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Bentonite produced in Xiazijie, Xinjiang (China) was characterized by X-ray diffraction (XRD), differential thermal analysis (DTA), thermogravimetric analysis (TG) and cation exchange capacity (CEC). The bentonite is composed of dioctahedral montmorillonite with predominant quantity, certain amounts of quartz, feldspar and illite and minor amounts of kaolinite, gypsum, etc. The raw bentonite has a CEC of 0.6497 meq·g^-1 and allows to be characterized as typical sodium bentonite. In order to bleach cottonseed oil, optimum conditions for sulfuric acid activation of the raw bentonites were investigated, which were obtained by selecting various acid strength, at 96-98℃ and activating for 4h with 1 : 2 solid-liquid ratio. The acid activation bentonites were suitable for decolorization of cottonseed oil through removing carotene and chlorophyll. The bleaching capabilities of different pigments with activated bentonite with treatment of 25% sulfuric acid were 70.3%, 73.1%, 83.2%, 81.8% and 88.9%, respectively. Bleaching with acid activated bentonite gave oils lower peroxide values and acid values. 相似文献
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<正>在制备大功率整流器、可控硅、硅靶摄像管、核探测器和集成电路等方面中子嬗变掺杂(简称NTD)硅已经得到广泛应用.近来,GaAs等化合物半导体材料的中子嬗变掺杂亦有报导. 相似文献
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酶法酯交换棉籽毛油合成生物柴油 总被引:2,自引:0,他引:2
以戊二醛交联壳聚糖固定A.niger Li-38脂肪酶,固定条件为0.015%的戊二醛,交联50min。以该固定化酶催化棉籽毛油合成生物柴油,反应条件为:以叔丁醇为反应介质,醇油摩尔比1:1,水分含量0.6%,反应温度55℃,酶载量为8%,分批补加甲醇,反应28h后最终转化率达到89.1%。该固定化酶的贮藏稳定性较好,室温放置12d,酶活保持80%以上,30d时酶活为46.8%。固定化酶在30~70℃,pH值5.5~6.5之间较稳定,其热稳定性和pH稳定性较游离酶有所提高。固定化酶可重复使用7次,转化率保持在80%以上。 相似文献
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核热泉高温堆是具有满功率自然循环特性的熔盐球床堆,其特有的冷却剂横向流动特性需要基于径向分区换料的燃料循环方案,以及相应的燃料管理优化分析方法。局部搜索算法和模拟退火算法是普遍应用于轻水堆换料优化问题的随机性优化方法。本文应用这两种方法对核热泉高温堆的换料优化问题进行了分析。分析结果表明,相比于局部搜索算法,模拟退火算法能以较高的概率跳出局部最优陷阱,获得全局最优的优化结果,且优化质量独立于初始解的选取。最终的优化结果给出了较好的堆芯功率展平与压制燃料中心温度的效果。针对核热泉高温堆的一维分区换料方式,模拟退火算法是非常合适的优化分析方法。 相似文献