The objective of this study was to evaluate the effect of temperature on germination of Pinus tabuliformis Carrière seed, Pinus gerardiana Wall. ex D. Don and Pinus roxburghii Sarg. Seeds of three species were di...The objective of this study was to evaluate the effect of temperature on germination of Pinus tabuliformis Carrière seed, Pinus gerardiana Wall. ex D. Don and Pinus roxburghii Sarg. Seeds of three species were distributed in Petri dishes with 1% agar solution;for the first step it was placed on a 2-way Grant’s thermogradient plate (a bi-directional incubator) for a period of 28 days and during the second step in an incubator type B.O.D. also for 28 days with non-germinated seeds in the first step. This instrument allows an assessment of a wide regime of constant and alternating temperatures, resulting to 144 different combinations of temperature, scheduled to the temperatures 4°C - 40°C. The lighting regime was 12 hours photoperiod for the two stages of the experiment. The best temperature for the germination of P. tabuliformis was 26.2°C (minimum of 7.9°C and maximum 37.0°C) and P. roxburghii was 15.6°C (minimum 10, 4°C and maximum 37.0°C). The seeds are neutral photoblastic. P. gerardiana showed low germination percentage (below 10%). The temperature that provided the highest germination percentage for P. tabuliformis was 26.2°C and 15.6°C for P. roxburghii.展开更多
Goal: Formulation of empiric formula, which establishes relations between major matrix parameters of ceramic materials and composites and the coefficient of resistance to material thermogradient. Method: Harcpurt’s m...Goal: Formulation of empiric formula, which establishes relations between major matrix parameters of ceramic materials and composites and the coefficient of resistance to material thermogradient. Method: Harcpurt’s method of cooling of water in boiling regime till disappearance of water. Results: It is proved that work-pieces reveal maximum thermal resistance and preservation of exploitation properties, when total closed porosity is within 2% - 8%, and pore sizes vary within 1 - 6 mcm. Besides, they are more or less of spherical form and are spread equally in the matrix. Conclusion: Thermogradient effect formula was defined for complex form work-pieces, when surfaces in the pieces are transacted several times by angles of various curvature radii.展开更多
文摘The objective of this study was to evaluate the effect of temperature on germination of Pinus tabuliformis Carrière seed, Pinus gerardiana Wall. ex D. Don and Pinus roxburghii Sarg. Seeds of three species were distributed in Petri dishes with 1% agar solution;for the first step it was placed on a 2-way Grant’s thermogradient plate (a bi-directional incubator) for a period of 28 days and during the second step in an incubator type B.O.D. also for 28 days with non-germinated seeds in the first step. This instrument allows an assessment of a wide regime of constant and alternating temperatures, resulting to 144 different combinations of temperature, scheduled to the temperatures 4°C - 40°C. The lighting regime was 12 hours photoperiod for the two stages of the experiment. The best temperature for the germination of P. tabuliformis was 26.2°C (minimum of 7.9°C and maximum 37.0°C) and P. roxburghii was 15.6°C (minimum 10, 4°C and maximum 37.0°C). The seeds are neutral photoblastic. P. gerardiana showed low germination percentage (below 10%). The temperature that provided the highest germination percentage for P. tabuliformis was 26.2°C and 15.6°C for P. roxburghii.
文摘Goal: Formulation of empiric formula, which establishes relations between major matrix parameters of ceramic materials and composites and the coefficient of resistance to material thermogradient. Method: Harcpurt’s method of cooling of water in boiling regime till disappearance of water. Results: It is proved that work-pieces reveal maximum thermal resistance and preservation of exploitation properties, when total closed porosity is within 2% - 8%, and pore sizes vary within 1 - 6 mcm. Besides, they are more or less of spherical form and are spread equally in the matrix. Conclusion: Thermogradient effect formula was defined for complex form work-pieces, when surfaces in the pieces are transacted several times by angles of various curvature radii.
