磷酸二氢铵脱除气相氯化钾的模拟与实验

脱除生物质燃烧中气相氯化钾,有助于消除受热面的积灰和腐蚀。采用热力学化学平衡分析方法探索了磷酸二氢铵脱除气相氯化钾的反应特性,考察了温度和化学计量比对反应的影响,结果表明磷酸二氢铵在700～950℃范围内可以有效地将气相氯化钾主要转化为磷酸氢二钾。利用X射线衍射分析对沉降炉实验得到的反应产物进行物相分析,探索了磷钾摩尔比、停留时间、温度对磷酸二氢铵脱除氯化钾的影响,实验结果表明增加停留时间以及磷钾摩尔比均可以促进KCl的脱除,停留时间3 s,磷钾摩尔比为1时,700～1000℃下的反应产物中未检测到物相KCl,而生成了磷酸氢二钾、磷酸二氢钾、偏磷酸钾、焦磷酸钾、磷酸钾铵、磷酸二氢铵钾等产物。结果有助于深入研究磷酸二氢铵用于脱除燃烧中碱金属离子。     

Gypsum crystallization and potassium chloride regeneration by reaction of calcium chloride solution with potassium sulfate solution or solid

Gypsum crystallization along with the simultaneous regeneration of KCl was investigated by the reaction of CaCl2 solution with K2SO4.Well developed sheet structure gypsum crystals were produced when K2SO4 solution was added into the CaCl2 solution by slow titration or in multiple stages over 2-8 h followed by 2 h equilibration.In order to regenerate KCl solution as concentrated as possible,K2SO4 solid was added into the given CaCl2 solution instead of K2SO4 solution,obtaining gypsum crystals with almost the same quality by multistage addition with[SO4 2-]/[Ca 2+]molar ratio no larger than 0.8.However,impurity of K2SO4·CaSO4·H2O was detected by XRD and was further confirmed by SEM-EDS in the produced crystals when the[SO4 2-]/[Ca 2+] ratio increased to 1.1.It is proved that appearance of the double sulfate is attributed to the relatively high concentration of K2SO4.So,it is essential to properly control the[SO4 2-]/[Ca 2+]ratio and make sure[Ca 2+ ]in excess to suppress the solubility of CaSO4 even at the expense of low calcium removal rate.     

温度对S135钻杆钢在3.5%KCl溶液中腐蚀行为的影响

基于理论分析和采用挂片实验,SEM以及电化学测量技术,研究了S135钻杆钢在不同温度下3.5%KCl溶液中的腐蚀行为.结果表明:钻杆钢试样开路电位随着温度升高负移;不同温度下的腐蚀控制因素是造成腐蚀速率变化的主要原因;电化学腐蚀主要受阳极反应控制;系统"弥散效应"随温度升高而增强,平均腐蚀速率呈现先增加后降低的趋势.     

KCl对微波法制备均分散α-Fe2O3纳米粒子的影响

用微波辅照法制备了均分散α-Fe2O3纳米粒子.粒子的形状基本上是假立方体,粒子的大小与体系中的氯离子浓度呈很好的线型关系.氯离子浓度越大粒子越大.陈化时间随KCl用量的增加而缩短.实验事实表明在α-Fe2O3粒子的成长过程中,初生微晶直接向晶核上沉积起了很大的作用.     

Contributions of Titin and Collagen to Passive Stress in Muscles from mdm Mice with a Small Deletion in Titin’s Molecular Spring

Muscular dystrophy with myositis (mdm) is a naturally occurring mutation in the mouse Ttn gene that results in higher passive stress in muscle fibers and intact muscles compared to wild-type (WT). The goal of this study was to test whether alternative splicing of titin exons occurs in mdm muscles, which contain a small deletion in the N2A-PEVK regions of titin, and to test whether splicing changes are associated with an increase in titin-based passive tension. Although higher levels of collagen have been reported previously in mdm muscles, here we demonstrate alternative splicing of titin in mdm skeletal muscle fibers. We identified Z-band, PEVK, and C-terminus Mex5 exons as splicing hotspots in mdm titin using RNA sequencing data and further reported upregulation in ECM-associated genes. We also treated skinned mdm soleus fiber bundles with trypsin, trypsin + KCl, and trypsin + KCL + KI to degrade titin. The results showed that passive stress dropped significantly more after trypsin treatment in mdm fibers (11 ± 1.6 mN/mm²) than in WT fibers (4.8 ± 1 mN/mm²; p = 0.0004). The finding that treatment with trypsin reduces titin-based passive tension more in mdm than in WT fibers supports the hypothesis that exon splicing leads to the expression of a stiffer and shorter titin isoform in mdm fibers. After titin extraction by trypsin + KCl + KI, mdm fibers (6.7 ± 1.27 mN/mm²) had significantly higher collagen-based passive stress remaining than WT fibers (2.6 ± 1.3 mN/mm²; p = 0.0014). We conclude that both titin and collagen contribute to higher passive tension of mdm muscles.     

Experimental study of the formation of natural gas hydrates in the presence of NaCl and KCl

In this work, the conditions for the formation of natural gas hydrate in pure water as well as in the presence of two electrolytic inhibitors of NaCl and KCl were investigated at different concentrations using the isochoric method. This study has been conducted on natural gas source field (Pazanan2 region) and due to the uniqueness of this gas, it may be considered significant. In order to estimate the conditions for the formation of natural gas hydrate in the presence of pure water, hydrate equations have been used. Experiments were carried out at the different temperatures and pressures.     

KCl部分替代NaCl对宣威火腿细菌多样性的影响

为探究KCl部分替代NaCl腌制的宣威火腿中细菌多样性和群落结构，以100% NaCl腌制的宣威火腿为对照组，分别以KCl替代30%、40%、50%和60% NaCl进行腌制作为实验组，基于Illumina MiSeq高通量测序技术对火腿表面和内部细菌16S rRNA的V3～V4区进行扩增和测序，进而比较不同KCl替代比例宣威火腿微生物的群落结构组成及多样性差异。结果表明：不同KCl替代组火腿表面共得到257 777 条序列和6 153 个操作分类单元，在火腿内部共得到248 102 条序列和5 704 个操作分类单元；尽管不同KCl替代组的火腿在微生物丰度上存在一定差异，但各KCl替代组火腿表面和内部样本在门水平上的优势菌群均为变形菌门和厚壁菌门，KCl部分替代NaCl使火腿表面和内部变形菌门的相对丰度增加，均在40% KCl替代组中最高，且显著高于对照组（P＜0.05）；不同KCl替代比例腌制的宣威火腿细菌群落结构存在较大相似性，但在一定程度上降低了火腿表面菌群丰度和群落多样性，内部菌群丰度和群落多样性则无显著差异。     

Membrane behavior of bentonite-amended compacted clay

The performance of landfill liners can be enhanced if they exhibit a semipermeable membrane behavior, which restricts the migration of contaminants. Consequently, enhancing the membrane property of clays used for liners is becoming increasingly important. As bentonite has already proven to be an excellent additive for improving the membrane behavior of clay, the hydraulic conductivities and membrane behaviors of a locally available clay, known as Fukakusa clay, amended with different amounts of dry bentonite (5%, 10%, 15%, and 20%) were herein evaluated. The chemico-osmotic efficiency coefficient, ω, was obtained under different concentration differences of KCl solution (0.5, 1, 5, 10, and 50 mM) for specimens in rigid-wall cells. The test results show that the ω of unamended clay is very low and can be ignored unless amended with bentonite, and that hydraulic conductivity k is suitably low (1.58×10⁻⁹ m/s). Additionally, ω decreased as the KCl concentration increased, which is consistent with the theory that increasing concentration causes progressively greater shrinkage of the diffuse-double layers of the clay particles. Furthermore, the mechanisms that influence the membrane behavior are discussed from the viewpoints of the diffuse-double layer and the interparticle pore size with the assistance of SEM.     

控制剂种类对多元醇热法制备纳米银材料形貌的影响

纳米银材料的性能由其形貌、纯度和微观尺寸决定。采用多元醇热法,研究不同控制剂种类对制备纳米银材料的影响。结果表明,控制剂种类及剂量对多元醇热法制备纳米银材料的形貌和纯度起着关键作用。当控制剂无水硫酸钠浓度为5 mmol/L,剂量为700μL时,可制得粒径为200~500 nm的纳米银颗粒。当控制剂氯化钾浓度为5 mmol/L,剂量为400μL时,可制备长度为3μm,线径为200 nm,长径比为15的高纯度纳米银棒。制得的高纯度纳米银颗粒、纳米银棒在电子元件、材料、生物等领域具有广泛的应用前景。