A novel vapor-liquid-solid circulating fluidized bed evaporator, meaning for enhancing heat transfer and preventing fouling, is applied to wheat straw black liquor, which is the primary pollutant in China’s papermaki...A novel vapor-liquid-solid circulating fluidized bed evaporator, meaning for enhancing heat transfer and preventing fouling, is applied to wheat straw black liquor, which is the primary pollutant in China’s papermaking industry. It is treated by alkali recovery, in which evaporation is a key process. The experimental results show that the vapor-liquid-solid three-phase boiling heat transfer coefficient is enhanced by 20%～40% than that of vapor-liquid two-phase boiling flow, also, the novel evaporator exhibits an excellent function of fouling prevention.展开更多
Intrinsic time quantum geometrodynamics is a formulation of quantum gravity naturally adapted to 3 + 1 dimensions. In this paper we construct its analogous 2 + 1 formulation, taking note of the mathematical structures...Intrinsic time quantum geometrodynamics is a formulation of quantum gravity naturally adapted to 3 + 1 dimensions. In this paper we construct its analogous 2 + 1 formulation, taking note of the mathematical structures which are preserved. We apply the resulting construction to convert the BTZ black hole metric to ITQG framework. We then modify the BTZ black hole in order to investigate the existence of the P-V criticality in ITQG theory.展开更多
Black phosphorus(BP)is an attractive material for two-dimensional(2D)electronics and optoelectronics given its direct optical band gap in the bulk.However,the vulnerability of BP to oxygen and moisture under ambient c...Black phosphorus(BP)is an attractive material for two-dimensional(2D)electronics and optoelectronics given its direct optical band gap in the bulk.However,the vulnerability of BP to oxygen and moisture under ambient conditions has been a significant impediment for the adoption of this material towards practical applications.This vulnerability has also curtailed the development of additively manufactured,solution processed,ink-jet printed BP devices,which are cost-effective alternatives to lithographically patterned rigid electronics and optoelectronics based on silicon.In this work,we have fabricated stable BP electronic devices on flexible and compliant substrates using low-cost,additive manufacturing techniques with ink-jet printing through scalable chemical exfoliation routes.To address the stability issues with BP,ionic liquids(ILs)were used as a passivation layer on the surface of the BP to minimize oxidative degradation.The enhanced stability of BP was inferred through Raman spectroscopy and scanning probe microscopy techniques,where no observable changes in the A^(1)_(g)and A^(2)_(g)Raman vibrational modes were observed with time for the BP films passivated with ILs over a period of 168 h under ambient conditions.On the other hand,a blue-shift in these Raman modes was evident for unpassivated samples.Atomic probe microscopy measurements clearly revealed the difference in the surface characteristics through localized regions of degradation that intensified with time,which was clearly absent in IL/BP samples.The stability measurements were also conducted in electronic device platforms for IL coated BP devices,where the temperature T dependence of the I_(ds)-V_(ds)characteristic was measured from T~5.4 to 335 K.Prototypical demonstrations of stabilized ILs/BP devices at ambient printed on flexible polyimide substrates were also made.The irradiation with broadband radiation appears to have a significant influence on the electrical behavior of BP,evident through the variation of photocurrent with temperature.Overall,our study shows that by engineering the exfoliation chemistry of BP with the use of ILs,highly concentrated BP inks can be additively manufactured,that present remarkable opportunities for the large-area integration of BP in printed and flexible electronics using low-cost,scalable approaches benefiting from the direct bandgap characteristics of BP in the bulk.展开更多
文摘A novel vapor-liquid-solid circulating fluidized bed evaporator, meaning for enhancing heat transfer and preventing fouling, is applied to wheat straw black liquor, which is the primary pollutant in China’s papermaking industry. It is treated by alkali recovery, in which evaporation is a key process. The experimental results show that the vapor-liquid-solid three-phase boiling heat transfer coefficient is enhanced by 20%～40% than that of vapor-liquid two-phase boiling flow, also, the novel evaporator exhibits an excellent function of fouling prevention.
文摘Intrinsic time quantum geometrodynamics is a formulation of quantum gravity naturally adapted to 3 + 1 dimensions. In this paper we construct its analogous 2 + 1 formulation, taking note of the mathematical structures which are preserved. We apply the resulting construction to convert the BTZ black hole metric to ITQG framework. We then modify the BTZ black hole in order to investigate the existence of the P-V criticality in ITQG theory.
基金the National Science Foundation(No.NSF ECCS 1753933)the Office of Naval Research(ONR)(No.ONR N00014-19-1-2142)that enabled us to pursue this work.
文摘Black phosphorus(BP)is an attractive material for two-dimensional(2D)electronics and optoelectronics given its direct optical band gap in the bulk.However,the vulnerability of BP to oxygen and moisture under ambient conditions has been a significant impediment for the adoption of this material towards practical applications.This vulnerability has also curtailed the development of additively manufactured,solution processed,ink-jet printed BP devices,which are cost-effective alternatives to lithographically patterned rigid electronics and optoelectronics based on silicon.In this work,we have fabricated stable BP electronic devices on flexible and compliant substrates using low-cost,additive manufacturing techniques with ink-jet printing through scalable chemical exfoliation routes.To address the stability issues with BP,ionic liquids(ILs)were used as a passivation layer on the surface of the BP to minimize oxidative degradation.The enhanced stability of BP was inferred through Raman spectroscopy and scanning probe microscopy techniques,where no observable changes in the A^(1)_(g)and A^(2)_(g)Raman vibrational modes were observed with time for the BP films passivated with ILs over a period of 168 h under ambient conditions.On the other hand,a blue-shift in these Raman modes was evident for unpassivated samples.Atomic probe microscopy measurements clearly revealed the difference in the surface characteristics through localized regions of degradation that intensified with time,which was clearly absent in IL/BP samples.The stability measurements were also conducted in electronic device platforms for IL coated BP devices,where the temperature T dependence of the I_(ds)-V_(ds)characteristic was measured from T~5.4 to 335 K.Prototypical demonstrations of stabilized ILs/BP devices at ambient printed on flexible polyimide substrates were also made.The irradiation with broadband radiation appears to have a significant influence on the electrical behavior of BP,evident through the variation of photocurrent with temperature.Overall,our study shows that by engineering the exfoliation chemistry of BP with the use of ILs,highly concentrated BP inks can be additively manufactured,that present remarkable opportunities for the large-area integration of BP in printed and flexible electronics using low-cost,scalable approaches benefiting from the direct bandgap characteristics of BP in the bulk.
