In this study, an organic electrolyte solution based on zinc acetate/diethylene glycol(ZA/DEG) is introduced for the selective purification of cyclotetramethylene tetranitramine(HMX) high explosive from its identical ...In this study, an organic electrolyte solution based on zinc acetate/diethylene glycol(ZA/DEG) is introduced for the selective purification of cyclotetramethylene tetranitramine(HMX) high explosive from its identical homologue cyclotrimethylene trinitramine(RDX). The dielectric constant of various organic solutions were investigated through Electrochemical Impedance Spectroscopy(EIS) in the range of 1.0 Hz—30 MHz. and some quantum-chemical descriptors of RDX and HMX dissolutions in the ZA cosolvent were analyzed using Density Functional Theory(DFT). The results show dielectric constant and solubility of RDX is higher than that of HMX, and by increasing of ZA concentration in DEG solvent, the values of dielectric constants were enhanced. Furthermore, the presence of ZA cosolvent on the solubility of two explosives was statistically investigated by Central Composite Design(CCD) of experiment, and some solubility parameters including activity coefficient, dissolving enthalpy, and mixing enthalpies were determined. The experimental results indicate that the weight ratio of RDX to HMX solubility in the proposed organic electrolyte changes up to 30 times, which provides a selective and sequential separation method to separate two materials with similar chemical properties with a separation efficiency>98% and HMX purity> 99.8%. The X-Ray Diffraction(XRD) analysis, High-Performance Liquid Chromatography(HPLC), Laser-Induced Breakdown Spectroscopy(LIBS), and Fourier Transform Infrared Spectroscopy(FT-IR) approves the acceptable quality of the separated materials. The proposed method makes the efficient and safe purification of high-quality HMX for application in oil and gas well perforating gun charges, using a nonvolatile and inflammable organic electrolyte.展开更多
Densities and viscosities were measured as a function of composition for binary liquid mixture of diethylerie glycol monoethyl ether [CH3CH2O(CH2)2O(CH2)2OH] + water from 293.15 to 333.15 K at atmospheric pressur...Densities and viscosities were measured as a function of composition for binary liquid mixture of diethylerie glycol monoethyl ether [CH3CH2O(CH2)2O(CH2)2OH] + water from 293.15 to 333.15 K at atmospheric pressure, with a capillary pycnometer and Ubbelohde capillary viscometer respectively. From the experimental data, the excess molar volume V^E, viscosity deviation △η, and the excess energy of activation for viscous flow △G^*E were calculated. These data were correlated by the Redlich-Kister type equations to obtain the coefficients and standard deviations. The results showed a strong molecular interaction between diethylene glycol monoethyl ether and water.展开更多
The solubility and hydrolysis of carbonyl sulfide in binary mixture of diethylene glycol diethyl ether and water are studied as a function of composition. The use of an aqueous solution of diethylene glycol diethyl et...The solubility and hydrolysis of carbonyl sulfide in binary mixture of diethylene glycol diethyl ether and water are studied as a function of composition. The use of an aqueous solution of diethylene glycol diethyl ether enhances the solubility and hydrolysis rate of carbonyl sulfide compared with that in pure water. The composition of the mixture with maximum hydrolysis rate varies with temperature. The thermophysical properties including density, viscosity, and surface tension as a function of composition at 20℃ under atmospheric pressure as well as liquid-liquid equilibrium (LLE) data over the temperature range from 28℃ to 90℃ are also measured for the binary mixture.展开更多
AIM: To analyze the clinical presentation of venous diethylene glycol (DEG) poisoning in patients with preexisting severe liver disease and factors that correlate with DEG poisoning. METHODS: Retrospective chart revie...AIM: To analyze the clinical presentation of venous diethylene glycol (DEG) poisoning in patients with preexisting severe liver disease and factors that correlate with DEG poisoning. METHODS: Retrospective chart review was performed to analyze the epidemiology, clinical presentation, hepatorenal functions, hemodynamics and pathological characteristics of 64 patients with severe liver disease who received intravenous armillarisin-A, the solvent of which was DEG. Comparative analyses of correlating factors and causes for poisoning were based on the presence or absence of poisoning. RESULTS: Of the 64 patients who received armillarisin-A, 15 were found to have DEG poisoning. Twelve poisoned patients died. After a mean of 5 d, the poisoned patients displayed acute renal failure. Metabolic acidosis occurred in 13 cases. BUN, Cr, and CO2 values were significantly elevated and exacerbation of digestive tract symptoms and/or symptom was noted in 11 cases. Neurological system impairment was observed in 10 cases after 2 wk. Compared to the 49 non-poisoned patients, the poisoned patients exhibited significantly lower RBC and Hb values and higher WBC count. Renal biopsy from the poisoned patientsrevealed acute tubular necrosis and interstitial nephritis. Significant differences in preexisting severe hepatitis, ascites, renal disease, and diuretic therapy were found between groups. Prior to diethylene glycol injections, the mean values for neutral granular cells, BUN, Cr, calcium and phosphorous ions differed significantly between groups. CONCLUSION: Venous diethylene glycol poisoning is characterized by oliguric acute renal failure, metabolic acidosis, digestive symptoms, nervous system impairment, and a high probability of anemia and WBC proliferation. Mortality is high. Correlative factors include preexisting severe liver disease, renal disease, and infection.展开更多
Samples of preparations contaminated by diethylene glycol(DEG),diethylene glycol raw materials and laboratory prepared solutions were measured to get NIR spectra.Then the iden-tification models were developed using th...Samples of preparations contaminated by diethylene glycol(DEG),diethylene glycol raw materials and laboratory prepared solutions were measured to get NIR spectra.Then the iden-tification models were developed using the collected spectra and the spectra of distilled water,propylene glyool and the preparations without diethylene glyool.Besides,the quantification model was also established for determining the concentration of diethylene glyool in the pre-parations.V alidation results show the identification and quantification models have ideal pre-diction performance.The emergency NIR models are rapid,easy to use and accurate,and can be implemented for identifying diethylene glycol raw material,screening the preparations contam-inated by diethylene glycol in the markets and analyzing the concentrations of DEG.展开更多
The homogeneous system of 12-tungstophosphoric acid and diethylene glycol was studied using IR and NMR spectra. It was found that the protons in 12-tungstophosphoric acid formed proton oxonium ions with the hydroxyl o...The homogeneous system of 12-tungstophosphoric acid and diethylene glycol was studied using IR and NMR spectra. It was found that the protons in 12-tungstophosphoric acid formed proton oxonium ions with the hydroxyl oxygen in diethylene glycol by hydrogen-bonds, and the formed proton oxonium ions could react with the terminal oxygens of heteropoly anions. The dehydration-cyclization mechanism of diethylene glycol in the presence of heteropoly acid was also proposed.展开更多
BACKGROUND: Measurement of the osmol gap (OG) is a technique that is used frequently in toxic alcohol poisonings (ethylene glycol (EG) and methanol) as a rapid means to estimate exposure, and can be performed i...BACKGROUND: Measurement of the osmol gap (OG) is a technique that is used frequently in toxic alcohol poisonings (ethylene glycol (EG) and methanol) as a rapid means to estimate exposure, and can be performed in virtually all hospital laboratories. The value of the OG has not been previously evaluated for diethylene glycol (DEG) exposures. The primary objective of this study was to evaluate the utility of the OG in estimating DEG serum concentrations using the most common formula that is currently used for estimating methanol, ethanol, and ethylene glycol concentrations.METHODS: This was a controlled laboratory investigation using serum samples individually spiked with a known quantity of toxic alcohol compared to no toxic alcohol. Test samples were spiked with ethanol, DEG, EG, and methanol. Serum chemistries and osmolality and osmolarity were determined, and the OG was determined for each specimen.RESULTS: The percent error of estimating DEG concentrations of 26.3% was similar to the mean percent error for estimating other alcohol concentrations, 30.5%±5.6% (P〉0.05, 95% confidence interval 16.7%-44.3%).CONCLUSION: The severity of metabolic effects associated with DEG and the need to appropriately determine rescue treatments mandate early detection of significant exposures for effective triage and patient management. Our results indicate that the percent error of the osmol gap method for estimating DEG concentration is similar to that of other toxic alcohols; this simple technique could be a valuable clinical tool, since quantitative DEG analysis is rarely available.展开更多
Background There was a hospital outbreak of venous diethylene glycol poisoning in Guangzhou, China. It is the only massive episode of venous diethylene glycol poisoning in history. Here we report its clinical features...Background There was a hospital outbreak of venous diethylene glycol poisoning in Guangzhou, China. It is the only massive episode of venous diethylene glycol poisoning in history. Here we report its clinical features, laboratory findings, and imaging appearances. Methods The clinical features of 15 venous diethylene glycol poisoning patients with liver disease were analyzed and summarized. Their laboratory findings and imaging appearances were comparatively analyzed before and after poisoning. Results All poisoned patients presented with oliguric acute renal failure with anuria after a mean of 6 days. Carbon dioxide combination power of 13 patients dropped after a mean of 9 days with valley value on the 10th day, when metabolic acidosis developed. Gastroenteric symptoms or aggravation of gastroenteric symptoms were displayed in 11 patients after a mean of 9 days. Neurological system impairment was observed in 10 patients after a mean of 14 days. Seven patients had low fever after a mean of 6 days. Causes of death of 14 patients included multiple organ dysfunction syndrome, severe lung infection and massive haemorrhage of digestive tract. Blood creatinine and urea nitrogen were abnormal after a mean of 5 days with peak value on the 11th and 14th days, respectively. Serum calcium had no obvious change, and phosphorus was distinctively increased. Liver functions did not change significantly. Poisoned patients had higher white blood cell counts, but lower red blood cell counts and hemoglobin value. Of the 7 patients who exhibited mild moderate or severe patchy consolidation shadowing in the lung, 2 manifested mild or severe gaseous distention and dilation of gastroentedc tract. Conclusions Main features of venous diethylene glycol poisoning in patients with liver disease include oliguric acute renal failure, metabolic acidosis, gastroenteric symptoms or aggravation of gastroenteric symptoms, neurological system impairment and low fever, with a mortality rate of 93.33% in poisoned patients. There is also higher white blood cell counts and anemia, patchy consolidation shadowing in the lung, gaseous distention and dilation of gastroenteric tract, which occurs later than mild patchy consolidation shadowing and earlier than moderate patchy consolidation shadowing in the lung.展开更多
The binding mechanism between 9-vinyladenine and pyrimidine base thymine in methanol was studied with UV-visible spectrophotometric method. Based on this study, using thymine as a template molecule, 9-vinyladenine as ...The binding mechanism between 9-vinyladenine and pyrimidine base thymine in methanol was studied with UV-visible spectrophotometric method. Based on this study, using thymine as a template molecule, 9-vinyladenine as a novel functional monomer and diethylene glycol dimethacrylate as a new cross-linker, a specific diethylene glycol dimethacrylate-based molecularly imprinted polymeric membrane was prepared over a cellulose support. Then, the resultantly polymeric membrane morphologies were visualized with scanning electron microscopy and its permselectivity was examined using thymine, uracil, cytosine, adenine and guanine as substrates. This result showed that the imprinting polymeric membrane prepared with diethylene glycol dimethacrylate exhibited higher transport capacity for the template molecule thymine and its optimal analog uracil than other nucleic acid bases. The membrane also took on higher permselectivity than the imprinted membrane made with ethylene glycol dimethacrylate as a cross-linker. When a mixture including five nucleic acid bases thymine, uracil, cytosine, adenine and guanine passed through the diethylene glycol dimethacrylate-based thymine-imprinted polymeric membrane, recognition of the membrane for the template molecule thymine and its optimal analog uracil was demonstrated. It was predicted that the molecularly imprinted membrane prepared with diethylene glycol dimethacrylate as cross-linker might be applicable to thymine assay of absolute hydrolysates of DNA or uracil assay of absolute hydrolysates of RNA in biological samples because of its high selectivity for the template molecule thymine and its optimal analog uracil.展开更多
The performance of dye-sensitized solar cells(DSSCs) consisting of anatase TiO_2 nanoparticles that were synthesized via a hydrothermal method was studied.The synthesized TiO_2 nanoparticles were characterized by X-...The performance of dye-sensitized solar cells(DSSCs) consisting of anatase TiO_2 nanoparticles that were synthesized via a hydrothermal method was studied.The synthesized TiO_2 nanoparticles were characterized by X-ray diffraction(XRD),nitrogen sorption analysis,scanning electron microscopy(SEM),high resolution transmission electron microscopy(HRTEM),and UV-vis spectroscopy.Then the J-Vcurve,electrochemical impedance spectroscopy(EIS),and open-circuit voltage decay(OCVD) measurement were applied to evaluate the photovoltaic performance of DSSCs.Compared with the commercial TiO_2nanoparticles(P25),the synthesized-TiO_2 nanoparticles showed better performance.By adding diethylene glycol(DEG) before the hydrothermal process,the synthesized TiO_2 nanoparticles(hereafter referred to as TiO_2-DEG particles) shows narrower size distribution,larger specific surface area,higher crystallinity,and less surface defects than TiO_2(DEG free) particles.The analysis of photovoltaic properties of DSSCs based on TiO_2-DEG particles showed that the recombination of electron-hole pairs was decreased and the trapping of carries in grain boundaries restrained.It was believed that the photoelectrode fabricated with the as-prepared TiO_2 nanoparticles improved the loading amount of dye sensitizers(N719).and enhanced the photocurrent of the DSSCs.As a result,the TiO_2-DEG particle based cells achieved a photo-to-electricity conversion efficiency(η) of 7.90%,which is higher than 7.53%for the cell based on TiO2(DEG free) and 6.59%for the one fabricated with P25.展开更多
The transition metal complexes of triaminoguanidine(TAG-M,where M=Cobalt(Co)or Iron(Fe))have been prepared.The catalytic effect of these complexes on the thermolysis of energetic composite based on nitrocellulose and ...The transition metal complexes of triaminoguanidine(TAG-M,where M=Cobalt(Co)or Iron(Fe))have been prepared.The catalytic effect of these complexes on the thermolysis of energetic composite based on nitrocellulose and diethylene glycol dinitrate,has been investigated.Extensive characterization of the resulting energetic composites was carried out using scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and differential scanning calorimetry(DSC).Isoconversional kinetic analysis was performed to determine the Arrhenius parameters associated with the thermolysis of the elaborated energetic formulations.It is found that TAG-M complexes have strong catalytic effect on the thermo-kinetic decomposition of NC/DEGDN by decreasing the apparent activation energy and significantly increased the total heat release.The models that govern the decomposition processes are also studied,and it is revealed that different reaction processes are accomplished by introduction metal complexes of triaminoguanidine.Overall,this study serves as a valuable reference for future research focused on the investigation of catalytic combustion features of solid propellants.展开更多
基金financial support of this work by Malek-ashtar University of Technology (I.R. Iran)。
文摘In this study, an organic electrolyte solution based on zinc acetate/diethylene glycol(ZA/DEG) is introduced for the selective purification of cyclotetramethylene tetranitramine(HMX) high explosive from its identical homologue cyclotrimethylene trinitramine(RDX). The dielectric constant of various organic solutions were investigated through Electrochemical Impedance Spectroscopy(EIS) in the range of 1.0 Hz—30 MHz. and some quantum-chemical descriptors of RDX and HMX dissolutions in the ZA cosolvent were analyzed using Density Functional Theory(DFT). The results show dielectric constant and solubility of RDX is higher than that of HMX, and by increasing of ZA concentration in DEG solvent, the values of dielectric constants were enhanced. Furthermore, the presence of ZA cosolvent on the solubility of two explosives was statistically investigated by Central Composite Design(CCD) of experiment, and some solubility parameters including activity coefficient, dissolving enthalpy, and mixing enthalpies were determined. The experimental results indicate that the weight ratio of RDX to HMX solubility in the proposed organic electrolyte changes up to 30 times, which provides a selective and sequential separation method to separate two materials with similar chemical properties with a separation efficiency>98% and HMX purity> 99.8%. The X-Ray Diffraction(XRD) analysis, High-Performance Liquid Chromatography(HPLC), Laser-Induced Breakdown Spectroscopy(LIBS), and Fourier Transform Infrared Spectroscopy(FT-IR) approves the acceptable quality of the separated materials. The proposed method makes the efficient and safe purification of high-quality HMX for application in oil and gas well perforating gun charges, using a nonvolatile and inflammable organic electrolyte.
文摘Densities and viscosities were measured as a function of composition for binary liquid mixture of diethylerie glycol monoethyl ether [CH3CH2O(CH2)2O(CH2)2OH] + water from 293.15 to 333.15 K at atmospheric pressure, with a capillary pycnometer and Ubbelohde capillary viscometer respectively. From the experimental data, the excess molar volume V^E, viscosity deviation △η, and the excess energy of activation for viscous flow △G^*E were calculated. These data were correlated by the Redlich-Kister type equations to obtain the coefficients and standard deviations. The results showed a strong molecular interaction between diethylene glycol monoethyl ether and water.
文摘The solubility and hydrolysis of carbonyl sulfide in binary mixture of diethylene glycol diethyl ether and water are studied as a function of composition. The use of an aqueous solution of diethylene glycol diethyl ether enhances the solubility and hydrolysis rate of carbonyl sulfide compared with that in pure water. The composition of the mixture with maximum hydrolysis rate varies with temperature. The thermophysical properties including density, viscosity, and surface tension as a function of composition at 20℃ under atmospheric pressure as well as liquid-liquid equilibrium (LLE) data over the temperature range from 28℃ to 90℃ are also measured for the binary mixture.
文摘AIM: To analyze the clinical presentation of venous diethylene glycol (DEG) poisoning in patients with preexisting severe liver disease and factors that correlate with DEG poisoning. METHODS: Retrospective chart review was performed to analyze the epidemiology, clinical presentation, hepatorenal functions, hemodynamics and pathological characteristics of 64 patients with severe liver disease who received intravenous armillarisin-A, the solvent of which was DEG. Comparative analyses of correlating factors and causes for poisoning were based on the presence or absence of poisoning. RESULTS: Of the 64 patients who received armillarisin-A, 15 were found to have DEG poisoning. Twelve poisoned patients died. After a mean of 5 d, the poisoned patients displayed acute renal failure. Metabolic acidosis occurred in 13 cases. BUN, Cr, and CO2 values were significantly elevated and exacerbation of digestive tract symptoms and/or symptom was noted in 11 cases. Neurological system impairment was observed in 10 cases after 2 wk. Compared to the 49 non-poisoned patients, the poisoned patients exhibited significantly lower RBC and Hb values and higher WBC count. Renal biopsy from the poisoned patientsrevealed acute tubular necrosis and interstitial nephritis. Significant differences in preexisting severe hepatitis, ascites, renal disease, and diuretic therapy were found between groups. Prior to diethylene glycol injections, the mean values for neutral granular cells, BUN, Cr, calcium and phosphorous ions differed significantly between groups. CONCLUSION: Venous diethylene glycol poisoning is characterized by oliguric acute renal failure, metabolic acidosis, digestive symptoms, nervous system impairment, and a high probability of anemia and WBC proliferation. Mortality is high. Correlative factors include preexisting severe liver disease, renal disease, and infection.
文摘Samples of preparations contaminated by diethylene glycol(DEG),diethylene glycol raw materials and laboratory prepared solutions were measured to get NIR spectra.Then the iden-tification models were developed using the collected spectra and the spectra of distilled water,propylene glyool and the preparations without diethylene glyool.Besides,the quantification model was also established for determining the concentration of diethylene glyool in the pre-parations.V alidation results show the identification and quantification models have ideal pre-diction performance.The emergency NIR models are rapid,easy to use and accurate,and can be implemented for identifying diethylene glycol raw material,screening the preparations contam-inated by diethylene glycol in the markets and analyzing the concentrations of DEG.
基金Supported by the National Natural Science Foundation of China
文摘The homogeneous system of 12-tungstophosphoric acid and diethylene glycol was studied using IR and NMR spectra. It was found that the protons in 12-tungstophosphoric acid formed proton oxonium ions with the hydroxyl oxygen in diethylene glycol by hydrogen-bonds, and the formed proton oxonium ions could react with the terminal oxygens of heteropoly anions. The dehydration-cyclization mechanism of diethylene glycol in the presence of heteropoly acid was also proposed.
文摘BACKGROUND: Measurement of the osmol gap (OG) is a technique that is used frequently in toxic alcohol poisonings (ethylene glycol (EG) and methanol) as a rapid means to estimate exposure, and can be performed in virtually all hospital laboratories. The value of the OG has not been previously evaluated for diethylene glycol (DEG) exposures. The primary objective of this study was to evaluate the utility of the OG in estimating DEG serum concentrations using the most common formula that is currently used for estimating methanol, ethanol, and ethylene glycol concentrations.METHODS: This was a controlled laboratory investigation using serum samples individually spiked with a known quantity of toxic alcohol compared to no toxic alcohol. Test samples were spiked with ethanol, DEG, EG, and methanol. Serum chemistries and osmolality and osmolarity were determined, and the OG was determined for each specimen.RESULTS: The percent error of estimating DEG concentrations of 26.3% was similar to the mean percent error for estimating other alcohol concentrations, 30.5%±5.6% (P〉0.05, 95% confidence interval 16.7%-44.3%).CONCLUSION: The severity of metabolic effects associated with DEG and the need to appropriately determine rescue treatments mandate early detection of significant exposures for effective triage and patient management. Our results indicate that the percent error of the osmol gap method for estimating DEG concentration is similar to that of other toxic alcohols; this simple technique could be a valuable clinical tool, since quantitative DEG analysis is rarely available.
文摘Background There was a hospital outbreak of venous diethylene glycol poisoning in Guangzhou, China. It is the only massive episode of venous diethylene glycol poisoning in history. Here we report its clinical features, laboratory findings, and imaging appearances. Methods The clinical features of 15 venous diethylene glycol poisoning patients with liver disease were analyzed and summarized. Their laboratory findings and imaging appearances were comparatively analyzed before and after poisoning. Results All poisoned patients presented with oliguric acute renal failure with anuria after a mean of 6 days. Carbon dioxide combination power of 13 patients dropped after a mean of 9 days with valley value on the 10th day, when metabolic acidosis developed. Gastroenteric symptoms or aggravation of gastroenteric symptoms were displayed in 11 patients after a mean of 9 days. Neurological system impairment was observed in 10 patients after a mean of 14 days. Seven patients had low fever after a mean of 6 days. Causes of death of 14 patients included multiple organ dysfunction syndrome, severe lung infection and massive haemorrhage of digestive tract. Blood creatinine and urea nitrogen were abnormal after a mean of 5 days with peak value on the 11th and 14th days, respectively. Serum calcium had no obvious change, and phosphorus was distinctively increased. Liver functions did not change significantly. Poisoned patients had higher white blood cell counts, but lower red blood cell counts and hemoglobin value. Of the 7 patients who exhibited mild moderate or severe patchy consolidation shadowing in the lung, 2 manifested mild or severe gaseous distention and dilation of gastroentedc tract. Conclusions Main features of venous diethylene glycol poisoning in patients with liver disease include oliguric acute renal failure, metabolic acidosis, gastroenteric symptoms or aggravation of gastroenteric symptoms, neurological system impairment and low fever, with a mortality rate of 93.33% in poisoned patients. There is also higher white blood cell counts and anemia, patchy consolidation shadowing in the lung, gaseous distention and dilation of gastroenteric tract, which occurs later than mild patchy consolidation shadowing and earlier than moderate patchy consolidation shadowing in the lung.
文摘The binding mechanism between 9-vinyladenine and pyrimidine base thymine in methanol was studied with UV-visible spectrophotometric method. Based on this study, using thymine as a template molecule, 9-vinyladenine as a novel functional monomer and diethylene glycol dimethacrylate as a new cross-linker, a specific diethylene glycol dimethacrylate-based molecularly imprinted polymeric membrane was prepared over a cellulose support. Then, the resultantly polymeric membrane morphologies were visualized with scanning electron microscopy and its permselectivity was examined using thymine, uracil, cytosine, adenine and guanine as substrates. This result showed that the imprinting polymeric membrane prepared with diethylene glycol dimethacrylate exhibited higher transport capacity for the template molecule thymine and its optimal analog uracil than other nucleic acid bases. The membrane also took on higher permselectivity than the imprinted membrane made with ethylene glycol dimethacrylate as a cross-linker. When a mixture including five nucleic acid bases thymine, uracil, cytosine, adenine and guanine passed through the diethylene glycol dimethacrylate-based thymine-imprinted polymeric membrane, recognition of the membrane for the template molecule thymine and its optimal analog uracil was demonstrated. It was predicted that the molecularly imprinted membrane prepared with diethylene glycol dimethacrylate as cross-linker might be applicable to thymine assay of absolute hydrolysates of DNA or uracil assay of absolute hydrolysates of RNA in biological samples because of its high selectivity for the template molecule thymine and its optimal analog uracil.
基金supported by National Natural Science Foundation of China(No.21476162)China International Science and Technology Project(Nos.2012DFG41980,S2016G3413)
文摘The performance of dye-sensitized solar cells(DSSCs) consisting of anatase TiO_2 nanoparticles that were synthesized via a hydrothermal method was studied.The synthesized TiO_2 nanoparticles were characterized by X-ray diffraction(XRD),nitrogen sorption analysis,scanning electron microscopy(SEM),high resolution transmission electron microscopy(HRTEM),and UV-vis spectroscopy.Then the J-Vcurve,electrochemical impedance spectroscopy(EIS),and open-circuit voltage decay(OCVD) measurement were applied to evaluate the photovoltaic performance of DSSCs.Compared with the commercial TiO_2nanoparticles(P25),the synthesized-TiO_2 nanoparticles showed better performance.By adding diethylene glycol(DEG) before the hydrothermal process,the synthesized TiO_2 nanoparticles(hereafter referred to as TiO_2-DEG particles) shows narrower size distribution,larger specific surface area,higher crystallinity,and less surface defects than TiO_2(DEG free) particles.The analysis of photovoltaic properties of DSSCs based on TiO_2-DEG particles showed that the recombination of electron-hole pairs was decreased and the trapping of carries in grain boundaries restrained.It was believed that the photoelectrode fabricated with the as-prepared TiO_2 nanoparticles improved the loading amount of dye sensitizers(N719).and enhanced the photocurrent of the DSSCs.As a result,the TiO_2-DEG particle based cells achieved a photo-to-electricity conversion efficiency(η) of 7.90%,which is higher than 7.53%for the cell based on TiO2(DEG free) and 6.59%for the one fabricated with P25.
文摘The transition metal complexes of triaminoguanidine(TAG-M,where M=Cobalt(Co)or Iron(Fe))have been prepared.The catalytic effect of these complexes on the thermolysis of energetic composite based on nitrocellulose and diethylene glycol dinitrate,has been investigated.Extensive characterization of the resulting energetic composites was carried out using scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and differential scanning calorimetry(DSC).Isoconversional kinetic analysis was performed to determine the Arrhenius parameters associated with the thermolysis of the elaborated energetic formulations.It is found that TAG-M complexes have strong catalytic effect on the thermo-kinetic decomposition of NC/DEGDN by decreasing the apparent activation energy and significantly increased the total heat release.The models that govern the decomposition processes are also studied,and it is revealed that different reaction processes are accomplished by introduction metal complexes of triaminoguanidine.Overall,this study serves as a valuable reference for future research focused on the investigation of catalytic combustion features of solid propellants.