关于近于凸函数

本文研究了近于凸函数的新子族的偏差性质,积分表示;还得到最初几项系数的精确估计。     

Solvent Extraction Calculation Model for Purex Process in Pulsed Sieve Plate Column

A new calculation code PULCO has been developed to simulate the Purex extraction process in a pulsed column. The model for the PULCO code is based on the mass transfer taking place at the interface between dispersed drops and continuous phase fluid. The following physical quantities of the moving drop are included in the model for each period of drop motion in a pulsed column:

1. Mass transfer coefficient from liquid drop to continuous phase

2. Diameter and velocity of moving drop in the pulsed column

3. Holdup of dispersed and continuous phases in the pulsed column

4. Longitudinal dispersion coefficient in the pulsed column.

To establish the validity of the PULCO code, experiments were performed using a 50 mm diameter pulsed column which had a sieve plate section height of 2 m and plates spaced 50 mm apart. The experiments were performed by CY tests with use of unirradiated U and Pu. The experimental concentration profiles fitted well with the calculated concentration profiles.     

Consideration on Effective Diffusivity of Strontium in Granite

Abstract

Diffusive behavior of strontium and certain kinds of divalent cations in Inada granite were studied by a through-diffusion method. In order to examine the effect of sorption onto overall diffusive behavior, two kinds of solutions were used: 0.1M KCl solution and deionized water. The effective diffusion coefficient (D_e ) and rock capacity factor (a) were (2.0–3.6) xl0–¹³ m²/s and less than 0.022 in 0.1M KCl solution and (0.32–1.7) x 10 ^?13m²/s and 1.5–2.4 in deionized water respectively. The D_e , and α in deionized water were much larger than those in 0.1M KCl solution. These results are well explained by taking into account the diffusion of sorbed ion or the surface diffusion. In support of this mechanism, most D_e , values of Sr reported for various rocks are found proportional to the sorptivity ( _ρR_d )-In the case that the sorptivity is low, D_e of Sr depends on porosity like that of nonsorbed iodide. The effective diffusion coefficient of Sr in rocks was well explained by taking into account pore and surface diffusion and was expressed as D_e=2.1 xl0^?10 _? ^1.3+3.5xl0″^?12 _ρR_d . The effective diffusion coefficient of divalent cations in the granite was found proportional to their diffusion coefficients in bulk solution.     

环形通道内液态铅铋合金流动换热特性实验研究

通过对环形通道内液态铅铋合金的流动换热特性进行实验研究,得到了气泡泵注气对液态金属流动的影响,并拟合出环形通道内液态铅铋合金的摩擦系数关系式和换热特性关系式。结果表明：采用气泡泵注气能有效提升铅铋合金的质量流速;相同Reynolds数下环形通道内液态铅铋合金的摩擦系数大于由布拉休斯公式计算得到的摩擦系数;液态铅铋合金对流换热过程中,导热项占主导地位,并且Nusselt数随Peclet数的增大而增大。     

中温SOFC密封玻璃热稳定性研究

研究了一种热稳定性好的中温固体氧化物燃料电池密封玻璃. 研究表明, 此密封玻璃的热膨胀系数(室温～631℃)为9.8×10^-6/K, 与8YSZ电解质的热膨胀系数10.0×10^-6/K(室温～631℃)接近, 并且在700℃热处理300h后, 该密封玻璃的热膨胀系数几乎没有变化. 粘度实验表明, 玻璃在700℃下具有足够的刚性, 适合于运行温度在700℃左右SOFC的密封. 化学相容性的研究显示, 在700℃下与8YSZ反应300h后没有发现显著的界面反应.     

一种新型的机液集成变速器

提出了一种新型的机液集成变速器,介绍了其结构、工作原理和结构特点,总参数选择及系统设计方法,可指导新产品的研究开发,满足众多领域对低转速、大扭矩、高效率、低能耗变速器的需要.     

Hierarchical Spatially Varying Coefficient Process Model

The spatially varying coefficient process model is a nonstationary approach to explaining spatial heterogen-eity by allowing coefficients to vary across space. In this article, we develop a methodology for generalizing this model to accommodate geographically hierarchical data. This article considers two-level hierarchical structures and allow for the coefficients of both low-level and high-level units to vary over space. We assume that the spatially varying low-level coefficients follow the multivariate Gaussian process, and the spatially varying high-level coefficients follow the multivariate simultaneous autoregressive model that we develop by extending the standard simultaneous autoregressive model to incorporate multivariate data. We apply the proposed model to transaction data of houses sold in 2014 in a part of the city of Los Angeles. The results show that the proposed model predicts housing prices and fits the data effectively.     

光面爆破在卡鲁玛尾水隧洞开挖中的改进与应用

在乌干达卡鲁玛尾水隧洞8#支洞Ⅲ类围岩开挖中,为了解决光面爆破施工中用的25mm细药卷短缺、绑扎光面爆破药串用的竹片无法买到等问题,采用了经过加工的32mm常规药卷,调整了光面爆破孔内装药结构和装药方法,并在选用常规周边光面爆破孔孔距条件下,适当减小光面爆破层厚度,将周边光面爆破孔密集系数提高到1.25~1.43。爆破实践表明:通过一系列改进,即便在只有最常见的32mm常规药卷和导爆索条件下,仍能取得良好的光面爆破效果。这一改进简化了光面爆破药串加工工序,减少了光面爆破层脱落需要克服的阻力,减轻了爆破对洞周被保留岩体的伤害。     

轴流涡轮与排气壳扩压段一维耦合设计研究

为探究轴流涡轮耦合排气壳扩压段的一维设计变量选取规律,提高排气壳扩压段的性能,参考现有NRCC叶栅导叶模型,采用自编程序,结合理论分析构建轴流涡轮与排气扩压段耦合的一维设计模型。详细分析耦合设计中影响扩压段的静压恢复系数以及总体性能的因素。研究结果表明：扩压段面积比、平均倾角、扩张角以及壁面摩擦系数等设计参数不仅影响扩压段的静压恢复系数,也影响涡轮的气动效率;本研究模型在面积比为3.5、平均倾角为30°、扩张角δ为5°时整体性能最优;涡轮出口气流的马赫数、叶顶泄漏流以及出口旋流对扩压段的性能有很大影响,出口半径比的增大会使得静压恢复系数降低,因此在耦合设计时应充分考虑涡轮以上参数的选择。