共查询到20条相似文献,搜索用时 78 毫秒
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以LED-UV365/PDS为研究体系,考察了对碘帕醇(IPM)的降解效能。实验结果表明,单独PDS、单独UV365辐照基本无法降解IPM,LED-UV365/PDS体系可显著促进IPM的降解,且反应过程符合假一级反应,这主要得益于反应体系产生的活性物种(HO·、SO4·-、O2·-和1O2),其中HO·的贡献最大。研究了PDS浓度、pH、天然有机物(NOM)和阴离子(HCO3-、Cl-)浓度对IPM降解效果的影响,结果表明IPM的降解率随PDS浓度的增加逐步升高。在酸性、碱性、中性条件下,LED-UV365/PDS体系均可高效降解IPM。NOM因具有内滤波效应以及对活性物种的捕获作用,可明显抑制IPM的降解效果;通过实验与计算获得NOM在365 nm处的吸光系数为26.52 L/(g·cm);阴离子存在... 相似文献
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作为X-射线造影剂的三碘苯甲酸衍生物经历了从离子型到非离子型的发展过程[1~3]。衍生物中的碘具有低毒性、高造影密度及与苯环结合牢固的特点,目前尚难以用其他元素取代[1]。离子型三碘苯甲酸衍生物由于存在电荷、化学毒性、高渗透压等缺点,逐步为非离子型所取代。但目前进口造影剂碘帕醇(Iopamidol)、碘海醇(Iohexol)和碘普罗胺(Iopromide)仍存在高渗问题[4]。为改善非离子单体的性能,我们采用间苯二甲酸为起始物,分别用硝化→酯化→酰胺化→还原→碘化→乙酰氨化和硝化→还原→碘化→酰… 相似文献
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碘普罗胺是一种在临床上应用广泛的碘造影剂。本文先介绍了碘普罗胺的重要性,再从国内和国外两个角度分析了专利中其合成工艺路线,重点讨论了不同合成路线的特点和优劣,并进行了比较和总结。 相似文献
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甲磺酸帕珠沙星的合成工艺改进 总被引:2,自引:0,他引:2
以左氧氟沙星的中间体--(S)-9,10-二氟-3-甲基-7-氧代-2,3-二氢-7H-吡啶[1,2,3-de][1,4]苯并噁嗪-6-羧酸乙酯为起始原料,经过与氰乙酸乙酯缩合、水解脱羧、1,2-二溴乙烷环合、水解、霍夫曼降解、成盐得到喹诺酮类抗菌药甲磺酸帕珠沙星.总收率达到43.8%,并对目标产物,进行了元素分析,IR,1H NMR,13C NMR,MS等确认.与文献报道相比,该合成工艺路线具有反应条件温和,收率较高,适合工业化生产. 相似文献
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A. K. Sen Ramesh Kumar Darshan Lal A. K. Srivastava 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1990,49(1):65-74
The dimers and trimers of norbornadiene have a unique polycyclic strained structure and are of great practical value. A systematic study of the synthesis of norbornadiene from dicyclopentadiene and acetylene under pressure has been carried out. The effects of various operating parameters on product distribution have been determined. The optimum conditions for the synthesis are: (i) temperature, 290°C; (ii) residence period, 16 min; (iii) mole ratio of C2H2:N2: dicyclopentadiene, 1:1:0.4; and (iv) initial pressure at ambient temperature, 8.894 × 105 nm?2. Under these conditions the conversion of norbornadiene is 41.74% on the basis of dicyclopentadiene consumed. The loss of dicyclopentadiene due to polymerisation has been estimated from its balance. A kinetic study of the synthesis from cyclopentadiene has also been carried out. 相似文献
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以取代苯胺为原料,经甲酰化、胺解合成了二个二苯基脲衍生物,利用元素分析、红外光谱对目标化合物进行了结构表征,并讨论了反应温度、反应时间对收率的影响。 相似文献
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Anjana Bhattacharya Jagannath Das Swapan Mitra Sisir K. Roy 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1992,54(4):399-407
Silicoaluminophosphate (SAPO-5) molecular sieves have been synthesised from reaction mixtures having a molar composition of: 0.7–1.0 Al2O3:0.7–1.0 P2O5:0.01–2.0 SiO2:xR:40 H2O (where R = (C2H3)3N or (C2H3)4NOH and x = 1.5–2.5 for (C2H5)5N and 0.5 for (C2H5)4NOH, at 473 K using various sources of alumina and silica. The effects of (i) varying the crystallinity of the alumina source (boehmite) and (ii) the use of different silica sources such as freshly prepared silica either from sodium silicate or paddy husk extract, silica gel from commercial water-glass, and tetraethyl orthosilicate have been studied. The crystallinity of boehmite has been found to have a strong effect on its reactivity towards the formation of SAPO-5. The activity of boehmite for SAPO-5 formation increased with a decrease in its crystallinity (or with increase in its moisture content). Any silica source devoid of sodium ions could be employed for the synthesis of SAPO-5. The process of crystallisation started as early as within 1.5 h of reaction and incorporation of silicon into the AlPO4 framework has been noted at this stage. Formation of some tridymite phase as impurity has been observed under conditions such as (i) SiO2 concentration > 1.7 mole and (ii) x > 2.0 when R = (C2H5)3N. 相似文献
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采用聚乙二醇、间苯二甲酸双羟二乙酯磺酸钠、无机盐与对苯二甲酸双羟二乙酯共聚合的方法合成了一种新型抗静电聚对苯二甲酸乙二酯(PET)树脂。该树脂的体积电阻率达到10~8Ω·cm数量级,静电半衰期达到0.02s,且不受长时间水洗的影响,其抗静电性能明显优于用共混等其他方法获得的抗静电PET树脂。 相似文献
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以对苯二甲酸和碘为原料,50%发烟硫酸为溶剂,制得2,3,5,6-四碘对苯二甲酸,再通过氯化亚砜进行酰氯化,最后与葡甲胺反应合成了标题化合物。其结构通过元素分析、红外光谱、核磁共振氢谱,质谱得到确证。运用正交实验优化了酰胺化反应条件:三乙胺为缚酸剂,四碘对苯二甲酰氯和葡甲胺为反应物,它们的物质的量比为2.1∶1∶2.4,反应温度为40℃时,产率高达71.5%。 相似文献