[Objective] This paper aims to study a new method of extracting pumpkin polysaccharide from pumpkin. Single factor experiments were conducted to examine the effects of extracting time,temperature,the solid-liquid rati...[Objective] This paper aims to study a new method of extracting pumpkin polysaccharide from pumpkin. Single factor experiments were conducted to examine the effects of extracting time,temperature,the solid-liquid ratio and pH value on the extraction yield of polysaccharide from pumpkin. [Method] The best enzyme ratio and extraction conditions for complex enzymes extraction were determined through orthogonal tests. Scavenging ·OH and O-2 activities of pumpkin polysaccharides were also investigated by salicylic acid and improved self-oxidation of o-pheno methods respectively. [Results] The results showed that the biggest extraction yield of polysaccharide from pumpkin can be got when adding 1% cellulose enzyme,1.5% pectinase,1.0% papain and Na2HPO4-citric acid buffer solution (pH was 4.6),and oscillating for 30 min under water at 40 ℃ with the solid-liquid ratio of 1:30. In addition,pumpkin polysaccharides had a strong activity of eliminating ·OH,but very weak activity to scavenge O-2. [Conclusion] This study provided basic data for research and application of Pumpkin polysaccharide.展开更多
N-valeronitrile-N'-methylimidazolium hexafluorophosphate ([C 4 CNmim]+ PF 6),as a novel ionic liquid with polar nitrile functional group,was prepared.The structure of the ionic liquid was characterized by using IR...N-valeronitrile-N'-methylimidazolium hexafluorophosphate ([C 4 CNmim]+ PF 6),as a novel ionic liquid with polar nitrile functional group,was prepared.The structure of the ionic liquid was characterized by using IR and 1 H NMR.As a medium,the ionic liquid plays an important role in copolymerization of carbon monoxide (CO) with styrene (St).Some synthetic conditions were determined,including the usage of ionic liquid,palladium composite catalyst and methanol,CO pressure,reaction time and reaction temperature.The influence of these factors on catalytic activity was analyzed.The results show that the catalytic activity has reached 1 724.1 gStCO/(gPd·h) and the catalyst could be reused 5 times under the optimal condition:composite catalyst 0.015 mmol,ionic liquid 3 mL,methanol 0.75 mL,CO pressure 2MPa,reaction time 2 h and reaction temperature 70℃.This CO/St copolymerization within [C 4 CNmim]+ PF 6 system could facilitate ionic liquids with efficient and economical applications to polymeric materials.展开更多
The bacterial pre-oxidation process of arsenic-containing gold concentrates and the bacterial activity under different chloride ion concentrations were studied by using a mixture of thermophilic strains TCJ domesticat...The bacterial pre-oxidation process of arsenic-containing gold concentrates and the bacterial activity under different chloride ion concentrations were studied by using a mixture of thermophilic strains TCJ domesticated in production.The experimental result shows that with different samples and leaching systems,the adaptability and Cl- tolerance of bacteria are different,and that appropriate chloride ion concentration is conductive to bacterial oxidation,while higher chloride ion concentration will inhibit the bacterial activity and affect the pre-oxidation performance.Under the present production conditions,TCJ can adapt to the changes of water quality in the source of water and its critical chloride ion tolerance value is 2.7 g/L.展开更多
Conversion of methane by steam reforming was carried out by means of dielectric-barrier discharge.A systemic procedure was employed to determine the suitable experimental conditions.It was found that one of the plasma...Conversion of methane by steam reforming was carried out by means of dielectric-barrier discharge.A systemic procedure was employed to determine the suitable experimental conditions.It was found that one of the plasma generators can match the system best.A higher power input can always bring a higher conversion,but the selectivity to C2H6 decreased from 52.48% to 39.43% as the power increased from 20W to 49W.When discharge distance was 4mm,selectivities to almost all main products reached the max.The inner electrode made of stainless steel and the outer electrode with aluminum foil were one of the best options which can obviously enhance the conversion of methane.A larger flow rate always resulted in a lower conversion of methane.In the most time,19.93% steam promoted conversion of methane.展开更多
Tungsten film(W film) is deposited by using the ion beam assisted deposition(IBAD) on the 316 L substrate surface in this experiment. The micro structure and nano-hardness of the film are investigated by scanning elec...Tungsten film(W film) is deposited by using the ion beam assisted deposition(IBAD) on the 316 L substrate surface in this experiment. The micro structure and nano-hardness of the film are investigated by scanning electron microscopy(SEM) and nano-indentation tester. The tribological behavior of W film under lubrication by oil with ZDDP and MoDTC is evaluated by a SRV test machine. The tribo-film formed on the worn surfaces is investigated by X-ray photoelectron spectroscopy(XPS) to find out the tribological mechanisms between the W film and the two additional additives. The result shows that the W film lubricated by ZDDP and MoDTC-blended base oil has synergistic effects on the friction reduction property, while the anti-wear property is mainly caused by the hard surface of W film.展开更多
In the interest of accelerating aniline degradation, Fe2+ and chelated Fe2+ activated persulfate oxidations were investigated in neutral pH condition. Three kinds of chelating agents were selected including citric aci...In the interest of accelerating aniline degradation, Fe2+ and chelated Fe2+ activated persulfate oxidations were investigated in neutral pH condition. Three kinds of chelating agents were selected including citric acid, oxalic acid and ethylenediamine tetraaceatate(EDTA) to maintain available Fe2+. The results indicate that the concentration of chelating agent and ferrous ion didn't follow a linear relationship with the degradation rate of aniline. A 1/1 ratio of chelating agent/Fe2+ results in a higher degradation rate compared to the results by other ratios. The oxidation enhancement factor using oxalic acid was found to be relatively low. In contrast, citric acid is more suitable chelating agent in the ferrous iron activated persulfate system and aniline exhibits a highest degradation with a persulfate/Fe2+/citric acid/aniline molar ratio of 50/25/25/1 compared to other molar ratios.展开更多
Chlamydomonas reinhardtii(C.reinhardtii) was used to study adsorption of cadmium(Cd) from aqueous media within various experimental conditions.Results showed that the adsorption process was very fast,with most of the ...Chlamydomonas reinhardtii(C.reinhardtii) was used to study adsorption of cadmium(Cd) from aqueous media within various experimental conditions.Results showed that the adsorption process was very fast,with most of the adsorption occurring within 30 min of contact time and the equilibrium state was reached in about 60 min.The adsorption ability of the algae increases with the increasing adsorptions sites on cells.Maximum adsorption was observed at the initial Cd concentration of 100 mg/L and pH 6.0. The adsorption was markedly inhibited in the presence of calcium and magnesium ions at 10 mM and the Cd removal efficiency was reduced by 16.54%and 14.99%respectively.This study would be a finding of note with regard to practical wastewater treatment.展开更多
In this paper, design and construction of a modified cold molybdenum cathode Penning ion source was described. It consists of copper cylindrical anode with two cone ends and two movable cold molybdenum cathodes. The t...In this paper, design and construction of a modified cold molybdenum cathode Penning ion source was described. It consists of copper cylindrical anode with two cone ends and two movable cold molybdenum cathodes. The two cathodes were placed symmetrically at two ends of the anode. The modifications were decrease the length of the cylindrical anode to 4 cm instead of 6 cm, transform the copper emission electrode shape from plate of 40 mm length, 25 mm width and 2 mm thickness to disc of 20 mm diameter and 2 mm thickness and transform the inner uncovered area of the emission electrode from slit of 30 mm length and 10 mm width to disc of 5 mm diameter. The copper emission electrode was placed in the middle of the cylindrical anode and has aperture in the center of different diameters. Faraday cup was placed at different distances from the emission electrode aperture. The electrical discharge and the output ion beam characteristics of the modified ion source were measured at different pressures using argon gas. It was found that the optimum operating conditions of the modified ion source are; anode-cathode distance equal to 6 mm, emission electrode aperture diameter equal to 2.5 mm and emission electrode aperture, Faraday cup distance equals 3 cm. The effect of axial samarium cobalt permanent magnet of intensity equal to 300 Gauss on the discharge characteristics of the ion source was determined.展开更多
Chloride ion transport in reclaimed soil solutions filled with fly ash （FA） was investigated by measuring the hydraulic parameters （i,e. water retention curves and hydraulic conductivity） of three substrates, name...Chloride ion transport in reclaimed soil solutions filled with fly ash （FA） was investigated by measuring the hydraulic parameters （i,e. water retention curves and hydraulic conductivity） of three substrates, namely GSL, GFA, and CFA. Similar simulations were carried out under certain weather conditions. The different boundary conditions of chloride transport were also discussed from FA texture, cover soil thickness, groundwater table level, and initial chloride concentration. Furthermore, the sensitivities of chloride ions to these effect factors were analyzed. The results show that the different top soil thickness and initial chloride concentration have no effect on salinity of topsoil solution in the monitoring points, but they can clearly change the chloride concentration of FA layers. The sensibilities from top soil thickness and initial chloride content are exceedingly weak to the salinity balance based on two dimensions of the time and concentration. While the different FA texture and groundwater table not only affect the salinity equilibrium process of the whole reclaimed soil profile, but also change its balance state. Generally, coarse FA particles and high groundwater table can defer the salinity balance process of the reclaimed soil solution, and they also increase the chloride concentration of FA layer solutions, and even topsoil ones.展开更多
A rigorous approach is proposed to model the mean ion activity coefficient for strong electrolyte systems using the Poisson-Boltzmann equation. An effective screening radius similar to the Debye decay length is introd...A rigorous approach is proposed to model the mean ion activity coefficient for strong electrolyte systems using the Poisson-Boltzmann equation. An effective screening radius similar to the Debye decay length is introduced to define the local composition and new boundary conditions for the central ion. The crystallographic ion size is also considered in the activity coefficient expressions derived and non-electrostatic contributions are neglected. The model is presented for aqueous strong electrolytes and compared with the classical Debye-Hfickel （DH） limiting law for dilute solutions. The radial distribution function is compared with the DH and Monte Carlo studies. The mean ion activity coefficients are calculated for 1：1 aqueous solutions containing strong electrolytes composed of alkali halides. The individual ion activity coefficients and mean ion activity coefficients in mixed sol- vents are predicted with the new equations.展开更多
基金Supported by the Key Scientific and Technological Project of Henan Province (102102110157)the Scientific Research Found Project of Henan University of Urban Construction (2010JZD008)~~
文摘[Objective] This paper aims to study a new method of extracting pumpkin polysaccharide from pumpkin. Single factor experiments were conducted to examine the effects of extracting time,temperature,the solid-liquid ratio and pH value on the extraction yield of polysaccharide from pumpkin. [Method] The best enzyme ratio and extraction conditions for complex enzymes extraction were determined through orthogonal tests. Scavenging ·OH and O-2 activities of pumpkin polysaccharides were also investigated by salicylic acid and improved self-oxidation of o-pheno methods respectively. [Results] The results showed that the biggest extraction yield of polysaccharide from pumpkin can be got when adding 1% cellulose enzyme,1.5% pectinase,1.0% papain and Na2HPO4-citric acid buffer solution (pH was 4.6),and oscillating for 30 min under water at 40 ℃ with the solid-liquid ratio of 1:30. In addition,pumpkin polysaccharides had a strong activity of eliminating ·OH,but very weak activity to scavenge O-2. [Conclusion] This study provided basic data for research and application of Pumpkin polysaccharide.
基金Supported by National Natural Science Foundation of China (No.20476080)Tianjin Natural Science Foundation (No.07JCYBJC00600)
文摘N-valeronitrile-N'-methylimidazolium hexafluorophosphate ([C 4 CNmim]+ PF 6),as a novel ionic liquid with polar nitrile functional group,was prepared.The structure of the ionic liquid was characterized by using IR and 1 H NMR.As a medium,the ionic liquid plays an important role in copolymerization of carbon monoxide (CO) with styrene (St).Some synthetic conditions were determined,including the usage of ionic liquid,palladium composite catalyst and methanol,CO pressure,reaction time and reaction temperature.The influence of these factors on catalytic activity was analyzed.The results show that the catalytic activity has reached 1 724.1 gStCO/(gPd·h) and the catalyst could be reused 5 times under the optimal condition:composite catalyst 0.015 mmol,ionic liquid 3 mL,methanol 0.75 mL,CO pressure 2MPa,reaction time 2 h and reaction temperature 70℃.This CO/St copolymerization within [C 4 CNmim]+ PF 6 system could facilitate ionic liquids with efficient and economical applications to polymeric materials.
基金Project(2007AA060902) supported by the National High Technology Research and Development Program of ChinaProject(2010CB630905) supported by the National Basic Research Program of China
文摘The bacterial pre-oxidation process of arsenic-containing gold concentrates and the bacterial activity under different chloride ion concentrations were studied by using a mixture of thermophilic strains TCJ domesticated in production.The experimental result shows that with different samples and leaching systems,the adaptability and Cl- tolerance of bacteria are different,and that appropriate chloride ion concentration is conductive to bacterial oxidation,while higher chloride ion concentration will inhibit the bacterial activity and affect the pre-oxidation performance.Under the present production conditions,TCJ can adapt to the changes of water quality in the source of water and its critical chloride ion tolerance value is 2.7 g/L.
基金Supported by the National iqatural Science Foundation of China （20606023, 20490203）.
文摘Conversion of methane by steam reforming was carried out by means of dielectric-barrier discharge.A systemic procedure was employed to determine the suitable experimental conditions.It was found that one of the plasma generators can match the system best.A higher power input can always bring a higher conversion,but the selectivity to C2H6 decreased from 52.48% to 39.43% as the power increased from 20W to 49W.When discharge distance was 4mm,selectivities to almost all main products reached the max.The inner electrode made of stainless steel and the outer electrode with aluminum foil were one of the best options which can obviously enhance the conversion of methane.A larger flow rate always resulted in a lower conversion of methane.In the most time,19.93% steam promoted conversion of methane.
基金the Beijing Natural Science Foundation (3132023)the National Natural Science Foundation of China (51275494 and 51005218)+1 种基金the Fundamental Research Funds for the Central Universities (2652012115 and 2652013081)the Tribology Science Fund of State Key Laboratory of Tribology (SKLTKF13B10) for their financial support to this research
文摘Tungsten film(W film) is deposited by using the ion beam assisted deposition(IBAD) on the 316 L substrate surface in this experiment. The micro structure and nano-hardness of the film are investigated by scanning electron microscopy(SEM) and nano-indentation tester. The tribological behavior of W film under lubrication by oil with ZDDP and MoDTC is evaluated by a SRV test machine. The tribo-film formed on the worn surfaces is investigated by X-ray photoelectron spectroscopy(XPS) to find out the tribological mechanisms between the W film and the two additional additives. The result shows that the W film lubricated by ZDDP and MoDTC-blended base oil has synergistic effects on the friction reduction property, while the anti-wear property is mainly caused by the hard surface of W film.
基金Project(2010B050200007)supported by the Foundation of Science and Technology Planning Project of Guangdong Province,ChinaProject(2011ZM0054)supported by the Fundamental Research Funds for the Central Universities,China+1 种基金Project(2011K0013)supported by the Research Fund Program of Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology,ChinaProject(2012)supported by the Research Funds of Guangdong Provincial Key Laboratory of Atmospheric environment and Pollution Control,China
文摘In the interest of accelerating aniline degradation, Fe2+ and chelated Fe2+ activated persulfate oxidations were investigated in neutral pH condition. Three kinds of chelating agents were selected including citric acid, oxalic acid and ethylenediamine tetraaceatate(EDTA) to maintain available Fe2+. The results indicate that the concentration of chelating agent and ferrous ion didn't follow a linear relationship with the degradation rate of aniline. A 1/1 ratio of chelating agent/Fe2+ results in a higher degradation rate compared to the results by other ratios. The oxidation enhancement factor using oxalic acid was found to be relatively low. In contrast, citric acid is more suitable chelating agent in the ferrous iron activated persulfate system and aniline exhibits a highest degradation with a persulfate/Fe2+/citric acid/aniline molar ratio of 50/25/25/1 compared to other molar ratios.
基金supported by Beijing Elitist Foundation(Grant no.2005IA05016012)Beijing New Century Talent Foundation(Grant no.011 005400601)
文摘Chlamydomonas reinhardtii(C.reinhardtii) was used to study adsorption of cadmium(Cd) from aqueous media within various experimental conditions.Results showed that the adsorption process was very fast,with most of the adsorption occurring within 30 min of contact time and the equilibrium state was reached in about 60 min.The adsorption ability of the algae increases with the increasing adsorptions sites on cells.Maximum adsorption was observed at the initial Cd concentration of 100 mg/L and pH 6.0. The adsorption was markedly inhibited in the presence of calcium and magnesium ions at 10 mM and the Cd removal efficiency was reduced by 16.54%and 14.99%respectively.This study would be a finding of note with regard to practical wastewater treatment.
文摘In this paper, design and construction of a modified cold molybdenum cathode Penning ion source was described. It consists of copper cylindrical anode with two cone ends and two movable cold molybdenum cathodes. The two cathodes were placed symmetrically at two ends of the anode. The modifications were decrease the length of the cylindrical anode to 4 cm instead of 6 cm, transform the copper emission electrode shape from plate of 40 mm length, 25 mm width and 2 mm thickness to disc of 20 mm diameter and 2 mm thickness and transform the inner uncovered area of the emission electrode from slit of 30 mm length and 10 mm width to disc of 5 mm diameter. The copper emission electrode was placed in the middle of the cylindrical anode and has aperture in the center of different diameters. Faraday cup was placed at different distances from the emission electrode aperture. The electrical discharge and the output ion beam characteristics of the modified ion source were measured at different pressures using argon gas. It was found that the optimum operating conditions of the modified ion source are; anode-cathode distance equal to 6 mm, emission electrode aperture diameter equal to 2.5 mm and emission electrode aperture, Faraday cup distance equals 3 cm. The effect of axial samarium cobalt permanent magnet of intensity equal to 300 Gauss on the discharge characteristics of the ion source was determined.
基金Supported by the National Natural Science Foundation of China （51274013） the International Cooperation Projects of Anhui, China （10080703026） Acknowledgements We thank the work group of soil information systems and solute transport models from Osnabrueck University of Applied Sciences, Germany for providing us their experimental work.
文摘Chloride ion transport in reclaimed soil solutions filled with fly ash （FA） was investigated by measuring the hydraulic parameters （i,e. water retention curves and hydraulic conductivity） of three substrates, namely GSL, GFA, and CFA. Similar simulations were carried out under certain weather conditions. The different boundary conditions of chloride transport were also discussed from FA texture, cover soil thickness, groundwater table level, and initial chloride concentration. Furthermore, the sensitivities of chloride ions to these effect factors were analyzed. The results show that the different top soil thickness and initial chloride concentration have no effect on salinity of topsoil solution in the monitoring points, but they can clearly change the chloride concentration of FA layers. The sensibilities from top soil thickness and initial chloride content are exceedingly weak to the salinity balance based on two dimensions of the time and concentration. While the different FA texture and groundwater table not only affect the salinity equilibrium process of the whole reclaimed soil profile, but also change its balance state. Generally, coarse FA particles and high groundwater table can defer the salinity balance process of the reclaimed soil solution, and they also increase the chloride concentration of FA layer solutions, and even topsoil ones.
基金Supported by the National Natural Science Foundation of China(21206010)
文摘A rigorous approach is proposed to model the mean ion activity coefficient for strong electrolyte systems using the Poisson-Boltzmann equation. An effective screening radius similar to the Debye decay length is introduced to define the local composition and new boundary conditions for the central ion. The crystallographic ion size is also considered in the activity coefficient expressions derived and non-electrostatic contributions are neglected. The model is presented for aqueous strong electrolytes and compared with the classical Debye-Hfickel （DH） limiting law for dilute solutions. The radial distribution function is compared with the DH and Monte Carlo studies. The mean ion activity coefficients are calculated for 1：1 aqueous solutions containing strong electrolytes composed of alkali halides. The individual ion activity coefficients and mean ion activity coefficients in mixed sol- vents are predicted with the new equations.
