碳纳米管作为新型催化材料的发展

纳米材料真正作为研究领域的历史至今还不到一个世纪,在这不到一世纪时间里,纳米材料在人们越来越炽热的关注中飞速发展。作为纳米材料,其粒子由于尺寸的微观性,以及量子力学的出现,便具有了一些特殊的性质,包括量子尺寸效应、小尺寸效应、表面效应以及宏观量子隧道效应。在石油化工领域,催化剂是整个行业的命脉之一,而纳米材料由于其特殊的性质,使其在催化材料方面也开始逐渐崭露头角,并被专业人士视为富有前景的新型催化材料。本文中将以碳纳米管(CNTs)为例着重介绍其作为催化材料的发展进程并进行展望。     

浅析疏水阀的选型及配管

介绍了蒸汽加热设备或管道的蒸汽疏水方式;简述了蒸汽管道疏水量的估算方法;总结了有关疏水阀选型、布置及配管等方面的设计经验。     

钛矿渣-页岩烧结制品的工艺研究

测试分析钛矿渣和页岩的矿物组成、化学成分,把钛矿渣加入到页岩中制备烧结砖。研究钛矿渣与页岩的配比及其烧成制度对烧结制品抗压强度的影响,并利用X射线衍射仪、扫描电子显微镜对烧结砖进行微观结构分析。通过正交实验确定了各因素对烧结砖抗压强度的影响程度由大到小顺序为:烧结温度﹥钛矿渣掺量﹥保温时间,烧结砖制备的最佳工艺条件:钛矿渣掺量为10%,烧结温度为1 100℃,保温时间为2h。钛矿渣-页岩烧结制品结构致密,并有大量长石类矿物相生成,使得制品抗压强度增强。     

A constitutive model for saturated compacted soils under undrained shear condition

Abstract

In this paper, elasto‐plastic constitutive equations extended from theory of plasticity and based on laws of thermo‐dynamics were derived to predict the mechanical behavior of saturated geological media. Besides, these equations can also be adapted to form the stiffness matrix for finite element analysis on deformation and stress distribution in geotechnical engineering practice. The test data were obtained from compacted crushed mudstone under consolidated un‐drained triaxial tests with pore water pressure measurement. The preparation of the specimen was different from those which had usually been adopted. Hence, it is hoped that this study will throw some light on the constitutive equations applied on compacted geological media.     

Study on AdaBoost-based link quality prediction mechanism

The link quality was vulnerable to the complexity environment in wireless sensor network.Obtaining link quality information in advance could reduce energy consumption of nodes.After analyzing the existing link quality prediction methods,AdaBoost-based link quality prediction mechanism was put forward.Link quality samples in deferent scenarios were collected.Density-based unsupervised clustering algorithm was employed to classify training samples into deferent link quality levels.The AdaBoost with SVM-based component classifiers was adopted to build link quality prediction mechanism.Experimental results show that the proposed mechanism has better prediction precision.     

液-固流化床回收废旧印刷电路板金属研究

采用液-固流化床对废旧印刷电路板资源化利用进行研究,通过分析颗粒在流化床中的运动机理,计算不同颗粒在流化床中的沉降末速度,并探讨影响颗粒沉降末速度的因素。结果表明,颗粒干扰沉降末速度随着颗粒密度和粒度的增大而增大,随着颗粒体积分数的增大而减小;对不同粒级不同给料量进行分选,随着上升水速的增大,金属回收率随之下降,品位随之提高;在实验范围内,给料量对液-固流化床中金属与非金属的分选效果基本无影响。     

遥控液压打渣机在有色冶金工业中的应用

一种遥控液压打渣机越来越多的应用到我国有色冶金工业的炉窑维修中,它改变了传统的炉窑维修方式,带来了拆除效率和作业安全上的提升.本文回顾总结了有色冶金炉窑维修装备的历史,阐述了遥控液压打渣机应用的特点和优势,指出遥控液压打渣机在有色冶金炉窑的维修中的广泛应用将是发展方向.     

Compression Stability of Reversed Austenite in 9Ni Steel

The effect of compressive stress on the stability of reversed austenite in 9Ni steel was investigated by uniaxial and hydrostatic compression.It was found that the uniaxial compressive pressure promoted the γ→α transformation,while the hydrostatic pressure suppressed the γ→α transformation.The pressure dependent transformation behavior can be explained according to thermodynamic analysis.     

Influence of Erosion and Deposition on Metallic First Mirror in HT-7 Tokamak

Dedicated experiments in the HT-7 tokamak were performed to investigate the in-fluence of erosion and deposition on the mirror samples.The first mirror (FM) samples made of polycrystalline (PC) stainless steel (SS),molybdenum (Mo) and tungsten (W) were fixed on a holder at an angle of 45 with respect to the horizontal plane and set at different locations with different connection lengths along the magnetic field.The optical reflectivity of the first mirror was measured by a spectrophotometer before and after plasma exposure.It was found that the surface morphology and specular reflectivity of the mirror samples after the exposure were different with respect to the different distances from the mirror surface to the last closed flux surface (LCFS) of the plasma in the tokamak.It was also found that shortening the connection length before the mirror surface would weaken the influence of the plasma erosion and impurity deposition on the mirror surface.In order to maintain the optical characteristics of the mirror surface,it is necessary to adopt the in-situ cleaning and mirror protection techniques.     

Adhesion energy can regulate vesicle fusion and stabilize partially fused states

Release of neurotransmitters from nerve terminals occurs by fusion of synaptic vesicles with the plasma membrane, and this process is highly regulated. Although major molecular components that control docking and fusion of vesicles to the synaptic membrane have been identified, the detailed mechanics of this process is not yet understood. We have developed a mathematical model that predicts how adhesion forces imposed by docking and fusion molecular machinery would affect the fusion process. We have computed the membrane stress that is produced by adhesion-driven vesicle bending and find that it is compressive. Further, our computations of the membrane curvature predict that strong adhesion can create a metastable state with a partially opened pore that would correspond to the ‘kiss and run’ release mode. Our model predicts that the larger the vesicle size, the more likely the metastable state with a transiently opened pore. These results contribute to understanding the mechanics of the fusion process, including possible clamping of the fusion by increasing molecular adhesion, and a balance between ‘kiss and run’ and full collapse fusion modes.