k阶最近邻距离混合点过程分解模型的适用性判断条件的修正

对k阶最近邻距离混合点过程分解模型的判断条件进行修正,使该模型的适用范围更接近于真实.数值试验发现,参数R的理论值较大或者较小均不影响模型适用范围的判断条件.对适用范围的理论临界值可能产生影响的主要是该临界值附近的R分析临界值及其附近R与相应的理论值之间的差异,结合计算值,对所确定的临界值进行修正.结果发现:修正后的临界值-般都小于原临界值;无论临界值是否修正,点的个数对临界值的影响相似,即数据点数目较少时,临界值较大,数据点数目较大时,临界值较小;临界状态下,k的初始有效值基本随着数据点数目的增加而有所增加.     

Cosmic rays from the knee to the ankle

The shape and composition of the primary spectrum as well as the large-scale anisotropy in the arrival direction of cosmic rays are key elements to understand the origin, acceleration and propagation of the Galactic radiation. Besides the well-known knee and ankle features, the measured energy spectrum exhibits also a less pronounced but still clear deviation from a single power law between the knee and the ankle, with a spectral hardening at $\sim 2\times {10}^{16}\text{eV}$ and a steepening at $\sim {10}^{17}\text{eV}$. The average mass composition gets heavier after the knee till $\sim {10}^{17}\text{eV}$, where a bending of the heavy component is observed. An indication of a hardening of the light component just above ${10}^{17}\text{eV}$ has been measured as well. First indications of anisotropy of the arrival direction in the southern hemisphere have been reported at $\sim {10}^{15}\text{eV}$.     

中心螺管模型线圈交流损耗计算及测试

中心螺管模型线圈选用 Nb Ti/ Cu复合超导材料 ,超导股线直径 0 .85 m m,Cu截面积与 Nb Ti截面积比为 1.38;经过 4级绞缆和成型 ,导体尺寸为 17.4 mm× 17.4 m m,中心冷却孔直径 4 .1m m。线圈用超临界氦冷却 ,流体进口温度为 3.8- 4 .2 K,压力 6 bar,每个流道流量 2 .2 g/ s。用量热法对中心螺管模型线圈进行了交流损耗测试并与计算值相比较 ,3次交流损耗电流分别是 :30 0 A/ s速度励磁和放电 ,最大电流 5 k A ,交流损耗测量值为每脉冲 78.3J;30 0 A / s速度励磁和放电 ,最大电流 7k A ,交流损耗测量值为每脉冲 14 0 .7J;4 0 0 A/ s速度励磁和放电 ,最大电流 7k A,交流损耗测量值为每脉冲14 5 .4 J;计算值分别为每脉冲 98J,1385 J,14 2 J;两者较好相符。