Re-evaluation of Radiation-Energy Transfer to an Extraction Solvent in a Minor-Actinide-Separation Process Based on Consideration of Radiation Permeability

ABSTRACT

Absorbed-dose estimation is essential for evaluation of the radiation tolerance of minor-actinide-separation processes. We propose a dose-evaluation method based on radiation permeability, with comparisons of heterogeneous structures seen in the solvent-extraction process, such as emulsions forming in the mixture of the organic and aqueous phases. A demonstration of radiation-energy-transfer simulation is performed with a focus on the minor-actinide-recovery process from high-level liquid waste with the aid of the Monte Carlo radiation-transport code PHITS. The simulation results indicate that the dose absorbed by the extraction solvent from alpha radiation depends upon the emulsion structure, and that from beta and gamma radiation depends upon the mixer-settler-apparatus size. Non-negligible contributions of well-permeable gamma rays were indicated in terms of the plant operation of the minor-actinide-separation process.     

β－C_2S固溶体稳定的热力学研究

从热力学理论出发，利用Ｘ射线衍射定性和定量的方法，对β－Ｃ＿２Ｓ固溶体的稳定性进行了分析和研究。经热力学理论推导得出β－Ｃ＿２Ｓ稳定的热力学条件，即掺入的微量元素的化学位μ＿ｉ须小于β－Ｃ＿２Ｓ的反应自由焓△Ｇ＿β，μ＿ｉ＜△Ｇ＿β．并定量地计算出一种微量元素稳定β－Ｃ＿２Ｓ的临界掺加量为；多种微量元素对β－Ｃ＿２Ｓ的稳定性判断条件为：     

基底断裂“隐性活动”对鄂尔多斯盆地上古生界天然气成藏的作用

鄂尔多斯盆地北东向基底断裂中、新生代“隐性”活动对上古生界天然气富集高产和成藏有明显控制作用。采用渗透率异常频率分析方法，预测了盆地中东部地区上古生界裂缝的分布，并建立了裂缝发育与基底断裂之间的成因关系，指出基底断裂后期活动不仅对盆地上古生界致密储集层的裂缝发育有控制作用，而且对天然气成藏有促进作用。应该重视盆地北东向基底断裂发育区次生天然气藏的勘探。图7参23     

Identification of a minor component of the sex pheromone ofLeucoptera malifoliella (Lepidoptera,lyonetiidae)

A new minor component in the female volatile extract ofLeucoptera malifoliella (Costa) (Lepidoptera, Lyonetiidae) has been identified as 5,9-dimethyloctadecane (2). The amount detected of the minor compound2 ranged from 4 to 8% in comparison with the major component 5,9-dimethylheptadecane (1). Neither compound has been found in the male volatile extract. The identification has been based on its spectroscopic properties and Chromatographic behavior in comparison with an authentic synthetic sample. The synthesis has been carried out through a short route from 2,6-dimethylcyclohexanone (3). In field tests, compound2 appears to act as a Synergist of the major component1 when mixed with the latter in a 1000.1– 5 ratio.     

A study on cashew nut oil composition

Eight samples of cashew nut oil were assayed, and the component triacylglycerols, fatty acids and several unsaponifiable compounds were analyzed by gas chromatography (GC) and high-performance liquid chromatography (HPLC). Total lipid amount, unsaponifiable percentage, fatty acids, sterols, triterpene alcohols and tocopherols are reported here. The combination of GC and HPLC enhanced the resolution of compound classes.     

堆热法提取浮萍多糖

浮萍多糖具有免疫调节能力,是一种很有发展前景的药物原料.为了广泛开发利用浮萍资源,有效提取浮萍多糖,应用堆热法从浮萍中提取多糖,实验结果显示堆热法提取浮萍多糖的最佳工艺条件为浮萍堆热5 d,80℃浸提8 h后,4倍体积无水乙醇沉淀2次,浮萍多糖纯度和收率分别为32%和0.17%.     

Observations on the oxidation behavior of Ni-Cr alloys containing minor additions of group III,IV, or V elements

The corrosion of a number of experimental ternary Ni-15 wt. % Cr-0.5wt. %X alloys (where X= Y, La, Ce, Sm, Th, U, Zr, or V) has been assessed in pure oxygen at 900° C for periods of exposure up to 450 hr, and compared with the behavior of an Ni-15% Cr control alloy. It has been established that while all of the alloys oxidize in accordance with a protective, approximately parabolic regime, considerable differences in oxidation rates are exhibited. In particular, additions of La, Ce, and Th bring about progressively enhanced rates of oxidation relative to the binary alloy, whereas Y, Sm, V, U, and Zr effect increasingly reduced rates of oxidation in the order given. The rate constant for the Th-bearing alloy is about two orders of magnitude larger than that for the alloy containing Zr. Such differences in behavior seem to be associated with subtle variations in the morphology/composition of the corrosion products from alloy to alloy. The observations are considered in the light of earlier published literature concerning the effects of rare-earth and other reactive elements on the oxidation behavior of Ni/Cr alloys.This work has been carried out with the support of Procurement Executive, Ministry of Defence.     

微量Sc元素对Al-Cu合金组织与性能的影响

采用拉伸力学性能测试、扫描电镜与能谱分析等方法，研究了不同量稀土元素Sc对Al-4Cu合金组织与性能的影响。结果表明：稀土元素Sc能够细化Al-4Cu合金的晶粒组织，改善枝晶网胞；当Sc含量小于0．2％时，Al-4Cu合金的抗拉强度δb和屈服强度δ0.2提高约20MPa；当Sc含量为0．3％～0．4％时，抗拉强度δb和屈服强度δ0.2有所降低；当Sc含量为0．5％时，抗拉强度δb和屈服强度δ0.2又有所升高，但低于未添加Sc的Al-4Cu合金；Sc对合金的伸长率几乎没有影响。微量Sc元素添加到Al-4Cu合金中，当Sc含量小于0．2％时，基本上以固溶的形式溶入合金基体中；当Sc含量为0．3％。0．5％时，除部分固溶于Al基体中外，大部分形成起强化作用的Al3Sc相及交互作用AlCuSc相，AlCuSc相是Al-Cu-Sc系合金中的有害相，它使合金的力学性能在一定程度上有所降低。     

排水系统中雨水检查井局部水头损失分析北大核心CSCD

在对排水系统中的排水管道进行设计时,除沿程水头损失外,局部水头损失也会在特定情况下占比较大,同样不可忽略。为此,根据排水管道及雨水检查井模型的试验数据,计算了不同工况下雨水检查井的局部水头损失系数,并对计算结果进行了分析。分析结果表明:雨水检查井主支管流量比对局部水头损失系数的影响较大,为主要影响因素。随流量比的增加,局部水头损失系数增幅可达1.2;雨水检查井形状及主支管接合角度为非主要影响因素,二者对局部水头损失系数的影响均小于0.2,下游水深及出流总流量对雨水检查井局部水头损失系数几乎不产生影响;所得结果与已有成果的对比分析表明,设置对称侧支管可减小雨水检查井的局部水头损失。该结果有助于深入认识雨水检查井局部水头损失的变化特点,为实际工程中优化城市排水系统设计、完善城市洪水管理方案提供计算依据。     

高职院校设置文秘辅修专业的探索与实践

论述在高职院校开设文秘辅修专业的重要意义,并以广东外语艺术职业学院为例,探讨如何开设文秘辅修专业,并且就开设文秘辅修专业应该具备的保障条件提出建议.