采用X线衍射(X-ray diffraction,XRD)和扫描电镜(scanning electron microscope,SEM)对以电镀法制备的PbO_2/Ti阳极进行表征,以阳极氧化电流占比系数γ描述苯酚氧化与析氧反应之间的影响机制,并基于法拉第定律建立描述有机物氧化进程的...采用X线衍射(X-ray diffraction,XRD)和扫描电镜(scanning electron microscope,SEM)对以电镀法制备的PbO_2/Ti阳极进行表征,以阳极氧化电流占比系数γ描述苯酚氧化与析氧反应之间的影响机制,并基于法拉第定律建立描述有机物氧化进程的通用阶段反应动力学模型;在不同电流密度和进水流量条件下进行苯酚阳极氧化实验。研究结果表明:电极表面晶相主要为β-PbO_2,晶粒平均直径为50.23 nm,形成的团聚体粒径在5~10μm之间。PbO_2/Ti阳极析氧电位约为1.78 V;液相中苯酚的存在可抑制氧气析出,且析氧反应电阻由无苯酚情况下的148.3?增大至195.9?。回归分析和F检验结果证明理论预测值与实验数据之间具有一致性。展开更多
To improve the tribological behavior of biodiesel soot(BDS) in liquid paraffin(LP), the order of biodiesel soot was increased through thermally oxidized treatment at 500 ℃, and the oil solubility was then improved th...To improve the tribological behavior of biodiesel soot(BDS) in liquid paraffin(LP), the order of biodiesel soot was increased through thermally oxidized treatment at 500 ℃, and the oil solubility was then improved through a modification using oleylamine(OLA). The BDS and thermally oxidized oleylamine-modified BDS(T-BDS-OLA)were characterized through various methods including the use of TG, FETEM, Raman spectroscopy, FTIR, and a zeta potentiometer. The tribological properties and mechanisms of the BDS before and after the thermally oxidized treatment modification were investigated using a ball-on-disc reciprocating tribometer, FESEM, 3 D laser-scanning microscopy, and Raman spectroscopy. The results showed that T-BDS-OLA has a higher degree of order than the BDS, with an onion-like microstructure. BDS and T-BDS-OLA can both improve the antifriction and antiwear properties of LP at a soot content of 0.1%-0.4%, while T-BDS-OLA in LP shows better antifriction and antiwear properties than BDS. The tribological mechanisms can be attributed to both types of soot acting as spacing and roll bearing between the friction surfaces. In addition, the exfoliated graphitic sheets from T-BDS-OLA can form a carbon lubrication layer providing easy sliding.展开更多
Lanthanum hydroxide/graphene oxide nanocomposites(La(OH)3/GO)modified by octadecylamine(OCA),oleylamine(OLA),and polyvinylpyrrolidone(PVP)were prepared,respectively,as the base oil additives.The dispersion stability o...Lanthanum hydroxide/graphene oxide nanocomposites(La(OH)3/GO)modified by octadecylamine(OCA),oleylamine(OLA),and polyvinylpyrrolidone(PVP)were prepared,respectively,as the base oil additives.The dispersion stability of different modified La(OH)3/GO in base oil was studied by means of centrifugation.The tribological properties of oleophilic La(OH)3/GO in base oil were investigated using an UMT ball-disc tribometer.The micro-morphology and chemical composition of the worn surface were characterized by 3 D laser microscope,SEM,EDS,XPS,and Raman spectroscopy,respectively.The wettability performance of the worn surface was also studied based on the contact angle measurements.The test results showed that the OLA-La(OH)3/GO nanocomposites had good dispersion stability in base oil.The anti-wear performance of base oil was improved significantly by the addition of OLA-La(OH)3/GO nanocomposites.The characterizations of worn surface showed that the OLA-La(OH)3/GO nanocomposites could form the metal oxide and graphene protective films effectively on the friction interface and thus increased the oil wettability of the worn surface,thereby resulting in an improved wear resistance.展开更多
Polycyclic aromatic hydrocarbons (PAHs) contamination of topsoil in Benxi City, Northeast China was investigated in this study, and sampling sites were located in industrial area and residential area. Results demonstr...Polycyclic aromatic hydrocarbons (PAHs) contamination of topsoil in Benxi City, Northeast China was investigated in this study, and sampling sites were located in industrial area and residential area. Results demonstrate that there is high variability in the total PAHs concentrations, ranging from 783.00 ng/g to 729 076.29 ng/g dry weight in the topsoil of Benxi City and the pollution in industrial area is the most serious. The results also present that higher molecular weight PAHs (4–6 rings) contribute substantially (79.03%) to the overall content of PAHs. The PAHs sources were determined with factor analysis by nonnegative constraints, and the results show that PAHs originating from traffic tunnel, power plant, coke oven and residential emission sources, account for 27.10%, 40.81%, 20.11% and 11.98%, respectively, of the total. The PAHs pollution is the most serious around Benxi Iron and Steel Group Corporation, and the PAHs mainly originate from coke oven and traffic tunnel, with the average contribution rate of 57.40% and 42.60%, respectively. The source apportionment results are basically consistent with the industry distribution, and the geographical and climatic characteristics of the study area.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 51675153)the Major Science and Technology Special Project in Anhui (Grant No. 17030901084)
文摘To improve the tribological behavior of biodiesel soot(BDS) in liquid paraffin(LP), the order of biodiesel soot was increased through thermally oxidized treatment at 500 ℃, and the oil solubility was then improved through a modification using oleylamine(OLA). The BDS and thermally oxidized oleylamine-modified BDS(T-BDS-OLA)were characterized through various methods including the use of TG, FETEM, Raman spectroscopy, FTIR, and a zeta potentiometer. The tribological properties and mechanisms of the BDS before and after the thermally oxidized treatment modification were investigated using a ball-on-disc reciprocating tribometer, FESEM, 3 D laser-scanning microscopy, and Raman spectroscopy. The results showed that T-BDS-OLA has a higher degree of order than the BDS, with an onion-like microstructure. BDS and T-BDS-OLA can both improve the antifriction and antiwear properties of LP at a soot content of 0.1%-0.4%, while T-BDS-OLA in LP shows better antifriction and antiwear properties than BDS. The tribological mechanisms can be attributed to both types of soot acting as spacing and roll bearing between the friction surfaces. In addition, the exfoliated graphitic sheets from T-BDS-OLA can form a carbon lubrication layer providing easy sliding.
基金supported by the National Natural Science Foundation of China(Grant No.51675153)。
文摘Lanthanum hydroxide/graphene oxide nanocomposites(La(OH)3/GO)modified by octadecylamine(OCA),oleylamine(OLA),and polyvinylpyrrolidone(PVP)were prepared,respectively,as the base oil additives.The dispersion stability of different modified La(OH)3/GO in base oil was studied by means of centrifugation.The tribological properties of oleophilic La(OH)3/GO in base oil were investigated using an UMT ball-disc tribometer.The micro-morphology and chemical composition of the worn surface were characterized by 3 D laser microscope,SEM,EDS,XPS,and Raman spectroscopy,respectively.The wettability performance of the worn surface was also studied based on the contact angle measurements.The test results showed that the OLA-La(OH)3/GO nanocomposites had good dispersion stability in base oil.The anti-wear performance of base oil was improved significantly by the addition of OLA-La(OH)3/GO nanocomposites.The characterizations of worn surface showed that the OLA-La(OH)3/GO nanocomposites could form the metal oxide and graphene protective films effectively on the friction interface and thus increased the oil wettability of the worn surface,thereby resulting in an improved wear resistance.
基金Under the auspices of Program of National Soil Pollution Survey (No. 6HBZJ1002)
文摘Polycyclic aromatic hydrocarbons (PAHs) contamination of topsoil in Benxi City, Northeast China was investigated in this study, and sampling sites were located in industrial area and residential area. Results demonstrate that there is high variability in the total PAHs concentrations, ranging from 783.00 ng/g to 729 076.29 ng/g dry weight in the topsoil of Benxi City and the pollution in industrial area is the most serious. The results also present that higher molecular weight PAHs (4–6 rings) contribute substantially (79.03%) to the overall content of PAHs. The PAHs sources were determined with factor analysis by nonnegative constraints, and the results show that PAHs originating from traffic tunnel, power plant, coke oven and residential emission sources, account for 27.10%, 40.81%, 20.11% and 11.98%, respectively, of the total. The PAHs pollution is the most serious around Benxi Iron and Steel Group Corporation, and the PAHs mainly originate from coke oven and traffic tunnel, with the average contribution rate of 57.40% and 42.60%, respectively. The source apportionment results are basically consistent with the industry distribution, and the geographical and climatic characteristics of the study area.
