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 共查询到11条相似文献,搜索用时 62 毫秒
1.
杨军浩 《染料工业》2002,39(3):34-37
一般的酸性染料溶解度较小,而本文所介绍的单或双偶氮酸性染料,实际上是以碱金属盐的形成存在,由于加入了(按重量计)80%-30%的木质素磺酸铵,改善了室温的冷水溶解度。木质素磺酸铵既作为标准化试剂,用来调节高强度染料到稳定的商品染料,同时又能提高染料在室温时冷水溶解度。  相似文献   

2.
本文探讨了pH、助剂和研磨对酸性染料性能的影响。实验结果显示:适宜的pH和助剂可提高酸性染料的溶解度,研磨对提高酸性染料的溶解度没有作用且使色光变暗。  相似文献   

3.
Cancer has been a major health problem in the world in the past decades. It is urgent to develop new, effective and safe drugs for the treatment of cancer. There are many pentacyclic triterpenoids with positive anti-tumor activity and safety in nature. Oleanolic acid (OA), as one of the pentacyclic triterpenoids, also has broad biological activities including liver protection, anti-inflammatory, hypoglycemic, antiviral and anti-tumor. Therefore, to investigate its anti-tumor activity and mechanism, many OA derivatives have been developed. Some derivatives are less toxic to normal hepatocytes, which may be due to the strong liver protection ability of OA. However, the poor water solubility of OA is one of the main reasons for the weak anti-tumor activity. It is reported that some OA derivatives could enhance solubility by chemically linking some hydrophilic groups to improve anti-tumor activity. This review not only summarizes the highly water-soluble OA derivatives that can improve anti-tumor activity reported in recent years, but also introduces their possible anti-tumor mechanisms.  相似文献   

4.
马子川  崔振水 《化学世界》2001,42(8):407-409
在低浓度水溶液中 ,木质素磺酸可被臭氧 ( O3 )氧化降解。其氧化产物的紫外吸收光谱、1H核磁共振谱和红外光谱有明显改变。在臭氧作用下木质素磺酸大分子中的芳香结构被破坏 ,转化为CH3CO RO;R CO CH3O;CH3SO2 R三类链状化合物 ,原木质素大分子中的磺酸基主要被转化为 SO2 -4  相似文献   

5.
制备了不同季铵盐三丁基甲基氯化铵(MTBAC)、四甲基氯化铵(TMAC)、苄基三乙基氯化铵(TEBA)和氯化胆碱(ChCl)分别与DL-乳酸(HL)以摩尔比1:9合成的深度共熔溶剂,并将用于溶解桉木粉中木质素。结果表明,由苄基三乙基氯化铵/DL-乳酸(TEBA/HL)合成的深度共熔溶剂处理桉木粉,在90 ℃下反应10 h,木质素溶解率达92.3wt%,综纤维素溶解率仅为8.3wt%;同时,木质素与综纤维素溶解选择性系数之比K达到158.5,表明TEBA/HL对木质素的溶解选择性最佳。通过红外光谱(FT-IR)分析各分离产物,证明提取物中有木质素特征官能团。通过凝胶渗透色谱(GPC)分析表明分离产物相对分子质量均有所降低。通过固体13C核磁共振谱(CP/MAS 13C NMR)分析90 ℃下TEBA/HL中分离产物结构,证明其结构征符合阔叶材木质素结构特点。  相似文献   

6.
电导率法对偏钒酸铵在草酸溶液中的溶解研究   总被引:1,自引:0,他引:1  
利用电导率法,对偏钒酸铵在草酸溶液中的反应溶解进行测量分析,找出偏钒酸铵在草酸中的反应及反应溶解度的变化情况。实验得出偏钒酸铵在草酸中钒的价态发生V5+→VO2+(黄色)→V3+(绿色)→VO2+(蓝色)的反应溶解性的变化,其原因是由于偏钒酸铵和草酸生成络合物(NH4)2[(VO)2(C2O4)3],降低了溶液中起电荷传递作用的离子浓度,而且络合离子的存在会阻碍导电粒子的定向移动,因此,电导率随浓度的增加而降低。  相似文献   

7.
以湖北稻草秸秆为研究对象,研究了超低酸水解木质纤维素的适宜条件,测定了适宜条件下的超低酸法水解15种不同种类秸秆的纤维素及半纤维素的转化率、还原糖得率及结晶度的变化。实验结果表明:秸秆投料量3 g、硫酸投料量45 mL(硫酸质量分数0.05%)、搅拌转速500 r/min、反应温度210 ℃、反应时间10 min为适宜的水解条件。对15种不同种类秸秆的水解结果统计得到,随着秸秆中木质素含量的增大,纤维素和半纤维素的转化率都逐渐降低,还原糖得率逐渐降低;通过SEM和X衍射分析水解前后的木质纤维素结构,得到了木质素影响水解过程的方式:1)木质素含量越大,纤维素的结晶度越大,纤维素的非晶化越困难,从而影响了纤维素的水解;2)原木质素不溶于反应体系且在酸性条件下相对稳定,富木质素层的木质素阻碍反应物与产物扩散,使富木质素层内的纤维素、半纤维素水解速率降低;3)木质素含量越高,木质纤维素的富木质素层越厚、强度越大,水解时难以从颗粒表面脱落,进一步降低水解速率。  相似文献   

8.
针对酸性水汽提装置开工后,净化水氨氮含量持续高,严重冲击下游装置,引起净化水回用率低,对此现象分析查找原因,找出是由于固定铵的脱除率太低造成成,对消除固定铵的影响进行理论分析,发现少量注碱能有效降低净化水中氨氮含量,不会引起生产波动,通过计算调整数据,不断实验摸索,分析数据后,得出了一些操作要点,通过此法可以有效降低净化水氨氮,确保净化水质量合格。  相似文献   

9.
杨雪 《中氮肥》2014,(1):61-64
对蒸馏-中和滴定法测定废水中氨氮含量的分析方法进行了研究。用磷酸盐缓冲溶液代替轻质氧化镁调节水样呈微碱性,以硫酸代替硼酸作为吸收液,以氢氧化钠标准溶液代替硫酸标准溶液滴定,经过实际样品和标准样品的测定,并与国标法进行了试验比对,证明改进后的方法对于高氨氮含量废水测定具有精密度好、准确度高的特点。  相似文献   

10.
The solubilities of isophthalic acid (1) in binary acetic acid (2)+water (3) solvent mixtures were determined in a pressurized vessel. The temperature range was from 373.2 to 473.2K and the range of the mole fraction of acetic acid in the solvent mixtures was from x2 0 to 1. A new method to measure the solubility was developed, which solved the problem of sampling at high temperature. The experimental results indicated that within the temperature range studied, the solubilities of isophthalic acid in all mixtures showed an increasing trend with increasing temperature. The experimental solubilities were correlated by the Buchowski equation, and the calculate results showed good agreement with the experimental solubilities. Furthermore, the mixed solvent systems were found to exhibit a maximum solubility effect on the solubility, which may be attributed to the intermolecular association between the solute and the solvent mixture. The maximum solubility effect was well modeled by the modified Wilson equation.  相似文献   

11.
《分离科学与技术》2012,47(8):1108-1119
An acid dye molecule surface-imprinted material was prepared successfully for the dye removal from water by using a novel molecular surface-imprinting technique. The cationic monomer acryloyloxyethyl trimethyl ammonium chloride (DAC) was used as functional monomer, and sunset yellow was used as a model compound of water-soluble acid dyes. In the aqueous solution, DAC molecules were combined around sunset yellow molecules via electrostatic interaction. The graft/cross-linking copolymerization of DAC and the crosslinker on SiO2 particles was initiated by a surface-initiating system of –NH2/S2O82-, resulting in the sunset yellow molecule surface-imprinted material MIP-PDAC/SiO2. MIP-PDAC/SiO2 possesses special recognition property for sunset yellow.  相似文献   

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