The supersaturated solution of MgO· 3B2O3 18% MgSO4 H2O was prepared and then reacted under hydrothermal condition at 120℃ . The solid phases of the different time were identified by means of chemical analysis, ...The supersaturated solution of MgO· 3B2O3 18% MgSO4 H2O was prepared and then reacted under hydrothermal condition at 120℃ . The solid phases of the different time were identified by means of chemical analysis, XRD, FT IR, SEM. The results show that the solid phases are spherical and sheet szaibelyite, which is different from those of non hydrothermal condition. On these grounds we suggested the crystallization mechanism of szaibelyite under the hydrothermal condition and then discussed the effects of hydrothermal properties on the crystallization mechanism.展开更多
Disintegration of rock is one of the primary processes of soil formation and geomorphology and is affected considerably by water and heat.This study focused on the disintegration characteristics under laboratory condi...Disintegration of rock is one of the primary processes of soil formation and geomorphology and is affected considerably by water and heat.This study focused on the disintegration characteristics under laboratory conditions of typical purple mudstone from the Tuodian group of Jurassic red beds(J3t) in Tuodian Town,Shuangbai county,Yunnan Province of southern China.The fresh mudstone was subjected to alternating applications of water,heat and hydrothermal interaction during five treatments:wetting-drying(WD),saturation(ST),refrigeration-heating(RH),a combination of wetting-drying and refrigeration-heating(WDRH),and a combination of saturation and refrigeration-heating(STRH).Each treatment was run in twenty-four cycles.The results showed that there are three types of disintegration:collapsing disintegration,exfoliation disintegration and imperceptible disintegration.The cumulative disintegration rate(percentage of cumulative disintegrated mass to the initiative sample mass passed through a 2 mm sieve) produced a 'S'-shape function when related to treatment cycle time and closely fit a logistic model(R2 > 0.99).The rank order of the cumulative disintegration rate resulting from the five treatments was as the following:WDRH > STRH > ST > WD > RH.Because of alternating periods of moisture and dryness,WD caused the most disintegration,while RH alone resulted in imperceptible disintegration.Additionally,there was a negative correlation between the disintegration rate of each treatment cycle(percentage of disintegrated mass to the treated sample mass) and treatment cycle number.There was a positive correlation between this rate and temperature change under moist conditions,indicating that a change in temperature greatly accelerates the disintegration of parent rock when water was supplied.展开更多
Characteristics of thermal-hydraulic interaction of LBE （45w%Pb-55w%Bi） and lead with subcooled water in pool water were investigated experimentally. Two kinds of interaction zones （deformation and fragmentation） ...Characteristics of thermal-hydraulic interaction of LBE （45w%Pb-55w%Bi） and lead with subcooled water in pool water were investigated experimentally. Two kinds of interaction zones （deformation and fragmentation） and three kinds of interaction zones （solidification, deformation and fragmentation） were observed during LBE droplet/water interaction and lead droplet/water interaction, respectively. The fragmentation zone （FZ） could be identified exactly by two border lines： spontaneous nucleation temperature and minimum film boiling temperature. Within fragmentation zone, 10% to 35% tiny debris （diameter 〈 1 mm） of LBE and 5 to 8 kPa peak pressure generated with increasing the LBE temperature and no effect with increasing the subcooling of water. Only 2%-4% tiny debris （diameter 〈 1 mm） of lead and 2 kPa peak pressure generated regardless of lead and water temperature.展开更多
The plasma polymerization method and dynamic ion-beam mixed implantation method were employed to coat ultra-thin polymer films on copper plates. Experiments indicated that steady dropwise condensation of steam at atmo...The plasma polymerization method and dynamic ion-beam mixed implantation method were employed to coat ultra-thin polymer films on copper plates. Experiments indicated that steady dropwise condensation of steam at atmospheric pressure occurred. The condensation heat transfer coefficients increased by approximately 3 and 5－7 times for the polytrimethylvinylsilane film and polytetrafluoroethylene film respectively, compared with the value for film condensation under the same experimental conditions. The temperatures on the condensing surface and inside the test block were found to be rapidly and randomly fluctuated. The properties of the coated films and advantages of the methods used in this investigation were discussed briefly.展开更多
The mixed metal/metal sulphide(Ag@CoS)with reduced graphene oxide(rGO)nanocomposite(Ag@CoS/rGO)was synthesized for the possible electrode in supercapacitors.Ag@CoS was successfully deposited on the rGO nanosheets by h...The mixed metal/metal sulphide(Ag@CoS)with reduced graphene oxide(rGO)nanocomposite(Ag@CoS/rGO)was synthesized for the possible electrode in supercapacitors.Ag@CoS was successfully deposited on the rGO nanosheets by hydrothermal method,implying the growth of 2D Ag and CoS-based hexagonal-like structure on the rGO framework.The synthesized nanocomposite was subjected to structural,morphological and electrochemical studies.The XRD results show that the prepared nanocomposite material exhibits a combination of hexagonal and cubic phase due to the presence of CoS and Ag phases together.The band appearing at nearly 470.33 cm^−1 in FTIR spectra can be ascribed to the absorption of S—S bond in the Ag@CoS/rGO nanocomposite.The clear hexagonal structure was analysed by SEM and TEM with the grain sizes ranging from nanometer to micrometer.The electrode material exhibits excellent cyclic stability with a specific capacitance of 1580 F/g at a current density of 0.5 A/g without any loss of capacitive retention even after 1000 cycles.Based on the electrochemical performance,it can be inferred that the prepared novel nanocomposite material is very suitable for using as an electrode for electrochemical supercapacitor applications.展开更多
The everyday fluctuations of temperature and humidity lead to fluctuation of stress on the stones constituting many constructions and produce in long term some kinds of fatigue damage. This paper investigates the comb...The everyday fluctuations of temperature and humidity lead to fluctuation of stress on the stones constituting many constructions and produce in long term some kinds of fatigue damage. This paper investigates the combined role of stone properties variability and environmental conditions on the generation and the amplification of stress variation and fatigue. Thus, the randomness and spatial variability 0fthe mechanical, thermal and hydraulic properties are taken into account in a finite elements model of typical stone wall masonry of Chambord Castle. The quantification of the impact of this spatial variability on the variability of generated stress is performed.展开更多
In case of accident at a nuclear power plant, water sources may not be available for a long period of time and the core heats up due to the residual power. Any attempt to inject water during core degradation can lead ...In case of accident at a nuclear power plant, water sources may not be available for a long period of time and the core heats up due to the residual power. Any attempt to inject water during core degradation can lead to quenching and further fragmentation of core material. The fragmentation of fuel rods and melting of reactor core materials may result in the formation of a ＂debris bed＂. The typical particle size in a debris bed might reach few millimeters （characteristic length-scale： 1-5 mm）. The two-phase flow model for reflood of the degraded core is briefly introduced in this paper. It is implemented into the ICARE-CATHARE code, developed by IRSN （Institut de radioprotection et de surete nucleaire）, to study severe accident scenarios in pressurized water reactors. Currently, the French IRSN sets up two experimental facilities to study debris bed reflooding, PEARL and PRELUDE, and validate safety models. The PRELUDE program studies the complex two phase flow （water/steam）, in a porous medium （diameter 180 mm, height 200 mm）, initially heated to a high temperature （400℃ or 700℃）. On the basis of the experimental results, thermal hydraulic features at the quench front have been analyzed. The two-phase flow model shows a good agreement with PRELUDE experimental results.展开更多
Within the OECD/NEA Benchmarking of Thermal-Hydraulic Loop Models for Lead-Alloy Cooled Advanced Nuclear Energy Systems （LACANES）, the Institute for Neutron Physics and Reactor Technology takes part in the validatio...Within the OECD/NEA Benchmarking of Thermal-Hydraulic Loop Models for Lead-Alloy Cooled Advanced Nuclear Energy Systems （LACANES）, the Institute for Neutron Physics and Reactor Technology takes part in the validation process of system codes and the characterization of the thermal-hydraulic behavior of an experimental loop operated with liquid lead-bismuth-eutectics. To confirm the calculations, the results were compared to experimental data obtained from the HELIOS facility at the Seoul National University and to the results of other benchmark participants. The comparison showed that the calculations are within measurement tolerance but nevertheless discrepancies among the participants exist. The pressure drop estimation is determined by a variety of empirical correlations for the friction and the form loss coefficients. Hence, uncertainty and sensitivity measures were applied to find out which parameter is more relevant for the overall pressure drop. In the frame of this investigation, the system code TRACE and the software system for uncertainty and sensitivity, SUSA, were used. The results show that the total pressure drop varies between -30 and ＋15% related to the reference case.展开更多
The research focuses on the effect of air movement through building constructions. Although the typical air movement inside building constructions is quite small （velocity is of order -10-5 m/s）, this research shows...The research focuses on the effect of air movement through building constructions. Although the typical air movement inside building constructions is quite small （velocity is of order -10-5 m/s）, this research shows the impact on the heat and moisture characteristics. The paper presents a case study on the modeling and simulation of 2D heat and moisture transport with and without air movement for a building construction using a state-of-art multiphysics FEM software tool. Most other heat and moisture related models don＇t include airflow or use a steady airflow through the construction during the simulation period. However, in this model, the wind induced pressure is dynamic and thus also the airflow through the construction is dynamic. For this particular case study, the results indicate that at the intemal surface, the vapor pressure is almost not influenced by both the 2D effect and the wind speed. The temperatures at the inner surface are mostly influenced by the 2D effect. Only at wind pressure differences above 30 Pa, the airflow has a significant effect. At the extemal surface, the temperatttres are not influenced by both the 2D effect and the wind speed. However, the vapor pressure seems to be quite dependent on the wind induced pressure. Overall it is concluded that air movement through building materials seems to have a significant impact on the heat and moisture characteristics. In order to verify this statement and validate the models, new in-depth experiments including air flow through materials are recommended.展开更多
Power generation using small temperature difference such as ocean thermal energy conversion(OTEC)and discharged thermal energy conversion(DTEC)is expected to be the countermeasures against global warming problem.As am...Power generation using small temperature difference such as ocean thermal energy conversion(OTEC)and discharged thermal energy conversion(DTEC)is expected to be the countermeasures against global warming problem.As ammonia and ammonia/water are used in evaporators for OTEC and DTEC as working fluids,the research of their local boiling heat transfer is important for improvement of the power generation efficiency.Measurements of local boiling heat transfer coefficients were performed for ammonia/water mixture(z=0.9-1)on a vertical flat plate heat exchanger in a range of mass flux(7.5-15 kg/m2s),heat flux(15-23 kW/m 2),and pressure(0.7-0.9 MPa).The result shows that in the case of ammonia/water mixture,the local heat transfer coefficients increase with an increase of mass flux and composition of ammonia,and decrease with an increase of heat flux.展开更多
TiO2 nanorod arrays （NRAs） were prepared on,fluorine doped tin oxide （FTO） substrates by a facile two-step hydrothermal method. The nanorods were selectively grown on the FTO regions which were covered with TiO2 s...TiO2 nanorod arrays （NRAs） were prepared on,fluorine doped tin oxide （FTO） substrates by a facile two-step hydrothermal method. The nanorods were selectively grown on the FTO regions which were covered with TiO2 seeding layer. It took 5 h to obtain the compact arrays with the nanorod length of -2 μm and diameter of-50 nm. The photoelectrochemical （PEC） properties of TiO2 NRAs are also investigated. It is demonstrated that the TiO2 NRAs indicate the good photoelectric conversion ability with an efficiency of 0.22% at a full-wavelength irradiation. A photocurrent density of 0.21 mA/cm2 is observed at 0,7 V versus the saturated calomel electrode （SCE）. More evidences suggest that the charge transferring resistance is lowered at an irradiation, while the flat-band potential （Vgb） is shifted towards the positive side.展开更多
The pyrolysis properties of five different pyrolysis tars, which the tars from 1# to 5# are obtained by pyrolyzing the sewage sludges of anaerobic digestion and indigestion from the A2/O wastewater treatment process, ...The pyrolysis properties of five different pyrolysis tars, which the tars from 1# to 5# are obtained by pyrolyzing the sewage sludges of anaerobic digestion and indigestion from the A2/O wastewater treatment process, those from the activated sludge process and the indigested sludge from the continuous SBR process respectively, were studied by thermal gravimetric analysis at a heating rate of 10 ℃/min in the nitrogen atmosphere. The results show that the pyrolysis processes of the pyrolysis tars of 1#, 2#, 3# and 5# all can be divided into four stages: the stages of light organic compounds releasing, heavy polar organic compounds decomposition, heavy organic compounds decomposition and the residual organic compounds decomposition. However, the process of 4# pyrolysis tar is only divided into three stages: the stages of light organic compounds releasing, decomposition of heavy polar organic compounds and the residual heavy organic compounds respectively. Both the sludge anaerobic digestion and the "anaerobic" process in wastewater treatment processes make the content of light organic compounds in tars decrease, but make that of heavy organic compounds with complex structure increase. Besides, both make the pyrolysis properties of the tars become worse. The pyrolysis reaction mechanisms of the five pyrolysis tars have been studied with Coats-Redfern equation. It shows that there are the same mechanism functions in the first stage for the five tars and in the second and third stage for the tars of 1#, 2#, 3# and 5#, which is different with the function in the second stage for 4# tar. The five tars are easy to volatile.展开更多
The underwater heat exhausting source can cause the thermal difference of the surrounding and surface water.In this paper,the thermal character caused by the underwater heat exhausting source is studied by numerical s...The underwater heat exhausting source can cause the thermal difference of the surrounding and surface water.In this paper,the thermal character caused by the underwater heat exhausting source is studied by numerical simulation and experiment.The results show that the thermal floating distance is related with the sailing velocity of the underwater target.The higher the velocity is,the longer the hot wake is,and the broader the hot scope is.The relative distance of the thermal floating spot is almost in a logarithmic law with the velocity.The experimental results are accordant with the numerical simulation,and the obvious hot wake can be observed by the moving underwater heat exhausting source testing with temperature sensors and infrared camera.展开更多
文摘The supersaturated solution of MgO· 3B2O3 18% MgSO4 H2O was prepared and then reacted under hydrothermal condition at 120℃ . The solid phases of the different time were identified by means of chemical analysis, XRD, FT IR, SEM. The results show that the solid phases are spherical and sheet szaibelyite, which is different from those of non hydrothermal condition. On these grounds we suggested the crystallization mechanism of szaibelyite under the hydrothermal condition and then discussed the effects of hydrothermal properties on the crystallization mechanism.
基金supported by National Natural Science Foundation of China (Grant No.40971168)National Basic Research Program of China (973 Program) (Grant No. 2007CB407206)
文摘Disintegration of rock is one of the primary processes of soil formation and geomorphology and is affected considerably by water and heat.This study focused on the disintegration characteristics under laboratory conditions of typical purple mudstone from the Tuodian group of Jurassic red beds(J3t) in Tuodian Town,Shuangbai county,Yunnan Province of southern China.The fresh mudstone was subjected to alternating applications of water,heat and hydrothermal interaction during five treatments:wetting-drying(WD),saturation(ST),refrigeration-heating(RH),a combination of wetting-drying and refrigeration-heating(WDRH),and a combination of saturation and refrigeration-heating(STRH).Each treatment was run in twenty-four cycles.The results showed that there are three types of disintegration:collapsing disintegration,exfoliation disintegration and imperceptible disintegration.The cumulative disintegration rate(percentage of cumulative disintegrated mass to the initiative sample mass passed through a 2 mm sieve) produced a 'S'-shape function when related to treatment cycle time and closely fit a logistic model(R2 > 0.99).The rank order of the cumulative disintegration rate resulting from the five treatments was as the following:WDRH > STRH > ST > WD > RH.Because of alternating periods of moisture and dryness,WD caused the most disintegration,while RH alone resulted in imperceptible disintegration.Additionally,there was a negative correlation between the disintegration rate of each treatment cycle(percentage of disintegrated mass to the treated sample mass) and treatment cycle number.There was a positive correlation between this rate and temperature change under moist conditions,indicating that a change in temperature greatly accelerates the disintegration of parent rock when water was supplied.
文摘Characteristics of thermal-hydraulic interaction of LBE （45w%Pb-55w%Bi） and lead with subcooled water in pool water were investigated experimentally. Two kinds of interaction zones （deformation and fragmentation） and three kinds of interaction zones （solidification, deformation and fragmentation） were observed during LBE droplet/water interaction and lead droplet/water interaction, respectively. The fragmentation zone （FZ） could be identified exactly by two border lines： spontaneous nucleation temperature and minimum film boiling temperature. Within fragmentation zone, 10% to 35% tiny debris （diameter 〈 1 mm） of LBE and 5 to 8 kPa peak pressure generated with increasing the LBE temperature and no effect with increasing the subcooling of water. Only 2%-4% tiny debris （diameter 〈 1 mm） of lead and 2 kPa peak pressure generated regardless of lead and water temperature.
基金the National Natural Science Foundation of China (No. 59906002) and the Foundation for Young Teachers of Dalian University of Technology.
文摘The plasma polymerization method and dynamic ion-beam mixed implantation method were employed to coat ultra-thin polymer films on copper plates. Experiments indicated that steady dropwise condensation of steam at atmospheric pressure occurred. The condensation heat transfer coefficients increased by approximately 3 and 5－7 times for the polytrimethylvinylsilane film and polytetrafluoroethylene film respectively, compared with the value for film condensation under the same experimental conditions. The temperatures on the condensing surface and inside the test block were found to be rapidly and randomly fluctuated. The properties of the coated films and advantages of the methods used in this investigation were discussed briefly.
文摘The mixed metal/metal sulphide(Ag@CoS)with reduced graphene oxide(rGO)nanocomposite(Ag@CoS/rGO)was synthesized for the possible electrode in supercapacitors.Ag@CoS was successfully deposited on the rGO nanosheets by hydrothermal method,implying the growth of 2D Ag and CoS-based hexagonal-like structure on the rGO framework.The synthesized nanocomposite was subjected to structural,morphological and electrochemical studies.The XRD results show that the prepared nanocomposite material exhibits a combination of hexagonal and cubic phase due to the presence of CoS and Ag phases together.The band appearing at nearly 470.33 cm^−1 in FTIR spectra can be ascribed to the absorption of S—S bond in the Ag@CoS/rGO nanocomposite.The clear hexagonal structure was analysed by SEM and TEM with the grain sizes ranging from nanometer to micrometer.The electrode material exhibits excellent cyclic stability with a specific capacitance of 1580 F/g at a current density of 0.5 A/g without any loss of capacitive retention even after 1000 cycles.Based on the electrochemical performance,it can be inferred that the prepared novel nanocomposite material is very suitable for using as an electrode for electrochemical supercapacitor applications.
文摘The everyday fluctuations of temperature and humidity lead to fluctuation of stress on the stones constituting many constructions and produce in long term some kinds of fatigue damage. This paper investigates the combined role of stone properties variability and environmental conditions on the generation and the amplification of stress variation and fatigue. Thus, the randomness and spatial variability 0fthe mechanical, thermal and hydraulic properties are taken into account in a finite elements model of typical stone wall masonry of Chambord Castle. The quantification of the impact of this spatial variability on the variability of generated stress is performed.
文摘In case of accident at a nuclear power plant, water sources may not be available for a long period of time and the core heats up due to the residual power. Any attempt to inject water during core degradation can lead to quenching and further fragmentation of core material. The fragmentation of fuel rods and melting of reactor core materials may result in the formation of a ＂debris bed＂. The typical particle size in a debris bed might reach few millimeters （characteristic length-scale： 1-5 mm）. The two-phase flow model for reflood of the degraded core is briefly introduced in this paper. It is implemented into the ICARE-CATHARE code, developed by IRSN （Institut de radioprotection et de surete nucleaire）, to study severe accident scenarios in pressurized water reactors. Currently, the French IRSN sets up two experimental facilities to study debris bed reflooding, PEARL and PRELUDE, and validate safety models. The PRELUDE program studies the complex two phase flow （water/steam）, in a porous medium （diameter 180 mm, height 200 mm）, initially heated to a high temperature （400℃ or 700℃）. On the basis of the experimental results, thermal hydraulic features at the quench front have been analyzed. The two-phase flow model shows a good agreement with PRELUDE experimental results.
文摘Within the OECD/NEA Benchmarking of Thermal-Hydraulic Loop Models for Lead-Alloy Cooled Advanced Nuclear Energy Systems （LACANES）, the Institute for Neutron Physics and Reactor Technology takes part in the validation process of system codes and the characterization of the thermal-hydraulic behavior of an experimental loop operated with liquid lead-bismuth-eutectics. To confirm the calculations, the results were compared to experimental data obtained from the HELIOS facility at the Seoul National University and to the results of other benchmark participants. The comparison showed that the calculations are within measurement tolerance but nevertheless discrepancies among the participants exist. The pressure drop estimation is determined by a variety of empirical correlations for the friction and the form loss coefficients. Hence, uncertainty and sensitivity measures were applied to find out which parameter is more relevant for the overall pressure drop. In the frame of this investigation, the system code TRACE and the software system for uncertainty and sensitivity, SUSA, were used. The results show that the total pressure drop varies between -30 and ＋15% related to the reference case.
文摘The research focuses on the effect of air movement through building constructions. Although the typical air movement inside building constructions is quite small （velocity is of order -10-5 m/s）, this research shows the impact on the heat and moisture characteristics. The paper presents a case study on the modeling and simulation of 2D heat and moisture transport with and without air movement for a building construction using a state-of-art multiphysics FEM software tool. Most other heat and moisture related models don＇t include airflow or use a steady airflow through the construction during the simulation period. However, in this model, the wind induced pressure is dynamic and thus also the airflow through the construction is dynamic. For this particular case study, the results indicate that at the intemal surface, the vapor pressure is almost not influenced by both the 2D effect and the wind speed. The temperatures at the inner surface are mostly influenced by the 2D effect. Only at wind pressure differences above 30 Pa, the airflow has a significant effect. At the extemal surface, the temperatttres are not influenced by both the 2D effect and the wind speed. However, the vapor pressure seems to be quite dependent on the wind induced pressure. Overall it is concluded that air movement through building materials seems to have a significant impact on the heat and moisture characteristics. In order to verify this statement and validate the models, new in-depth experiments including air flow through materials are recommended.
基金supported by the fund for the 21st Century Center of Excellence program(Advanced Science and Technology for Utilization of Ocean Energy)
文摘Power generation using small temperature difference such as ocean thermal energy conversion(OTEC)and discharged thermal energy conversion(DTEC)is expected to be the countermeasures against global warming problem.As ammonia and ammonia/water are used in evaporators for OTEC and DTEC as working fluids,the research of their local boiling heat transfer is important for improvement of the power generation efficiency.Measurements of local boiling heat transfer coefficients were performed for ammonia/water mixture(z=0.9-1)on a vertical flat plate heat exchanger in a range of mass flux(7.5-15 kg/m2s),heat flux(15-23 kW/m 2),and pressure(0.7-0.9 MPa).The result shows that in the case of ammonia/water mixture,the local heat transfer coefficients increase with an increase of mass flux and composition of ammonia,and decrease with an increase of heat flux.
基金supported by the Science and Technology Projects of Xuzhou City(No.KC14SM088)the Natural Science Fund for Colleges and Universities in Jiangsu Province(No.15KJB430031)
文摘TiO2 nanorod arrays （NRAs） were prepared on,fluorine doped tin oxide （FTO） substrates by a facile two-step hydrothermal method. The nanorods were selectively grown on the FTO regions which were covered with TiO2 seeding layer. It took 5 h to obtain the compact arrays with the nanorod length of -2 μm and diameter of-50 nm. The photoelectrochemical （PEC） properties of TiO2 NRAs are also investigated. It is demonstrated that the TiO2 NRAs indicate the good photoelectric conversion ability with an efficiency of 0.22% at a full-wavelength irradiation. A photocurrent density of 0.21 mA/cm2 is observed at 0,7 V versus the saturated calomel electrode （SCE）. More evidences suggest that the charge transferring resistance is lowered at an irradiation, while the flat-band potential （Vgb） is shifted towards the positive side.
基金supported by the project of Tianjin higher education under contract (20060522)the project of Tianjin Polytechnic University (2230004)
文摘The pyrolysis properties of five different pyrolysis tars, which the tars from 1# to 5# are obtained by pyrolyzing the sewage sludges of anaerobic digestion and indigestion from the A2/O wastewater treatment process, those from the activated sludge process and the indigested sludge from the continuous SBR process respectively, were studied by thermal gravimetric analysis at a heating rate of 10 ℃/min in the nitrogen atmosphere. The results show that the pyrolysis processes of the pyrolysis tars of 1#, 2#, 3# and 5# all can be divided into four stages: the stages of light organic compounds releasing, heavy polar organic compounds decomposition, heavy organic compounds decomposition and the residual organic compounds decomposition. However, the process of 4# pyrolysis tar is only divided into three stages: the stages of light organic compounds releasing, decomposition of heavy polar organic compounds and the residual heavy organic compounds respectively. Both the sludge anaerobic digestion and the "anaerobic" process in wastewater treatment processes make the content of light organic compounds in tars decrease, but make that of heavy organic compounds with complex structure increase. Besides, both make the pyrolysis properties of the tars become worse. The pyrolysis reaction mechanisms of the five pyrolysis tars have been studied with Coats-Redfern equation. It shows that there are the same mechanism functions in the first stage for the five tars and in the second and third stage for the tars of 1#, 2#, 3# and 5#, which is different with the function in the second stage for 4# tar. The five tars are easy to volatile.
基金supported by Key Laboratory for National Defence of Underwater Observing and Control Technology fund number 9140c2603100805
文摘The underwater heat exhausting source can cause the thermal difference of the surrounding and surface water.In this paper,the thermal character caused by the underwater heat exhausting source is studied by numerical simulation and experiment.The results show that the thermal floating distance is related with the sailing velocity of the underwater target.The higher the velocity is,the longer the hot wake is,and the broader the hot scope is.The relative distance of the thermal floating spot is almost in a logarithmic law with the velocity.The experimental results are accordant with the numerical simulation,and the obvious hot wake can be observed by the moving underwater heat exhausting source testing with temperature sensors and infrared camera.
