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关键词

Colebrook隐式方程 1

三维构造 1

仅有输出响应;系统模态参数识别;空间曲线拟合;频谱混叠 1

原位统计分布分析表征技术 1

可接受的风险评价 1

地质曲面 1

增材制造 1

多源地质数据 1

富水性 1

川藏高速公路 1

广域电磁法 1

形状优化 1

成本-安全均衡优化 1

拓扑优化 1

拟流场法 1

指数模型;参数估计;线性最小二乘法;非线性拟合 1

插值—逼近拟合 1

摩擦因数 1

显式方程 1

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Analysis of statistical thermodynamic model for binary protein adsorption equilibria on cation exchange adsorbent

ZHOU Xiaopeng, SU Xueli, SUN Yan

《化学科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 103-112 doi: 10.1007/s11705-007-0020-x

摘要: A study of nonlinear competitive adsorption equilibria of proteins is of fundamental importance in understanding the behavior of preparative chromatographic separation. This work describes the nonlinear binary protein adsorption equilibria on ion exchangers by the statistical thermodynamic (ST) model. The single-component and binary protein adsorption isotherms of bovine hemoglobin (Hb) and bovine serum albumin (BSA) on SP Sepharose FF were determined by batch adsorption experiments in 0.05 mol/L sodium acetate buffer at three pH values (4.5, 5.0 and 5.5) and three NaCl concentrations (0.05, 0.10 and 0.15 mol/L) at pH 5.0. The ST model was found to depict the effects of pH and ionic strength on the single-component equilibria well, with model parameters depending on the pH and ionic strength. Moreover, the ST model gave acceptable fitting to the binary adsorption data with the fitted single-component model parameters, leading to the estimation of the binary ST model parameter. The effects of pH and ionic strength on the model parameters are reasonably interpreted by the electrostatic and thermodynamic theories. Results demonstrate the availability of the ST model for describing nonlinear competitive protein adsorption equilibria in the presence of two proteins.

关键词: fundamental importance     single-component equilibria     acceptable fitting     hemoglobin     chromatographic separation    

复杂地质曲面三维插值—逼近拟合构造方法

李明超,缪正建,刘菲,王刚

《中国工程科学》 2011年 第13卷 第12期   页码 103-107

摘要:

针对水利水电工程多源地质数据的特点,充分考虑了地质精度要求、曲面连续性和数据存储量等多方面的均衡,提出并实现了基于NURBS(non-uniform rational B-splines,非均匀有理样条曲线)技术的复杂地质曲面插值—逼近拟合构造方法。该方法对于工程关键区域集中且均匀分布的原始数据,采用NURBS蒙皮插值方法,使曲面严格通过这些数据点;对于周边区域分布离散的数据,采用NURBS逼近拟合方法,使曲面在给定精度下充分逼近原始数据;最后对整体曲面的地质结构合理性、几何性和精度进行检查分析和调整。实例表明,该方法所构造的地质曲面能满足地质工程师的实际需要,并能为进一步的三维地质建模提供基础。

关键词: 地质曲面     插值—逼近拟合     三维构造     多源地质数据    

Separation mechanism for double cylinder with shrink fitting system used for ceramics conveying rollers

Wenbin LI, Hiromasa SAKAI, Shota HARADA, Yasushi TAKASE, Nao-Aki NODA

《机械工程前沿(英文)》 2011年 第6卷 第3期   页码 277-286 doi: 10.1007/s11465-011-0234-y

摘要:

Steel conveying rollers used in hot rolling mills must be exchanged frequently at great cost because hot conveyed strips induce wear and deterioration on the surface of roller in short periods. In previous studies, new roller structure was considered which has a ceramics sleeve connected with two steel shafts at both ends by shrink fitting. Here, although the ceramics sleeve can be used for many years, the steel shafts sometimes have to be exchanged for maintenance and reconstruction under the corrosive atmosphere. Since the thermal expansion coefficient of steel is about five times larger than that of ceramics, it is necessary to investigate how to separate the shrink fitting system by heating outside of sleeve and cooling inside of the shaft. Although how to separate the real roller has been discussed in the previous study, the separation mechanism has not been clarified yet. Therefore, in this study, several types of more fundamental models are investigated to understand the separation mechanism of real roller by the application of the finite element method. The results may be useful for designs of new rollers.

关键词: contact     ceramics     thermal stress     heating     finite element method    

与地球同步:碳氮循环在保护地球宜居性中面临的挑战 Views & Comments

Robert Socolow

《工程(英文)》 2016年 第2卷 第1期   页码 21-22 doi: 10.1016/J.ENG.2016.01.012

Investigating peak stresses in fitting and repair patches of buried polyethylene gas pipes

Reza KHADEMI ZAHEDI, Pouyan ALIMOURI, Hooman KHADEMI ZAHEDI, Mohammad SHISHESAZ

《结构与土木工程前沿(英文)》 2020年 第14卷 第1期   页码 147-168 doi: 10.1007/s11709-019-0587-6

摘要: Nowadays, polyethylene composes a large number of natural gas distribution pipelines installed under the ground. The focus of the present contribution is two fold. One of the objectives is to investigate the applicability of polyethylene fittings in joining polyethylene gas pipes which are electrofused onto the pipe ends and buried under the ground, by estimating stress distribution using finite element method. The second objective is to study the effectiveness of polyethylene repair patches which are used to mend the defected pipelines by performing a finite element analysis to calculate peak stress values. Buried polyethylene pipelines in the natural gas industry, can be imposed by sever loadings including the soil-structure interaction, traffic load, soil’s column weight, internal pressure, and thermal loads resulting from daily and/or seasonal temperature changes. Additionally, due to the application of pipe joints, and repair patches local stresses superimposed on the aforementioned loading effects. The pipe is assumed to be made of PE80 resin and its jointing socket, and the repair patch is PE100 material. The computational analysis of stresses and the computer simulations are performed using ANSYS commercial software. According to the results, the peak stress values take place in the middle of the fitting and at its internal surface. The maximum stress values in fitting and pipe are below the allowable stresses which shows the proper use of introduced fitting is applicable even in hot climate areas of Ahvaz, Iran. Although the buried pipe is imposed to the maximum values of stresses, the PE100 socket is more sensitive to a temperature drop. Furthermore, all four studied patch arrangements show significant reinforcing effects on the defected section of the buried PE gas pipe to transfer applied loads. Meanwhile, the defected buried medium density polyethylene gas pipe and its saddle fused patch can resist the imposed mechanical and thermal loads of 22°C temperature increase. Moreover, increasing the saddle fusion patch length to 12 inches reduces the maximum stress values in the pipe, significantly.

关键词: Ansys software     polyethylene     buried pipelines     polyethylene joints     polyethylene patches     peak von Mises stress     soil-pipe interaction     temperature variation    

phosphorus-nitrogen based flame retardant and multi-walled carbon nanotubes for enhanced electrical conductivity and acceptable

Yong Luo, Yuhui Xie, Renjie Chen, Ruizhi Zheng, Hua Wu, Xinxin Sheng, Delong Xie, Yi Mei

《化学科学与工程前沿(英文)》 2021年 第15卷 第5期   页码 1332-1345 doi: 10.1007/s11705-021-2035-0

摘要: Design and exploitation of flame retardant polymers with high electrical conductivity are desired for polymer applications in electronics. Herein, a novel phosphorus-nitrogen intumescent flame retardant was synthesized from pentaerythritol octahydrogen tetraphosphate, phenylphosphonyl dichloride, and aniline. Low-density polyethylene was combined with the flame retardant and multi-walled carbon nanotubes to form a nanocomposite material via a ball-milling and hot-pressing method. The electrical conductivity, mechanical properties, thermal performance, and flame retardancy of the composites were investigated using a four-point probe instrument, universal tensile machine, thermogravimetric analysis, and cone calorimeter tests, respectively. It was found that the addition of multi-walled carbon nanotubes can significantly improve the electrical conductivity and mechanical properties of the low-density polyethylene composites. Furthermore, the combination of multi-walled carbon nanotubes and phosphorus–nitrogen flame retardant remarkably enhances the flame retardancy of matrixes with an observed decrease of the peak heat release rate and total heat release of 49.8% and 51.9%, respectively. This study provides a new and effective methodology to substantially enhance the electrical conductivity and flame retardancy of polymers with an attractive prospect for polymer applications in electrical equipment.

关键词: MWCNTs     PEPA     electrical conductivity     flame retardant     low density polyethylene    

Uncovering the evolution of tin use in the United States and its implications

《环境科学与工程前沿(英文)》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1406-6

摘要:

• US tin use decreases as the GDP value added by manufacturing sector increases.

关键词: Tin use     GDP     Curve fitting     Logistic model     Gompertz model    

广域电磁法和拟流场法精细探测技术——以井工一矿水害探测为例 Article

何继善

《工程(英文)》 2018年 第4卷 第5期   页码 667-675 doi: 10.1016/j.eng.2018.09.006

摘要:

井工一矿存在严重的老空区和水害。以往的单一勘探方法,如地震法、直流电法、音频大地电磁法、可控源音频大地电磁法、瞬变电磁法等,均未能探明老采空区范围和水害赋存情况。为了解决这个难题,联合采用广域电磁法和井- 地拟流场法的三位一体立体式探测技术,并利用三维反演电阻率资料精准获取富水区域和采空区的位置,确定了不同层位水的连通性,为井工一矿的安全生产提供了可靠的技术保障。结果合理、成效显著,释放了近4 km2 的可采面积。

关键词: 广域电磁法     拟流场法     采空区     富水性     精细探测    

New response surface model and its applications in aerodynamic optimization of axial compressor blade profile

LIU Xiaojia, NING Fangfei

《能源前沿(英文)》 2008年 第2卷 第4期   页码 541-549 doi: 10.1007/s11708-008-0077-3

摘要: A parametric method for the axial compressor 2D blade profiles is proposed in which the blade geometries are defined with the parameters commonly used for blade definition, which ensures that the geometric significance is clear and an unreasonable blade profile is not generated. Several illustrations are presented to show the fitting precision of the method. A novel response surface model is proposed which regards the objective distribution function in the vicinity of a sample as normal school, and then generates the response surface function in the whole design space by a linear combination of distribution functions of all the samples. Based on this model, a numerical aerodynamic optimization platform for the axial compressor 2D blade profiles is developed, by which aerodynamic optimization of two compressor blade profiles are presented.

关键词: definition     objective distribution     fitting precision     combination     numerical aerodynamic    

采用线性和非线性拟合方法进行指数模型参数估计 Article

Ping YANG,Chao-peng WU,Yi-lu GUO,Hong-bo LIU,Hui HUANG,Hang-zhou WANG,Shu-yue ZHAN,Bang-yi TAO,Quan-quan MU,Qiang WANG,Hong SONG

《信息与电子工程前沿(英文)》 2017年 第18卷 第3期   页码 434-444 doi: 10.1631/FITEE.1601683

摘要: 本文探讨了通过线性和非线性拟合方法估计指数模型中的未知参数。基于多元函数极值定理及泰勒级数展开,从理论上证明了:在实验测量数据中包含噪声的情况下,通过线性拟合方法所得到的参数估计值并不能保证指数模型的残差平方和达到最小。通过数值仿真对线性和非线性拟合方法的结果进行了对比,仿真结果显示:线性方法只能获得未知参数的次优估计,但非线性方法给出更准确的结果。利用水下图像和成像距离数据对水体光谱衰减系数进行了估计,结果证实非线性拟合方法能够对参数估计准确度有明显的提升。

关键词: 指数模型;参数估计;线性最小二乘法;非线性拟合    

仅用结构响应数据识别系统模态参数的方法研究

霍兵勇,易伟建

《中国工程科学》 2015年 第17卷 第1期   页码 151-160

摘要:

随着实验模态分析方法的广泛应用和不断发展,在工程应用中,研究者希望能减少限制条件,增加分析的可靠性。本文发展一种识别系统模态参数的新方法,本方法无需知道系统的输入信息且不用建立系统模型,仅通过对测试记录的响应信号进行频谱分析即可识别系统的模态参数,依据系统中各响应点的信号,先采用离散反卷积方法从各响应点信号中分离出谐波参数作为初步的识别结果,在此基础之上,结合频域空间曲线拟合的方法修正识别结果中受频谱混叠影响而偏差较大的谐波参数,再联合这些已提取的谐波参数得到系统的模态参数。通过对实际结构测试数据的分析,证明本方法只用输出数据识别的模态参数与模态分析软件用传递函数识别的结果一致。

关键词: 仅有输出响应;系统模态参数识别;空间曲线拟合;频谱混叠    

Aerodynamic impact of train-induced wind on a moving motor-van

Jiajun HE; Huoyue XIANG; Yongle LI; Bin HAN

《结构与土木工程前沿(英文)》 2022年 第16卷 第7期   页码 909-927 doi: 10.1007/s11709-022-0833-1

摘要: The newly-built single-level rail-cum-road bridge brings the issue of the aerodynamic impact of train-induced wind on road automobiles. This research introduced a validated computational fluid dynamics (CFD) model regarding this concern. Such an aerodynamic impact mechanism was explored; a relationship between the transverse distance between train and motor-van (hereinfafter referred to as van) and the aerodynamic effects on the van was explored to help the optimization of bridge decks, and the relationship between the automobile speed and aerodynamic variations of a van was fitted to help traffic control. The fitting results are accurate enough for further research. It is noted that the relative speed of the two automobiles is not the only factor that influences the aerodynamic variations of the van, even at a confirmed relative velocity, the aerodynamic variations of the van vary a lot as the velocity proportion changes, and the most unfavorable case shows an increase of over 40% on the aerodynamic variations compared to the standard case. The decay of the aerodynamic effects shows that not all the velocity terms would enhance the aerodynamic variations; the coupled velocity term constrains the variation amplitude of moments and decreases the total amplitude by 20%–40%.

关键词: rail-cum-road bridge     aerodynamic impact     train-induced wind     CFD     aerodynamic force     quantitative analysis     fitting    

一种将拓扑优化设计转化为增材制造结构的实现方法 Article

刘书田, 李取浩, 刘君欢, 陈文炯, 张永存

《工程(英文)》 2018年 第4卷 第2期   页码 277-285 doi: 10.1016/j.eng.2017.09.002

摘要:
拓扑优化是一种用于确定最佳结构构型以获得所需性能的功能强大的设计方法。它已被广泛用于工程领域,如航空航天和汽车行业,以提高所设计结构的性能。然而,拓扑优化和工程应用之间仍然存在着一些明显阻碍拓扑优化应用的空白。其中一个空白是如何将拓扑结果(尤其是那些使用变密度框架获得的拓扑结果)解释为参数化计算机辅助设计(CAD)模型,以为随后进行的形状优化和制造创造条件。本文提出了一种将拓扑优化结果解释为适用于增材制造的STL 模型和参数化CAD 模型的新方法。在这个方法中,我们将首先提取拓扑优化结果的骨架,以确保可以保持原有形状,并使用滤波手段来获得更加光滑的边界。经过这一过程后,拓扑优化结果边界的节点分布更密集,这将为后续的曲线拟合提供便利。该方法基于均匀B 样条曲线的曲率和曲率导数,提出了一种自适应的B 样条拟合方法,以获得满足误差要求的含最少控制点的参数化CAD 模型。通过一个案例研究对所提出的方法进行了详细的描述,并通过另外两个示例证明了所提出方法的有效性和鲁棒性。

关键词: 拓扑优化     增材制造     特征保持     自适应拟合     形状优化    

基于成本-安全均衡的川藏高速公路规划设计方法研究 Article

李成谦, 丁烈云, 钟波涛

《工程(英文)》 2019年 第5卷 第2期   页码 337-349 doi: 10.1016/j.eng.2018.12.008

摘要:

山区高速公路的规划设计是通过合规性检查来保障其运营安全的。然而,仅仅依赖于合规性检查会误导工程设计人员在实际操作中选取符合规范的且成本造价最低的方案作为最终的设计方案,而该方案的整体风险水平却是未知的,这将给项目运营带来巨大的安全隐患。本文提出了一种基于成本- 安全均衡的高速公路规划设计方法,该方法主要包括以下四个步骤:① 分别提取项目成本与安全的影响因素,以少量参数化的方式来表达高速公路的设计方案;② 建立风险因素与项目成本之间的预估方程式;③ 通过构造事故树模型,在众多设计参数中识别出风险因素;④ 将可接受风险分析理论引入交通安全评价中,提出了一种在可接受风险范围内求解具有成本效益的最优解的算法,以帮助管理者决策。该方法在位于海拔梯度大、山脉范围广的川藏高速公路工程项目中得到了应用和验证。实验结果表明,该方法显著提高了项目设计的安全性以及成本效益。

关键词: 高速公路规划设计     成本-安全均衡优化     可接受的风险评价     川藏高速公路    

计算管内湍动流体摩擦因数的显式新方程

王勇,阮奇

《中国工程科学》 2006年 第8卷 第6期   页码 83-88

摘要:

管内湍动流体摩擦因数是雷诺数和相对粗糙度的二元非线性函数,由Colebrook隐式方程计算摩擦因数要用迭代的方法求解,很不方便。为了得到形式简单、精度高的计算摩擦因数的显式方程,提出了二元非线性多项式智能拟合法。该法将二元非线性多项式转化成多元线性多项式并建立线性最小二乘法标准矩阵,用遗传算法结合矩阵法对多项式的项数、项型式项指数及项系数进行搜索得到最优的拟合函数式。用该法拟合了Colebrook方程解的数据,得到一个计算管内湍动流体摩擦因数的显式新方程。在雷诺数3.000≤Re≤108、相对粗糙度0≤e/d≤0.05的范围内,该方程计算结果与Colebrook方程的平均偏差为0.5%,最大偏差不超过1.8%,与实验数据偏差为2.3%。新方程具有形式简单、精度高、适用范围广的优点,且便于简化成光滑管或阻力平方区等情况下的计算摩擦因数的方程。

关键词: 湍动流动     摩擦因数     Colebrook隐式方程     遗传算法     智能拟合法     显式方程    

标题 作者 时间 类型 操作

Analysis of statistical thermodynamic model for binary protein adsorption equilibria on cation exchange adsorbent

ZHOU Xiaopeng, SU Xueli, SUN Yan

期刊论文

复杂地质曲面三维插值—逼近拟合构造方法

李明超,缪正建,刘菲,王刚

期刊论文

Separation mechanism for double cylinder with shrink fitting system used for ceramics conveying rollers

Wenbin LI, Hiromasa SAKAI, Shota HARADA, Yasushi TAKASE, Nao-Aki NODA

期刊论文

与地球同步:碳氮循环在保护地球宜居性中面临的挑战

Robert Socolow

期刊论文

Investigating peak stresses in fitting and repair patches of buried polyethylene gas pipes

Reza KHADEMI ZAHEDI, Pouyan ALIMOURI, Hooman KHADEMI ZAHEDI, Mohammad SHISHESAZ

期刊论文

phosphorus-nitrogen based flame retardant and multi-walled carbon nanotubes for enhanced electrical conductivity and acceptable

Yong Luo, Yuhui Xie, Renjie Chen, Ruizhi Zheng, Hua Wu, Xinxin Sheng, Delong Xie, Yi Mei

期刊论文

Uncovering the evolution of tin use in the United States and its implications

期刊论文

广域电磁法和拟流场法精细探测技术——以井工一矿水害探测为例

何继善

期刊论文

New response surface model and its applications in aerodynamic optimization of axial compressor blade profile

LIU Xiaojia, NING Fangfei

期刊论文

采用线性和非线性拟合方法进行指数模型参数估计

Ping YANG,Chao-peng WU,Yi-lu GUO,Hong-bo LIU,Hui HUANG,Hang-zhou WANG,Shu-yue ZHAN,Bang-yi TAO,Quan-quan MU,Qiang WANG,Hong SONG

期刊论文

仅用结构响应数据识别系统模态参数的方法研究

霍兵勇,易伟建

期刊论文

Aerodynamic impact of train-induced wind on a moving motor-van

Jiajun HE; Huoyue XIANG; Yongle LI; Bin HAN

期刊论文

一种将拓扑优化设计转化为增材制造结构的实现方法

刘书田, 李取浩, 刘君欢, 陈文炯, 张永存

期刊论文

基于成本-安全均衡的川藏高速公路规划设计方法研究

李成谦, 丁烈云, 钟波涛

期刊论文

计算管内湍动流体摩擦因数的显式新方程

王勇,阮奇

期刊论文