车门内饰板优化分析及模具设计

利用CAE分析软件Moldex3D先找出整个设计是否存在缺陷,为了增加优化效率,采用田口实验设计法规划控制因子与配置。L9(34)直交表来求得成型条件的最佳化参数组别,观察结果并找出最佳成型条件,以降低成型后所发生的体积收缩率以及翘曲位移量。由S/N因子反应表可看出对于Z轴变形量在塑料温度209℃、保压时间11.025 s、冷却时间17.85 s时较优良。Z轴的翘曲从1.64 mm降低到1.04 mm,整体改善了36.5%,最终根据优化结果进行了模具设计。     

Green touch for hydrogen production via alkaline electrolysis: The semi-flexible PV panels mounted wind turbine design,production and performance analysis

The novel solar-wind integrated system has been firstly used for hydrogen production in literature with validating theoretical, simulated and experimental studies. This integrated system consists of two main parts; solar-assisted wind turbine and alkaline electrolysis cell.In the first part of this system, the semi-flexible PV panels are smoothly integrated on the vertical axis wind turbine blade. This is a unique design in literature, unlike the hybrid systems that include wind turbines and solar PV panels in published literature. The production and testing of the hybrid integrated system in a single structure were performed both in laboratory conditions and also the system was set up the roof of ATU (Adana Alparslan Turkes Science and Technology University) in Adana. The second part includes hydrogen production via alkaline electrolysis system. The cathodes consist of nickel-coated copper (Cu/Ni) and nickel-vanadium binary coated copper (Cu/NiV), that was produced via electrodeposition technique by self-supporting. The performance of electrodes was compared in 1 M KOH solution via I–V behavior, electrochemical impedance spectroscopy, and long term cathodic polarization analysis. Results showed that polarization resistance was decreased almost 4 times by NiV when comparing the Ni. The surface inhomogeneity values were 0.91 and 0.81 for Cu/Ni and Cu/NiV respectively. The hydrogen gas evolved at the cathodes was also measured and higher volumes were detected for NiV binary coating.     

Investigation of seasonal variations of Beijing pavement condition data using unevenly spaced dynamic panel data model

Beijing municipal highway administration started to collect pavement condition data on its major expressways since 2006. It is advised in the Chinese practice standard that data collection shall be conducted on annual basis. However, pavement data are usually collected at different seasons of the year, which may cause significant seasonal variations in the observed condition. Moreover, for some reasons, data are missing for some of the pavement sections at certain years, which could bring up difficulties in performance model estimation and inference. These concerns have been simply neglected in past practice. This study proposed an unevenly spaced dynamic panel data model to investigate the seasonal patterns of a performance indicator called Ride Quality Index (RQI). A quasi-differencing approach was adopted for the estimation. Data collected from the 5th Ring Road of Beijing were used in the case study. It was found that RQI data collected during the fall season are expected to be lower than that collected during the spring or summer seasons. Findings from this research would be helpful to pavement engineers in using unevenly spaced pavement condition data for future condition estimation.     

Efficiency optimisation of the thermal energy storage unit in the form of the ceiling panel for summer conditions

The thermal energy storage unit in the form of the ceiling panel made of the gypsum‐microencapsulated phase change material composite with internal U‐shaped channels was optimised applying previously developed 1D‐3D numerical simulator. Calculations were carried out for variable inlet velocities of air, different properties of the composite expressed by enthalpy‐temperature curves, and summer climatic conditions in Central Poland (Warsaw). Optimal working temperature ranges of the composite were determined. Moreover, studies showed that for Central Poland, composites with wide ranges of the working temperature are preferred due to significant daily variations of ambient temperature during the whole summer.     

Impact of flat roof–integrated solar photovoltaic installation mode on building fire safety

This paper quantifies experimentally the fire‐induced reradiation to roof surface created by flame extension on the back of the flat roof–integrated photovoltaic (PV) array. A gas burner underneath the tilted PV panels was employed as the fire source. The effects of the PV tilt angle, distance from PV panel to roof, and fire heat release rate (HRR) were investigated. The flame extension geometries and flame reradiation heat flux distribution were recorded. The results show that the flame extension length and vertical thickness (ie, the vertical distance from the back surface of the PV panel to the extension flame profile) are reduced with the increase of PV tilt angle and panel‐roof distance but are increased with increases in the fire HRR. A unified nondimensional HRR coupled with all these factors is proposed to quantify the flame extension geometry. Furthermore, a general equation based on the physical relationship between flame radiation and flame geometry is developed to characterize the distribution of reradiation heat flux on the roof surface with the nondimensional local flame thickness. Finally, suggestions regarding PV installations on flat roofs and the selection of roofing materials are given to decrease the possibility of flame propagation underneath the PV arrays.     

双面板非金属孔内渗油研究

双面板非金属孔内渗油是PCB感光阻焊制程中最常见的品质缺陷之一。就双面板非金属孔内渗油的品质问题进行了研究,设计试验对各影响因素进行分析,确定双面板非金属孔内渗油的根本原因及改善方向。     

阴极铜剥片装置的优化改造

针对阴极剥片机组核心区域剥片装置故障高的问题 , 结合生产操作 , 以及实际检修过程 , 从设备的角度分析剥片装置故障率高的主要原因 , 根据原因提出设备改进方案 , 降低剥片装置故障率，保证剥片机组稳定运行，并且通过改进检修方式，减少故障检修时间，降低检修劳动强度。     

Composite and non-composite behaviors of foam-insulated concrete sandwich panels

The structural behaviors of foam-insulated concrete sandwich panels subjected to uniform pressure have been evaluated. This study showed that the interface conditions such as composite and non-composite had a significant effect on the response of foam-insulated concrete sandwich panels, indicating that the simulated shear tie resistance should indeed be incorporated in numerical analyses. Finite element models were developed to simulate the detailed shear resistance of connectors and the nonlinear behaviors of concrete, foam and rebar components. The models were then validated using data from static tests performed at the University of Missouri. The modeling approach used here was compatible with the American Concrete Institute (ACI) Code and existing design practices. The results of this study will therefore provide improved methodology for the analysis and design of foam-insulated sandwich panels under both static and blast loadings.     

Spatial agglomeration and productivity in Italy: A panel smooth transition regression approach

The paper analyses the nonlinearities in the impact of localization, diversity, urbanization and competition on firm‐level total factor productivity (TFP), using a large sample of Italian firms from 1999 to 2007. We adopt a panel smooth transition regression model, so that the TFP elasticities are free to vary smoothly across two or more extreme values. Results show that localization economies and Jacobian externalities materialize only for values of, respectively, intra‐industry agglomeration and extra‐sectoral diversity above a certain threshold. Local competition exerts a positive effect on productivity, even though the marginal impact shrinks at high levels of competition. We find instead no evidence of diseconomies of agglomeration.