共查询到19条相似文献,搜索用时 250 毫秒
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敌百虫生产有三种原料:甲醇、三氯化磷和三氯乙醛。一般来说,甲醇、三氯化磷杂质较少,质量比较稳定。三氯乙醛则杂质较多,质量波动较大,对敌百虫质量影响比较显著。本文就三氯乙醛对敌百虫质量的影响和对三氯乙醛二次蒸馏工艺加以探讨。 相似文献
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本文研究了三氯乙醛的不同含量及碱溶液浓度对三氯乙醛碱解产物-氯仿含量的影响。探明了在实验条件范围内,要使三氯乙醛碱解反应产物氯仿有较高的含量,三氯乙醛含量应不低于70%,原料中乙醇含量尽可能少,碱解所用氢氧化钠浓度在10%左右。 相似文献
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研究了水合氯醛结晶工艺 ,当等摩尔的三氯乙醛和水混合 ,萃取剂氯仿加入量2 5%~ 35% ,加入的温度 4 0~ 50℃ ,在结晶前期加入结晶改良剂HS时 ,产品结晶时间和烘干时间缩短一半 ,产率 84 %、纯度 99 5%。 相似文献
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新颖昆虫蜕皮加速剂--抑虫肼的合成 总被引:2,自引:0,他引:2
抑虫肼是一种新颖昆虫蜕皮加速剂。它对鳞翅目害虫高度有效,是一种既安全又有选择性的蜕皮激素杀虫剂。抑虫肼的合成采用乙苯和三氯乙醛或三氯乙酰氯反应,生成2,2,2-三氯-(4-乙苯基)乙酮,再秒叔丁基肼反应,最后和3,5-二甲基苯甲酰氯反应而制备。 相似文献
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以两种异臭化合物β-环柠檬醛和β-紫罗兰酮作为前体物,进行氯化试验。研究两种前体物在25℃恒温黑暗条件氯化24 h后消毒副产物(DBPs)的生成及影响因素。试验结果表明,β-环柠檬醛和β-紫罗兰酮氯化后均会生成三氯甲烷(TCM)、二氯乙醛(DCAL)、三氯乙醛(TCAL)、二氯丙酮(DCP)和三氯丙酮(TCP),且加氯量、pH和腐植酸浓度均会影响两种前体物氯化后消毒副产物的生成量。两种前体物的试验结果有一定的相似性,随着加氯量的增加,TCM、DCP、TCP的生成量均增加;随着pH的增大,TCM的生成量增加,DCP和TCP的生成量减少,碱性条件会抑制DCAL的生成,而酸性条件会抑制TCAL的生成;随着腐植酸浓度的增加,TCM的生成量增加。 相似文献
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污泥生物炭中氮硫元素含量高,其氮硫行为和环境效应对全球气候变化的影响不容忽视。以往的研究中,研究者往往以富碳生物炭作为主要研究对象,关注碳对全球气候变化的行为和功效,而对氮硫元素的作用关注不够。本文从原始污泥基本性质到其热解过程,再到生物炭的老化,逐步对污泥生物炭整个生命周期内氮硫的行为及其环境效应研究进行综述,并对未来应注重开展的研究方向进行展望,为生物炭中氮硫元素固定、释放及与之关联的环境效应和温室气体排放控制研究提供理论基础。分析表明,污泥中氮元素含量普遍高于硫元素,且热解过程中氮比硫更容易转移至气相产物。氮硫元素随热解温度的增加,在三相产物中的分配都是炭中持续减少,油中先增后减,气中一直增加。高温(>800℃)条件下,气相中的氮含量高于固相,而硫元素则仍然主要存在于固相中。污泥生物炭老化及其环境效应研究表明,污泥生物炭氮硫元素与土壤的相互作用及其温室效应问题在今后的研究中应引起重视。 相似文献
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Ivan V. Gmoshinski Vladimir A. Shipelin Nikita V. Trusov Sergey A. Apryatin Kristina V. Mzhelskaya Antonina A. Shumakova Andrey N. Timonin Nikolay A. Riger Dmitry B. Nikityuk 《International journal of molecular sciences》2021,22(11)
We studied the effects of the addition of large neutral amino acids, such as tyrosine (Tyr) and tryptophan (Trp), in mice DBA/2J and tetrahybrid mice DBCB receiving a high-fat, high-carbohydrate diet (HFCD) for 65 days. The locomotor activity, anxiety, muscle tone, mass of internal organs, liver morphology, adipokines, cytokines, and biochemical indices of animals were assessed. The Tyr supplementation potentiated increased anxiety in EPM and contributed to a muscle tone increase, a decrease in the AST/ALT ratio, and an increase in protein anabolism in both mice strains. Tyr contributed to a decrease in liver fatty degeneration and ALT reduction only in DBCB that were sensitive to the development of obesity. The addition of Trp caused an increase in muscle tone and potentiated an increase in anxiety with age in animals of both genotypes. Trp had toxic effects on the livers of mice, which was manifested in increased fatty degeneration in DBCB, edema, and the appearance of micronuclei in DBA/2J. The main identified effects of Tyr on mice are considered in the light of its modulating effect on the dopamine neurotransmitter metabolism, while for the Trp supplement, effects were presumably associated with the synthesis of its toxic metabolites by representatives of the intestinal microflora. 相似文献
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Mostafa Khodakarami 《Polymer-Plastics Technology and Engineering》2017,56(18):2019-2042
Separation and purification techniques are applied in many important fields, such as in the medical, chemical, metallurgical, environmental, and pharmaceutical industries. Recent advances in separation science and the urgent need for highly selective purification have necessitated a rapid progress with respect to the reagents, chemicals, and surfactants used in separation processes to attain a high efficiency and selectivity. Polymeric materials have attracted considerable interest, and they have been widely used as extractants, catalysts, and modifiers, in separation and purification processes. This review outlines the recent advances in the use of novel polymers, natural and synthetic, in different separation and purification techniques. Various separation techniques such as chromatography, crystallization, precipitation, distillation, electrophoresis, filtration, and mineral processing methods are discussed, and the polymers used in each method are described in terms of their properties, structure, and function. The application of polymers shows great promise in achieving a highly efficient separation, especially in the areas of membrane separation and water purification. The rational design of new multifunctional polymers with triggered functions presumably presents new opportunities for the development of advanced separation methods. 相似文献