Analytical modeling and experimental study of tensile strength of asphalt concrete composite at low temperatures

In this study, analytical modeling of the tensile strength of hot-mix asphalt (HMA) mixtures at low temperatures was developed. To do this, HMA mixtures were treated as a two-phase composite material with aggregates (coarse and fine) dispersed in an asphalt mastic matrix. A two-phase composite model, which was similar to Papanicolaou and Bakos's [J. Reinforced Plast. Compos. 11 (1992) 104] model with a particle embedded in an infinite matrix, was proposed. Unlike Papanicolaou and Bakos's model, an axial stress was introduced to the fiber end to consider the load transferred from the asphalt mastic the aggregate. Efforts were also made to consider the effect of aggregate gradation, asphalt mastic degradation, and interfacial damage between the aggregates and asphalt mastic matrix on the tensile strength of the HMA mixtures. Experimental investigations were conducted to validate the developed theoretical relations. A reasonable agreement was found between the predicted tensile strength and the experimental results at low temperatures. Parameters affecting the tensile strength of asphalt mixtures were discussed based on the calculated results.     

油田企业优化备件管理的设想

针对油田企业装备设施系统备件管理的庞杂性，提出了4种优化备件管理的设想。在备件分类管理、库存管理模式及备件供应环节和管理流程上，结合计算机辅助技术，形成优化管理模式。提出的优化思路可以运用于石油石化企业的备件管理中，改进业务流程，促进物流管理一体化。     

热轧乳液自动吹风系统的节能改进

本文从工厂实际应用出发，说明了热轧乳液自动吹风系统的改造原因、改造设计方案及改造后的经济效益。     

主动推送模式下的情报需求预测模型

针对主动推送模式下的情报需求预测问题,提出了基于案例推理的解决方案。设计了进行情报需求预测案例分析的工作流程,建立了案例属性描述模型;应用最近邻法进行案例的相似度评价,并通过信息增益的计算确定每个属性的权值,获得相似案例(集);提出了方案调整和推理策略。     

A low-noise fully-differential CMOS preamplifier for neural recording applications

A fully-differential bandpass CMOS preamplifier for extracellular neural recording is presented in this paper.The capacitive-coupled and capacitive-feedback topology is adopted.We describe the main noise sources of the proposed preamplifier and discuss the methods for achieving the lowest input-referred noise.The preamplifier has a midband gain of 43 dB and a DC gain of 0.The-3 dB upper cut-off frequency of the preamplifier is 6.8 kHz.The lower cut-off frequency can be adjusted for amplifying the field or action potentials located in different bands.It has an input-referred noise of 3.36 μVrms integrated from 1 Hz to 6.8 kHz for recording the local field potentials(LFPs)and the mixed neural spikes with a power dissipation of 24.75 μW from 3.3 V supply.When the passband is configured as 100 Hz-6.8 kHz for only recording spikes,the noise is measured to be 3.01 μVrms.The 0.115 mm2 prototype chip is designed and fabricated in 0.35-μm N-well CMOS(complementary metal oxide semiconductor)2P4M process.     

Web页面流图形工具的设计与实现

Web页面流图形工具是在Eclipse平台上开发的扩展插件,插件本身是一个图形编辑器,采用GEF框架技术在编辑器中使用图形拖动等方式,以可视化的方式绘制Web页面间的关系,极大地提升了Web开发效率。     

基于区域限定模型的最短路径算法研究

研究地理信息系统中最短路径问题,提高最短路径的搜索速率。针对地理信息系统GIS中最短路径是根据路径权值最小原则选取的,需要逐个遍历系统中所有路径,传统的Di jkstra算法逐个比较所有路径的权值计算量大,不能快速找出最短路径的问题。提出一种基于区域限定模型的算法选取最短路径,采用区域限定模型减少参与计算的路径信息数目,并在此基础上使用启发式搜索策略快速找到最短路径,这样就避免了对系统中所有路径信息遍历带来的计算量大、搜索速率不高的问题。实验证明,改进方法能够快速将最短路径搜索出来,满足地理信息系统实时性的要求,取得了满意的结果。     

基于频率域的图像显著性区域提取方法

针对图像的显著性区域提取方法存在区域边界不明确、分辨率不高、显著性目标不准确等问题,提出了一种使用高斯差分滤波器的组合来保持原图像更多的频率信息,然后在频率域里利用颜色和亮度两个特征来计算显著图,最后用均值偏移方法结合自适应阈值方法从显著图中提取显著性区域。实验结果表明,使用高斯滤波器的方法不仅输出完整分辨率的显著图,而且能准确地突出显著性目标,使区域具有明确的边界,并且分割的查准率和查全率都好于多尺度分析方法和Itti方法。