A numerical model was established to predict and optimise the chemical cleaning process of Polyvinylidene Fluo- ride （PVDF） Ultrafiltration （UF） membranes with the results from the experiment that applied the Resp...A numerical model was established to predict and optimise the chemical cleaning process of Polyvinylidene Fluo- ride （PVDF） Ultrafiltration （UF） membranes with the results from the experiment that applied the Response Sur- face Method （RSM） and Central Composite Design （CCD）. The factors considered in the experimental design were sodium hydroxide （NaOH） concentration, sodium bypochlorite concentration （NaCIO）, citric acid concentration and cleaning duration, The interactions between the factors were investigated with the numerical model. Humic acid （20 mg· L-1） was used as the model foulant, and chemical enhanced backflush （CEB） was employed to sim- ulate the chemical cleaning process. The concentrations of sodium hydroxide, sodium hypochlorite, citric acid and cleaning duration tested during the experiments were in the range of 0.1%-0.3% 100-300 mg· L-1 1%-3% and 0.5-1.5 h, respectively. Among the variables, the sodium hypochlorite concentration and the cleaning dura- tion showed a positive relationship involving the increased efficiency of the chemical cleaning. The chemical cleaning efficiency was hardly improved with increasing concentrations of sodium hydroxide. However, the data was sharply decreased when at a low level of sodium hydroxide concentration. In total, 54 sets of cleaning schemes with 80% to 100K cleaning efficiency were observed with the R＆M model after calibration.展开更多
This article refers to the study on the performance of mesoporous silica used as the catalyst for oxidative desulfurization reactions. The test results revealed that under mild reaction conditions using tert-butyl hyd...This article refers to the study on the performance of mesoporous silica used as the catalyst for oxidative desulfurization reactions. The test results revealed that under mild reaction conditions using tert-butyl hydroperoxide as the oxidizing agent the content of dibenzothiophene(DBT) contained in oil samples could be reduced from 5000 ppm to less than 5 ppm. Furthermore,the mesoporous silica material can be easily regenerated and recycled.展开更多
In structure of manufacture of PFER （primary fuel and energy resources） in Central Asia region the leading place occupies now organic fuel. Thus about half of total amount of power resources it is necessary on the n...In structure of manufacture of PFER （primary fuel and energy resources） in Central Asia region the leading place occupies now organic fuel. Thus about half of total amount of power resources it is necessary on the natural gas which basic stocks are concentrated in Turkmenistan and Uzbekistan. More than 95% of all electric power in Tajikistan is developed by hydroelectric power stations. Use of hydrogen as energy carrier allows to consider and solve power problems in close connection with ecological. At a large factory electrolysis of water with capacity of 450 t/day and more expenses of the electric power on 1 m3 hydrogen can be finished by capacity up to 4.0-4.5 kWt.h. At such expense of the electric power in a number of power situations electrolysis of water, even in modem conditions can become a competitive method of obtaining of hydrogen.展开更多
A new process is developed by using compound Mn as intermediate to produce Cl2from HCl,with the following steps.(1)HCl steam is decomposed by intermediate Mn2O3to produce Cl2and Mn Cl2at 500°C.(2)Produced Mn Cl2i...A new process is developed by using compound Mn as intermediate to produce Cl2from HCl,with the following steps.(1)HCl steam is decomposed by intermediate Mn2O3to produce Cl2and Mn Cl2at 500°C.(2)Produced Mn Cl2is oxidized by water steam to produce Mn O at 450°C.(3)The Mn O compound is oxidized by air to yield Mn2O3.The X-ray diffraction(XRD)crystallite characterization results indicate the high conversion in each step under the optimum experimental conditions.Long term experiments for continuous conversion of HCl to Cl2by using Mn2O3as intermediate in a fixed bed reactor indicate that over 90%of HCl could be converted to Cl2on stream of 30 h.The production of Cl2from HCl with Mn compound as an intermediate and atmospheric steam is a feasible and recyclable process.展开更多
Guava leaf tea has been used as a folk medicine for treating hyperglycemic conditions in Asia and Africa. The hypoglycemic efficacy of guava leaf has been documented by many scientists in these regions, but the hypogl...Guava leaf tea has been used as a folk medicine for treating hyperglycemic conditions in Asia and Africa. The hypoglycemic efficacy of guava leaf has been documented by many scientists in these regions, but the hypoglycemic mechanism is poorly understood. Guava leaves were extracted with methanol and the crude extract was partitioned against hexane, ethyl acetate, and butanol in sequence. The leftover in water is defined as the aqueous partition. A second smaller batch was extracted with hot water directly. Oral glucose tolerance test was carried out on healthy mice instead of diabetic mice that lack endogenous insulin. Glucose uptake was examined with 3T3-L1 adipocytes. Oxidative effect on PTP1B （protein tyrosine phosphatase 1b） was carried out with real-time PTP1B enzymatic assay. The aqueous partition of guava leaf extract possesses a potent inhibitory effect on PTP1B enzymatic activity and this PTP1B inhibition is through a slow oxidative but reversible inactivation on the enzyme. The reversible inactivation would suggest guava leaf extract may augment PTP1B inhibition alongside the endogenous H2O2 which itself is induced by insulin. In addition, our study confirmed the hypoglycemic efficacy being associated with guava leaf and found the most effective molecules reside in the aqueous partition which is also less cytotoxic to Chinese hamster ovary cells when compared to other less polar partitions. The guava leaf extract can modulate insulin activity through a redox regulation on PP1B enzymatic activity. It is speculated that a compound similar to gallocatechin in the aqueous partition can reduce an oxygen molecule to hydrogen peroxide which in turn oxidizes the catalytic residue Cys in PTP1B. Therefore, the guava leaf tea can serve as a functional hypoglycemic drink that is suitable for either healthy or diabetic subjects.展开更多
Insect gut epithelial cells produce reactive oxygen species （ROS） and antimicrobial peptides （AMPs） to protect hosts from pathogenic microorganisms. In this study, we evaluate the pathogenicity of Pseudomonas aeru...Insect gut epithelial cells produce reactive oxygen species （ROS） and antimicrobial peptides （AMPs） to protect hosts from pathogenic microorganisms. In this study, we evaluate the pathogenicity of Pseudomonas aeruginosa and Bacillus bombysepticus in the silkworm, Bombyx mori. Survival curves show that B. bombysepticus is deadly when larval silkworms are infected orally. Bacterial infection caused intestinal hydrogen peroxide （H202） and nitric oxide （NO） levels to increase significantly by 8 and 16 h post-infection （hpi）, respectively. Real-time quantitative polymerase chain reaction （qPCR） analysis shows that the transcription levels of dual oxidase （Duox） and catalase （CAT） are highly up-regulated by P. aeruginosa infection at 8 hpi. P. aeruginosa infection induced nitric oxide synthase 2 （NOS2） expression at 16 hpi, which contributes to the generation of NO. mRNA levels of AMP genes, specifically Glovorin 2 and Glovorin 3, which obviously increase during the eady infection stage. These results indicate that invading bacteria ele.vate intestinal ROS and NO levels and induce AMP gene transcription, which contributes to intestinal immune defense.展开更多
Anodic urea oxidation reaction(UOR)is an intriguing half reaction that can replace oxygen evolution reaction(OER)and work together with hydrogen evolution reaction(HER)toward simultaneous hydrogen fuel generation and ...Anodic urea oxidation reaction(UOR)is an intriguing half reaction that can replace oxygen evolution reaction(OER)and work together with hydrogen evolution reaction(HER)toward simultaneous hydrogen fuel generation and urea-rich wastewater purification;however,it remains a challenge to achieve overall urea electrolysis with high efficiency.Herein,we report a multifunctional electrocatalyst termed as Rh/Ni V-LDH,through integration of nickel-vanadium layered double hydroxide(LDH)with rhodium single-atom catalyst(SAC),to achieve this goal.The electrocatalyst delivers high HER mass activity of0.262 A mg^(-1) and exceptionally high turnover frequency(TOF)of 2.125 s^(-1) at an overpotential of100 m V.Moreover,exceptional activity toward urea oxidation is addressed,which requires a potential of 1.33 V to yield 10 mA cm^(-2),endorsing the potential to surmount the sluggish OER.The splendid catalytic activity is enabled by the synergy of the Ni V-LDH support and the atomically dispersed Rh sites(located on the Ni-V hollow sites)as evidenced both experimentally and theoretically.The selfsupported Rh/Ni V-LDH catalyst serving as the anode and cathode for overall urea electrolysis(1 mol L^(-1) KOH with 0.33 mol L^(-1) urea as electrolyte)only requires a small voltage of 1.47 V to deliver 100 mA cm^(-2) with excellent stability.This work provides important insights into multifunctional SAC design from the perspective of support sites toward overall electrolysis applications.展开更多
基金Supported by State Key Laboratory of Urban Water Resource and Environment(2016DX01)the Fundamental Research Funds for the Central University(NSRIF.2014096)Science and Technology Planning Project of Chancheng District(2013A1044)
文摘A numerical model was established to predict and optimise the chemical cleaning process of Polyvinylidene Fluo- ride （PVDF） Ultrafiltration （UF） membranes with the results from the experiment that applied the Response Sur- face Method （RSM） and Central Composite Design （CCD）. The factors considered in the experimental design were sodium hydroxide （NaOH） concentration, sodium bypochlorite concentration （NaCIO）, citric acid concentration and cleaning duration, The interactions between the factors were investigated with the numerical model. Humic acid （20 mg· L-1） was used as the model foulant, and chemical enhanced backflush （CEB） was employed to sim- ulate the chemical cleaning process. The concentrations of sodium hydroxide, sodium hypochlorite, citric acid and cleaning duration tested during the experiments were in the range of 0.1%-0.3% 100-300 mg· L-1 1%-3% and 0.5-1.5 h, respectively. Among the variables, the sodium hypochlorite concentration and the cleaning dura- tion showed a positive relationship involving the increased efficiency of the chemical cleaning. The chemical cleaning efficiency was hardly improved with increasing concentrations of sodium hydroxide. However, the data was sharply decreased when at a low level of sodium hydroxide concentration. In total, 54 sets of cleaning schemes with 80% to 100K cleaning efficiency were observed with the R＆M model after calibration.
文摘This article refers to the study on the performance of mesoporous silica used as the catalyst for oxidative desulfurization reactions. The test results revealed that under mild reaction conditions using tert-butyl hydroperoxide as the oxidizing agent the content of dibenzothiophene(DBT) contained in oil samples could be reduced from 5000 ppm to less than 5 ppm. Furthermore,the mesoporous silica material can be easily regenerated and recycled.
文摘In structure of manufacture of PFER （primary fuel and energy resources） in Central Asia region the leading place occupies now organic fuel. Thus about half of total amount of power resources it is necessary on the natural gas which basic stocks are concentrated in Turkmenistan and Uzbekistan. More than 95% of all electric power in Tajikistan is developed by hydroelectric power stations. Use of hydrogen as energy carrier allows to consider and solve power problems in close connection with ecological. At a large factory electrolysis of water with capacity of 450 t/day and more expenses of the electric power on 1 m3 hydrogen can be finished by capacity up to 4.0-4.5 kWt.h. At such expense of the electric power in a number of power situations electrolysis of water, even in modem conditions can become a competitive method of obtaining of hydrogen.
基金Supported by the National High Technology Research and Development Program of China(2011AA060703)the Innovation Funds of institute of processes engineering of Chinese Academy of Sciences(062702)
文摘A new process is developed by using compound Mn as intermediate to produce Cl2from HCl,with the following steps.(1)HCl steam is decomposed by intermediate Mn2O3to produce Cl2and Mn Cl2at 500°C.(2)Produced Mn Cl2is oxidized by water steam to produce Mn O at 450°C.(3)The Mn O compound is oxidized by air to yield Mn2O3.The X-ray diffraction(XRD)crystallite characterization results indicate the high conversion in each step under the optimum experimental conditions.Long term experiments for continuous conversion of HCl to Cl2by using Mn2O3as intermediate in a fixed bed reactor indicate that over 90%of HCl could be converted to Cl2on stream of 30 h.The production of Cl2from HCl with Mn compound as an intermediate and atmospheric steam is a feasible and recyclable process.
文摘Guava leaf tea has been used as a folk medicine for treating hyperglycemic conditions in Asia and Africa. The hypoglycemic efficacy of guava leaf has been documented by many scientists in these regions, but the hypoglycemic mechanism is poorly understood. Guava leaves were extracted with methanol and the crude extract was partitioned against hexane, ethyl acetate, and butanol in sequence. The leftover in water is defined as the aqueous partition. A second smaller batch was extracted with hot water directly. Oral glucose tolerance test was carried out on healthy mice instead of diabetic mice that lack endogenous insulin. Glucose uptake was examined with 3T3-L1 adipocytes. Oxidative effect on PTP1B （protein tyrosine phosphatase 1b） was carried out with real-time PTP1B enzymatic assay. The aqueous partition of guava leaf extract possesses a potent inhibitory effect on PTP1B enzymatic activity and this PTP1B inhibition is through a slow oxidative but reversible inactivation on the enzyme. The reversible inactivation would suggest guava leaf extract may augment PTP1B inhibition alongside the endogenous H2O2 which itself is induced by insulin. In addition, our study confirmed the hypoglycemic efficacy being associated with guava leaf and found the most effective molecules reside in the aqueous partition which is also less cytotoxic to Chinese hamster ovary cells when compared to other less polar partitions. The guava leaf extract can modulate insulin activity through a redox regulation on PP1B enzymatic activity. It is speculated that a compound similar to gallocatechin in the aqueous partition can reduce an oxygen molecule to hydrogen peroxide which in turn oxidizes the catalytic residue Cys in PTP1B. Therefore, the guava leaf tea can serve as a functional hypoglycemic drink that is suitable for either healthy or diabetic subjects.
基金supported by the National Natural Science Foundation of China(No.31272497)
文摘Insect gut epithelial cells produce reactive oxygen species （ROS） and antimicrobial peptides （AMPs） to protect hosts from pathogenic microorganisms. In this study, we evaluate the pathogenicity of Pseudomonas aeruginosa and Bacillus bombysepticus in the silkworm, Bombyx mori. Survival curves show that B. bombysepticus is deadly when larval silkworms are infected orally. Bacterial infection caused intestinal hydrogen peroxide （H202） and nitric oxide （NO） levels to increase significantly by 8 and 16 h post-infection （hpi）, respectively. Real-time quantitative polymerase chain reaction （qPCR） analysis shows that the transcription levels of dual oxidase （Duox） and catalase （CAT） are highly up-regulated by P. aeruginosa infection at 8 hpi. P. aeruginosa infection induced nitric oxide synthase 2 （NOS2） expression at 16 hpi, which contributes to the generation of NO. mRNA levels of AMP genes, specifically Glovorin 2 and Glovorin 3, which obviously increase during the eady infection stage. These results indicate that invading bacteria ele.vate intestinal ROS and NO levels and induce AMP gene transcription, which contributes to intestinal immune defense.
基金finically supported by the National Key R&D Program of China(2017YFE0120500)the National Natural Science Foundation of China(51972129,51702150,and 21725102)+2 种基金the Key Research and Development Program of Hubei(2020BAB079)Bintuan Science and Technology Program(2020DB002,and 2022DB009)the Science and Technology Innovation Committee Foundation of Shenzhen(JCYJ20210324141613032 and JCYJ20190809142019365)。
文摘Anodic urea oxidation reaction(UOR)is an intriguing half reaction that can replace oxygen evolution reaction(OER)and work together with hydrogen evolution reaction(HER)toward simultaneous hydrogen fuel generation and urea-rich wastewater purification;however,it remains a challenge to achieve overall urea electrolysis with high efficiency.Herein,we report a multifunctional electrocatalyst termed as Rh/Ni V-LDH,through integration of nickel-vanadium layered double hydroxide(LDH)with rhodium single-atom catalyst(SAC),to achieve this goal.The electrocatalyst delivers high HER mass activity of0.262 A mg^(-1) and exceptionally high turnover frequency(TOF)of 2.125 s^(-1) at an overpotential of100 m V.Moreover,exceptional activity toward urea oxidation is addressed,which requires a potential of 1.33 V to yield 10 mA cm^(-2),endorsing the potential to surmount the sluggish OER.The splendid catalytic activity is enabled by the synergy of the Ni V-LDH support and the atomically dispersed Rh sites(located on the Ni-V hollow sites)as evidenced both experimentally and theoretically.The selfsupported Rh/Ni V-LDH catalyst serving as the anode and cathode for overall urea electrolysis(1 mol L^(-1) KOH with 0.33 mol L^(-1) urea as electrolyte)only requires a small voltage of 1.47 V to deliver 100 mA cm^(-2) with excellent stability.This work provides important insights into multifunctional SAC design from the perspective of support sites toward overall electrolysis applications.
