Based on the data of slash pine planting density in age 7,8,13 and thinning intensity in age 19,breast-height form-factor,H/DBH and normal form quotient were analyzed,so as to study the effect of stand density on stem form.

Based on the Brink revised formula,a generalized stem form model was established,by which the changes of tree stem of Chinese fir ( Cunninghamia lanceolata ) plantation can be well described at different sites,densities and ages.

Based on previous research achievement,the paper details the main contents and conclusions, which are as follow:(1) Form factor is not only an important indicator to reflect the full extent of stem form,but also is the important factor to calculate the volume of standing-tree and stand factor.

Finite element simulation based on microscopic mechanism of concrete shrinkage deformation;

Value of shrinkage deformation under different humidity is recorded by micrometer gauge.

Based on comparing tests between the drying shrinkage of small type concrete block packed wall at different air hummidity and different restraint condition of steel bar length,the effect of the level-direction pulling steel bar on the drying shrinkage of small type concrete block packed wall were studied.

The article analyzes the main causes of cracks in air-entrained concrete wall from dry shrinkage deformation of air-entrained concrete building block and mortar,temperature fluctuation,settlement deformation of masonry and irrational building structure,and proposes measures to control wall cracks,in order to ensure normal utilization and security of wall.

The article introduces the concept of waterproofing for subway station with sandwich structure and analyses the temperature stress on side wall concrete and the dry shrinkage deformation and volume deformation of the concrete with some conclusions on causes for side wall cracking.