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以三聚氯氰、二乙胺、对硝基酚、1,2-二溴乙烷、水杨醛、对羟基苯甲醛、香草醛和异香草醛为原料,采用高度稀释法合成了一类新型的含三嗪环的席夫碱大环化合物,并通过IR、1H NMR和ESI/MS对其结构进行了表征。紫外光谱研究表明,席夫碱大环5对Fe3+离子有专一性识别作用。 相似文献
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在室温和无溶剂研磨条件下,氯化锌催化1-苯基-3-芳基-4-甲酰基吡唑与4-氨基安替比林反应生成一系列新型吡唑席夫碱,收率68.5%~79.3%。通过IR,1 H NMR对其结构进行了表征。该方法具有快速、简便、环境友好等特点。 相似文献
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在超声波作用下,以自制的低分子量羧甲基壳聚糖与香草醛为原料,制备了低分子量羧甲基壳聚糖香草醛席夫碱。利用FI-IR对其结构进行了表征,研究了香草醛与羧甲基壳聚糖中氨基的反应摩尔比、反应温度、反应时间及超声波功率对产物氨基取代度的影响。结果表明:当香草醛与羧甲基壳聚糖中氨基的摩尔比为1∶0.8、反应时间为3 h、反应温度为70℃、超声波作用功率为70 W时,羧甲基壳聚糖香草醛席夫碱的氨基取代度可达到82.5%;将羧甲基壳聚糖席夫碱与羧甲基壳聚糖的抗菌性能进行了比较,发现羧甲基壳聚糖香草醛席夫碱对金黄葡萄球菌和大肠埃希菌的抑菌圈宽度分别比羧甲基壳聚糖的抑菌圈宽0.7 mm和0.5 mm。 相似文献
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《纤维素科学与技术》2017,(4):36-41
以香草醛为改性试剂,对壳寡糖的羟基进行季铵化修饰合成了O-季铵化壳寡糖席夫碱,通过紫外-可见吸收光谱法、粘度测定、循环伏安法研究了合成的席夫碱与DNA之间的作用方式。结果表明:加入DNA后,O-季铵化壳寡糖席夫碱在271 nm和233 nm处的吸收峰位置均发生了红移,强度分别发生了增色和减色效应;在DNA中加入O-季铵化壳寡糖席夫碱后,DNA的粘度增大,且增大程度与O-季铵化壳寡糖席夫碱的加入量呈正相关;循环伏安曲线显示O-季铵化壳寡糖席夫碱会使DNA/K_4Fe(CN)_6体系的氧化还原峰电流减小,式量电位发生正移。以上实验结果表明O-季铵化壳寡糖席夫碱与DNA主要是以嵌插方式作用的。 相似文献
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Solid solutions of diphosphates of zinc and copper and of zinc and cobalt were synthesized from mixtures of pure diphosphates at temperatures up to 1000°C. Their X-ray diffractometry patterns varied continuously from one end member to the other. Solid solutions of orthophosphates of composition Zn3−x Cox(PO4 )2, with x = 0.4–1.6, were formed at temperatures up to 950°C; all exhibited the structure of γ-Zn3 (PO4 )2. Solid solutions of orthophosphates of composition Zn3−x Cux (PO4 )2 exhibited more-complex behavior. At 1000°C and copper contents of 20–80 mol%, a phase that is related to Cu3 (PO4 )2, termed here the "ε-phase," predominated. At 850°–950°C and in the region from 20 mol% to ∼33 mol% of copper, the solid solutions (the "η-phase") adopted the structure of graftonite. At 800°–900°C and 10–15 mol% of copper, the solid solutions exhibited a new structure (the "δ-phase"), which we found to be related to the mineral sarcopside. At temperatures 950°C, the solutions that contained 5–15 mol% of copper (the "β-phase") had the structure of β-Zn3 (PO4 )2, whereas at 800°–850°C, solutions with 5 mol% of copper (the "-phase") exhibited the structure of γ-Zn3 (PO4 )2. Attempts to synthesize Cu+ ZnPO4 and Cu+ Cu2+ Zn3 (PO4 )3 were unsuccessful. 相似文献
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为了提高油田的生产效率,设计最佳的油气集输处理的工艺流程,更好地完成油气水分离处理的任务。对油气集输工艺技术进行优化,发挥高效油气水分离处理设备的优势,提高油气水处理的质量,保证油气集输工艺顺利实施,获得最佳的油田产量外输。 相似文献
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建设创新型国家是我们中华民族的历史责任。“自主创新、重点突破、支撑发展、引领未来”的16字方针应当成为我们未来创新活动的指南。建设创新型国家把自主创新放在首位,并提出了引领未来的高标准要求。钢铁科技创新必须突出重点,抓住创新成果产业化这个关键,支撑起行业和国民经济的发展。 相似文献
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相比已经完善丰富的开采和勘探技术,油气的运输以及储存却仍然存在不足之处。我国对能源安全提出更加严格要求的同时,对区域经济的发展规划也有足够重视。因此,保障油气管道的安全则成为了我国能源安全战略的重中之重。在阐释油气管道现阶段在储运安全保障技术发展状况的基础上,分析了现存的问题及解决问题的手段,并指出未来可能使用的目标策略,为今后研究者提供一定程度上的借鉴经验。 相似文献
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膜的污染和劣化及其防治对策 总被引:25,自引:0,他引:25
较为系统地介绍了膜污染和劣化的定义和特点,因膜污染和劣化而造成的膜性能变化,以及如何预防、减少或清除膜污染和劣化的一些通用方法。 相似文献
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James L. White David G. Salladay David O. Quisenberry Donald L. MacLean 《应用聚合物科学杂志》1972,16(11):2811-2827
Gel permeation chromatographic (GPC) and thin-layer chromatographic (TLC) studies of polystyrene, polybutadienes (BR), and their copolymers (SBR) have been carried out. GPC primarily separates them on the basis of molecular size, and TLC, on the basis of composition. Methods of obtaining absolute molecular weight distributions for BR and SBR based upon variations of the Strasbourg Universal Calibration procedure are described. In particular, [η]–M relationships in both the GPC solvent (THF) and in a second solvent (toluene) were used; in addition, results of statistical mechanical calculations for \documentclass{article}\pagestyle{empty}\begin{document}$\overline {s^2 }$\end{document} (based on the assumption of negligible steric hindrance and freely rotating bonds) were applied. An experimental comparison of these methods was carried out, and use of the [η]–M relationships for both solvents was found to give satisfactory results. The predictions of the statistical theory were too low. A detailed study of polymer–solvent–gel interaction in the GPC unit was made through investigation of ternary phase equilibrium in the (polystyrene)–THF–(polymer) system. The polymers studied included BR and SBR with varying styrene contents. Experimental techniques for TLC separations of BR, SBR, and polystyrene according to the composition are described. 相似文献