Exhaust gas temperature is an important factor in NOx, THC and PM emissions of engines. Especially 2D temperature and concentration distribution plays an important role for the engine efficiency. A thermocouple is int...Exhaust gas temperature is an important factor in NOx, THC and PM emissions of engines. Especially 2D temperature and concentration distribution plays an important role for the engine efficiency. A thermocouple is intrinsically a point temperature measurement method and noncontact 2D temperature distribution cannot be attained by thermocouples. Recently, as a measurement technique with high sensitivity and high response, laser diagnostics has been developed and applied to the actual engine combustions. With these engineering developments, transient phenomena such as start-ups and load changes in engines have been gradually elucidated in various conditions. In this study, the theoretical and experimental research has been conducted in order to develop the noncontact and fast response 2D temperature and concentration distribution measurement method. The method is based on a Computed Tomography （CT） method using absorption spectra of water vapor at 1388 nm. It has been demonstrated that the method has been successfully applied to engine exhausts to measure 2D temperature distributions.展开更多
In this work, 16 kinds of [FeCl4]--based magnetic ionic liquids （ILs） with different cation structures have been designed and synthesized, and their structures are characterized by IR and Raman spectroscopy. Then th...In this work, 16 kinds of [FeCl4]--based magnetic ionic liquids （ILs） with different cation structures have been designed and synthesized, and their structures are characterized by IR and Raman spectroscopy. Then the lower critical solution temperature （LCST）-type phase behavior of these magnetic ILs in water is investigated as a function of concentration. It is shown that cat- ion structure, alkyl chain length and molar ratio of FeCl3/chloride IL have a significant influence on the LCST of the mixtures. The phase separation temperature can be tuned efficiently by these factors. Meanwhile, the LCST-type phase separation pro- cess is also investigated by dynamic light scattering. The results support the mechanism that the hydrogen bonds of the [Fefl4]- anion with water have been gradually disrupted to form ILs aggregates with increasing temperature. In addition, the stability of the ILs in water is also examined in some details. These LCST-type phase separation systems may have potential applications in extraction and separation techniques at room temperature.展开更多
Band structure and component content are the key factors for determining the activity of semiconductor heterojunction. In this study, a novel Bi5O7I/BiOBrxI1-x heterostructure was synthesized by a simple hydrobromic ...Band structure and component content are the key factors for determining the activity of semiconductor heterojunction. In this study, a novel Bi5O7I/BiOBrxI1-x heterostructure was synthesized by a simple hydrobromic （HBr） acid etching method through transforming partial of Bi5O7I to I ion doped BiOBr （BiOBrxI1-x） at room temperature without adding extra dopant. Both the band structure and component content of Bi5O7I/BiOBrxI1-x alter with the additive HBr acid. The Bi5O7I/BiOBrxI1-x （S3.0） sample exhibits the best photocatalytic activity, 6 times higher than that of pure Bis071, for the degradation of methyl orange under visible-light （2 〉 420 nm）. The activity enhancement of Bi5O7I/BiOBrxI1-x is primarily ascribed to the improved separation efficiency of photocharges, originated from the adjustable band structure and component content, The significant findings of this paper provide a facile way to construct highly efficient semiconductor heterojunction via playing the synergetic effect of adjustable band struc- ture and component content for purifying organic pollutants in wastewater.展开更多
A thermally tunable terahertz metamaterial absorber(MA) with InS b embedded in a metal-dielectric-metal structure is proposed. The transmission and tuning properties of the proposed metamaterial absorber are analyzed ...A thermally tunable terahertz metamaterial absorber(MA) with InS b embedded in a metal-dielectric-metal structure is proposed. The transmission and tuning properties of the proposed metamaterial absorber are analyzed for the temperature ranging from 160 K to 350 K. The simulated results show that the maximum absorption of the absorber is nearly 99.8% at a full-width at half-maximum(FWHM) of 38 GHz, and the absorption frequency can be dynamically tuned from 0.82 THz to 1.02 THz.展开更多
A terahertz bandpass filter with the sandwich structure consisting of thermally tunable vanadium dioxide(VO2) thin film,silica substrate and subwavelength rectangular Cu hole arrays is designed and theoretically analy...A terahertz bandpass filter with the sandwich structure consisting of thermally tunable vanadium dioxide(VO2) thin film,silica substrate and subwavelength rectangular Cu hole arrays is designed and theoretically analyzed.The results show that the transmittance of the filter can be actively tuned by controlling the temperature of VO2,the narrow band terahertz(THz) waves with the transmittance from 85.2% to 10.5% can be well selected at the frequency of 1.25 THz when the temperature changes from 50 ℃ to 80 ℃,and the maximum modulation depth of this terahertz bandpass filter can achieve 74.7%.展开更多
文摘Exhaust gas temperature is an important factor in NOx, THC and PM emissions of engines. Especially 2D temperature and concentration distribution plays an important role for the engine efficiency. A thermocouple is intrinsically a point temperature measurement method and noncontact 2D temperature distribution cannot be attained by thermocouples. Recently, as a measurement technique with high sensitivity and high response, laser diagnostics has been developed and applied to the actual engine combustions. With these engineering developments, transient phenomena such as start-ups and load changes in engines have been gradually elucidated in various conditions. In this study, the theoretical and experimental research has been conducted in order to develop the noncontact and fast response 2D temperature and concentration distribution measurement method. The method is based on a Computed Tomography （CT） method using absorption spectra of water vapor at 1388 nm. It has been demonstrated that the method has been successfully applied to engine exhausts to measure 2D temperature distributions.
基金supported by the National Natural Science Foundation of China (21473050, 21403060)Program for Innovative Research Team in Science and Technology in University of Henan Province (16IRTSTHN002)+1 种基金Plan for Scientific Innovation Talent of Henan Province of China (144200510004)the Natural Science Research Program of Henan Educational Committee (2010A150014)
文摘In this work, 16 kinds of [FeCl4]--based magnetic ionic liquids （ILs） with different cation structures have been designed and synthesized, and their structures are characterized by IR and Raman spectroscopy. Then the lower critical solution temperature （LCST）-type phase behavior of these magnetic ILs in water is investigated as a function of concentration. It is shown that cat- ion structure, alkyl chain length and molar ratio of FeCl3/chloride IL have a significant influence on the LCST of the mixtures. The phase separation temperature can be tuned efficiently by these factors. Meanwhile, the LCST-type phase separation pro- cess is also investigated by dynamic light scattering. The results support the mechanism that the hydrogen bonds of the [Fefl4]- anion with water have been gradually disrupted to form ILs aggregates with increasing temperature. In addition, the stability of the ILs in water is also examined in some details. These LCST-type phase separation systems may have potential applications in extraction and separation techniques at room temperature.
基金supported by the National Natural Science Foundation of China(51772118,51472005)State Key Laboratory of Structural Chemistry(20160014)+2 种基金Anhui Provincial Natural Science Foundation(1708085MB32)the Natural Science Foundation of Educational Committee of Anhui Province(gxyq ZD2016414,KJ2014B08)Innovation Team of Design and Application of Advanced Energetic Materials
文摘Band structure and component content are the key factors for determining the activity of semiconductor heterojunction. In this study, a novel Bi5O7I/BiOBrxI1-x heterostructure was synthesized by a simple hydrobromic （HBr） acid etching method through transforming partial of Bi5O7I to I ion doped BiOBr （BiOBrxI1-x） at room temperature without adding extra dopant. Both the band structure and component content of Bi5O7I/BiOBrxI1-x alter with the additive HBr acid. The Bi5O7I/BiOBrxI1-x （S3.0） sample exhibits the best photocatalytic activity, 6 times higher than that of pure Bis071, for the degradation of methyl orange under visible-light （2 〉 420 nm）. The activity enhancement of Bi5O7I/BiOBrxI1-x is primarily ascribed to the improved separation efficiency of photocharges, originated from the adjustable band structure and component content, The significant findings of this paper provide a facile way to construct highly efficient semiconductor heterojunction via playing the synergetic effect of adjustable band struc- ture and component content for purifying organic pollutants in wastewater.
基金supported by the National Basic Research Program of China(No.2014CB339800)the National High Technology Research and Development Program of China(No.2011AA010205)the National Natural Science Foundation of China(Nos.61171027 and 10904076)
文摘A thermally tunable terahertz metamaterial absorber(MA) with InS b embedded in a metal-dielectric-metal structure is proposed. The transmission and tuning properties of the proposed metamaterial absorber are analyzed for the temperature ranging from 160 K to 350 K. The simulated results show that the maximum absorption of the absorber is nearly 99.8% at a full-width at half-maximum(FWHM) of 38 GHz, and the absorption frequency can be dynamically tuned from 0.82 THz to 1.02 THz.
基金supported by the National High Technology Research and Development Program of China(No.2011AA010205)the National Natural Science Foundation of China(Nos.61171027 and 10904076)the Tianjin City High School Science&Technology Fund Planning Project(No.20120706)
文摘A terahertz bandpass filter with the sandwich structure consisting of thermally tunable vanadium dioxide(VO2) thin film,silica substrate and subwavelength rectangular Cu hole arrays is designed and theoretically analyzed.The results show that the transmittance of the filter can be actively tuned by controlling the temperature of VO2,the narrow band terahertz(THz) waves with the transmittance from 85.2% to 10.5% can be well selected at the frequency of 1.25 THz when the temperature changes from 50 ℃ to 80 ℃,and the maximum modulation depth of this terahertz bandpass filter can achieve 74.7%.
