利用80C31单片机串行口实现多个LED显示的一种简单方法

介绍利用80C31单片机串行口、廉价的74HC164和74HC244集成实现多个LED显示的一种简单方法,利用该方法设计的多路LED显示系统具有硬件结构简单、软件编程容易和价格低廉的特点。     

燕山水库泄洪洞进水塔施工期观测资料分析

简单介绍了泄洪导流洞监测仪器埋设情况,并从原始观测资料入手对各仪器的观测资料进行了一致性分析和相关性分析,获得了进水塔混凝土施工期和运行期的应力性态,对指导建筑物后期施工和运行管理具有重要意义,并为相关工程设计、施工提供了借鉴.     

气保焊丝锈蚀原因及对策

从内外因素两个方面分析了导致气保焊丝生锈的原因。指出加强粗拉前处理、镀前处理、控制好镀液浓度 ,并采取镀后防护等措施 (如焊丝表面涂敷防锈油 ) ,可有效提高焊丝防锈能力 ,防锈期可达一年以上 ,且对焊接无不良影响。     

干式电力变压器微机温度监控仪电磁兼容性设计

论述了对变电站用电子装置－－干式电力变压器微机温度监控仪的兼容性研究工作和实验结果,对变电站的干扰和传播进行了分析,还介绍了本仪表所采用的各种主要抗干扰措施。     

基于补偿参数的多零序电流互感器的小电流接地系统单相接地故障选线方法

采用多零序电流互感器结构和补偿参数介入的方法,研究了小电流接地系统单相接地故障选线问题。设计了系统的拓扑结构,分析了不同性质补偿参数对各零序电流互感器电流幅值和相位影响的规律及对故障选线灵敏度的影响问题。分析了不同补偿参数条件下流过故障点零序电流的变化规律及故障电流的安全性问题。该选线方法的选线判据具有很高的可靠性和适应性,能够准确识别出故障线路,有效解决目前小电流接地系统单相接地故障选线领域存在的可靠性差和适应性低的技术问题。     

Purification of Metallurgical Grade Silicon Via the Mg-Si Alloy Refining and Acid Leaching Process

Silicon - A novel process by combining Mg-Si alloy refining and acid leaching was suggested to purify metallurgical grade Si (MG-Si) in this paper. The proposed process was mainly composed of three...     

多功能激光能量／功率表

本文介绍了一种采GNk-80单板计算机来进行激光功率，能量测量及激光能量计定标的实验装置。并给出了装置的结构和程序流程图。     

Convolutional Neural Network Based on Spatial Pyramid for Image Classification

A novel convolutional neural network based on spatial pyramid for image classification is proposed. The network exploits image features with spatial pyramid representation. First, it extracts global features from an original image, and then different layers of grids are utilized to extract feature maps from different convolutional layers. Inspired by the spatial pyramid, the new network contains two parts, one of which is just like a standard convolutional neural network, composing of alternating convolutions and subsampling layers. But those convolution layers would be averagely pooled by the grid way to obtain feature maps, and then concatenated into a feature vector individually. Finally, those vectors are sequentially concatenated into a total feature vector as the last feature to the fully connection layer. This generated feature vector derives benefits from the classic and previous convolution layer, while the size of the grid adjusting the weight of the feature maps improves the recognition efficiency of the network. Experimental results demonstrate that this model improves the accuracy and applicability compared with the traditional model.     

Evaluation of the effect of vacuum on mold filling in the magnesium EPC process

The combination of magnesium alloys with the expendable pattern casting (EPC) process will bring a bright future for the application of magnesium alloys. Vacuum is a pre-requisite parameter in the EPC process of magnesium alloys, because without vacuum, the fluidity of the magnesium alloy in the EPC process is too poor to fill the mold completely, especially for the thin-section castings. In this investigation, the effect of vacuum on the fluidity of AZ91 magnesium alloy has been explored. A modified model has been presented to explain the effect of vacuum on mold filling, which was verified by optical microscopy.The results obtained indicate that vacuum is the most effective parameter in improving the fluidity, the effect of vacuum on the fluidity interacting strongly with the pouring temperature and coating. Vacuum greatly changes the mass and heat transfer in the EPC process. Vacuum may not only control the profile of the metal–foam interface, which will influence the mass transfer process, but may also greatly speed up the removal rate of pattern decomposition products at the metal–coating interface. It also changes the primary heat-transfer mode to heat convention, which has a great influence on the distribution of the casting temperature field and solidification process. The microstructures of castings cast with vacuum exhibit a fine grain size and a small amount of precipitated Mg₁₇Al₁₂, but vary insignificantly with the location in the castings.     

连续随机变量的一种离散逼近方法及其在随机规划中的应用

逼近算法是解随机规划问题的有效方法,本文用一种新的方法构造离散随机变量序列,使其收敛到连续随机变量,给出了一种解二阶段随机规划问题的逼近方法。