In order to achieve the improvement of the driving comfort and energy efficiency,an new e-CVT flexible full hybrid electric system(E2FHS) is proposed,which uses an integrated main drive motor and generator to take the...In order to achieve the improvement of the driving comfort and energy efficiency,an new e-CVT flexible full hybrid electric system(E2FHS) is proposed,which uses an integrated main drive motor and generator to take the place of the original automatic or manual transmission to realize the functions of continuously variable transmission(e-CVT).The design and prototype realization of the E2FHS system for a plug-in hybrid vehicle(PHEV) is performed.In order to analyze and optimize the parameters and the power flux between different parts of the E2FHS,simulation software is developed.Especially,in order to optimize the performance of the energy economy improvement of the E2FHS,the effect of the different energy management controllers is investigated,and an adaptive online-optimal energy management controller for the E2FHS is built and validated by the prototype PHEV.展开更多
Zn-ion hybrid supercapacitors(SCs)are considered as promising energy storage owing to their high energy density compared to traditional SCs.How to realize the miniaturization,patterning,and flexibility of the Zn-ion S...Zn-ion hybrid supercapacitors(SCs)are considered as promising energy storage owing to their high energy density compared to traditional SCs.How to realize the miniaturization,patterning,and flexibility of the Zn-ion SCs without affecting the electrochemical performances has special meanings for expanding their applications in wearable integrated electronics.Ti_(3)C_(2)T_(x) cathode with outstanding conductivity,unique lamellar structure and good mechanical flexibility has been demonstrated tremen-dous potential in the design of Zn-ion SCs,but achieving long cycling stability and high rate stability is still big challenges.Here,we proposed a facile laser writing approach to fabricate patterned Ti_(3)C_(2)T_(x)-based Zn-ion micro-supercapacitors(MSCs),followed by the in-situ anneal treatment of the assembled MSCs to improve the long-term stability,which exhibits 80%of the capacitance retention even after 50,000 charge/discharge cycles and superior rate stability.The influence of the cathode thickness on the electrochemical performance of the MSCs is also studied.When the thickness reaches 0.851μm the maximum areal capacitance of 72.02 mF cm^(−2)at scan rate of 10 mV s^(−1),which is 1.77 times higher than that with a thickness of 0.329μm(35.6 mF cm^(−2)).Moreover,the fab-ricated Ti_(3)C_(2)T_(x) based Zn-ion MSCs have excellent flexibility,a digital timer can be driven by the single device even under bending state,a flexible LED displayer of“TiC”logo also can be easily lighted by the MSC arrays under twisting,crimping,and winding conditions,demonstrating the scalable fabrication and application of the fabricated MSCs in portable electronics.展开更多
One of the most exciting new developments in energy storage technology is flexible Zn-ion hybrid supercapacitors(f-ZIHSCs),which combine the high energy of Zn-ion batteries with high-power supercapacitors to satisfy t...One of the most exciting new developments in energy storage technology is flexible Zn-ion hybrid supercapacitors(f-ZIHSCs),which combine the high energy of Zn-ion batteries with high-power supercapacitors to satisfy the needs of portable flexible electronics.However,the development of f-ZHSCs is still in its infancy,and there are numerous barriers to overcome before they can be widely implemented for practical applications.This review gives an up-to-date description of recent achievements and underlying concepts in energy storage mechanisms of f-ZIHSCs and emphasizes the critical role of cathode,anode,and electrolyte materials systems in speeding the prosperity of f-ZIHSCs.The innovative nanostructured-based cathode materials for f-ZIHSCs include carbon(e.g.,porous carbon,heteroatom-doped carbon,biomass-derived porous carbon,graphene,etc.),metal-oxides,MXenes,and metal/covalentorganic frameworks,and other materials(e.g.,activated carbon,phosphorene,etc.)are mainly focused.Afterward,the latest developments in flexible anode and electrolyte frameworks and impacts of electrolyte compositions on the electrochemical properties of f-ZIHSC are elaborated.Subsequently,the advancements based on fabrication designs,including quasi-solid-state,micro,fiber-shaped,and all climate-changed f-ZIHSCs,are discussed in detail.Lastly,a summary of current challenges and recommendations for the future progress of advanced f-ZIHSC are addressed.This review article is anticipated to further understand the viable strategies and achievable approaches for assembling high-performance f-ZIHSCs and boost the technical revolutions on cathode,anode,and electrolytes for f-ZIHSC devices.展开更多
This paper proposes the use of the flexible tolerance method(FTM) modified with scaling of variables and hybridized with different unconstrained optimization methods to solve real constrained optimization problems.The...This paper proposes the use of the flexible tolerance method(FTM) modified with scaling of variables and hybridized with different unconstrained optimization methods to solve real constrained optimization problems.The benchmark problems used to analyze the performance of the methods were taken from G-Suite functions.The original method(FTM) and other four proposed methods:(i) FTM with scaling of variables(FTMS),(ii) FTMS hybridized with BFGS(FTMS-BFGS),(iii) FTMS hybridized with modified Powell's method(FTMS-Powell)and(iv) FTMS hybridized with PSO(FTMS-PSO), were implemented. The success rates of the methods were 80%,100%, 75%, 95% and 85%, for FTM, FTMS, FTMS-BFGS, FTMS-Powell and FTMS-PSO, respectively. Numerical experiments including real constrained problems indicated that FTMS gave the best performance, followed by FTMSPowell and FTMS-PSO. Despite the inferior performance compared to FTMS and FTMS-Powell, the FTMS-PSO method presented some advantages since good different initial points could be obtained, which allow exploring different routes through the solution space and to escape from local optima. The proposed methods proved to be an effective way of improving the performance of the original FTM.展开更多
The previous low-order approximate nonlinear formulations succeeded in capturing the stiffening terms, but failed in simulation of mechanical systems with large deformation due to the neglect of the high-order deforma...The previous low-order approximate nonlinear formulations succeeded in capturing the stiffening terms, but failed in simulation of mechanical systems with large deformation due to the neglect of the high-order deformation terms. In this paper, a new hybrid-coordinate formulation is proposed, which is suitable for flexible multibody systems with large deformation. On the basis of exact strain- displacement relation, equations of motion for flexible multi-body system are derived by using virtual work principle. A matrix separation method is put forward to improve the efficiency of the calculation. Agreement of the present results with those obtained by absolute nodal coordinate formulation (ANCF) verifies the correctness of the proposed formulation. Furthermore, the present results are compared with those obtained by use of the linear model and the low-order approximate nonlinear model to show the suitability of the proposed models.展开更多
During the launching stage,hydrodynamic pressure and adapters' reaction loads can influence the vehicle's rigid motion as well as cause its structural vibration,which is a typical rigid-flexible coupling dynam...During the launching stage,hydrodynamic pressure and adapters' reaction loads can influence the vehicle's rigid motion as well as cause its structural vibration,which is a typical rigid-flexible coupling dynamic problem. This paper presents a 2-D rigid-flexible coupling model to calculate the vehicle's dynamic responses in that period.The vehicle was equivalent to a flexure beam with axial deformation. Hybrid coordinate and modal superposition methods were used to describe its large rigid displacement and small deformation. By the second Lagrange equation,the vehicle centroid's displacements,rotational angle and modal coordinates were chosen as generalized coordinates and then the vehicle 's rigid-flexible coupling dynamic equations were obtained. By numerical simulation,the results of vehicle's motion parameters and transverse internal loads were acquired.The calculation results showed that differences of the vehicle's motion parameters between the rigid-flexible coupling model and the rigid body assumption are noticeable and the peak magnitude of the vehicle's transverse internal loads in the rigid-flexible coupling model is higher remarkably than that in the rigid body assumption.展开更多
Aiming at the flexible flowshop group scheduling problem,taking sequence dependent setup time and machine skipping into account, a mathematical model for minimizing makespan is established,and a hybrid differential ev...Aiming at the flexible flowshop group scheduling problem,taking sequence dependent setup time and machine skipping into account, a mathematical model for minimizing makespan is established,and a hybrid differential evolution( HDE) algorithm based on greedy constructive procedure( GCP) is proposed,which combines differential evolution( DE) with tabu search( TS). DE is applied to generating the elite individuals of population,while TS is used for finding the optimal value by making perturbation in selected elite individuals. A lower bounding technique is developed to evaluate the quality of proposed algorithm. Experimental results verify the effectiveness and feasibility of proposed algorithm.展开更多
Together with the development of high-performance advanced electronics,flexible supercapacitors(SCs)with tailored nanostructures have great attraction.Electrochemically deposited nanosheet arrays of nickel magnesium s...Together with the development of high-performance advanced electronics,flexible supercapacitors(SCs)with tailored nanostructures have great attraction.Electrochemically deposited nanosheet arrays of nickel magnesium selenide(NixMg3-xSe4,NMgS)with high capacitance provide high potentials as a positive electrode in flexible SCs.To further enhance their electrochemical properties and long-term cycling stability,a promising strategy of surface engineering with conducting polymer poly(3,4-ethylenedioxythiophene)(PEDOT)is proposed.The present work proposes the construction of PEDOT shielded NMgS(P@NMgS-2)on a flexible carbon cloth substrate via a hierarchical electrodeposition technique.Benefitting from the synergistic effect,the P@NMgS-2 exhibits an excellent areal capacitance value of 1440 mF cm^(-2)at 4 mA cm^(-2).A novel shape-adaptable polymer gel electrolyte-assisted flexible quasi-solid-state hybrid SC(FQHSC)device constructed with P@NMgS-2 as a positive electrode and activated carbon as a negative electrode demonstrates the maximum power and energy density values of 14.13 mW cm^(-2)and 0.18 mWh cm^(-2),respectively,followed by outstanding cycling stability(∼100%capacitance retention over 50,000 cycles).Furthermore,the FQHSC device successfully powered electronic devices with no serious degradation upon bending and twisting for wearable electronic applications.展开更多
The polymeric gel electrolytes are attractive owing to their higher ionic conductivities than those of dry polymer electrolytes and lowered water activity for enlarged potential window.However,the ionic conductivity a...The polymeric gel electrolytes are attractive owing to their higher ionic conductivities than those of dry polymer electrolytes and lowered water activity for enlarged potential window.However,the ionic conductivity and mechanical strength of the Na-ion conducting polymeric gel electrolytes are limited by below 20 mS cm−1 and 2.2 MPa.Herein,we demonstrate Na-ion conducting and flexible polymeric hydrogel electrolytes of the chemically coupled poly(diallyldimethylammonium chloride)-dextrin-N,N′-methylene-bisacrylamide film immersed in NaClO_(4) solution(ex-DDA-Dex+NaClO_(4))for flexible sodium-ion hybrid capacitors(f-NIHC).In particular,the anion exchange reaction and synergistic interaction of ex-DDA-Dex with the optimum ClO_(4)−enable to greatly improve the ionic conductivity up to 27.63 mS cm−1 at 25◦C and electrochemical stability window up to 2.6 V,whereas the double networking structure leads to achieve both the mechanical strength(7.48 MPa)and softness of hydrogel electrolytes.Therefore,the f-NIHCs with the ex-DDA-Dex+NaClO_(4) achieved high specific and high-rate capacities of 192.04 F g^(−1)at 500 mA g^(−1)and 116.06 F g^(−1)at 10000 mA g^(−1),respectively,delivering a large energy density of 120.03Wh kg^(−1)at 906Wkg^(−1)and long cyclability of 70%over 500 cycles as well as demonstrating functional operation under mechanical stresses.展开更多
Carbon nanofibers films are typical flexible electrode in the field of energy storage,but their application in Zinc-ion hybrid capacitors(ZIHCs)is limited by the low energy density due to the lack of active adsorption...Carbon nanofibers films are typical flexible electrode in the field of energy storage,but their application in Zinc-ion hybrid capacitors(ZIHCs)is limited by the low energy density due to the lack of active adsorption sites.In this work,an in-situ exfoliation strategy is reported to modulate the chemisorption sites of carbon nanofibers by high pyridine/pyrrole nitrogen doping and carbonyl functionalization.The experimental results and theoretical calculations indicate that the highly electronegative pyridine/pyrrole nitrogen dopants can not only greatly reduce the binding energy between carbonyl group and Z n2+by inducing charge delocalization of the carbonyl group,but also promote the adsorption of Zn2+by bonding with the carbonyl group to form N–Zn–O bond.Benefit from the multiple highly active chemisorption sites generated by the synergy between carbonyl groups and pyridine/pyrrole nitrogen atoms,the resulting carbon nanofibers film cathode displays a high energy density,an ultralong-term lifespan,and excellent capacity reservation under commercial mass loading(14.45 mg cm-2).Particularly,the cathodes can also operate stably in flexible or quasi-solid devices,indicating its application potential in flexible electronic products.This work established a universal method to solve the bottleneck problem of insufficient active adsorption sites of carbon-based ZIHCs.Imoproved should be changed into Improved.展开更多
The following is proved: 1) The linear independence of assumed stress modes is the necessary and sufficient condition for the nonsingular flexibility matrix; 2) The equivalent assumed stress modes lead to the identica...The following is proved: 1) The linear independence of assumed stress modes is the necessary and sufficient condition for the nonsingular flexibility matrix; 2) The equivalent assumed stress modes lead to the identical hybrid element. The Hilbert stress subspace of the assumed stress modes is established. So, it is easy to derive the equivalent orthogonal normal stress modes by Schmidt's method. Because of the resulting diagonal flexibility matrix, the identical hybrid element is free from the complex matrix inversion so that the hybrid efficiency, is improved greatly. The numerical examples show that the method is effective.展开更多
Although aqueous zinc ion hybrid capacitors have advantageous integration of batteries and supercapacitors,they still suffer from the inherent problems of dendrite growth and interfacial side reactions on Zn anodes.He...Although aqueous zinc ion hybrid capacitors have advantageous integration of batteries and supercapacitors,they still suffer from the inherent problems of dendrite growth and interfacial side reactions on Zn anodes.Herein,a universal fast zinc-ion diffusion layer on a three-dimensional(3 D)mesh structure model is demonstrated to effectively improve Zn plating/stripping reversibility.The fast ion diffusion alloy layer accelerates the Zn^(2+)migration in an orderly manner to homogenize Zn^(2+)flux and overcomes the defects of the commercial mesh substrate,effectively avoiding dendrite growth and side reactions.Consequently,the proof-of-concept silver-zinc alloy modified stainless steel mesh delivers superb reversibility with the high coulombic efficiency over 99.4%at 4 mA cm^(-2)after 1600 cycles and excellent reliability of over 830 h at 1 mA cm^(-2),Its feasibility is also evidenced in commercial zinc ion hybrid capacitors with activated carbon as the cathode.This work enriches the fundamental comprehension of fast zinc-ion diffusion layer combined with a 3 D substrate on the Zn deposition and opens a universal approach to design advanced host for Zn electrodes in zinc ion hybrid capacitors.展开更多
Hybrid supercapacitors have shown great potentials to fulfill the demand of future diverse applications such as electric vehicles and portable/wearable electronics.In particular,aqueous zinc-ion hybrid supercapacitors...Hybrid supercapacitors have shown great potentials to fulfill the demand of future diverse applications such as electric vehicles and portable/wearable electronics.In particular,aqueous zinc-ion hybrid supercapacitors(ZHSCs)have gained much attention due to their low-cost,high energy density,and environmental friendliness.Nevertheless,typical ZHSCs use Zn metal anode and normal liquid electrolyte,causing the dendrite issue,restricted working temperature,and inferior device flexibility.Herein,a novel flexible Zn-ion hybrid supercapacitor(FZHSC)is developed by using activated carbon(AC)anode,δ-MnO_(2) cathode,and innovative PVA-based gel electrolyte.In this design,heavy Zn anode and its dendrite issue are avoided and layered cathode with large interlayer spacing is employed.In addition,flexible electrodes are prepared and integrated with an anti-freezing,stretchable,and compressible hydrogel electrolyte,which is attained by simultaneously using glycerol additive and freezing/thawing technique to regulate the hydrogen bond and microstructure.The resulting FZHSC exhibits good rate capability,high energy density(47.86 Wh kg^(−1);3.94 mWh cm^(−3)),high power density(5.81 kW kg^(−1);480 mW cm^(−3)),and excellent cycling stability(~91%capacity retention after 30000 cycles).Furthermore,our FZHSC demonstrates outstanding flexibility with capacitance almost unchanged even after various continuous shape deformations.The hydrogel electrolyte still maintains high ionic conductivity at ultralow temperatures(≤−30℃),enabling the FZHSC cycled well,and powering electronic timer robustly within an all-climate temperature range of−30~80℃.This work highlights that the promising Zn metal-free aqueous ZHSCs can be designed with great multifunctionality for more practical application scenarios.展开更多
Bundled hybrid offset riser (BHOR) global strength analysis, which is more complex than single line offset riser global strength analysis, was carried out in this paper. At first, the equivalent theory is used to deal...Bundled hybrid offset riser (BHOR) global strength analysis, which is more complex than single line offset riser global strength analysis, was carried out in this paper. At first, the equivalent theory is used to deal with BHOR, and then its global strength in manifold cases was analyzed, along with the use of a three-dimensional nonlinear time domain finite element program. So the max bending stress, max circumferential stress, and max axial stress in the BHOR bundle main section (BMS) were obtained, and the values of these three stresses in each riser were obtained through the "stress distribution method". Finally, the Max Von Mises stress in each riser was given and a check was made whether or not they met the demand. This paper provides a reference for strength analysis of the bundled hybrid offset riser and some other bundled pipelines.展开更多
We report a wire-shaped three-dimensional(3D)-hybrid supercapacitor with high volumetric capacitance and high energy density due to an interconnected 3D-configuration of the electrode allowing for large number of elec...We report a wire-shaped three-dimensional(3D)-hybrid supercapacitor with high volumetric capacitance and high energy density due to an interconnected 3D-configuration of the electrode allowing for large number of electrochemical active sites,easy access of electrolyte ions,and facile charge transport for flexible wearable applications.The interconnected and compact electrode delivers a high volumetric capacitance(gravimetric capacitance)of 73 F cm−3(2446 F g−1),excellent rate capability,and cycle stability.The 3D-nickel cobalt-layered double hydroxide onto 3D-nickel wire(NiCo LDH/3D-Ni)//the 3D-manganese oxide onto 3D-nickel wire(Mn3O4/3D-Ni)hybrid supercapacitor exhibits energy density of 153.3 Wh kg−1 and power density of 8810 W kg−1.The red lightemitting diode powered by the as-prepared hybrid supercapacitor can operate for 80 min after being charged for tens of seconds and exhibit excellent electrochemical stability under various deformation conditions.The results verify that such wire-shaped 3D-hybrid supercapacitors are promising alternatives for batteries with long charge–discharge times,for smart wearable and implantable devices.展开更多
基金Project(2007CB209707) supported by the National Basic Research Program of China
文摘In order to achieve the improvement of the driving comfort and energy efficiency,an new e-CVT flexible full hybrid electric system(E2FHS) is proposed,which uses an integrated main drive motor and generator to take the place of the original automatic or manual transmission to realize the functions of continuously variable transmission(e-CVT).The design and prototype realization of the E2FHS system for a plug-in hybrid vehicle(PHEV) is performed.In order to analyze and optimize the parameters and the power flux between different parts of the E2FHS,simulation software is developed.Especially,in order to optimize the performance of the energy economy improvement of the E2FHS,the effect of the different energy management controllers is investigated,and an adaptive online-optimal energy management controller for the E2FHS is built and validated by the prototype PHEV.
基金National Natural Science Foundation of China(51672308,51972025,61888102 and 62004187).
文摘Zn-ion hybrid supercapacitors(SCs)are considered as promising energy storage owing to their high energy density compared to traditional SCs.How to realize the miniaturization,patterning,and flexibility of the Zn-ion SCs without affecting the electrochemical performances has special meanings for expanding their applications in wearable integrated electronics.Ti_(3)C_(2)T_(x) cathode with outstanding conductivity,unique lamellar structure and good mechanical flexibility has been demonstrated tremen-dous potential in the design of Zn-ion SCs,but achieving long cycling stability and high rate stability is still big challenges.Here,we proposed a facile laser writing approach to fabricate patterned Ti_(3)C_(2)T_(x)-based Zn-ion micro-supercapacitors(MSCs),followed by the in-situ anneal treatment of the assembled MSCs to improve the long-term stability,which exhibits 80%of the capacitance retention even after 50,000 charge/discharge cycles and superior rate stability.The influence of the cathode thickness on the electrochemical performance of the MSCs is also studied.When the thickness reaches 0.851μm the maximum areal capacitance of 72.02 mF cm^(−2)at scan rate of 10 mV s^(−1),which is 1.77 times higher than that with a thickness of 0.329μm(35.6 mF cm^(−2)).Moreover,the fab-ricated Ti_(3)C_(2)T_(x) based Zn-ion MSCs have excellent flexibility,a digital timer can be driven by the single device even under bending state,a flexible LED displayer of“TiC”logo also can be easily lighted by the MSC arrays under twisting,crimping,and winding conditions,demonstrating the scalable fabrication and application of the fabricated MSCs in portable electronics.
基金supported by the Research Fund for International Scientists(52250410342)Scientific Research start-up grant for Youth Researchers at Lanzhou University,the National Natural Science Foundation of China(51972153)the Fundamental Research Funds for the Central Universities(lzujbky-2021-sp64)and Supercomputing Center of Lanzhou University.
文摘One of the most exciting new developments in energy storage technology is flexible Zn-ion hybrid supercapacitors(f-ZIHSCs),which combine the high energy of Zn-ion batteries with high-power supercapacitors to satisfy the needs of portable flexible electronics.However,the development of f-ZHSCs is still in its infancy,and there are numerous barriers to overcome before they can be widely implemented for practical applications.This review gives an up-to-date description of recent achievements and underlying concepts in energy storage mechanisms of f-ZIHSCs and emphasizes the critical role of cathode,anode,and electrolyte materials systems in speeding the prosperity of f-ZIHSCs.The innovative nanostructured-based cathode materials for f-ZIHSCs include carbon(e.g.,porous carbon,heteroatom-doped carbon,biomass-derived porous carbon,graphene,etc.),metal-oxides,MXenes,and metal/covalentorganic frameworks,and other materials(e.g.,activated carbon,phosphorene,etc.)are mainly focused.Afterward,the latest developments in flexible anode and electrolyte frameworks and impacts of electrolyte compositions on the electrochemical properties of f-ZIHSC are elaborated.Subsequently,the advancements based on fabrication designs,including quasi-solid-state,micro,fiber-shaped,and all climate-changed f-ZIHSCs,are discussed in detail.Lastly,a summary of current challenges and recommendations for the future progress of advanced f-ZIHSC are addressed.This review article is anticipated to further understand the viable strategies and achievable approaches for assembling high-performance f-ZIHSCs and boost the technical revolutions on cathode,anode,and electrolytes for f-ZIHSC devices.
基金CAPES(Coordenacao de Aperfeicoamento de Pessoal de Nível Superior)CNPq(Conselho Nacional de Desenvolvimento Científicoe Tecnológico,grant number 161464/2013-0)for the financial support
文摘This paper proposes the use of the flexible tolerance method(FTM) modified with scaling of variables and hybridized with different unconstrained optimization methods to solve real constrained optimization problems.The benchmark problems used to analyze the performance of the methods were taken from G-Suite functions.The original method(FTM) and other four proposed methods:(i) FTM with scaling of variables(FTMS),(ii) FTMS hybridized with BFGS(FTMS-BFGS),(iii) FTMS hybridized with modified Powell's method(FTMS-Powell)and(iv) FTMS hybridized with PSO(FTMS-PSO), were implemented. The success rates of the methods were 80%,100%, 75%, 95% and 85%, for FTM, FTMS, FTMS-BFGS, FTMS-Powell and FTMS-PSO, respectively. Numerical experiments including real constrained problems indicated that FTMS gave the best performance, followed by FTMSPowell and FTMS-PSO. Despite the inferior performance compared to FTMS and FTMS-Powell, the FTMS-PSO method presented some advantages since good different initial points could be obtained, which allow exploring different routes through the solution space and to escape from local optima. The proposed methods proved to be an effective way of improving the performance of the original FTM.
基金the National Natural Science Foundation of China(10472066,50475021).
文摘The previous low-order approximate nonlinear formulations succeeded in capturing the stiffening terms, but failed in simulation of mechanical systems with large deformation due to the neglect of the high-order deformation terms. In this paper, a new hybrid-coordinate formulation is proposed, which is suitable for flexible multibody systems with large deformation. On the basis of exact strain- displacement relation, equations of motion for flexible multi-body system are derived by using virtual work principle. A matrix separation method is put forward to improve the efficiency of the calculation. Agreement of the present results with those obtained by absolute nodal coordinate formulation (ANCF) verifies the correctness of the proposed formulation. Furthermore, the present results are compared with those obtained by use of the linear model and the low-order approximate nonlinear model to show the suitability of the proposed models.
文摘During the launching stage,hydrodynamic pressure and adapters' reaction loads can influence the vehicle's rigid motion as well as cause its structural vibration,which is a typical rigid-flexible coupling dynamic problem. This paper presents a 2-D rigid-flexible coupling model to calculate the vehicle's dynamic responses in that period.The vehicle was equivalent to a flexure beam with axial deformation. Hybrid coordinate and modal superposition methods were used to describe its large rigid displacement and small deformation. By the second Lagrange equation,the vehicle centroid's displacements,rotational angle and modal coordinates were chosen as generalized coordinates and then the vehicle 's rigid-flexible coupling dynamic equations were obtained. By numerical simulation,the results of vehicle's motion parameters and transverse internal loads were acquired.The calculation results showed that differences of the vehicle's motion parameters between the rigid-flexible coupling model and the rigid body assumption are noticeable and the peak magnitude of the vehicle's transverse internal loads in the rigid-flexible coupling model is higher remarkably than that in the rigid body assumption.
基金Shanghai Municipal Natural Science Foundation of China(No.10ZR1431700)
文摘Aiming at the flexible flowshop group scheduling problem,taking sequence dependent setup time and machine skipping into account, a mathematical model for minimizing makespan is established,and a hybrid differential evolution( HDE) algorithm based on greedy constructive procedure( GCP) is proposed,which combines differential evolution( DE) with tabu search( TS). DE is applied to generating the elite individuals of population,while TS is used for finding the optimal value by making perturbation in selected elite individuals. A lower bounding technique is developed to evaluate the quality of proposed algorithm. Experimental results verify the effectiveness and feasibility of proposed algorithm.
基金This work was supported by the National Research Foundation of Korea Grant funded by the Korea government(MSIP)(No.2018R1A6A1A03025708 and No.2020R1A2B5B01002318).
文摘Together with the development of high-performance advanced electronics,flexible supercapacitors(SCs)with tailored nanostructures have great attraction.Electrochemically deposited nanosheet arrays of nickel magnesium selenide(NixMg3-xSe4,NMgS)with high capacitance provide high potentials as a positive electrode in flexible SCs.To further enhance their electrochemical properties and long-term cycling stability,a promising strategy of surface engineering with conducting polymer poly(3,4-ethylenedioxythiophene)(PEDOT)is proposed.The present work proposes the construction of PEDOT shielded NMgS(P@NMgS-2)on a flexible carbon cloth substrate via a hierarchical electrodeposition technique.Benefitting from the synergistic effect,the P@NMgS-2 exhibits an excellent areal capacitance value of 1440 mF cm^(-2)at 4 mA cm^(-2).A novel shape-adaptable polymer gel electrolyte-assisted flexible quasi-solid-state hybrid SC(FQHSC)device constructed with P@NMgS-2 as a positive electrode and activated carbon as a negative electrode demonstrates the maximum power and energy density values of 14.13 mW cm^(-2)and 0.18 mWh cm^(-2),respectively,followed by outstanding cycling stability(∼100%capacitance retention over 50,000 cycles).Furthermore,the FQHSC device successfully powered electronic devices with no serious degradation upon bending and twisting for wearable electronic applications.
基金National Research Foundation,Grant/Award Number:NRF-2020R1A3B2079803Korea Institute for Advancement of Technology,Grant/Award Number:P0026069。
文摘The polymeric gel electrolytes are attractive owing to their higher ionic conductivities than those of dry polymer electrolytes and lowered water activity for enlarged potential window.However,the ionic conductivity and mechanical strength of the Na-ion conducting polymeric gel electrolytes are limited by below 20 mS cm−1 and 2.2 MPa.Herein,we demonstrate Na-ion conducting and flexible polymeric hydrogel electrolytes of the chemically coupled poly(diallyldimethylammonium chloride)-dextrin-N,N′-methylene-bisacrylamide film immersed in NaClO_(4) solution(ex-DDA-Dex+NaClO_(4))for flexible sodium-ion hybrid capacitors(f-NIHC).In particular,the anion exchange reaction and synergistic interaction of ex-DDA-Dex with the optimum ClO_(4)−enable to greatly improve the ionic conductivity up to 27.63 mS cm−1 at 25◦C and electrochemical stability window up to 2.6 V,whereas the double networking structure leads to achieve both the mechanical strength(7.48 MPa)and softness of hydrogel electrolytes.Therefore,the f-NIHCs with the ex-DDA-Dex+NaClO_(4) achieved high specific and high-rate capacities of 192.04 F g^(−1)at 500 mA g^(−1)and 116.06 F g^(−1)at 10000 mA g^(−1),respectively,delivering a large energy density of 120.03Wh kg^(−1)at 906Wkg^(−1)and long cyclability of 70%over 500 cycles as well as demonstrating functional operation under mechanical stresses.
基金funds from the National Natural Science Foundation of China(51772082,51804106,and 51574117)the Natural Science Foundation of Hunan Province(2019JJ30002,2019JJ50061 and 2020CB1007)Natural Science Foundation of Guangdong Providence(2018A030310571)。
文摘Carbon nanofibers films are typical flexible electrode in the field of energy storage,but their application in Zinc-ion hybrid capacitors(ZIHCs)is limited by the low energy density due to the lack of active adsorption sites.In this work,an in-situ exfoliation strategy is reported to modulate the chemisorption sites of carbon nanofibers by high pyridine/pyrrole nitrogen doping and carbonyl functionalization.The experimental results and theoretical calculations indicate that the highly electronegative pyridine/pyrrole nitrogen dopants can not only greatly reduce the binding energy between carbonyl group and Z n2+by inducing charge delocalization of the carbonyl group,but also promote the adsorption of Zn2+by bonding with the carbonyl group to form N–Zn–O bond.Benefit from the multiple highly active chemisorption sites generated by the synergy between carbonyl groups and pyridine/pyrrole nitrogen atoms,the resulting carbon nanofibers film cathode displays a high energy density,an ultralong-term lifespan,and excellent capacity reservation under commercial mass loading(14.45 mg cm-2).Particularly,the cathodes can also operate stably in flexible or quasi-solid devices,indicating its application potential in flexible electronic products.This work established a universal method to solve the bottleneck problem of insufficient active adsorption sites of carbon-based ZIHCs.Imoproved should be changed into Improved.
文摘The following is proved: 1) The linear independence of assumed stress modes is the necessary and sufficient condition for the nonsingular flexibility matrix; 2) The equivalent assumed stress modes lead to the identical hybrid element. The Hilbert stress subspace of the assumed stress modes is established. So, it is easy to derive the equivalent orthogonal normal stress modes by Schmidt's method. Because of the resulting diagonal flexibility matrix, the identical hybrid element is free from the complex matrix inversion so that the hybrid efficiency, is improved greatly. The numerical examples show that the method is effective.
基金financially supported by the National Natural Science Foundation of China(51901249,U1904216)。
文摘Although aqueous zinc ion hybrid capacitors have advantageous integration of batteries and supercapacitors,they still suffer from the inherent problems of dendrite growth and interfacial side reactions on Zn anodes.Herein,a universal fast zinc-ion diffusion layer on a three-dimensional(3 D)mesh structure model is demonstrated to effectively improve Zn plating/stripping reversibility.The fast ion diffusion alloy layer accelerates the Zn^(2+)migration in an orderly manner to homogenize Zn^(2+)flux and overcomes the defects of the commercial mesh substrate,effectively avoiding dendrite growth and side reactions.Consequently,the proof-of-concept silver-zinc alloy modified stainless steel mesh delivers superb reversibility with the high coulombic efficiency over 99.4%at 4 mA cm^(-2)after 1600 cycles and excellent reliability of over 830 h at 1 mA cm^(-2),Its feasibility is also evidenced in commercial zinc ion hybrid capacitors with activated carbon as the cathode.This work enriches the fundamental comprehension of fast zinc-ion diffusion layer combined with a 3 D substrate on the Zn deposition and opens a universal approach to design advanced host for Zn electrodes in zinc ion hybrid capacitors.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.52072136,51972257,51872104,and 52172229)the Ningxia Key R&D Program(2019BFG02018)the Fundamental Research Funds for the Central Universities(WUT:2021IVA115,2021IVA071).
文摘Hybrid supercapacitors have shown great potentials to fulfill the demand of future diverse applications such as electric vehicles and portable/wearable electronics.In particular,aqueous zinc-ion hybrid supercapacitors(ZHSCs)have gained much attention due to their low-cost,high energy density,and environmental friendliness.Nevertheless,typical ZHSCs use Zn metal anode and normal liquid electrolyte,causing the dendrite issue,restricted working temperature,and inferior device flexibility.Herein,a novel flexible Zn-ion hybrid supercapacitor(FZHSC)is developed by using activated carbon(AC)anode,δ-MnO_(2) cathode,and innovative PVA-based gel electrolyte.In this design,heavy Zn anode and its dendrite issue are avoided and layered cathode with large interlayer spacing is employed.In addition,flexible electrodes are prepared and integrated with an anti-freezing,stretchable,and compressible hydrogel electrolyte,which is attained by simultaneously using glycerol additive and freezing/thawing technique to regulate the hydrogen bond and microstructure.The resulting FZHSC exhibits good rate capability,high energy density(47.86 Wh kg^(−1);3.94 mWh cm^(−3)),high power density(5.81 kW kg^(−1);480 mW cm^(−3)),and excellent cycling stability(~91%capacity retention after 30000 cycles).Furthermore,our FZHSC demonstrates outstanding flexibility with capacitance almost unchanged even after various continuous shape deformations.The hydrogel electrolyte still maintains high ionic conductivity at ultralow temperatures(≤−30℃),enabling the FZHSC cycled well,and powering electronic timer robustly within an all-climate temperature range of−30~80℃.This work highlights that the promising Zn metal-free aqueous ZHSCs can be designed with great multifunctionality for more practical application scenarios.
基金Supported by the National Natural Science Foundation of China (Grant No.51009033)
文摘Bundled hybrid offset riser (BHOR) global strength analysis, which is more complex than single line offset riser global strength analysis, was carried out in this paper. At first, the equivalent theory is used to deal with BHOR, and then its global strength in manifold cases was analyzed, along with the use of a three-dimensional nonlinear time domain finite element program. So the max bending stress, max circumferential stress, and max axial stress in the BHOR bundle main section (BMS) were obtained, and the values of these three stresses in each riser were obtained through the "stress distribution method". Finally, the Max Von Mises stress in each riser was given and a check was made whether or not they met the demand. This paper provides a reference for strength analysis of the bundled hybrid offset riser and some other bundled pipelines.
基金supported by national research foundation of Korea(NRF)(No.NRF-2019R1H1A2039743)S-Oil corporation,and “Human Resources Program in Energy Technology” of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)granted financial resource from the Ministry of Trade,Industry and Energy,Republic of Korea(No.20194010201890)
文摘We report a wire-shaped three-dimensional(3D)-hybrid supercapacitor with high volumetric capacitance and high energy density due to an interconnected 3D-configuration of the electrode allowing for large number of electrochemical active sites,easy access of electrolyte ions,and facile charge transport for flexible wearable applications.The interconnected and compact electrode delivers a high volumetric capacitance(gravimetric capacitance)of 73 F cm−3(2446 F g−1),excellent rate capability,and cycle stability.The 3D-nickel cobalt-layered double hydroxide onto 3D-nickel wire(NiCo LDH/3D-Ni)//the 3D-manganese oxide onto 3D-nickel wire(Mn3O4/3D-Ni)hybrid supercapacitor exhibits energy density of 153.3 Wh kg−1 and power density of 8810 W kg−1.The red lightemitting diode powered by the as-prepared hybrid supercapacitor can operate for 80 min after being charged for tens of seconds and exhibit excellent electrochemical stability under various deformation conditions.The results verify that such wire-shaped 3D-hybrid supercapacitors are promising alternatives for batteries with long charge–discharge times,for smart wearable and implantable devices.