提高φ76mm轧管机组毛管直度

介绍了在φ76mm轧管机组后配置链式冷床对减小毛管弯曲度的使用效果。实践表明,经冷床冷却的毛管,弯曲度明显减小,满足了冷拔机上料系统的要求。     

Weight hierarchies of linear codes satisfying the almost chain condition

The weight hierarchy of a linear [n, k;q] code C over GF(q) is the sequence (d1,d2,..., dk) where dr is the size of the smallest support of an r-dimensional subcode of C. An [n,k;q] code satisfies the chain condition if there exists subcodes D1 D2 … Dk = C of C such that Dr has dimension r and support of size dr for all r. Further, C satisfies the almost chain condition if it does not satisfy the chain condition, but there exist subcodes Dr of dimension r and support of size dr for all r such that D2 D3 Dk = C and D1 D3. A simple necessary condition for a sequence to be the weight hierarchy of a code satisfying the almost chain condition is given. Further, explicit constructions of such codes are given, showing that in almost all cases, the necessary conditions are also sufficient.     

HFETR 全厂断电试验及其结果分析

本文综述了 HFETR 内全厂断电试验结果,并与理论分析结果(全厂断电后瞬态流量和元件盒内温度场计算)进行了比较。结果表明,二者符合得较好(偏差在4%之内)。这说明理论分析是正准的,HFETR 在全厂断电情况下是安全的。     

基于层次分析法的流域生态决策评价系统

探讨以西藏高原流域(涵盖金沙江、澜沧江、怒江和雅鲁藏布江流域)中典型区域为对象的流域生态决策评价系统实现方法.在制定流域生态环境质量评价指标体系的基础上,选用层次分析方法(AHP)建立了决策评价模型,并采用Java语言以组件的方式实现模型程序,设计并实现了流域生态决策评价系统.以流域中各种生态系统为例,系统进行了决策评价,结果表明通过决策评价模型得到的结果与野外科学考察所观测到的实际现象基本一致.在流域中针叶林、灌木林生态系统类型对流域生态环境质量具有直接影响,河流生态系统的生态环境质量优于湖泊生态系统.