资源类型

期刊论文 166

会议视频 1

年份

2024 1

2023 13

2022 8

2021 10

2020 11

2019 15

2018 8

2017 10

2016 6

2015 13

2014 11

2013 7

2012 11

2011 3

2010 8

2009 5

2008 8

2007 7

2006 1

2005 5

展开 ︾

关键词

增材制造 5

三点弯曲梁 2

农业面源污染 2

即时医疗 2

电子束 2

选择性激光熔化 2

2D—3D配准 1

Casimir力 1

DPP）；分布式功率转换器；开关电容转换器 1

GIS 1

MPPT）；差分功率处理（Differential power processing 1

PCMCIA 1

RGB-D 1

SPSS 1

TNT装药爆炸 1

WAPI 1

三峡升船机 1

三维点云；孔洞修补；立体匹配；B样条 1

下肢机器人；捕获点；步态相位；人机系统平衡 1

展开 ︾

检索范围：

排序： 展示方式：

Room temperature liquid metal: its melting point, dominating mechanism and applications

Junheng FU, Chenglin ZHANG, Tianying LIU, Jing LIU

《能源前沿（英文）》 2020年 第14卷 第1期   页码 81-104 doi: 10.1007/s11708-019-0653-8

摘要： The room temperature liquid metal (LM) is recently emerging as a new class of versatile materials with fascinating characteristics mostly originated from its simultaneous metallic and liquid natures. The melting point is a typical parameter to describe the peculiarity of LM, and a pivotal factor to consider concerning its practical applications such as phase change materials (PCMs) and advanced thermal management. Therefore, the theoretical exploration into the melting point of LM is an essential issue, which can be of special value for the design of new LM materials with desired properties. So far, some available strategies such as molecular dynamics (MD) simulation and classical thermodynamic theory have been applied to perform correlative analysis. This paper is primarily dedicated to performing a comprehensive overview regarding typical theoretical strategies on analyzing the melting points. It, then, presents evaluations on several factors like components, pressure, size and supercooling that may be critical for melting processes of liquid metal. After that, it discusses applications associated with the characteristic of low melting points of LM. It is expected that a great many fundamental and practical works are to be conducted in the coming future.

关键词： melting point     liquid metal     crystal     thermodynamics     molecular dynamics    

HTML PDF 收藏

Phase change effect of low melting point metal for an automatic cooling of USB flash memory

Haoshan GE, Jing LIU

《能源前沿（英文）》 2012年 第6卷 第3期   页码 207-209 doi: 10.1007/s11708-012-0204-z

HTML PDF 收藏

Liquid metal as energy transportation medium or coolant under harsh environment with temperature below zero centigrade

Yunxia GAO, Lei WANG, Haiyan LI, Jing LIU

《能源前沿（英文）》 2014年 第8卷 第1期   页码 49-61 doi: 10.1007/s11708-013-0285-3

摘要： The current highly integrated electronics and energy systems are raising a growing demand for more sophisticated thermal management in harsh environments such as in space or some other cryogenic environment. Recently, it was found that room temperature liquid metals (RTLM) such as gallium or its alloys could significantly reduce the electronics temperature compared with the conventional coolant, like water, oil or more organic fluid. However, most of the works were focused on RTLM which may subject to freeze under low temperature. So far, a systematic interpretation on the preparation and thermal properties of liquid metals under low temperature (here defined as lower than 0°C) has not yet been available and related applications in cryogenic field have been scarce. In this paper, to promote the research along this important direction and to overcome the deficiency of RTLM, a comprehensive evaluation was proposed on the concept of liquid metal with a low melting point below zero centigrade, such as mercury, alkali metal and more additional alloy candidates. With many unique virtues, such liquid metal coolants are expected to open a new technical frontier for heat transfer enhancement, especially in low temperature engineering. Some innovative ways for making low melting temperature liquid metal were outlined to provide a clear theoretical guideline and perform further experiments to discover new materials. Further, a few promising applied situations where low melting temperature liquid metals could play irreplaceable roles were detailed. Finally, some main factors for optimization of low temperature coolant were summarized. Overall, with their evident merits to meet various critical requirements in modern advanced energy and power industries, liquid metals with a low melting temperature below zero centigrade are expected to be the next-generation high-performance heat transfer medium in thermal managements, especially in harsh environment in space.

关键词： liquid metal     cryogenics     low melting point     thermal management     aircraft     liquid cooling     space exploration    

HTML PDF 收藏

双层辉光离子渗金属技术特点

高原,徐晋勇,高清,安晋平,徐重

《中国工程科学》 2008年 第10卷 第2期   页码 26-30

摘要：

分析了双层辉光技术的特点，指出该技术在材料表面合金化方面，是一项适合于高熔点金属 表面合金化和采用高熔点金属对铁基或某些熔点较高的有色金属材料进行表面合金化的工艺技术.

关键词： 双层辉光离子渗金属技术     高熔点金属     空心阴极效应     阴极溅射     扩散    

HTML PDF 收藏

A steam dried municipal solid waste gasification and melting process

Gang XIAO, Baosheng JIN, Mingjiang NI, Kefa CEN, Yong CHI, Zhongxin TAN

《环境科学与工程前沿（英文）》 2011年 第5卷 第2期   页码 193-204 doi: 10.1007/s11783-010-0268-0

摘要： Considering high-moisture municipal solid waste (MSW) of China, a steam dried MSW gasification and melting process was proposed, the feasibility was tested, and the mass and energy balance was analyzed. Preliminary experiments were conducted using a fixed-bed drying apparatus, a 200 kg per day fluidized-bed gasifier, and a swirl melting furnace. Moisture percentage was reduced from 50% to 20% roughly when MSW was dried by slightly superheated steam of 150°C–350°C within 40 min. When the temperature was less than 250°C, no incondensable gas was produced during the drying process. The gasifier ran at 550°C–700°Cwith an air equivalence ratio (ER) of 0.2–0.4. The temperature of the swirl melting furnace reached about 1240°C when the gasification ER was 0.3 and the total ER was 1.1. At these conditions, the fly ash concentration in the flue gas was 1.7 g·(Nm ) , which meant over 95% fly ash was trapped in the furnace and discharged as slag. 85% of Ni and Cr were bound in the slag, as well as 60% of Cu. The mass and energy balance analysis indicates that the boiler heat efficiency of an industrial MSW incineration plant reaches 86.97% when MSW is dried by steam of 200°C. The boiler heat efficiency is sensitive to three important parameters, including the temperature of preheated MSW, the moisture percentage of dried MSW and the fly ash percentage in the total ash.

关键词： municipal solid waste (MSW)     steam drying     gasification and melting    

HTML PDF 收藏

用于介观模拟电子束选区熔化的数据挖掘技术 Article

钱亚, 闫文韬, 林峰

《工程（英文）》 2019年 第5卷 第4期   页码 746-754 doi: 10.1016/j.eng.2019.06.006

摘要：

 在电子束选区熔化技术（EBSM）工艺中，制造部件的性质受到每一道熔道沉积质量的影响。然而，熔道的形成受到各种物理现象和工艺参数的支配，这些参数之间的相关性十分复杂，难以通过实验得出。近来，介观建模技术已成为模拟电子束（EB）熔化过程以及揭示特定熔道形貌的形成机制的手段。尽管如此，人们对工艺参数与熔道特征之间的相关性尚未有定量的理解。本文从介观模拟的结果出发，研究了熔道的形态特征，同时引入了熔道宽度和高度等关键性描述指标，以便从数值上评估沉积质量。本文还定量研究了各种工艺参数的影响，从而导出了工艺条件和熔道特征之间的相关性。最后，本文提出了一种由介观建模和数据挖掘技术组成的仿真驱动优化框架，并讨论了框架的潜力和局限性。

关键词： 电子束选区熔化     介观模型     数据挖掘    

HTML PDF 收藏

Investigation on multiple-melting behavior of nano-CaCO3/polypropylene composites

LIN Zhidan, ZENG Chunlian, MAI Kancheng

《化学科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 81-86 doi: 10.1007/s11705-007-0017-5

摘要： The multiple melting-peak behavior of polypropylene (PP) in nano-CaCO/PP composites and modified nano-CaCO/PP composites were investigated under the condition of isothermal crystallization and nonisothermal crystallization. The result indicated that the addition of nano-CaCO markedly increased the crystallization temperatures of PP and induced the formation of the β-crystal of PP. The crystallization temperatures of nano-CaCO/PP composites modified by reactive monomers were further increased, but the melting-peak intensity of the β-crystal of PP was not greatly influenced. While in the presence of dicumyl peroxide, nano-CaCO/PP composites modified by reactive monomers led to the significant increase in the melting-peak intensity of the β-crystal of PP. The double melting-peak of PP was observed, which was attributed to the formation of two kinds of different crystallization forms of α-crystal or β-crystal during the crystallization of PP. With the increase of crystallization temperatures, the double melting-peak moved toward the high-temperature side. The intensity of high-temperature melting peak was higher than that of low-temperature melting peak in nano-CaCO/PP composites. While in modified nano-CaCO/PP composites crystallized at higher temperature, the intensity of high-temperature melting peak was lower than that of low-temperature melting peak. The isothermal crystallization time had little effect on the melting temperatures.

关键词： polypropylene     nano-CaCO/PP     presence     melting-peak behavior     low-temperature    

HTML PDF 收藏

Differences in microstructure and properties between selective laser melting and traditional manufacturing

Bo SONG,Xiao ZHAO,Shuai LI,Changjun HAN,Qingsong WEI,Shifeng WEN,Jie LIU,Yusheng SHI

《机械工程前沿（英文）》 2015年 第10卷 第2期   页码 111-125 doi: 10.1007/s11465-015-0341-2

摘要：

Selective laser melting (SLM), as one of the additive manufacturing technologies, is widely investigated to fabricate metal parts. In SLM, parts are manufactured directly from powders in a layer-by-layer fashion; SLM also provides several advantages, such as production of complex parts with high three-dimensional accuracy, compared with other additive manufacturing technologies. Therefore, SLM can be applied in aeronautics, astronautics, medicine, and die and mould industry. However, this technique differs from traditional methods, such as casting and forging; for instance, the former greatly differs in terms of microstructure and properties of products. This paper summarizes relevant studies on metal material fabrication through SLM. Based on a work completed in Huazhong Univ. Sci Tech., Rapid Manuf. Center (HUST-RMC) and compared with characteristics described in other reported studies, microstructure, properties, dimensional accuracy, and application of SLM are presented.

关键词： selective laser melting     microstructure     performance     application    

HTML PDF 收藏

Build orientation determination of multi-feature mechanical parts in selective laser melting via multi-objective

《机械工程前沿（英文）》 2023年 第18卷 第2期 doi: 10.1007/s11465-022-0737-8

摘要： Selective laser melting (SLM) is a unique additive manufacturing (AM) category that can be used to manufacture mechanical parts. It has been widely used in aerospace and automotive using metal or alloy powder. The build orientation is crucial in AM because it affects the as-built part, including its part accuracy, surface roughness, support structure, and build time and cost. A mechanical part is usually composed of multiple surface features. The surface features carry the production and design knowledge, which can be utilized in SLM fabrication. This study proposes a method to determine the build orientation of multi-feature mechanical parts (MFMPs) in SLM. First, the surface features of an MFMP are recognized and grouped for formulating the particular optimization objectives. Second, the estimation models of involved optimization objectives are established, and a set of alternative build orientations (ABOs) is further obtained by many-objective optimization. Lastly, a multi-objective decision making method integrated by the technique for order of preference by similarity to the ideal solution and cosine similarity measure is presented to select an optimal build orientation from those ABOs. The weights of the feature groups and considered objectives are achieved by a fuzzy analytical hierarchy process. Two case studies are reported to validate the proposed method with numerical results, and the effectiveness comparison is presented. Physical manufacturing is conducted to prove the performance of the proposed method. The measured average sampling surface roughness of the most crucial feature of the bracket in the original orientation and the orientations obtained by the weighted sum model and the proposed method are 15.82, 10.84, and 10.62 μm, respectively. The numerical and physical validation results demonstrate that the proposed method is desirable to determine the build orientations of MFMPs with competitive results in SLM.

关键词： selective laser melting (SLM)     build orientation determination     multi-feature mechanical part (MFMP)     fuzzy analytical hierarchy process     multi-objective decision making (MODM)    

HTML PDF 收藏

STRENGTHENING NON-POINT SOURCE POLLUTION CONTROL TO PROMOTE AGRICULTURAL GREEN DEVELOPMENT

《农业科学与工程前沿（英文）》 2023年 第10卷 第4期   页码 503-509 doi: 10.15302/J-FASE-2023528

摘要：

STRENGTHENING NON-POINT SOURCE POLLUTION CONTROL TO PROMOTE AGRICULTURAL GREEN DEVELOPMENT

关键词： GREEN     AGRICULTURAL     PROMOTE     POLLUTION     SOURCE     DEVELOPMENT     POINT     STRENGTHENING     CONTROL    

HTML PDF 收藏

Study on the crystal morphology and melting behavior of isothermally crystallized composites of short

Mingtao RUN, Hongzan SONG, Yanping HAO

《化学科学与工程前沿（英文）》 2009年 第3卷 第3期   页码 255-264 doi: 10.1007/s11705-009-0008-9

摘要： The spherulites of the short carbon fiber(SCF)/poly (trimethylene terephthalate) (PTT) composites formed in limited space at designed temperatures, and their melting behaviors were studied by the polarized optical microscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM), respectively. The results suggest that SCF content, isothermal crystallization temperatures, and the film thicknesses influence the crystal morphology of the composites. The dimension of the spherulites is decreased with increasing SCF content, but whether banded or nonbanded spherulites will form in the composites is not dependent on SCF content. However, the crystal morphology of the composites depends strongly on the temperature. When the isothermal crystallization temperatures increase from 180°C to 230°C, the crystal morphology of SCF/PTT composites continuously changes in the following order: nonbanded → banded → nonbanded spherulites. Discontinuous circle lines form in the film when the film thickness increases from 30 to 60 μm. Basing on the SEM observation, it is found that these circle lines are cracks formed due to the constriction difference of the different parts of the spherulites. These cracks are formed when the film is cooled from the isothermal crystallization temperature to the room temperature at a slow cooling rate; while they will disappear gradually at different temperatures in the heating process. The crack will appear/disappear first around the center of the spherulite when the film was cooled/heated. The nontwisted or slightly twisted lamellas will reorganize to form highly twisted lamellas inducing apparent banded texture of the spherulites.

关键词： poly(trimethylene terephthalate)     short carbon fiber     banded spherulites     crack    

HTML PDF 收藏

Trajectory planning of mobile robots using indirect solution of optimal control method in generalized point-to-point

M. NAZEMIZADEH, H. N. RAHIMI, K. AMINI KHOIY

《机械工程前沿（英文）》 2012年 第7卷 第1期   页码 23-28 doi: 10.1007/s11465-012-0304-9

摘要：

This paper presents an optimal control strategy for optimal trajectory planning of mobile robots by considering nonlinear dynamic model and nonholonomic constraints of the system. The nonholonomic constraints of the system are introduced by a nonintegrable set of differential equations which represent kinematic restriction on the motion. The Lagrange’s principle is employed to derive the nonlinear equations of the system. Then, the optimal path planning of the mobile robot is formulated as an optimal control problem. To set up the problem, the nonlinear equations of the system are assumed as constraints, and a minimum energy objective function is defined. To solve the problem, an indirect solution of the optimal control method is employed, and conditions of the optimality derived as a set of coupled nonlinear differential equations. The optimality equations are solved numerically, and various simulations are performed for a nonholonomic mobile robot to illustrate effectiveness of the proposed method.

关键词： mobile robot     trajectory planning     nonlinear dynamic     optimal control    

HTML PDF 收藏

Research on low emission MSW gasification and melting system

XIAO Gang, NI Mingjiang, CHI Yong, JIN Yuqi, ZHANG Jiaquan, MIAO Qi, CEN Kefa

《环境科学与工程前沿（英文）》 2007年 第1卷 第4期   页码 498-503 doi: 10.1007/s11783-007-0080-7

摘要： In order to eliminate secondary pollution caused by municipal solid waste (MSW) incineration, a MSW gasification and melting process is proposed. The process is expected to reduce the emission of pollutants, especially heavy-meta

关键词： gasification     incineration     municipal     heavy-meta     secondary    

HTML PDF 收藏

Two-dimensional modeling of sintering of a powder layer on top of nonporous substrate

Tiebing CHEN, Yuwen ZHANG,

《机械工程前沿（英文）》 2010年 第5卷 第2期   页码 143-148 doi: 10.1007/s11465-010-0006-0

摘要： Selective laser sintering (SLS) of a two-component metal powder layer on the top of multiple sintered layers by a moving Gaussian laser beam is modeled. The loose metal powder layer is composed of a powder mixture with significantly different melting points. The physical model that accounts the shrinkage induced by melting is described by using a temperature-transforming model. The effects of the porosity and the thickness of the atop loose powder layer with different numbers of the existing sintered metal powder layers below on the sintering process are numerically investigated. The present work will provide a better understanding to simulate much more complicated three-dimensional SLS process.

关键词： laser     sintering     melting     solidification     heat transfer    

HTML PDF 收藏

Toward autonomous mining: design and development of an unmanned electric shovel via point cloud-based

《机械工程前沿（英文）》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0686-2

摘要： With the proposal of intelligent mines, unmanned mining has become a research hotspot in recent years. In the field of autonomous excavation, environmental perception and excavation trajectory planning are two key issues because they have considerable influences on operation performance. In this study, an unmanned electric shovel (UES) is developed, and key robotization processes consisting of environment modeling and optimal excavation trajectory planning are presented. Initially, the point cloud of the material surface is collected and reconstructed by polynomial response surface (PRS) method. Then, by establishing the dynamical model of the UES, a point to point (PTP) excavation trajectory planning method is developed to improve both the mining efficiency and fill factor and to reduce the energy consumption. Based on optimal trajectory command, the UES performs autonomous excavation. The experimental results show that the proposed surface reconstruction method can accurately represent the material surface. On the basis of reconstructed surface, the PTP trajectory planning method rapidly obtains a reasonable mining trajectory with high fill factor and mining efficiency. Compared with the common excavation trajectory planning approaches, the proposed method tends to be more capable in terms of mining time and energy consumption, ensuring high-performance excavation of the UES in practical mining environment.

关键词： autonomous excavation     unmanned electric shovel     point cloud     excavation trajectory planning    

HTML PDF 收藏

标题 作者 时间 类型 操作

Room temperature liquid metal: its melting point, dominating mechanism and applications

Junheng FU, Chenglin ZHANG, Tianying LIU, Jing LIU

期刊论文

Phase change effect of low melting point metal for an automatic cooling of USB flash memory

Haoshan GE, Jing LIU

期刊论文

Liquid metal as energy transportation medium or coolant under harsh environment with temperature below zero centigrade

Yunxia GAO, Lei WANG, Haiyan LI, Jing LIU

期刊论文

双层辉光离子渗金属技术特点

高原,徐晋勇,高清,安晋平,徐重

期刊论文

A steam dried municipal solid waste gasification and melting process

Gang XIAO, Baosheng JIN, Mingjiang NI, Kefa CEN, Yong CHI, Zhongxin TAN

期刊论文

用于介观模拟电子束选区熔化的数据挖掘技术

钱亚, 闫文韬, 林峰

期刊论文

Investigation on multiple-melting behavior of nano-CaCO3/polypropylene composites

LIN Zhidan, ZENG Chunlian, MAI Kancheng

期刊论文

Differences in microstructure and properties between selective laser melting and traditional manufacturing

Bo SONG,Xiao ZHAO,Shuai LI,Changjun HAN,Qingsong WEI,Shifeng WEN,Jie LIU,Yusheng SHI

期刊论文

Build orientation determination of multi-feature mechanical parts in selective laser melting via multi-objective

期刊论文

STRENGTHENING NON-POINT SOURCE POLLUTION CONTROL TO PROMOTE AGRICULTURAL GREEN DEVELOPMENT

期刊论文

Study on the crystal morphology and melting behavior of isothermally crystallized composites of short

Mingtao RUN, Hongzan SONG, Yanping HAO

期刊论文

Trajectory planning of mobile robots using indirect solution of optimal control method in generalized point-to-point

M. NAZEMIZADEH, H. N. RAHIMI, K. AMINI KHOIY

期刊论文

Research on low emission MSW gasification and melting system

XIAO Gang, NI Mingjiang, CHI Yong, JIN Yuqi, ZHANG Jiaquan, MIAO Qi, CEN Kefa

期刊论文

Two-dimensional modeling of sintering of a powder layer on top of nonporous substrate

Tiebing CHEN, Yuwen ZHANG,

期刊论文

Toward autonomous mining: design and development of an unmanned electric shovel via point cloud-based

期刊论文