Laminar mesoporous structure of modified montmorillonite clays and its formation mechanism

Zr-pillared clays were prepared by heating and ultrasonic methods in intercalation process.The resultants were characterized by XRD,N2 adsorption-desorption,SEM,and TG/DTA analysis.Ultrasonic technology accelerated the pillaring process effectively and obtained better ordered structure than by heating method.The specific surface area and pore volume of the Zr-pillared clays increased by about 13 and 3 times respectively.Rare earth metal(Ce)was introduced into Zr-pillared clays by co-intercalation and dipping method.The specific surface area was increased by co-intercalation approach,but it was decreased dramatically by dipping method.Thermal stability of Ce modified samples prepared by co-intercalation method was enhanced in comparison with Zr-pillared clays.Modification mechanism and "corrugation-like" structural mode of intercalation process was proposed basing on the double XRD peaks in small-angle range of pillared clays,which was related to the deformation of silicate layer.     

Hibiscus sabdariffa L. confesctionery gels,in vitro digestion,antioxidant activity and phenolic compounds quantification: a nutraceutical application

Dehydrated Hibiscus sabdariffa (Roselle) is usually used as the raw material of popular beverages, where the exhausted calyx, still rich in polyphenols and fibre, is discarded. The aim of the present study is to evaluate the possibility of adding Roselle's whole calyx to a confectionery product elaborated with gelatin, quantifying the concentration of released polyphenols (Folin–Ciocalteu) during an in vitro digestion and the expression of antioxidant activity [Ferric reducing antioxidant power (FRAP) and N,N‐dimethyl‐p‐phenylenediamine dihydrochloride (DMPD)] during this process. Results show that hardness and elongation of Roselle‐gelatin gums respond to a quadratic model where single components and binary mixtures show significant contributions to hardness and elongation behaviour respectively. Ten grams of Roselle‐gelatin gum express a higher antioxidant activity (FRAP) than 250 mL of the infusion prepared by a traditionally procedure. A significant proportion of the radical scavenging (DMPD) activity could have been lost during the elaboration process of the gums, and although more studies should be done, a hypothesis explaining this effect is included.     

活性染料蛋白类防沾色剂的制备

以明胶和自制的阳离子交联改性剂WLS为原料,制备了一种阳离子明胶蛋白助剂,并与聚乙烯基吡咯烷酮(PVP)复配,制成一种新型防沾色助剂,应用于活性染料染色棉织物皂洗后处理。以白布沾色K/S值和色布耐皂洗色牢度为评价指标,运用正交试验确定了有利于改善活性染料染色棉织物皂洗防沾色的阳离子明胶蛋白助剂的合成条件,其为:m(明胶蛋白)∶m(WLS)=1∶10,Na OH用量为WLS用量的1.8%,反应温度70℃,反应时间3h;PVP与阳离子明胶蛋白复配质量比为1:50。     

A/C比对Ce3+掺杂的Al-Ca-Ba闪烁玻璃发光性能的影响

选取了具有良好化学稳定性的Al-Ca-Ba玻璃系统作为闪烁体的基质系统,研究了Ce3+在该玻璃系统中的发光特性以及该玻璃系统中A/C(Al2O3/CaO)比值对发光性能的影响。研究结果表明,Ce3+在Al-Ca-Ba玻璃系统中的发光较其它玻璃系统激发与发射波长均发生了明显的红移效应,Stokes位移变大,原因跟该玻璃系统较高的光碱度相关;Al-Ca-Ba玻璃闪烁体中A/C比值对发光性能具有非常重要的影响,其比值处于12CaO.7Al2O3这一低熔区域范围内,发光性能最好。     

Ce:Fe:LiNbO_3晶体生长及其在红光波段的体全息存储特性

用提拉法从熔体中生长了 Ｃｅ：Ｆｅ：ＬｉＮｂＯ３晶体．研究了 Ｃｅ：Ｆｅ：ＬｉＮｂＯ３晶体在 ６３３ｎｍ波段的体全息存储特性,对不同掺杂浓度的 Ｃｅ：Ｆｅ：ＬｉＮｂＯ３和Ｆｅ：ＬｉＮｂＯ３晶体进行了全息时间常数和吸收光谱的测定与比较．实验表明,Ｃｅ：Ｆｅ：ＬｉＮｂＯ３晶体对红光的灵敏度优于Ｆｅ：ＬｉＮｂＯ３晶体,它是一种优良的体全息记录材料．     

新型高光输出快响应的LaCl3:Ce晶体时间响应性能测量

LaCl3:Ce晶体是新型高发光产额、快衰减的无机晶体。利用皮秒级激光器和纳秒脉冲源对国产该类晶体的时间响应性能进行测量;同时推算并使用了用脉冲法获得晶体发光衰减常数的简单估算公式。实验结果表明:LaCl3:Ce晶体对皮秒脉冲器的时间响应衰减时间常数为25 ns,与文献符合较好;对纳秒脉冲源的时间响应衰减时间常数为69.13 ns。衰减时间的差异考虑为发光机制的不同与环境散射的影响。     

Ⅲ型裂纹非对称动态扩展解的基本形式

通过复变函数论的方法,对Ⅲ型裂纹非对称动态扩展解的基本形式进行推导。采用自相似函数的途径可获得解析解的一般表达式,使得问题相应地简化,并具有一定的普遍性。应用该法可迅速地将所讨论的问题转化为Keldysh-Sedov问题,而这一类问题容易用通常的Muskhelishvili方法解决。利用已获得的解析解和叠加原理,可求得任意复杂问题的解。     

微量的砷、硼和稀土Ce对黄铜冷凝管耐蚀行为的影响

采用扫描金相—微区成分分析,拉伸力学性能测试和x射线衍射生物相分析等手段对加入微量的砷、硼和稀土Ce黄铜冷凝管的腐蚀特性进行了观察和分析。结果表明:不仅单独加入微量的砷、硼和稀土Ce能抑制HSn70-1黄铜冷凝管的脱锌腐蚀,砷、硼和稀土Ce的联合加入能更有效地协同抑制HSn70-1黄铜冷凝管的脱锌腐蚀。     

生物预酸化处理明胶废水对活性污泥减量化的作用

明胶废水具有高钙、高COD等特点而难于处理。通过对明胶废水进行生物预酸化处理,研究了活性污泥法处理明胶废水过程中COD去除率、MLSS、MLVSS以及无机灰分的变化。结果表明,经过生物预酸化处理后,明胶废水的p H由11.8降至7.4左右,COD由1 058 mg/L降至671 mg/L。后续活性污泥法处理过程中,与未进行生物预酸化处理相比,MLSS、MLVSS呈明显下降趋势,最终COD去除率达到90%;同时由于反应器维持在较低的p H下运行,避免了曝气生成CaCO_3沉淀,污泥无机灰分减少。生物预酸化处理对污泥减量化有明显贡献。