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钝顶螺旋藻多糖sevage法脱蛋白工艺的研究 总被引:2,自引:0,他引:2
为了研究钝顶螺旋藻多糖Sevage法除蛋白工艺。采用单因素试验确定了氯仿-正丁醇体积比、Sevage试剂的添加量、振摇时间、脱蛋白次数对钝顶螺旋藻多糖脱蛋白效果的影响。在单因素试验基础上,采用正交试验确定了钝顶螺旋藻多糖Sevage法除蛋白的最佳工艺条件。结果表明,四个因素中,仅振摇时间对脱蛋白效果影响较弱,其他三个因素对脱蛋白效果均有明显影响;其中,氯仿-正丁醇体积比对除蛋白效果的影响最大,与Sevage试剂添加量和脱蛋白次数的影响相比达到差异极显著水平(P<0.01)。振摇时间20m in条件下,Sevage法脱除钝顶螺旋藻多糖蛋白的最佳工艺条件为:氯仿-正丁醇的体积比为4:1,Sevage试剂添加量为多糖溶液的2倍,脱蛋白次数2次。 相似文献
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在纤维素分解酶或碱存在下,用星形粉碎机处理高位苔藓泥炭,研究了该机械化学作用对泥炭中水可溶多糖级分组成的影响。由于机械化学转化,导致多糖的产率、多分散性、分子量和光密度发生了变化。机械化学处理对泥炭水溶级分中的单糖组成也有影响。 相似文献
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以香菇多糖为研究对象,采用单因素实验对香菇多糖的微波提取工艺进行了研究,比较了微波功率,辐射时间和加热温度等因素对多糖提取率的影响,并得到了微波法提取香菇多糖的最佳工艺条件为:微波功率800W,辐射时间15min,加热温度80℃。通过实验结果发现,微波法具有节能、省时、操作便利和提取率高等特点。 相似文献
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采用布氏黏度计对桑枝多糖的黏度进行测定,分别考察温度、剪切速率以及pH值对桑枝多糖黏度的影响,结果表明:桑枝多糖溶液为假塑性流体,随着温度的升高其黏度逐渐降低且两者的关系符合阿累尼乌斯模型,温度和浓度对其黏度的综合影响可用数学模型η=-5.924 5exp 2.48/RT-0.123 8C+3.421×10-4C2)进行预测,适用范围温度20~80℃,浓度1%~8%;剪切速率对其黏度的影响可用幂律模型η=Mγn进行拟合,黏度随剪切速率的增加而降低,酸和碱均使桑枝多糖溶液黏度下降,中性条件下黏度值最高,说明桑枝多糖是中性多糖. 相似文献
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The optical properties of foreign metal submonolayers formed on Au, Ag, Cu, Pt and Pd electrodes through the underpotential deposition have been investigated by specular reflectivity measurement. Based on the spectral characteristics, 14 adsorbate-substrate systems were classified into 2 groups. The first group, involving Bi on Au, Cu on Au, Pb on Au, Tl on Au, Tl on Ag and Cd on Cu, is characterized by the similarity of the optical properties of the adsorbed metal in the submonolayer to those of bulk metal. The first monolayer was found to form through several submonolayer stages, in which the optical constants are slightly different from each other. In the second group, involving Cd on Au, In on Au, Sn on Au, Ag on Pt, Bi on Pt, Cu on Pt, Pb on Pt and Bi on Pd, the spectra of submonolayer observed experimentally differ from those calculated with the assumption that the optical properties of adatom and substrate are the same as those of corresponding bulk metal. The difference in the work functions between adsorbate and substrate materials in this group is larger than those in the first group.From these findings, some considerations were made to interpret the origin of the specular reflectance change due to the presence of metal adlayer on the electrode surface. The results allow a tentative conclusion that the reflectivity change is predominantly attributed to the optical properties of the adsorbed submonolayer, but at the same time the work function of the substrate and the interband transition in visible should also be taken into consideration. 相似文献
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将水热法和电解过程相结合,制备出一种新型的钛基纳米多孔网状铂电极(nanoPt),它具有特殊的网络状结构及巨大的表面积. 循环伏安曲线表明,在碱性溶液中,甲酸在nanoPt上的氧化电流密度远远大于在多晶Pt上的电流密度,其氧化峰电流几乎是后者的100倍;恒电位电解时,甲酸在nanoPt上的氧化电流开始时随时间的增加而增加,随后达到稳定,其稳定电流也明显高于多晶Pt;在nanoPt上甲酸的非线性现象出现的电流密度范围要比在多晶铂上的宽. 多次循环扫描和长时间电解实验表明. 这种钛基nanoPt结构稳定,催化剂颗粒不易脱落,有可能作为一种新型的燃料电池阳极材料而得到应用. 相似文献
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汽车空调行业ODS替代品的需求与预测 总被引:5,自引:1,他引:4
易旭 《精细与专用化学品》1999,(22)
本文对中国汽车空调行业随轿车工业的发展而迅速发展及汽车空调CFC-12替代计划的实施做了简单的介绍,并就汽车空调ODS淘汰过程中的替代品HFC-134a和润滑油的变化进行了分析和需求量的预测。 相似文献
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In the new EniChem process cyclohexanone oxime is directly synthesized by ammoximation of cyclohexanone with ammonia and hydrogen peroxide on titanium silicalite catalyst. The ammoximation reaction is suitable for the synthesis of several oximes by reaction of the corresponding ketones with ammonia and hydrogen peroxide on titanium silicalite. New results on ketones ammoximation and on reaction byproducts are reported. The effect of some reaction parameters on the oxime yield and on byproducts formation is discussed. 相似文献