The semi-coke was prepared by solid heat carrier with dry distillation in single factor method. The pore structures of raw coal and semi-coke were characterized by Brunauer-Emmett-Teller (BET) and scanning electron mi...The semi-coke was prepared by solid heat carrier with dry distillation in single factor method. The pore structures of raw coal and semi-coke were characterized by Brunauer-Emmett-Teller (BET) and scanning electron microscope (SEM). The results show that the adsorption and desorption isotherm of semi-coke are not coincident. There was a wide pore distribution on the semi-coke, in which mesopores and micropores account for a considerable proportion. Also there are many more secondary pores. With the increase of the final temperature of heat carrier and constant temperature, as well as the decrease of volume ratio of coal and hot carrier reactor, specific surface area and pore volume of semi-coke increased rapidly first and then decreased and finally increased, along with the rapidly reduction of average pore size. SEM photos show that the surface of semi-coke becomes increasingly rough and glossy.展开更多
Enlarging the fleet of gas carriers would make it possible to respond to the growing demand for hydrocarbon gases,but it will increase carbon dioxide emissions.The International Maritime Organization(IMO)has developed...Enlarging the fleet of gas carriers would make it possible to respond to the growing demand for hydrocarbon gases,but it will increase carbon dioxide emissions.The International Maritime Organization(IMO)has developed the energy efficiency design index(EEDI)with the objective of carbon emission reduction for new ships.In this paper,thirty gas carriers transporting liquefied natural gas(LNG)and liquefied petroleum gas(LPG)and equipped with various types of main engines are considered.As shown by the calculation of the attained EEDI,2 of the 13 LPG carriers and 6 of the 17 LNG carriers under study do not comply with the EEDI requirements.To meet the stringent EEDI requirements,applying thermochemical regenerators(TCRs)fed by main engine exhaust gases is suggested.Mathematical modeling is applied to analyze the characteristics of the combined gas-turbine-electric and diesel-electric power plant with thermochemical recuperation of the exhaust gas heat.Utilizing TCR on gas carriers with engines fueled by syngas produced from boil-off gas(BOG)reduces the carbon content by 35%and provides the energy efficiency required by IMO without the use of other technologies.展开更多
Bulk graphene nanofilms feature fast electronic and phonon transport in combination with strong light-matter interaction and thus have great potential for versatile applications,spanning from photonic,electronic,and o...Bulk graphene nanofilms feature fast electronic and phonon transport in combination with strong light-matter interaction and thus have great potential for versatile applications,spanning from photonic,electronic,and optoelectronic devices to charge-stripping and electromagnetic shielding,etc.However,large-area flexible close-stacked graphene nanofilms with a wide thickness range have yet to be reported.Here,we report a polyacrylonitrile-assisted’substrate replacement’strategy to fabricate large-area free-standing graphene oxide/polyacrylonitrile nanofilms(lateral size~20 cm).Linear polyacrylonitrile chains-derived nanochannels promote the escape of gases and enable macro-assembled graphene nanofilms(nMAGs)of 50-600 nm thickness following heat treatment at 3,000℃.The uniform nMAGs exhibit 802-1,540 cm^(2)V-1s-1carrier mobility,4.3-4.7 ps carrier lifetime,and>1,581 W m^(-1)K^(-1)thermal conductivity(n MAG-assembled 10μm-thick films,mMAGs).nMAGs are highly flexible and show no structure damage even after 1.0×10^(5)cycles of folding-unfolding.Furthermore,n MAGs broaden the detection region of graphene/silicon heterojunction from near-infrared to mid-infrared and demonstrate higher absolute electromagnetic interference(EMI)shielding effectiveness than state-of-the-art EMI materials of the same thickness.These results are expected to lead to the broad applications of such bulk nanofilms,especially as micro/nanoelectronic and optoelectronic platforms.展开更多
The study deals with a new regenerative air heat exchanger with an intermediate heat carrier used in the systems of room ventilation.A physical and mathematical model of the heat transfer process is proposed.The...The study deals with a new regenerative air heat exchanger with an intermediate heat carrier used in the systems of room ventilation.A physical and mathematical model of the heat transfer process is proposed.The influence of design and operating parameters on the temperature efficiency of the heat exchanger is analyzed.The possibility of a significant increase in its efficiency with a decrease in the packing diameter is shown.As a result of calculations,it was found that with a decrease in the filling height,the maximum temperature efficiency shifted towards a decrease in the air flow rate from its value determined from the equality of water equivalents of liquid and air.展开更多
This paper deals with the radiation effects of different kinds ofradiant carriers used in making far infrared textile materials.From two radiation experiments,methods of testing radiation ef-fects of carriers have bee...This paper deals with the radiation effects of different kinds ofradiant carriers used in making far infrared textile materials.From two radiation experiments,methods of testing radiation ef-fects of carriers have been found,results of the experiments arediscussed.Finally,some conclusions for choosing appropriateradiant carrier are drawn.展开更多
基金financial support from the Major State Basic Research Development Program of China (No. 2012CB214902)the National Natural Science Foundation of China (No. 51104159) are greatly appreciated
文摘The semi-coke was prepared by solid heat carrier with dry distillation in single factor method. The pore structures of raw coal and semi-coke were characterized by Brunauer-Emmett-Teller (BET) and scanning electron microscope (SEM). The results show that the adsorption and desorption isotherm of semi-coke are not coincident. There was a wide pore distribution on the semi-coke, in which mesopores and micropores account for a considerable proportion. Also there are many more secondary pores. With the increase of the final temperature of heat carrier and constant temperature, as well as the decrease of volume ratio of coal and hot carrier reactor, specific surface area and pore volume of semi-coke increased rapidly first and then decreased and finally increased, along with the rapidly reduction of average pore size. SEM photos show that the surface of semi-coke becomes increasingly rough and glossy.
文摘Enlarging the fleet of gas carriers would make it possible to respond to the growing demand for hydrocarbon gases,but it will increase carbon dioxide emissions.The International Maritime Organization(IMO)has developed the energy efficiency design index(EEDI)with the objective of carbon emission reduction for new ships.In this paper,thirty gas carriers transporting liquefied natural gas(LNG)and liquefied petroleum gas(LPG)and equipped with various types of main engines are considered.As shown by the calculation of the attained EEDI,2 of the 13 LPG carriers and 6 of the 17 LNG carriers under study do not comply with the EEDI requirements.To meet the stringent EEDI requirements,applying thermochemical regenerators(TCRs)fed by main engine exhaust gases is suggested.Mathematical modeling is applied to analyze the characteristics of the combined gas-turbine-electric and diesel-electric power plant with thermochemical recuperation of the exhaust gas heat.Utilizing TCR on gas carriers with engines fueled by syngas produced from boil-off gas(BOG)reduces the carbon content by 35%and provides the energy efficiency required by IMO without the use of other technologies.
基金supported by the National Natural Science Foundation of China(No.52090030)the China Postdoctoral Science Foundation(2022T150558,2020M681819)+1 种基金the Fundamental Research Funds for the Central Universities(No.2021FZZX001-17)the Postdoctoral Research Program of Zhejiang Province(ZJ2021145).
文摘Bulk graphene nanofilms feature fast electronic and phonon transport in combination with strong light-matter interaction and thus have great potential for versatile applications,spanning from photonic,electronic,and optoelectronic devices to charge-stripping and electromagnetic shielding,etc.However,large-area flexible close-stacked graphene nanofilms with a wide thickness range have yet to be reported.Here,we report a polyacrylonitrile-assisted’substrate replacement’strategy to fabricate large-area free-standing graphene oxide/polyacrylonitrile nanofilms(lateral size~20 cm).Linear polyacrylonitrile chains-derived nanochannels promote the escape of gases and enable macro-assembled graphene nanofilms(nMAGs)of 50-600 nm thickness following heat treatment at 3,000℃.The uniform nMAGs exhibit 802-1,540 cm^(2)V-1s-1carrier mobility,4.3-4.7 ps carrier lifetime,and>1,581 W m^(-1)K^(-1)thermal conductivity(n MAG-assembled 10μm-thick films,mMAGs).nMAGs are highly flexible and show no structure damage even after 1.0×10^(5)cycles of folding-unfolding.Furthermore,n MAGs broaden the detection region of graphene/silicon heterojunction from near-infrared to mid-infrared and demonstrate higher absolute electromagnetic interference(EMI)shielding effectiveness than state-of-the-art EMI materials of the same thickness.These results are expected to lead to the broad applications of such bulk nanofilms,especially as micro/nanoelectronic and optoelectronic platforms.
基金This work was supported by a state contract with the IT SB RAS№121031800217-8.
文摘The study deals with a new regenerative air heat exchanger with an intermediate heat carrier used in the systems of room ventilation.A physical and mathematical model of the heat transfer process is proposed.The influence of design and operating parameters on the temperature efficiency of the heat exchanger is analyzed.The possibility of a significant increase in its efficiency with a decrease in the packing diameter is shown.As a result of calculations,it was found that with a decrease in the filling height,the maximum temperature efficiency shifted towards a decrease in the air flow rate from its value determined from the equality of water equivalents of liquid and air.
文摘This paper deals with the radiation effects of different kinds ofradiant carriers used in making far infrared textile materials.From two radiation experiments,methods of testing radiation ef-fects of carriers have been found,results of the experiments arediscussed.Finally,some conclusions for choosing appropriateradiant carrier are drawn.
