高炉富氧鼓风的现状及机前供氧

阐述了高炉生产采用富氧大喷煤的必要性，国内高炉富氧鼓风的现状，以及机前富氧的优点和应采取的安全措施。     

大港歧北斜坡三维地震深层目标精细处理及地质效果分析

歧北斜坡深层沙二、沙三段发育沿岸滩坝、辫状河水道及斜坡扇沉积体系。储层总体比较发育,但是横向变化大,单层厚度薄。现有地震资料横、纵向上地震分辨率低,无法满足砂体追踪和精细储层预测的要求。通过运用叠前反褶积、静校正、能量调整、叠后提高分辨率等技术,并实施处理解释一体化工作模式,处理质量过程控制等方法,使处理成果地震资料在保持地层波组特征不变的情况下,纵横向分辨率有了较大程度的提高,成像特征有了较大幅度的改善,基本上满足了地质需求。利用新处理的资料,通过井震结合,储层地球物理特征分析,在常规波阻抗反演的基础上,利用拟波阻抗反演的方法预测了沙二、三段各油组砂体的空间展布规律。取得了较好的地质效果。     

动态信道切换及静默策略下的LTE-U共存方案

提出了一种针对非授权频段的长期演进(LTE-U)系统在5 GHz非授权频段与WIFI系统共存的方案.该方案基于先听后说(LBT)信道接入机制,通过引入动态信道切换技术,有效避免了因LTE-U系统长时间占用同一信道而对无线保真(WIFI)系统造成的干扰.在此基础上,对LBT机制中的静默时长进行了优化,以进一步提升LTE-U与WIFI系统共存的效率.理论分析和实验结果表明,所提方案可使LTE-U与WIFI在同频段和谐共存,并取得较好的系统性能.     

Joint underwater target detection and tracking with the Bernoulli filter using an acoustic vector sensor

In this paper, we study the problem of joint underwater target detection and tracking using an acoustic vector sensor (AVS). For this challenging problem, first a realistic frequency domain simulation is set up. The outputs of this simulation generate the two dimensional FRequency–AZimuth (FRAZ) image. On this image, the random finite set (RFS) framework is employed to characterize the target state and sensor measurements. We propose to use the Bernoulli filter, which is the optimal Bayes filter emerged from the RFS framework for randomly on/off switching single dynamic systems. Moreover, to increase the performance of detection and azimuth tracking in low signal-to-noise ratio (SNR) scenarios, a track-before-detect (TBD) measurement model for AVS is proposed to be used with the Bernoulli filter. Sequential Monte Carlo (SMC) implementation is preferred for the Bernoulli filter recursions. Extensive simulation results prove the performance gain obtained by the proposed approach both in estimation accuracy and detection range of the system.     

基于测前迭代仿真的模拟电路故障诊断方法

针对非线性模拟电路中元件表现出的折线故障特征,提出一种基于测前迭代仿真的模拟电路统一故障诊断方法.在测前将线性元件参数分段划分区间,在各区间进行仿真得到节点电压平面上的点计算斜率特征,对于斜率变化的区间重新进行参数扫描,并通过迭代仿真得到连续平滑的折线轨迹上的点作为测后诊断依据;在测后诊断中,通过计算实测点到各条折线轨迹的点集合的最小距离来定位电路故障,并根据测前仿真的分段信息对故障元件的参数区间进行识别.文中利用计算机程序实现了测前迭代仿真和测后故障定位及参数区间识别,能够同时诊断容差电路元件的硬故障(开路、短路)和软故障(元件参数变化至容差允许范围之外).最后通过实例的仿真实验和实际电路实验验证了该方法的有效性.     

线上教学案例

当因疫情原因无法进行线下授课时,如何做好线上授课就显得非常重要。文章主要从以下方面论述了作者的线上教学情况,即课前准备、授课方式、课后作业、课后巩固、考试。     

高校普及网页系统教学中系统开发前的知识

为了让更多人掌握网页系统开发前的知识,有必要在高等院校里对其知识进行普及化教学,具体介绍了Internet信息服务(IIS)、Dreamweaver、Access和Excel等相关知识。学生只有掌握了这些开发前知识,才能更好地设计和测试网页系统功能。     

TIFF格式在设计与印刷中的作用

印前设计与制作软件日益丰富多样,支持输出的格式也越来越多.由于跨平台、多软件融合制作及文件的复杂性,需要解决输出时常出现的一些问题.TIFF格式可起到设计与印刷的桥梁作用,从而提高制作和输出所需要的效果.?＃     

Dynamic crack propagation in steel line pipes. Part I: Experimental investigation

An experimental-theoretical research project on dynamic crack propagation on steel line pipes intended for arctic service was developed. The aim of this study is to characterize the dynamic material behavior, to propose line pipe qualification tests, and to identify the variables that govern the dynamic fracture process and their relationships. The first part of this research involves the experimental work and outlines a practical test to assess fitness for service of arctic pipelines. Burst tests of line pipes samples at low temperature were carried out and crack extension vs. time was measured. The axial crack fracture mechanism was quasi-cleavage in the center of the pipe wall with lateral shear lips. A pressure range for LBB (leak before break) condition was obtained. In Part II of this research a new model for the assessment of the dynamic material properties from the analysis of test results obtained in Part I is developed.     

基于动态规划的红外弱小运动目标的实时检测方法研究

文章针对低信噪比下红外弱小运动目标的特点,提出了一种正向动态规划算法。分析了算法的检测性能,并对算法实现中的一些关键问题进行了讨论。实验表明,该算法适应性强,能有效地完成对低信噪比下弱小运动目标的实时检测、识别与跟踪。