负载钒酸铋/石墨烯功能织物对染料的光催化降解

将氧化石墨烯和钒酸铋溶胶负载到棉织物上,通过紫外还原得到负载钒酸铋/石墨烯功能织物.以活性黑KN-B为降解对象,研究了功能织物在可见光下的催化活性,并探讨了染料结构对光催化效果的影响.结果表明:在可见光照射120 min后,功能织物对质量浓度为20 mg/L的活性黑KN-B染液的降解率超过90％,重复使用5次后的降解率...     

高效液相色谱法测定缓解视疲劳片中原花青素的含量

目的建立缓解视疲劳片中原花青素的含量测定方法。方法原花青素经铁盐催化降解为花青素离子后进行HPLC分析。通过正交试验优化降解条件为:1.0 mL供试品溶液加10 mg/mL硫酸高铁铵溶液0.2 mL和正丁醇-盐酸混合液(97:3,v/v)8.8 mL,100℃水浴加热1 h。色谱条件:Ultimate XB-C18色谱柱(4.6 mm×150 mm,5μm),流动相为甲醇-0.1%磷酸(45:55),流速0.5 mL/min,柱温30℃,检测波长530 nm。结果原花青素在考察的浓度范围内线性良好(r=0.9994),检出限9.33μg/mL,定量限31.12μg/mL,平均回收率95.56%。结论此方法操作简单,重现性好,可为该产品的质量控制提供参考。     

水溶性β-1,3-葡聚糖制备及应用研究的进展

水溶性β-1,3-葡聚糖具有独特、优越的生理及药理活性。现将以水不溶性酵母β-1,3-葡聚糖和可得然胶为原料,通过降解法和化学修饰法制备水溶性β-1,3-葡聚糖的研究及其应用进展怍一综述。     

Effects of temperature,pH and light on the stability of aloin A and characterisation of its major degradation products

This study explored the stability and degradation products of aloin A under varying pH, temperature and light conditions usually encountered in processing. The stability of aloin A was significantly affected by temperature and pH. The content of aloin A decreased by more than 90% within 12 h at 50 °C and within 6 h at 70 °C, respectively. A significant decrease in stability was also observed at higher pHs. At pH 8.0, less than 2% of aloin A remained within 12 h. However, aloin A exhibited good stability at acidic pH levels with 94% remaining at pH 2.0 for 14 days. Light exerted no influence on the stability during the experimental period (14 days). Aloe‐emodin, elgonica‐dimers A and B were characterised as major degradation products of aloin A at pH 5.0 or below, and elgonica‐dimers were mainly formed at 4 °C as well. 10‐hydroxyaloins A and B were found under any condition except at pH 2.0 and 3.0, and they were mainly formed under high temperature, neutral‐basic and any light conditions.     

降解木片树脂的白腐菌菌种选育与脱除树脂过程

通过在自然界采集、室内平板初筛及平板变色反应复筛得到了20株白腐菌菌株，并对变色系数最小的一株菌株G进行松木片固体接种实验。测定经2种不同浓度无机盐稀释的菌悬液接种松木片3天、5天、7天、9天后的木紊、树脂降解情况。结果显示，随着接种时间增加，松木片失重率逐渐增大，Klason木素、酸溶木素和总木紊含量逐渐下降，苯-醇抽出物和二氯甲烷抽出物含景也逐渐减少。表面扫描电镜照片表明，接种白腐菌的木片细胞壁上产生了明显的腐朽沟槽等现象；白腐菌菌丝在木片表面的生长呈由少到多、由凌乱到较有规律排列；松木片切片断面显微结构显示菌丝在细胞壁部位及胞间层也开始出现，这说明菌丝开始向细胞内部渗透。     

核壳结构Fe3O4纳米催化剂催化降解酸性废水的研究

利用静电自组装法,将羧甲基纤维素(CMC)组装到Fe3O4上得到Fe3O4@CMC,再通过自由基聚合反应将丙烯酸(AA)和丙烯酰胺(AM)接枝交联到Fe3O4@CMC上,制备出F e3O4@CMC-g-p(AA-co-AM)(Fe3O4@hydrogel)微球。利用TEM、XRD、FTIR、TGA、XPS、BET等技术对Fe3O4hydrogel微球进行了表征,并将其作为催化剂应用于类芬顿高级氧化反应中催化降解酸性红73。结果表明:Fe3O4@hydrogel仍为反尖晶石型结构,共聚物CMC-g-p(AA-c o-AM)成功包覆在Fe3O4表面,且含量为17.7%,复合微球平均粒径在10n m左右,饱和磁化强度为44.8 emu/g,BET表面积为73.5m2/g,平均孔直径为8.3nm,为介孔结构。Fe3O4@hydrogel微球对酸性染料废水有良好的催化降解性能,通过调节芬顿反应体系中初始pH值、催化剂用量以及H2O2浓度,得到反应最适条件为pH3.5、H2O210mmol/l、催化剂用量200mg/l。在此条件下3h内能达到对酸性红7399.83%以上的降解。     

增强回补途径对谷氨酸棒状杆菌合成L-异亮氨酸的影响（英文）

该实验考察和比较增强回补途径对谷氨酸棒状杆菌合成Lacterium glutamicum-异亮氨酸的影响。通过以L-异亮氨酸生产菌Corynebppc YI为出发菌株,分别采用基因组整合和质粒的方式过表达磷酸烯醇式丙酮酸羧化酶编码基因及丙酮酸羧化酶编码基因pyc。结果表明,获得pyc基因组整合和质粒过表达菌株ILE01和ILE02,摇瓶条件下菌株L-异亮氨酸产量分别提高17. 3%(6. 1 g/L)和9. 6%(5. 7 g/L)、发酵罐条件下分别提高11. L7%(24. 8 g/L)和8. 1%(24. 0 g/L)。获得ppc基因组整合和质粒过表达菌株ILE03和ILE04,摇瓶条件下菌株-异亮氨酸产量分别提高(30. 8%(6. 8 g/L)和13. 5%(5. 9 g/L)、发酵罐条件下分别提高15. 8%(25. 7 g/L)和9. 5%24. 3 g/L)。此外,过表达pyc和ppc还可不同程度地提高L-异亮氨酸转化率。然而采用质粒过表达pyc和ppc均使得菌株生物量下降。因此,过表达pyc和ppc均能显著提高L-异亮氨酸产量和转化率,基因组整合的过表达方式效果优于质粒...     

荔枝果皮总花色苷及降解指数的测定

本文研究了荔枝果皮总花色苷及其降解指数的含量测定。结果表明,当荔枝果皮发生褐变时,1％盐酸甲醇提取液花色苷及降解指数含量显著偏高。荔枝果皮总花色苷及花色苷降解指数可以很好地反映出提取液中花色苷的降解情况。     

辐射在壳聚糖降解中应用

作为一种资源丰富、用途广泛天然高分子化合物,壳聚糖广泛应用于化工、食品、农业、环保、医药等众多领域,由于分子量对壳聚糖性质具有很大影响,不同分子量壳聚糖性质差异很大,将壳聚糖降解到需要分子量是其应用前提。辐射降解壳聚糖方法,有能量使用率高,环境污染小等特点;但目前存在辐射处理量小,产品成本高,降解率有待提高等不足。该文概述壳聚糖低聚物在实际中应用,详细介绍辐射降解方法研究进展。     

Ascorbic acid degradation kinetics in mushrooms in a high-temperature short-time process controlled by a thermoresistometer

The degradation of ascorbic acid was studied in mushrooms heated at temperatures between 110 and 140°C, high-temperature short-time conditions, in a five-channel computer-controlled thermoresistometer. The kinetics parameters were calculated on the assumption that there are 2 degradation mechanisms, one aerobic (during the first few seconds of the process) and the other anaerobic. The 2 stages followed first-order reaction kinetics, with E_a=46.36 kJ/mol for aerobic degradation and E_a=49.57 kJ/mol for anaerobic degradation.