In this work,we developed a continuous preparation strategy for the production of high-solidscontent waterborne polyurethane(WPU)emulsions via high-gravity-assisted emulsification in a rotating packed bed(RPB)reactor....In this work,we developed a continuous preparation strategy for the production of high-solidscontent waterborne polyurethane(WPU)emulsions via high-gravity-assisted emulsification in a rotating packed bed(RPB)reactor.By adjusting the experimental parameters and formula,WPU emulsions with a high solids content of 55%and alow viscosity were prepared.Preliminary applications of the high-solids-content WPU as a thermally insulating material were demonstrated.RPB emulsification is an economical and environmentally friendly production strategy because of the low energy consumption,short emulsification time,and effective devolatilization.This study demonstrated an effective method for preparation of high-solids-content WPU,moving toward commercialization and industrialization.展开更多
The combustion (ballistic) properties of a high solid loading composite solid propellant family (Butalites) was studied experimentally by using propellant formulations based on hydroxy-terminated polybutadiene pre...The combustion (ballistic) properties of a high solid loading composite solid propellant family (Butalites) was studied experimentally by using propellant formulations based on hydroxy-terminated polybutadiene pre-polymer (HTPB) as a fuel binder main backbone, bimodal system ammonium perchlorate oxidizer (AP) and aluminum powder (AI) as metallic fuel. Burning rates were doubled at various pressures, when solids loading (AP and 17% A1) were increased from 80 to 88% and the measured characteristic velocity values were increased by about 100m/sec. The pressure exponent (n) values were lower with 80-85% solids loading. The burning rates were increased by about 2-5% when comparing the data obtained by static firing with those obtained by the strand burner method.展开更多
Low-cost thermal insulation porous ceramics with uniform pore diameter and low bulk density were prepared with soda-ash dregs and felsic tailings.We investigated the effect of temperature,foaming agent,fluxing agent,A...Low-cost thermal insulation porous ceramics with uniform pore diameter and low bulk density were prepared with soda-ash dregs and felsic tailings.We investigated the effect of temperature,foaming agent,fluxing agent,Al_(2)O_(3)and CaO content on the pore structure and crystal phase of porous ceramics.The effect of Ca^(2+)in soda-ash dregs on the preparation of quartz-feldspar based porous ceramics was studied.The results showed that the contribution of Ca^(2+)to the preparation of porous ceramics in this system was mainly to accelerate the Si-O bond fracture and reduce the sintering temperature at the initial stage of sintering,which destroyed the needle-like feldspar in the high temperature melt and reduced the melt viscosity,thus reduced the foaming resistance and promoted the porous products with uniform pore size distribution.The Ca^(2+)content on the high side can participate in the formation of crystals in sintering.The generated needle-like diopside and augite,which have small length-diameter ratio,will negligibly change in the viscosity of melt at high temperatures,and their inhibition effect on pores is not as good as that of feldspar with large length-diameter ratio,resulting in the merger and collapse of pores.But the increase of diopside and augite can improve the compressive strength of porous products to some extent.Porous ceramic products containing needle-like feldspar phase can be prepared by using two kinds of solid waste,which can improve the compressive strength of the products and reduce the raw material cost and energy consumption while comprehensively utilizing the double solid waste.The optimal product has a bulk density of 0.45 g/cm^(3),a compressive strength of 3.17 MPa,and a thermal conductivity of 0.11 W/(m·K).展开更多
A new quaternary rare-earth sulfide, Cs0.75(6)Er443(5)In3.32(6)S12 (1), is discovered by high temperature solid state reactions with a slight excess of CsCI flux. The structure is characterized by single-cryst...A new quaternary rare-earth sulfide, Cs0.75(6)Er443(5)In3.32(6)S12 (1), is discovered by high temperature solid state reactions with a slight excess of CsCI flux. The structure is characterized by single-crystal X-ray diffraction data, while crystallizes in hexagonal space group P63/m (No. 176) with a = 12.0329(6), c = 3.8693(5)A, V= 485.18(7) A3, Z = 1, Mr = 1606.57, Dc = 5.499 g/cm3,μ = 25.457 mm-1, F(000) = 752, the final R = 0.0337 and wR = 0.0904 for 328 observed reflections with I 〉 2σ(I). Its structure features a three-dimensional framework with hexagonal channels that are centered by Cs cations. Such channels are formed by double chains of edge-sharing M(1)S6 (M(1) = Er(1)/In(1)) octahedra and single chains of Er(2)S6 triprism interconnected by corner-sharing. The syntheses, single-crystal analyses, optical band gap and magnetic property are reported.展开更多
The conversion of rice hulls into fermentable saccharides was explored through steam pretreatment employing 2.5% SO_(2).The in teraction between temperature and time was assessed by means of the response surface metho...The conversion of rice hulls into fermentable saccharides was explored through steam pretreatment employing 2.5% SO_(2).The in teraction between temperature and time was assessed by means of the response surface method to achieve optimum contents of C6-sugars in water-insoluble solids(WIS)and C5-sugars in the liquor.Pretreatment carried out at 218℃ for 2.3 min released liquor containing 55.4 g/L of sugars(29.1 g/L of xylose).In parallel,the WIS was subjected to enzymatic saccharification using different solid and enzyme loads via an experimental design:assays using 22.0% WIS and 20.0 filter paper units(FPU)/g led to 90.6 g/L of glucose,corresponding to a yield of 86.4% and an overall yield of 72.4%.The data reported are the highest ever found for such raw material,making it attractive to compete with conventi on al lig no cellulosic biomass.展开更多
In the last several decades, circulating fluidized bed reactors have been studied in many aspects including hydrodynamics, heat and mass transfer and gas–solid two phase contacting. However, despite the abundance of ...In the last several decades, circulating fluidized bed reactors have been studied in many aspects including hydrodynamics, heat and mass transfer and gas–solid two phase contacting. However, despite the abundance of review papers on hydrodynamics, there is no summary paper on gas–solid contact efficiency to date, especially on high density circulating fluidized beds(CFBs). This paper gives an introduction to, and a review of the measurement of contact efficiency in circulating fluidized bed riser. Firstly, the popular testing method of contact efficiency including the method of heating transfer experiment and hot model reaction are discussed, then previous published papers are reviewed based on the discussed methods. Some key results of the experimental work are described and discussed. Gas–solid contact efficiency is affected by the operating conditions as well as the particle size distribution. The result of the contact efficiency shows that the CFB riser is far away from an ideal plug flow reactor due to the characteristics of hydrodynamics in the riser. Lacunae in the available literature have been delineated and recommendations have been made for further work.展开更多
Borehole inclinometers are important observation instruments used to measure ground tilt movement and monitor crustal deformation of solid tides and geological landslide disasters.They are widely used in oil explorati...Borehole inclinometers are important observation instruments used to measure ground tilt movement and monitor crustal deformation of solid tides and geological landslide disasters.They are widely used in oil exploration,mineral resource drilling,well logging,exploration and other fields.There is potential for development of rock stress strain monitoring tools.Many types of tiltmeters have been installed,such as SQ-7,FSQ,VS and JB.However,these tiltmeters are generally installed in a deep cave to avoid the interference of temperature,humidity,and human activities.With the urbanization of human society,suitable installation locations are difficult to find.To solve the problem,a two-component borehole tiltmeter,named the CBT-type tiltmeter,is proposed in this paper.It can be installed in a borehole less than500 m deep to eliminate environmental influences.The tiltmeter is composed of two sophisticated gravitational swing and two capacitive transducers.From preliminary theory and experiment analysis,its linear correlation coefficient is higher than 0.99,its co-seismic response is rapid and its noise level is up to 10 4arc seconds in practice.展开更多
Dry corn straw(DCS)is usually used in anaerobic digestion(AD),but fresh corn straw(FCS)has been given less consideration.In this study,the thermophilic AD of single-substrate(FCS and DCS)and co-digestion(straw with ca...Dry corn straw(DCS)is usually used in anaerobic digestion(AD),but fresh corn straw(FCS)has been given less consideration.In this study,the thermophilic AD of single-substrate(FCS and DCS)and co-digestion(straw with cattle manure)were investigated.The results show that when FCS was used as the single-substrate for AD,the methane production was 144 mL·g^(−1)·VS^(−1),which was 7.5%and 19.6%higher than that of single DCS and FCS with cattle manure,respectively.In addition,the structure of FCS was loose and coarse,which was easier to be degraded than DCS.At the hydrolysis and acidification stages,Clostridium_sensu_stricto_1,Clostridium_sensu_stricto_7 and Sporosarcina promoted the decomposition of organic matter,leading to volatile fatty acids(VFAs)accumulation.Methanosarcina(54.4%)activated multifunctional methanogenic pathways to avoid the VFAs inhibition,which was important at the CH_(4) production stage.The main pathway was hydrogenotrophic methanogenesis,with genes encoding formylmethanofuran dehydrogenase(K00200-K00203)and tetrahydromethanopterin Smethyltransferase(K00577-K00584).Methanosarcina also activated acetotrophic and methylotrophic methanogenesis pathways,with genes encoding acetyl phosphate(K13788)and methyl-coenzyme M reductase(K04480,K14080 and K14081),respectively.In the co-digestion,the methanogenic potential of FCS was also confirmed.This provides a scientific basis for regulating AD of crop straw.展开更多
Ammonium sulfate residue is a particulate solid and is produced during the manufacture of ammonium sulfate fertilizer. The residue used in this study contained a large portion of calcium carbonate, from which active l...Ammonium sulfate residue is a particulate solid and is produced during the manufacture of ammonium sulfate fertilizer. The residue used in this study contained a large portion of calcium carbonate, from which active lime (CaO) was recovered via thermal decomposition. We used a purpose-built device to decom- pose the residue in a semi-suspension state. We found that CaO had the highest activity when residue was decomposed at 850-900 ~C. Our experiments indicated that ammonium sulfate residue should be decom- posed in a suspension state to produce active CaO. Based on our laboratory test findings, an industrial-scale production line with a high solid/gas ratio in a suspension state was devised. The optimal operating con- ditions for the decomposition of the ammonium sulfate residue to produce high quality CaO were also investigated.We found that the CaCO3 decomposition rate was high and the CaO product was highly active, averaging 170 s by the citric acid method. Morphology measurements showed that the CaO product had a porous structure and a large specific surface ensuring high activity.展开更多
An analytical model is established to study the influence of lattice distortion and fraction of Hf on the yield strength of the BCC TiNbTaZrHfx multi-component high entropy alloys (HEAs). Meanwhile, the mechanism of...An analytical model is established to study the influence of lattice distortion and fraction of Hf on the yield strength of the BCC TiNbTaZrHfx multi-component high entropy alloys (HEAs). Meanwhile, the mechanism of solid solution strengthening caused by lattice distortion is also discussed in the HEA. The distorted unit cell is introduced to indicate the lattice distortion effects induced by the differences of the atomic size and shear modulus by doping other elements in Ti-based metal. The results show that the calculated values of the alloying yield strength considering the path of least resistance are obtained with regard to various grain sizes for the equiatomic TiNbTaZrHf HEA, which is well in line with the experimental results. Furthermore, it is predicted that the alloying yield strength is the largest value in the case of the same grain size for the Hf atomic fraction of 0.122. The meaningful modeling could provide a theoretical method to investigate the yield strength and alloying design of other BCC HEAs in the future.展开更多
High solid content CO_(2)-based cationic waterborne polyurethanes(CWPUs)were prepared using CO_(2)-polyols as soft segment and Nmethyl diethanolamine(MDEA)as hydrophilic group.The resulting stable aqueous dispersion d...High solid content CO_(2)-based cationic waterborne polyurethanes(CWPUs)were prepared using CO_(2)-polyols as soft segment and Nmethyl diethanolamine(MDEA)as hydrophilic group.The resulting stable aqueous dispersion displayed a high solid content of 52%with a low MDEA loading of 3.52 wt%.This novel structural CWPU can provide excellent adhesive strength,whose T-peel strength could reach 173.48N/5cm,20%higher than that of ester-based cationic waterborne polyurethane(87.55 N/5cm).The CO_(2)-based CWPU film showed only 2 wt%swelling percentage after 240 min immersion in water,and no change was observed during its immersion in 5 wt%sodium hydroxide solution.The tensile strength of CO_(2)-WPUs dropped slowly to 91.2%after 480 min immersion in a 5 wt%sodium hydroxide solution,whereas that of esterbased CWPUs dropped quickly to 32%after 240 min and their mechanical properties were lost after 360 min immersion.Meanwhile,the retention of the tensile strength of the CO_(2)-CWPUs was 81.5%even after 720 min immersion in 10 wt%H_(2)O_(2) solution,while it was only ca.38%for the ester-based CWPUs.These results indicated that the cationic CO_(2)-based CWPU may be promising waterborne adhesive with outstanding ageing resistance due to its synergistic effect from carbonate and ether groups of CO_(2)-polyol structure.展开更多
A novel organic fluorophor with high solid state luminescent efficiency based on 1,4-bis(2,2-di(pyridin-2-yl)- vinyl)benzene (BDP2VB) was designed and synthesized. It emits faintly in solution, but becomes a str...A novel organic fluorophor with high solid state luminescent efficiency based on 1,4-bis(2,2-di(pyridin-2-yl)- vinyl)benzene (BDP2VB) was designed and synthesized. It emits faintly in solution, but becomes a strong emitter in the aggregate state, demonstrating its aggregation induced emission (AIE) property. According to the crystal struc- ture analysis, J-type aggregation was formed in the packing mode of the molecule, which was demonstrated to be beneficial to gain high fluorescent quantum efficiency in solid state. Additionally, the emission color of BDP2VB can change dramatically in solid state as well as in solution by the protonation stimuli.展开更多
High inlet solid loading is one of the most important features of cyclone separators in high density circulating fluidized beds (CFB). In this work, the effect of high solid loading on pressure drop in a reverse-flo...High inlet solid loading is one of the most important features of cyclone separators in high density circulating fluidized beds (CFB). In this work, the effect of high solid loading on pressure drop in a reverse-flow cyclone was experimentally studied. The particles used were sand and 2zAl203. Art extended range of inlet solid loadings (M), up to 30 kg of solids/kg of air was tested at different inlet air velocities (Vin=16~24 m/s), well beyond the solid loading range reported before. The experiments showed that, in the tested range of solid loadings, the cyclone pressure drop decreased dramatically with increasing solid loading when M〈7.5 kg/kg and then almost remained constant. A new semi-empirical model for predicting cyclone pressure drop was also developed. The calculated and experimental results showed good agreement for particle free flow and particle laden flow.展开更多
Ⅰ. INTRODUCTION 13C-CPMAS, the combination of magic angle spinning of specimen (MAS) with high power proton decoupling and 1H-13C cross-polarization (CP), is proved to be a powerful means for research. It enables...Ⅰ. INTRODUCTION 13C-CPMAS, the combination of magic angle spinning of specimen (MAS) with high power proton decoupling and 1H-13C cross-polarization (CP), is proved to be a powerful means for research. It enables us to have obtained high resolution NMR spectra of展开更多
An improved method for trace level quantification of dicyandiamide in stream water has been developed. This method includes sample pretreatment using solid phase extraction.The extraction procedure(including loading,...An improved method for trace level quantification of dicyandiamide in stream water has been developed. This method includes sample pretreatment using solid phase extraction.The extraction procedure(including loading, washing, and eluting) used a flow rate of1.0 m L/min, and dicyandiamide was eluted with 20 m L of a methanol/acetonitrile mixture(V/V = 2:3), followed by pre-concentration using nitrogen evaporation and analysis with high performance liquid chromatography–ultraviolet spectroscopy(HPLC–UV). Sample extraction was carried out using a Waters Sep-Pak AC-2 Cartridge(with activated carbon).Separation was achieved on a ZIC-Hydrophilic Interaction Liquid Chromatography(ZIC-HILIC)(50 mm × 2.1 mm, 3.5 μm) chromatography column and quantification was accomplished based on UV absorbance. A reliable linear relationship was obtained for the calibration curve using standard solutions(R^2〉 0.999). Recoveries for dicyandiamide ranged from 84.6% to 96.8%, and the relative standard deviations(RSDs, n = 3) were below 6.1% with a detection limit of 5.0 ng/m L for stream water samples.展开更多
基金the National Key Research and Development Program of China(Grant Nos.2017YFB-0404302 and 2017YFB0404300).
文摘In this work,we developed a continuous preparation strategy for the production of high-solidscontent waterborne polyurethane(WPU)emulsions via high-gravity-assisted emulsification in a rotating packed bed(RPB)reactor.By adjusting the experimental parameters and formula,WPU emulsions with a high solids content of 55%and alow viscosity were prepared.Preliminary applications of the high-solids-content WPU as a thermally insulating material were demonstrated.RPB emulsification is an economical and environmentally friendly production strategy because of the low energy consumption,short emulsification time,and effective devolatilization.This study demonstrated an effective method for preparation of high-solids-content WPU,moving toward commercialization and industrialization.
文摘The combustion (ballistic) properties of a high solid loading composite solid propellant family (Butalites) was studied experimentally by using propellant formulations based on hydroxy-terminated polybutadiene pre-polymer (HTPB) as a fuel binder main backbone, bimodal system ammonium perchlorate oxidizer (AP) and aluminum powder (AI) as metallic fuel. Burning rates were doubled at various pressures, when solids loading (AP and 17% A1) were increased from 80 to 88% and the measured characteristic velocity values were increased by about 100m/sec. The pressure exponent (n) values were lower with 80-85% solids loading. The burning rates were increased by about 2-5% when comparing the data obtained by static firing with those obtained by the strand burner method.
基金Supported by the National Natural Science Foundation of China(No.51674161)Major Basic Research Projects of Shandong Province Natural Science Foundation(No.ZR2017ZC0735)+1 种基金Open Topic of Key Laboratory of Gold Mineralization Processes and Resource Utilization Subordinated to the Ministry of Land and Resources and Key Laboratory of Metallogenic Geological Process and Resources Utilization in Shandong Province(No.Kfkt201812)Research on Precious Metal Mineral Achievement Integration and Tailings Comprehensive Utilization in Shandong Province(Shandong Geological Exploration Document:[2018]No.10)。
文摘Low-cost thermal insulation porous ceramics with uniform pore diameter and low bulk density were prepared with soda-ash dregs and felsic tailings.We investigated the effect of temperature,foaming agent,fluxing agent,Al_(2)O_(3)and CaO content on the pore structure and crystal phase of porous ceramics.The effect of Ca^(2+)in soda-ash dregs on the preparation of quartz-feldspar based porous ceramics was studied.The results showed that the contribution of Ca^(2+)to the preparation of porous ceramics in this system was mainly to accelerate the Si-O bond fracture and reduce the sintering temperature at the initial stage of sintering,which destroyed the needle-like feldspar in the high temperature melt and reduced the melt viscosity,thus reduced the foaming resistance and promoted the porous products with uniform pore size distribution.The Ca^(2+)content on the high side can participate in the formation of crystals in sintering.The generated needle-like diopside and augite,which have small length-diameter ratio,will negligibly change in the viscosity of melt at high temperatures,and their inhibition effect on pores is not as good as that of feldspar with large length-diameter ratio,resulting in the merger and collapse of pores.But the increase of diopside and augite can improve the compressive strength of porous products to some extent.Porous ceramic products containing needle-like feldspar phase can be prepared by using two kinds of solid waste,which can improve the compressive strength of the products and reduce the raw material cost and energy consumption while comprehensively utilizing the double solid waste.The optimal product has a bulk density of 0.45 g/cm^(3),a compressive strength of 3.17 MPa,and a thermal conductivity of 0.11 W/(m·K).
基金Supported by the National Natural Science Foundation of China(90922021,20773130,20733003,20803080,20973175)"Knowledge Innovation Program of the Chinese Academy of Sciences"(KJCX2-YW-H20,CXJJ-11-M71)
文摘A new quaternary rare-earth sulfide, Cs0.75(6)Er443(5)In3.32(6)S12 (1), is discovered by high temperature solid state reactions with a slight excess of CsCI flux. The structure is characterized by single-crystal X-ray diffraction data, while crystallizes in hexagonal space group P63/m (No. 176) with a = 12.0329(6), c = 3.8693(5)A, V= 485.18(7) A3, Z = 1, Mr = 1606.57, Dc = 5.499 g/cm3,μ = 25.457 mm-1, F(000) = 752, the final R = 0.0337 and wR = 0.0904 for 328 observed reflections with I 〉 2σ(I). Its structure features a three-dimensional framework with hexagonal channels that are centered by Cs cations. Such channels are formed by double chains of edge-sharing M(1)S6 (M(1) = Er(1)/In(1)) octahedra and single chains of Er(2)S6 triprism interconnected by corner-sharing. The syntheses, single-crystal analyses, optical band gap and magnetic property are reported.
基金supported by Coordination for the Improvement of Higher Education Personnel Foundation,Mmistry of Education in Brazil(Grant No.POS-DOC-88881.170076/2018-01).
文摘The conversion of rice hulls into fermentable saccharides was explored through steam pretreatment employing 2.5% SO_(2).The in teraction between temperature and time was assessed by means of the response surface method to achieve optimum contents of C6-sugars in water-insoluble solids(WIS)and C5-sugars in the liquor.Pretreatment carried out at 218℃ for 2.3 min released liquor containing 55.4 g/L of sugars(29.1 g/L of xylose).In parallel,the WIS was subjected to enzymatic saccharification using different solid and enzyme loads via an experimental design:assays using 22.0% WIS and 20.0 filter paper units(FPU)/g led to 90.6 g/L of glucose,corresponding to a yield of 86.4% and an overall yield of 72.4%.The data reported are the highest ever found for such raw material,making it attractive to compete with conventi on al lig no cellulosic biomass.
基金Supported by the Scientific Research Funds from China University of Petroleum(Beijing)(No.2462014YJRC018)partially supported by the National Natural Science Foundation of China(No.21506253 and No.91534204)
文摘In the last several decades, circulating fluidized bed reactors have been studied in many aspects including hydrodynamics, heat and mass transfer and gas–solid two phase contacting. However, despite the abundance of review papers on hydrodynamics, there is no summary paper on gas–solid contact efficiency to date, especially on high density circulating fluidized beds(CFBs). This paper gives an introduction to, and a review of the measurement of contact efficiency in circulating fluidized bed riser. Firstly, the popular testing method of contact efficiency including the method of heating transfer experiment and hot model reaction are discussed, then previous published papers are reviewed based on the discussed methods. Some key results of the experimental work are described and discussed. Gas–solid contact efficiency is affected by the operating conditions as well as the particle size distribution. The result of the contact efficiency shows that the CFB riser is far away from an ideal plug flow reactor due to the characteristics of hydrodynamics in the riser. Lacunae in the available literature have been delineated and recommendations have been made for further work.
基金the research grant from Institute of Crustal Dynamics,CEA (No.ZDJ2013-07)Key Project of the National Twelfth-Five Year Research Program of China (No.2012BAK19B)
文摘Borehole inclinometers are important observation instruments used to measure ground tilt movement and monitor crustal deformation of solid tides and geological landslide disasters.They are widely used in oil exploration,mineral resource drilling,well logging,exploration and other fields.There is potential for development of rock stress strain monitoring tools.Many types of tiltmeters have been installed,such as SQ-7,FSQ,VS and JB.However,these tiltmeters are generally installed in a deep cave to avoid the interference of temperature,humidity,and human activities.With the urbanization of human society,suitable installation locations are difficult to find.To solve the problem,a two-component borehole tiltmeter,named the CBT-type tiltmeter,is proposed in this paper.It can be installed in a borehole less than500 m deep to eliminate environmental influences.The tiltmeter is composed of two sophisticated gravitational swing and two capacitive transducers.From preliminary theory and experiment analysis,its linear correlation coefficient is higher than 0.99,its co-seismic response is rapid and its noise level is up to 10 4arc seconds in practice.
基金supported by the Shaanxi Youth Thousand Talents Project(A279021901)the Scientific and Technological Activities for Overseas Researchers in Shaanxi Province(20200002)+3 种基金the Chinese Universities Scientific Fund(2452021112)the Key Research and Development Project of Shaanxi Province(2020NY-114)the Double first-class construction project funded by Northwest A&F University,Northwest A&F University Young Talent Project(Z111021902)the USA Energy Foundation(G-2206-33957).
文摘Dry corn straw(DCS)is usually used in anaerobic digestion(AD),but fresh corn straw(FCS)has been given less consideration.In this study,the thermophilic AD of single-substrate(FCS and DCS)and co-digestion(straw with cattle manure)were investigated.The results show that when FCS was used as the single-substrate for AD,the methane production was 144 mL·g^(−1)·VS^(−1),which was 7.5%and 19.6%higher than that of single DCS and FCS with cattle manure,respectively.In addition,the structure of FCS was loose and coarse,which was easier to be degraded than DCS.At the hydrolysis and acidification stages,Clostridium_sensu_stricto_1,Clostridium_sensu_stricto_7 and Sporosarcina promoted the decomposition of organic matter,leading to volatile fatty acids(VFAs)accumulation.Methanosarcina(54.4%)activated multifunctional methanogenic pathways to avoid the VFAs inhibition,which was important at the CH_(4) production stage.The main pathway was hydrogenotrophic methanogenesis,with genes encoding formylmethanofuran dehydrogenase(K00200-K00203)and tetrahydromethanopterin Smethyltransferase(K00577-K00584).Methanosarcina also activated acetotrophic and methylotrophic methanogenesis pathways,with genes encoding acetyl phosphate(K13788)and methyl-coenzyme M reductase(K04480,K14080 and K14081),respectively.In the co-digestion,the methanogenic potential of FCS was also confirmed.This provides a scientific basis for regulating AD of crop straw.
基金Wengfu Phosphate Fertilizer Plant(WPFP),WengFu(Group) Co.,Ltd,Guizhou,China for financial supportgrants from National Science and Technology Support Program(No.2012BAA08B00)Science and Technology Integrated Innovation Project of Shaanxi Province(No.2012KTZB03-04)
文摘Ammonium sulfate residue is a particulate solid and is produced during the manufacture of ammonium sulfate fertilizer. The residue used in this study contained a large portion of calcium carbonate, from which active lime (CaO) was recovered via thermal decomposition. We used a purpose-built device to decom- pose the residue in a semi-suspension state. We found that CaO had the highest activity when residue was decomposed at 850-900 ~C. Our experiments indicated that ammonium sulfate residue should be decom- posed in a suspension state to produce active CaO. Based on our laboratory test findings, an industrial-scale production line with a high solid/gas ratio in a suspension state was devised. The optimal operating con- ditions for the decomposition of the ammonium sulfate residue to produce high quality CaO were also investigated.We found that the CaCO3 decomposition rate was high and the CaO product was highly active, averaging 170 s by the citric acid method. Morphology measurements showed that the CaO product had a porous structure and a large specific surface ensuring high activity.
基金support from the National Natural Science Foundation of China (No. 11372103 and 11572118)the Hunan Provincial Science Fund for Distinguished Young Scholars (No. 2015JJ1006)+1 种基金the Fok Ying-Tong Education Foundation, China (No. 141005)the project of Innovation-driven Plan of Central South University, the State Key Laboratory of Powder Metallurgy
文摘An analytical model is established to study the influence of lattice distortion and fraction of Hf on the yield strength of the BCC TiNbTaZrHfx multi-component high entropy alloys (HEAs). Meanwhile, the mechanism of solid solution strengthening caused by lattice distortion is also discussed in the HEA. The distorted unit cell is introduced to indicate the lattice distortion effects induced by the differences of the atomic size and shear modulus by doping other elements in Ti-based metal. The results show that the calculated values of the alloying yield strength considering the path of least resistance are obtained with regard to various grain sizes for the equiatomic TiNbTaZrHf HEA, which is well in line with the experimental results. Furthermore, it is predicted that the alloying yield strength is the largest value in the case of the same grain size for the Hf atomic fraction of 0.122. The meaningful modeling could provide a theoretical method to investigate the yield strength and alloying design of other BCC HEAs in the future.
基金financially supported by the National Natural Science Foundation of China(No.32071686)。
文摘High solid content CO_(2)-based cationic waterborne polyurethanes(CWPUs)were prepared using CO_(2)-polyols as soft segment and Nmethyl diethanolamine(MDEA)as hydrophilic group.The resulting stable aqueous dispersion displayed a high solid content of 52%with a low MDEA loading of 3.52 wt%.This novel structural CWPU can provide excellent adhesive strength,whose T-peel strength could reach 173.48N/5cm,20%higher than that of ester-based cationic waterborne polyurethane(87.55 N/5cm).The CO_(2)-based CWPU film showed only 2 wt%swelling percentage after 240 min immersion in water,and no change was observed during its immersion in 5 wt%sodium hydroxide solution.The tensile strength of CO_(2)-WPUs dropped slowly to 91.2%after 480 min immersion in a 5 wt%sodium hydroxide solution,whereas that of esterbased CWPUs dropped quickly to 32%after 240 min and their mechanical properties were lost after 360 min immersion.Meanwhile,the retention of the tensile strength of the CO_(2)-CWPUs was 81.5%even after 720 min immersion in 10 wt%H_(2)O_(2) solution,while it was only ca.38%for the ester-based CWPUs.These results indicated that the cationic CO_(2)-based CWPU may be promising waterborne adhesive with outstanding ageing resistance due to its synergistic effect from carbonate and ether groups of CO_(2)-polyol structure.
基金973 Program,the National Natural Science Foundation of China,the Research Fund for the Doctoral Program of Higher Education of China,the Project of Jilin Province
文摘A novel organic fluorophor with high solid state luminescent efficiency based on 1,4-bis(2,2-di(pyridin-2-yl)- vinyl)benzene (BDP2VB) was designed and synthesized. It emits faintly in solution, but becomes a strong emitter in the aggregate state, demonstrating its aggregation induced emission (AIE) property. According to the crystal struc- ture analysis, J-type aggregation was formed in the packing mode of the molecule, which was demonstrated to be beneficial to gain high fluorescent quantum efficiency in solid state. Additionally, the emission color of BDP2VB can change dramatically in solid state as well as in solution by the protonation stimuli.
基金supported by National High-tech Research and Development Program of China under Grant No.2006AA05A103
文摘High inlet solid loading is one of the most important features of cyclone separators in high density circulating fluidized beds (CFB). In this work, the effect of high solid loading on pressure drop in a reverse-flow cyclone was experimentally studied. The particles used were sand and 2zAl203. Art extended range of inlet solid loadings (M), up to 30 kg of solids/kg of air was tested at different inlet air velocities (Vin=16~24 m/s), well beyond the solid loading range reported before. The experiments showed that, in the tested range of solid loadings, the cyclone pressure drop decreased dramatically with increasing solid loading when M〈7.5 kg/kg and then almost remained constant. A new semi-empirical model for predicting cyclone pressure drop was also developed. The calculated and experimental results showed good agreement for particle free flow and particle laden flow.
文摘Ⅰ. INTRODUCTION 13C-CPMAS, the combination of magic angle spinning of specimen (MAS) with high power proton decoupling and 1H-13C cross-polarization (CP), is proved to be a powerful means for research. It enables us to have obtained high resolution NMR spectra of
基金Department of Chemistry at Mississippi State University for financial support for this project
文摘An improved method for trace level quantification of dicyandiamide in stream water has been developed. This method includes sample pretreatment using solid phase extraction.The extraction procedure(including loading, washing, and eluting) used a flow rate of1.0 m L/min, and dicyandiamide was eluted with 20 m L of a methanol/acetonitrile mixture(V/V = 2:3), followed by pre-concentration using nitrogen evaporation and analysis with high performance liquid chromatography–ultraviolet spectroscopy(HPLC–UV). Sample extraction was carried out using a Waters Sep-Pak AC-2 Cartridge(with activated carbon).Separation was achieved on a ZIC-Hydrophilic Interaction Liquid Chromatography(ZIC-HILIC)(50 mm × 2.1 mm, 3.5 μm) chromatography column and quantification was accomplished based on UV absorbance. A reliable linear relationship was obtained for the calibration curve using standard solutions(R^2〉 0.999). Recoveries for dicyandiamide ranged from 84.6% to 96.8%, and the relative standard deviations(RSDs, n = 3) were below 6.1% with a detection limit of 5.0 ng/m L for stream water samples.