MoO3 structures transition from nanoflowers to nanorods and their sensing performances

Morphology transformation and crystal growth strategies of metal oxide semiconductors are still extensively studied in material science recently, because the morphology and crystallinity significantly affect the physicochemical characteristics of metal oxide nanomaterials. However, understanding the morphology changes of α-MoO₃ induced by annealing is still a challenge. Herein, the nanostructure transition of α-MoO₃ induced by the annealing temperature is carefully investigated via the XRD and SEM methods. It can be found that crystallization is highly dependent on the annealing temperature. Interestingly, the MoO₃ nanoflowers can change into nanosheets at 500 °C. Afterward, the nanosheets turned into microrods with the increase in annealing temperature due to the continuous growth of MoO₃ crystal. On the other hand, the sensing performances of various MoO₃ nanostructures are studied toward ethanol gas. Compared to the MoO₃ nanoflowers and microrods, the MoO₃ nanosheets-based sensor exhibits superior sensing performance to ethanol, and the maximum response value is 8.06.

     

膨胀石墨吸附苦卤中有色物质研究

将膨胀石墨加压制成低密度板后,对海盐苦卤进行动态吸附脱色实验。确定了最佳工艺条件:温度20℃,苦卤溶液浓度(以溶液中X-计)为2mol/L,溶液pH=6,动态吸附流速为6mL/min,脱色率大于95%。膨胀石墨低密度板对海盐苦卤的饱和吸附量,比颗粒活性炭大12倍。吸附后的膨胀石墨低密度板,经加热到120℃并抽真空的方法脱附,可循环使用15次以上。     

基于EGIS的矿区环境信息管理系统研究

本文以矿区环境为研究对象,将环境地理信息系统（EGIS）技术引入矿区环境管理,构建了矿区环境信息管理系统,就系统的网络体系构建、软件体系流程、数据管理、环境数学模型以及系统功能做了详细阐述.该系统在利用EGIS技术实现对矿区空间地理～空间可视化的形式对结果数据进行展示,为矿区环境规划提供决策支持.     

全封闭湿式多盘制动器温度场的有限元分析

建立了全封闭湿式多盘制动器摩擦元件的有限元分析模型,针对摩擦盘产生热-机失稳现象,应用ANSYS有限元分析软件对全封闭湿式多盘制动器初始接触压力和瞬态温度场进行了分析。有限元分析结果表明,湿式多盘制动器摩擦界面上的接触压力沿摩擦盘半径方向不均匀分布,导致了输入摩擦盘的热流密度分布不均匀;在制动过程中摩擦盘沿半径方向温度梯度过大,导致全封闭湿式多盘制动器对偶摩擦盘的破坏。为提高其使用寿命,在进行制动器结构设计和摩擦材料的选择时,应考虑由热引起的弹性变形对摩擦盘压力场和温度场分布的影响。     

气体泄漏动态模拟与辅助决策技术研究

针对石化企业气体泄漏应急管理问题，分析气体泄漏扩散的经典高斯模型，并结合经典模型中的瞬时模型和连续扩散模型的优缺点，提出了改进的动态连续烟团积分气体扩散模型，基于GIS实现泄漏扩散的动态可视化展示。结合加权最短路径优先算法，构建多目标多任务的气体泄漏应急过程的动态研判模型，实现事故状态下的应急物资快速调度和应急疏散指引等辅助决策功能并与GIS界面结合。系统可为突发性气体泄漏事故下的应急指挥与管理提供有效的辅助决策依据。     

容积负荷对悬浮载体生物流化床处理效果的影响

采用悬浮载体生物流化床工艺处理城市生活污水，考察了容积负荷对其处理效果的影响。结果表明，当容积负荷〈15kgCOD／（m^3·d）时，系统对COD的去除率变化不大，平均为93．16％，当容积负荷〉15kgCOD／（m^3·d）时，虽然系统对COD的平均去除率仍有85．15％，但出水平均COD已达195．39mg／L，不能满足《污水综合排放标准》（GB8978-1996）的要求；系统对氨氮的去除率随容积负荷的增加呈下降趋势，当容积负荷为1～25kgCOD／（m^3·d）时，系统出水氨氮平均浓度为9．69mg／L；系统对TN的去除率先随容积负荷的增加而增加，当容积负荷〉17kgCOD／（m^3·d）后，则随容积负荷的增加而下降，当容积负荷为15～17kgCOD／（m^3·d）时，系统对TN的去除效果最佳。综合考虑，当容积负荷为15kgCOD／（m^3·d）时，悬浮载体生物流化床工艺的除污效果较好。     

Corrosion rate of ordinary and high-performance concrete subjected to chloride attack by AC impedance spectroscopy

Corrosion of reinforcing steel in concrete is studied by using AC impedance. Subjected to different conditions and chloride concentrations, a laboratory study was conducted to estimate the corrosion rate of reinforcing steel embedded in ordinary Portland concrete (OPC) and high-performance concrete (HPC).One hundred and four OPC and HPC concrete cylinders embedded with a single reinforcing steel bar were exposed to sodium chloride solution with 0%, 1%, 3% and 5% concentrations. Specimens were also subjected to pre-conditioning and drying-wetting cycles.The AC Impedance technique (IS) was used to determine the corrosion rate of the reinforced concrete cylinders. In order to interpret the AC impedance spectra, several electrical equivalent circuits were employed.This investigation aims to compare IS with commonly used corrosion assessment techniques, such as Tafel plot (TP) and linear Polarization (LP).Results confirm that data obtained from AC impedance can be used to calculate the corrosion rate of reinforcing steel. A reasonable agreement with the results of TP and LP techniques is demonstrated. It is found that the corrosion rates obtained by AC impedance technique are lower than TP by 5–20%, while results of LP are 20–30% higher than those of TP.     

气象条件对城市燃气日负荷的影响

分析了气象条件对燃气日负荷的影响,发现日平均气温、气压和降水等气象因子和燃气日负荷的关系非常密切,得出了其相关关系。