Homogeneous films with tailored microporous structures are crucial for several applications;however,fabricating such films presents significant challenges.This is primarily because most microporous materials have crys...Homogeneous films with tailored microporous structures are crucial for several applications;however,fabricating such films presents significant challenges.This is primarily because most microporous materials have crystal sizes in the nanoand micrometer ranges,which inevitably generates intergranular spaces in the films,thereby complicating the fabrication of these thin films.In this study,functionalized metal–organic polyhedra(MOPs)are used as discrete microporous units and assembled into homogenous microporous films.The generation of intergranular spaces is avoided while controlling packing parameters and film thicknesses.Initially,the MOP units,influenced by van der Waals forces between carbon chains of functionalized adipic acids,display an affinity to form spindle-shaped blocks and islands.As the MOP concentration increases,these structures self-assembled into a hexagonally packed structure with an in-plane orientation and a maximum stacking of two layers of MOPs.By contrast,un-functionalized MOPs form a disordered film structure owing to random agglomeration.Evidently,functionalized adipic acid influences the orientation of the MOP network films with uniformly distributed micropores,effectively preventing the formation of intergranular spaces.Additionally,formaldehyde adsorption and desorption experiments revealed that the MOP network films possess superior adsorption and desorption capacities.The proposed approach signifies a breakthrough in the fabrication of homogenous microporous films.展开更多
A thorough study of regular and quasi-regular polyhedra shows that the symmetries of these polyhedra identically describe the quantization of orbital angular momentum, of spin, and of total angular momentum, a fact wh...A thorough study of regular and quasi-regular polyhedra shows that the symmetries of these polyhedra identically describe the quantization of orbital angular momentum, of spin, and of total angular momentum, a fact which permits one to assign quantum states at the vertices of these polyhedra assumed as the average particle positions. Furthermore, if the particles are fermions, their wave function is anti-symmetric and its maxima are identically the same as those of repulsive particles, e.g., on a sphere like the spherical shape of closed shells, which implies equilibrium of these particles having average positions at the aforementioned maxima. Such equilibria on a sphere are solely satisfied at the vertices of regular and quasi-regular polyhedra which can be associated with the most probable forms of shells both in Nuclear Physics and in Atomic Cluster Physics when the constituent atoms possess half integer spins. If the average sizes of the constituent particles are known, then the average sizes of the resulting shells become known as well. This association of Symmetry with Quantum Mechanics leads to many applications and excellent results.展开更多
In the late phase of Bombyx mori nucleopolyhedrovirus(BmNPV)infection,a large amount of polyhedra appear in the infected cell nucleolus,these polyhedra being dense protein crystals protecting the incorporated virions ...In the late phase of Bombyx mori nucleopolyhedrovirus(BmNPV)infection,a large amount of polyhedra appear in the infected cell nucleolus,these polyhedra being dense protein crystals protecting the incorporated virions from the harsh environment.To investigate whether the foreign protein could be immobilized into the polyhedra of BmNPV,two recombinant baculoviruses were generated by a novel BmNPV polyhedrin-plus(polh +)Bac-to-Bac system,designated as vBmBac(polh +)-enhanced green fluorescent protein(EGFP)and vBmBac(polh +)-LacZ,which can express the polyhedrin and foreign protein simultaneously.Light microscopy analysis showed that all viruses produced polyhedra of normal appearance.Green fluorescence can be apparently detected on the surface of the vBmBac(polh +)-EGFP polyhedra,but not the BmNPV polyhedra.Fluorescence analysis and anti-desiccation testing confirmed that EGFP was embedded in the polyhedra.As expected,the vBmBac(polh +)-LacZ polyhedra contained an amount of LacZ and had a higherβ-galactosidase activity.Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE)and Western blotting were also performed to verify if the foreign proteins were immobilized into polyhedra.This study provides a new inspiration for efficient preservation of useful proteins and development of new pesticides with toxic proteins.展开更多
Silicon(Si)holds promise as an anode material for lithium-ion batteries(LIBs)as it is widely avail-able and characterized by high specific capacity and suitable working potential.However,the relatively low electrical ...Silicon(Si)holds promise as an anode material for lithium-ion batteries(LIBs)as it is widely avail-able and characterized by high specific capacity and suitable working potential.However,the relatively low electrical conductivity of Si and the significantly high extent of volume expansion realized dur-ing lithiation hinder its practical application.We prepared N-doped carbon polyhedral micro cage en-capsulated Si nanoparticles derived from Co-Mo bimetal metal-organic framework(MOFs)(denoted as Si/CoMo@NCP)and explored their lithium storage performance as anode materials to address these prob-lems.The Si/CoMo@NCP anode exhibited a high reversible lithium storage capacity(1013 mAh g^(−1)at 0.5 A g^(−1)after 100 cycles),stable cycle performance(745 mAh g^(−1)at 1 A g^(−1)after 400 cycles),and excellent rate performance(723 mAh g^(−1)at 2 A g^(−1)).Also,the constructed the full-cell NCM 811//Si/CoMo@NCP exhibited well reversible capacity.The excellent electrochemical performances of Si/CoMo@NCP were at-tributed to two unique properties.The encapsulation of NCP with doped nitrogen and porous structural carbon improves the electrical conductivity and cycling stability of the molecules.The introductions of metallic cobalt and its oxides help to improve the rate capability and lithiation capacity of the materials following multi-electron reaction mechanisms.展开更多
The nature and origin of a fundamental quantum QSPR （QQSPR） equation are discussed. In principle, as any molecular structure can be associated to quantum mechanical density functions （DF）, a molecular set can be r...The nature and origin of a fundamental quantum QSPR （QQSPR） equation are discussed. In principle, as any molecular structure can be associated to quantum mechanical density functions （DF）, a molecular set can be reconstructed as a quantum multimolecular polyhedron （QMP）, whose vertices are formed by each molecular DF. According to QQSPR theory, complicated kinds of molecular properties, like biological activity or toxicity, of molecular sets can be calculated via the quantum expectation value of an approximate Hermitian operator, which can be evaluated with the geometrical information contained in the attached QMP via quantum similarity matrices. Practical ways of solving the QQSPR problem from the point of view of QMP geometrical structure are provided. Such a development results into a powerful algorithm, which can be implemented within molecular design as an alternative to the current classical QSPR procedures.展开更多
Archimedean solids were first proposed by the ancient Greek philosopher Archimedes.Unfortunately,this aspect of his work was not well-documented.It was not until 1619 that the mathematician Johannes Kepler reconstruct...Archimedean solids were first proposed by the ancient Greek philosopher Archimedes.Unfortunately,this aspect of his work was not well-documented.It was not until 1619 that the mathematician Johannes Kepler reconstructed the complete set of 13 Archimedean solids[1].Among these solids,only the snub cube and snub dodecahedron are chiral.展开更多
Catalytic cleavage ofβ-O-4 linkages is an essential but challenging step in the depolymerization of lignin.Here,we report the templated electrosynthesis of a hydrophobic metal-organic polyhedral catalyst(Cu-MOP-e),wh...Catalytic cleavage ofβ-O-4 linkages is an essential but challenging step in the depolymerization of lignin.Here,we report the templated electrosynthesis of a hydrophobic metal-organic polyhedral catalyst(Cu-MOP-e),which exhibits excellent hydrothermal stability and exceptional activity for this reaction.The oxidative cleavage of 2-phenoxyacetophenone,1,a lignin model compound,over Cu-MOP-e at 90℃for 1 h affords full conversion with yields of the monomer products phenol and benzoic acid of 99%.The reusability of Cu-MOP-e was confirmed by carrying out ten cycles of reaction.The mechanism of catalyst-substrate binding was investigated by highresolution synchrotron X-ray powder diffraction,in situ X-ray absorption spectroscopy,electron paramagnetic resonance spectroscopy,and density functional theory(DFT)calculations.The combination of optimal porosity and active Cu(Ⅱ)sites provides confined binding of 2-phenoxyacetophenone,thus promoting the cleavage ofβ-O-4 linkage under relatively mild conditions.展开更多
Mixed matrix membranes(MMMs)are designed by incorporating microporous inorganic fillers into polymer matrix for the integration of inorganics’excellent gas separation performance with polymers’promising flexibility....Mixed matrix membranes(MMMs)are designed by incorporating microporous inorganic fillers into polymer matrix for the integration of inorganics’excellent gas separation performance with polymers’promising flexibility.However,due to the complex interphase interaction,the prevention of long-term aging is still challenging and the poor processability/recyclability of MMMs hinders their extensive applications.Herein,a coordination assembly protocol is developed for the fabrication of MMMs with both excellent processability/recyclability upon thermal annealing and promising dimension stability even under high gas pressure.Polymers bearing isophthalic acid(IPA)as side chains are applied to coordinate with Cu^(2+)and the assembled 2.5 nm microporous metal-organic polyhedra(MOP),{Cu_(24)IPA_(24)},serves as multi-functional cross-linkers for the polymer network formation.The MOPs’well-defined microporosity grants MMMs the capability for O_(2)/N_(2) separation while their activated dynamics at high temperatures(>120℃)endows polymer networks with excellent processability.In contrast to conventional supramolecular units,the MOPs possess unique logarithmic ligand-exchange kinetics and they show nearly frozen bonding dynamics at room temperature,ensuring promising dimensional stability to overcome the long-term aging and high gas pressure effect.This work not only provides fundamental understanding of the unique relaxation dynamics of complex systems with intertwined dynamics of supramolecular bonds and polymer chains,but also paves new avenues for the fabrication of robust and recyclable MMMs and elastomers.展开更多
Zinc-air batteries have recently attracted considerable interest owing to the larger storage capacity and lower cost compared to their lithium-ion counterparts. Electrode catalysts for the oxygen reduction reaction （...Zinc-air batteries have recently attracted considerable interest owing to the larger storage capacity and lower cost compared to their lithium-ion counterparts. Electrode catalysts for the oxygen reduction reaction （ORR） and oxygen evolution reaction （OER） play a critical role in the operation of rechargeable zinc-air batteries. Herein, we report a simple and scalable strategy to fabricate porous carbon polyhedra using Zn-doped Co-based zeolitic imidazolate frameworks （ZnCo-ZIFs） as precursors. Strikingly, Zn doping leads to smaller Co nanoparticles and higher nitrogen content, which in turn enhances the ORR and OER activities of the obtained porous carbon polyhedra. The synergistic effect of the N-doped carbon and cobalt nanoparticles in the composite, the improved conductivity resulting from the high graphitization of carbon, and the large surface area of the porous polyhedral structure resulted in porous carbon polyhedra with excellent ORR and OER electrocatalytic activity in alkaline media. More importantly, air cathodes based on the optimal porous carbon polyhedra further exhibited superior performance to Pt/C catalysts in primary and rechargeable zinc-air batteries.展开更多
A series of unique nanowire superstructures, Cu2O nanowire polyhedra, have been synthesized through a cost-effective hydrothermal route. Three types of nanowire polyhedra, namely octahedra, concave octahedra, and hexa...A series of unique nanowire superstructures, Cu2O nanowire polyhedra, have been synthesized through a cost-effective hydrothermal route. Three types of nanowire polyhedra, namely octahedra, concave octahedra, and hexapods, were formed in high morphological yields （90%） by reducing cupric acetate with o-anisidine or o-phenetidine in the presence of carboxylic acids. The architectures of these Cu2O nanowire polyhedra were examined by electron microscopy, which revealed ordered, highly aligned CU2O nanowires within the polyhedral outlines. The growth of the Cu2O nanowire polyhedra is controlled by the orientation and growth rates of the nanowire branches which are adjusted by addition of carboxylic acids. Compared to the Cu2O samples reported in the recent literature, the Cu2O nanowire octahedra exhibit notably enhanced photocatalytic activities for dye degradation in the presence of H202 under visible light, probably due to the high-density charge carriers photoexcited from the branched nanowires with their special structures. Additionally, the discussion in the recent literature of the photocatalytic activity of Cu2O in the absence of H2O2 for direct photodegradation of dyes seems questionable.展开更多
The challenge for single-atom catalysts in various C-C cross coupling reaction exists in the development of solid supporting materials.It has been desired tofind a supporting material designed in molecular level to an...The challenge for single-atom catalysts in various C-C cross coupling reaction exists in the development of solid supporting materials.It has been desired tofind a supporting material designed in molecular level to anchor a single-atom catalyst and provide high degree of dispersion and substrate access in aqueous media.Here,we prepared discrete cages of metal-organic polyhedra anchoring single Pd atom(MOP-BPY(Pd))and successfully performed a Suzuki-Miyaura cross coupling reaction with various substrates in aqueous media.It was revealed that each tetrahedral cage of MOP-BPY(Pd)has 4.5 Pd atoms on average and retained its high degree of dispersion up to 3 months in water.The coupling efficiencies of the Suzuki-Miyaura cross coupling reaction exhibited more than 90.0%for various substrates we have tested in the aqueous media,which is superior to those of the molecular Pd complex and metal-organic framework(MOF)anchoring Pd atoms.Moreover,MOP-BPY(Pd)was successfully recovered and recycled without performance degradation.展开更多
Based on the concept of gauge function, the pseudo minimum translational distance (PMTD) between two convex objects is defined in this paper. PMTD not only provides a measure of the clearance between two separating ob...Based on the concept of gauge function, the pseudo minimum translational distance (PMTD) between two convex objects is defined in this paper. PMTD not only provides a measure of the clearance between two separating objects, but also quantifies the penetration of two objects intersecting each other. It is proved that the PMTD is differentiate almost everywhere w. r.t. the configuration variable of the objects. Algorithms for calculating PMTD and its derivative are also presented.展开更多
An octahedrite is a 4-valent polyhedron with only 3-faces and 4-faces. We study edge-partitions of some octahedrites, medial and related polyhedra into central circuits.
Metal-organic polyhedra(MOPs)have emerged as versatile platforms for artificial models of biological systems due to their discrete structure and modular nature.However,the design and fabrication of MOPs with special f...Metal-organic polyhedra(MOPs)have emerged as versatile platforms for artificial models of biological systems due to their discrete structure and modular nature.However,the design and fabrication of MOPs with special functionality for mimicking biological processes are challenging.Inspired by the breathing mechanism of lungs,we developed a new type of MOP(a breathing MOP,denoted as NUT-101)by directly using azobenzene units as the pillars of the polyhedra to coordinate with Zr-based metal clusters.In addition to considerable thermal and chemical stability,the obtained MOP exhibits photocontrollable breathing behavior.Upon irradiation with visible or UV light,the configuration of azobenzene units transforms,leading to reversible expansion or contraction of the cages and,correspondingly,capture or liberation of CO_(2)molecules.Such a breathing behavior of NUT-101 is further confirmed by density functional theory(DFT)calculation.This system might establish an avenue for the construction of new materials with particular functionality that mimic biological processes.展开更多
Metal-organic polyhedra(MOPs)possess a microporous framework and impose hierarchical constraints on their surface ligands,leading to the long-ignored,logarithmic ligand exchange dynamics.Herein,polymer networks with M...Metal-organic polyhedra(MOPs)possess a microporous framework and impose hierarchical constraints on their surface ligands,leading to the long-ignored,logarithmic ligand exchange dynamics.Herein,polymer networks with MOP as nanoscale cross-linkers(MOP-CNs)can integrate unique ligand exchange dynamics and microporosity,affording vitrimer-like gas separation membranes with promising mechanical performance and(re)processability.All the ligands on the MOP surfaces are confined and correlated via a 3D coordination framework and their neighboring spaces,giving rise to a high energy barrier for ligand exchange.Therefore,MOP-CNs demonstrate high mechanical strengths at room temperature due to their negligible ligand dynamics.The thermo-activated ligand exchange process with integrated network topology enables facile(re)processing and high solvo-resistance at high temperatures.This facilitates Arrhenius type temperature dependence of flowability and stress relaxation,giving rise to the simultaneous achievement of promising mechanical strengths and(re)processability.Finally,the cage topologies of MOPs endow the materials with a bonus microporous feature and spur their applications as gas separation membranes.展开更多
Creating and rendering intermediate geometric primitives is one of the approaches to visualize data sets in 3D space. Some algorithms have been developed to construct isosurface from uniformly distributed 3D data sets...Creating and rendering intermediate geometric primitives is one of the approaches to visualize data sets in 3D space. Some algorithms have been developed to construct isosurface from uniformly distributed 3D data sets. These algorithms assume that the function value varies linearly along edges of each cell. But to irregular 3D data sets, this assumption is inapplicable. Moreover, the depth sorting of cells is more complicated for irregular data sets, which is indispensable for generating isosurface images or semitransparent isosurface images, if Z-buffer method is not adopted.In this paper, isosurface models based on the assumption that the function value has nonlinear distribution within a tetrahedroll are proposed. The depth sorting algorithm and data structures are developed for the irregular data sets in which cells may be subdivided into tetrahedra. The implementation issues of this algorithm are discussed and experimental results are shown to illustrate potentials of this technique.展开更多
Photoresponsiveness of materials is critical to their tunability and efficiency in terminal applications.Photoresponsive metal-organic polyhedra(PMOPs)feature intrinsic pores and remote controllability,but aggregation...Photoresponsiveness of materials is critical to their tunability and efficiency in terminal applications.Photoresponsive metal-organic polyhedra(PMOPs)feature intrinsic pores and remote controllability,but aggregation of PMOPs in solid state hampers their photoresponsiveness seriously.Herein,we report the construction of a new PMOP(Cu_(24)(C_(16)H_(12)N_(2)O_(4))_(12)(C_(18)H_(22)O_(5))12,denoted as MOP-PR-LA),where long alkyl(LA)chains act as the intermolecular poles,propping against adjacent PMOP molecules to create individual microenvironment benefiting the isomerization of photoresponsive(PR)moieties.Upon ultraviolet(UV)-and visible-light irradiation,MOP-PR-LA is much easier to isomerize than the counterpart MOP-PR without LA.For propylene adsorption,MOP-PR has a low change of adsorption capacity(9.9%),while that of MOP-PR-LA reaches 58.6%.Density functional theory calculations revealed that PR in the cis state has a negative effect on adsorption,while the trans state of PR favors adsorption.This work might open an avenue for the construction of photoresponsive materials with high responsiveness and controllability.展开更多
Metal-organic polyhedra(MOPs)have emerged as novel porous platforms for proton conduction,however,the concerted employment of both linker and metal cluster vertex is rarely applied for the fabrication of MOPs-based hi...Metal-organic polyhedra(MOPs)have emerged as novel porous platforms for proton conduction,however,the concerted employment of both linker and metal cluster vertex is rarely applied for the fabrication of MOPs-based high conducting materials.Herein we report the synthesis of sulfonate-functionalized polyoxovanadate-based MOPs for enhanced proton conduction via the synergistic effect from linker and metal cluster node.MOPs 1 and 2 exhibit octahedral cage configuration constructed from{V_(5)O_(9)Cl}vertex and 5-sulfoisophthalate linker.Owing to the ordered packing of octahedral cages along three axes,3D interpenetrated open channels that are lined with high-density sulfonates are thus formed within 2.Coupled with the proton-conductive{V_(5)O_(9)Cl}vertexs as well as protonated counterions,an extensive H-bonded network is therefore generated for facile proton transfer.2 exhibits high proton conductivity of 3.02×10^(-2)S cm^(-1)at 65℃under 90%RH,recording the highest value for MOPs pellet sample.This value is enhanced~1order of magnitude compared with that of carboxylate-functionalized analogue 3,clearly illustrating the advantage of combining linker and metal cluster node for enhanced proton conduction.This work will further promote the exploitation of high proton conductive MOPs-based materials by the synergy design strategy.展开更多
Supported by the National Natural Science Foundation of China,the research team led by Dr.Cao Xiaoyu(曹晓宇)at the State Key Laboratory of Physical Chemistry of Solid Surfaces and College of Chemistry and Chemical Eng...Supported by the National Natural Science Foundation of China,the research team led by Dr.Cao Xiaoyu(曹晓宇)at the State Key Laboratory of Physical Chemistry of Solid Surfaces and College of Chemistry and Chemical Engineering,Collaborative Innovation Centre of Chemistry for Energy Materials,Xiamen University,assembled a new series of molecular polyhedra,the face-rotating polyhedra(FRP).This展开更多
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean Government(MSIT)(Nos.NRF-2021R1C1C2012825,2022R1A2B5B01001826,2022R1A5A2021216,and No.RS-2023-00218255)。
文摘Homogeneous films with tailored microporous structures are crucial for several applications;however,fabricating such films presents significant challenges.This is primarily because most microporous materials have crystal sizes in the nanoand micrometer ranges,which inevitably generates intergranular spaces in the films,thereby complicating the fabrication of these thin films.In this study,functionalized metal–organic polyhedra(MOPs)are used as discrete microporous units and assembled into homogenous microporous films.The generation of intergranular spaces is avoided while controlling packing parameters and film thicknesses.Initially,the MOP units,influenced by van der Waals forces between carbon chains of functionalized adipic acids,display an affinity to form spindle-shaped blocks and islands.As the MOP concentration increases,these structures self-assembled into a hexagonally packed structure with an in-plane orientation and a maximum stacking of two layers of MOPs.By contrast,un-functionalized MOPs form a disordered film structure owing to random agglomeration.Evidently,functionalized adipic acid influences the orientation of the MOP network films with uniformly distributed micropores,effectively preventing the formation of intergranular spaces.Additionally,formaldehyde adsorption and desorption experiments revealed that the MOP network films possess superior adsorption and desorption capacities.The proposed approach signifies a breakthrough in the fabrication of homogenous microporous films.
文摘A thorough study of regular and quasi-regular polyhedra shows that the symmetries of these polyhedra identically describe the quantization of orbital angular momentum, of spin, and of total angular momentum, a fact which permits one to assign quantum states at the vertices of these polyhedra assumed as the average particle positions. Furthermore, if the particles are fermions, their wave function is anti-symmetric and its maxima are identically the same as those of repulsive particles, e.g., on a sphere like the spherical shape of closed shells, which implies equilibrium of these particles having average positions at the aforementioned maxima. Such equilibria on a sphere are solely satisfied at the vertices of regular and quasi-regular polyhedra which can be associated with the most probable forms of shells both in Nuclear Physics and in Atomic Cluster Physics when the constituent atoms possess half integer spins. If the average sizes of the constituent particles are known, then the average sizes of the resulting shells become known as well. This association of Symmetry with Quantum Mechanics leads to many applications and excellent results.
基金supported by the National Basic Research Program(973)of China(No.2012CB114600)the Zhejiang Provincial Natural Science Foundation(No.Y3110058)the Public Agricultural Program of Zhejiang Province(No.2012C32G2010076),China
文摘In the late phase of Bombyx mori nucleopolyhedrovirus(BmNPV)infection,a large amount of polyhedra appear in the infected cell nucleolus,these polyhedra being dense protein crystals protecting the incorporated virions from the harsh environment.To investigate whether the foreign protein could be immobilized into the polyhedra of BmNPV,two recombinant baculoviruses were generated by a novel BmNPV polyhedrin-plus(polh +)Bac-to-Bac system,designated as vBmBac(polh +)-enhanced green fluorescent protein(EGFP)and vBmBac(polh +)-LacZ,which can express the polyhedrin and foreign protein simultaneously.Light microscopy analysis showed that all viruses produced polyhedra of normal appearance.Green fluorescence can be apparently detected on the surface of the vBmBac(polh +)-EGFP polyhedra,but not the BmNPV polyhedra.Fluorescence analysis and anti-desiccation testing confirmed that EGFP was embedded in the polyhedra.As expected,the vBmBac(polh +)-LacZ polyhedra contained an amount of LacZ and had a higherβ-galactosidase activity.Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE)and Western blotting were also performed to verify if the foreign proteins were immobilized into polyhedra.This study provides a new inspiration for efficient preservation of useful proteins and development of new pesticides with toxic proteins.
基金the National Natural Science Foundation of China(NSFC,No.21203116)the Innovation Capability Support Plan of Shaanxi Province(Grant No.2022WGZJ-25)the Foundation of Shaanxi University of Science and Tech-nology(Grant No.210210031 and 210210032).
文摘Silicon(Si)holds promise as an anode material for lithium-ion batteries(LIBs)as it is widely avail-able and characterized by high specific capacity and suitable working potential.However,the relatively low electrical conductivity of Si and the significantly high extent of volume expansion realized dur-ing lithiation hinder its practical application.We prepared N-doped carbon polyhedral micro cage en-capsulated Si nanoparticles derived from Co-Mo bimetal metal-organic framework(MOFs)(denoted as Si/CoMo@NCP)and explored their lithium storage performance as anode materials to address these prob-lems.The Si/CoMo@NCP anode exhibited a high reversible lithium storage capacity(1013 mAh g^(−1)at 0.5 A g^(−1)after 100 cycles),stable cycle performance(745 mAh g^(−1)at 1 A g^(−1)after 400 cycles),and excellent rate performance(723 mAh g^(−1)at 2 A g^(−1)).Also,the constructed the full-cell NCM 811//Si/CoMo@NCP exhibited well reversible capacity.The excellent electrochemical performances of Si/CoMo@NCP were at-tributed to two unique properties.The encapsulation of NCP with doped nitrogen and porous structural carbon improves the electrical conductivity and cycling stability of the molecules.The introductions of metallic cobalt and its oxides help to improve the rate capability and lithiation capacity of the materials following multi-electron reaction mechanisms.
文摘The nature and origin of a fundamental quantum QSPR （QQSPR） equation are discussed. In principle, as any molecular structure can be associated to quantum mechanical density functions （DF）, a molecular set can be reconstructed as a quantum multimolecular polyhedron （QMP）, whose vertices are formed by each molecular DF. According to QQSPR theory, complicated kinds of molecular properties, like biological activity or toxicity, of molecular sets can be calculated via the quantum expectation value of an approximate Hermitian operator, which can be evaluated with the geometrical information contained in the attached QMP via quantum similarity matrices. Practical ways of solving the QQSPR problem from the point of view of QMP geometrical structure are provided. Such a development results into a powerful algorithm, which can be implemented within molecular design as an alternative to the current classical QSPR procedures.
文摘Archimedean solids were first proposed by the ancient Greek philosopher Archimedes.Unfortunately,this aspect of his work was not well-documented.It was not until 1619 that the mathematician Johannes Kepler reconstructed the complete set of 13 Archimedean solids[1].Among these solids,only the snub cube and snub dodecahedron are chiral.
基金supported by the Engineering and Physical Sciences Research Council(EPSRC),UK(grant nos.EP/I011870 and EP/K014706/2)the Royal Society,UK(grant no.IC170327)+2 种基金the National Natural Science Foundation of China(grant nos.22273108,21733011,and 21890761)the European Research Council(ERC)under the European Union’s Horizon 2020 Research and Innovation Program,Brussels,Belgium(grant no.742401,NANOCHEM)the Beijing Natural Science Foundation,China(grant no.2222043).
文摘Catalytic cleavage ofβ-O-4 linkages is an essential but challenging step in the depolymerization of lignin.Here,we report the templated electrosynthesis of a hydrophobic metal-organic polyhedral catalyst(Cu-MOP-e),which exhibits excellent hydrothermal stability and exceptional activity for this reaction.The oxidative cleavage of 2-phenoxyacetophenone,1,a lignin model compound,over Cu-MOP-e at 90℃for 1 h affords full conversion with yields of the monomer products phenol and benzoic acid of 99%.The reusability of Cu-MOP-e was confirmed by carrying out ten cycles of reaction.The mechanism of catalyst-substrate binding was investigated by highresolution synchrotron X-ray powder diffraction,in situ X-ray absorption spectroscopy,electron paramagnetic resonance spectroscopy,and density functional theory(DFT)calculations.The combination of optimal porosity and active Cu(Ⅱ)sites provides confined binding of 2-phenoxyacetophenone,thus promoting the cleavage ofβ-O-4 linkage under relatively mild conditions.
基金supported by the National Natural Science Foundation of China (22241501, 92261117)the Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology+2 种基金the Open Fund of the China Spallation Neutron Source Songshan Lake Science City (DG24313519)the TCL Science and Technology Innovation FundGuangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices
文摘Mixed matrix membranes(MMMs)are designed by incorporating microporous inorganic fillers into polymer matrix for the integration of inorganics’excellent gas separation performance with polymers’promising flexibility.However,due to the complex interphase interaction,the prevention of long-term aging is still challenging and the poor processability/recyclability of MMMs hinders their extensive applications.Herein,a coordination assembly protocol is developed for the fabrication of MMMs with both excellent processability/recyclability upon thermal annealing and promising dimension stability even under high gas pressure.Polymers bearing isophthalic acid(IPA)as side chains are applied to coordinate with Cu^(2+)and the assembled 2.5 nm microporous metal-organic polyhedra(MOP),{Cu_(24)IPA_(24)},serves as multi-functional cross-linkers for the polymer network formation.The MOPs’well-defined microporosity grants MMMs the capability for O_(2)/N_(2) separation while their activated dynamics at high temperatures(>120℃)endows polymer networks with excellent processability.In contrast to conventional supramolecular units,the MOPs possess unique logarithmic ligand-exchange kinetics and they show nearly frozen bonding dynamics at room temperature,ensuring promising dimensional stability to overcome the long-term aging and high gas pressure effect.This work not only provides fundamental understanding of the unique relaxation dynamics of complex systems with intertwined dynamics of supramolecular bonds and polymer chains,but also paves new avenues for the fabrication of robust and recyclable MMMs and elastomers.
文摘Zinc-air batteries have recently attracted considerable interest owing to the larger storage capacity and lower cost compared to their lithium-ion counterparts. Electrode catalysts for the oxygen reduction reaction （ORR） and oxygen evolution reaction （OER） play a critical role in the operation of rechargeable zinc-air batteries. Herein, we report a simple and scalable strategy to fabricate porous carbon polyhedra using Zn-doped Co-based zeolitic imidazolate frameworks （ZnCo-ZIFs） as precursors. Strikingly, Zn doping leads to smaller Co nanoparticles and higher nitrogen content, which in turn enhances the ORR and OER activities of the obtained porous carbon polyhedra. The synergistic effect of the N-doped carbon and cobalt nanoparticles in the composite, the improved conductivity resulting from the high graphitization of carbon, and the large surface area of the porous polyhedral structure resulted in porous carbon polyhedra with excellent ORR and OER electrocatalytic activity in alkaline media. More importantly, air cathodes based on the optimal porous carbon polyhedra further exhibited superior performance to Pt/C catalysts in primary and rechargeable zinc-air batteries.
基金This work was financially supported by the National Natural Science Foundation of China （No. 21071079）, the Research Fund of the State Key Laboratory of Materials-Oriented Chemical Engineering （2009）, and the Young Teachers Fund of Nanjing University of Technology.
文摘A series of unique nanowire superstructures, Cu2O nanowire polyhedra, have been synthesized through a cost-effective hydrothermal route. Three types of nanowire polyhedra, namely octahedra, concave octahedra, and hexapods, were formed in high morphological yields （90%） by reducing cupric acetate with o-anisidine or o-phenetidine in the presence of carboxylic acids. The architectures of these Cu2O nanowire polyhedra were examined by electron microscopy, which revealed ordered, highly aligned CU2O nanowires within the polyhedral outlines. The growth of the Cu2O nanowire polyhedra is controlled by the orientation and growth rates of the nanowire branches which are adjusted by addition of carboxylic acids. Compared to the Cu2O samples reported in the recent literature, the Cu2O nanowire octahedra exhibit notably enhanced photocatalytic activities for dye degradation in the presence of H202 under visible light, probably due to the high-density charge carriers photoexcited from the branched nanowires with their special structures. Additionally, the discussion in the recent literature of the photocatalytic activity of Cu2O in the absence of H2O2 for direct photodegradation of dyes seems questionable.
基金the Basic Science Research Program(No.NRF-2019R1A2C4069764)by Convergent Technology R&D Program for Hum an Augm entation(No.2019M3C1B8077549)through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT.
文摘The challenge for single-atom catalysts in various C-C cross coupling reaction exists in the development of solid supporting materials.It has been desired tofind a supporting material designed in molecular level to anchor a single-atom catalyst and provide high degree of dispersion and substrate access in aqueous media.Here,we prepared discrete cages of metal-organic polyhedra anchoring single Pd atom(MOP-BPY(Pd))and successfully performed a Suzuki-Miyaura cross coupling reaction with various substrates in aqueous media.It was revealed that each tetrahedral cage of MOP-BPY(Pd)has 4.5 Pd atoms on average and retained its high degree of dispersion up to 3 months in water.The coupling efficiencies of the Suzuki-Miyaura cross coupling reaction exhibited more than 90.0%for various substrates we have tested in the aqueous media,which is superior to those of the molecular Pd complex and metal-organic framework(MOF)anchoring Pd atoms.Moreover,MOP-BPY(Pd)was successfully recovered and recycled without performance degradation.
基金the National Natural Science Foundation of China (Grant Nos. 59805004, 59990470) the National Distinguished Youth Foundation (Grant No. 59725514).
文摘Based on the concept of gauge function, the pseudo minimum translational distance (PMTD) between two convex objects is defined in this paper. PMTD not only provides a measure of the clearance between two separating objects, but also quantifies the penetration of two objects intersecting each other. It is proved that the PMTD is differentiate almost everywhere w. r.t. the configuration variable of the objects. Algorithms for calculating PMTD and its derivative are also presented.
文摘An octahedrite is a 4-valent polyhedron with only 3-faces and 4-faces. We study edge-partitions of some octahedrites, medial and related polyhedra into central circuits.
基金This study was supported by the National Science Fund for Excellent Young Scholars(no.21722606)the National Natural Science Foundation of China(nos.21676138,21878149,21808110,and 21576137)the China Postdoctoral Science Foundation(no.2018M632295).
文摘Metal-organic polyhedra(MOPs)have emerged as versatile platforms for artificial models of biological systems due to their discrete structure and modular nature.However,the design and fabrication of MOPs with special functionality for mimicking biological processes are challenging.Inspired by the breathing mechanism of lungs,we developed a new type of MOP(a breathing MOP,denoted as NUT-101)by directly using azobenzene units as the pillars of the polyhedra to coordinate with Zr-based metal clusters.In addition to considerable thermal and chemical stability,the obtained MOP exhibits photocontrollable breathing behavior.Upon irradiation with visible or UV light,the configuration of azobenzene units transforms,leading to reversible expansion or contraction of the cages and,correspondingly,capture or liberation of CO_(2)molecules.Such a breathing behavior of NUT-101 is further confirmed by density functional theory(DFT)calculation.This system might establish an avenue for the construction of new materials with particular functionality that mimic biological processes.
基金The work is supported by the National Natural Science Foundation of China(grant nos.51873067 and 21961142018)the Natural Science Foundation of Guangdong Province(grant no.2021A1515012024).
文摘Metal-organic polyhedra(MOPs)possess a microporous framework and impose hierarchical constraints on their surface ligands,leading to the long-ignored,logarithmic ligand exchange dynamics.Herein,polymer networks with MOP as nanoscale cross-linkers(MOP-CNs)can integrate unique ligand exchange dynamics and microporosity,affording vitrimer-like gas separation membranes with promising mechanical performance and(re)processability.All the ligands on the MOP surfaces are confined and correlated via a 3D coordination framework and their neighboring spaces,giving rise to a high energy barrier for ligand exchange.Therefore,MOP-CNs demonstrate high mechanical strengths at room temperature due to their negligible ligand dynamics.The thermo-activated ligand exchange process with integrated network topology enables facile(re)processing and high solvo-resistance at high temperatures.This facilitates Arrhenius type temperature dependence of flowability and stress relaxation,giving rise to the simultaneous achievement of promising mechanical strengths and(re)processability.Finally,the cage topologies of MOPs endow the materials with a bonus microporous feature and spur their applications as gas separation membranes.
文摘Creating and rendering intermediate geometric primitives is one of the approaches to visualize data sets in 3D space. Some algorithms have been developed to construct isosurface from uniformly distributed 3D data sets. These algorithms assume that the function value varies linearly along edges of each cell. But to irregular 3D data sets, this assumption is inapplicable. Moreover, the depth sorting of cells is more complicated for irregular data sets, which is indispensable for generating isosurface images or semitransparent isosurface images, if Z-buffer method is not adopted.In this paper, isosurface models based on the assumption that the function value has nonlinear distribution within a tetrahedroll are proposed. The depth sorting algorithm and data structures are developed for the irregular data sets in which cells may be subdivided into tetrahedra. The implementation issues of this algorithm are discussed and experimental results are shown to illustrate potentials of this technique.
基金the National Key R&D Program of China(No.2022YFB3806800)the National Science Fund for Distinguished Young Scholars(No.22125804)+1 种基金the National Natural Science Foundation of China(No.22078155)the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Photoresponsiveness of materials is critical to their tunability and efficiency in terminal applications.Photoresponsive metal-organic polyhedra(PMOPs)feature intrinsic pores and remote controllability,but aggregation of PMOPs in solid state hampers their photoresponsiveness seriously.Herein,we report the construction of a new PMOP(Cu_(24)(C_(16)H_(12)N_(2)O_(4))_(12)(C_(18)H_(22)O_(5))12,denoted as MOP-PR-LA),where long alkyl(LA)chains act as the intermolecular poles,propping against adjacent PMOP molecules to create individual microenvironment benefiting the isomerization of photoresponsive(PR)moieties.Upon ultraviolet(UV)-and visible-light irradiation,MOP-PR-LA is much easier to isomerize than the counterpart MOP-PR without LA.For propylene adsorption,MOP-PR has a low change of adsorption capacity(9.9%),while that of MOP-PR-LA reaches 58.6%.Density functional theory calculations revealed that PR in the cis state has a negative effect on adsorption,while the trans state of PR favors adsorption.This work might open an avenue for the construction of photoresponsive materials with high responsiveness and controllability.
基金supported by the National Natural Science Foundation of China(Nos.92161111,21901037,21901038,21871042)Shanghai Pujiang Program(No.19PJ1400200)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning and International Cooperation Fund of Science and Technology Commission of Shanghai Municipality(No.21130750100)。
文摘Metal-organic polyhedra(MOPs)have emerged as novel porous platforms for proton conduction,however,the concerted employment of both linker and metal cluster vertex is rarely applied for the fabrication of MOPs-based high conducting materials.Herein we report the synthesis of sulfonate-functionalized polyoxovanadate-based MOPs for enhanced proton conduction via the synergistic effect from linker and metal cluster node.MOPs 1 and 2 exhibit octahedral cage configuration constructed from{V_(5)O_(9)Cl}vertex and 5-sulfoisophthalate linker.Owing to the ordered packing of octahedral cages along three axes,3D interpenetrated open channels that are lined with high-density sulfonates are thus formed within 2.Coupled with the proton-conductive{V_(5)O_(9)Cl}vertexs as well as protonated counterions,an extensive H-bonded network is therefore generated for facile proton transfer.2 exhibits high proton conductivity of 3.02×10^(-2)S cm^(-1)at 65℃under 90%RH,recording the highest value for MOPs pellet sample.This value is enhanced~1order of magnitude compared with that of carboxylate-functionalized analogue 3,clearly illustrating the advantage of combining linker and metal cluster node for enhanced proton conduction.This work will further promote the exploitation of high proton conductive MOPs-based materials by the synergy design strategy.
文摘Supported by the National Natural Science Foundation of China,the research team led by Dr.Cao Xiaoyu(曹晓宇)at the State Key Laboratory of Physical Chemistry of Solid Surfaces and College of Chemistry and Chemical Engineering,Collaborative Innovation Centre of Chemistry for Energy Materials,Xiamen University,assembled a new series of molecular polyhedra,the face-rotating polyhedra(FRP).This
