This paper introduces a new method of measuring the coordinates of building corner based on GPS-RTK,Vertical Extension.

Zidovudine prevents human immunodeficiency virus mother to child vertical transmission;

Construction of mouse model of vertical transmission by oral infection of Toxoplasma gondii;

Establishing mouse model of vertical transmission of Toxoplasma gondii;

A convenient method in solving the spiral perpendicular to the extruded object;

By taking the strategy of uniting geometry with algebra and using the method of minimal value, the relationships of intersection, parallels and perpendicular between two three dimensional spaces in four-dimensional descriptive geometry are investigated and the calculation formula of the distance between two three-dimensional spaces are given.

By taking the strategy of uniting geometry with algebra and utilizing the principle that the dot product of two perpendicular lines is zero, all the perpendicular problems encountered in four-dimensional space are systematically discussed.

The vertical distribution characteristics of respirable particles in autumn of Shijiazhuang;

Vertical distribution characteristics of photosynthetically active radiation in maize canopy and its controlling factors;

Soil of formation characteristics and soil vertical distribution in Altay mountains area,Xinjiang;