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CFD simulation of ammonia-based CO_2 absorption in a spray column 被引量:1
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作者 赵杰 金保昇 徐寅 《Journal of Southeast University(English Edition)》 EI CAS 2015年第4期479-488,共10页
A comprehensive computational fluid dynamics(CFD) model is developed based on the gas-liquid two-phase hydrodynamics,gas-liquid mass-transfer theory and chemical reaction kinetics,and the ammonia-based CO2 absorptio... A comprehensive computational fluid dynamics(CFD) model is developed based on the gas-liquid two-phase hydrodynamics,gas-liquid mass-transfer theory and chemical reaction kinetics,and the ammonia-based CO2 absorption in a spray column is numerically studied.The Euler-Lagrange model is applied to describe the behavior of gas-liquid twophase flowand heat transfer.The dual-film theory and related correlations are adopted to model the gas-liquid mass transfer and chemical absorption process.The volatilization model of multi-component droplet is utilized to account for ammonia slippage.The effect of operation parameters on CO2 removal efficiency is numerically studied.The results showa good agreement with the previous experimental data,proving the validity of the proposed model.The profile studies of gasphase velocity and CO2 concentration suggest that the flowfield has a significant impact on the CO2 concentration field.Also,the local CO2 absorption rate is influenced by both local turbulence and the local liquid-gas ratio.Furthermore,the velocity field of gas phase is optimized by the method of adjusting the orifice plate,and the results showthat the CO2 removal efficiency is improved by approximately 4%. 展开更多
关键词 CO_2 absorption spray column computational fluid dynamics(CFD) aqueous ammonia
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CO_2 absorption into a phase change absorbent: Water-lean potassium prolinate/ethanol solution 被引量:8
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作者 Yangyang Bian Shufeng Shen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第11期2318-2326,共9页
Phase change solvents are attractive energy-efficient absorbents for carbon dioxide(CO_2) capture due to CO_2-rich phase formation. Potassium prolinate + water + ethanol(ProK/W/Eth) solution has shown good capture cha... Phase change solvents are attractive energy-efficient absorbents for carbon dioxide(CO_2) capture due to CO_2-rich phase formation. Potassium prolinate + water + ethanol(ProK/W/Eth) solution has shown good capture characteristics as a promising one in our previous work. In this work, absorption rate of CO_2, solubility of N2 O,and heat of absorption for ProK/W/Eth solution were investigated using a stirred cell reactor and a CPA201 reaction calorimeter and these results were also compared with the aqueous ProK and 30 mass% MEA solutions.Using ethanol as a solvent can substantially increase the CO_2 physical solubility and the absorption rate of CO_2 in ProK/W/Eth solutions is far higher than that in aqueous 30 mass% MEA solutions especially at a low CO_2 loading range. Solid precipitation, obtained from the liquid-to-solid phase change absorption, was analyzed by13 C NMR and DSC-TGA. The enthalpy change for ProK/W/Eth solutions at various CO_2 loading was also discussed. 展开更多
关键词 CO2 absorption Phase CHANGE ABSORBENT POTASSIUM prolinate ETHANOL Heat of absorption
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Structural and microwave absorption properties of CoFe_(2)O_(4)/residual carbon composites
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作者 Yuanchun Zhang Shengtao Gao +3 位作者 Xingzhao Zhang Dacheng Ma Chuanlei Zhu Jun He 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期221-232,共12页
Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary society.In this work,CoFe_(2)O_... Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary society.In this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal method.Various mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these composites.Consequently,compared with pure residual carbon materials,this composite offers superior capabilities in microwave absorption.At 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 mm.Moreover,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of 1.18mm.This study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality. 展开更多
关键词 coal gasification slag residual carbon hydrothermal method microwave absorption CoFe_(2)O_(4)
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Designing Electronic Structures of Multiscale Helical Converters for Tailored Ultrabroad Electromagnetic Absorption
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作者 Zhaobo Feng Chongbo Liu +7 位作者 Xin Li Guangsheng Luo Naixin Zhai Ruizhe Hu Jing Lin Jinbin Peng Yuhui Peng Renchao Che 《Nano-Micro Letters》 SCIE EI CAS 2025年第1期439-455,共17页
Atomic-scale doping strategies and structure design play pivotal roles in tailoring the electronic structure and physicochemical property of electromagnetic wave absorption(EMWA)materials.However,the relationship betw... Atomic-scale doping strategies and structure design play pivotal roles in tailoring the electronic structure and physicochemical property of electromagnetic wave absorption(EMWA)materials.However,the relationship between configuration and electromagnetic(EM)loss mechanism has remained elusive.Herein,drawing inspiration from the DNA transcription process,we report the successful synthesis of novel in situ Mn/N co-doped helical carbon nanotubes with ultrabroad EMWA capability.Theoretical calculation and EM simulation confirm that the orbital coupling and spin polarization of the Mn–N4–C configuration,along with cross polarization generated by the helical structure,endow the helical converters with enhanced EM loss.As a result,HMC-8 demonstrates outstanding EMWA performance,achieving a minimum reflection loss of−63.13 dB at an ultralow thickness of 1.29 mm.Through precise tuning of the graphite domain size,HMC-7 achieves an effective absorption bandwidth(EAB)of 6.08 GHz at 2.02 mm thickness.Furthermore,constructing macroscale gradient metamaterials enables an ultrabroadband EAB of 12.16 GHz at a thickness of only 5.00 mm,with the maximum radar cross section reduction value reaching 36.4 dB m2.This innovative approach not only advances the understanding of metal–nonmetal co-doping but also realizes broadband EMWA,thus contributing to the development of EMWA mechanisms and applications. 展开更多
关键词 Metal-nonmetal co-doping 3d-2p orbital coupling Spin polarization Helical structure Broadband EM wave absorption
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Removal characteristics of CO_2 using aqueous MEA/AMP solutions in the absorption and regeneration process 被引量:16
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作者 Won-Joon Choi Jong-Beom Seo +2 位作者 Sang-Yong Jang Jong-Hyeon Jung Kwang-Joong Oh 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第7期907-913,共7页
The carbon dioxide (CO2) removal efficiency, reaction rate, and CO2 loading into aqueous blended monoethanolamine (MEA) + 2-amino-2-methyl-l-propanol (AMP) solutions to enhance absorption characteristics of MEA... The carbon dioxide (CO2) removal efficiency, reaction rate, and CO2 loading into aqueous blended monoethanolamine (MEA) + 2-amino-2-methyl-l-propanol (AMP) solutions to enhance absorption characteristics of MEA and AMP were carried out by the absorption/regeneration process. As a result, compared to aqueous MEA and AMP solutions, aqueous blended MEA + AMP solutions have a higher CO2 loading than MEA and a higher reaction rate than AMP. The CO2 loading of rich amine of aqueous 18 wt.% MEA + 12 wt.% AMP solution was 0.62 mol CO2/mol amine, which is 51.2% more than 30 wt.% MEA (0.41 mol CO2/mol amine). Consequently, blending MEA and AMP could be an effective way to design considering economical efficiency and used to operate absorber for a long time. 展开更多
关键词 carbon dioxide MONOETHANOLAMINE 2-amino-2-methyl-1-propanol absorption regeneration
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Absorption characteristics of new solvent based on a blend of AMP and 1,8-diamino-p-menthane for CO_2 absorption 被引量:2
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作者 Sang-Sup Lee Seong-Man Mun +3 位作者 Won-Joon Choi Byoung-Moo Min Sang-Won Cho Kwang-Joong Oh 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2012年第5期897-902,共6页
Aqueous 1,8-diamino-p-menthane (KIER-C3) and commercially available amine solutions were tested for CO2 absorption. A 2-amino-2-methyl-1-propanol (AMP) solution with an addition of KIER-C3 showed 9.3% and 31.6% hi... Aqueous 1,8-diamino-p-menthane (KIER-C3) and commercially available amine solutions were tested for CO2 absorption. A 2-amino-2-methyl-1-propanol (AMP) solution with an addition of KIER-C3 showed 9.3% and 31.6% higher absorption rate for CO2 than the AMP solution with an addition of monoethanolamine (MEA) and ammonia (NH3), respectively. The reaction rate constant for CO2 absorption by the AMP/KIER-C3 solution was determined by the following equation: k2,AMP/C3 = 7.702×106 exp (-2248.03/T). A CO2 loading ratio of the AMP/KIER-C3 solution was also 2 and 3.4-times higher than that of the AMP/NH3 solution and the AMP/MEA solution, respectively. Based on the experimental results, KIER-C3 may be used as an excellent additive to increase CO2 absorption capability of AMP. 展开更多
关键词 carbon dioxide absorption rate and capacity 1 8-diamino-p-menthane 2-amino-2-methyl-1-propanol
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Heat of absorption of CO_2 in aqueous N,N-diethylethanolamine+ N-methyl-1,3-propanediamine solutions at 313 K 被引量:3
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作者 Katarzyna Sobala Hanna Kierzkowska-Pawlak 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第3期628-633,共6页
Differential heat of absorption of CO_2 in aqueous solutions of N,N-diethylethanolamine(DEEA) and activated DEEA solutions up to a total concentration of 2 mol·L^(-1) was measured as a function of CO_2 loading at... Differential heat of absorption of CO_2 in aqueous solutions of N,N-diethylethanolamine(DEEA) and activated DEEA solutions up to a total concentration of 2 mol·L^(-1) was measured as a function of CO_2 loading at 313.15 K using a reaction calorimeter. In order to analyze the performance of N-methyl-1,3-propanediamine(MAPA)as an activator, DEEA blended solutions containing 0.05, 0.1 and 0.2 mol·L^(-1) MAPA were studied. The heat of CO_2 absorption in single DEEA solutions was unaffected by changing the DEEA concentration in the range of(0.5–2) mol·L^(-1). On the other hand, increasing the concentration of MAPA in aqueous amine mixtures of(DEEA + MAPA) raised the heat of absorption. 展开更多
关键词 CO2 CAPTURE Differential heat of absorption N N-diethylethanolamine N-methyl-1 3-propanediamine AMINE blends
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Removal of high concentration CO_2 from natural gas at elevated pressure via absorption process in packed column 被引量:3
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作者 L.S.Tan K.K.Lau +1 位作者 M.A.Bustam A.M.Shariff 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2012年第1期7-10,共4页
Carbon dioxide (CO2) removal is an essential step in natural gas (NG) processing to provide high quality gas stream products and minimize operational difficulties. This preliminary study alms to investigate the re... Carbon dioxide (CO2) removal is an essential step in natural gas (NG) processing to provide high quality gas stream products and minimize operational difficulties. This preliminary study alms to investigate the removal of CO2 at high concentration level from the mixture of CO2-NG gas stream at elevated pressure via absorption process. This is to explore the possibility of exploring high CO2 content natural gas reserves by treatment at offshore platform. A mixed amine solvent, Stonvent-II, was used for the absorption of approximately 75 vol% CO2 in CO2-NG stream at a pressure of 10 barg. The initial solvent temperature was varied in order to study the impact of initial temperature on the absorption performance. Preliminary study at temperatures of 35 ℃ and 45 ℃ indicates that Stonvent-II was able to perform almost 100% removal of CO2 under both conditions. However, the CO2 absorption effect took place faster when the initial liquid temperature was lower. This is because when the initial liquid temperature is high, the temperature increase in the packing bed caused by the reaction heat is high which impacts the efficiency of absorption negatively. 展开更多
关键词 CO2 capture absorption packed column AMINE mild pressures
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Simulation and energy performance assessment of CO_2 removal from crude synthetic natural gas via physical absorption process 被引量:2
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作者 Wanjun Guo Fei Feng +2 位作者 Guohui Song Jun Xiao Laihong Shen 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2012年第6期633-638,共6页
The paper presents an energy performance assessment of CO2 removal for crude synthetic natural gas (SNG) upgrade by Selexol absorption process. A simplified process simulation of the Selexol process concerning power... The paper presents an energy performance assessment of CO2 removal for crude synthetic natural gas (SNG) upgrade by Selexol absorption process. A simplified process simulation of the Selexol process concerning power requirement and separation performance was developed. The assessment indicates that less pressure difference between crude SNG and absorption pressure favors the energy performance of CO2 removal process. When both crude SNG and absorption pressures are 20 bar, CO2 removal process has the best energy performance. The optimal specific power consumption of the CO2 removal process is 566 kJ/kgCO2. The sensitivity analysis shows that the CO2 removal efficiency would significantly influence the total power consumption of the removal process, as well as higher heating value (HHV) and CO2 content in SNG. However, the specific power consumption excluding crude SNG and SNG compressions changes little with the variance of CO2 removal efficiency. If by-product CO2 is compressed for CO2 capture, the process would turn into a CO2-sink for the atmosphere. Correspondingly, an increase of 281 kJ/kgCO2 in specific power consumption is required for compressing the separated CO2. 展开更多
关键词 CO2 removal physical absorption synthetic natural gas power consumption
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Enhancing electromagnetic wave absorption with core‐shell structured SiO_(2)@MXene@MoS_(2) nanospheres 被引量:1
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作者 Xuewen Jiang Qian Wang +7 位作者 Limeng Song Hongxia Lu Hongliang Xu Gang Shao Hailong Wang Rui Zhang Changan Wang Bingbing Fan 《Carbon Energy》 SCIE EI CAS CSCD 2024年第8期90-104,共15页
Material composition and structural design are important factors influencing the electromagnetic wave(EMW)absorption performance of materials.To alleviate the impedance mismatch attributed to the high dielectric const... Material composition and structural design are important factors influencing the electromagnetic wave(EMW)absorption performance of materials.To alleviate the impedance mismatch attributed to the high dielectric constant of Ti_(3)C_(2)T_(x)MXene,we have successfully synthesized core‐shell structured SiO_(2)@MXene@MoS_(2)nanospheres.This architecture,comprising SiO_(2) as the core,MXene as the intermediate layer,and MoS_(2) as the outer shell,is achieved through an electrostatic self‐assembly method combined with a hydrothermal process.This complex core‐shell structure not only provides a variety of loss mechanisms that effectively dissipate electromagnetic energy but also prevents self‐aggregation of MXene and MoS_(2) nanosheets.Notably,the synergistic combination of SiO_(2) and MoS_(2) with highly conductive MXene enables the suitable dielectric constant of the composites,ensuring optimal impedance matching.Therefore,the core‐shell structured SiO_(2)@MXene@MoS_(2) nanospheres exhibit excellent EMW absorption performance,featuring a remarkable minimum reflection loss(RL_(min))of−52.11 dB(2.4 mm).It is noteworthy that these nanospheres achieve an ultra‐wide effective absorption bandwidth(EAB)of 6.72 GHz.This work provides a novel approach for designing and synthesizing high‐performance EMW absorbers characterized by“wide bandwidth and strong reflection loss.” 展开更多
关键词 core‐shell structure electromagnetic wave absorption multiloss mechanism SiO_(2)@MXene@MoS_(2)
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Mixed‑Dimensional Assembly Strategy to Construct Reduced Graphene Oxide/Carbon Foams Heterostructures for Microwave Absorption,Anti‑Corrosion and Thermal Insulation 被引量:2
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作者 Beibei Zhan Yunpeng Qu +8 位作者 Xiaosi Qi Junfei Ding Jiao‑jing Shao Xiu Gong Jing‑Liang Yang Yanli Chen Qiong Peng Wei Zhong Hualiang Lv 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第11期1-18,共18页
Considering the serious electromagnetic wave(EMW)pollution problems and complex application condition,there is a pressing need to amalgamate multiple functionalities within a single substance.However,the effective int... Considering the serious electromagnetic wave(EMW)pollution problems and complex application condition,there is a pressing need to amalgamate multiple functionalities within a single substance.However,the effective integration of diverse functions into designed EMW absorption materials still faces the huge challenges.Herein,reduced graphene oxide/carbon foams(RGO/CFs)with two-dimensional/three-dimensional(2D/3D)van der Waals(vdWs)heterostructures were meticulously engineered and synthesized utilizing an efficient methodology involving freeze-drying,immersing absorption,secondary freeze-drying,followed by carbonization treatment.Thanks to their excellent linkage effect of amplified dielectric loss and optimized impedance matching,the designed 2D/3D RGO/CFs vdWs heterostructures demonstrated commendable EMW absorption performances,achieving a broad absorption bandwidth of 6.2 GHz and a reflection loss of-50.58 dB with the low matching thicknesses.Furthermore,the obtained 2D/3D RGO/CFs vdWs heterostructures also displayed the significant radar stealth properties,good corrosion resistance performances as well as outstanding thermal insulation capabilities,displaying the great potential in complex and variable environments.Accordingly,this work not only demonstrated a straightforward method for fabricating 2D/3D vdWs heterostructures,but also outlined a powerful mixeddimensional assembly strategy for engineering multifunctional foams for electromagnetic protection,aerospace and other complex conditions. 展开更多
关键词 Multifunctionality Reduced graphene oxide/carbon foams 2D/3D van der Waals heterostructures Electromagnetic wave absorption Thermal insulation
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Experimental Study of the Absorption and Regeneration Performance of Several Candidate Solvents for PostCombustion CO_2 Capture
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作者 Gao Jie Chen Xin +3 位作者 Tong Ming Kang Wanzhong Zhou Yanbo Lu Jun 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2017年第4期55-64,共10页
At present monoethanolamine(MEA) remains as the standard industrial solvent for CO_2 capture processes. But due to the degradation and high energy consumption problems of MEA, new efficient solvents should be found. I... At present monoethanolamine(MEA) remains as the standard industrial solvent for CO_2 capture processes. But due to the degradation and high energy consumption problems of MEA, new efficient solvents should be found. In the present work, the absorption and regeneration performance of a hybrid solvent MEA-methanol was studied and compared to the aqueous solutions of monoethanolamine(MEA), diethanolamine(DEA) and triethanolamine(TEA) in a bubbling reactor. Also the performance of MEA-methanol solutions(including the absorption performance, regeneration performance,cyclic absorption performance, density and viscosity) was studied with different MEA concentrations. A pilot-plant CO_2 capture test bed was used to study the potential of MEA-methanol to replace aqueous MEA in industrial use. The results showed that the initial absorption rate of MEA-methanol solvent is the fastest compared with other solvents. The 30% MEA-methanol had a faster mass transfer coefficient, a higher CO_2 absorption efficiency and a lower regeneration energy consumption than aqueous MEA. And through the study of the reaction heat of CO_2 into MEA-methanol and aqueous MEA,it can be concluded that the desorption heat of rich MEA-methanol is only about 30% of rich aqueous MEA solvent in the regeneration process which showed that 30% MEA-methanol solvent is a promising candidate for CO_2 capture. 展开更多
关键词 MEA MEA-methanol post combustion CO2 CAPTURE absorption REGENERATION
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Visual experimental study of nanofluids application to promote CO_(2) absorption in a bubble column
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作者 Shangyuan Cheng Guisheng Qi +1 位作者 Yuliang Li Yixuan Yang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第3期228-237,共10页
The addition of dispersed-phase nanoparticles in the liquid phase can enhance the gas-liquid transfer process as the suspended nanoparticles affect the transfer process inside the fluid through microdisturbance or mic... The addition of dispersed-phase nanoparticles in the liquid phase can enhance the gas-liquid transfer process as the suspended nanoparticles affect the transfer process inside the fluid through microdisturbance or micro-convection effects.In this article,a high-speed digital camera was used to visualize the bubble behavior of CO_(2) in pure water and nanofluids to examine the effects of CO_(2) gas flow rate,nanoparticle solid content and type on the bubble behavior in the fluids.The CO_(2) absorption performance in three water-based nanofluids were compared in a bubbler.And the mass transfer characteristics during CO_(2) bubble absorption and the reasons for the enhanced gas-liquid mass transfer effect of nanoparticles were analyzed.The results showed that the presence of nanoparticles affected the formation process of bubbles in the fluid,shortened the bubble detachment time,reduced the detachment diameter,effectively increased the gas-liquid contact area,and improved the bubbles detachment frequency.The system with MCM-41 corresponded to a higher overall mass transfer coefficient.Uncalined MCM-41 contained surfactant that enhanced foaming behavior in water.This prevented the transfer of CO_(2) to some extent,and the CO_(2) absorption by uncalined MCM-41/H_(2)O was 5.34%higher than that by pure water.Compared with SiO_(2) nanoparticles with the same particle size and the same composition,MCM-41 had a higher adsorption capacity and better hydrophilicity due to its larger specific surface area and rich porous structure,which was more favorable to accelerate the collision between nanoparticles and CO_(2) bubbles to cause micro-convection.Under the condition of 0.1%(mass)solid content,the enhancement of CO_(2) absorption process by MCM-41 nanoparticles was more significant and improved by 16.9%compared with pure water. 展开更多
关键词 Nanofluids CO_(2) absorption Mass transfer MCM-41 Bubble column
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An integrated technology for the absorption and utilization of CO_(2)in alkanolamine solution for the preparation of BaCO_(3)in a high-gravity environment
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作者 Kangrui Nie Ruize Shang +3 位作者 Fuming Miao Liuxiang Wang Youzhi Liu Weizhou Jiao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第8期117-125,共9页
In this study,an integrated technology is proposed for the absorption and utilization of CO_(2)in alkanolamine solution for the preparation of BaCO_(3)in a high-gravity environment.The effects of absorbent type,high-g... In this study,an integrated technology is proposed for the absorption and utilization of CO_(2)in alkanolamine solution for the preparation of BaCO_(3)in a high-gravity environment.The effects of absorbent type,high-gravity factor,gas/liquid ratio,and initial BaCl2concentration on the absorption rate and amount of CO_(2)and the preparation of BaCO_(3)are investigated.The results reveal that the absorption rate and amount of CO_(2)follow the order of ethyl alkanolamine(MEA)>diethanol amine(DEA)>N-methyldiethanolamine(MDEA),and thus MEA is the most effective absorbent for CO_(2)absorption.The absorption rate and amount of CO_(2)under high gravity are higher than that under normal gravity.Notably,the absorption rate at 75 min under high gravity is approximately 2 times that under normal gravity.This is because the centrifugal force resulting from the high-speed rotation of the packing can greatly increase gas-liquid mass transfer and micromixing.The particle size of BaCO_(3)prepared in the rotating packed bed is in the range of 57.2—89 nm,which is much smaller than that prepared in the bubbling reactor(>100.3 nm),and it also has higher purity(99.6%)and larger specific surface area(14.119 m^(2)·g^(-1)).It is concluded that the high-gravity technology has the potential to increase the absorption and utilization of CO_(2)in alkanolamine solution for the preparation of BaCO_(3).This study provides new insights into carbon emissions reduction and carbon utilization. 展开更多
关键词 High-gravity technology Wet absorption CO_(2)capture Enhanced mass transfer CO_(2)utilization Barium carbonate
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Highly enhanced UV absorption and light emission of monolayer WS_(2)through hybridization with Ti_(2)N MXene quantum dots and g-C_(3)N_(4)quantum dots
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作者 Anir S.Sharbirin Rebekah E.Kong +5 位作者 Wendy B.Mato Trang Thu Tran Eunji Lee Jolene W.P.Khor Afrizal L.Fadli Jeongyong Kim 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第6期31-39,共9页
Two-dimensional(2D)transition metal dichalcogenides(TMD)are atomically thin semiconductors with promising optoelectronic applications across the visible spectrum.However,their intrinsically weak light absorption and t... Two-dimensional(2D)transition metal dichalcogenides(TMD)are atomically thin semiconductors with promising optoelectronic applications across the visible spectrum.However,their intrinsically weak light absorption and the low photoluminescence quantum yield(PLQY)restrict their performance and potential use,especially in ultraviolet(UV)wavelength light ranges.Quantum dots(QD)derived from 2D materials(2D/QD)provide efficient light absorption and emission of which energy can be tuned for desirable light wavelength.In this study,we greatly enhanced the photon absorption and PLQY of monolayer(1L)tungsten disulfide(WS_(2))in the UV range via hybridization with 2D/QD,particularly titanium nitride MXene QD(Ti_(2)N MQD)and graphitic carbon nitride QD(GCNQD).With the hybridization of MQD or GCNQD,1LWS_(2)showed a maximum PL enhancement by 15 times with 300 nm wavelength excitation,while no noticeable enhancement was observed when the excitation photon energy was less than the bandgap of the QD,indicating that UV absorption by the QD played a crucial role in enhancing the light emission of 1L-WS_(2)in our 0D/2D hybrid system.Our findings present a convenient method for enhancing the photo-response of 1L-WS_(2)to UV light and offer exciting possibilities for harvesting UV energy using 1L-TMD. 展开更多
关键词 monolayer TMD WS_(2) 2D-derived quantum dots UV absorption energy transfer
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Synthesis and microwave absorption performance of heat-treated RF/SiO_(2)aerogels
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作者 Xinli Ye Hao Yu +4 位作者 Kai Zheng Shan Li Xiaomin Ma Bangxiao Mao Junxiong Zhang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第4期177-186,共10页
The well-designed composite with satisfactory electromagnetic microwave absorption at high temperatures remains a serious challenge.Herein,we fabricated a resorcinol-formaldehyde/silica dioxide composite aerogel(RF/Si... The well-designed composite with satisfactory electromagnetic microwave absorption at high temperatures remains a serious challenge.Herein,we fabricated a resorcinol-formaldehyde/silica dioxide composite aerogel(RF/SiO_(2))with a three-dimensional network structure using sol-gel,atmospheric pressure drying technique as well as heat-treated processes to achieve enhanced microwave absorption capabilities in the low frequency range.The pristine RF/SiO_(2)aerogel presented a typical micropores structure with a surface area,porous volume,and density of 146.82 m^(2)/g,62.40%,and 0.28 cm^(3)/g,respectively.Remarkably,the RF/SiO_(2)aerogel showed an effective absorption bandwidth of 3.56 GHz and a minimum reflection loss value of-46.10 d B at 2.25 mm after being heat-treated at 1500°C,while the maximum effective absorption bandwidth was 3.60 GHz at 2.30 mm.The intricate three-dimensional networks possessed remarkable impedance matching,multiple attenuation mechanisms,interfacial polarization,and dielectric loss,which were attributed to the exceptional ability to absorb electromagnetic microwaves.It offered a fresh approach to creating adaptable and effective microwave absorption materials in military defense. 展开更多
关键词 RF/SiO_(2) AEROGEL Heat-treated Microwave absorption
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Low-frequency and dual-band microwave absorption properties of novel VB-group disulphides(3R–TaS_(2))nanosheets
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作者 Liquan Fan Honglin Ai +8 位作者 Meiye Jiao Yao Li Yongheng Jin Yiru Fu Jing Wang Yuwei Wang Deqing Zhang Guangping Zheng Junye Cheng 《Nano Materials Science》 EI CAS CSCD 2024年第5期635-646,共12页
As electromagnetic technology advances and demand for electronic devices grows,concerns about electromagnetic pollution intensify.This has spurred focused research on innovative electromagnetic absorbers,particularly ... As electromagnetic technology advances and demand for electronic devices grows,concerns about electromagnetic pollution intensify.This has spurred focused research on innovative electromagnetic absorbers,particularly chalcogenides,noted for their superior absorption capabilities.In this study,we successfully synthesize 3R–TaS_(2)nanosheets using a straightforward calcination method for the first time.These nanosheets exhibit significant absorption capabilities in both the C-band(4–8 GHz)and Ku-band(12–18 GHz)frequency ranges.By optimizing the calcination process,the complex permittivity of TaS_(2)is enhanced,specifically for those synthesized at 1000℃for 24 h.The nanosheets possess dual-band absorption properties,with a notable minimum reflection loss(RLmin)of41.4 dB in the C-band,and an average absorption intensity exceeding 10 dB in C-and Ku-bands,in the absorbers with a thickness of 5.6 mm.Additionally,the 3R–TaS_(2)nanosheets are demonstrated to have an effective absorption bandwidth of 5.04 GHz(3.84–8.88 GHz)in the absorbers with thicknesses of 3.5–5.5 mm.The results highlight the multiple reflection effects in 3R–TaS_(2)as caused by their stacked structures,which could be promising low-frequency absorbers. 展开更多
关键词 3R-TaS_(2) NANOSHEETS Electromagnetic wave absorption Reflection loss
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Construction of enhanced multi-polarization and high performance electromagnetic wave absorption by self-growing ZnFe_(2)O_(4)on Cu_(9)S_(5)
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作者 Wenxiong Chen Honglong Xing 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第8期1922-1934,共13页
The development of 3D structural composites with electromagnetic(EM)wave absorption could attenuate EM waves.Herein,magnetized flower-like Cu_(9)S_(5)/ZnFe_(2)O_(4)composites were fabricated through a multistep hydrot... The development of 3D structural composites with electromagnetic(EM)wave absorption could attenuate EM waves.Herein,magnetized flower-like Cu_(9)S_(5)/ZnFe_(2)O_(4)composites were fabricated through a multistep hydrothermal method.The crystallographic and surface phase chemical information,morphological structure,and magnetic and EM parameters of the composites were analyzed.The prepared Cu_(9)S_(5)/ZnFe_(2)O_(4)composites have multiple loss paths for EM waves and present an overall 3D flower-like structure.The Cu_(9)S_(5)/ZnFe_(2)O_(4)composites exhibit a minimum reflection loss of-54.38 dB and a broad effective absorption bandwidth of 5.92 GHz.Through magnetization,ZnFe_(2)O_(4)particles are self-assembled and grown on the surfaces of Cu_(9)S_(5).Such a modification is conducive to the generation of additional cross-linking contact sites and the effective introduction of a large number of phase interfaces,crystalline defects,special three-dimensional flower-like structures,and magneto-electrical coupling loss effects.Moreover,the synergistic effect of multiple loss strategies effectively improves EM wave absorption by the material.This work can provide a strategy for the use of magnetizationmodified sulfide composite functional materials in EM wave absorption. 展开更多
关键词 self-assembled material electromagnetic wave absorption enhanced multi-polarization effect Cu_(9)S_(5)/ZnFe_(2)O_(4)composites radar cross-section
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PRP点注联合CO_2点阵激光治疗烧伤后增生瘢痕的效果观察
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作者 邓婉斯 李宁静 翁学君 《中文科技期刊数据库(引文版)医药卫生》 2024年第10期0025-0028,共4页
观察自体富小板血浆(PRP)点注技术与CO_2点阵激光技术联合治疗烧伤后增生瘢痕的临床疗效和安全性。方法 将在本院烧伤整形科就诊的烧伤后并发瘢痕增生患者列为本次研究对象,依据访谈和研究知情同意书签署结果将知情同意参与本次研究的3... 观察自体富小板血浆(PRP)点注技术与CO_2点阵激光技术联合治疗烧伤后增生瘢痕的临床疗效和安全性。方法 将在本院烧伤整形科就诊的烧伤后并发瘢痕增生患者列为本次研究对象,依据访谈和研究知情同意书签署结果将知情同意参与本次研究的30例患者纳为观察组,并选择未参与本研究,接受常规治疗的30例患者作为对照组。对照组按照瘢痕增生常规给予CO_2点阵激光治疗;观察组采用自体PRP微针点注技术联合CO_2点阵激光治疗。每2个月治疗一次,连续治疗3次为一疗程,观察并记录治疗前后两组的皮损治疗效果、温哥华瘢痕量表(VSS)评分以及治疗过程中的不良反应发生率。结果 观察组统计共90.00%的治疗有效率高于对照组统计66.67%的治疗有效率,组间统计学差异明显(P<0.05);两组到诊时的首次VSS测试结果,平均得分相近(P>0.05),一疗程后,两组的VSS评分均有明显下降,观察组的下降幅度大于对照组(P<0.01);治疗过程中,观察组的不良反应发生率明显低于对照组(P<0.05)。结论 自体PRP点注技术联合CO_2点阵激光治疗烧伤后瘢痕增生,不仅疗效显著,且安全性高,还能有效改善VSS评分,值得临床推广用。 展开更多
关键词 PRP CO_2点阵激光 瘢痕增生 疗效 不良反应
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加气灌溉对番茄地土壤CO_2排放的调控效应 被引量:12
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作者 陈慧 侯会静 +2 位作者 蔡焕杰 朱艳 王超 《中国农业科学》 CAS CSCD 北大核心 2016年第17期3380-3390,共11页
【目的】CO_2是大气中最重要的温室气体,对全球变暖起到重要作用。加气灌溉通过改善土壤通气状态,提高作物产量、品质及水分利用效率等已被大量研究证实,然而加气灌溉引起的土壤环境效应研究较少,且通过静态箱法系统地研究加气灌溉对设... 【目的】CO_2是大气中最重要的温室气体,对全球变暖起到重要作用。加气灌溉通过改善土壤通气状态,提高作物产量、品质及水分利用效率等已被大量研究证实,然而加气灌溉引起的土壤环境效应研究较少,且通过静态箱法系统地研究加气灌溉对设施菜地土壤CO_2排放影响的研究尚未见报道。因此,分析加气灌溉对土壤CO_2排放的影响,对评估加气灌溉技术的农田生态效应具有重要作用。【方法】供试番茄品种为‘飞越’,通过温室小区试验利用文丘里计作为加气设备,通过地下滴灌系统实现水气结合的加气灌溉方式。采用静态箱-气相色谱法对温室番茄地土壤CO_2排放进行原位观测,研究加气灌溉对土壤CO_2排放的调控效应。试验按灌水量(充分灌溉、亏缺灌溉)和加气(加气、不加气)的双因素设计,设置4个处理,分别为:加气亏缺灌溉(AI1)、不加气亏缺灌溉(CK1)、加气充分灌溉(AI2)和不加气充分灌溉(CK2),每个处理3个重复。研究加气和充分灌溉较不加气和亏缺灌溉对温室番茄地土壤CO_2排放、土壤水分、土壤温度和土壤有机碳的影响。【结果】番茄整个生育期,不同加气灌溉模式下土壤CO_2排放通量随移植后天数增加呈波动性变化,总体呈现先增加后减小的趋势,峰值均出现在番茄开花坐果期。加气和充分灌溉处理较对应的不加气和亏缺灌溉处理增加了番茄整个生育期土壤CO_2平均排放通量和排放量,但差异不显著(P>0.05)。AI1、CK1、AI2和CK2处理土壤CO_2平均排放通量分别为229.31、193.66、259.10和224.76 mg·m^(-2)·h^(-1),且以AI2处理土壤CO_2排放量最大(6 383.43 kg·hm^(-2)),分别是AI1、CK1和CK2处理的1.12、1.32和1.13倍。此外,不同加气灌溉模式下土壤充水孔隙率(WFPS)在番茄整个生育期内大致呈下降的趋势;土壤温度(T)大致呈上升的趋势,且同一时刻处理间土壤温度差异较小;而土壤有机碳(SOC)含量呈波动性变化且番茄整个生育期SOC含量变化幅度较小。加气灌溉较对应的不加气灌溉降低了T和WFPS,增加了SOC含量,但差异均不显著(P>0.05);充分灌溉较对应的亏缺灌溉增加了WFPS和SOC,但不显著,对T的影响不一。此外,经相关性分析可知,土壤CO_2排放通量与土壤充水孔隙率呈负相关,与土壤温度和有机碳呈正相关,但相关性均不显著(P>0.05)。【结论】通过温室小区试验得出,加气灌溉增加了土壤CO_2排放,但不显著(P>0.05)。研究结果为评估加气灌溉技术的农田生态效应和设施菜地温室气体减排提供了一定的参考和科学依据。 展开更多
关键词 加气灌溉 CO_2 排放 土壤 番茄 有机碳
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