The contents ofMg, Al, Si, Ti, Cr, Mn, Fe, Co, Cu, Ga, As, Se, Cd, Sb, Pb and Bi in high purity nickel were determined by high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS）. The sample was diss...The contents ofMg, Al, Si, Ti, Cr, Mn, Fe, Co, Cu, Ga, As, Se, Cd, Sb, Pb and Bi in high purity nickel were determined by high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS）. The sample was dissolved in HNO3 and HCI by microwave digestion. Most of the spectral interferences could be avoided by measuring in the high resolution mode. The matrix effects because of the presence of excess HC1 and nickel were evaluated. Correction for matrix effects was made using Sc, Rh and T1 as internal standards. The optimum conditions for the determination were tested and discussed. The detection limits range from 0.012 to 1.76 ~tg/g depending on the type of elements. The applicability of the proposed method is also validated by the analysis of high purity nickel reference material （NIST SRM 671）. The relative standard deviation （RSD） is less than 3.3%. Results for determination of trace elements in high purity nickel were presented.展开更多
Most existing network representation learning algorithms focus on network structures for learning.However,network structure is only one kind of view and feature for various networks,and it cannot fully reflect all cha...Most existing network representation learning algorithms focus on network structures for learning.However,network structure is only one kind of view and feature for various networks,and it cannot fully reflect all characteristics of networks.In fact,network vertices usually contain rich text information,which can be well utilized to learn text-enhanced network representations.Meanwhile,Matrix-Forest Index(MFI)has shown its high effectiveness and stability in link prediction tasks compared with other algorithms of link prediction.Both MFI and Inductive Matrix Completion(IMC)are not well applied with algorithmic frameworks of typical representation learning methods.Therefore,we proposed a novel semi-supervised algorithm,tri-party deep network representation learning using inductive matrix completion(TDNR).Based on inductive matrix completion algorithm,TDNR incorporates text features,the link certainty degrees of existing edges and the future link probabilities of non-existing edges into network representations.The experimental results demonstrated that TFNR outperforms other baselines on three real-world datasets.The visualizations of TDNR show that proposed algorithm is more discriminative than other unsupervised approaches.展开更多
A new test method—the load relaxation test after the peak value, was used to investigate rockburst proneness. Two new concepts—fountain and inductive rockbursts, were proposed to distinguish two kinds of rockbursts....A new test method—the load relaxation test after the peak value, was used to investigate rockburst proneness. Two new concepts—fountain and inductive rockbursts, were proposed to distinguish two kinds of rockbursts. The breaking process of rock, mutation condition and occasion of rockburst and source of kinetic energy of rockburst were discussed.展开更多
The contents of Cr, Cu, Ni, As, Cd and Pb in coal fly ash were determined by a high resolution inductively coupled plasma mass spectrometry method. The sample digestions were performed in closed microwave vessels with...The contents of Cr, Cu, Ni, As, Cd and Pb in coal fly ash were determined by a high resolution inductively coupled plasma mass spectrometry method. The sample digestions were performed in closed microwave vessels with HNO3, HClO4 and FIE The optimum conditions for the determination were obtained. The applicability of the proposed method was validated by the analysis of coal fly ash reference material （NIST SRM 1633a）. The results show that most of the spectral interferences can be avoided by measuring in the high resolution mode （maximum mass resolution R=9 000）. The detection limit is from 0.05 to 0.21 μg/g, and the precision is fine with relative standard deviation less than 4.3%.展开更多
An analytical method, using sector field inductively coupled plasma mass spectrometry （SF-ICP-MS） for rapid simultaneous determination of Be, Na, Mg, Si, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, As, Sn, Sb, Pb and Bi in e...An analytical method, using sector field inductively coupled plasma mass spectrometry （SF-ICP-MS） for rapid simultaneous determination of Be, Na, Mg, Si, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, As, Sn, Sb, Pb and Bi in electrolytic manganese metal, was described. At the beginning, the samples were decomposed by HNO3 and H2504, and then analyzed by SF-ICP-MS. Most of the spectral interferences could be avoided by measuring in different mass resolution modes. The matrix effects due to the excess of sulfuric acid and Mn were evaluated. Correction of matrix effects was conducted by using the internal standard elements. The optimum condition for the determination was investigated and discussed. The detection limit is in the range of 0.001-0.169 gg/L. The current method is applied to the determination of trace impurities in electrolytic manganese metal. And experiments show that good results can be obtained much faster, more accurately and conveniently by current method.展开更多
An inductively coupled plasma mass spectrometry(ICP-MS) method was developed for the determination of Na, Mg, Al,K, Ca, Ti, Cr, Co, Ni, Cu, Ga, As, Mo, Ag, Cd and Pb in MnZn ferrites. The sample was digested by HNO3+H...An inductively coupled plasma mass spectrometry(ICP-MS) method was developed for the determination of Na, Mg, Al,K, Ca, Ti, Cr, Co, Ni, Cu, Ga, As, Mo, Ag, Cd and Pb in MnZn ferrites. The sample was digested by HNO3+HCl with microwave digestion followed by dilution with ultrapure water, then the above 16 impurity elements in the solution were analyzed directly by ICP-MS. The impurity elements were introduced by the helium gas or hydrogen gas into the octopole reaction system(ORS) to eliminate the polyatomic interferences caused by the high salty matrixes. The matrix effect was minimized through matrix matching,and Be, Y and Rh were used as internal standard elements. The working parameters of the instrument were optimized. The results show that the method has good precision and high accuracy. The detection limits for the investigated elements are in the range of0.9-37.5 ng/L, the relative standard deviation of each element is within 1.1%-4.8%, and the recovery of each element is 90%-108%.展开更多
A new outboard inductive damping valve without any electronic control system is developed. Its working principle,structure and external characteristic are studied. Its mathematical model is presented and its damping c...A new outboard inductive damping valve without any electronic control system is developed. Its working principle,structure and external characteristic are studied. Its mathematical model is presented and its damping characteristic is investigated on the basis of fluid continuity equation,differential equations of motion and Bernoulli equation. The influence of the valve parameters on the damping characteristic is studied numerically. The effects of outboard inductive damping valve and common damping valve on ride and tire load are compared also. The external characteristic of the valve is verified in bench test. The results show that the valve’s mathematical model is quite accurate and the developed valve can be adjust in two stages,which can also meet the requirements of the dynamic characteristic of the vehicle suspension system.展开更多
OBJECTIVE Cerebral ischemia or ischemic stroke is due to insufficient blood supply to the brain,which causes hypoxia or ischemia in some areas.This work aimed to quantify the minerals and heavy metals in Qishiwei Zhen...OBJECTIVE Cerebral ischemia or ischemic stroke is due to insufficient blood supply to the brain,which causes hypoxia or ischemia in some areas.This work aimed to quantify the minerals and heavy metals in Qishiwei Zhenzhu pill in vivo and in vitro,analyze its effect on the types and abundance of intestinal flora,and study its mechanism on inflammation and apoptosis pathways as a treatment for cerebral ischemia.METHODS Microwave digestion and inductively coupled plasma mass spectrometry(ICP-MS)were used to determine the minerals and heavy metals in 10 batches of Qishiwei Zhenzhu pill in vitro.With the use of the middle cerebral artery obstruction(MCAO)model,ICP-MS was applied to determine the content of minerals and heavy metals in hepatic portal vein blood,abdominal aortic blood,brain,liver,kidney,hair,urine and feces at different time periods.On this model,the ileum,cecum,and colon tissues were tested for intestinal pathology,and 16S rRNA was used for sequencing.Species taxonomy,αdiversity,and species microbial composition and structure analysis were also performed.Polymerase chain reaction and Western blotting were employed to determine the mRNA and protein expression of p38 MAPK,caspase-3,IL^(-1)βand TNF-αin the ischemic brain tissues of rats.RESULTS The average content of heavy metals in the 10 batches of Qishiwei Zhenzhu pill samples is in the descending order Hg>Cu>Pb.Significant differences in the metal elements are found among Qishiwei Zhenzhu pill from different manufacturers but not among the different batches of the same manufacturer.An extremely low content of heavy metals are absorbed into the blood or accumulated in the brain,liver,kidney,and other tissues.Stool is the main excretion route of minerals and heavy metals from Qishiwei Zhenzhu pill.This medicine helps repair the intestinal mucosa in MCAO rats.At the phylum level,it can regulate the abundance of Firmicutes and Proteobacteria in the intestinal flora of rats with cerebral ischemia.At the genus level,it can adjust the abundance of Escherichia Shigella.At the species level,it can adjust the abundance of Lactobacillus yoelii and Lactobacillus reuteri.Cluster classification results show that Qishiwei Zhenzhu pill can improve the intestinal flora of rats with cerebral ischemia,reduce the mRNA and protein expression of caspase-3 and IL^(-1)βin rat brain tissues,and have a tendency to decrease the mRNA expression of p38 MAPK and TNF-α.CONCLUSION Quantifying the minerals and heavy metals in Qishiwei Zhenzhu pill in vivo and in vitro will help improve their quality standards.Minerals and heavy metals are mainly excreted in feces,accumulate in extremely low levels in various tissues,and do not damage the intestinal mucosa.The effective material basis of Qishiwei Zhenzhu pill in treating cerebral ischemia may be related to their Li,Cr,and Cd elements.These pills can improve the environment of intestinal flora,and their mechanism of treatment for cerebral ischemia may be related to the down-regulation of IL^(-1)βinflammatory factor and inhibition of cell apoptosis.展开更多
A transformation of naphthalene-based coalescenced mesophase pitch(NMP)to mesophase microbeads was achieved by heating a mixture of NMP and fullerene(C_(60)).This is different from the conventional process of the liqu...A transformation of naphthalene-based coalescenced mesophase pitch(NMP)to mesophase microbeads was achieved by heating a mixture of NMP and fullerene(C_(60)).This is different from the conventional process of the liquid-phase carbonization of isotropic pitch to the emergence of carbon microbeads in the matrix and finally their growth to form a 100%anisotropic bulk meso-phase,but rather a reverse transformation.The effects of C_(60) loading and reaction temperature on the morphological transformation of mesophase were investigated by polarizing optical and scanning electron microscopies.The physical changes in the NMP induced by C_(60) were characterized by thermogravimetric analysis,Fourier transform infrared spectroscopy,X-ray diffractometry and Raman spectroscopy.The results show that the coalesced NMP can be converted to a spherical type at 300-320℃ with the addition of 5%C_(60),and the size of the mesophase microbeads increases with increasing temperature.Furthermore,a model is established to ex-plain the unique induction effect of C_(60) in the transformation process.This work makes the morphological transformation of MP con-trollable,and provides a new idea for the understanding and research of mesophase pitch.展开更多
Using ultra-fine sample for determination 42 elements by pressurized acid digestion -ICP-MS, the mass of test portion can be reduced to 2 mg yet maintain the representation. And acid used for digestion could be reduce...Using ultra-fine sample for determination 42 elements by pressurized acid digestion -ICP-MS, the mass of test portion can be reduced to 2 mg yet maintain the representation. And acid used for digestion could be reduced to less than 0.5 mL, reaction time also largely reduced.展开更多
Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect trace metal impurities in reagents such as H2O2, HNO3and H2SO4. The limit of detection to metal elements can be down to 2-20 ng/L in H2O2 and HN...Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect trace metal impurities in reagents such as H2O2, HNO3and H2SO4. The limit of detection to metal elements can be down to 2-20 ng/L in H2O2 and HNO3 and 0.1-1.0 ng/L in H2SO4.展开更多
Inductively coupled plasma mass spectrometry (ICP-MS) was applied to determine copper, arsenic, cadmium, lead in athletic food using Sc, Ge, In, Bi as an internal standard. The linear correlation factor for four eleme...Inductively coupled plasma mass spectrometry (ICP-MS) was applied to determine copper, arsenic, cadmium, lead in athletic food using Sc, Ge, In, Bi as an internal standard. The linear correlation factor for four elements are higher than 0.999. Recoveries of spiked samples are in the range of 85.5%-115.5% and precision was fine, RSD is lower than 5.0%. And these are close agreement with the reference values in three standard reference materials of GBW08503, NBS1568, GBW08571. It indicates that the method is simple, rapid, sensitive and accurate, which can meet the demand for copper, arsenic, cadmium, lead analysis in athletic food.展开更多
The isotopic analysis of 232Pu plutonium in 5×10-12 g/g samples using a multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) is described. IRMM-290b and uranium (UTB750) were used to correct th...The isotopic analysis of 232Pu plutonium in 5×10-12 g/g samples using a multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) is described. IRMM-290b and uranium (UTB750) were used to correct the metrical data, and the analytical precision is about 0.5%.展开更多
Six massive ores in the Jinchuan deposit were dated by Re-Os technique. The Os concentrations and isotopic ratios were determined by N-TIMS, while Re and Pt concentrations were determined by ICP-MS. The samples gave a...Six massive ores in the Jinchuan deposit were dated by Re-Os technique. The Os concentrations and isotopic ratios were determined by N-TIMS, while Re and Pt concentrations were determined by ICP-MS. The samples gave an isochron age of (852±25) Ma with an initial 187Os/188Os ratio of 0.255 ± 0.014. A 7-point Pt-Os isochrone gives an age of (870±38) Ma with an initial 186Os/188Os ratio of 0.119 84±0.000 27.展开更多
To improve precision of analytical results of pressurized acid digestion-ICP-MS, the first step is to improve the homogeneity by reducing the particle size of sample. Using of ultra-fine sample (-500 mesh) can reduce ...To improve precision of analytical results of pressurized acid digestion-ICP-MS, the first step is to improve the homogeneity by reducing the particle size of sample. Using of ultra-fine sample (-500 mesh) can reduce the mass of the sample and the acid. The satisfactory precision is achieved at 2 mg sampling mass.展开更多
The application of inductively coupled plasma mass spectrometry (ICP-MS) for determination of boron in water and urine samples was described. The detect limit (3σ) was 0.057 μg/L. The precision of the method was les...The application of inductively coupled plasma mass spectrometry (ICP-MS) for determination of boron in water and urine samples was described. The detect limit (3σ) was 0.057 μg/L. The precision of the method was less than 2%. Multi-elements including Cr, Cu, Cd, Ba, Sr, Mn, Co, Tl, Li, Pb, Ca, Fe, K, Na, Mg, P, Si and Zn could be measured simultaneously. The method was successfully used in practice.展开更多
A method of analysis trace element chloride in cleaning products by Inductively Coupled Plasma-Mass Sepctrometry (ICPMS) was studied. It has good precision (RSD<5%). The LOD is 0.06 μg/L (n=7). The recovery is 93....A method of analysis trace element chloride in cleaning products by Inductively Coupled Plasma-Mass Sepctrometry (ICPMS) was studied. It has good precision (RSD<5%). The LOD is 0.06 μg/L (n=7). The recovery is 93.7%-110.0%.展开更多
In this paper,the determination of six heavy metal ions (arsenic,lead,cadmium,chromium,mercury and nickel) in the Chinese Herb by inductively coupled plasma-mass spectrometry (ICP-MS) was studied.The samples were dige...In this paper,the determination of six heavy metal ions (arsenic,lead,cadmium,chromium,mercury and nickel) in the Chinese Herb by inductively coupled plasma-mass spectrometry (ICP-MS) was studied.The samples were digested by nitric acid and hydrogen peroxide in a microwave oven.The Sc,Y,In,Bi were added as internal standards to eliminate the matrix interferences.The results show that most of the relative standard deviations of these trace elements were below 3.5%,the standard recoveries of these elements were in the range of 91%-107%,and the detection limits were in the range of 0.001-0.006 μg·L-1. This method is accurate,rapid,convenience,and can be applied to the determination of arsenic,lead,cadmium,chromium,mercury and nickel in Chinese Herb with good results.展开更多
基金Project(21075138) supported by the National Natural Science Foundation of ChinaProject(cstc2011jjA0780) supported by Natural Science Foundation of Chongqing City,ChinaProject(KJ121311) supported by Educational Commission of Chongqing City of China
文摘The contents ofMg, Al, Si, Ti, Cr, Mn, Fe, Co, Cu, Ga, As, Se, Cd, Sb, Pb and Bi in high purity nickel were determined by high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS）. The sample was dissolved in HNO3 and HCI by microwave digestion. Most of the spectral interferences could be avoided by measuring in the high resolution mode. The matrix effects because of the presence of excess HC1 and nickel were evaluated. Correction for matrix effects was made using Sc, Rh and T1 as internal standards. The optimum conditions for the determination were tested and discussed. The detection limits range from 0.012 to 1.76 ~tg/g depending on the type of elements. The applicability of the proposed method is also validated by the analysis of high purity nickel reference material （NIST SRM 671）. The relative standard deviation （RSD） is less than 3.3%. Results for determination of trace elements in high purity nickel were presented.
基金Projects(11661069,61763041) supported by the National Natural Science Foundation of ChinaProject(IRT_15R40) supported by Changjiang Scholars and Innovative Research Team in University,ChinaProject(2017TS045) supported by the Fundamental Research Funds for the Central Universities,China
文摘Most existing network representation learning algorithms focus on network structures for learning.However,network structure is only one kind of view and feature for various networks,and it cannot fully reflect all characteristics of networks.In fact,network vertices usually contain rich text information,which can be well utilized to learn text-enhanced network representations.Meanwhile,Matrix-Forest Index(MFI)has shown its high effectiveness and stability in link prediction tasks compared with other algorithms of link prediction.Both MFI and Inductive Matrix Completion(IMC)are not well applied with algorithmic frameworks of typical representation learning methods.Therefore,we proposed a novel semi-supervised algorithm,tri-party deep network representation learning using inductive matrix completion(TDNR).Based on inductive matrix completion algorithm,TDNR incorporates text features,the link certainty degrees of existing edges and the future link probabilities of non-existing edges into network representations.The experimental results demonstrated that TFNR outperforms other baselines on three real-world datasets.The visualizations of TDNR show that proposed algorithm is more discriminative than other unsupervised approaches.
文摘A new test method—the load relaxation test after the peak value, was used to investigate rockburst proneness. Two new concepts—fountain and inductive rockbursts, were proposed to distinguish two kinds of rockbursts. The breaking process of rock, mutation condition and occasion of rockburst and source of kinetic energy of rockburst were discussed.
基金Project (04JJ40016) supported by the Natural Science Foundation of Hunan Province, China
文摘The contents of Cr, Cu, Ni, As, Cd and Pb in coal fly ash were determined by a high resolution inductively coupled plasma mass spectrometry method. The sample digestions were performed in closed microwave vessels with HNO3, HClO4 and FIE The optimum conditions for the determination were obtained. The applicability of the proposed method was validated by the analysis of coal fly ash reference material （NIST SRM 1633a）. The results show that most of the spectral interferences can be avoided by measuring in the high resolution mode （maximum mass resolution R=9 000）. The detection limit is from 0.05 to 0.21 μg/g, and the precision is fine with relative standard deviation less than 4.3%.
基金Project(21075138)supported by the National Natural Science Foundation of ChinaProject(cstc2013jcyjA10088)supported by Chongqing Natural Science Foundation,ChinaProject(KJ121311)supported by Scientific and Technological Research Program of Chongqing Municipal Education Commission,China
文摘An analytical method, using sector field inductively coupled plasma mass spectrometry （SF-ICP-MS） for rapid simultaneous determination of Be, Na, Mg, Si, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, As, Sn, Sb, Pb and Bi in electrolytic manganese metal, was described. At the beginning, the samples were decomposed by HNO3 and H2504, and then analyzed by SF-ICP-MS. Most of the spectral interferences could be avoided by measuring in different mass resolution modes. The matrix effects due to the excess of sulfuric acid and Mn were evaluated. Correction of matrix effects was conducted by using the internal standard elements. The optimum condition for the determination was investigated and discussed. The detection limit is in the range of 0.001-0.169 gg/L. The current method is applied to the determination of trace impurities in electrolytic manganese metal. And experiments show that good results can be obtained much faster, more accurately and conveniently by current method.
基金Project(21271187)supported by the National Natural Science Foundation of ChinaProject(cstc2013jcyj A10088)supported by the Chongqing Natural Science Foundation,China+1 种基金Projects(2013FJ3093,2013SK3268)supported by the Science and Technology Project of Hunan Province,ChinaProject(KJZH14217)supported by Achievement Transfer Education in Chongqing,China
文摘An inductively coupled plasma mass spectrometry(ICP-MS) method was developed for the determination of Na, Mg, Al,K, Ca, Ti, Cr, Co, Ni, Cu, Ga, As, Mo, Ag, Cd and Pb in MnZn ferrites. The sample was digested by HNO3+HCl with microwave digestion followed by dilution with ultrapure water, then the above 16 impurity elements in the solution were analyzed directly by ICP-MS. The impurity elements were introduced by the helium gas or hydrogen gas into the octopole reaction system(ORS) to eliminate the polyatomic interferences caused by the high salty matrixes. The matrix effect was minimized through matrix matching,and Be, Y and Rh were used as internal standard elements. The working parameters of the instrument were optimized. The results show that the method has good precision and high accuracy. The detection limits for the investigated elements are in the range of0.9-37.5 ng/L, the relative standard deviation of each element is within 1.1%-4.8%, and the recovery of each element is 90%-108%.
基金Sponsored by the Major Program of the Chinese Academy of Sciences (QYY2008K012)
文摘A new outboard inductive damping valve without any electronic control system is developed. Its working principle,structure and external characteristic are studied. Its mathematical model is presented and its damping characteristic is investigated on the basis of fluid continuity equation,differential equations of motion and Bernoulli equation. The influence of the valve parameters on the damping characteristic is studied numerically. The effects of outboard inductive damping valve and common damping valve on ride and tire load are compared also. The external characteristic of the valve is verified in bench test. The results show that the valve’s mathematical model is quite accurate and the developed valve can be adjust in two stages,which can also meet the requirements of the dynamic characteristic of the vehicle suspension system.
文摘OBJECTIVE Cerebral ischemia or ischemic stroke is due to insufficient blood supply to the brain,which causes hypoxia or ischemia in some areas.This work aimed to quantify the minerals and heavy metals in Qishiwei Zhenzhu pill in vivo and in vitro,analyze its effect on the types and abundance of intestinal flora,and study its mechanism on inflammation and apoptosis pathways as a treatment for cerebral ischemia.METHODS Microwave digestion and inductively coupled plasma mass spectrometry(ICP-MS)were used to determine the minerals and heavy metals in 10 batches of Qishiwei Zhenzhu pill in vitro.With the use of the middle cerebral artery obstruction(MCAO)model,ICP-MS was applied to determine the content of minerals and heavy metals in hepatic portal vein blood,abdominal aortic blood,brain,liver,kidney,hair,urine and feces at different time periods.On this model,the ileum,cecum,and colon tissues were tested for intestinal pathology,and 16S rRNA was used for sequencing.Species taxonomy,αdiversity,and species microbial composition and structure analysis were also performed.Polymerase chain reaction and Western blotting were employed to determine the mRNA and protein expression of p38 MAPK,caspase-3,IL^(-1)βand TNF-αin the ischemic brain tissues of rats.RESULTS The average content of heavy metals in the 10 batches of Qishiwei Zhenzhu pill samples is in the descending order Hg>Cu>Pb.Significant differences in the metal elements are found among Qishiwei Zhenzhu pill from different manufacturers but not among the different batches of the same manufacturer.An extremely low content of heavy metals are absorbed into the blood or accumulated in the brain,liver,kidney,and other tissues.Stool is the main excretion route of minerals and heavy metals from Qishiwei Zhenzhu pill.This medicine helps repair the intestinal mucosa in MCAO rats.At the phylum level,it can regulate the abundance of Firmicutes and Proteobacteria in the intestinal flora of rats with cerebral ischemia.At the genus level,it can adjust the abundance of Escherichia Shigella.At the species level,it can adjust the abundance of Lactobacillus yoelii and Lactobacillus reuteri.Cluster classification results show that Qishiwei Zhenzhu pill can improve the intestinal flora of rats with cerebral ischemia,reduce the mRNA and protein expression of caspase-3 and IL^(-1)βin rat brain tissues,and have a tendency to decrease the mRNA expression of p38 MAPK and TNF-α.CONCLUSION Quantifying the minerals and heavy metals in Qishiwei Zhenzhu pill in vivo and in vitro will help improve their quality standards.Minerals and heavy metals are mainly excreted in feces,accumulate in extremely low levels in various tissues,and do not damage the intestinal mucosa.The effective material basis of Qishiwei Zhenzhu pill in treating cerebral ischemia may be related to their Li,Cr,and Cd elements.These pills can improve the environment of intestinal flora,and their mechanism of treatment for cerebral ischemia may be related to the down-regulation of IL^(-1)βinflammatory factor and inhibition of cell apoptosis.
文摘A transformation of naphthalene-based coalescenced mesophase pitch(NMP)to mesophase microbeads was achieved by heating a mixture of NMP and fullerene(C_(60)).This is different from the conventional process of the liquid-phase carbonization of isotropic pitch to the emergence of carbon microbeads in the matrix and finally their growth to form a 100%anisotropic bulk meso-phase,but rather a reverse transformation.The effects of C_(60) loading and reaction temperature on the morphological transformation of mesophase were investigated by polarizing optical and scanning electron microscopies.The physical changes in the NMP induced by C_(60) were characterized by thermogravimetric analysis,Fourier transform infrared spectroscopy,X-ray diffractometry and Raman spectroscopy.The results show that the coalesced NMP can be converted to a spherical type at 300-320℃ with the addition of 5%C_(60),and the size of the mesophase microbeads increases with increasing temperature.Furthermore,a model is established to ex-plain the unique induction effect of C_(60) in the transformation process.This work makes the morphological transformation of MP con-trollable,and provides a new idea for the understanding and research of mesophase pitch.
文摘Using ultra-fine sample for determination 42 elements by pressurized acid digestion -ICP-MS, the mass of test portion can be reduced to 2 mg yet maintain the representation. And acid used for digestion could be reduced to less than 0.5 mL, reaction time also largely reduced.
文摘Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect trace metal impurities in reagents such as H2O2, HNO3and H2SO4. The limit of detection to metal elements can be down to 2-20 ng/L in H2O2 and HNO3 and 0.1-1.0 ng/L in H2SO4.
文摘Inductively coupled plasma mass spectrometry (ICP-MS) was applied to determine copper, arsenic, cadmium, lead in athletic food using Sc, Ge, In, Bi as an internal standard. The linear correlation factor for four elements are higher than 0.999. Recoveries of spiked samples are in the range of 85.5%-115.5% and precision was fine, RSD is lower than 5.0%. And these are close agreement with the reference values in three standard reference materials of GBW08503, NBS1568, GBW08571. It indicates that the method is simple, rapid, sensitive and accurate, which can meet the demand for copper, arsenic, cadmium, lead analysis in athletic food.
文摘The isotopic analysis of 232Pu plutonium in 5×10-12 g/g samples using a multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) is described. IRMM-290b and uranium (UTB750) were used to correct the metrical data, and the analytical precision is about 0.5%.
文摘Six massive ores in the Jinchuan deposit were dated by Re-Os technique. The Os concentrations and isotopic ratios were determined by N-TIMS, while Re and Pt concentrations were determined by ICP-MS. The samples gave an isochron age of (852±25) Ma with an initial 187Os/188Os ratio of 0.255 ± 0.014. A 7-point Pt-Os isochrone gives an age of (870±38) Ma with an initial 186Os/188Os ratio of 0.119 84±0.000 27.
文摘To improve precision of analytical results of pressurized acid digestion-ICP-MS, the first step is to improve the homogeneity by reducing the particle size of sample. Using of ultra-fine sample (-500 mesh) can reduce the mass of the sample and the acid. The satisfactory precision is achieved at 2 mg sampling mass.
文摘The application of inductively coupled plasma mass spectrometry (ICP-MS) for determination of boron in water and urine samples was described. The detect limit (3σ) was 0.057 μg/L. The precision of the method was less than 2%. Multi-elements including Cr, Cu, Cd, Ba, Sr, Mn, Co, Tl, Li, Pb, Ca, Fe, K, Na, Mg, P, Si and Zn could be measured simultaneously. The method was successfully used in practice.
文摘A method of analysis trace element chloride in cleaning products by Inductively Coupled Plasma-Mass Sepctrometry (ICPMS) was studied. It has good precision (RSD<5%). The LOD is 0.06 μg/L (n=7). The recovery is 93.7%-110.0%.
文摘In this paper,the determination of six heavy metal ions (arsenic,lead,cadmium,chromium,mercury and nickel) in the Chinese Herb by inductively coupled plasma-mass spectrometry (ICP-MS) was studied.The samples were digested by nitric acid and hydrogen peroxide in a microwave oven.The Sc,Y,In,Bi were added as internal standards to eliminate the matrix interferences.The results show that most of the relative standard deviations of these trace elements were below 3.5%,the standard recoveries of these elements were in the range of 91%-107%,and the detection limits were in the range of 0.001-0.006 μg·L-1. This method is accurate,rapid,convenience,and can be applied to the determination of arsenic,lead,cadmium,chromium,mercury and nickel in Chinese Herb with good results.
