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Measurement and correlation of supercritical CO

Hiroshi MACHIDA, Ryosuke TAGUCHI, Yoshiyuki SATO, Louw J. FLOURUSSE, Cor J. PETERS, Richard L. SMITH

《化学科学与工程前沿(英文)》 2009年 第3卷 第1期   页码 12-19 doi: 10.1007/s11705-009-0151-3

摘要: Ionicliquids combined with supercritical fluid technology hold great promise as working solvents for developing compact processes. Ionic liquids, which are organic molten salts, typically have extremely low volatility and high functionality, but possess high viscosities, surface tensions and low diffusion coefficients, which can limit their applicability. CO , on the other hand, especially in its supercritical state, is a green solvent that can be used advantageously when combined with the ionic liquid to provide viscosity and surface tension reduction and to promote mass transfer. The solubility of CO in the ionic liquid is key to estimating the important physical properties that include partition coefficients, viscosities, densities, interfacial tensions, thermal conductivities and heat capacities needed in contactor design. In this work, we examine a subset of available high pressure pure component ionic liquid PVT data and high pressure CO - ionic liquid solubility data and report new correlations for CO -ionic liquid systems with equations of state that have some industrial applications including: (1) general, (2) fuel desulfurization, (3) CO capture, and (4) chiral separation. New measurements of solubility data for the CO and 1-butyl-3-methylimidazolium octyl sulfate, [bmim][OcSO ] system are reported and correlated. In the correlation of the CO ionic liquid phase behavior, the Peng-Robinson and the Sanchez-Lacombe equations of state were considered and are compared. It is shown that excellent correlation of CO solubility can be obtained with either equation and they share some common characteristics regarding interaction parameters. In the Sanchez-Lacombe equation, parameters that are derived from the supercritical region were found to be important for obtaining good correlation of the CO -ionic liquid solubility data.

关键词: compact processes     chiral ionic liquids     separations     thermodynamic properties     equations of state    

A review on membrane distillation in process engineering: design and exergy equations, materials and

《化学科学与工程前沿(英文)》 2022年 第16卷 第5期   页码 592-613 doi: 10.1007/s11705-021-2105-3

摘要: One of the problems that most afflicts humanity is the lack of clean water. Water stress, which is the pressure on the quantity and quality of water resources, exists in many places throughout the World. Desalination represents a valid solution to the scarcity of fresh water and several technologies are already well applied and successful (such as reverse osmosis), producing about 100 million m3·d−1 of fresh water. Further advances in the field of desalination can be provided by innovative processes such as membrane distillation. The latter is of particular interest for the treatment of waste currents from conventional desalination processes (for example the retentate of reverse osmosis) as it allows to desalt highly concentrated currents as it is not limited by concentration polarization phenomena. New perspectives have enhanced research activities and allowed a deeper understanding of mass and heat transport phenomena, membrane wetting, polarization phenomena and have encouraged the use of materials particularly suitable for membrane distillation applications. This work summarizes recent developments in the field of membrane distillation, studies for module length optimization, commercial membrane modules developed, recent patents and advancement of membrane material.

关键词: membrane distillation     recent developments     heat and mass transfer     wetting     membrane material    

Parametric equations for notch stress concentration factors of rib–deck welds under bending loading

《结构与土木工程前沿(英文)》 2021年 第15卷 第3期   页码 595-608 doi: 10.1007/s11709-021-0720-1

摘要: The effective notch stress approach for evaluating the fatigue strength of rib–deck welds requires notch stress concentration factors obtained from complex finite element analysis. To improve the efficiency of the approach, the notch stress concentration factors for three typical fatigue-cracking modes (i.e., root–toe, root–deck, and toe–deck cracking modes) were thoroughly investigated in this study. First, we developed a model for investigating the effective notch stress in rib–deck welds. Then, we performed a parametric analysis to investigate the effects of multiple geometric parameters of a rib–deck weld on the notch stress concentration factors. On this basis, the multiple linear stepwise regression analysis was performed to obtain the optimal regression functions for predicting the notch stress concentration factors. Finally, we employed the proposed formulas in a case study. The notch stress concentration factors estimated from the developed formulas show agree well with the finite element analysis results. The results of the case study demonstrate the feasibility and reliability of the proposed formulas. It also shows that the fatigue design curve of FAT225 seems to be conservative for evaluating the fatigue strength of rib–deck welds.

关键词: notch stress concentration factor     rib–deck weld     parametric analysis     regression analysis     parametric equation    

Solving nonlinear differential equations of Vanderpol, Rayleigh and Duffing by AGM

null

《机械工程前沿(英文)》 2014年 第9卷 第2期   页码 177-190 doi: 10.1007/s11465-014-0288-8

摘要:

In the present paper, three complicated nonlinear differential equations in the field of vibration, which are Vanderpol, Rayleigh and Duffing equations, have been analyzed and solved completely by Algebraic Method (AGM). Investigating this kind of equations is a very hard task to do and the obtained solution is not accurate and reliable. This issue will be emerged after comparing the achieved solutions by numerical method (Runge-Kutte 4th). Based on the comparisons which have been made between the gained solutions by AGM and numerical method, it is possible to indicate that AGM can be successfully applied for various differential equations particularly for difficult ones. The results reveal that this method is not only very effective and simple, but also reliable, and can be applied for other complicated nonlinear problems.

关键词: Algebraic Method (AGM)     Angular Frequency     Vanderpol     Rayleigh     Duffing    

Proca电磁理论的若干问题

黄志洵

《中国工程科学》 2005年 第7卷 第3期   页码 6-12

摘要:

2004年6月,位于西非Oklo的美国Los Alamos实验室的核工业反应堆对实验数据做再分析后得出结论说,近20亿年内精细结构常数减小了4.5×10-8。常数不常,意味着光速有很小的变化。这是最新的与狭义相对论不符的实验报告。另一方面,光子如有质量,Maxwell方程组将被Proca方程组所取代,而磁矢位(势)A将成为可观测量。而过去和现在都有许多方法测量光子的质量。

文章的主要目的是在Proca理论框架内研究电磁波波速,发现即使在自由空间(真空)条件下也会出现超光速传播;同时又对波导与Proca波的截止现象做了比较,给出了相应的结果。

关键词: 狭义相对论     Maxwell方程组     Proca方程组     电磁波波速     光子的静止质量    

真实空气中TNT装药爆炸近区冲击波传播特性研究

周丰峻,郑磊,孙云厚,张鏖,夏明

《中国工程科学》 2017年 第19卷 第6期   页码 18-26 doi: 10.15302/J-SSCAE-2017.06.004

摘要:

本文基于点源爆炸理论,建立了面源、线源和点源TNT装药强爆炸解,填补了面源与线源强爆炸解的空白;采用真实空气状态方程进行分析计算,研究了真实空气条件下球形TNT装药爆炸近区冲击波的传播特性。通过算例分析,计算结果与已有文献资料数据吻合较好。本文的研究成果对爆炸力学和防护工程研究起到了重要的参考作用。

关键词: TNT装药爆炸     真实空气状态方程     面源装药     线源装药     点源装药     抗爆防护    

Significant progress in solution of nonlinear equations at displacement of structure and heat transfer

M. R. AKBARI,D. D. GANJI,M. NIMAFAR,A. R. AHMADI

《机械工程前沿(英文)》 2014年 第9卷 第4期   页码 390-401 doi: 10.1007/s11465-014-0313-y

摘要:

In this paper, we aim to promote the capability of solving two complicated nonlinear differential equations: 1) Static analysis of the structure with variable cross section areas and materials with slope-deflection method; 2) the problem of one dimensional heat transfer with a logarithmic various surface A(x) and a logarithmic various heat generation G(x) with a simple and innovative approach entitled “Akbari-Ganji’s method” (AGM). Comparisons are made between AGM and numerical method, the results of which reveal that this method is very effective and simple and can be applied for other nonlinear problems. It is significant that there are some valuable advantages in this method and also most of the differential equations sets can be answered in this manner while in other methods there is no guarantee to obtain the good results up to now. Brief excellences of this method compared to other approaches are as follows: 1) Differential equations can be solved directly by this method; 2) without any dimensionless procedure, equation(s) can be solved; 3) it is not necessary to convert variables into new ones. According to the aforementioned assertions which are proved in this case study, the process of solving nonlinear equation(s) is very easy and convenient in comparison to other methods.

关键词: AGM     extended surface     heat transfer     slope-deflection method    

Advances in tissue state recognition in spinal surgery: a review

Hao Qu, Yu Zhao

《医学前沿(英文)》 2021年 第15卷 第4期   页码 575-584 doi: 10.1007/s11684-020-0816-3

摘要: Spinal disease is an important cause of cervical discomfort, low back pain, radiating pain in the limbs, and neurogenic intermittent claudication, and its incidence is increasing annually. From the etiological viewpoint, these symptoms are directly caused by the compression of the spinal cord, nerve roots, and blood vessels and are most effectively treated with surgery. Spinal surgeries are primarily performed using two different techniques: spinal canal decompression and internal fixation. In the past, tactile sensation was the primary method used by surgeons to understand the state of the tissue within the operating area. However, this method has several disadvantages because of its subjectivity. Therefore, it has become the focus of spinal surgery research so as to strengthen the objectivity of tissue state recognition, improve the accuracy of safe area location, and avoid surgical injury to tissues. Aside from traditional imaging methods, surgical sensing techniques based on force, bioelectrical impedance, and other methods have been gradually developed and tested in the clinical setting. This article reviews the progress of different tissue state recognition methods in spinal surgery and summarizes their advantages and disadvantages.

关键词: spinal surgery     tissue state recognition     image     force sensing     bioelectrical impedance    

Effectiveness of state incentives for promoting wind energy: A panel data examination

Deepak SANGROYA,Jogendra NAYAK

《能源前沿(英文)》 2015年 第9卷 第3期   页码 247-258 doi: 10.1007/s11708-015-0364-8

摘要: Over the last decade, India has started to concentrate earnestly on renewable energy. The Indian government, as well as different state governments, are adopting policy instruments such as feed in tariff, captive consumption, renewable purchase obligation and generation based incentive etc. aimed at renewable energy development. This paper evaluates the effectiveness of state level incentives for the development of wind energy in India. Fixed effect panel data modelling technique of econometric analysis is used to analyse the data of 26 Indian states in 11 years. The results show that feed in tariff and captive consumption are the significant predictors of wind energy development. However, renewable purchase obligation does not affect wind energy significantly.

关键词: India     wind energy development     state incentives     econometric analysis     panel data    

Scrutiny of non-linear differential equations Euler-Bernoulli beam with large rotational deviation by

M. R. AKBARI,M. NIMAFAR,D. D. GANJI,M. M. AKBARZADE

《机械工程前沿(英文)》 2014年 第9卷 第4期   页码 402-408 doi: 10.1007/s11465-014-0316-8

摘要:

The kinematic assumptions upon which the Euler-Bernoulli beam theory is founded allow it to be extended to more advanced analysis. Simple superposition allows for three-dimensional transverse loading. Using alternative constitutive equations can allow for viscoelastic or plastic beam deformation. Euler-Bernoulli beam theory can also be extended to the analysis of curved beams, beam buckling, composite beams and geometrically nonlinear beam deflection. In this study, solving the nonlinear differential equation governing the calculation of the large rotation deviation of the beam (or column) has been discussed. Previously to calculate the rotational deviation of the beam, the assumption is made that the angular deviation of the beam is small. By considering the small slope in the linearization of the governing differential equation, the solving is easy. The result of this simplification in some cases will lead to an excessive error. In this paper nonlinear differential equations governing on this system are solved analytically by Akbari-Ganji’s method (AGM). Moreover, in AGM by solving a set of algebraic equations, complicated nonlinear equations can easily be solved and without any mathematical operations such as integration solving. The solution of the problem can be obtained very simply and easily. Furthermore, to enhance the accuracy of the results, the Taylor expansion is not needed in most cases via AGM manner. Also, comparisons are made between AGM and numerical method (Runge-Kutta 4th). The results reveal that this method is very effective and simple, and can be applied for other nonlinear problems.

关键词: AGM     critical load of columns     large deformations of beam     nonlinear differential equation    

稳定线性热分层环境下火灾烟气羽流积分解及实验分析

方俊,疏学明,袁宏永,郑昕

《中国工程科学》 2004年 第6卷 第1期   页码 37-43

摘要:

对稳定线性热分层环境下湍浮力羽流无量纲积分方程首次采用数值解法进行求解,得出浮力通量、动量通量等参量在轴线上的变化规律以及羽流中性浮力点的高度和羽流最大上升高度。2种不同尺度空间及不同烟气羽流出口条件的实验表明,实际火灾烟气羽流最大上升高度与理论计算结果及文献经验公式相符,从而表明积分模型数值解的有效性,并为高大空间火灾烟气输运规律研究及探测技术发展提供了理论及实验依据。

关键词: 稳定线性热分层环境     火灾烟气羽流     积分解     实验分析    

Digital image correlation-based structural state detection through deep learning

《结构与土木工程前沿(英文)》 2022年 第16卷 第1期   页码 45-56 doi: 10.1007/s11709-021-0777-x

摘要: This paper presents a new approach for automatical classification of structural state through deep learning. In this work, a Convolutional Neural Network (CNN) was designed to fuse both the feature extraction and classification blocks into an intelligent and compact learning system and detect the structural state of a steel frame; the input was a series of vibration signals, and the output was a structural state. The digital image correlation (DIC) technology was utilized to collect vibration information of an actual steel frame, and subsequently, the raw signals, without further pre-processing, were directly utilized as the CNN samples. The results show that CNN can achieve 99% classification accuracy for the research model. Besides, compared with the backpropagation neural network (BPNN), the CNN had an accuracy similar to that of the BPNN, but it only consumes 19% of the training time. The outputs of the convolution and pooling layers were visually displayed and discussed as well. It is demonstrated that: 1) the CNN can extract the structural state information from the vibration signals and classify them; 2) the detection and computational performance of the CNN for the incomplete data are better than that of the BPNN; 3) the CNN has better anti-noise ability.

关键词: structural state detection     deep learning     digital image correlation     vibration signal     steel frame    

Biological pretreatment of corn stover by solid state fermentation of

Jian ZHANG, Xin REN, Wenqun CHEN, Jie BAO

《化学科学与工程前沿(英文)》 2012年 第6卷 第2期   页码 146-151 doi: 10.1007/s11705-012-1220-6

摘要: Biological pretreatment is a promising way to overcome the biorecalcitrance of cleaving the supermolecular structure of lignocellulose by lignin degrading enzymes from microorganisms. Solid state fermentation of corn stover with the white-rot fungus was carried out and the efficiency of this pretreatment was evaluated. The enzymatic hydrolysis yield reached a maximum when the corn stover was biologically pretreated for nine days, and the hydrolysis yield decreased sharply if the solid state fermentation was carried out for more than nine days. A possible explanation for this sharp decrease is that not only the lignin degrading enzymes (LiP and MnP) were secreted, but also other metabolites, which were toxic or fatal to the hydrolysis enzymes resulting in the lower hydrolysis yield were generated during the prolonged period of biopretreatment. These results are useful to help determine the optimal timing and to understand the lignin structure and degradation mechanism in biological pretreatment processes.

关键词: biological pretreatment     Phanerochaete chrysosporium     solid state fermentation     biorecalcitrance     hydrolysis yield    

数据驱动的随机微分方程辨识 Article

王亚森, 方华臻, 金骏阳, 马贵君, 何心, 代星, 岳作功, 程骋, 张海涛, 浦栋麟, 伍冬睿, 袁烨, Jorge Gonçalves, Jürgen Kurths, 丁汉

《工程(英文)》 2022年 第17卷 第10期   页码 244-252 doi: 10.1016/j.eng.2022.02.007

摘要:

随机微分方程(SDE)是一种广泛用于描述受不同来源噪声干扰的复杂过程或现象的数学模型。由于数据固有的强随机性和系统动力学的复杂性,控制系统的SDE的辨识通常是一个挑战。辨识SDE的现有参数化方法的实用性通常受到数据资源不足的限制。本研究提出了一种通过稀疏贝叶斯学习(SBL)技术从候选基函数空间中搜索简洁但物理必需的表示形式来辨识SDE的新框架。更重要的是,利用SBL的解析可处理性开发了一种可以通过少量数据来高效地构建辨识SDE的线性回归模型的方法。本文利用股票和石油价格、轴承变化和风速的真实数据,以及包括广义维纳(Wiener)过程和朗之万方程在内的著名随机动力系统的仿真数据,验证了所提出框架的有效性。该框架旨在帮助专家从自然科学、经济学和工程领域的随机现象中提取随机数学模型,用于分析、预测和决策。

关键词: 数据驱动方法     系统辨识     稀疏贝叶斯学习     随机微分方程     随机现象    

Development of a constitutive model for rockfills and similar granular materials based on the disturbed state

Mehdi VEISKARAMI, Ali GHORBANI, Mohammadreza ALAVIPOUR

《结构与土木工程前沿(英文)》 2012年 第6卷 第4期   页码 365-378 doi: 10.1007/s11709-012-0178-2

摘要: Behavior of rockfills was investigated experimentally and theoretically. A series of standard triaxial compression tests were carried out on a quarried rockfill material at different stress levels. It was found that both the stress level and the shear stress ratio, like most of granular materials, controls the behavior of rockfill materials. At lower shear stress ratios the behavior is much more similar to a nonlinear elastic solid. When the shear stress goes further, the stress-strain curve shows an elasto-plastic behavior which suggests using the disturbed state concept to develop a constitutive model to predict the stress-strain behavior. The presented constitutive model complies reasonably with the experimental data.

关键词: constitutive model     granular material     rockfill     plasticity     disturbed state concept     stress level    

标题 作者 时间 类型 操作

Measurement and correlation of supercritical CO

Hiroshi MACHIDA, Ryosuke TAGUCHI, Yoshiyuki SATO, Louw J. FLOURUSSE, Cor J. PETERS, Richard L. SMITH

期刊论文

A review on membrane distillation in process engineering: design and exergy equations, materials and

期刊论文

Parametric equations for notch stress concentration factors of rib–deck welds under bending loading

期刊论文

Solving nonlinear differential equations of Vanderpol, Rayleigh and Duffing by AGM

null

期刊论文

Proca电磁理论的若干问题

黄志洵

期刊论文

真实空气中TNT装药爆炸近区冲击波传播特性研究

周丰峻,郑磊,孙云厚,张鏖,夏明

期刊论文

Significant progress in solution of nonlinear equations at displacement of structure and heat transfer

M. R. AKBARI,D. D. GANJI,M. NIMAFAR,A. R. AHMADI

期刊论文

Advances in tissue state recognition in spinal surgery: a review

Hao Qu, Yu Zhao

期刊论文

Effectiveness of state incentives for promoting wind energy: A panel data examination

Deepak SANGROYA,Jogendra NAYAK

期刊论文

Scrutiny of non-linear differential equations Euler-Bernoulli beam with large rotational deviation by

M. R. AKBARI,M. NIMAFAR,D. D. GANJI,M. M. AKBARZADE

期刊论文

稳定线性热分层环境下火灾烟气羽流积分解及实验分析

方俊,疏学明,袁宏永,郑昕

期刊论文

Digital image correlation-based structural state detection through deep learning

期刊论文

Biological pretreatment of corn stover by solid state fermentation of

Jian ZHANG, Xin REN, Wenqun CHEN, Jie BAO

期刊论文

数据驱动的随机微分方程辨识

王亚森, 方华臻, 金骏阳, 马贵君, 何心, 代星, 岳作功, 程骋, 张海涛, 浦栋麟, 伍冬睿, 袁烨, Jorge Gonçalves, Jürgen Kurths, 丁汉

期刊论文

Development of a constitutive model for rockfills and similar granular materials based on the disturbed state

Mehdi VEISKARAMI, Ali GHORBANI, Mohammadreza ALAVIPOUR

期刊论文