virtual

• We recall that the principle of virtual displacements is a statement of equilibrium .
  前面已叙述过，虚位移原理是对平衡的一种描述。
• We can use the principle of virtual power to establish consistent boundary conditions .
  我们可以采用虚功率原理建立相容的边界条件。
• Clearly the virtual rotation about a is the geometric equivalent of taking moments about a .
  显然绕A的虚转动在几何上等价于对A点取矩。
• Beginning in the spring of 1915, they poured out articles and books in a virtual flood .
  从1915年春开始，他们的文章和书籍象洪水一般泛滥。
• In this example, then, the surface forms a virtual image 180mm to the left of the vertex .
  因此，在本例中这曲面在顶点左方180mm处形成一虚象。
• The image here is spoken of as virtual just as is the familiar image generated by a plane mirror .
  这时的像叫做虚像，正如由平面镜所生成的熟知的像一样。
• There is a virtual limit on how long we can hope to remain alive, however lucky and robust we are .
  不管我们多么幸运，多么强健，我们所希望的长寿实际上有个限度。
• The initial or frozen-in double refraction is replaced by an equivalent or virtual state of stress .
  初双折射或被冻结的双折射，可用一个等效或有效应力状态来代替。
• The virtual displacement method specifies that the sum of the shaded areas is equal to the sum of the stippled areas .
  虚位移法规定阴影面积之和等于点画面积之和。