In order to understand the occurrence and the developmental regularity of seabuckthorn carpenterworm (Holcocerus hippophaecolus) and predict its population density, the developmental threshold temperature (C) and effe...In order to understand the occurrence and the developmental regularity of seabuckthorn carpenterworm (Holcocerus hippophaecolus) and predict its population density, the developmental threshold temperature (C) and effective accumulative tem- perature (K) of the carpenterworm pupae and eggs were analyzed under the conditions of constant and variable temperatures. The results show that the values of C and K of the carpenterworm pupae are (12.1 ± 0.2) °C and (295.2 ± 4.1) day-degrees at constant temperatures, and (15.5 ± 0.4) °C and (202.4 ± 13.1) day-degrees at variable temperatures. However, the values of C and K of the eggs at variable temperatures are (16.7 ± 0.8) °C and (101.5 ± 12.6) day-degrees. The differences of developmental threshold and effective accumulative temperature under the conditions of constant and variable temperatures of the carpenterworm pupae accord with the developmental regularity of most insects in nature. By comparing five different constant temperatures, the conclusion is that the optimum developmental temperature of the pupae is 21 °C when both the pupation of the mature larvae and the eclosion of the pupae are very accordant. Moreover, the percentage of eclosion is over 90%. The average developmental durations of the carpenter- worm pupae and eggs are 31 and 16 d at variable temperatures.展开更多
The effects of Ni addition on the liquid phase separation and giant magnetoresi stance (GMR) of Cu Co alloys were discussed. The results reveal that Ni additio n can partially restrain the liquid phase separation of C...The effects of Ni addition on the liquid phase separation and giant magnetoresi stance (GMR) of Cu Co alloys were discussed. The results reveal that Ni additio n can partially restrain the liquid phase separation of Cu Co alloys, resultin g in a decrease of volume fraction for the Co rich particles separated from the liquid phase and in refined microstructures. The composition analyses indicate t hat Ni is dissolved in both the Co rich and the Cu rich phases, but Ni content in the Co rich phase is much higher than that in the Cu matrix. At the same ti me, Ni addition enhance the solubility between Cu and Co, especially Cu in Co s olid solution. Ni alloying into Cu Co alloys can fully prevent the liquid phase separation during melt spinning, which is very beneficial to improve GMR of Cu Co alloys.展开更多
This article studied the diversity of Amphipoda＇s environmental adaptation using statistic method- ology based on the seasonal investigation data obtained from the East China Sea waters （23°30′- 33°N, 118...This article studied the diversity of Amphipoda＇s environmental adaptation using statistic method- ology based on the seasonal investigation data obtained from the East China Sea waters （23°30′- 33°N, 118°30′128°E） from 1997 to 2000. Fifty-four Amphipoda species were identified： among which eight species could stand a temperature difference over 10 ℃ and eight species could tolerate the temperature gap ranged from 5 to 10 ℃; while only six species could stand the salinity fluctuation more than 5. Based on above facts as well as calculated optimal temperature and salinity we divided all Amphipoda species into four groups： （1） eurythermic and euryhalinous species including Lestrigonus schizogeneios, L. macrophthalmus, Tetrathyrus forcipatus, L. bengalensis and Hyperi- oides sibaginis; （2） temperate-warm species containing Hyperoche medusarum, Parathemisto gau- dichaudi, Themisto japonica and Hyperia galba; （3） oceanic tropical species consisted of Oxycephalus clausi~ Lyeaea pulex, Eupronoe minuta, Simorhychotus antennarius, O. poreelus, Platyscelus ovoides and Rhabdosoma ahitei; （4） subtropical species involving one nearshore subtropical water species （Corophium uenoi） and 37 offshore subtropical ones. Compared with other zooplankton such as Eu- phausia and Chaetognatha, Amphipoda was characterized by low dominance but wide distribution in the East China Sea, and this could be ascribed to its high adaptation diversity.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
The ductility of as-fabricated Ti-6AI-4V fails far short of the requirements for biomedical titanium alloy implants and the heat treatment remains the only applicable option for improvement of their mechanical propert...The ductility of as-fabricated Ti-6AI-4V fails far short of the requirements for biomedical titanium alloy implants and the heat treatment remains the only applicable option for improvement of their mechanical properties. In the present study, the decomposition of as-fabricated martensite was investigated to provide a general understanding on the kinetics of its phase transformation. The decomposition of as- fabricated martensite was found to be slower than that of water-quenched martensite. It indicates that specific heat treatment strategy is needed to be explored for as.fabricated Ti-6AI-4V. Three strategies of heat treatment were proposed based on different phase transformation mechanisms and classified as subtransus treatment, supersolvus treatment and mixed treatment. These specific heat treatments were conducted on selective laser melted samples to investigate the evolutions of microstructure and mechanical properties. The subtransus treatment leaded to a basket-weave structure without changing the morphology of columnar prior β grains. The supersolvus treatment resulted in a lamellar structure and equiaxed β grains. The mixed treatment yielded a microstructure that combines both features of the subtransus treatment and supersolvus treatment. The subtransus treatment is found to be the best choice among these three strategies for as.fabricated Ti-6AI-4V to be used as biomedical implants.展开更多
文摘In order to understand the occurrence and the developmental regularity of seabuckthorn carpenterworm (Holcocerus hippophaecolus) and predict its population density, the developmental threshold temperature (C) and effective accumulative tem- perature (K) of the carpenterworm pupae and eggs were analyzed under the conditions of constant and variable temperatures. The results show that the values of C and K of the carpenterworm pupae are (12.1 ± 0.2) °C and (295.2 ± 4.1) day-degrees at constant temperatures, and (15.5 ± 0.4) °C and (202.4 ± 13.1) day-degrees at variable temperatures. However, the values of C and K of the eggs at variable temperatures are (16.7 ± 0.8) °C and (101.5 ± 12.6) day-degrees. The differences of developmental threshold and effective accumulative temperature under the conditions of constant and variable temperatures of the carpenterworm pupae accord with the developmental regularity of most insects in nature. By comparing five different constant temperatures, the conclusion is that the optimum developmental temperature of the pupae is 21 °C when both the pupation of the mature larvae and the eclosion of the pupae are very accordant. Moreover, the percentage of eclosion is over 90%. The average developmental durations of the carpenter- worm pupae and eggs are 31 and 16 d at variable temperatures.
文摘The effects of Ni addition on the liquid phase separation and giant magnetoresi stance (GMR) of Cu Co alloys were discussed. The results reveal that Ni additio n can partially restrain the liquid phase separation of Cu Co alloys, resultin g in a decrease of volume fraction for the Co rich particles separated from the liquid phase and in refined microstructures. The composition analyses indicate t hat Ni is dissolved in both the Co rich and the Cu rich phases, but Ni content in the Co rich phase is much higher than that in the Cu matrix. At the same ti me, Ni addition enhance the solubility between Cu and Co, especially Cu in Co s olid solution. Ni alloying into Cu Co alloys can fully prevent the liquid phase separation during melt spinning, which is very beneficial to improve GMR of Cu Co alloys.
基金The China Major Research Plan of the National Natural Science Foundation of China under contract No.90511005"908" Project under contract No.908-02-01-03
文摘This article studied the diversity of Amphipoda＇s environmental adaptation using statistic method- ology based on the seasonal investigation data obtained from the East China Sea waters （23°30′- 33°N, 118°30′128°E） from 1997 to 2000. Fifty-four Amphipoda species were identified： among which eight species could stand a temperature difference over 10 ℃ and eight species could tolerate the temperature gap ranged from 5 to 10 ℃; while only six species could stand the salinity fluctuation more than 5. Based on above facts as well as calculated optimal temperature and salinity we divided all Amphipoda species into four groups： （1） eurythermic and euryhalinous species including Lestrigonus schizogeneios, L. macrophthalmus, Tetrathyrus forcipatus, L. bengalensis and Hyperi- oides sibaginis; （2） temperate-warm species containing Hyperoche medusarum, Parathemisto gau- dichaudi, Themisto japonica and Hyperia galba; （3） oceanic tropical species consisted of Oxycephalus clausi~ Lyeaea pulex, Eupronoe minuta, Simorhychotus antennarius, O. poreelus, Platyscelus ovoides and Rhabdosoma ahitei; （4） subtropical species involving one nearshore subtropical water species （Corophium uenoi） and 37 offshore subtropical ones. Compared with other zooplankton such as Eu- phausia and Chaetognatha, Amphipoda was characterized by low dominance but wide distribution in the East China Sea, and this could be ascribed to its high adaptation diversity.
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.
基金Acknowledgements The authors are grateful for the financial support from the National Natural Science Foundation of China （Grant Nos. 51361130032 and 51472139） and the Doctor Subject Foundation of the Ministry of Education of China （Grant No. 20120002130002）.
文摘The ductility of as-fabricated Ti-6AI-4V fails far short of the requirements for biomedical titanium alloy implants and the heat treatment remains the only applicable option for improvement of their mechanical properties. In the present study, the decomposition of as-fabricated martensite was investigated to provide a general understanding on the kinetics of its phase transformation. The decomposition of as- fabricated martensite was found to be slower than that of water-quenched martensite. It indicates that specific heat treatment strategy is needed to be explored for as.fabricated Ti-6AI-4V. Three strategies of heat treatment were proposed based on different phase transformation mechanisms and classified as subtransus treatment, supersolvus treatment and mixed treatment. These specific heat treatments were conducted on selective laser melted samples to investigate the evolutions of microstructure and mechanical properties. The subtransus treatment leaded to a basket-weave structure without changing the morphology of columnar prior β grains. The supersolvus treatment resulted in a lamellar structure and equiaxed β grains. The mixed treatment yielded a microstructure that combines both features of the subtransus treatment and supersolvus treatment. The subtransus treatment is found to be the best choice among these three strategies for as.fabricated Ti-6AI-4V to be used as biomedical implants.
