This paper describes an effective method for determining chlordiazepoxide. An excess of sodium tetraphenylboron is added to precipitate chlordiazepoxide in HAc NaAc buffer solution (pH=4.0). After filtering off the p...This paper describes an effective method for determining chlordiazepoxide. An excess of sodium tetraphenylboron is added to precipitate chlordiazepoxide in HAc NaAc buffer solution (pH=4.0). After filtering off the precipitate, the excessive sodium tetraphenylboron in the filtrate is titrated with cetyltrimethylammonium bromide standard solution, with bromophenol blue as indicator. The method is simple and rapid, it has been applied for the determination of chlordiazepoxide raw materials with satisfactory results. The recovery is between 99.58% and 100.4%, the relative error is less than ± 0.50% . Experiments show that the method gives the same results as the approach using nonaqueous titration (ChP).展开更多
Over the past few years, OSL and TCN datings of glacial material from High Asia have come into fashion. To this day, however, these techniques do not permit safe calibration. The intensity of the cosmic ray flux is be...Over the past few years, OSL and TCN datings of glacial material from High Asia have come into fashion. To this day, however, these techniques do not permit safe calibration. The intensity of the cosmic ray flux is being modulated by the solar and terrestrial magnetic fields and their secular fluctuations in the past. So far, these variations cannot be converted into the respective local TCN production rates for High Asia. We have reason to believe that the ages that are being calculated despite these uneertainties are generally overestimated. This assessment is supported by eonventional radiocarbon dates and above＂ all by the glacial chronology developed independently on the basis of the Quaternary geological method. The strongly emerging evidence for a much more extensive LGM glaciation of High Asia is, however, either being ignored or rejected by many authors, solely on the basis of the above-mentioned uncalibrated datings. This self-conceit based on the ＂dating fallacy＂, as we call it, should be avoided since it goes decidedly against the standards of the scientific method established in Quaternary geology and makes a fundamental scientific discussion impossible.展开更多
Iin this paper an isosbestic dual--wavelength spectrophotometric method for the simultaneous determination of zinc and cadmium using meso--tetrakis [4-(trimethylammonium) phenyl] porphine has been developed. The inter...Iin this paper an isosbestic dual--wavelength spectrophotometric method for the simultaneous determination of zinc and cadmium using meso--tetrakis [4-(trimethylammonium) phenyl] porphine has been developed. The interference from excess of reagent was masked by adding lead ions solution.The molar absorptivities (Ae) for zinc and cadmium were 6. 54 × 105 and 4. 27 × 105 L. mol-1. cm-1,respectively. The method could be used to determine zinc and cadmium in synthetic mixtures, and the satisfied results were obtained.展开更多
This paper reviews the development of exchange oscillopolarographic titration research, and focuses on its change in the past 20 years. At different temperatures, indicators, pH, and other situations, exchange oscillo...This paper reviews the development of exchange oscillopolarographic titration research, and focuses on its change in the past 20 years. At different temperatures, indicators, pH, and other situations, exchange oscillopolarographic titration was used to detect phosphorus, silver, lead, thallium, cobalt, nickel, potassium bromate, potassium ferricyanide sodium tetraphenylborate, hydroxyquinoline. It also can be used in the determination of sulfate in extracted phosphoric acid, vitamin C, and trace mercury in industrial waste water. This method is high sensitive and selective. Further it can omit the separating steps, simplify the testing procedures, save analyte samples, and detect the very weak acids and alkalis. Phenomena are obvious and deviation is negligible.展开更多
Aiming at the defects of traditional four-wheel aligner such as many sensors,complex operation and slow detection speed,a fast and accurate 3D four-wheel alignment detection method is studied.Firstly,a new and special...Aiming at the defects of traditional four-wheel aligner such as many sensors,complex operation and slow detection speed,a fast and accurate 3D four-wheel alignment detection method is studied.Firstly,a new and special circle center target board is designed to calibrate the camera,and then the registration of the homography matrix is optimized by using the improved RANSAC(Random sample consensus)algorithm combined with the designed special target board,and the parameters of the wheel alignment system are adjusted by using the space vector principle.Accurate measurements are made to obtain the parameters of the four-wheel alignment.Design a calibration comparison experiment between the traditional target board and the new type of target board,and conduct a comparative test with the existing four-wheel aligner of the depot.The experimental results show that the use of the new target board-binding optimization algorithm can improve the calibration efficiency by about 9%to 21%,while improving the calibration accuracy by about 10.6%to 17.8%.And through the real vehicle test,it is verified that the use of the new target combined with the optimization algorithm can ensure the accuracy and reliability of the four-wheel positioning.This method has a certain significance in the rapid detection of vehicle four-wheel alignment parameters.展开更多
文摘This paper describes an effective method for determining chlordiazepoxide. An excess of sodium tetraphenylboron is added to precipitate chlordiazepoxide in HAc NaAc buffer solution (pH=4.0). After filtering off the precipitate, the excessive sodium tetraphenylboron in the filtrate is titrated with cetyltrimethylammonium bromide standard solution, with bromophenol blue as indicator. The method is simple and rapid, it has been applied for the determination of chlordiazepoxide raw materials with satisfactory results. The recovery is between 99.58% and 100.4%, the relative error is less than ± 0.50% . Experiments show that the method gives the same results as the approach using nonaqueous titration (ChP).
文摘Over the past few years, OSL and TCN datings of glacial material from High Asia have come into fashion. To this day, however, these techniques do not permit safe calibration. The intensity of the cosmic ray flux is being modulated by the solar and terrestrial magnetic fields and their secular fluctuations in the past. So far, these variations cannot be converted into the respective local TCN production rates for High Asia. We have reason to believe that the ages that are being calculated despite these uneertainties are generally overestimated. This assessment is supported by eonventional radiocarbon dates and above＂ all by the glacial chronology developed independently on the basis of the Quaternary geological method. The strongly emerging evidence for a much more extensive LGM glaciation of High Asia is, however, either being ignored or rejected by many authors, solely on the basis of the above-mentioned uncalibrated datings. This self-conceit based on the ＂dating fallacy＂, as we call it, should be avoided since it goes decidedly against the standards of the scientific method established in Quaternary geology and makes a fundamental scientific discussion impossible.
文摘Iin this paper an isosbestic dual--wavelength spectrophotometric method for the simultaneous determination of zinc and cadmium using meso--tetrakis [4-(trimethylammonium) phenyl] porphine has been developed. The interference from excess of reagent was masked by adding lead ions solution.The molar absorptivities (Ae) for zinc and cadmium were 6. 54 × 105 and 4. 27 × 105 L. mol-1. cm-1,respectively. The method could be used to determine zinc and cadmium in synthetic mixtures, and the satisfied results were obtained.
文摘This paper reviews the development of exchange oscillopolarographic titration research, and focuses on its change in the past 20 years. At different temperatures, indicators, pH, and other situations, exchange oscillopolarographic titration was used to detect phosphorus, silver, lead, thallium, cobalt, nickel, potassium bromate, potassium ferricyanide sodium tetraphenylborate, hydroxyquinoline. It also can be used in the determination of sulfate in extracted phosphoric acid, vitamin C, and trace mercury in industrial waste water. This method is high sensitive and selective. Further it can omit the separating steps, simplify the testing procedures, save analyte samples, and detect the very weak acids and alkalis. Phenomena are obvious and deviation is negligible.
基金Anhui Province Key Research and Development Program(No.2022107020012)Shenzhen Science and Technology Innovation Project(No.JSGG20191129102008260)。
文摘Aiming at the defects of traditional four-wheel aligner such as many sensors,complex operation and slow detection speed,a fast and accurate 3D four-wheel alignment detection method is studied.Firstly,a new and special circle center target board is designed to calibrate the camera,and then the registration of the homography matrix is optimized by using the improved RANSAC(Random sample consensus)algorithm combined with the designed special target board,and the parameters of the wheel alignment system are adjusted by using the space vector principle.Accurate measurements are made to obtain the parameters of the four-wheel alignment.Design a calibration comparison experiment between the traditional target board and the new type of target board,and conduct a comparative test with the existing four-wheel aligner of the depot.The experimental results show that the use of the new target board-binding optimization algorithm can improve the calibration efficiency by about 9%to 21%,while improving the calibration accuracy by about 10.6%to 17.8%.And through the real vehicle test,it is verified that the use of the new target combined with the optimization algorithm can ensure the accuracy and reliability of the four-wheel positioning.This method has a certain significance in the rapid detection of vehicle four-wheel alignment parameters.
