Static mechanical experiments were carried out on granite after and under different temperatures using an electro-hydraulic and servo-controlled material testing machine with a heating device. Variations in obvious fo...Static mechanical experiments were carried out on granite after and under different temperatures using an electro-hydraulic and servo-controlled material testing machine with a heating device. Variations in obvious form, stress-strain curve, peak strength, peak strain and elastic modulus with temperature were analyzed and the essence of rock failure modes was explored. The results indicate that, compared with granite after the high temperature treatment, the brittle-ductile transition critical temperature is lower, the densification stage is longer, the elastic modulus is smaller and the damage is larger under high temperature. In addition, the peak stress is lower and the peak strain is greater, but both of them change more obviously with the increase of temperature compared with that of granite after the high temperature treatment. Furthermore, the failure modes of granite after the high temperature treatment and under high temperature show a remarkable difference. Below 100 ℃, the failure modes of granite under both conditions are the same, presenting splitting failure. However, after 100 ℃, the failure modes of granite after the high temperature treatment and under high temperature present splitting failure and shear failure, respectively.展开更多
Well known for their good performance,thin film transistors (TFTs) with active layers which were nickel induced laterally crystallized,are fabricated by conventional process of dual gate CMOS.The influence of pre h...Well known for their good performance,thin film transistors (TFTs) with active layers which were nickel induced laterally crystallized,are fabricated by conventional process of dual gate CMOS.The influence of pre high temperature treatment of device fabrication on the performance of TFTs is also investigated.The experiment shows that the high temperature treatment affects the performance of the devices strongly.The best performance is obtained by adopting pre treatment of 1000℃.The mobility of 314cm 2/(V·s) is obtained at NMOS TFTs with pre treatment of 1000℃,which is 10% and 22% higher than that treated at 1100℃ and without pre high temperature treatment,respectively.A maximum on/off current ratio of 3×10 8 is also obtained at 1000℃.Further investigation of uniformity verifies that the result is reliable.展开更多
The aim of this study was to investigate changes of polyphenols content and the antioxidant activity of mulberry fruit powder after heating at high temperature.The mulberry fruit powder was heated by baking method at ...The aim of this study was to investigate changes of polyphenols content and the antioxidant activity of mulberry fruit powder after heating at high temperature.The mulberry fruit powder was heated by baking method at different temperature and time.The DPPH scavenging ability,the OH^(•-) scavenging ability and the O_(2)^(•-) scavenging ability were used to evaluate the changes in the antioxidant activity of the mulberry fruit powder after the heat treatment.The results showed that 74.87%of the polyphenols in the mulberry powder were lost after heating at 150℃for 5 min,and almost all the polyphenols were lost with the increase of the heating time and temperature.The antioxidant experiment showed that the DPPH scavenging rate,OH^(•-) scavenging rate and O_(2)^(•-) scavenging rate of mulberry fruit powder were 68.90%,39.15%and 14.09%,respectively after treatment at 150℃ for 5 min.Mulberry fruit powder still has some potential to be added to baked goods as a functional ingredient.展开更多
Seeds of Dodonaea viscosa （L.） Jacq, a representative species in dry and hot valleys in Southwest China, were chosen as experimental materials. In this experiment, the D. viscosa seeds were treated at 40, 60, 80 and...Seeds of Dodonaea viscosa （L.） Jacq, a representative species in dry and hot valleys in Southwest China, were chosen as experimental materials. In this experiment, the D. viscosa seeds were treated at 40, 60, 80 and 100℃ respectively before germination to study impacts of high temperature treatment on their generation rate and to further discuss the roles of fire during the process of vegetation formation in dry and hot valley areas of China. The results show that when the temperature was higher than 40 ℃, the germination rate of D. viscosa seeds was significantly higher than that of the control group, and the heat shock effect was apparent. The germination rate was the highest when the seeds were treated at 80 ℃ for 10 min, reaching 63.00%±2.55%. There was still a significant heat shock effect on the D. viscosa seeds which were stored for one year. In comparison with the conventional method of soaking seeds in hot water, the germination rate of D. viscose seeds which were treated at high temperature before germination increased significantly.展开更多
Carbon spheres with size of 50-300 nm were synthesized via a solvent-thermal reaction with calcium carbide and chloroform as reactants in a sealed autoclave.The morphologies and microstructures of carbon spheres befor...Carbon spheres with size of 50-300 nm were synthesized via a solvent-thermal reaction with calcium carbide and chloroform as reactants in a sealed autoclave.The morphologies and microstructures of carbon spheres before and after high temperature treatment(HTT) were characterized by X-ray diffractometry(XRD) ,scanning electronic microscopy(SEM) ,energy diffraction spectroscopy(EDS) ,and transmission electron microscopy(TEM) .The formation mechanism of carbon spheres was discussed.The results indicate that the carbon spheres convert to hollow polyhedron through HTT.Carbon spheres are composed of entangled and curve graphitic layers with short range order similar to cotton structure,and carbon polyhedron with dimension of 50-250 nm and shell thickness of 15-30 nm.The change of solid spheres to hollow polyhedron with branches gives a new evidence for formation mechanism of hollow carbon spheres.展开更多
Heat-treated wood has good dimensional stability,corrosion resistance and visual quality,but it is prone to mold,which limits its application.Based on the pH value of heat-treated wood,this study examines the factors ...Heat-treated wood has good dimensional stability,corrosion resistance and visual quality,but it is prone to mold,which limits its application.Based on the pH value of heat-treated wood,this study examines the factors affecting the pathogenesis causing heat-treated wood mold.Normally,the pH value of the heat-treated wood is between 4.38 and 5.10,which is suitable for the growth of mold.However,the pH of the heat-treated copper-containing material is between 6.63 and 7.12,which deviates the treated wood from the comfortable growth conditions for the mold,thereby reducing the occurrence of mold.展开更多
The aim of this work is firstly to optimize T6 heat-treatment of low-pressure sand-cast Mg-10Gd-3Y-0.5Zr alloy,and then systematically investigate the mechanical behavior of the T6-treated alloy from room temperature ...The aim of this work is firstly to optimize T6 heat-treatment of low-pressure sand-cast Mg-10Gd-3Y-0.5Zr alloy,and then systematically investigate the mechanical behavior of the T6-treated alloy from room temperature to 300℃.It turned out that the optimum T6 heat-treatments for the tested alloy are 525℃×12 h+225℃×14 h and 525℃×12 h+250℃×12 h which integrated age-hardening and tensile properties into account,respectively.The strength of the T6-treated alloy indicates obvious anomalous temperature dependence from room temperature to 300℃,namely both ultimate tensile strength and yield strength of the tested alloy firstly increase with tensile temperature,and then decrease as temperature increases further.Elongation increased with temperature monotonously.The tensile fracture mode of the tested alloy changes from transgranular fracture to intergranular fracture with the increasing of test temperature.展开更多
Felt base carbon/carbon composites fabricated by super-high pressure impregnation carbonization process (SPIC) were heat treated at high temperature 2773K. The oxidation properties of felt base carbon/carbon composite...Felt base carbon/carbon composites fabricated by super-high pressure impregnation carbonization process (SPIC) were heat treated at high temperature 2773K. The oxidation properties of felt base carbon/carbon composites were investigated at different temperatures (773-1173K), and the microstructures of carbon/carbon composites were studied by SEM and X-ray diffraction. The experimental results showed that the inter-laminar distance of (002) plane (d002) deceased while the microcrystalline stack height (Lc) increased. The oxidation rate of felt base carbon/carbon composites was invari-able at certain temperatures. The oxidation mechanism of carbon/carbon composites changed remarkably at the oxidation temperature 973K. At the initial oxidation stage of carbon/carbon composites, carbon matrix was oxidized much more rapidly than carbon felt.展开更多
Nano hafnium carbide（HfC） powders were synthesized by sol-gel combining hightemperature rapid heat treatment process using citric acid and hafnium tetrachloride as the raw materials. The effects of ball milling trea...Nano hafnium carbide（HfC） powders were synthesized by sol-gel combining hightemperature rapid heat treatment process using citric acid and hafnium tetrachloride as the raw materials. The effects of ball milling treatment on the phase and morphology of pyrolysis products（HfO_2-C） and final HfC product were investigated and the influences of heat treatment temperature and holding time on the structure and properties of the synthesized hafnium carbide powders were also studied. The experimental results showed that the HfO_2-C powders with good uniformity and small particle size were prepared by controlling the milling time. Pure HfC powders with an average particle size of 500 nm were obtained at 1 700 ℃ with a holding time of 3 min, and the oxygen content was about 0.69 wt%, lower than that of the hafnium carbide powders prepared by SPS（0.97%）.展开更多
基金Projects(51304241,11472311,51322403)supported by the National Natural Science Foundation of ChinaProject(2015CX005)supported by Innovation Driven Plan of Central South University,China+1 种基金Project(2016zzts456)supported by Independent Exploration and Innovation Foundation of Central South University,ChinaProject(2015CB060200)supported by the National Basic Research Program of China
文摘Static mechanical experiments were carried out on granite after and under different temperatures using an electro-hydraulic and servo-controlled material testing machine with a heating device. Variations in obvious form, stress-strain curve, peak strength, peak strain and elastic modulus with temperature were analyzed and the essence of rock failure modes was explored. The results indicate that, compared with granite after the high temperature treatment, the brittle-ductile transition critical temperature is lower, the densification stage is longer, the elastic modulus is smaller and the damage is larger under high temperature. In addition, the peak stress is lower and the peak strain is greater, but both of them change more obviously with the increase of temperature compared with that of granite after the high temperature treatment. Furthermore, the failure modes of granite after the high temperature treatment and under high temperature show a remarkable difference. Below 100 ℃, the failure modes of granite under both conditions are the same, presenting splitting failure. However, after 100 ℃, the failure modes of granite after the high temperature treatment and under high temperature present splitting failure and shear failure, respectively.
文摘Well known for their good performance,thin film transistors (TFTs) with active layers which were nickel induced laterally crystallized,are fabricated by conventional process of dual gate CMOS.The influence of pre high temperature treatment of device fabrication on the performance of TFTs is also investigated.The experiment shows that the high temperature treatment affects the performance of the devices strongly.The best performance is obtained by adopting pre treatment of 1000℃.The mobility of 314cm 2/(V·s) is obtained at NMOS TFTs with pre treatment of 1000℃,which is 10% and 22% higher than that treated at 1100℃ and without pre high temperature treatment,respectively.A maximum on/off current ratio of 3×10 8 is also obtained at 1000℃.Further investigation of uniformity verifies that the result is reliable.
基金This project is funded by the Livelihood Plan Project of Department of Science and Technology of Liaoning Province(2021JH2/10300069,2019-ZD-0845)Department of Education of Liaoning Province(LJKZ0918)National College Students’Innovation and Entrepreneurship Training Program(202210163013).
文摘The aim of this study was to investigate changes of polyphenols content and the antioxidant activity of mulberry fruit powder after heating at high temperature.The mulberry fruit powder was heated by baking method at different temperature and time.The DPPH scavenging ability,the OH^(•-) scavenging ability and the O_(2)^(•-) scavenging ability were used to evaluate the changes in the antioxidant activity of the mulberry fruit powder after the heat treatment.The results showed that 74.87%of the polyphenols in the mulberry powder were lost after heating at 150℃for 5 min,and almost all the polyphenols were lost with the increase of the heating time and temperature.The antioxidant experiment showed that the DPPH scavenging rate,OH^(•-) scavenging rate and O_(2)^(•-) scavenging rate of mulberry fruit powder were 68.90%,39.15%and 14.09%,respectively after treatment at 150℃ for 5 min.Mulberry fruit powder still has some potential to be added to baked goods as a functional ingredient.
基金Supported by the National Water Pollution Control and Treatment Science and Technology Major Project(2012ZX07101-003-04-04)~~
文摘Seeds of Dodonaea viscosa （L.） Jacq, a representative species in dry and hot valleys in Southwest China, were chosen as experimental materials. In this experiment, the D. viscosa seeds were treated at 40, 60, 80 and 100℃ respectively before germination to study impacts of high temperature treatment on their generation rate and to further discuss the roles of fire during the process of vegetation formation in dry and hot valley areas of China. The results show that when the temperature was higher than 40 ℃, the germination rate of D. viscosa seeds was significantly higher than that of the control group, and the heat shock effect was apparent. The germination rate was the highest when the seeds were treated at 80 ℃ for 10 min, reaching 63.00%±2.55%. There was still a significant heat shock effect on the D. viscosa seeds which were stored for one year. In comparison with the conventional method of soaking seeds in hot water, the germination rate of D. viscose seeds which were treated at high temperature before germination increased significantly.
基金Project(2006CB600901) supported by the National Basic Research Program of ChinaProject(0991015) supported by Guangxi Natural Science Foundation,ChinaProject(200808MS083) supported by Guangxi Education Department Foundation,China
文摘Carbon spheres with size of 50-300 nm were synthesized via a solvent-thermal reaction with calcium carbide and chloroform as reactants in a sealed autoclave.The morphologies and microstructures of carbon spheres before and after high temperature treatment(HTT) were characterized by X-ray diffractometry(XRD) ,scanning electronic microscopy(SEM) ,energy diffraction spectroscopy(EDS) ,and transmission electron microscopy(TEM) .The formation mechanism of carbon spheres was discussed.The results indicate that the carbon spheres convert to hollow polyhedron through HTT.Carbon spheres are composed of entangled and curve graphitic layers with short range order similar to cotton structure,and carbon polyhedron with dimension of 50-250 nm and shell thickness of 15-30 nm.The change of solid spheres to hollow polyhedron with branches gives a new evidence for formation mechanism of hollow carbon spheres.
基金Provincial Science and Technology Research Project of Guangdong(2014A040401043)
文摘Heat-treated wood has good dimensional stability,corrosion resistance and visual quality,but it is prone to mold,which limits its application.Based on the pH value of heat-treated wood,this study examines the factors affecting the pathogenesis causing heat-treated wood mold.Normally,the pH value of the heat-treated wood is between 4.38 and 5.10,which is suitable for the growth of mold.However,the pH of the heat-treated copper-containing material is between 6.63 and 7.12,which deviates the treated wood from the comfortable growth conditions for the mold,thereby reducing the occurrence of mold.
基金This work was supported by the National Natural Science Foundation of China （Nos. 50672025, 50730003）, The research fund for the Doctoral Program of Higher Education （No. 20070251008）.
基金This work is supported by National Natural Science Foundation of China(Nos.51771115 and 51775334)National Science and Technology Major Project(2017ZX04006001)+1 种基金Joint Fund for Space Science and Technology(6141B06300401 and 6141B06310106)Science Innovation Foundation of Shanghai Academy of Spaceflight Technology(No.SAST2016048).
文摘The aim of this work is firstly to optimize T6 heat-treatment of low-pressure sand-cast Mg-10Gd-3Y-0.5Zr alloy,and then systematically investigate the mechanical behavior of the T6-treated alloy from room temperature to 300℃.It turned out that the optimum T6 heat-treatments for the tested alloy are 525℃×12 h+225℃×14 h and 525℃×12 h+250℃×12 h which integrated age-hardening and tensile properties into account,respectively.The strength of the T6-treated alloy indicates obvious anomalous temperature dependence from room temperature to 300℃,namely both ultimate tensile strength and yield strength of the tested alloy firstly increase with tensile temperature,and then decrease as temperature increases further.Elongation increased with temperature monotonously.The tensile fracture mode of the tested alloy changes from transgranular fracture to intergranular fracture with the increasing of test temperature.
文摘Felt base carbon/carbon composites fabricated by super-high pressure impregnation carbonization process (SPIC) were heat treated at high temperature 2773K. The oxidation properties of felt base carbon/carbon composites were investigated at different temperatures (773-1173K), and the microstructures of carbon/carbon composites were studied by SEM and X-ray diffraction. The experimental results showed that the inter-laminar distance of (002) plane (d002) deceased while the microcrystalline stack height (Lc) increased. The oxidation rate of felt base carbon/carbon composites was invari-able at certain temperatures. The oxidation mechanism of carbon/carbon composites changed remarkably at the oxidation temperature 973K. At the initial oxidation stage of carbon/carbon composites, carbon matrix was oxidized much more rapidly than carbon felt.
基金the National Key R&D Program of China(2017YFB0310400)the National Natural Science Foundation of China(51672197)
文摘Nano hafnium carbide（HfC） powders were synthesized by sol-gel combining hightemperature rapid heat treatment process using citric acid and hafnium tetrachloride as the raw materials. The effects of ball milling treatment on the phase and morphology of pyrolysis products（HfO_2-C） and final HfC product were investigated and the influences of heat treatment temperature and holding time on the structure and properties of the synthesized hafnium carbide powders were also studied. The experimental results showed that the HfO_2-C powders with good uniformity and small particle size were prepared by controlling the milling time. Pure HfC powders with an average particle size of 500 nm were obtained at 1 700 ℃ with a holding time of 3 min, and the oxygen content was about 0.69 wt%, lower than that of the hafnium carbide powders prepared by SPS（0.97%）.
