2,5-Dicyanofuran(DCF)is an important biomass-derived platform compound primarily used to prepare bio-based adiponitrile,which is the key precursor for the synthesis of nylon 66 and 1,6-hexanediisocyanate(HDI).In this ...2,5-Dicyanofuran(DCF)is an important biomass-derived platform compound primarily used to prepare bio-based adiponitrile,which is the key precursor for the synthesis of nylon 66 and 1,6-hexanediisocyanate(HDI).In this study,one-pot,green and safe synthesis of DCF from 2,5-diformylfuran(DFF)and hydroxylamine ionic liquid salts was proposed.Eco-friendly hydroxylamine ionic liquid salts were used as the nitrogen source.Ionic liquid exhibited three-fold function of cosolvent,catalysis and phase separation.The conversion of DFF and yield of DCF reached 100%under the following optimum reaction conditions:temperature of 120℃ for 70 min,volume ratio of paraxylene:[HSO_(3)-b-Py]HSO4 of 2:1,and molar ratio of DFF:(NH_(2)OH)_(2)[HSO_(3)-b-Py]HSO4 of 1:1.5.The reaction mechanism for the synthesis of DCF was proposed,and the kinetic model was established.The reaction order with respect to DFF and intermediate product 2,5-diformylfuran dioxime(DFFD)was 1.06 and 0.16,and the reaction activation energy was 64.07 kJ·mol^(-1) and 59.37 kJ·mol^(-1) respectively.After the reaction,the ionic liquid was easy to separate,recover and recycle.展开更多
Hydroxylamine sulfate （HAS） and sodium nitrite are used as the accelerators for zinc phos- phate coating on high carbon steel. Phase evolution of phosphate coating was investigated by X-ray diffraction. It is found ...Hydroxylamine sulfate （HAS） and sodium nitrite are used as the accelerators for zinc phos- phate coating on high carbon steel. Phase evolution of phosphate coating was investigated by X-ray diffraction. It is found that the phosphating coatings are mainly composed of hopeite Zn3Fe（PO4）2.4H2O and phosphophyllite Zn2Fe（PO4）2.4H2O. The microstructural changes of the phosphate coating, as a function of phosphating time, were evaluated by scanning elec- tron microscopy. Four-ball friction experiments reveal that hydroxylamine sulfate instead of sodium nitrite can effectively reduce the friction coefficient of lubricated phosphating coat- ing. Therefore, it may be expected that HAS will be widely used as a fast and ECO-friendly accelerator in phosphate industry.展开更多
Objective To purify a low-temperature hydroxylamine oxidase （HAO） from a heterotrophic nitrifying bacterium Acinetobacter sp. Y26 and investigate the enzyme property. Methods A HAO was purified by an anion-exchange ...Objective To purify a low-temperature hydroxylamine oxidase （HAO） from a heterotrophic nitrifying bacterium Acinetobacter sp. Y26 and investigate the enzyme property. Methods A HAO was purified by an anion-exchange and gel-filtration chromatography from strain Y16. The purity and molecular mass were determined by RP-HPLC and SDS-PAGE. The HAO activity was detected by monitoring the reduction of potassium ferricyanide using hydroxylamine as substrate and ferricyanide as electron acceptor. The partial amino acid sequence was determined by mass spectrometry. Results The low-temperature HAO with a molecular mass of 61 kDa was purified from strain Y26 by an anion-exchange and gel-filtration chromatography. The enzyme exhibited an ability to oxidize hydroxylamine in wide temperature range （4-40 ℃） in vitro using hydroxylamine as substrate and ferricyanide as electron acceptor. It was stable in the temperature range of 4 to 25 ℃ and pH range of 6.0 to 8.5 with less than 30% change in its activity. The optimal temperature and pH were 15 ℃ and 7.5, respectively. Three peptides were determined by mass spectrometry which were shown to be not identical to other reported HAOs. Conclusion This is the first study to purify a low-temperature HAO from a heterotrophic nitrifier Acinetobecter sp. It differs from other reported HAOs in molecular mass and enzyme properties. The findings of the present study have suggested that the strain Y26 passes through a hydroxylamine-oxidizing process catalyzed by a low-temperature HAO for ammonium removal.展开更多
It is the first reported that a new nitrogen-containing non-amino acid type organiccomponent 1 isolated from one of the well known traditional chinese herb medicines. Gastrodiaelela BI. Structure elucidation and unamb...It is the first reported that a new nitrogen-containing non-amino acid type organiccomponent 1 isolated from one of the well known traditional chinese herb medicines. Gastrodiaelela BI. Structure elucidation and unambiguous NMR assignments for the title compound werecarried out mainly Oil the basis of' 1D and 2D NMR experiments.展开更多
A novel chemiluminescence(CL) sensor, which can be used for hydroxylamine determination in combination with flow injection analysis, was developed by electrostatically immobilizing luminol and periodate on anion exch...A novel chemiluminescence(CL) sensor, which can be used for hydroxylamine determination in combination with flow injection analysis, was developed by electrostatically immobilizing luminol and periodate on anion exchange resin respectively. Hydroxylamine was sensed by its enhancing effect on the weak CL reaction between luminol and periodate, which were eluted from the ion exchange column. The response of the sensor to hydroxylamine was linear in the concentration range of 8.0×10^(-8)-2.0×10^(-6)mol/L with a detection limit of 4.0×10^(-8)mol/L hydroxylamine(3σ).The relative standard deviation(RSD) was 2.0% for 9 repetitive determinations at a hydroxylamine concentration of 5.0×10^(-7) mol/L. The sensor could be reused for over 400 times with a good reproducibility and was used to determine hydroxylamine in wastewater.展开更多
In the presence of ethyl alcohol or emulsifier OP,molybdenum(Ⅵ) forms 1∶1∶1'water soluble colored coordination com- pound with both of 2-(2-thiazolylazo)-5-diethylaminophenol (abbreviation TAE) and hydroxylamin...In the presence of ethyl alcohol or emulsifier OP,molybdenum(Ⅵ) forms 1∶1∶1'water soluble colored coordination com- pound with both of 2-(2-thiazolylazo)-5-diethylaminophenol (abbreviation TAE) and hydroxylamine.This deep blue coordination compound is inert characteristically and remains stable in 1.7 mol/L sulfuric acid,2.4 mol/L hydrochloric or ni- tric acid.It will not be decomposed by masking agents even on boiled,while in that case,almost all the colored coordination com- pounds formed by other metal ions will be decomposed completely.This inert character of the coordination compound of molybdenum(Ⅵ) and its utilization in improving the analytical selectivity have been discussed.In the coexistence of various for- eign ions,especially in the presence of a great quantity of tungsten,which always interferes with the determination of molybdenum,the direct determination of molybdenum in the aqueous solution by applying this system has shown an acceptable sensitivity and reproducibility.From the results of determination in some synthetic and standard samples,it seems feasible to use this system in the determination of molybdenum in nonferrous alloys.展开更多
In this paper the reaction of vinyl triazole derivatives with hydroxylamine hydrochloride under the action of sodium carbonate was studied. The result indicated that cyclization took place and new heterocyclic compoun...In this paper the reaction of vinyl triazole derivatives with hydroxylamine hydrochloride under the action of sodium carbonate was studied. The result indicated that cyclization took place and new heterocyclic compounds of 1,2-oxazocyclopentanes were obtained.展开更多
In this work,the 0.1-0.5 mol·L-1 N,N-dimethylhydroxylamine(DMHA) were irradiated to 5-25 kGy,and gaseous products of mainly hydrogen,methane,ethane and n-butane were measured by gas chromatography.The results sho...In this work,the 0.1-0.5 mol·L-1 N,N-dimethylhydroxylamine(DMHA) were irradiated to 5-25 kGy,and gaseous products of mainly hydrogen,methane,ethane and n-butane were measured by gas chromatography.The results show that the volume fraction of hydrogen and methane increases with the concentration of DMHA and dose,and the latter does not change markedly at high doses.展开更多
Partial nitrification is a key aspect of efficient nitrogen removal,although practically it suf-fers from long start-up cycles and unstable long-term operational performance.To address these drawbacks,this study inves...Partial nitrification is a key aspect of efficient nitrogen removal,although practically it suf-fers from long start-up cycles and unstable long-term operational performance.To address these drawbacks,this study investigated the effect of low intensity ultrasound treatment combined with hydroxylamine(NH2OH)on the performance of partial nitrification.Results showthat compared with the control group,low-intensity ultrasound treatment(0.10W/mL,15 min)combined with NH2OH(5 mg/L)reduced the time required for partial nitrification initiation by 6 days,increasing the nitrite accumulation rate(NAR)and ammonia nitro-gen removal rate(NRR)by 20.4% and 6.7%,respectively,achieving 96.48% NRR.Mechanis-tic analysis showed that NH2OH enhanced ammonia oxidation,inhibited nitrite-oxidizing bacteria(NOB)activity and shortened the time required for partial nitrification initiation.Furthermore,ultrasonication combined with NH2OH dosing stimulated EPS(extracellular polymeric substances)secretion,increased carbonyl,hydroxyl and amine functional group abundances and enhanced mass transfer.In addition,16S rRNA gene sequencing results showed that ultrasonication-sensitive Nitrospira disappeared from the ultrasound+NH_(2)OH system,while Nitrosomonas gradually became the dominant group.Collectively,the results of this study provide valuable insight into the enhancement of partial nitrification start-up during the process of wastewater nitrogen removal.展开更多
基金support from the National Natural Science Foundation of China(Nos.U20A20152,21236001 and 21878069).
文摘2,5-Dicyanofuran(DCF)is an important biomass-derived platform compound primarily used to prepare bio-based adiponitrile,which is the key precursor for the synthesis of nylon 66 and 1,6-hexanediisocyanate(HDI).In this study,one-pot,green and safe synthesis of DCF from 2,5-diformylfuran(DFF)and hydroxylamine ionic liquid salts was proposed.Eco-friendly hydroxylamine ionic liquid salts were used as the nitrogen source.Ionic liquid exhibited three-fold function of cosolvent,catalysis and phase separation.The conversion of DFF and yield of DCF reached 100%under the following optimum reaction conditions:temperature of 120℃ for 70 min,volume ratio of paraxylene:[HSO_(3)-b-Py]HSO4 of 2:1,and molar ratio of DFF:(NH_(2)OH)_(2)[HSO_(3)-b-Py]HSO4 of 1:1.5.The reaction mechanism for the synthesis of DCF was proposed,and the kinetic model was established.The reaction order with respect to DFF and intermediate product 2,5-diformylfuran dioxime(DFFD)was 1.06 and 0.16,and the reaction activation energy was 64.07 kJ·mol^(-1) and 59.37 kJ·mol^(-1) respectively.After the reaction,the ionic liquid was easy to separate,recover and recycle.
基金This work was supported by the Bengbu Yucheng New Materials Science and Technology Ltd. （No.2012QTXM0375） and the Natural Science Foundation of Anhui Province （No.1208085QE99）.
文摘Hydroxylamine sulfate （HAS） and sodium nitrite are used as the accelerators for zinc phos- phate coating on high carbon steel. Phase evolution of phosphate coating was investigated by X-ray diffraction. It is found that the phosphating coatings are mainly composed of hopeite Zn3Fe（PO4）2.4H2O and phosphophyllite Zn2Fe（PO4）2.4H2O. The microstructural changes of the phosphate coating, as a function of phosphating time, were evaluated by scanning elec- tron microscopy. Four-ball friction experiments reveal that hydroxylamine sulfate instead of sodium nitrite can effectively reduce the friction coefficient of lubricated phosphating coat- ing. Therefore, it may be expected that HAS will be widely used as a fast and ECO-friendly accelerator in phosphate industry.
基金supported by grants from National Natural Science Foundation of China(51078106)Heilongjiang Provincial Science Foundation for Distinguished Youth Scholar(JC200708)Heilongjiang Provincial Finance Foundation for Basic Sciences(CZ12BZSM06)
文摘Objective To purify a low-temperature hydroxylamine oxidase （HAO） from a heterotrophic nitrifying bacterium Acinetobacter sp. Y26 and investigate the enzyme property. Methods A HAO was purified by an anion-exchange and gel-filtration chromatography from strain Y16. The purity and molecular mass were determined by RP-HPLC and SDS-PAGE. The HAO activity was detected by monitoring the reduction of potassium ferricyanide using hydroxylamine as substrate and ferricyanide as electron acceptor. The partial amino acid sequence was determined by mass spectrometry. Results The low-temperature HAO with a molecular mass of 61 kDa was purified from strain Y26 by an anion-exchange and gel-filtration chromatography. The enzyme exhibited an ability to oxidize hydroxylamine in wide temperature range （4-40 ℃） in vitro using hydroxylamine as substrate and ferricyanide as electron acceptor. It was stable in the temperature range of 4 to 25 ℃ and pH range of 6.0 to 8.5 with less than 30% change in its activity. The optimal temperature and pH were 15 ℃ and 7.5, respectively. Three peptides were determined by mass spectrometry which were shown to be not identical to other reported HAOs. Conclusion This is the first study to purify a low-temperature HAO from a heterotrophic nitrifier Acinetobecter sp. It differs from other reported HAOs in molecular mass and enzyme properties. The findings of the present study have suggested that the strain Y26 passes through a hydroxylamine-oxidizing process catalyzed by a low-temperature HAO for ammonium removal.
文摘It is the first reported that a new nitrogen-containing non-amino acid type organiccomponent 1 isolated from one of the well known traditional chinese herb medicines. Gastrodiaelela BI. Structure elucidation and unambiguous NMR assignments for the title compound werecarried out mainly Oil the basis of' 1D and 2D NMR experiments.
基金Supported by the National Natural Science Foundation of China(No.2 9975 0 13,9835 110 )
文摘A novel chemiluminescence(CL) sensor, which can be used for hydroxylamine determination in combination with flow injection analysis, was developed by electrostatically immobilizing luminol and periodate on anion exchange resin respectively. Hydroxylamine was sensed by its enhancing effect on the weak CL reaction between luminol and periodate, which were eluted from the ion exchange column. The response of the sensor to hydroxylamine was linear in the concentration range of 8.0×10^(-8)-2.0×10^(-6)mol/L with a detection limit of 4.0×10^(-8)mol/L hydroxylamine(3σ).The relative standard deviation(RSD) was 2.0% for 9 repetitive determinations at a hydroxylamine concentration of 5.0×10^(-7) mol/L. The sensor could be reused for over 400 times with a good reproducibility and was used to determine hydroxylamine in wastewater.
文摘In the presence of ethyl alcohol or emulsifier OP,molybdenum(Ⅵ) forms 1∶1∶1'water soluble colored coordination com- pound with both of 2-(2-thiazolylazo)-5-diethylaminophenol (abbreviation TAE) and hydroxylamine.This deep blue coordination compound is inert characteristically and remains stable in 1.7 mol/L sulfuric acid,2.4 mol/L hydrochloric or ni- tric acid.It will not be decomposed by masking agents even on boiled,while in that case,almost all the colored coordination com- pounds formed by other metal ions will be decomposed completely.This inert character of the coordination compound of molybdenum(Ⅵ) and its utilization in improving the analytical selectivity have been discussed.In the coexistence of various for- eign ions,especially in the presence of a great quantity of tungsten,which always interferes with the determination of molybdenum,the direct determination of molybdenum in the aqueous solution by applying this system has shown an acceptable sensitivity and reproducibility.From the results of determination in some synthetic and standard samples,it seems feasible to use this system in the determination of molybdenum in nonferrous alloys.
文摘In this paper the reaction of vinyl triazole derivatives with hydroxylamine hydrochloride under the action of sodium carbonate was studied. The result indicated that cyclization took place and new heterocyclic compounds of 1,2-oxazocyclopentanes were obtained.
基金Supported by Natural Science Foundation of China(Contract No.20771074)Shanghai Leading Academic Disciplines(Contract No.S30109)
文摘In this work,the 0.1-0.5 mol·L-1 N,N-dimethylhydroxylamine(DMHA) were irradiated to 5-25 kGy,and gaseous products of mainly hydrogen,methane,ethane and n-butane were measured by gas chromatography.The results show that the volume fraction of hydrogen and methane increases with the concentration of DMHA and dose,and the latter does not change markedly at high doses.
文摘Partial nitrification is a key aspect of efficient nitrogen removal,although practically it suf-fers from long start-up cycles and unstable long-term operational performance.To address these drawbacks,this study investigated the effect of low intensity ultrasound treatment combined with hydroxylamine(NH2OH)on the performance of partial nitrification.Results showthat compared with the control group,low-intensity ultrasound treatment(0.10W/mL,15 min)combined with NH2OH(5 mg/L)reduced the time required for partial nitrification initiation by 6 days,increasing the nitrite accumulation rate(NAR)and ammonia nitro-gen removal rate(NRR)by 20.4% and 6.7%,respectively,achieving 96.48% NRR.Mechanis-tic analysis showed that NH2OH enhanced ammonia oxidation,inhibited nitrite-oxidizing bacteria(NOB)activity and shortened the time required for partial nitrification initiation.Furthermore,ultrasonication combined with NH2OH dosing stimulated EPS(extracellular polymeric substances)secretion,increased carbonyl,hydroxyl and amine functional group abundances and enhanced mass transfer.In addition,16S rRNA gene sequencing results showed that ultrasonication-sensitive Nitrospira disappeared from the ultrasound+NH_(2)OH system,while Nitrosomonas gradually became the dominant group.Collectively,the results of this study provide valuable insight into the enhancement of partial nitrification start-up during the process of wastewater nitrogen removal.
