摘要：应用所设计的阶梯铸件的铸型 ,以及钨铼热电偶和由ADAM系列A/D数据采集及转换模块构成的计算机多通道温度数据采集处理系统 ,对Ti- 15 - 3合金凝固冷却温度变化进行了实验测试与数据处理 .测试了合金的浇注温度 ,液相线温度和固相线温度 ,得出合金的凝固温度区间为 71℃ .对合金阶梯铸件的补缩冒口进行宏观形貌观察表明 :Ti- 15 - 3高强钛合金的凝固呈集中补缩的特征 ,且孔洞内表面光滑 .凝固组织观察表明 :由于受金属铸型内壁激冷作用和铸件尺寸较小的影响 ,合金在接近铸型内壁或铸件尺寸较小部位处的铸态晶粒组织较细小 。

摘要：理想情况下,基于Kalman滤波的组合导航系统在无故障时的滤波残差为白噪声,通常利用这个特点使用χ2检验法来检测系统是否发生了故障,但该方法往往具有较大的虚警率。为此,在分析了惯导(INS)和北斗(BDS)组合导航系统数学模型的基础上,提出一种新型实用的冗余设计,来检测INS/BDS组合导航系统是否发生故障。结果表明,该方法不仅降低了虚警,同时又提高了故障检测器的可靠性,而且检测结果的可信度也有很大提高,取得了较好的应用效果。

摘要：The nominal Ti44Al6Nb1.0Cr2.0V alloy was newly designed and prepared by vacuum consumable melting technique with the ingot sizes of d225 mm×320 mm. The results show that the average lamella colony size is 780-1830 μm. This as-cast alloy has a modified near lamellar(M-NL) structure that is composed of mainly larger(α2+γ) lamella colonies and smaller(B2+equiaxed γ) blocky morphology. It exhibits the moderate tensile properties at room temperature, in which the Region(5) yields the ultimate tensile strength(UTS) about 499 MPa and the elongation about 0.53%. The obvious brittle fracture characteristics and trans-granular interlamellar fracture are the predominant modes. After room temperature tensile testing, there are some <101] and a few 1/2<112] superdislocations in the γ phase. The as-cast microcrack is the main factor to deteriorate the tensile property, which results in the premature fracture, poor ductility and few dislocations. The addition of Nb, Cr and V can decrease stacking fault energy(SFE) obviously, which is helpful to enhancing the ductility of the alloy.

摘要：To improve the power efficiency and optimize the configuration of cold crucible using for continuous melting and directional solidification （DS）, based on experimental verification, 3D finite element （FE） models with various configuration-elements were developed to investigate the magnetic field in cold crucible. Magnetic flux density （B） was measured and calculated under different configuration parameters. These parameters include the inner diameter （D2）, the slit width （d）, the thickness of crucible wall, the section shape of the slit and the shield ring. The results show that the magnetic flux density in z direction （Bz） both at the slit and at the midpoint of segment will increase with the decrease of D2 or with the increase of the width of the slit and the section area of wedge slit or removing the shield ring. In addition, there is a worst wall thickness that can induce the minimum Bz for a cold crucible with a certain outer diameter.

摘要：设计INS/GPS组合导航系统时,考虑到观测量GPS位置和速度是正相关的,可通过降低单个滤波器的维度形成两个局部滤波器,主滤波器融合局部滤波器的状态估计,得到整个组合导航系统的误差状态估计值。同时,根据各局部滤波器的故障情况选择输出,仅利用未失效系统的局部滤波器得到可靠的最优误差状态估计值,使得容错性能大大提高。结果表明,由于采用了并行运算,增加了系统的余度,有效提高了导航系统的精度和可靠性,有较好的容错性和环境适应性,具有较高的应用价值。

摘要：目前,河北省对液位计的检定/校准,尚未建立完整的用于移动式液位计检定/校准的标准装置。河北省计量监督检测研究院廊坊分院（以下简称＂廊坊分院＂）研制的可移动式多参数液位计检定标准装置实现了液位计的高精度检定,同时可以规范国内液位计的计量,使液位计的计量器具量值准确可靠,确保使用单位的检定/校准数据准确。这对河北省及国内液位计检定具有一定的推动作用,具有很大的现实意义。