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101.
脱乙烷系统参数优化   总被引:1,自引:0,他引:1  
吉化300kt/a乙烯装置脱乙烷系统采用德国Linde公司双塔双压前脱乙烷技术,自1996年开始以来,运行良好,通过工程技术人员近两年的探索实践,对其工艺参数做了较大的优化调整,取得了较好的经济效益。  相似文献   
102.
A novel dicyclodextrinyl ditelluride (2-TeCD) compound was devised as a functional mimic of the glutathione peroxidase (GPX) enzymes that normally remove hydroperoxides from the cell. The GPX activity of the mimic was found to be 46.7 U microM(-1), which is 46 times as active as Ebselen, a well-known GPX mimic. A detailed steady-state kinetic study was undertaken to probe the reason for the high catalytic efficiency of 2-TeCD. This high efficiency can be explained based on both the binding of the substrate to the cyclodextrin and the catalytic mechanism of 2-TeCD, which is different from that of diselenide compounds. 2-TeCD exhibits good water solubility and is chemically and biologically stable. The biological effect of 2-TeCD was evaluated by its ability to protect mitochondria from oxidative damage. 2-TeCD exhibited excellent antioxidant capacity in comparison with Ebselen.  相似文献   
103.
Molecular dynamics (MD) simulations of-Al2O3, using a pairwise additive interaction potential of Pauling's type with four different radii for aluminum atoms, were analysed in order to determine the influence of the radius on the modification of coordination numbers of A1 relative to the ideal structure, at two different temperatures of 300 and 1500 K. It is found that the best choice is the radius of penta-coordinated aluminum, reproducing structural and vibrational properties of the compound in excellent agreement with experimentally observed properties.  相似文献   
104.
Si3N4陶瓷材料的高温氧化理论及其抗氧化研究现状   总被引:1,自引:0,他引:1  
从热力学、动力学和整体控速过程探讨了氮化硅陶瓷材料高温氧化理论和氧化性质,阐述了表面改性技术对氮化硅抗氧化性能的影响.并对表面改性提高氮化硅抗氧化性能进行了展望。  相似文献   
105.
穆振义 《上海染料》2006,34(1):40-47
该文重点讨论了异吲哚啉及异吲哚啉酮颜料的品种,分子结构,特性与应用;颜料的合成工艺,颜料化和相关中间体.该类颜料以黄色品种为主,由于存在分子间及分子内氢键、并构成立体的网状堆砌,具有优异的牢度性能和重要用途.  相似文献   
106.
The interaction and synergism of some polyoxyethylenated fatty alcohol ether (POE) nonionic surfactants (C12E2, C12E3, C10E5, C10E7, where Cx indicates number of carbon atoms in the chain and Ey indicates number of oxyethylene glycol ethers) with trioxyethylenated dodecyl sulfonate (C12E3S) in mixed monolayer formation at the surface and in mixed micelle formation in aqueous solutions were studied at 25 and 40°C by calculating interaction parameters (βα, βM) from surface tension-concentration data by use of Rosen's equations based on the nonideal solution theory. All the systems investigated adapt reasonably well to the nonideal model, with negative values of βσ and βM (where M means micelle and σ refers to the air-liquid interface) indicating a favorable interaction between the mixed surfactants. Either at a monolayer or in a mixed micelle, the attractive interaction becomes stronger when the alkyl chain in the POE surfactant is longer, i.e., when the POE becomes more hydrophobic. The interaction increases in the order C10E7<C10E5<C12E3, C12E2. For the two C10E n (n= 5,7)/C12E3S systems, as temperature increases from 25 to 40°C, the interaction increases in a mixed micelle, but it decreases in a mixed monolayer. Synergism in mixed micelle formation exists for C12E3S/C10E n mixtures when X1 M , the mole fraction of POE in a mixed micelle, is ≈0.4–0.8, whereas synergism does not occur in the systems of C12E3S/C12E m due to the large difference between CMC1 and CMC2, i.e., large |In(C 1 M /C 2 M )| value (where CMC=critical micelle concentration). The degree of synergism in mixed micelle formation is temperature independent and is 0.23, 0.18, and close to zero for C10E5/C12E3S, C10E7/C12E3S, and C12E m (m=2,3)/C12E3S systems, respectively. Synergism in surface tension reduction effectiveness occurs in C12E3S/C12E2 and C12E3S/C12E3 systems. The mole fractions of POE in the solution phase are 0.302 and 0.333 for the two mixtures at the point of maximum synergism.  相似文献   
107.
The different melting temperatures of N‐methyl morpholine N‐oxide (NMMO) hydrates in the cellulose–NMMO hydrate solution may be explained by the rather different crystal structures of NMMO hydrates, which are determined by the amount of the hydrates. The preparative process of cellulose–NMMO hydrate solution may result in cellulose structural change from cellulose I to cellulose II, depending on the amount of the hydrate. Mixtures of cellulose and NMMO hydrate in a blender was changed from the granules to slurry with increasing mixing time at 60–70°C, which is below the melting point of the NMMO hydrate. In the case of 15 wt % cellulose–NMMO hydrate granules, which were made by mixing for 20 min, the melting points of various NMMO hydrates were obtained as 77.8°C (n = 0.83), 70.2°C (n = 0.97), and 69.7°C (n = 1.23), respectively, depending on the hydrate number. However, the melting points of cellulose–NMMO hydrate slurry and solution were shifted lower than those of cellulose granules, while the mixing time of slurry and solution are 25 and 35 min, respectively. These melting behaviors indicate instantaneous liquefaction of the NMMO hydrate and the diffusion of the NMMO hydrate into cellulose during mixing in a blender. When cellulose was completely dissolved in NMMO hydrate, the crystal structure of cellulose showed only cellulose II structure. In the cellulose–NMMO products of granules or slurry obtained by high‐speed mixing, which is a new preparation method, they still retained the original cellulose I structure. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1687–1697, 2004  相似文献   
108.
PFSI/ePTFE composite proton exchange membranes were fabricated by impregnating perfluorosulfonic acid resin (PFSI resin, Nafion) into chemically modified expanded PTFE (ePTFE) matrix. Chemical modification of sodium-naphthalene treatment and N-methylol acrylamide (NMA) grafting decreased the contact angle of the as-received ePTFE from 125 ± 0.5° to 67 ± 0.5°, effectively converting the as-received hydrophobic ePTFE to a hydrophilic ePTFE matrix. The composite membrane fabricated with the hydrophilic ePTFE have higher impregnated PFSI loading, much lower porosity and better PTFE/PFSI interface contact, as compared to the composite membranes with the as-received ePTFE. This leads to much lower gas permeability and significantly improves the durability under an accelerated dry/wet cycle test. The fuel cell made from the PFSI/ePTFE composite membranes with hydrophilic ePTFE showed superior performance as compared to that with the composite membrane made from the as-received ePTFE and Nafion 211 membrane.  相似文献   
109.
乔木  张明  初小葵  黄大勇 《中国陶瓷》2003,39(3):26-28,25
本文研究了一种陶瓷吸塑模具,并着重阐述了陶瓷吸塑模具的材料、性能和特点以及该模具在制备过程中工艺路线和工艺要点。  相似文献   
110.
灭多威在棉花及土壤中降解动态及残留量研究   总被引:6,自引:0,他引:6  
慕卫  王开运 《农药》1996,35(3):31-33
按生产上常规用量,每亩喷施20%灭多威乳油60毫升防治二代棉铃虫,施药后7天在棉叶上及14天在土壤中其降解率分别为98.81%及88.09%;半衰期分别的1.56天及4.98天。防治二、三、四代棉铃虫,按有效剂量施药6次,有效成分72克/亩,棉籽和土壤中的最大残留量分别为0.023及0.084微克/克;再加大50%用量,有效成分108克/亩,最大残留量仅为0.034及0.214微克/克。结果表明,灭多威在棉叶上及土壤中降解较迅速,常规用量下,对棉籽及土壤污染较轻。  相似文献   
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