Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 336

年份

2023 30

2022 29

2021 20

2020 26

2019 15

2018 26

2017 21

2016 8

2015 28

2014 13

2013 10

2012 9

2011 11

2010 14

2009 9

2008 15

2007 19

2006 5

2005 2

2004 3

展开︾

关键词

农业面源污染 2

大气污染 2

1)幂模型 1

2R-1C模型；嵌入式系统；参数估计；非迭代方法；二次型 1

3D细胞容器 1

Beclin-1 1

GIS 1

GM(1 1

MOF基催化剂 1

PP 1

SARS-CoV-2干扰 1

SIMPLEC算法 1

SPSS 1

WPC 1

circRNA 1

square-twist折纸 1

三点弯曲梁 1

三酰甘油 1

上行非正交多址；Generalized Welch界等式；多级接收功率；序列分组 1

展开︾

检索范围：

排序：展示方式：

extractive heterogeneous-azeotropic distillation and hydrophilic pervaporation for enhanced separation of non-ideal

Eniko Haaz, Botond Szilagyi, Daniel Fozer, Andras Jozsef Toth

《化学科学与工程前沿（英文）》 2020年第14卷第5期页码 913-927 doi: 10.1007/s11705-019-1877-1

摘要： The separation of non-ideal mixtures using distillation can be an extremely complex process and there continues to be a need to further improve these techniques. A new method which combines extractive heterogeneous-azeotropic distillation (EHAD) and hydrophilic pervaporation (HPV) for the separation of non-ideal ternary mixtures is demonstrated. This improved distillation method combines the benefits of heterogeneous-azeotropic and extractive distillations in one column but no added materials are needed as is usually the case with pervaporation. The separation of water-methanol-ethyl acetate and water-methanol-isopropyl acetate mixtures were investigated to demonstrate the accuracy of the combined EHAD/HPV technique. There is not currently an established treatment strategy for the separation of the second mixtures in the literature. These separation processes were rigorously modelled and optimized using a professional flowsheet. The objective functions were total cost and energy consumption and heat integration was also investigated. The verification of the process modelling was carried out using laboratory-scale measurements. Extractive heterogeneous-distillation combined with methanol dehydration was found to be more efficient than conventional distillation for the separation of these highly non-ideal mixtures.

关键词： hydrophilic pervaporation non-ideal mixture modelling extractive heterogeneous-azeotropic distillation heat integration

HTML PDF 收藏

Capacity analysis for cognitive heterogeneous networks with ideal/non-ideal sensing

Tao HUANG, Ying-lei TENG, Meng-ting LIU, Jiang LIU

《信息与电子工程前沿（英文）》 2015年第16卷第1期页码 1-11 doi: 10.1631/FITEE.1400129

摘要： Due to irregular deployment of small base stations (SBSs), the interference in cognitive heterogeneous networks (CHNs) becomes even more complex; in particular, the uncertainty of spectrum mobility aggravates the interference context. In this case, how to analyze system capacity to obtain a closed-form expression becomes a crucial problem. In this paper we employ stochastic methods to formulate the capacity of CHNs and achieve a closed-form expression. By using discrete-time Markov chains (DTMCs), the spectrum mobility with respect to the arrival and departure of macro base station (MBS) users is modeled. Then an integral method is proposed to derive the interference based on stochastic geometry (SG). Also, the effect of sensing accuracy on network capacity is discussed by concerning false-alarm and miss-detection events. Simulation results are illustrated to show that the proposed capacity analysis method for CHNs can approximate the conventional sum methods without rigorous requirement for channel station information (CSI). Therefore, it turns out to be a feasible and efficient way to capture the network capacity in CHNs.

关键词： Cognitive heterogeneous networks Markov chain Stochastic geometry Homogeneous Poisson point process (HPPP)

HTML PDF 收藏

一种针对非理想电源对水下恒流缆系统影响的分析方法 Personal View

Yu-jia ZANG, Yan-hu CHEN, Can-jun YANG, De-jun LI, Ze-jian CHEN, Gul MUHAMMAD

《信息与电子工程前沿（英文）》 2020年第21卷第4期页码 604-614 doi: 10.1631/FITEE.1800737

摘要：在过去，非理想恒流电源对恒流海洋观测系统的影响是一个被忽视的问题。事实上，恒流电源的动态特性对整个系统，特别是对负载变化时的动态响应有很大影响。因此，在实际工程应用中有必要对非理想恒流电源进行校核。本文介绍一种校核非理想恒流电源是否满足水下恒流缆系统动态特性的方法，并提出一种描述非理想恒流电源的等效模型。通过该模型，可规范恒流电源动态特性的技术指标。首先，构造恒流海洋观测网络系统中单节点的最小系统，并推导其数学模型。其次，针对系统可能存在的掉电问题，分析对系统的输出电压响应，并验证所提模型。最后，采用所提模型校核实际应用中的恒流电源动态特性。

关键词：非理想恒流电源；恒流输入；海洋观测系统

HTML PDF 收藏

非理想条件下空分复用研究与应用 None

Ji-ying XIANG

《信息与电子工程前沿（英文）》 2018年第19卷第3期页码 357-366 doi: 10.1631/FITEE.1700827

摘要：对空分复用技术中的非理想因素进行了理论分析，并探讨了在上述非理想工程条件下空分复用的应用，给出了实测数据。对于信道条件非理想的场景，即多通道之间相关性高，条件数大，导致高层间干扰，需要通过最优化用户匹配和降维达到最优容量。对于信道测量非理想的场景，深入分析了反馈式和非反馈式的优劣，并指出即使信道不满足互易性条件，非反馈式也是优选方法。针对上述问题，进行了理论分析和外场实测。

关键词：第五代移动通讯；条件数；信道互易性；信道反馈测量模式；信道非反馈式测量模式

HTML PDF 收藏

Performance monitoring of non-gaussian chemical processes with modes-switching using globality-locality

Xin Peng, Yang Tang, Wenli Du, Feng Qian

《化学科学与工程前沿（英文）》 2017年第11卷第3期页码 429-439 doi: 10.1007/s11705-017-1675-6

摘要： In this paper, we propose a novel performance monitoring and fault detection method, which is based on modified structure analysis and globality and locality preserving (MSAGL) projection, for non-Gaussian processes with multiple operation conditions. By using locality preserving projection to analyze the embedding geometrical manifold and extracting the non-Gaussian features by independent component analysis, MSAGL preserves both the global and local structures of the data simultaneously. Furthermore, the tradeoff parameter of MSAGL is tuned adaptively in order to find the projection direction optimal for revealing the hidden structural information. The validity and effectiveness of this approach are illustrated by applying the proposed technique to the Tennessee Eastman process simulation under multiple operation conditions. The results demonstrate the advantages of the proposed method over conventional eigendecomposition-based monitoring methods.

关键词： non-Gaussian processes subspace projection independent component analysis locality preserving projection finite mixture model

HTML PDF 收藏

A study on quality evaluation for bituminous mixture using X-ray CT

Satoshi TANIGUCHI, Keiichiro OGAWA, Jun OTANI, Itaru NISHIZAKI

《结构与土木工程前沿（英文）》 2013年第7卷第2期页码 89-101 doi: 10.1007/s11709-013-0197-7

摘要： The objective of this paper is to propose a new quality evaluation method for asphalt concrete mixture using X-ray CT scanner. To achieve this aim, asphalt mixtures should be subjected to the X-ray CT scanning and its characteristics should be clarified. The approach employed in this study was as follows: 1) Coarse aggregate, fine aggregate, filler and bitumen were prepared; 2) dense-graded, coarse-graded and porous asphalt mixtures were made; 3) materials and mixtures were subjected to the X-ray CT scanning; 4) frequency of CT-value, threshold value, average slice CT-value, average segment CT-value were computed. In the material examination, CT-value of aggregate becomes smaller in the order of coarse aggregate, fine aggregate and filler and CT image of bitumen was nearly homogeneous. In the mixture examination, histograms of CT-value and four segmentation images made from CT images expressed the material and mixture characterization such as particle size and the difference in bitumen content and mixture type visibly and the bitumen content varies with the threshold values. In addition, the average segment CT-value without threshold value by dividing the fine aggregate from the coarse aggregate and average CT-value of the coarse aggregate, especially is highly correlated with average CT-value of the bitumen.

关键词： asphalt concrete mixture aggregate bitumen bitumen content quality evaluation X-ray CT

HTML PDF 收藏

基于刚性与非刚性Square-Twist胞元混合排布的折纸超材料设计与性能编程研究 Article

马家耀, 臧世玺, 陈焱, 由衷

《工程（英文）》 2022年第17卷第10期页码 82-92 doi: 10.1016/j.eng.2022.02.015

摘要：

相比由完全相同的胞元组成的超材料，由类型和性能均不同的胞元形成的超材料能够实现更大的力学性能调控范围。然而，目前关于此种超材料的几何设计和性能编程方法鲜有报道。本文通过将一系列不同类型的square-twist 折纸胞元进行空间排布，设计了一种新型折纸超材料。首先建立了超材料胞元的空间排布规则，保证了相邻胞元山-谷线折痕的几何匹配。进而进行了双轴拉伸实验，实验结果表明该新型超材料的变形能、最大刚度和初始峰值力均可由组成胞元的对应特性叠加得到，并且通过改变胞元类型、数量、几何参数、材料参数可以实现对超材料力学性能的大范围编程调控。此外，对具有固定胞元数量的超材料，通过改变山-谷线折痕的排布可以得到胞元类型与数量不同的一系列超材料，从而实现根据具体需求的力学性能重编程。本工作为可编程折纸超材料的设计提供了新的思路，在机械等工程领域具有广阔的应用前景。

关键词：折纸超材料超材料 square-twist折纸非周期性排布可编程性

HTML PDF 收藏

Fatigue of asphalt binder, mastic and mixture at low temperature

Dong WANG, Linbing WANG, Guoqing ZHOU

《结构与土木工程前沿（英文）》 2012年第6卷第2期页码 166-175 doi: 10.1007/s11709-012-0157-7

摘要： The fatigue damage is one of the most common distresses observed on the asphalt concrete pavement. To thoroughly understand the fatigue of asphalt concrete, the behaviors of the major components of asphalt concrete under cyclic loading are investigated respectively in this study. A new experiment method is developed to evaluate the performances of asphalt binder, mastic and fine aggregates mixture under cyclic tensile loading. The fatigue test results of asphalt binder show that the fatigue performance of asphalt binder is closely related with loading magnitude, temperature and loading rate. Mastic specimens with different filler content are tested and the results indicate that mastic specimens with 30% filler content show better fatigue resistance and higher permanent strain. The micro-structure analysis of mastic and mixture indicates that the fatigue resistance is closely related with the air void content of specimen. 3D digital specimens are developed to model the fatigue of the asphalt binder, mastic and mixture specimens based on the finite element method (FEM). Fatigue damage of asphalt concrete is simplified by a damage model. With proper selection of damage parameters, the simulation results agree well with laboratory test results and can be used as a basis for future fatigue research.

关键词： fatigue asphalt mixture asphalt binder mastic finite element method (FEM) X-ray tomography

HTML PDF 收藏

Impacts of climate change on optimal mixture design of blended concrete considering carbonation and chloride

Xiao-Yong WANG

《结构与土木工程前沿（英文）》 2020年第14卷第2期页码 473-486 doi: 10.1007/s11709-020-0608-5

摘要： Many studies on the mixture design of fly ash and slag ternary blended concrete have been conducted. However, these previous studies did not consider the effects of climate change, such as acceleration in the deterioration of durability, on mixture design. This study presents a procedure for the optimal mixture design of ternary blended concrete considering climate change and durability. First, the costs of CO emissions and material are calculated based on the concrete mixture and unit prices. Total cost is equal to the sum of material cost and CO emissions cost, and is set as the objective function of the optimization. Second, strength, slump, carbonation, and chloride ingress models are used to evaluate concrete properties. The effect of different climate change scenarios on carbonation and chloride ingress is considered. A genetic algorithm is used to find the optimal mixture considering various constraints. Third, illustrative examples are shown for mixture design of ternary blended concrete. The analysis results show that for ternary blended concrete exposed to an atmospheric environment, a rich mix is necessary to meet the challenge of climate change, and for ternary blended concrete exposed to a marine environment, the impact of climate change on mixture design is marginal.

关键词： ternary blended concrete climate change optimal mixture design carbonation chloride ingress

HTML PDF 收藏

Key stakeholders’ perspectives on the ideal partnering culture in construction projects

Gunnar J. LÜHR, Marian G. C. BOSCH-REKVELDT, Mladen RADUJKOVIC

《工程管理前沿（英文）》 2022年第9卷第2期页码 312-325 doi: 10.1007/s42524-020-0135-z

摘要： This paper examines the current state of project cultures in the German turnkey construction industry and the ideal project cultures in terms of partnering from the perspective of various key stakeholders (i.e., Investors, General Contractors, (Sub-)Contractors and Designers). To investigate the current and ideal cultures, data were gathered among the key stakeholders by means of a survey study with 72 respondents divided over 12 companies. The respondents rated the current and desired cultures by using the Organizational Culture Assessment Instrument, which belongs to the Competing Values Framework. The investigations show many similarities and differences between the stakeholder perspectives of the current and the idealized partnering project cultures. Mainly, the General Contractors desire more cooperative behaviors than the (Sub-)Contractors, and the Investors desire more pronounced flexibility than the General Contractors. All stakeholders desire a cultural change from highly competitive behaviors toward more cooperation. Changes in terms of clear procedures or more flexibility are only desired by the Designers. Defining both the current and an ideal partnering project culture enables academics and project managers to compare their actual project cultures to an ideal situation. With such an approach, academics and project managers could measure whether new tools or changes in resources affect their project cultures toward a partnering project culture.

关键词： project culture organisational culture partnering construction culture stakeholder perspectives German

HTML PDF 收藏

Simulation of abrasive flow machining process for 2D and 3D mixture models

Rupalika DASH,Kalipada MAITY

《机械工程前沿（英文）》 2015年第10卷第4期页码 424-432 doi: 10.1007/s11465-015-0366-6

摘要：

Improvement of surface finish and material removal has been quite a challenge in a finishing operation such as abrasive flow machining (AFM). Factors that affect the surface finish and material removal are media viscosity, extrusion pressure, piston velocity, and particle size in abrasive flow machining process. Performing experiments for all the parameters and accurately obtaining an optimized parameter in a short time are difficult to accomplish because the operation requires a precise finish. Computational fluid dynamics (CFD) simulation was employed to accurately determine optimum parameters. In the current work, a 2D model was designed, and the flow analysis, force calculation, and material removal prediction were performed and compared with the available experimental data. Another 3D model for a swaging die finishing using AFM was simulated at different viscosities of the media to study the effects on the controlling parameters. A CFD simulation was performed by using commercially available ANSYS FLUENT. Two phases were considered for the flow analysis, and multiphase mixture model was taken into account. The fluid was considered to be a Newtonian fluid and the flow laminar with no wall slip.

关键词： abrasive flow machining (AFM) computational fluid dynamics (CFD) modeling mixture model

HTML PDF 收藏

Simulation and analysis of grinding wheel based on Gaussian mixture model

Yulun CHI, Haolin LI

《机械工程前沿（英文）》 2012年第7卷第4期页码 427-432 doi: 10.1007/s11465-012-0350-3

摘要：

This article presents an application of numerical simulation technique for the generation and analysis of the grinding wheel surface topographies. The ZETA 20 imaging and metrology microscope is employed to measure the surface topographies. The Gaussian mixture model (GMM) is used to transform the measured non-Gaussian field to Gaussian fields, and the simulated topographies are generated. Some numerical examples are used to illustrate the viability of the method. It shows that the simulated grinding wheel topographies are similar with the measured and can be effective used to study the abrasive grains and grinding mechanism.

关键词： grinding wheel 3D topographies measurement Gaussian mixture model simulation

HTML PDF 收藏

Experimental study on capturing CO 2 greenhouse gas by mixture of ammonia and soil

Ying WU, Yifei WANG, Qinghua ZENG, Xin GONG, Zunhong YU,

《化学科学与工程前沿（英文）》 2009年第3卷第4期页码 468-473 doi: 10.1007/s11705-009-0257-7

摘要： This paper presents our study on removal of carbon dioxide (CO) greenhouse gas emissions by using the mixture of ammonia and soil. CO capture capacity using this method is 15% higher than the sum of ammonia chemical absorption capacity and soil physical adsorption capacity. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) are utilized to study this synergism. The removal effect is not only reflected in ammonia chemical reaction with CO. CO can also be absorbed by ammonium bicarbonate (NHHCO) crystal, which is the main component of the product, or wrapped in the pore of the crystal or packed in the gap between the crystal and the soil. CO can be permanently deposited as carbonated minerals in the subsoil earth layers.

关键词： electron microscopy product physical adsorption capacity spectroscopy

HTML PDF 收藏

Potassium carbonate-based ternary transition temperature mixture (deep eutectic analogues) for CO absorption

《环境科学与工程前沿（英文）》 2022年第16卷第7期 doi: 10.1007/s11783-021-1500-9

摘要：

•Addition of hindered amine increased thermal stability and viscosity of TTTM.

关键词： Ternary transition-temperature mixture FT-IR and thermal stability analysis Viscosity and correlation study Eyring’s absolute rate theory CO₂ solubility Density functional theory (DFT).

HTML PDF 收藏

Optimization of polyurethane-bonded thin overlay mixture designation for airport pavement

Xianrui LI; Ling XU; Qidi ZONG; Fu JIANG; Xinyao YU; Jun WANG; Feipeng XIAO

《结构与土木工程前沿（英文）》 2022年第16卷第8期页码 947-961 doi: 10.1007/s11709-022-0836-y

摘要： This research explored the application potential of PUM thin-overlay technology on airport rapid maintenance. The rapid curing process of polyurethane binder determines the limited time window for mixing and construction of polyurethane-bonded mixture (PUM), which presents significant difference with hot-mix asphalt (HMA) technology. Therefore, this research investigated and optimized the mix design of PUM for airport thin-overlay technology based on its thermosetting characteristics. First, limestone and basalt were comprehensively compared as an aggregate for PUM. Then, the effects of molding and curing conditions were studied in terms of mixing time, molding method, molding parameters and curing temperature. Statistical analysis was also conducted to evaluate the effects of gradation and particle size on PUM performances based on gray relational analysis (GRA), thus determining the key particle size to control PUM performances. Finally, the internal structural details of PUM were captured by X-ray CT scan test. The results demonstrated that it only took 12 hours to reach 75% of maximum strength at a curing temperature of 50 °C, indicating an efficient curing process and in turn allowing short traffic delay. The internal structural details of PUM presented distribution of tiny pores with few connective voids, guaranteeing waterproof property and high strength.

关键词： polyurethane-bonded mixture mix design optimization airport pavement thin overlay gray relational analysis