INVESTIGATION ON SELF-PROPAGATING HIGH-TEMPERATURE SYNTHESIS OF TiAl INTERMETALLIC COMPOUND

The self-propagating high-temperature syn-thesis method was used to synthesize the TiAl intermetalliccompound,and two kinds of synthesis modes were studied inthis paper.The results show that the thermal explosion modeis suitable for the synthesis of TiAI,the pre-heating tempera-ture has a great influence on the synthesis.Microstructurestudy show that the density of the sample fabricated by thermal explosion mode is higher than that fabricated by propa-gating mode.     

德国FH实践教学模式对应用型人才培养的启示

德国应用科学大学（FH）是德国高等教育体系的重要组成部分。在应用型人才培养方面,德国FH以能力为核心的实践教学模式具有值得借鉴的成功经验。为此,在分析高校机械工程实践教学特点与现状的基础上,通过对FH的应用型本科教育特点的总结,提出中国应用型高校应强化工程实践教学环节,注重实践教学内涵及改革实践教学方法,以提高学生的实践能力、创新能力和社会适应能力。     

Acoustical Modal Calculation for Rectangular Enclosure and Its Experimental Verification

ＡｃｏｕｓｔｉｃａｌＭｏｄａｌＣａｌｃｕｌａｔｉｏｎｆｏｒＲｅｃｔａｎｇｕｌａｒＥｎｃｌｏｓｕｒｅａｎｄＩｔｓＥｘｐｅｒｉｍｅｎｔａｌＶｅｒｉｆｉｃａｔｉｏｎＷＡＮＧＦｅｎｇｌｉｎＰＥＮＧＣｈｕｎｙｉｅＳＯＮＧＺｈｉｑｉｎＬＩＨｕａｍｉｎ（王峰林）...     

加劲肋对外伸端板连接火灾下破坏模式的影响

为研究外伸端板连接节点火灾下的破坏模式及承压加劲肋厚度对节点耐火性能及柱稳定性的影响,研究了热力耦合作用下节点的响应.采用钢结构设计理论和非线性有限元分析方法研究了节点火灾下的破坏模式、承压加劲肋的失稳及加劲肋厚度对节点耐火性能及柱稳定性的影响.结果表明:火灾下节点的破坏模式为:首先在端板和柱翼缘承拉区发生弯曲大变形,之后承压部分局部失稳并最终导致节点丧失承载力;承压加劲肋厚度对节点耐火性能有较大影响,火灾下加劲肋受到不断加大的热应力作用,但其临界应力随材料刚度退化而不断降低,较薄的承压加劲肋易发生失稳并引发柱腹板局部屈曲导致节点失效.适当增加承压加劲肋厚度可防止加劲肋的屈曲并有利于柱火灾下的稳定.     

模糊题设教学法的探索与实践

阐释了模糊题设教学法的概念及其运作模式．多年的教学实践表明,该法有助于激发学生的学习热情、形成良好的思维品质、发展智力．提高能力．     

X-band deflecting cavity design for ultra-short bunch length measurement of SXFEL at SINAP

For developing the X-ray Free Electron Lasers test facility(SXFEL) at Shanghai Institute of Applied Physics,Chinese Academy of Sciences(SINAP), ultra-short bunch is the crucial requirement for excellent lasing performance. It is a big challenge for deflecting cavity to measure the length of ultra-short bunch, and higher deflecting gradient is required for higher measurement resolution. X-band travelling wave deflecting structure has features of higher deflecting voltage and compact structure, which has good performance at ultra-short bunch length measurement. In this paper, a new X-band deflecting structure is designed to operate in HEM11-2π/3 mode.For suppressing the polarization of deflecting plane of the HEM11 mode, two symmetrical caves are added on the cavity wall to separate two polarized modes.     

济钢自动化产业发展模式的探讨

经过多年发展,济钢信息自动化在技术和管理等方面积累了诸多优势。高起点、高标准,以自动化部为核心,整合信息自动化技术力量,充分发挥信息自动化技术资源优势,在确保＂对内不断提升信息自动化管理、规划、建设、运维的能力和水平,确保系统安全稳定运行,促进系统应用不断深化挖潜和优化提升＂的基础上,赋予新型的管理体制和管理机制,大力发展以系统集成、以软带硬、信息化与自动化相结合的高科技产业,为济钢创造更多的经济效益和社会效益。     

Critical State of Granular Materials Based on the Sliding-Rolling Theory

By representing the assembly by a simplified column model, a constitutive theory was recently developed for a two-dimensional assembly of rods. This theory, referred to as the sliding-rolling theory, is extended in this paper to represent the triaxial stress-strain behavior of granular materials. The sliding-rolling theory provides a dilatancy rule and an expression for the slope of the line of zero dilatancy in the stress space. These rules are then combined with triaxial observations to provide a microstructural interpretation of the critical state of granular materials. According to the theory, the slope of the critical state line in the stress space depends on the interparticle friction angle and the degree of contact normal anisotropy. To verify the basic ideas of the sliding-rolling theory, numerical experiments are conducted using the discrete-element method on three-dimensional assemblies of spheres.     

复杂环境下结合EMD的GPS-IR水位反演方法

利用法国布雷斯特(Brest)港BRST测站和英国塞文大桥监测系统GNSS双频观测数据,分别在静态和高动态环境下进行GPS-IR水位反演,探究传统GNSS监测系统进行水位反演的可行性与精度.结果表明:L1波段反演精度高于L2波段;在静态场景下,GPS-IR水位反演结果与验潮站数据相关系数大于0.98,在高动态场景下,桥梁GPS-IR水位反演精度稍低.利用经验模态分解(EMD)方法对算法进行改进,提高了在桥梁复杂环境下GPS-IR水位反演结果的精度,均方根误差(RMSE)相比经典方法降低约50%.本文方法提高了GPS-IR技术在不同水域环境下的适用性,在水位监测中具有很好的应用前景.     

电动汽车PMSM MTPA控制系统滑模速度控制

为了提高电动汽车电机驱动系统对参数摄动和负载扰动的鲁棒性,同时削弱滑模变结构控制( SMVSC)固有的抖振,将一种改进的滑模控制策略应用于永磁同步电机(PMSM)最大转矩电流比(MTPA)控制调速系统中.采用最大转矩电流比控制方法分配定子直轴、交轴电流,将他们与转矩的关系分别拟合为低阶多项式,提高了该方法的工程实用性;...