One kind of tensor denotation of nth Beltrami axisymmetric and nonaxisymmetric spherical vortices, their classification and symmetries were discussed. Chaotic Phenomena will occur in the dynamic system of the nonaxisy...One kind of tensor denotation of nth Beltrami axisymmetric and nonaxisymmetric spherical vortices, their classification and symmetries were discussed. Chaotic Phenomena will occur in the dynamic system of the nonaxisymmetric Beltrami spherical vortices. From these aspects, it is shown that the tensor denotation has more meaningful characters and nonaxisymmetric Beltrami shperical vortices are various and very complex.展开更多
The Timed RAISE Specification Language (Timed RSL) is an extension of RAISE Specification Language by adding time constructors for specifying real-time applications. Duration Calculus (DC) is a real-time interval log...The Timed RAISE Specification Language (Timed RSL) is an extension of RAISE Specification Language by adding time constructors for specifying real-time applications. Duration Calculus (DC) is a real-time interval logic, which can be used to specify and reason about timing and logical constraints on dura- tion properties of Boolean states in a dynamic system. This paper gives a denotational semantics to a subset of Timed RSL expressions, using Duration Calculus extended with super-dense chop modality and notations to capture time point properties of piecewise continuous states of arbitrary types. Using this semantics, the paper presents a proof rule for verifying Timed RSL iterative expressions and implements the rule to prove the satisfaction by a sample Timed RSL specification of its real-time requirements.展开更多
Based on the denotation and connotation, this paper analyses the translation from English into Chinese in TEM-8. Connotation is one key to the understanding of the original text. Students should know connotation of wo...Based on the denotation and connotation, this paper analyses the translation from English into Chinese in TEM-8. Connotation is one key to the understanding of the original text. Students should know connotation of words in understanding and translating.展开更多
The author＇s paper is an attempt to investigate the success of the pedagogy of stylistics and pedagogical stylistics in the Namibian context. As an applied linguistics course, stylistics is eminently suitable for stu...The author＇s paper is an attempt to investigate the success of the pedagogy of stylistics and pedagogical stylistics in the Namibian context. As an applied linguistics course, stylistics is eminently suitable for study and analysis of literature, because it clearly explicates literary effects through linguistic analysis. Many scholars have illustrated the use of stylistics analysis for the purposes of studying literature and teaching it, which is, pedagogical stylistics. However, this paper combines both the study of Stylistics as a discipline, which is the pedagogy of Stylistics, and the use of stylistics for teaching literature in general and poetry in particular. Namibia adopted English as its official language 22 years ago. Since then, both teachers and students have been struggling with the analysis of poetry. This study is an empirical one using qualitative methods in the author＇s research to determine the impact of the study of Stylistics on the understanding and teaching of literature in Namibia. The author uses traditional British poetry from the 16th century up to the 20th century alongside postcolonial poetry to assess the importance of culture in understanding poetry and examine the advantage of using stylistics to teach the poems that the author selects.展开更多
In the paper, original formal-logical conception of syntactic and semantic： intensional and extensional senses of expressions of any language L is outlined. Syntax and bi-level intensional and extensional semantics o...In the paper, original formal-logical conception of syntactic and semantic： intensional and extensional senses of expressions of any language L is outlined. Syntax and bi-level intensional and extensional semantics of language L are characterized categorically： in the spirit of some Husserl＇s ideas of pure grammar, Le^niewski-Ajukiewicz＇s theory syntactic/semantic categories and in accordance with Frege＇s ontological canons, Bochefiski＇s famous motto--syntax mirrors ontology and some ideas of Suszko： language should be a linguistic scheme of ontological reality and simultaneously a tool of its cognition. In the logical conception of language L, its expressions should satisfy some general conditions of language adequacy. The adequacy ensures their unambiguous syntactic and semantic senses and mutual, syntactic, and semantic compatibility, correspondence guaranteed by the acceptance of a postulate of categorial compatibility syntactic and semantic （extensional and intensional） categories of expressions of L. From this postulate, three principles of compositionality follow： one syntactic and two semantic already known to Frege. They are treated as conditions of homomorphism partial algebra of L into algebraic models of L： syntactic, intensional, and extensional. In the paper, they are applied to some expressions with quantifiers. Language adequacy connected with the logical senses described in the logical conception of language L is, of course, an idealization, but only expressions with high degrees of precision of their senses, after due justification, may become theorems of science.展开更多
This paper deals with thematization as a fundamental step towards the determination of photography image discourses in order to index them. It deals with questions related to photographic reality, polysemy, denotation...This paper deals with thematization as a fundamental step towards the determination of photography image discourses in order to index them. It deals with questions related to photographic reality, polysemy, denotation and connotation, whose comprehension is fundamentally important for the interpretation of photography discourses. It also approaches aspects that have influenced photography analysis towards its thematization, such as the characterization of an image bank, the functions performed by photos, as well as technical and visual quality.展开更多
This paper first points out the deficiency of listing synonyms by some dictionaries,such as the Cobuild Dictionary and Merriam-Webster’s Dictionary of Synonyms,which,however,have actually failed in distinguishing bet...This paper first points out the deficiency of listing synonyms by some dictionaries,such as the Cobuild Dictionary and Merriam-Webster’s Dictionary of Synonyms,which,however,have actually failed in distinguishing between some synonyms.Then,the paper attempts to solve the problem by providing a brief review of relevant studies in the past few decades on near synonyms with a focus on differences in denotation,connotation and semantic prosody of words as well as various definitions of semantic prosody and related researches.By evaluating the relevant research and defintions of semantic prosody,the review concluded that the alleged dictionaries would be perfected with the provision of connotations or semantic prosodies for near synonyms before suggesting out the focus of future and further research into near synonyms.展开更多
Many English words and Chinese words have the same denotations but different connotations. This paper attempts to compare these words, and finds out the connotative differences between them and tries to analyze the ca...Many English words and Chinese words have the same denotations but different connotations. This paper attempts to compare these words, and finds out the connotative differences between them and tries to analyze the causes of the differences.展开更多
Through analyzing the paradigmatic and syntagmatic relations and exploring the case study of"red"and"black"in thedifferent culture backgrounds, the problems in the comprehension are put forward for...Through analyzing the paradigmatic and syntagmatic relations and exploring the case study of"red"and"black"in thedifferent culture backgrounds, the problems in the comprehension are put forward for the purpose of enhancing the learners' abilityof words comprehension based on a complex meaning system.展开更多
In course of a direct calculation we demonstrate the activity of parameters of the Lorentz transformation entering the original electric and magnetic field vectors E and H. The validity of the transformation is shown ...In course of a direct calculation we demonstrate the activity of parameters of the Lorentz transformation entering the original electric and magnetic field vectors E and H. The validity of the transformation is shown with the aid of the relation E <sup>2</sup>- H<sup>2</sup> = E'<sup>2</sup>- H'<sup>2 </sup>which holds for any suitable pair of the vectors E, H and E', H'. No special geometry of the vector pairs entering (E, H) and (E ', H') is assumed. The only limit applied in the paper concerns the velocity ratio betweeen v and c which should be smaller than unity.展开更多
Semantics,the study of meaning,is closely connected with translation,the practice of transferring meaning.The paper uses a lot of examples based on real translation practice to prove that semantics plays a very import...Semantics,the study of meaning,is closely connected with translation,the practice of transferring meaning.The paper uses a lot of examples based on real translation practice to prove that semantics plays a very important role in translation practice.Understanding and making good use of semantic relations,including synonymy,polysemy,homonymy and antonymy,are quite important for a translator to deal with some complicated semantic problems in translation practice.The paper also discusses the concept of denotative and connotative meanings,two basic types of meaning in Semantics.Denotation means the literal meaning of a word which is given in dictionaries;and connotation,the associative and suggestive meanings of a word in its context.Be cause of cultural difference,words with the same denotations may have totally different connotations,which is why the concept of denotation and connotation plays a very important role in English/Chinese translation.In order to translate a text into another language correctly,translator must totally understand the meaning of the original word,both denotative and connotative mean ing,and be aware of the potential connotations of the word in the target language.展开更多
The energy-efficient and green synthesis of zeolites that are highly demanded in the chemical industry has been a focus for decades.Here we report a highly efficient radical-route to accelerate the synthesis of zeolit...The energy-efficient and green synthesis of zeolites that are highly demanded in the chemical industry has been a focus for decades.Here we report a highly efficient radical-route to accelerate the synthesis of zeolites via using sodium persulfate(denoted as SPS)as an additive in the hydrothermal reaction system of SiO_(2)–TPAOH–H_(2)O.展开更多
Delicately fabricating efficient electro-catalysts to boost the catalytic kinetics of the oxygen evolution reaction(OER)is essential for realizing the efficient performance of water splitting into hydrogen to alleviat...Delicately fabricating efficient electro-catalysts to boost the catalytic kinetics of the oxygen evolution reaction(OER)is essential for realizing the efficient performance of water splitting into hydrogen to alleviate environmental issues and the energy crisis.Here,heterogeneous and hollow microspheres(denoted as CoS_(2)/MS_(2)-HPMS,M=Fe,FeCo)were obtained by the sulfurization of Fe^(3+)-decorated ZIF-67 hollow microspheres(ZIF-67-HMS).展开更多
Polyoxometalate(POM)-based molecular cluster batteries have attracted wide interest due to their rich redox properties.To date,no studies on POM-based ionic crystals for LIBs have been reported,although the redox-acti...Polyoxometalate(POM)-based molecular cluster batteries have attracted wide interest due to their rich redox properties.To date,no studies on POM-based ionic crystals for LIBs have been reported,although the redox-active metals can be incorporated and finely tuned in the ionic crystals.Herein,a POM-based ionic crystal(denoted as Composite 1)was prepared for the first time by the complexation of the trinuclear acetate-bridged cobalt-containing macrocation([Co_(3)O(CH_(3)CO_(2))_(6)(C_(5)H_(5)N)_(3)]^(+))with the anion[PMo_(12)O_(40)]^(3−).Further interaction of Composite 1 and single-walled carbon nanotubes(SWNTs)resulted in the formation of a novel Composite 1/SWNT nanocomposite through a facile one-pot strategy,in which the Composite 1 clusters were uniformly grown onto the surface of SWNTs.The as-prepared Composite 1/SWNT nanocomposite showed outstanding electrochemical performance as an anode material of LIBs by delivering a storage capacity of 1012 mA h g^(−1)at 100 mA g^(−1)for 100 cycles.The results may open a new pathway for exploring novel anode materials of LIBs.展开更多
Constructing one-dimensional(1D)hierarchical photocatalysts is deemed to be central to promoting photocatalytic capacity.In this paper,1D hierarchical structures composed of CdS nanosheets/nanoparticles on Ag nanowire...Constructing one-dimensional(1D)hierarchical photocatalysts is deemed to be central to promoting photocatalytic capacity.In this paper,1D hierarchical structures composed of CdS nanosheets/nanoparticles on Ag nanowires(denoted as 1D Ag@CdS core-shell hierarchical hetero-nanowires)have been fabricated via a wet-chemistry approach at low temperature.The optimization of the synthetic parameters indicates that the amounts of Cd(NO_(3))_(2)·4H_(2)O and thiourea play important roles in the construction of the 1D hierarchical structures.The as-prepared 1D hierarchical Ag@CdS core-shell hetero-nanowires exhibit efficient photocatalytic performance in both methyl orange(MO)degradation(degrade 96% of MO within 240 min)and hydrogen generation(73.5μmol h^(-1))from water splitting due to the unique hybrid nanoarchitecture.It is expected that this Ag@CdS hierarchical nanostructure could have potential in solar energy conversion and this fabrication technique could be used as a reference to design other 1D metal@semiconductor core-shell heteronanowires.展开更多
The exploration of highly efficient and stable non-noble metal electrocatalysts for oxygen evolution reaction(OER)is a crucial challenge.Herein,we demonstrate the design and fabrication of three-dimensional(3D)gallium...The exploration of highly efficient and stable non-noble metal electrocatalysts for oxygen evolution reaction(OER)is a crucial challenge.Herein,we demonstrate the design and fabrication of three-dimensional(3D)gallium-doped FeOOH/Ni_(3)S_(2)nanosheet arrays on a Ni foam(denoted as FeOOH/Ga-Ni_(3)S_(2))via a facile hydrothermal synthesis and their subsequent electrodeposition.Benefiting from the strong interfacial coupling effects between FeOOH and Ni_(3)S_(2),Ga doping in Ni_(3)S_(2)creates exposed active sites,and the optimal 3D FeOOH/Ga-Ni_(3)S_(2)electrocatalyst exhibits outstanding electrocatalytic performance towards OER,while requiring a low overpotential of 274 mV at 100 mA cm^(-2).In addition,it possesses impressive durability of up to 24 h even at 100 mA cm^(-2).Furthermore,density functional theory(DFT)calculations validate the improved conductivity and binding energy of oxygen-containing intermediates due to synergistic effects among multiple components and the optimised electronic structure of Ni_(3)S_(2)ascribed to Ga doping,which boosts the OER performance.This study provides new insight into the fabrication of highly active,stable,and cost-effective electrocatalysts.展开更多
We report an in situ preparation of ultrasmall Co–Mn–O spinel nanoparticles(4.4 nm)supported on nonoxidized carbon nanotubes(denoted as CMO@CNTs)as a bifunctional catalyst for oxygen reduction and evolution reaction...We report an in situ preparation of ultrasmall Co–Mn–O spinel nanoparticles(4.4 nm)supported on nonoxidized carbon nanotubes(denoted as CMO@CNTs)as a bifunctional catalyst for oxygen reduction and evolution reactions(ORR/OER).The preparation process involves the oxidization of divalent metal ions under alkaline conditions and the decomposition of nitrates in aqueous solution containing dispersed non-oxidized CNTs.The synthesized CMO nanoparticles strongly couple with the non-oxidized CNTs,which facilitates electron transfer and improves the catalytic activity.Other composites such as CMO@reduced graphene oxide,CMO@Vulcan X-72R,CMO@oxidized CNTs,and a physical mixture of CMO and CNTs were also prepared for comparison.Remarkably,CMO@CNTs exhibit a half wave potential of 0.91 V in 1 M KOH and higher kinetic current and better catalytic durability than Pt/C.Moreover,CMO@CNTs afford an electrocatalytic OER current density of 10 mA cm^(−2) at a low potential of 1.5 V and a small Tafel slope of 81.1 mV dec^(−1).Furthermore,CMO@CNTs display lower discharge/charge overpotential and more stable voltage plateau on cycling than that of Pt/C when employed as a cathode material in rechargeable Zn–air cells.This work indicates that CMO@CNTs are a promising,cheap and efficient bifunctional ORR/OER electrocatalyst for rechargeable metal–air batteries.展开更多
Herein,this paper describes the synthesis of sodium carboxymethyl cellulose(CMC)/iron oxides/multiwalled carbon nanotubes(MMWCNTs)composites(denoted as CMC/MMWCNTs)by a plasma technique and their application to the de...Herein,this paper describes the synthesis of sodium carboxymethyl cellulose(CMC)/iron oxides/multiwalled carbon nanotubes(MMWCNTs)composites(denoted as CMC/MMWCNTs)by a plasma technique and their application to the decontamination of europium ions from aqueous solutions under controlled laboratory conditions.Batch experiments were conducted to understand the interaction mechanism of europium ion sorption onto the surface of CMC/MMWCNTs nanoparticles and to evaluate the application prospects of CMC/MMWCNTs in the field of pollution remediation.The adsorption capacity of Eu(III)on CMC/MMWCNTs was greater than that of major adsorbents,illustrating that the conjugated CMC could increase the sorption capacity of CMC/MMWCNTs nanoparticles toward Eu(III)ions through providing multiple hydroxyl and carboxyl functional groups.The mutual interaction of Eu(III)ion immobilization on CMC/MMWCNTs was contributed to by outer-sphere surface complexation at low pH values,but inner-sphere surface complexation was the dominant interactional mechanism at high pH values.The experimental findings herein demonstrate that CMC/MMWCNTs composites can be highly effective adsorbents for the immobilization of Eu(III)ions or other trivalent actinide/lanthanide ions from large volumes of aqueous solution.展开更多
文摘One kind of tensor denotation of nth Beltrami axisymmetric and nonaxisymmetric spherical vortices, their classification and symmetries were discussed. Chaotic Phenomena will occur in the dynamic system of the nonaxisymmetric Beltrami spherical vortices. From these aspects, it is shown that the tensor denotation has more meaningful characters and nonaxisymmetric Beltrami shperical vortices are various and very complex.
基金This work is partially supported by the National Natural Science Foundation of China (No. 69773025).
文摘The Timed RAISE Specification Language (Timed RSL) is an extension of RAISE Specification Language by adding time constructors for specifying real-time applications. Duration Calculus (DC) is a real-time interval logic, which can be used to specify and reason about timing and logical constraints on dura- tion properties of Boolean states in a dynamic system. This paper gives a denotational semantics to a subset of Timed RSL expressions, using Duration Calculus extended with super-dense chop modality and notations to capture time point properties of piecewise continuous states of arbitrary types. Using this semantics, the paper presents a proof rule for verifying Timed RSL iterative expressions and implements the rule to prove the satisfaction by a sample Timed RSL specification of its real-time requirements.
文摘Based on the denotation and connotation, this paper analyses the translation from English into Chinese in TEM-8. Connotation is one key to the understanding of the original text. Students should know connotation of words in understanding and translating.
文摘The author＇s paper is an attempt to investigate the success of the pedagogy of stylistics and pedagogical stylistics in the Namibian context. As an applied linguistics course, stylistics is eminently suitable for study and analysis of literature, because it clearly explicates literary effects through linguistic analysis. Many scholars have illustrated the use of stylistics analysis for the purposes of studying literature and teaching it, which is, pedagogical stylistics. However, this paper combines both the study of Stylistics as a discipline, which is the pedagogy of Stylistics, and the use of stylistics for teaching literature in general and poetry in particular. Namibia adopted English as its official language 22 years ago. Since then, both teachers and students have been struggling with the analysis of poetry. This study is an empirical one using qualitative methods in the author＇s research to determine the impact of the study of Stylistics on the understanding and teaching of literature in Namibia. The author uses traditional British poetry from the 16th century up to the 20th century alongside postcolonial poetry to assess the importance of culture in understanding poetry and examine the advantage of using stylistics to teach the poems that the author selects.
文摘In the paper, original formal-logical conception of syntactic and semantic： intensional and extensional senses of expressions of any language L is outlined. Syntax and bi-level intensional and extensional semantics of language L are characterized categorically： in the spirit of some Husserl＇s ideas of pure grammar, Le^niewski-Ajukiewicz＇s theory syntactic/semantic categories and in accordance with Frege＇s ontological canons, Bochefiski＇s famous motto--syntax mirrors ontology and some ideas of Suszko： language should be a linguistic scheme of ontological reality and simultaneously a tool of its cognition. In the logical conception of language L, its expressions should satisfy some general conditions of language adequacy. The adequacy ensures their unambiguous syntactic and semantic senses and mutual, syntactic, and semantic compatibility, correspondence guaranteed by the acceptance of a postulate of categorial compatibility syntactic and semantic （extensional and intensional） categories of expressions of L. From this postulate, three principles of compositionality follow： one syntactic and two semantic already known to Frege. They are treated as conditions of homomorphism partial algebra of L into algebraic models of L： syntactic, intensional, and extensional. In the paper, they are applied to some expressions with quantifiers. Language adequacy connected with the logical senses described in the logical conception of language L is, of course, an idealization, but only expressions with high degrees of precision of their senses, after due justification, may become theorems of science.
文摘This paper deals with thematization as a fundamental step towards the determination of photography image discourses in order to index them. It deals with questions related to photographic reality, polysemy, denotation and connotation, whose comprehension is fundamentally important for the interpretation of photography discourses. It also approaches aspects that have influenced photography analysis towards its thematization, such as the characterization of an image bank, the functions performed by photos, as well as technical and visual quality.
文摘This paper first points out the deficiency of listing synonyms by some dictionaries,such as the Cobuild Dictionary and Merriam-Webster’s Dictionary of Synonyms,which,however,have actually failed in distinguishing between some synonyms.Then,the paper attempts to solve the problem by providing a brief review of relevant studies in the past few decades on near synonyms with a focus on differences in denotation,connotation and semantic prosody of words as well as various definitions of semantic prosody and related researches.By evaluating the relevant research and defintions of semantic prosody,the review concluded that the alleged dictionaries would be perfected with the provision of connotations or semantic prosodies for near synonyms before suggesting out the focus of future and further research into near synonyms.
文摘Many English words and Chinese words have the same denotations but different connotations. This paper attempts to compare these words, and finds out the connotative differences between them and tries to analyze the causes of the differences.
文摘Through analyzing the paradigmatic and syntagmatic relations and exploring the case study of"red"and"black"in thedifferent culture backgrounds, the problems in the comprehension are put forward for the purpose of enhancing the learners' abilityof words comprehension based on a complex meaning system.
文摘In course of a direct calculation we demonstrate the activity of parameters of the Lorentz transformation entering the original electric and magnetic field vectors E and H. The validity of the transformation is shown with the aid of the relation E <sup>2</sup>- H<sup>2</sup> = E'<sup>2</sup>- H'<sup>2 </sup>which holds for any suitable pair of the vectors E, H and E', H'. No special geometry of the vector pairs entering (E, H) and (E ', H') is assumed. The only limit applied in the paper concerns the velocity ratio betweeen v and c which should be smaller than unity.
文摘Semantics,the study of meaning,is closely connected with translation,the practice of transferring meaning.The paper uses a lot of examples based on real translation practice to prove that semantics plays a very important role in translation practice.Understanding and making good use of semantic relations,including synonymy,polysemy,homonymy and antonymy,are quite important for a translator to deal with some complicated semantic problems in translation practice.The paper also discusses the concept of denotative and connotative meanings,two basic types of meaning in Semantics.Denotation means the literal meaning of a word which is given in dictionaries;and connotation,the associative and suggestive meanings of a word in its context.Be cause of cultural difference,words with the same denotations may have totally different connotations,which is why the concept of denotation and connotation plays a very important role in English/Chinese translation.In order to translate a text into another language correctly,translator must totally understand the meaning of the original word,both denotative and connotative mean ing,and be aware of the potential connotations of the word in the target language.
基金financial support from the National Natural Science Foundation of China(21320102001,21621001,21571075)the National Key Research and Development Program of China(Grant No.2016YFB0701100)the 111 Project(B17020),and the Program for JLU Science and Technology Innovative Research Team.
文摘The energy-efficient and green synthesis of zeolites that are highly demanded in the chemical industry has been a focus for decades.Here we report a highly efficient radical-route to accelerate the synthesis of zeolites via using sodium persulfate(denoted as SPS)as an additive in the hydrothermal reaction system of SiO_(2)–TPAOH–H_(2)O.
基金supported by the National Natural Science Foundation of China(22162006 and 22102035)the Natural Science Foundation of Guangxi Province(2019GNSFGA245003,2021GNSFBA220077,and GUIKE AD23026050).
文摘Delicately fabricating efficient electro-catalysts to boost the catalytic kinetics of the oxygen evolution reaction(OER)is essential for realizing the efficient performance of water splitting into hydrogen to alleviate environmental issues and the energy crisis.Here,heterogeneous and hollow microspheres(denoted as CoS_(2)/MS_(2)-HPMS,M=Fe,FeCo)were obtained by the sulfurization of Fe^(3+)-decorated ZIF-67 hollow microspheres(ZIF-67-HMS).
基金supported by the National Nature Science Foundation of China(21625101,21521005)the National Key Research and Development Program of China(2017YFB0307303)the Fundamental Research Funds for the Central Universities(XK1802-6,XK1803-05,XK1902,12060093063).
文摘Polyoxometalate(POM)-based molecular cluster batteries have attracted wide interest due to their rich redox properties.To date,no studies on POM-based ionic crystals for LIBs have been reported,although the redox-active metals can be incorporated and finely tuned in the ionic crystals.Herein,a POM-based ionic crystal(denoted as Composite 1)was prepared for the first time by the complexation of the trinuclear acetate-bridged cobalt-containing macrocation([Co_(3)O(CH_(3)CO_(2))_(6)(C_(5)H_(5)N)_(3)]^(+))with the anion[PMo_(12)O_(40)]^(3−).Further interaction of Composite 1 and single-walled carbon nanotubes(SWNTs)resulted in the formation of a novel Composite 1/SWNT nanocomposite through a facile one-pot strategy,in which the Composite 1 clusters were uniformly grown onto the surface of SWNTs.The as-prepared Composite 1/SWNT nanocomposite showed outstanding electrochemical performance as an anode material of LIBs by delivering a storage capacity of 1012 mA h g^(−1)at 100 mA g^(−1)for 100 cycles.The results may open a new pathway for exploring novel anode materials of LIBs.
基金the Australian Research Council(ARC)through the Discovery Projects DP 130102274 and DP130102699 and from ISEM at UOWJiangsu Specially Appointed Professorship+2 种基金the Program of Jiangsu Innovative and Entrepreneurial Talentsthe use of the facilities in the UOW Electron Microscopy Centre,with particular thanks to David R.G.Mitchellsupport from the Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection and the Priority Academic Development Program of Jiangsu Higher Education Institutions(PAPD).
文摘Constructing one-dimensional(1D)hierarchical photocatalysts is deemed to be central to promoting photocatalytic capacity.In this paper,1D hierarchical structures composed of CdS nanosheets/nanoparticles on Ag nanowires(denoted as 1D Ag@CdS core-shell hierarchical hetero-nanowires)have been fabricated via a wet-chemistry approach at low temperature.The optimization of the synthetic parameters indicates that the amounts of Cd(NO_(3))_(2)·4H_(2)O and thiourea play important roles in the construction of the 1D hierarchical structures.The as-prepared 1D hierarchical Ag@CdS core-shell hetero-nanowires exhibit efficient photocatalytic performance in both methyl orange(MO)degradation(degrade 96% of MO within 240 min)and hydrogen generation(73.5μmol h^(-1))from water splitting due to the unique hybrid nanoarchitecture.It is expected that this Ag@CdS hierarchical nanostructure could have potential in solar energy conversion and this fabrication technique could be used as a reference to design other 1D metal@semiconductor core-shell heteronanowires.
基金supported by the Guangdong University of Technology Hundred Talents Program(No.220418136)Macao Young Scholars Program(AM2021009)+2 种基金Science and Technology Development Fund from Macao SAR(FDCT)(0081/2019/AMJ,0102/2019/A2,0154/2019/A3,and 0033/2019/AMJ)Shenzhen-Hong Kong-Macao Science and Technology Research Programme(Type C)(SGDX20210823103803017)the Shanghai Cooperation Organisation Science and Technology Partnership Program(No.2020E01020).
文摘The exploration of highly efficient and stable non-noble metal electrocatalysts for oxygen evolution reaction(OER)is a crucial challenge.Herein,we demonstrate the design and fabrication of three-dimensional(3D)gallium-doped FeOOH/Ni_(3)S_(2)nanosheet arrays on a Ni foam(denoted as FeOOH/Ga-Ni_(3)S_(2))via a facile hydrothermal synthesis and their subsequent electrodeposition.Benefiting from the strong interfacial coupling effects between FeOOH and Ni_(3)S_(2),Ga doping in Ni_(3)S_(2)creates exposed active sites,and the optimal 3D FeOOH/Ga-Ni_(3)S_(2)electrocatalyst exhibits outstanding electrocatalytic performance towards OER,while requiring a low overpotential of 274 mV at 100 mA cm^(-2).In addition,it possesses impressive durability of up to 24 h even at 100 mA cm^(-2).Furthermore,density functional theory(DFT)calculations validate the improved conductivity and binding energy of oxygen-containing intermediates due to synergistic effects among multiple components and the optimised electronic structure of Ni_(3)S_(2)ascribed to Ga doping,which boosts the OER performance.This study provides new insight into the fabrication of highly active,stable,and cost-effective electrocatalysts.
基金supported by MOST(no.2017YFA0206700)NSFC(no.21231005)MOE(no.B12015 and IRT13R30).
文摘We report an in situ preparation of ultrasmall Co–Mn–O spinel nanoparticles(4.4 nm)supported on nonoxidized carbon nanotubes(denoted as CMO@CNTs)as a bifunctional catalyst for oxygen reduction and evolution reactions(ORR/OER).The preparation process involves the oxidization of divalent metal ions under alkaline conditions and the decomposition of nitrates in aqueous solution containing dispersed non-oxidized CNTs.The synthesized CMO nanoparticles strongly couple with the non-oxidized CNTs,which facilitates electron transfer and improves the catalytic activity.Other composites such as CMO@reduced graphene oxide,CMO@Vulcan X-72R,CMO@oxidized CNTs,and a physical mixture of CMO and CNTs were also prepared for comparison.Remarkably,CMO@CNTs exhibit a half wave potential of 0.91 V in 1 M KOH and higher kinetic current and better catalytic durability than Pt/C.Moreover,CMO@CNTs afford an electrocatalytic OER current density of 10 mA cm^(−2) at a low potential of 1.5 V and a small Tafel slope of 81.1 mV dec^(−1).Furthermore,CMO@CNTs display lower discharge/charge overpotential and more stable voltage plateau on cycling than that of Pt/C when employed as a cathode material in rechargeable Zn–air cells.This work indicates that CMO@CNTs are a promising,cheap and efficient bifunctional ORR/OER electrocatalyst for rechargeable metal–air batteries.
基金National Natural Science Foundation of China(214011792167704511775168)。
文摘Herein,this paper describes the synthesis of sodium carboxymethyl cellulose(CMC)/iron oxides/multiwalled carbon nanotubes(MMWCNTs)composites(denoted as CMC/MMWCNTs)by a plasma technique and their application to the decontamination of europium ions from aqueous solutions under controlled laboratory conditions.Batch experiments were conducted to understand the interaction mechanism of europium ion sorption onto the surface of CMC/MMWCNTs nanoparticles and to evaluate the application prospects of CMC/MMWCNTs in the field of pollution remediation.The adsorption capacity of Eu(III)on CMC/MMWCNTs was greater than that of major adsorbents,illustrating that the conjugated CMC could increase the sorption capacity of CMC/MMWCNTs nanoparticles toward Eu(III)ions through providing multiple hydroxyl and carboxyl functional groups.The mutual interaction of Eu(III)ion immobilization on CMC/MMWCNTs was contributed to by outer-sphere surface complexation at low pH values,but inner-sphere surface complexation was the dominant interactional mechanism at high pH values.The experimental findings herein demonstrate that CMC/MMWCNTs composites can be highly effective adsorbents for the immobilization of Eu(III)ions or other trivalent actinide/lanthanide ions from large volumes of aqueous solution.
