硫酰氟的制备及在有机合成中的应用

硫酰氟作为广谱的熏蒸剂和杀虫剂,性能优异,应用较为广泛.而其独特的物理化学性质,在有机合成化学中的应用近年来也被相继报道.通过对硫酰氟物理化学性质进行介绍,并且对合成硫酰氟的方法、生产情况进行了简要的总结归纳,同时对以硫酰氟作为反应物及化学反应中间体,在有机合成中用于构建磺酰氟、烷基胺、脱氢化等应用进行介绍.期望通过硫...     

冻结过程中水分盐分结晶相变对盐渍土压力的影响

冻胀和盐胀导致土体变形破坏对建筑基础、公路铁路路基等构成严重威胁。本文开展了冻结过程中水分盐分结晶相变对盐渍土压力的影响试验研究,结果表明:冰晶压力随着含水率的增加而增大;在一定干密度和含水率下,盐结晶压力随着含盐量的增大而增大。冻结过程中,土压力首先保持不变,然后迅速增大,最后迅速降低至稳定。冰晶压力与盐结晶压力作为张应力作用在孔隙壁上使得土颗粒间相互挤压,达到峰值应力后,土体结构破坏和土颗粒重分布导致土压力迅速降低至稳定。此外,还讨论了传统盐结晶压力方程和冰晶压力方程的适用性,最后对冰晶压力方程进行了修正。     

不同盐沼湿地类型脱氮除磷效能及影响因素分析

采用沉水植物表面流湿地(沉水组)、挺水植物表面流湿地(挺水组)和浮床湿地(浮床组)3种盐沼湿地对长江口近岸低污染水体进行脱氮除磷效能的研究.结果表明,HRT为3d时,水组、挺水组、浮床组对NO3--N的去除率在高温时段分别为79.9％±13.2％、71.8％±15.2％、77.2％±13.2％,中温时段分别为39.4％...     

氢基质生物膜反应器同步去除溴酸盐和高氯酸盐的影响因素分析

基于H2-MBfR(氢基质生物膜反应器)研究pH、进水硝态氮(NO3--N)、亚硝态氮(NO2--N)以及回流比对同步去除溴酸盐(BrO3-)和高氯酸盐(ClO4)的影响.结果表明:提高进水pH,BrO3和ClO4的去除率呈现先升高后降低的趋势,溴酸盐与高氯酸盐的去除率在pH为7时达到最高值93.9％和91.6％.提高...     

添加剂对CTAB临界胶束浓度影响的研究

正十六烷基三甲基溴化铵「Ｃ１６Ｈ３３Ｎ（ＣＨ３）３Ｂｒ」是一种阳离子表面活性剂，它具有很强的杀菌能力，被广泛用于消毒，灭菌等。由于它易吸附于一般固体表面，因而常用作矿物浮选剂和直接染料固着剂，作为一种表面活性剂能形成胶束是它的一个重要特性。     

Effect of Salt Stress on the Expression and Promoter Methylation of the Genes Encoding the Mitochondrial and Cytosolic Forms of Aconitase and Fumarase in Maize

The influence of salt stress on gene expression, promoter methylation, and enzymatic activity of the mitochondrial and cytosolic forms of aconitase and fumarase has been investigated in maize (Zea mays L.) seedlings. The incubation of maize seedlings in 150-mM NaCl solution resulted in a several-fold increase of the mitochondrial activities of aconitase and fumarase that peaked at 6 h of NaCl treatment, while the cytosolic activity of aconitase and fumarase decreased. This corresponded to the decrease in promoter methylation of the genes Aco1 and Fum1 encoding the mitochondrial forms of these enzymes and the increase in promoter methylation of the genes Aco2 and Fum2 encoding the cytosolic forms. The pattern of expression of the genes encoding the mitochondrial forms of aconitase and fumarase corresponded to the profile of the increase of the stress marker gene ZmCOI6.1. It is concluded that the mitochondrial and cytosolic forms of aconitase and fumarase are regulated via the epigenetic mechanism of promoter methylation of their genes in the opposite ways in response to salt stress. The role of the mitochondrial isoforms of aconitase and fumarase in the elevation of respiration under salt stress is discussed.     

一种新稳定剂异噻唑啉酮产品的研究开发

研究开发了一种绿色环保的复合有机稳定剂,可替代铜盐用于异噻唑啉酮杀菌剂产品(Ⅱ类产品),从而避免重金属对环境的危害。且采用新稳定剂的异噻唑啉酮Ⅰ类产品可以直接加水稀释成Ⅱ类产品,不需要补加铜盐或其他稳定剂。采用新稳定剂的异噻唑啉酮杀菌剂产品(Ⅰ类和Ⅱ类),不仅具有更好的稳定性,而且具有更高的杀菌效率。     

不同龄期和硫酸盐作用下大理石粉对水泥固化氯离子性能影响研究

研究了硫酸盐作用下大理石粉对水泥固化氯离子性能的影响规律及作用机理.试验结果表明:水泥-大理石粉硬化浆体氯离子固化率,1d龄期之前快速增长,1～3d龄期增长变缓,3～7d龄期进一步减缓,7～28 d龄期时增加缓慢,1d、3d和7d龄期的分别达到28 d的50％、70％和95％.随着大理石粉掺量的增加,水泥浆体的氯离子固化率,6h、12 h、1d龄期增大,3d、7d、28 d龄期降低;随着硫酸盐浓度增加,其氯离子固化率降低.XRD分析表明大理石粉对水泥浆体28 d龄期的Freidel's盐生成量影响不大,硫酸盐抑制水泥-大理石粉浆体Freidel's盐生成.     

The extraction of potassium from K-feldspar ore by low temperature molten salt method

The low temperature molten salt method was used to extract potassium from K-feldspar ore, and some related factors including mass ratio between NaNO₃, NaOH, H₂O and K-feldspar ore, particle size of K-feldspar ore, reaction temperature and time were investigated, respectively. In addition, the optimum condition for this method was determined by a series of condition experiments. What was more, the K-feldspar ore and the leach residue after reaction based on the above optimum condition were analyzed by XRD, SEM and EDS, separately. The results of which indicated that the mechanism of extraction of potassium for this method was according to the ion exchange reaction between sodium ion and potassium ion, and the extraction ratio of potassium had an obvious improvement than that of traditional methods, which could reach up to 96.25%. Therefore, this method can be a feasible solution to extract potassium from K-feldspar ore for its low energy consumption and high efficiency.