Effect of polycarboxylate-type superplasticizer on the paste fluidity based on the water film thickness of flocs

The excess water film theory and the properties of flocs are integrated to examine the effect of the polycarboxylate-type superplasticizer on the paste fluidity.The theory states that excess water can surround the flocs rather than the particles and that the cell consists of a floc and a superficial water film.Experiments on limestone powder pastes were conducted to verify the theory.The superplasticizer dosage(sp%)and the water–powder ratio by volume(Vw/Vp)were systematically varied.A sedimentation balance method was used to measure the size distribution of the flocs in the limestone powder pastes.The water film thickness(WFT)of flocs was then calculated and shown to determine the paste fluidity.Based on this WFT of flocs,the effect of the sp on the paste fluidity was determined and then compared with the effect of water.     

MATLAB在水轮机模型综合特性处理中的应用

利用MATLAB语言强大的数据处理和三维曲面绘图功能,提出了一种处理水轮机模型综合特性曲线的三维曲面的方法。将水轮机等效率线处理成空间曲面。对某大型水电站混流式水轮机模型综合特性曲线进行了上述处理,并运用等值线法还原为等效率线与模型综合特性曲线进行对比。对比结果表明,运用该方法生成的数据误差小、精度满足工程要求。该方法简单易行,物理意义明确直观,实用性强。     

局部地区城市化及其与经济发展关系研究——以美国49个州为例

本文选取高度城市化国家美国为研究对象，对美国及其国内49个州的经济及城市化发展过程以及两者在发展过程中的相关关系进行分析，发现地区城市化发展特征差异明显，经济发展影响着城市化发展，相对的经济位置决定城市化水平的高低；但经济水平不是决定城市化发展的唯一因素，且经济发展对城市化的影响存在不同的阶段，传统的城市化理论已经在局部地区城市化发展中不再适用。     

Enrichment mechanisms of rare earth elements in marine hydrogenic ferromanganese crusts

A series of selective extraction experiments were conducted on marine hydrogenic ferromanganese crusts from the seamount near the Line Island to investigate the distribution of rare earth elements(REEs) and the mechanisms of combination between REEs and the hydrogenic ferromanganese crusts.The enrichment of REEs in hydrogenic ferromanganese crusts is attributed mainly to the mineral or oxide/hydroxide of the crust rather than the growth environment.The REEs are present mainly in amorphous ferric oxide/hydro...     

主机与CPCI总线通用信号处理板的通信

针对现代雷达信号处理,介绍了CPCI总线信号处理板与主机间的通信方法,分析了Win2000下WDM驱动程序的开发。借助Win2000操作系统,灵活组建了多板卡通用信号处理平台,可以满足不同信号处理任务需求。最后,结合SAR成像应用给出了一个使用实例。     

Wetting properties and interfacial microstructures of Sn–Zn–xGa solders on Cu substrate

The wetting properties and interfacial microstructures of Sn–9Zn–xGa lead-free solders with Cu substrate were investigated. The wetting property is improved remarkably with the increase of Ga content in the Sn–9Zn lead-free solder. The lower surface tension, which results from the decrease of the oxidation of the Zn atoms owing to the formation of the Ga-rich protective film covered on the liquid solder, is the key reason for the better wettability. During soldering, the Cu₅Zn₈ compounds layer form at the interface of Sn–9Zn/Cu and the IMCs formed at the solder/Cu surface become much thicker when the Ga content is from 0.1 wt.% to 3 wt.%. However, neither Cu–Sn compounds nor Ga-rich phases are observed at the solder/Cu surface.     

基于LonWorks现场总线和IC卡技术的智能停车场设计

本文介绍了基于LonWorks现场总线和IC卡技术组建智能停车场系统,并作为楼宇自动化系统(BAS)的一个子控制系统,以完成停车场的相关数据采集、自动监控、自动收费和防盗等功能.     

Order and Disorder in Amorphous and High-Entropy Materials

Order and disorder are important principles in materials science in which entropy is a measure of disorder in a system. For example, recently developed high-entropy alloys and amorphous alloys have drawn interest based on the ability to design their disorder to bring out different material characteristics. High-entropy alloys are controlled by chemical disorder, whereas amorphous alloys are governed by topological disorder. There is often a need to increase disorder or entropy in these materials to satisfy certain complex performance requirements. Here, we examine the roles of order, disorder, and entropy in amorphous and high-entropy alloys. Several key research topics are summarized, including high-entropy films, high-entropy ceramics, and high-entropy alloys. Moreover, there remain questions about the role of entropy stabilization in high-entropy ceramics. Here, we also report three novel porous light-weight high-entropy nitrides based on the NbTiAlSi system. Our findings clarify the general role of entropy in high-entropy ceramics.

     

Accelerated Backward Warping

In this paper a plane-based backward warping algorithm is proposed to generate novel viwews from multiple reference images.First.depth information is employed to reconstruct space planes from individual refernce images and calculate the potential occluding relationship between these planes.Then the planes which represent each identical space plane from different reference images are compared with each other to decide the one with the best sample rate to be preserved and used in the later warping period while the other samples are abandoned.While the image of a novel view is produced,traditional methods in computer graphics,such as visibility test.and clipping,are used to process the planes reconstructed.Then the planes processed are projected onto the desired image form the knowledge on which plane the desired image pixels are warped from can be acquired.Finally,pixels‘ depth of the desired image is calculated and then a ackwared warping is performed from these pixels to the reference images to obtain their colors.The storage requirement in the algorithm is small and increases slowly with the number of reference images increases.By combining the strategy of only preserving the best sample parts and the backward warping algorithm ,the sample problem could be well tackled.     

Coherence-enhancing line drawing for color images

Line drawing plays an important role in many image-based non-photorealistic applications. However, most existing approaches use a grayscale edge detector for line extraction, so that only luminance differences between nearby image pixels is taken into account, but the chrominance differences is ignored. This leads to the undesirable consequence that visually significant edges in adjacent regions with different colors of similar luminance cannot be detected. To address this limitation, we present a novel enhanced line drawing method based on a flow-based difference-of-Gaussians （FDoG） filter. Because of an inherent property of the thresholded DoG edge model, captured lines may appear dislodged from the true edges in the image. To this end, we provide a gradient-guided warping technique so that smooth and coherent lines can be extracted in the correct location. The GPU implementation of the proposed algorithms allows real-time performance, and experimental examples with various color images demonstrate the method＇s superior qualitative performance over previous approaches.