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超声波对木薯淀粉性质及结构的影响 总被引:5,自引:0,他引:5
考察了超声波对木薯淀粉理化性质及结构的影响. 结果表明,经超声处理后淀粉表观粘度下降,凝沉增强;经超声处理2 min,淀粉糊透明度提高,抗酶解能力降低;延长超声时间则导致糊透明度下降和抗酶解能力增强. FT-IR和XRD分析结果表明,超声作用未破坏淀粉分子基团,但淀粉结晶结构遭到破坏,结晶度下降. SEM分析显示,淀粉团粒结构减弱,受侵蚀的颗粒数量增多;淀粉-碘复合物分析表明,超声波造成淀粉大量降解,破坏支链结构和淀粉长链,直链淀粉含量增加. DSC分析表明,淀粉经超声处理后糊化焓基本不变,糊化温度升高. 相似文献
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对两种绿豆淀粉的化学组成、凝沉性质、溶解度、膨胀度、酸度、冻融稳定性和糊化性质进行分析。结果表明,两种绿豆淀粉各功能特性既有相似之处又存在差异。温度对溶解度和膨胀度的影响,时间对凝沉体积的影响,以及循环次数对析水率的影响,两种绿豆淀粉表现出相似的变化规律。而化学组成含量、酸度、糊化特性,以及相同条件下的凝沉体积、溶解度、膨胀度和冻融稳定性,两种淀粉又存在明显差异。陕北大明绿豆淀粉比黑龙江聚宝绿豆高的参数有:直链淀粉含量、灰分、凝沉体积、膨胀度、约68℃之后的溶解度、低循环次数下的冻融稳定性和各糊化特性参数中的黏度指标;而水分、低温下的溶解度、酸度和高循环下的冻融稳定性,以及起糊温度,黑龙江聚宝绿豆表现较高。 相似文献
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《当代化工》2020,(8)
利用高直链玉米淀粉制备羟丙基化高直链玉米淀粉,醚化剂为环氧丙烷,采用硫酸钠作为淀粉膨胀抑制剂,分别采用XRD测量羟丙基高直链玉米淀粉的结晶情况、DSC测量羟丙基高直链玉米淀粉的糊化温度和焓值变化、Brabender黏度仪测量羟丙基高直链玉米淀粉糊的情况。实验表明:环氧丙烷添加量与取代度呈正相关关系。X-射线衍射分析发现,羟丙基化淀粉的结晶类型没有改变,但是结晶度随着取代度的增加而下降。DSC结果表明,羟丙基化高直链玉米淀粉的糊化特性参数和焓值均降低。Brabender黏度分析表明,羟丙基化高直链玉米淀粉的峰值黏度随环氧丙烷添加量的增加而逐渐升高。凝沉特性分析表明,羟丙基改性能有效地提高其抗凝沉性。 相似文献
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淀粉磷酸酯是淀粉分子的羟基与磷酸盐在一定温度下发生酯化反应而生成的一种淀粉阴离子衍生物。与原淀粉相比,淀粉磷酸酯的糊粘度、透明度和稳定性较高,凝沉性弱,不易老化,冻融稳定性好,即使是很低的酯化程度,也能使糊的性质发生很大改变。因此,它广泛应用于造纸、纺织、食品、胶粘剂、医药等行业。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
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塔设备改造选型的分析 总被引:2,自引:0,他引:2
就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后,着重介绍一种新型塔板(导向梯形浮阀塔板)和一种新型填料(波环填料——乾隆帕克)。 相似文献
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