In this paper, an algorithm for simulating fluid flow and heat transfer for mold filling of shaped castings is presented. The main features of the algorithm include: 1) a simple but practical technique based on VOF me...In this paper, an algorithm for simulating fluid flow and heat transfer for mold filling of shaped castings is presented. The main features of the algorithm include: 1) a simple but practical technique based on VOF method to determine free surface, 2) an explicit scheme of enthalpy to solve the energy equation more efficiently, and 3) an effective treatment to modify the flux deviation due to pressure iteration. In order to verify these methods, well controlled experiments have been repeatedly done with both water analog and gray iron pouring experiments to record the flow patterns and temperature variations. The calculated results are in accordance with the experimental ones. For the applications, the simulated initial temperature distribution right after mold filling was used to analyse subsequent solidification and to predict shrinkage defects. Actual castings were poured and tested in a foundry plant. The reuslts show that the defects predication with considering fluid flow effects is more precise than that without considering the effects.展开更多
A kind of complex additive mainly containing Al, Mg, F, and O was prepared. The synthetical performances of the property-modified prebaked anodes containing additives were tested in laboratory. On the basis of ideal t...A kind of complex additive mainly containing Al, Mg, F, and O was prepared. The synthetical performances of the property-modified prebaked anodes containing additives were tested in laboratory. On the basis of ideal testing results obtained, a large number of industrial prebaked property-modified anodes are prepared in a large-scale aluminum company. Further more, they are all used in 160 kA prebaked anode aluminum electrolysis cells. The statistic result show that, compared with common anodes, the property-modified ones enhance current by 11.6 kg per ton aluminum averagely.展开更多
Based on the working of Lighthill and Hunt et al., in the present paper the author has established the topological rules adapting to analysing the skin-friction lines and the section streamlines in cascades. These rul...Based on the working of Lighthill and Hunt et al., in the present paper the author has established the topological rules adapting to analysing the skin-friction lines and the section streamlines in cascades. These rules are (1) for a rotor cascade without shroud band, the total number of nodal points equals that the saddle points on the skin-friction line vector fields in eachpitch range; (2) for an annular or straight cascade with no-clearances at blade ends, the total number of saddle points is two more than that of nodal points on the skin-friction line fields in a pitch; (3) the total number of saddles in the secondary flow fields on cross-sections in cascade is one less than that of nodes; (4) in the section streamline vector fields on a meridian surface penetrating a flow passage, and on leading and trailing edge sections, the total number of nodes is equal to that of saddles; (5) on the streamline vector fields of a blade-to-blade surface, the total number of nodes is one less than that of saddles.展开更多
Ⅰ. Introduction Over the past two decades, microwave remote sensing has evolved into a focal point in the remote sensing area. This is due to the fact that in microwave band, we can acquire physical parameters about ...Ⅰ. Introduction Over the past two decades, microwave remote sensing has evolved into a focal point in the remote sensing area. This is due to the fact that in microwave band, we can acquire physical parameters about ocean, terrain and atmosphere on all weather condition. Research and application work about the aerial passive micro wave remote sensors has been done at Changchun Institute of Geography since 1973, under the unitary planning of Academia Sinica. Microwave radiometers of six freqency bands have been developed. Numerous remote sensing experiments were carried out, and large amount of scientific data were accumulated. Recently, theoretical models have展开更多
Historical geographic information system construction echoes the call of academic development in the information era and demonstrates the in-depth advancement of history studies. In recent years, an increasing number ...Historical geographic information system construction echoes the call of academic development in the information era and demonstrates the in-depth advancement of history studies. In recent years, an increasing number of data platforms have been built to facilitate historical information storage, display, management and analysis. In such a context, the geographic information system(GIS) begins to contribute to the study of Chinese history. Its contribution is highlighted in nine areas: historical climate, fluvial landforms, town economies, rural settlements, hydraulic societies, environmental changes, ancient cities, ancient maps and HGIS-enabled research methods. The application of GIS to the study of Chinese history initiates a reform in research methods and at the same time upgrades the philosophy of history studies, facilitating the utilization of a diversity of historical data(documents, ancient maps, remote-sensing images, archaeological information, etc.) for dynamic tracing and multi-factor comprehensive research. At present, restricted by traditional disciplinary boundaries, the construction of HGIS platforms remains slow and insufficient, making it difficult to extensively apply GIS to the study of Chinese history.展开更多
1 Geological Background of Minerlization or Geologic Setting The northeast of Yunnan1 Pb-Zn-Ag-Ge polymetallic ore district is an important part of the southwestern margin of the Yangtze block Sichuan-Yunnan-Guizhou
The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and ...The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions展开更多
"Digital Earth"is one of integrated scientific technology based on development of information technology and modern space telemetry,and it possesses some special features such as application of great amount ..."Digital Earth"is one of integrated scientific technology based on development of information technology and modern space telemetry,and it possesses some special features such as application of great amount of geography data,which can describe the Earth in three dimensions and with higher resolution,i.e."virtual earth":the ordinary user also can readily obtain some information through certain means.Visualization and virtual reality are one展开更多
Systematic experimental studies on partial melting and subsolidus equilibration of three reconstituted spinel-peridotites have been carried out at temperatures ranging from 1000 to 1380℃ and pressures of 1.0 and 1.5 ...Systematic experimental studies on partial melting and subsolidus equilibration of three reconstituted spinel-peridotites have been carried out at temperatures ranging from 1000 to 1380℃ and pressures of 1.0 and 1.5 GPa. The results shows (1) during partial melting, Mg# [=Mg/(Mg+Fe)]and Cr# [=Cr/(Cr-Al)]of spinel increase with an increase in degrees of melting) (2) during subsolidus equilibration, with increasing temperatures, Mg# of spinel increases but Cr# of spinel remains almost unchanged in dunite and increases slightly in Iherzolite and harzburgite. The negative and quasi-linear Mg# -Cr# correlation of spinel represents an isotherm of total non-equilibrium. The same results have been obtained by means of mathematical modelling. It is also proved by Mg# -Cr# correlation of spinel in natural peridotites. As a result of the spinel subsolidus equilibration, only variation of Cr# of spinel is limited, and then Cr# of spinel can be used to estimate the relative degree of melting undergone by host rocks. The bigger Cr# of spinel is, the higher the degree of melting will be. By contrast, during crystallization magma, Mg# and Cr# of spinel decrease with decreasing temperatures. Likewise, Cr# of spinel in basalts may be used to indicate the feature of Cr2O3/Al2O3 of magma, and the compositional zoning of spinel may be used to study the evolution of magma (cooling rate and contamination).展开更多
Patchwork art culture has a long history and is also a kind of aestheticism fashion popular in the internet.Patchwork art of Baijia clothes is taken as the research object,and various application of patchwork art in C...Patchwork art culture has a long history and is also a kind of aestheticism fashion popular in the internet.Patchwork art of Baijia clothes is taken as the research object,and various application of patchwork art in Chinese traditional costumes in past thousand years is explained.As cultural identity of the Chinese nation,patchwork continuously nourishes and enriches world cultural relics.Its application research not only could bring rich inspiration for modern costume art but also has important actual significance and higher historical value.展开更多
The evolution of technology in 1990s resulted in the enormous growth of smartphones and the propagation of mobile applications (App) that marked new opportunities for healthcare centers and medical education. Apps hav...The evolution of technology in 1990s resulted in the enormous growth of smartphones and the propagation of mobile applications (App) that marked new opportunities for healthcare centers and medical education. Apps have altered health services from patient’s health monitoring to specialist’s appointments and consultations from specialized health facilities. It can be argued that a healthy society can bring forth sustainable economic development to its full potential while an unhealthy society cannot. However, a free movement of people, labour and right to residence which was built across East Africa (EA) borders enabled Tanzania and Kenya borders to have enormous interactions. Subsequently, increase the risk of highly communicable diseases such as Tuberculosis and Sexually transmitted infections in such a way that medical attention is unavoidable along the borders. Statistically, Android Operating System (OS) owns 83% of Africa’s mobile OS market. In addition, 25,794,560 internet users reported by Tanzania Communications Regulatory Authority (TCRA) together with the 22.86 million internet users provided by Kenya Digital which is equivalent to 46% and 43% of internet penetration in year 2020, disclose the need for Android mobile application for mapping health facilities both online and offline using Google map API, which will solve residents’ need to healthcare services on the presence or shortage of internet connections;using either Swahili or English language via Smartphone devices. The App incorporates Monitoring and Evaluation (M & E) tool for tracking application usage which will ease Admin’s task to generate daily and monthly reports in Excel and Comma-Separated Values (CSV) formats. The developed system received positive feedback from EA citizens and residents in the Arusha region and Namanga border crossing where 90.2% of the system evaluation conducted between Dec 2020 and Apr 2021 agreed upon App usage.展开更多
Bluetooth technology emerged over twenty years ago and has continuously improved throughout the years to meet diverse and complex applications. Initially invented to replace the need for physical data cables, Bluetoot...Bluetooth technology emerged over twenty years ago and has continuously improved throughout the years to meet diverse and complex applications. Initially invented to replace the need for physical data cables, Bluetooth offers users a quick and easy way to share data files over a wireless network. Traffic engineers and transportation engineering researchers have utilized the potential opportunities that exist with Bluetooth and have implemented this technology into traffic monitoring techniques. To gain a better understanding of Bluetooth sensors and how they work, a comprehensive literature search was conducted. Twenty-five articles were studied regarding case studies of Bluetooth sensor implementation for travel time measurement. Besides reviewing the literature and previous case studies, three new case studies in the State of Delaware, USA, were also conducted and carefully analyzed. The benefits and drawbacks associated with Bluetooth technology for travel time measurements have been identified in this paper. The overall conclusion of the authors is Bluetooth alone and by itself is not a proper technology for travel time measurements. More studies need to be conducted on the accuracy and overall application, before one can confidently utilize the Bluetooth technology for travel time measurements.展开更多
In the presence of ethyl alcohol or emulsifier OP,molybdenum(Ⅵ) forms 1∶1∶1'water soluble colored coordination com- pound with both of 2-(2-thiazolylazo)-5-diethylaminophenol (abbreviation TAE) and hydroxylamin...In the presence of ethyl alcohol or emulsifier OP,molybdenum(Ⅵ) forms 1∶1∶1'water soluble colored coordination com- pound with both of 2-(2-thiazolylazo)-5-diethylaminophenol (abbreviation TAE) and hydroxylamine.This deep blue coordination compound is inert characteristically and remains stable in 1.7 mol/L sulfuric acid,2.4 mol/L hydrochloric or ni- tric acid.It will not be decomposed by masking agents even on boiled,while in that case,almost all the colored coordination com- pounds formed by other metal ions will be decomposed completely.This inert character of the coordination compound of molybdenum(Ⅵ) and its utilization in improving the analytical selectivity have been discussed.In the coexistence of various for- eign ions,especially in the presence of a great quantity of tungsten,which always interferes with the determination of molybdenum,the direct determination of molybdenum in the aqueous solution by applying this system has shown an acceptable sensitivity and reproducibility.From the results of determination in some synthetic and standard samples,it seems feasible to use this system in the determination of molybdenum in nonferrous alloys.展开更多
The electroanalytical behaviour of xanthophyll was studied by differential pulse polarography and cyclic voltammetry.The reduction wave of xanthophyll at -0.92V(v.s.Ag/AgCl)in 1.25% tetrabutyl ammonium chloride soluti...The electroanalytical behaviour of xanthophyll was studied by differential pulse polarography and cyclic voltammetry.The reduction wave of xanthophyll at -0.92V(v.s.Ag/AgCl)in 1.25% tetrabutyl ammonium chloride solution(TBAC)was found for the first time.The optimum conditions for the determination of xanthophyll by DPP were established. The results from the application of cyclic voltammetry to study electrode process behaviour showed that the electrode reaction of xanthophyll at a hanging mercury electrode is quasi-reversible reaction.展开更多
This paper reports a new chemiluminescence system i.e.luminol- H_2O_2-IO_4^- catalyzed by sulphide ion(S^(2-)).Based on this catalysis,a new chemiluminescence(CL)method for the determination of trace S^(2-)is pro- pos...This paper reports a new chemiluminescence system i.e.luminol- H_2O_2-IO_4^- catalyzed by sulphide ion(S^(2-)).Based on this catalysis,a new chemiluminescence(CL)method for the determination of trace S^(2-)is pro- posed.The detection limit is 0.2μg/LS^(2-),the linear dynamic range is 5μg to 100βμg/L S^(2-)and the variation coefficient at an sulphide concentration of 100μg/L S^(2-)is 4.5%(n=10).The method has been satisfactory applied to the determination of trace sulphide ion in water.展开更多
A new highly sensitive spectrophotometric method has been developed for the determination of micro amounts of bismuth (Ⅲ), based on the formation of Bi (Ⅲ)—meso—tetrakis—(4—N—trimethylammonium phenyl) porphine ...A new highly sensitive spectrophotometric method has been developed for the determination of micro amounts of bismuth (Ⅲ), based on the formation of Bi (Ⅲ)—meso—tetrakis—(4—N—trimethylammonium phenyl) porphine [T (4TMAP) P] complex. In the presence of Cd (Ⅱ), Bi(Ⅲ) reacts almost instantaneously with T (4TMAP)P in a 0. 6 mol/l NaAc—HAC buffer (PH5.8) at room temperature. The composition of the complex is T(4TMAP)P: Bi=1:1. The absorbance complex obeys Beer's law over the Bi(Ⅲ) concentration range 0.1—1.4 μg/ml. The linear relative coefficient γ is 0.9998. The apparent molar absorptivity was 1.75×10~5 1. mol^(-1). cm^(-1) at 463nm. The relative standard deviation of the method is 1.50％ for Bi(Ⅲ) 7ug/10ml (10 determinations). The interference of foreign ions has been examined. This simple and rapid method can be applied to the assay of Bi(Ⅲ) in some tablets directly.展开更多
For the first time,fullerenes are applied to the study on the interface between two immisible electrolyte solutions.Experiments show they are a new kind of inhibitors. Obvious inhibitive behavior to the TMA^+ transfer...For the first time,fullerenes are applied to the study on the interface between two immisible electrolyte solutions.Experiments show they are a new kind of inhibitors. Obvious inhibitive behavior to the TMA^+ transfer across the water/nitrobenzene interface is observed.展开更多
A europium chelate of 5-chlorosulfoyl-2- thenoyltrifluoroacetone(CTTA)was investigated for precolumn derivatization of protein for high performance liquid chromatography.This new label was highly fluorescent and suita...A europium chelate of 5-chlorosulfoyl-2- thenoyltrifluoroacetone(CTTA)was investigated for precolumn derivatization of protein for high performance liquid chromatography.This new label was highly fluorescent and suitable for time-resolved fluorometric detection.The detective limit of protein is less than 0.3ug in sample with a volume of 100ul.Theoretically,the new label can also be used in gel electrophoresis and protein blotting.展开更多
The present paper reports a novel chemiluminescence,i.e,isopropyl alcohol-C10^--H_2O_2 system.The chemiluminescence intensity is proportional to the concentration of C10^- within certain range.Based on this fact,a new...The present paper reports a novel chemiluminescence,i.e,isopropyl alcohol-C10^--H_2O_2 system.The chemiluminescence intensity is proportional to the concentration of C10^- within certain range.Based on this fact,a new chemiluminescence method for the determination of micro amount of C10^- has been developed.The detection limit is 2.6 x 10^(-8)g/ml C10^- and the dynamic linear range is 2.6 x 10^(-8)g/ml to 2.3 x 10^(-5)g/ml C10^-.The method has good selectivlty and reproducibility.展开更多
文摘In this paper, an algorithm for simulating fluid flow and heat transfer for mold filling of shaped castings is presented. The main features of the algorithm include: 1) a simple but practical technique based on VOF method to determine free surface, 2) an explicit scheme of enthalpy to solve the energy equation more efficiently, and 3) an effective treatment to modify the flux deviation due to pressure iteration. In order to verify these methods, well controlled experiments have been repeatedly done with both water analog and gray iron pouring experiments to record the flow patterns and temperature variations. The calculated results are in accordance with the experimental ones. For the applications, the simulated initial temperature distribution right after mold filling was used to analyse subsequent solidification and to predict shrinkage defects. Actual castings were poured and tested in a foundry plant. The reuslts show that the defects predication with considering fluid flow effects is more precise than that without considering the effects.
文摘A kind of complex additive mainly containing Al, Mg, F, and O was prepared. The synthetical performances of the property-modified prebaked anodes containing additives were tested in laboratory. On the basis of ideal testing results obtained, a large number of industrial prebaked property-modified anodes are prepared in a large-scale aluminum company. Further more, they are all used in 160 kA prebaked anode aluminum electrolysis cells. The statistic result show that, compared with common anodes, the property-modified ones enhance current by 11.6 kg per ton aluminum averagely.
文摘Based on the working of Lighthill and Hunt et al., in the present paper the author has established the topological rules adapting to analysing the skin-friction lines and the section streamlines in cascades. These rules are (1) for a rotor cascade without shroud band, the total number of nodal points equals that the saddle points on the skin-friction line vector fields in eachpitch range; (2) for an annular or straight cascade with no-clearances at blade ends, the total number of saddle points is two more than that of nodal points on the skin-friction line fields in a pitch; (3) the total number of saddles in the secondary flow fields on cross-sections in cascade is one less than that of nodes; (4) in the section streamline vector fields on a meridian surface penetrating a flow passage, and on leading and trailing edge sections, the total number of nodes is equal to that of saddles; (5) on the streamline vector fields of a blade-to-blade surface, the total number of nodes is one less than that of saddles.
文摘Ⅰ. Introduction Over the past two decades, microwave remote sensing has evolved into a focal point in the remote sensing area. This is due to the fact that in microwave band, we can acquire physical parameters about ocean, terrain and atmosphere on all weather condition. Research and application work about the aerial passive micro wave remote sensors has been done at Changchun Institute of Geography since 1973, under the unitary planning of Academia Sinica. Microwave radiometers of six freqency bands have been developed. Numerous remote sensing experiments were carried out, and large amount of scientific data were accumulated. Recently, theoretical models have
基金a staged research result of “Silk Road-themed Historical Geographic Information System Construction”(14ZDB031)a major program funded by National Social Sciences Fund
文摘Historical geographic information system construction echoes the call of academic development in the information era and demonstrates the in-depth advancement of history studies. In recent years, an increasing number of data platforms have been built to facilitate historical information storage, display, management and analysis. In such a context, the geographic information system(GIS) begins to contribute to the study of Chinese history. Its contribution is highlighted in nine areas: historical climate, fluvial landforms, town economies, rural settlements, hydraulic societies, environmental changes, ancient cities, ancient maps and HGIS-enabled research methods. The application of GIS to the study of Chinese history initiates a reform in research methods and at the same time upgrades the philosophy of history studies, facilitating the utilization of a diversity of historical data(documents, ancient maps, remote-sensing images, archaeological information, etc.) for dynamic tracing and multi-factor comprehensive research. At present, restricted by traditional disciplinary boundaries, the construction of HGIS platforms remains slow and insufficient, making it difficult to extensively apply GIS to the study of Chinese history.
文摘1 Geological Background of Minerlization or Geologic Setting The northeast of Yunnan1 Pb-Zn-Ag-Ge polymetallic ore district is an important part of the southwestern margin of the Yangtze block Sichuan-Yunnan-Guizhou
文摘The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions
文摘"Digital Earth"is one of integrated scientific technology based on development of information technology and modern space telemetry,and it possesses some special features such as application of great amount of geography data,which can describe the Earth in three dimensions and with higher resolution,i.e."virtual earth":the ordinary user also can readily obtain some information through certain means.Visualization and virtual reality are one
文摘Systematic experimental studies on partial melting and subsolidus equilibration of three reconstituted spinel-peridotites have been carried out at temperatures ranging from 1000 to 1380℃ and pressures of 1.0 and 1.5 GPa. The results shows (1) during partial melting, Mg# [=Mg/(Mg+Fe)]and Cr# [=Cr/(Cr-Al)]of spinel increase with an increase in degrees of melting) (2) during subsolidus equilibration, with increasing temperatures, Mg# of spinel increases but Cr# of spinel remains almost unchanged in dunite and increases slightly in Iherzolite and harzburgite. The negative and quasi-linear Mg# -Cr# correlation of spinel represents an isotherm of total non-equilibrium. The same results have been obtained by means of mathematical modelling. It is also proved by Mg# -Cr# correlation of spinel in natural peridotites. As a result of the spinel subsolidus equilibration, only variation of Cr# of spinel is limited, and then Cr# of spinel can be used to estimate the relative degree of melting undergone by host rocks. The bigger Cr# of spinel is, the higher the degree of melting will be. By contrast, during crystallization magma, Mg# and Cr# of spinel decrease with decreasing temperatures. Likewise, Cr# of spinel in basalts may be used to indicate the feature of Cr2O3/Al2O3 of magma, and the compositional zoning of spinel may be used to study the evolution of magma (cooling rate and contamination).
文摘Patchwork art culture has a long history and is also a kind of aestheticism fashion popular in the internet.Patchwork art of Baijia clothes is taken as the research object,and various application of patchwork art in Chinese traditional costumes in past thousand years is explained.As cultural identity of the Chinese nation,patchwork continuously nourishes and enriches world cultural relics.Its application research not only could bring rich inspiration for modern costume art but also has important actual significance and higher historical value.
文摘The evolution of technology in 1990s resulted in the enormous growth of smartphones and the propagation of mobile applications (App) that marked new opportunities for healthcare centers and medical education. Apps have altered health services from patient’s health monitoring to specialist’s appointments and consultations from specialized health facilities. It can be argued that a healthy society can bring forth sustainable economic development to its full potential while an unhealthy society cannot. However, a free movement of people, labour and right to residence which was built across East Africa (EA) borders enabled Tanzania and Kenya borders to have enormous interactions. Subsequently, increase the risk of highly communicable diseases such as Tuberculosis and Sexually transmitted infections in such a way that medical attention is unavoidable along the borders. Statistically, Android Operating System (OS) owns 83% of Africa’s mobile OS market. In addition, 25,794,560 internet users reported by Tanzania Communications Regulatory Authority (TCRA) together with the 22.86 million internet users provided by Kenya Digital which is equivalent to 46% and 43% of internet penetration in year 2020, disclose the need for Android mobile application for mapping health facilities both online and offline using Google map API, which will solve residents’ need to healthcare services on the presence or shortage of internet connections;using either Swahili or English language via Smartphone devices. The App incorporates Monitoring and Evaluation (M & E) tool for tracking application usage which will ease Admin’s task to generate daily and monthly reports in Excel and Comma-Separated Values (CSV) formats. The developed system received positive feedback from EA citizens and residents in the Arusha region and Namanga border crossing where 90.2% of the system evaluation conducted between Dec 2020 and Apr 2021 agreed upon App usage.
文摘Bluetooth technology emerged over twenty years ago and has continuously improved throughout the years to meet diverse and complex applications. Initially invented to replace the need for physical data cables, Bluetooth offers users a quick and easy way to share data files over a wireless network. Traffic engineers and transportation engineering researchers have utilized the potential opportunities that exist with Bluetooth and have implemented this technology into traffic monitoring techniques. To gain a better understanding of Bluetooth sensors and how they work, a comprehensive literature search was conducted. Twenty-five articles were studied regarding case studies of Bluetooth sensor implementation for travel time measurement. Besides reviewing the literature and previous case studies, three new case studies in the State of Delaware, USA, were also conducted and carefully analyzed. The benefits and drawbacks associated with Bluetooth technology for travel time measurements have been identified in this paper. The overall conclusion of the authors is Bluetooth alone and by itself is not a proper technology for travel time measurements. More studies need to be conducted on the accuracy and overall application, before one can confidently utilize the Bluetooth technology for travel time measurements.
文摘In the presence of ethyl alcohol or emulsifier OP,molybdenum(Ⅵ) forms 1∶1∶1'water soluble colored coordination com- pound with both of 2-(2-thiazolylazo)-5-diethylaminophenol (abbreviation TAE) and hydroxylamine.This deep blue coordination compound is inert characteristically and remains stable in 1.7 mol/L sulfuric acid,2.4 mol/L hydrochloric or ni- tric acid.It will not be decomposed by masking agents even on boiled,while in that case,almost all the colored coordination com- pounds formed by other metal ions will be decomposed completely.This inert character of the coordination compound of molybdenum(Ⅵ) and its utilization in improving the analytical selectivity have been discussed.In the coexistence of various for- eign ions,especially in the presence of a great quantity of tungsten,which always interferes with the determination of molybdenum,the direct determination of molybdenum in the aqueous solution by applying this system has shown an acceptable sensitivity and reproducibility.From the results of determination in some synthetic and standard samples,it seems feasible to use this system in the determination of molybdenum in nonferrous alloys.
文摘The electroanalytical behaviour of xanthophyll was studied by differential pulse polarography and cyclic voltammetry.The reduction wave of xanthophyll at -0.92V(v.s.Ag/AgCl)in 1.25% tetrabutyl ammonium chloride solution(TBAC)was found for the first time.The optimum conditions for the determination of xanthophyll by DPP were established. The results from the application of cyclic voltammetry to study electrode process behaviour showed that the electrode reaction of xanthophyll at a hanging mercury electrode is quasi-reversible reaction.
文摘This paper reports a new chemiluminescence system i.e.luminol- H_2O_2-IO_4^- catalyzed by sulphide ion(S^(2-)).Based on this catalysis,a new chemiluminescence(CL)method for the determination of trace S^(2-)is pro- posed.The detection limit is 0.2μg/LS^(2-),the linear dynamic range is 5μg to 100βμg/L S^(2-)and the variation coefficient at an sulphide concentration of 100μg/L S^(2-)is 4.5%(n=10).The method has been satisfactory applied to the determination of trace sulphide ion in water.
文摘A new highly sensitive spectrophotometric method has been developed for the determination of micro amounts of bismuth (Ⅲ), based on the formation of Bi (Ⅲ)—meso—tetrakis—(4—N—trimethylammonium phenyl) porphine [T (4TMAP) P] complex. In the presence of Cd (Ⅱ), Bi(Ⅲ) reacts almost instantaneously with T (4TMAP)P in a 0. 6 mol/l NaAc—HAC buffer (PH5.8) at room temperature. The composition of the complex is T(4TMAP)P: Bi=1:1. The absorbance complex obeys Beer's law over the Bi(Ⅲ) concentration range 0.1—1.4 μg/ml. The linear relative coefficient γ is 0.9998. The apparent molar absorptivity was 1.75×10~5 1. mol^(-1). cm^(-1) at 463nm. The relative standard deviation of the method is 1.50％ for Bi(Ⅲ) 7ug/10ml (10 determinations). The interference of foreign ions has been examined. This simple and rapid method can be applied to the assay of Bi(Ⅲ) in some tablets directly.
文摘For the first time,fullerenes are applied to the study on the interface between two immisible electrolyte solutions.Experiments show they are a new kind of inhibitors. Obvious inhibitive behavior to the TMA^+ transfer across the water/nitrobenzene interface is observed.
文摘A europium chelate of 5-chlorosulfoyl-2- thenoyltrifluoroacetone(CTTA)was investigated for precolumn derivatization of protein for high performance liquid chromatography.This new label was highly fluorescent and suitable for time-resolved fluorometric detection.The detective limit of protein is less than 0.3ug in sample with a volume of 100ul.Theoretically,the new label can also be used in gel electrophoresis and protein blotting.
文摘The present paper reports a novel chemiluminescence,i.e,isopropyl alcohol-C10^--H_2O_2 system.The chemiluminescence intensity is proportional to the concentration of C10^- within certain range.Based on this fact,a new chemiluminescence method for the determination of micro amount of C10^- has been developed.The detection limit is 2.6 x 10^(-8)g/ml C10^- and the dynamic linear range is 2.6 x 10^(-8)g/ml to 2.3 x 10^(-5)g/ml C10^-.The method has good selectivlty and reproducibility.
