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High effective extraction of selected anthraquinones from Polygonum multiflorum using ionic liquids with ultrasonic assistance

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JOURNAL OF MOLECULAR LIQUIDS 2020年 314卷 113342-113342页

作者： Yuan, Ke Chen, Shiyu Chen, Xuemei Yao, Shun Wang, Xuejiao Song, Hang Zhu, Minghui Sichuan Univ Sch Chem Engn Dept Pharmaceut & Biol Engn Chengdu Peoples R China Chengdu Univ Tradit Chinese Med Sch Med & Life Sci Chengdu Peoples R China

In recent years, the toxicity of Polygonum multiflorum has been attributed to the anthraquinones. Therefore, the selective removal of anthraquinones will effectively improve the safety of Polygonum multiflorum. An ionic liquid-based extraction was firstly proposed to selectively extract anthraquinones from herbal powders with ultrasonic assistance. The relationship between selective extraction effect and important extraction conditions was investigated. Furthermore, the mechanism of the selective extraction was explored with the extraction kinetics and computation method. In addition, the recovery of ionic liquids was also investigated. Finally, high extraction efficiency (97.2%) and good selectivity (7.32) for anthraquinones from Polygonum multiflorum were achieved, and the ionic liquid was recovered with satisfactory recovery rate. It could provide a promising alternative method to isolate anthraquinones from other natural products. (C) 2020 Published by Elsevier B.V.

关键词： Selective extraction Ionic liquids Ultrasonic assistance High performance liquid chromatography Extraction kinetics computation method

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Effective thermal conductivity of sands estimated by Group method of Data Handling (GMDH) 10

Effective thermal conductivity of sands estimated by Group M...

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10th International Conference of Materials Processing and Characterization (ICMPC)

作者： Rizvi, Zarghaam Haider Husain, Syed Mohammad Baqir Haider, Hasan Wuttke, Frank Univ Kiel Geomech & Geotech Kiel Germany AMU Dept Comp Engn Aligarh Uttar Pradesh India KIET Dept Informat Technol Ghaziabad India

Effective thermal conductivity (ETC), the ability of soil mass to dissipate heat is of vital scientific and engineering interest for many subsurface energy storage and transportation processes. Many mathematical, empirical, semi-empirical and numerical methods are available to compute the ETC. However, these methods offer a specific solution to a considered soil type but are limited by boundary conditions and the time of computation in case of numerical methods which are more general in nature and could be applied to a wider range of soil types. Neural networks due to superior prediction capabilities have attracted much attention in the recent past. Here, in this paper we apply Group method of Data Handling (GMDH) from the class of neural network due to superior abilities in effectiveness of input parameter scaling and less computation time. Standard errors are calculated, and the model used to predict the ETC of two sands of different texture, mineralogical composition for full range of saturation. The model predicted experimental results are in good agreement for the pure quartz sand but for quartz-feldspar the model over predicts the ETC. The method is general and could be applied for wide range of geomaterial for effective parameter identification. © 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 10th International Conference of Materials Processing and Characterization.

关键词： computation method Effective thermal conductivity Group method of data handling Heat transport Neural network

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A simple and accurate calculation method for finite-conductivity fracture

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JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING 2018年 161卷 590-598页

作者： Luo, Wanjing Wang, Xiaodong Liu, Pengcheng Tian, Qing China Univ Geosci Beijing Sch Energy Resources Beijing 100083 Peoples R China

A simple, rapid and accurate method was developed to calculate the performance of a well intercepted by finite-conductivity fractures. A conductivity influence function ( CIF) in Laplace domain has been proposed to build bridges between the finite-conductivity fracture and the uniform-flux fracture. Results show that CIF increases as the dimensionless time before a critical point while it keeps constant after the critical point. A long time approximate solution of CIF in the real domain has been obtained to calculate the shape factor of a finite-conductivity fracture in a bounded rectangular reservoir. Results show that our method can be used for rapid computation of finite-conductivity fractures in different boundary conditions. The method can easily accurately analyze and evaluate the performances of a well intercepted by finite-conductivity fractures.

关键词： Finite-conductivity fracture Conductivity influence function Shape factor Fractured well computation method

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Partially coupled extended stochastic gradient algorithm for nonlinear multivariable output error moving average systems

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ENGINEERING computationS 2017年第2期34卷 629-647页

作者： Wang, Xuehai Ding, Feng Jiangnan Univ Sch Internet Things Engn Wuxi Peoples R China

Purpose-The purpose of this paper is to study the parameter estimation problem of nonlinear multivariable output error moving average systems. Design/methodology/approach-A partially coupled extended stochastic gradient algorithm is presented for nonlinear multivariable systems by using the decomposition technique. Findings-The proposed algorithm can realize the coupled computation of the parameter estimates between subsystems. Originality/value-This paper develops a coupled parameter estimation algorithm for nonlinear multivariable systems and directly estimates the system parameters without over-parameterization.

关键词： computation method Numerical algorithm Nonlinear system Parameter estimation Multivariable system

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Beam propagation and mode coupling study in a coupled waveguide structure by using scalar finite element method

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OPTIK 2016年第3期127卷 1237-1244页

作者： Raghuwanshi, Sanjeev Kumar Palodiya, Vikram Indian Sch Mines Dept Elect Engn Dhanbad 826004 Bihar India

Here we present the propagation of pulse in a coupled waveguide structures. Finite element method has been effectively applied to analyze the closely coupled waveguide structure. The mode coupling phenomena is well described in this paper. It is demonstrated that there are substantial amount of power exchange takes place between various modes. We excite the structure with original mode pattern which can be well approximated by slightly deviated Gaussian shape pulse. Then we apply the mode propagation concept to estimate the mode beating phenomena in coupled structure. The effect of waveguide separation is well demonstrated by using examples. We too derive the Fresnel equation and discuss a solution strategy in terms of the finite element method. We apply the transparent boundary condition to avoid the unwanted reflections from the artificial computation windows. (c) 2015 Elsevier GmbH. All rights reserved.

关键词： computation method Coupled waveguide structure Waveguide dispersion Mode propagation Transparent boundary condition

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A method for improved accuracy in three dimensions for determining wheel/rail contact points

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VEHICLE SYSTEM DYNAMICS 2015年第11期53卷 1620-1640页

作者： Yang, Xinwen Gu, Shaojie Zhou, Shunhua Zhou, Yu Lian, Songliang Tongji Univ Key Lab Rd & Traff Engn Minist Educ Shanghai 201804 Peoples R China

Searching for the contact points between wheels and rails is important because these points represent the points of exerted contact forces. In order to obtain an accurate contact point and an in-depth description of the wheel/rail contact behaviours on a curved track or in a turnout, a method with improved accuracy in three dimensions is proposed to determine the contact points and the contact patches between the wheel and the rail when considering the effect of the yaw angle and the roll angle on the motion of the wheel set. The proposed method, with no need of the curve fitting of the wheel and rail profiles, can accurately, directly, and comprehensively determine the contact interface distances between the wheel and the rail. The range iteration algorithm is used to improve the computation efficiency and reduce the calculation required. The present computation method is applied for the analysis of the contact of rails of CHINA (CHN) 75 kg/m and wheel sets of wearing type tread of China's freight cars. In addition, it can be proved that the results of the proposed method are consistent with that of Kalker's program CONTACT, and the maximum deviation from the wheel/rail contact patch area of this two methods is approximately 5%. The proposed method, can also be used to investigate static wheel/rail contact. Some wheel/rail contact points and contact patch distributions are discussed and assessed, wheel and rail non-worn and worn profiles included.

关键词： computation method multi-point contact wheel/rail interaction iteration algorithm

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An elastic mechanics model and computation method for geotechnical material

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Engineering Sciences 2010年第3期8卷 49-56页

作者： Zheng Yingren Gao Hong Zheng Lushi Department of Civil Engineering Logistical Engineering University Chongqing 400041 China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China

Internal friction characteristic is one of the basic properties of geotechnical materials and it exists in mechanical elements all the time. However,until now internal friction is only considered in limit analysis and plastic mechanics but not included in elastic theory for rocks and soils. We consider that internal friction exists in both elastic state and plastic state of geotechnical materials,so the mechanical unit of friction material is constituted. Based on study results of soil tests,the paper also proposes that cohesion takes effect first and internal friction works gradually with the increment of deformation. By assuming that the friction coefficient is proportional to the strain,the internal friction is computed. At last,by imitating the linear elastic mechanics,the nonlinear elastic mechanics model of friction material is established,where the shear modulus G is not a constant. The new model and the traditional elastic model are used simultaneously to analyze an elastic foundation. The results indicate that the displacements computed by the new model are less than those from the traditional method,which agrees with the fact and shows that the mechanical units of friction material are suitable for geotechnical material.

关键词： geotechnical material elastic mechanics model computation method

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Vertical vibration of the vehicle model with higher degree of freedom

Vertical vibration of the vehicle model with higher degree o...

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6th Conference on Modelling of Mechanical and Mechatronic Systems (MMaMS)

作者： Soukup, J. Skocilas, J. Skocilasova, B. JE Purkyne Univ Usti Nad Labem Fac Prod Technol & Management Dept Machines & Mech Okraji 1001 Usti Nad Labem 40001 Czech Republic Czech Tech Univ Fac Mech Engn Dept Proc Engn Tech 4 Prague 16607 Czech Republic

ISBN: (纸本)9781510800717

New method of solution of the motion equation of the mechanical system with higher degree of freedom is applied on the investigation of the vertical vibration of the vehicle. Mechanical model is composed from three spatially elastically supported and bounded bodies. Model represents the chassis of railroad vehicle with elastic and dissipative elements. Proposed method enables to determine the vertical displacement of the arbitrary point of the system. (C) 2014 Published by Elsevier Ltd.

关键词： higher DOF vibration vehicle model computation method

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The Research of the computation method for the Ratio of Land Price to House Price

The Research of the Computation Method for the Ratio of Land...

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2nd International Conference on Information Management, Innovation Management and Industrial Engineering

作者： Zhou Ziming Wang Haobai Zhejiang Univ City Coll Sch Business Hangzhou 310003 Zhejiang Peoples R China

ISBN: (纸本)9780769538761

The ratio of land price to house price (LPHP-ratio) is an indicator commonly used to reflect the relationship between house price and land price. However, the precise computation method for the ratio has long remained unspecific, and the different results using different computation methods will exert different influence upon people's perception and judgment of the real relationship between house price and land price. Three different types of LPHP-ratios, namely Static-LPHP-ratio, Dynamic-LPHP-ratio and Internal-LPHP-ratio are proposed in this paper using different methods of computation. An empirical study on the real estate market in Hangzhou during the period 2003-2008 is reported and discussed in the following.

关键词： ratio of land price to house price (LPHP-ratio) Static-LPHP-ratio Dynamic-LPHP-ratio Internal-LPHP-ratio computation method

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Decomposition based least squares iterative estimation algorithm for output error moving average systems

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ENGINEERING computationS 2014年第4期31卷 709-725页

作者： Zhang, Wenge Jiangnan Univ Minist Educ Key Lab Adv Proc Control Light Ind Wuxi Peoples R China

Purpose - The purpose of this paper is to solve the heavy computational problem of parameter estimation algorithm. Design/methodology/approach - Presents a decomposition least squares based iterative identification algorithm. Findings - Can estimate the parameters for linear or pseudo-linear systems and have lower computational burden. Originality/value - This paper adopts a decomposition technique to solve engineering computation problems and offers a potential and efficient algorithm.

关键词： computation method Numerical algorithm

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