不变

• In the special case in which w'is zero, the mechanical energy remains constant or is conserved .
  在W’等于零的特殊情况下，机械能保持不变或称保守。
• Motive power is, in quantity, invariable in nature, it is never either produced or destroyed .
  原动力在数量上实质是不变的，它绝不会产生也不会消失。
• In other words, the magnitude of the angular momentum is increased, its direction remaining the same .
  换句话说，即角动量的大小增加了，但其方向不变。
• This results in a decreasing amplitude in the first case and constant amplitude in the second .
  在第一种情况下，它导致振幅递减；在第二种情况下，振幅不变。
• The stabilizer of the number k, written stk, is the set of all permutations of g that leave k fixed .
  G中保持K不变的置换所成之集称为数K的稳定子，记作Stk。
• She would pray for him, sitting up in bed unaided, her head lifted, her voice steady .
  她就会不用搀扶，自个从床上坐起来，抬着头，用镇定不变的声音为他祈祷。
• He may know that history is the foe of permanence, but no leader is entitled to resignation .
  他可能知道，历史是不会永久不变的，但是，没有一个领袖听天由命。
• Tides and ocean currents, which remain constant, have no effect on the correction for vehicle speed changes .
  保持不变的潮泛和海流对校正运动体速度的改变没有影响。
• There is no place for the thrifty and hardworking to put their money with assurance of preserving its value .
  没有地方可让勤劳节俭的人们存钱，并保证钱的价值不变。
• One approach consists of varying only the total flow thereby maintaining the same thrust chamber hardware .
  有一种方法是仅改变推进剂总流量，而推力室结构保持不变。