填料-旋流板脱硫塔在净化加压变脱改造中的设计与应用

阐述了以塑料阶梯环填料与带溢流锥双程叶片旋流塔板组合的新型复合脱硫塔的设计开发,其结构特点为旋流板塔板采用了双程叶片结构,溢流装置采用新型带螺旋叶片结构,塔上部设置高2.53m填料层,改进并优化了喷淋装置及气体进、出口结构等。通过实际应用,证明该型脱硫塔在净化加压变换气脱硫工序中的应用是成功的。     

不锈钢冶炼用不烧镁钙砖的研制及应用

介绍了冶炼不锈钢用不烧镁钙砖的研制过程及其在冶炼不锈钢的 90tAOD炉炉帽和 90t装入包包底的应用情况。结果表明 :在 90t装入包包底的使用寿命达 1 1 0次 ,最大侵蚀速度仅为 1 .50mm·次 -1 左右 ;在 90tAOD炉炉帽上的使用寿命达 2 1 7次 ,最大侵蚀速度仅 0 .55mm·次-1 ,但存在裂纹和剥落现象 ,今后应改进砖型设计 ,增加调整砖 ,以消除砌缝 ,提高衬砖的整体性和稳固性     

One‐step synthesis and ring‐opening polymerization of novel macrocyclic(arylene multisulfide) oligomers

A series of macrocyclic(arylene multisulfide) oligomers were synthesized under high dilution conditions by reacting diphenyl ether/diphenyl/diphenyl disulfide/diphenyl methane with dichloro disulfide in the presence of a trace amount of iron powder by a one‐step reaction. From MALDI‐TOF mass spectra, it was established that the repeating units of the cyclization ranged from two to seven and the unit of macrocyclic(arylene multisulfide) oligomers had one to seven sulfur atoms. The macrocyclic oligomers readily underwent ring‐opening polymerization in the melt, resulting in linear, high molecular weight polymultisulfides. DSC thermograms demonstrated that the four polymultisulfides, derived from the macrocyclic(arylene multisulfide) oligomers, are amorphous in nature. The macrocyclic(arylene multisulfide) oligomers and polymers were analyzed by MALDI‐TOF‐MS, IR, HPLC, NMR, DSC, and TGA methods. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 735–741, 2004     

云母填料尺寸效应对水在环氧涂层中扩散行为的影响

以3种不同尺寸（124μm、38μm和19μm）的片状云母粉为填料，应用质量法和电化学阻抗法（EIS）研究云母填料尺寸效应对水在环氧涂层中的扩散行为的影响。结果表明在几种涂层中，水的扩散总是分为两个阶段：扩散初期阶段和平衡扩散阶段。浸泡初期水在涂层中的扩散行为除了124μm云母环氧涂层基本符合理想菲克扩散行为外，38μm云母环氧涂层和19μm云母环氧涂层均符合理想的菲克扩散定律，即涂层的吸水与浸泡时间的1／2次方成正比。但是水在几种涂层中的扩散系数却各不相同，其中38μm云母环氧涂层的扩散系数最小。     

国外以合成生物高聚物为基的可降解塑料

目前国外有三类重要的生物降解塑料,第一类是以天然高聚物为基的,第二类是以天然单体合成的高聚物为基的,第三类是以发酵过程生产的高聚物为基的。第一类已有大量论文报道,本文只综述第二类及第三类生物降解塑料的制造、特点、应用及发展现状和前景。     

Effect of Acceptor and Donor Dopants on the Dielectric and Tunable Properties of Barium Strontium Titanate

The effects of different concentrations of Mn²⁺, Mg²⁺, Al³⁺, Fe³⁺, La³⁺, and Nb⁵⁺ on the dielectric and tunable properties of Ba_0.6Sr_0.4TiO₃ ceramics were investigated. It was found that doping in small amounts with acceptor ions such as Mg²⁺, Fe³⁺, and Al³⁺ could meliorate the dielectric properties clearly. Decrease of dielectric loss was attributed to the formation of compensating defects originating from acceptor substitution. It was concluded that the tunability was linked to both the dielectric constant and the grain size. A higher figure of merit was obtained by doping the ceramics with smaller ions of Al and Fe, compared to Ti.     

一步法合成硫化剂双25的新方法

报道一种有机过氧化物 2 ,5 -二甲基 -2 ,5 -双 (叔丁过氧基 )己烷 (简称双 2 5 )的合成新方法。研究了反应温度、过氧化氢浓度、反应物摩尔比以及反应物加入顺序对产品产率、品质的影响。该双2 5与硅橡胶硫化后的混炼胶物经各种性能测试 ,结果表明具有优良的性能     

W2-3乙烯基酯树脂在精细化工中的应用

研究了W2-3酚醛环氧乙烯基酯树脂在精细化工生产的许多环节中的防腐蚀应用,对实际工程应用提出了一些建议.     

Foaming and chain extension of completely biodegradable poly(propylene carbonate) using DPT as blowing agent

Completely biodegradable foams of poly(propylene carbonate) (PPC) derived from carbon dioxide and propylene oxide were fabricated using N, N′-dinitroso pentamethylene tetramine (DPT) as chemical blowing agent, and urea as the activator to lower the decomposition temperature of DPT. Thermal decomposition behavior and gas evolution behavior of the DPT composite with various urea to DPT ratios were investigated to optimize the composition of the blowing agent. The formulation of blowing agent mixture and foaming condition, the foam morphologies, the molecular weight change, as well as the mechanical properties of produced PPC foams were studied extensively. The experimental results demonstrated that the greatest blowing ratio of 14.8 can be afforded in case 12 phr blowing agent was used at 170 °C for 30 min. Gel permeation chromatography (GPC) and thermal analysis revealed that DPT acted as both chain-extension agent and blowing agent for PPC matrix. The molecular weight of PPC subjected to foaming increased by 76%. The foamed PPC exhibited superior mechanical properties and can be used as packaging material for many practical applications.     

Detecting changes of the Yellow River Estuary via SAR images based on a local fit-search model and kernel-induced graph cuts

The Yellow River Estuary area of China is under great pressure from both human intervention and natural processes. For analysis of the changes in this area, this article presents a novel change-detection method based on a local fit-search model and kernel-induced graph cuts in multitemporal synthetic aperture radar images. Change detection involves assigning a label to every pixel. This task is naturally formulated in terms of energy minimization, which can be effectively solved by graph cuts. The difference image is transformed implicitly by a kernel function so that an alternative to complex modelling of the original data makes the piecewise constant model become applicable for graph cuts formulation. An issue is that graph cuts are sensitive to the initial estimate. The local fit-search model is proposed to approximate to the local histogram while selecting an optimal threshold for the initial labelling, which leads to an effective constraint for graph cuts and computational benefits as well. Visual and quantitative analyses obtained on the Yellow River Estuary data set confirm the effectiveness of the proposed method and that it outperforms the other state-of-the-art methods of change detection.