A reliable method non-destructive X-ray test of wood defects with computer digital image processing technique was presented in the paper which made the knot-hole in wood clear and easily recognized. It was the first t...A reliable method non-destructive X-ray test of wood defects with computer digital image processing technique was presented in the paper which made the knot-hole in wood clear and easily recognized. It was the first time to use maximtun entropy to determine the threshold of binary picture and thc result was satisfying. The improved Robert was used in the paper in the paper to outline the knot-hole so that the processing was almost on real time.展开更多
The HDPFF (heavy-disaster-period of forest fire) takes up 1 / 4-1 / 3 of all observation years, but the loss takes up 80-90% of all. The author studied the relations between forest fire activity in Heilongiiang Provin...The HDPFF (heavy-disaster-period of forest fire) takes up 1 / 4-1 / 3 of all observation years, but the loss takes up 80-90% of all. The author studied the relations between forest fire activity in Heilongiiang Province from 1950 to 1989 and activity of sunspot, SSTA (sea surface temperature abnormality) of the North Pacific Ocean. The study discovered that : (1 )there was a negative correlation between forest fire condition in Heilongjiang Province and annual average of sunspot relative numbers, furthermore, the heavy-disaster-period was prone to occur in valley year and the next year; (2) SSTA in the North Pacific Ocean markedly influenced the forest fire activity and the level of its conditions in Heilongjiang province.展开更多
According to the data of wood analysis and biomass invcstigation, wc analyse the relationship among scotch pine stock, the growth of volume and its density, thc relationship between bio-productivity and its density as...According to the data of wood analysis and biomass invcstigation, wc analyse the relationship among scotch pine stock, the growth of volume and its density, thc relationship between bio-productivity and its density as well as the law of the distribution of biomass of various organs of the scotch pine. The conclusions showcd that the stock, volume, growth, bio produetivity and its density were interrclated closely. The appropriate density was 620--820 individuls / hm2 of mid-aged trees. The distributions of biomass on various organs werc different at different age stage. This paper gave the evidence to value artificial scotch pine, its structures and functions.展开更多
文摘A reliable method non-destructive X-ray test of wood defects with computer digital image processing technique was presented in the paper which made the knot-hole in wood clear and easily recognized. It was the first time to use maximtun entropy to determine the threshold of binary picture and thc result was satisfying. The improved Robert was used in the paper in the paper to outline the knot-hole so that the processing was almost on real time.
文摘The HDPFF (heavy-disaster-period of forest fire) takes up 1 / 4-1 / 3 of all observation years, but the loss takes up 80-90% of all. The author studied the relations between forest fire activity in Heilongiiang Province from 1950 to 1989 and activity of sunspot, SSTA (sea surface temperature abnormality) of the North Pacific Ocean. The study discovered that : (1 )there was a negative correlation between forest fire condition in Heilongjiang Province and annual average of sunspot relative numbers, furthermore, the heavy-disaster-period was prone to occur in valley year and the next year; (2) SSTA in the North Pacific Ocean markedly influenced the forest fire activity and the level of its conditions in Heilongjiang province.
文摘According to the data of wood analysis and biomass invcstigation, wc analyse the relationship among scotch pine stock, the growth of volume and its density, thc relationship between bio-productivity and its density as well as the law of the distribution of biomass of various organs of the scotch pine. The conclusions showcd that the stock, volume, growth, bio produetivity and its density were interrclated closely. The appropriate density was 620--820 individuls / hm2 of mid-aged trees. The distributions of biomass on various organs werc different at different age stage. This paper gave the evidence to value artificial scotch pine, its structures and functions.
