Biochar is increasingly proposed as a soil amendment, with reports of benefits to soil physical, chemical and biological properties. In this study, different biochars were produced from 6 feedstocks, including straw a...Biochar is increasingly proposed as a soil amendment, with reports of benefits to soil physical, chemical and biological properties. In this study, different biochars were produced from 6 feedstocks, including straw and poultry manure, at 3 pyrolysis temperatures （200, 300 and 500℃） and then added separately to a calcareous soil. Their effects on soil properties and maize growth were evaluated in a pot experiment. The biochars derived from crop straw had much higher C but smaller N concentrations than those derived from poultry manure. Carbon concentrations, pH and EC values increased with increasing pyrolysis temperature. Biochar addition resulted in increases in mean maize dry matter of 12.73% and NPK concentrations of 30, 33 and 283%, respectively. Mean soil pH values were increased by 0.45 units. The biochar-amended soils had 44, 55, 254 and 537% more organic C, total N, Olsen-P and available K, respectively, than the control on average. Both feedstocks and pyrolysis temperature determined the characteristics of the biochar. Biochars with high mineral concentrations may act as mineral nutrient supplements.展开更多
The rheological behaviors of feedstocks for powder extrusion molding, in the temperature range of 40～80 ℃ and the Newton shear rate of 3～800 s -1 , were studied. The effects of feedstock constitution, shear rate an...The rheological behaviors of feedstocks for powder extrusion molding, in the temperature range of 40～80 ℃ and the Newton shear rate of 3～800 s -1 , were studied. The effects of feedstock constitution, shear rate and temperature on apparent viscosity, shear stress and active energy were investigated. The viscose flow active energy of PEM feedstocks is 15.89～90.77 kJ/mol. Based on this research, the PEM technical parameters have optimized. [展开更多
L-malate is an intermediate of the tricarboxylic acid cycle which is naturally occurred in various microorganisms,and it has been widely applied in polymer,beverage and food,textile,agricultural and pharmaceutical ind...L-malate is an intermediate of the tricarboxylic acid cycle which is naturally occurred in various microorganisms,and it has been widely applied in polymer,beverage and food,textile,agricultural and pharmaceutical industries.Driven by the pursuit of a sustainable economy,microbial production of L-malate has received much attention in last decades.In this review,we focus on the utilization of wastes and/or byproducts as feedstocks for the microbial production of L-malate.Firstly,we present the recent developments on the natural or engineered metabolic pathways that dedicate to the biosynthesis of L-malate,and also provide a comprehensive discussions on developing high-efficient producers.Then,the recent achievements in microbial production of L-malate from various carbon sources were concluded and discussed.Furthermore,some abundant non-food feedstocks which have been used for microbial production of other chemicals were reviewed,as they may be potential candidate feedstock for L-malate production in future.Finally,we outlined the major challenges and proposed further improvements for the production of L-malate.展开更多
The increasing accumulation of discarded plastics has already caused serious environmental pollution.Simple landfills and incineration will inevitably lead to the loss of the abundant carbon resources contained in pla...The increasing accumulation of discarded plastics has already caused serious environmental pollution.Simple landfills and incineration will inevitably lead to the loss of the abundant carbon resources contained in plastic waste.In contrast,photoconversion technology provides a green and sustainable solution to the global plastic waste crisis by converting plastics into hydrogen fuel and valuable chemicals.This review briefly introduces the advantages of photoconversion technology and highlights recent research progress,with a focus on photocatalyst design as well as the thermodynamics and kinetics of the reaction process.It discusses in detail the degradation of typical common plastic types into hydrogen and fine chemicals via photoconversion.Additionally,it outlines future research directions,including the application of artificial intelligence in catalyst design.Although photocatalytic technology remains at the laboratory stage,with challenges in catalyst performance and industrial scalability,the potential for renewable energy generation and plastic valorization is promising.展开更多
The main feedstocks for bioethanol are sugarcane （Saccharum offic- inarum） and maize （Zea mays）, both of which are C4 grasses, highly efficient at converting solar energy into chemical energy, and both are food cr...The main feedstocks for bioethanol are sugarcane （Saccharum offic- inarum） and maize （Zea mays）, both of which are C4 grasses, highly efficient at converting solar energy into chemical energy, and both are food crops. As the systems for lignocellulosic bioethanol production become more efficient and cost effective, plant biomass from any source may be used as a feedstock for bioethanol production. Thus, a move away from using food plants to make fuel is possible, and sources of biomass such as wood from forestry and plant waste from cropping may be used. However, the bioethanol industry will need a continuous and reliable supply of biomass that can be produced at a low cost and with minimal use of water, fertilizer and arable land. As many C4 plants have high light, water and nitrogen use efficiency, as compared with C3 species, they are ideal as feedstock crops. We consider the productivity and resource use of a number of candidate plant species, and discuss biomass ＇quality＇, that is, the composition of the plant cell wall.展开更多
Metabolic engineering to produce tricarboxylic acid(TCA)cycle-derived chemicals is usually associated with problems of low production yield and impaired cellular metabolism.In this work,we found that fatty acid(FA)fee...Metabolic engineering to produce tricarboxylic acid(TCA)cycle-derived chemicals is usually associated with problems of low production yield and impaired cellular metabolism.In this work,we found that fatty acid(FA)feedstocks could enable high-yield production of TCA cycle-derived chemicals,while maintaining an efficient and balanced metabolic flux of the glyoxylate-TCA cycle,which is favorable for both product synthesis and cell growth.Here,we designed a novel synthetic pathway for production of β-alanine,an important TCA cycle-derived product,from FAs with a high theortecial yield of 1.391 g/g.By introducing panD,improving aspA,and knocking out iclR,glyoxylate shunt was highly activated in FAs and the yield of β-alanine reached 0.71 g/g from FAs,much higher than from glucose.Blocking the TCA cycle at icd/sucA/fumAC nodes could increase β-alanine yield in a flask cultivation,but severely reduced cell growth and FA utilization during fed-batch processes.Replenishing oxaloacetate by knocking out aspC and recovering fumAC could restore the growth and lead to a titer of 35.57 g/l.After relieving the oxidative stress caused by FA metabolism,β-alanine production could reach 72.05 g/l with a maximum yield of 1.24 g/g,about 86% of the theoretical yield.Our study thus provides a promising strategy for the production of TCA cycle-derived chemicals.展开更多
The use of abundant and cheap one carbon(C1)feedstocks to produce value-added chemicals is an important approach for achieving carbon neutrality and tackling environmental problems.The conversion of C1 feedstocks to h...The use of abundant and cheap one carbon(C1)feedstocks to produce value-added chemicals is an important approach for achieving carbon neutrality and tackling environmental problems.The conversion of C1 feedstocks to high-value chemicals is dependent on efficient C1 assimilation pathways and microbial chassis adapted for efficient incorporation.Here,we opted to summarize the natural and synthetic C1 assimilation pathways and their key factors for metabolizing C1 feedstock.Accordingly,we discussed the metabolic engineering strategies for enabling the microbial utilization of C1 feedstocks for the bioproduction of value-added chemicals.In addition,we highlighted future perspectives of C1-based biomanufacturing for achieving a low-carbon footprint for the biosynthesis of chemicals.展开更多
The difunctionalization of bicyclo[1.1.0]butanes is an under-explored transformation that accesses to moieties that are otherwise difficult to prepare.Herein,a new oxidative radical alkylarylation of N-aryl bicyclobut...The difunctionalization of bicyclo[1.1.0]butanes is an under-explored transformation that accesses to moieties that are otherwise difficult to prepare.Herein,a new oxidative radical alkylarylation of N-aryl bicyclobutyl amides with C(sp^(3))−H feedstocks is achieved in an atom-economic and photocatalyst-and light-free manner.This protocol follows a sequential C(sp^(3))–H/C(sp^(2))–H functionalization,providing an efficient route for diversity-oriented synthesis of functionalized 3-spirocyclobutyl oxindoles.In particular,a wide range of C(sp^(3))−H feedstocks,including ether,alcohol,amine,thioether,polychlorinated methane,silane,acetone,acetonitrile,toluene,and alkane are all suitable for the C(sp^(3))−H functionalization,demonstrating the broad applicability of this transformation.展开更多
In the usage phase,diesel engines fuelled with diesel-biodiesel blends produced lower soot,HC and CO emissions.However,the environmental effects should include the greenhouse gas(GHG)emissions.GHG variations of biodie...In the usage phase,diesel engines fuelled with diesel-biodiesel blends produced lower soot,HC and CO emissions.However,the environmental effects should include the greenhouse gas(GHG)emissions.GHG variations of biodiesel production from three generation feedstocks were analyzed based on the land use change(LUC).Adequate land use change could keep the biodiversity and did not cause the increase of GHG emissions.The choice for feedstocks of biodiesel in China was comprehensively analyzed based on the land use type,the precipitation and the oil contents and the cultivation conditions of plants.Then,the suggestions for biodiesel development in China were given.Results showed that China should thoroughly abandon the first generation feedstocks due to the lack of arable land.Jatropha curcas(J.curcas),Pistacia chinensis Bunge(P.chinensis),Comus wilsoniana(C.wilsoniana)and Xanthoceras sorbifolium Bunge(X.sorbifolium)were considered as the most promising feedstocks for biodiesel production.It is suggested to plant X.sorbifolium in sand lands in the north and northwest of China with less natural rainfall and the others in south and southwest of China.The concern for microalgae should be transmitted to engineering microalgae cultivated in wastewater.The microalgae biodiesel refinery should be developed together with wastewater proposal industry and coal fired power plants.Lastly,only natural gas-based or biomass-based methanol can be used for biodiesel production.展开更多
The quest for sustainable energy solutions has intensified the search for alternative feedstocks that can supplement or replace fossil fuels. Obtaining fuels or chemicals through the conversion of renewable biomass is...The quest for sustainable energy solutions has intensified the search for alternative feedstocks that can supplement or replace fossil fuels. Obtaining fuels or chemicals through the conversion of renewable biomass is a promising candidate [1,2]. Some noblemetal-based (e.g., Pt, Pd and Rh) catalysts exhibit significant catalytic activity to the conversion reaction of these biomass.展开更多
A comparative study on the performance of gas atomized(GA)and rotating-disk atomized(RDA)aluminum alloy powders produced on industrial scale for laser directed energy deposition(L-DED)process was carried out.The powde...A comparative study on the performance of gas atomized(GA)and rotating-disk atomized(RDA)aluminum alloy powders produced on industrial scale for laser directed energy deposition(L-DED)process was carried out.The powder characteristics,the printing process window,and the quality,microstructure,and mechanical properties of printed parts were taken into account for comparison and discussion.The results demonstrate that the RDA powder is superior to the GA powder in terms of sphericity,surface quality,internal defects,flowability,and apparent density,together with a larger printing process window during the L-DED parts fabrication.Besides,the resultant parts from the RDA powder have higher dimensional accuracy,lower internal defects,more uniform and finer microstructure,and more favorable mechanical properties than those from the GA powder.展开更多
Methane(CH4),the predominant component of natural gas and shale gas,is regarded as a promising carbon feedstock for chemical synthesis[1].However,considering the extreme stability of CH4 molecules,it's quite chall...Methane(CH4),the predominant component of natural gas and shale gas,is regarded as a promising carbon feedstock for chemical synthesis[1].However,considering the extreme stability of CH4 molecules,it's quite challenging in simultaneously achieving high activity and selectivity for target products under mild conditions,especially when synthesizing high-value C2t chemicals such as ethanol[2].The conversion of methane to ethanol by photocatalysis is promising for achieving transformation under ambient temperature and pressure conditions.Currently,the apparent quantum efficiency(AQE)of solar-driven methane-to-ethanol conversion is generally below 0.5%[3,4].Furthermore,the stability of photocatalysts remains inadequate,offering substantial potential for further improvement.展开更多
Ti-6Al-4V alloy powder was taken as raw material. 60%（mass fraction） paraffin, 35%low density polyethylene and 5%stearic acid were employed as binders to prepare injection feedstocks. Capillary rheometer was adopted...Ti-6Al-4V alloy powder was taken as raw material. 60%（mass fraction） paraffin, 35%low density polyethylene and 5%stearic acid were employed as binders to prepare injection feedstocks. Capillary rheometer was adopted to determine the rheological parameters and to analyze the rheological properties of the feedstocks at different milling time, powder loading and temperature. It is indicated through the results that the viscosity increases and the value of n decreases with the increase of milling time. The more the powder loading is, the higher the viscosity is. The empirical formula on the relationship between the viscosity and the powder loading is： ηr=η/ηb=A（1-Ф/Фmax）/^- m . The value m is calculated as 0.33. The flow activation energy Ea decreases with the increase of shear rate.展开更多
In the present study,the transesterification of glycerol trioleate was carried out over a basic ionic liquid,1-butyl-3- methylimidazolium hydroxide（[Bmim]OH） and an 87.2%yield of methyl ester was achieved.The produc...In the present study,the transesterification of glycerol trioleate was carried out over a basic ionic liquid,1-butyl-3- methylimidazolium hydroxide（[Bmim]OH） and an 87.2%yield of methyl ester was achieved.The product was isolated through simple decantation from the biphasic system due to the immiscibility of[BmimJOH with ester.[Bmim]OH can be easily recovered and reused six times without dramatic decrease in ester yield.展开更多
Biochar has been widely applied for the remediation of petroleum-contaminated soil.However,the effect of biochar on the transport of petroleum degradation bacteria has not been studied.A typical Gram-positive petroleu...Biochar has been widely applied for the remediation of petroleum-contaminated soil.However,the effect of biochar on the transport of petroleum degradation bacteria has not been studied.A typical Gram-positive petroleum degradation bacteria-Corynebacterium variabile HRJ4 was used to study the effect of different biochars on bacterial transport and retention.Results indicated that the addition of biochar in sand was effective for reducing the transport of bacteria and poplar sawdust biochar(PSBC)had a stronger hinder effect than corn straw biochar(CSBC).The hindrance was more evident with pyrolysis temperature of biochar raised from 300℃ to 600℃,which was attributed to the increase of specific surface area(309 times).The hindrance effect also enhanced with higher application rate of biochar.Furthermore,the reduction of HRJ4 transport was more obvious in higher(25 mmol/L)concentration of Na Cl solution owing to electrostatic attraction enhancement.The adsorption of biochar to HRJ4 was defined to contribute to the hindrance of HRJ4 transport mainly.Combining the influence of feedstocks and pyrolysis temperature on HRJ4 transport,it suggested that specific surface area had the greatest effect on HRJ4 transport,and pore-filling,electrostatic force also contributed to HRJ4 retained in quartz sand column.At last,phenol transportation experiment indicated that the restriction of biochar on HRJ4 enhanced the phenol removal rate in the column.This study provides a theoretical basis for the interaction of biochar and bacteria,which is vital for the remediation of oil-contaminated soil and groundwater in the field.展开更多
This work reports the preparation of bulk and KIT-6-diluted W-Nb-O mixed oxide bronzes by a reflux method. The influence of the incorporation of Nb and a mesoporous silica on the physicochemical features of the cataly...This work reports the preparation of bulk and KIT-6-diluted W-Nb-O mixed oxide bronzes by a reflux method. The influence of the incorporation of Nb and a mesoporous silica on the physicochemical features of the catalysts is studied. The addition of Nb favors the formation of single-phase oxide bronze structure, with improved Lewis acidity;while the incorporation of KIT-6 gives rise to well-dispersed mixed metal oxide particles on the diluter. These diluted W-Nb-O catalysts present enhanced surface areas and mesopore volumes. The materials have been tested in the valorization of an aqueous model mixture (acetol/propanal/ethanol/acetic acid/water weight ratio of 5/25/10/30/30), through C-C bond formation reactions. The increase in the Lewis nature of surface acid sites stands as the key point to maximize the total organic yield during the reaction (C5-C10 products). The best catalysts maintain their catalytic behavior after five consecutive uses.展开更多
3D Euler double-fluid model was applied and three different feedstocks and reverts formations were simulated. By calculating and analyzing the state of gas and solid fluxion in absorber using three different methods o...3D Euler double-fluid model was applied and three different feedstocks and reverts formations were simulated. By calculating and analyzing the state of gas and solid fluxion in absorber using three different methods of the feedstocks and reverts in recirculating fluidized bed, described the behavior of gas and solid through the gas-phase velocity, turbulence intensity, gas-solid sliding velocity, and density of particles. The results show that the feedstocks and reverts enters into absorption tower through two symmetrical feedings and are mixed with flue gas. Based on the respective analysis of each model and the com- parison analysis of the three models, this paper drew conclusions. The turbulence intensity of absorption tower is high, gas-solid sliding speed is big, and granule concentration near the axis is high, which has advantages for desulfurization and im- proving the utilization rate of absorbent.展开更多
This paper describes a brief review of biodiesel R & D developmental trends at Tarbiat Modares University (TMU) bio- energy research laboratories (lab.), Tehran, Iran. The developmental trends at includes potentia...This paper describes a brief review of biodiesel R & D developmental trends at Tarbiat Modares University (TMU) bio- energy research laboratories (lab.), Tehran, Iran. The developmental trends at includes potential and feasibility study, cultivation of a sample bioenrgy farm, technology innovation and its scale up (patents) for fuel processing, and finally the fuel application in diesel engines. A national investigation was carried out to find out the possible potential of sustainable feedstock for biodiesel production. The results showed that easily available biodiesel feedstock is waste cooking oil with a maximum potential of 750 mil.lit and an approximately 350 mil.lit. of collectable waste cooking oil. A castor oil plant farm was cultivated to harvest castor plant seeds, extract its oil, produce biodiesel fuel and use it in diesel engines. This led to a series of patent and consequently technology innovation from 7 lit. lab. scale to semi-continuous, semi-industrial scale of 2 ton capacity.展开更多
A late fall frost may significantly affect sugar crops’ stem sugar composition, yield and juice quality for biofuel and bioproduct manufacture. Research on the effects of late fall frost in sugarcane is well document...A late fall frost may significantly affect sugar crops’ stem sugar composition, yield and juice quality for biofuel and bioproduct manufacture. Research on the effects of late fall frost in sugarcane is well documented, but information is lacking for sweet sorghum. Three and six commercial cultivars of sugarcane and sweet sorghum, respectively, were selected and evaluated for exposure to a late fall frost (-2.8°C) in Griffin, Georgia, USA. Under the same controlled environmental conditions in a screen house, the late fall frost induced more damage to sugarcane than sweet sorghum stems. The frost caused damage to sugarcane tissue and for juice to exude from stems, whereas similar behavior was not observed for sweet sorghum. In both sugarcane and sweet sorghum, the glucose/fructose ratio was significantly reduced, but this change may not be totally directly related to the frost effect. Overall, these initial results suggest that sweet sorghum may have a better tolerance to fall frost than sugarcane. Two sweet sorghum cultivars, Grassl and M81E, responded well to the late fall frost, and they can possibly be used as feedstocks for biofuel/bioproduct manufacture in areas susceptible to frosts including northern regions of the Southeastern US.展开更多
Recent efforts and advances in additive manufacturing(AM) on different types of new materials are presented and reviewed. Special attention is paid to the material design of cladding layers, the choice of feedstock ma...Recent efforts and advances in additive manufacturing(AM) on different types of new materials are presented and reviewed. Special attention is paid to the material design of cladding layers, the choice of feedstock materials, the metallurgical behavior and synthesis principle during the AM process, and the resulted microstructures and properties, as well as the relationship between these factors. Thereafter,the trend of development in the future is forecasted, including: Effects of the particles size and size distribution of powders; Approaches for producing fine microstructures; Opportunities for creating new materials by AM; Wide applications in reconditioning of damaged components; Challenges for deep understanding and applications of the AMed new materials. The idea of "Develop Materials" or "Create Materials" by AM is highlighted, but a series of scientific, technological and engineering problems remain to be solved in future.展开更多
基金supported by the National Natural Science Foundation of China (41171211)the Special Fund for Agro-Scientific Research in the Public Interest, China (201303095-2)
文摘Biochar is increasingly proposed as a soil amendment, with reports of benefits to soil physical, chemical and biological properties. In this study, different biochars were produced from 6 feedstocks, including straw and poultry manure, at 3 pyrolysis temperatures （200, 300 and 500℃） and then added separately to a calcareous soil. Their effects on soil properties and maize growth were evaluated in a pot experiment. The biochars derived from crop straw had much higher C but smaller N concentrations than those derived from poultry manure. Carbon concentrations, pH and EC values increased with increasing pyrolysis temperature. Biochar addition resulted in increases in mean maize dry matter of 12.73% and NPK concentrations of 30, 33 and 283%, respectively. Mean soil pH values were increased by 0.45 units. The biochar-amended soils had 44, 55, 254 and 537% more organic C, total N, Olsen-P and available K, respectively, than the control on average. Both feedstocks and pyrolysis temperature determined the characteristics of the biochar. Biochars with high mineral concentrations may act as mineral nutrient supplements.
文摘The rheological behaviors of feedstocks for powder extrusion molding, in the temperature range of 40～80 ℃ and the Newton shear rate of 3～800 s -1 , were studied. The effects of feedstock constitution, shear rate and temperature on apparent viscosity, shear stress and active energy were investigated. The viscose flow active energy of PEM feedstocks is 15.89～90.77 kJ/mol. Based on this research, the PEM technical parameters have optimized. [
基金This work was supported by the National Key R&D Program of China(2018YFA0901500)the National Natural Science Foundation of China(21706124,21727818)+1 种基金the Key Science and Technology Project of Jiangsu Province(BE2016389)the Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture of China.
文摘L-malate is an intermediate of the tricarboxylic acid cycle which is naturally occurred in various microorganisms,and it has been widely applied in polymer,beverage and food,textile,agricultural and pharmaceutical industries.Driven by the pursuit of a sustainable economy,microbial production of L-malate has received much attention in last decades.In this review,we focus on the utilization of wastes and/or byproducts as feedstocks for the microbial production of L-malate.Firstly,we present the recent developments on the natural or engineered metabolic pathways that dedicate to the biosynthesis of L-malate,and also provide a comprehensive discussions on developing high-efficient producers.Then,the recent achievements in microbial production of L-malate from various carbon sources were concluded and discussed.Furthermore,some abundant non-food feedstocks which have been used for microbial production of other chemicals were reviewed,as they may be potential candidate feedstock for L-malate production in future.Finally,we outlined the major challenges and proposed further improvements for the production of L-malate.
基金supported by the Jiangsu Distinguished Professor Project,China(Grant No.RC20240909)the Jiangsu University Foundation,China(Grant No.22JDG033).
文摘The increasing accumulation of discarded plastics has already caused serious environmental pollution.Simple landfills and incineration will inevitably lead to the loss of the abundant carbon resources contained in plastic waste.In contrast,photoconversion technology provides a green and sustainable solution to the global plastic waste crisis by converting plastics into hydrogen fuel and valuable chemicals.This review briefly introduces the advantages of photoconversion technology and highlights recent research progress,with a focus on photocatalyst design as well as the thermodynamics and kinetics of the reaction process.It discusses in detail the degradation of typical common plastic types into hydrogen and fine chemicals via photoconversion.Additionally,it outlines future research directions,including the application of artificial intelligence in catalyst design.Although photocatalytic technology remains at the laboratory stage,with challenges in catalyst performance and industrial scalability,the potential for renewable energy generation and plastic valorization is promising.
基金supported by the Australian Research Council (ARC) though ARC-linkage project LP0883808
文摘The main feedstocks for bioethanol are sugarcane （Saccharum offic- inarum） and maize （Zea mays）, both of which are C4 grasses, highly efficient at converting solar energy into chemical energy, and both are food crops. As the systems for lignocellulosic bioethanol production become more efficient and cost effective, plant biomass from any source may be used as a feedstock for bioethanol production. Thus, a move away from using food plants to make fuel is possible, and sources of biomass such as wood from forestry and plant waste from cropping may be used. However, the bioethanol industry will need a continuous and reliable supply of biomass that can be produced at a low cost and with minimal use of water, fertilizer and arable land. As many C4 plants have high light, water and nitrogen use efficiency, as compared with C3 species, they are ideal as feedstock crops. We consider the productivity and resource use of a number of candidate plant species, and discuss biomass ＇quality＇, that is, the composition of the plant cell wall.
基金National Key Research and Development Project of China(Grant No.2018YFA0901400)National Natural Science Foundation of China(Grant No.32070068).
文摘Metabolic engineering to produce tricarboxylic acid(TCA)cycle-derived chemicals is usually associated with problems of low production yield and impaired cellular metabolism.In this work,we found that fatty acid(FA)feedstocks could enable high-yield production of TCA cycle-derived chemicals,while maintaining an efficient and balanced metabolic flux of the glyoxylate-TCA cycle,which is favorable for both product synthesis and cell growth.Here,we designed a novel synthetic pathway for production of β-alanine,an important TCA cycle-derived product,from FAs with a high theortecial yield of 1.391 g/g.By introducing panD,improving aspA,and knocking out iclR,glyoxylate shunt was highly activated in FAs and the yield of β-alanine reached 0.71 g/g from FAs,much higher than from glucose.Blocking the TCA cycle at icd/sucA/fumAC nodes could increase β-alanine yield in a flask cultivation,but severely reduced cell growth and FA utilization during fed-batch processes.Replenishing oxaloacetate by knocking out aspC and recovering fumAC could restore the growth and lead to a titer of 35.57 g/l.After relieving the oxidative stress caused by FA metabolism,β-alanine production could reach 72.05 g/l with a maximum yield of 1.24 g/g,about 86% of the theoretical yield.Our study thus provides a promising strategy for the production of TCA cycle-derived chemicals.
基金supported by the Provincial Outstanding Youth Foundation of Jiangsu Province(BK20211529)the National Science Fund for Excellent Young Scholars(22122806)the Fundamental Research Funds for the Central Universities(JUSRP22031).
文摘The use of abundant and cheap one carbon(C1)feedstocks to produce value-added chemicals is an important approach for achieving carbon neutrality and tackling environmental problems.The conversion of C1 feedstocks to high-value chemicals is dependent on efficient C1 assimilation pathways and microbial chassis adapted for efficient incorporation.Here,we opted to summarize the natural and synthetic C1 assimilation pathways and their key factors for metabolizing C1 feedstock.Accordingly,we discussed the metabolic engineering strategies for enabling the microbial utilization of C1 feedstocks for the bioproduction of value-added chemicals.In addition,we highlighted future perspectives of C1-based biomanufacturing for achieving a low-carbon footprint for the biosynthesis of chemicals.
基金funded by National Natural Science Foundation of China(No.22201070).
文摘The difunctionalization of bicyclo[1.1.0]butanes is an under-explored transformation that accesses to moieties that are otherwise difficult to prepare.Herein,a new oxidative radical alkylarylation of N-aryl bicyclobutyl amides with C(sp^(3))−H feedstocks is achieved in an atom-economic and photocatalyst-and light-free manner.This protocol follows a sequential C(sp^(3))–H/C(sp^(2))–H functionalization,providing an efficient route for diversity-oriented synthesis of functionalized 3-spirocyclobutyl oxindoles.In particular,a wide range of C(sp^(3))−H feedstocks,including ether,alcohol,amine,thioether,polychlorinated methane,silane,acetone,acetonitrile,toluene,and alkane are all suitable for the C(sp^(3))−H functionalization,demonstrating the broad applicability of this transformation.
基金supported by the Key Research and Development Program of Shaanxi Province(2019ZDLGY15-07)the Youth Innovation Team of Shaanxi Universities,and National Engineering Laboratory for Mobile Source Emission Control Technology(NELMS2017B02)。
文摘In the usage phase,diesel engines fuelled with diesel-biodiesel blends produced lower soot,HC and CO emissions.However,the environmental effects should include the greenhouse gas(GHG)emissions.GHG variations of biodiesel production from three generation feedstocks were analyzed based on the land use change(LUC).Adequate land use change could keep the biodiversity and did not cause the increase of GHG emissions.The choice for feedstocks of biodiesel in China was comprehensively analyzed based on the land use type,the precipitation and the oil contents and the cultivation conditions of plants.Then,the suggestions for biodiesel development in China were given.Results showed that China should thoroughly abandon the first generation feedstocks due to the lack of arable land.Jatropha curcas(J.curcas),Pistacia chinensis Bunge(P.chinensis),Comus wilsoniana(C.wilsoniana)and Xanthoceras sorbifolium Bunge(X.sorbifolium)were considered as the most promising feedstocks for biodiesel production.It is suggested to plant X.sorbifolium in sand lands in the north and northwest of China with less natural rainfall and the others in south and southwest of China.The concern for microalgae should be transmitted to engineering microalgae cultivated in wastewater.The microalgae biodiesel refinery should be developed together with wastewater proposal industry and coal fired power plants.Lastly,only natural gas-based or biomass-based methanol can be used for biodiesel production.
文摘The quest for sustainable energy solutions has intensified the search for alternative feedstocks that can supplement or replace fossil fuels. Obtaining fuels or chemicals through the conversion of renewable biomass is a promising candidate [1,2]. Some noblemetal-based (e.g., Pt, Pd and Rh) catalysts exhibit significant catalytic activity to the conversion reaction of these biomass.
基金supported by the National Natural Science Foundation of China(No.52074157)Department of Education of Guangdong Province,China(No.2023KTSCX121)Shenzhen Science and Technology Programs,China(Nos.JSGG20210802154210032,JCYJ20210324104608023,JSGG20180508152608855)。
文摘A comparative study on the performance of gas atomized(GA)and rotating-disk atomized(RDA)aluminum alloy powders produced on industrial scale for laser directed energy deposition(L-DED)process was carried out.The powder characteristics,the printing process window,and the quality,microstructure,and mechanical properties of printed parts were taken into account for comparison and discussion.The results demonstrate that the RDA powder is superior to the GA powder in terms of sphericity,surface quality,internal defects,flowability,and apparent density,together with a larger printing process window during the L-DED parts fabrication.Besides,the resultant parts from the RDA powder have higher dimensional accuracy,lower internal defects,more uniform and finer microstructure,and more favorable mechanical properties than those from the GA powder.
基金the support from the National Natural Science Foundation of China(52202306)Program from Guangdong Introducing Innovative and Entrepreneurial Teams(2019ZT08L101 and RCTDPT-2020-001)+1 种基金Shenzhen Key Laboratory of Eco-materials and Renewable Energy(ZDSYS20200922160400001)the Provincial Talent Plan of Guangdong(2023TB0012).
文摘Methane(CH4),the predominant component of natural gas and shale gas,is regarded as a promising carbon feedstock for chemical synthesis[1].However,considering the extreme stability of CH4 molecules,it's quite challenging in simultaneously achieving high activity and selectivity for target products under mild conditions,especially when synthesizing high-value C2t chemicals such as ethanol[2].The conversion of methane to ethanol by photocatalysis is promising for achieving transformation under ambient temperature and pressure conditions.Currently,the apparent quantum efficiency(AQE)of solar-driven methane-to-ethanol conversion is generally below 0.5%[3,4].Furthermore,the stability of photocatalysts remains inadequate,offering substantial potential for further improvement.
文摘Ti-6Al-4V alloy powder was taken as raw material. 60%（mass fraction） paraffin, 35%low density polyethylene and 5%stearic acid were employed as binders to prepare injection feedstocks. Capillary rheometer was adopted to determine the rheological parameters and to analyze the rheological properties of the feedstocks at different milling time, powder loading and temperature. It is indicated through the results that the viscosity increases and the value of n decreases with the increase of milling time. The more the powder loading is, the higher the viscosity is. The empirical formula on the relationship between the viscosity and the powder loading is： ηr=η/ηb=A（1-Ф/Фmax）/^- m . The value m is calculated as 0.33. The flow activation energy Ea decreases with the increase of shear rate.
基金Financial supports from the Fundamental Research Funds for the Central Universities (No.TD2010-1,YX2011-36,TD2011-11)the National Natural Science Foundation of China(No.31170556)+3 种基金Research Fund for the Doctoral Program of Higher Education of China(No.20100014120007)China Postdoctoral Science Foundation(No.20110490303)Beijing Forestry University Young Scientist Fund(No.BLX2009003)Major State Basic Research Development Program of China(973 Program,No.2010CB732204)
文摘In the present study,the transesterification of glycerol trioleate was carried out over a basic ionic liquid,1-butyl-3- methylimidazolium hydroxide（[Bmim]OH） and an 87.2%yield of methyl ester was achieved.The product was isolated through simple decantation from the biphasic system due to the immiscibility of[BmimJOH with ester.[Bmim]OH can be easily recovered and reused six times without dramatic decrease in ester yield.
基金the National Natural Science Foundation of China(Nos.U1806216,41877372)the 111 program,Ministry of Education,China(No.T2017002)。
文摘Biochar has been widely applied for the remediation of petroleum-contaminated soil.However,the effect of biochar on the transport of petroleum degradation bacteria has not been studied.A typical Gram-positive petroleum degradation bacteria-Corynebacterium variabile HRJ4 was used to study the effect of different biochars on bacterial transport and retention.Results indicated that the addition of biochar in sand was effective for reducing the transport of bacteria and poplar sawdust biochar(PSBC)had a stronger hinder effect than corn straw biochar(CSBC).The hindrance was more evident with pyrolysis temperature of biochar raised from 300℃ to 600℃,which was attributed to the increase of specific surface area(309 times).The hindrance effect also enhanced with higher application rate of biochar.Furthermore,the reduction of HRJ4 transport was more obvious in higher(25 mmol/L)concentration of Na Cl solution owing to electrostatic attraction enhancement.The adsorption of biochar to HRJ4 was defined to contribute to the hindrance of HRJ4 transport mainly.Combining the influence of feedstocks and pyrolysis temperature on HRJ4 transport,it suggested that specific surface area had the greatest effect on HRJ4 transport,and pore-filling,electrostatic force also contributed to HRJ4 retained in quartz sand column.At last,phenol transportation experiment indicated that the restriction of biochar on HRJ4 enhanced the phenol removal rate in the column.This study provides a theoretical basis for the interaction of biochar and bacteria,which is vital for the remediation of oil-contaminated soil and groundwater in the field.
基金Financial support by the Spanish Government(RTI2018-099668-B-C21,PGC2018-097277-B-100,and SEV-2016-0683)the Severo Ochoa Excellence Program(SVP-2014-068669)the “La Caixa-Severo Ochoa” Foundation,respectively,for their fellowships~~
文摘This work reports the preparation of bulk and KIT-6-diluted W-Nb-O mixed oxide bronzes by a reflux method. The influence of the incorporation of Nb and a mesoporous silica on the physicochemical features of the catalysts is studied. The addition of Nb favors the formation of single-phase oxide bronze structure, with improved Lewis acidity;while the incorporation of KIT-6 gives rise to well-dispersed mixed metal oxide particles on the diluter. These diluted W-Nb-O catalysts present enhanced surface areas and mesopore volumes. The materials have been tested in the valorization of an aqueous model mixture (acetol/propanal/ethanol/acetic acid/water weight ratio of 5/25/10/30/30), through C-C bond formation reactions. The increase in the Lewis nature of surface acid sites stands as the key point to maximize the total organic yield during the reaction (C5-C10 products). The best catalysts maintain their catalytic behavior after five consecutive uses.
文摘3D Euler double-fluid model was applied and three different feedstocks and reverts formations were simulated. By calculating and analyzing the state of gas and solid fluxion in absorber using three different methods of the feedstocks and reverts in recirculating fluidized bed, described the behavior of gas and solid through the gas-phase velocity, turbulence intensity, gas-solid sliding velocity, and density of particles. The results show that the feedstocks and reverts enters into absorption tower through two symmetrical feedings and are mixed with flue gas. Based on the respective analysis of each model and the com- parison analysis of the three models, this paper drew conclusions. The turbulence intensity of absorption tower is high, gas-solid sliding speed is big, and granule concentration near the axis is high, which has advantages for desulfurization and im- proving the utilization rate of absorbent.
文摘This paper describes a brief review of biodiesel R & D developmental trends at Tarbiat Modares University (TMU) bio- energy research laboratories (lab.), Tehran, Iran. The developmental trends at includes potential and feasibility study, cultivation of a sample bioenrgy farm, technology innovation and its scale up (patents) for fuel processing, and finally the fuel application in diesel engines. A national investigation was carried out to find out the possible potential of sustainable feedstock for biodiesel production. The results showed that easily available biodiesel feedstock is waste cooking oil with a maximum potential of 750 mil.lit and an approximately 350 mil.lit. of collectable waste cooking oil. A castor oil plant farm was cultivated to harvest castor plant seeds, extract its oil, produce biodiesel fuel and use it in diesel engines. This led to a series of patent and consequently technology innovation from 7 lit. lab. scale to semi-continuous, semi-industrial scale of 2 ton capacity.
文摘A late fall frost may significantly affect sugar crops’ stem sugar composition, yield and juice quality for biofuel and bioproduct manufacture. Research on the effects of late fall frost in sugarcane is well documented, but information is lacking for sweet sorghum. Three and six commercial cultivars of sugarcane and sweet sorghum, respectively, were selected and evaluated for exposure to a late fall frost (-2.8°C) in Griffin, Georgia, USA. Under the same controlled environmental conditions in a screen house, the late fall frost induced more damage to sugarcane than sweet sorghum stems. The frost caused damage to sugarcane tissue and for juice to exude from stems, whereas similar behavior was not observed for sweet sorghum. In both sugarcane and sweet sorghum, the glucose/fructose ratio was significantly reduced, but this change may not be totally directly related to the frost effect. Overall, these initial results suggest that sweet sorghum may have a better tolerance to fall frost than sugarcane. Two sweet sorghum cultivars, Grassl and M81E, responded well to the late fall frost, and they can possibly be used as feedstocks for biofuel/bioproduct manufacture in areas susceptible to frosts including northern regions of the Southeastern US.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 51775525, 51605456 and 51701198)
文摘Recent efforts and advances in additive manufacturing(AM) on different types of new materials are presented and reviewed. Special attention is paid to the material design of cladding layers, the choice of feedstock materials, the metallurgical behavior and synthesis principle during the AM process, and the resulted microstructures and properties, as well as the relationship between these factors. Thereafter,the trend of development in the future is forecasted, including: Effects of the particles size and size distribution of powders; Approaches for producing fine microstructures; Opportunities for creating new materials by AM; Wide applications in reconditioning of damaged components; Challenges for deep understanding and applications of the AMed new materials. The idea of "Develop Materials" or "Create Materials" by AM is highlighted, but a series of scientific, technological and engineering problems remain to be solved in future.
