Bi系2223高温超导带材力学性质

对4种Bi系2223高温超导带材77 K下的力学性质进行了实验研究.通过选择合适的合金包套替代传统的银包套,带材的机械性能能有所提高,但电学性质有所降低,尤其是内包套采用合金、外包套采用银,其机械性能反而低于纯银包套带材.通过X射线衍射图谱发现,当包套采用合金材料,尤其是内包套采用合金、外包套仍采用纯银,会大大降低样品中2223相的体积含量.相比较临界电流密度,n值对材料的破坏更为敏感.利用X光同步辐射技术初步探讨了银包套带材在室温和77 K下的损伤破坏过程.     

拉伸应变硬化指数（n值）的测量结果不确定度评定

介绍了拉伸应变硬化指数（n值）的测量结果不确定度的评定方法。按照力和相应的应变等不同因素,对用最小二乘法得到的n值进行不确定度评定。     

2000安高温超导输电电缆的研制

介绍了6m长2000A高温超导直流电缆－－Bi-2223/Ag带材的主要性能和该高温超导输电电缆的设计、绕制和试验结果。电缆的导体由8层共238根Bi-2223/Ag带材在不锈钢波纹管骨架上螺旋绕制而成,导体的内径为41．5mm,导体层间绝缘,导体层外侧有低温电绝缘。电缆芯的外径为48mm,它安装在低温容器内,并与两个终端相连。电缆的直流耐压大于2．5kV。在液氮下的实验表明,电缆的临界电流为2480A,n值为7．7,接头总电阻为0．1μΩ,均优于设计指标。在1h传输2kA电流的运行中,电缆的传输特性稳定。经4次热循环,电缆的临界电流没有降低。     

基于Yule-Nielsen的半色调印刷品的光谱预测模型

介绍了Yule-Nielsen修正光谱Neugebauer方程的色彩预测模型.通过分析有效网点面积率、油墨铺展在不同叠印条件下,光谱反射率的预测模型,说明了物理网点扩大对方程的影响,然后又通过分析纸张的点传递函数PSF和概率模型,指出了光学网点扩大对方程的影响,更优化了模型,最后对Yule-Nielsen方程参数n值,具体做了解释并用迭代法求得最佳的n值.     

DC performance and AC loss of cable-in-conduit conductors for International Thermonuclear Experimental Reactor

A reliable prediction of AC loss is essential for the application of International Thermonuclear Experimental Reactor(ITER) cable-in-conduit conductors(CICCs);however,the calculation of AC loss of ITER CICCs is a cumbersome task due to the complicated geometry of the multistage cables and the extreme operating conditions in ITER.In this paper,we described the models developed for hysteresis and coupling loss calculation,which can be suitable for the construction of ITER magnetic system.Meanwhile,we compared the results of theoretical analysis with the SULTAN test result to evaluate the numerical model we used.In addition,we introduced the n-value and AC loss with transport current for CICCs based on the DC measurement results at SULTAN,which lays the foundation for the further study.     

Magnetization of Multifilamentary Superconductor Nb3Sn in Perpendicular Field

Hysteresis loss is one of the electromagnetic characteristics controlled by time evolution of magnetic field and current distribution inside the conductor. Brandt＇s method allows us to model the interaction of the conductor with an external magnetic field. Instead of the constant critical current density （Jc =CONST）, the Jc scaling law from current-voltage （I-V） measurement is used to model the magnetization loop. By comparing the calculated results with the measured data, it is shown that the Jc scaling law, i.e. the deviatoric strain model, is not useful in a very low field. To solve this problem, the Kim model about Jc as a function of applied field has been applied in the low field case. This method can be used to predict the hysteresis loss of Nb3Sn filamentary strand.     

ST钢硬变硬化指数n值测定

进行三种ST钢的应变硬化指数n值试验,分析试验结果,研究n值在整个应变区间的变化趋势.     

Review of research and measurement for application properties of HTS tapes

Research and development of high-temperature superconducting (HTS) apparatus are ongoing in the world with the great progress on the HTS tapes in recent years. The most attractive applications require the HTS tapes to perform well upon the application of an alternative current (AC) and/or an AC magnetic field. The electromagnetic properties of the HTS tapes including anisotropy, uniformity, alternative current (AC losses) and stability as well as mechanical characteristics are important fundamental parameters for these applications. This paper summarizes and focuses on several typical measurement principles and methods as well as apparatuses of those characteristic parameters except for their stability developed in past several years in China.     

马氏体体积分数对双相钢变形行为的影响

 通过Crussard Jaoul （C J）分析和n值的分段分析对不同马氏体含量双相钢的变形行为进行了研究。C J分析时采用连续数据绘制C J曲线,避免了取点拟合过程中的不连续性,n值的分段分析基于微分原理,直观给出了不同应变量下的n值。结合对两者的分析,认为只有较低马氏体含量的双相钢才具有双屈服特性,并且双相钢的第二阶段硬化的拐点只有在一定量的马氏体发生变形时才出现。同时在小应变量下双相钢中的应变硬化速率随马氏体含量的增加而升高,而在低马氏体含量下n值会出现最大值。     

Lukasiewicz n值命题逻辑系统中公式的一般真度和形式推演结论的不可靠度估计

 在Lukasiewicz n值命题逻辑系统中引入命题公式的一般真度概念并讨论其性质,说明一般真度满足Kolmogorov公理.在形式推演中,引进公式的不可靠度和前提的必要度概念,证明在Lukasiewicz n值逻辑系统中,一个有效推理的结论的不可靠度不超过各前提的不可靠度与其必要度的乘积之和.通过不可靠度在全体公式集上建立逻辑伪距离空间,证明逻辑伪距离空间中没有孤立点,利用逻辑伪距离在全体公式集F(S)中提出两种不同形式的近似推理模式.