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Parametric control of UAV U-turns in turbulent wind conditions based on global optimization 认领 引用
1
作者 Liguo TAN Yongcheng XIONG +3 位作者 Changqing HU Jianfeng LI Oleg KUZENKOV Samvel NALCHAJYAN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第1期398-409,共12页
Unmanned aircraft are highly vulnerable to crosswind-induced turbulence during complex maneuvers such as turning,which can significantly compromise control and reduce autopilot effectiveness.This paper presents a nove... Unmanned aircraft are highly vulnerable to crosswind-induced turbulence during complex maneuvers such as turning,which can significantly compromise control and reduce autopilot effectiveness.This paper presents a novel control strategy to improve the controllability of unmanned aircraft in challenging wind conditions.First,the equations of motion for the aircraft are reformulated as a system of stochastic differential equations,which are subsequently transformed into a deterministic form.By modeling turbulence as a Gaussian random process and incorporating it directly into the control system,the proposed method proactively compensates for the adverse effects of turbulence.The transformation is achieved using semi-invariant techniques.Second,the control problem is formulated as an optimization task,aiming to minimize the deviation between the actual and desired turn characteristics,specifically the angular velocity.Finally,a new numerical method with proven global convergence is employed to compute the optimal autopilot parameters.Simulation results using a medium-range unmanned aircraft model under continuous turbulent gusts demonstrate that the proposed method significantly outperforms existing approaches,ensuring both stability and precision in turbulent wind conditions. 展开更多
关键词 Parametric control Rigid-wing unmanned aerial vehicle Stochastic system Global optimization Evolutionary algorithm
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Buckling and parametric excitation stability optimization of fluid-conveying pipes by frequency design 认领 引用
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作者 Xiaoye MAO Kexin CHANG +3 位作者 Jie JING Tianchang DENG Hu DING Liqun CHEN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2026年第4期675-694,共20页
A methodology is proposed to enhance the buckling and parametric excitation stability of fluid-conveying pipes by designing their natural frequencies.As a direct indicator of structural stiffness with respect to defor... A methodology is proposed to enhance the buckling and parametric excitation stability of fluid-conveying pipes by designing their natural frequencies.As a direct indicator of structural stiffness with respect to deformation,which is intrinsically related to the overall structural stability,the natural frequency is adopted as the primary design criterion for enhancing system stability.Based on the generalized Hamilton's principle,the governing equation for a multi-restrained pipe system is derived.The analysis reveals that,the natural frequencies can be maximized by appropriately selecting the constraint locations,which induces the best buckling stability.Although increasing the flow velocity generally reduces the natural frequency,the optimal constraint location remains relatively unchanged,eventually approaching the location of the maximal critical flow speed,beyond which the pipe loses its static stability.Furthermore,the proposed method introduces additional nodes into the natural mode shape,indicating that a higher energy threshold is required to trigger the resonance.Consequently,the parametric resonance under pulsating flow conditions becomes more difficult to initiate.Meanwhile,with the frequency design,the pipe can prevent the occurrence of parametric resonance with smaller critical damping.Compared with other approaches aimed at enhancing the stability of fluid-conveying pipe systems,the proposed method offers greater practicality for engineering applications,as it only requires adjusting the constraint locations and the optimal location is insensitive to the flow speed. 展开更多
关键词 fluid-conveying pipe frequency design static bifurcation stability of parametric resonance optimal stability
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Automatic gating and riser system design and defect control for K4169 superalloy guide blade casting based on parametric 3D modeling-simulation integrated system 认领 引用
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作者 Le-chuan Li Ya-jun Yin +4 位作者 Bing-zheng Fan Guo-yan Shui Xiao-yuan Ji Jian-xin Zhou Lei Jin 《China Foundry》 SCIE EI CAS CSCD 2026年第1期20-30,共11页
Automation and intelligence have become the primary trends in the design of investment casting processes.However,the design of gating and riser systems still lacks precise quantitative evaluation criteria.Numerical si... Automation and intelligence have become the primary trends in the design of investment casting processes.However,the design of gating and riser systems still lacks precise quantitative evaluation criteria.Numerical simulation plays a significant role in quantitatively evaluating current processes and making targeted improvements,but its limitations lie in the inability to dynamically reflect the formation outcomes of castings under varying process conditions,making real-time adjustments to gating and riser designs challenging.In this study,an automated design model for gating and riser systems based on integrated parametric 3D modeling-simulation framework is proposed,which enhances the flexibility and usability of evaluating the casting process by simulation.Firstly,geometric feature extraction technology is employed to obtain the geometric information of the target casting.Based on this information,an automated design framework for gating and riser systems is established,incorporating multiple structural parameters for real-time process control.Subsequently,the simulation results for various structural parameters are analyzed,and the influence of these parameters on casting formation is thoroughly investigated.Finally,the optimal design scheme is generated and validated through experimental verification.Simulation analysis and experimental results show that using a larger gate neck(24 mm in side length) and external risers promotes a more uniform temperature distribution and a more stable flow state,effectively eliminating shrinkage cavities and enhancing process yield by 15%. 展开更多
关键词 numerical simulation automatic design investment casting parametric 3D modeling gating and riser system
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Continuous fiber paths optimization for composite structures with stress and manufacturing constraints using a parametric level set method 认领 引用
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作者 Huiqiang Guo Zhengguang Li +2 位作者 Jiantao Bai Ran Zhang Wenjie Zuo 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第4期361-382,共22页
Fiber-reinforced composite materials are widely used in engineering fields.The design of curvilinear fiber paths is significant for improving the mechanical and manufacturing performances of the composite materials.Th... Fiber-reinforced composite materials are widely used in engineering fields.The design of curvilinear fiber paths is significant for improving the mechanical and manufacturing performances of the composite materials.Therefore,this paper presents an optimization method for curvilinear fibers with stress and manufacturing constraints.The membrane-embedded model is adopted to simulate the composite materials because it does not require extensive constitutive tests.Curvilinear fiber paths are described using the parametric level set method,which naturally avoids the crossing of fiber tows.The fiber optimization model is to minimize structural compliance with stress and manufacturing constraints.Adjoint method is used to obtain the sensitivity information of the objective and constraint functions.Numerical examples demonstrate the effectiveness of the proposed optimization method.The structural stiffness of the optimized composites has been significantly increased while satisfying the stress and manufacturing constraints. 展开更多
关键词 Fiber-reinforced composite material Membrane-embedded model Curvilinear fiber optimization Parametric level set method
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Parametric Modeling of Glottal Flow in Form of Piecewise Differential Equations 认领 引用
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作者 MUSHTAQ Tahir MURTAZA Sadaf +2 位作者 SALEEM Muhammad FARHAD Khurram EJAZ Muhammad Faisal 《Journal of Shanghai Jiaotong university(Science)》 EI 2026年第4期1048-1056,I0021,共9页
For realistic speech generation,variation in glottal waveform models has long been proposed.Due to simplicity and efficiency,the parametric models of the glottal flow are very popular in the field of speech generation... For realistic speech generation,variation in glottal waveform models has long been proposed.Due to simplicity and efficiency,the parametric models of the glottal flow are very popular in the field of speech generation.The proposed work presents a new approach to modeling the glottal flow.The current model is comprised of two piecewise differential equations that generate a glottal pulse.The first and second differential equations generate the opening and closing phases of the vocal folds,respectively while the closed phase is taken as zero.There are four parameters involved in the proposed model to bring variation in the shape of the glottal pulse.The current model is very flexible in designing a glottal pulse and is comparable with the famous Liljencrants-Fant model,Rosenberg model,and KLGLOTT88 model.This comparison supports its successful implementation as a voice source in speech synthesis which also leads to the validity of our differential equation-based glottal model. 展开更多
关键词 glottal flow Liljencrants-Fant glottal model vocal folds parametric model differential form
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Parametric modeling and CFD simulations of steelmaking converters with different lining structures 认领 引用
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作者 Shuang Wu Jiang-Shan Zhang +5 位作者 Qi-Qi Jiang Yu-Hong Liu Shu-Feng Yang Yan Yu Xu-Feng Liu Qing Liu 《Journal of Iron and Steel Research International》 SCIE EI CSCD 2026年第2期488-505,共18页
In the converter steelmaking process,the flow dynamics is closely related to the refractory lining structure of the bath,such as hearth height-to-diameter(H/D)ratio and lining erosion at different campaign stages.The ... In the converter steelmaking process,the flow dynamics is closely related to the refractory lining structure of the bath,such as hearth height-to-diameter(H/D)ratio and lining erosion at different campaign stages.The step of pre-processing in computational fluid dynamics(CFD)simulation is time-consuming for different lining structures,and usually takes around a week per case using the traditional direct modeling method.A parametric modeling tool has been developed to quickly generate various converter structures with quality structured grids within seconds,based on Python and OpenFOAM software.CFD simulations were established and validated using hydraulic modeling to investigate the flow dynamics and lining erosion characteristics in a 100 t top–bottom combined blowing converter under different H/D ratios and campaign stages(initial,middle,and late).The results show that the average molten bath velocity is positively correlated with bath depth.An increase in bath depth extends the path length for kinetic energy transfer of combined blowing gas streams.Excessively large bath depth or diameter will deteriorate the flow pattern and result into corresponding dead zones.Furnace wall and bottom erosion intensifies at higher H/D ratios but decreases in the late campaign stages.The H/D ratio of 1.67 is recommended in the initial design stage considering the flow characteristics.In the late campaign stage,increasing the bottom-blowing flow rate and carrying out furnace maintenance operations are recommended to maintain metallurgical efficiency and lining safety. 展开更多
关键词 Parametric modeling Structured mesh Converter Lining structure Numerical simulation
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A 6-17μm tunable and high-pulse-energy far-infrared laser based on a BaGa4Se7optical parametric oscillator 认领 引用
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作者 Kejun Wang Hui Kong +2 位作者 Xiaoxia Li Dongbo Lv Peng Xie 《Chinese Physics B》 SCIE EI CAS CSCD 2026年第1期507-512,共6页
Tunable mid-infrared and far-infrared laser output was demonstrated based on BaGa4Se7crystals and an optical parametric oscillator(OPO).With a 1.06μm Nd:YAG laser and a double-pass singly resonant OPO cavity,a ... Tunable mid-infrared and far-infrared laser output was demonstrated based on BaGa4Se7crystals and an optical parametric oscillator(OPO).With a 1.06μm Nd:YAG laser and a double-pass singly resonant OPO cavity,a laser energy output of 2.2 mJ at 10μm was obtained.By tuning the angle and temperature,a tunable laser output covering the wavelength range from 6μm to 17μm was obtained with a tuning precision better than 3 nm.The corresponding optical-to-optical conversion efficiency was 2.8%,and the slope efficiency was 4.4%.The damage effect of the output laser on detectors was also investigated,and point damage to the detector occurred at an output energy of 16.4μJ.The laser system has the advantages of miniaturization,a wide tuning range,high energy and high tuning resolution.Its broadband laser characteristics make it highly valuable for applications in atmospheric detection,infrared spectroscopy and electro-optical countermeasures. 展开更多
关键词 BaGa4Se7 tunable laser optical parametric oscillator far-infrared laser
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Non-reciprocal and artificial A-type systems in waveguide QED with parametrically modulated superconducting qubits 认领 引用
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作者 Bing-Jie Chen Li Li +5 位作者 Rui-Yang Gong Silu Zhao Shi Xiao Xiaohui Song Zhongcheng Xiang Dongning Zheng 《Chinese Physics B》 SCIE EI CAS CSCD 2026年第6期572-584,共13页
We present a non-local quantum system based on a waveguide QED architecture,comprising two spatially separated and largely detuned superconducting transmon qubits.By applying parametric frequency modulation to one of ... We present a non-local quantum system based on a waveguide QED architecture,comprising two spatially separated and largely detuned superconducting transmon qubits.By applying parametric frequency modulation to one of the qubits,we establish a tunable coherent channel between the two far-detuned qubits,thereby forming anΛ-type three-level system.We demonstrate that tuning the modulation amplitude enables the observation of spectral evolution from electromagnetically induced transparency(EIT)to Autler–Townes splitting(ATS).Furthermore,by exploiting the interplay between the non-local waveguide phase and system dissipation,the system achieves significant non-reciprocal microwave transmission and direction-selective photon emission.The scheme operates without external magnetic fields,offering an efficient pathway for realizing on-chip integrated quantum routers and isolators. 展开更多
关键词 waveguide QED superconducting qubits parametric modulation
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Characterization of entangled photon pairs generated by type-Ⅱspontaneous parametric down-conversion in BBO crystal 认领 引用
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作者 ZHAO Guanjie SHAO Qianhe +4 位作者 GAO Yiqian ZHANG Shurui LIU Yingjun TIAN Changyong LI Zhengyong 《红外与激光工程》 EI CAS CSCD 北大核心 2026年第6期422-428,共7页
Photon pairs generated by spontaneous parametric down-conversion(SPDC)exhibit nonclassical correlations in polarization,frequency,and photon number,and have attracted extensive attention in quantum optics research.The... Photon pairs generated by spontaneous parametric down-conversion(SPDC)exhibit nonclassical correlations in polarization,frequency,and photon number,and have attracted extensive attention in quantum optics research.The spectral distribution and photon-number statistics of entangled photon pairs are important physical characteristics for understanding the generation mechanism and statistical properties of the down converted light field.Here the type-Ⅱ SPDC in a beta-barium borate(BBO)crystal is employed to generate polarization-entangled photon pairs,and their spectral characteristics,photon-number distribution,and entanglement properties are experimentally investigated in detail.Methods A continuous-wave laser with a wavelength of 404 nm is used as the pump source and focused into a 10-mm long BBO crystal cut for type-Ⅱ phase matching to induce the nonlinear interaction.According to the phase-matching conditions,the relationships between the emission angle and wavelength of the signal and idler photons are analyzed to predict the spatial distribution of the down-converted light field.After the crystal,long pass and band-pass filters are applied to suppress the residual pump light and background noise.The spectral characteristics of the generated photons are measured by a tunable grating monochromator combined with a single-photon detector,and the photon counting rate is recorded at different wavelengths to obtain the spectral distribution over a broad wavelength range.Subsequently,the monochromator is replaced with a photon-number resolving detector to directly measure the photon-number statistics of the parametric down-conversion field in the time domain.The statistical property of the light field is evaluated using the Q factor.In addition,a Bell test setup consisting of beam splitters,half-wave plates,polarization beam splitters,interference filters,and four single photon detectors is constructed to measure nonclassical correlations and verify the entanglement using the Clauser-Horne-Shimony-Holt(CHSH)inequality.Results and Discussion The experimental observations confirm that the BBO crystal operates in the type-Ⅱ SPDC regime.Two emission rings corresponding to orthogonally polarized photons are observed in the far field,which agree well with the theoretical phase-matching analysis(Fig.3).The measured spectral photon rate shows a broadband distribution in the range from 700 nm to 900 nm(Fig.5).The counting rate reaches a maximum value of 990 counts per second at the wavelength of 785 nm,indicating that the degenerate wavelength region corresponds to the highest photon generation efficiency.The measured spectrum is consistent with the prediction of the phase-matching model.Photon-number-resolved measurements reveal distinct statistical features of the generated light field(Fig.6).The distribution can be clearly divided into two parts.The lower part corresponds to background noise that approximately follows a Gaussian distribution,while the upper part presents a comb-like structure.Pronounced peaks appear only at even photon numbers of 0,2,4,6,8,10,and 12,which directly indicates that photons are generated in pairs during the SPDC process.The calculated Q factor is 1.302,demonstrating that the photon number distribution obeys a super-Poissonian statistic.To further verify the quantum correlation,the Bell test is performed using experimental setup in Fig.2.The obtained CHSH parameter shows S=2.415±0.138,which exceeds the classical limit of 2 by about three standard deviations,confirming the existence of entanglement between the generated photon pairs.Conclusions In conclusion,entangled photon pairs generated by type-Ⅱ spontaneous parametric down conversion in a BBO crystal are experimentally characterized.The spatial emission pattern,broadband spectral distribution,photon-number statistics,and polarization entanglement are systematically measured and analyzed.Broadband emission from 700 nm to 900 nm,a peak counting rate at 785 nm,super-Poissonian photon-number statistics,and clear violation of the Bell inequality are observed.These results provide a detailed characterization of the spectral and statistical properties of the SPDC photon pairs. 展开更多
关键词 entangled photon pairs parametric down-conversion BBO crystal single-photon detection
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Joint geostatistical seismic inversion of elastic and petrophysical properties using stochastic co-simulation models based on parametric copulas 认领 引用
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作者 Daniel Vázquez-Ramírez Martín ADíaz-Viera Raúl del Valle-García 《Petroleum Science》 SCIE EI CAS CSCD 2026年第2期608-625,共18页
Seismic properties play a fundamental role in the geological and petrophysical modeling of reservoirs due to their dependence on petrophysical properties.Most existing stochastic seismic inversion methods are based on... Seismic properties play a fundamental role in the geological and petrophysical modeling of reservoirs due to their dependence on petrophysical properties.Most existing stochastic seismic inversion methods are based on Gaussian probability distribution functions and assume linear dependence.Examples include sequential Gaussian co-simulation(SGCS)and direct sequential simulation(DSS).In contrast,spatial stochastic co-simulation methods based on Bernstein copulas(BCCS)have recently been developed.These methods do not require a specific distribution type or linear dependence,thereby overcoming the limitations of traditional approaches.In this context,we propose a novel approach for the joint seismic inversion of elastic and petrophysical properties using parametric copulas within a Bayesian inference framework.A joint probability distribution is constructed using well-scale petrophysical and elastic property data,fitted to parametric copula functions and treated as prior information.The model parameters are then updated a posteriori using petrophysical properties scaled by a moving window averaging method and seismic properties upscaled using the Backus averaging method.The resulting posterior model is used within the inversion process to generate elastic property realizations at the seismic scale.The inverse problem is solved using a simulated annealing algorithm that minimizes a global objective function combining the root-mean-square(RMS)error between synthetic and observed seismic traces,and the semivariogram error between the simulated and target variogram models.For each elastic realization,a reflectivity series is computed and convolved with a seismic wavelet to generate a synthetic seismic trace.The best-fitting elastic realization is then used to simulate the corresponding petrophysical property using the same joint probability distribution.The proposed method was applied to a deepwater reservoir case study to estimate total porosity and acoustic impedance at the seismic scale.Results demonstrate that the use of parametric copulas reduces computational cost and execution time while enabling effective integration of nonlinear dependencies.The synthetic traces exhibit RMS errors below 8%,validating the accuracy and robustness of the copulabased inversion framework. 展开更多
关键词 Geostatistical seismic inversion Bayesian inference Joint probability distribution function Parametric copula Petrophysical simulation Seismic property simulation
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Less-parametric point cloud upsampling network 认领 引用
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作者 Aihua Ling Hongfang Liu +1 位作者 Junwen Wang Ruyu Liu 《Optoelectronics Letters》 EI 2026年第1期53-57,共5页
In the field of aircraft design and maintenance,with the innovation of cabin cable three-dimensional(3D)scanning and sensor technology,high-precision cabin point cloud data has become the key to improving the accuracy... In the field of aircraft design and maintenance,with the innovation of cabin cable three-dimensional(3D)scanning and sensor technology,high-precision cabin point cloud data has become the key to improving the accuracy of cabin navigation and building a realistic virtual reality environment.In the face of largescale point cloud data,how to efficiently and uniformly construct a realistic virtual reality environment has become a challenge.In this paper,we propose a new low-parametric point cloud upsampling network(LPNet),which is based on the no-learn model to learn the complementary geometric knowledge between point clouds based on some simple data transformations,to efficiently retain the geometric properties of point clouds,and then input the results into the up-sampling module,and simply insert a few layers of multilayer perceptron(MLP)to efficiently generate high-resolution point clouds.It is able to efficiently generate high-resolution point clouds,showing great flexibility and realizing the efficient use of computational resources. 展开更多
关键词 aircraft design maintenancewith sensor technologyhigh precision building realistic virtual reality environmentin virtual reality environment point cloud upsampling aircraft design maintenance D scanning low parametric network
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Parametric Optimization of Battery Capacity and Electric Motor Power for Electric Vehicles under Varying Loads and Capacities 认领 引用
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作者 Ivan Pliško Mihael Cipek Danijel Pavkovic 《Energy Engineering》 EI 2026年第7期243-263,共21页
Nowadays,battery electric vehicles are increasingly used,from passenger cars to heavy-duty commercial vehicles,trains,and ships,all in an effort to reduce greenhouse gas emissions.In electric vehicles,battery capacity... Nowadays,battery electric vehicles are increasingly used,from passenger cars to heavy-duty commercial vehicles,trains,and ships,all in an effort to reduce greenhouse gas emissions.In electric vehicles,battery capacity significantly affects their range and performance,but a larger battery also increases the vehicle's mass and cost.This paper proposes parametric optimization of battery capacity and peak electric motor power for electric vehicles under different load types and vehicle capacities.A computational model of an electric vehicle is developed,with parameters such as battery capacity,payload,and peak motor power being variable.Using parametric optimization algorithms,the optimal electric vehicle configuration for different load types and battery capacities is determined.Based on the optimization results,the relationships between the parameters are analyzed,and a conclusion is presented. 展开更多
关键词 Electric vehicles battery capacity motor power parametric optimization different load computational model
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Energy,exergy,economic performance evaluation and parametric optimization of organic Rankine cycle for low-temperature flue gas waste heat recovery 认领 引用
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作者 Jun-sheng Feng Hao Wu +2 位作者 Xin-ni Cheng Liang Zhao Hui Dong 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2025年第7期1830-1843,共14页
To further enhance the recovery rate of low-temperature waste heat,the low-temperature flue gas in the sinter annular cooler was chosen as the heat source of an organic Rankine cycle(ORC)system,and the comprehensive e... To further enhance the recovery rate of low-temperature waste heat,the low-temperature flue gas in the sinter annular cooler was chosen as the heat source of an organic Rankine cycle(ORC)system,and the comprehensive evaluation of energy,exergy and economic performance of the ORC system was conducted deeply.The energy,exergy and economic performance models of the ORC system were established,and proper candidate organic working fluids(OWFs)were selected based on the thermo-physical properties of OWF and operating characteristics of ORC system.Then,the effects of ORC crucial parameters on the system energy,exergy and economic performances were evaluated in detail.Finally,the bi-objective optimization based on the genetic algorithm was conducted to analyze the optimal performance of the ORC system under the designed ORC crucial parameters,and the exergy efficiency and electricity production cost were set as the evaluation indexes of parametric optimization.The results indicate that the ORC system with the higher evaporation temperature and lower condensation temperature can obtain the larger system exergy efficiency and smaller electricity production cost.The smaller the superheat degree of OWF and pinch-point temperature difference in the evaporator are,the better the energy and exergy performances of the ORC system are.Under the optimization results,R245fa has the best comprehensive performance with the exergy efficiency of 46.34%and electricity production cost of 0.12123$/kWh among the selected candidate OWFs,which should be preferentially chosen as the OWF of the ORC system. 展开更多
关键词 Sinter Waste heat recovery Organic Rankine cycle Exergy efficiency Electricity production cost Parametric optimization
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Parametric study to implement a water-weakening process in UDEC 认领 引用
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作者 Fengchang Bu Michel Jaboyedoff +3 位作者 Marc-Henri Derron Lei Xue Yuan Cui Chao Xu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2025年第3期1378-1386,共9页
Despite the prevalence and validity of the universal distinct element code(UDEC)in simulations in geotechnics domain,water-weakening process of rock models remains elusive.Prior research has made positive contribution... Despite the prevalence and validity of the universal distinct element code(UDEC)in simulations in geotechnics domain,water-weakening process of rock models remains elusive.Prior research has made positive contributions to a presupposed link between modelling parameters and saturation degree,Sr.Nevertheless,this effort presents inaccurate results and limited implications owing to the misleading interpretation,that is,devoid of the basic logic in UDEC that modelling parameters should be calibrated by tested macroscopic properties in contrast to a presupposed relation with Sr.To fill this gap,a new methodology is proposed by coupling a computationally efficient parametric study with the simulation of water-weakening mechanisms.More specifically,tested macroscopic properties with different Sr values are input into parametric relations to acquire initial modelling parameters that are sequentially calibrated and modulated until simulations are in line with geomechanical tests.Illustrative example reveals that numerical water-weakening effects on macroscopic properties,mechanical behaviours,and failure configurations are highly consistent with tested ones with noticeable computational expediency,implying the feasibility and simplicity of this methodology.Furthermore,with compatibility across various numerical models,the proposed methodology substantially extends the applicability of UDEC in simulating water-weakening geotechnical problems. 展开更多
关键词 Parametric analysis Universal distinct element code(UDEC) Water-weakening Rock strength
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Effect of Tooth Geometry on Multi-cycle Meshing Temperature of POM Worm Gears:Parametric Study via an Adaptive Iteration Algorithm 认领 引用
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作者 Kaixing Li Wujiao Xu +1 位作者 Yonggang Liu Datong Qin 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2025年第2期427-439,共13页
Meshing temperature analyses of polymer gears reported in the literature mainly concern the effects of various material combinations and loading conditions,as their impacts could be seen in the first few meshing cycle... Meshing temperature analyses of polymer gears reported in the literature mainly concern the effects of various material combinations and loading conditions,as their impacts could be seen in the first few meshing cycles.However,the effects of tooth geometry parameters could manifest as the meshing cycles increase.This study investigated the effects of tooth geometry parameters on the multi-cycle meshing temperature of polyoxymethylene(POM)worm gears,aiming to control the meshing temperature elevation by tuning the tooth geometry.Firstly,a finite element(FE)model capable of separately calculating the heat generation and simulating the heat propagation was established.Moreover,an adaptive iteration algorithm was proposed within the FE framework to capture the influence of the heat generation variation from cycle to cycle.This algorithm proved to be feasible and highly efficient compared with experimental results from the literature and simulated results via the full-iteration algorithm.Multi-cycle meshing temperature analyses were conducted on a series of POM worm gears with different tooth geometry parameters.The results reveal that,within the range of 14.5°to 25°,a pressure angle of 25°is favorable for reducing the peak surface temperature and overall body temperature of POM worm gears,which influence flank wear and load-carrying capability,respectively.However,addendum modification should be weighed because it helps with load bearing but increases the risk of severe flank wear.This paper proposes an efficient iteration algorithm for multi-cycle meshing temperature analysis of polymer gears and proves the feasibility of controlling the meshing temperature elevation during multiple cycles by tuning tooth geometry. 展开更多
关键词 POM worm gears Multi-cycle meshing temperature Adaptive iteration algorithm Tooth geometry parameters Parametric study
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Parametric design for the valve seat of a high-temperature and high-pressure valve inside wind tunnels 认领 引用 被引量：2
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作者 Fengwei HOU Haifeng SHU +4 位作者 Binbin WU Chengliang YU Zhehui MA Wenqing LI Jinyuan QIAN 《Journal of Zhejiang University-SCIENCE A》 SCIE EI CAS CSCD 2025年第3期266-276,共11页
A high-temperature and high-pressure valve is the key equipment of a wind tunnel system;it controls the generation of high-temperature and high-pressure gas.To reduce the adverse impact of high-temperature and high-pr... A high-temperature and high-pressure valve is the key equipment of a wind tunnel system;it controls the generation of high-temperature and high-pressure gas.To reduce the adverse impact of high-temperature and high-pressure gas on the strength of the valve body,a cooling structure is set on the valve seat.This can significantly reduce the temperature of the valve body and valve seat.The effects of its structure on the cooling characteristics and stress of the valve seat are studied,and six main parameters that can completely describe the geometry of the cooling structure are proposed.The central composite design method is used to select sample points,and the multi-objective genetic algorithm(MOGA)method is used for optimal structural design.A modification method according to the main parameters for the valve seat is proposed.The results show that the cooling structure weakens the pressure-bearing capability of the valve seat.Among the six main parameters of the valve seat,the distance from the end face of the lower hole to the Z-axis and the distance from the axis of the lower hole to the origin of the coordinates have the most obvious effects on the average stress of the valve seat.An optimum design value is proposed.This work can provide a reference for the design of high-temperature and high-pressure valves. 展开更多
关键词 Control valve Valve seat Optimization Parametric design
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Towards Room-Temperature Exciton-Polariton Supersolidity Driven by Guided Optical Parametric Oscillation 认领 引用
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作者 Lingyu Tian Yusong Gan +3 位作者 Ying Shi Luobing Xu Huawen Xu Qihua Xiong 《Chinese Physics Letters》 SCIE EI CAS CSCD 2025年第9期68-76,共9页
Supersolidity is a counterintuitive quantum phase of matter where the long-range spatial order of a solid coexists with the frictionless flow characteristic of a superfluid.Recently,evidence of supersolidity has been ... Supersolidity is a counterintuitive quantum phase of matter where the long-range spatial order of a solid coexists with the frictionless flow characteristic of a superfluid.Recently,evidence of supersolidity has been demonstrated in polariton condensates in III-V photonic crystal microcavities by condensing into a topological bound state in the continuum,offering a new light-matter hybrid platform for exploring such quantum phase.In this work,we propose a theoretical scheme for realizing room-temperature supersolidity based on halide perovskite exciton polaritons operating in the optical parametric oscillation regime.By employing a waveguide microcavity geometry,we confine polariton scattering direction in reciprocal space,enabling controlled momentum selection.Leveraging the intrinsic nonlinear interactions among polaritons,we theoretically demonstrate the spontaneous breaking of both continuous translational symmetry and global phase symmetry,i.e.,the evidence of supersolidity.Furthermore,we identify a tunable phase transition sequence in our system:from a Bose-Einstein condensate to a supersolid phase,and ultimately to an insulating phase,as the nonlinear interaction strength increases. 展开更多
关键词 polariton condensates room temperature supersolidity condensing topological bound state theoretical scheme exciton polaritons quantum phase transition optical parametric oscillation quantum phase matter
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Spectral photon-number distribution of parametric down-conversion and generation of heralded Fock states 认领 引用
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作者 Yan-Sheng Bao Bo-Chen Wang +1 位作者 Chang-Yong Tian Zheng-Yong Li 《Chinese Physics B》 SCIE EI CAS CSCD 2025年第7期410-415,共6页
Photon pairs with large nondegeneracy have recently attracted increasing interest, which gives rise to an urgent demand for revealing their complete and accurate spectral distribution. By thoroughly analyzing parametr... Photon pairs with large nondegeneracy have recently attracted increasing interest, which gives rise to an urgent demand for revealing their complete and accurate spectral distribution. By thoroughly analyzing parametric down-conversion(PDC), we put forward a model to directly describe the spatial-spectral distribution of these photon pairs, which is experimentally demonstrated by a 532-nm pumped type-I PDC in a beta barium borate(BBO) crystal. The measured spectral curves show good agreement with the theoretical predictions over the entire spectral range. We further demonstrate that, as signal wavelength increases, the photon pairs are initially spectrally distinguishable, then partly indistinguishable, finally completely indistinguishable with a maximum bandwidth of approximately 500 nm. Utilizing photon-number-resolving single-photon detectors(SPD), we observe the average photon number decreases significantly more slowly than the spectral intensity as the wavelength deviates from the peak, and the photon numbers follow a quasi-Poisson distribution well for wavelengths around the peak, but a thermal distribution better describes the statistics near the spectral boundaries. Finally,we use the signal photons as the trigger to generate heralded Fock states up to 10 photons in near-infrared range, which are suitable for quantum simulation and quantum key distribution in optical fiber networks. 展开更多
关键词 photon-number distribution parametric down-conversion Fock state
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Modeling stopping power of ions in plasmas using parametric potentials 认领 引用
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作者 Tanguy Barges Delattre Sébastien Rassou Jean-Christophe Pain 《Matter and Radiation at Extremes》 SCIE EI CAS CSCD 2025年第6期86-100,共15页
We present a study of the ion stopping power due to free and bound electrons in a warm dense plasma.Our main goal is to propose a method of stopping-power calculation expected to be valid for any ionization degree.The... We present a study of the ion stopping power due to free and bound electrons in a warm dense plasma.Our main goal is to propose a method of stopping-power calculation expected to be valid for any ionization degree.The free-electron contribution is described by the Maynard–Deutsch–Zimmerman formula,and the bound-electron contribution relies on the Bethe formula with corrections,in particular taking into account density and shell effects.The results of the bound-state computation using three different parametric potentials are investigated within the Garbet formalism for the mean excitation energy.The first parametric potential is due to Green,Sellin,and Zachor,the second one was proposed by Yunta,and the third one was introduced by Klapisch in the framework of atomic-structure computations.The results are compared with those of self-consistent average-atom calculations.This approach correctly bridges the limits of neutral and fully ionized matter. 展开更多
关键词 warm dense plasmaour free bound electrons maynard deutsch zimmerman formulaand parametric potentials ion stopping power bethe formula free electrons bound electrons
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ESTIMATES OF ALL TERMS OF HOMOGENEOUS POLYNOMIAL EXPANSIONS FOR THE SUBCLASSES OF G-PARAMETRIC STARLIKE MAPPINGS OF COMPLEX ORDER IN SEVERAL COMPLEX VARIABLES 认领 引用
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作者 Liangpeng XIONG Qingchao WANG Xiaoying SIMA 《Acta Mathematica Scientia》 SCIE CSCD 2025年第4期1555-1566,共12页
In this paper,the class of starlike functions of complex order γ(γ∈ℂ−{0})is extended from the case on unit disk U=(z∈C:|z|<1)to the case on the unit ball B in a complex Banach space or the unit polydisk Un i... In this paper,the class of starlike functions of complex order γ(γ∈ℂ−{0})is extended from the case on unit disk U=(z∈C:|z|<1)to the case on the unit ball B in a complex Banach space or the unit polydisk Un in Cn.Let g be a convex function in U. We mainly establish the sharp bounds of all terms of homogeneous polynomial expansions for a subclass of g-parametric starlike mappings of complex order γ on B (resp.Un)when the mappings f are k-fold symmetric, k ∈ N. Our results partly solve the Bieberbach conjecture in several complex variables and generalize some prior works. 展开更多
关键词 class starlike functions complex order g parametric starlike mappings unit polydisk bieberbach co convex function homogeneous polynomial expansions banach space
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