偶氮二异丁腈制备低密度不饱和聚酯树脂制品

以偶氮二异丁腈(AIBN)为发泡剂兼引发剂、CaCO3为成核剂制备了低密度不饱和聚酯树脂制品(LDUPRP)。以成型温度、AIBN用量和CaCO3用量作为三因素,设计L25(53)正交试验以确定制备LDUPRP的最佳配比和成型条件。结果表明:AIBN作为发泡剂适用于不饱和聚酯树脂(UPR)体系;LDUPRP的最佳制备条件为成型温度80℃、AIBN用量为树脂质量的2%、CaCO3用量为树脂质量的3%,此时制得的样品密度为0.452g/cm3,压缩强度达13.64MPa,比压缩强度为30.18MPa/(gcm-3),与硬质聚氨酯泡沫相近。红外光谱(FTIR)分析表明,AIBN引发UPR固化的结果与过氧化苯甲酸叔丁酯(TBPB)一致;丙酮萃取法和差示扫描量热(DSC)分析表明,AIBN用量为树脂质量的2%时树脂的固化度最高;样品断面分析表明,成核剂及其用量对泡孔形态有一定影响,不含CaCO3时形成狭长的泡孔,当CaCO3用量为树脂质量的7%时LDUPRP出现并泡现象。     

基于统计抽样的压水堆燃料组件性能分析不确定度量化研究

为能在给出数值模拟结果的同时提供置信区间,本文开展了压水堆燃料性能分析、组件燃耗和热工水力学分析计算的不确定度量化研究。采用西安交通大学自主开发的不确定度分析程序平台NECP UNICORN,分别耦合了轻水堆燃料性能分析程序FEMAXI、压水堆群常数计算程序NECP Bamboo Lattice和热工水力子通道程序CTF。首先针对不同物理过程的特点,分析需要考虑的不确定度来源。然后针对核数据协方差矩阵稀疏且不满秩的特点,应用COST方法以减少样本量。结果表明,对于燃料性能分析,边界条件、几何参数和材料性质对燃料中心温度有显著影响。对于燃耗过程,核数据和几何参数对特征值、功率分布、两群常数和核子密度的不确定度有显著影响。对于热工水力分析过程,边界条件、几何参数和模型系数对冷却剂温度和包壳温度的不确定度有较大影响。针对每种物理场,分别量化其输入输出参数的不确定度,对于后续量化复杂系统多物理耦合过程的不确定度具有重要意义。     

基于第一性原理的氢化锆热散射律计算分析

声子态密度是计算热散射律数据的基本参数。氢化锆（ZrHx）中含氢量的变化会导致晶体结构的变化，进而影响其声子态密度。国际上一般通过拟合实验数据获得ZrHx中氢的参数化的声子态密度，不能体现氢化锆真实的晶体结构。本文基于δ-ZrH1.5和ε-ZrH2，采用第一性原理计算了ZrHx中氢的声子态密度，研究分析不同方法获得的声子态密度对热散射截面的影响，以及对含氢化锆的TRIGA反应堆的反应性的影响。数值结果表明，与ENDF/B-Ⅷ.0和JEFF-3.3评价核数据库中的声子态密度模型相比，用第一性原理计算得到的声子态密度模型能产生更精确的热散射截面，且显著提高TRIGA反应堆反应性计算的精度。     

新形势下我国珠宝首饰市场需求分析与预测

2008年,我国人均GDP首次超过3 000美元,我国珠宝首饰市场进入一个高速发展的关键时期。文章在概述我国珠宝市场新变化的基础上,研究影响珠宝消费的主要因素,采用2002—2013年的国民收入、城镇居民家庭人均收入、农村居民家庭纯收入、珠宝销售额等数据,引入需求—收入弹性系数,对我国珠宝首饰消费的收入影响因素进行量化分析,并对未来5年我国珠宝市场消费量进行预测,预计2020年我国珠宝消费量有望超过12 000亿元,并在此基础上提出加大投入抢占高端市场,加强渠道建设扩大市场份额等应对我国珠宝市场深层次变化的建议。     

The neutronics studies of a fusion fission hybrid reactor using pressure tube blankets

In this paper, a fusion fission hybrid reactor used for energy producing is proposed based on the situation of nuclear power in China. The pressurized light water is applied as the coolant. The fuel assemblies are loaded in the pressure tubes with a modular type structure. The neutronics analysis is performed to get the suitable design and prove the feasibility. The energy multiplication and tritium self-sustaining are evaluated. The neutron load is also cared. From different candidates, the PWR spent fuel is selected as the feed fuel. The results show that the hybrid reactor can meet the expected reactor core lifetime of 5 years with 1000 MWe power output. Two ways are discussed including burning the discharged PWR spent fuel and burning the reprocessed plutonium. The energy multiplication is big enough and the tritium can be self-sustaining for both of the two ways. The neutron wall load in the operating time is kept smaller than the one of ITER. The way to use the reprocessed plutonium brings low neutron wall load, but also brings additional difficulties in operating the hybrid reactor. The way to use the discharged spent fuel is proposed to be a better choice currently.     

求解广义鞍点问题的一个双参数维数分裂方法

针对一类广义鞍点问题,利用HSS迭代方法的思想,将单参数维数分裂方法推广到双参数形式。先得到双参数维数分裂迭代法的迭代格式并得到相应的求解广义鞍点问题的双参数DS分裂迭代法,然后证明了该迭代方法是收敛的,改进和推广了求解广义鞍点问题的单参数维数分裂迭代算法。数值实验也验证了双参数DS分裂迭代法比单参数MDS分裂迭代法有效。     

泡沫塑料发泡剂的研究进展

介绍了泡沫塑料常用的发泡剂,比较了各种发泡剂,如AC发泡剂及多种物理发泡剂的优缺点,并提出水发泡是今后发泡剂的发展方向。     

离子液体系中原位酶解高效糖化玉米秸秆

合成了14种具有代表性的离子液体,从中筛选了具有较好秸秆溶解能力和环境友好特性的室温离子液[Meim]DMP。该离子液体可以高效处理秸秆,并且可以进行原位酶解糖化,比未处理秸秆的糖化率提高了2.4倍,实现了天然纤维素材料利用的绿色转化工艺。而且,经过原位酶解之后离子液体[Meim]DMP可以有效地回收使用,重复使用5次后仍然保持很好的性能。     

伴随网络法分析输出对电源的灵敏度

根据特勒根定理．利用伴随网络推导出计算输出对电源的灵敏度的简捷公式。实例分析表明，该式与直接求导法的结果一致，且有利于大型网络的计算机数值分析计算。     

Development and Verification of Thermal Neutron Scattering Law Data Producing Module in Nuclear Data Processing Code NECP-Atlas

Based on the theory of thermal neutron scattering, the thermal neutron scattering law data producing module was implemented in the nuclear data processing code NECP-Atlas. In the coherent elastic scattering, the cubic approximation and the atomic site approximation in the conventional method were removed. The anisotropic displacement parameters (ADPs) method was used to obtain the accurate coherent elastic scattering law data considering the influence of the different atomic positions and the direction of the forces, which makes the coherent scattering model suitable for any crystal structure. The effective width model or the free gas model was used to consider the diffusion effect in the liquid target. The discrete oscillator model was used to consider the internal vibration of the polyatomic molecular target, and the Sk-ld approximation was used to consider the inter-molecular coherence effect in liquid target. D in D₂O, H in LiH and metal beryllium were selected to verify the new sab_calc module. Compared with the conventional method, the accuracy of the coherent elastic scattering law data of metal beryllium calculated by ADPs method is improved by about 10%. The numerical results of ICSBEP benchmarks show that metal beryllium using ADPs method makes the calculated keff closer to experimental reference value, about 60 pcm on average.