Inductively coupled plasma optical emission spectrometric approach（1CP-OES） is used to determine the potassium content as principal component in pyrotechnic compositions used for fireworks and firecrackers. Element ...Inductively coupled plasma optical emission spectrometric approach（1CP-OES） is used to determine the potassium content as principal component in pyrotechnic compositions used for fireworks and firecrackers. Element of potassium is conunonly found in potassium nitrate and potassium perchlorate in pyrotechnic compositions in fireworks and firecrackers. Statistical analysis shows that potassium nitrate content in pyrotechnics is between 10% to 60% and the potassium perchlorate content is between 20% to 70%,which counted in the content of potassium element is between 4% to 23%. Concept of this method： considering the weight of the sample is 400rag,constant volume is 1L and the concentration of potassium is between 10 mg/L to 90 mg/L in sample solution, the determination scope of the method for the potassium content would be between 1% to 23%.Further experiments proved that the fitting correlation coefficient of potassium calibration curve is 0.9997 or higher, recovery is 89.15%-100.23%.The allowable differential value is 0.4% between two single tests under repeatable conditions. This method can completely satisfy the requirements of the fireworks and firecrackers industry with high accuracy and good precision.展开更多
Inductively coupled plasma optical emission spectrometric approach（ICP-OES）is used to determine the magnesium and aluminum content as principal components in pyrotechnic compositions used for fireworks and firecrack...Inductively coupled plasma optical emission spectrometric approach（ICP-OES）is used to determine the magnesium and aluminum content as principal components in pyrotechnic compositions used for fireworks and firecrackers. Elements of magnesium and aluminum are commonly found in aluminum powder or magnesium-aluminum alloy powder in pyrotechnic compositions in fireworks and firecrackers. Statistical analysis shows that the magnesium content in pyrotechnics is between 8% to 30% and the aluminum content is between 8% to 35%（roughly）.Concept of this method： suppose the weight of the sample is 400rag,constant volume is IL and the concentlation of magnesium and aluminum is between 12mg/L to 160mg/L in sample solution, the determination scope of the method for magnesium and aluminum content would be between 3% to 40%.Further experiments proved that the fitting correlation coefficient of the magnesium calibration curve is 0.9999 or higher, recovery is 101.01% -101.96%.The fitting correlation coefficient of the aluminum calibration curve is 0.9999 or higher, recovery is 99.36%-103.07%. The allowable differential value is 0.4% between two single tests under repeatable conditions. This method can completely satisfy the requirements of the fireworks and firecrackers industry with high accuracy and good precision.展开更多
An experimental setup was built up to carry out radio frequency (RF) inductively coupled plasma (ICP) and dielectric barrier discharge (DBD), and to depict the optical emission spectra (OES) of the discharges. OES fro...An experimental setup was built up to carry out radio frequency (RF) inductively coupled plasma (ICP) and dielectric barrier discharge (DBD), and to depict the optical emission spectra (OES) of the discharges. OES from argon ICP and DBD plasmas in visible and near ultraviolet region were measured. For argon ICP, the higher RF power input (higher than 500 W for our machine), the higher degree of argon plasma ionization. But that doesn't mean a higher mean electron energy. With the increase in the power input, the mean electron energy increases slightly, whereas the density of electron increases apparently On the contrary, argon DBD discharge behaves in the manner of a pulsed DC discharge on optical emission spectroscopy and V-I characteristics. DBD current is composed of a series of pulses equally spaced in temporal domain. The Kinetics of DBD emission strength is mainly governed by the frequency of the current pulse.展开更多
The ion line of 434.8 nm and atom line of 419.8 nm of Ar plasma produced by an inductively coupled plasma （ICP） were measured by optical emission spectroscopy and the influences from the working gas pressure, radio-...The ion line of 434.8 nm and atom line of 419.8 nm of Ar plasma produced by an inductively coupled plasma （ICP） were measured by optical emission spectroscopy and the influences from the working gas pressure, radio-frequency （RF） power and different positions in the discharge chamber on the line intensities were investigated in this study. It was found that the intensity of Ar atom line increased firstly and then saturated with the increase of the pressure. The line intensity of Ar^＋, on the other hand, reached a maximum value and then decreased along with the pressure. The intensity of the line in an RF discharge also demonstrated a jumping mode and a hysteresis phenomenon with the RF power. When the RF power increased to 400 W, the discharge jumped from the E-mode to the H-mode where the line intensity of Ar atom demonstrated a sudden increase, while the intensity of Ar^＋ ion only changed slightly. If the RF power decreased from a high value, e.g., 1000 W, the discharge would jump from the H-mode back to the E-mode at a power of 300 W. At this time the intensities of Ar and Ar^＋ lines would also decrease sharply. It was also noticed in this paper that the intensity of the ion line depended on the detective location in the chamber, namely at the bottom of the chamber the line was more intense than that in the middle of the chamber, but less intense than at the top, which is considered to be related to the capacitance coupling ability of the ICP plasma in different discharge areas.展开更多
The phylogenetic relationship for classification traits and eight mineral elements in brown rice （Oryza sativa L.） from Yunnan Province in China was carried out using microwave assisted digestion followed by inducti...The phylogenetic relationship for classification traits and eight mineral elements in brown rice （Oryza sativa L.） from Yunnan Province in China was carried out using microwave assisted digestion followed by inductively coupled plasma atomic emission spectroscopy, and the analytical procedures were carefully controlled and validated. In general, the results show that the mean levels of K, Ca, Mg, Fe and Cu in brown rice for 789 accessions of rice landraces was distinctly lower than that of improved cultivars. They further demonstrate that Ca plays an important role in the differentiation of subspecies indica-japonica, especially to enhance adaptation of cold stress, and that five mineral elements in brown rice enhance the eurytopicity from landrace to improved cultivar. Hierarchical cluster analysis, using average linkage from SPSS software based on eight mineral elements in brown rice, showed that Yunnan rice could be grouped into rice landrace and improved cultivar, with the rice landrace being further clustered into five subgroups, and that, interestingly, purple rice does not cluster with either of the groups. Our present data confirm that indica is the closest relative of late rice and white rice, and that they constitute rice landraces together, whereas japonica is the closest relatives of non-nuda, early-mid and glutinous rice. It is further shown that japonica, non-nuda, early-mid, glutinous, white and red rice might be more primitive than indica, nuda, late, non-glutinous and purple rice, respectively.展开更多
文摘Inductively coupled plasma optical emission spectrometric approach（1CP-OES） is used to determine the potassium content as principal component in pyrotechnic compositions used for fireworks and firecrackers. Element of potassium is conunonly found in potassium nitrate and potassium perchlorate in pyrotechnic compositions in fireworks and firecrackers. Statistical analysis shows that potassium nitrate content in pyrotechnics is between 10% to 60% and the potassium perchlorate content is between 20% to 70%,which counted in the content of potassium element is between 4% to 23%. Concept of this method： considering the weight of the sample is 400rag,constant volume is 1L and the concentration of potassium is between 10 mg/L to 90 mg/L in sample solution, the determination scope of the method for the potassium content would be between 1% to 23%.Further experiments proved that the fitting correlation coefficient of potassium calibration curve is 0.9997 or higher, recovery is 89.15%-100.23%.The allowable differential value is 0.4% between two single tests under repeatable conditions. This method can completely satisfy the requirements of the fireworks and firecrackers industry with high accuracy and good precision.
文摘Inductively coupled plasma optical emission spectrometric approach（ICP-OES）is used to determine the magnesium and aluminum content as principal components in pyrotechnic compositions used for fireworks and firecrackers. Elements of magnesium and aluminum are commonly found in aluminum powder or magnesium-aluminum alloy powder in pyrotechnic compositions in fireworks and firecrackers. Statistical analysis shows that the magnesium content in pyrotechnics is between 8% to 30% and the aluminum content is between 8% to 35%（roughly）.Concept of this method： suppose the weight of the sample is 400rag,constant volume is IL and the concentlation of magnesium and aluminum is between 12mg/L to 160mg/L in sample solution, the determination scope of the method for magnesium and aluminum content would be between 3% to 40%.Further experiments proved that the fitting correlation coefficient of the magnesium calibration curve is 0.9999 or higher, recovery is 101.01% -101.96%.The fitting correlation coefficient of the aluminum calibration curve is 0.9999 or higher, recovery is 99.36%-103.07%. The allowable differential value is 0.4% between two single tests under repeatable conditions. This method can completely satisfy the requirements of the fireworks and firecrackers industry with high accuracy and good precision.
基金This work is supported by the National Science Foundation of China No.19835030.
文摘An experimental setup was built up to carry out radio frequency (RF) inductively coupled plasma (ICP) and dielectric barrier discharge (DBD), and to depict the optical emission spectra (OES) of the discharges. OES from argon ICP and DBD plasmas in visible and near ultraviolet region were measured. For argon ICP, the higher RF power input (higher than 500 W for our machine), the higher degree of argon plasma ionization. But that doesn't mean a higher mean electron energy. With the increase in the power input, the mean electron energy increases slightly, whereas the density of electron increases apparently On the contrary, argon DBD discharge behaves in the manner of a pulsed DC discharge on optical emission spectroscopy and V-I characteristics. DBD current is composed of a series of pulses equally spaced in temporal domain. The Kinetics of DBD emission strength is mainly governed by the frequency of the current pulse.
基金supported by National Natural Science Foundation of China (Nos.50277003,10505005)
文摘The ion line of 434.8 nm and atom line of 419.8 nm of Ar plasma produced by an inductively coupled plasma （ICP） were measured by optical emission spectroscopy and the influences from the working gas pressure, radio-frequency （RF） power and different positions in the discharge chamber on the line intensities were investigated in this study. It was found that the intensity of Ar atom line increased firstly and then saturated with the increase of the pressure. The line intensity of Ar^＋, on the other hand, reached a maximum value and then decreased along with the pressure. The intensity of the line in an RF discharge also demonstrated a jumping mode and a hysteresis phenomenon with the RF power. When the RF power increased to 400 W, the discharge jumped from the E-mode to the H-mode where the line intensity of Ar atom demonstrated a sudden increase, while the intensity of Ar^＋ ion only changed slightly. If the RF power decreased from a high value, e.g., 1000 W, the discharge would jump from the H-mode back to the E-mode at a power of 300 W. At this time the intensities of Ar and Ar^＋ lines would also decrease sharply. It was also noticed in this paper that the intensity of the ion line depended on the detective location in the chamber, namely at the bottom of the chamber the line was more intense than that in the middle of the chamber, but less intense than at the top, which is considered to be related to the capacitance coupling ability of the ICP plasma in different discharge areas.
基金Supported by the National Natural Science Foundation of China (30660092)the Cooperation Program between Province and Zhejiang University from Yunnan Provincial Scientific and Technology Department (2006YX12)the Yunnan Introduction and Foster Talent Program (2005PY01-14)
文摘The phylogenetic relationship for classification traits and eight mineral elements in brown rice （Oryza sativa L.） from Yunnan Province in China was carried out using microwave assisted digestion followed by inductively coupled plasma atomic emission spectroscopy, and the analytical procedures were carefully controlled and validated. In general, the results show that the mean levels of K, Ca, Mg, Fe and Cu in brown rice for 789 accessions of rice landraces was distinctly lower than that of improved cultivars. They further demonstrate that Ca plays an important role in the differentiation of subspecies indica-japonica, especially to enhance adaptation of cold stress, and that five mineral elements in brown rice enhance the eurytopicity from landrace to improved cultivar. Hierarchical cluster analysis, using average linkage from SPSS software based on eight mineral elements in brown rice, showed that Yunnan rice could be grouped into rice landrace and improved cultivar, with the rice landrace being further clustered into five subgroups, and that, interestingly, purple rice does not cluster with either of the groups. Our present data confirm that indica is the closest relative of late rice and white rice, and that they constitute rice landraces together, whereas japonica is the closest relatives of non-nuda, early-mid and glutinous rice. It is further shown that japonica, non-nuda, early-mid, glutinous, white and red rice might be more primitive than indica, nuda, late, non-glutinous and purple rice, respectively.
