CNG储气井套管远场涡流检测的设备研制

在研究远场涡流理论的基础上,针对CNG储气井套管损伤的特点,设计研发一套远场涡流检测系统。重点阐述了激励线圈和检测线圈的功能及设计,该远场涡流检测系统可以用于CNG储气井套管损伤检测。     

基于响应面法的电永磁吸盘优化设计

文中提出了一种基于响应面法的电永磁吸盘充退磁吸力及材料使用量的多目标优化方法。该方法选取电永磁吸盘结构的部分关键参数作为设计变量建立响应面模型,并采用目标驱动优化设计产生候选点,最后选出符合预期目标的设计变量参数。通过该方法优化后的电永磁吸盘,在充磁工作状态下的吸附力提升了35.7%,退磁卸载状态下的残余吸力减小了92%,工作性能得到了显著提升,同时优化了材料的使用量,提高了产品的费效比。     

Simultaneous Modification of Alumina and MgO·Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Inclusions by Calcium Treatment During Electroslag Remelting of Stainless Tool Steel

Calcium modification of both alumina and MgO·Al₂O₃ inclusions during protective gas electroslag remelting (P-ESR) of 8Cr17MoV stainless steel and its effect on nitrides and primary carbides were studied by analyzing the transient evolution of oxide and sulfide inclusions in the P-ESR process. The oxide inclusions that were not removed during P-ESR without calcium treatment were found to retain their original state until in as-cast ingot. Calcium treatment modified all MgO·Al₂O₃ and alumina inclusions that had not been removed in the P-ESR process to liquid/partially liquid CaO-Al₂O₃-(MgO) with uniformly distributed elements, in addition to a small proportion of partially modified inclusions of a CaO-MgO-Al₂O₃ core surrounded by a liquid CaO-Al₂O₃. The modification of low-MgO-containing MgO·Al₂O₃ inclusions involves the preferential reduction of MgO from the MgO·Al₂O₃ inclusion by calcium and the reaction of calcium with Al₂O₃ in the inclusion. It is the incomplete/complete reduction of MgO from the spinel by calcium that contributes to the modification of spinels. Alumina inclusions were liquefied by direct reaction with calcium. Calcium treatment during P-ESR refining also provided an effective approach to prevent the formation of nitrides and primary carbides in stainless steel through modifying their preferred nucleation sites (alumina and MgO·Al₂O₃ inclusions) to calcium aluminates, which made no contribution to improving the steel cleanliness.     

铁氧体行波移相-馈电一体化网络的设计与分析

提出了在波导铁氧体移相器传输方向上加载定向耦合开槽以实现移相馈电一体化网络的设计思路.网络以铁氧体移相器实现对信号的相位控制,在铁氧体传输方向上加载多个耦合能力不同的定向耦合开槽以实现对信号的幅度控制.分析了该结构的设计原理,利用HFSS仿真软件对该结构进行仿真分析,并依据计算结果设计制作了样品,样品实测性能与理论计算较为吻合.     

FAST: Fuzzy Decision-Based Resource Admission Control Mechanism for MANETs

Mobile Ad Hoc Networks (MANETs) have inherently dynamic topologies and heterogeneous network environments. Due to the distributed, multi-hop nature of these networks, as well as limited network resource, wireless capacity and random mobility of nodes, Quality of Service (QoS) provisioning faces severe challenges, especially in multicast scenarios. Resource admission control is one of the most effective methods for resource utilization and QoS guaranteed. In this paper, we combine resource admission control technologies and intelligent methods, propose a fuzzy decision-based resource admission control mechanism for MANETs (FAST), which can fast respond to dynamic topology changes and unstable link status. FAST also supports multicast and destination heterogeneity. Users can choose multiple evaluation parameters with different weights of services in fuzzy decision. Simulation results have proved the efficiency of the mechanism.     

战术导弹控制系统BIT设计方法

战术导弹控制系统测试是其研制、生产和交付使用阶段的重要环节,为了快速便捷地完成对控制系统功能性能指标测试,及时检测和隔离故障,保证导弹安全、准时发射,根据新一代导弹控制系统设计特点,重点针对导弹交付后使用阶段测试需求,提出一种分布式与集中式相结合的机内测试(BIT)方案,详细给出了单机分布式BIT和系统集中式BIT的设计方法,该方法在无外部设备辅助测试的条件下可覆盖控制系统所有硬件资源,实现控制系统工作状态和工作性能的快速评估,为导弹或运载火箭控制系统测试性设计提供参考。     

半导体芯片银凸点微电极生长技术

银点微电极生长技术主要用于ISS181系列高压超高速开关二极管的电极成型,是一项制约ISS181封装国产化的瓶颈技术。该项目研究采用了自主开发的流动独立供液、独立供电,整体控制工艺,用于100 mm芯片电极成型,保证银凸点微电极高度40 靘,误差?5%。做到微区银点生长有效控制,大面积一致性好。在流量8 L/min,电压6.5 V,占空比10%的条件下,得到了最佳结果。     

高压液相色谱法测定纸质食品接触材料中亚甲基双硫氰酸酯的迁移量

目的 建立纸质食品接触材料中亚甲基双硫氰酸酯迁移量的高压液相色谱测定方法。方法 食品模拟物(水、3%乙酸-水溶液、10%乙醇-水溶液和橄榄油)中的亚甲基双硫氰酸酯通过高压液相色谱进行分离, 采用二极管阵列检测器进行测定。水基食品模拟物直接进样, 油基食品模拟物经乙腈萃取后进样, 外标法定量。结果 3种水基食品模拟物中, 亚甲基双硫氰酸酯在0.5~50 mg/L范围内线性关系良好, 定量下限为0.5 mg/L, 平均回收率为88.2%~97.4%, 相对标准偏差为0.44%~6.54%; 油基食品模拟物中, 亚甲基双硫氰酸酯在1.0~20 mg/kg范围内线性关系良好, 定量下限为1.0 mg/kg, 平均回收率为99.3%~104.7%, 相对标准偏差为0.75%~3.15%。结论 该方法准确、简便、快速, 可用于纸质食品接触材料中亚甲基双硫氰酸酯迁移量的实际检验工作。     

钢芯铝型线绞线与钢芯铝绞线的主要性能对比

提出了导线截面利用率的概念,基于S、Z铝型线导体,给出了几种与常用规格圆线同心绞钢芯铝绞线对应的型线同心绞钢芯铝型绞线,将两者的部分基本参数和特性作了对比。结果表明:型线同心绞的钢芯铝型线绞线比圆线同心绞钢芯铝绞线的导体截面利用率约高15%,若截面积相等,钢芯铝型线绞线的直径约减小9%,其他性能几乎相同;若两者直径相等,则钢芯铝型线绞线的导体截面积、单位质量和抗拉力较大,同时直流电阻减小而载流量增大。钢芯铝型线绞线的安装可采用常规金具,具有一定的缓覆冰性能和较好的弧垂特性,将是输电线路使用中的一种重要线种。     

Test Results for Leakage and Rotordynamic Coefficients of Floating Ring Seals in a High-Pressure,High-Speed Turbopump

Test results are presented for short floating ring seals (D = 53.0 mm, L/D = 0.15) using a smooth surface and a round-hole pattern defined as a damper floating ring seal (h/C_r = 3, γ = 0.34: the ratio of hole area to surface area) for supplied pressures of 3.0, 5.0, and 7.0 MPa, respectively, with the shaft operating speed up to 24,800 rpm. The measured data includes leakage, attitude angle, eccentricity ratio, and rotordynamic coefficients such as stiffness, damping, and inertia. When the floating ring seals are locked up, the eccentricity ratio of the smooth surface floating ring seal is lower than that of the damper floating ring seal. The attitude angle increases linearly with the operating speeds. The damping coefficients of the damper floating ring seal are higher than those of the floating ring seal. Whirl frequency ratios of the floating ring seal are lower than the damper floating ring seal with high eccentricity ratio at low operating speed range. The design parameters determined from these test results will be used for high-pressure and high-speed turbopump seals in a liquid rocket engine system.