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新型PB-PSOI器件表面电场和温度分布模型研究

孙伟锋,高珊,陆生礼,陈军宁

《中国工程科学》 2009年 第11卷 第11期   页码 82-87

摘要:

根据泊松方程和热扩散方程提出了新型PB-PSOI 器件漂移区的二维表面电场分布模型和温度分布模型,模型计算结果与Medici模拟结果相一致。根据所提出的模型,重点研究了埋氧化层厚度及长度对漂移区表面电场分布和温度分布的影响,最后给出了PB-PSOI 器件的埋氧化层厚度和长度的优化设计方法。

关键词: PB-PSOI     表面电场     温度分布     埋氧化层    

Response surface regression analysis on FeCrBSi particle in-flight properties by plasma spray

Runbo MA,Lihong DONG,Haidou WANG,Shuying CHEN,Zhiguo XING

《机械工程前沿(英文)》 2016年 第11卷 第3期   页码 250-257 doi: 10.1007/s11465-016-0401-2

摘要:

This work discusses the interactive effects between every two of argon flow rate, voltage, and spray distance on in-flight particles by plasma spray and constructs models that can be used in predicting and analyzing average velocity and temperature. Results of the response surface methodology show that the interactive effects between voltage and spray distance on particle in-flight properties are significant. For a given argon flow rate, particle velocity and temperature response surface are obviously bending, and a saddle point exists. With an increase in spray distance, the interactive effects between voltage and argon flow rate on particle in-flight properties appear gradually and then weaken. With an increase in voltage, the interactive effects between spray distance and argon flow rate on particle in-flight properties change from appearing to strengthening and then to weakening.

关键词: particle velocity     particle temperature     interactive effects     response surface    

Grafting of PEG400 onto the surface of LLDPE/SMA film

CHEN Gufeng, ZHANG Yi, XU Jiarui, ZHU Yafei

《化学科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 128-131 doi: 10.1007/s11705-007-0024-6

摘要: Linear low-density polyethylene (LLDPE) was melt and blended with styrene-maleic anhydride copolymer (SMA). The blending films were then immersed in poly(ethylene glycol)400 (PEG400) at room temperature. The surface composition of the blend films was determined by Fourier transform infra-red spectroscopy coupled with a variable incidence angle attenuated total reflection accessory (ATR-FTIR). Results show that PEG400 can be grafted onto the surface of the films via esterification with SMA. The immersion of PEG promotes the enrichment of SMA onto the surface of the films. The water contact angle data show that grafting of PEG400 onto PE can greatly improve the hydrophilicity of the PE surface. These experiments show that surface functionalization of polyethylene films by blending SMA and then surface grafting of PEG is feasible, which suggest an effective and simple route for PE surface modification via blending and grafting.

关键词: hydrophilicity     temperature     effective     immersion     reflection accessory    

Characteristics and application of road absorbing solar energy

Zhihua ZHOU, Shan HU, Xiaoyan ZHANG, Jian ZUO

《能源前沿(英文)》 2013年 第7卷 第4期   页码 525-534 doi: 10.1007/s11708-013-0278-2

摘要: If the heat of road surface can be stored in summer, the road surface temperature will be decreased to prevent permanent deformation of pavement. Besides, if the heat stored is released, it can supply heat for buildings or raise the road surface temperature for snow melting in winter. A road-solar energy system was built in this study, and the heat transfer mechanism and effect of the system were analyzed according to the monitored solar radiant heat, the solar energy absorbed by road and the heat stored by soil. The results showed that the road surface temperature was mainly affected by solar radiation, but the effect is hysteretic in nature. The temperature of the solar road surface was 3°C–6°C lower than that of the ordinary road surface. The temperature of the solar road along the vertical direction was 2°C–5°C lower than that of the ordinary road. The temperature difference increased as the distance to the heat transfer tubes decreased. The average solar collector efficiency of the system was 14.4%, and the average solar absorptivity of road surface was 36%.

关键词: solar energy     road-solar energy system     road surface temperature     solar absorptivity of road surface     solar collector efficiency of system    

Predictive model to decouple the contributions of friction and plastic deformation to machined surface

Subhash ANURAG, Yuebin GUO,

《机械工程前沿(英文)》 2010年 第5卷 第3期   页码 247-255 doi: 10.1007/s11465-010-0097-7

摘要: Temperature on the machined surface is critical for surface integrity and the performance of a precision component. However, the temperature of a machined surface is challenging for in-situ measurement. Furthermore, the individual contribution of tool/work friction and plastic deformation of work materials to surface temperature is very difficult to quantify because the measured temperature is always the resultant temperature. This lack of understanding on the temperature distribution blocks the design of effective cutting tool geometries and materials to minimize surface temperature. This study provides a finite element method based on a predictive model to decouple the contributions of tool/work friction and material plastic deformation to surface temperature in a dry cutting process. The study shows that the plastic deformation of work material contributes to the majority of surface temperature, whereas the tool/work friction contribution is secondary. High temperatures are produced when more materials are plowed under the cutting edge. A large tool/work friction leads to higher surface temperatures, and the use of a cutting tool with physical properties in process simulation significantly improves the accuracy of predicted surface temperatures. Residual stress reversal from subsurface maximum residual to surface maximum residual stress may occur when tool/work friction increases.

关键词: surface temperature     friction     residual stress     finite element analysis (FEA)     dry cutting     tool property    

利用嫦娥一号卫星微波探测仪数据反演月球表面物理温度

李芸,姜景山,王振占,张德海,张晓辉

《中国工程科学》 2013年 第15卷 第7期   页码 106-112

摘要:

本文利用理论研究的结果,建立了月表物理温度反演模型,结合嫦娥一号微波探测仪(CELMS)数据对全月球物理温度进行了反演。同时分析了物理温度变化对微波辐射的影响及其与表面地形等的关系,为其他月表信息反演提供了依据和物理温度的测量信息。

关键词: 嫦娥一号微波探测仪     月球表面物理温度     反演    

Thermal analysis of lubricated three-dimensional contact bodies considering interface roughness

《机械工程前沿(英文)》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0672-8

摘要: Surface roughness and thermal action are of remarkable importance in the lubrication performance of mechanical components, especially in extreme conditions. However, available studies mainly focus on the full-film lubrication conditions without considering temperature rise and real 3D surface roughness due to the complexity of surface topography and temperature characteristics. Moreover, studies on the interfacial thermal behaviors of 3D rough surface lubricated contact in an extended range of working conditions remain limited. In this paper, a deterministic mixed thermal elastohydrodynamic lubrication model considering real 3D surface roughness and thermal effects is proposed. In this model, pressure and temperature are coupled with each other, the computation of elastic deformation is accelerated through the discrete convolution and fast Fourier transform method, the temperature field is calculated with the column sweeping technique, and the semi-system method is introduced to improve convergence and numerical stability under severe conditions. The model is validated by comparing its results with available published numerical and experimental results. The thermal behaviors of the contact interface are studied in a wide range of working conditions. The influences of surface roughness and thermal effect on lubrication performance are revealed. The results show that the proposed model can be used as a powerful analysis tool for lubrication performance and temperature prediction in various heavy-load, high-speed lubricated components over a wide range of lubrication conditions.

关键词: thermal elastohydrodynamic lubrication     surface roughness effect     thermal effect     temperature characteristics     severe conditions    

深表土冻结壁变形规律

郭永富

《中国工程科学》 2011年 第13卷 第11期   页码 81-88

摘要:

利用ANSYS软件建立数学模型,分析不同地压、不同冻结壁厚度、不同冻结壁平均温度、不同开挖段高与冻结壁变形之间的关系。通过研究发现,井帮位移随冻结壁平均温度的降低、冻结壁厚度的增大而减小,随施工段高增大、地层地压值的增大而增大,且地压值的变化对冻结壁的变形影响最为显著。据此提出了深表土冻结壁应按变形条件进行设计,且施工段高是影响冻结壁稳定性的极为重要的参数,在施工中应严格控制。研究提出当冻结壁厚度为10 m左右,平均温度达到-20 ℃时,采取降低冻结壁平均温度的方式比增加冻结壁厚度能更加有效地提高冻结壁的

关键词: 井帮位移     冻结壁厚度     平均温度     掘砌段高    

大体积混凝土受寒潮袭击时半无限平面问题的无限平面化

黄达海,王从峰

《中国工程科学》 2002年 第4卷 第7期   页码 33-39

摘要:

在分析混凝土表面裂缝特点的基础上,针对受寒潮袭击中的大体积混凝土,提出表面裂缝问题的半无限平面假设。利用混凝土传热的延迟性质,研究了任意降温过程中半无限平面问题无限平面化的条件。采用叠加原理,提出了环境温度任意下降时混凝土表面温度及表层温度计算的新方法。利用400mm×400 mm×220 mm块状试件,构造了混凝土表面开裂问题的半无限平面模型。在室外环境下,对混凝土表面温度与表层温度进行了连续测量,并对该方法进行了验证。试验结果表明,在环境温度单调下降的条件下,对混凝土受寒潮袭击时的半无限平面问题进行无限平面化处理是可行的。

关键词: 混凝土     表层温度     半无限平面问题     降温过程     条件等价性     模型试验    

Surface modification of titanium dioxide for electrophoretic particles

PENG Xuhui, LE Yuan, BIAN Shuguang, LI Woyuan, WU Wei, DAI Haitao, CHEN Jianfeng

《化学科学与工程前沿(英文)》 2007年 第1卷 第4期   页码 338-342 doi: 10.1007/s11705-007-0061-1

摘要: To prepare stable electrophoretic ink (E Ink) needs color particles to be uniformly dispersed in the organic medium. Thus, t-he modification of inorganic particle surface is required. In this paper, Titanium dioxide modified by alumina has been studied. The surface composition and structures of modified particles have been characterized by X-ray photoelectron spectrometer (XPS), X-ray diffractometer (XRD) and Fourier transform infrared spectrometer (FT-IR). The dispersibility and electrophoretic mobility of these particles in tetrachloroethylene (TCE) have been investigated by laser particle size analyzer, static sedimentation and electrophoretic instrument. Effects of temperature, pH value and stirring rate on the dispersibility and the charge property of samples have been discussed. The results indicate the settle time of modified TiO can last 120 h with the response time of 35 s under the optimized modifying conditions, in which temperature is 85°C–90°C, pH is 8–9 and stirring rate is 800 r · min. The dispersibility and electrophoretic mobility have been significantly improved, which means that the modified TiO is suitable for electrophoretic ink particles.

关键词: inorganic particle     temperature     tetrachloroethylene     transform     optimized modifying    

An optimized solar-air degree-day method to evaluate energy demand for poultry buildings in different climate zones

Yang WANG, Baoming LI

《农业科学与工程前沿(英文)》 2020年 第7卷 第4期   页码 478-489 doi: 10.15302/J-FASE-2019289

摘要:

The degree-day method is widely used to determine energy consumption but cannot be directly applied to poultry buildings without improvements in its accuracy. This study was designed to optimize the degree-day calculation and proposes a solar-air degree-day method, which can be used to calculate the cooling and heating degree-days and the annual cooling and heating loads under different climate conditions for poultry buildings. In this paper, the solar-air degree-day method was proposed, which considers the effects of solar radiation with different wall orientations and surface colors. Five Chinese cities, Harbin, Beijing, Chongqing, Kunming and Guangzhou, were selected to represent different climate zones to determine the solar-air degree-days. The heating and cooling energy requirements for different climates were compared by DeST (Designer’s Simulation Toolkit) simulation and the solar-air degree-day method. Approaches to decrease energy consumption were developed. The results showed that the maximum relative error was less than 10%, and the new method was not significantly different from the DeST simulation ( >0.05). The accuracy of calculating energy requirements was improved by the solar-air degree-day method in the different climate zones. Orientation and surface color effects on energy consumption need to be considered, and external walls of different orientations should have different surface colors.

关键词: base temperature     energy consumption     solar radiation     orientation     surface color    

Cell surface protein engineering for high-performance whole-cell catalysts

Hajime Nakatani,Katsutoshi Hori

《化学科学与工程前沿(英文)》 2017年 第11卷 第1期   页码 46-57 doi: 10.1007/s11705-017-1609-3

摘要: Cell surface protein engineering facilitated by accumulation of information on genome and protein structure involves heterologous production and modification of cell surface proteins using genetic engineering, and is important for the development of high-performance whole-cell catalysts. In this field, cell surface display is a major technology by exposing target proteins, such as enzymes, on the cell surface using a carrier protein. The target proteins are fused to the carrier proteins that transport and tether them to the cell surface, as well as to a secretion signal. This paper reviews cell surface display systems for prokaryotic and eukaryotic cells from the perspective of carrier proteins, which determine the number of displayed molecules, and the localization, size, and direction ( or terminal anchoring) of the passengers. We also discuss advanced methods for displaying multiple enzymes and a new method for the immobilization of whole-cell catalysts using adhesive surface proteins.

关键词: cell surface engineering     surface display     whole-cell catalysts     bioprocess    

Emerging challenges to structural integrity technology for high-temperature applications

TU Shantung

《机械工程前沿(英文)》 2007年 第2卷 第4期   页码 375-387 doi: 10.1007/s11465-007-0066-y

摘要: Structural integrity technology has been widely used with great success for the design, manufacture and failure prevention of modern constructions such as chemical and petrochemical plants, power generation and energy conversion systems, as well as space and oceanic exploration. The modern needs of structural integrity technology are largely attributed to the increase of service temperature of the structures that results in the efficiency improvement in energy conversion and chemical processing technologies. Besides the needs arising from large-scale high-temperature plants, the high tech developments, such as micro chemo-mechanical systems and high-power electronics, provide new challenges to structural integrity technology. The present paper summarizes the recent technical progresses in large process plants and the aviation industry, micro chemo-mechanical systems, fuel cells, high-temperature electronics, and packaging and coating technologies. The state-of-the-art of structural integrity technology for high temperature applications is reviewed. Suggestions are provided for the improvement of current design and assessment methods.

关键词: manufacture     aviation industry     conversion     petrochemical     temperature    

An Exploration of Surface Integrity Remanufacturing for Aeroengine Components

Qiao Xiang,Yong He,Ting-hong Hou

《工程管理前沿(英文)》 2016年 第3卷 第2期   页码 107-114 doi: 10.15302/J-FEM-2016025

摘要: Surface integrity is the major factor impacting on the operation quality, service life and reliability of the aeroengine components. The surface integrity of aeroengine component is damaged by the failures such as crack, deformation, oxidation, corrosion, erosion, and microstructural degeneration. It adopts advanced remanufacturing technologies to restore or improve the surface integrity and regenerate these high value parts. This paper firstly puts forward the concept, namely surface integrity remanufacturing for aeroengine components, and its connotation. The key remanufacturing technologies have been developed to repair the components with surface damages. Ultimately, some application examples of surface integrity remanufacturing technologies as well as their effects in aeroengine maintenance are introduced. The discarded components have been reused and their service lives have been extended and their reliability has been increased by implementing surface integrity remanufacturing. It has realized “The Repaired Components Outpacing the New Ones”, material saving, energy saving, and emission reduction.

关键词: aeroengine component     surface integrity     remanufacturing     surface integrity remanufacturing    

Review on mechanism and process of surface polishing using lasers

Arun KRISHNAN, Fengzhou FANG

《机械工程前沿(英文)》 2019年 第14卷 第3期   页码 299-319 doi: 10.1007/s11465-019-0535-0

摘要: Laser polishing is a technology of smoothening the surface of various materials with highly intense laser beams. When these beams impact on the material surface to be polished, the surface starts to be melted due to the high temperature. The melted material is then relocated from the ‘peaks to valleys’ under the multidirectional action of surface tension. By varying the process parameters such as beam intensity, energy density, spot diameter, and feed rate, different rates of surface roughness can be achieved. High precision polishing of surfaces can be done using laser process. Currently, laser polishing has extended its applications from photonics to molds as well as bio-medical sectors. Conventional polishing techniques have many drawbacks such as less capability of polishing freeform surfaces, environmental pollution, long processing time, and health hazards for the operators. Laser polishing on the other hand eliminates all the mentioned drawbacks and comes as a promising technology that can be relied for smoothening of initial topography of the surfaces irrespective of the complexity of the surface. Majority of the researchers performed laser polishing on materials such as steel, titanium, and its alloys because of its low cost and reliability. This article gives a detailed overview of the laser polishing mechanism by explaining various process parameters briefly to get a better understanding about the entire polishing process. The advantages and applications are also explained clearly to have a good knowledge about the importance of laser polishing in the future.

关键词: laser polishing     surface roughness     process parameters     mechanism    

标题 作者 时间 类型 操作

新型PB-PSOI器件表面电场和温度分布模型研究

孙伟锋,高珊,陆生礼,陈军宁

期刊论文

Response surface regression analysis on FeCrBSi particle in-flight properties by plasma spray

Runbo MA,Lihong DONG,Haidou WANG,Shuying CHEN,Zhiguo XING

期刊论文

Grafting of PEG400 onto the surface of LLDPE/SMA film

CHEN Gufeng, ZHANG Yi, XU Jiarui, ZHU Yafei

期刊论文

Characteristics and application of road absorbing solar energy

Zhihua ZHOU, Shan HU, Xiaoyan ZHANG, Jian ZUO

期刊论文

Predictive model to decouple the contributions of friction and plastic deformation to machined surface

Subhash ANURAG, Yuebin GUO,

期刊论文

利用嫦娥一号卫星微波探测仪数据反演月球表面物理温度

李芸,姜景山,王振占,张德海,张晓辉

期刊论文

Thermal analysis of lubricated three-dimensional contact bodies considering interface roughness

期刊论文

深表土冻结壁变形规律

郭永富

期刊论文

大体积混凝土受寒潮袭击时半无限平面问题的无限平面化

黄达海,王从峰

期刊论文

Surface modification of titanium dioxide for electrophoretic particles

PENG Xuhui, LE Yuan, BIAN Shuguang, LI Woyuan, WU Wei, DAI Haitao, CHEN Jianfeng

期刊论文

An optimized solar-air degree-day method to evaluate energy demand for poultry buildings in different climate zones

Yang WANG, Baoming LI

期刊论文

Cell surface protein engineering for high-performance whole-cell catalysts

Hajime Nakatani,Katsutoshi Hori

期刊论文

Emerging challenges to structural integrity technology for high-temperature applications

TU Shantung

期刊论文

An Exploration of Surface Integrity Remanufacturing for Aeroengine Components

Qiao Xiang,Yong He,Ting-hong Hou

期刊论文

Review on mechanism and process of surface polishing using lasers

Arun KRISHNAN, Fengzhou FANG

期刊论文