In this paper,the occurrence and development mechanism of strain on the cross-section during the wood drying is explored.Therefore,strain regularity on the cross-section of 50 mm thickness elm(Ulmus rubra)board at the...In this paper,the occurrence and development mechanism of strain on the cross-section during the wood drying is explored.Therefore,strain regularity on the cross-section of 50 mm thickness elm(Ulmus rubra)board at the temperature of 40℃and 80℃is detected via digital image correlation technology.Hence,the difference between tangential and radial strain at surface and core layers was denoted.The results showed that strain distribution in the width direction of the board is uneven.Moreover,a large drying shrinkage strain occurs at the near-core layer,while the maximum strain difference reaches 4.08%.Hence,the surface of the board is cracked along the thickness direction.The radial strain of the board is higher than the tangential strain in the early stage of drying,while these strains are reversed in the later stage of drying.The temperature is related to the difference between the tangential and radial strains of the elm board.These differences at the core layer are larger than those of the surface layer.The conducted research results provide a theoretical basis for process optimization.展开更多
A newly drying technology, intermittent-contact drying of veneer with flexible screen belt (ICD-fbs), was invented and used in poplar veneer drying. Productive test was carried out for validating the practical use of ...A newly drying technology, intermittent-contact drying of veneer with flexible screen belt (ICD-fbs), was invented and used in poplar veneer drying. Productive test was carried out for validating the practical use of this drying method. The test result shows that to dispose flexible screen belts on the two sides of hot board could help steam discharge remarkably. The veneer dried using ICD-fsb method had smooth and level surface, less deformation and warping, even moisture content, and high utilization rate. The time for opening hot board to discharge steam,which, early or late, is a key to obtain good drying result, was determined at the time when the core's temperature of veneer reaches 100℃ (vaporization). Using ICD-fsb method, the shrinking rates in tangent of veneer were from 1.90% to 2.26% for veneer of 0.4 mm in thickness,2.49% to 4.50% for veneer of 1 mm in thickness and 1.34% to 3.30% for veneer of 1.7 mm in thickness, which are much lower than the results obtained by other drying methods. The method of ICD-fsb offers a reliable technological guarantee for solving the deformation problem of veneer drying, especially the deformation of wood from quick-growing plantation.展开更多
Drying technology of angiotensin converting enzyme （ACE） inhibitory peptides derived from bovine casein was investigated. No significance was observed on ACE inhibitory activity of products prepared by spay drying a...Drying technology of angiotensin converting enzyme （ACE） inhibitory peptides derived from bovine casein was investigated. No significance was observed on ACE inhibitory activity of products prepared by spay drying and freeze drying （P〉0.05）. Spay drying was the best drying process for practical industry production. The inlet temperature ranged from 140℃ to 160℃ and the exit temperature ranged from 70 ℃ to 90 ℃ during the spay drying process. Under the optimal conditions, scale-up of angiotensin converted enzyme inhibitory peptide from 1 L to 10 L and the experiment was successively conducted. Peptide yield was 29% and half inhibitory concentration （IC50） was 0.53 g. L^-1.展开更多
The relation between technology parameters and performance index of the wheat three-stage concurrent-flow drying technology is studied by use of quadratic orthogonial rotate combinative experiment design method.The op...The relation between technology parameters and performance index of the wheat three-stage concurrent-flow drying technology is studied by use of quadratic orthogonial rotate combinative experiment design method.The optimum parameters of drying technology are obtained by nonlinear optimize corresponding regression model and test.All experiment was finished in concurrent-flow grain drying experiment table.The results of this study will be significant for designing energy-saving grain drying machine.展开更多
Based on the state of characteristics of dry warming of modern climate changing,the response of growth,output and quality of main economic crops such as cotton,flax and winter rape and characteristic crop such as vini...Based on the state of characteristics of dry warming of modern climate changing,the response of growth,output and quality of main economic crops such as cotton,flax and winter rape and characteristic crop such as vinifera and apple were discussed.The coping technology for climate changing and measurements for serving the agricultural were provided.展开更多
All-solid-state lithium-sulfur batteries(ASSLSBs)employing sulfide solid electrolytes are one of the most promising next-generation energy storage systems due to their potential for higher energy density and safety.Ho...All-solid-state lithium-sulfur batteries(ASSLSBs)employing sulfide solid electrolytes are one of the most promising next-generation energy storage systems due to their potential for higher energy density and safety.However,scalable fabrication of sheet-type sulfur cathodes with high sulfur loading and excellent performances remains challenging.In this work,sheet-type freestanding sulfur cathodes with high sulfur loading were fabricated by dry electrode technology.The unique fibrous morphologies of polytetrafluoroethylene(PTFE)binders in dry electrodes not only provides excellent mechanical properties but also uncompromised ionic/electronic conductance.Even employed with thickened dry cathodes with high sulfur loading of 2 mg cm^(-2),ASSLSBs still exhibit outstanding rate performance and cycle stability.Moreover,the all-solid-state lithium-sulfur monolayer pouch cells(9.2 m Ah)were also demonstrated and exhibited excellent safety under a harsh test situation.This work verifies the potential of dry electrode technology in the scalable fabrication of thickened sulfur cathodes and will promote the practical applications of ASSLSBs.展开更多
In this study,a trifunctional strategy was developed to prepare a confined Ni-based catalyst(Ni-CeO_(2)@SiO_(2))for dry reforming of methane(DRM)of two main greenhouse gases-CO_(2)and CH_(4).The Ni-CeO_(2)@SiO_(2)cata...In this study,a trifunctional strategy was developed to prepare a confined Ni-based catalyst(Ni-CeO_(2)@SiO_(2))for dry reforming of methane(DRM)of two main greenhouse gases-CO_(2)and CH_(4).The Ni-CeO_(2)@SiO_(2)catalyst was fabricated by utilizing the confinement effect of the SiO_(2)shell and the synergistic interaction between Ni-Ce and the decoking effect of CeO_(2).The catalysts were systematically characterized via X-ray diffraction,N_(2 )adsorption/desorption,transmission electron microscopy,energy dispersive X-ray spectroscopy,hydrogen temperature reduction and desorption set by program,oxygen temperature program desorption,Raman spectroscopy,thermogravimetric analysis,and in situ diffuse reflectance infrared Fourier transform spectroscopy measurements to reveal their physicochemical properties and reaction mechanism.The Ni-CeO_(2)@SiO_(2)catalyst exhibited higher activity and stability than the catalyst synthesized via the traditional impregnation method.In addition,no carbon deposition was detected over Ni-CeO_(2)@SiO_(2)after a 100 h durability test at 800℃,and the average particle size of Ni nanoparticles(NPs)in the catalyst increased from 5.01 to 5.77 nm.Remarkably,Ni-CeO_(2)@SiO_(2)also exhibited superior low-temperature stability;no coke deposition was observed when the catalyst was reacted at 600℃ for 20 h.The high coking and sintering resistance of this confined Ni-based DRM catalyst can be attributed to its trifunctional effect.The trifunctional strategy developed in this study could be used as a guideline to design other high-performance catalysts for CO_(2)and CH4 dry forming and accelerate their industrialization.展开更多
The flexibility of MIP technology to meet market demand is mainly introduced in this study. Their commercial application and technical principle are analyzed too. The MIP technology with wide feed adaptability can for...The flexibility of MIP technology to meet market demand is mainly introduced in this study. Their commercial application and technical principle are analyzed too. The MIP technology with wide feed adaptability can form a good combination with other technologies. The MIP technology has been applied extensively in China. Based on this platform, the CGP, MIP-LTG and MIP-DCR technologies have been developed, which can further improve the flexibility of MIP technology. Based on its novel reaction control technique with a sole sequential two-zone riser, the MIP users can easily switch to different operating modes between producing either more clean gasoline and propylene or diesel through changing the catalysts and varying the operating conditions. That offers MIP users with enough production flexibility and a rational production arrangement to meet the market demand. The MIP-DCR technology with less dry gas and coke yields can provide a more flexible operating mode since the catalysts to oil ratio has become an independent variable.展开更多
The cognition of active sites in the Ni-based catalysts plays a vital role and remains a huge challenge in improving catalytic performance of low temperature CO_(2) dry reforming of methane(LTDRM).In this work,typical...The cognition of active sites in the Ni-based catalysts plays a vital role and remains a huge challenge in improving catalytic performance of low temperature CO_(2) dry reforming of methane(LTDRM).In this work,typical catalysts of SiO_(2) and γ-Al_(2)O_(3) supported Ni and Ni-Ce were designed and prepared.Importantly,the difference in the chemical speciations of active sites on the Ni-based catalysts is revealed by advanced characterizations and further estimates respective catalytic performance for LTDRM.Results show that larger[Ni0-]particles mixed with[Ni-O-Sin])species on the Ni/SiO_(2)(R)make CH_(4) excessive decomposition,leading to poor activity and stability.Once the Ce species is doped,however,superior activity(59.0%CH_(4) and 59.8%CO_(2) conversions),stability and high H_(2)/CO ratio(0.96)at 600℃ can be achieved on the Ni-Ce/SiO_(2)(R),in comparison with other catalysts and even reported studies.The improved performance can be ascribed to the formation of integral([Ni0_(n))]-[CeⅢ-□-CeⅢ])species on the Ni-Ce/SiO_(2)(R)catalyst,containing highly dispersed[Ni]particles and rich oxygen vacancies,which can synergistically establish a new stable balance between gasification of carbon species and CO_(2) dissocia-tion.With respect to Ni-Ce/γ-Al_(2)O_(3)(R),the Ni and Ce precursors are easily captured by extra-framework Al_(n)-OH groups and further form stable isolated([Ni0_(n))]-[Ni-O-Al_(n)])and[CeⅢ-O-Al_(n)]species.In such a case,both of them preferentially accelerate CO_(2) adsorption and dissociation,causing more car-bon deposition due to the disproportionation of superfuous CO product.This deep distinguishment of chemical speciations of active sites can guide us to further develop new efficient Ni-based catalysts for LTDRM in the future.展开更多
With the aim of controlling the problem of fine particles in the flue gas of lead-zinc smelting,a low-temperature plasma-electrocoagulation and electric bag composite dedusting experimental platform was designed by co...With the aim of controlling the problem of fine particles in the flue gas of lead-zinc smelting,a low-temperature plasma-electrocoagulation and electric bag composite dedusting experimental platform was designed by combining electrocoagulation and electric bag composite dust removal technology based on the research of low-temperature plasma technology.Firstly,the properties of fine particles in flue gas from lead-zinc smelting were analyzed,and the effects of input voltage,filter wind speed,dust concentration,and pulse-jet ash-cleaning cycle on the dust collection efficiency of the integrated device were studied.Then,the energy efficiency of the integrated technology was analyzed,and the control mechanism of the fine particles was revealed.The experimental results show that the integrated technology of low-temperature plasma-electrocoagulation and electric bag composite dust removal achieves a fine particle removal efficiency of more than 99.99%and the energy consumption per unit mass of the dust is only 0.008 k W·h/g.The integrated technology has broad application prospects and farreaching practical significance for the lead-zinc smelting industry to achieve ultra-low emission targets for flue gas and achieve energy-saving and emission reduction effects.展开更多
Nanotechnology is a field of research with objects up to 100 nm in size. Nanomaterials belong to a wide area in the field of material engineering. These include nanolayers, nanoslabs, nanopores, nanotubes, nanofibers,...Nanotechnology is a field of research with objects up to 100 nm in size. Nanomaterials belong to a wide area in the field of material engineering. These include nanolayers, nanoslabs, nanopores, nanotubes, nanofibers, nanoparticles and quantum dots. Nanostructures are characterized by special properties due to their nanometric dimensions. The natural properties of nanostructures allow their wide application in various industries. The paper presents an overview of the application and significance of nanostructures in fuel cell technology, with particular emphasis on nanocatalysts. The article includes the classification of nanomaterials, new hybrid nanostructures, types of surface modification, division by area of application, with particular emphasis on nanomaterials in the advanced energy system. The design and operation of fuel cells and the role of nanoparticles have been described taking into account existing solutions to reduce generator costs. The high price of low temperature fuel cells depends on the number of nanoparticles used. The article describes the risk associated with using products at the nano scale. Higher concentrations of these extremely active materials can be dangerous and can cause ecological problems and harm natural ecosystems.展开更多
Firstly, physical and chemical properties of dust removed from BOF gas are analyzed, and then the cold banding technology of dust removed from BOF gas and its application are introduced. Tests have proved that using c...Firstly, physical and chemical properties of dust removed from BOF gas are analyzed, and then the cold banding technology of dust removed from BOF gas and its application are introduced. Tests have proved that using cooled agglomerated pellets made of the dust removed from BOF gas and small amounts of modified starch as a coolant and slagging agent in steel production can bring about considerable economic, social and environmental benefits.展开更多
There is a prominent,complex and diverse three-dimensional climate and a variety of meteorological disasters in Qujing area. The risk zoning of low-temperature disasters for flue-cured tobacco planting in Qujing area ...There is a prominent,complex and diverse three-dimensional climate and a variety of meteorological disasters in Qujing area. The risk zoning of low-temperature disasters for flue-cured tobacco planting in Qujing area was studied to provide reference for drawing on advantages and avoiding disadvantages in flue-cured tobacco planting,disaster reduction,and disaster relief services. According to the production practice of fluecured tobacco and local climate analysis,it was determined that flue-cured tobacco in Qujing area was very vulnerable to low temperature during the seedling stage（ from early February to middle April） and in the mature period（ from early July to early September）. Based on the quantitative analysis and evaluation of risk of disaster-causing factors,sensitivity of disaster-breeding environment,vulnerability of carriers,and disaster prevention and reduction capability,a risk assessment model of meteorological disasters was established to precisely evaluate and zone the risk of low-temperature disasters for flue-cured tobacco planting in allusion to the seedling and mature stage in Qujing area by using GIS technology. The risk of lowtemperature disasters for flue-cured tobacco planting during the two periods was divided into four grades,namely low,medium,high and very high risk.展开更多
A new technology of raising rice seedlings in dry nursery began to be adopted in early 1980’s inChina. It expanded in Northeast of the Country and spreaded from North to South in the followingyears. In 1995, it was l...A new technology of raising rice seedlings in dry nursery began to be adopted in early 1980’s inChina. It expanded in Northeast of the Country and spreaded from North to South in the followingyears. In 1995, it was listed as one of the national popularization project during the ’Ninth Five-Year-Plan’ by the Country Government. The total area was up to 9.3 million hm~2 in 1996 (cover-ing 80% paddy field in the northern parts of China). The expected popularized area will be up to15.3 million hm~2 in 2000 according to the Ministry of Agriculture, half of the total rice-growingarea in China.展开更多
为探究不同干制工艺对牡蛎干特征气味的影响及其形成机制,该研究以焯水牡蛎为对照(CK),研究了真空冷冻干制(vacuum freeze drying,VFD)、热风干制(hot air drying,HAD)、真空干制(vacuum drying,VD)、自然晒干(solar drying,SD)4种干制...为探究不同干制工艺对牡蛎干特征气味的影响及其形成机制,该研究以焯水牡蛎为对照(CK),研究了真空冷冻干制(vacuum freeze drying,VFD)、热风干制(hot air drying,HAD)、真空干制(vacuum drying,VD)、自然晒干(solar drying,SD)4种干制工艺对牡蛎干脂肪酸组成和挥发性物质的影响。结果表明,牡蛎经干制加工后脂肪酸含量显著减少(P<0.05),VFD、VD、SD、HAD组总脂肪酸含量分别减少19.45%、49.27%、27.69%、46.63%,其中饱和脂肪酸减少21.39%~45.17%,不饱和脂肪酸减少20.66%~52.21%。电子鼻结果显示5组样品的香气特征明显不同,高温干制(HAD、VD)显著增加了氮氧化合物的浓度。采用气相色谱-离子迁移谱(gas chromatography-ion mobility spectrometry,GC-IMS)从5组样品中共鉴别出71种挥发性化合物,主成分分析和指纹图谱表明,5组样品的挥发性物质存在显著差异,通过偏最小二乘回归模型(partial least squares regression model,PLS-DA)和变量投影重要度(variable importance for the projection,VIP)筛选了31种差异性挥发性化合物,包括庚醛、丁醛、2-甲基-2-戊烯醛、2-庚酮、1-戊烯-3-酮、2-丁酮、1-辛烯-3-醇等,Pearson相关性分析表明,游离脂肪酸中的C15:0、C16:1、C16:0、C18:3、C18:4、C20:0、C20:1、C20:2与牡蛎干中的多种特征挥发性化合物的形成密切相关。展开更多
基金supported by the National Natural Science Foundation of China(No.31901242)Heilongjiang Science Foundation Project(No.LH2020C038)National Undergraduate Training Programs for Innovations(No.202110225074)。
文摘In this paper,the occurrence and development mechanism of strain on the cross-section during the wood drying is explored.Therefore,strain regularity on the cross-section of 50 mm thickness elm(Ulmus rubra)board at the temperature of 40℃and 80℃is detected via digital image correlation technology.Hence,the difference between tangential and radial strain at surface and core layers was denoted.The results showed that strain distribution in the width direction of the board is uneven.Moreover,a large drying shrinkage strain occurs at the near-core layer,while the maximum strain difference reaches 4.08%.Hence,the surface of the board is cracked along the thickness direction.The radial strain of the board is higher than the tangential strain in the early stage of drying,while these strains are reversed in the later stage of drying.The temperature is related to the difference between the tangential and radial strains of the elm board.These differences at the core layer are larger than those of the surface layer.The conducted research results provide a theoretical basis for process optimization.
基金This work is supported by "Xing Huo" Program of the Ministry of Agriculture, P. R. China.
文摘A newly drying technology, intermittent-contact drying of veneer with flexible screen belt (ICD-fbs), was invented and used in poplar veneer drying. Productive test was carried out for validating the practical use of this drying method. The test result shows that to dispose flexible screen belts on the two sides of hot board could help steam discharge remarkably. The veneer dried using ICD-fsb method had smooth and level surface, less deformation and warping, even moisture content, and high utilization rate. The time for opening hot board to discharge steam,which, early or late, is a key to obtain good drying result, was determined at the time when the core's temperature of veneer reaches 100℃ (vaporization). Using ICD-fsb method, the shrinking rates in tangent of veneer were from 1.90% to 2.26% for veneer of 0.4 mm in thickness,2.49% to 4.50% for veneer of 1 mm in thickness and 1.34% to 3.30% for veneer of 1.7 mm in thickness, which are much lower than the results obtained by other drying methods. The method of ICD-fsb offers a reliable technological guarantee for solving the deformation problem of veneer drying, especially the deformation of wood from quick-growing plantation.
基金Supported by Scientific Research Foundation for Young Scholars of Heilongjiang Province of China (QC07C25)The National High Technology Research and Development Program of China (2008AA10Z315)
文摘Drying technology of angiotensin converting enzyme （ACE） inhibitory peptides derived from bovine casein was investigated. No significance was observed on ACE inhibitory activity of products prepared by spay drying and freeze drying （P〉0.05）. Spay drying was the best drying process for practical industry production. The inlet temperature ranged from 140℃ to 160℃ and the exit temperature ranged from 70 ℃ to 90 ℃ during the spay drying process. Under the optimal conditions, scale-up of angiotensin converted enzyme inhibitory peptide from 1 L to 10 L and the experiment was successively conducted. Peptide yield was 29% and half inhibitory concentration （IC50） was 0.53 g. L^-1.
文摘The relation between technology parameters and performance index of the wheat three-stage concurrent-flow drying technology is studied by use of quadratic orthogonial rotate combinative experiment design method.The optimum parameters of drying technology are obtained by nonlinear optimize corresponding regression model and test.All experiment was finished in concurrent-flow grain drying experiment table.The results of this study will be significant for designing energy-saving grain drying machine.
基金Supported by Special Fund of Public Industry from Ministry of Science and Technology (GYHY200806021)National Natural Science Foundation Emphases Item of China (40830957)+2 种基金Project of Researches on Drought Meteorological Science (IAM200811)Special Fund for Climatic Change in China Meteorological Bureau (CCSS-09-14)Technology-aid Project in Gansu (090NKCA118)~~
文摘Based on the state of characteristics of dry warming of modern climate changing,the response of growth,output and quality of main economic crops such as cotton,flax and winter rape and characteristic crop such as vinifera and apple were discussed.The coping technology for climate changing and measurements for serving the agricultural were provided.
基金supported by the National Key Research and Development Program of China(2021YFB2500300)the National Natural Science Foundation of China(22075029,22108151,22109084)the China Postdoctoral Science Foundation(2021TQ0164)。
文摘All-solid-state lithium-sulfur batteries(ASSLSBs)employing sulfide solid electrolytes are one of the most promising next-generation energy storage systems due to their potential for higher energy density and safety.However,scalable fabrication of sheet-type sulfur cathodes with high sulfur loading and excellent performances remains challenging.In this work,sheet-type freestanding sulfur cathodes with high sulfur loading were fabricated by dry electrode technology.The unique fibrous morphologies of polytetrafluoroethylene(PTFE)binders in dry electrodes not only provides excellent mechanical properties but also uncompromised ionic/electronic conductance.Even employed with thickened dry cathodes with high sulfur loading of 2 mg cm^(-2),ASSLSBs still exhibit outstanding rate performance and cycle stability.Moreover,the all-solid-state lithium-sulfur monolayer pouch cells(9.2 m Ah)were also demonstrated and exhibited excellent safety under a harsh test situation.This work verifies the potential of dry electrode technology in the scalable fabrication of thickened sulfur cathodes and will promote the practical applications of ASSLSBs.
文摘In this study,a trifunctional strategy was developed to prepare a confined Ni-based catalyst(Ni-CeO_(2)@SiO_(2))for dry reforming of methane(DRM)of two main greenhouse gases-CO_(2)and CH_(4).The Ni-CeO_(2)@SiO_(2)catalyst was fabricated by utilizing the confinement effect of the SiO_(2)shell and the synergistic interaction between Ni-Ce and the decoking effect of CeO_(2).The catalysts were systematically characterized via X-ray diffraction,N_(2 )adsorption/desorption,transmission electron microscopy,energy dispersive X-ray spectroscopy,hydrogen temperature reduction and desorption set by program,oxygen temperature program desorption,Raman spectroscopy,thermogravimetric analysis,and in situ diffuse reflectance infrared Fourier transform spectroscopy measurements to reveal their physicochemical properties and reaction mechanism.The Ni-CeO_(2)@SiO_(2)catalyst exhibited higher activity and stability than the catalyst synthesized via the traditional impregnation method.In addition,no carbon deposition was detected over Ni-CeO_(2)@SiO_(2)after a 100 h durability test at 800℃,and the average particle size of Ni nanoparticles(NPs)in the catalyst increased from 5.01 to 5.77 nm.Remarkably,Ni-CeO_(2)@SiO_(2)also exhibited superior low-temperature stability;no coke deposition was observed when the catalyst was reacted at 600℃ for 20 h.The high coking and sintering resistance of this confined Ni-based DRM catalyst can be attributed to its trifunctional effect.The trifunctional strategy developed in this study could be used as a guideline to design other high-performance catalysts for CO_(2)and CH4 dry forming and accelerate their industrialization.
文摘The flexibility of MIP technology to meet market demand is mainly introduced in this study. Their commercial application and technical principle are analyzed too. The MIP technology with wide feed adaptability can form a good combination with other technologies. The MIP technology has been applied extensively in China. Based on this platform, the CGP, MIP-LTG and MIP-DCR technologies have been developed, which can further improve the flexibility of MIP technology. Based on its novel reaction control technique with a sole sequential two-zone riser, the MIP users can easily switch to different operating modes between producing either more clean gasoline and propylene or diesel through changing the catalysts and varying the operating conditions. That offers MIP users with enough production flexibility and a rational production arrangement to meet the market demand. The MIP-DCR technology with less dry gas and coke yields can provide a more flexible operating mode since the catalysts to oil ratio has become an independent variable.
基金financially supported by the National Natural Science Foundation of China (22006059, 21968015)National Engineering Laboratory for Flue Gas Pollutants Control Technology and Equipment (NEL-KF-201905)+1 种基金Applied Basic Research Program of Yunnan Province, China (202101AU070154, 2019FD034)Analysis and Testing Fund of Kunming University of Science and Technology (2020 T20200006)
文摘The cognition of active sites in the Ni-based catalysts plays a vital role and remains a huge challenge in improving catalytic performance of low temperature CO_(2) dry reforming of methane(LTDRM).In this work,typical catalysts of SiO_(2) and γ-Al_(2)O_(3) supported Ni and Ni-Ce were designed and prepared.Importantly,the difference in the chemical speciations of active sites on the Ni-based catalysts is revealed by advanced characterizations and further estimates respective catalytic performance for LTDRM.Results show that larger[Ni0-]particles mixed with[Ni-O-Sin])species on the Ni/SiO_(2)(R)make CH_(4) excessive decomposition,leading to poor activity and stability.Once the Ce species is doped,however,superior activity(59.0%CH_(4) and 59.8%CO_(2) conversions),stability and high H_(2)/CO ratio(0.96)at 600℃ can be achieved on the Ni-Ce/SiO_(2)(R),in comparison with other catalysts and even reported studies.The improved performance can be ascribed to the formation of integral([Ni0_(n))]-[CeⅢ-□-CeⅢ])species on the Ni-Ce/SiO_(2)(R)catalyst,containing highly dispersed[Ni]particles and rich oxygen vacancies,which can synergistically establish a new stable balance between gasification of carbon species and CO_(2) dissocia-tion.With respect to Ni-Ce/γ-Al_(2)O_(3)(R),the Ni and Ce precursors are easily captured by extra-framework Al_(n)-OH groups and further form stable isolated([Ni0_(n))]-[Ni-O-Al_(n)])and[CeⅢ-O-Al_(n)]species.In such a case,both of them preferentially accelerate CO_(2) adsorption and dissociation,causing more car-bon deposition due to the disproportionation of superfuous CO product.This deep distinguishment of chemical speciations of active sites can guide us to further develop new efficient Ni-based catalysts for LTDRM in the future.
基金supported by the State Key Laboratory of Organic Geochemistry,GIGCAS(No.SKLOG-201909)the Fundamental Research Funds for the Central Universities(2009QH03)funded by the Open Foundation of Shaanxi Key Laboratory of Lacustrine Shale Gas Accumulation and Exploitation(under planning).
文摘With the aim of controlling the problem of fine particles in the flue gas of lead-zinc smelting,a low-temperature plasma-electrocoagulation and electric bag composite dedusting experimental platform was designed by combining electrocoagulation and electric bag composite dust removal technology based on the research of low-temperature plasma technology.Firstly,the properties of fine particles in flue gas from lead-zinc smelting were analyzed,and the effects of input voltage,filter wind speed,dust concentration,and pulse-jet ash-cleaning cycle on the dust collection efficiency of the integrated device were studied.Then,the energy efficiency of the integrated technology was analyzed,and the control mechanism of the fine particles was revealed.The experimental results show that the integrated technology of low-temperature plasma-electrocoagulation and electric bag composite dust removal achieves a fine particle removal efficiency of more than 99.99%and the energy consumption per unit mass of the dust is only 0.008 k W·h/g.The integrated technology has broad application prospects and farreaching practical significance for the lead-zinc smelting industry to achieve ultra-low emission targets for flue gas and achieve energy-saving and emission reduction effects.
文摘Nanotechnology is a field of research with objects up to 100 nm in size. Nanomaterials belong to a wide area in the field of material engineering. These include nanolayers, nanoslabs, nanopores, nanotubes, nanofibers, nanoparticles and quantum dots. Nanostructures are characterized by special properties due to their nanometric dimensions. The natural properties of nanostructures allow their wide application in various industries. The paper presents an overview of the application and significance of nanostructures in fuel cell technology, with particular emphasis on nanocatalysts. The article includes the classification of nanomaterials, new hybrid nanostructures, types of surface modification, division by area of application, with particular emphasis on nanomaterials in the advanced energy system. The design and operation of fuel cells and the role of nanoparticles have been described taking into account existing solutions to reduce generator costs. The high price of low temperature fuel cells depends on the number of nanoparticles used. The article describes the risk associated with using products at the nano scale. Higher concentrations of these extremely active materials can be dangerous and can cause ecological problems and harm natural ecosystems.
文摘Firstly, physical and chemical properties of dust removed from BOF gas are analyzed, and then the cold banding technology of dust removed from BOF gas and its application are introduced. Tests have proved that using cooled agglomerated pellets made of the dust removed from BOF gas and small amounts of modified starch as a coolant and slagging agent in steel production can bring about considerable economic, social and environmental benefits.
基金Supported by China National Tobacco Corporation(Yunnan Tobacco Science and Technology Program No.[2014]302,program contract number:2014YN22)
文摘There is a prominent,complex and diverse three-dimensional climate and a variety of meteorological disasters in Qujing area. The risk zoning of low-temperature disasters for flue-cured tobacco planting in Qujing area was studied to provide reference for drawing on advantages and avoiding disadvantages in flue-cured tobacco planting,disaster reduction,and disaster relief services. According to the production practice of fluecured tobacco and local climate analysis,it was determined that flue-cured tobacco in Qujing area was very vulnerable to low temperature during the seedling stage（ from early February to middle April） and in the mature period（ from early July to early September）. Based on the quantitative analysis and evaluation of risk of disaster-causing factors,sensitivity of disaster-breeding environment,vulnerability of carriers,and disaster prevention and reduction capability,a risk assessment model of meteorological disasters was established to precisely evaluate and zone the risk of low-temperature disasters for flue-cured tobacco planting in allusion to the seedling and mature stage in Qujing area by using GIS technology. The risk of lowtemperature disasters for flue-cured tobacco planting during the two periods was divided into four grades,namely low,medium,high and very high risk.
文摘A new technology of raising rice seedlings in dry nursery began to be adopted in early 1980’s inChina. It expanded in Northeast of the Country and spreaded from North to South in the followingyears. In 1995, it was listed as one of the national popularization project during the ’Ninth Five-Year-Plan’ by the Country Government. The total area was up to 9.3 million hm~2 in 1996 (cover-ing 80% paddy field in the northern parts of China). The expected popularized area will be up to15.3 million hm~2 in 2000 according to the Ministry of Agriculture, half of the total rice-growingarea in China.
文摘为探究不同干制工艺对牡蛎干特征气味的影响及其形成机制,该研究以焯水牡蛎为对照(CK),研究了真空冷冻干制(vacuum freeze drying,VFD)、热风干制(hot air drying,HAD)、真空干制(vacuum drying,VD)、自然晒干(solar drying,SD)4种干制工艺对牡蛎干脂肪酸组成和挥发性物质的影响。结果表明,牡蛎经干制加工后脂肪酸含量显著减少(P<0.05),VFD、VD、SD、HAD组总脂肪酸含量分别减少19.45%、49.27%、27.69%、46.63%,其中饱和脂肪酸减少21.39%~45.17%,不饱和脂肪酸减少20.66%~52.21%。电子鼻结果显示5组样品的香气特征明显不同,高温干制(HAD、VD)显著增加了氮氧化合物的浓度。采用气相色谱-离子迁移谱(gas chromatography-ion mobility spectrometry,GC-IMS)从5组样品中共鉴别出71种挥发性化合物,主成分分析和指纹图谱表明,5组样品的挥发性物质存在显著差异,通过偏最小二乘回归模型(partial least squares regression model,PLS-DA)和变量投影重要度(variable importance for the projection,VIP)筛选了31种差异性挥发性化合物,包括庚醛、丁醛、2-甲基-2-戊烯醛、2-庚酮、1-戊烯-3-酮、2-丁酮、1-辛烯-3-醇等,Pearson相关性分析表明,游离脂肪酸中的C15:0、C16:1、C16:0、C18:3、C18:4、C20:0、C20:1、C20:2与牡蛎干中的多种特征挥发性化合物的形成密切相关。
