资源类型

期刊论文 637

会议视频 8

年份

2024 21

2023 68

2022 59

2021 41

2020 46

2019 47

2018 41

2017 43

2016 25

2015 28

2014 27

2013 26

2012 33

2011 12

2010 21

2009 13

2008 19

2007 20

2006 7

2005 9

展开 ︾

关键词

优化 18

多目标优化 9

优化设计 8

遗传算法 6

稳健设计 4

不确定性 3

动态规划 3

智能制造 3

能源 3

一阶分析法 2

五品联动 2

仿真优化 2

分布式优化 2

可靠性灵敏度 2

粒子群优化算法 2

贝叶斯优化 2

非线性 2

1)幂模型 1

AAC 1

展开 ︾

检索范围:

排序: 展示方式:

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    

Comprehensive performance analysis and optimization of 1,3-dimethylimidazolylium dimethylphosphate-waterbinary mixture for a single effect absorption refrigeration system

Gorakshnath TAKALKAR, Ahmad K. SLEITI

《能源前沿(英文)》 2022年 第16卷 第3期   页码 521-535 doi: 10.1007/s11708-021-0720-9

摘要: The energy and exergy analyses of the absorption refrigeration system (ARS) using H O-[mmim][DMP] mixture were investigated for a wide range of temperature. The equilibrium Dühring ( - - ) and enthalpy ( - - ) of mixture were assessed using the excess Gibbs free non-random two liquid (NRTL) model for a temperature range of 20°C to 140°C and from 0.1 to 0.9. The performance validation of the ARS cycle showed a better coefficient of performance (COP) of 0.834 for H O-[mmim][DMP] in comparison to NH -H O, H O-LiBr, H O-[emim][DMP], and H O-[emim][BF4]. Further, ARS performances with various operating temperatures of the absorber ( ), condenser ( ), generator ( ), and evaporator ( ) were simulated and optimized for a maximum COP and exergetic COP (ECOP). The effects of from 50°C to 150°C and and from 30°C to 50°C on COP and ECOP, the , , and circulation ratio (CR) of the ARS were evaluated and optimized for from 5°C to 15°C. The optimization revealed that needed to achieve a maximum COP which was more than that for a maximum ECOP. Therefore, this investigation provides criteria to select low grade heat source temperature. Most of the series flow of the cases of cooling water from the condenser to the absorber was found to be better than the absorber to the condenser.

关键词: ionic liquid driven absorption cycle     H2O-[mmim][DMP]     coefficient of performance (COP)     exergy analysis     thermodynamics mixture property    

模拟系统的混合测试优化方法

梅文娟,刘震,李欧行,苏元章,梅渝松,龙泳吉

《信息与电子工程前沿(英文)》 2023年 第24卷 第9期   页码 1302-1315 doi: 10.1631/FITEE.2200512

摘要: 由于模拟系统在现代电子设备中起着至关重要作用,模拟系统测试优化已引起学术界和工业界广泛关注。尽管现有方法能实现测试策略的自动生成,但是由于复杂结构和多变的运行环境的影响,模拟系统难以有效生成诊断策略。因此,受到系统拓扑结构和冗余信息的影响,生成的测试策略在实际应用中缺乏可行性。此外,现有方法假设相互独立的测试项需要串行执行,增加了测试时间消耗。为解决上述问题,本文提出用于生成混合测试策略的启发式规划方法。实验证明,相较现有方法生成的策略,启发式规划方法和卷展启发式规划方法生成的策略具有更少层数和更低测试代价。通过对混合“或”节点的自适应优化和测试代价更新,该方法能提供更可行的优化方案并降低测试产生的代价。因此,本文提出的方法具有更高的优化效率。

关键词: 故障诊断     启发式搜索     动态规划     测试优化    

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    

Experimental research on catalysts and their catalytic mechanism for hydrogen production by gasification of peanut shell in supercritical water

PEI Aixia, GUO Liejin, JIN Hui

《能源前沿(英文)》 2007年 第1卷 第4期   页码 451-456 doi: 10.1007/s11708-007-0066-2

摘要: Peanut shell, mixed with sodium carboxymethylcellulose, was gasified at a temperature of 450°C and a pressure range from 24 to 27 MPa with the presence of different catalysts, including KCO, ZnCl and Raney-Ni. The experimental results show that different catalysts have greatly different effects on the reaction. Gasification efficiency (GE), hydrogen gasification efficiency (GHE), carbon gasification efficiency (GCE), yield of hydrogen production ( ) and potential yield of hydrogen production () are applied to describe the catalytic efficiency. From the result of gaseous components, ZnCl has the highest hydrogen selectivity, KCO is lower, and Raney-Ni is the lowest, but Raney-Ni is the most favorable to gasify biomass among the three catalysts, and its , , reach 126.84%, 185.71%, 94.24%, respectively. As expected, hydrogen selectivity increased and CH reduced rapidly when the mixture of ZnCl and Raney-Ni is used under the same condition. The optimization mixture appeared when 0.2 g of ZnCl was added to 1 g of Raney-Ni, 43.56 g · kg of hydrogen pro duction was obtained. In addition, the catalytic mechanisms of different catalysts were analyzed, and the possible reaction pathway was brought forward, which helped to explain the experiment phenomena and results correctly.

关键词: presence     Raney-Ni     biomass     optimization mixture     possible reaction    

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    

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    

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    

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    

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    

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).    

A study on fatigue damage of asphalt mixture under different compaction using 3D-microstructural characteristics

Jing HU, Pengfei LIU, Bernhard STEINAUER

《结构与土木工程前沿(英文)》 2017年 第11卷 第3期   页码 329-337 doi: 10.1007/s11709-017-0407-9

摘要: The aim of this paper is investigating the microstructural characteristics of asphalt mixture under different compaction powers. In order to achieve this aim, a test track was built to provide asphalt mixture specimens and X-ray computed tomography (XCT) device was used to scan the internal structure. The aggregate particles and air-voids were extracted using Digital Image Processing (DIP), so the relationship between compaction and air-voids was determined at first, and then, the effect of aggregate particles on the morphology of air-voids can be evaluated, finally, fatigue properties of asphalt mixture with different air-void ratio were measured by indirect tensile fatigue test as well. The research results release the distribution of microstructures in asphalt pavement. 3D fractal dimension is an effective indicator to quantize the complexity of aggregate particles and air-voids; suffering the same compaction power, aggregates cause different constitutions of air-voids in asphalt mixture; investigation in this paper can present the essential relationship between microstructures and fatigue properties.

关键词: asphalt mixture     microstructure     morphology     digital image processing     fatigue damage    

strength of concrete containing micro-silica, nano-silica, and polypropylene fibers using extreme vertices mixture

Fatemeh ZAHIRI, Hamid ESKANDARI-NADDAF

《结构与土木工程前沿(英文)》 2019年 第13卷 第4期   页码 821-830 doi: 10.1007/s11709-019-0518-6

摘要: Many studies have evaluated the effects of additives such as nano-silica (NS), micro-silica (MS) and polymer fibers on optimizing the mechanical properties of concrete, such as compressive strength. Nowadays, with progress in cement industry provides, it has become possible to produce cement type I with strength classes of 32.5, 42.5, and 52.5 MPa. On the one hand, the microstructure of cement has changed, and modified by NS, MS, and polymers; therefore it is very important to determine the optimal percentage of each additives for those CSCs. In this study, 12 mix designs containing different percentages of MS, NS, and polymer fibers in three cement strength classes(CSCs) (32.5, 42.5, and 52.5 MPa) were designed and constructed based on the mixture method. Results indicated the sensitivity of each CSCs can be different on the NS or MS in compressive strength of concrete. Consequently, strength classes have a significant effect on the amount of MS and NS in mix design of concrete. While, polymer fibers don’t have significant effect in compressive strength considering CSCs.

关键词: mixture method     compressive strength     nano-silica     micro-silica     polypropylene fibers    

Silicon carbide waste as a source of mixture materials for cement mortar

Zhengwu Jiang, Qiang Ren, Haoxin Li, Qing Chen

《环境科学与工程前沿(英文)》 2017年 第11卷 第5期 doi: 10.1007/s11783-017-0974-y

摘要: This paper presents an investigation of the feasibility of recycling silicon carbide waste (SCW) as a source of mixture materials in the production of cement mortar. Mortars with SCW were prepared by replacing different amounts of cement with SCW, and the properties of the resulting mortars, such as the fluidity, strength and shrinkage, were studied in this work. Thermogravimetry-differential scanning calorimetry and scanning electron microscopy were employed to understand the reasons for the property changes of the mortars. The results indicate that SCW decreases the initial and 1-h fluidity of fresh mortar but improves the loss of fluidity. The mortar with SCW exhibits a lower strength at 3 d and 7 d but a higher strength at 28 d and 56 d compared to the control. The shrinkage rate of cement mortar with SCW shows an obvious decrease as the replacement ratio increases. In addition, the content of calcium hydroxide in hardened paste also shows that SCW has some impact on the hydration of the cement-SCW system. The microstructures of the hardened paste also show evidence for a later strength change of mortar containing SCW. This work provides a strategic reference for possibly applying SCW as a mixture material in the production of cement mortar.

关键词: Silicon carbide waste     Cement mortar     Fluidity     Strength     Shrinkage    

Thermal and catalytic pyrolysis of a synthetic mixture representative of packaging plastics residue

Simona Colantonio, Lorenzo Cafiero, Doina De Angelis, Nicolò M. Ippolito, Riccardo Tuffi, Stefano Vecchio Ciprioti

《化学科学与工程前沿(英文)》 2020年 第14卷 第2期   页码 288-303 doi: 10.1007/s11705-019-1875-3

摘要: A synthetic mixture of real waste packaging plastics representative of the residue from a material recovery facility (plasmix) was submitted to thermal and catalytic pyrolysis. Preliminary thermogravimetry experiments coupled with Fourier transform infrared spectroscopy were performed to evaluate the effects of the catalysts on the polymers’ degradation temperatures and to determine the main compounds produced during pyrolysis. The thermal and catalytic experiments were conducted at 370°C, 450°C and 650°C using a bench scale reactor. The oil, gas, and char yields were analyzed and the compositions of the reaction products were compared. The primary aim of this study was to understand the effects of zeolitic hydrogen ultra stable zeolite Y (HUSY) and hydrogen zeolite socony mobil-5 (HZSM5) catalysts with high silica content on the pyrolysis process and the products’ quality. Thermogravimetry showed that HUSY significantly reduces the degradation temperature of all the polymers—particularly the polyolefines. HZSM5 had a significant effect on the degradation of polyethylene due to its smaller pore size. Mass balance showed that oil is always the main product of pyrolysis, regardless of the process conditions. However, all pyrolysis runs performed at 370°C were incomplete. The use of either zeolites resulted in a decrease in the heavy oil fraction and the prevention of wax formation. HUSY has the best performance in terms of the total monoaromatic yield (29 wt-% at 450°C), while HZSM5 promoted the production of gases (41 wt-% at 650°C). Plasmix is a potential input material for pyrolysis that is positively affected by the presence of the two tested zeolites. A more effective separation of polyethylene terephthalate during the selection process could lead to higher quality pyrolysis products.

关键词: packaging plastics waste     plasmix     pyrolysis     zeolite catalyst     degradation temperature    

标题 作者 时间 类型 操作

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

期刊论文

Comprehensive performance analysis and optimization of 1,3-dimethylimidazolylium dimethylphosphate-waterbinary mixture for a single effect absorption refrigeration system

Gorakshnath TAKALKAR, Ahmad K. SLEITI

期刊论文

模拟系统的混合测试优化方法

梅文娟,刘震,李欧行,苏元章,梅渝松,龙泳吉

期刊论文

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

Satoshi TANIGUCHI, Keiichiro OGAWA, Jun OTANI, Itaru NISHIZAKI

期刊论文

Experimental research on catalysts and their catalytic mechanism for hydrogen production by gasification of peanut shell in supercritical water

PEI Aixia, GUO Liejin, JIN Hui

期刊论文

Fatigue of asphalt binder, mastic and mixture at low temperature

Dong WANG, Linbing WANG, Guoqing ZHOU

期刊论文

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

Xiao-Yong WANG

期刊论文

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

Rupalika DASH,Kalipada MAITY

期刊论文

Simulation and analysis of grinding wheel based on Gaussian mixture model

Yulun CHI, Haolin LI

期刊论文

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

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

期刊论文

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

期刊论文

A study on fatigue damage of asphalt mixture under different compaction using 3D-microstructural characteristics

Jing HU, Pengfei LIU, Bernhard STEINAUER

期刊论文

strength of concrete containing micro-silica, nano-silica, and polypropylene fibers using extreme vertices mixture

Fatemeh ZAHIRI, Hamid ESKANDARI-NADDAF

期刊论文

Silicon carbide waste as a source of mixture materials for cement mortar

Zhengwu Jiang, Qiang Ren, Haoxin Li, Qing Chen

期刊论文

Thermal and catalytic pyrolysis of a synthetic mixture representative of packaging plastics residue

Simona Colantonio, Lorenzo Cafiero, Doina De Angelis, Nicolò M. Ippolito, Riccardo Tuffi, Stefano Vecchio Ciprioti

期刊论文