道路标线涂料的正交试验研究

以苯乙烯为反应性溶剂，废旧聚苯乙烯泡沫塑料、不饱和聚酯树脂为主要原料制备道路标线涂料，通过正交试验确定了涂料的最佳配比。制备的道路标线涂料具有施工方便、涂膜厚度适当、附着力强、气候适应性强等特点。并通过电镜分析对涂膜的微观结构进行了初步探讨。     

聚合物不可入孔隙体积影响因素研究

采用双段塞法分析了部分水解聚丙烯酰胺 (HPAM)的相对分子质量、岩心孔隙分布、温度及矿化度对聚合物的不可入孔隙体积 (VIP)的影响规律。分析结果表明 ,VIP随HPAM的相对分子质量的增大而增大 ;VIP随着岩心平均孔隙半径增大、温度升高、矿化度增加而减小。在不断变化的地层条件下 ,HPAM的VIP可能出现高值的现象 ,这将严重影响聚合物驱的波及系数 ,从而使聚合物驱的原油采收率降低。     

改进PSO 算法在振荡式注汽速度优化中的应用

针对蒸汽驱恒定式注汽速度驱油效果差的现状,提出了一种基于改进PSO( Particle Swarm Optimization) 算法的蒸汽驱振荡式注汽速度优化方法。该方法建立了蒸汽驱注汽速度数学模型,采用改进粒子群优化算法对此模型进行求解并优化振荡式注汽速度,最后得到蒸汽驱振荡式注汽速度最优方案。改进粒子群优化算法引入混沌优化算子产生初始解,依据各粒子适应值的距离,完成对各个粒子的自适应变异,同时引入极值扰动算子对个体历史最优值和全局最优值实施随机扰动,加快了收敛速度,提高了种群的可进化能力。实验结果表明: 所建立模型准确,优化算法有效。通过此方法可指导蒸汽驱注采方案合理编制,指导蒸汽驱高效运行。     

Time‐resolved in situ tomography for the analysis of evolving metal‐foam granulates

An experimental setup has been developed that allows for capturing up to 25 tomograms s^?1 using the white X‐ray beam at the experimental station EDDI of BESSY II, Berlin, Germany. The key points are the use of a newly developed, precise and fast rotation stage, a very efficient scintillator and a fast CMOS camera. As a first application, the foaming of aluminium alloy granules at 923 K was investigated in situ. Formation and growth of bubbles in the liquid material were observed and found to be influenced by the limited thermal conductivity in the bulk granules. Changes that took place between two tomographic frames separated in time by 39 ms could be detected and analysed quantitatively.     

还原氧化石墨烯@泡沫镍载CoO纳米花电极制备及催化CO2性能

本文以氧化石墨烯包覆泡沫镍电极(GO@NF)作为基底,采用水热法在GO@NF基底上原位生长CoO纳米花,同时GO在水热过程中被同步热还原为还原氧化石墨烯(RGO),从而一步制得还原氧化石墨烯包覆泡沫镍负载CoO纳米花电极(CoO/RGO@NF)。使用XRD和SEM对CoO/RGO@NF电极进行表征,发现CoO纳米花均匀生长在泡沫镍三维网络结构上,CoO纳米花为大量针状纳米棒围绕一个中心而成的花状结构,纳米棒的长度约为10 ~ 15 μm,直径约为100 ~ 200 nm。使用循环伏安和线性扫描法测试了CoO/RGO@NF电极电催化CO₂的还原性能,在-0.76 V（vs. SHE）电位下,CoO/RGO@NF电极电催化CO₂还原的电流效率达到70.9%,产甲酸法拉第效率达到65.2%,甲酸产率为59.8 μmol·h^-1·cm^-2,且电极可持续稳定电催化还原CO₂ 4 h,表明CoO/RGO@NF电极对CO₂电还原有着优良的催化活性、选择性和稳定性。     

Controlled water flooding of polymer electrolyte fuel cells applying superhydrophobic gas diffusion layer

Water transport is critical to the successful implementation of polymer electrolyte fuel cells (PEFC), especially in long-term and dynamic operation in automotives. Liquid water appears in the fuel cells not only from the water generated at the cathode catalyst layer but also as a result of condensation of water vapor from the humidified gases. In this study, we report a simple approach to prepare a superhydrophobic gas diffusion layer by chemical vapor deposition of polydimethylsiloxane without significant change in pore size of gas diffusion layer unlike other approach adding hydrophobic agent such as polytetrafluoroethylene. A superhydrophobic coating on the GDL can be obtained, leading to exceptionally enhanced power performance and stability of PEFC especially at a high current where water transport becomes more critical.     

Flame spread over the surface of thermal insulation materials in different environments

Experiments were conducted in a plateau area in Lhasa and a plain area in Hefei China to investigate the flame spread characteristics on thermal insulation materials under different environmental conditions (pressure and oxygen concentration).Molded polystyrene foam (EPS) and extruded polystyrene foam (XPS) samples were placed horizontally on a small-scale flame spread experimental bench.Changes in the average length of the pool fire,flame spread speed,average flame height,and length of preheating zone were used to determine the effect of the plateau and plain environments on flame spread characteristics.These parameters were all larger in Hefei than in Lhasa,which indicates the fire hazard in Hefei will be higher than that in Lhasa if insulation materials of the same size are used.     

Properties of Absorbent Acrylic Foam Prepared Based on the Method of High Internal Phase Emulsion

Acrylate and methacrylate monomers absorbent acrylate foams were prepared based on the method of high internal phase emulsion (HIPE). The influence of reaction conditions on liquid absorption by acrylate foams was studied. The reaction conditions included monomer ratio, cross-linker amount, initiator amount, emulsifier amount, emulsion concentration, emulsification temperature, and the curing time. The reaction conditions were determined to achieve the best liquid absorption by acrylate foams. Acrylate foams were analyzed with Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results showed that when the monomer ratio was 9:1, cross-linking agent was 30% of monomer amount, initiator amount was 4% of the reactants amount, emulsifier amount was 8% of the reactants amount, the ratio of aqueous phase to oil phase was 32:1, emulsification temperature was 75°C, and curing time was 1.5 h, we could prepare the acrylate foam material with the best liquid absorption. Reaction of monomer and cross-linking agent was confirmed by FTIR analysis. The pore sizes of acrylate foam were between 1 μm and 8 μm according to SEM analysis. This material was very suitable to absorb aqueous fluids.