Oxidation behavior of 2.25Cr-1Mo steel with prior tempering at different temperatures

The oxidation behavior of a normalized 2.25Cr-1Mo steel tempered previously for 10 hr at different temperatures between 873 and 1023 K has been studied up to a maximum duration of 1000 hr in air at 773–973 K. The oxidation resistance of the steel was found to decrease significantly with the temperature of tempering. Tempering of this steel is reported to cause microstructural changes involving precipitation of Cr as carbides and a decrease in the effective (free) Cr contents, that could influence the oxidation resistance of the Cr-containing alloys. Relative compositions across the thickness of the oxide scales, as analyzed by SEM/EDX and SIMS, suggest that a less Cr-rich (and less protective) and thicker scale on the steel formed because previous tempering caused extensive depletion of free Cr.     

热连轧机工作辊热辊形仿真研究

采用差分法建立了轧辊二维瞬态温度场及热辊形的预报模型 ,可用于实际生产的在线热辊形预报 ;利用实际生产参数模拟轧制和空冷过程中的工作辊热辊形 ,计算结果与实测值相符 ;就不同条件下工作辊热变形规律进行了分析 ,对热轧生产的工艺安排、组织和热磨辊具有实际意义     

铸轧辊的改进设计

对铸轧辊辊芯的表层处理、辊芯的结构、铸轧辊的装配进行了改进设计 ,提高了铸轧辊的性能 ,延长了使用寿命     

高速线材轧机锥套故障分析与改进

高速线材生产线精轧机、预精轧机使用的锥套，在材质、结构、处理工艺及生产操作上存在诸多不当之处，为此进行了多项改进，使锥套故障彻底排除，使用寿命达3～5月，而价格仅为进口件的1／3。     

环件开式辗扩力和力矩计算

用上限法分析了环件开式辗扩变形，导出了辗扩力和力矩计算公式，阐述了辗扩力和力矩与辗扩进给速度的关系。根据环件辗扩实验结果，对文中的辗扩力和力矩计算公式进行了验证。     

Anti-periodic solutions in a ring of four neurons with multiple delays

This paper is concerned with the existence and exponential stability of anti-periodic solutions of bidirectional associative memory (BAM) neural networks with multiple delays. Applying inequality techniques and Lyapunov method, Sufficient conditions which ensure the existence and exponential stability of anti-periodic solutions of the BAM neural networks are presented. Our results are new and supplement some previously known ones.     

飞腾平台中硬件数据压缩的驱动设计与实现

数据压缩是有效处理大数据的关键技术,在飞腾处理器平台上基于zlib库的数据压缩通常采用软件的方式实现,在数据处理量大而且实时性要求较高的情况下,已经难以满足需求。针对这个问题,通过研究zlib编程函数库,结合飞腾处理器的特性,完成了飞腾平台中硬件数据压缩的驱动设计与实现,其中提出了双向DMA传输技术和基于一致性内存的命令环机制,从而进一步提高了基于硬件的数据压缩的效率。通过实验证实了飞腾平台中采用硬件数据压缩改进的有效性。     

Annular ring slot antenna design with reconfigurable polarization

A microstrip‐fed conventional annular ring slot (ARS) antenna with linear polarization (LP) is initially studied. To generate two orthogonal degenerate modes for circular polarization (CP) radiations, two identical meandering perturbation slots (MPS) are symmetrically loaded into the ARS. By further incorporating a PIN diode switch across each MPS, the proposed antenna can switch between left‐hand CP (LHCP), right‐hand CP (RHCP), and LP. All three polarizations have shown good impedance bandwidth and broad CP bandwidth that can satisfy the wireless local area network (WLAN) 2.4‐GHz operating band (2400–2480 MHz). Furthermore, desirable gains of 1.8–2.0 dBi and 2.40–2.84 dBic are also exhibited at LP and LHCP/RHCP, respectively. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:110–120, 2016.     

二维圆环结构中弹性波传播的谱单元分析

为研究弹性波在结构中的波场特征,推导建立一种任意四边形二维谱单元,将其应用于二维圆环结构中的波传播行为模拟.以矩形平板结构中弹性导波传播分析为例,通过与传统有限元分析结果对比,验证所建立谱单元的有效性.有裂纹和无裂纹二维圆环结构谱单元模拟结果表明:弹性波在圆环结构中传播会发生频散;圆环结构表面的裂纹对瑞利波的传播影响最大;根据其反射波包位置可以确定损伤位置.     

浅谈葛铺矿综合自动化环网平台建设和使用情况

根据我国当前工业自动化的发展成果、葛铺矿工业环网的建设需求、矿井井下巷道的分布结构和矿井未来发展的需要,从MACH-4002核心交换机的选取到系统VLAN划分方式等方面,综述了葛铺矿综合自动化环网平台的建设方案,并阐述了环网平台的使用情况。