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Alternative energy development strategies for China towards 2030

Linwei MA , Zheng LI , Feng FU , Weidou NI , Xiliang ZHANG ,

《能源前沿(英文)》 2009年 第3卷 第1期   页码 2-10 doi: 10.1007/s11708-009-0014-0

摘要: The purposes, objectives and technology pathways for alternative energy development are discussed with the aim of reaching sustainable energy development in China. Special attention has been paid to alternative power and alternative vehicle fuels. Instead of limiting alternative energy to energy sources such as nuclear and renewable energy, the scope of discussion is extended to alternative technologies such as coal power with carbon capture and sequestration (CCS), electric and hydrogen vehicles. In order to take account of the fact that China’s sustainable energy development involves many dimensions, a six-dimensional indicator set has been established and applied with the aim of comprehensively evaluating different technology pathways in a uniform way. The analysis reaches the following conclusions: (a) in the power sector, wind power, nuclear power and hydro power should be developed as much as possible, while R&D of solar power and coal power with CCS should be strengthened continuously for future deployment. (b) in the transportation sector, there is no foreseeable silver bullet to replace oil on a large scale within the time frame of 20 to 30 years. To ease the severe energy security situation, expedient choices like coal derived fuels could be developed. However, its scale should be optimized in accordance to the trade-off of energy security benefits, production costs and environmental costs. Desirable alternative fuels (or technologies) like 2nd generation biofuels and electrical vehicles should be the subject of intensive R&D with the objective to be cost effective as early as possible.

关键词: alternative energy     China energy     technology pathway     six-dimensional evaluation    

A total torque index for dynamic performance evaluation of a radial symmetric six-legged robot

Kejia LI, Xilun DING, Marco CECCARELL

《机械工程前沿(英文)》 2012年 第7卷 第2期   页码 219-230 doi: 10.1007/s11465-012-0320-9

摘要:

This article focuses on the dynamic index and performance of a radial symmetric six-legged robot. At first the structure of the robot is described in brief and its inverse kinematics is presented. Then the dynamic model is formulated as based on the Lagrange equations. A novel index of total torque is proposed by considering the posture of the supporting legs. The new index can be used to optimize the leg’s structure and operation for consuming minimum power and avoiding unstable postures of the robot. A characterization of the proposed six-legged robot is obtained by a parametric analysis of robot performance through simulation using the presented dynamic model. Main influences are outlined as well as the usefulness of the proposed performance index.

关键词: six-legged robots     dynamic modeling     performance index    

The computational fluid dynamic modeling of downwash flow field for a six-rotor UAV

Yongjun ZHENG, Shenghui YANG, Xingxing LIU, Jie WANG, Tomas NORTON, Jian CHEN, Yu TAN

《农业科学与工程前沿(英文)》 2018年 第5卷 第2期   页码 159-167 doi: 10.15302/J-FASE-2018216

摘要: The downwash flow field of the multi-rotor unmanned aerial vehicle (UAV), formed by propellers during operation, has a significant influence on the deposition, drift and distribution of droplets as well as the spray width of the UAV for plant protection. To study the general characteristics of the distribution of the downwash airflow and simulate the static wind field of multi-rotor UAVs in hovering state, a 3D full-size physical model of JF01-10 six-rotor plant protection UAV was constructed using SolidWorks. The entire flow field surrounding the UAV and the rotation flow fields around the six rotors were established in UG software. The physical model and flow fields were meshed using unstructured tetrahedral elements in ANSYS software. Finally, the downwash flow field of UAV was simulated. With an increased hovering height, the ground effect was reduced and the minimum current velocity increased initially and then decreased. In addition, the spatial proportion of the turbulence occupied decreased. Furthermore, the appropriate operational hovering height for the JF01-10 is considered to be 3 m. These results can be applied to six-rotor plant protection UAVs employed in pesticide spraying and spray width detection.

关键词: CFD simulation     downwash flow field     numerical analysis     plant protection     six-rotor UAV    

Economic Growth Model Based on Six Basic Factors of Production—Xu Growth Rate Equation

Shou-bo Xu,Zong-yuan Huang

《工程管理前沿(英文)》 2014年 第1卷 第2期   页码 160-175 doi: 10.15302/J-FEM-2014024

摘要: This paper proposes an economic growth model based on the Six Basic Factors of Production and Xu Growth Rate Equation for the first time, which fills-in the deficits of the New Classical Economic Growth Model based on the Solow Model. The empirical analysis indicates that over the past three decades, the consumption of six basic factors of production had complicated relations with economic growth. In some years, the consumption rate of the basic factors of production was meager, but the economy witnessed relatively rocketing growth rate; in some years, the factors of production consumption rate was very high, but the economy growth rate slowed down. In general, economy grows at the expenses of huge consumption of four factors. There is an obvious characteristic of huge input and low efficiency. The average contribution rate of technological advance peaks in the middle, while it drops down at two ends. Noticeably, since 2004, the technology contribution rate generally shows a downward trend, reasons of which should be explored systematically in aspects like economic policy and industry structure with a view to boost further transformation of the macro-economy scientific growth model.

关键词: six basic factors of production     economic growth model     Xu Growth Rate Equation    

Sorption and desorption of pymetrozine on six Chinese soils

Mingxing GAO,Yingying LI,Hong YANG,Yucheng GU

《环境科学与工程前沿(英文)》 2016年 第10卷 第1期   页码 1-10 doi: 10.1007/s11783-014-0715-4

摘要: Pymetrozine is a selective insecticide with a unique chemical structure and mode to control hemipteran and homopteran. While pymetrozine has brought great benefits to crop production by killing insects, its residues in soil may have a detrimental effect on environment. Therefore, it is of great importance to investigate its behaviors in soil. In this study, the sorption and desorption of pymetrozine on six Chinese soils were investigated using a batch equilibrium approach to understand its mobile behavior in the soils. Both sorption and desorption isotherms of pymetrozine were in good agreement with the Freundlich model. The sorption coefficient varied between 3.37 and 58.32 mL?g and the sorption isotherms were nonlinear, with 1/ ranging from 0.57 to 0.91. A regression equation was proposed to predict the sorption of pymetrozine on six different soil samples: log = 4.3708 − 4.5709 × log (pH in 0.01mol·L CaCl ) + 0.4700 × log OC% + 0.0057 × sand (%) + 0.0022 × CEC(clay), with = 0.9982. The organic carbon content of soil positively affected the sorption of pymetrozine, but soil pH had a negative effect on the sorption. Additionally, effects of CaCl concentration, soil to solution ratio and pesticide form were investigated. The sorption was promoted with an increase in soil to solution ratio and a decrease in CaCl concentration. The possible variation of the five formulated products of pymetrozine was also investigated.

关键词: desorption     pymetrozine     sorption     soil    

A novel six-legged walking machine tool for

Jimu LIU, Yuan TIAN, Feng GAO

《机械工程前沿(英文)》 2020年 第15卷 第3期   页码 351-364 doi: 10.1007/s11465-020-0594-2

摘要: The manufacture and maintenance of large parts in ships, trains, aircrafts, and so on create an increasing demand for mobile machine tools to perform operations. However, few mobile robots can accommodate the complex environment of industrial plants while performing machining tasks. This study proposes a novel six-legged walking machine tool consisting of a legged mobile robot and a portable parallel kinematic machine tool. The kinematic model of the entire system is presented, and the workspace of different components, including a leg, the body, and the head, is analyzed. A hierarchical motion planning scheme is proposed to take advantage of the large workspace of the legged mobile platform and the high precision of the parallel machine tool. The repeatability of the head motion, body motion, and walking distance is evaluated through experiments, which is 0.11, 1.0, and 3.4 mm, respectively. Finally, an application scenario is shown in which the walking machine tool steps successfully over a 250 mm-high obstacle and drills a hole in an aluminum plate. The experiments prove the rationality of the hierarchical motion planning scheme and demonstrate the extensive potential of the walking machine tool for operations on large parts.

关键词: legged robot     parallel mechanism     mobile machine tool     in-situ machining    

立体偏转测量系统几何参数的性能分析与评价 Article

徐永佳, 高峰, 蒋向前

《工程(英文)》 2018年 第4卷 第6期   页码 806-815 doi: 10.1016/j.eng.2018.10.007

摘要:

本文提出了一种新颖的几何参数分析方法,以提高立体偏转系统的测量精度。立体偏转测量可用于获得自由曲面的三维形貌信息。基于立体偏转测量的测量系统通常由条纹显示屏、主相机和参考相机组成。立体偏转测量系统组件的布置对于实现高精度测量十分重要。本文分析和评估了立体偏转测量系统的4个几何参数:主相机与被测物体表面之间的距离、主相机光线与被测表面法线之间的角度、条纹显示屏与被测物体之间的距离,以及主相机和参考相机之间的角度。本文通过模拟和实验数据对这些几何参数对测量精度的影响进行了验证。实验结果证实了这些参数对测量精度的影响。基于本文所提出的分析方法,一个立体偏转系统被搭建并且被用于测量一个标准的凹面镜。通过与凹面镜的给定表面参数进行比较,该系统的全局测量精度可达154.2 nm。

关键词: 光学测量     误差分析     立体偏转测量     三维形貌测量     性能评估     模拟    

Numerical evaluation of group-pile foundation subjected to cyclic horizontal load

Youngji JIN, Xiaohua BAO, Yoshimitsu KONDO, Feng ZHANG,

《结构与土木工程前沿(英文)》 2010年 第4卷 第2期   页码 196-207 doi: 10.1007/s11709-010-0021-6

摘要: In this paper, three-dimensional (3D) finite element analyses of a real-scale group-pile foundation subjected to horizontal cyclic loading are conducted using a program named DBLEAVES. In the simulations, nonlinear behaviors of ground and piles are described by subloading model and the axial-force dependent model (AFD model) which considered the axial-force dependency in the nonlinear moment-curvature relations. In order to consider the influence of an effective stress path on the prediction of the group-pile foundation, the analyses are conducted within the framework of the soil-water coupling method with finite-difference and finite-element regime. The material parameters of soils are determined based on conventional triaxial drained compression tests on undisturbed and remolded specimens. The applicability of the proposed numerical method is encouraging, and therefore, it is quite confident to say that the method can be used to predict the mechanical behaviors of group-pile foundation to a satisfactory accuracy, particularly with the effective stress analysis.

关键词: group-pile foundation     real-scale cyclic loading test     three-dimensional finite element method (3D-FEM)     soil-water coupling analysis     undisturbed and remolded specimens    

城市道路网运行实时动态评价理论和技术研究

全永燊,郭继孚,温慧敏,孙建平

《中国工程科学》 2011年 第13卷 第1期   页码 43-48

摘要:

从道路网运行的基本特性入手,着重分析了路网运行的随机波动性、递延传导效应和周期规律性。在此基础上,剖析了迄今国内外一直沿用的道路“负荷度”路网评价理论的局限性,提出一套适用于路网整体实时动态评价的理论和技术方法,解决了无盲区实时数据采集与处理、路网运行时空动态分析、评价指标阈值标定等关键技术难题,为交通战略规划、实时动态路网功况诊断等提供了全新的技术手段,北京市的实证研究初步证明了所提出的理论和技术体系科学、有效、实用。

关键词: 路网实时动态评价     负荷度评价     递延传导效应     “五维”拥堵指数    

舰船修理文件编制六维度管理方法研究

陈志敏,阳斌

《中国工程科学》 2015年 第17卷 第5期   页码 83-89

摘要:

针对舰船基地级修理文件编制规律与技术特点,提出了成系统、科学的基地级修理文件编制六维度管理方法。在分析舰船装备基地级修理文件国外编制现状的基础上,针对修理文件编制难度大、内容多、涉及外协单位多、质量和进度管理难度大的特点,梳理出基地级修理文件体系,提出了从要求、样例、维修分析、知识库、质量管理、进度管理六个维度对修理文件编制的质量和进度进行管理的创新方法,从工程可操作性上对修理文件的编制管理方法进行了阐述,其研究成果对落实舰船装备基地级修理文件编制工作具有重要意义。

关键词: 舰船;修理文件;六维度管理方法;维修分析    

“一带一路”沿线六大经济走廊优势产业及制造业国际合作现状分析

汤永川,潘云鹤,张雪,黄江杰

《中国工程科学》 2019年 第21卷 第4期   页码 60-68 doi: 10.15302/J-SSCAE-2019.04.003

摘要:

“一带一路”建设正在从谋篇布局的“大写意”阶段转向精耕细作的“工笔画”阶段,这一转向升级对我国制造业国际合作提出更高的要求。本文基于联合国发布的国际贸易数据,以“一带一路”沿线六大经济走廊为重点研究对象,运用显性比较优势指数方法综合分析了六大经济走廊沿线国家比较优势产业。同时,应用多维尺度分析方法探讨了我国与六大经济走廊沿线国家总体贸易和制造业合作情况。最后,聚焦六大经济走廊沿线国家优势产业和要素禀赋,提出了我国与“一带一路”沿线国家制造业高质量合作的发展方向。

关键词: “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    

Three-dimensional stability analysis of the dam foundation at Baise

XU Qianjun, LI Xu, CHEN Zuyu

《结构与土木工程前沿(英文)》 2007年 第1卷 第2期   页码 217-221 doi: 10.1007/s11709-007-0026-y

摘要: It is usually difficult to determine the actual safety factors of rock masses in an ordinary two-dimensional stability analysis if the safety factors of the different cross sections in the rock mass vary significantly. In addition to the actual slope, arch dam abutment, and the actual foundation of a high building, another example is that the different cross sections of the foundation in the monolith of a gravity dam vary significantly, just like the condition at the overflow dam in the Baise project. A three-dimensional stability analysis method based on the upper-bound theorem was employed to solve this problem. The parameters used in the analysis were obtained from geomechanics tests, as well as continuity simulations of the randomly distributed joints. Two failure patterns against sliding are analyzed. One pattern is the foundation slide along deep-seated planes which were determined by calculations. The other pattern is the foundation slide along the planes across the bottom of the high steps in the foundation pit. The results indicate that a special overflow dam monolith can be considered to be safe in case of considering the three dimensional effect. However, a key wall with a depth of 5m must be constructed at the upper side of this monolith in order to ensure the safety of the foundation.

关键词: ordinary two-dimensional     randomly     monolith     three-dimensional stability     different    

A hybrid deep learning model for robust prediction of the dimensional accuracy in precision milling of

《机械工程前沿(英文)》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0688-0

摘要: The use of artificial intelligence to process sensor data and predict the dimensional accuracy of machined parts is of great interest to the manufacturing community and can facilitate the intelligent production of many key engineering components. In this study, we develop a predictive model of the dimensional accuracy for precision milling of thin-walled structural components. The aim is to classify three typical features of a structural component—squares, slots, and holes—into various categories based on their dimensional errors (i.e., “high precision,” “pass,” and “unqualified”). Two different types of classification schemes have been considered in this study: those that perform feature extraction by using the convolutional neural networks and those based on an explicit feature extraction procedure. The classification accuracy of the popular machine learning methods has been evaluated in comparison with the proposed deep learning model. Based on the experimental data collected during the milling experiments, the proposed model proved to be capable of predicting dimensional accuracy using cutting parameters (i.e., “static features”) and cutting-force data (i.e., “dynamic features”). The average classification accuracy obtained using the proposed deep learning model was 9.55% higher than the best machine learning algorithm considered in this paper. Moreover, the robustness of the hybrid model has been studied by considering the white Gaussian and coherent noises. Hence, the proposed hybrid model provides an efficient way of fusing different sources of process data and can be adopted for prediction of the machining quality in noisy environments.

关键词: precision milling     dimensional accuracy     cutting force     convolutional neural networks     coherent noise    

Electronic and mechanical responses of two-dimensional HfS

Mohammad SALAVATI

《结构与土木工程前沿(英文)》 2019年 第13卷 第2期   页码 486-494 doi: 10.1007/s11709-018-0491-5

摘要: During the last decade, numerous high-quality two-dimensional (2D) materials with semiconducting electronic character have been synthesized. Recent experimental study (Sci. Adv. 2017;3: e1700481) nevertheless confirmed that 2D ZrSe and HfSe are among the best candidates to replace the silicon in nanoelectronics owing to their moderate band-gap. We accordingly conducted first-principles calculations to explore the mechanical and electronic responses of not only ZrSe and HfSe , but also ZrS and HfS in their single-layer and free-standing form. We particularly studied the possibility of engineering of the electronic properties of these attractive 2D materials using the biaxial or uniaxial tensile loadings. The comprehensive insight provided concerning the intrinsic properties of HfS , HfSe , ZrS , and ZrSe can be useful for their future applications in nanodevices.

关键词: 2D materials     mechanical     electronic     DFT    

A dimensional analysis on asphalt binder fracture and fatigue cracking

Qian ZHAO, Zhoujing YE

《结构与土木工程前沿(英文)》 2018年 第12卷 第2期   页码 201-206 doi: 10.1007/s11709-017-0402-1

摘要: Fracture and fatigue cracking in asphalt binder are two of most serious problems for pavement engineers. In this paper, we present a new comprehensive approach, which consists both of dimensional analysis using Buckingham Theorem and -integral analysis based on classic fracture mechanics, to evaluate the fracture and fatigue on asphalt binder. It is discovered that the dimensional analysis could provide a new perspective to analyze the asphalt fracture and fatigue cracking mechanism.

关键词: Dimensional analysis     asphalt     fracture     fatigue cracking    

标题 作者 时间 类型 操作

Alternative energy development strategies for China towards 2030

Linwei MA , Zheng LI , Feng FU , Weidou NI , Xiliang ZHANG ,

期刊论文

A total torque index for dynamic performance evaluation of a radial symmetric six-legged robot

Kejia LI, Xilun DING, Marco CECCARELL

期刊论文

The computational fluid dynamic modeling of downwash flow field for a six-rotor UAV

Yongjun ZHENG, Shenghui YANG, Xingxing LIU, Jie WANG, Tomas NORTON, Jian CHEN, Yu TAN

期刊论文

Economic Growth Model Based on Six Basic Factors of Production—Xu Growth Rate Equation

Shou-bo Xu,Zong-yuan Huang

期刊论文

Sorption and desorption of pymetrozine on six Chinese soils

Mingxing GAO,Yingying LI,Hong YANG,Yucheng GU

期刊论文

A novel six-legged walking machine tool for

Jimu LIU, Yuan TIAN, Feng GAO

期刊论文

立体偏转测量系统几何参数的性能分析与评价

徐永佳, 高峰, 蒋向前

期刊论文

Numerical evaluation of group-pile foundation subjected to cyclic horizontal load

Youngji JIN, Xiaohua BAO, Yoshimitsu KONDO, Feng ZHANG,

期刊论文

城市道路网运行实时动态评价理论和技术研究

全永燊,郭继孚,温慧敏,孙建平

期刊论文

舰船修理文件编制六维度管理方法研究

陈志敏,阳斌

期刊论文

“一带一路”沿线六大经济走廊优势产业及制造业国际合作现状分析

汤永川,潘云鹤,张雪,黄江杰

期刊论文

Three-dimensional stability analysis of the dam foundation at Baise

XU Qianjun, LI Xu, CHEN Zuyu

期刊论文

A hybrid deep learning model for robust prediction of the dimensional accuracy in precision milling of

期刊论文

Electronic and mechanical responses of two-dimensional HfS

Mohammad SALAVATI

期刊论文

A dimensional analysis on asphalt binder fracture and fatigue cracking

Qian ZHAO, Zhoujing YE

期刊论文