The crystallization has significant influence on fluidity of slag and slag discharge of entrained-flow-bed(EFB) gasifier. The crystallization characteristics and fluidity of five synthetic slags with different MgO/CaO...The crystallization has significant influence on fluidity of slag and slag discharge of entrained-flow-bed(EFB) gasifier. The crystallization characteristics and fluidity of five synthetic slags with different MgO/CaO ratios prepared on the basis of the range of oxide contents of Zhundong coal ash were investigated in this study. The results show that with the MgO/CaO ratio increase, the initial crystallization temperature increases, and the main temperature range of crystallization ratio growth moves to higher temperature range gradually which causes Tp25(Tp25is the temperature corresponding to the viscosity of 25 Pa·s)to increase. Mg-rich crystals are formed preferentially than Ca-rich crystals when adding the same amount of MgO and CaO during cooling. The effective slagging operating temperature range decrease from 217 ℃ for the slag with a 0:4 MgO/CaO ratio to 44 ℃ for the slag with a 4:0 MgO/CaO ratio with the MgO/CaO ratio increase. The slags with 2:2 and 1:3 MgO/CaO ratios show similar effective slagging operating temperature range, Tp25and the temperature corresponding to the viscosity of 2 Pa·s.However, compared with the slag with a 1:3 MgO/CaO ratio, the crystallization ratio and rate of slag with a 2:2 MgO/CaO ratio are lower within lower temperature range(1300–1200 ℃), causing its lower critical viscosity temperature and wider actual operating temperature range. Of the five slags, the widest effective slagging operating temperature range and the lowest Tp25of the slag with a 0:4 MgO/CaO ratio due to its low crystallization ratio, and wider actual operating temperature range of the slag with a 2:2 MgO/CaO ratio make the two slags suitable for slag discharge of EFB gasifier.展开更多
China has paid considerable attention to developing and implementing a carbon labeling system in response to increasing environmental issues such as global warming.This paper aims to provide a theoretical basis for fo...China has paid considerable attention to developing and implementing a carbon labeling system in response to increasing environmental issues such as global warming.This paper aims to provide a theoretical basis for formulating and implementing a carbon labeling system in China through a study of consumer acceptance behavior and its influencing factors.This paper constructed an extended model of consumers’acceptance behavior of carbon neutral labels based on the theories and methods of Unified Theory of Acceptance and Use of Technology(UTAUT)and analyzed the effects of five factors(carbon label cognition,performance expectancy,effort expectancy,social influence,and facilitating factors)on consumer carbon neutral label acceptance and adoption.The structural equation model analysis revealed that carbon label cognition,performance expectancy,social influence,and facilitating factors significantly,and positively impact consumers’acceptance of carbon neutral labels.Moreover,carbon label cognition,performance expectancy,and facilitating factors significantly,and positively affect consumers’carbon neutral label adoption behavior.Meanwhile,carbon label cognition,and effort expectancy have no significant impact on consumers’willingness to accept carbon neutral labels,which in turn significantly impacts consumers’carbon neutral label adoption behavior.According to the research findings,increasing the promotion of carbon labeling and improving the practical strategies and management recommendations for carbon label design are proposed.展开更多
<div style="text-align:justify;"> Due to the poor anti-clogging performance of the common drip irrigation emitters, this paper designed a new bionic flow channel in the emitter based on the shape of sh...<div style="text-align:justify;"> Due to the poor anti-clogging performance of the common drip irrigation emitters, this paper designed a new bionic flow channel in the emitter based on the shape of shark dorsal fin. After preliminary structural design, the computational fluid dynamics (CFD) simulation showed that the bionic emitter exhibited superior anti-clogging performance and reasonable hydraulic performance. The passage rate of particles of the bionic emitter in simulation reached 96.3% which was 37.6% higher than 70% of traditional emitter, and the discharge exponent reached 0.4995 which was close to traditional emitter. Physical experiments were consistent with the CFD results, which confirmed the correctness of simulation. After a short cycle anti-clogging performance experiment, the bionic emitter still maintained 96.09% of the initial flow rate. </div>展开更多
Excess crude glycerol derived as a by-product from biodiesel industry prompts the need to valorise glycerol to value-added chemicals.In this context,catalytic steam reforming of glycerol(SRG) was proposed as a promisi...Excess crude glycerol derived as a by-product from biodiesel industry prompts the need to valorise glycerol to value-added chemicals.In this context,catalytic steam reforming of glycerol(SRG) was proposed as a promising and sustainable alternative for producing renewable hydrogen(H2).Herein,the development of nickel(Ni) supported on ceria-modified mesoporous γ-alumina(γ-Al2 O3) catalysts and their applications in catalytic SRG(at550-750℃ atmospheric pressure and weight hourly space velocity,WHSV,of 44,122 ml·g^-1·h^-1(STP)) is presented.Properties of the developed catalysts were characterised using many technique s.The findings show that ceria modification improved Ni dispersion on γ-Al2 O3 catalyst support with highly active small Ni particles,which led to a remarkable catalytic performance with the total glycerol conversion(ca.99%),glycerol conversion into gaseous products(ca.77%) and H2 yield(ca.62%).The formation rate for H2 production(14.4 ×10^(-5)mol·s^-1·g^-1, TOF(H2)=3412 s^-1) was significantly improved with the Ni@12 Ce-Al2 O3 catalyst,representing nearly a 2-fold increase compared with that of the conventional Ni@AI2 O3 catalyst.In addition,the developed catalyst also exhibited comparatively high stability(for 12 h) and coke resistance ability.展开更多
An experimental investigation was conducted to understand the roles of the Br?nsted acid H_2SO_4 and Lewis acid Al_2(SO_4)_3 in methyl levulinate(ML) production from biomass carbohydrates, including glucose,fructose a...An experimental investigation was conducted to understand the roles of the Br?nsted acid H_2SO_4 and Lewis acid Al_2(SO_4)_3 in methyl levulinate(ML) production from biomass carbohydrates, including glucose,fructose and cellulose. The product distributions with different catalysts revealed that the Lewis acid was responsible for the isomerization of methyl glucoside(MG), producing a significant amount of the subsequent product 5-methoxymethylfurfural(MMF), while the Br?nsted acid facilitated the production of ML from MMF. Al_2(SO_4)_3 was efficient for monosaccharide conversion but not for cellulose. Using ball-milled cellulose with Al_2(SO_4)_3 resulted in a desired ML yield within a reasonable reaction time. The significant catalysis performances of two types of acids will guide the design of efficient catalytic processes for the selective conversion of biomass into levulinate esters.展开更多
With the help of Aspen Plus,a two-dimensional unsteady CFD model is developed to simulate the coal gasification process in a fixed bed gasifier.A developed and validated two dimensional CFD model for coal gasification...With the help of Aspen Plus,a two-dimensional unsteady CFD model is developed to simulate the coal gasification process in a fixed bed gasifier.A developed and validated two dimensional CFD model for coal gasification has been used to predict and assess the viability of the syngas generation from coal gasification employing the updraft fixed bed gasifier.The process rate model and the sub-model of gas generation are determined.The particle size variation and char burning during gasification are also taken into account.In order to verify the model and increase the understanding of gasification characteristics,a set of experiments and numerical comparisons have been carried out.The simulated results in the bed are used to predict the composition of syngas and the conversion of carbon.The model proposed in this paper is a promising tool for simulating the coal gasification process in a fixed bed gasifier.展开更多
Conversion of levulinic acid and its esters into versatile y-valerolactone(GVL)is a pivotal and challenging step in biorefineries,limited by high catalyst cost,the use of hydrogen atmosphere,or tedious catalyst prepar...Conversion of levulinic acid and its esters into versatile y-valerolactone(GVL)is a pivotal and challenging step in biorefineries,limited by high catalyst cost,the use of hydrogen atmosphere,or tedious catalyst preparation and recycling process.Here we have successfully synthesized a ternary magnetic nanoparticle catalyst(Al_(2)O_(3)-ZrO_(2)/Fe_(3)O_(4)(5)),over which biomass-derived methyl levulinate(ML)can be quantitively converted to GVL with an extremely high selectivity of>99%and yield of-98%in the absence of molecular hydrogen.Al_(2)O_(3)-ZrO_(2)/Fe_(3)O_(4)(5)incorporates simultaneously inexpensive alumina and zirconia onto magnetite support by a facile coprecipitation method,giving rise to a core-shell structure,welldistributed acid-base sites,and strong magnetism,as evidenced by the X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),transmission electron microscopy(TEM),high-angle annular dark-field scanning-TEM(HAADF-STEM),SEM-energy dispersive Xray spectroscopy(SEM-EDX),temperature-programmed desorption of ammonia(NH3-TPD),temperature-programmed desorption of carbon dioxide(CO_(2)-TPD),pyridine-adsorption infrared spectra(Py-IR),and vibrating sample magnetometry(VSM).Such characteristics enable it to be highly active and easily recycled by a magnet for at least five cycles with a slight loss of its catalytic activity,avoiding a time-consuming and energy-intensive reactivation process.It is found that there was a synergistic effect among the metal oxides,and the high efficiency and selectivity originating from such synergism are evidenced by kinetic studies.Furthermore,a reaction mechanism regarding the hydrogenation of ML to GVL is proposed by these findings,coupled with gas chromatography-mass spectrometry(GC-MS)analysis.Accordingly,this readily synthesized and recovered magnetic nanocatalyst for conversion of biomassderived ML into GVL can provide an eco-friendly and safe way for biomass valorization.展开更多
Metal particles such as aluminum( Al),magnesium( Mg),boron( B) and nickel( Ni),as well as Mg/Al alloy( Mg/Al = 3/4) are currently the most widely used ingredients in modified doublebase propellants. In this contributi...Metal particles such as aluminum( Al),magnesium( Mg),boron( B) and nickel( Ni),as well as Mg/Al alloy( Mg/Al = 3/4) are currently the most widely used ingredients in modified doublebase propellants. In this contribution,the combustion properties of the metal species are studied by means of the high-speed photography technique and the non-contact wavelet-based measurement of flame temperature distribution. The combustion process of the Al,Mg and Mg/Al samples shows both gas phase reaction and surface oxidation,which yield volatile and nonvolatile products,corresponding to the oxide and suboxide respectively. However,the combustion of B and Ni shows only gas phase reaction,due to their high melting point as well as high enthalpy of vaporization. In addition to the experiments,a hypothetical combustion model has been proposed to clarify the combustion characteristics of metal species in modified double-base propellants.展开更多
In this study,the Powder River Basin(PRB)coal fast pyrolysis was conducted at 700°C in the atmosphere of syngas produced by CH4-CO2 reforming in two different patterns,including the double reactors pattern(the fi...In this study,the Powder River Basin(PRB)coal fast pyrolysis was conducted at 700°C in the atmosphere of syngas produced by CH4-CO2 reforming in two different patterns,including the double reactors pattern(the first reactor is for syngas production and the second is for coal pyrolysis)and double layers pattern(catalyst was at upper layer and coal was at lower layer).Besides,pure gases atmosphere including N2,H2,CO,H2-CO were also tested to investigate the mechanism of the coal pyrolysis under different atmospheres.The pyrolysis products including gas,liquid and char were characterized,the result showed that,compared with the inert atmosphere,the tar yield is improved with the reducing atmospheres,as well as the tar quality.The hydrogen partial pressure is the key point for that improvement.In the atmosphere of H2,the tar yield was increased by 31.3%and the contained BTX(benzene,toluene and xylene)and naphthalene were increased by 27.1%and 133.4%.The double reactors pattern also performed outstandingly,with 25.4%increment of tar yield and 25.0%and 79.4%for the BTX and naphthalene.The double layers pattern is not effective enough due to the low temperature(700°C)in which the Ni-based catalyst was not fully activated.展开更多
<b><span style="font-family:Verdana;">Purpos</span><span style="font-family:Verdana;">e</span></b><span style="font-family:Verdana;">:</b>&...<b><span style="font-family:Verdana;">Purpos</span><span style="font-family:Verdana;">e</span></b><span style="font-family:Verdana;">:</b></span><span style="font-family:Verdana;"> To explore the clinical efficacy of Changmaile II combined with </span><span style="font-family:""><span style="font-family:Verdana;">cyclic estrogen/progesterone therapy in treating hypomenorrhea caused by intrau</span><span style="font-family:Verdana;">terine adhesion (IUA) and its effect on the endometrium after the </span><span style="font-family:Verdana;">separation procedure for intrauterine adhesion. <b></span><b><span style="font-family:Verdana;">Methods</span></b></span><span style="font-family:Verdana;">:</b></span><span style="font-family:""><span style="font-family:Verdana;"> Sixty patients with IUA confirmed by hysteroscopy in the Second People’s Hospital of Fujian University of Traditional Chinese Medicine from March 2020 to December 2020 were selected and randomly divided into the control group and the observation group, with 30 cases in each group. After the separation procedure for intrauterine adhesion, the observation group underwent the cyclic estrogen/progesterone therapy alone, while the observation group was administered the in-hospital preparation of Changmaile II in addition to the therapy of the observation group. Menstrual recovery, endometrial thickness, and the diagnostic grading scores of IUA after 3 menstrual cycles were measured in both groups. <b></span><b><span style="font-family:Verdana;">Results</span></b></span><span style="font-family:Verdana;">:</b></span><span style="font-family:""><span style="font-family:Verdana;"> After the treatment for 3 menstrual cycles, the total effective rate was higher in the observation group (73.33%) than in the control group (53.33%) (P < 0.05). The period flow was heavier in the observation group than in the control group (P < 0.05). The endometrial thickness of both groups was thicker than before treatment (P < 0.05), nonetheless the difference between the groups was not statistically significant (P > 0.05). After treatment, the diagnostic grading scores of IUA were higher in the observation group than in the control group (P < 0.05). <b></span><b><span style="font-family:Verdana;">Conclusions</span></b></span><span style="font-family:Verdana;">:</b></span><span style="font-family:Verdana;"> Changmaile II combined with estrogen and progesterone artificial cycle therapy could increase the menstrual volume and endometrial thickness of patients with intrauterine adhesion, while promoting the endometrial repair, with</span><span style="font-family:""> </span><span style="font-family:Verdana;">better efficacy than artificial cycle therapy alone.</span>展开更多
The structural evolution and gasification reactivity of biochar prepared from the pyrolysis of wheat straw were investigated by in-situ Raman spectroscopy and thermogravimetric analysis.The Raman spectra consisted of ...The structural evolution and gasification reactivity of biochar prepared from the pyrolysis of wheat straw were investigated by in-situ Raman spectroscopy and thermogravimetric analysis.The Raman spectra consisted of a combination of four Lorentzian bands(D1,D2,D4,G)and one Gaussian band(D3)in the first-order region.The experimental results showed that the addition of catalysts or the presence of ash could improve the CO_(2) gasification reactivity of biochar and result in a larger ID1/IG ratio and a lower IG/IALL ratio,meaning that the carbon structure was less ordered,and there were also more active sites such as amorphous carbon and cross-linked structures;Ca-based catalysts and K-based catalysts changed the evolution of biochar structure in a different way in CO_(2) atmosphere,the ID3/ID1 of Ca-based biochar was close to the value of non-catalyst biochar and decreased slowly,indicating that the Ca-based catalysts can stabilize the aromatic rings,while the IG/IALL of K-based biochar decreases significantly and the ID3/ID1 increased significantly,indicating the increase of carbon structure defects and the cracking of large aromatic rings in bio-char into small ones;a scheme of K and Ca reaction with biochar in CO_(2) gasification process was proposed.展开更多
Denitrification is one of the major processes causing nitrogen loss from arable soils.This study aimed to investigate the responses of nir S-type denitrifier communities to different chronic fertilization regimes acro...Denitrification is one of the major processes causing nitrogen loss from arable soils.This study aimed to investigate the responses of nir S-type denitrifier communities to different chronic fertilization regimes across the black soil region of Northeast China.Soil samples were collected from sites located in the north(NB),middle(MB),and south(SB)of the black soil region of Northeast China,each with four chronic fertilization regimes:no fertilizer(No F),chemical fertilizer(CF),manure(M),and chemical fertilizer plus manure(CFM).Methods of quantitative polymerase chain reaction(q PCR)and Illumina Mi Seq sequencing were applied to assess the abundance and composition of denitrifier communities by targeting the nir S gene.The results showed that the M and CFM regimes significantly increased the abundances of nir S-type denitrifiers compared with No F at the three locations.The majority of nir S sequences were grouped as unclassified denitrifiers,and the different fertilizers induced little variation in the relative abundance of known nir S-type denitrifier taxa.Over 90%of the sequences were shared among the four fertilization regimes at each location,but none of the abundant operational taxonomic units(OTUs)were shared among the three locations.Principal coordinate analysis(PCo A)revealed that the communities of nir S-type denitrifier were separated into three groups that corresponded with their locations.Although similar fertilization regimes did not induce consistent changes in the nir S-type denitrifier communities,soil p H and NO-3-N content simultaneously and significantly influenced the structure of nir S-type denitrifier communities at the three locations.Our results highlight that geographical separation rather than chronic fertilization was the dominant factor determining the nir S-type denitrifier community structures,and similar chronic fertilization regimes did not induce consistent shifts of nir S-type denitrifier communities in the black soils.展开更多
Scattering is a huge challenge for microscopic imaging.Indeed,it is difficult to observe target chemicals in scattering media by means of the current Gaussian beam-based stimulated Raman scattering(SRS)microscopy,sinc...Scattering is a huge challenge for microscopic imaging.Indeed,it is difficult to observe target chemicals in scattering media by means of the current Gaussian beam-based stimulated Raman scattering(SRS)microscopy,since the tight focus of the Gaussian beam is destroyed after propagating through a certain distance.Bessel beams,featuring self-reconstructing property,may bring a solution to this problem.By combining Bessel beams with SRS microscopy,we can probe the SRS signal from a scattering medium.In this paper,using the beam propagation method,we first simulate the propagation of the Bessel beam as well as the generation and self-reconstruction of SRS signals.By adding glass beads along the beam propagation path in order to simulate scattering,the propagation of the Bessel beams and the generation of the SRS signals will change.Then,we design a series of simulations to investigate the influence of the size,position,number,and distribution of the added glass beads on the generation of the SRS signals.A preliminary experiment is also carried out to confirm the simulation predictions.Results demonstrate that the SRS signals can be generated or be recovered at a certain depth in scattering media,and that such signals are greatly affected by the parameters of the scatters.展开更多
Nitrogen(N),phosphate(P),and potassium(K)are the three most important nutrients applied into agricultural soils,but the impacts of their single or combined application on soil fungal community structure and stability ...Nitrogen(N),phosphate(P),and potassium(K)are the three most important nutrients applied into agricultural soils,but the impacts of their single or combined application on soil fungal community structure and stability are still open questions.Using qPCR and Illumina Miseq sequencing,the variation of soil fungal communities in response to long-term addition of N,P,or K fertilization alone and their combinations in a Mollisol field was investigated in this study.In addition,the fungal community resistance indices and network structure were studied.Results showed that N fertilizations(N,NK,NP and NPK treatments)rather than P,K fertilizations(P,K and PK treatments)significantly increased fungal abundance,but decreased fungal diversity and shifted fungal community structures when compared to non-fertilization(NoF).Additionally,N fertilization treatments presented lower resistance of fungal communities to environment disturbances than those of P,K fertilization treatments.More numbers and higher abundances of changed fungal taxa at the genus and OTU levels were induced by N fertilizations rather than by addition of P,K fertilizers.In addition,N fertilizations induced a more changeable fungal network and complex pathogenic subnetwork with many positive interactions among responding plant pathogens(RP,the changeable plant pathogens induced by fertilizers addition compared to NoF)when compared to P,K fertilizations.These RP directly and negatively influenced fungal community resistance examined by structural equation modeling(SEM),which were indirectly detrimental to soybean yields.Our findings revealed that addition of N fertilizers significantly disturbed fungal communities and promoted pathogenic interactions,and provided insights into the optimization of fertilization strategies toward agricultural sustainability.展开更多
基金supported by the National Natural Science Foundation of China(21878082).
文摘The crystallization has significant influence on fluidity of slag and slag discharge of entrained-flow-bed(EFB) gasifier. The crystallization characteristics and fluidity of five synthetic slags with different MgO/CaO ratios prepared on the basis of the range of oxide contents of Zhundong coal ash were investigated in this study. The results show that with the MgO/CaO ratio increase, the initial crystallization temperature increases, and the main temperature range of crystallization ratio growth moves to higher temperature range gradually which causes Tp25(Tp25is the temperature corresponding to the viscosity of 25 Pa·s)to increase. Mg-rich crystals are formed preferentially than Ca-rich crystals when adding the same amount of MgO and CaO during cooling. The effective slagging operating temperature range decrease from 217 ℃ for the slag with a 0:4 MgO/CaO ratio to 44 ℃ for the slag with a 4:0 MgO/CaO ratio with the MgO/CaO ratio increase. The slags with 2:2 and 1:3 MgO/CaO ratios show similar effective slagging operating temperature range, Tp25and the temperature corresponding to the viscosity of 2 Pa·s.However, compared with the slag with a 1:3 MgO/CaO ratio, the crystallization ratio and rate of slag with a 2:2 MgO/CaO ratio are lower within lower temperature range(1300–1200 ℃), causing its lower critical viscosity temperature and wider actual operating temperature range. Of the five slags, the widest effective slagging operating temperature range and the lowest Tp25of the slag with a 0:4 MgO/CaO ratio due to its low crystallization ratio, and wider actual operating temperature range of the slag with a 2:2 MgO/CaO ratio make the two slags suitable for slag discharge of EFB gasifier.
基金supported by the National Social Science Foundation of China[Grant number.17BXW104]the Innorative School Project in Higher Education of Guangdong,China[Grant number.2016WZDXM025].
文摘China has paid considerable attention to developing and implementing a carbon labeling system in response to increasing environmental issues such as global warming.This paper aims to provide a theoretical basis for formulating and implementing a carbon labeling system in China through a study of consumer acceptance behavior and its influencing factors.This paper constructed an extended model of consumers’acceptance behavior of carbon neutral labels based on the theories and methods of Unified Theory of Acceptance and Use of Technology(UTAUT)and analyzed the effects of five factors(carbon label cognition,performance expectancy,effort expectancy,social influence,and facilitating factors)on consumer carbon neutral label acceptance and adoption.The structural equation model analysis revealed that carbon label cognition,performance expectancy,social influence,and facilitating factors significantly,and positively impact consumers’acceptance of carbon neutral labels.Moreover,carbon label cognition,performance expectancy,and facilitating factors significantly,and positively affect consumers’carbon neutral label adoption behavior.Meanwhile,carbon label cognition,and effort expectancy have no significant impact on consumers’willingness to accept carbon neutral labels,which in turn significantly impacts consumers’carbon neutral label adoption behavior.According to the research findings,increasing the promotion of carbon labeling and improving the practical strategies and management recommendations for carbon label design are proposed.
文摘<div style="text-align:justify;"> Due to the poor anti-clogging performance of the common drip irrigation emitters, this paper designed a new bionic flow channel in the emitter based on the shape of shark dorsal fin. After preliminary structural design, the computational fluid dynamics (CFD) simulation showed that the bionic emitter exhibited superior anti-clogging performance and reasonable hydraulic performance. The passage rate of particles of the bionic emitter in simulation reached 96.3% which was 37.6% higher than 70% of traditional emitter, and the discharge exponent reached 0.4995 which was close to traditional emitter. Physical experiments were consistent with the CFD results, which confirmed the correctness of simulation. After a short cycle anti-clogging performance experiment, the bionic emitter still maintained 96.09% of the initial flow rate. </div>
基金funding from European Union's Horizon 2020 research and innovation programme under grant agreement No.872102financial support by the Petroleum Technology Development Fund(PTDF),Nigeria(PTDF/ED/OSS/PHD/IA/1209/17)+2 种基金financial support from the European Commission Marie Sklodowska-Curie Individual Fellowship(H2020-MSCAIF-NTPleasure-748196)the Chinese Scholarship Council(CSC)for her academic visiting fellowship at the University of Manchester(No.201708440477)the Foundation of Department of Education of Guangdong Province(Nos.2017KZDXM085,2018KZDXM070)。
文摘Excess crude glycerol derived as a by-product from biodiesel industry prompts the need to valorise glycerol to value-added chemicals.In this context,catalytic steam reforming of glycerol(SRG) was proposed as a promising and sustainable alternative for producing renewable hydrogen(H2).Herein,the development of nickel(Ni) supported on ceria-modified mesoporous γ-alumina(γ-Al2 O3) catalysts and their applications in catalytic SRG(at550-750℃ atmospheric pressure and weight hourly space velocity,WHSV,of 44,122 ml·g^-1·h^-1(STP)) is presented.Properties of the developed catalysts were characterised using many technique s.The findings show that ceria modification improved Ni dispersion on γ-Al2 O3 catalyst support with highly active small Ni particles,which led to a remarkable catalytic performance with the total glycerol conversion(ca.99%),glycerol conversion into gaseous products(ca.77%) and H2 yield(ca.62%).The formation rate for H2 production(14.4 ×10^(-5)mol·s^-1·g^-1, TOF(H2)=3412 s^-1) was significantly improved with the Ni@12 Ce-Al2 O3 catalyst,representing nearly a 2-fold increase compared with that of the conventional Ni@AI2 O3 catalyst.In addition,the developed catalyst also exhibited comparatively high stability(for 12 h) and coke resistance ability.
基金supported by the National Key R&D Program of China (No. 2016YFE0112800)the European Union’s Horizon 2020 research and innovation programme (No. 690142)+1 种基金the project Agro Cycle (Sustainable techno-economic solutions for the agricultural value chain)the National Natural Science Foundation of China (No. 31671572)
文摘An experimental investigation was conducted to understand the roles of the Br?nsted acid H_2SO_4 and Lewis acid Al_2(SO_4)_3 in methyl levulinate(ML) production from biomass carbohydrates, including glucose,fructose and cellulose. The product distributions with different catalysts revealed that the Lewis acid was responsible for the isomerization of methyl glucoside(MG), producing a significant amount of the subsequent product 5-methoxymethylfurfural(MMF), while the Br?nsted acid facilitated the production of ML from MMF. Al_2(SO_4)_3 was efficient for monosaccharide conversion but not for cellulose. Using ball-milled cellulose with Al_2(SO_4)_3 resulted in a desired ML yield within a reasonable reaction time. The significant catalysis performances of two types of acids will guide the design of efficient catalytic processes for the selective conversion of biomass into levulinate esters.
基金The research was supported by the National Key Research and Development Project(2016YFB060040202).
文摘With the help of Aspen Plus,a two-dimensional unsteady CFD model is developed to simulate the coal gasification process in a fixed bed gasifier.A developed and validated two dimensional CFD model for coal gasification has been used to predict and assess the viability of the syngas generation from coal gasification employing the updraft fixed bed gasifier.The process rate model and the sub-model of gas generation are determined.The particle size variation and char burning during gasification are also taken into account.In order to verify the model and increase the understanding of gasification characteristics,a set of experiments and numerical comparisons have been carried out.The simulated results in the bed are used to predict the composition of syngas and the conversion of carbon.The model proposed in this paper is a promising tool for simulating the coal gasification process in a fixed bed gasifier.
基金financed by the National Natural Science Foundation of China(31671572)the National Key R&D Program of China(2016YFE0112800)the Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(IRT-17R105)。
文摘Conversion of levulinic acid and its esters into versatile y-valerolactone(GVL)is a pivotal and challenging step in biorefineries,limited by high catalyst cost,the use of hydrogen atmosphere,or tedious catalyst preparation and recycling process.Here we have successfully synthesized a ternary magnetic nanoparticle catalyst(Al_(2)O_(3)-ZrO_(2)/Fe_(3)O_(4)(5)),over which biomass-derived methyl levulinate(ML)can be quantitively converted to GVL with an extremely high selectivity of>99%and yield of-98%in the absence of molecular hydrogen.Al_(2)O_(3)-ZrO_(2)/Fe_(3)O_(4)(5)incorporates simultaneously inexpensive alumina and zirconia onto magnetite support by a facile coprecipitation method,giving rise to a core-shell structure,welldistributed acid-base sites,and strong magnetism,as evidenced by the X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),transmission electron microscopy(TEM),high-angle annular dark-field scanning-TEM(HAADF-STEM),SEM-energy dispersive Xray spectroscopy(SEM-EDX),temperature-programmed desorption of ammonia(NH3-TPD),temperature-programmed desorption of carbon dioxide(CO_(2)-TPD),pyridine-adsorption infrared spectra(Py-IR),and vibrating sample magnetometry(VSM).Such characteristics enable it to be highly active and easily recycled by a magnet for at least five cycles with a slight loss of its catalytic activity,avoiding a time-consuming and energy-intensive reactivation process.It is found that there was a synergistic effect among the metal oxides,and the high efficiency and selectivity originating from such synergism are evidenced by kinetic studies.Furthermore,a reaction mechanism regarding the hydrogenation of ML to GVL is proposed by these findings,coupled with gas chromatography-mass spectrometry(GC-MS)analysis.Accordingly,this readily synthesized and recovered magnetic nanocatalyst for conversion of biomassderived ML into GVL can provide an eco-friendly and safe way for biomass valorization.
基金Supported by the Science and Technology on Combustion and Explosion Laboratory Foundation(9140C350319140C35161)
文摘Metal particles such as aluminum( Al),magnesium( Mg),boron( B) and nickel( Ni),as well as Mg/Al alloy( Mg/Al = 3/4) are currently the most widely used ingredients in modified doublebase propellants. In this contribution,the combustion properties of the metal species are studied by means of the high-speed photography technique and the non-contact wavelet-based measurement of flame temperature distribution. The combustion process of the Al,Mg and Mg/Al samples shows both gas phase reaction and surface oxidation,which yield volatile and nonvolatile products,corresponding to the oxide and suboxide respectively. However,the combustion of B and Ni shows only gas phase reaction,due to their high melting point as well as high enthalpy of vaporization. In addition to the experiments,a hypothetical combustion model has been proposed to clarify the combustion characteristics of metal species in modified double-base propellants.
基金The author would like to appreciate the funding supports of the State of Wyoming and China Scholarship Council.Without their supports,the international collaboration on clean energy technology development would have been impossible.
文摘In this study,the Powder River Basin(PRB)coal fast pyrolysis was conducted at 700°C in the atmosphere of syngas produced by CH4-CO2 reforming in two different patterns,including the double reactors pattern(the first reactor is for syngas production and the second is for coal pyrolysis)and double layers pattern(catalyst was at upper layer and coal was at lower layer).Besides,pure gases atmosphere including N2,H2,CO,H2-CO were also tested to investigate the mechanism of the coal pyrolysis under different atmospheres.The pyrolysis products including gas,liquid and char were characterized,the result showed that,compared with the inert atmosphere,the tar yield is improved with the reducing atmospheres,as well as the tar quality.The hydrogen partial pressure is the key point for that improvement.In the atmosphere of H2,the tar yield was increased by 31.3%and the contained BTX(benzene,toluene and xylene)and naphthalene were increased by 27.1%and 133.4%.The double reactors pattern also performed outstandingly,with 25.4%increment of tar yield and 25.0%and 79.4%for the BTX and naphthalene.The double layers pattern is not effective enough due to the low temperature(700°C)in which the Ni-based catalyst was not fully activated.
文摘<b><span style="font-family:Verdana;">Purpos</span><span style="font-family:Verdana;">e</span></b><span style="font-family:Verdana;">:</b></span><span style="font-family:Verdana;"> To explore the clinical efficacy of Changmaile II combined with </span><span style="font-family:""><span style="font-family:Verdana;">cyclic estrogen/progesterone therapy in treating hypomenorrhea caused by intrau</span><span style="font-family:Verdana;">terine adhesion (IUA) and its effect on the endometrium after the </span><span style="font-family:Verdana;">separation procedure for intrauterine adhesion. <b></span><b><span style="font-family:Verdana;">Methods</span></b></span><span style="font-family:Verdana;">:</b></span><span style="font-family:""><span style="font-family:Verdana;"> Sixty patients with IUA confirmed by hysteroscopy in the Second People’s Hospital of Fujian University of Traditional Chinese Medicine from March 2020 to December 2020 were selected and randomly divided into the control group and the observation group, with 30 cases in each group. After the separation procedure for intrauterine adhesion, the observation group underwent the cyclic estrogen/progesterone therapy alone, while the observation group was administered the in-hospital preparation of Changmaile II in addition to the therapy of the observation group. Menstrual recovery, endometrial thickness, and the diagnostic grading scores of IUA after 3 menstrual cycles were measured in both groups. <b></span><b><span style="font-family:Verdana;">Results</span></b></span><span style="font-family:Verdana;">:</b></span><span style="font-family:""><span style="font-family:Verdana;"> After the treatment for 3 menstrual cycles, the total effective rate was higher in the observation group (73.33%) than in the control group (53.33%) (P < 0.05). The period flow was heavier in the observation group than in the control group (P < 0.05). The endometrial thickness of both groups was thicker than before treatment (P < 0.05), nonetheless the difference between the groups was not statistically significant (P > 0.05). After treatment, the diagnostic grading scores of IUA were higher in the observation group than in the control group (P < 0.05). <b></span><b><span style="font-family:Verdana;">Conclusions</span></b></span><span style="font-family:Verdana;">:</b></span><span style="font-family:Verdana;"> Changmaile II combined with estrogen and progesterone artificial cycle therapy could increase the menstrual volume and endometrial thickness of patients with intrauterine adhesion, while promoting the endometrial repair, with</span><span style="font-family:""> </span><span style="font-family:Verdana;">better efficacy than artificial cycle therapy alone.</span>
基金supported by the Shanghai Engineering Research Center of Coal Gasification(18DZ2283900)the Fundamental Research Funds for the Central Universities and the National Natural Science Foundation of China(21676091).
文摘The structural evolution and gasification reactivity of biochar prepared from the pyrolysis of wheat straw were investigated by in-situ Raman spectroscopy and thermogravimetric analysis.The Raman spectra consisted of a combination of four Lorentzian bands(D1,D2,D4,G)and one Gaussian band(D3)in the first-order region.The experimental results showed that the addition of catalysts or the presence of ash could improve the CO_(2) gasification reactivity of biochar and result in a larger ID1/IG ratio and a lower IG/IALL ratio,meaning that the carbon structure was less ordered,and there were also more active sites such as amorphous carbon and cross-linked structures;Ca-based catalysts and K-based catalysts changed the evolution of biochar structure in a different way in CO_(2) atmosphere,the ID3/ID1 of Ca-based biochar was close to the value of non-catalyst biochar and decreased slowly,indicating that the Ca-based catalysts can stabilize the aromatic rings,while the IG/IALL of K-based biochar decreases significantly and the ID3/ID1 increased significantly,indicating the increase of carbon structure defects and the cracking of large aromatic rings in bio-char into small ones;a scheme of K and Ca reaction with biochar in CO_(2) gasification process was proposed.
基金the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB15010103)the National Key Research and Development Program of China(No.2017YFD0200604)+1 种基金the National Natural Science Foundation of China(No.41771284)the Chinese Biodiversity Monitoring and Research Network(Sino BON).
文摘Denitrification is one of the major processes causing nitrogen loss from arable soils.This study aimed to investigate the responses of nir S-type denitrifier communities to different chronic fertilization regimes across the black soil region of Northeast China.Soil samples were collected from sites located in the north(NB),middle(MB),and south(SB)of the black soil region of Northeast China,each with four chronic fertilization regimes:no fertilizer(No F),chemical fertilizer(CF),manure(M),and chemical fertilizer plus manure(CFM).Methods of quantitative polymerase chain reaction(q PCR)and Illumina Mi Seq sequencing were applied to assess the abundance and composition of denitrifier communities by targeting the nir S gene.The results showed that the M and CFM regimes significantly increased the abundances of nir S-type denitrifiers compared with No F at the three locations.The majority of nir S sequences were grouped as unclassified denitrifiers,and the different fertilizers induced little variation in the relative abundance of known nir S-type denitrifier taxa.Over 90%of the sequences were shared among the four fertilization regimes at each location,but none of the abundant operational taxonomic units(OTUs)were shared among the three locations.Principal coordinate analysis(PCo A)revealed that the communities of nir S-type denitrifier were separated into three groups that corresponded with their locations.Although similar fertilization regimes did not induce consistent changes in the nir S-type denitrifier communities,soil p H and NO-3-N content simultaneously and significantly influenced the structure of nir S-type denitrifier communities at the three locations.Our results highlight that geographical separation rather than chronic fertilization was the dominant factor determining the nir S-type denitrifier community structures,and similar chronic fertilization regimes did not induce consistent shifts of nir S-type denitrifier communities in the black soils.
基金National Key Rssearch and Development Pro-gram of China(2018YFC0910600)National Natural Science Foundation of China(81871397,81627807,11727813,91859109,81571725)+3 种基金Fok Ying Tung Education Foundation(161104)Program for the Young Top-notch Talent of Shaanxi ProvinceResearch Fund for Young Star of Science and Technology in Shaanxi Province(2018KJXX-018)Funded Projects for the Scientfic and Technological Activities for Exellent Overseas Rssearchers in Shaanxi Province(2017017).
文摘Scattering is a huge challenge for microscopic imaging.Indeed,it is difficult to observe target chemicals in scattering media by means of the current Gaussian beam-based stimulated Raman scattering(SRS)microscopy,since the tight focus of the Gaussian beam is destroyed after propagating through a certain distance.Bessel beams,featuring self-reconstructing property,may bring a solution to this problem.By combining Bessel beams with SRS microscopy,we can probe the SRS signal from a scattering medium.In this paper,using the beam propagation method,we first simulate the propagation of the Bessel beam as well as the generation and self-reconstruction of SRS signals.By adding glass beads along the beam propagation path in order to simulate scattering,the propagation of the Bessel beams and the generation of the SRS signals will change.Then,we design a series of simulations to investigate the influence of the size,position,number,and distribution of the added glass beads on the generation of the SRS signals.A preliminary experiment is also carried out to confirm the simulation predictions.Results demonstrate that the SRS signals can be generated or be recovered at a certain depth in scattering media,and that such signals are greatly affected by the parameters of the scatters.
基金This study was financially supported from the Strategic Priority Research Program of Chinese Academy of Sciences(XDA28020201)the National Natural Science Foundation of China(41907035)the Natural Science Foundation of Heilongjiang Province(ZD2018009).
文摘Nitrogen(N),phosphate(P),and potassium(K)are the three most important nutrients applied into agricultural soils,but the impacts of their single or combined application on soil fungal community structure and stability are still open questions.Using qPCR and Illumina Miseq sequencing,the variation of soil fungal communities in response to long-term addition of N,P,or K fertilization alone and their combinations in a Mollisol field was investigated in this study.In addition,the fungal community resistance indices and network structure were studied.Results showed that N fertilizations(N,NK,NP and NPK treatments)rather than P,K fertilizations(P,K and PK treatments)significantly increased fungal abundance,but decreased fungal diversity and shifted fungal community structures when compared to non-fertilization(NoF).Additionally,N fertilization treatments presented lower resistance of fungal communities to environment disturbances than those of P,K fertilization treatments.More numbers and higher abundances of changed fungal taxa at the genus and OTU levels were induced by N fertilizations rather than by addition of P,K fertilizers.In addition,N fertilizations induced a more changeable fungal network and complex pathogenic subnetwork with many positive interactions among responding plant pathogens(RP,the changeable plant pathogens induced by fertilizers addition compared to NoF)when compared to P,K fertilizations.These RP directly and negatively influenced fungal community resistance examined by structural equation modeling(SEM),which were indirectly detrimental to soybean yields.Our findings revealed that addition of N fertilizers significantly disturbed fungal communities and promoted pathogenic interactions,and provided insights into the optimization of fertilization strategies toward agricultural sustainability.
