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镀液组成对木材化学镀镍金属沉积速率的影响 总被引:4,自引:0,他引:4
黄金田 《内蒙古农业大学学报(自然科学版)》2005,26(1):57-60
为了确定镀液组成对木材化学镀镍金属沉积速率的影响,本文用点滴法加入镀液的方法进行了木材化学镀镍实验,分析了木材化学镀镀镍镀液的主盐浓度、还原剂浓度、络合剂浓度等对金属镍沉积速率的影响,从而得出木材化学镀镍比较理想的镀液组成。这对于利用化学镀镍这一金属加工技术对木材进行化学镀,对进一步研究木材与金属的复合以及开发功能性木质复合材料具有重要的实际意义。 相似文献
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【目的】研究化学打顶对棉花光合特性及不同部位棉铃物质积累的影响和变化规律,为棉花优质高产提供基础。【方法】以新陆中70号和新陆中82号为材料,设置2种化学打顶药剂,人工打顶为对照。【结果】在喷施药剂10 d后,化学打顶处理的主茎功能叶净光合速率较人工打顶高,中上部叶片SPAD值化学打顶处理高于人工打顶处理,而新陆中82号下部叶片SPAD值表现为化学打顶低于人工打顶;新陆中70号积累量大于新陆中82号,但积累速率小于新陆中82号;化学打顶处理的全铃干物质积累表现为前2个花期促进后期棉铃的物质积累,2个品种分别是发育35和28 d后,而7月21日开花期促进是前期棉铃的物质积累,分别是发育28和21 d内;化学打顶处理的前2个开花期的增长特征值时间较人工打顶处理的有所推迟或增加,而7月21日开花期表现为化学打顶处理较人工打顶均有前移和增加,最大增长速率均表现为化学打顶处理大于人工打顶处理。【结论】化学打顶可以提高棉花主茎功能叶的光合作用,加速棉铃物质积累速率,有利于棉铃集中吐絮。 相似文献
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化学动力学远不及化学热力学完美,作者认为基本原因之一就是长期局限于以浓度随时间的变化率来定义反应速率,因此提出了新的速率关系式:dξ/dt=-(dG)T·p/ Adt。根据新的速率关系式可以得到新的速率方程,例如r=EG/nF。新的速率方程几乎包括了影响溶液中化学反应速率的主要因素,如物质的本性、浓度、压力、温度、电解质的电导甚至催化作用。并对几个反应的速率现象和几个反应的机理作了解释。 相似文献
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为了解莲藕中酚类化合物的化学氧化,寻求控制莲藕褐变的有效方法,针对莲藕中的主要酚类化合物邻苯二酚、没食子酸及多巴进行了化学氧化模拟试验.结果表明,pH对化学氧化反应后褐变指数的影响最大,其次是酚类化合物的种类,反应温度的影响最小.酚类化合物在碱性条件下更易褐变;3种酚类化合物发生化学氧化反应的速率由快到慢依次是多巴、没食子酸、邻苯二酚.在莲藕加工过程中可以选择多巴及没食子酸含量较低的莲藕品种,并控制好pH,可以有效减缓莲藕中酚类化合物化学氧化反应的速率,达到防止莲藕褐变的目的. 相似文献
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通过化学沉积法制备Fe-B化学镀层,用电化学方法分析了偶接铝、镀液组分和沉积工艺对Fe-B化学沉积行为的影响.结果表明,偶接铝使体系的沉积电位负移,降低了Fe-B合金化学沉积的极化阻力,特别是金属离子还原的极化阻力,从而诱导Fe-B的化学沉积.镀层的沉积速率依赖于镀液组分和沉积工艺. 相似文献
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本文报道菜籽油甲酯化反应的适宜条件为菜籽油/甲醇(摩尔比)为1/6,0.5%NaOCH_3作催化剂,反应温度40~60℃之间,反应时间在1小时内。用NMR—24B型核磁共振仪作为分析检测手段。动力学研究表明,该反应分为两个阶段:开始的四级对峙反应,速度常数的数量级为10~(-4)、表观活化能65.2KJ·mol~(-1);后面的二级对峙反应,速度常数的数量级为10~(-2)。本研究为菜籽油甲酯化在工业上生产加脂剂提供了理论上的参考数据。 相似文献
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【目的】通过对65个甘薯品种苗期茎尖醇溶提取物清除1,1-二苯基-2-三硝基苯肼(DPPH•)反应过程中相关指标的研究,探索其清除DPPH•的行为特征差异。【方法】测定65个品种苗期茎尖醇溶提取物在0.1、0.2、0.4、0.8、1.6、2.0 mg•mL-1 6个浓度下清除DPPH•反应的0—210 min中19个时间点的DPPH•清除率,计算反应速率及其变化、各品种的EC50和各浓度下清除率达到50%与80%所需时间,并根据这些指标对65个品种进行聚类分析。【结果】?甘薯苗期茎尖醇溶提取物的清除DPPH•行为在65个品种间虽然表现为连续性,但聚类分析能将其分为5种行为类型,并以类型Ⅱ、Ⅲ为主。?类型Ⅰ包含1个品种,0—1 min和1—3 min的反应速率、210 min的清除率均显著小于其它类型,醇溶提取物浓度达2.0 mg•mL-1时清除率仍不能达到50%。?类型Ⅱ包含44个品种,平均抗氧化能力显著优于类型Ⅰ,次于其它3种类型。醇溶提取物浓度达到0.8 mg•mL-1时有24个品种能达到50%清除能力,平均需时83.89 min,但无品种能达到80%;而2.0 mg•mL-1时有37个品种能达到80%清除率,平均需时59.23 min。④类型Ⅲ包含17个品种,其清除率曲线变化趋势、210 min的清除率、EC50、反应速率以及清除率达到50%和80%的品种比例及所需时间均介于类型Ⅱ与类型Ⅳ之间,并偏向类型Ⅳ。⑤类型Ⅳ包括一个品种,类型Ⅴ包括2个品种。两者的EC50低于前3种类型,均在0.4 mg•mL-1时就能达到50%,在0.8 mg•mL-1就能达到80%,且所需时间显著低于其它类型。而两者主要区别体现在反应速率的变化方面。【结论】在利用DPPH•清除法评定甘薯苗期茎尖醇溶提取物抗氧化能力过程中需要综合考虑清除率随反应时间、醇溶提取物浓度的变化趋势、阶段反应速率、反应消耗时间、EC50多项抗氧化反应行为特征指标。 相似文献
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HUANG Da-ming CHANG Wei-zhong ZHANG Zhi-cai CUI Feng-jie XIAO Xiang QIAN Jing-yaInstitute of Bioengineering School of Food Science Biotechnology Jiangsu University Zhenjiang 《(《农业科学与技术》)编辑部》2008,(2)
[Objective] In order to study the anti-oxidation and inhibitory effect on nonenzymatic glycation reaction of EGB fermentation extraction biotransformed by Hericium erinaceus.[Method]The free radical scavenging ability and reducing capacity of DPPH as well as inhibitory rate of nonenzymatic glycation reaction were measured targets for comparing changes of anti-oxidation and inhibitory effect on nonenzymatic glycation reaction of fermentation lyophilizer and fermentation extraction before and after EGB fermention adsorbed by AB-8 macroporous resin. The EGB fermention was biotransformed by Hericium erinaceus.[Result]After adsorbed by AB-8 macroporous resin,the bioactive matters were concentrated and separated. The free radical scavenging rate,reducing capacity and inhibitory rate of nonenzymatic glycation reaction were increased significantly after adsorbed by AB-8 macroporous resin.[Conclusion]AB-8 macroporous resin could be used for preliminary concentration of EGB fermentation which was biotransformed by Hericium erinaceus. 相似文献
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[Objective] In order to study the anti-oxidation and inhibitory effect on nonenzymatic glycation reaction of EGB fermentation extraction bio-transformed by Hericium erinaceus. [Method] The free radical scavenging ability and reducing capacity of DPPH as well as inhibitory rate of nonenzymatic glycation reaction were measured targets for comparing changes of anti-oxidation and inhibitory effect on nonenzymatic glycation reaction of fermentation ly-ophilizer and fermentation extraction before and after EGB fermention adsorbed by AB-8 macroporous resin. The EGB fermention was biotransformed by He-ricium erinaceus. [Result]After adsorbed by AB-8 macropous resin,the bioactive matters were concentrated and separated. The free radical scavenging rate, reducing capacity and inhibitory rate of nononzymatic glycation reaction were increased significantly after adsorbed by AB-8 macroporons resin. [Con-dusion] AB-8 macroporous resin could be used for preliminary concenuation of EGB fermentation which was biotransfonned by Hericium erinaceus. 相似文献
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[目的]研究猴头菌转化EGB发酵液提取物抗氧化及抑制非酶糖基化活性。[方法]以DPPH自由基清除率和还原力两种抗氧化能力及非酶糖基化抑制率为考察指标,比较了猴头菌转化EGB发酵液经AB-8大孔树脂吸附前后,发酵液冻干物、提取物抗氧化及抑制非酶糖基能力的变化。[结果]发酵液经AB-8大孔树脂吸附后可浓缩分离活性物质,吸附后的提取物自由基清除率、还原力、非酶糖基化抑制率均显著提高。提取物中可能含有三萜皂甙类和黄酮类成分。[结论]AB-8树脂可用于猴头菌转化EGB发酵液提取物的初步浓缩。 相似文献
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《(《农业科学与技术》)编辑部》2008,(2)
[Objective] In order to study the anti-oxidation and inhibitory effect on nonenzymatic glycation reaction of EGB fermentation extraction biotransformed by Hericium erinaceus.[Method]The free radical scavenging ability and reducing capacity of DPPH as well as inhibitory rate of nonenzymatic glycation reaction were measured targets for comparing changes of anti-oxidation and inhibitory effect on nonenzymatic glycation reaction of fermentation lyophilizer and fermentation extraction before and after EGB fermention adsorbed by AB-8 macroporous resin. The EGB fermention was biotransformed by Hericium erinaceus.[Result]After adsorbed by AB-8 macroporous resin,the bioactive matters were concentrated and separated. The free radical scavenging rate,reducing capacity and inhibitory rate of nonenzymatic glycation reaction were increased significantly after adsorbed by AB-8 macroporous resin.[Conclusion]AB-8 macroporous resin could be used for preliminary concentration of EGB fermentation which was biotransformed by Hericium erinaceus. 相似文献