The active oxygen species in the catalytic oxidation system of Fe(Ⅲ)PcTs-t-BuOOH were identified,and the mechanism of the catalytic oxidation of phenolic substrates was proposed.Quinone imine molecules,the main produ...The active oxygen species in the catalytic oxidation system of Fe(Ⅲ)PcTs-t-BuOOH were identified,and the mechanism of the catalytic oxidation of phenolic substrates was proposed.Quinone imine molecules,the main products of catalytic oxidation reaction,can be adsorbed on the surface of CdTe QDs,resulting in their fluorescence quenching.A dual function of catalytic oxidation and fluorescence sensing was developed for the determination of dichlorophenol(DCP)based on the Fe(Ⅲ)PcTs-BuOOH-CdTe QDs system.The linear detection range of DCP was 1×10^(-6)-1.3×10^(-4) mol/L,and the detection limit 2.4×10^(-7) mol/L.This method was characterized by high selectivity,good repeatability and desirable stability,presenting promising potentials for analyzing DCP concentration in real water samples.展开更多
A novel fiber optic sensor based on optical composite oxygen-sensitive film was developed for determination of 2,4-dichlorophenol(DCP).The optical composite oxygen-sensitive film consists of tris(2,2’-bipyridyl)dichl...A novel fiber optic sensor based on optical composite oxygen-sensitive film was developed for determination of 2,4-dichlorophenol(DCP).The optical composite oxygen-sensitive film consists of tris(2,2’-bipyridyl)dichloro ruthenium(II)hexahydrate(Ru(bpy)3Cl2)as the fluorescence indicator and iron(III)tetrasulfophthalocyanine(Fe(III)PcTs)as bionic enzyme.A lock-in amplifier was used for detecting the lifetime of the composite oxygen-sensitive film by measuring the phase delay of the sensor head.The different variables affecting the sensor performance were evaluated and optimized.Under the optimal conditions(i e,pH 6.0,25℃,Fe(III)PcTs concentration of 5.0×10^-5 mol/L),the linear detection range,detection limit and response time of the fiber optic sensor are 3.0×10^-7-9.0×10^-5 mol/L,4.8×10^-8 mol/L(S/N=3),and 220 s,respectively.The sensor displays high selectivity,good repeatability and stability,which have good potentials in analyzing DCP concentration in practical water samples.展开更多
The nitrogen-containing compounds in Changqing crude oil, its atmospheric residue(AR), and vacuum reside(VR) were characterized by negative and positive ion electrospray ionization(ESI) Fourier transform ion cyclotron...The nitrogen-containing compounds in Changqing crude oil, its atmospheric residue(AR), and vacuum reside(VR) were characterized by negative and positive ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). The heteroatom compounds(N_1, N_2, N_1O_1, O_1, and O_2 class species) could be identified by the negative ESI analysis, while the positive mode could only detect the N_1, N_2, and N_1O_1 class species. Among them, the N_1 class species were found to be predominant in crude oil, as confirmed by either negative or positive ESI analyses,which were similar in composition to AR and VR. These compounds with higher abundance were characterized by double bond equivalent(DBE) values and carbon numbers. The composition of these compounds in crude oil and its AR as well as VR was correlated with their different boiling range, DBE values and carbon numbers. The negative ESI analysis showed that the abundant N_1 class species in crude oil and AR were centered at a DBE value of 12, and these species were likely benzocarbazoles, while the N_1 class species with the DBE value ranging from 13 to 16 having more complicated molecular structures were dominant in VR. And the positive ESI analysis gave the information of the abundant N_1 class species in crude oil, AR, and VR having the DBE values in the range of 10, 9―11, and 10―16, respectively, which were likely the compounds with the core of quinoline and benzoquinoline. The analysis confirmed that the distillation process in refinery preferentially removed the low DBE value and low molecular N-class species and brought them into the light and medium distillates, while those N-class species having a high molecular condensation in the molecules with large carbon number remained in the residual oil and could continually affect the downstream oil refining process.展开更多
Mangrove ecosystem has an important ecological function. But since it is distributed in land-sea alternating region,mangrove is vulnerable to environmental pollution. Mangrove area of Guangdong Province greatly decrea...Mangrove ecosystem has an important ecological function. But since it is distributed in land-sea alternating region,mangrove is vulnerable to environmental pollution. Mangrove area of Guangdong Province greatly decreased after the 1950 s,and it declined to the minimum in the1990 s and then gradually increased. Mangrove area of Guangdong Province quickly increased from 2001 to now,and its area in 2014 was 19 824. 53 hm^2,in which Zhanjiang accounted for 72%. During 2001-2014,mangrove area of Guangdong Province increased significantly,in which the newly increased mangrove area in Zhanjiang,Yangjiang,Jiangmen,Zhuhai,Guangzhou and Shantou was larger,with obvious increase magnitude; mangrove area in east Guangdong during 2001-2005 increased quickly,while increase magnitude of mangrove area in west Guangdong and the Pearl River Delta was improved significantly after 2005. Additionally,mangrove species in Guangdong Province continuously decreased from south to north,showing as west Guangdong > the Pearl River Delta > east Guangdong. Mangrove of Guangdong Province could be protected strictly from shoreline control,ecological protection,function upgrading,and ecological restoration.展开更多
基金Funded by the National Natural Science Foundation of China(No.61205062)the Hubei Provincial Department of Education Scientific Research Program Guidance Project(No.B2020282)。
文摘The active oxygen species in the catalytic oxidation system of Fe(Ⅲ)PcTs-t-BuOOH were identified,and the mechanism of the catalytic oxidation of phenolic substrates was proposed.Quinone imine molecules,the main products of catalytic oxidation reaction,can be adsorbed on the surface of CdTe QDs,resulting in their fluorescence quenching.A dual function of catalytic oxidation and fluorescence sensing was developed for the determination of dichlorophenol(DCP)based on the Fe(Ⅲ)PcTs-BuOOH-CdTe QDs system.The linear detection range of DCP was 1×10^(-6)-1.3×10^(-4) mol/L,and the detection limit 2.4×10^(-7) mol/L.This method was characterized by high selectivity,good repeatability and desirable stability,presenting promising potentials for analyzing DCP concentration in real water samples.
基金Funded by the National Natural Science Foundation of China(No.61205062)the Scientific Research Foundation for Doctor of University(No.2019Y02)。
文摘A novel fiber optic sensor based on optical composite oxygen-sensitive film was developed for determination of 2,4-dichlorophenol(DCP).The optical composite oxygen-sensitive film consists of tris(2,2’-bipyridyl)dichloro ruthenium(II)hexahydrate(Ru(bpy)3Cl2)as the fluorescence indicator and iron(III)tetrasulfophthalocyanine(Fe(III)PcTs)as bionic enzyme.A lock-in amplifier was used for detecting the lifetime of the composite oxygen-sensitive film by measuring the phase delay of the sensor head.The different variables affecting the sensor performance were evaluated and optimized.Under the optimal conditions(i e,pH 6.0,25℃,Fe(III)PcTs concentration of 5.0×10^-5 mol/L),the linear detection range,detection limit and response time of the fiber optic sensor are 3.0×10^-7-9.0×10^-5 mol/L,4.8×10^-8 mol/L(S/N=3),and 220 s,respectively.The sensor displays high selectivity,good repeatability and stability,which have good potentials in analyzing DCP concentration in practical water samples.
基金supported by the Young Talent Fund of University Association for Science and Technoloqy in Shaanxi, China (No. 20160222)The PetroChina Innovation Foundation (No. 2016D-5007-0404)the Natural Science Basic Research Plan in Shaanxi Province of China (No. 2017JQ2034)
文摘The nitrogen-containing compounds in Changqing crude oil, its atmospheric residue(AR), and vacuum reside(VR) were characterized by negative and positive ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). The heteroatom compounds(N_1, N_2, N_1O_1, O_1, and O_2 class species) could be identified by the negative ESI analysis, while the positive mode could only detect the N_1, N_2, and N_1O_1 class species. Among them, the N_1 class species were found to be predominant in crude oil, as confirmed by either negative or positive ESI analyses,which were similar in composition to AR and VR. These compounds with higher abundance were characterized by double bond equivalent(DBE) values and carbon numbers. The composition of these compounds in crude oil and its AR as well as VR was correlated with their different boiling range, DBE values and carbon numbers. The negative ESI analysis showed that the abundant N_1 class species in crude oil and AR were centered at a DBE value of 12, and these species were likely benzocarbazoles, while the N_1 class species with the DBE value ranging from 13 to 16 having more complicated molecular structures were dominant in VR. And the positive ESI analysis gave the information of the abundant N_1 class species in crude oil, AR, and VR having the DBE values in the range of 10, 9―11, and 10―16, respectively, which were likely the compounds with the core of quinoline and benzoquinoline. The analysis confirmed that the distillation process in refinery preferentially removed the low DBE value and low molecular N-class species and brought them into the light and medium distillates, while those N-class species having a high molecular condensation in the molecules with large carbon number remained in the residual oil and could continually affect the downstream oil refining process.
文摘Mangrove ecosystem has an important ecological function. But since it is distributed in land-sea alternating region,mangrove is vulnerable to environmental pollution. Mangrove area of Guangdong Province greatly decreased after the 1950 s,and it declined to the minimum in the1990 s and then gradually increased. Mangrove area of Guangdong Province quickly increased from 2001 to now,and its area in 2014 was 19 824. 53 hm^2,in which Zhanjiang accounted for 72%. During 2001-2014,mangrove area of Guangdong Province increased significantly,in which the newly increased mangrove area in Zhanjiang,Yangjiang,Jiangmen,Zhuhai,Guangzhou and Shantou was larger,with obvious increase magnitude; mangrove area in east Guangdong during 2001-2005 increased quickly,while increase magnitude of mangrove area in west Guangdong and the Pearl River Delta was improved significantly after 2005. Additionally,mangrove species in Guangdong Province continuously decreased from south to north,showing as west Guangdong > the Pearl River Delta > east Guangdong. Mangrove of Guangdong Province could be protected strictly from shoreline control,ecological protection,function upgrading,and ecological restoration.
