The section which is cross to optical axis of anisotropic mineral has no pleochroism and absorption.
举一反三
- The isotropic mineral has no pleochroism, and there are no positive or negative relief.
- The protein has the properties of UV absorption, which has the maximum absorption peak at 260nm.( )
- When member is subjected to the eccentric loads, the wrong description of neutral axis is ( ). A: The position of the neutral axis is independent of external forces and eccentricity B: The neutral axis and the point of the external force are on opposite sides of the cross section centroid respectively C: The neutral axis is related to the shape and size of the section D: The closer the external force point is to the centroid, the farther the neutral axis is from the centroid
- In practical use, only the load which is close to pivot cross section needs to consider the change of mc. ( )
- For plane bending the characteristics of deformation are ( ). A: The cross section remains plane when bent; B: The axis after deformation is a plane curve; C: All external loads act on the same plane; D: The axis after deformation is in the same plane with the loading plane.