不同类型植物甾醇对蛋鸡脂类代谢的影响

旨在研究不同类型植物甾醇对蛋鸡脂类代谢的影响。选用72只30周龄伊莎褐蛋鸡,随机分为3组,每组8个重复,每重复3只。试验分组如下:(1)对照组,饲喂基础日粮;(2)天然植物甾醇组(NP),饲喂基础日粮+22.2 mg/kg天然植物甾醇(纯度为90%,植物甾醇净含量为20 mg/kg);(3)水溶性植物甾醇组(WP),饲喂基础日粮+50 mg/kg水溶性植物甾醇(纯度为40%,植物甾醇净含量为20 mg/kg)。试验为期8周。结果表明,添加2种植物甾醇使第4周血清三酰甘油(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)含量较对照组均有降低的趋势(P<0.1);WP组第4周脂蛋白脂酶(LPL)、肝脂酶(HL)和总酯酶(TL)活性较对照组有提高趋势,NP组血清HL活性也有提高的趋势(P<0.1),但在第8周各组均无显著差异;WP组第8周的蛋黄胆固醇含量显著低于NP组(P<0.05),而NP组与对照组差异不显著。本试验结果提示2种植物甾醇均有降低血脂和提高脂蛋白代谢酶活性的趋势,且此趋势随着时间的延长而逐渐消失,但对蛋黄胆固醇沉积无显著影响,只有WP在饲喂一段时间后有一定降低作用。     

盐酸处理对谷朊粉理化性质改良的研究

利用盐酸处理改善谷朊粉的溶解度、乳化性、起泡性等理化性质,研究盐酸与谷朊粉的相对浓度、反应温度、反应时间、盐酸浓度对谷朊粉理化性质的影响。结果表明,盐酸处理改良谷朊粉理化性质的最佳条件:谷朊粉质量百分比为8%,盐酸∶谷朊粉为3.5∶100(质量比),反应温度65℃。试验证明,盐酸处理对谷朊粉的溶解度、乳化性及其稳定性、起泡性及其稳定性都有显著作用。     

植物甾醇的乳化及其应用研究进展

植物甾醇主要来源于植物油脂,具有降低血清中胆固醇含量等多种生理功能.但植物甾醇属脂溶性物质,不能与水溶性物质混溶,使其应用受到限制,对植物甾醇进行乳化可改善其水溶性,从而拓宽其应用范围.综述了植物甾醇的乳化处理及其应用研究进展.     

从海盐中提取氯化钠的探讨

本文介绍了从海盐提取氯化钠的方法,既有理论又有实践,确定了较好的工艺条件。     

Synthesis,characterization and solubility of mixed zirconium-cerium molybdate precipitates

The reaction between fission products Mo(VI) and Zr(IV) in hot nitric acid solution during the spent fuel dissolution process leads to the formation of hydrated zirconium molybdate precipitate. This solid can include other metallic cations at the 4th oxidation state (+ IV) inside the crystal such as Pu(IV).

Precipitations in the inactive surrogate system of mixed zirconium-cerium molybdates Mo-Zr(IV)-Ce(IV) were performed all over the cerium molar percentage scale from 0 to 100%, Ce(IV) being used as a surrogate of Pu(IV). The crystal structures were identified from powder X-ray diffraction patterns and complementary investigations by SEM and elemental analyses were carried out. The solid composition pointed out two phases that are ZrMo₂O₇(OH)₂(H₂O)₂ and Ce₃Mo₆O₂₄(H₂O)₄. Each of these compounds was proved being a solid solution within which the Zr^IV and Ce^IV atoms can substitute each other.

Moreover, the influence of the cerium molar fraction on the precipitate solubility was investigated and showed a strong evolution of solubility not only with the nature of the precipitate and the Ce content, but also with the nitric acid concentration.     

Radiokrypton in the Atmosphere

A new reprocessing technology, FLUOREX, is proposed for the thermal reactor cycle. In the dissolution process of FLUOREX, it needs to estimate the concentration of fluoride ion in the solution to avoid formation of insoluble plutonium precipitate. We measured the solubility products of lanthanide fluorides, LaF₃, CeF₃, and NdF₃ in nitric acid solution and evaluate the concentration of fluoride ion in the dissolution process. Solubilities were measured by both of dissolution method and precipitation method. The solubility products are about 10¹ to 10² times larger than those in water. This largeness may be caused by higher ionic strength of nitric acid solution. The newly obtained solubility products for the lanthanides are useful to calculate the maximum concentration of plutonium ions in the FLUOREX dissolution process, although the further study for the solubility products for plutonium tetrafluoride is needed in the nitric acid solution.     

Reactive Wetting of Metallic Plated Steels by Liquid Sodium

Sodium wetting experiments were performed to investigate the reactive wetting of metallic plating materials by liquid sodium at 250°C for the ultrasonic sensor of the under-sodium viewer. SUS304 stainless steel specimens were electrolytically plated with four metallic materials (nickel, palladium, gold, and indium) that have different solubilities in sodium, and the spreading velocity of sodium droplets on the metallic plated specimens was measured. It was confirmed that the spreading velocity increased as the solubility increased, and the constant α on the spreading velocity on the plated specimens was unique for the plating materials and was proportional to the logarithm of the solubility of the plating materials. Furthermore, it is considered possible to select plating materials based on solubility from the result of this study.     

铀在北山地下水中的种态分布及溶解度分析

为了解铀酰离子在北山地下水中的吸附、扩散和迁移行为,利用地球化学计算软件PHREEQC,采用由OECD/NEA发布的最新铀的热力学数据,计算了铀在我国高放废物地质处置库重点研究区甘肃北山地下水中的种态分布,并分析了围岩中存在的方解石对铀溶解度的影响。计算结果表明,在北山地下水组成不变的前提下,在偏酸性条件下,铀主要以UO₂F⁺、UO₂SO₄、UO₂²⁺、UO₂F₂和UO₂(SO₄)₂^2-的形式存在,而在中性至弱碱性条件下,主要以 UO₂(CO₃)^4-₃、UO₂(CO₃)₂^2-、UO₂(OH)₃^-和UO₂(OH)₄^2-的形式存在。我国计划建造的高放废物处置库的设计深度为地下500～1000m,其水岩体系一般呈弱碱性。在这样的弱碱性水岩体系中,以阴离子形式存在的铀酰配合物具有较强的可移动性。当地下水的pH=7.56时,在Eh<24mV的条件下,铀主要以沥青铀矿的形式存在,而在更高的Eh条件下,则主要以UO₂²⁺与CO₃^2-和OH^-形成的阴离子配合物的形式存在。当地下水与空气接触时,O₂的存在会使Eh升高,此时铀的主要存在种态为UO₂²⁺及其各种配合物。当围岩体系中存在方解石时,在pH<8.0的条件下,铀在地下水中的溶解度会显著提高,而在更高pH条件下,方解石对铀的溶解度无明显影响。