Heat transport in one kind of double-bond linear chains of fullerenes （C60＇s） is investigated by the classical nonequilibrium molecular dynamics method. It is found that the negative differential thermal resistance...Heat transport in one kind of double-bond linear chains of fullerenes （C60＇s） is investigated by the classical nonequilibrium molecular dynamics method. It is found that the negative differential thermal resistance （NDTR） is more likely to occur at larger temperature difference and shorter length. In addition, with the increase of the length, the thermal conductivity of the chains increases, and NDTR region shrinks and vanishes in the end. The temperature profiles reveal that a large temperature jump exists at a high-temperature boundary of the chains when NDTR occurs. These results may be helpful for designing thermal devices where low-dimensional C60 polymers can be used.展开更多
Using Lindblad approach to study decoherence of quantum systems, we study the decoherence and decay of entangled states, formed by two basic states of a chain of thee qubits. We look on these states for a possible reg...Using Lindblad approach to study decoherence of quantum systems, we study the decoherence and decay of entangled states, formed by two basic states of a chain of thee qubits. We look on these states for a possible regular dependence on their decay as a function of their energy separation between the basic states under different types of environments. We didn’t find regular or significant dependence on this energy separation for the type of environment considered.展开更多
The stability of the linear chain structure of three α clusters for 12C against the bending and fission is investigated in the cranking covariant density functional theory, in which the equation of motion is solved o...The stability of the linear chain structure of three α clusters for 12C against the bending and fission is investigated in the cranking covariant density functional theory, in which the equation of motion is solved on a 3D lattice with the inverse Hamiltonian and the Fourier spectral methods. Starting from a twisted three α initial configuration, it is found that the linear chain structure is stable when the rotational frequency is within the range of ~2.0-~2.5 MeV. Beyond this range, the final states are not stable against fission. By examining the density distributions and the occupation of single-particle levels, however, these fissions are found to arise from the occupation of unphysical continuum with large angular momenta. To properly remove these unphysical continuum, a damping function for the cranking term is introduced. Eventually, the stable linear chain structure could survive up to the rotational frequency ~3.5 MeV, but the fission still occurs when the rotational frequency approaches ~4.0 MeV.展开更多
The plastification modification of poly （vinyl chloride） （PVC） with the long-chain linear polyester （LP） synthesized by linear dodecanedioic acid （DC12） or tetradecanedioic acid （DC14） with different diols i...The plastification modification of poly （vinyl chloride） （PVC） with the long-chain linear polyester （LP） synthesized by linear dodecanedioic acid （DC12） or tetradecanedioic acid （DC14） with different diols is investigated. The processing characteristics, mechanical properties and extraction property of the PVC/LP blends in different solvents （xylene, cyclohexane, ethanol） were also studied in detail. All results were compared with that of the PVC plasticized with dioctyl phthalate （DOP）. The results show that the molecular weight, molecular structure and loading of LP greatly influence the mechanical properties of the PVC/LP blends. The processability and the mechanical properties of PVC plasticized by LP are comparable to those of the corresponding PVC/DOP blends. However, the PVC/LP blends posses much better migration resistance property than the corresponding PVC/DOP blends, which makes the long-chain linear polyester become a very good plasticizer candidate for PVC industry.展开更多
Linear carbon chains as new one-dimensional(1D)nanomaterials attract attention for the predicted outstanding properties.However,the high reactivity of linear carbon chains hampers further experimental research.To date...Linear carbon chains as new one-dimensional(1D)nanomaterials attract attention for the predicted outstanding properties.However,the high reactivity of linear carbon chains hampers further experimental research.To date,different methods have been developed to synthesize new materials containing linear carbon chains.Among them,the arc-discharge method is a practical way to prepare both finite and infinite linear carbon chains.This review provides a brief discussion of the recent progress in the techniques to prepare carbon chain-based materials and then focuses on the arc-discharge method.The configuration of apparatus,optimal conditions,and the corresponding mechanism of arc-discharge method to prepare long linear carbon chain inside multi-walled carbon nanotubes are summarized in detail.The characterization techniques are introduced to evaluate the quality of products.Moreover,remaining challenges and perspectives are presented for further investigation of long linear carbon chains.展开更多
The title complex [NH4]n [WAgS4]n crystallizes in the tetragonalspace group I4 with crystallographic parameters: a = b = 7. 994 (2 ), c = 5. 855 (2 ):A,V = 373. g(2) A3, Z=2, Dc= 3. 89 g/cm3, F(000) = 392, μ= 19. 27 ...The title complex [NH4]n [WAgS4]n crystallizes in the tetragonalspace group I4 with crystallographic parameters: a = b = 7. 994 (2 ), c = 5. 855 (2 ):A,V = 373. g(2) A3, Z=2, Dc= 3. 89 g/cm3, F(000) = 392, μ= 19. 27 mm-l , A(MoKα) = 0. 71069, Mr = 438. 01, and the convergence factors R = 0. 045, Rw =0. 055 for 341 observed reflections (I>3σ(I)). The anion structure can be viewed as apolymeric single chain consisting of unlimited extended rhombic fragruents of -AgS2W-which are alternately perpendicular to each other. Additionally, influence of di- and tri-valent complex cations on the assembIy of WS2-4 and Ag+ is briefly discussed.展开更多
With respect to different risk preference of an agent in a supply chain, linear-contract models are designed according to the principal-agent theory. The study shows that the risk preference of an agent directly corre...With respect to different risk preference of an agent in a supply chain, linear-contract models are designed according to the principal-agent theory. The study shows that the risk preference of an agent directly correlates with the incentive compensation coefficient of principal, order quantity of principal and production capability level of the agent. The principal should offer an appropriate incentive contract according to the risk preference of the agent, or choose an agent holding a different risk preference to establish the supply chain.展开更多
Two new complexes, [W2Ag2S8?Ca(DMF)6]n 1 and [WAgS4?Na(DMF)3]n 2, have been synthesized and characterized. Single-crystal X-ray analyses show both 1 and 2 have {WAgS4}n anion linear chains, but 1 has a discrete [Ca(DM...Two new complexes, [W2Ag2S8?Ca(DMF)6]n 1 and [WAgS4?Na(DMF)3]n 2, have been synthesized and characterized. Single-crystal X-ray analyses show both 1 and 2 have {WAgS4}n anion linear chains, but 1 has a discrete [Ca(DMF)6]2+ cation while 2 is a linear chain. UV-Visible-Near-IR spectroscopy data show that the bandgaps of the two complexes are 1.86 and 1.99 eV, respectively. Electrical conductivity measurements reveal the conductivities of 1 and 2 are 10?7 and 10?8 Scm?1, respectively and they exhibit thermally activated temperature depen- dence, which may be attributed to semiconductors.展开更多
The syntheses and structures of eleven novel polymeric transition metal complexes having one dimensional chain structures or three dimensional networks are summarized. They are prepared from the controlled assemblin...The syntheses and structures of eleven novel polymeric transition metal complexes having one dimensional chain structures or three dimensional networks are summarized. They are prepared from the controlled assembling reactions in organic solvents and characterized by X ray diffraction analyses. The spectroscopic or magnetic properties of some complexes are studied.展开更多
The thermodynamic properties of linear protein solutions are discussed by a statistical me-chanics theory with a lattice model. The numerical results show that the Gibbs function of the solution decreases, and the pro...The thermodynamic properties of linear protein solutions are discussed by a statistical me-chanics theory with a lattice model. The numerical results show that the Gibbs function of the solution decreases, and the protein chemical potential is enhanced with increase of the protein concentration for dilute solutions. The influences of chain length and temperature on the Gibbs function of the solution as well as the protein chemical potential are analyzed.As an application of the theory, the chemical potentials of some mutants of type I antifreeze proteins are computed and discussed.展开更多
Two new A-D-A porphyrin derivatives,denoted as XLP-I and XLP-II,were prepared through extending theπ-conjugation of thienothiophene-porphyrin center with phenylethynyl bridges and electron-deficient ethylrhodanine te...Two new A-D-A porphyrin derivatives,denoted as XLP-I and XLP-II,were prepared through extending theπ-conjugation of thienothiophene-porphyrin center with phenylethynyl bridges and electron-deficient ethylrhodanine terminal units,and varying the structures of alkyl chain(linear vs branched)on peripheral thienothiophene substitutions of porphyrin rings.Both molecules show strong absorption in UV–visible–near-infrared region,good thermal stability,suitable energy levels,and ordered molecular packing in solid state.In organic solar cells,PC71BM was used as electron acceptor,and porphyrin small molecules were used as electron donors.The device based on XLP-I exhibits a power conversion efficiency(PCE)of 8.30%,an open circuit voltage(Voc)of 0.894 eV,and a fill factor(FF)of 62.1%.In contrast,the device based on XLP-II presents an inferior performance with a PCE of 3.14%,a Voc of 0.847 eV,and a FF of 49.3%.The better performance of XLP-I based device is mainly attributed to its optimized film morphology,excellent absorption,and well-balanced charge transport properties.展开更多
Carbyne is an infinitely long linear chain of carbon atoms with sp1hybridization and the truly one-dimensional allotrope of carbon.While obtaining freestanding carbyne is still an open challenge,the study of confined ...Carbyne is an infinitely long linear chain of carbon atoms with sp1hybridization and the truly one-dimensional allotrope of carbon.While obtaining freestanding carbyne is still an open challenge,the study of confined carbyne,linear chains of carbon encapsulated in carbon nanotubes,provides a pathway to explore carbyne and its remarkable properties in a well-defined environment.In this review,we discuss the basics and recent advances in studying single confined carbyne chains by Raman spectroscopy,which is their primary spectroscopic characterization method.We highlight where single carbyne chain studies are needed to advance our understanding of confined carbyne as a material system and provide an overview of the open questions that need to be addressed and of those aspects currently under debate.展开更多
This paper studies a discrete one-dimensional monatomic Klein Gordon chain with only quartic nearest-neighbour interactions, in which the compact-like discrete breathers can be explicitly constructed by an exact separ...This paper studies a discrete one-dimensional monatomic Klein Gordon chain with only quartic nearest-neighbour interactions, in which the compact-like discrete breathers can be explicitly constructed by an exact separation of their time and space dependence. Introducing the trying method, it proves that compact-like discrete breathers exist in this nonlinear system. It also discusses the linear stability of the compact-like discrete breathers, when the coefficient （β） of quartic on-site potential and the coupling constant （K4） of quartic interactive potential satisfy the given conditions, they are linearly stable.展开更多
Invariant measures of Markov chains in discrete or continuous time with a countable set of states are characterized by its steady state recurrence relations. Exemplarily, we consider transition matrices and Q-matrices...Invariant measures of Markov chains in discrete or continuous time with a countable set of states are characterized by its steady state recurrence relations. Exemplarily, we consider transition matrices and Q-matrices with upper bandwidth n and lower bandwidth 1 where the invariant measures satisfy an (n + 1)-order linear difference equation. Markov chains of this type arise from applications to queueing problems and population dynamics. It is the purpose of this paper to point out that the forward use of this difference equation is subject to some hitherto unobserved aspects. By means of the concept of generalized continued fractions (GCFs), we prove that each invariant measure is a dominated solution of the difference equation such that forward computation becomes numerically unstable. Furthermore, the GCF-based approach provides a decoupled recursion in which the phenomenon of numerical instability does not appear. The procedure results in an iteration scheme for successively computing approximants of the desired invariant measure depending on some truncation level N. Increasing N leads to the desired solution. A comparison study of forward computation and the GCF-based approach is given for Q-matrices with upper bandwidth 1 and 2.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11004082 and 11005048the Natural Science Foundation of Guangdong Province under Grant No 2014A030313367
文摘Heat transport in one kind of double-bond linear chains of fullerenes （C60＇s） is investigated by the classical nonequilibrium molecular dynamics method. It is found that the negative differential thermal resistance （NDTR） is more likely to occur at larger temperature difference and shorter length. In addition, with the increase of the length, the thermal conductivity of the chains increases, and NDTR region shrinks and vanishes in the end. The temperature profiles reveal that a large temperature jump exists at a high-temperature boundary of the chains when NDTR occurs. These results may be helpful for designing thermal devices where low-dimensional C60 polymers can be used.
文摘Using Lindblad approach to study decoherence of quantum systems, we study the decoherence and decay of entangled states, formed by two basic states of a chain of thee qubits. We look on these states for a possible regular dependence on their decay as a function of their energy separation between the basic states under different types of environments. We didn’t find regular or significant dependence on this energy separation for the type of environment considered.
基金supported by the National Key R&D Program of China(Grant Nos.2018YFA0404400,and 2017YFE0116700)the National Natural Science Foundation of China(Grant Nos.11621131001,and 11875075)the Laboratory Computing Resource Center at Argonne National Laboratory
文摘The stability of the linear chain structure of three α clusters for 12C against the bending and fission is investigated in the cranking covariant density functional theory, in which the equation of motion is solved on a 3D lattice with the inverse Hamiltonian and the Fourier spectral methods. Starting from a twisted three α initial configuration, it is found that the linear chain structure is stable when the rotational frequency is within the range of ~2.0-~2.5 MeV. Beyond this range, the final states are not stable against fission. By examining the density distributions and the occupation of single-particle levels, however, these fissions are found to arise from the occupation of unphysical continuum with large angular momenta. To properly remove these unphysical continuum, a damping function for the cranking term is introduced. Eventually, the stable linear chain structure could survive up to the rotational frequency ~3.5 MeV, but the fission still occurs when the rotational frequency approaches ~4.0 MeV.
基金the Engineering Developing Foundation of Tongji University
文摘The plastification modification of poly （vinyl chloride） （PVC） with the long-chain linear polyester （LP） synthesized by linear dodecanedioic acid （DC12） or tetradecanedioic acid （DC14） with different diols is investigated. The processing characteristics, mechanical properties and extraction property of the PVC/LP blends in different solvents （xylene, cyclohexane, ethanol） were also studied in detail. All results were compared with that of the PVC plasticized with dioctyl phthalate （DOP）. The results show that the molecular weight, molecular structure and loading of LP greatly influence the mechanical properties of the PVC/LP blends. The processability and the mechanical properties of PVC plasticized by LP are comparable to those of the corresponding PVC/DOP blends. However, the PVC/LP blends posses much better migration resistance property than the corresponding PVC/DOP blends, which makes the long-chain linear polyester become a very good plasticizer candidate for PVC industry.
基金Project supported by the Fund from the Huzhou Key Laboratory of Environmental Functional Materials and Pollution Control at Huzhou University
文摘Linear carbon chains as new one-dimensional(1D)nanomaterials attract attention for the predicted outstanding properties.However,the high reactivity of linear carbon chains hampers further experimental research.To date,different methods have been developed to synthesize new materials containing linear carbon chains.Among them,the arc-discharge method is a practical way to prepare both finite and infinite linear carbon chains.This review provides a brief discussion of the recent progress in the techniques to prepare carbon chain-based materials and then focuses on the arc-discharge method.The configuration of apparatus,optimal conditions,and the corresponding mechanism of arc-discharge method to prepare long linear carbon chain inside multi-walled carbon nanotubes are summarized in detail.The characterization techniques are introduced to evaluate the quality of products.Moreover,remaining challenges and perspectives are presented for further investigation of long linear carbon chains.
文摘The title complex [NH4]n [WAgS4]n crystallizes in the tetragonalspace group I4 with crystallographic parameters: a = b = 7. 994 (2 ), c = 5. 855 (2 ):A,V = 373. g(2) A3, Z=2, Dc= 3. 89 g/cm3, F(000) = 392, μ= 19. 27 mm-l , A(MoKα) = 0. 71069, Mr = 438. 01, and the convergence factors R = 0. 045, Rw =0. 055 for 341 observed reflections (I>3σ(I)). The anion structure can be viewed as apolymeric single chain consisting of unlimited extended rhombic fragruents of -AgS2W-which are alternately perpendicular to each other. Additionally, influence of di- and tri-valent complex cations on the assembIy of WS2-4 and Ag+ is briefly discussed.
基金The paper is supported by National Natural Science Foundation of China under Grant No60372085,60404011the Youth Foundation of Northwestern Polytechnical University
文摘With respect to different risk preference of an agent in a supply chain, linear-contract models are designed according to the principal-agent theory. The study shows that the risk preference of an agent directly correlates with the incentive compensation coefficient of principal, order quantity of principal and production capability level of the agent. The principal should offer an appropriate incentive contract according to the risk preference of the agent, or choose an agent holding a different risk preference to establish the supply chain.
基金This research was supported by the State Key Laboratory of Structural Chemistry, the National Science and Technology of China (001CB1089), the Chinese Academy of Sciences (CAS), the National Science Foundation of China (20273073, 20333070, 90206040)
文摘Two new complexes, [W2Ag2S8?Ca(DMF)6]n 1 and [WAgS4?Na(DMF)3]n 2, have been synthesized and characterized. Single-crystal X-ray analyses show both 1 and 2 have {WAgS4}n anion linear chains, but 1 has a discrete [Ca(DMF)6]2+ cation while 2 is a linear chain. UV-Visible-Near-IR spectroscopy data show that the bandgaps of the two complexes are 1.86 and 1.99 eV, respectively. Electrical conductivity measurements reveal the conductivities of 1 and 2 are 10?7 and 10?8 Scm?1, respectively and they exhibit thermally activated temperature depen- dence, which may be attributed to semiconductors.
文摘The syntheses and structures of eleven novel polymeric transition metal complexes having one dimensional chain structures or three dimensional networks are summarized. They are prepared from the controlled assembling reactions in organic solvents and characterized by X ray diffraction analyses. The spectroscopic or magnetic properties of some complexes are studied.
基金This work was supported by the National Natural Science Foundation of China （No.10764003 and No.30560039）.
文摘The thermodynamic properties of linear protein solutions are discussed by a statistical me-chanics theory with a lattice model. The numerical results show that the Gibbs function of the solution decreases, and the protein chemical potential is enhanced with increase of the protein concentration for dilute solutions. The influences of chain length and temperature on the Gibbs function of the solution as well as the protein chemical potential are analyzed.As an application of the theory, the chemical potentials of some mutants of type I antifreeze proteins are computed and discussed.
基金the national key R&D program for international collaboration(No.2021YFE0191500)the National Natural Science Foundation of China(No.51473053)+3 种基金the Natural Science Foundation of Hunan Province(No.2019JJ50603)the Peacock Team Project funding from Shenzhen Science and Technology Innovation Committee(No.KQTD2015033110182370)the Fundamental Research Project funding from Shenzhen Science and Technology Innovation Committee(No.JCYJ 20190809150213448).X.Zhu thanks the financial support from Hong Kong Research Grants Council(HKBU 12304320).
文摘Two new A-D-A porphyrin derivatives,denoted as XLP-I and XLP-II,were prepared through extending theπ-conjugation of thienothiophene-porphyrin center with phenylethynyl bridges and electron-deficient ethylrhodanine terminal units,and varying the structures of alkyl chain(linear vs branched)on peripheral thienothiophene substitutions of porphyrin rings.Both molecules show strong absorption in UV–visible–near-infrared region,good thermal stability,suitable energy levels,and ordered molecular packing in solid state.In organic solar cells,PC71BM was used as electron acceptor,and porphyrin small molecules were used as electron donors.The device based on XLP-I exhibits a power conversion efficiency(PCE)of 8.30%,an open circuit voltage(Voc)of 0.894 eV,and a fill factor(FF)of 62.1%.In contrast,the device based on XLP-II presents an inferior performance with a PCE of 3.14%,a Voc of 0.847 eV,and a FF of 49.3%.The better performance of XLP-I based device is mainly attributed to its optimized film morphology,excellent absorption,and well-balanced charge transport properties.
基金funding from the Deutsche Forschungsgemeinschaft(DFG)under the Emmy Noether Initiative(HE 8642/1-1)
文摘Carbyne is an infinitely long linear chain of carbon atoms with sp1hybridization and the truly one-dimensional allotrope of carbon.While obtaining freestanding carbyne is still an open challenge,the study of confined carbyne,linear chains of carbon encapsulated in carbon nanotubes,provides a pathway to explore carbyne and its remarkable properties in a well-defined environment.In this review,we discuss the basics and recent advances in studying single confined carbyne chains by Raman spectroscopy,which is their primary spectroscopic characterization method.We highlight where single carbyne chain studies are needed to advance our understanding of confined carbyne as a material system and provide an overview of the open questions that need to be addressed and of those aspects currently under debate.
基金Project supported by the National Natural Science Foundation of China (Grant No 10574011)Natural Science Foundation of Heilongjiang Province, China (Grant No A200506)
文摘This paper studies a discrete one-dimensional monatomic Klein Gordon chain with only quartic nearest-neighbour interactions, in which the compact-like discrete breathers can be explicitly constructed by an exact separation of their time and space dependence. Introducing the trying method, it proves that compact-like discrete breathers exist in this nonlinear system. It also discusses the linear stability of the compact-like discrete breathers, when the coefficient （β） of quartic on-site potential and the coupling constant （K4） of quartic interactive potential satisfy the given conditions, they are linearly stable.
文摘Invariant measures of Markov chains in discrete or continuous time with a countable set of states are characterized by its steady state recurrence relations. Exemplarily, we consider transition matrices and Q-matrices with upper bandwidth n and lower bandwidth 1 where the invariant measures satisfy an (n + 1)-order linear difference equation. Markov chains of this type arise from applications to queueing problems and population dynamics. It is the purpose of this paper to point out that the forward use of this difference equation is subject to some hitherto unobserved aspects. By means of the concept of generalized continued fractions (GCFs), we prove that each invariant measure is a dominated solution of the difference equation such that forward computation becomes numerically unstable. Furthermore, the GCF-based approach provides a decoupled recursion in which the phenomenon of numerical instability does not appear. The procedure results in an iteration scheme for successively computing approximants of the desired invariant measure depending on some truncation level N. Increasing N leads to the desired solution. A comparison study of forward computation and the GCF-based approach is given for Q-matrices with upper bandwidth 1 and 2.
