This paper researched a promising biological treatment of methyl violet waste water by methods of activated sludge.Effects of temperature and pH were studied on this process.Kinetic equation ...This paper researched a promising biological treatment of methyl violet waste water by methods of activated sludge.Effects of temperature and pH were studied on this process.Kinetic equation of the substrate biodegradation was investigated in the experimental range.It was studied and simulated that flow within the bubble region of this bioreactor according to the κ ε two fluid equation.Simulation results agree well with experimental data.展开更多
The hydrolysis process and mechanisms of unique as-prepared KCrO2 and K3 CrO4 were systematically investigated. The characterization results of XRD, IR and SEM show that the hydrolysis reaction can be realized at a lo...The hydrolysis process and mechanisms of unique as-prepared KCrO2 and K3 CrO4 were systematically investigated. The characterization results of XRD, IR and SEM show that the hydrolysis reaction can be realized at a low reaction temperature of 80 ℃ and a reaction time of 24 h. Moreover, the greyish-green α-CrOOH with a hexagonal plate-like morphology and a large size of 10 μm is formed via the hydrolysis of the single-phase hexagonal KCrO2, while the green sol-gel of amorphous Cr(OH)3 with a lumpy aggregate morphology is generated through the hydrolysis of a cubic K3 CrO4. It is a facile and rapid method to synthesize pure-phase chromium oxyhydroxide via the above hydrolysis.展开更多
To understand the reaction behaviour of the reactive dye with amino groups on protein fibres,the reaction kinetics of competitive hydrolysis and ammonolysis of a monochlorotriazina reactive dye were studied at 50-80℃...To understand the reaction behaviour of the reactive dye with amino groups on protein fibres,the reaction kinetics of competitive hydrolysis and ammonolysis of a monochlorotriazina reactive dye were studied at 50-80℃ and pH=8-10 by high performance liquid chromatography(HPLC).The results showed the pseudo-first-order phenomenon for the general reaction of concurrent hydrolysis and ammonolysis of the dyes.The ammonolysis reaction was always faster than the hydrolysis reaction in the range of temperature and pH employed,but the preference for ammonolysis to hydrolysis reaction decreased with the increase of temperature and pH value.The ratios of ammonolysis/hydrolysis rate constant reduced from 17.6 to 5.4 when the temperature increased from 50 to 80℃ in pH=10,and from 7.2 to 5.4 when the pH value increased from 8 to 10 at 80℃.展开更多
Promoted by active indium produced in situ by Sm/InCl3 ?4H2O system, arylidenecyano- acetates undergo reductive cyclodimerization to afford cyclopentamine derivatives with high stereoselectivity under mild conditions ...Promoted by active indium produced in situ by Sm/InCl3 ?4H2O system, arylidenecyano- acetates undergo reductive cyclodimerization to afford cyclopentamine derivatives with high stereoselectivity under mild conditions in aqueous media.展开更多
A novel fluidized electrochemical reactor that integrated advanced electrochemical oxidation with activated carbon (AC) fluidization in a single cell was developed to model pollutant p-nitrophenol (PNP) abatement. AC ...A novel fluidized electrochemical reactor that integrated advanced electrochemical oxidation with activated carbon (AC) fluidization in a single cell was developed to model pollutant p-nitrophenol (PNP) abatement. AC fluidization could enhance COD removal by 22%-30%. In such a combined process, synergetic effects on PNP and COD removal was found, with their removal rate being enhanced by 137.8% and 97.8%, respectively. AC could be electrochemically regenerated and reused, indicating the combined process would be promising for treatment of biorefractory organic pollutants.展开更多
We evaluated the effect of water temperature on the growth and physiology of the Chinese longsnout catfish （Leiocassis longirostris Günther）. The fish were reared at four temperatures （20, 25, 30, and 35℃） a...We evaluated the effect of water temperature on the growth and physiology of the Chinese longsnout catfish （Leiocassis longirostris Günther）. The fish were reared at four temperatures （20, 25, 30, and 35℃） and sampled on days 7, 20, and 30. We measured plasma levels of insulin, free thyroxine （FT4）, free 3,5,3＇-triiodothyronine （FT3）, lysozyme and leukocyte phagocytic activity. The optimum water temperature for growth was 27.7℃. The plasma levels of insulin and FT4 declined significantly （P〈0.05） on day 30 at temperatures above 20℃. Lysozyme activity was significantly （P〈0.05） lower at 25℃ than at other temperatures. We conclude that final weight, insulin, FT4, and lysozyme were significantly affected by water temperature.展开更多
Gas-phase dehydration of glycerol to produce acmlein was investigated over commercial catalysts based on γ-Al2O3, viz. A-64, A-56,1-62, AP-10, AP-56, AP-64 and KR-104. To understand the effect of Cl anions, HCl-impre...Gas-phase dehydration of glycerol to produce acmlein was investigated over commercial catalysts based on γ-Al2O3, viz. A-64, A-56,1-62, AP-10, AP-56, AP-64 and KR-104. To understand the effect of Cl anions, HCl-impregnated sup- ports have been investigated in the dehydration reaction of glycerol at 375 ℃. For comparison, various H-zeolites were also examined. It was found that the glycerol conversion over the solid acid catalysts was strongly dependent on their acidity and surface area. And the relationship between the catalytic activity and the acidity of the catalysts was discussed. The outstanding properties of Pt/γ-Al2O3 catalyst systems for the dehydration of glycerol were revealed. Pt/γ-Al2O3 catalyst （AP-64） showed the highest catalytic activity after 50 h of reaction with an acrolein selectivity of 65% at a conversion of glycerol of 90%. Based on these results, catalysts based on γ-Al2O3 appear to be most promising for gas phase dehydration of glycerol.展开更多
Vanadium oxide （VOx） nanostructures, synthesized by hydrothermal treatment using dodecylamine as template, were evaluated for the selective catalytic reduction of NOx with ammonia （NH3-SCR）, The effect of solvent ...Vanadium oxide （VOx） nanostructures, synthesized by hydrothermal treatment using dodecylamine as template, were evaluated for the selective catalytic reduction of NOx with ammonia （NH3-SCR）, The effect of solvent type in the reaction mixture （EtOH/（EtOH ＋ H20）） and time of hydrolysis was studied. The obtained materials were characterized by XRD, SEM, TEM and BET, The VOx nanorods （80-120 nm diameter and 1-4 μm length） were synthesized in 25 vol% EtOH/（EtOH ＋ H20） and the open-ended multiwalled VOx nanotube （50-100 nm inner diameter, 110-180 nm outer diameter and 0,5-2 pm length） synthesized in 50 vol% EtOH/（EtOH ＋ H20）. VOx nanotuhes performed the superior NH3-SCR activity under a gas hourly space velocity of 12,000 h-1 at low temperature of 250 ~C （NOx conversion of 893g ＆ N2 selectivity of 100%）, while most of the developed Vanadia base catalysts are active at high temperature （〉350 ℃）. The superior NH3-SCR activity ofVOx nanotubes at low tem- perature is related to nanocrystalline structure, special nanotube morphology as well as high specific surface area.展开更多
Identifying active sites and catalytic mechanism of the oxygen reduction reaction under anhydrous conditions are crucial for the development of next generation proton exchange membrane fuel cells(PEMFCs)operated at a ...Identifying active sites and catalytic mechanism of the oxygen reduction reaction under anhydrous conditions are crucial for the development of next generation proton exchange membrane fuel cells(PEMFCs)operated at a temperature>100℃.Here,by employing density functional theory calculations,we studied ORR on flat and stepped Pt(111)surfaces with both(110)and(100)type of steps.We found that,in contrast to ORR under hydrous conditions,(111)terrace sites are not active for ORR under anhydrous conditions,because of weakened binding of ORR intermediates induced by O*accumulation on the surface.On the other hand,step edges,which are generally not active for ORR under hydrous conditions,are predicted to be the active sites for ORR under anhydrous conditions.Among them,(110)type step edge with a unique configuration of accumulated O stabilizes O_(2)adsorption and facilitates O_(2)dissociation,which lead an overpotential<0.4 V.To improve ORR catalysts in high-temperature PEMFCs,it is desirable to maximize(110)step edge sites that present between two(111)facets of nanoparticles.展开更多
The perovskite type rare earth iron complex (REIC) oxide La 1-x Ce xFeO 3 is designed and prepared as water gas shift catalyst. Activity evaluation and heat resisting test show that the perovskite type compounds La 1-...The perovskite type rare earth iron complex (REIC) oxide La 1-x Ce xFeO 3 is designed and prepared as water gas shift catalyst. Activity evaluation and heat resisting test show that the perovskite type compounds La 1-x Ce xFeO 3(·K) has a good thermal stability if x is less than or equal to 0.5 . But when x is greater than 0.5 , La 1-x Ce xFeO 3(·K) will turn out to be ceria and magnetite partially or completely at high temperature in the shift reaction atmosphere. In the case of x=0.5, the conversion of carbon monoxide is about 68% at 530 ℃. Potassium can greatly improve the low temperature activity, but slightly lower the high temperature activity, and has little impact on the thermal stability. La 0.5 Ce 0.5 FeO 3 (·K) is a promising chromium free high temperature shift catalyst.展开更多
The aim of the research was to obtain both an excellent effluent for reuse and a reduced sludge production simultaneously by a combination process of anaerobic phase and Membrane bioreactor （MBR） technology in treat...The aim of the research was to obtain both an excellent effluent for reuse and a reduced sludge production simultaneously by a combination process of anaerobic phase and Membrane bioreactor （MBR） technology in treating domestic wastewater. During the experimental period of three months, excellent removals for COD, NH3-H, TN were obtained, and mean removals were 91.87%, 96.13%, and 69. 23%, respectively. Whereas, at first 20 days, the removal for TP was only about 15.87%. In the following days, about 30% of raw water was introduced into the anaerobic reactor to supply organics for denitrificatien and release of polyphosphate, then a significant improvement for TP removal was observed, and mean removal of TP increased to 76.35%. During the operational period, it was investigated that the permeate could meet the requirements of several water criteria for reuse except free chlorine, and a mean excess sludge yield coefficient of 0.137 g MLSS/g COD was obtained. Therefore, the predicted goals of permeate for reuse and excess sludge reduction could be both achieved after dosing a certain quantity of disinfectant into the permeate.展开更多
Two lab-scale reactors, suspended-sludge and fluidized.bed, were conducted with the feed of ammonium-rich synthetic wastewater devoid of COD. Completely autotrophic nitrogen-removal process was fulfilled in both react...Two lab-scale reactors, suspended-sludge and fluidized.bed, were conducted with the feed of ammonium-rich synthetic wastewater devoid of COD. Completely autotrophic nitrogen-removal process was fulfilled in both reactors and the maximum efficiencies of nitrogen removal were achieved, 65% in the suspended-sludge reactor and 73% in the fluidized-bed reactor respectively. Different from the steady performance of the fluldized-bed reactor, the suspended-sludge reactor came to deteriorate constantly after a period of stable operation, resulting in almost complete loss of the N-removal ability in the suspending system. Molecular methods such as PCR and FISH were employed for describing the microbial characteristics in two systems. This study suggests that a biofllm system is a suitable configuration for completely autotrophic N-removal with more feasibility and stability than a suspending system.展开更多
Flooding/submergence of rice fields is a severe problem in South and South-East Asia, affecting more than 20 million hectares of rice every year. Submergence creates hypoxic or anoxic condition causing poor germinatio...Flooding/submergence of rice fields is a severe problem in South and South-East Asia, affecting more than 20 million hectares of rice every year. Submergence creates hypoxic or anoxic condition causing poor germination, seedling establishment,and enormous yield loss. Standing water in the field from weeks to months also leads to significant yield losses when large part of aerial tissues is under water. For flash flooding, a rice variety FR1A3 with tolerant gene(SUB1A) was identified. SNORKEL1 and SNORKEL2 have been identified for their ability to survive deep-water flooding by rapid elongation. Submergence stress has also been reported to adversely affect cell division and damage cellular and organelle membranes. Research on antioxidative enzymes response and genes that confer tolerance to prolonged flooding is in progress. Here we review the different anoxia responsive genes and the potential involvement of antioxidative enzymes, such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase, which occur in cells of rice plant exposed to submergence stress.展开更多
Hexamethylenediamine(HMDA) is an important reagent for the synthesis of Nylon-6,6, and it is usually produced by the hydrogenation of adiponitrile using a toxic reagent of hydrocyanic acid. Herein, we developed an env...Hexamethylenediamine(HMDA) is an important reagent for the synthesis of Nylon-6,6, and it is usually produced by the hydrogenation of adiponitrile using a toxic reagent of hydrocyanic acid. Herein, we developed an environmental friendly route to produce HMDA via catalytic reductive amination of 1,6-hexanediol(HDO) in the presence of hydrogen. The activities of several heterogeneous metal catalysts such as supported Ni, Co, Ru, Pt, Pd catalysts were screened for the present reaction in supercritical ammonia without any additives. Among the catalysts examined, Ru/Al_2O_3 presented a high catalytic activity and highest selectivity for the desired product of HMDA. The high performance of Ru/Al_2O_3 was discussed based on the Ru dispersion and the surface properties like the acid-basicity. In addition, the reaction parameters such as reaction temperature,time, H_2 and NH_3 pressure were examined, and the reaction processes were discussed in detail.展开更多
We constructed an expression cassette of the organophosphorus pesticide degrading （opal） gene under the control of the E8 promoter. Then opd was transformed into tomato fruit using an agroinfiltration transient expr...We constructed an expression cassette of the organophosphorus pesticide degrading （opal） gene under the control of the E8 promoter. Then opd was transformed into tomato fruit using an agroinfiltration transient expression system. β-Glucuronidase （GUS） staining, reverse transcription-polymerase chain reaction （RT-PCR）, wavelength scanning, and fluorescent reaction were performed to examine the expression of the opd gene and the hydrolysis activity on coumaphos of organo- phosphorus hydrolase （OPH） in tomato fruit. The results show that the agroinfiltrated tomato fruit-expressed OPH had the maximum hydrolysis activity of about 11.59 Uhng total soluble protein. These results will allow us to focus on breeding transgenic plants that could not only enhance the degrading capability of fruit and but also hold no negative effects on pest control when spraying organophosphorus pesticides onto the seedlings in fields.展开更多
In this work,a facile process was reported to fabricate amorphous carbon-coated MnO micropeanuts(MPs)with 1.8μm in length and 1.0μm in width using hydrothermal reaction followed by heat treatment in the oxygen-free ...In this work,a facile process was reported to fabricate amorphous carbon-coated MnO micropeanuts(MPs)with 1.8μm in length and 1.0μm in width using hydrothermal reaction followed by heat treatment in the oxygen-free environment.With Mn Cl_2 and KMnO_4 dissolved in the mixture of ethylene glycol and water,MnCO_3 MP precursors were obtained via the hydrothermal reaction with dopamine as surfactant.Then MnCO_3 MP was annealed at 600°C in the N_2 atmosphere and was transformed into MnO MP,and simultaneously the formed polydopamine during the hydrothermal reaction was carbonized to produce amorphous carbon-coating on the MnO MP surface.In contrast,MnCO_3 nanoparticle(NP)precursor was formed without the addition of dopamine and MnO NP agglomerates were prepared after pyrolysis.The carbonization of polydopamine during thermolysis improves the electrical conductivity and thermal stability of the MnO MP and thus its electrochemical performance as electrode materials for lithium ion battery.Hopefully,this facile strategy for fabricating and designing carbon-coated materials would inspire more novel nanostructures and applications thereof.展开更多
文摘This paper researched a promising biological treatment of methyl violet waste water by methods of activated sludge.Effects of temperature and pH were studied on this process.Kinetic equation of the substrate biodegradation was investigated in the experimental range.It was studied and simulated that flow within the bubble region of this bioreactor according to the κ ε two fluid equation.Simulation results agree well with experimental data.
基金Project(R2018SCH02)supported by the High-level Talents Foundation of Chongqing University of Art and Sciences,ChinaProject(P2018CH10)supported by Major Cultivation Program of Chongqing University of Arts and Sciences,China+1 种基金Project(cstc2019jcyj-msxmX0788)supported by the Natural Science Foundation of Chongqing,ChinaProject(KJQN201901342)supported by the Science and Technology Research Program of Chongqing Municipal Education Commission,China。
文摘The hydrolysis process and mechanisms of unique as-prepared KCrO2 and K3 CrO4 were systematically investigated. The characterization results of XRD, IR and SEM show that the hydrolysis reaction can be realized at a low reaction temperature of 80 ℃ and a reaction time of 24 h. Moreover, the greyish-green α-CrOOH with a hexagonal plate-like morphology and a large size of 10 μm is formed via the hydrolysis of the single-phase hexagonal KCrO2, while the green sol-gel of amorphous Cr(OH)3 with a lumpy aggregate morphology is generated through the hydrolysis of a cubic K3 CrO4. It is a facile and rapid method to synthesize pure-phase chromium oxyhydroxide via the above hydrolysis.
文摘To understand the reaction behaviour of the reactive dye with amino groups on protein fibres,the reaction kinetics of competitive hydrolysis and ammonolysis of a monochlorotriazina reactive dye were studied at 50-80℃ and pH=8-10 by high performance liquid chromatography(HPLC).The results showed the pseudo-first-order phenomenon for the general reaction of concurrent hydrolysis and ammonolysis of the dyes.The ammonolysis reaction was always faster than the hydrolysis reaction in the range of temperature and pH employed,but the preference for ammonolysis to hydrolysis reaction decreased with the increase of temperature and pH value.The ratios of ammonolysis/hydrolysis rate constant reduced from 17.6 to 5.4 when the temperature increased from 50 to 80℃ in pH=10,and from 7.2 to 5.4 when the pH value increased from 8 to 10 at 80℃.
文摘Promoted by active indium produced in situ by Sm/InCl3 ?4H2O system, arylidenecyano- acetates undergo reductive cyclodimerization to afford cyclopentamine derivatives with high stereoselectivity under mild conditions in aqueous media.
文摘A novel fluidized electrochemical reactor that integrated advanced electrochemical oxidation with activated carbon (AC) fluidization in a single cell was developed to model pollutant p-nitrophenol (PNP) abatement. AC fluidization could enhance COD removal by 22%-30%. In such a combined process, synergetic effects on PNP and COD removal was found, with their removal rate being enhanced by 137.8% and 97.8%, respectively. AC could be electrochemically regenerated and reused, indicating the combined process would be promising for treatment of biorefractory organic pollutants.
基金Supported by the Earmarked Fund for Modern Agro-industry Technology Research System (No. NYCYTX-49-19)Special Fund for Agroscientific Research in the Public Interest (No. 201003020)
文摘We evaluated the effect of water temperature on the growth and physiology of the Chinese longsnout catfish （Leiocassis longirostris Günther）. The fish were reared at four temperatures （20, 25, 30, and 35℃） and sampled on days 7, 20, and 30. We measured plasma levels of insulin, free thyroxine （FT4）, free 3,5,3＇-triiodothyronine （FT3）, lysozyme and leukocyte phagocytic activity. The optimum water temperature for growth was 27.7℃. The plasma levels of insulin and FT4 declined significantly （P〈0.05） on day 30 at temperatures above 20℃. Lysozyme activity was significantly （P〈0.05） lower at 25℃ than at other temperatures. We conclude that final weight, insulin, FT4, and lysozyme were significantly affected by water temperature.
基金supported by the Ministry of Education and Science of the Russian Federation (contract № 02.G25.31.0119)a project part of the state task in the field of scientific activity ( № 10.1686.2014/K)
文摘Gas-phase dehydration of glycerol to produce acmlein was investigated over commercial catalysts based on γ-Al2O3, viz. A-64, A-56,1-62, AP-10, AP-56, AP-64 and KR-104. To understand the effect of Cl anions, HCl-impregnated sup- ports have been investigated in the dehydration reaction of glycerol at 375 ℃. For comparison, various H-zeolites were also examined. It was found that the glycerol conversion over the solid acid catalysts was strongly dependent on their acidity and surface area. And the relationship between the catalytic activity and the acidity of the catalysts was discussed. The outstanding properties of Pt/γ-Al2O3 catalyst systems for the dehydration of glycerol were revealed. Pt/γ-Al2O3 catalyst （AP-64） showed the highest catalytic activity after 50 h of reaction with an acrolein selectivity of 65% at a conversion of glycerol of 90%. Based on these results, catalysts based on γ-Al2O3 appear to be most promising for gas phase dehydration of glycerol.
基金the Iran Nanotechnology Initiative Council for the financial and other supports
文摘Vanadium oxide （VOx） nanostructures, synthesized by hydrothermal treatment using dodecylamine as template, were evaluated for the selective catalytic reduction of NOx with ammonia （NH3-SCR）, The effect of solvent type in the reaction mixture （EtOH/（EtOH ＋ H20）） and time of hydrolysis was studied. The obtained materials were characterized by XRD, SEM, TEM and BET, The VOx nanorods （80-120 nm diameter and 1-4 μm length） were synthesized in 25 vol% EtOH/（EtOH ＋ H20） and the open-ended multiwalled VOx nanotube （50-100 nm inner diameter, 110-180 nm outer diameter and 0,5-2 pm length） synthesized in 50 vol% EtOH/（EtOH ＋ H20）. VOx nanotuhes performed the superior NH3-SCR activity under a gas hourly space velocity of 12,000 h-1 at low temperature of 250 ~C （NOx conversion of 893g ＆ N2 selectivity of 100%）, while most of the developed Vanadia base catalysts are active at high temperature （〉350 ℃）. The superior NH3-SCR activity ofVOx nanotubes at low tem- perature is related to nanocrystalline structure, special nanotube morphology as well as high specific surface area.
基金supported through the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical, Biological, and Geosciences Division under DE-SC0010379the support from an ECS Toyota Young Investigator Fellowship
文摘Identifying active sites and catalytic mechanism of the oxygen reduction reaction under anhydrous conditions are crucial for the development of next generation proton exchange membrane fuel cells(PEMFCs)operated at a temperature>100℃.Here,by employing density functional theory calculations,we studied ORR on flat and stepped Pt(111)surfaces with both(110)and(100)type of steps.We found that,in contrast to ORR under hydrous conditions,(111)terrace sites are not active for ORR under anhydrous conditions,because of weakened binding of ORR intermediates induced by O*accumulation on the surface.On the other hand,step edges,which are generally not active for ORR under hydrous conditions,are predicted to be the active sites for ORR under anhydrous conditions.Among them,(110)type step edge with a unique configuration of accumulated O stabilizes O_(2)adsorption and facilitates O_(2)dissociation,which lead an overpotential<0.4 V.To improve ORR catalysts in high-temperature PEMFCs,it is desirable to maximize(110)step edge sites that present between two(111)facets of nanoparticles.
文摘The perovskite type rare earth iron complex (REIC) oxide La 1-x Ce xFeO 3 is designed and prepared as water gas shift catalyst. Activity evaluation and heat resisting test show that the perovskite type compounds La 1-x Ce xFeO 3(·K) has a good thermal stability if x is less than or equal to 0.5 . But when x is greater than 0.5 , La 1-x Ce xFeO 3(·K) will turn out to be ceria and magnetite partially or completely at high temperature in the shift reaction atmosphere. In the case of x=0.5, the conversion of carbon monoxide is about 68% at 530 ℃. Potassium can greatly improve the low temperature activity, but slightly lower the high temperature activity, and has little impact on the thermal stability. La 0.5 Ce 0.5 FeO 3 (·K) is a promising chromium free high temperature shift catalyst.
文摘The aim of the research was to obtain both an excellent effluent for reuse and a reduced sludge production simultaneously by a combination process of anaerobic phase and Membrane bioreactor （MBR） technology in treating domestic wastewater. During the experimental period of three months, excellent removals for COD, NH3-H, TN were obtained, and mean removals were 91.87%, 96.13%, and 69. 23%, respectively. Whereas, at first 20 days, the removal for TP was only about 15.87%. In the following days, about 30% of raw water was introduced into the anaerobic reactor to supply organics for denitrificatien and release of polyphosphate, then a significant improvement for TP removal was observed, and mean removal of TP increased to 76.35%. During the operational period, it was investigated that the permeate could meet the requirements of several water criteria for reuse except free chlorine, and a mean excess sludge yield coefficient of 0.137 g MLSS/g COD was obtained. Therefore, the predicted goals of permeate for reuse and excess sludge reduction could be both achieved after dosing a certain quantity of disinfectant into the permeate.
文摘Two lab-scale reactors, suspended-sludge and fluidized.bed, were conducted with the feed of ammonium-rich synthetic wastewater devoid of COD. Completely autotrophic nitrogen-removal process was fulfilled in both reactors and the maximum efficiencies of nitrogen removal were achieved, 65% in the suspended-sludge reactor and 73% in the fluidized-bed reactor respectively. Different from the steady performance of the fluldized-bed reactor, the suspended-sludge reactor came to deteriorate constantly after a period of stable operation, resulting in almost complete loss of the N-removal ability in the suspending system. Molecular methods such as PCR and FISH were employed for describing the microbial characteristics in two systems. This study suggests that a biofllm system is a suitable configuration for completely autotrophic N-removal with more feasibility and stability than a suspending system.
文摘Flooding/submergence of rice fields is a severe problem in South and South-East Asia, affecting more than 20 million hectares of rice every year. Submergence creates hypoxic or anoxic condition causing poor germination, seedling establishment,and enormous yield loss. Standing water in the field from weeks to months also leads to significant yield losses when large part of aerial tissues is under water. For flash flooding, a rice variety FR1A3 with tolerant gene(SUB1A) was identified. SNORKEL1 and SNORKEL2 have been identified for their ability to survive deep-water flooding by rapid elongation. Submergence stress has also been reported to adversely affect cell division and damage cellular and organelle membranes. Research on antioxidative enzymes response and genes that confer tolerance to prolonged flooding is in progress. Here we review the different anoxia responsive genes and the potential involvement of antioxidative enzymes, such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase, which occur in cells of rice plant exposed to submergence stress.
基金supported by the National Basic Research Program of China(2016YFA0602900)Youth Innovation Promotion Association CAS(2016206)Jilin Provincial Science and Technology Program of China(20150301012GX)
文摘Hexamethylenediamine(HMDA) is an important reagent for the synthesis of Nylon-6,6, and it is usually produced by the hydrogenation of adiponitrile using a toxic reagent of hydrocyanic acid. Herein, we developed an environmental friendly route to produce HMDA via catalytic reductive amination of 1,6-hexanediol(HDO) in the presence of hydrogen. The activities of several heterogeneous metal catalysts such as supported Ni, Co, Ru, Pt, Pd catalysts were screened for the present reaction in supercritical ammonia without any additives. Among the catalysts examined, Ru/Al_2O_3 presented a high catalytic activity and highest selectivity for the desired product of HMDA. The high performance of Ru/Al_2O_3 was discussed based on the Ru dispersion and the surface properties like the acid-basicity. In addition, the reaction parameters such as reaction temperature,time, H_2 and NH_3 pressure were examined, and the reaction processes were discussed in detail.
基金Project supported by the National Key Technology R&D Program of China(No.2007BAD59B06)the International Science and Technology Cooperation Program of China(No.2007DFA31260)
文摘We constructed an expression cassette of the organophosphorus pesticide degrading （opal） gene under the control of the E8 promoter. Then opd was transformed into tomato fruit using an agroinfiltration transient expression system. β-Glucuronidase （GUS） staining, reverse transcription-polymerase chain reaction （RT-PCR）, wavelength scanning, and fluorescent reaction were performed to examine the expression of the opd gene and the hydrolysis activity on coumaphos of organo- phosphorus hydrolase （OPH） in tomato fruit. The results show that the agroinfiltrated tomato fruit-expressed OPH had the maximum hydrolysis activity of about 11.59 Uhng total soluble protein. These results will allow us to focus on breeding transgenic plants that could not only enhance the degrading capability of fruit and but also hold no negative effects on pest control when spraying organophosphorus pesticides onto the seedlings in fields.
基金the National Natural Science Foundation of China(21303249,21301187,21425103,21473240)the Natural Science Foundation of Jiangsu province,China(BK2012007)
文摘In this work,a facile process was reported to fabricate amorphous carbon-coated MnO micropeanuts(MPs)with 1.8μm in length and 1.0μm in width using hydrothermal reaction followed by heat treatment in the oxygen-free environment.With Mn Cl_2 and KMnO_4 dissolved in the mixture of ethylene glycol and water,MnCO_3 MP precursors were obtained via the hydrothermal reaction with dopamine as surfactant.Then MnCO_3 MP was annealed at 600°C in the N_2 atmosphere and was transformed into MnO MP,and simultaneously the formed polydopamine during the hydrothermal reaction was carbonized to produce amorphous carbon-coating on the MnO MP surface.In contrast,MnCO_3 nanoparticle(NP)precursor was formed without the addition of dopamine and MnO NP agglomerates were prepared after pyrolysis.The carbonization of polydopamine during thermolysis improves the electrical conductivity and thermal stability of the MnO MP and thus its electrochemical performance as electrode materials for lithium ion battery.Hopefully,this facile strategy for fabricating and designing carbon-coated materials would inspire more novel nanostructures and applications thereof.
