Diphenyl carbonate(DPC)is one of the versatile carbonates,and is often used for the production of polycarbonates.In recent years,the catalytic synthesis of DPC has become an important topic but the development of a hi...Diphenyl carbonate(DPC)is one of the versatile carbonates,and is often used for the production of polycarbonates.In recent years,the catalytic synthesis of DPC has become an important topic but the development of a highly active metal-free catalyst is a great challenge.Herein,a series of ionic liquids-SBA-15 hybrid catalysts with different functional groups have been developed for the synthesis of DPC under solventfree condition,which are effective and clean instead of the metal-containing catalysts.It is found that in the presence of[SBA-15-IL-OH]Br catalyst,methyl phenyl carbonate(MPC)conversion of 80.5%along with 99.6%DPC selectivity is achieved,the TOF value is thrice higher than the best value reported by using transition metal-based catalysts.Moreover,the catalyst displays remarkable stability and recyclability.This work provides a new idea to design and prepare eco-friendly catalysts in a broad range of applications for the green synthesis of carbonates.展开更多
Polybrominated diphenyl ethers(PBDEs)are a kind of serious pollutants in the ocean.Biodegradation is considered as an economical and safe way for PBDEs removal and reductive debromination dominates the initial pathway...Polybrominated diphenyl ethers(PBDEs)are a kind of serious pollutants in the ocean.Biodegradation is considered as an economical and safe way for PBDEs removal and reductive debromination dominates the initial pathway of anaerobic degradation.On the basis of experimental study,Octa-BDE 197,Hepta-BDE 183,Hexa-BDE 153,Penta-BDE 99 and Tetra-BDE 47 were selected as the initial degradation objects,and their debromination degradation were studied using density functional theory.The structures were optimized by Gaussian 09 program.Furthermore,the molecular orbitals and charge distribution were analyzed.All C-Br bond dissociation energies at different positions including ortho,meta and para bromine atoms were calculated and the sequence of debromination was obtained.There is a close relationship between molecular structure,charge,molecular orbital and C-Br bond.All PBDEs exhibited similar debromination pathways with preferential removal of meta and para bromines.展开更多
Organoseleniums are a class of compounds attracting attention across the globe owing to their Glutathione peroxidase(GPx)mimicry,which confers on them a strong antioxidant activity.Diphenyl diselenide(DPDS)is an Organ...Organoseleniums are a class of compounds attracting attention across the globe owing to their Glutathione peroxidase(GPx)mimicry,which confers on them a strong antioxidant activity.Diphenyl diselenide(DPDS)is an Organoselenium whose GPx mimetic property has been suggested to rely on the oxidation of non-protein or protein thiols critical to the activities of some sulfhydryl enzymes.This study,therefore investigated the GPx mimic/antioxidant property of DPDS as well as the role of thiols of two key sulfhydryl enzymes,cerebral Na^(+)/K^(+)-ATPase(sodium pump)and hepatic delta-aminolevulinic acid dehydratase(δ-ALAD)in the GPx mimicry of DPDS.Albino Wistar rats were euthanized,and the liver and brain were removed and used to assay for the effect of DPDS on lipid peroxidation induced by two prooxidants[Fe2^(+)(10μM)and H2O2,(1 mM)]as well as the activities of the sulfhydryl enzymes.The results revealed that DPDS profoundly(P<0.05)counteracted Fe2^(+)and H2O2-induced lipid peroxidation in the rats’hepatic and cerebral tissues.Furthermore,the results of assay systems for lipid peroxidation and sodium pump revealed that DPDS inhibited Na^(+)/K^(+)-ATPase and lipid peroxidation in the brain tissue homogenates in the same reaction system.A similar result was obtained in the assay system for lipid peroxidation and hepaticδ-ALAD as DPDS simultaneously inhibited the enzyme’s activity and lipid peroxidation.This suggests that the GPx mimetic property of DPDS may be linked to the enzymes’loss of activity,which further validates the suggestions that the enzymes’inhibition,as well as the antioxidant action of DPDS,rely on the oxidation of critical thiols of the enzymes.However,the GPx mimicry of DPDS should be investigated in the presence of thiol-blocking or oxidizing agents in biological systems in order to further ascertain the role of protein thiols.展开更多
To understand potential ecotoxicological effects of electrical and electronic equipment waste (e-waste) recycling and polybrominated diphenyl ethers (PBDEs) bioaccumulation in loaches, a semi-field experiment usin...To understand potential ecotoxicological effects of electrical and electronic equipment waste (e-waste) recycling and polybrominated diphenyl ethers (PBDEs) bioaccumulation in loaches, a semi-field experiment using Chinese loach (Misgurnus anguiUicaudatus) as experimental fish was performed. Larval loaches were kept in net-cage for three months in an e-wastes recycling site and a reference site in Southeastern China. There was significant difference of the survival rate between the loaches from the e-wastes recycling site (27%, 19/70) and from reference site (70%, 49/70). Histopathological responses were also found in all the livers examined in loaches from the e-wastes recycling site. These results showed that mixed pollutants resulted from e-wastes recycling led to ecotoxicological effects on loaches. The bioaccumulation of polybrominated diphenyl ethers (PBDEs), the main pollutants in e-waste, in loaches was also studied, the mean concentration of total PBDEs in sediment was 6726.17 ng/g wet weight and in water samples was 4.08 ng/L (dissolved phase). BDE 209 was the dominant congener in sediment and with relatively high concentration in water. Relatively low concentration of BDE 209 (less than 0.01% of total PBDEs) and high concentration of BDE47 (up to 39.34% of total PBDEs) were detected in loaches.展开更多
The 12-molybdosphoric acid mixed with titania (MPA-TiO2) was found to be a novel and efficient catalyst for the synthesis of diphenyl carbonate (DPC) via transesterification of dimethyl carbonate (DMC) and pheno...The 12-molybdosphoric acid mixed with titania (MPA-TiO2) was found to be a novel and efficient catalyst for the synthesis of diphenyl carbonate (DPC) via transesterification of dimethyl carbonate (DMC) and phenol. The X-ray diffraction (XRD) and infrared (IR) techniques were employed to characterize the prepared catalysts. The effect of the weight ratio of the 12-molybdosphoric acid to titania on the transesterification was investigated. A 13.1% yield of DPC and an 11.6% yield of methyl phenyl carbonate (MPC) were obtained over MPA-TiO2 with the weight ratio of MPA to TiO2 as 5:1.展开更多
The deactivation cause of lead-zinc double oxide for synthesis of diphenyl carbonate (DPC) by transesterification of dimethyl carbonate (DMC) with phenol has been investigated. X-ray diffraction (XRD), X-ray pho...The deactivation cause of lead-zinc double oxide for synthesis of diphenyl carbonate (DPC) by transesterification of dimethyl carbonate (DMC) with phenol has been investigated. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), thermogravimetry analysis (TG), atomic absorption spectroscopy and elementary analysis are employed for the catalyst characterization. The results show that, the formation of Pb4O(OC6H5)6 through the reaction of phenol and lead species in the catalyst leads to the crystal phase change of active component and serious leaching of lead, which is the cause of the catalyst deactivation. In addition, the composition of the leached lead is ascertained to be a mixture of Pb4O(OC6H5)6 and PbO with the weight percentage of 62.7% and 37.3%, respectively.展开更多
We measured 39 polybrominated diphenyl ethers (PBDEs) in the muscle tissue of three species of fish (Sciaenops ocellatus,Sparus macrocephalus,and Lateolabrax japonicus) and four species of shellfish (Tegillarca g...We measured 39 polybrominated diphenyl ethers (PBDEs) in the muscle tissue of three species of fish (Sciaenops ocellatus,Sparus macrocephalus,and Lateolabrax japonicus) and four species of shellfish (Tegillarca granosa,Cyclina sinensis,Sinonovacula constricta,and Ostrea cucullata) that were collected downstream of electronic-waste recycling plants in Taizhou,China.A total of 24 PBDE congeners (PBDE 24) in the samples were detected.The PBDE 24 (total PBDE) ranged from 545.4 to 1688.7 ng/kg ww (wet weight).The mean PBDE 24 concentration was 1382.6 ng/kg ww in fish and 858.1 ng/kg ww in shellfish.The lower brominated congeners were detected at relatively high concentrations in all species.The penta-products,produced from e-waste,were found at relatively low levels.A principal component analysis suggested a significant correlation among di-,tri-,tetra-,and hepta-BDEs for the three species of fish.Similarly,we found a significant correlation between mono-and tri-BDEs in the shellfish.Our results suggested that the processes of PBDE metabolism and elimination were similar in both fish and shellfish.In addition,the primary source of PBDEs appeared to be from the debromination of high brominated PBDEs.展开更多
Diphenyl oxalate was synthesized from transesterification of dimethyl oxalate with phenol over TS-1 ( 2.5 wt% Ti ) catalyst. TS-1 catalyst, as a heterogeneous catalyst, showed excellent selectivity of diphenyl oxalat...Diphenyl oxalate was synthesized from transesterification of dimethyl oxalate with phenol over TS-1 ( 2.5 wt% Ti ) catalyst. TS-1 catalyst, as a heterogeneous catalyst, showed excellent selectivity of diphenyl oxalate and methylphenyl oxalate compared with other homogeneous catalysts. Lewis acid sites on TS-1 catalyst were the active sites for transesterification of dimethyl oxalate with phenol. The high selectivity was closely related to the weak acid sites over TS-1.展开更多
Two ternary complexes of RE(ClO_4)_3-DPSO-phen and two binary complexes of RE(ClO_4)_3-phen have been synthesized (RE=Eu, Tb; DPSO=diphenyl sulfoxide, phen=1,10-phenanthroline). Elemental analysis and TG-DTA studies s...Two ternary complexes of RE(ClO_4)_3-DPSO-phen and two binary complexes of RE(ClO_4)_3-phen have been synthesized (RE=Eu, Tb; DPSO=diphenyl sulfoxide, phen=1,10-phenanthroline). Elemental analysis and TG-DTA studies suggest that the ternary complexes consist of RE(ClO_4)_3(DPSO)(phen)_3·nH_2O (n=1, 3) and binary complexes consist of RE(phen)_4(ClO_4)_3. IR spectra studies indicate that the DPSO ligand is bonded with RE(Ⅲ) through oxygen atom in sulfinyl group and phen ligand is bonded to RE(Ⅲ) through nitrogen atom. The molar conductivities measured in the acetonitrile solution indicate that two inorganic anions ClO_4^- are coordinated and binary complexes are nonelectrolyte. In the fluorescent spectra it was found that the fluorescence emission intensity of the ternary complexes more intensive than that of the binary complexes.展开更多
CuO-CoO-MnO/SiO2 nanocomposite aerogels were prepared by using tetraethyl orthosilicate (TEOS) as Si source, and aqueous solution of Cu, Co and Mn acetates as transition metal sources via sol-gel process and supercr...CuO-CoO-MnO/SiO2 nanocomposite aerogels were prepared by using tetraethyl orthosilicate (TEOS) as Si source, and aqueous solution of Cu, Co and Mn acetates as transition metal sources via sol-gel process and supercritical drying (SCD) technique. The effect of synthesis conditions on gelation was investigated. Moreover, the composition of the CuO-CoO-MnO/SiO2 nanocomposite aerogels was characterized by electron dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS), and the specific surface area of the nanocomposite aerogels was determined by the Brunauer-Emmett-Teller (BET) method. Diphenyl carbonate (DPC) as the product was analyzed by gas chromatography (GC). The experimental results show that the range of optimal temperature for gelation is 30-45 ℃, and the pH is 3.0-4.5. CuO-CoO-MnO/SiO2 nanocomposite aerogels are porous with a specific surface area of 384.9-700.6 m2/g. Compared to CO2 SCD, ethanol SCD is even favorable to the formation of aerogel with high specific surface area. The transition metals content in the nanocomposite aerogels can be controlled to be 0.71at%-13.77at%. With CuO-CoO-MnO/SiO2 nanocomposite aerogels as catalyst carrier, the yield of DPC is in direct proportion to the atomic fraction of transition metals in the nanocomposite aerogels, and it is up to 26.31 mass%, which is much higher than that via other porous carriers.展开更多
Objective:To investigate the metabolites of polybrominated diphenyl ether 99(BDE-99)and its related cytochrome P450s in an in vitro system.Methods:Rat primary hepatocytes were isolated and treated with BDE-99 for ...Objective:To investigate the metabolites of polybrominated diphenyl ether 99(BDE-99)and its related cytochrome P450s in an in vitro system.Methods:Rat primary hepatocytes were isolated and treated with BDE-99 for 24-72 h.Metabolites were then extracted from the hepatocytes and media,and detected by GC/MS.Several mRNAs of metabolic enzymes were also extracted from the same cells and the gene expression levels were determined using quantitative real-time PCR.In addition,selected recombinant cytochrome P450s(CYPs) were expressed in a bacurovirus/sf9 system,and these were further used to explore the metabolism of BDE-99 in vitro.The parent depletion approach was used for screening the ability of CYPs to eliminate BDE-99.Results: A reductively debrominated metabolite,BDE-47,and three oxidative metabolites,2,4,5-tribromophenol,5-OH-BDE-47,and 5'-OH-BDE-99,were identified from the BDE-99-treated rat hepatocytes,whereas no MeO metabolite was detected in the system.RT-PCR analysis showed that CYP 3A23/3A1,1A2,and 2B1/2 were induced by BDE-99.Furthermore,using the heterological expressed CYP proteins in in vitro BDE-99 metabolism experiments we found that CYP1A2 and CYP3A4 showed the highest metabolic efficiency for BDE-99,with the metabolic clearance rates of CYP1A2 and CYP3A4 being 30.3%and 27.7%,respectively.CYP1A1 and CYP2A6 displayed relatively low clearance rates,while CYP2E1 seemed not to be associated with the BDE-99 metabolism.Conclusions:In our in vitro rat primary hepatocyte metabolism system,four metabolites of BDE-99 were identified,and CYP3A4 and CYP1A2 were demonstrated to be involved in the BDE-99 metabolism.展开更多
Optimized calculations of 209 polychlorinated diphenyl ethers (PCDEs) and diphenyl ethers were carried out at the B3LYP/6-31G^* level with the Gaussian 98 program. Based on the theoretical linear solvation energy r...Optimized calculations of 209 polychlorinated diphenyl ethers (PCDEs) and diphenyl ethers were carried out at the B3LYP/6-31G^* level with the Gaussian 98 program. Based on the theoretical linear solvation energy relationship (TLSER) model, the obtained structural parameters were taken as theoretical descriptors to establish the novel QSPR model for predicting aqueous solubility (-lgSw) of PCDEs. The model obtained in this work contains two variables: mean molecular polarizability (a) and the most positive partial charge on a hydrogen atom (qH^+), of which RE = 0.9606 and SD = 0.32. And the results of cross-validation test also show that the model exhibits optimum stability and better predictive power. Moreover, the predictive power of the new model is better than that of MCIs method.展开更多
Using the molecular electronegativity distance vector descriptors derived directly from the molecular topological structures, the relative retention time (RRT) of polybrominated diphenyl ethers (PBDEs) were predic...Using the molecular electronegativity distance vector descriptors derived directly from the molecular topological structures, the relative retention time (RRT) of polybrominated diphenyl ethers (PBDEs) were predicted. A four-variable regression model (M30) with the correlation coefficient of 0.9816 and the root mean square errors of 0.061 was developed using a training set including 30 PBDEs. The correlation coefficient of 0.9841 and the root mean square errors of 0.054 between the values of RRT predicted by M30 and the RRT observed for 16 external PBDEs show a good predictive potential of M30. The descriptors included in the M30 represent four interactions between four pairs of atom types, i.e., atom -C= and -C=, -C= and 〉C=, 〉C= and 〉C=, -C= and -Br.展开更多
Hydrogen storage in Liquid Organic Hydrogen Carrier(LOHC)systems is appealing for the safe storage and distribution of excess renewable energy via existing gasoline infrastructures to end-users.We present the eutectic...Hydrogen storage in Liquid Organic Hydrogen Carrier(LOHC)systems is appealing for the safe storage and distribution of excess renewable energy via existing gasoline infrastructures to end-users.We present the eutectic mixture of biphenyl and diphenyl ether of its first use as a LOHC material.The material is hydrogenated with 99%selectivity without the cleavage of C–O bond,with commercial heterogeneous catalysts,which is confirmed by nuclear magnetic spectroscopy and gas chromatography-mass spectrometry.Equilibrium concentration,dehydrogenation enthalpy,and thermo-neutral temperature are calculated using a density functional theory.The results indicate that O-atom-containing material exhibits more favorable dehydrogenation thermodynamics than that of the hydrocarbon analogue.The H2-rich material contains6.8 wt%of gravimetric hydrogen storage capacity.A preliminary study of catalytic dehydrogenation on a continuous reactor is presented to demonstrate a reversibility of this material.展开更多
The transesterification of diphenyl carbonate (DPC) with 1,4-butyldiol (BD) was kinetically investigated in the presence of lithium acetate catalyst at 465 K.The reaction was followed by the measurement of the qua...The transesterification of diphenyl carbonate (DPC) with 1,4-butyldiol (BD) was kinetically investigated in the presence of lithium acetate catalyst at 465 K.The reaction was followed by the measurement of the quantity of phenol which was distilled from the reactor.The experiments supported the assumption that the phenyl ester groups in DPC and phenyl hdroxybutyl carbonate (PHBH) had the same reactivity,and the transesterification obeyed first-order kinetics with respect to DPC and BD,and a rate equation was derived.The reaction rate was found to be first order with respect to the catalyst concentration as well.When those data were incorporated in the rate equation,excellent agreement between calculated values and the observed ones was recognized over a wide range.展开更多
A fluorescent ternary europium complex containing bis (diphenyl phosphine oxide) methane which functioned as both a neutral and anion ligand, and thenoyltrifluoroacetonato anion was synthesized and characterized by e...A fluorescent ternary europium complex containing bis (diphenyl phosphine oxide) methane which functioned as both a neutral and anion ligand, and thenoyltrifluoroacetonato anion was synthesized and characterized by elemental analysis, DTA TG analysis, UV Vis, FT IR and MS spectroscopy. The chemical formula is proved to be Eu(TTA)(MPPO)(HMPPO)·(NO 3)·2H 2O. Its luminescence quantum efficiency(in acetonitrile, 26 3%) is approximately the same as that of the commonly used red emission luminescent compound, Eu(TTA) 3(TPPO) 2 (TPPO is triphenyl phosphine oxide). The new complex has comparatively long fluorescence lifetime.展开更多
Sixty sediment samples were collected from the main Songhua River in three years. Twelve polybrominated diphenyl ether( PBDE) congeners( BDE17,28,47,66,99,100,153,154,138,183,and BDE-209) were detected to state the po...Sixty sediment samples were collected from the main Songhua River in three years. Twelve polybrominated diphenyl ether( PBDE) congeners( BDE17,28,47,66,99,100,153,154,138,183,and BDE-209) were detected to state the pollution situation. The results showed that the total concentration of total PBDEs ranges from 0. 424 to 23. 0 ng / g dry weight,with the mean of 3. 02 ng / g,and the total PBDEs concentration is at relative low level compared with those worldwide. The congener profile showed that BDE-209 is the dominant congener that accounts for more than 80. 1% of total PBDEs in sediments,followed by BDE-47 and BDE-99. These profiles are consistent with a high consumption of Deca-BDEs for the brominated flame retardant market in China. The results of spatial and seasonal observations indicated that local sources,temperature variation, and hydrologic conditions are significant factors on PBDEs concentrations. Hazard quotients suggested that PBDEs pose no potential risk to benthic organisms in detected area at present.展开更多
Eight new brominated 2'(4')-nitro-3-hydroxy diphenyl ethers have been designed and synthesized. The structures of new compounds were confirmed by ^1H NMR, IR and HRMS. The bioactivity tests showed that these compo...Eight new brominated 2'(4')-nitro-3-hydroxy diphenyl ethers have been designed and synthesized. The structures of new compounds were confirmed by ^1H NMR, IR and HRMS. The bioactivity tests showed that these compounds possessed antibacterial activities against the tested bacteria. These new compounds cannot be transformed into dioxins when they were manufactured and used.展开更多
基金support from the National Natural Science Foundation of China(No.21808048 and U1704251)Training Plan for University's Young Backbone Teachers of Henan Province(2021GGJS121)+5 种基金Program for Science&Technology Innovation Talents in Universities of Henan Province(23HASTIT014)Postgraduate Education Reform and Quality Improvement Project of Henan Province(YJS2022KC22)Project funded by China Postdoctoral Science Foundation(No.2018M632782)Project funded by Postdoctoral Research Grant in Henan Province(No.001802030)Key Project of Science and Technology Program of Henan Province(No.222102230109,212102310330 and 182102210050)the Science Research Start-up Fund of Henan Institute of Science and Technology(No.2015031).
文摘Diphenyl carbonate(DPC)is one of the versatile carbonates,and is often used for the production of polycarbonates.In recent years,the catalytic synthesis of DPC has become an important topic but the development of a highly active metal-free catalyst is a great challenge.Herein,a series of ionic liquids-SBA-15 hybrid catalysts with different functional groups have been developed for the synthesis of DPC under solventfree condition,which are effective and clean instead of the metal-containing catalysts.It is found that in the presence of[SBA-15-IL-OH]Br catalyst,methyl phenyl carbonate(MPC)conversion of 80.5%along with 99.6%DPC selectivity is achieved,the TOF value is thrice higher than the best value reported by using transition metal-based catalysts.Moreover,the catalyst displays remarkable stability and recyclability.This work provides a new idea to design and prepare eco-friendly catalysts in a broad range of applications for the green synthesis of carbonates.
基金the National Natural Science Foundation of China(Nos.41406090,42176045)the Science Foundation of Qingdao Agricultural University(No.631302)+1 种基金the Fujian Key Laboratory of Functional Marine Sensing Materials,Minjiang University(No.MJUKF-FMSM202102)the Natural Science Foundation of Shandong Province(Nos.ZR2019 MB020,ZR2020MB119)。
文摘Polybrominated diphenyl ethers(PBDEs)are a kind of serious pollutants in the ocean.Biodegradation is considered as an economical and safe way for PBDEs removal and reductive debromination dominates the initial pathway of anaerobic degradation.On the basis of experimental study,Octa-BDE 197,Hepta-BDE 183,Hexa-BDE 153,Penta-BDE 99 and Tetra-BDE 47 were selected as the initial degradation objects,and their debromination degradation were studied using density functional theory.The structures were optimized by Gaussian 09 program.Furthermore,the molecular orbitals and charge distribution were analyzed.All C-Br bond dissociation energies at different positions including ortho,meta and para bromine atoms were calculated and the sequence of debromination was obtained.There is a close relationship between molecular structure,charge,molecular orbital and C-Br bond.All PBDEs exhibited similar debromination pathways with preferential removal of meta and para bromines.
文摘Organoseleniums are a class of compounds attracting attention across the globe owing to their Glutathione peroxidase(GPx)mimicry,which confers on them a strong antioxidant activity.Diphenyl diselenide(DPDS)is an Organoselenium whose GPx mimetic property has been suggested to rely on the oxidation of non-protein or protein thiols critical to the activities of some sulfhydryl enzymes.This study,therefore investigated the GPx mimic/antioxidant property of DPDS as well as the role of thiols of two key sulfhydryl enzymes,cerebral Na^(+)/K^(+)-ATPase(sodium pump)and hepatic delta-aminolevulinic acid dehydratase(δ-ALAD)in the GPx mimicry of DPDS.Albino Wistar rats were euthanized,and the liver and brain were removed and used to assay for the effect of DPDS on lipid peroxidation induced by two prooxidants[Fe2^(+)(10μM)and H2O2,(1 mM)]as well as the activities of the sulfhydryl enzymes.The results revealed that DPDS profoundly(P<0.05)counteracted Fe2^(+)and H2O2-induced lipid peroxidation in the rats’hepatic and cerebral tissues.Furthermore,the results of assay systems for lipid peroxidation and sodium pump revealed that DPDS inhibited Na^(+)/K^(+)-ATPase and lipid peroxidation in the brain tissue homogenates in the same reaction system.A similar result was obtained in the assay system for lipid peroxidation and hepaticδ-ALAD as DPDS simultaneously inhibited the enzyme’s activity and lipid peroxidation.This suggests that the GPx mimetic property of DPDS may be linked to the enzymes’loss of activity,which further validates the suggestions that the enzymes’inhibition,as well as the antioxidant action of DPDS,rely on the oxidation of critical thiols of the enzymes.However,the GPx mimicry of DPDS should be investigated in the presence of thiol-blocking or oxidizing agents in biological systems in order to further ascertain the role of protein thiols.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(No. KZCX2-YW-420-3)the National Basic Research Program (973) of China (No. 2003CB415005)the National Natural Science Foundation of China (No.20437020, 20677074)
文摘To understand potential ecotoxicological effects of electrical and electronic equipment waste (e-waste) recycling and polybrominated diphenyl ethers (PBDEs) bioaccumulation in loaches, a semi-field experiment using Chinese loach (Misgurnus anguiUicaudatus) as experimental fish was performed. Larval loaches were kept in net-cage for three months in an e-wastes recycling site and a reference site in Southeastern China. There was significant difference of the survival rate between the loaches from the e-wastes recycling site (27%, 19/70) and from reference site (70%, 49/70). Histopathological responses were also found in all the livers examined in loaches from the e-wastes recycling site. These results showed that mixed pollutants resulted from e-wastes recycling led to ecotoxicological effects on loaches. The bioaccumulation of polybrominated diphenyl ethers (PBDEs), the main pollutants in e-waste, in loaches was also studied, the mean concentration of total PBDEs in sediment was 6726.17 ng/g wet weight and in water samples was 4.08 ng/L (dissolved phase). BDE 209 was the dominant congener in sediment and with relatively high concentration in water. Relatively low concentration of BDE 209 (less than 0.01% of total PBDEs) and high concentration of BDE47 (up to 39.34% of total PBDEs) were detected in loaches.
文摘The 12-molybdosphoric acid mixed with titania (MPA-TiO2) was found to be a novel and efficient catalyst for the synthesis of diphenyl carbonate (DPC) via transesterification of dimethyl carbonate (DMC) and phenol. The X-ray diffraction (XRD) and infrared (IR) techniques were employed to characterize the prepared catalysts. The effect of the weight ratio of the 12-molybdosphoric acid to titania on the transesterification was investigated. A 13.1% yield of DPC and an 11.6% yield of methyl phenyl carbonate (MPC) were obtained over MPA-TiO2 with the weight ratio of MPA to TiO2 as 5:1.
基金This work was supported by National Natural Science Foundation of China (No.20636030 No.20176008)Natural Science Foundation of Tianjin(No.07 JCZDJC00100)
文摘The deactivation cause of lead-zinc double oxide for synthesis of diphenyl carbonate (DPC) by transesterification of dimethyl carbonate (DMC) with phenol has been investigated. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), thermogravimetry analysis (TG), atomic absorption spectroscopy and elementary analysis are employed for the catalyst characterization. The results show that, the formation of Pb4O(OC6H5)6 through the reaction of phenol and lead species in the catalyst leads to the crystal phase change of active component and serious leaching of lead, which is the cause of the catalyst deactivation. In addition, the composition of the leached lead is ascertained to be a mixture of Pb4O(OC6H5)6 and PbO with the weight percentage of 62.7% and 37.3%, respectively.
基金supported by the Wenling Science and Technology Bureau of Zhejiang Province (No. 2007-35)
文摘We measured 39 polybrominated diphenyl ethers (PBDEs) in the muscle tissue of three species of fish (Sciaenops ocellatus,Sparus macrocephalus,and Lateolabrax japonicus) and four species of shellfish (Tegillarca granosa,Cyclina sinensis,Sinonovacula constricta,and Ostrea cucullata) that were collected downstream of electronic-waste recycling plants in Taizhou,China.A total of 24 PBDE congeners (PBDE 24) in the samples were detected.The PBDE 24 (total PBDE) ranged from 545.4 to 1688.7 ng/kg ww (wet weight).The mean PBDE 24 concentration was 1382.6 ng/kg ww in fish and 858.1 ng/kg ww in shellfish.The lower brominated congeners were detected at relatively high concentrations in all species.The penta-products,produced from e-waste,were found at relatively low levels.A principal component analysis suggested a significant correlation among di-,tri-,tetra-,and hepta-BDEs for the three species of fish.Similarly,we found a significant correlation between mono-and tri-BDEs in the shellfish.Our results suggested that the processes of PBDE metabolism and elimination were similar in both fish and shellfish.In addition,the primary source of PBDEs appeared to be from the debromination of high brominated PBDEs.
基金This work was supported by the National Natural Science Foundation of China(20276050)Foundation for University Key Teacher by the Ministry of Educationthe Department of Science and Technology of Yunnan Province for the project on Technology Collaboration and Development in China.
文摘Diphenyl oxalate was synthesized from transesterification of dimethyl oxalate with phenol over TS-1 ( 2.5 wt% Ti ) catalyst. TS-1 catalyst, as a heterogeneous catalyst, showed excellent selectivity of diphenyl oxalate and methylphenyl oxalate compared with other homogeneous catalysts. Lewis acid sites on TS-1 catalyst were the active sites for transesterification of dimethyl oxalate with phenol. The high selectivity was closely related to the weak acid sites over TS-1.
文摘Two ternary complexes of RE(ClO_4)_3-DPSO-phen and two binary complexes of RE(ClO_4)_3-phen have been synthesized (RE=Eu, Tb; DPSO=diphenyl sulfoxide, phen=1,10-phenanthroline). Elemental analysis and TG-DTA studies suggest that the ternary complexes consist of RE(ClO_4)_3(DPSO)(phen)_3·nH_2O (n=1, 3) and binary complexes consist of RE(phen)_4(ClO_4)_3. IR spectra studies indicate that the DPSO ligand is bonded with RE(Ⅲ) through oxygen atom in sulfinyl group and phen ligand is bonded to RE(Ⅲ) through nitrogen atom. The molar conductivities measured in the acetonitrile solution indicate that two inorganic anions ClO_4^- are coordinated and binary complexes are nonelectrolyte. In the fluorescent spectra it was found that the fluorescence emission intensity of the ternary complexes more intensive than that of the binary complexes.
基金Funded by the Hebei Natural Science Foundation(No.E2011209003)the Science and Technology Development Foundation of Hebei (No. 10215606D)the Ph D Programs Foundation of Hebei United University
文摘CuO-CoO-MnO/SiO2 nanocomposite aerogels were prepared by using tetraethyl orthosilicate (TEOS) as Si source, and aqueous solution of Cu, Co and Mn acetates as transition metal sources via sol-gel process and supercritical drying (SCD) technique. The effect of synthesis conditions on gelation was investigated. Moreover, the composition of the CuO-CoO-MnO/SiO2 nanocomposite aerogels was characterized by electron dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS), and the specific surface area of the nanocomposite aerogels was determined by the Brunauer-Emmett-Teller (BET) method. Diphenyl carbonate (DPC) as the product was analyzed by gas chromatography (GC). The experimental results show that the range of optimal temperature for gelation is 30-45 ℃, and the pH is 3.0-4.5. CuO-CoO-MnO/SiO2 nanocomposite aerogels are porous with a specific surface area of 384.9-700.6 m2/g. Compared to CO2 SCD, ethanol SCD is even favorable to the formation of aerogel with high specific surface area. The transition metals content in the nanocomposite aerogels can be controlled to be 0.71at%-13.77at%. With CuO-CoO-MnO/SiO2 nanocomposite aerogels as catalyst carrier, the yield of DPC is in direct proportion to the atomic fraction of transition metals in the nanocomposite aerogels, and it is up to 26.31 mass%, which is much higher than that via other porous carriers.
基金supported by 973 program(No.2009CB941701)NSFC grant(No.30972508)MOE Foundation for PhD Program(No 20093234110002)
文摘Objective:To investigate the metabolites of polybrominated diphenyl ether 99(BDE-99)and its related cytochrome P450s in an in vitro system.Methods:Rat primary hepatocytes were isolated and treated with BDE-99 for 24-72 h.Metabolites were then extracted from the hepatocytes and media,and detected by GC/MS.Several mRNAs of metabolic enzymes were also extracted from the same cells and the gene expression levels were determined using quantitative real-time PCR.In addition,selected recombinant cytochrome P450s(CYPs) were expressed in a bacurovirus/sf9 system,and these were further used to explore the metabolism of BDE-99 in vitro.The parent depletion approach was used for screening the ability of CYPs to eliminate BDE-99.Results: A reductively debrominated metabolite,BDE-47,and three oxidative metabolites,2,4,5-tribromophenol,5-OH-BDE-47,and 5'-OH-BDE-99,were identified from the BDE-99-treated rat hepatocytes,whereas no MeO metabolite was detected in the system.RT-PCR analysis showed that CYP 3A23/3A1,1A2,and 2B1/2 were induced by BDE-99.Furthermore,using the heterological expressed CYP proteins in in vitro BDE-99 metabolism experiments we found that CYP1A2 and CYP3A4 showed the highest metabolic efficiency for BDE-99,with the metabolic clearance rates of CYP1A2 and CYP3A4 being 30.3%and 27.7%,respectively.CYP1A1 and CYP2A6 displayed relatively low clearance rates,while CYP2E1 seemed not to be associated with the BDE-99 metabolism.Conclusions:In our in vitro rat primary hepatocyte metabolism system,four metabolites of BDE-99 were identified,and CYP3A4 and CYP1A2 were demonstrated to be involved in the BDE-99 metabolism.
基金funded by the 973 National Basic Research Program of China (2003CB415002)China Postdoctoral Science Foundation (No. 2003033486)
文摘Optimized calculations of 209 polychlorinated diphenyl ethers (PCDEs) and diphenyl ethers were carried out at the B3LYP/6-31G^* level with the Gaussian 98 program. Based on the theoretical linear solvation energy relationship (TLSER) model, the obtained structural parameters were taken as theoretical descriptors to establish the novel QSPR model for predicting aqueous solubility (-lgSw) of PCDEs. The model obtained in this work contains two variables: mean molecular polarizability (a) and the most positive partial charge on a hydrogen atom (qH^+), of which RE = 0.9606 and SD = 0.32. And the results of cross-validation test also show that the model exhibits optimum stability and better predictive power. Moreover, the predictive power of the new model is better than that of MCIs method.
基金the National Basic Research Program of China(2003CB415002)the National Natural Science Foundation of China(No.20377022) the Guangxi Natural Science Fund(No.0236063)for their financial supports.
文摘Using the molecular electronegativity distance vector descriptors derived directly from the molecular topological structures, the relative retention time (RRT) of polybrominated diphenyl ethers (PBDEs) were predicted. A four-variable regression model (M30) with the correlation coefficient of 0.9816 and the root mean square errors of 0.061 was developed using a training set including 30 PBDEs. The correlation coefficient of 0.9841 and the root mean square errors of 0.054 between the values of RRT predicted by M30 and the RRT observed for 16 external PBDEs show a good predictive potential of M30. The descriptors included in the M30 represent four interactions between four pairs of atom types, i.e., atom -C= and -C=, -C= and 〉C=, 〉C= and 〉C=, -C= and -Br.
基金supported by the Technology Development Program to Solve Climate Changes of the National Research Foundation(NRF)funded by the Ministry of Science,ICT,and Future Planning(2015M1A2A2074688)KISTI-HPC(KSC-2018-CRE-0022)for computational resourcesthe KIST institutional program funded by the Korea Institute of Science and Technology(2E29610).
文摘Hydrogen storage in Liquid Organic Hydrogen Carrier(LOHC)systems is appealing for the safe storage and distribution of excess renewable energy via existing gasoline infrastructures to end-users.We present the eutectic mixture of biphenyl and diphenyl ether of its first use as a LOHC material.The material is hydrogenated with 99%selectivity without the cleavage of C–O bond,with commercial heterogeneous catalysts,which is confirmed by nuclear magnetic spectroscopy and gas chromatography-mass spectrometry.Equilibrium concentration,dehydrogenation enthalpy,and thermo-neutral temperature are calculated using a density functional theory.The results indicate that O-atom-containing material exhibits more favorable dehydrogenation thermodynamics than that of the hydrocarbon analogue.The H2-rich material contains6.8 wt%of gravimetric hydrogen storage capacity.A preliminary study of catalytic dehydrogenation on a continuous reactor is presented to demonstrate a reversibility of this material.
基金supported by the Key Projects in the National Science & Technology Pillar Program during the Eleventh Five-Year Plan Period(2006BAE02B03)
文摘The transesterification of diphenyl carbonate (DPC) with 1,4-butyldiol (BD) was kinetically investigated in the presence of lithium acetate catalyst at 465 K.The reaction was followed by the measurement of the quantity of phenol which was distilled from the reactor.The experiments supported the assumption that the phenyl ester groups in DPC and phenyl hdroxybutyl carbonate (PHBH) had the same reactivity,and the transesterification obeyed first-order kinetics with respect to DPC and BD,and a rate equation was derived.The reaction rate was found to be first order with respect to the catalyst concentration as well.When those data were incorporated in the rate equation,excellent agreement between calculated values and the observed ones was recognized over a wide range.
文摘A fluorescent ternary europium complex containing bis (diphenyl phosphine oxide) methane which functioned as both a neutral and anion ligand, and thenoyltrifluoroacetonato anion was synthesized and characterized by elemental analysis, DTA TG analysis, UV Vis, FT IR and MS spectroscopy. The chemical formula is proved to be Eu(TTA)(MPPO)(HMPPO)·(NO 3)·2H 2O. Its luminescence quantum efficiency(in acetonitrile, 26 3%) is approximately the same as that of the commonly used red emission luminescent compound, Eu(TTA) 3(TPPO) 2 (TPPO is triphenyl phosphine oxide). The new complex has comparatively long fluorescence lifetime.
基金Sponsored by the National Natural Science Foundation of China(Grant No.21277038)
文摘Sixty sediment samples were collected from the main Songhua River in three years. Twelve polybrominated diphenyl ether( PBDE) congeners( BDE17,28,47,66,99,100,153,154,138,183,and BDE-209) were detected to state the pollution situation. The results showed that the total concentration of total PBDEs ranges from 0. 424 to 23. 0 ng / g dry weight,with the mean of 3. 02 ng / g,and the total PBDEs concentration is at relative low level compared with those worldwide. The congener profile showed that BDE-209 is the dominant congener that accounts for more than 80. 1% of total PBDEs in sediments,followed by BDE-47 and BDE-99. These profiles are consistent with a high consumption of Deca-BDEs for the brominated flame retardant market in China. The results of spatial and seasonal observations indicated that local sources,temperature variation, and hydrologic conditions are significant factors on PBDEs concentrations. Hazard quotients suggested that PBDEs pose no potential risk to benthic organisms in detected area at present.
文摘Eight new brominated 2'(4')-nitro-3-hydroxy diphenyl ethers have been designed and synthesized. The structures of new compounds were confirmed by ^1H NMR, IR and HRMS. The bioactivity tests showed that these compounds possessed antibacterial activities against the tested bacteria. These new compounds cannot be transformed into dioxins when they were manufactured and used.