. The results show that the electroviscous effects increase with the increase in the relaxation time De, the slip coefficient , and the wall zeta potential 0. However, the increase in the inverse of the electrical double-layer (EDL) thickness K, the electrical oscillating Reynolds number Re, and the ionic P'eclet number Pe can decrease the electroviscous effects. We also demonstrate that the electroviscous effect on the EMHD flows of generalized Maxwell fluids is larger than that of Newtonian fluids. This work will be useful in designing EMHD flows in parallel plate microchannels.

Couple stress nanofluid flow through a bifurcated artery—Application of catheterization process

In this article,we are exploring the hemodynamics of nanofluid,flowing through a bifurcated artery with atherosclerosis in the presence of a catheter.For treating obstruction in the artery,one can use the catheter whose outer surface is carrying the drug coated with nano-particles.The resultant solvent is considered as blood nano-fluid.Blood being a complex fluid,is modeled by couple stress fluid.In the presence of nano-particles,the temperature and the concentration distribution are understood in a bifurcated stenotic artery.The concluded mathematical model is governed by coupled non-linear equations,and are solved by using the homotopy perturbation method.Consequently,we have explored is the effects of fluid and the embedded geometric parameters on the hemodynamics characteristics.It is also realized that high wall shear stress exists for couple stress nano-fluid when compared to Newtonian nano-fluid.which is computed at a location corresponding to maximum constriction(z=12.5)of the artery.

Analysis of waveguide structure for surface plasmon polariton interference

This paper describes a multi-reflected mode based on a narrow waveguide to enlarge the interferential area of surface plasmon polaritons （SPPs）. A reasonable thickness of metal film is coated under the waveguide, the incident angle and the waveguide thickness are optimized in order to effectively increase interferential area. This is a key point for research into the Coos Hǎnchen shift to optimize the waveguide thickness. Finally, the SPP interferential field is simulated with the finite-difference time-domain （FDTD） technique to prove the optimized results, and indicates that not only is the interferential area enlarged, but the high contrast is also maintained. Furthermore, the mode can fabricate some specific interferential patterns by adding some modulating techniques to the waveguide. So the mode has potential application in the fabrication of sub-wavelength patterns.

Dynamics of optical rogue waves in inhomogeneous nonlinear waveguides

We propose a unified theory to construct exact rogue wave solutions of the （2＋1）-dimensional nonlinear Schr6dinger equation with varying coefficients. And then the dynamics of the first- and the second-order optical rogues are investigated. Finally, the controllability of the optical rogue propagating in inhomogeneous nonlinear waveguides is discussed. By properly choosing the distributed coefficients, we demonstrate analytically that rogue waves can be restrained or even be annihilated, or emerge periodically and sustain forever. We also figure out the center-of-mass motion of the rogue waves.

新时代背景对UID设计师的影响因素

UID是"User Interface Designer"的英文简称,中文译为UI设计师,主要工作范畴是在广告、媒体、网络、娱乐、移动、教学等领域,从事多媒体设计、制作、开发、教育等方面工作。其设计内容包括:平面设计(GUI)、网页设计(WUI)、移动界面设计(MUI)、游戏设计(PUI)、媒体设计(Me UI)。本文举例分析在新时代背景下影响UI设计师的若干因素。

利用UID的唯一性解决大型服务器及多客户端用户的设置问题

石油行业对大型服务器的应用一般是将大型石油应用软件安装到服务器上,如果所有研究人员通过其多个网络客户端对其登录。这就需要很多并不固定的用户供他们使用,常规的用户管理理念无法满足这样的用户设置。本文以油田勘探解释系统为例,阐述如何利用UID的唯一性来解决大型服务器及多客户端用户的设置问题。这样既保证了各用户数据的安全与共享,又满足了用户对建立个性化用户的需要。

用UID的唯一性配置大型服务器客户端

石油行业对大型服务器的应用一般是将大型石油应用软件安装到服务器上,如果所有研究人员通过其多个网络客户端对其访问,这就需要很多并不固定的用户供他们使用,常规的用户管理理念无法满足这样的用户设置。本文以油田勘探解释系统为例,阐述如何利用UID的唯一性来解决大型服务器及多客户端用户的设置问题。这样既保证了各用户数据的安全与共享,又满足了用户对建立个性化用户的需要。

Metalcraft公司推出UID电缆标签

Metalcraft公司宣布可提供定制的UID电缆标签，用于解决标记电线电缆的难题，使美国国防部的承包商能符合UID标准。

基于GS1标准化UID条码技术的医用高值耗材追溯监管

主要通过介绍基于GS1(Global Standard1)全球标准编码体系编制结构的唯一标识UDI(Unique Device Identification)编码的耗材管理系统,通过对不同高值耗材编码体系的分析研究,建立全球唯一的物资字典库,实现耗材从出厂到应用于病人的信息化管理。该体系主要通过采用UDI相应的编码体系来管理高值耗材的识别和追溯;本系统符合医院关于提高医疗器械风险管理的要求。

液氮抑制32650型磷酸铁锂电池组热失控传播特性试验研究

文章从磷酸铁锂电池组热失控危险特性出发,通过试验研究32650型磷酸铁锂电池单体热失控特征及其电池组间热失控传播过程。探究利用液氮喷淋阻断电池组间热失控传播,分析液氮对磷酸铁锂电池的防灭火效能。结果表明:单体锂电池热失控可划分为被动加热、安全阀泄压、自反应、喷射火、明火熄灭等5个阶段,单体电池温度变化曲线呈倒“V”形。液氮可有效阻断电池组间的热失控传播,能够大幅降低喷射火阶段的电池峰值温度。且喷淋时间越长,阻止电池组热失控传播越明显。30 s液氮喷淋条件下,除电池A1外,其他电池未进入安全阀泄压阶段。