In order to compare the influence of the initial refrigerant and the new refrigerant to test system better , the volume refrigeration capacity per unit , cop and the ratio of pressure were calculated and compared from the basic refrigerant loop 为了更好的比较原有制冷工质和新型替代工质对测试系统的影响,本文从基本的制冷循环出发,对循环的单位容积制冷量、 cop以及循环压比等参数进行了计算比较。
The maximum designed compression ratio of two types of special - shaped columns is presented with two methods of curvature ductility and big - small eccentricity failure . and the advantages and disadvantages of the designed compression ratio determined by the two methods is compared to 用截面曲率延性和大小偏心临界破坏点两种方法确定它们的轴压比限值，并比较了两种方法确定轴压比限值的优缺点。
An optimizing method with constant pressure ratio is initially applied to the mixed refrigerant cycle . this method greatly simplifies the calculation of the cycle , and is helpful in numerical optimization of various cycles , especially in the complex cycles 本文首次采用混合工质制冷机循环的定运行压比优化方法，大大减少了循环的计算量，为各种混合工质制冷机循环，尤其是复杂循环的数值优化奠定了基础。
Four conclusions were obtained : 1 ) the ideal maximum performance of rbcc engine is basically determined by the match of rbcc " s basic operating parameters such as the ratios of primary / secondary mass flow rate , total pressure , total temperature and the ratio of overall oxidant / fuel mass flow rate , etc 主要获得如下结论： 1 )基本工作参数的匹配，如引射比、总压比、总温比，决定了引射发动机最大可能获得的性能。
The characteristics of longitudinal and lateral frame columns are different from general frame columns , due to the high depth - to - width ratio of cross - sections and withstanding large vertical loads . the axial compressive ratio is a very important factor in columns design 纵、横向框架柱具有与一般框架柱不同的特点，如柱截面高宽比较大，且承受很大的竖向荷载，其轴压比设计问题是柱设计的一个非常重要的因素。
3 analysis on axial compression ratio of l , t and + - shaped columns is undertaken . it indicates that for l and t - shaped columns , axial compression ration is very low when web is in compression , but for + - shaped columns , axial compression ratio approaches to that of rectangular columns 3对l 、 t 、十形柱轴压比限值进行计算分析，指出l 、 t形柱当腹板受压时轴压比限值很低，十形柱轴压比限值同矩形柱相差不多。
