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Toru Ujihara - One of the best experts on this subject based on the ideXlab platform.
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temperature dependence of double shockley stacking fault behavior in Nitrogen doped 4h sic studied by in situ synchrotron x ray topography
Acta Materialia, 2020Co-Authors: Fumihiro Fujie, Shunta Harada, Kenji Hanada, Hiromasa Suo, Haruhiko Koizumi, Tomohisa Kato, Miho Tagawa, Toru UjiharaAbstract:Abstract We observed the behavior of double Shockley stacking faults (DSFs) in 4H-SiC crystals with Nitrogen Concentrations of 1.0 × 1019–2.6 × 1019 cm−3 over an extensive temperature range (1380–1910 K) by in-situ synchrotron X-ray topography. For a Nitrogen Concentration of 2.6 × 1019 cm−3, the expansion velocity of the DSFs exponentially increased with temperature in the range from 1370 to 1650 K. In contrast, at a Nitrogen Concentration of 1.0 × 1019 cm−3, this velocity decreased above 1610 K and the DSFs shrank above 1730 K. The DSF energy, the magnitude of which is the driving force on partial dislocation (PD) movement, was quantitatively estimated from the radius of the curvature of bowed-out partial PDs pinned by threading screw dislocations (TSDs), showing a positive temperature dependence and lying in the range from −0.6 to 0.8 mJ/m2 for 1630–1910 K at a Nitrogen Concentration of 1.0 × 1019 cm−3. The DSF expansion and shrinkage behavior can be understood by the simple temperature and Nitrogen Concentration dependence of the DSF energy.
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temperature dependence of double shockley stacking fault behavior in Nitrogen doped 4h sic studied by in situ synchrotron x ray topography
Social Science Research Network, 2020Co-Authors: Fumihiro Fujie, Shunta Harada, Kenji Hanada, Hiromasa Suo, Haruhiko Koizumi, Tomohisa Kato, Miho Tagawa, Toru UjiharaAbstract:We observed the behavior of double Shockley stacking faults (DSFs) in 4H-SiC crystals with Nitrogen Concentrations of 1.0×1019-2.6×1019 cm−3 over an extensive temperature range (1380-1910 K) by in-situ synchrotron X-ray topography. For a Nitrogen Concentration of 2.6×1019 cm−3, the expansion velocity of the DSFs exponentially increased with temperature for temperatures in the range from 1370 to 1650 K. In contrast, at a Nitrogen Concentration of 1.0×1019 cm−3, this velocity decreased above 1610 K and the DSFs shrank above 1730 K. The DSF energy, considered to be the driving force for DSF expansion, was quantitatively estimated from the radius of the curvature of bowed-out partial dislocations (PDs) pinned by threading screw dislocations (TSDs), showing a positive temperature dependence and lying in the range from −0.6 to 0.8 mJ/m2 at a Nitrogen Concentration of 1.0×1019 cm−3. The DSF expansion and shrinkage behavior can be understood by the simple temperature and Nitrogen Concentration dependence of the DSF energy.
Hidehisa Fukata - One of the best experts on this subject based on the ideXlab platform.
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leaf litter Nitrogen Concentration in hinoki cypress forests in relation to the time of leaf fall under different climatic conditions in japan
Ecological Research, 2010Co-Authors: Yoshiyuki Inagaki, Atsushi Sakai, Shiro Okuda, Asami Nakanishi, Shozo Shibata, Hidehisa FukataAbstract:Leaf-litter Nitrogen Concentration was investigated for 17 hinoki cypress (Chamaecyparis obtusa Endlicher) forests in the Kochi region on the Pacific Ocean side and the Kyoto region on the Sea of Japan side in Japan where both the amount of precipitation and frequency of typhoon attacks differ between regions. Leaf properties were predicted from climatic, stand, and soil properties by multiple regression analysis. Fresh-leaf Nitrogen was higher in the Kyoto than Kochi regions and was higher where soil C/N ratio is lower. The time of leaf-fall, i.e., 50% of the annual leaf fall, showed a difference of 86 days among the forests and occurred earlier in forests at higher altitudes. The time of leaf-fall at higher altitudes was earlier due to the higher susceptibility to strong winds from typhoons. Leaf-litter Nitrogen Concentration of annual leaf-fall or winter leaf-fall was lower when the time of leaf-fall occurred later. The results indicate that Nitrogen resorption is proficient when leaf-fall occurs later, leading to lower leaf-litter Nitrogen Concentration.
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effects of thinning on leaf fall and leaf litter Nitrogen Concentration in hinoki cypress chamaecyparis obtusa endlicher plantation stands in japan
Forest Ecology and Management, 2008Co-Authors: Yoshiyuki Inagaki, Shigeo Kuramoto, Atsushi Torii, Yoshiki Shinomiya, Hidehisa FukataAbstract:Abstract The effects of thinning on fresh-leaf Nitrogen Concentration, leaf-litter Nitrogen Concentration, and leaf-fall phenology were evaluated over 3 years in two evergreen hinoki cypress ( Chamaecyparis obtusa Endlicher) plantations at different elevations (TNG and FMY) and with different site characteristics on Shikoku Island in southern Japan. Two adjacent study plots (400 m 2 ) were selected: in one plot thinning was conducted in 2002 where about 50% of trees were removed and in the other plot no trees were cut as the control. The plantation at a higher elevation (TNG) was characterized by higher soil Nitrogen mineralization, higher fresh-leaf and leaf-litter Nitrogen Concentration and earlier leaf-fall than that at a lower elevation (FMY). The net Nitrogen mineralization in the surface soil and fresh-leaf Nitrogen Concentration in the thinned plots was significantly greater than in the control plots across both sites. Leaf-litter Nitrogen Concentration was marginally higher in the thinned plots than in the control plots and was negatively correlated with the time of 50% annual leaf-fall. When severe typhoons affected the area in 2004, leaf-fall became earlier and the leaf-litter Nitrogen Concentration was greater in the thinned plots. The results suggest that the time of leaf-fall is an important factor affecting leaf-litter Nitrogen Concentration. The results imply that the effects of severe typhoons are greater in the thinned plots and plantations at a higher elevation.
Hiromasa Suo - One of the best experts on this subject based on the ideXlab platform.
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temperature dependence of double shockley stacking fault behavior in Nitrogen doped 4h sic studied by in situ synchrotron x ray topography
Acta Materialia, 2020Co-Authors: Fumihiro Fujie, Shunta Harada, Kenji Hanada, Hiromasa Suo, Haruhiko Koizumi, Tomohisa Kato, Miho Tagawa, Toru UjiharaAbstract:Abstract We observed the behavior of double Shockley stacking faults (DSFs) in 4H-SiC crystals with Nitrogen Concentrations of 1.0 × 1019–2.6 × 1019 cm−3 over an extensive temperature range (1380–1910 K) by in-situ synchrotron X-ray topography. For a Nitrogen Concentration of 2.6 × 1019 cm−3, the expansion velocity of the DSFs exponentially increased with temperature in the range from 1370 to 1650 K. In contrast, at a Nitrogen Concentration of 1.0 × 1019 cm−3, this velocity decreased above 1610 K and the DSFs shrank above 1730 K. The DSF energy, the magnitude of which is the driving force on partial dislocation (PD) movement, was quantitatively estimated from the radius of the curvature of bowed-out partial PDs pinned by threading screw dislocations (TSDs), showing a positive temperature dependence and lying in the range from −0.6 to 0.8 mJ/m2 for 1630–1910 K at a Nitrogen Concentration of 1.0 × 1019 cm−3. The DSF expansion and shrinkage behavior can be understood by the simple temperature and Nitrogen Concentration dependence of the DSF energy.
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temperature dependence of double shockley stacking fault behavior in Nitrogen doped 4h sic studied by in situ synchrotron x ray topography
Social Science Research Network, 2020Co-Authors: Fumihiro Fujie, Shunta Harada, Kenji Hanada, Hiromasa Suo, Haruhiko Koizumi, Tomohisa Kato, Miho Tagawa, Toru UjiharaAbstract:We observed the behavior of double Shockley stacking faults (DSFs) in 4H-SiC crystals with Nitrogen Concentrations of 1.0×1019-2.6×1019 cm−3 over an extensive temperature range (1380-1910 K) by in-situ synchrotron X-ray topography. For a Nitrogen Concentration of 2.6×1019 cm−3, the expansion velocity of the DSFs exponentially increased with temperature for temperatures in the range from 1370 to 1650 K. In contrast, at a Nitrogen Concentration of 1.0×1019 cm−3, this velocity decreased above 1610 K and the DSFs shrank above 1730 K. The DSF energy, considered to be the driving force for DSF expansion, was quantitatively estimated from the radius of the curvature of bowed-out partial dislocations (PDs) pinned by threading screw dislocations (TSDs), showing a positive temperature dependence and lying in the range from −0.6 to 0.8 mJ/m2 at a Nitrogen Concentration of 1.0×1019 cm−3. The DSF expansion and shrinkage behavior can be understood by the simple temperature and Nitrogen Concentration dependence of the DSF energy.
Fumihiro Fujie - One of the best experts on this subject based on the ideXlab platform.
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temperature dependence of double shockley stacking fault behavior in Nitrogen doped 4h sic studied by in situ synchrotron x ray topography
Acta Materialia, 2020Co-Authors: Fumihiro Fujie, Shunta Harada, Kenji Hanada, Hiromasa Suo, Haruhiko Koizumi, Tomohisa Kato, Miho Tagawa, Toru UjiharaAbstract:Abstract We observed the behavior of double Shockley stacking faults (DSFs) in 4H-SiC crystals with Nitrogen Concentrations of 1.0 × 1019–2.6 × 1019 cm−3 over an extensive temperature range (1380–1910 K) by in-situ synchrotron X-ray topography. For a Nitrogen Concentration of 2.6 × 1019 cm−3, the expansion velocity of the DSFs exponentially increased with temperature in the range from 1370 to 1650 K. In contrast, at a Nitrogen Concentration of 1.0 × 1019 cm−3, this velocity decreased above 1610 K and the DSFs shrank above 1730 K. The DSF energy, the magnitude of which is the driving force on partial dislocation (PD) movement, was quantitatively estimated from the radius of the curvature of bowed-out partial PDs pinned by threading screw dislocations (TSDs), showing a positive temperature dependence and lying in the range from −0.6 to 0.8 mJ/m2 for 1630–1910 K at a Nitrogen Concentration of 1.0 × 1019 cm−3. The DSF expansion and shrinkage behavior can be understood by the simple temperature and Nitrogen Concentration dependence of the DSF energy.
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temperature dependence of double shockley stacking fault behavior in Nitrogen doped 4h sic studied by in situ synchrotron x ray topography
Social Science Research Network, 2020Co-Authors: Fumihiro Fujie, Shunta Harada, Kenji Hanada, Hiromasa Suo, Haruhiko Koizumi, Tomohisa Kato, Miho Tagawa, Toru UjiharaAbstract:We observed the behavior of double Shockley stacking faults (DSFs) in 4H-SiC crystals with Nitrogen Concentrations of 1.0×1019-2.6×1019 cm−3 over an extensive temperature range (1380-1910 K) by in-situ synchrotron X-ray topography. For a Nitrogen Concentration of 2.6×1019 cm−3, the expansion velocity of the DSFs exponentially increased with temperature for temperatures in the range from 1370 to 1650 K. In contrast, at a Nitrogen Concentration of 1.0×1019 cm−3, this velocity decreased above 1610 K and the DSFs shrank above 1730 K. The DSF energy, considered to be the driving force for DSF expansion, was quantitatively estimated from the radius of the curvature of bowed-out partial dislocations (PDs) pinned by threading screw dislocations (TSDs), showing a positive temperature dependence and lying in the range from −0.6 to 0.8 mJ/m2 at a Nitrogen Concentration of 1.0×1019 cm−3. The DSF expansion and shrinkage behavior can be understood by the simple temperature and Nitrogen Concentration dependence of the DSF energy.
Yoshiyuki Inagaki - One of the best experts on this subject based on the ideXlab platform.
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leaf litter Nitrogen Concentration in hinoki cypress forests in relation to the time of leaf fall under different climatic conditions in japan
Ecological Research, 2010Co-Authors: Yoshiyuki Inagaki, Atsushi Sakai, Shiro Okuda, Asami Nakanishi, Shozo Shibata, Hidehisa FukataAbstract:Leaf-litter Nitrogen Concentration was investigated for 17 hinoki cypress (Chamaecyparis obtusa Endlicher) forests in the Kochi region on the Pacific Ocean side and the Kyoto region on the Sea of Japan side in Japan where both the amount of precipitation and frequency of typhoon attacks differ between regions. Leaf properties were predicted from climatic, stand, and soil properties by multiple regression analysis. Fresh-leaf Nitrogen was higher in the Kyoto than Kochi regions and was higher where soil C/N ratio is lower. The time of leaf-fall, i.e., 50% of the annual leaf fall, showed a difference of 86 days among the forests and occurred earlier in forests at higher altitudes. The time of leaf-fall at higher altitudes was earlier due to the higher susceptibility to strong winds from typhoons. Leaf-litter Nitrogen Concentration of annual leaf-fall or winter leaf-fall was lower when the time of leaf-fall occurred later. The results indicate that Nitrogen resorption is proficient when leaf-fall occurs later, leading to lower leaf-litter Nitrogen Concentration.
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effects of thinning on leaf fall and leaf litter Nitrogen Concentration in hinoki cypress chamaecyparis obtusa endlicher plantation stands in japan
Forest Ecology and Management, 2008Co-Authors: Yoshiyuki Inagaki, Shigeo Kuramoto, Atsushi Torii, Yoshiki Shinomiya, Hidehisa FukataAbstract:Abstract The effects of thinning on fresh-leaf Nitrogen Concentration, leaf-litter Nitrogen Concentration, and leaf-fall phenology were evaluated over 3 years in two evergreen hinoki cypress ( Chamaecyparis obtusa Endlicher) plantations at different elevations (TNG and FMY) and with different site characteristics on Shikoku Island in southern Japan. Two adjacent study plots (400 m 2 ) were selected: in one plot thinning was conducted in 2002 where about 50% of trees were removed and in the other plot no trees were cut as the control. The plantation at a higher elevation (TNG) was characterized by higher soil Nitrogen mineralization, higher fresh-leaf and leaf-litter Nitrogen Concentration and earlier leaf-fall than that at a lower elevation (FMY). The net Nitrogen mineralization in the surface soil and fresh-leaf Nitrogen Concentration in the thinned plots was significantly greater than in the control plots across both sites. Leaf-litter Nitrogen Concentration was marginally higher in the thinned plots than in the control plots and was negatively correlated with the time of 50% annual leaf-fall. When severe typhoons affected the area in 2004, leaf-fall became earlier and the leaf-litter Nitrogen Concentration was greater in the thinned plots. The results suggest that the time of leaf-fall is an important factor affecting leaf-litter Nitrogen Concentration. The results imply that the effects of severe typhoons are greater in the thinned plots and plantations at a higher elevation.
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inter annual variations of leaf fall phenology and leaf litter Nitrogen Concentration in a hinoki cypress chamaecyparis obtusa endlicher stand
Ecological Research, 2008Co-Authors: Yoshiyuki Inagaki, Atsushi Sakai, Shigeo Kuramoto, Eiji Kodani, Tsuyoshi Yamada, Tatsuro KawasakiAbstract:Inter-annual variations in leaf-fall phenology and leaf-litter Nitrogen Concentration were investigated for 13 years in a coniferous plantation of hinoki cypress trees (Chamaecyparis obtusa Endlicher) in Kochi, southern Japan. Mean annual Nitrogen Concentration in the leaf litter ranged from 5.97 to 7.12 g kg−1. The removal of 30 percent of the trees’ basal area in the 3rd year had little effect on leaf-litter Nitrogen Concentration. The Nitrogen Concentration in the leaf litter was not correlated with the mean temperature from March to October. The leaf-fall duration, i.e., time between 10 and 90% of the annual leaf fall, was shorter and the leaf-litter Nitrogen Concentration was lower when the solar radiation from March to October was higher. The results suggest that the hinoki trees shed their leaves abruptly and have lower leaf-litter Nitrogen Concentration when the solar radiation is higher and that effects of temperature on leaf-fall properties may not be strong in warm climate areas.