资源类型

期刊论文 99

年份

2023 2

2022 6

2021 8

2020 8

2019 9

2018 5

2017 7

2016 6

2015 5

2014 2

2013 2

2012 4

2011 4

2010 3

2009 2

2008 10

2007 11

2004 1

2000 1

展开 ︾

关键词

3D打印 1

Grade 91钢 1

“一带一路”,制造业,六大经济走廊,显性比较优势指数,多维尺度分析 1

产品设计;知识推送;适用概率匹配;多维情境;个性化 1

人工蜂群算法 1

人群流动系数 1

代理模型 1

信息物理系统 1

假肢矫形器 1

先进反应堆 1

光流计算 1

光谱成像;计算成像;光谱仪 1

出口 1

函数逼近能力 1

压力驱动 1

双基地MIMO阵列;发射角;接收角;MUSIC方法;泰勒展开;计算量 1

发电 1

可搜索公钥加密;带关键字搜索的无证书公钥加密;双线性对;计算性Diffie-Hellman问题 1

展开 ︾

检索范围:

排序: 展示方式:

Reduced kinetic mechanism of -heptane oxidation in modeling polycyclic aromatic hydrocarbon formation in opposed-flow diffusion flames

ZHONG Beijing, XI Jun

《能源前沿(英文)》 2008年 第2卷 第3期   页码 326-332 doi: 10.1007/s11708-008-0047-9

摘要: A reduced mechanism, which could couple with the multidimensional computational fluid dynamics code for quantitative description of a reacting flow, was developed for chemical kinetic modeling of polycyclic aromatic hydrocarbon formation in an opposed-flow diffusion flame. The complete kinetic mechanism, which comprises 572 reactions and 108 species, was reduced to a simplified mechanism that includes only 83 reactions and 56 species through sensitivity analysis. The results computed via this reduced mechanism are nearly indistinguishable from those via the detailed mechanism, which demonstrate that the model based on this reduced mechanism can properly describe -heptane oxidation chemistry and quantitatively predict polycyclic aromatic hydrocarbon (such as benzene, naphthalene, phenanthrene and pyrene) formation in opposed-flow diffusion flames.

关键词: phenanthrene     multidimensional computational     sensitivity analysis     polycyclic     mechanism    

简析工程的多维属性

徐长山,屈磊

《中国工程科学》 2013年 第15卷 第11期   页码 92-96

摘要:

工程作为人类改造自然界,构建人工自然的“造物”活动,具有多维属性,包括工程的阶段性、整体性、动态性、矛盾性、创新型、开放性、人文性、风险性、伦理性、价值性十个方面。这十个方面的属性是对工程特征全貌的一种概括,而且是具有哲学意义的抽象。本文正是从哲学意义上对工程的多维属性进行的解析。

关键词: 工程     多维     属性    

提高光流估计性能的渐进性高斯多维预滤波方法的研究

付昀,徐维朴

《中国工程科学》 2004年 第6卷 第12期   页码 56-61

摘要:

基于光流计算方法统一框架理论,研究了一种利用高斯多维滤波器的渐进性和时空性提高光流估计性能的有效方法。在保持现有光流计算方法的前提下,通过调节时间维和空间维的方差参数,改变时空预滤波和光滑效果,突出时间混叠和光流主信息,从而提高重构视频序列的信噪比。试验中以标准的Flower Garden和Football序列的前50帧作为参考图像序列,以LK算法为参考光流算法。结果显示,滤波窗口为5×5时的最佳时间方差参数为0.4,最佳空间方差参数为[1.6,2.0];加入高斯多维预滤波前后利用光流场重构图像的平均峰值信噪比PSNR提高2.572dB,提高幅度为13.6%。

关键词: 光流计算     高斯多维滤波     峰值信噪比     运动估计    

Standard model of knowledge representation

Wensheng YIN

《机械工程前沿(英文)》 2016年 第11卷 第3期   页码 275-288 doi: 10.1007/s11465-016-0372-3

摘要:

Knowledge representation is the core of artificial intelligence research. Knowledge representation methods include predicate logic, semantic network, computer programming language, database, mathematical model, graphics language, natural language, etc. To establish the intrinsic link between various knowledge representation methods, a unified knowledge representation model is necessary. According to ontology, system theory, and control theory, a standard model of knowledge representation that reflects the change of the objective world is proposed. The model is composed of input, processing, and output. This knowledge representation method is not a contradiction to the traditional knowledge representation method. It can express knowledge in terms of multivariate and multidimensional. It can also express process knowledge, and at the same time, it has a strong ability to solve problems. In addition, the standard model of knowledge representation provides a way to solve problems of non-precision and inconsistent knowledge.

关键词: knowledge representation     standard model     ontology     system theory     control theory     multidimensional representation    

Research on Multidimensional Connotations of Megaproject Construction Organization Citizenship Behavior

Qing-hua He,De-lei Yang,Yong-kui Li,Lan Luo

《工程管理前沿(英文)》 2015年 第2卷 第2期   页码 148-153 doi: 10.15302/J-FEM-2015024

摘要: Based on a literature review and the context characteristics of construction megaprojects (CMPs), a multidimensional connotation model of CMP citizenship behavior was proposed, including definitions, actors, and dimensions. Organizational citizenship behavior includes Cooperation Behavior (CoB), Collaboration Behavior (ClB), Innovation Behavior (IB), Voice Behavior (VB),Conscientiousness & Dedication Behavior (CDB), Benefit Defense Behavior (BDB) and Guanxi (Relations) Maintenance Behavior (GMB). Actors were divided into three levels that were project managers (individual), participant agents (group) and project organization (network).

关键词: construction megaproject (CMP)     organizational citizenship behavior     connotation     grounded theory    

基于适用概率匹配与多维情境驱动的设计知识推送技术 None

Shu-you ZHANG, Ye GU, Xiao-jian LIU, Jian-rong TAN

《信息与电子工程前沿(英文)》 2018年 第19卷 第2期   页码 235-245 doi: 10.1631/FITEE.1700763

摘要: 为了提高产品智能设计过程中设计知识的使用效率和质量,有必要向设计人员主动推送设计知识。知识推送主要包括知识匹配和匹配结果的合理推送两个方面。针对现有知识匹配通常缺乏智能性和匹配结果推送缺少个性化的问题,提出基于适用概率匹配和多维情境驱动的设计知识推送技术。构建包括设计知识表示向量、设计案例特征向量和映射布尔矩阵等的训练样本集,通过贝叶斯理论计算设计知识适用与不适用于设计内容的概率,即二者之间的匹配度,得到推送知识集。构建等级化设计内容模型对推送知识集进行过滤,通过设计知识、设计上下文、设计内容和设计人员等多维情境驱动,实现个性化的设计知识推送。在数控机床智能设计平台中的知识推送应用,证明了该技术的可行性和正确性。

关键词: 产品设计;知识推送;适用概率匹配;多维情境;个性化    

Challenges of high dam construction to computational mechanics

ZHANG Chuhan

《结构与土木工程前沿(英文)》 2007年 第1卷 第1期   页码 12-33 doi: 10.1007/s11709-007-0002-6

摘要: The current situations and growing prospects of China s hydro-power development and high dam construction are reviewed, giving emphasis to key issues for safety evaluation of large dams and hydro-power plants, especially those associated with application of state-of-the-art computational mechanics. These include but are not limited to: stress and stability analysis of dam foundations under external loads; earthquake behavior of dam-foundation-reservoir systems, mechanical properties of mass concrete for dams, high velocity flow and energy dissipation for high dams, scientific and technical problems of hydro-power plants and underground structures, and newly developed types of dam-Roll Com pacted Concrete (RCC) dams and Concrete Face Rock-fill (CFR) dams. Some examples demonstrating successful utilizations of computational mechanics in high dam engineering are given, including seismic nonlinear analysis for arch dam foundations, nonlinear fracture analysis of arch dams under reservoir loads, and failure analysis of arch dam-foundations. To make more use of the computational mechanics in high dam engineering, it is pointed out that much research including different computational methods, numerical models and solution schemes, and verifications through experimental tests and filed measurements is necessary in the future.

关键词: reservoir     engineering     hydro-power development     state-of-the-art computational     earthquake    

Investigation of carbon dioxide photoreduction process in a laboratory-scale photoreactor by computational

《化学科学与工程前沿(英文)》 2022年 第16卷 第7期   页码 1149-1163 doi: 10.1007/s11705-021-2096-0

摘要: The production of solar fuels via the photoreduction of carbon dioxide to methane by titanium oxide is a promising process to control greenhouse gas emissions and provide alternative renewable fuels. Although several reaction mechanisms have been proposed, the detailed steps are still ambiguous, and the limiting factors are not well defined. To improve our understanding of the mechanisms of carbon dioxide photoreduction, a multiphysics model was developed using COMSOL. The novelty of this work is the computational fluid dynamic model combined with the novel carbon dioxide photoreduction intrinsic reaction kinetic model, which was built based on three-steps, namely gas adsorption, surface reactions and desorption, while the ultraviolet light intensity distribution was simulated by the Gaussian distribution model and Beer-Lambert model. The carbon dioxide photoreduction process conducted in a laboratory-scale reactor under different carbon dioxide and water moisture partial pressures was then modeled based on the intrinsic kinetic model. It was found that the simulation results for methane, carbon monoxide and hydrogen yield match the experiments in the concentration range of 10−4 mol·m–3 at the low carbon dioxide and water moisture partial pressure. Finally, the factors of adsorption site concentration, adsorption equilibrium constant, ultraviolet light intensity and temperature were evaluated.

关键词: carbon dioxide photoreduction     computational fluid dynamic simulation     kinetic model     Langmuir adsorption    

AMMONIA DISPERSION FROM MULTI-FLOOR VERSUS STANDARD SINGLE-FLOOR PIG PRODUCTION FACILITIES BASED ON COMPUTATIONAL

《农业科学与工程前沿(英文)》 2023年 第10卷 第3期   页码 374-389 doi: 10.15302/J-FASE-2023501

摘要:

● NH3 dispersion from a multi-floor pig building was compared to a single-floor building.

关键词: pig building     computational fluid dynamics     ammonia     dispersion    

Computational fluid dynamics simulation of aerosol transport and deposition

Yingjie TANG, Bing GUO

《环境科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 362-377 doi: 10.1007/s11783-011-0365-8

摘要: In this article computational fluid dynamics (CFD) simulation of aerosol transport and deposition, i.e. the transport and deposition of particles in an aerosol, is reviewed. The review gives a brief account of the basics of aerosol mechanics, followed by a description of the general CFD approach for flow field simulation, turbulence modeling, wall treatments and simulation of particle motion and deposition. Then examples from the literature are presented, including CFD simulation of particle deposition in human respiratory tract and particle deposition in aerosol devices. CFD simulation of particle transport and deposition may provide information that is difficult to obtain through physical experiments, and it may help reduce the number of experiments needed for device design. Due to the difficulty of describing turbulent flow and particle-eddy interaction, turbulent dispersion of particles remains one of the greatest challenges for CFD simulation. However, it is possible to take a balanced approach toward quantitative description of aerosol dispersion using CFD simulation in conjunction with empirical relations.

关键词: computational fluid dynamics (CFD)     aerosol     transport     deposition    

Introduction to the special section on the Symposium on Computational Fluid Dynamics and Molecular Simulation

Tianwei TAN, Peiyong QIN,

《化学科学与工程前沿(英文)》 2010年 第4卷 第3期   页码 241-241 doi: 10.1007/s11705-009-0285-3

A time−space porosity computational model for concrete under sulfate attack

《结构与土木工程前沿(英文)》 doi: 10.1007/s11709-023-0985-7

摘要: The deterioration of the microscopic pore structure of concrete under external sulfate attack (ESA) is a primary cause of degradation. Nevertheless, little effort has been invested in exploring the temporal and spatial development of the porosity of concrete under ESA. This study proposes a mechanical–chemical model to simulate the spatiotemporal distribution of the porosity. A relationship between the corrosion damage and amount of ettringite is proposed based on the theory of volume expansion. In addition, the expansion strain at the macro-scale is obtained using a stress analysis model of composite concentric sphere elements and the micromechanical mean-field approach. Finally, considering the influence of corrosion damage and cement hydration on the diffusion of sulfate ions, the expansion deformation and porosity space−time distribution are obtained using the finite difference method. The results demonstrate that the expansion strains calculated using the suggested model agree well with previously reported experimental results. Moreover, the tricalcium aluminate concentration, initial elastic modulus of cement paste, corrosion damage, and continuous hydration of cement significantly affect concrete under ESA. The proposed model can forecast and assess the porosity of concrete covers and provide a credible approach for determining the residual life of concrete structures under ESA.

关键词: expansion deformation     porosity     internal expansion stress     external sulfate attack     mechanical–chemical coupling model    

Stormwater treatment: examples of computational fluid dynamics modeling

Gaoxiang YING, John SANSALONE, Srikanth PATHAPATI, Giuseppina GAROFALO, Marco MAGLIONICO, Andrea BOLOGNESI, Alessandro ARTINA

《环境科学与工程前沿(英文)》 2012年 第6卷 第5期   页码 638-648 doi: 10.1007/s11783-012-0442-7

摘要: Control of rainfall-runoff particulate matter (PM) and PM-bound chemical loads is challenging; in part due to the wide gradation of PM complex geometries of many unit operations and variable flow rates. Such challenges and the expense associated with resolving such challenges have led to the relatively common examination of a spectrum of unit operations and processes. This study applies the principles of computational fluid dynamics (CFD) to predict the particle and pollutant clarification behavior of these systems subject to dilute multiphase flows, typical of rainfall-runoff, within computationally reasonable limits, to a scientifically acceptable degree of accuracy. The Navier-Stokes (NS) system of nonlinear partial differential equations for multi-phase hydrodynamics and separation of entrained particles are solved numerically over the unit operation control volume with the boundary and initial conditions defined and then solved numerically until the desired convergence criteria are met. Flow rates examined are scaled based on sizing of common unit operations such as hydrodynamic separators (HS), wet basins, or filters, and are examined from 1 to 100 percent of the system maximum hydraulic operating flow rate. A standard turbulence model is used to resolve flow, and a discrete phase model (DPM) is utilized to examine the particle clarification response. CFD results closely follow physical model results across the entire range of flow rates. Post-processing the CFD predictions provides an in-depth insight into the mechanistic behavior of unit operations by means of three dimensional (3-D) hydraulic profiles and particle trajectories. Results demonstrate the role of scour in the rapid degradation of unit operations that are not maintained. Comparisons are provided between measured and CFD modeled results and a mass balance error is identified. CFD is arguably the most powerful tool available for our profession since continuous simulation modeling.

关键词: stormwater     unit operations and processes (UOPs)     hydrodynamic separation     filtration     adsorption     computational fluid dynamics (CFD)     turbulence modeling     discrete phase model     particle separation     detention/retention basins     clarification    

Confinement effects in methanol to olefins catalysed by zeolites: A computational review

German Sastre

《化学科学与工程前沿(英文)》 2016年 第10卷 第1期   页码 76-89 doi: 10.1007/s11705-016-1557-3

摘要: Small pore zeolites, containing 8-rings as the largest, are widely employed as catalysts in the process of methanol-to-olefins (MTO). Reactants and products diffuse with constraints through 8-rings and this is one of the reaction bottlenecks related to zeolite micropore topology. Small pore zeolites and silicon-aluminophosphates(SAPOs) containing cavities, where olefins are mainly formed through the hydrocarbon pool (HP) mechanism, are frequently tested for MTO. Shape selectivity of transition states within the side-chain methylation will be reviewed as this is one of the controlling steps of the MTO process, with particular attention to the role of hexamethylbenzene (HMB) and heptamethylbenzenium cation (HeptaMB ), which are the most tipically detected reaction intermediates, common to the paring and side-chain routes within the HP mechanism. The relative stability of these and other species will be reviewed in terms of confinement effects in different cage-based zeolites. The role of the different alkylating agents, methanol, dimethyl ether (DME), and surface methoxy species (SMS) will also be reviewed from the computational viewpoint.

关键词: small pore zeolites     SAPOs     methanol-to-olefins     hydrocarbon pool mechanism     alkylation of polymethylbenzenes    

An investigation of ballistic response of reinforced and sandwich concrete panels using computational

Mohammad HANIFEHZADEH, Bora GENCTURK

《结构与土木工程前沿(英文)》 2019年 第13卷 第5期   页码 1120-1137 doi: 10.1007/s11709-019-0540-8

摘要: Structural performance of nuclear containment structures and power plant facilities is of critical importance for public safety. The performance of concrete in a high-speed hard projectile impact is a complex problem due to a combination of multiple failure modes including brittle tensile fracture, crushing, and spalling. In this study, reinforced concrete (RC) and steel-concrete-steel sandwich (SCSS) panels are investigated under high-speed hard projectile inpact. Two modeling techniques, smoothed particle hydrodynamics (SPH) and conventional finite element (FE) analysis with element erosion are used. Penetration depth and global deformation are compared between doubly RC and SCSS panels in order to identify the advantages of the presence of steel plates over the reinforcement layers. A parametric analysis of the front and rear plate thicknesses of the SCSS configuration showed that the SCSS panel with a thick front plate has the best performance in controlling the hard projectile. While a thick rear plate is effective in the case of a large and soft projectile as the plate reduces the rear deformation. The effects of the impact angle and impact velocity are also considered. It was observed that the impact angle for the flat nose missile is critical and the front steel plate is effective in minimizing penetration depth.

关键词: concrete panels     projectile impact     finite element modeling     smoothed particle hydrodynamics     strain rate effect    

标题 作者 时间 类型 操作

Reduced kinetic mechanism of -heptane oxidation in modeling polycyclic aromatic hydrocarbon formation in opposed-flow diffusion flames

ZHONG Beijing, XI Jun

期刊论文

简析工程的多维属性

徐长山,屈磊

期刊论文

提高光流估计性能的渐进性高斯多维预滤波方法的研究

付昀,徐维朴

期刊论文

Standard model of knowledge representation

Wensheng YIN

期刊论文

Research on Multidimensional Connotations of Megaproject Construction Organization Citizenship Behavior

Qing-hua He,De-lei Yang,Yong-kui Li,Lan Luo

期刊论文

基于适用概率匹配与多维情境驱动的设计知识推送技术

Shu-you ZHANG, Ye GU, Xiao-jian LIU, Jian-rong TAN

期刊论文

Challenges of high dam construction to computational mechanics

ZHANG Chuhan

期刊论文

Investigation of carbon dioxide photoreduction process in a laboratory-scale photoreactor by computational

期刊论文

AMMONIA DISPERSION FROM MULTI-FLOOR VERSUS STANDARD SINGLE-FLOOR PIG PRODUCTION FACILITIES BASED ON COMPUTATIONAL

期刊论文

Computational fluid dynamics simulation of aerosol transport and deposition

Yingjie TANG, Bing GUO

期刊论文

Introduction to the special section on the Symposium on Computational Fluid Dynamics and Molecular Simulation

Tianwei TAN, Peiyong QIN,

期刊论文

A time−space porosity computational model for concrete under sulfate attack

期刊论文

Stormwater treatment: examples of computational fluid dynamics modeling

Gaoxiang YING, John SANSALONE, Srikanth PATHAPATI, Giuseppina GAROFALO, Marco MAGLIONICO, Andrea BOLOGNESI, Alessandro ARTINA

期刊论文

Confinement effects in methanol to olefins catalysed by zeolites: A computational review

German Sastre

期刊论文

An investigation of ballistic response of reinforced and sandwich concrete panels using computational

Mohammad HANIFEHZADEH, Bora GENCTURK

期刊论文