A series of glucose derivatives have been used as chelating reagents to extract metal ions in supercritical carbon dioxide. With perfluoro-l-octanesulfonic acid tetraethylammonium salt as additive, glucose derivatives...A series of glucose derivatives have been used as chelating reagents to extract metal ions in supercritical carbon dioxide. With perfluoro-l-octanesulfonic acid tetraethylammonium salt as additive, glucose derivatives were selective for Sr^2+ and Pb^2+ extraction in supercritical carbon dioxide.展开更多
Rechargeable aqueous zinc ion batteries(AZIBs)were considered as one of the most promising candidates for large-scale energy storage due to the merits of high safety and inexpensiveness.As AZIBs cathode material,Mn O_...Rechargeable aqueous zinc ion batteries(AZIBs)were considered as one of the most promising candidates for large-scale energy storage due to the merits of high safety and inexpensiveness.As AZIBs cathode material,Mn O_(2)possesses great merits but was greatly hindered due to the sluggish diffusion kinetic of Zn^(2+) during electrochemical operations.Herein,deep Zn^(2+) ions intercalatedδ-Mn O_(2)(Zn-Mn O_(2))was achieved by the in situ electrochemical deposition route,which significantly enhanced the diffusion ability of Zn^(2+) due to the synergistic effects of Zn^(2+) pillars and structural H;O.The resultant Zn-Mn O_(2)based AZIBs delivers a record capacity of 696 m Ah/g(0.5 m Ah/cm^(2))based on the initial mass loading,which is approaching the theoretical capacity of Mn O_(2)with a two-electrons reaction.In-situ Raman studies reveal highly reversible Zn^(2+)ions insertion/extraction behaviors and here the Zn-Mn O_(2)plays the role of a container during the charge–discharge process.Further charge storage mechanism investigations point out the insertion/extraction of Zn^(2+) and H^(+) coincides,and such process is significantly facilitated results from superior interlayered configurations of Zn-Mn O_(2)The excellent electrochemical performance of Zn-Mn O_(2)achieved in this work suggests the deep ions pre-intercalation strategy may aid in the future development of advanced cathodes for AZIBs.展开更多
1 Introduction As the lightest metal with the unique properties of energy production and storage,lithium is regarded as the new century energy metal.Lithium and its compounds were widely used in various industrial fie...1 Introduction As the lightest metal with the unique properties of energy production and storage,lithium is regarded as the new century energy metal.Lithium and its compounds were widely used in various industrial fields,especially in展开更多
For plasma source, the extraction of negative ions is quite different from that of positive ions. To understand the effect of extraction field on plasma, the time-dependent behavior of negative hydrogen ion extraction...For plasma source, the extraction of negative ions is quite different from that of positive ions. To understand the effect of extraction field on plasma, the time-dependent behavior of negative hydrogen ion extraction from a negative ion source has been studied by particle-in-cell simulation in the collisionless limit. The simulations have shown that, due to the difference in dynamics between electrons and ions, the imbalance of the numbers of charged particles occurs in the source, results in the broadening of plasma sheath and the great increase of plasma potential. The resultant high sheath field and the ambipolar electric field in plasma make the negatively charged particles congregate inside the sheath and move toward the extraction outlet. The emission area of negative ions is much smaller than that of the extraction aperture, which is in sharp contrast to the case of positive ion extraction.展开更多
A new type of calixarenes containing amino acid ester derivatives has been synthesized. Their 1H NMR characteristics are discussed. Metal ion extraction experiment has shown that calixarene amino acid esters (2a...A new type of calixarenes containing amino acid ester derivatives has been synthesized. Their 1H NMR characteristics are discussed. Metal ion extraction experiment has shown that calixarene amino acid esters (2a, 2b) possess good extraction efficiency for transition metal ions (Cu 2+ , Ni 2+ , Zn 2+ ) and poor extraction efficiency for alkali metal ions (Na +, K +).展开更多
A new thee-dimensional code, ion optics simulator (IOS), to simulate ion beam extraction is developed in visual C++ language. The theoretical model, the flowchart of code, and the results of calculation as an exam...A new thee-dimensional code, ion optics simulator (IOS), to simulate ion beam extraction is developed in visual C++ language. The theoretical model, the flowchart of code, and the results of calculation as an example are presented.展开更多
In order to study the key technology and physics of RF driven negative ion source for neutral beam injector in China, the Hefei utility negative ions test equipment with RF source was developed at Institute of Plasma ...In order to study the key technology and physics of RF driven negative ion source for neutral beam injector in China, the Hefei utility negative ions test equipment with RF source was developed at Institute of Plasma Physics, Chinese Academy of Sciences(ASIPP). Its negative ion source can be equipped with single or double RF drivers. There is a plasma expansion chamber with depth of 19 mm and an enhanced filter field. A three electrodes negative ion accelerator was employed to extract and accelerate the negative ions, which are plasma grid,extraction grid and ground grid. And there are several diagnostic tools for the plasma and beam parameters measurement. The characteristics of plasma generation, negative ion production and extraction were studied on the test equipment. The negative ion beam was extracted from the RF driven negative ion source for the first time. The detailed structure and main results are presented in this article.展开更多
Ionic liquids as green solvents have shown important application in the extraction and separation of nonferrous metals.The new application perspective,the important fundamental and the applied studies of the extractio...Ionic liquids as green solvents have shown important application in the extraction and separation of nonferrous metals.The new application perspective,the important fundamental and the applied studies of the extraction and separation of nonferrous metals in ionic liquids,including the dissolution and corrosion of metal and metal oxide,hydrometallurgy of chalcopyrite and metallic oxidized ore,and extraction and separation of metal ions,are introduced.展开更多
Manganese dioxide(MnO_(2)) is considered as a potential cathode material for aqueous magnesium-ion batteries. However, the charge/discharge mechanism of MnO_(2)in aqueous electrolyte is still unclear. In present study...Manganese dioxide(MnO_(2)) is considered as a potential cathode material for aqueous magnesium-ion batteries. However, the charge/discharge mechanism of MnO_(2)in aqueous electrolyte is still unclear. In present study, highly porous δ-MnO_(2) is investigated, which delivers a high capacity of 252.1 m Ah g^(-1) at 0.05 A g^(-1) and excellent rate capability, i.e., 109.7 m Ah g^(-1) at 1 A g^(-1), but a low-capacity retention of 54.4% after 800 cycles at 1 A g^(-1). The two-step discharging process, namely a consequent H^(+) and Mg^(2+) insertion reaction, is verified, by comparing the electrochemical performance of δ-MnO_(2) in 1 M MgCl_(2) and 1 M MnCl_(2) aqueous electrolyte and analyzing detailedly the Mg content and the bonding state of Mn at different charge/discharge state. Furthermore, partial irreversibility of Mg^(-1) ion insertion/extraction is observed, which may be one of the major reasons leading to capacity decay.展开更多
Effective extraction and regeneration of radioactive iodide is one of urgent concerns for the safe utilization of nuclear energy.As a novel environmentally benign ion separation technique,electrochemically switched io...Effective extraction and regeneration of radioactive iodide is one of urgent concerns for the safe utilization of nuclear energy.As a novel environmentally benign ion separation technique,electrochemically switched ion extraction(ESIE)process can be applied for effective capture and recovery of iodide ions(I^(-)).Herein,a novel kelp seaweed-like core/shell I^(-)imprinted polypyrrole@bismuth oxyiodide(PPy/I^(-)@BiOI)composite film is successfully prepared for the selective I^(-)capture in the ESIE system.It is found that the I^(-)can be easily trapped in the PPy/I^(-)@BiOI film after I^(-)is in situ desorbed from the film by an electrochemical reduction process since it offers particular electroactive binding sites for I^(-)extraction.The I^(-)imprinted PPy/I^(-)@BiOI film displays an extraction capacity as high as 325.2 mg·g^(-1)for I^(-)with favorable stability.In particular,the extraction and desorption of I^(-)is achieved by adjusting the redox potential and the pristine PPy/I^(-)@BiOI film can be regenerated and reused for multiple times without decrease in extraction capacity.It is expected that such a PPy/I^(-)@BiOI film would be useful as an electrochemically switched renewable extractor that could capture and regenerate I^(-)from radioactive water.展开更多
Novel macrocyclic monooxa-diselkylene-1,ω-dioxy substituted calix[4]arene derivatives 1a-5a were synthesized by the reaction of calix[4]arene dibromides 1-5 with the disodium salt of bis(2-selenylethyl)ether in the...Novel macrocyclic monooxa-diselkylene-1,ω-dioxy substituted calix[4]arene derivatives 1a-5a were synthesized by the reaction of calix[4]arene dibromides 1-5 with the disodium salt of bis(2-selenylethyl)ether in the yields between 28% and 64%. Their structures were characterized by proton and carbon NMR spectra. X-Ray structure analysis of la further confirmed the cone conformation of compounds 1a-5a. An interesting host-guest complex of la with dichloromethane via CH/π and C1/π interactions was elucidated. Extraction experiments showed that these novel monooxa-diselkylene-1,ω-dioxy substituted calix[4]arene derivatives 1a-5a had strong extraction ability towards mercury ion. The interaction of Hg^2+with the calix ligand has also been investigated by 1^H NMR titration.展开更多
Vacuum arc ion sources are known for delivering high currents of ion beams in many technological applications. There is a great need in the present ion accelerator injection research for a titanium vacuum arc source t...Vacuum arc ion sources are known for delivering high currents of ion beams in many technological applications. There is a great need in the present ion accelerator injection research for a titanium vacuum arc source to produce high-ionized plasma, in which its parameter is extremely important to match the extractors geometry and the extraction voltage. In this paper, the radial and angular distributions of the titanium cathodic vacuum arc plasma parameters are measured by a cylindrical Langmuir probe and analyzed by the Druyvesteyn method from the I-V curves. The electron density ne is about 10^(17)m^(-3) and the effective electron temperature Tefr is in the range of 6.12-11.11 eV in the free expansion cup before the ion extraction. The measured distribution of ne over the expansion cross-section is non-uniform and axially unsymmetrical with its form similar to the Gaussian distribution, and most of the plasma is concentrated into an area whose radius is smaller than 5 mm. Teff has a nearly uniform distribution over the expansion cross-section during the discharge. The results of the plasma parameters' non-uniformity encourage the researchers to make some optimization designs to improve the parameter distributions, and then to facilitate ion extraction.展开更多
A 1-dodecanethiol-based phase-transfer protocol is developed for the extraction of noble metal ions from aqueous solution to a hydrocarbon phase, which calls for first mixing the aqueous metal ion solution with an eth...A 1-dodecanethiol-based phase-transfer protocol is developed for the extraction of noble metal ions from aqueous solution to a hydrocarbon phase, which calls for first mixing the aqueous metal ion solution with an ethanolic solution of 1-dodecanethiol, and then extracting the coordination compounds formed between noble metal ions and 1-dodecanethiol into a non-polar organic solvent. A number of characterization techniques, including inductively coupled plasma atomic emission spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis demonstrate that this protocol could be applied to extract a wide variety of noble metal ions from water to dichlorometh- ane with an efficiency of 〉96%, and has high selectivity for the separation of the noble metal ions from other transition metals. It is therefore an attractive alternative for the extraction of noble metals from water, soil, or waste printed circuit boards.展开更多
The extraction of negative ions inevitably leads to the destruction of the original plasma state. To understand the effect of extraction on a plasma sheath under a weak magnetic filter field, the time-dependent behavi...The extraction of negative ions inevitably leads to the destruction of the original plasma state. To understand the effect of extraction on a plasma sheath under a weak magnetic filter field, the time-dependent behavior of H- ion extraction from a negative ion source has been studied by particle-in-cell simulation in the collisionless limit. The simulation results have shown that the plasma sheath would undergo a transient process, in which there exists an edge electrostatic wave that propagates counterclockwise along the wall with a velocity of 4 mm/ns until it reaches the other side of extraction aperture. The thickness of the plasma sheath and the plasma potential both increase greatly at the final quasi-steady-state. For comparison, the results of extracting positive ions are also given.展开更多
A new extraction system is designed for a penning ion source DUHOCAMIS (dual hollow cathode ion source for metal ion beams) being installed at the Institute of Heavy Ion Physics,Peking University.We have analyzed th...A new extraction system is designed for a penning ion source DUHOCAMIS (dual hollow cathode ion source for metal ion beams) being installed at the Institute of Heavy Ion Physics,Peking University.We have analyzed theoretically the central particle trajectories in the extraction region for ions having different q/m ratios and then compared our results with the simulation results of CST (Computer Simulation Technology) software.The validity of the system is verified and some analytical formulas are obtained which will be used for the optimization of the extraction system as well as the experimental setup.展开更多
China is a major producer of rhenium, which is widely used in aerospace technologies (as superalloy) and petrochemical industries (as catalyst). There is a gap between the demand and fact for the enrichment of rhe...China is a major producer of rhenium, which is widely used in aerospace technologies (as superalloy) and petrochemical industries (as catalyst). There is a gap between the demand and fact for the enrichment of rhenium, due to its rather small content (10-9) in the earth's crust. Also, there is no available single occurrence of mineral rhenium. Instead, the rhenium is associated with either molybdenum or copper (of up to 0.2% in content) as a by-product in metallurgical industry. This makes the separation of rhenium from the major mineral metals a challenge. The recent progresses in the separation and enrichment of rhenium were reviewed in this paper, especially, the advances in China. The details of varied separation methods used either in laboratories or factories, such as ion-exchange, solvent extraction, separation utilizing extractive resins, liquid membrane, or novel materials, etc., were elaborated. Comparison of the different methods was disclosed and an outlook on the rhenium chemistry and industry in the future was brought forward.展开更多
The emission spectra of a series of naphthalene end-labeled oligo-oxyethylene(N-P_n-N) and their facilitated transport of cations across liquid membranes have beeninvestigated. Alkali-metal cations enhance or inhibit ...The emission spectra of a series of naphthalene end-labeled oligo-oxyethylene(N-P_n-N) and their facilitated transport of cations across liquid membranes have beeninvestigated. Alkali-metal cations enhance or inhibit the intramolecular excimer formation ofN-P_n-N remarkably, suggesting that the polyether chain of N-P_n-N in solution complexes with thecations, and the orientation of the terminal chromophores depends on the cation size and the lengthof the polyether chain. These compounds are able to act as carriers to facilitate transport ofalkali-metal cations through organic liquid membranes. The transport efficiencies are comparablewith those of cyclic carriers such as crown ethers, and show remarkable selectivity.展开更多
基金The project was sponsored by the National Natural Science Foundation of China(No.20607031)the Scientific Research Foundation for the Returned 0verseas Chinese Scholars,State Education Ministry(2006-331)+1 种基金We are also grateful to Key Natural Science Fundation of South-Central University for Nationalities(YZZ05001)"Youth Chen-Guang Project"of Wuhan Bureau of Science and Technology(20065004116-34)for financial supports.
文摘A series of glucose derivatives have been used as chelating reagents to extract metal ions in supercritical carbon dioxide. With perfluoro-l-octanesulfonic acid tetraethylammonium salt as additive, glucose derivatives were selective for Sr^2+ and Pb^2+ extraction in supercritical carbon dioxide.
基金financially supported by the National Natural Science Foundation of China(Nos.51772138,51572118,and 51601082)the Fundamental Research Funds for the Central Universities(No.lzujbky-2020-59)。
文摘Rechargeable aqueous zinc ion batteries(AZIBs)were considered as one of the most promising candidates for large-scale energy storage due to the merits of high safety and inexpensiveness.As AZIBs cathode material,Mn O_(2)possesses great merits but was greatly hindered due to the sluggish diffusion kinetic of Zn^(2+) during electrochemical operations.Herein,deep Zn^(2+) ions intercalatedδ-Mn O_(2)(Zn-Mn O_(2))was achieved by the in situ electrochemical deposition route,which significantly enhanced the diffusion ability of Zn^(2+) due to the synergistic effects of Zn^(2+) pillars and structural H;O.The resultant Zn-Mn O_(2)based AZIBs delivers a record capacity of 696 m Ah/g(0.5 m Ah/cm^(2))based on the initial mass loading,which is approaching the theoretical capacity of Mn O_(2)with a two-electrons reaction.In-situ Raman studies reveal highly reversible Zn^(2+)ions insertion/extraction behaviors and here the Zn-Mn O_(2)plays the role of a container during the charge–discharge process.Further charge storage mechanism investigations point out the insertion/extraction of Zn^(2+) and H^(+) coincides,and such process is significantly facilitated results from superior interlayered configurations of Zn-Mn O_(2)The excellent electrochemical performance of Zn-Mn O_(2)achieved in this work suggests the deep ions pre-intercalation strategy may aid in the future development of advanced cathodes for AZIBs.
基金Financial support from the National Natural Science Foundation of China (21276194)the Specialized Research Fund for the Doctoral Program of Chinese Higher Education (20101208110003)the Key Pillar Program of Tianjin Municipal Science and Technology (11ZCKGX02800)
文摘1 Introduction As the lightest metal with the unique properties of energy production and storage,lithium is regarded as the new century energy metal.Lithium and its compounds were widely used in various industrial fields,especially in
基金supported by National Natural Science Foundation of China(No.11105130)
文摘For plasma source, the extraction of negative ions is quite different from that of positive ions. To understand the effect of extraction field on plasma, the time-dependent behavior of negative hydrogen ion extraction from a negative ion source has been studied by particle-in-cell simulation in the collisionless limit. The simulations have shown that, due to the difference in dynamics between electrons and ions, the imbalance of the numbers of charged particles occurs in the source, results in the broadening of plasma sheath and the great increase of plasma potential. The resultant high sheath field and the ambipolar electric field in plasma make the negatively charged particles congregate inside the sheath and move toward the extraction outlet. The emission area of negative ions is much smaller than that of the extraction aperture, which is in sharp contrast to the case of positive ion extraction.
文摘A new type of calixarenes containing amino acid ester derivatives has been synthesized. Their 1H NMR characteristics are discussed. Metal ion extraction experiment has shown that calixarene amino acid esters (2a, 2b) possess good extraction efficiency for transition metal ions (Cu 2+ , Ni 2+ , Zn 2+ ) and poor extraction efficiency for alkali metal ions (Na +, K +).
文摘A new thee-dimensional code, ion optics simulator (IOS), to simulate ion beam extraction is developed in visual C++ language. The theoretical model, the flowchart of code, and the results of calculation as an example are presented.
基金supported by the Key Program of Research and Development of Hefei Science Center,CAS(No.2016HSCKPRD002)National Natural Science Foundation of China(Nos.11505224,11505225,11575240,11675215,11675216)
文摘In order to study the key technology and physics of RF driven negative ion source for neutral beam injector in China, the Hefei utility negative ions test equipment with RF source was developed at Institute of Plasma Physics, Chinese Academy of Sciences(ASIPP). Its negative ion source can be equipped with single or double RF drivers. There is a plasma expansion chamber with depth of 19 mm and an enhanced filter field. A three electrodes negative ion accelerator was employed to extract and accelerate the negative ions, which are plasma grid,extraction grid and ground grid. And there are several diagnostic tools for the plasma and beam parameters measurement. The characteristics of plasma generation, negative ion production and extraction were studied on the test equipment. The negative ion beam was extracted from the RF driven negative ion source for the first time. The detailed structure and main results are presented in this article.
基金Project(50904031) supported by the National Natural Science Foundation of ChinaProject(2008E0049M) supported by the Natural Science Foundation of Yunnan Province,China+1 种基金Project(07Z40082) supported by the Science Foundation of the Education Department of Yunnan Province,ChinaProject(2007-16) supported by the Science Foundation of Kunming University of Science and Technology,China
文摘Ionic liquids as green solvents have shown important application in the extraction and separation of nonferrous metals.The new application perspective,the important fundamental and the applied studies of the extraction and separation of nonferrous metals in ionic liquids,including the dissolution and corrosion of metal and metal oxide,hydrometallurgy of chalcopyrite and metallic oxidized ore,and extraction and separation of metal ions,are introduced.
基金financial support by the National Natural Science Foundation of China (21975168)the Sichuan Science and Technology Program (2021JDJQ0020)the Fundamental Research Funds for the Central Universities (No. 1082204112219)。
文摘Manganese dioxide(MnO_(2)) is considered as a potential cathode material for aqueous magnesium-ion batteries. However, the charge/discharge mechanism of MnO_(2)in aqueous electrolyte is still unclear. In present study, highly porous δ-MnO_(2) is investigated, which delivers a high capacity of 252.1 m Ah g^(-1) at 0.05 A g^(-1) and excellent rate capability, i.e., 109.7 m Ah g^(-1) at 1 A g^(-1), but a low-capacity retention of 54.4% after 800 cycles at 1 A g^(-1). The two-step discharging process, namely a consequent H^(+) and Mg^(2+) insertion reaction, is verified, by comparing the electrochemical performance of δ-MnO_(2) in 1 M MgCl_(2) and 1 M MnCl_(2) aqueous electrolyte and analyzing detailedly the Mg content and the bonding state of Mn at different charge/discharge state. Furthermore, partial irreversibility of Mg^(-1) ion insertion/extraction is observed, which may be one of the major reasons leading to capacity decay.
基金supported by the National Natural Science Foundation of China(U21A20303,22108188,U20A20141)the National Key Research and Development Program of China(2017YFE0129200)+1 种基金the Natural Science Foundation of Shanxi Province(201901D211054)JSPS KAKENHI Grant 19K12395,Japan。
文摘Effective extraction and regeneration of radioactive iodide is one of urgent concerns for the safe utilization of nuclear energy.As a novel environmentally benign ion separation technique,electrochemically switched ion extraction(ESIE)process can be applied for effective capture and recovery of iodide ions(I^(-)).Herein,a novel kelp seaweed-like core/shell I^(-)imprinted polypyrrole@bismuth oxyiodide(PPy/I^(-)@BiOI)composite film is successfully prepared for the selective I^(-)capture in the ESIE system.It is found that the I^(-)can be easily trapped in the PPy/I^(-)@BiOI film after I^(-)is in situ desorbed from the film by an electrochemical reduction process since it offers particular electroactive binding sites for I^(-)extraction.The I^(-)imprinted PPy/I^(-)@BiOI film displays an extraction capacity as high as 325.2 mg·g^(-1)for I^(-)with favorable stability.In particular,the extraction and desorption of I^(-)is achieved by adjusting the redox potential and the pristine PPy/I^(-)@BiOI film can be regenerated and reused for multiple times without decrease in extraction capacity.It is expected that such a PPy/I^(-)@BiOI film would be useful as an electrochemically switched renewable extractor that could capture and regenerate I^(-)from radioactive water.
基金Project supported by the National Natural Science Foundation of China (No. 20472036).
文摘Novel macrocyclic monooxa-diselkylene-1,ω-dioxy substituted calix[4]arene derivatives 1a-5a were synthesized by the reaction of calix[4]arene dibromides 1-5 with the disodium salt of bis(2-selenylethyl)ether in the yields between 28% and 64%. Their structures were characterized by proton and carbon NMR spectra. X-Ray structure analysis of la further confirmed the cone conformation of compounds 1a-5a. An interesting host-guest complex of la with dichloromethane via CH/π and C1/π interactions was elucidated. Extraction experiments showed that these novel monooxa-diselkylene-1,ω-dioxy substituted calix[4]arene derivatives 1a-5a had strong extraction ability towards mercury ion. The interaction of Hg^2+with the calix ligand has also been investigated by 1^H NMR titration.
文摘Vacuum arc ion sources are known for delivering high currents of ion beams in many technological applications. There is a great need in the present ion accelerator injection research for a titanium vacuum arc source to produce high-ionized plasma, in which its parameter is extremely important to match the extractors geometry and the extraction voltage. In this paper, the radial and angular distributions of the titanium cathodic vacuum arc plasma parameters are measured by a cylindrical Langmuir probe and analyzed by the Druyvesteyn method from the I-V curves. The electron density ne is about 10^(17)m^(-3) and the effective electron temperature Tefr is in the range of 6.12-11.11 eV in the free expansion cup before the ion extraction. The measured distribution of ne over the expansion cross-section is non-uniform and axially unsymmetrical with its form similar to the Gaussian distribution, and most of the plasma is concentrated into an area whose radius is smaller than 5 mm. Teff has a nearly uniform distribution over the expansion cross-section during the discharge. The results of the plasma parameters' non-uniformity encourage the researchers to make some optimization designs to improve the parameter distributions, and then to facilitate ion extraction.
基金supported by the 100 Talents Program of the Chinese Academy of Sciences, National Natural Science Foundation of China (Nos. 21173226, 21376247)State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences (Nos. MPCS-2011-D-08, MPCS-2010-C-02)
文摘A 1-dodecanethiol-based phase-transfer protocol is developed for the extraction of noble metal ions from aqueous solution to a hydrocarbon phase, which calls for first mixing the aqueous metal ion solution with an ethanolic solution of 1-dodecanethiol, and then extracting the coordination compounds formed between noble metal ions and 1-dodecanethiol into a non-polar organic solvent. A number of characterization techniques, including inductively coupled plasma atomic emission spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis demonstrate that this protocol could be applied to extract a wide variety of noble metal ions from water to dichlorometh- ane with an efficiency of 〉96%, and has high selectivity for the separation of the noble metal ions from other transition metals. It is therefore an attractive alternative for the extraction of noble metals from water, soil, or waste printed circuit boards.
基金Supported by National Natural Science Foundation of China (11105130)Science and Technology Development Foundation of CAEP (2012B0402056)
文摘The extraction of negative ions inevitably leads to the destruction of the original plasma state. To understand the effect of extraction on a plasma sheath under a weak magnetic filter field, the time-dependent behavior of H- ion extraction from a negative ion source has been studied by particle-in-cell simulation in the collisionless limit. The simulation results have shown that the plasma sheath would undergo a transient process, in which there exists an edge electrostatic wave that propagates counterclockwise along the wall with a velocity of 4 mm/ns until it reaches the other side of extraction aperture. The thickness of the plasma sheath and the plasma potential both increase greatly at the final quasi-steady-state. For comparison, the results of extracting positive ions are also given.
基金Supported by National Natural Science Foundation of China (10775011)
文摘A new extraction system is designed for a penning ion source DUHOCAMIS (dual hollow cathode ion source for metal ion beams) being installed at the Institute of Heavy Ion Physics,Peking University.We have analyzed theoretically the central particle trajectories in the extraction region for ions having different q/m ratios and then compared our results with the simulation results of CST (Computer Simulation Technology) software.The validity of the system is verified and some analytical formulas are obtained which will be used for the optimization of the extraction system as well as the experimental setup.
基金supported by the National Natural Science Foundation of China(Nos.21472194,21701073 and 21772202)the Fundamental Research Funds for the Central Universities(No. lzujbky-2017-12)
文摘China is a major producer of rhenium, which is widely used in aerospace technologies (as superalloy) and petrochemical industries (as catalyst). There is a gap between the demand and fact for the enrichment of rhenium, due to its rather small content (10-9) in the earth's crust. Also, there is no available single occurrence of mineral rhenium. Instead, the rhenium is associated with either molybdenum or copper (of up to 0.2% in content) as a by-product in metallurgical industry. This makes the separation of rhenium from the major mineral metals a challenge. The recent progresses in the separation and enrichment of rhenium were reviewed in this paper, especially, the advances in China. The details of varied separation methods used either in laboratories or factories, such as ion-exchange, solvent extraction, separation utilizing extractive resins, liquid membrane, or novel materials, etc., were elaborated. Comparison of the different methods was disclosed and an outlook on the rhenium chemistry and industry in the future was brought forward.
文摘The emission spectra of a series of naphthalene end-labeled oligo-oxyethylene(N-P_n-N) and their facilitated transport of cations across liquid membranes have beeninvestigated. Alkali-metal cations enhance or inhibit the intramolecular excimer formation ofN-P_n-N remarkably, suggesting that the polyether chain of N-P_n-N in solution complexes with thecations, and the orientation of the terminal chromophores depends on the cation size and the lengthof the polyether chain. These compounds are able to act as carriers to facilitate transport ofalkali-metal cations through organic liquid membranes. The transport efficiencies are comparablewith those of cyclic carriers such as crown ethers, and show remarkable selectivity.