信源可信度对核电公众接受影响的研究

公众对核电的态度受各种信息的影响,信息源可信度是说服力的重要决定因素.在我国,核安全监管机构、核电企业和专家是主要的核信息发布源,研究不同信息源可信度对公众核电态度的影响对核电的可持续发展十分重要.本研究基于源可信度理论,考察了公众对不同信源的可信度认知,构建了核电公众接受回归模型并开展实证研究.研究发现,不同源的可信...     

给水管网的分形

从管网生长的物理机制角度入手,对管网生长的分形特性进行了探讨,介绍了管网生长的动力源、速度、自组织生长过程,分析了管网形态各异的原因及其自仿射性,阐述了分形理论用于管网优化的前景,以期促进分形理论在管网工程中的应用。     

模拟退火算法在线热源反问题数值求解中的应用

提出采用模拟退火算法(simulated annealing,SA)来数值求解线热源反问题.探讨了如何设计算法使之适合反问题求解,并给出了算法求解的伪代码;通过线源正问题的模拟数据,使用设计的SA算法进行反问题求解,以此来验证算法求解的准确性和可靠性,并对一组实测数据进行了计算.结果表明,该算法不但可以实现两个参数同时、快速反演,而且具有求解精度高,对初始条件依赖少,编制容易等优点.     

Hybrid Nanostructures for Energy Storage Applications

Materials engineering plays a key role in the field of energy storage. In particular, engineering materials at the nanoscale offers unique properties resulting in high performance electrodes and electrolytes in various energy storage devices. Consequently, considerable efforts have been made in recent years to fulfill the future requirements of electrochemical energy storage using these advanced materials. Various multi‐functional hybrid nanostructured materials are currently being studied to improve energy and power densities of next generation storage devices. This review describes some of the recent progress in the synthesis of different types of hybrid nanostructures using template assisted and non‐template based methods. The potential applications and recent research efforts to utilize these hybrid nanostructures to enhance the electrochemical energy storage properties of Li‐ion battery and supercapacitor are discussed. This review also briefly outlines some of the recent progress and new approaches being explored in the techniques of fabrication of 3D battery structures using hybrid nanoarchitectures.     

Occurrence and Distribution of Carbazoles and Benzocarbazoles in Tertiary Niger Delta Source Rocks

The distributions of carbazoles and benzocarbazoles in source rocks from the Northern depobelt of the Tertiary Niger Delta, Nigeria, have been investigated by gas chromatography-mass spectrometry (GC-MS). Biomarker compositions of the source rocks indicate that the source rocks were formed from organic matter of mixed origin (terrestrial and marine) and are either immature or at early maturity stage. The carbazoles distributions in the source rocks are dominated by C₀-C₂-carbazoles and strong variation was observed in their distributions with increasing maturity. Among the C₁-carbazoles, 1-methylcarbazole shows a decrease trend at the immature stage and an increase trend at higher maturity levels. 2- and 3-methylcarbazoles display an increasing trend with increasing maturity while 4-methylcarbazole exhibits a decreasing pattern with increasing maturity. Within the C₂-carbazoles isomers, 1,8- and 2,7-dimethylcarbazoles, show an increasing trend with increasing maturity while the partially exposed isomers 1,3- and 1,6-dimethylcarbazoles decrease with increasing maturity. The ratio of benzo[a]carbazole/benzo[a]carbazole +benzo[c]carbazole varies significantly from 0.36 to 0.55 in the entire maturity range, indicating a strong maturity dependence. These results show that maturity will have great effect on the use of carbazoles and benzocarbazoles distributions as oil migration parameter in the Niger Delta.     

Effects of age heat treatment and thermomechanical processing on microstructure and mechanical behavior of LAZ1010 Mg alloy

An Mg–Li–Al–Zn (designated as LAZ1010) alloy containing about 10 wt% of Li has been prepared by melting and solidification in a carbon steel crucible, and extruded at a billet preheating temperature of 200 °C with an extrusion ratio of approximately 29. Effects of age heat treatments and thermomechanical processing on microstructures and mechanical properties were performed in this study. Hardness, optical microscopy, X-ray diffraction studies, and tensile testes were carried out to explore the variations in microstructures and mechanical behaviors during processing. The results showed that LAZ1010 alloy presented age hardening effect at temperatures below 50 °C. Rapid decrease in hardness with aging temperature at intermediate temperatures should be resulted from the transformation of θ phase into the equilibrium phase AlLi. Kocks–Mecking type plots were used to illustrate different stages of work hardening of the cold rolled specimens. The results indicated that cold rolled LAZ1010 alloy showed stage III and stage IV work hardening behaviors.     

水源热泵与调峰锅炉供热系统运行参数的选择

以采用单管顺流式供暖系统的某建筑物供热热源改造工程为研究对象,探讨了水源热泵 调峰锅炉联合供热系统运行参数的设计基准及热水流量的约束条件。通过对供暖系统热力失调度的计算分析,说明采用设计基准选择的运行参数合理。     

热渗耦合作用下地下埋管换热器的传热分析

为确定地下水渗流对U型地下埋管换热器的影响,基于热渗耦合作用下的数学模型,采用整体求解方法求得管内流体、地下埋管换热器及周围土壤的温度场数值解。分析了地下水渗流对传热过程的影响,结果表明地下水流动对原温度场的影响明显,而且地下水流速越高影响越大。进一步分析了有渗流时不同土壤类型对地下埋管换热器的影响情况,在饱和状态下导热系数是主要的影响因素。     

Denitrification potential and rates of complex carbon source from dairy effluents in activated sludge system

A predictive model for the denitrification performance of complex carbon sources was proposed based on compositional data. Potential and rates of denitrification of single dairy components (lactose, lactate, proteins, fat), as well as binary and complex (modelled "process water") mixtures were assessed using test for nitrogen uptake rate (NUR). In all experiments, denitrification potential of mixtures was found to be significantly higher than the sum of individual potentials and denitrification rate with the readily biodegradable moiety of the mixtures was similar to the highest rate obtained with individual components (lactose or lactate). This work shows that activated sludge acclimated to dairy components can be modelled as a single biomass where the maximal anoxic growth rate of the biomass limits the denitrification rate with dairy components. As a consequence, lactose or lactate determine the maximal denitrification rate possible using dairy effluents.     

高能脉冲电源及其在铸造中的应用研究

介绍自行研制的一款电压在1～3 kV、最大峰值电流可达1.7MA的脉冲发生装置--XJDMC型高能脉冲电源。电源的电压、输出能量可以调节,能够对充电电压、储能电容、充放电时间进行设置。研究了电压在1、2 kV,电流脉冲峰值为1.7MA时对Al-4wt%Cu合金铸造组织的影响。分析了Al-4wt%Cu合金组织的晶粒尺寸和脉冲电流、电压、冲击频率以及电路自振荡频率之间的相关性。结果表明：脉冲电压2kV、电容的冲击频率为0.5 Hz、电路的振荡频率为50 Hz时,脉冲电流对Al-4wt%Cu合金作用后,晶粒尺寸由1.5mm减小到0.2 mm。在合金凝固过程中施加脉冲电流能够有效细化晶粒尺寸,提高合金的力学性能。