电石渣在燃煤电厂脱硫工艺中的应用研究进展

近年来,电石渣在燃煤电厂干法脱硫工艺的应用中取得了较多进展,但在湿法脱硫的应用中仍存在消溶特性差、亚硫酸钙氧化率低、石膏脱水困难等诸多问题,导致其难以大规模推广。本文从电石渣的理化性质出发,分析了孔隙结构、反应温度、Ca/S摩尔比对脱硫效率的影响,并探讨了电石渣作为脱硫剂对循环流化床锅炉效率及运行的影响,结合电石渣的消溶特性、浆液氧化特性及石膏脱水特性,分析了电石渣在湿法脱硫工艺应用中存在的问题,提出了一种以电石渣为原料,利用燃煤机组再生水深度处理系统生产石灰石浆液的工艺路线,并在2×660MW超超临界燃煤机组再生水深度处理系统中进行了可行性试验,当Ca(OH)₂纯度≥95%时,合理的污泥掺配比例区间为50%~70%,所产石膏达到了二级石膏的品质要求。     

钒对中碳非调质钢疲劳性能的影响

采用旋转弯曲疲劳实验研究了含钒的38MnVS钢与不含钒的38MnS钢在热锻态和退火态下的疲劳行为.结果表明,V元素主要通过析出强化和组织细化改善铁素体 珠光体型非调质钢的疲劳性能.在热锻态,V(C,N)呈细小弥散分布,与铁素体间具有特定位向关系,具有明显的析出强化和细化组织作用.铁索体的强化使得疲劳裂纹萌生和扩展的抗力提高,因而38MnVS钢的疲劳性能明显优于38MnS钢;在退火态,V(C,N)质点长大,与铁素体间失去共格关系,不再具有明显的析出强化作用,因而退火态38MnVS钢的疲劳性能明显低于热锻态,而与38MnS钢的疲劳性能相当.     

D301阴离子交换树脂对大豆异黄酮分离特性的影响

为更好地将离子交换树脂应用于大豆异黄酮的分离纯化,研究了乙醇含量、pH、温度、初始浓度等条件对D301阴离子交换树脂吸附分离大豆异黄酮的影响。静态吸附实验结果表明,该树脂在以水为溶剂、pH 8左右、40℃时对大豆异黄酮有最好的吸附效果。穿透曲线实验表明,动态饱和吸附量受温度影响较大,当柱温为50℃、初始浓度C07.03 mg/mL时,饱和吸附量为105.0 mg/g干树脂。洗脱曲线实验表明,采用体积分数75%乙醇洗脱,异黄酮回收率为89.3%,产品中大豆异黄酮含量高达56.0%,含量比原料提高了十几倍。表明D301阴离子交换树脂对大豆异黄酮的分离纯化具有较好的选择性和应用前景。     

模拟高钠高放废物铁硼磷酸盐玻璃固化体的结构和性能

以36Fe2O3--10B2O3--54P2O5为基础玻璃,制备了不同模拟高钠高放废物包容量的铁硼磷酸盐玻璃固化体,用Fourier变换红外光谱测试方法系统研究了由废物包容量引起的玻璃固化体结构变化,并用溶解速率法初步测试了固化体的化学性能。结果表明:随着废物包容量的增加,固化体试样结构中(PO4)3-四面体基团增加,[BO3]基团向[BO4]基团转变,磷酸盐基团彼此间的连接程度减小,Fe—O—P键在包容量为25%(质量分数)到30%时存在量较大。玻璃固化体网络结构以(PO4)3-四面体基团为主,易水化的(PO3)-磷酸盐基团的含量很小。但固化体结构中[BO3]基团的存在量还较大,该组分的基础玻璃网络形成体氧化物配比还可进一步优化。当废物包容量小于40%时,固化体不同浸泡周期的质量损失速率均在10--8 g/(cm2·min)数量级。     

Precipitation of MC phase and precipitation strengthening in hot rolled Nb–Mo and Nb–Ti steels

Hot rolled Nb–Mo steel of yield strength 600 MPa and Nb–Ti steel of yield strength 525 MPa with polygonal and acicular ferrite microstructure have been developed. Using physicochemical phase analysis, XRD, TEM and EDS, the distribution, morphology, composition, crystal structure and particle size of precipitates were observed and identified in these steels. The results revealed that the steels containing both Nb and Mo exhibited fine and uniformly distributed MC-type carbides, while the carbides were coarse and sparsely distributed in the steels containing Nb and Ti. The physicochemical phase analysis showed MC-type carbides contain both Nb and Mo, and the ratio of Mo/Nb was 0.41. Meanwhile, the mass% of the fine particles (<10 nm in size) of Nb–Mo steel was 58.4%, and higher than that of Nb–Ti steel with 30.0%. Therefore, the results of strengthening mechanisms analysis showed the higher strength of Nb–Mo steel than that of Nb–Ti steel is attributed to its relatively more prominent precipitation strengthening effect. The yield strength increments from precipitation hardening of Nb–Mo steel attained 182.7 MPa and higher than that of Nb–Ti steel.     

High-Current-Density field emission from self-heating printed carbon nanotubes

High-current-density field emitters are considered as the potential and necessary components for compact high definition x-ray sources and high-power cold cathode microwave amplifiers. In this report, high-current-density field emission from self-heating printed carbon nanotubes is introduced. Large emission current causes large heat that increases the temperature of the emitters. The temperature is estimated to be more than ~1600 K. Localized surface field and high temperature both drive more electrons escaping from the emitters, and the maximum current density is larger than ~2.7 A/cm² that will satisfy the need of most vacuum electron devices including x-ray sources and microwave electron devices.     

Geothermal resources of the Beijing area, China

Hot water resources were discovered in 1970 at a fairly shallow depth below the city of Beijing. The total areal extent of the geothermal field is presently estimated at more than 100 km². The two known thermal aquifers are composed of fractured dolomites and the temperature of the aquifers ranges from 53 to 80°C. Based on the production-drawdown history of the Beijing geothermal field, for the period 1971–1981, the unit step response of the reservoir is obtained. Parameters of a simple lumped two-capacitor model, matched with the unit step response, furnish some information on dimensions and overall potential of the Beijing reservoir.     

离子液体-分子溶剂复合萃取剂脱除水中酚类化合物

构建了疏水性离子液体-分子溶剂复合萃取剂,并研究了其对酚类化合物的萃取性能。结果表明,与纯离子液体萃取剂相比,三己基十四烷基溴化（[P₆₆₆₁₄]Br）-乙酸乙酯复合萃取剂在显著降低萃取剂黏度的同时,获得了较高的酚类溶质分配系数。当萃取剂中[P₆₆₆₁₄]Br摩尔分数为20%时,苯酚的分配系数为345,是纯乙酸乙酯为萃取剂时的5.3倍,是[omim]BF₄、[C₁₂mim]NTf₂等常规疏水离子液体的9~60倍;比纯[P₆₆₆₁₄]Br为萃取剂时的分配系数下降25.3%,黏度却比纯[P₆₆₆₁₄]Br降低99%以上。COSMO-RS研究表明[P₆₆₆₁₄]Br与苯酚之间较强的氢键作用是获得较高苯酚分配系数的关键因素。该复合萃取剂对间苯三酚、4-氯苯酚和2,5-二硝基苯酚等物质也有良好的萃取能力。上述结果为开发兼具良好热力学性能和动力学性能的脱酚萃取剂提供了新的思路。     

全球LNG船运市场及运输船技术发展分析

介绍全球LNG海运现状,对LNG运输船关键技术进行分析。随着LNG需求及贸易的不断增长,全球LNG贸易商对LNG运输船需求将明显增长,LNG运输船容积向大型化发展。LNG运输船推进系统是制约其发展的关键技术之一,节省燃料、高效、可回收BOG的推进系统,是未来发展的方向。LNG运输船液货舱主要以薄膜型、独立球型液舱储罐为主,薄膜型液舱储罐性能更优,造价低,受到船东青睐。     

建筑防水涂料用硅丙乳液的制备与性能

介绍了有机无机复合建筑防水涂料用硅丙乳液的研制背景、制备方法及主要性能。所制备的硅丙乳液有机硅含量达12％，其与水泥和细砂集料混合均匀后形成的有机无机复合防水涂料对常用建筑材料粘接力强，形成的弹性胶膜吸水率低、防水性好、耐老化性高、产品性能稳定。