Wire-mesh honeycomb catalysts for selective catalytic reduction of NO with NH3

Both flat and corrugated wire mesh sheets were coated with aluminum powder by using electrophoretic deposition (EPD) method. Controlled thermal sintering of coated samples yielded uniform porous aluminum layer with a thickness of 100 μm that was attached firmly on the wire meshes. Subsequent controlled calcination formed a finite thickness of Al₂O₃ layer on the outer surface of each deposited aluminum particles, which resulted in the formation of Al₂O₃/Al double-layered composite particles that were attached firmly on the wire surface to form a certain thickness of porous layer. A rectangular-shaped wire-mesh honeycomb (WMH) module with triangular-shaped channels was manufactured by packing alternately the flat sheet and corrugated sheet of the Al₂O₃/Al-coated wire meshes. This WMH was further coated with V₂O₅-MoO₃-WO₃ catalyst by wash-coating method to be applied for the selective catalytic reduction (SCR) of NO with NH₃. With an optimized catalyst loading of 16 wt%, WMH catalyst module shows more than 90% NO conversion at 240 °C and almost complete NO conversion at temperatures higher than 300 °C at GHSV 5,000 h⁻¹. When compared with conventional ceramic honeycomb catalyst, WMH catalyst gives NO conversion higher by 20% due to reduced mass transfer resistance by the existence of three dimensional opening holes in WMH.     

Photoshop CS中绘图的异常现象及处理方法

Photoshop CS是一款功能强大的图像处理软件，目前已被广泛的应用于各个领域。针对Photoshop CS的初学者在学习过程中经常会碰到的一些异常现象进行介绍，并给出解决的方法。     

Bend stiffness of laminate microstructures containing three dissimilar materials

This article examines the effective flexural modulus of a multilayered micro-system evolving into alternative layered structures consisting of three dissimilar materials. A multiscale model of the bending stiffness is presented to capture the impact of changing the constituent materials, the layer architecture and the cross-section geometry. The results are plotted onto maps to show the existence of specific domains, within which fall the effective properties of all possible tri-material multilayered configurations. The potential to stiffen a bi-material system is demonstrated by integrating additional layers of a more flexible material for given constraints on the volume fraction. The proposed scheme is conducive to contrast structural alternatives in constrained and unconstrained design. A case study shows how the maps enable optimum selection among various design concepts, which may range from monolithic materials with alternative shape geometries to systems consisting of two and three materials arranged in dissimilar multiple layer architectures.     

利用测井资料确定地层的强度参数

弹性常数的研究及其应用得出:动态参数对解决岩石力学问题更为有效。切变模量、杨氏模量、体积模量及泊松比的关系式都与测井的密度值、横液时差和纵波时差有关。根据测井资料确定的各种弹性模量值同样适用于解决各种岩石力学问题。     

分层的应用层组播协议研究

在P2P视频直播网络中,用户频繁地加入或离开组播组会造成数据传输中断。该文提出一种新的基于分层分簇思想的应用层组播协议,基于视频直播中的用户行为分析,通过分层获得一个有效层来减少组播树中的节点失效次数。仿真实验表明,该协议能够有效提高稳定性,减少平均组播时延并具有可扩展性。     

Corrosion resistance of tannic acid,d-limonene and nano-ZrO_2 modified epoxy coatings in acid corrosion environments

The protection of rusted carbon steel in acid corrosion environments is of great significance for equipment to keep safe operation.In this work,we presented a method to protect the rusted steel by ru st conversion treatment and epoxy coating.Tannic acid was selected as rust conversion agent.Tannic acid,D-limonene and nano-ZrO₂were used to improve the corrosion resistance of epoxy coatings.The Raman spectra,Xray diffraction and 3 D confocal images were used to characterize the rust conversion reaction.Ad hesion test showed that the loss of wet adhesion of the optimal coating was relatively low due to the addition of tannic acid,limonene and nano-ZrO(2).The corrosion resistance of five different coatings was investigated by scanning electron microscopy(SEM)and electrochemical analysis.Results show that after 264 h acid immersion,the low frequency resistance of the optimal coating consisting of rust conversion treatment and additives is 10⁷Ωcm²,three orders magnitude higher than that of the pristine coating.Moreover,SEM indicates that the optimal coating possesses a smooth surface and an unbroken interface between substrate and coating.Accordingly,the corrosion-resistant mechanism of the hybrid coating is proposed.     

同类货物集装箱装载问题的启发式算法

提出了求解同类货物集装箱装载问题的一种启发式算法.算法中采用了层的思想,集装箱的每个面都可用来构建层.通过对二维布局、层高组合和用来构建层的集装箱面的选择等三个方面的优化求解,得到了具有较高装载率的集装箱装载方案.实例结果表明,该算法是求解同类货物集装箱装载问题的一种行之有效的方法.     

针对固态驱动器的NFTL算法性能优化

用于闪存的NFTL算法随着闪存技术的发展表现出空间利用率低、擦除效率不高等不足,为保证读速度牺牲Flash读性能上的优势,而且不适用于固态驱动器。基于此,提出一种改进方案,利用增加内存中存放的包括有效位图和反向映射表等元数据的方式改进NFTL算法使其适用于固态驱动器,取得一定的性能提升。