Corrosion behavior of brass coinage was investigated in synthetic sweat solution by electrochemical measurement and surface analysis methods including scanning electron microscope （SEM） and energy dispersive X-ray s...Corrosion behavior of brass coinage was investigated in synthetic sweat solution by electrochemical measurement and surface analysis methods including scanning electron microscope （SEM） and energy dispersive X-ray spectrometer （EDX）. It is indicated that chloride ions in sweat solution accelerate the anodic active dissolution of brass, which is the main reason of pitting corrosion and dezincification corrosion. Meanwhile, lactic acid and ammonia water also promote the anode reaction. The corrosion products on the surface are mainly composed of basic copper chloride, cuprous oxide, the complex consisting of urea in association with copper, and few lactate ion. The kinetics of pitting corrosion development obeys the following equation of J0=0.3735（t＋185.93）^-1/2, and the process is controlled by dissolution of salt deposited on pit surface.展开更多
The syntheses and structures of a novel series of polynuclear coinage metal cluster compounds are discussed. The most fascinating structural characteristic of the Au-Ag alloy clusters with Au_18Ag_19 and Au_18Ag_19 co...The syntheses and structures of a novel series of polynuclear coinage metal cluster compounds are discussed. The most fascinating structural characteristic of the Au-Ag alloy clusters with Au_18Ag_19 and Au_18Ag_19 cores and phosphine ligands, which were prepared by the reduction of mononuclear coinage metal complexes R3PAuX and R3PAgX with NaBH4 in organic solution, is their construction from 13-atom gold-centred icosahedral Au_7Ag_6 building blocks. The structures of the polynuclear coinage metal clusters with R2dtc ligands are variable with either unlimited linear chain or triangular M3 units.展开更多
Soon after Roman mint masters began issuing the silver denarius （traditional date 187 B.C.）, they discovered that they could employ coinage as newspapers and PR by individualizing the imagery on each side of the coi...Soon after Roman mint masters began issuing the silver denarius （traditional date 187 B.C.）, they discovered that they could employ coinage as newspapers and PR by individualizing the imagery on each side of the coin with references to their ancestry, current events, and/or their religious offices to increase their name recognition in order to win votes. It should come as no surprise that the Divine Julius ordered his mint masters to issue coinage that advertised all of the above features to circulate his good reputation in what our modern political scientists would call propaganda. After Julius＇ enemies began to attack his reputation, some of his partisans boasted of their closeness to him on coinage by recycling specific coin images. What is surprising is how these partisans adopted the exact imagery Julius had used to advertise his own religious résumé on their coinage, even though these religious images could not and did not apply to them specifically. Apparently, Julius＇ religious résumé no longer demonstrated a religious portfolio, but had transformed into a badge of partisanship, however thinly it applied, so that the religious symbols themselves retained only the function of an association with Julius without their original and intrinsic meaning.展开更多
The paper is entitled“Coinage in Akan Among Senior High School Students”.It aims to investigate coinage used by senior high school students.This paper also investigates other word formation processes involved in coi...The paper is entitled“Coinage in Akan Among Senior High School Students”.It aims to investigate coinage used by senior high school students.This paper also investigates other word formation processes involved in coined words and the reasons why the students use them in their everyday conversation.The collected data from direct elicitation and interviews were categorized into the types of coined words and analyzed in terms of their formation processes by using a method of analysis based on theories as proposed by Yule(1985),Potter(1975),O’Grady and Guzman(1996),and Gerber(1968).The findings show that there are 10 groups of word formation processes in this study.This paper presents a qualitative analysis of the findings of a sociolinguistic survey geared towards coinage as used by students of both Osei Tutu Senior High School and Bisease Community/Senior High School speech communities.It is also imperative to state that these two schools are located in typical Akan speaking communities.Osei Tutu Senior High School,situated in Akropong,in the Ashanti region of Ghana,is a single sex school(boys’school)and Bisease Community/Senior High School on the other hand is situated in Ajumako-Bisease in the central region.The latter is a mixed school.展开更多
Coinage bonds, a type of noncovalent interaction, occur between group 11elements (Au, Ag, and Cu) with electron donor groups. Despite theoretical validation,empirical evidence remains limited. In this study, an aggreg...Coinage bonds, a type of noncovalent interaction, occur between group 11elements (Au, Ag, and Cu) with electron donor groups. Despite theoretical validation,empirical evidence remains limited. In this study, an aggregation-inducedemission (AIE)-active Au(I) complex, ITCPAu, which exhibits Au⋅⋅⋅I coinagebonds, was revealed based on the single-crystal X-ray diffraction and theoreticalcalculations. Further examination of the luminescence properties of theITCPAu revealed multiswitchable behavior, including mechanochromism and thermochromism.Nearly pure white-light emission was achieved with CommissionInternationale de L’Eclairage (CIE) 1931 chromaticity coordinates of (0.30, 0.31)by grinding the green-emissive ITCPAu monomer crystals. Moreover, visualizationand manipulation of solid-state molecular motion (SSMM) in the yellow-emissiveITCPAu dimer crystals, driven by the robust Au⋅⋅⋅I coinage bonds, were revealedthrough a combination of crystal engineering and luminescent properties. Furthermore,to support the robust Au⋅⋅⋅I coinage bonds, a versatile carrier for small solventmolecules in crystal lattices was developed for uptake and release. Our findings provideexperimental and theoretical evidence for Au⋅⋅⋅I coinage bonds, highlightingtheir ability to boost photoluminescence quantum yield (PLQY) and trigger SSMM,emphasizing their potential in developing smart materials with stimuli-responsiveproperties.展开更多
Bottom-up constructing all-metal functional materials is challenging,because the metal clusters are prone to lose their original structures during coalensence.In this work,we report that closed-shell coinage metal sup...Bottom-up constructing all-metal functional materials is challenging,because the metal clusters are prone to lose their original structures during coalensence.In this work,we report that closed-shell coinage metal superatoms can achieve direct chemical bonding without losing their electronic properties.The reason is that the supermolecule formed by two superatoms has the same number of bonding and anti-bonding supermolecular orbitals,in which the bonding orbitals contribute to bonding and the antibonding orbitals with anti-phase orbitals delocalized over each monomer to maintain the individual geometric and electronic structural properties.Further analysis indicates the interactions between two superatoms are too weak to break the structure of monomers,which is confirmed by the first-principles molecular dynamics simulations.With these superatoms as the basic units,a series of robust one-dimensional and two-dimensional nanostructures are fabricated.Our findings provide a general strategy to take advantage of superatoms in regulating bonding compared to natural atoms,which paves the way for the bottom-up design of materials with collective properties.展开更多
This paper presents three computer games that are used in the teaching of ancient numismatics.All three applications-Craveler,NumisGames,and Graveler-were developed within the last years with the aim of teaching stude...This paper presents three computer games that are used in the teaching of ancient numismatics.All three applications-Craveler,NumisGames,and Graveler-were developed within the last years with the aim of teaching students numismatics through a playful approach.The different didactic goals,learning conditions,and outcomes are summarized and discussed.展开更多
A corrosion discoloration model for copper-nickel alloys in Cl^(−)environments was established using CIE-Lab,UV-VIS absorption spectroscopy,X-ray diffraction,and X-ray photoelectron spectroscopy.The corrosion discolor...A corrosion discoloration model for copper-nickel alloys in Cl^(−)environments was established using CIE-Lab,UV-VIS absorption spectroscopy,X-ray diffraction,and X-ray photoelectron spectroscopy.The corrosion discoloration process and the corresponding main corrosion products can be summarized as follows:silver-white(Cu+Ni)→green(NiO)→reddishbrown(NiO+Cu_(2)O)→black(NiO+Cu_(2)O+CuO).Density functional theory was employed to explain the corrosion process of copper-nickel alloys and the detrimental effect of Cl^(−).The results indicate that adsorbates preferentially bind to nickel,leading to the preferential formation of NiO,which imparts a green appearance to the surface.Furthermore,the difficulty in forming nickel cation vacancies and the higher diffusion barrier for nickel inhibit the migration of species within the oxide layer.Notably,nickel also suppresses carrier migration within the oxide layer,reducing the charge transfer rate.In contrast,the promotion of corrosion by Cl^(−)is primarily attributed to the reduction in surface work function and the formation energy of cation vacancies.展开更多
Currency is one of indispensable mechanism for the commercial economy development. As the complexity of the British New England commercial economy growing, the urgent need for a stable value currency as a means of pay...Currency is one of indispensable mechanism for the commercial economy development. As the complexity of the British New England commercial economy growing, the urgent need for a stable value currency as a means of payment of daily trading. But the currency was always a problem restricting the development of commercial economy of New England, which was not only related to the economic management function of colonial government itself, but also a political game between colonies and her mother country government.展开更多
It is generally acknowledged that language-change is universal,continuous,and,to very considerable extent,regular.The universality and continuity of the process of language-change is noted greatly.All living languages...It is generally acknowledged that language-change is universal,continuous,and,to very considerable extent,regular.The universality and continuity of the process of language-change is noted greatly.All living languages are subject to it.The core of language-change is lexical,and a language ' s vocabulary change proves to be more revolutionary for the language ' s slow evolution.展开更多
Ligand plays a critical role in determining the physicochemical properties and functionalities of metal nano-clusters,as the ligand molecules interact with a significant amount of metal atoms in the core through vario...Ligand plays a critical role in determining the physicochemical properties and functionalities of metal nano-clusters,as the ligand molecules interact with a significant amount of metal atoms in the core through various binding moieties.Compared with the most commonly employed thiolate molecule,alkynyl ligand represents a new avenue to prepare coinage metal nanoclusters due to its capability of binding to the metal atoms with either a bonding or a bonding or both.In this review,we first describe the definition of atomically precise metal nano-clusters and the significance of ligand in metal nanoclusters.Then,the impact and unique advantages of employing alkynyl ligand for fabricating coinage metal nanoclusters are discussed,with focus on the enrichment of interfacial binding structure,the regulation of physicochemical properties,and the improvement of func-tionalities.Some explicit examples are provided,aiming to elucidate the structure-property-functionality rela-tionship at the atomic level.Finally,a conclusion and introspective outlook regarding designing alkynyl ligand for future regulation of the structure/property/functionality of metal nanoclusters is presented.展开更多
基金Project(21276036)supported by the National Natural Science Foundation of ChinaProject(2009AA05Z120)supported by the National High-tech Research and Development Program of China+1 种基金Project(2014025018)supported by the Liaoning Provincial Natural Science Foundation of ChinaProject(3132014323)supported by the Fundamental Research Funds for the Central Universities,China
文摘Corrosion behavior of brass coinage was investigated in synthetic sweat solution by electrochemical measurement and surface analysis methods including scanning electron microscope （SEM） and energy dispersive X-ray spectrometer （EDX）. It is indicated that chloride ions in sweat solution accelerate the anodic active dissolution of brass, which is the main reason of pitting corrosion and dezincification corrosion. Meanwhile, lactic acid and ammonia water also promote the anode reaction. The corrosion products on the surface are mainly composed of basic copper chloride, cuprous oxide, the complex consisting of urea in association with copper, and few lactate ion. The kinetics of pitting corrosion development obeys the following equation of J0=0.3735（t＋185.93）^-1/2, and the process is controlled by dissolution of salt deposited on pit surface.
文摘The syntheses and structures of a novel series of polynuclear coinage metal cluster compounds are discussed. The most fascinating structural characteristic of the Au-Ag alloy clusters with Au_18Ag_19 and Au_18Ag_19 cores and phosphine ligands, which were prepared by the reduction of mononuclear coinage metal complexes R3PAuX and R3PAgX with NaBH4 in organic solution, is their construction from 13-atom gold-centred icosahedral Au_7Ag_6 building blocks. The structures of the polynuclear coinage metal clusters with R2dtc ligands are variable with either unlimited linear chain or triangular M3 units.
文摘Soon after Roman mint masters began issuing the silver denarius （traditional date 187 B.C.）, they discovered that they could employ coinage as newspapers and PR by individualizing the imagery on each side of the coin with references to their ancestry, current events, and/or their religious offices to increase their name recognition in order to win votes. It should come as no surprise that the Divine Julius ordered his mint masters to issue coinage that advertised all of the above features to circulate his good reputation in what our modern political scientists would call propaganda. After Julius＇ enemies began to attack his reputation, some of his partisans boasted of their closeness to him on coinage by recycling specific coin images. What is surprising is how these partisans adopted the exact imagery Julius had used to advertise his own religious résumé on their coinage, even though these religious images could not and did not apply to them specifically. Apparently, Julius＇ religious résumé no longer demonstrated a religious portfolio, but had transformed into a badge of partisanship, however thinly it applied, so that the religious symbols themselves retained only the function of an association with Julius without their original and intrinsic meaning.
文摘The paper is entitled“Coinage in Akan Among Senior High School Students”.It aims to investigate coinage used by senior high school students.This paper also investigates other word formation processes involved in coined words and the reasons why the students use them in their everyday conversation.The collected data from direct elicitation and interviews were categorized into the types of coined words and analyzed in terms of their formation processes by using a method of analysis based on theories as proposed by Yule(1985),Potter(1975),O’Grady and Guzman(1996),and Gerber(1968).The findings show that there are 10 groups of word formation processes in this study.This paper presents a qualitative analysis of the findings of a sociolinguistic survey geared towards coinage as used by students of both Osei Tutu Senior High School and Bisease Community/Senior High School speech communities.It is also imperative to state that these two schools are located in typical Akan speaking communities.Osei Tutu Senior High School,situated in Akropong,in the Ashanti region of Ghana,is a single sex school(boys’school)and Bisease Community/Senior High School on the other hand is situated in Ajumako-Bisease in the central region.The latter is a mixed school.
基金National Key R&D Program of China,Grant/Award Number:2022YFE0104100National Natural Science Foundation of China,Grant/Award Number:52073242+9 种基金Research Institute for Smart Energy(CDAQ)Research Centre for Nanoscience and Nanotechnology(CE2H)Research Centre for Carbon-Strategic Catalysis(CE2L)Miss Clarea Au for the Endowed Professorship in Energy,Grant/Award Number:847SHong Kong Research Grants Council,Grant/Award Numbers:PolyU 153053/20P,PolyU 25301524Guangdong Provincial Natural Science Foundation-General Project,Grant/Award Number:2024A1515010422PolyU,Grant/Award Numbers:WZ0Z,BEBA,CDB5,CE2NPolyU Shenzhen Research InstituteBaichengbaiyuan special launchInnovation and Technology Commission,Grant/Award Number:ITC-CNERC14SC01。
文摘Coinage bonds, a type of noncovalent interaction, occur between group 11elements (Au, Ag, and Cu) with electron donor groups. Despite theoretical validation,empirical evidence remains limited. In this study, an aggregation-inducedemission (AIE)-active Au(I) complex, ITCPAu, which exhibits Au⋅⋅⋅I coinagebonds, was revealed based on the single-crystal X-ray diffraction and theoreticalcalculations. Further examination of the luminescence properties of theITCPAu revealed multiswitchable behavior, including mechanochromism and thermochromism.Nearly pure white-light emission was achieved with CommissionInternationale de L’Eclairage (CIE) 1931 chromaticity coordinates of (0.30, 0.31)by grinding the green-emissive ITCPAu monomer crystals. Moreover, visualizationand manipulation of solid-state molecular motion (SSMM) in the yellow-emissiveITCPAu dimer crystals, driven by the robust Au⋅⋅⋅I coinage bonds, were revealedthrough a combination of crystal engineering and luminescent properties. Furthermore,to support the robust Au⋅⋅⋅I coinage bonds, a versatile carrier for small solventmolecules in crystal lattices was developed for uptake and release. Our findings provideexperimental and theoretical evidence for Au⋅⋅⋅I coinage bonds, highlightingtheir ability to boost photoluminescence quantum yield (PLQY) and trigger SSMM,emphasizing their potential in developing smart materials with stimuli-responsiveproperties.
基金the National Science Foundation of China(Nos.11974136 and 11674123).
文摘Bottom-up constructing all-metal functional materials is challenging,because the metal clusters are prone to lose their original structures during coalensence.In this work,we report that closed-shell coinage metal superatoms can achieve direct chemical bonding without losing their electronic properties.The reason is that the supermolecule formed by two superatoms has the same number of bonding and anti-bonding supermolecular orbitals,in which the bonding orbitals contribute to bonding and the antibonding orbitals with anti-phase orbitals delocalized over each monomer to maintain the individual geometric and electronic structural properties.Further analysis indicates the interactions between two superatoms are too weak to break the structure of monomers,which is confirmed by the first-principles molecular dynamics simulations.With these superatoms as the basic units,a series of robust one-dimensional and two-dimensional nanostructures are fabricated.Our findings provide a general strategy to take advantage of superatoms in regulating bonding compared to natural atoms,which paves the way for the bottom-up design of materials with collective properties.
文摘This paper presents three computer games that are used in the teaching of ancient numismatics.All three applications-Craveler,NumisGames,and Graveler-were developed within the last years with the aim of teaching students numismatics through a playful approach.The different didactic goals,learning conditions,and outcomes are summarized and discussed.
基金supported by the Key Program of the National Natural Science Foundation of China(Grant No.51131007)the National Key Research and Development Program of China(Grant No.2021YFC2803102).
文摘A corrosion discoloration model for copper-nickel alloys in Cl^(−)environments was established using CIE-Lab,UV-VIS absorption spectroscopy,X-ray diffraction,and X-ray photoelectron spectroscopy.The corrosion discoloration process and the corresponding main corrosion products can be summarized as follows:silver-white(Cu+Ni)→green(NiO)→reddishbrown(NiO+Cu_(2)O)→black(NiO+Cu_(2)O+CuO).Density functional theory was employed to explain the corrosion process of copper-nickel alloys and the detrimental effect of Cl^(−).The results indicate that adsorbates preferentially bind to nickel,leading to the preferential formation of NiO,which imparts a green appearance to the surface.Furthermore,the difficulty in forming nickel cation vacancies and the higher diffusion barrier for nickel inhibit the migration of species within the oxide layer.Notably,nickel also suppresses carrier migration within the oxide layer,reducing the charge transfer rate.In contrast,the promotion of corrosion by Cl^(−)is primarily attributed to the reduction in surface work function and the formation energy of cation vacancies.
文摘Currency is one of indispensable mechanism for the commercial economy development. As the complexity of the British New England commercial economy growing, the urgent need for a stable value currency as a means of payment of daily trading. But the currency was always a problem restricting the development of commercial economy of New England, which was not only related to the economic management function of colonial government itself, but also a political game between colonies and her mother country government.
文摘It is generally acknowledged that language-change is universal,continuous,and,to very considerable extent,regular.The universality and continuity of the process of language-change is noted greatly.All living languages are subject to it.The core of language-change is lexical,and a language ' s vocabulary change proves to be more revolutionary for the language ' s slow evolution.
基金supported by the open funds of Key Laboratory of Functional Inorganic Material Chemistry(Heilongjiang University),Ministry of Education,Chinathe funding from Guangdong Natural Science Funds(No.2023A0505050107).
文摘Ligand plays a critical role in determining the physicochemical properties and functionalities of metal nano-clusters,as the ligand molecules interact with a significant amount of metal atoms in the core through various binding moieties.Compared with the most commonly employed thiolate molecule,alkynyl ligand represents a new avenue to prepare coinage metal nanoclusters due to its capability of binding to the metal atoms with either a bonding or a bonding or both.In this review,we first describe the definition of atomically precise metal nano-clusters and the significance of ligand in metal nanoclusters.Then,the impact and unique advantages of employing alkynyl ligand for fabricating coinage metal nanoclusters are discussed,with focus on the enrichment of interfacial binding structure,the regulation of physicochemical properties,and the improvement of func-tionalities.Some explicit examples are provided,aiming to elucidate the structure-property-functionality rela-tionship at the atomic level.Finally,a conclusion and introspective outlook regarding designing alkynyl ligand for future regulation of the structure/property/functionality of metal nanoclusters is presented.
