Carbon materials are a key component in energy storage and conversion devices and their microstructure plays a crucial role in determining device performance.However,traditional carbon materials are unable to meet the...Carbon materials are a key component in energy storage and conversion devices and their microstructure plays a crucial role in determining device performance.However,traditional carbon materials are unable to meet the requirements for applications in emerging fields such as renewable energy and electric vehicles due to limitations including a disordered structure and uncontrolled defects.With an aim of realizing devisable structures,adjustable functions,and performance breakthroughs,superstructured carbons is proposed and represent a category of carbon-based materials,characterized by precisely-built pores,networks,and interfaces.Superstructured carbons can overcome the limitations of traditional carbon materials and improve the performance of energy storage and conversion devices.We review the structure-activity relationships of superstructured carbons and recent research advances from three aspects including a precisely customized pore structure,a dense carbon network framework,and a multi-component highly coupled interface between the different components.Finally,we provide an outlook on the future development of and practical challenges in energy storage and conversion devices.展开更多
Carbon materials are key components in energy storage and conversion devices and most directly impact device performance.The need for advanced carbon materials has become more pressing with the increasing demand for h...Carbon materials are key components in energy storage and conversion devices and most directly impact device performance.The need for advanced carbon materials has become more pressing with the increasing demand for high-performance energy conversion and storage facilities.Nonetheless,realizing significant performance improvements across devices remains challenging because of the difficulties in controlling irreg-ularly organized microstructures and the specific carbon structures concerned.With the aim of realizing devis-able structures,adjustable functions,and performance breakthroughs,this review proposes the concept of superstructured carbons.In fact,superstructured carbons are a category of carbon-based materials charac-terized by precisely built pores,networks,and interfaces.This unique category meets the particular func-tional demands of high-performance devices and exceeds the rigid structure of traditional carbons.In the context of these superstructured carbons,we present methods for realizing both custom-built structures and target-oriented functionalities.For specific energy-related reactions,we emphasize the targeted property-structure relationships in these well-defined superstructured carbons.Finally,future developments and practi-cability challenges of superstructured carbons are also proposed.展开更多
In the scale-up of water electrolysis,commercial systems require catalysts that are effective,stable,and earth-abundant.Although platinum group metal(PGM)catalysts exhibit remarkable activity,the high cost and scarcit...In the scale-up of water electrolysis,commercial systems require catalysts that are effective,stable,and earth-abundant.Although platinum group metal(PGM)catalysts exhibit remarkable activity,the high cost and scarcity significantly increase the overall capital expenses for alkaline water oxidation[1].As a more sustainable alternative,non-PGM catalysts—particularly first-row(3d)transitionmetal(oxy)hydroxides—show great promise for water oxidation.However,from a theoretical standpoint(e.g.,Pourbaix diagrams)[2],these active phases are often difficult to detect compared to PGM under oxygen evolution reaction(OER)conditions,underscoring the need to stabilize them during operation.Moreover,the rapid degradation of these metal(oxy)hydroxides is potential-dependent and typically occurs at high overpotentials required to achieve practical current densities,often associated with the dissolution of catalytic metal sites or phase segregation under harsh OER conditions[3].Together,these factors present a critical challenge in the development of metal(oxy)hydroxide catalysts—namely,stabilizing both the active phases and active sites,particularly during long-term operations at high current densities[4].展开更多
A WDM compatible Edge-to-Edge Self-Routed optical packet switched network that simplifies the optical processing is proposed. The system employs all-optical packet label generation and recognition using coded superstr...A WDM compatible Edge-to-Edge Self-Routed optical packet switched network that simplifies the optical processing is proposed. The system employs all-optical packet label generation and recognition using coded superstructured Fiber Bragg gratings.展开更多
Carbon superstructures with multiscale hierarchies and functional attributes represent an appealing cathode candidate for zinc hybrid capacitors,but their tailor-made design to optimize the capacitive activity remains...Carbon superstructures with multiscale hierarchies and functional attributes represent an appealing cathode candidate for zinc hybrid capacitors,but their tailor-made design to optimize the capacitive activity remains a confusing topic.Here we develop a hydrogen-bond-oriented interfacial super-assembly strategy to custom-tailor nanosheet-intertwined spherical carbon superstructures(SCSs)for Zn-ion storage with double-high capacitive activity and durability.Tetrachlorobenzoquinone(H-bond acceptor)and dimethylbenzidine(H-bond donator)can interact to form organic nanosheet modules,which are sequentially assembled,orientally compacted and densified into well-orchestrated superstructures through multiple H-bonds(N-H···O).Featured with rich surface-active heterodiatomic motifs,more exposed nanoporous channels,and successive charge migration paths,SCSs cathode promises high accessibility of built-in zincophilic sites and rapid ion diffusion with low energy barriers(3.3Ωs-0.5).Consequently,the assembled Zn||SCSs capacitor harvests all-round improvement in Zn-ion storage metrics,including high energy density(166 Wh kg-1),high-rate performance(172 m Ah g^(-1)at 20 A g^(-1)),and long-lasting cycling lifespan(95.5%capacity retention after 500,000 cycles).An opposite chargecarrier storage mechanism is rationalized for SCSs cathode to maximize spatial capacitive charge storage,involving high-kinetics physical Zn^(2+)/CF_(3)SO_(3)-adsorption and chemical Zn^(2+)redox with carbonyl/pyridine groups.This work gives insights into H-bond-guided interfacial superassembly design of superstructural carbons toward advanced energy storage.展开更多
Fiber-shaped energy storage devices are indispensable parts of wearable and portable electronics.Aqueous rechargeable Ni/Fe battery is a very appropriate energy storage device due to their good safety without organic ...Fiber-shaped energy storage devices are indispensable parts of wearable and portable electronics.Aqueous rechargeable Ni/Fe battery is a very appropriate energy storage device due to their good safety without organic electrolytes, high ionic conductivity, and low cost. Unfortunately, the low energy density,poor power density and cycling performance hinder its further practical applications. In this study, in order to obtain high performance negative iron-based material, we first synthesized a-iron oxide(α-Fe2O3) nanorods(NRs) with superstructures on the surface of highly conductive carbon nanotube fibers(CNTFs), then electrically conductive polypyrrole(PPy) was coated to enhance the electron, ion diffusion and cycle stability. The as-prepared α-Fe2O3@PPy NRs/CNTF electrode shows a high specific capacity of 0.62 Ah cm-3 at the current density of 1 A cm-3. Furthermore, the Ni/Fe battery that was assembled by the above negative electrode shows a maximum volumetric energy density of 15.47 mWh cm-3 with228.2 mW cm-3 at a current density of 1 A cm-3. The cycling durability and mechanical flexibility of the Ni/Fe battery were tested, which show good prospect for practical application. In summary, these merits make it possible for our Ni/Fe battery to have practical applications in next generation flexible energy storage devices.展开更多
The vibration response and noise caused by subway trains can affect the safety and comfort of superstructures.To study the dynamic response characteristics of subway stations and superstructures under train loads with...The vibration response and noise caused by subway trains can affect the safety and comfort of superstructures.To study the dynamic response characteristics of subway stations and superstructures under train loads with a hard combination,a numerical model is developed in this study.The indoor model test verified the accuracy of the numerical model.The influence laws of different hard combinations,train operating speeds and modes were studied and evaluated accordingly.The results show that the frequency corresponding to the peak vibration acceleration level of each floor of the superstructure property is concentrated at 10–20 Hz.The vibration response decreases in the high-frequency parts and increases in the lowfrequency parts with increasing distance from the source.Furthermore,the factors,such as train operating speed,operating mode,and hard combination type,will affect the vibration of the superstructure.The vibration response under the reversible operation of the train is greater than that of the unidirectional operation.The operating speed of the train is proportional to its vibration response.The vibration amplification area appears between the middle and the top of the superstructure at a higher train speed.Its vibration acceleration level will exceed the limit value of relevant regulations,and vibration-damping measures are required.Within the scope of application,this study provides some suggestions for constructing subway stations and superstructures.展开更多
Improving the surface atoms utilization efficiency of catalysts is extremely important for large-scale H_(2)production by electrochemical water splitting,but it remains a great challenge.Herein,we reported two kinds o...Improving the surface atoms utilization efficiency of catalysts is extremely important for large-scale H_(2)production by electrochemical water splitting,but it remains a great challenge.Herein,we reported two kinds of Mo O_(3)-polyoxometalate hybrid nanobelt superstructures(MoO_(3)-POM HNSs,POM=PW_(12)O_(40)and Si W_(12)O_(40))using a simple hydrothermal method.Such superstructure with highly uniform nanoparticles as building blocks can expose more surface atoms and emanate increased specific surface area.The incorporated POMs generated abundant oxygen vacancies,improved the electronic mobility,and modulated the surface electronic structure of MoO_(3),allowing to optimize the H^(*)adsorption/desorption and dehydrogenation kinetics of catalyst.Notably,the as-prepared MoO_(3)-PW_(12)O_(40)HNSs electrodes not only displayed the low overpotentials of 108 mV at 10 mA/cm^(2)current density in 0.5 mol/L H_(2)SO_(4)electrolyte but also displayed excellent long-term stability.The hydrogen evolution reaction(HER)performance of MoO_(3)-POM superstructures is significantly better than that of corresponding bulk materials MoO_(3)@PW_(12)O_(40)and Mo O_(3)@Si W_(12)O_(40),and the overpotentials are about 8.3 and 4.9 times lower than that of single Mo O_(3).This work opens an avenue for designing highly surface-exposed catalysts for electrocatalytic H_(2)production and other electrochemical applications.展开更多
Designing carbon materials with ideal stable hierarchical porous structures and fiexible functional properties for efficient and sustainable Zn2+ion storage still faces great challenges. Herein, the threedimensional c...Designing carbon materials with ideal stable hierarchical porous structures and fiexible functional properties for efficient and sustainable Zn2+ion storage still faces great challenges. Herein, the threedimensional carbon superstructures with spherical nanofiower-like structures were tailor-made by the self-assembly strategy. Specifically, organic polymer units(i.e., organic motifs) were formed by tetrachloro-p-benzoquinone(TBQ) and 2,6-diamino anthraquinone(DAQ) via a noble-metal-free catalyzed coupling reaction. Subsequently, the organic motifs assemble into spherical nanofiower-like superstructures induced by intermolecular hydrogen bonding and aromatic π-π stacking interactions. Welldesigned carbon superstructures can provide a stable backbone that effectively blocks structural stacking and collapse. Meanwhile, the hierarchical porous structures in 3D carbon superstructures provide continuous charge transport pathways to greatly shorten the ion diffusion distance, and as a result, the carbon superstructures-based zinc-ion hybrid capacitors(ZIHCs) provide a capacity of 245 m Ah/g at 0.5 A/g, a high energy density of 152 Wh/kg and an ultra-long life of 300,000 cycles at 20 A/g. The excellent electrochemical performance is also attributed to the corresponding charge storage mechanism, i.e., the alternate binding of Zn^(2+)/CF_(3)SO_(3)^(-) ions. Besides, the high-level N/O motifs improve the surface properties of the carbon superstructures and reduce the ion migration barriers for more efficient charge storage. This paper provides insights into the design of advanced carbon-based cathodes and presents a fundamental understanding of their charge storage mechanisms.展开更多
Constructing hierarchical nanostructures with highly exposed surfaces is a promising strategy for developing advanced cathode materials in aqueous batteries.Herein,we employed a competitive coordination strategy to op...Constructing hierarchical nanostructures with highly exposed surfaces is a promising strategy for developing advanced cathode materials in aqueous batteries.Herein,we employed a competitive coordination strategy to optimize the characteristics of nickel metal-organic framework(Ni-MOF).Specifically,the acetate ions were employed as precise regulators,exerting a distinct influence on the morphology of the Ni-MOF and leading to a structural transition from a block structure to a two-dimensional(2D)layered structure.The optimized Ni-MOF exhibits a unique superstructure composed of hierarchical 2D layers assembled into flower-like architectures.This distinctive superstructure increases the electrochemically active surface area of Ni-MOF(N-2)and provides abundant pathways for electron/ion transfer,thereby facilitating efficient electrochemical reactions.Remarkably,the assembled aqueous alkaline N-2//Zn battery demonstrated enhanced specific capacity(0.446 mAh·cm^(-2)at 1 mA·cm^(-2))and excellent maximum energy/power density(0.789 mWh·cm^(-2)/17.262 mW·cm^(-2)).This work not only offers valuable insights into regulating MOF morphology,but also makes a contribution toward enhancing the application potential of MOFs in aqueous batteries.展开更多
The rise of Zn-ion hybrid capacitor(ZHC)has imposed high requirements on carbon cathodes,including reasonable configuration,high specific surface area,multiscale pores,and abundant defects.To achieve this objective,a ...The rise of Zn-ion hybrid capacitor(ZHC)has imposed high requirements on carbon cathodes,including reasonable configuration,high specific surface area,multiscale pores,and abundant defects.To achieve this objective,a template-oriented strategy coupled with multi-heteroatom modification is proposed to precisely synthesize a three-dimensional boron/nitrogen-rich carbon nanoflake-interconnected micro/nano superstructure,referred to as BNPC.The hierarchically porous framework of BNPC shares short channels for fast Zn2+transport,increased adsorption-site accessibility,and structural robustness.Additionally,the boron/nitrogen incorporation effect significantly augments Zn2+adsorption capability and more distinctive pseudocapacitive nature,notably enhancing Zn-ion storage and transmission kinetics by performing the dual-storage mechanism of the electric double-layer capacitance and Faradaic redox process in BNPC cathode.These merits contribute to a high capacity(143.7 mAh g^(-1)at 0.2 A g^(-1))and excellent rate capability(84.5 mAh g^(-1)at 30 A g^(-1))of BNPC-based aqueous ZHC,and the ZHC still shows an ultrahigh capacity of 108.5 mAh g^(-1)even under a high BNPC mass loading of 12 mg cm^(-2).More critically,the BNPC-based flexible device also sustains notable cyclability over 30,000 cycles and low-rate self-discharge of 2.13 mV h-1 along with a preeminent energy output of 117.15 Wh kg^(-1)at a power density of 163.15Wkg^(-1),favoring a creditable applicability in modern electronics.In/ex-situ analysis and theoretical calculations elaborately elucidate the enhanced charge storage mechanism in depth.The findings offer a promising platform for the development of advanced carbon cathodes and corresponding electrochemical devices.展开更多
Pyrrhotite naturally occurs in various superstructures including magnetic(4C)and non-magnetic(5C,6C)types,each with distinct physicochemical properties and flotation behaviors.Challenges in accurately identifying and ...Pyrrhotite naturally occurs in various superstructures including magnetic(4C)and non-magnetic(5C,6C)types,each with distinct physicochemical properties and flotation behaviors.Challenges in accurately identifying and quantifying these superstructures hinder the optimization of pyrrhotite depression in flotation processes.To address this critical issue,synchrotron X-ray powder diffraction(S-XRPD)with Rietveld refinement was employed to quantify the distribution of superstructures in the feed and flotation concentrates of a copper–gold ore.To elucidate the mechanisms influencing depression,density functional theory(DFT)calculations were conducted to explore the electronic structures and surface reactivity of the pyrrhotite superstructures toward the adsorption of water,oxygen and hydroxyl ions(OH-)as dominant species present in the flotation process.S-XRPD analysis revealed that flotation recovery rates of pyrrhotite followed the order of 4C<6C<5C.DFT calculations indicated that the Fe 3d and S 3p orbital band centers exhibited a similar trend relative to the Fermi level with 4C being the closest.The Fe3d band center suggested that the 4C structure possessed a more reactive surface toward the oxygen reduction reaction,promoting the formation of hydrophilic Fe-OH sites.The S 3p band center order also implied that xanthate on the non-magnetic 5C and 6C surfaces could oxidize to dixanthogen,increasing hydrophobicity and floatability,while 4C formed less hydrophobic metal-xanthate complexes.Adsorption energy and charge transfer analyses of water,hydroxyl ions and molecular oxygen further supported the high reactivity and hydrophilic nature of 4C pyrrhotite.The strong bonding with hydroxyl ions indicated enhanced surface passivation by hydrophilic Fe–OOH complexes,aligning with the experimentally observed flotation order(4C<6C<5C).These findings provide a compelling correlation between experimental flotation results and electronic structure calculations,delivering crucial insights for optimizing flotation processes and improving pyrrhotite depression.This breakthrough opens up new opportunities to enhance the efficiency of flotation processes in the mining industry.展开更多
Employing experimental equipment and techniques,such as electron backscatter diffraction,transmission Kikuchi diffraction,and transmission electron microscopy,the microstructure,phase structure,and orientation relatio...Employing experimental equipment and techniques,such as electron backscatter diffraction,transmission Kikuchi diffraction,and transmission electron microscopy,the microstructure,phase structure,and orientation relationships of 0.6μm electroplated nickel(Ni)steel following annealing at 580-650℃for 15-30 hours were investigated.A comprehensive analysis was conducted to gain insights into the complex changes in the material's properties due to the annealing process.The results reveal that prolonged annealing led to considerable long-range diffusion of surface Ni atoms into the substrate of the 0.6μm Ni-plated steel.This diffusion process resulted in the formation of an alloy diffusion layer,approximately 4μm in thickness,which altered the material's microstructural characteristics.The extent of diffusion and its effect on the microstructure and structure were meticulously quantified.At the annealing temperature,the diffused Ni in the substrate,acting as an austenite-stabilizing element,expanded the austenite phase region.The alloy layer at this temperature predominantly consisted of the face-centered cubic(FCC)-structuredγ(Fe,Ni)solid solution.Upon cooling to room temperature,the alloy diffusion layer evolved into a dual-layer composite structure.The upper layer mainly comprised the FCC-structuredγ(Fe,Ni)solid solution,interspersed with a minor FCC compound superstructure phase.The lower layer underwent a diffusionless phase transformation during cooling,which led to the formation of the body-centered tetragonal/body-centered cubic-structured martensite.This phase,which is known for its high hardness and numerous variants,maintained the classic Kurdjumov-Sachs orientation relationship with the upper FCC parent phase,and it satisfied the close-packed plane{111}γ//{110}α′and close-packed direction<110>γ//<111>α′.A detailed analysis of the different phases within the alloy layer and their phase transitions was presented,offering an in-depth understanding of the material's characteristics.展开更多
This article discusses the design strategy of complex mountain highway bridges.During the research phase,details were obtained based on prior literature review and analysis of engineering materials from mountainous ar...This article discusses the design strategy of complex mountain highway bridges.During the research phase,details were obtained based on prior literature review and analysis of engineering materials from mountainous area bridges.After analyzing the design characteristics of complex mountainous area road and bridge projects,the principles for the design of bridges on complex mountainous area expressways were proposed.The research on bridge design was carried out from five dimensions:bridge type selection,foundation design,superstructure design,connection part design,and material and technological innovation.Eventually,a relatively complete design system was formed.It is expected that this paper can provide technical references and value for road and bridge projects in China and promote the sustainable development of China’s road traffic system from a macro perspective.展开更多
A series of TiAl+Nb alloys with various Nb contents has been employed to explore phase relationship and the evolution of microstructure.A new ordered γ derivative (γ1) has been observed in the alloy containing 20 at...A series of TiAl+Nb alloys with various Nb contents has been employed to explore phase relationship and the evolution of microstructure.A new ordered γ derivative (γ1) has been observed in the alloy containing 20 at% Nb.The additional diffraction spots added to the diffraction pattern of L10 (TiAl) structure have been found in the alloy containing Nb up to 11 at% in terms of further ordering.The transformation from L10 (TiAl) structure to the further ordering phase,γ1,is a continuous ordering process with the substitution of Nb atoms for Ti atoms in alloys with over-stoichiometric Al content of TiAl.The possible transformtion characterzation has been discussed.展开更多
Earthquake performance of a flexible one-story building isolated with a variable frequency pendulum isolator （VFPI） under near-fault and far-field ground motions is investigated. The frictional forces mobilized at t...Earthquake performance of a flexible one-story building isolated with a variable frequency pendulum isolator （VFPI） under near-fault and far-field ground motions is investigated. The frictional forces mobilized at the interface of the VFPI are assumed to be velocity dependent. The interaction between frictional forces of the VFPI in two horizontal directions is duly considered and coupled differential equations of motion of the isolated system in the incremental form are solved iteratively. The response of the system with bi-directional interaction is compared with those without interaction. In addition, the effects of velocity dependence on the response of the isolated system are also investigated. Moreover, a parametric study is carried out to critically examine the influence of important parameters on bi-directional interaction effects of the frictional forces of the VFPI. These parameters are： the superstructure time period, frequency variation factor （FVF） and friction coefficient of the VFPI. From the above investigations, it is observed that the dependence of the friction coefficient on relative velocity of the system does not have a noticeable effect on the peak response of the system isolated with VFPI, and that the bi-directional interaction of frictional forces of the VFPI is important and if neglected, isolator displacements will be underestimated and the superstructure acceleration and base shear will be overestimated.展开更多
This paper presents a superstructure-based formulation for the synthesis of mass-exchange networks (MENs) considering multiple components. The superstructure is simplified by directly using the mass separation agents ...This paper presents a superstructure-based formulation for the synthesis of mass-exchange networks (MENs) considering multiple components. The superstructure is simplified by directly using the mass separation agents (MSA) from their sources, and therefore the automatic synthesis of the multi-component system involved in the MENs can be achieved without choosing a 'key-component' either for the whole process or the mass exchangers. A mathematical model is proposed to carry out the optimization process. The concentrations, flow rates, matches and unit operation displayed in the obtained network constitute the exact representation of the mass exchange process in terms of all species in the system. An example is used to illustrate and demonstrate the application of the proposed method.展开更多
The work presented in this paper serves as numerical verification of the analytical model developed in the companion paper for nonlinear dynamic analysis of multi-base seismically isolated structures. To this end, two...The work presented in this paper serves as numerical verification of the analytical model developed in the companion paper for nonlinear dynamic analysis of multi-base seismically isolated structures. To this end, two numerical examples have been analyzed using the computational algorithm incorporated into program 3D-BASIS-ME-MB, developed on the basis of the newly-formulated analytical model. The first example concerns a seven-story model structure that was tested on the earthquake simulator at the University at Buflhlo and was also used as a verification example for program SAP2000. The second example concerns a two-tower, multi-story structure with a split-level seismic-isolation system. For purposes of verification, key results produced by 3D-BASIS-ME-MB are compared to experimental results, or results obtained from other structural/finite element programs. In both examples, the analyzed structure is excited under conditions of bearing uplift, thus yielding a case of much interest in verifying the capabilities of the developed analysis tool.展开更多
Sodium-ion batteries(SIBs)are proved as one of the most acceptable candidates for replacing lithium-ion batteries in some fields by virtue of a similar“rocking chair”mechanism and the abundance of sodium.The voltage...Sodium-ion batteries(SIBs)are proved as one of the most acceptable candidates for replacing lithium-ion batteries in some fields by virtue of a similar“rocking chair”mechanism and the abundance of sodium.The voltage,rate performance,and energy density of these batteries are mainly determined by the cath-odes.Hence,a Li-Ni-Co co-substituted P2-Na_(0.67)[Li_(0.1)(Mn_(0.7)Ni_(0.2)Co_(0.1))_(0.9)]O_(2)(NLMNC)with ribbon super-structure is prepared with the aim of multi-ion synergistic modification.Owing to the addition of Ni and Co,the Jahn-Teller distortion of Mn can be suppressed corresponding with the improved structural stability,and a little bit of oxygen redox activities is triggered.When with the substitution of 10%Li,the X-ray diffraction(XRD)peaks of NLMNC show the ribbon superstructure at about 21°and 22°.The smooth charge/discharge profiles of the NLMNC cathode exhibit the solid-solution reaction.In addition,the platform at high voltage disappears corresponding with the existing oxygen redox activities being suppressed which may be related to the ribbon superstructure and the promotion of the Ni redox.Such NLMNC cathode can deliver a reversible discharge capacity of 123.5 mA h g^(-1)at 10 mA g^(-1).Even if the current density increases to 500 mA g^(-1),a reversible discharge capacity of 112.8 mA h g^(-1)still can be ob-tained.The distinguished cycling stability is related to the reversible migration of Li+between the metal oxide layer and the interlayer and low volume change during cycling.It is also needing to be mentioned that the capacity retention of NLMNC cathode is about 94.4%(based on the highest discharge capacity)after 100 cycles.This work presents an effective route to develop high-performance cathodes for SIBs.展开更多
For the optimal design of a heat exchanger network,the inlet and outlet stream temperatures of each heat exchanger in the network should be known.An explicit analytical solution of stream temperatures of an arbi-trary...For the optimal design of a heat exchanger network,the inlet and outlet stream temperatures of each heat exchanger in the network should be known.An explicit analytical solution of stream temperatures of an arbi-trary connected heat exchanger network was introduced,which is suitable for the thermal calculation of heat ex-changer networks.For the heat exchanger network synthesis,this solution was further developed and coupled with the stage-wise superstructure heat exchanger networks.The new calculation procedure reduced the computer mem-ory requirement dramatically.On the basis of this solution,a mathematical model for synthesis of heat exchanger networks with genetic algorithm was formulated,which is always feasible and no iteration is needed.Two examples were calculated with the proposed approach and better results were obtained.展开更多
文摘Carbon materials are a key component in energy storage and conversion devices and their microstructure plays a crucial role in determining device performance.However,traditional carbon materials are unable to meet the requirements for applications in emerging fields such as renewable energy and electric vehicles due to limitations including a disordered structure and uncontrolled defects.With an aim of realizing devisable structures,adjustable functions,and performance breakthroughs,superstructured carbons is proposed and represent a category of carbon-based materials,characterized by precisely-built pores,networks,and interfaces.Superstructured carbons can overcome the limitations of traditional carbon materials and improve the performance of energy storage and conversion devices.We review the structure-activity relationships of superstructured carbons and recent research advances from three aspects including a precisely customized pore structure,a dense carbon network framework,and a multi-component highly coupled interface between the different components.Finally,we provide an outlook on the future development of and practical challenges in energy storage and conversion devices.
基金supported by the National Basic Research Program of China(2014CB932400)the National Natural Science Foundation of China(Nos.51932005,52022041 and 52172040)Taishan Scholar Project of Shandong Province(No.tsqnz20221118).
文摘Carbon materials are key components in energy storage and conversion devices and most directly impact device performance.The need for advanced carbon materials has become more pressing with the increasing demand for high-performance energy conversion and storage facilities.Nonetheless,realizing significant performance improvements across devices remains challenging because of the difficulties in controlling irreg-ularly organized microstructures and the specific carbon structures concerned.With the aim of realizing devis-able structures,adjustable functions,and performance breakthroughs,this review proposes the concept of superstructured carbons.In fact,superstructured carbons are a category of carbon-based materials charac-terized by precisely built pores,networks,and interfaces.This unique category meets the particular func-tional demands of high-performance devices and exceeds the rigid structure of traditional carbons.In the context of these superstructured carbons,we present methods for realizing both custom-built structures and target-oriented functionalities.For specific energy-related reactions,we emphasize the targeted property-structure relationships in these well-defined superstructured carbons.Finally,future developments and practi-cability challenges of superstructured carbons are also proposed.
文摘In the scale-up of water electrolysis,commercial systems require catalysts that are effective,stable,and earth-abundant.Although platinum group metal(PGM)catalysts exhibit remarkable activity,the high cost and scarcity significantly increase the overall capital expenses for alkaline water oxidation[1].As a more sustainable alternative,non-PGM catalysts—particularly first-row(3d)transitionmetal(oxy)hydroxides—show great promise for water oxidation.However,from a theoretical standpoint(e.g.,Pourbaix diagrams)[2],these active phases are often difficult to detect compared to PGM under oxygen evolution reaction(OER)conditions,underscoring the need to stabilize them during operation.Moreover,the rapid degradation of these metal(oxy)hydroxides is potential-dependent and typically occurs at high overpotentials required to achieve practical current densities,often associated with the dissolution of catalytic metal sites or phase segregation under harsh OER conditions[3].Together,these factors present a critical challenge in the development of metal(oxy)hydroxide catalysts—namely,stabilizing both the active phases and active sites,particularly during long-term operations at high current densities[4].
文摘A WDM compatible Edge-to-Edge Self-Routed optical packet switched network that simplifies the optical processing is proposed. The system employs all-optical packet label generation and recognition using coded superstructured Fiber Bragg gratings.
基金financially supported by the National Natural Science Foundation of China(Nos.22272118,22172111,and 22309134)the Science and Technology Commission of Shanghai Municipality,China(Nos.22ZR1464100,20ZR1460300,and 19DZ2271500)+2 种基金the China Postdoctoral Science Foundation(2022M712402),the Shanghai Rising-Star Program(23YF1449200)the Zhejiang Provincial Science and Technology Project(2022C01182)the Fundamental Research Funds for the Central Universities(2023-3-YB-07)。
文摘Carbon superstructures with multiscale hierarchies and functional attributes represent an appealing cathode candidate for zinc hybrid capacitors,but their tailor-made design to optimize the capacitive activity remains a confusing topic.Here we develop a hydrogen-bond-oriented interfacial super-assembly strategy to custom-tailor nanosheet-intertwined spherical carbon superstructures(SCSs)for Zn-ion storage with double-high capacitive activity and durability.Tetrachlorobenzoquinone(H-bond acceptor)and dimethylbenzidine(H-bond donator)can interact to form organic nanosheet modules,which are sequentially assembled,orientally compacted and densified into well-orchestrated superstructures through multiple H-bonds(N-H···O).Featured with rich surface-active heterodiatomic motifs,more exposed nanoporous channels,and successive charge migration paths,SCSs cathode promises high accessibility of built-in zincophilic sites and rapid ion diffusion with low energy barriers(3.3Ωs-0.5).Consequently,the assembled Zn||SCSs capacitor harvests all-round improvement in Zn-ion storage metrics,including high energy density(166 Wh kg-1),high-rate performance(172 m Ah g^(-1)at 20 A g^(-1)),and long-lasting cycling lifespan(95.5%capacity retention after 500,000 cycles).An opposite chargecarrier storage mechanism is rationalized for SCSs cathode to maximize spatial capacitive charge storage,involving high-kinetics physical Zn^(2+)/CF_(3)SO_(3)-adsorption and chemical Zn^(2+)redox with carbonyl/pyridine groups.This work gives insights into H-bond-guided interfacial superassembly design of superstructural carbons toward advanced energy storage.
基金This work was supported by the National Natural Science Foundation of China (51972162 and 51703241)the Postdoctoral Foundation of Jiangsu Province (2019Z203 and 2019K001)the Science and Technology Project of Nanchang (2017-SJSYS008)
文摘Fiber-shaped energy storage devices are indispensable parts of wearable and portable electronics.Aqueous rechargeable Ni/Fe battery is a very appropriate energy storage device due to their good safety without organic electrolytes, high ionic conductivity, and low cost. Unfortunately, the low energy density,poor power density and cycling performance hinder its further practical applications. In this study, in order to obtain high performance negative iron-based material, we first synthesized a-iron oxide(α-Fe2O3) nanorods(NRs) with superstructures on the surface of highly conductive carbon nanotube fibers(CNTFs), then electrically conductive polypyrrole(PPy) was coated to enhance the electron, ion diffusion and cycle stability. The as-prepared α-Fe2O3@PPy NRs/CNTF electrode shows a high specific capacity of 0.62 Ah cm-3 at the current density of 1 A cm-3. Furthermore, the Ni/Fe battery that was assembled by the above negative electrode shows a maximum volumetric energy density of 15.47 mWh cm-3 with228.2 mW cm-3 at a current density of 1 A cm-3. The cycling durability and mechanical flexibility of the Ni/Fe battery were tested, which show good prospect for practical application. In summary, these merits make it possible for our Ni/Fe battery to have practical applications in next generation flexible energy storage devices.
基金National Natural Science Foundation of China under Grant No.51578463。
文摘The vibration response and noise caused by subway trains can affect the safety and comfort of superstructures.To study the dynamic response characteristics of subway stations and superstructures under train loads with a hard combination,a numerical model is developed in this study.The indoor model test verified the accuracy of the numerical model.The influence laws of different hard combinations,train operating speeds and modes were studied and evaluated accordingly.The results show that the frequency corresponding to the peak vibration acceleration level of each floor of the superstructure property is concentrated at 10–20 Hz.The vibration response decreases in the high-frequency parts and increases in the lowfrequency parts with increasing distance from the source.Furthermore,the factors,such as train operating speed,operating mode,and hard combination type,will affect the vibration of the superstructure.The vibration response under the reversible operation of the train is greater than that of the unidirectional operation.The operating speed of the train is proportional to its vibration response.The vibration amplification area appears between the middle and the top of the superstructure at a higher train speed.Its vibration acceleration level will exceed the limit value of relevant regulations,and vibration-damping measures are required.Within the scope of application,this study provides some suggestions for constructing subway stations and superstructures.
基金financially supported by the Program for the Development of Science and Technology of Jilin Province(Nos.YDZJ202201ZYTS313,YDZJ202201ZYTS395,20240402072GH,and 20240101004JJ)the National Natural Science Foundation of China(Nos.22201097 and 52171210)。
文摘Improving the surface atoms utilization efficiency of catalysts is extremely important for large-scale H_(2)production by electrochemical water splitting,but it remains a great challenge.Herein,we reported two kinds of Mo O_(3)-polyoxometalate hybrid nanobelt superstructures(MoO_(3)-POM HNSs,POM=PW_(12)O_(40)and Si W_(12)O_(40))using a simple hydrothermal method.Such superstructure with highly uniform nanoparticles as building blocks can expose more surface atoms and emanate increased specific surface area.The incorporated POMs generated abundant oxygen vacancies,improved the electronic mobility,and modulated the surface electronic structure of MoO_(3),allowing to optimize the H^(*)adsorption/desorption and dehydrogenation kinetics of catalyst.Notably,the as-prepared MoO_(3)-PW_(12)O_(40)HNSs electrodes not only displayed the low overpotentials of 108 mV at 10 mA/cm^(2)current density in 0.5 mol/L H_(2)SO_(4)electrolyte but also displayed excellent long-term stability.The hydrogen evolution reaction(HER)performance of MoO_(3)-POM superstructures is significantly better than that of corresponding bulk materials MoO_(3)@PW_(12)O_(40)and Mo O_(3)@Si W_(12)O_(40),and the overpotentials are about 8.3 and 4.9 times lower than that of single Mo O_(3).This work opens an avenue for designing highly surface-exposed catalysts for electrocatalytic H_(2)production and other electrochemical applications.
基金financially supported by the National Natural Science Foundation of China (Nos. 22272118, 22172111, 21905207, and 22309134)the Science and Technology Commission of Shanghai Municipality (Nos. 22ZR1464100, 20ZR1460300, and 19DZ2271500)+2 种基金China Postdoctoral Science Foundation (No. 2022M712402), Shanghai Rising-Star Program (No. 23YF1449200)Zhejiang Provincial Science and Technology Project (No. 2022C01182)the Fundamental Research Funds for the Central Universities (Nos. 22120210529 and 2023–3-YB-07)。
文摘Designing carbon materials with ideal stable hierarchical porous structures and fiexible functional properties for efficient and sustainable Zn2+ion storage still faces great challenges. Herein, the threedimensional carbon superstructures with spherical nanofiower-like structures were tailor-made by the self-assembly strategy. Specifically, organic polymer units(i.e., organic motifs) were formed by tetrachloro-p-benzoquinone(TBQ) and 2,6-diamino anthraquinone(DAQ) via a noble-metal-free catalyzed coupling reaction. Subsequently, the organic motifs assemble into spherical nanofiower-like superstructures induced by intermolecular hydrogen bonding and aromatic π-π stacking interactions. Welldesigned carbon superstructures can provide a stable backbone that effectively blocks structural stacking and collapse. Meanwhile, the hierarchical porous structures in 3D carbon superstructures provide continuous charge transport pathways to greatly shorten the ion diffusion distance, and as a result, the carbon superstructures-based zinc-ion hybrid capacitors(ZIHCs) provide a capacity of 245 m Ah/g at 0.5 A/g, a high energy density of 152 Wh/kg and an ultra-long life of 300,000 cycles at 20 A/g. The excellent electrochemical performance is also attributed to the corresponding charge storage mechanism, i.e., the alternate binding of Zn^(2+)/CF_(3)SO_(3)^(-) ions. Besides, the high-level N/O motifs improve the surface properties of the carbon superstructures and reduce the ion migration barriers for more efficient charge storage. This paper provides insights into the design of advanced carbon-based cathodes and presents a fundamental understanding of their charge storage mechanisms.
基金supported by the National Natural Science Foundation of China(No.52371240)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_3510).
文摘Constructing hierarchical nanostructures with highly exposed surfaces is a promising strategy for developing advanced cathode materials in aqueous batteries.Herein,we employed a competitive coordination strategy to optimize the characteristics of nickel metal-organic framework(Ni-MOF).Specifically,the acetate ions were employed as precise regulators,exerting a distinct influence on the morphology of the Ni-MOF and leading to a structural transition from a block structure to a two-dimensional(2D)layered structure.The optimized Ni-MOF exhibits a unique superstructure composed of hierarchical 2D layers assembled into flower-like architectures.This distinctive superstructure increases the electrochemically active surface area of Ni-MOF(N-2)and provides abundant pathways for electron/ion transfer,thereby facilitating efficient electrochemical reactions.Remarkably,the assembled aqueous alkaline N-2//Zn battery demonstrated enhanced specific capacity(0.446 mAh·cm^(-2)at 1 mA·cm^(-2))and excellent maximum energy/power density(0.789 mWh·cm^(-2)/17.262 mW·cm^(-2)).This work not only offers valuable insights into regulating MOF morphology,but also makes a contribution toward enhancing the application potential of MOFs in aqueous batteries.
基金Natural Science Foundation of Xinjiang Uygur Autonomous Region,Grant/Award Number:2023D01C11National Natural Science Foundation of China,Grant/Award Numbers:22369019,U2003216+2 种基金Special Projects on Regional Collaborative Innovation-SCO Science and Technology Partnership Program,International Science and Technology Cooperation Program,Grant/Award Number:2022E01020Tianshan Talent Training Program,Grant/Award Number:2023TSYCLJ0019National Key Research and Development Program of China,Grant/Award Numbers:2022YFB4101600,2022YFB4101601。
文摘The rise of Zn-ion hybrid capacitor(ZHC)has imposed high requirements on carbon cathodes,including reasonable configuration,high specific surface area,multiscale pores,and abundant defects.To achieve this objective,a template-oriented strategy coupled with multi-heteroatom modification is proposed to precisely synthesize a three-dimensional boron/nitrogen-rich carbon nanoflake-interconnected micro/nano superstructure,referred to as BNPC.The hierarchically porous framework of BNPC shares short channels for fast Zn2+transport,increased adsorption-site accessibility,and structural robustness.Additionally,the boron/nitrogen incorporation effect significantly augments Zn2+adsorption capability and more distinctive pseudocapacitive nature,notably enhancing Zn-ion storage and transmission kinetics by performing the dual-storage mechanism of the electric double-layer capacitance and Faradaic redox process in BNPC cathode.These merits contribute to a high capacity(143.7 mAh g^(-1)at 0.2 A g^(-1))and excellent rate capability(84.5 mAh g^(-1)at 30 A g^(-1))of BNPC-based aqueous ZHC,and the ZHC still shows an ultrahigh capacity of 108.5 mAh g^(-1)even under a high BNPC mass loading of 12 mg cm^(-2).More critically,the BNPC-based flexible device also sustains notable cyclability over 30,000 cycles and low-rate self-discharge of 2.13 mV h-1 along with a preeminent energy output of 117.15 Wh kg^(-1)at a power density of 163.15Wkg^(-1),favoring a creditable applicability in modern electronics.In/ex-situ analysis and theoretical calculations elaborately elucidate the enhanced charge storage mechanism in depth.The findings offer a promising platform for the development of advanced carbon cathodes and corresponding electrochemical devices.
基金supported by the Australian Research Council Linkage Project(No.LP200200717)co sponsored by Newmont Corporation(United States)and Vega Industries(India)+1 种基金the Powder Diffraction Beamline at the Australia’s Nuclear Science and Technology Organisation(No.PDR19870),Australiathe Centre for Microscopy and Microanalysis at the University of Queensland(No.1366),Australia。
文摘Pyrrhotite naturally occurs in various superstructures including magnetic(4C)and non-magnetic(5C,6C)types,each with distinct physicochemical properties and flotation behaviors.Challenges in accurately identifying and quantifying these superstructures hinder the optimization of pyrrhotite depression in flotation processes.To address this critical issue,synchrotron X-ray powder diffraction(S-XRPD)with Rietveld refinement was employed to quantify the distribution of superstructures in the feed and flotation concentrates of a copper–gold ore.To elucidate the mechanisms influencing depression,density functional theory(DFT)calculations were conducted to explore the electronic structures and surface reactivity of the pyrrhotite superstructures toward the adsorption of water,oxygen and hydroxyl ions(OH-)as dominant species present in the flotation process.S-XRPD analysis revealed that flotation recovery rates of pyrrhotite followed the order of 4C<6C<5C.DFT calculations indicated that the Fe 3d and S 3p orbital band centers exhibited a similar trend relative to the Fermi level with 4C being the closest.The Fe3d band center suggested that the 4C structure possessed a more reactive surface toward the oxygen reduction reaction,promoting the formation of hydrophilic Fe-OH sites.The S 3p band center order also implied that xanthate on the non-magnetic 5C and 6C surfaces could oxidize to dixanthogen,increasing hydrophobicity and floatability,while 4C formed less hydrophobic metal-xanthate complexes.Adsorption energy and charge transfer analyses of water,hydroxyl ions and molecular oxygen further supported the high reactivity and hydrophilic nature of 4C pyrrhotite.The strong bonding with hydroxyl ions indicated enhanced surface passivation by hydrophilic Fe–OOH complexes,aligning with the experimentally observed flotation order(4C<6C<5C).These findings provide a compelling correlation between experimental flotation results and electronic structure calculations,delivering crucial insights for optimizing flotation processes and improving pyrrhotite depression.This breakthrough opens up new opportunities to enhance the efficiency of flotation processes in the mining industry.
文摘Employing experimental equipment and techniques,such as electron backscatter diffraction,transmission Kikuchi diffraction,and transmission electron microscopy,the microstructure,phase structure,and orientation relationships of 0.6μm electroplated nickel(Ni)steel following annealing at 580-650℃for 15-30 hours were investigated.A comprehensive analysis was conducted to gain insights into the complex changes in the material's properties due to the annealing process.The results reveal that prolonged annealing led to considerable long-range diffusion of surface Ni atoms into the substrate of the 0.6μm Ni-plated steel.This diffusion process resulted in the formation of an alloy diffusion layer,approximately 4μm in thickness,which altered the material's microstructural characteristics.The extent of diffusion and its effect on the microstructure and structure were meticulously quantified.At the annealing temperature,the diffused Ni in the substrate,acting as an austenite-stabilizing element,expanded the austenite phase region.The alloy layer at this temperature predominantly consisted of the face-centered cubic(FCC)-structuredγ(Fe,Ni)solid solution.Upon cooling to room temperature,the alloy diffusion layer evolved into a dual-layer composite structure.The upper layer mainly comprised the FCC-structuredγ(Fe,Ni)solid solution,interspersed with a minor FCC compound superstructure phase.The lower layer underwent a diffusionless phase transformation during cooling,which led to the formation of the body-centered tetragonal/body-centered cubic-structured martensite.This phase,which is known for its high hardness and numerous variants,maintained the classic Kurdjumov-Sachs orientation relationship with the upper FCC parent phase,and it satisfied the close-packed plane{111}γ//{110}α′and close-packed direction<110>γ//<111>α′.A detailed analysis of the different phases within the alloy layer and their phase transitions was presented,offering an in-depth understanding of the material's characteristics.
文摘This article discusses the design strategy of complex mountain highway bridges.During the research phase,details were obtained based on prior literature review and analysis of engineering materials from mountainous area bridges.After analyzing the design characteristics of complex mountainous area road and bridge projects,the principles for the design of bridges on complex mountainous area expressways were proposed.The research on bridge design was carried out from five dimensions:bridge type selection,foundation design,superstructure design,connection part design,and material and technological innovation.Eventually,a relatively complete design system was formed.It is expected that this paper can provide technical references and value for road and bridge projects in China and promote the sustainable development of China’s road traffic system from a macro perspective.
文摘A series of TiAl+Nb alloys with various Nb contents has been employed to explore phase relationship and the evolution of microstructure.A new ordered γ derivative (γ1) has been observed in the alloy containing 20 at% Nb.The additional diffraction spots added to the diffraction pattern of L10 (TiAl) structure have been found in the alloy containing Nb up to 11 at% in terms of further ordering.The transformation from L10 (TiAl) structure to the further ordering phase,γ1,is a continuous ordering process with the substitution of Nb atoms for Ti atoms in alloys with over-stoichiometric Al content of TiAl.The possible transformtion characterzation has been discussed.
文摘Earthquake performance of a flexible one-story building isolated with a variable frequency pendulum isolator （VFPI） under near-fault and far-field ground motions is investigated. The frictional forces mobilized at the interface of the VFPI are assumed to be velocity dependent. The interaction between frictional forces of the VFPI in two horizontal directions is duly considered and coupled differential equations of motion of the isolated system in the incremental form are solved iteratively. The response of the system with bi-directional interaction is compared with those without interaction. In addition, the effects of velocity dependence on the response of the isolated system are also investigated. Moreover, a parametric study is carried out to critically examine the influence of important parameters on bi-directional interaction effects of the frictional forces of the VFPI. These parameters are： the superstructure time period, frequency variation factor （FVF） and friction coefficient of the VFPI. From the above investigations, it is observed that the dependence of the friction coefficient on relative velocity of the system does not have a noticeable effect on the peak response of the system isolated with VFPI, and that the bi-directional interaction of frictional forces of the VFPI is important and if neglected, isolator displacements will be underestimated and the superstructure acceleration and base shear will be overestimated.
基金Supported by the National Natural Science Foundation of China （20976022）
文摘This paper presents a superstructure-based formulation for the synthesis of mass-exchange networks (MENs) considering multiple components. The superstructure is simplified by directly using the mass separation agents (MSA) from their sources, and therefore the automatic synthesis of the multi-component system involved in the MENs can be achieved without choosing a 'key-component' either for the whole process or the mass exchangers. A mathematical model is proposed to carry out the optimization process. The concentrations, flow rates, matches and unit operation displayed in the obtained network constitute the exact representation of the mass exchange process in terms of all species in the system. An example is used to illustrate and demonstrate the application of the proposed method.
基金Multidisciplinary Center for Earthquake Engineering Research
文摘The work presented in this paper serves as numerical verification of the analytical model developed in the companion paper for nonlinear dynamic analysis of multi-base seismically isolated structures. To this end, two numerical examples have been analyzed using the computational algorithm incorporated into program 3D-BASIS-ME-MB, developed on the basis of the newly-formulated analytical model. The first example concerns a seven-story model structure that was tested on the earthquake simulator at the University at Buflhlo and was also used as a verification example for program SAP2000. The second example concerns a two-tower, multi-story structure with a split-level seismic-isolation system. For purposes of verification, key results produced by 3D-BASIS-ME-MB are compared to experimental results, or results obtained from other structural/finite element programs. In both examples, the analyzed structure is excited under conditions of bearing uplift, thus yielding a case of much interest in verifying the capabilities of the developed analysis tool.
基金the National Natural Science Foundation of China(No.52173246)the Science and Tech-nology Development Plan of Suzhou(No.ZXL2022176)Natural Sci-ence Foundation of the Jiangsu Higher Education Institutions(No.22KJA430009)and the“111 Project”(No.B13013).
文摘Sodium-ion batteries(SIBs)are proved as one of the most acceptable candidates for replacing lithium-ion batteries in some fields by virtue of a similar“rocking chair”mechanism and the abundance of sodium.The voltage,rate performance,and energy density of these batteries are mainly determined by the cath-odes.Hence,a Li-Ni-Co co-substituted P2-Na_(0.67)[Li_(0.1)(Mn_(0.7)Ni_(0.2)Co_(0.1))_(0.9)]O_(2)(NLMNC)with ribbon super-structure is prepared with the aim of multi-ion synergistic modification.Owing to the addition of Ni and Co,the Jahn-Teller distortion of Mn can be suppressed corresponding with the improved structural stability,and a little bit of oxygen redox activities is triggered.When with the substitution of 10%Li,the X-ray diffraction(XRD)peaks of NLMNC show the ribbon superstructure at about 21°and 22°.The smooth charge/discharge profiles of the NLMNC cathode exhibit the solid-solution reaction.In addition,the platform at high voltage disappears corresponding with the existing oxygen redox activities being suppressed which may be related to the ribbon superstructure and the promotion of the Ni redox.Such NLMNC cathode can deliver a reversible discharge capacity of 123.5 mA h g^(-1)at 10 mA g^(-1).Even if the current density increases to 500 mA g^(-1),a reversible discharge capacity of 112.8 mA h g^(-1)still can be ob-tained.The distinguished cycling stability is related to the reversible migration of Li+between the metal oxide layer and the interlayer and low volume change during cycling.It is also needing to be mentioned that the capacity retention of NLMNC cathode is about 94.4%(based on the highest discharge capacity)after 100 cycles.This work presents an effective route to develop high-performance cathodes for SIBs.
基金Supported by Shanghai Leading Academic Discipline Project (No.T0503)Shanghai Pujiang Program (No.05PJ14078)Ji-angsu Cuilong Copper Industry Co.,Ltd.
文摘For the optimal design of a heat exchanger network,the inlet and outlet stream temperatures of each heat exchanger in the network should be known.An explicit analytical solution of stream temperatures of an arbi-trary connected heat exchanger network was introduced,which is suitable for the thermal calculation of heat ex-changer networks.For the heat exchanger network synthesis,this solution was further developed and coupled with the stage-wise superstructure heat exchanger networks.The new calculation procedure reduced the computer mem-ory requirement dramatically.On the basis of this solution,a mathematical model for synthesis of heat exchanger networks with genetic algorithm was formulated,which is always feasible and no iteration is needed.Two examples were calculated with the proposed approach and better results were obtained.
