In this study,polyacrylic acid(PAA)films were employed as a model system,and a series of PAA films with tunable water wettability was systematically prepared by varying molecular weight and curing temperature.Using at...In this study,polyacrylic acid(PAA)films were employed as a model system,and a series of PAA films with tunable water wettability was systematically prepared by varying molecular weight and curing temperature.Using attenuated total reflectance Fourier-transform infrared spectroscopy(ATR-FTIR),the molecular configurations of surface carboxyl groups(COOH),free carboxyl(COOH_(f))and hydrogen-bonded carboxyl(COOH_(HB),were directly correlated with the polar component of surface energy(γ^(s,p)).By decomposing theγ^(s,p)values of the PAA thin films as a sum of the contributions of COOH_(f)and COOH_(H B),the intrinsic polar component of surface energy of COOH_(H B)(γ_(H B)^(s,p*))was quantified for the first time as 8.34 mN/m,significantly lower than that of COOH_(f)(γ_(f)^(s,p*)=34 mN/m).This result highlights that hydrogen bonding markedly reduces theγ^(s,p),providing a rational explanation for the relatively large water contact angle observed on PAA thin films.Furthermore,it establishes a thermodynamic basis for estimating the fraction of surface COOH_(H B)groups(f H B)from wettability measurements.Further extension of the model to carboxyl-terminated self-assembled monolayers(COOH-SAMs)revealed that surface COOH density(ΣCOOH)critically regulates wetting behavior:whenΣCOOH ranges from 4.30 to 5.25 nm^(-2),COOH groups predominantly exist in a free state and facilitate effective hydration layers,thereby promoting superhydrophilicity.Overall,this study not only establishes a unified thermodynamic framework linking surface COOH configurations to macroscopic wettability,but also validates its universality by extending it to COOH-SAMs systems,thereby providing a unified theoretical framework for the controllable design of hydrophilicity in various COOH-functionalized surfaces.展开更多
The precise tuning of magnetic nanoparticle size and magnetic domains,thereby shaping magnetic properties.However,the dynamic evolution mechanisms of magnetic domain configurations in relation to electromagnetic(EM)at...The precise tuning of magnetic nanoparticle size and magnetic domains,thereby shaping magnetic properties.However,the dynamic evolution mechanisms of magnetic domain configurations in relation to electromagnetic(EM)attenuation behavior remain poorly understood.To address this gap,a thermodynamically controlled periodic coordination strategy is proposed to achieve precise modulation of magnetic nanoparticle spacing.This approach unveils the evolution of magnetic domain configurations,progressing from individual to coupled and ultimately to crosslinked domain configurations.A unique magnetic coupling phenomenon surpasses the Snoek limit in low-frequency range,which is observed through micromagnetic simulation.The crosslinked magnetic configuration achieves effective low-frequency EM wave absorption at 3.68 GHz,encompassing nearly the entire C-band.This exceptional magnetic interaction significantly enhances radar camouflage and thermal insulation properties.Additionally,a robust gradient metamaterial design extends coverage across the full band(2–40 GHz),effectively mitigating the impact of EM pollution on human health and environment.This comprehensive study elucidates the evolution mechanisms of magnetic domain configurations,addresses gaps in dynamic magnetic modulation,and provides novel insights for the development of high-performance,low-frequency EM wave absorption materials.展开更多
Dense cropping increases crop yield but intensifies resource competition,which reduces single plant yield and limits potential yield growth.Optimizing canopy spacing could enhance resource utilization,support crop mor...Dense cropping increases crop yield but intensifies resource competition,which reduces single plant yield and limits potential yield growth.Optimizing canopy spacing could enhance resource utilization,support crop morphological development and increase yield.Here,a three-year study was performed to verify the feasibility of adjusting row spacing to further enhance yield in densely planted soybeans.Of three row-spacing configurations(40-40,20-40,and 20-60 cm)and two planting densities(normal 180,000 plants ha 1 and high 270,000 plants ha 1).The differences in canopy structure,plant morphological development,photosynthetic capacity and their impact on yield were analyzed.Row spacing configurations have a significant effect on canopy transmittance(CT).The 20-60 cm row spacing configuration increased CT and creates a favorable canopy light environment,in which plant height is reduced,while branching is promoted.This approach reduces plant competition,optimizes the developments of leaf area per plant,specific leaf area,leaf area development rate,leaf area duration and photosynthetic physiological indices(F_(v)/F_(m),ETR,P_(n)).The significant increase of 11.9%-34.2%in canopy apparent photosynthesis(CAP)is attributed to the significant optimization of plant growth and photosynthetic physiology through CT,an important contributing factor to yield increases.The yield in the 20-60 cm treatment is 4.0%higher than in equidistant planting under normal planting density,but 5.9%under high density,primarily driven by CAP and pod number.These findings suggest that suitable row spacing configurations optimize the light environment for plants,promote source-sink transformation in soybeans,and further improve yield.In practice,a 20-60 cm row spacing configuration could be employed for high-density soybean planting to achieve a more substantial yield gain.展开更多
Recent advances in earth science and exploration have made deepwater channel-levee systems a research focus.We collected and analyzed over 10000 km of two-dimensional multichannel seismic data from the offshore Indus ...Recent advances in earth science and exploration have made deepwater channel-levee systems a research focus.We collected and analyzed over 10000 km of two-dimensional multichannel seismic data from the offshore Indus Basin to identify channellevee systems at various hierarchical levels depending on their seismic reflection characteristics.Seismic facies analysis was integrated with well data to map the spatial distribution of channel-levee systems in the offshore Indus Basin across various geological periods,and the factors influencing their development were discussed.These systems within the basin were identified using a developed,refined three-tier classification method.The first-order system consists of multiple spatially stacked complexes,the second-order system continuously developed multistage channel-levee bodies,and the third-order system represents the smallest identifiable sedimentary units on seismic profiles.Our findings demonstrate the evolution of the offshore Indus Basin from a single-stage channel with lateral migration to multistage vertical channel stacking from the Miocene to the Pleistocene.Tectonic activities exert their effect on channel-levee systems through their influence on the relative sea level.They also trigger volcanic or seismic events and affect siliciclastic supply.Warm and humid climate conditions form large river systems,which aid in the transport of terrestrial debris to the basin margin.Most channel-levee systems are assumed to have formed during low sea-level periods.This study offers new insights into the formation and evolution of turbidite sedimentary systems in the offshore Indus Basin and presents a practical classification method for comprehending gravity-flow sedimentary configurations and deepwater hydrocarbon exploration.展开更多
The field-reversed configuration(FRC)plasma thruster driven by rotating magnetic field(RMF),abbreviated as the RMF-FRC thruster,is a new type of electric propulsion technology that is expected to accelerate the deep s...The field-reversed configuration(FRC)plasma thruster driven by rotating magnetic field(RMF),abbreviated as the RMF-FRC thruster,is a new type of electric propulsion technology that is expected to accelerate the deep space exploration.An experimental prototype,including diagnostic devices,was designed and constructed based on the principles of the RMF-FRC thruster,with an RMF frequency of 210 kHz and a maximum peak current of 2 kA.Under the rated operating conditions,the initial plasma density was measured to be 5×10^(17)m^(-3),and increased to 2.2×10^(19)m^(-3)after the action of RMF.The coupling efficiency of RMF was about 53%,and the plasma current reached 1.9 kA.The axial magnetic field changed in reverse by 155 Gauss,successfully reversing the bias magnetic field of 60 Gauss,which verifies the formation of FRC plasma.After optimization research,it was found that when the bias magnetic field is 100 Gauss,the axial magnetic field reverse variation caused by FRC is the highest at 164 Gauss.The experimental results are discussed and strategies are proposed to improve the performance of the prototype.展开更多
The influence of geometric configuration on the friction characteristics during incremental sheet forming of AA5052 was analyzed by integrating surface morphology and its characteristic parameters,along with plastic s...The influence of geometric configuration on the friction characteristics during incremental sheet forming of AA5052 was analyzed by integrating surface morphology and its characteristic parameters,along with plastic strain,contact pressure,and area.The interface promotes lubrication and support when wall angles were≤40°,a 0.5 mm-thin sheet was used,and a 10 mm-large tool radius was employed.This mainly results in micro-plowing and plastic extrusion flow,leading to lower friction coefficient.However,when wall angles exceed 40°,significant plastic strain roughening occurs,leading to inadequate lubrication on the newly formed surface.Increased sheet thickness and decreased tool radius elevate contact pressure.These actions trigger micro-cutting and adhesion,potentially leading to localized scuffing and dimple tears,and higher friction coefficient.The friction mechanisms remain unaffected by the part’s plane curve features.As the forming process progresses,abrasive wear intensifies,and surface morphology evolves unfavorably for lubrication and friction reduction.展开更多
In the context of the“dual carbon”goals,to address issues such as high energy consumption,high costs,and low power quality in the rapid development of electrified railways,this study focused on the China Railways Hi...In the context of the“dual carbon”goals,to address issues such as high energy consumption,high costs,and low power quality in the rapid development of electrified railways,this study focused on the China Railways High-Speed 5 Electric Multiple Unit and proposed a mathematical model and capacity optimization method for an onboard energy storage system using lithium batteries and supercapacitors as storage media.Firstly,considering the electrical characteristics,weight,and volume of the storage media,a mathematical model of the energy storage system was established.Secondly,to tackle problems related to energy consumption and power quality,an energy management strategy was proposed that comprehensively considers peak shaving and valley filling and power quality by controlling the charge/discharge thresholds of the storage system.Thecapacity optimization adopted a bilevel programming model,with the series/parallel number of storage modules as variables,considering constraints imposed by the Direct Current to Direct Current converter,train load,and space.An improved Particle Swarm Optimization algorithm and linear programming solver were used to solve specific cases.The results show that the proposed onboard energy storage system can effectively achieve energy savings,reduce consumption,and improve power qualitywhile meeting the load and space limitations of the train.展开更多
Hydroxyapatite nanoparticles(HAP NPs)were synthesized by a one‐step hydrothermal method.The surface of HAP NPs was grafted-SH and-COOH chelating groups via in situ surface‐modification with iminodiacetic acid(IDA)an...Hydroxyapatite nanoparticles(HAP NPs)were synthesized by a one‐step hydrothermal method.The surface of HAP NPs was grafted-SH and-COOH chelating groups via in situ surface‐modification with iminodiacetic acid(IDA)and 3‐mercaptopropyl trimethoxysilane(MPS)to afford dual surface‐capped nano‐amendment HAPIDA/MPS.The structure of HAP‐IDA/MPS was characterized,and its adsorption performance for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)was evaluated.The total adsorption capacity of 0.10 g HAP‐IDA/MPS nano‐amendment for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)with an initial mass concentration of 20 mg·L^(-1) reached 13.7 mg·g^(-1),about 4.3 times as much as that of HAP.Notably,HAP‐IDA/MPS nano‐amendment displayed the highest immobilization rate for Hg^(2+),possibly because of its chemical reaction with-SH to form sulfide,possessing the lowest solubility product constant among a variety of metal sulfides.展开更多
Iterative multireference configuration interaction (IMRCI) is proposed. It is exploited to compute the electronic energies of H2O and CH2(singlet and triplet states) at equilibrium and non-equilibrium geometries. The ...Iterative multireference configuration interaction (IMRCI) is proposed. It is exploited to compute the electronic energies of H2O and CH2(singlet and triplet states) at equilibrium and non-equilibrium geometries. The potential energy curves of H2O, CH2(singlet and triplet states) and N2 have also been calculated with IMRCI as well as the M?ller Plesset perturbation theory (MP2, MP3, and MP4), the coupled cluster method with single and double substitutions (CCSD), and CCSD with perturbative triples correction (CCSD(T)).These calculations demonstrate that IMRCI results are independent of the initial guess of configuration functions in the reference space and converge quickly to the results of the full configuration interaction. The IMRCI errors relative to the full configuration interaction results are at the order of magnitude of 10-5 hartree within just 2-4 iterations. Further,IMRCI provides an efficient way to find on the potential energy surface the leading electron configurations which, as correct reference states, will be very helpful for the single-reference and multireference theoretical models to obtain accurate results.展开更多
With the increase in the quantity and scale of Static Random-Access Memory Field Programmable Gate Arrays (SRAM-based FPGAs) for aerospace application, the volume of FPGA configuration bit files that must be stored ha...With the increase in the quantity and scale of Static Random-Access Memory Field Programmable Gate Arrays (SRAM-based FPGAs) for aerospace application, the volume of FPGA configuration bit files that must be stored has increased dramatically. The use of compression techniques for these bitstream files is emerging as a key strategy to alleviate the burden on storage resources. Due to the severe resource constraints of space-based electronics and the unique application environment, the simplicity, efficiency and robustness of the decompression circuitry is also a key design consideration. Through comparative analysis current bitstream file compression technologies, this research suggests that the Lempel Ziv Oberhumer (LZO) compression algorithm is more suitable for satellite applications. This paper also delves into the compression process and format of the LZO compression algorithm, as well as the inherent characteristics of configuration bitstream files. We propose an improved algorithm based on LZO for bitstream file compression, which optimises the compression process by refining the format and reducing the offset. Furthermore, a low-cost, robust decompression hardware architecture is proposed based on this method. Experimental results show that the compression speed of the improved LZO algorithm is increased by 3%, the decompression hardware cost is reduced by approximately 60%, and the compression ratio is slightly reduced by 0.47%.展开更多
Increasing the sintering rate of powder compact is a critical challenge of powder metallurgical materials,and adjusting component distribution in particles aggregate present significant effect on the microstructure of...Increasing the sintering rate of powder compact is a critical challenge of powder metallurgical materials,and adjusting component distribution in particles aggregate present significant effect on the microstructure of sintered product,especially for multi-phase compact with local heterogeneity.Here,a case study of W–Ni–Co powder compact was adopted to illustrate the novel strategy to enhance the sintering of multi-phase compact with desired microstructure by adjusting the particle configurations.The plasma synthesis route was developed for the first time to independently adjust the configurations of W–Ni–Co nanopowders with core-shell and homogeneous structures,which facilitates to ascertain the sintering response induced exclusively by particle configurations.Comparison on sintering response further indicates that core-shell powder presents greatly promoted sintering than homogeneous one,and full-dense and uniform compact with grain size of 1.37μm was obtained by solid sintering,which is several to dozens of times smaller than that obtained by conventional liquid sintering.Theoretical and experimental Investigation on elemental immigration visualized the distinct mass diffusion behavior of powder compacts,and clarified the mass transport path promoted densification mechanism determined by powder configurations.Importantly,full-coherent phase interface induced superior strength and plasticity in alloy sintered using core-shell powder,which highlights the importance of microstructural regulation on improving the mechanical property that superior than most of previously reported tungsten heavy alloys.In summary,this work paves a new way for fast sintering of multi-phase compacts,and provides intrinsic understandings on densification mechanism of powder compact.展开更多
The design of wide-range high-efficiency aerodynamic configurations is one of the most important key technologies in the research of near-space hypersonic vehicles.A double-sided intake configuration with different in...The design of wide-range high-efficiency aerodynamic configurations is one of the most important key technologies in the research of near-space hypersonic vehicles.A double-sided intake configuration with different inlets on the upper and lower surfaces is proposed to adapt to widerange flight.Firstly,the double-sided intake configuration’s design method and flight profile are delineated.Secondly,Computational Fluid Dynamics(CFD)numerical simulation based on multi-Graphics Processing Unit(GPU)parallel computing is adopted to evaluate the vehicle’s performance comprehensively,aiming to verify the feasibility of the proposed scheme.This evaluation encompasses a wide-range basic aerodynamic characteristics,inlet performance,and heat flux at critical locations.The results show that the inlets of the designed integration configuration can start up across Mach number 3.5 to 8.The vehicle possesses multi-point cruising capability by flipping the fuselage.Simultaneously,a 180°rotation of the fuselage can significantly decrease the heat accumulation on the lower surface of the vehicle,particularly at the inlet lip,further decreasing the temperature gradient across the vehicle structure.This study has some engineering value for the aerodynamic configuration design of wide-range vehicles.However,further study reveals that the flow phenomena at the intersection of two inlets are complex,posing potential adverse impacts on propulsion efficiency.Therefore,it is imperative to conduct additional research to delve into this matter comprehensively.展开更多
This study introduces a novel approach to addressing the challenges of high-dimensional variables and strong nonlinearity in reservoir production and layer configuration optimization.For the first time,relational mach...This study introduces a novel approach to addressing the challenges of high-dimensional variables and strong nonlinearity in reservoir production and layer configuration optimization.For the first time,relational machine learning models are applied in reservoir development optimization.Traditional regression-based models often struggle in complex scenarios,but the proposed relational and regression-based composite differential evolution(RRCODE)method combines a Gaussian naive Bayes relational model with a radial basis function network regression model.This integration effectively captures complex relationships in the optimization process,improving both accuracy and convergence speed.Experimental tests on a multi-layer multi-channel reservoir model,the Egg reservoir model,and a real-field reservoir model(the S reservoir)demonstrate that RRCODE significantly reduces water injection and production volumes while increasing economic returns and cumulative oil recovery.Moreover,the surrogate models employed in RRCODE exhibit lightweight characteristics with low computational overhead.These results highlight RRCODE's superior performance in the integrated optimization of reservoir production and layer configurations,offering more efficient and economically viable solutions for oilfield development.展开更多
The introduction of metal single atoms(SAs)and nanoparticles(NPs)are effective approaches to mod-ify electronic configuration of semiconductors,whereas recognizing the synergistic effects of metal SAs and NPs are stil...The introduction of metal single atoms(SAs)and nanoparticles(NPs)are effective approaches to mod-ify electronic configuration of semiconductors,whereas recognizing the synergistic effects of metal SAs and NPs are still challenging in photocatalytic water purification.Herein,a general strategy is achieved by subsequentially anchoring Fe SAs and Fe NPs in graphitic carbon nitride.The modification of Fe SAs and Fe NPs improves the energy band structure and constructs a gradient charge polarization,directly expanding the optical absorption range and facilitating the efficient separation and transfer of charge car-riers.With the assistance of the gradient charge polarization,pollutants are readily oxidated by h+,which strengthens the continuous reduction of O2 on Fe NPs for pollutant oxidation in water.This work rein-forces the synergistic effect of SAs and NPs on electronic configuration modulation at the atomic level,which exhibits great potential for the construction of an efficient and sustainable water purification sys-tem.展开更多
Sodium-ion batteries(SIBs)have recently gained wildly interest due to the abundance of sodium,lower production costs,and better low-temperature performance compared to lithium-ion batteries(LIBs).Among various cathode...Sodium-ion batteries(SIBs)have recently gained wildly interest due to the abundance of sodium,lower production costs,and better low-temperature performance compared to lithium-ion batteries(LIBs).Among various cathode materials of SIBs,O_(3)-type NaNi_(0.4)Fe_(0.2)Mn_(0.4)O_(2)(NFM424)demonstrates high capacity and ease of synthesis,yet suffers from structural degradation and sluggish Na^(+)kinetics caused by large ionic radius and strong electrostatic interactions.To overcome these issues,a configuration strategy combined with TiO_(2) and Co_(3)O_(4) by a simple solid-state reaction method was introduced to improve structural and electrochemical stability.XRD,SEM,TEM,and various electrochemical characterizations as well as TGA/DSC tests were conducted.The resulting NaNi_(0.4)Fe_(0.2)Mn_(0.3)Co_(0.05)Ti_(0.05)O_(2)(NFMCT)cathode mitigated Jahn-Teller distortions and Na^(+)/vacancy ordering while enhancing phase integrity and diffusion pathways.The obtained NFMCT maintained 93.7 mAh·g^(−1) after 550 cycles at 1 C,with superior rate capabilities at 2 C and 5 C.These findings deepen the understanding of configuration strategy by using multi-element oxide and highlight a practical strategy for designing high-performance SIB cathodes.展开更多
Objective To configure the complex traditional Chinese medicine(TCM)prescription using digit topology circle and to derive digit topology circle.Methods The basic digit topology circles were constructed.Different digi...Objective To configure the complex traditional Chinese medicine(TCM)prescription using digit topology circle and to derive digit topology circle.Methods The basic digit topology circles were constructed.Different digit topology circles were derived using basic digit topology circle,the character strings,and the digit groups.Different digit topology circles with ternary Chinese medicine were derived by adding ternary Chinese medicine into digit topology circles.The valuable TCM prescriptions were configured using the derived digit topology circles.Results Nine simple basic digit topology circles were constructed from the character strings.Multiple digit topology circles and some digit topology circles with ternary Chinese medicine were derived using basic digit topology circles,the character strings,and the digit groups.Four complex TCM prescriptions were configured using four derived digit topology circles digit topology circles,respectively.Conclusion The digit topology circles can be used to configure some existing TCM prescriptions and many novel TCM prescriptions.It has been verified that some existing TCM prescriptions have been used successfully to treat patients with diseases.Some novel valuable TCM prescriptions configured by digit topology circles may be used to treat patients with diseases.展开更多
Through on-site investigations and case analyses of green mines in Huizhou City,and by integrating technical measures including soil improvement,plant configuration,and community construction,this study proposes a pla...Through on-site investigations and case analyses of green mines in Huizhou City,and by integrating technical measures including soil improvement,plant configuration,and community construction,this study proposes a plant configuration model tailored for ecological restoration in the mining areas of Huizhou.The implementation of a multi-level configuration model that predominantly employs native plant species,combined with a"soil-vegetation-microorganism"collaborative restoration strategy,can significantly enhance vegetation coverage in mining areas,increase soil organic matter content,and reduce the bioavailability of heavy metals in the soil.Based on field research and case study analyses,several optimization recommendations are proposed from the perspectives of slope stability and soil and water conservation.Ultimately,it summarizes plant configuration models and their application effects in the ecological restoration of green mines in Huizhou City.These findings may serve as valuable references for the ecological restoration of mines in South China.展开更多
This paper presents a new capacity planning method that utilizes the complementary characteristics of wind and solar power output.It addresses the limitations of relying on a single metric for a comprehensive assessme...This paper presents a new capacity planning method that utilizes the complementary characteristics of wind and solar power output.It addresses the limitations of relying on a single metric for a comprehensive assessment of complementarity.To enable more accurate predictions of the optimal wind-solar ratio,a comprehensive complementarity rate is proposed,which allows for the optimization of wind-solar capacity based on this measure.Initially,the Clayton Copula function is employed to create a joint probability distribution model for wind and solar power,enabling the calculation of the comprehensive complementarity rate.Following this,a joint planning model is developed to enhance the system’s economy and reliability.The goal is to minimize total costs,load deficit rates,and curtailment rates by applying an ImprovedMulti-Objective Particle SwarmOptimization algorithm(IMOPSO).Results show that when the proportion of wind power reaches 70%,the comprehensive complementarity rate is optimized.This optimization leads to a 14.83%reduction in total costs and a 9.27%decrease in curtailment rates.Compared to existing studies,this paper offers a multidimensional analysis of the relationship between the comprehensive complementarity rate and the optimal wind-solar ratio,thereby improving predictive accuracy and providing a valuable reference for research on the correlation between wind and solar power.展开更多
In response to the issue of determining the appropriate capacity when hybrid energy storage systems(HESS)collaborate with thermal power units(TPU)in the system’s secondary frequency regulation,a configuration method ...In response to the issue of determining the appropriate capacity when hybrid energy storage systems(HESS)collaborate with thermal power units(TPU)in the system’s secondary frequency regulation,a configuration method for HESS based on the analysis of frequency regulation demand analysis is proposed.And a corresponding simulation platform is developed.Firstly,a frequency modulation demand method for reducing the frequency modulation losses of TPU is proposed.Secondly,taking into comprehensive consideration that flywheel energy storage features rapid power response and battery energy storage has the characteristic of high energy density,a coordinated control strategy for HESS considering the self-recovery of state of charge(SOC)is put forward.Then,to measure the economic and technical performance of HESS in assisting the secondary frequency modulation of TPU,an optimized configurationmodel considering the full-life-cycle economy and frequency modulation performance of TPU and HESS system is constructed.Finally,a visual simulation platform for the combined frequency modulation of TPU and HESS is developed based on Matlab Appdesigner.Theresults of calculation examples indicate that the proposed configuration method can improve the overall economic efficiency and frequency modulation performance of TPU and HESS;The control strategy can not only prolong the service life of battery energy storage but also enhance the continuous response ability of HESS;The visual simulation platform is easy to use,and the simulation results are accurate and reliable.展开更多
Origami mechanisms are extensively employed in various engineering applications due to their exceptional folding performance and deformability.The key to designing origami mechanisms lies in the design of the creases....Origami mechanisms are extensively employed in various engineering applications due to their exceptional folding performance and deformability.The key to designing origami mechanisms lies in the design of the creases.The crease design is often derived from experience and inspiration,so it is crucial to have a systematic approach to crease design.In this paper,a novel synthesis approach based on graph theory is proposed,which effectively addresses the challenge of designing the creases in origami mechanisms.The essence of this method lies in the acquisition of the double symmetrical crease pattern through the directed graph product operation of two subgraphs.The crease pattern can be simplified by employing a technique that eliminates certain creases while preserving the non-isomorphism and symmetry of the pattern.An improved mixed-integer linear programming model is developed to achieve an automatic distribution of the peak_valley creases of the origami.The proposed method ultimately generates 12 unique double symmetrical crease patterns.The new method proposed in this paper,through systematic design,significantly improves the efficiency of mechanism design while opening up broad prospects for exploring new mechanism structures,thereby greatly expanding its application potential in cutting-edge fields such as aerospace engineering and intelligent robots.展开更多
文摘In this study,polyacrylic acid(PAA)films were employed as a model system,and a series of PAA films with tunable water wettability was systematically prepared by varying molecular weight and curing temperature.Using attenuated total reflectance Fourier-transform infrared spectroscopy(ATR-FTIR),the molecular configurations of surface carboxyl groups(COOH),free carboxyl(COOH_(f))and hydrogen-bonded carboxyl(COOH_(HB),were directly correlated with the polar component of surface energy(γ^(s,p)).By decomposing theγ^(s,p)values of the PAA thin films as a sum of the contributions of COOH_(f)and COOH_(H B),the intrinsic polar component of surface energy of COOH_(H B)(γ_(H B)^(s,p*))was quantified for the first time as 8.34 mN/m,significantly lower than that of COOH_(f)(γ_(f)^(s,p*)=34 mN/m).This result highlights that hydrogen bonding markedly reduces theγ^(s,p),providing a rational explanation for the relatively large water contact angle observed on PAA thin films.Furthermore,it establishes a thermodynamic basis for estimating the fraction of surface COOH_(H B)groups(f H B)from wettability measurements.Further extension of the model to carboxyl-terminated self-assembled monolayers(COOH-SAMs)revealed that surface COOH density(ΣCOOH)critically regulates wetting behavior:whenΣCOOH ranges from 4.30 to 5.25 nm^(-2),COOH groups predominantly exist in a free state and facilitate effective hydration layers,thereby promoting superhydrophilicity.Overall,this study not only establishes a unified thermodynamic framework linking surface COOH configurations to macroscopic wettability,but also validates its universality by extending it to COOH-SAMs systems,thereby providing a unified theoretical framework for the controllable design of hydrophilicity in various COOH-functionalized surfaces.
基金supported by the National Natural Science Foundation of China(22265021,52231007,and 12327804)the Aeronautical Science Foundation of China(2020Z056056003)Jiangxi Provincial Natural Science Foundation(20232BAB212004).
文摘The precise tuning of magnetic nanoparticle size and magnetic domains,thereby shaping magnetic properties.However,the dynamic evolution mechanisms of magnetic domain configurations in relation to electromagnetic(EM)attenuation behavior remain poorly understood.To address this gap,a thermodynamically controlled periodic coordination strategy is proposed to achieve precise modulation of magnetic nanoparticle spacing.This approach unveils the evolution of magnetic domain configurations,progressing from individual to coupled and ultimately to crosslinked domain configurations.A unique magnetic coupling phenomenon surpasses the Snoek limit in low-frequency range,which is observed through micromagnetic simulation.The crosslinked magnetic configuration achieves effective low-frequency EM wave absorption at 3.68 GHz,encompassing nearly the entire C-band.This exceptional magnetic interaction significantly enhances radar camouflage and thermal insulation properties.Additionally,a robust gradient metamaterial design extends coverage across the full band(2–40 GHz),effectively mitigating the impact of EM pollution on human health and environment.This comprehensive study elucidates the evolution mechanisms of magnetic domain configurations,addresses gaps in dynamic magnetic modulation,and provides novel insights for the development of high-performance,low-frequency EM wave absorption materials.
基金supported by the Biological Breeding-National Science and Technology Major Project(2023ZD0403305)National Natural Science Foundation of China(32101845)+1 种基金the National Key Research and Development Program of China(2023YFE0105000)the China Agriculture Research System(CARS-04).
文摘Dense cropping increases crop yield but intensifies resource competition,which reduces single plant yield and limits potential yield growth.Optimizing canopy spacing could enhance resource utilization,support crop morphological development and increase yield.Here,a three-year study was performed to verify the feasibility of adjusting row spacing to further enhance yield in densely planted soybeans.Of three row-spacing configurations(40-40,20-40,and 20-60 cm)and two planting densities(normal 180,000 plants ha 1 and high 270,000 plants ha 1).The differences in canopy structure,plant morphological development,photosynthetic capacity and their impact on yield were analyzed.Row spacing configurations have a significant effect on canopy transmittance(CT).The 20-60 cm row spacing configuration increased CT and creates a favorable canopy light environment,in which plant height is reduced,while branching is promoted.This approach reduces plant competition,optimizes the developments of leaf area per plant,specific leaf area,leaf area development rate,leaf area duration and photosynthetic physiological indices(F_(v)/F_(m),ETR,P_(n)).The significant increase of 11.9%-34.2%in canopy apparent photosynthesis(CAP)is attributed to the significant optimization of plant growth and photosynthetic physiology through CT,an important contributing factor to yield increases.The yield in the 20-60 cm treatment is 4.0%higher than in equidistant planting under normal planting density,but 5.9%under high density,primarily driven by CAP and pod number.These findings suggest that suitable row spacing configurations optimize the light environment for plants,promote source-sink transformation in soybeans,and further improve yield.In practice,a 20-60 cm row spacing configuration could be employed for high-density soybean planting to achieve a more substantial yield gain.
基金the National Natural Science Foundation of China(Nos.42076220,42206234,42476228)the Laoshan Laboratory Science and Technology Innovation Project(Nos.LSKJ202203404,LSKJ202203401)+2 种基金the Laoshan Laboratory‘14th FiveYear Plan’Major Project(No.2021QNLM020001-1)the Project of China Geological Survey(Nos.DD20230317,DD20230410,DD20190818,DD20191032,DD20160152)the Asia Cooperation Foundation‘China-Pakistan Oil and Gas Resource Potential Assessment and Capacity Training’。
文摘Recent advances in earth science and exploration have made deepwater channel-levee systems a research focus.We collected and analyzed over 10000 km of two-dimensional multichannel seismic data from the offshore Indus Basin to identify channellevee systems at various hierarchical levels depending on their seismic reflection characteristics.Seismic facies analysis was integrated with well data to map the spatial distribution of channel-levee systems in the offshore Indus Basin across various geological periods,and the factors influencing their development were discussed.These systems within the basin were identified using a developed,refined three-tier classification method.The first-order system consists of multiple spatially stacked complexes,the second-order system continuously developed multistage channel-levee bodies,and the third-order system represents the smallest identifiable sedimentary units on seismic profiles.Our findings demonstrate the evolution of the offshore Indus Basin from a single-stage channel with lateral migration to multistage vertical channel stacking from the Miocene to the Pleistocene.Tectonic activities exert their effect on channel-levee systems through their influence on the relative sea level.They also trigger volcanic or seismic events and affect siliciclastic supply.Warm and humid climate conditions form large river systems,which aid in the transport of terrestrial debris to the basin margin.Most channel-levee systems are assumed to have formed during low sea-level periods.This study offers new insights into the formation and evolution of turbidite sedimentary systems in the offshore Indus Basin and presents a practical classification method for comprehending gravity-flow sedimentary configurations and deepwater hydrocarbon exploration.
基金supported by National Natural Science Foundation of China (NSFC) (Nos.62201217 and 51821005)。
文摘The field-reversed configuration(FRC)plasma thruster driven by rotating magnetic field(RMF),abbreviated as the RMF-FRC thruster,is a new type of electric propulsion technology that is expected to accelerate the deep space exploration.An experimental prototype,including diagnostic devices,was designed and constructed based on the principles of the RMF-FRC thruster,with an RMF frequency of 210 kHz and a maximum peak current of 2 kA.Under the rated operating conditions,the initial plasma density was measured to be 5×10^(17)m^(-3),and increased to 2.2×10^(19)m^(-3)after the action of RMF.The coupling efficiency of RMF was about 53%,and the plasma current reached 1.9 kA.The axial magnetic field changed in reverse by 155 Gauss,successfully reversing the bias magnetic field of 60 Gauss,which verifies the formation of FRC plasma.After optimization research,it was found that when the bias magnetic field is 100 Gauss,the axial magnetic field reverse variation caused by FRC is the highest at 164 Gauss.The experimental results are discussed and strategies are proposed to improve the performance of the prototype.
基金the support of the Key Research and Development Program of Shaanxi Province,China(No.2021GXLH-Z-049)。
文摘The influence of geometric configuration on the friction characteristics during incremental sheet forming of AA5052 was analyzed by integrating surface morphology and its characteristic parameters,along with plastic strain,contact pressure,and area.The interface promotes lubrication and support when wall angles were≤40°,a 0.5 mm-thin sheet was used,and a 10 mm-large tool radius was employed.This mainly results in micro-plowing and plastic extrusion flow,leading to lower friction coefficient.However,when wall angles exceed 40°,significant plastic strain roughening occurs,leading to inadequate lubrication on the newly formed surface.Increased sheet thickness and decreased tool radius elevate contact pressure.These actions trigger micro-cutting and adhesion,potentially leading to localized scuffing and dimple tears,and higher friction coefficient.The friction mechanisms remain unaffected by the part’s plane curve features.As the forming process progresses,abrasive wear intensifies,and surface morphology evolves unfavorably for lubrication and friction reduction.
基金funded by the National Natural Science Foundation of China(52167013)the Key Program of Natural Science Foundation of Gansu Province(24JRRA225)Natural Science Foundation of Gansu Province(23JRRA891).
文摘In the context of the“dual carbon”goals,to address issues such as high energy consumption,high costs,and low power quality in the rapid development of electrified railways,this study focused on the China Railways High-Speed 5 Electric Multiple Unit and proposed a mathematical model and capacity optimization method for an onboard energy storage system using lithium batteries and supercapacitors as storage media.Firstly,considering the electrical characteristics,weight,and volume of the storage media,a mathematical model of the energy storage system was established.Secondly,to tackle problems related to energy consumption and power quality,an energy management strategy was proposed that comprehensively considers peak shaving and valley filling and power quality by controlling the charge/discharge thresholds of the storage system.Thecapacity optimization adopted a bilevel programming model,with the series/parallel number of storage modules as variables,considering constraints imposed by the Direct Current to Direct Current converter,train load,and space.An improved Particle Swarm Optimization algorithm and linear programming solver were used to solve specific cases.The results show that the proposed onboard energy storage system can effectively achieve energy savings,reduce consumption,and improve power qualitywhile meeting the load and space limitations of the train.
文摘Hydroxyapatite nanoparticles(HAP NPs)were synthesized by a one‐step hydrothermal method.The surface of HAP NPs was grafted-SH and-COOH chelating groups via in situ surface‐modification with iminodiacetic acid(IDA)and 3‐mercaptopropyl trimethoxysilane(MPS)to afford dual surface‐capped nano‐amendment HAPIDA/MPS.The structure of HAP‐IDA/MPS was characterized,and its adsorption performance for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)was evaluated.The total adsorption capacity of 0.10 g HAP‐IDA/MPS nano‐amendment for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)with an initial mass concentration of 20 mg·L^(-1) reached 13.7 mg·g^(-1),about 4.3 times as much as that of HAP.Notably,HAP‐IDA/MPS nano‐amendment displayed the highest immobilization rate for Hg^(2+),possibly because of its chemical reaction with-SH to form sulfide,possessing the lowest solubility product constant among a variety of metal sulfides.
基金supported by the National Natural Science Foundation of China(No.21473008 and No.21873011)
文摘Iterative multireference configuration interaction (IMRCI) is proposed. It is exploited to compute the electronic energies of H2O and CH2(singlet and triplet states) at equilibrium and non-equilibrium geometries. The potential energy curves of H2O, CH2(singlet and triplet states) and N2 have also been calculated with IMRCI as well as the M?ller Plesset perturbation theory (MP2, MP3, and MP4), the coupled cluster method with single and double substitutions (CCSD), and CCSD with perturbative triples correction (CCSD(T)).These calculations demonstrate that IMRCI results are independent of the initial guess of configuration functions in the reference space and converge quickly to the results of the full configuration interaction. The IMRCI errors relative to the full configuration interaction results are at the order of magnitude of 10-5 hartree within just 2-4 iterations. Further,IMRCI provides an efficient way to find on the potential energy surface the leading electron configurations which, as correct reference states, will be very helpful for the single-reference and multireference theoretical models to obtain accurate results.
基金supported in part by the National Key Laboratory of Science and Technology on Space Microwave(Grant Nos.HTKJ2022KL504009 and HTKJ2022KL5040010).
文摘With the increase in the quantity and scale of Static Random-Access Memory Field Programmable Gate Arrays (SRAM-based FPGAs) for aerospace application, the volume of FPGA configuration bit files that must be stored has increased dramatically. The use of compression techniques for these bitstream files is emerging as a key strategy to alleviate the burden on storage resources. Due to the severe resource constraints of space-based electronics and the unique application environment, the simplicity, efficiency and robustness of the decompression circuitry is also a key design consideration. Through comparative analysis current bitstream file compression technologies, this research suggests that the Lempel Ziv Oberhumer (LZO) compression algorithm is more suitable for satellite applications. This paper also delves into the compression process and format of the LZO compression algorithm, as well as the inherent characteristics of configuration bitstream files. We propose an improved algorithm based on LZO for bitstream file compression, which optimises the compression process by refining the format and reducing the offset. Furthermore, a low-cost, robust decompression hardware architecture is proposed based on this method. Experimental results show that the compression speed of the improved LZO algorithm is increased by 3%, the decompression hardware cost is reduced by approximately 60%, and the compression ratio is slightly reduced by 0.47%.
基金supported by the National Natural Science Foundation of China(No.52130407,52174342,52441408)Beijing Natural Science Foundation(No.2232044,IS23050).
文摘Increasing the sintering rate of powder compact is a critical challenge of powder metallurgical materials,and adjusting component distribution in particles aggregate present significant effect on the microstructure of sintered product,especially for multi-phase compact with local heterogeneity.Here,a case study of W–Ni–Co powder compact was adopted to illustrate the novel strategy to enhance the sintering of multi-phase compact with desired microstructure by adjusting the particle configurations.The plasma synthesis route was developed for the first time to independently adjust the configurations of W–Ni–Co nanopowders with core-shell and homogeneous structures,which facilitates to ascertain the sintering response induced exclusively by particle configurations.Comparison on sintering response further indicates that core-shell powder presents greatly promoted sintering than homogeneous one,and full-dense and uniform compact with grain size of 1.37μm was obtained by solid sintering,which is several to dozens of times smaller than that obtained by conventional liquid sintering.Theoretical and experimental Investigation on elemental immigration visualized the distinct mass diffusion behavior of powder compacts,and clarified the mass transport path promoted densification mechanism determined by powder configurations.Importantly,full-coherent phase interface induced superior strength and plasticity in alloy sintered using core-shell powder,which highlights the importance of microstructural regulation on improving the mechanical property that superior than most of previously reported tungsten heavy alloys.In summary,this work paves a new way for fast sintering of multi-phase compacts,and provides intrinsic understandings on densification mechanism of powder compact.
基金co-supported by the Foundation of National Key Laboratory of Science and Technology on Aerodynamic Design and Research,China(No.614220121020114)the Key R&D Projects of Hunan Province,China(No.2023GK2022)。
文摘The design of wide-range high-efficiency aerodynamic configurations is one of the most important key technologies in the research of near-space hypersonic vehicles.A double-sided intake configuration with different inlets on the upper and lower surfaces is proposed to adapt to widerange flight.Firstly,the double-sided intake configuration’s design method and flight profile are delineated.Secondly,Computational Fluid Dynamics(CFD)numerical simulation based on multi-Graphics Processing Unit(GPU)parallel computing is adopted to evaluate the vehicle’s performance comprehensively,aiming to verify the feasibility of the proposed scheme.This evaluation encompasses a wide-range basic aerodynamic characteristics,inlet performance,and heat flux at critical locations.The results show that the inlets of the designed integration configuration can start up across Mach number 3.5 to 8.The vehicle possesses multi-point cruising capability by flipping the fuselage.Simultaneously,a 180°rotation of the fuselage can significantly decrease the heat accumulation on the lower surface of the vehicle,particularly at the inlet lip,further decreasing the temperature gradient across the vehicle structure.This study has some engineering value for the aerodynamic configuration design of wide-range vehicles.However,further study reveals that the flow phenomena at the intersection of two inlets are complex,posing potential adverse impacts on propulsion efficiency.Therefore,it is imperative to conduct additional research to delve into this matter comprehensively.
基金supported by the National Natural Science Foundation of China under Grant 52325402,52274057,and 52074340the National Key R&D Program of China under Grant 2023YFB4104200+2 种基金the Major Scientific and Technological Projects of CNOOC under Grant CCL2022RCPS0397RSN111 Project under Grant B08028China Scholarship Council under Grant 202306450108.
文摘This study introduces a novel approach to addressing the challenges of high-dimensional variables and strong nonlinearity in reservoir production and layer configuration optimization.For the first time,relational machine learning models are applied in reservoir development optimization.Traditional regression-based models often struggle in complex scenarios,but the proposed relational and regression-based composite differential evolution(RRCODE)method combines a Gaussian naive Bayes relational model with a radial basis function network regression model.This integration effectively captures complex relationships in the optimization process,improving both accuracy and convergence speed.Experimental tests on a multi-layer multi-channel reservoir model,the Egg reservoir model,and a real-field reservoir model(the S reservoir)demonstrate that RRCODE significantly reduces water injection and production volumes while increasing economic returns and cumulative oil recovery.Moreover,the surrogate models employed in RRCODE exhibit lightweight characteristics with low computational overhead.These results highlight RRCODE's superior performance in the integrated optimization of reservoir production and layer configurations,offering more efficient and economically viable solutions for oilfield development.
基金the National Natural Science Foundation of China(Nos.52100032 and 52350005)the Basic and Applied Basic Research Project of Guangzhou(Nos.2024A04J3679, 2024A03J0088)+2 种基金the Introduced Innovative Research and Development Team Project under the“The Pearl River Talent Recruitment Program”of Guangdong Province(No.2019ZT08L387)the Special Basic Research Fund for Central Public Research Institutes of China(No.PMzx703-202204-152)the Research Fund Program of Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology(No.2023B1212060016).
文摘The introduction of metal single atoms(SAs)and nanoparticles(NPs)are effective approaches to mod-ify electronic configuration of semiconductors,whereas recognizing the synergistic effects of metal SAs and NPs are still challenging in photocatalytic water purification.Herein,a general strategy is achieved by subsequentially anchoring Fe SAs and Fe NPs in graphitic carbon nitride.The modification of Fe SAs and Fe NPs improves the energy band structure and constructs a gradient charge polarization,directly expanding the optical absorption range and facilitating the efficient separation and transfer of charge car-riers.With the assistance of the gradient charge polarization,pollutants are readily oxidated by h+,which strengthens the continuous reduction of O2 on Fe NPs for pollutant oxidation in water.This work rein-forces the synergistic effect of SAs and NPs on electronic configuration modulation at the atomic level,which exhibits great potential for the construction of an efficient and sustainable water purification sys-tem.
基金funded by the National Natural Science Foundation of China(Grants 21701083 and 22179054)Jiangsu Provincial Key Research and Development Program(BZ2023010)2023 Jiangsu Government Scholarship for Overseas Studies.
文摘Sodium-ion batteries(SIBs)have recently gained wildly interest due to the abundance of sodium,lower production costs,and better low-temperature performance compared to lithium-ion batteries(LIBs).Among various cathode materials of SIBs,O_(3)-type NaNi_(0.4)Fe_(0.2)Mn_(0.4)O_(2)(NFM424)demonstrates high capacity and ease of synthesis,yet suffers from structural degradation and sluggish Na^(+)kinetics caused by large ionic radius and strong electrostatic interactions.To overcome these issues,a configuration strategy combined with TiO_(2) and Co_(3)O_(4) by a simple solid-state reaction method was introduced to improve structural and electrochemical stability.XRD,SEM,TEM,and various electrochemical characterizations as well as TGA/DSC tests were conducted.The resulting NaNi_(0.4)Fe_(0.2)Mn_(0.3)Co_(0.05)Ti_(0.05)O_(2)(NFMCT)cathode mitigated Jahn-Teller distortions and Na^(+)/vacancy ordering while enhancing phase integrity and diffusion pathways.The obtained NFMCT maintained 93.7 mAh·g^(−1) after 550 cycles at 1 C,with superior rate capabilities at 2 C and 5 C.These findings deepen the understanding of configuration strategy by using multi-element oxide and highlight a practical strategy for designing high-performance SIB cathodes.
基金National Natural Science Foundation of China(91748125)National Administration of Traditional Chinese Medicine’s National Inheritance Studio Construction Project for Famous Veteran Traditional Chinese Medicine Experts([2022]75)。
文摘Objective To configure the complex traditional Chinese medicine(TCM)prescription using digit topology circle and to derive digit topology circle.Methods The basic digit topology circles were constructed.Different digit topology circles were derived using basic digit topology circle,the character strings,and the digit groups.Different digit topology circles with ternary Chinese medicine were derived by adding ternary Chinese medicine into digit topology circles.The valuable TCM prescriptions were configured using the derived digit topology circles.Results Nine simple basic digit topology circles were constructed from the character strings.Multiple digit topology circles and some digit topology circles with ternary Chinese medicine were derived using basic digit topology circles,the character strings,and the digit groups.Four complex TCM prescriptions were configured using four derived digit topology circles digit topology circles,respectively.Conclusion The digit topology circles can be used to configure some existing TCM prescriptions and many novel TCM prescriptions.It has been verified that some existing TCM prescriptions have been used successfully to treat patients with diseases.Some novel valuable TCM prescriptions configured by digit topology circles may be used to treat patients with diseases.
文摘Through on-site investigations and case analyses of green mines in Huizhou City,and by integrating technical measures including soil improvement,plant configuration,and community construction,this study proposes a plant configuration model tailored for ecological restoration in the mining areas of Huizhou.The implementation of a multi-level configuration model that predominantly employs native plant species,combined with a"soil-vegetation-microorganism"collaborative restoration strategy,can significantly enhance vegetation coverage in mining areas,increase soil organic matter content,and reduce the bioavailability of heavy metals in the soil.Based on field research and case study analyses,several optimization recommendations are proposed from the perspectives of slope stability and soil and water conservation.Ultimately,it summarizes plant configuration models and their application effects in the ecological restoration of green mines in Huizhou City.These findings may serve as valuable references for the ecological restoration of mines in South China.
基金This work was supported by Inner Mongolia Natural Science Foundation Project and the Optimization of Exergy Efficiency of a Hybrid Energy Storage System with Crossover Control for Wind Power(2023JQ04).
文摘This paper presents a new capacity planning method that utilizes the complementary characteristics of wind and solar power output.It addresses the limitations of relying on a single metric for a comprehensive assessment of complementarity.To enable more accurate predictions of the optimal wind-solar ratio,a comprehensive complementarity rate is proposed,which allows for the optimization of wind-solar capacity based on this measure.Initially,the Clayton Copula function is employed to create a joint probability distribution model for wind and solar power,enabling the calculation of the comprehensive complementarity rate.Following this,a joint planning model is developed to enhance the system’s economy and reliability.The goal is to minimize total costs,load deficit rates,and curtailment rates by applying an ImprovedMulti-Objective Particle SwarmOptimization algorithm(IMOPSO).Results show that when the proportion of wind power reaches 70%,the comprehensive complementarity rate is optimized.This optimization leads to a 14.83%reduction in total costs and a 9.27%decrease in curtailment rates.Compared to existing studies,this paper offers a multidimensional analysis of the relationship between the comprehensive complementarity rate and the optimal wind-solar ratio,thereby improving predictive accuracy and providing a valuable reference for research on the correlation between wind and solar power.
基金supported by a Key Project of the National Natural Science Foundation of China under Grant 52337004.
文摘In response to the issue of determining the appropriate capacity when hybrid energy storage systems(HESS)collaborate with thermal power units(TPU)in the system’s secondary frequency regulation,a configuration method for HESS based on the analysis of frequency regulation demand analysis is proposed.And a corresponding simulation platform is developed.Firstly,a frequency modulation demand method for reducing the frequency modulation losses of TPU is proposed.Secondly,taking into comprehensive consideration that flywheel energy storage features rapid power response and battery energy storage has the characteristic of high energy density,a coordinated control strategy for HESS considering the self-recovery of state of charge(SOC)is put forward.Then,to measure the economic and technical performance of HESS in assisting the secondary frequency modulation of TPU,an optimized configurationmodel considering the full-life-cycle economy and frequency modulation performance of TPU and HESS system is constructed.Finally,a visual simulation platform for the combined frequency modulation of TPU and HESS is developed based on Matlab Appdesigner.Theresults of calculation examples indicate that the proposed configuration method can improve the overall economic efficiency and frequency modulation performance of TPU and HESS;The control strategy can not only prolong the service life of battery energy storage but also enhance the continuous response ability of HESS;The visual simulation platform is easy to use,and the simulation results are accurate and reliable.
基金Supported by National Natural Science Foundation of China(Grant Nos.52375028,52205040)Hebei Provincial Natural Science Foundation(Grant Nos.E2024203052,E2024203105)Science and Technology Project of Hebei Education Department(Grant No.QN2023206).
文摘Origami mechanisms are extensively employed in various engineering applications due to their exceptional folding performance and deformability.The key to designing origami mechanisms lies in the design of the creases.The crease design is often derived from experience and inspiration,so it is crucial to have a systematic approach to crease design.In this paper,a novel synthesis approach based on graph theory is proposed,which effectively addresses the challenge of designing the creases in origami mechanisms.The essence of this method lies in the acquisition of the double symmetrical crease pattern through the directed graph product operation of two subgraphs.The crease pattern can be simplified by employing a technique that eliminates certain creases while preserving the non-isomorphism and symmetry of the pattern.An improved mixed-integer linear programming model is developed to achieve an automatic distribution of the peak_valley creases of the origami.The proposed method ultimately generates 12 unique double symmetrical crease patterns.The new method proposed in this paper,through systematic design,significantly improves the efficiency of mechanism design while opening up broad prospects for exploring new mechanism structures,thereby greatly expanding its application potential in cutting-edge fields such as aerospace engineering and intelligent robots.
