A biodegradable and green organic compound octadecyl dimethyl benzyl amm-onium chloride(ODBAC)was used as an efficient inhibitor for cold rolled steel(CRS)in phosphoric acid(H_(3)PO_(4)).The mechanism of adsorption an...A biodegradable and green organic compound octadecyl dimethyl benzyl amm-onium chloride(ODBAC)was used as an efficient inhibitor for cold rolled steel(CRS)in phosphoric acid(H_(3)PO_(4)).The mechanism of adsorption and film formation of ODBAC on CRS was studied through experimental and theoretical calculations.The weight loss method shows that the inhibition efficiency of ODBAC can reach 92.01%at a concentration of 10 mg·L^(-1).The adsorption of ODBAC on the CRS surface conforms to the Langmuir isotherm model,which is a mixed adsorption mainly based on physical adsorption.The X-ray photoelectron spectroscopy(XPS)and contact angle results confirmed the existence of the ODBAC film and steel surface's hydrophobicity has been significantly enhanced.Electrochemical test results reveal that the film's formation mainly inhibits the cathodic corrosion reaction and effectively increases the charge transfer resistance.Quantum chemical calculations have found that N18 in ODBAC and C24 and C25 on the benzene ring are the key active adsorption sites.Molecular dynamics simulation results indicate that ODBAC can sharply reduce the free fraction volume to 8%and inhibit the diffusion of corrosion particles,meaning that the formed ODBAC film makes it difficult for corrosion particles to penetrate,thus improving the corrosion resistance of CRS in H_(3)PO_(4).展开更多
A novel and selective method for the fast determination of trace amounts of chromium species in water samples has been developed. The procedure is based on the selective formation of chromium diethyldithiocarbamate co...A novel and selective method for the fast determination of trace amounts of chromium species in water samples has been developed. The procedure is based on the selective formation of chromium diethyldithiocarbamate complexes at different pH in the presence of Mn（Ⅱ） as an enhancement agent of chromium signals followed by elution with organic eluents and determination by atomic flame absorption spectrometry. The maximum capacity of the employed disks was found to be （396±3） pg and （376±2） pg for Cr（Ⅲ） and Cr（Ⅵ）, respectively. The detection limit of the proposed method is 49 and 43 ng·L^-1 for Cr（Ⅲ） and Cr（Ⅵ）, respectively. The proposed method was successfully applied for determination of chromium species Cr（Ⅲ） and Cr（Ⅵ） in different water samples.展开更多
A simple and reproducible method for the rapid extraction and determination of trace amounts of copper（Ⅱ） ions using octadecyl-bonded silica membrane disks modified by N,N′-disalicylideneethylenediamine （DESDA） ...A simple and reproducible method for the rapid extraction and determination of trace amounts of copper（Ⅱ） ions using octadecyl-bonded silica membrane disks modified by N,N′-disalicylideneethylenediamine （DESDA） and atomic absorption spectrometry was presented. The method is based on complex formation on the surface of the ENVI-18 DISK^TM disks followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution is efficient and quantitative. The effects of potential interfering ions, pH, ligand amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to about be 1000 mL providing a preconcentration factor of 500. The maximum capacity of the disks was found to be （389±4） μg for Cu^2＋. The limit of detection of the proposed method is 5 ng per liter. The method was applied to the extraction and recovery of copper in different water samples.展开更多
A simple and reproducible method for the rapid extraction and determination of trace amounts of copper（Ⅱ） ions using octadecyl-bonded silica membrane disks modified by 1,5-diphenylcarbazide （DPC） and atomic absor...A simple and reproducible method for the rapid extraction and determination of trace amounts of copper（Ⅱ） ions using octadecyl-bonded silica membrane disks modified by 1,5-diphenylcarbazide （DPC） and atomic absorption spectrometry was presented, which was based on complex formation on the surface of the ENVI-18 DISK^TM disks followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution was efficient and quantitative. The effect of potential interfering ions, pH, ligand amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to be about 1000 mL providing a preconcentration factor of 400. The maximum capacity of the disks was found to be （255±5） lag for Cu^2＋, and the limit of detection of the proposed method was 5 ng per 1000 mL. The method was applied to the extraction and recovery of copper in different water samples.展开更多
Eleven compounds were isolated from Gypsophila oldhamiana and identified as octadecyl E-p-coumarate(1),octadecyl caffeate (2), ferulic acid (3), soya-cerebrosideⅠ(4), soya-cerebrosideⅡ(5), D-3-methyl-chiroinsitol (6...Eleven compounds were isolated from Gypsophila oldhamiana and identified as octadecyl E-p-coumarate(1),octadecyl caffeate (2), ferulic acid (3), soya-cerebrosideⅠ(4), soya-cerebrosideⅡ(5), D-3-methyl-chiroinsitol (6), α-spinasterol-3-O-β-D-glucopyranoside (7), α-spinasterol(8), β-sitosterol(9),daucosterol (10), sucrose (11). Compounds 1～7 were obtained from this plant for the first time; Compounds 1～3 were isolated from caryophllaceae family for the first time.展开更多
基金support from National Natural Science Foundation of China(52161016)Joint Key Project of Agricultural Fundamental Research in Yunnan Province(202101BD070001-017)+2 种基金Yunnan Provincial Academician Workstation(202305AF150009)Special Project of“Top Young Talents”of Yunnan Ten Thousand Talents Plan(51900109)Special Project of“Leading Talents of Industrial Technology”of Yunnan Ten Thousand Talents Plan(80201408)are acknowledged.
文摘A biodegradable and green organic compound octadecyl dimethyl benzyl amm-onium chloride(ODBAC)was used as an efficient inhibitor for cold rolled steel(CRS)in phosphoric acid(H_(3)PO_(4)).The mechanism of adsorption and film formation of ODBAC on CRS was studied through experimental and theoretical calculations.The weight loss method shows that the inhibition efficiency of ODBAC can reach 92.01%at a concentration of 10 mg·L^(-1).The adsorption of ODBAC on the CRS surface conforms to the Langmuir isotherm model,which is a mixed adsorption mainly based on physical adsorption.The X-ray photoelectron spectroscopy(XPS)and contact angle results confirmed the existence of the ODBAC film and steel surface's hydrophobicity has been significantly enhanced.Electrochemical test results reveal that the film's formation mainly inhibits the cathodic corrosion reaction and effectively increases the charge transfer resistance.Quantum chemical calculations have found that N18 in ODBAC and C24 and C25 on the benzene ring are the key active adsorption sites.Molecular dynamics simulation results indicate that ODBAC can sharply reduce the free fraction volume to 8%and inhibit the diffusion of corrosion particles,meaning that the formed ODBAC film makes it difficult for corrosion particles to penetrate,thus improving the corrosion resistance of CRS in H_(3)PO_(4).
文摘A novel and selective method for the fast determination of trace amounts of chromium species in water samples has been developed. The procedure is based on the selective formation of chromium diethyldithiocarbamate complexes at different pH in the presence of Mn（Ⅱ） as an enhancement agent of chromium signals followed by elution with organic eluents and determination by atomic flame absorption spectrometry. The maximum capacity of the employed disks was found to be （396±3） pg and （376±2） pg for Cr（Ⅲ） and Cr（Ⅵ）, respectively. The detection limit of the proposed method is 49 and 43 ng·L^-1 for Cr（Ⅲ） and Cr（Ⅵ）, respectively. The proposed method was successfully applied for determination of chromium species Cr（Ⅲ） and Cr（Ⅵ） in different water samples.
文摘A simple and reproducible method for the rapid extraction and determination of trace amounts of copper（Ⅱ） ions using octadecyl-bonded silica membrane disks modified by N,N′-disalicylideneethylenediamine （DESDA） and atomic absorption spectrometry was presented. The method is based on complex formation on the surface of the ENVI-18 DISK^TM disks followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution is efficient and quantitative. The effects of potential interfering ions, pH, ligand amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to about be 1000 mL providing a preconcentration factor of 500. The maximum capacity of the disks was found to be （389±4） μg for Cu^2＋. The limit of detection of the proposed method is 5 ng per liter. The method was applied to the extraction and recovery of copper in different water samples.
文摘A simple and reproducible method for the rapid extraction and determination of trace amounts of copper（Ⅱ） ions using octadecyl-bonded silica membrane disks modified by 1,5-diphenylcarbazide （DPC） and atomic absorption spectrometry was presented, which was based on complex formation on the surface of the ENVI-18 DISK^TM disks followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution was efficient and quantitative. The effect of potential interfering ions, pH, ligand amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to be about 1000 mL providing a preconcentration factor of 400. The maximum capacity of the disks was found to be （255±5） lag for Cu^2＋, and the limit of detection of the proposed method was 5 ng per 1000 mL. The method was applied to the extraction and recovery of copper in different water samples.
文摘Eleven compounds were isolated from Gypsophila oldhamiana and identified as octadecyl E-p-coumarate(1),octadecyl caffeate (2), ferulic acid (3), soya-cerebrosideⅠ(4), soya-cerebrosideⅡ(5), D-3-methyl-chiroinsitol (6), α-spinasterol-3-O-β-D-glucopyranoside (7), α-spinasterol(8), β-sitosterol(9),daucosterol (10), sucrose (11). Compounds 1～7 were obtained from this plant for the first time; Compounds 1～3 were isolated from caryophllaceae family for the first time.
