A new insight into rapid oxidation of alloy 925 contaminated by oxide powder

Rapid oxidation takes place both in the labora-tory and in industrial conditions when alloy 925 is con-taminated by oxide powder,and the oxidation rate is much ...     

原子转移自由基方法合成聚合物刷的研究进展

从聚合物刷基底的选择和聚合方法的优化两方面介绍了原子转移自由基聚合方法合成聚合物刷的研究进展,讨论了聚合物刷在图案化材料表面、提高材料表面的生物相容性及其它方面的应用情况,并对其前景进行了展望.     

Shielding effectiveness of boron-containing ores in Liaoning province of China against gamma rays and thermal neutrons

In this study, the mass attenuation coefficient of boron-containing ores in the Liaoning province of China was calculated using Win XCOM software to investigate the shielding effectiveness of these ores against gamma rays. The mass attenuation coefficients were also calculated using MCNP-4 B code and compared with Win XCOM results; consequently, a good consistency between the results of Win XCOM and MCNP-4 B was observed. Furthermore, the G-P fitting method was used to evaluate the values of exposure buildup factor(EBF) in the energy range of 0.015–15 Me V up to 40 mean free paths. Among the selected ores, boron-bearing iron concentrate ore(M3)was determined to be the best gamma ray shielding ore owing to its higher values of mass attenuation coefficient and equivalent atomic number and lower value of EBF.Moreover, American Evaluated Nuclear Data File(ENDF/B-VII) was used to analyze the shielding effectivenessagainst thermal neutrons. It was determined that Szaibelyite(M2) is the best thermal neutron shielding material.This study would be useful for demonstrating the potential of boron-containing ores for applications in the field of nuclear engineering and technology.     

Preliminary analysis of tritium fuel cycle in Z-pinch-driven fusion–fission hybrid reactor

Attaining tritium self-sufficiency is indispensable in a Z-pinch-driven fusion–fission hybrid reactor(ZFFR).In this paper,a conceptual design is presented in which the Z-FFR tritium cycle system was divided into eight subsystems.A theoretical analysis of tritium inventory based on the mean residence time was performed to quantitatively obtain the tritium distribution in each subsystem.Tritium self-sufficiency judgment criteria were established using a tritium mass flow analysis method.The dependency relationships between the burning rate,tritium breeding ratio,extraction efficiency,and tritium self-sufficiency were also specified for the steady state.     

Smart fabric strain sensor comprising reduced graphene oxide with structure-based negative piezoresistivity

Journal of Materials Science - Fabric strain sensors have attracted significantly increased interest as wearable electronics for their flexibility, softness, and wearing comfort in recent years....     

基于缓存映射项重用距离的闪存地址映射方法

经典的闪存转换层(flash translation layer, FTL)地址映射方法DFTL(demand-based FTL)将全局映射信息放在闪存中,仅缓存最近最常使用的映射信息,解决了页级映射策略中映射信息较大和缓存容量有限的矛盾.但是,DFTL没有充分利用负载的空间局部性特点提高缓存命中率;在缓存失效时频繁的脏映射项换出也会导致大量的映射页写操作;此外,它未能优化垃圾回收过程中有效页迁移导致的写放大问题.针对上述不足,提出一种基于缓存映射项重用距离的地址映射方法IRR-FTL(inter-reference recency-based FTL),通过设置映射页缓存槽,充分挖掘负载空间局部性;基于缓存映射项重用距离实现负载自适应的写缓存映射表冷热分区,并分别采取不同的管理策略,减少映射页写操作;此外,实现基于重用距离的冷热数据分离存储,提高垃圾回收效率.通过采用多种负载对该方法进行验证实验,实验结果表明IRR-FTL相比DFTL缓存命中率提高29.1%,平均响应时间降低了27.3%,擦除次数降低了10.7%.     

男平脚内裤裆底破损原因分析及结构设计优化

通过对样片与人体配伍关系分析,得出男平脚内裤裆底破损的原因在于:结构简化后的后片属平面结构,在适应人体臀部的服用过程中造成过度拉伸。文章提出了结构设计的优化方案。     

完善新区共用水系统实现零排放

针对公司新区共用水处理系统存在的问题,结合新区共用水处理系统的用户应用方式,研究出解决问题方案,达到减少新水的索取,实现零排放.     

济钢小型材全连轧生产线设备改造及工艺优化

济钢第一小型轧钢厂全连轧生产线投产初期存在加热炉出钢节奏慢、粗轧机立辊减速机设计传动能力小等问题。通过合理选择和设计高速级传动齿轮参数、优化完善粗轧孔型、实施多线切分轧制技术等,使设备装备水平显著提高,万吨钢设备故障误时由3.5h减少到0.986h,2007年年生产能力达到127万t。     

结构抗火试验室通风状况的数值模拟及分析

利用Fluent软件对结构抗火试验室内的气流组织进行了模拟,分析了影响试验室内污染物分布的因素,结合实测对模拟结果进行了验证.提出了不同的通风改造方案,并在数值模拟的基础上优选出最终方案,以改善试验室人员的工作环境.