Intrinsic electric-magnetic property and special nano-micro architecture of functional materials have a significant effect on its electromagnetic wave energy conversion,especially in the microwave absorption(MA) field...Intrinsic electric-magnetic property and special nano-micro architecture of functional materials have a significant effect on its electromagnetic wave energy conversion,especially in the microwave absorption(MA) field.Herein,porous Ni1-xCox@Carbon composites derived from metal-organic framework(MOF)were successfully synthesized via solvothermal reaction and subsequent annealing treatments.Benefiting from the coordination,carbonized bimetallic Ni-Co-MOF maintained its initial skeleton and transformed into magnetic-carbon composites with tunable nano-micro structure.During the thermal decomposition,generated magnetic particles/clusters acted as a catalyst to promote the carbon sp^2 arrangement,forming special core-shell architecture.Therefore,pure Ni@C microspheres displayed strong MA behaviors than other Ni1-xCox@Carbon composites.Surprisingly,magnetic-dielectric Ni@C composites possessed the strongest reflection loss value-59.5 dB and the effective absorption frequency covered as wide as 4.7 GHz.Meanwhile,the MA capacity also can be boosted by adjusting the absorber content from 25% to 40%.Magnetic-dielectric synergy effect of MOF-derived Ni1-xCox@Carbon microspheres was confirmed by the off-axis electron holography technology making a thorough inquiry in the MA mechanism.展开更多
The catalytic activities are generally believed to be relevant to the electronic states of their active center, but understanding this relationship is usually difficult. Here, we design two types of catalysts for elec...The catalytic activities are generally believed to be relevant to the electronic states of their active center, but understanding this relationship is usually difficult. Here, we design two types of catalysts for electrocatalytic urea via a coordination strategy in a metal–organic frameworks: Cu^(Ⅲ)-HHTP and Cu^(Ⅱ)-HHTP. Cu^(Ⅲ)-HHTP exhibits an improved urea production rate of 7.78 mmol h^(−1)g^(−1) and an enhanced Faradaic efficiency of 23.09% at-0.6 V vs. reversible hydrogen electrode, in sharp contrast to Cu^(Ⅱ)-HHTP.Isolated CuⅢspecies with S = 0 spin ground state are demonstrated as the active center in Cu^(Ⅲ)-HHTP, different from Cu^(Ⅱ) with S = 1/2 in Cu^(Ⅱ)-HHTP. We further demonstrate that isolated Cu^(Ⅲ)with an empty dx2-y20orbital in Cu^(Ⅲ)-HHTP experiences a single-electron migration path with a lower energy barrier in the C–N coupling process, while Cu^(Ⅱ)with a single-spin state( d_(x2-y2)^(1)) in Cu^(Ⅱ)-HHTP undergoes a two-electron migration pathway.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
Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions.However,the unpleasant odor and instability o...Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions.However,the unpleasant odor and instability of the organosulfur,as well as the mass-transfer resistance that exists in multiphase catalysis,have often limited the catalytic application of Cu-MOFs in C-S coupling reactions.In this paper,a Cu-MOFs catalyst modified by cetyltrimethylammonium bromide(CTAB)was designed to enhance mass transfer by increasing the adsorption of organic substrates using the long alkanes of CTAB.Concurrently,elemental sulfur was used to replace organosulfur to achieve a highly efficient and atom-economical multicomponent C-S coupling reaction.展开更多
In the pursuit of advancing molecular sensing through surface-enhanced Raman spectroscopy(SERS),the combination of plasmonic nanoparticles and metal-organic frameworks(MOFs)has emerged as a highly effective approach t...In the pursuit of advancing molecular sensing through surface-enhanced Raman spectroscopy(SERS),the combination of plasmonic nanoparticles and metal-organic frameworks(MOFs)has emerged as a highly effective approach to enhance the sensitivity and selectivity of SERS substrates.However,most prior investigations have predominantly focused on MOF-coated plasmonic nanoparticles in core@shell or layer-by-layer configurations,leaving a notable knowledge gap in exploring alternative configurations.Herein we present a facile method to construct a particle-on-mirror architecture by selectively coating a MOF,zeolitic imidazolate framework-8(ZIF-8),onto the tips of Au nanostars and subsequently depositing the resultant nanoparticles onto a Au film.This design integrates the electric field enhancement at the sharp tips and nanogaps,along with the molecular enrichment function within the porous MOF immobilized at the tips and nanogaps,leading to a substantial boost in the SERS signal intensity.Such a unique SERS platform enables consistent and outstanding SERS performance for analytes of different sizes.This work opens up a promising strategy for constructing multifunctional nanostructures for sensitive SERS detection in real-life scenarios.展开更多
In order to reduce the environmental impact of conventional sludge treatment methods and to utilize the energy in sludge more effectively,a coupled system based on sewage sludge gasifier(SSG),solid oxide fuel cells(SO...In order to reduce the environmental impact of conventional sludge treatment methods and to utilize the energy in sludge more effectively,a coupled system based on sewage sludge gasifier(SSG),solid oxide fuel cells(SOFC),supercritical CO_(2)cycle(S-CO_(2)),and organic Rankine cycle(ORC)is proposed.The clean syngas obtained from sludge gasification is mixed with CH4 and then first utilized by the fuel cell.The exhaust gas from the fuel cell is fully combusted in the afterburning chamber and then enters the bottom cycle system consisting of S-CO_(2)&ORC to generate electricity.To understand the performance of the system,thermodynamic and economic analyses were conducted to examine the project's performance.The thermodynamics as well as the economics of the coupled system were analyzed to arrive at the following conclusions,the power production of the system is 37.34 MW;the exergy efficiency is 55.62%,and the net electrical efficiency is 61.48%.The main exergy destruction is the gasifier and SOFC,accounting for 62.45%of the total exergy destruction.It takes only6.13 years to repay the construction investment in the novel system,and the project obtains a NPV of 17723820USD during 20 years lifetime.The above findings indicate that the new coupled system has a better performance in terms of energy utilization and economy.展开更多
Metal–organic gel(MOG)derived composites are promising multi-functional materials due to their alterable composition,identifiable chemical homogeneity,tunable shape,and porous structure.Herein,stable metal–organic h...Metal–organic gel(MOG)derived composites are promising multi-functional materials due to their alterable composition,identifiable chemical homogeneity,tunable shape,and porous structure.Herein,stable metal–organic hydrogels are prepared by regulating the complexation effect,solution polarity and curing speed.Meanwhile,collagen peptide is used to facilitate the fabrication of a porous aerogel with excellent physical properties as well as the homogeneous dispersion of magnetic particles during calcination.Subsequently,two kinds of heterometallic magnetic coupling systems are obtained through the application of Kirkendall effect.FeCo/nitrogen-doped carbon(NC)aerogel demonstrates an ultra-strong microwave absorption of−85 dB at an ultra-low loading of 5%.After reducing the time taken by atom shifting,a FeCo/Fe3O4/NC aerogel containing virus-shaped particles is obtained,which achieves an ultra-broad absorption of 7.44 GHz at an ultra-thin thickness of 1.59 mm due to the coupling effect offered by dual-soft-magnetic particles.Furthermore,both aerogels show excellent thermal insulation property,and their outstanding radar stealth performances in J-20 aircraft are confirmed by computer simulation technology.The formation mechanism of MOG is also discussed along with the thermal insulation and electromagnetic wave absorption mechanism of the aerogels,which will enable the development and application of novel and lightweight stealth coatings.展开更多
Dimerized small-molecule acceptors(SMAs) built by the conventional connection of terminal groups of monomers have contributed to exciting long-term stabilities of organic solar cells(OSCs). However, device efficiencie...Dimerized small-molecule acceptors(SMAs) built by the conventional connection of terminal groups of monomers have contributed to exciting long-term stabilities of organic solar cells(OSCs). However, device efficiencies, especially fill factors(FFs), still need to be improved. This probably originates from unsymmetrical molecular structure/conformation-determined less compact/ordered molecular stackings, such as ineffective stackings of constraint terminals. Herein, an exotic dimerized SMA of BC-Th is established by bridging the branched groups(BC-type, branch coupling) of two monomers rather than conventional terminal units(TC-type, terminal coupling). Benefiting from the three-dimensional conformation and more uncurbed terminals,BC-Th exhibits multiple molecular orientations along with a larger dielectric constant and electron mobility compared with TCTh. Finally, an efficiency of 17.43% is achieved by BC-Th-based OSCs, along with the highest FF of 79.13% among all dimerized SMAs-based OSCs to date. When introducing L8-BO as the third component, overall enhanced efficiency of 18.05%and FF of 80.11% are further afforded. Contrarily, TC-Th-based OSCs exhibit much inferior PCE of 16.29% and FF of 74.81%,demonstrating the great advantages of “branch coupling” over “terminal coupling” when building dimerized SMAs.展开更多
Polymer-based composite electrolytes composed of three-dimensional Li_(6.4)La_(3)Zr_(2)Al_(0.2)O_(12)(3D-LLZAO)have attracted increasing attention due to their continuous ion conduction and satisfactory mechanical pro...Polymer-based composite electrolytes composed of three-dimensional Li_(6.4)La_(3)Zr_(2)Al_(0.2)O_(12)(3D-LLZAO)have attracted increasing attention due to their continuous ion conduction and satisfactory mechanical properties.However,the organic/inorganic interface is incompatible,resulting in slow lithium-ion transport at the interface.Therefore,the compatibility of organic/inorganic interface is an urgent problem to be solved.Inspired by the concept of“gecko eaves”,polymer-based composite solid electrolytes with dense interface structures were designed.The bridging of organic/inorganic interfaces was established by introducing silane coupling agent(3-chloropropyl)trimethoxysilane(CTMS)into the PEO-3D-LLZAO(PL)electrolyte.The in-situ coupling reaction improves the interface affinity,strengthens the organic/inorganic interaction,reduces the interface resistance,and thus achieves an efficient interface ion transport network.The prepared PEO-3D-LLZAO-CTMS(PLC)electrolyte exhibits enhanced ionic conductivity of 6.04×10^(-4)S cm^(-1)and high ion migration number(0.61)at 60℃and broadens the electrochemical window(5.1 V).At the same time,the PLC electrolyte has good thermal stability and high mechanical properties.Moreover,the Li Fe PO_(4)|PLC|Li battery has excellent rate performance and cycling stability with a capacity decay rate of 2.2%after 100 cycles at 60℃and 0.1 C.These advantages of PLC membranes indicate that this design approach is indeed practical,and the in-situ coupling method provides a new approach to address interface compatibility issues.展开更多
Electrocatalytic synthesis of urea from CO_(2)and NO_(3)^(-)under ambient conditions provides an appealing alternative to the traditional energy-intensive urea synthetic protocol.Highly active and selective electrocat...Electrocatalytic synthesis of urea from CO_(2)and NO_(3)^(-)under ambient conditions provides an appealing alternative to the traditional energy-intensive urea synthetic protocol.Highly active and selective electrocatalysts for efficient urea production are therefore urgently desired owing to the unsatisfactory performance of the thus far reported catalysts.Herein,a phthalocyaninebased(Pc-based)covalent organic framework(COF),namely Co Pc-COF,fabricated from the nucleophilic substitution reaction of hexadecafluorophthalocyaninato cobalt with octahydroxylphthalocyanine cobalt,in situ grew on the surface of multilayered Ti O_(2)nanotubes(NTs),generating the Co Pc-COF@Ti O_(2)NTs composite.Powder X-ray diffraction analysis in combination with electron microscopy measurements discloses the uniform coating of crystalline Co Pc-COF on the multilayered Ti O_(2)NTs in Co Pc-COF@Ti O_(2)NTs.Remarkably,electrochemical tests reveal the superior electrocatalytic activity of Co Pc-COF@Ti O_(2)NTs towards urea production from CO_(2)and NO3-with a record-high yield of 1,205μg h^(-1)cm^(-2)and an outstanding Faraday efficiency of 49%at-0.6 V versus reversible hydrogen electrode due to the significant synergistic catalysis effect.In situ attenuated total reflection infrared spectroscopic investigation and theoretical calculations unveil the efficient C–N coupling reaction between*CO intermediate derived from CO_(2)on Co Pc moieties and*NH2intermediate formed from NO_(3)^(-)on Ti O_(2)NTs during the urea formation process over Co Pc-COF@Ti O_(2)NTs.This work should be helpful towards designing and fabricating high-performance electrocatalysts for sustainable synthesis of urea through efficient synergistic effect of multiactive centers.展开更多
MOF-based core-shell structures with high surface area, abundant active sites, and broad absorption bands are viable alternatives to traditional single-component photocatalysts. In this report, we describe the design ...MOF-based core-shell structures with high surface area, abundant active sites, and broad absorption bands are viable alternatives to traditional single-component photocatalysts. In this report, we describe the design and construction of delicate Ag nanowires@NH_(2)-UiO-66 with a core-shell structure for use as photocatalysts in imine synthesis under light. The optimized composites exhibited 80% imine production, which was higher than both MOF and Ag NWs. The significant improvement in photocatalytic activity under light may be attributed to the plasmonic effect of silver nanowires and their core-shell structure, which promotes the separation of electron-hole pairs. Moreover, the photocatalytic activity of the core-shell nanostructure may provide valuable insight into the design and construction of MOF-based composite photocatalysts for oxidative coupling of amines.展开更多
社会—生态韧性作为社会生态系统(Social-Ecological System,SES)的动态属性,其研究涉及自然、社会和经济的大量信息和复杂的耦合关系,对于城市治理领域,尤其在城市规划与治理实践层面有着重要的指导意义。研究基础数据为Web of Science...社会—生态韧性作为社会生态系统(Social-Ecological System,SES)的动态属性,其研究涉及自然、社会和经济的大量信息和复杂的耦合关系,对于城市治理领域,尤其在城市规划与治理实践层面有着重要的指导意义。研究基础数据为Web of Science(WoS)核心合集中2 906篇基础研究成果和345篇筛选后的精准研究成果,初步分析表明过去的20年内,关于社会—生态韧性的研究引起了各个学科的关注,并将持续成为地理学、生态学、城市管理学等学科共同关注的焦点。在此基础上,文章概述了社会—生态韧性在不同学科领域的研究成果,主要集中在韧性机制、韧性评估和韧性管理等多个层面,对于社会—生态韧性在城市治理层面的应用提升有借鉴作用。同时文章概述了韧性研究的内涵和主要发展过程,经历了从工程韧性到生态韧性再到社会—生态韧性的演变,形成了支撑现代韧性理论的基础支柱。从社会—生态韧性理论在城市治理的应用层面来说,需要关注到以下几个关键问题:社会系统与生态系统之间的相互作用以及动态的适应过程;社会—生态韧性对于城市规划和治理方式的影响;跨学科的社会—生态韧性研究框架和城市治理模式的构建。展开更多
With an extended Su–Schrieffer–Heeger model and Green's function method, the spin–orbit coupling(SOC) effects on spin admixture of electronic states and quantum transport in organic devices are investigated. Th...With an extended Su–Schrieffer–Heeger model and Green's function method, the spin–orbit coupling(SOC) effects on spin admixture of electronic states and quantum transport in organic devices are investigated. The role of lattice distortion induced by the strong electron–lattice interaction in organics is clarified in contrast with a uniform chain. The results demonstrate an enhanced SOC effect on the spin admixture of frontier eigenstates by the lattice distortion at a larger SOC,which is explained by the perturbation theory. The quantum transport under the SOC is calculated for both nonmagnetic and ferromagnetic electrodes. A more notable SOC effect on total transmission and current is observed for ferromagnetic electrodes, where spin filtering induced by spin-flipped transmission and suppression of magnetoresistance are obtained.Unlike the spin admixture, a stronger SOC effect on transmission exists for the uniform chain rather than the organic lattices with distortion. The reason is attributed to the modified spin-polarized conducting states in the electrodes by lattice configuration, and hence the spin-flip transmission, instead of the spin admixture of eigenstates. This work is helpful to understand the SOC effect in organic spin valves in the presence of lattice distortion.展开更多
基金Project supported by the National Natural Science Foundation of China(No.21672178)the National Foundation for Fostering Talents in Basic Science(No.J1310024)~~
基金supported by the Ministry of Science and Technology of China (973 Project No. 2018YFA0209102)the National Natural Science Foundation of China (11727807, 51725101, 51672050, 61790581)Science and Technology Commission of Shanghai Municipality (16DZ2260600)。
文摘Intrinsic electric-magnetic property and special nano-micro architecture of functional materials have a significant effect on its electromagnetic wave energy conversion,especially in the microwave absorption(MA) field.Herein,porous Ni1-xCox@Carbon composites derived from metal-organic framework(MOF)were successfully synthesized via solvothermal reaction and subsequent annealing treatments.Benefiting from the coordination,carbonized bimetallic Ni-Co-MOF maintained its initial skeleton and transformed into magnetic-carbon composites with tunable nano-micro structure.During the thermal decomposition,generated magnetic particles/clusters acted as a catalyst to promote the carbon sp^2 arrangement,forming special core-shell architecture.Therefore,pure Ni@C microspheres displayed strong MA behaviors than other Ni1-xCox@Carbon composites.Surprisingly,magnetic-dielectric Ni@C composites possessed the strongest reflection loss value-59.5 dB and the effective absorption frequency covered as wide as 4.7 GHz.Meanwhile,the MA capacity also can be boosted by adjusting the absorber content from 25% to 40%.Magnetic-dielectric synergy effect of MOF-derived Ni1-xCox@Carbon microspheres was confirmed by the off-axis electron holography technology making a thorough inquiry in the MA mechanism.
基金supported by“Key Program for International S&T Cooperation Projects of China”from the Ministry of Science and Technology of China(Grant No.2019YFE0123000)the National Natural Science Foundation of China(Grant Nos.91961125 and 21905019)+2 种基金Science and Technology Project of Guangdong Province(No.2020B0101370001)Chemistry and Chemical Engineering Guangdong Laboratory(No.1932004)the Project from China Petrochemical Corporation(No.S20L00151).
文摘The catalytic activities are generally believed to be relevant to the electronic states of their active center, but understanding this relationship is usually difficult. Here, we design two types of catalysts for electrocatalytic urea via a coordination strategy in a metal–organic frameworks: Cu^(Ⅲ)-HHTP and Cu^(Ⅱ)-HHTP. Cu^(Ⅲ)-HHTP exhibits an improved urea production rate of 7.78 mmol h^(−1)g^(−1) and an enhanced Faradaic efficiency of 23.09% at-0.6 V vs. reversible hydrogen electrode, in sharp contrast to Cu^(Ⅱ)-HHTP.Isolated CuⅢspecies with S = 0 spin ground state are demonstrated as the active center in Cu^(Ⅲ)-HHTP, different from Cu^(Ⅱ) with S = 1/2 in Cu^(Ⅱ)-HHTP. We further demonstrate that isolated Cu^(Ⅲ)with an empty dx2-y20orbital in Cu^(Ⅲ)-HHTP experiences a single-electron migration path with a lower energy barrier in the C–N coupling process, while Cu^(Ⅱ)with a single-spin state( d_(x2-y2)^(1)) in Cu^(Ⅱ)-HHTP undergoes a two-electron migration pathway.
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support from the National Natural Science Foundation of China(22078130)the Fundamental Research Funds for the Central Universities(1042050205225990/010)Starting Research Fund of Qingyuan Innovation Laboratory(00523001).
文摘Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions.However,the unpleasant odor and instability of the organosulfur,as well as the mass-transfer resistance that exists in multiphase catalysis,have often limited the catalytic application of Cu-MOFs in C-S coupling reactions.In this paper,a Cu-MOFs catalyst modified by cetyltrimethylammonium bromide(CTAB)was designed to enhance mass transfer by increasing the adsorption of organic substrates using the long alkanes of CTAB.Concurrently,elemental sulfur was used to replace organosulfur to achieve a highly efficient and atom-economical multicomponent C-S coupling reaction.
基金supported by Hong Kong Innovation and Technology Commission(Innovation and Technology Support Programme(Seed),No.ITS/176/22)Shenzhen Science and Technology Innovation Commission(No.JSGGKQTD20221101115701006)+1 种基金the University Development Fund(No.UDF01002665)the Program of Guangdong Introducing Innovative and Entrepreneurial Teams(No.2019ZT08L101).
文摘In the pursuit of advancing molecular sensing through surface-enhanced Raman spectroscopy(SERS),the combination of plasmonic nanoparticles and metal-organic frameworks(MOFs)has emerged as a highly effective approach to enhance the sensitivity and selectivity of SERS substrates.However,most prior investigations have predominantly focused on MOF-coated plasmonic nanoparticles in core@shell or layer-by-layer configurations,leaving a notable knowledge gap in exploring alternative configurations.Herein we present a facile method to construct a particle-on-mirror architecture by selectively coating a MOF,zeolitic imidazolate framework-8(ZIF-8),onto the tips of Au nanostars and subsequently depositing the resultant nanoparticles onto a Au film.This design integrates the electric field enhancement at the sharp tips and nanogaps,along with the molecular enrichment function within the porous MOF immobilized at the tips and nanogaps,leading to a substantial boost in the SERS signal intensity.Such a unique SERS platform enables consistent and outstanding SERS performance for analytes of different sizes.This work opens up a promising strategy for constructing multifunctional nanostructures for sensitive SERS detection in real-life scenarios.
基金supported by the National Nature Science Fund of China(No.52276006)Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.51821004)。
文摘In order to reduce the environmental impact of conventional sludge treatment methods and to utilize the energy in sludge more effectively,a coupled system based on sewage sludge gasifier(SSG),solid oxide fuel cells(SOFC),supercritical CO_(2)cycle(S-CO_(2)),and organic Rankine cycle(ORC)is proposed.The clean syngas obtained from sludge gasification is mixed with CH4 and then first utilized by the fuel cell.The exhaust gas from the fuel cell is fully combusted in the afterburning chamber and then enters the bottom cycle system consisting of S-CO_(2)&ORC to generate electricity.To understand the performance of the system,thermodynamic and economic analyses were conducted to examine the project's performance.The thermodynamics as well as the economics of the coupled system were analyzed to arrive at the following conclusions,the power production of the system is 37.34 MW;the exergy efficiency is 55.62%,and the net electrical efficiency is 61.48%.The main exergy destruction is the gasifier and SOFC,accounting for 62.45%of the total exergy destruction.It takes only6.13 years to repay the construction investment in the novel system,and the project obtains a NPV of 17723820USD during 20 years lifetime.The above findings indicate that the new coupled system has a better performance in terms of energy utilization and economy.
基金the National Natural Science Foundation of China(22265021)the Aeronautical Science Foundation of China(2020Z056056003).
文摘Metal–organic gel(MOG)derived composites are promising multi-functional materials due to their alterable composition,identifiable chemical homogeneity,tunable shape,and porous structure.Herein,stable metal–organic hydrogels are prepared by regulating the complexation effect,solution polarity and curing speed.Meanwhile,collagen peptide is used to facilitate the fabrication of a porous aerogel with excellent physical properties as well as the homogeneous dispersion of magnetic particles during calcination.Subsequently,two kinds of heterometallic magnetic coupling systems are obtained through the application of Kirkendall effect.FeCo/nitrogen-doped carbon(NC)aerogel demonstrates an ultra-strong microwave absorption of−85 dB at an ultra-low loading of 5%.After reducing the time taken by atom shifting,a FeCo/Fe3O4/NC aerogel containing virus-shaped particles is obtained,which achieves an ultra-broad absorption of 7.44 GHz at an ultra-thin thickness of 1.59 mm due to the coupling effect offered by dual-soft-magnetic particles.Furthermore,both aerogels show excellent thermal insulation property,and their outstanding radar stealth performances in J-20 aircraft are confirmed by computer simulation technology.The formation mechanism of MOG is also discussed along with the thermal insulation and electromagnetic wave absorption mechanism of the aerogels,which will enable the development and application of novel and lightweight stealth coatings.
基金supported by the Ministry of Science and Technology of China (National Key R&D Program of China,2022YFB4200400, 2019YFA0705900)the National Natural Science Foundation of China (21935007, 52025033, 22204119),Tianjin City(22JCQNJC00530)Haihe Laboratory of Sustainable Chemical Transformations。
文摘Dimerized small-molecule acceptors(SMAs) built by the conventional connection of terminal groups of monomers have contributed to exciting long-term stabilities of organic solar cells(OSCs). However, device efficiencies, especially fill factors(FFs), still need to be improved. This probably originates from unsymmetrical molecular structure/conformation-determined less compact/ordered molecular stackings, such as ineffective stackings of constraint terminals. Herein, an exotic dimerized SMA of BC-Th is established by bridging the branched groups(BC-type, branch coupling) of two monomers rather than conventional terminal units(TC-type, terminal coupling). Benefiting from the three-dimensional conformation and more uncurbed terminals,BC-Th exhibits multiple molecular orientations along with a larger dielectric constant and electron mobility compared with TCTh. Finally, an efficiency of 17.43% is achieved by BC-Th-based OSCs, along with the highest FF of 79.13% among all dimerized SMAs-based OSCs to date. When introducing L8-BO as the third component, overall enhanced efficiency of 18.05%and FF of 80.11% are further afforded. Contrarily, TC-Th-based OSCs exhibit much inferior PCE of 16.29% and FF of 74.81%,demonstrating the great advantages of “branch coupling” over “terminal coupling” when building dimerized SMAs.
基金supported by the Key Program(U20A20235)funded by the National Natural Science Foundation of Chinathe National Natural Science Foundation of China(52171127,51974242)+3 种基金the Natural Science Basic Research Program of Shaanxi(2023-JC-QN-0595)the Regional Innovation Capability Guidance Program of Shaanxi(2022QFY10-06)the Key R&D Program of Xianyang Science and Technology Bureau(2021ZDYF-GY-0029)the Program of Xi’an Science and Technology Bureau(23GXFW0066)。
文摘Polymer-based composite electrolytes composed of three-dimensional Li_(6.4)La_(3)Zr_(2)Al_(0.2)O_(12)(3D-LLZAO)have attracted increasing attention due to their continuous ion conduction and satisfactory mechanical properties.However,the organic/inorganic interface is incompatible,resulting in slow lithium-ion transport at the interface.Therefore,the compatibility of organic/inorganic interface is an urgent problem to be solved.Inspired by the concept of“gecko eaves”,polymer-based composite solid electrolytes with dense interface structures were designed.The bridging of organic/inorganic interfaces was established by introducing silane coupling agent(3-chloropropyl)trimethoxysilane(CTMS)into the PEO-3D-LLZAO(PL)electrolyte.The in-situ coupling reaction improves the interface affinity,strengthens the organic/inorganic interaction,reduces the interface resistance,and thus achieves an efficient interface ion transport network.The prepared PEO-3D-LLZAO-CTMS(PLC)electrolyte exhibits enhanced ionic conductivity of 6.04×10^(-4)S cm^(-1)and high ion migration number(0.61)at 60℃and broadens the electrochemical window(5.1 V).At the same time,the PLC electrolyte has good thermal stability and high mechanical properties.Moreover,the Li Fe PO_(4)|PLC|Li battery has excellent rate performance and cycling stability with a capacity decay rate of 2.2%after 100 cycles at 60℃and 0.1 C.These advantages of PLC membranes indicate that this design approach is indeed practical,and the in-situ coupling method provides a new approach to address interface compatibility issues.
基金supported by the National Natural Science Foundation of China(22235001,22175020,21871024)the Interdisciplinary Research Project for Young Teachers of USTB(FRFIDRY-21-028)。
文摘Electrocatalytic synthesis of urea from CO_(2)and NO_(3)^(-)under ambient conditions provides an appealing alternative to the traditional energy-intensive urea synthetic protocol.Highly active and selective electrocatalysts for efficient urea production are therefore urgently desired owing to the unsatisfactory performance of the thus far reported catalysts.Herein,a phthalocyaninebased(Pc-based)covalent organic framework(COF),namely Co Pc-COF,fabricated from the nucleophilic substitution reaction of hexadecafluorophthalocyaninato cobalt with octahydroxylphthalocyanine cobalt,in situ grew on the surface of multilayered Ti O_(2)nanotubes(NTs),generating the Co Pc-COF@Ti O_(2)NTs composite.Powder X-ray diffraction analysis in combination with electron microscopy measurements discloses the uniform coating of crystalline Co Pc-COF on the multilayered Ti O_(2)NTs in Co Pc-COF@Ti O_(2)NTs.Remarkably,electrochemical tests reveal the superior electrocatalytic activity of Co Pc-COF@Ti O_(2)NTs towards urea production from CO_(2)and NO3-with a record-high yield of 1,205μg h^(-1)cm^(-2)and an outstanding Faraday efficiency of 49%at-0.6 V versus reversible hydrogen electrode due to the significant synergistic catalysis effect.In situ attenuated total reflection infrared spectroscopic investigation and theoretical calculations unveil the efficient C–N coupling reaction between*CO intermediate derived from CO_(2)on Co Pc moieties and*NH2intermediate formed from NO_(3)^(-)on Ti O_(2)NTs during the urea formation process over Co Pc-COF@Ti O_(2)NTs.This work should be helpful towards designing and fabricating high-performance electrocatalysts for sustainable synthesis of urea through efficient synergistic effect of multiactive centers.
基金the Fujian Science Technology Innovation Laboratory for Optoelectronic Information of China (Nos.2021ZR105 and 2021ZZ103)financial support from the National Natural Science Foundation of China (Nos.22071246 and22033008)。
文摘MOF-based core-shell structures with high surface area, abundant active sites, and broad absorption bands are viable alternatives to traditional single-component photocatalysts. In this report, we describe the design and construction of delicate Ag nanowires@NH_(2)-UiO-66 with a core-shell structure for use as photocatalysts in imine synthesis under light. The optimized composites exhibited 80% imine production, which was higher than both MOF and Ag NWs. The significant improvement in photocatalytic activity under light may be attributed to the plasmonic effect of silver nanowires and their core-shell structure, which promotes the separation of electron-hole pairs. Moreover, the photocatalytic activity of the core-shell nanostructure may provide valuable insight into the design and construction of MOF-based composite photocatalysts for oxidative coupling of amines.
文摘社会—生态韧性作为社会生态系统(Social-Ecological System,SES)的动态属性,其研究涉及自然、社会和经济的大量信息和复杂的耦合关系,对于城市治理领域,尤其在城市规划与治理实践层面有着重要的指导意义。研究基础数据为Web of Science(WoS)核心合集中2 906篇基础研究成果和345篇筛选后的精准研究成果,初步分析表明过去的20年内,关于社会—生态韧性的研究引起了各个学科的关注,并将持续成为地理学、生态学、城市管理学等学科共同关注的焦点。在此基础上,文章概述了社会—生态韧性在不同学科领域的研究成果,主要集中在韧性机制、韧性评估和韧性管理等多个层面,对于社会—生态韧性在城市治理层面的应用提升有借鉴作用。同时文章概述了韧性研究的内涵和主要发展过程,经历了从工程韧性到生态韧性再到社会—生态韧性的演变,形成了支撑现代韧性理论的基础支柱。从社会—生态韧性理论在城市治理的应用层面来说,需要关注到以下几个关键问题:社会系统与生态系统之间的相互作用以及动态的适应过程;社会—生态韧性对于城市规划和治理方式的影响;跨学科的社会—生态韧性研究框架和城市治理模式的构建。
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11974215,21933002,and 12274264)。
文摘With an extended Su–Schrieffer–Heeger model and Green's function method, the spin–orbit coupling(SOC) effects on spin admixture of electronic states and quantum transport in organic devices are investigated. The role of lattice distortion induced by the strong electron–lattice interaction in organics is clarified in contrast with a uniform chain. The results demonstrate an enhanced SOC effect on the spin admixture of frontier eigenstates by the lattice distortion at a larger SOC,which is explained by the perturbation theory. The quantum transport under the SOC is calculated for both nonmagnetic and ferromagnetic electrodes. A more notable SOC effect on total transmission and current is observed for ferromagnetic electrodes, where spin filtering induced by spin-flipped transmission and suppression of magnetoresistance are obtained.Unlike the spin admixture, a stronger SOC effect on transmission exists for the uniform chain rather than the organic lattices with distortion. The reason is attributed to the modified spin-polarized conducting states in the electrodes by lattice configuration, and hence the spin-flip transmission, instead of the spin admixture of eigenstates. This work is helpful to understand the SOC effect in organic spin valves in the presence of lattice distortion.
