Trends of the temperature variations recorded in δ18O in Hongyuan peat cellulose are similar to those recorded in δ18O of Jinchuan peat cellulose and in δ18O of Dunde ice core. Climate events have been identified t...Trends of the temperature variations recorded in δ18O in Hongyuan peat cellulose are similar to those recorded in δ18O of Jinchuan peat cellulose and in δ18O of Dunde ice core. Climate events have been identified to be globally homogeneous. Two notable climate transition periods have been detected in the past 6000 years, namely 4000 aBP with climate shifting from cold to warm and 1500 aBP with climate shifting from warm to relatively cold. Power spectrum analysis was performed to investigate the periodical signals in the δ18O time series. Typical periodicities of 1200-1087 a, 752 a, 444 a, 325 a, 213 a, 127-123 a, 88 a, 79 a were discovered, indicating an integrated influence on Hongyuan climate from solar, monsoon and ocean activities. Solar forcing has been addressed to be the main driving forcing of Hongyuan climate.展开更多
Understanding the rate of snowmelt helps inform how water stored as snow will transform into streamflow. Data from 87 snow telemetry （SNOTEL） stations across the Southern Rocky Mountains were used to estimate spatio...Understanding the rate of snowmelt helps inform how water stored as snow will transform into streamflow. Data from 87 snow telemetry （SNOTEL） stations across the Southern Rocky Mountains were used to estimate spatio-temporal melt factors. Decreases in snow water equivalent were correlated to temperature at these monitoring stations for eight half-month periods from early March through late June. Time explained 70% of the variance in the computed snow melt factors. A residual linear correlation model was used to explain subsequent spatial variability. Longitude, slope, and land cover type explained further variance. For evergreen trees, canopy density was relevant to find enhanced melt rates; while for all other land cover types, denoted as non- evergreen, lower melt rates were found at high elevation, high latitude and north facing slopes, denoting that in cold environments melting is less effective than in milder sites. A change in the temperature sensor about mid-way through the time series （1990 to 2013） created a discontinuity in the temperature dataset. An adjustment to the time series yield larger computed melt factors.展开更多
In the present paper, we have studied the effect of Ge addition on the physical properties of Se-Sn-Pb chalcogenide ma- terial. The necessary physical parameters which have important role in determining the structure ...In the present paper, we have studied the effect of Ge addition on the physical properties of Se-Sn-Pb chalcogenide ma- terial. The necessary physical parameters which have important role in determining the structure and strength of the material viz. constraints, coordination number etc. have been calculated. The increasing trend has been found in cohesive energy, heat of atomization and mean bond energy. The glass transition has been studied using the Tichy-Ticha and Lankhorst approaches, which also increases with the increasing Ge contents. The increase in these physical parameters is due to the increasing covalent character in the material.展开更多
Cu-Al-Co and Cu-Al-Zr alloys were explored with Co or Zr additions in Cu-Al alloys for high temperature shape memory alloys. Samples were quenched after homogenized at 850℃ for 48h. It was found that both Cu-Al-Co an...Cu-Al-Co and Cu-Al-Zr alloys were explored with Co or Zr additions in Cu-Al alloys for high temperature shape memory alloys. Samples were quenched after homogenized at 850℃ for 48h. It was found that both Cu-Al-Co and Cu-Al-Zr show AlCus martensitic phase at room temperature and exhibit martensitic transformation temperatures higher than 200℃, showing the potentials for developing as high temperature shape memory alloys. Thermal cycles were performed by DSC instrument on both Cu-Al-Co and Cu-Al-Zr alloys. The results show that Cu-Al-Co loses its martensitic transformation after five thermal cycles, and Cu-Al-Zr exhibits no martensitic transformation in the second thermal cycle.展开更多
The temperature and magnetic moment depend-ence for assessing localized heating utilizing a new class of Manganese-Zinc-Gadolinium mag-netic nanoparticles was studied. These particles showed heating effect when subjec...The temperature and magnetic moment depend-ence for assessing localized heating utilizing a new class of Manganese-Zinc-Gadolinium mag-netic nanoparticles was studied. These particles showed heating effect when subjected to alter-nating filed. Alternatively, a new approach was used to get disperse heating without spot heating by using the synthesis of particles at controlled Curie temperature of less than 44oC. The study reports a simple synthesis of Mn0.5Zn0.5GdxFe(2-x)O4 nanoparticles using chemical co- precipita-tion technique. The particles exhibited Curie temperature of 42篊 and high magnitude of mag-netic moments. The particles showed sigmoid behavior of dependence between temperature and magnetic moments. The Nuclear Magnetic Resonance spectroscopy showed T1 depend-ence on temperature in the range of 10-45篊. The particles may have high promise for self con-trolled magnetic hyperthermia application and its monitoring.展开更多
The automated energy generating complex allows obtaining heat energy from waste coal-water slurry fuel （WCF） that is a mixture of fine coal particles from coal enrichment wastes with water. The mixture is blown into...The automated energy generating complex allows obtaining heat energy from waste coal-water slurry fuel （WCF） that is a mixture of fine coal particles from coal enrichment wastes with water. The mixture is blown into the swirl chamber under the pressure through the special sprayers. The received heat energy is used in different ways. One of the important issues is to estimate the heat losses through the walls of this chamber. In this paper we solved the boundary problem of mathematical physics to estimate the temperature fields in the walls of the swirl chamber. The obtained solution allows us to estimate the heat losses through the waUs of the swid chamber. The task of the mathematical physics has been solved by a numerical finite-difference method. The method for solving this prob- lem can be used in the calculation of temperature fields and evaluation of heat losses in other thermal power units.展开更多
文摘Trends of the temperature variations recorded in δ18O in Hongyuan peat cellulose are similar to those recorded in δ18O of Jinchuan peat cellulose and in δ18O of Dunde ice core. Climate events have been identified to be globally homogeneous. Two notable climate transition periods have been detected in the past 6000 years, namely 4000 aBP with climate shifting from cold to warm and 1500 aBP with climate shifting from warm to relatively cold. Power spectrum analysis was performed to investigate the periodical signals in the δ18O time series. Typical periodicities of 1200-1087 a, 752 a, 444 a, 325 a, 213 a, 127-123 a, 88 a, 79 a were discovered, indicating an integrated influence on Hongyuan climate from solar, monsoon and ocean activities. Solar forcing has been addressed to be the main driving forcing of Hongyuan climate.
文摘Understanding the rate of snowmelt helps inform how water stored as snow will transform into streamflow. Data from 87 snow telemetry （SNOTEL） stations across the Southern Rocky Mountains were used to estimate spatio-temporal melt factors. Decreases in snow water equivalent were correlated to temperature at these monitoring stations for eight half-month periods from early March through late June. Time explained 70% of the variance in the computed snow melt factors. A residual linear correlation model was used to explain subsequent spatial variability. Longitude, slope, and land cover type explained further variance. For evergreen trees, canopy density was relevant to find enhanced melt rates; while for all other land cover types, denoted as non- evergreen, lower melt rates were found at high elevation, high latitude and north facing slopes, denoting that in cold environments melting is less effective than in milder sites. A change in the temperature sensor about mid-way through the time series （1990 to 2013） created a discontinuity in the temperature dataset. An adjustment to the time series yield larger computed melt factors.
文摘In the present paper, we have studied the effect of Ge addition on the physical properties of Se-Sn-Pb chalcogenide ma- terial. The necessary physical parameters which have important role in determining the structure and strength of the material viz. constraints, coordination number etc. have been calculated. The increasing trend has been found in cohesive energy, heat of atomization and mean bond energy. The glass transition has been studied using the Tichy-Ticha and Lankhorst approaches, which also increases with the increasing Ge contents. The increase in these physical parameters is due to the increasing covalent character in the material.
基金supported by the National Natural Science Foundation of China(No.20271002)Aviation Science Foundation of China(No.00G51007).
文摘Cu-Al-Co and Cu-Al-Zr alloys were explored with Co or Zr additions in Cu-Al alloys for high temperature shape memory alloys. Samples were quenched after homogenized at 850℃ for 48h. It was found that both Cu-Al-Co and Cu-Al-Zr show AlCus martensitic phase at room temperature and exhibit martensitic transformation temperatures higher than 200℃, showing the potentials for developing as high temperature shape memory alloys. Thermal cycles were performed by DSC instrument on both Cu-Al-Co and Cu-Al-Zr alloys. The results show that Cu-Al-Co loses its martensitic transformation after five thermal cycles, and Cu-Al-Zr exhibits no martensitic transformation in the second thermal cycle.
文摘The temperature and magnetic moment depend-ence for assessing localized heating utilizing a new class of Manganese-Zinc-Gadolinium mag-netic nanoparticles was studied. These particles showed heating effect when subjected to alter-nating filed. Alternatively, a new approach was used to get disperse heating without spot heating by using the synthesis of particles at controlled Curie temperature of less than 44oC. The study reports a simple synthesis of Mn0.5Zn0.5GdxFe(2-x)O4 nanoparticles using chemical co- precipita-tion technique. The particles exhibited Curie temperature of 42篊 and high magnitude of mag-netic moments. The particles showed sigmoid behavior of dependence between temperature and magnetic moments. The Nuclear Magnetic Resonance spectroscopy showed T1 depend-ence on temperature in the range of 10-45篊. The particles may have high promise for self con-trolled magnetic hyperthermia application and its monitoring.
基金the project No.2010-218-02-174 by the Governmental Order of the Russian Federation of April 9,2010 No.218'On measures of federal support of cooperation between higher educational institutions and enterprises which realize complex projects of hi-tech production development
文摘The automated energy generating complex allows obtaining heat energy from waste coal-water slurry fuel （WCF） that is a mixture of fine coal particles from coal enrichment wastes with water. The mixture is blown into the swirl chamber under the pressure through the special sprayers. The received heat energy is used in different ways. One of the important issues is to estimate the heat losses through the walls of this chamber. In this paper we solved the boundary problem of mathematical physics to estimate the temperature fields in the walls of the swirl chamber. The obtained solution allows us to estimate the heat losses through the waUs of the swid chamber. The task of the mathematical physics has been solved by a numerical finite-difference method. The method for solving this prob- lem can be used in the calculation of temperature fields and evaluation of heat losses in other thermal power units.
