带式输送机系统的设计与设备选型(一)

1通用带式输送机技术的发展情况 带式输送机与其他运输方式相比具有运距长，能力大，投资省，运费低，操作简单安全，管理维修容易，能耗低，污染小等优势而逐渐成为各行业物料搬运的主要手段。高强度的钢绳芯带式输送机因其为矿山开采和矿石输送工艺创造了十分有利的条件而在各种矿山外部输送中得到快速发展。近年来随着水泥厂规模迅速扩大，带式输送在水泥行业已成为矿石原料输送的首选方案。     

粉尘含碳球团还原方式及气氛对其还原挥发性能的影响

在1150℃和1250℃、0．1L／min和10L／min的气量下，对通人含不同CO2量的氮气影响粉尘含碳球团还原速度的实验研究表明：以滚动方式所造球团中，氧化物的还原完全以间接还原的方式进行，气氛中非还原气体流速（或流量）的增加对粉尘含碳球团氧化铁还原速度有显著的降低作用，但还原温度提高则对气量增加造成的氧化铁还原速度降低有显著的抵消作用．气氛对球团中锌的挥发速度影响很小，对铅的挥发速度几乎不产生影响．     

聚乙烯醇存在下耐尔蓝－铈钼、钪钼杂多酸体系连续光度测定铈和钪

在聚乙烯醇（ＰＶＡ）存在下，耐尔蓝（ＮＢ）与铈钼、钪钼杂多酸络阴离子形成离子缔合物，其最大吸收均位于５８５ｎｍ，表观摩尔吸光度分别为εｃｗ＝３．５２×１０６和εＳｃ＝３．５９×１０＿５Ｌ·ｍｏｌˉ１·ｃｍˉ１，铈和钪服从比耳定律的浓度范围分别为０～０．８μｇ／２５ｍｌ和０～２．０μｇ／２５ｍｌ，测定极限分别为１．３ｎｇＣｅ／ｍｌ（ｎ＝１０）和３．０ｎｇＳｃ／ｍｌ（ｎ＝７），对于０．０２μｇＣｅ／ｍｌ或０．０４μｇＳｃ／ｍｌ测定的相对标准偏差分别为２．７％（ｎ＝９）和２．８％（ｎ＝１０），离子缔合物的摩尔比分别为Ｃｅ：Ｍｏ：ＮＢ＝１：６：４和Ｓｃ：Ｍｏ：ＮＢ＝１：１２：３。本法用于地质标样分析，结果满意。     

Thermal and crystallization characteristics of poly(ethylene terephthalate) with poly(oxybenzoate‐p‐trimethylene terephthalate) copolymer

Poly(ethylene terephthalate) (PET) was blended with two different poly(oxybenzoate‐p‐trimethylene terephthalate) copolymers, designated T28 and T64, with the level of copolymer varying from 1 to 15 wt %. All samples were prepared by solution blending in a 60/40 (by weight) phenol/tetrachloroethane solvent at 50°C. The crystallization behavior of the samples was studied by DSC. The results indicate that both T28 and T64 accelerated the crystallization rate of PET in a manner similar to that of a nucleating agent. The acceleration of PET crystallization rate was most pronounced in the PET/T64 blends with a maximum level at 5 wt % of T64. The melting temperatures for the blends are comparable to that of pure PET. The observed changes in crystallization behavior are explained by the effect of the physical state of the copolyester during PET crystallization as well as the amount of copolymer in the blends. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1599–1606, 2002     

Synthesis and Morphology of TiO2 Nanotube Arrays by Anodic Oxidation Using Modified Glycerol-Based Electrolytes

Titanium dioxide (TiO₂) nanotube arrays were prepared by electrochemical anodization of titanium sheets in the glycerol 176 mL/H₂O 44 mL/NH₄F 0.5 wt% electrolytes modified with H₂SO₄ and NaAc addition. The surface morphologies, average inner diameter, and the length of the nanotube arrays changed with the solution pH in the range from 5.6 to 4.0 by adding H₂SO₄. A uniform surface morphology of the nanotubes with average inner diameter of ∼80 nm and a length of ∼1000 nm was obtained when the solution pH was 5.0. The growth rates of the nanotubes were remarkably enhanced by NaAc addition in the range of 0.04–0.14 M . With NaAc addition of 0.10 M , the length of the nanotube arrays reached 4.16 μm after an 8-h anodization, increasing 3.23 μm compared with no NaAc addition. The relationship between solution pH and growth of TiO₂ nanotubes was analyzed by current–time curves, solution electrical conductivities, and scanning electron microscopy (SEM), and the role of NaAc was also discussed based on SEM and solution electrical conductivities.     

Intramolecular vs intermolecular formation of bityrosine upon photoreaction of poly(l-tyrosine) in dilute aqueous solution

Summary The molecular weight dependence of the rate of the formation of bityrosine upon irradiation of poly(L-tyrosine) at 300 nm has been investigated in dilute aqueous solution, pH 12. The samples studied were the monodisperse monomer, dimer, trimer, and hexamer, as well as two polydisperse polymers with average degrees of polymerization of 10² and 10³. The reaction is predominantly intermolecular in the monodisperse oligomers, but it is predominantly intramolecular in the two polymers. The intramolecular reaction in the polymers involves phenolic rings on monomers i and i+j, with j>5. The steric restraints imposed by the backbone of the chain make it unlikely that two rings will approach one another with the appropriate geometry for reaction if j<5.     

民办高校外籍教师的绩效管理研究

探讨民办高校外籍教师绩效管理应遵循制度化、科学化、精细化、人文化等原则:民办高校外籍教师绩效管理的内容应包括制度管理、教学管理、生活管理及绩效考核等方面.     

荔浦县旅游形象定位研究

根据荔浦县的自然地理、文化传统和社会心理方面的特点,认为荔浦旅游形象的核心要素是以溶洞为代表的旅游资源和以荔浦芋为代表的民俗文化,因此荔浦县的旅游形象可提炼为"洞绝天下,‘芋'(誉)满神州".     

高校和谐平安校园建设研究

围绕创建和谐平安校园、实现学校新一轮发展的战略目标,必须要建立健全的思想政治工作机制,完善沟通机制,健全保障机制,构建公平公正的法治环境。     

普通高校学生自主学习能力探究

自主学习是主体教育思想在教学领域的反映,其本意是学生由他主学习转向自主学习。学生自主学习,是符合学生学习的本质和特点的,也是培养未来具有自主性、创造性、创新性人才的根本要求,本文提出实现学生自主学习,应注意激发学生兴趣,运用多种手段提高教学质量,多让学生动手动脑,提高学生的自主学习能力,才能真正突出学生的主体地位。