Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ ...Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.展开更多
A highly sensitive spectrophotometric method for the determination of siliconwas developed.In the presence of aliphatic alcohol ethoxyehther（AEO-9）,theoptimum condition for quantitative formation of the ion-associat...A highly sensitive spectrophotometric method for the determination of siliconwas developed.In the presence of aliphatic alcohol ethoxyehther（AEO-9）,theoptimum condition for quantitative formation of the ion-association complexof siliconvanadomolybdate blue-Rhodamine 6G in aqueous phase was investigated,The maximum absorption wavelength of the complex was 556 nm.The apparentmolar absorptivity was 2.07×10<sup>5</sup> 1 mol<sup>-1</sup> cm<sup>-1</sup> at 556 nm and Beer’s law wasobeyed in the solution of silicon with concentrations from O to 2.0μg/25ml,This method has been applied to the determination of the amounts of trace siliconin different water samples with satisfactory results.展开更多
A newly isolated bacterium was screened out for its survival on medium with 6 000 mg/L kraft lignin as the sole carbon source and energy, and identified as Pandoraea sp. by 16S rRNA gene sequence analysis. The biodegr...A newly isolated bacterium was screened out for its survival on medium with 6 000 mg/L kraft lignin as the sole carbon source and energy, and identified as Pandoraea sp. by 16S rRNA gene sequence analysis. The biodegradation experiment was carried out in mineral salt medium, containing 5 000 mg/L kraft lignin as only carbon and energy at pH 8.0 and 30℃. Under these conditions, significant reduction in color and lignin content by the strain was observed after incubation for 5 d. The strain attains maximum reduction capability in color （44.6%） and lignin content （39.9%） within 5 d of incubation, and reduced chemical oxygen demand（COD） from initial concentration 7 399 to 3 980 mg/L at maximum reduction level of 46.2% on the 4th day. The total ion chromatograph （TIC） of compounds presented in the chloroform extract of control and bacterial treated samples shows the formation of several lignin-related aromatic compounds including some small molecular lignin fragments, indicating a strong destruction in the lignin structure.展开更多
A simple,specific,accurate and precise spectrophotometric stability indicating method is developed for determination of itraconazole in the presence of its oxidative degradation product and in pharmaceutical formulati...A simple,specific,accurate and precise spectrophotometric stability indicating method is developed for determination of itraconazole in the presence of its oxidative degradation product and in pharmaceutical formulations.A newly developed spectrophotometric method called ratio difference method by measuring the difference in amplitudes between 230 and 265nm of ratio spectra.The calibration curve is linear over the concentration range of 5~25μg·mL-1 with mean percentage recovery of 99.81±1.002.Selective quantification of itraconazole,singly in bulk form,pharmaceutical formulations and in the presence of its oxidative degradation product is demonstrated.The results have been statistically compared with a pharmacopeial method.展开更多
A simple,specific,accurate and precise spectrophotometric stability indicating method is developed for determination of bambuterol hydrochloride(BH)in the presence of its degradation product terbutaline(TERB)and in ph...A simple,specific,accurate and precise spectrophotometric stability indicating method is developed for determination of bambuterol hydrochloride(BH)in the presence of its degradation product terbutaline(TERB)and in pharmaceutical formulations.A newly developed spectrophotometric method called ratio difference method by measuring the difference in amplitudes between 245 and 260nm of ratio spectra.The calibration curves are linear over the concentration range of 0.1~1mg·mL-1 for BH and 0.1~0.7mg·mL-1 for TERB with mean percentage recovery of 100.56±0.751 and 99.88±1.183,respectively.The selectivity of the proposed method is checked using laboratory prepared mixtures.The proposed method has been successfully applied to the analysis of BH in pharmaceutical dosage forms without interference from other dosage form additives and the results have been statistically compared with pharmacopeial method.展开更多
Simultaneous determination of heavy metal cations and accurate quantitative prediction of them are of great interest in analytical chemistry.This work has focused on a comprehensive comparison of partial least squares...Simultaneous determination of heavy metal cations and accurate quantitative prediction of them are of great interest in analytical chemistry.This work has focused on a comprehensive comparison of partial least squares(PLS-1)and artificial neural networks(ANN)as two types of chemometric methods.For this purpose,aluminum,iron and copper were studied as three analytes whose UV-Vis absorption spectra highly overlap each other.Accordance with determined parameters(ligand concentration,pH,waiting times,the relationship between absorbance and concentration of metal ion effect and foreign ions)are provided and the optimum conditions.After establishing the optimum conditions for Fe^(3+),Al^(3+) and Cu^(2+) containing mixtures spectrophotometric determinations and the data calibration method of least squares(PLS-1)regression,and artificial neural network(ANN)methods were used.Chemometric methods are applied in a fast,simple,and the results are applicable.展开更多
基金the financial support provided by the National Natural Science Foundation of China(Grant No.11872013).
文摘Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.
文摘A highly sensitive spectrophotometric method for the determination of siliconwas developed.In the presence of aliphatic alcohol ethoxyehther（AEO-9）,theoptimum condition for quantitative formation of the ion-association complexof siliconvanadomolybdate blue-Rhodamine 6G in aqueous phase was investigated,The maximum absorption wavelength of the complex was 556 nm.The apparentmolar absorptivity was 2.07×10<sup>5</sup> 1 mol<sup>-1</sup> cm<sup>-1</sup> at 556 nm and Beer’s law wasobeyed in the solution of silicon with concentrations from O to 2.0μg/25ml,This method has been applied to the determination of the amounts of trace siliconin different water samples with satisfactory results.
基金Project(50925417) supported by the National Funds for Distinguished Young Scientists,ChinaProject(50830301) supported by the Key program of the National Natural Science Foundation of ChinaProject(2012BAC12B03) supported by the National 12th Five-year Plan for Science and Technology Support,China
文摘A newly isolated bacterium was screened out for its survival on medium with 6 000 mg/L kraft lignin as the sole carbon source and energy, and identified as Pandoraea sp. by 16S rRNA gene sequence analysis. The biodegradation experiment was carried out in mineral salt medium, containing 5 000 mg/L kraft lignin as only carbon and energy at pH 8.0 and 30℃. Under these conditions, significant reduction in color and lignin content by the strain was observed after incubation for 5 d. The strain attains maximum reduction capability in color （44.6%） and lignin content （39.9%） within 5 d of incubation, and reduced chemical oxygen demand（COD） from initial concentration 7 399 to 3 980 mg/L at maximum reduction level of 46.2% on the 4th day. The total ion chromatograph （TIC） of compounds presented in the chloroform extract of control and bacterial treated samples shows the formation of several lignin-related aromatic compounds including some small molecular lignin fragments, indicating a strong destruction in the lignin structure.
文摘A simple,specific,accurate and precise spectrophotometric stability indicating method is developed for determination of itraconazole in the presence of its oxidative degradation product and in pharmaceutical formulations.A newly developed spectrophotometric method called ratio difference method by measuring the difference in amplitudes between 230 and 265nm of ratio spectra.The calibration curve is linear over the concentration range of 5~25μg·mL-1 with mean percentage recovery of 99.81±1.002.Selective quantification of itraconazole,singly in bulk form,pharmaceutical formulations and in the presence of its oxidative degradation product is demonstrated.The results have been statistically compared with a pharmacopeial method.
文摘A simple,specific,accurate and precise spectrophotometric stability indicating method is developed for determination of bambuterol hydrochloride(BH)in the presence of its degradation product terbutaline(TERB)and in pharmaceutical formulations.A newly developed spectrophotometric method called ratio difference method by measuring the difference in amplitudes between 245 and 260nm of ratio spectra.The calibration curves are linear over the concentration range of 0.1~1mg·mL-1 for BH and 0.1~0.7mg·mL-1 for TERB with mean percentage recovery of 100.56±0.751 and 99.88±1.183,respectively.The selectivity of the proposed method is checked using laboratory prepared mixtures.The proposed method has been successfully applied to the analysis of BH in pharmaceutical dosage forms without interference from other dosage form additives and the results have been statistically compared with pharmacopeial method.
文摘Simultaneous determination of heavy metal cations and accurate quantitative prediction of them are of great interest in analytical chemistry.This work has focused on a comprehensive comparison of partial least squares(PLS-1)and artificial neural networks(ANN)as two types of chemometric methods.For this purpose,aluminum,iron and copper were studied as three analytes whose UV-Vis absorption spectra highly overlap each other.Accordance with determined parameters(ligand concentration,pH,waiting times,the relationship between absorbance and concentration of metal ion effect and foreign ions)are provided and the optimum conditions.After establishing the optimum conditions for Fe^(3+),Al^(3+) and Cu^(2+) containing mixtures spectrophotometric determinations and the data calibration method of least squares(PLS-1)regression,and artificial neural network(ANN)methods were used.Chemometric methods are applied in a fast,simple,and the results are applicable.
