期刊文献+
共找到12篇文章
< 1 >
每页显示 20 50 100
Calculation of Interaction Parameters from Immiscible Phase Diagram of Alkali Metal or Alkali Earth Metal-Halide System by Means of Subregular Solution Model 被引量:1
1
作者 Zhaochun ZHANG, Deliang CUI, Baibiao HUANG, Xiaoyan QIN and Minhua JIANG (Institute of Crystal Materials, Shandong University, Jinan 250100, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第3期354-356,共3页
In this paper, the interaction parameters in the subregular solution model, λ1 and λ2, are regarded as a linear function of temperature, T. Therefore, the molar excess Gibbs energy of A-B binary system may be reexpr... In this paper, the interaction parameters in the subregular solution model, λ1 and λ2, are regarded as a linear function of temperature, T. Therefore, the molar excess Gibbs energy of A-B binary system may be reexpressed as follows:Gm^E=xAxB[(λ11+λ12T)+(λ21+λ22T)xB]The calculation of the model parameters, λ11, λ12, λ21and λ22, was carried out numerically from the phase diagrams for 11 alkali metal-alkali halide or alkali earth metal-halide systems. In addition, artificial neural network trained by known data has been used to predict the values of these model parameters. The predicted results are in good agreement with the .calculated ones. The applicability of the subregular solution model to the alkali metal-alkali halide or alkali earth metal-halide systems were tested by comparing the available experimental composition along the boundary of miscibility gap with the calculated ones which were obtained by using genetic algorithm. The good agreement between the calculated and experimental results across the entire liquidus is valid evidence in support of the model. 展开更多
关键词 In calculation of Interaction parameters from Immiscible Phase Diagram of Alkali Metal or Alkali Earth Metal-Halide System by Means of Subregular Solution Model
下载PDF
Parameter calculation and result storage for phase-field simulation in α-Mg dendrite growth of Mg-5-wt% Zn alloy
2
作者 陈伟鹏 侯华 +2 位作者 张云涛 柳伟 赵宇宏 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期616-622,共7页
Parameter calculation and result storage, as two necessary steps in phase-field simulation play an important role in ensuring the accuracy of simulation results. A strategy of parameter calculation and result storage ... Parameter calculation and result storage, as two necessary steps in phase-field simulation play an important role in ensuring the accuracy of simulation results. A strategy of parameter calculation and result storage is presented for phase-field simulation in α-Mg dendrite growth of Mg-5-wt% Zn alloy under isothermal solidification. Based on the phase diagram and empirical formulas, key parameters of the phase-field model, such as equilibrium partition coefficient k, liquidus slope m, solutal diffusion coefficient in liquid Dl, and solutal diffusion coefficient in solid Ds, can be obtained.Both structured grid method and structured point method can be used to store simulation results, but using the latter method will reduce about 60% storage space and 37.5% storage time compared with the former. Finally, convergent simulation results of α-Mg dendrite growth are obtained and they are in good agreement with the experimental results about optical micrograph, which verify the accuracy of parameters and stability of storage method. 展开更多
关键词 parameter calculation result storage phase-field method dendrite growth
下载PDF
Intention Estimation of Adversarial Spatial Target Based on Fuzzy Inference 被引量:2
3
作者 Wenjia Xiang Xiaoyu Li +4 位作者 Zirui He Chenjing Su Wangchi Cheng Chao Lu Shan Yang 《Intelligent Automation & Soft Computing》 SCIE 2023年第3期3627-3639,共13页
Estimating the intention of space objects plays an important role in air-craft design,aviation safety,military and otherfields,and is an important refer-ence basis for air situation analysis and command decision-making... Estimating the intention of space objects plays an important role in air-craft design,aviation safety,military and otherfields,and is an important refer-ence basis for air situation analysis and command decision-making.This paper studies an intention estimation method based on fuzzy theory,combining prob-ability to calculate the intention between two objects.This method takes a space object as the origin of coordinates,observes the target’s distance,speed,relative heading angle,altitude difference,steering trend and etc.,then introduces the spe-cific calculation methods of these parameters.Through calculation,values are input into the fuzzy inference model,andfinally the action intention of the target is obtained through the fuzzy rule table and historical weighted probability.Ver-ified by simulation experiment,the target intention inferred by this method is roughly the same as the actual behavior of the target,which proves that the meth-od for identifying the target intention is effective. 展开更多
关键词 Intension estimation motion parameters calculation fuzzy inference fuzzy rule table historical weighted probability
下载PDF
Optimization of dewatering schemes for a deep foundation pit near the Yangtze River, China 被引量:4
4
作者 Yang You Changhong Yan +2 位作者 Baotian Xu Shi Liu Canhui Che 《Journal of Rock Mechanics and Geotechnical Engineering》 CSCD 2018年第3期555-566,共12页
A deep foundation pit constructed for an underground transportation hub was excavated near the Yangtze River. Among the strata, there are two confined aquifers, between which lies an aquiclude that is partially missin... A deep foundation pit constructed for an underground transportation hub was excavated near the Yangtze River. Among the strata, there are two confined aquifers, between which lies an aquiclude that is partially missing. To guarantee the safety of pit excavation, the piezometric head of the upper confined aquifer, where the pit bottom is located, should be 1 m below the pit bottom, while that of the lower confined aquifer should be dewatered down to a safe water level to avoid uplift problem. The Yangtze River levee is notably close to the pit, and its deformation caused by dewatering should be controlled. A pumping test was performed to obtain the hydraulic conductivity of the upper confined aquifer. The average value of the hydraulic conductivity obtained from analytical calculation is 20.45 m/d, which is larger than the values from numerical simulation(horizontal hydraulic conductivity K_H = 16 m/d and vertical hydraulic conductivity K_V = S m/d). The difference between K_H and K_V indicates the anisotropy of the aquifer. Two dewatering schemes were designed for the construction and simulated by the numerical models for comparison purposes. The results show that though the first scheme could meet the dewatering requirements, the largest accumulated settlement and differential settlement would be94.64 mm and 3.3‰, respectively, greatly exceeding the limited values. Meanwhile, the second scheme,in which the bottoms of the waterproof curtains in ramp B and the river side of ramp A are installed at a deeper elevation of-28 m above sea level, and 27 recharge wells are set along the levee, can control the deformation of the levee significantly. 展开更多
关键词 Deep foundation pit Parameter calculation Dewatering schemes Numerical simulation
下载PDF
ANALYSIS MODEL ON GRADUAL CHANGE PRINCIPLE OF EFFECT ZONES OF LAYER FACE FOR ROLLED CONTROL CONCRETE DAM 被引量:1
5
作者 顾冲时 宋敬衖 方海挺 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第11期1523-1529,共7页
The effect zones of layer face for RCC (rolled control concrete) dam have gradual change characteristics. Based on the analysis thought of complex material, a model was built to analyze above principle of RCC dam by... The effect zones of layer face for RCC (rolled control concrete) dam have gradual change characteristics. Based on the analysis thought of complex material, a model was built to analyze above principle of RCC dam by use of series-wound and shunt-wound connection. Some methods were proposed to determine the instantaneous Young's modulus, delayed Young's modulus and viscosity coefficient of effect zones of layer face. Above models and methods were used to mine the principle of gradual change of key calculation parameters which can response the characteristics of effect zones. The principle of gradual change was described. A model was established to analyze the threedimensional viscoelastic problem of RCC dam. Above programs were developed. The examples show that the proposed models and methods to determine the key calculation parameters of effect zones can reflect the status of RCC dam accurately. 展开更多
关键词 (rolled control concrete dam) effect zones calculation parameter principle of gradual change viscoelastic model
下载PDF
New Mathematical Model Based on Affine ransformation for Remote Sensing Image with High Resolution
6
作者 ZHANG Jianqing ZHANG Zuxun 《Geo-Spatial Information Science》 2003年第1期49-53,共5页
This paper calculates the parameters of image position and orientation,proposes a mathematical model and adopts a new method with three steps of transformations based on parallel ray projection.Every step of the model... This paper calculates the parameters of image position and orientation,proposes a mathematical model and adopts a new method with three steps of transformations based on parallel ray projection.Every step of the model is strict,and the map function of each transformation is the first order polynomials and other simple function.The final calculation of the parameters is for the linear equations with good status.As a result,the problem of the relativity of image parameter calculation is solved completely.Some experiments are carried out. 展开更多
关键词 remote sensing image high resolution parameter calculation Affine transformation mathematical model
下载PDF
Analysis and Research on Equivalent Model of Airbus A380 Wing Beam
7
作者 LIU Yuqing REN Zheyu +1 位作者 XUAN Hao MA Zhuqiao 《International Journal of Plant Engineering and Management》 2020年第4期205-222,共18页
With the development of aviation industry,civil aviation has become an indispensable part.Our team will take all the structural dimensions,loads and material parameters in the wing beam structure as the specific value... With the development of aviation industry,civil aviation has become an indispensable part.Our team will take all the structural dimensions,loads and material parameters in the wing beam structure as the specific values determined during the structural design to conduct deflection analysis on the wing beam structure of A380 passenger plane.According to the deflection and parameters analyzed,the stress distribution and maximum stress position on the wing beam can be known.Through the analysis of the wing parameters,the finite element analysis of the wing beam,the mesh sensitivity analysis,and the analysis of the wing tip deflection,the relevant safety factors of the aircraft are obtained.The results show that the wing of airbus A380 is more reliable and safer through the calculation of deflection,stress and safety factor. 展开更多
关键词 airbus A380 model parameter calculation wing beam analysis
下载PDF
Performance calculation and improved model research of direct-drive permanent magnet generator based on FEM 被引量:1
8
作者 ZHANG Jian LI HeMing +2 位作者 LUO YingLi DOU Na CUI XueShen 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第8期2338-2345,共8页
In some control strategies of the direct-rive permanent magnet generator(DDPMG),the mathematics model is excessively simplified and some complex nonlinear characteristics,such as core saturation and cross-saturation,a... In some control strategies of the direct-rive permanent magnet generator(DDPMG),the mathematics model is excessively simplified and some complex nonlinear characteristics,such as core saturation and cross-saturation,are generally neglected.To solve this problem,this paper utilizes the frozen element permeability method to compute the armature self-and mutual-inductance,permanent magnet d-and q-axis flux varying with d-axis and q-axis current,then an improved model is presented in which the core saturation and cross-saturation between d-axis and q-axis are considered effectively.Based on this model,the method for computing the performance of the generators is also proposed.Taking a 1.5-MW DDPMG as an example,the time-stepping finite element method(T-S FEM) is adopted to analyze the performance with no-load and loaded conditions,the results show a good agreement with the ones obtained by the improved model.Compared with the simplified model,it is demonstrated that the presented model has the high efficiency and reliability and can provide a good reference for optimization design of DDPMG and other PM motors. 展开更多
关键词 d-q axis cross-saturation DDPMG improved simulation model parameters calculation Time-stepping FEM
原文传递
Refined analysis and construction parameter calculation for full-span erection of the continuous steel box girder bridge with long cantilevers 被引量:4
9
作者 Jin-feng WANG Tian-mei WU +2 位作者 Jiang-tao ZHANG Hua-wei XIANG Rong-qiao XU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2020年第4期268-279,共12页
To accurately control the full-span erection of continuous steel box girder bridges with complex cross-sections and long cantilevers, both the augmented finite element method(A-FEM) and the degenerated plate elements ... To accurately control the full-span erection of continuous steel box girder bridges with complex cross-sections and long cantilevers, both the augmented finite element method(A-FEM) and the degenerated plate elements are adopted in this paper. The entire construction process is simulated by the A-FEM with the mesh-separation-based approximation technique, while the degenerated plate elements are constructed based on 3D isoparametric elements, making it suitable for analysis of a thin-walled structure. This method significantly improves computational efficiency by avoiding numerous degrees of freedom(DoFs) when analyzing complex structures. With characteristics of the full-span erection technology, the end-face angle of adjacent girder segments, the preset distance of girder segments from the design position, and the temperature difference are selected as control parameters, and they are calculated through the structural response of each construction stage. Engineering practice shows that the calculation accuracy of A-FEM is verified by field-measured results. It can be applied rapidly and effectively to evaluate the matching state of girder segments and the stress state of bearings as well as the thermal effect during full-span erection. 展开更多
关键词 Continuous steel box girder bridges Full-span erection Augmented finite element method(A-FEM) Construction control Construction parameter calculation
原文传递
剥脱法估算药代动力学参数的FORTRAN—Ⅳ程序
10
作者 汤仲明 《军事医学科学院院刊》 1982年第5期595-599,共5页
许多药物在非静脉给药后的血药浓度曲线表现为三个明显时相:即血药浓度随时间而上升的吸收相;药物迅速向组织转运,使血药浓度迅速下降的分布(α)相;药物在体内达到拟分布平衡后,血药浓度按单指数式下降的清除(β)相。
关键词 pharmacokinetic parameters FORTRAN computer program for obtaining pharmacokinetic parameters calculation of pharmacokinetic parameters based on residual method.
原文传递
Evaluation and comparison of various fast fluid dynamics modeling methods for predicting airflow around buildings
11
作者 Shu Zheng Zhiqiang John Zhai +3 位作者 Yi Wang Yu Xue Lin Duanmu Wei Liu 《Building Simulation》 SCIE EI CSCD 2022年第6期1083-1095,共13页
Computational fluid dynamics(CFD)methods are being increasingly used for predicting airflow fields around buildings,but personal computers can still take tens of hours to create a single design using traditional compu... Computational fluid dynamics(CFD)methods are being increasingly used for predicting airflow fields around buildings,but personal computers can still take tens of hours to create a single design using traditional computing models.Considering both accuracy and efficiency,this study compared the performances of the conventional algorithm PIMPLE,fast fluid dynamics(FFD),semi-Lagrangian PISO(SLPISO),and implicit fast fluid dynamics(IFFD)in OpenFOAM for simulating wind flow around buildings.The effects of calculation parameters,including grid resolution,discrete-time step,and calculation time for these methods are analyzed.The results of the simulations are compared with wind tunnel tests.It is found that IFFD and FFD have the fastest calculation speeds,but also have the largest discrepancies with test data.The PIMPLE algorithm has the highest accuracy,but with the slowest calculation speed.The calculation speeds of the FFD,SLPISO,and IFFD models are 6.3,3 and 13.3 times faster than the PIMPLE model,respectively.The calculation accuracy and speed of the SLPISO model are in between those of the IFFD,FFD and PIMPLE models.An appropriate algorithm for a project may be chosen based on the requirements of the project. 展开更多
关键词 fast fluid dynamics calculation parameters calculation accuracy calculation efficiency
原文传递
Structural determination of eleven new preschisanartane-type schinortriterpenoids from two Schisandra species and structural revision of preschisanartanin J using NMR computation method
12
作者 HU Kun LI Xing-Ren +2 位作者 TANG Jian-Wei Li Xiao-Nian PUNO Pema-Tenzin 《Chinese Journal of Natural Medicines》 SCIE CAS CSCD 2019年第12期970-981,共12页
Nineteen preschisanartane-type schinortriterpenoids(SNTs),among which eleven ones were previously undescribed,were isolated from two Schisandra species,S.sphaerandra and S.rubriflora.Their structures were determined u... Nineteen preschisanartane-type schinortriterpenoids(SNTs),among which eleven ones were previously undescribed,were isolated from two Schisandra species,S.sphaerandra and S.rubriflora.Their structures were determined using 1 D and 2 D NMR spectroscopic analyses,NMR data comparison,quantum chemical calculation of NMR parameters,electronic circular dichroism(ECD),X-ray single crystal diffraction,and chemical derivation.Furthermore,structural re-examination of a few previously reported preschisanartane-type SNTs led to the structural revision of preschisanartanin J.Besides,it is suggested that the reported structures of arisanlactone D and schilancidilactone W should be re-checked.Finally,a few isolated SNTs were found to possess neurite outgrowthpromoting activities,and protective activities against neural injuries. 展开更多
关键词 Schisandra sphaerandra Schisandra rubriflora Preschisanartane-type schinortriterpenoids Structural revision Quantum chemical calculation of NMR parameters
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部