期刊文献+
共找到163篇文章
< 1 2 9 >
每页显示 20 50 100
Entransy dissipation minimization for liquid-solid phase change processes 被引量:41
1
作者 XIA ShaoJun,CHEN LinGen & SUN FengRui Postgraduate School,Naval University of Engineering,Wuhan 430033,China 《Science China(Technological Sciences)》 SCIE EI CAS 2010年第4期960-968,共9页
The liquid-solid phase change process of a simple one-dimensional slab is studied in this paper.By taking entransy dissipation minimization as optimization objective,the optimal external reservoir temperature profiles... The liquid-solid phase change process of a simple one-dimensional slab is studied in this paper.By taking entransy dissipation minimization as optimization objective,the optimal external reservoir temperature profiles are derived by using optimal control theory under the condition of a fixed freezing or melting time.The entransy dissipation corresponding to the optimal heat exchange strategies of minimum entransy dissipation is 8/9 of that corresponding to constant reservoir temperature operations,which is independent of all system parameters.The obtained results for entransy dissipation minimization are also compared with those obtained for the optimal heat exchange strategies of minimum entropy generation and constant reservoir temperature operations by numerical examples.The obtained results can provide some theoretical guidelines for the choice of optimal cooling or heating strategy in practical liquid-solid phase change processes. 展开更多
关键词 liquid-solid phase change process entransy DISSIPATION MINIMIZATION optimal control FINITE time THERMODYNAMICS GENERALIZED THERMODYNAMIC optimization
原文传递
Crystallization Process of Superlattice-Like Sb/SiO_2 Thin Films for Phase Change Memory Application
2
作者 Xiao-Qin Zhu Rui Zhang +4 位作者 Yi-Feng Hu Tian-Shu Lai Jian-Hao Zhang Hua Zou Zhi-Tang Song 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第5期99-103,共5页
After compositing with SiO_2 layers, it is shown that superlattice-like Sb/SiO_2 thin films have higher crystallization temperature(~240°C), larger crystallization activation energy(6.22 e V), and better data... After compositing with SiO_2 layers, it is shown that superlattice-like Sb/SiO_2 thin films have higher crystallization temperature(~240°C), larger crystallization activation energy(6.22 e V), and better data retention ability(189°C for 10 y). The crystallization of Sb in superlattice-like Sb/SiO_2 thin films is restrained by the multilayer interfaces. The reversible resistance transition can be achieved by an electric pulse as short as 8 ns for the Sb(3 nm)/SiO_2(7 nm)-based phase change memory cell. A lower operation power consumption of 0.09 m W and a good endurance of 3.0 × 10~6 cycles are achieved. In addition, the superlattice-like Sb(3 nm)/SiO_2(7 nm) thin film shows a low thermal conductivity of 0.13 W/(m·K). 展开更多
关键词 Sb Crystallization process of Superlattice-Like Sb/SiO2 Thin Films for phase change Memory Application SiO
下载PDF
Model-based optimal design of phase change ionic liquids for efficient thermal energy storage 被引量:3
3
作者 Huaiwei Shi Xiang Zhang +1 位作者 Kai Sundmacher Teng Zhou 《Green Energy & Environment》 SCIE CSCD 2021年第3期392-404,共13页
The selection of phase change material(PCM)plays an important role in developing high-efficient thermal energy storage(TES)processes.Ionic liquids(ILs)or organic salts are thermally stable,non-volatile,and non-flammab... The selection of phase change material(PCM)plays an important role in developing high-efficient thermal energy storage(TES)processes.Ionic liquids(ILs)or organic salts are thermally stable,non-volatile,and non-flammable.Importantly,researchers have proved that some ILs possess higher latent heat of fusion than conventional PCMs.Despite these attractive characteristics,yet surprisingly,little research has been performed to the systematic selection or structural design of ILs for TES.Besides,most of the existing work is only focused on the latent heat when selecting PCMs.However,one should note that other properties such as heat capacity and thermal conductivity could affect the TES performance as well.In this work,we propose a computer-aided molecular design(CAMD)based method to systematically design IL PCMs for a practical TES process.The effects of different IL properties are simultaneously captured in the IL property models and TES process models.Optimal ILs holding a best compromise of all the properties are identified through the solution of a formulated CAMD problem where the TES performance of the process is maximized.[MPyEtOH][TfO]is found to be the best material and excitingly,the identified top nine ILs all show a higher TES performance than the traditional PCM paraffin wax at 10 h thermal charging time. 展开更多
关键词 Ionic liquid phase change material Thermal energy storage Computer-aided molecular design process modelling and evaluation
下载PDF
Improving the data retention of phase change memory by using a doping element in selected Ge_2Sb_2Te_5
4
作者 Yaoyao Lu Daolin Cai +5 位作者 Yifeng Chen Shuai Yan Lei Wu Yuanguang Liu Yang Li Zhitang Song 《Journal of Semiconductors》 EI CAS CSCD 2019年第4期29-34,共6页
The crystallization characteristics of a ubiquitous T-shaped phase change memory(PCM) cell, under SET current pulse and very small disturb current pulse, have been investigated by finite element modelling. As analyzed... The crystallization characteristics of a ubiquitous T-shaped phase change memory(PCM) cell, under SET current pulse and very small disturb current pulse, have been investigated by finite element modelling. As analyzed in this paper, the crystallization region under SET current pulse presents first on the corner of the bottom electron contact(BEC) and then promptly forms a filament shunting down the amorphous phase to achieve the low-resistance state, whereas the tiny disturb current pulse accelerates crystallization at the axis of symmetry in the phase change material. According to the different crystallization paths, a new structure of phase change material layer is proposed to improve the data retention for PCM without impeding SET operation.This structure only requires one or two additional process steps to dope nitrogen element in the center region of phase change material layer to increase the crystallization temperature in this confined region. The electrical-thermal characteristics of PCM cells with incremental doped radius have been analyzed and the best performance is presented when the doped radius is equal to the radius of the BEC. 展开更多
关键词 phase change memory CRYSTALLIZATION process SET CURRENT PULSE small disturb CURRENT PULSE finite ELEMENT simulation
下载PDF
寒区相变蓄热墙体多因素热特性研究
5
作者 邱菊 恽定康 +1 位作者 张宇 刘昌宇 《建筑节能(中英文)》 CAS 2024年第3期126-131,共6页
在墙体中应用相变材料可以显著改善墙体的保温蓄热能力,但相变材料厚度和墙体构造的选择尚需科学论证。基于寒区气象特点,选择适用于寒区建筑外墙的相变储能材料,从墙体的传热特性角度出发,通过建立不同相变材料层厚度和多种构造的相变... 在墙体中应用相变材料可以显著改善墙体的保温蓄热能力,但相变材料厚度和墙体构造的选择尚需科学论证。基于寒区气象特点,选择适用于寒区建筑外墙的相变储能材料,从墙体的传热特性角度出发,通过建立不同相变材料层厚度和多种构造的相变墙体模型,研究多种情况相变墙体的热特性。结果表明,相变墙体在冬季的保温蓄热能力受相变材料层位置和厚度影响,夏季效果主要受相变材料厚度影响;相变材料厚度为40 mm的中间型相变墙体和相变材料厚度为60 mm的内侧型相变墙体比较适合寒区建筑应用。研究所得结论可为寒区相变墙体的结构设计优化提供参考。 展开更多
关键词 寒区 相变材料 传热过程 影响因素 热学性能
下载PDF
基于PCM的轻质智能调温墙体材料设计
6
作者 万孝军 《江苏建材》 2024年第1期12-14,共3页
基于相变材料(Phase Change Material,简称PCM)的轻质智能调温墙体,通过将PCM覆盖在墙壁内部,具有储存热量和环保等优点的相变材料可以实现室内温度自动调节。提出了一种基于PCM的轻质智能调温墙体设计方案,结合加气混凝土的生产工艺流... 基于相变材料(Phase Change Material,简称PCM)的轻质智能调温墙体,通过将PCM覆盖在墙壁内部,具有储存热量和环保等优点的相变材料可以实现室内温度自动调节。提出了一种基于PCM的轻质智能调温墙体设计方案,结合加气混凝土的生产工艺流程,探索采用后浸渍法和直接加入法,结果表明本材料可以有效地减小室内温度波动和能耗,实现初步的自动温控效果,为建筑节能提供了一种新的解决方案。 展开更多
关键词 相变材料 特性研究 工艺制备
下载PDF
双翅片矩形相变储能单元蓄热性能实验研究 被引量:3
7
作者 罗意彬 段文超 +3 位作者 严景好 李杰 孙小琴 廖曙光 《储能科学与技术》 CAS CSCD 北大核心 2024年第2期405-415,共11页
以双翅片矩形相变储能单元为研究对象,开展不同边界温度下(50℃、55℃、64℃、69℃、73℃)相变材料熔化过程的可视化实验,通过观察相变材料固液相变界面、温度和液相率变化分析储能单元内相变材料的熔化行为和传热规律,探究不同边界温... 以双翅片矩形相变储能单元为研究对象,开展不同边界温度下(50℃、55℃、64℃、69℃、73℃)相变材料熔化过程的可视化实验,通过观察相变材料固液相变界面、温度和液相率变化分析储能单元内相变材料的熔化行为和传热规律,探究不同边界温度对储能单元蓄热性能的影响。研究表明:熔化后期储能单元内出现的熔化死角极大延长了蓄热时间,熔化死角用时比均大于30%;边界温度增加,固液相界面形状无明显变化,相变材料内温度分布及变化趋势相似,但固液相界面演化进程加快,自然对流加强,相变材料内温度分布不均匀性最大增加60%,相变温度最大增加2.9℃;边界温度从50℃提高至73℃时,完全熔化时间缩短510 min,且边界温度越低时(Fo)/(Ste)越大,表明在边界温度较低时,增加边界温度对相变材料的强化传热效果更明显。 展开更多
关键词 双翅片 矩形相变储能单元 边界温度 熔化过程 自然对流
下载PDF
针对机械热处理工艺在弛豫控制相变技术中的研究
8
作者 王金海 《科学技术创新》 2024年第2期93-97,共5页
机械热处理工艺在驰豫控制相变技术中的研究旨在通过调控材料的组织结构和相变行为,改善材料的力学性能和性能稳定性。该研究主要包括加热工艺优化、相变动力学研究、材料结构调控、相变组织演变模拟和相变产物性能调控等方面。通过本研... 机械热处理工艺在驰豫控制相变技术中的研究旨在通过调控材料的组织结构和相变行为,改善材料的力学性能和性能稳定性。该研究主要包括加热工艺优化、相变动力学研究、材料结构调控、相变组织演变模拟和相变产物性能调控等方面。通过本研究,找出实现材料性能的优化和稳定性的提高措施。本研究对于提高材料性能和开发新型材料具有重要意义,并在多个领域具有广泛的应用前景。 展开更多
关键词 机械 热处理工艺 弛豫控制 相变技术
下载PDF
相变储能材料在新能源领域的应用 被引量:1
9
作者 周文凯 王赛羽 《化工设计通讯》 CAS 2024年第2期91-93,共3页
为了使相变储能材料在新能源领域中得到更广泛的应用,我们需要更高效地储存和利用新能源,以缓解不可再生资源逐渐枯竭和环境污染问题。深入探讨了相变储能材料的特点和意义,分析了其分类依据,并详细介绍了相变储能材料在太阳能热利用系... 为了使相变储能材料在新能源领域中得到更广泛的应用,我们需要更高效地储存和利用新能源,以缓解不可再生资源逐渐枯竭和环境污染问题。深入探讨了相变储能材料的特点和意义,分析了其分类依据,并详细介绍了相变储能材料在太阳能热利用系统、燃料电池系统、电力系统等领域的应用。同时,我们对相变储能材料的发展进行了展望,并建议我国加大对其研究开发的力度,积极制定相关应用计划,以推动我国新能源储存技术的发展。这不仅能促进新能源领域的发展,还能为我国的可持续发展做出重要贡献。 展开更多
关键词 新能源 相变储能材料 储能技术 相变过程
下载PDF
生物质泡沫炭研究进展
10
作者 李晓阳 叶远镕 +3 位作者 陈洪雷 冯晓静 李经洽 赵鑫 《当代化工研究》 CAS 2024年第15期20-23,共4页
泡沫炭是一种三维多孔泡沫状轻质炭材料,因其密度低、强度高、良好的导电导热性能及优异的化学稳定性等引起人们的广泛关注。生物质被用于制备泡沫材料最广泛的原材料,有着价格便宜、种类丰富、对环境污染小及易于得到且可再生等优点。... 泡沫炭是一种三维多孔泡沫状轻质炭材料,因其密度低、强度高、良好的导电导热性能及优异的化学稳定性等引起人们的广泛关注。生物质被用于制备泡沫材料最广泛的原材料,有着价格便宜、种类丰富、对环境污染小及易于得到且可再生等优点。介绍了以生物质为原料制备的各种生物质泡沫炭及其应用,并结合当前生物质泡沫炭的研究现状,对今后的方向作出展望。 展开更多
关键词 泡沫炭 生物质 发泡工艺 相变储能 孔结构
下载PDF
聚乳酸基相变材料研究进展
11
作者 招兆璋 黄锦涛 闵永刚 《现代塑料加工应用》 CAS 北大核心 2024年第3期44-47,共4页
综述了聚乳酸基相变材料的多种制备工艺,包括溶剂蒸发法、气凝胶成型法、混合复合挤出法、静电纺丝法和3D打印法。介绍了聚乳酸基相变材料在建筑、纺织品、药用抑菌和食品包装等领域的应用,并对聚乳酸基相变材料的发展趋势进行了展望。
关键词 聚乳酸基 相变材料 制备工艺 应用
下载PDF
一起误触发导致换流器阀组换相失败故障的分析
12
作者 朱奕琦 江一睿 周刚 《电气开关》 2024年第1期98-100,共3页
换相失败是直流输电系统的常见故障,是由于晶闸管换流阀存在元件恢复阻断能力特性造成的。对某换流站换流器阀组换相失败原因进行分析,通过告警分析、换相过程分析,查明换相过程中电磁干扰或触发回路板卡异常导致换流阀误触发,从而造成... 换相失败是直流输电系统的常见故障,是由于晶闸管换流阀存在元件恢复阻断能力特性造成的。对某换流站换流器阀组换相失败原因进行分析,通过告警分析、换相过程分析,查明换相过程中电磁干扰或触发回路板卡异常导致换流阀误触发,从而造成换相失败。该故障提示我们重视控制主机程序优化,及时更新维护电磁屏蔽元件和触发板卡,避免产生亚稳态时换流阀误触发的情况。 展开更多
关键词 换流阀 换相失败 换相过程分析 误触发
下载PDF
高温下金属材料组织及夹杂物变化过程的原位观察
13
作者 杨春 《甘肃冶金》 2024年第4期108-112,118,共6页
随着工业技术的不断发展,对新材料的研发也有了更高要求。利用高温共聚焦显微镜的显微成像系统对不锈钢和碳钢热轧钢板以一定范围内的升降温速率原位观察试样在加热和冷却过程中显微组织的变化,通过实验观察确定各阶段相变的起始和结束... 随着工业技术的不断发展,对新材料的研发也有了更高要求。利用高温共聚焦显微镜的显微成像系统对不锈钢和碳钢热轧钢板以一定范围内的升降温速率原位观察试样在加热和冷却过程中显微组织的变化,通过实验观察确定各阶段相变的起始和结束点、奥氏体晶粒变化全过程以及钢中夹杂物在钢液中的聚集、长大等行为。 展开更多
关键词 高温共聚焦显微镜 高温金相 原位观察 相变过程 夹杂物行为
下载PDF
Coupled models of heat transfer and phase transformation for the run-out table in hot rolling 被引量:4
14
作者 Shui-xuan CHEN Jun ZOU Xin FU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第7期932-939,共8页
Mathematical models are been proposed to simulate the thermal and metallurgical behaviors of the strip occtLrring on the run-out table (ROT) in a hot strip mill. A variational method is utilized for the discretizati... Mathematical models are been proposed to simulate the thermal and metallurgical behaviors of the strip occtLrring on the run-out table (ROT) in a hot strip mill. A variational method is utilized for the discretization of the governing transient conduction-convection equation, with heat transfer coefficients adaptively determined by the actual mill data. To consider the thermal effect of phase transformation during cooling, a constitutive equation for describing austenite decomposition kinetics of steel in air and water cooling zones is coupled with the heat transfer model. As the basic required inputs in the numerical simulations, thermal material properties are experimentally measured for three carbon steels and the least squares method is used to statistically derive regression models for the properties, including specific heat and thermal conductivity. The numerical simulation and experimental results show that the setup accuracy of the temperature prediction system of ROT is effectively improved. 展开更多
关键词 Run-out table (ROT) Cooling process Heat transfer phase change Material properties
下载PDF
An Experimental Study on Thermal Characteristics of Laurie Acid as a Latent Heat Storage Material during Melting Process 被引量:1
15
作者 Ahmet SARI 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第2期240-243,共4页
The objective of this study was to establish the thermal characteristics of the lauric acid (95% purity) as a latent heat storage material filled in the annulus of vertical concentric double pipe during its melting pr... The objective of this study was to establish the thermal characteristics of the lauric acid (95% purity) as a latent heat storage material filled in the annulus of vertical concentric double pipe during its melting process,The temperature data were used to determine the thermal characteristics,including the temporal temperature variations and the effects of the mass flow rate and the inlet temperature of the heat transfer fluid on the heat transfer coefficient and the heat charging fraction during the melting process,The results indicated that the time to reach to heat charging fraction of 1.0 could be altered by changing the mass flow rate and the inlet temperature of the heat transfer fluid. 展开更多
关键词 lauric acid phase change material thermal characteristics melting process
下载PDF
Plasma-Particle Transfer Process with Phase-Changeand Chemistry Effects
16
作者 WangBoyi TianWendong 《Journal of Thermal Science》 SCIE EI CAS CSCD 1998年第2期97-103,共7页
A numerical model is proposed to analyze mass, momentum, and energy transfer between plasma andparticles in d.c. arc-heated and confined jet reactors at atmospheric pressure. It emphasizes the phasechange and thermal ... A numerical model is proposed to analyze mass, momentum, and energy transfer between plasma andparticles in d.c. arc-heated and confined jet reactors at atmospheric pressure. It emphasizes the phasechange and thermal chemistry of particles and includes some other effects such as flow turbulence, gascompressibility and temperature-dependence of the transport properties under the plasma condition.Example calculations for plasma-dissociated zircon process indicate the influences of reactor operationparameters on the plasma jet and particle behavior. 展开更多
关键词 plasma-particle interaction transfer process turbulent jet phase change thermal chemistry numerical model
原文传递
The etching process and mechanism analysis of Ta-Sb2Te3 film based on inductively coupled plasma
17
作者 Yongkang Xu Sannian Song +2 位作者 Wencheng Fang Chengxing Li Zhitang Song 《Journal of Semiconductors》 EI CAS CSCD 2020年第12期12-16,共5页
Compared to the conventional phase change materials,the new phase change material Ta-Sb2Te3 has the advantages of excellent data retention and good material stability.In this letter,the etching characteristics of Ta-S... Compared to the conventional phase change materials,the new phase change material Ta-Sb2Te3 has the advantages of excellent data retention and good material stability.In this letter,the etching characteristics of Ta-Sb2Te3 were studied by using CF4/Ar.The results showed that when CF4/Ar=25/25,the etching power was 600 W and the etching pressure was 2.5 Pa,the etching speed was up to 61 nm/min.The etching pattern of Ta-Sb2Te3 film had a smooth side wall and good perpendicularity(close to 90°),smooth surface of the etching(RMS was 0.51nm),and the etching uniformity was fine.Furthermore,the mechanism of this etching process was analyzed by X-ray photoelectron spectroscopy(XPS).The main damage mechanism of ICP etching in CF4/Ar was studied by X-ray diffraction(XRD). 展开更多
关键词 new phase change material inductively couple plasma etching process etching characteristics mechanism
下载PDF
具备近似等压放电过程的近似等温压缩CO_(2)储能系统特性研究 被引量:3
18
作者 赵攀 张仕强 +3 位作者 许文盼 吴汶泽 刘艾杰 王江峰 《西安交通大学学报》 EI CAS CSCD 北大核心 2023年第1期34-44,共11页
为满足小容量特殊负载对(近似)稳定电能供应的需求,本文遵循(近似)等温压缩空气储能的基本原理,采用液压活塞和压力容器壁内置螺旋盘管换热的方式,基于气/液相变过程,提出了具备近似等压放电过程的近似等压等温压缩CO_(2)储能系统。通... 为满足小容量特殊负载对(近似)稳定电能供应的需求,本文遵循(近似)等温压缩空气储能的基本原理,采用液压活塞和压力容器壁内置螺旋盘管换热的方式,基于气/液相变过程,提出了具备近似等压放电过程的近似等压等温压缩CO_(2)储能系统。通过建立系统核心部件的热力学分析模型与性能评价指标,分析了该系统在初次充放电循环中的性能,探究了压力容器初始压力、最大压力和螺旋盘管水温等参数变化时的系统性能,探索了系统有、无螺旋盘管换热对性能的影响规律。结果表明,该系统在初次充放电循环中充放电效率、热效率和能量密度分别为62.67%、53.05%和0.500 3 kW·h·m^(-3)。同时,该系统在放电过程中可以获得近似恒定的电能输出,输出功率在636~840 kW范围内变化。本文的研究工作可丰富压缩气体储能理论体系,具有重要的实用价值和现实意义。 展开更多
关键词 压缩CO_(2)储能 近似等温过程 气/液相变 近似等压放电
下载PDF
基于Pickering乳化技术环氧树脂相变支撑剂的制备及评价 被引量:2
19
作者 曲占庆 樊家铖 +4 位作者 郭天魁 石一曼 陈铭 刘晓强 王美佳 《中国石油大学学报(自然科学版)》 EI CAS CSCD 北大核心 2023年第4期111-118,共8页
常规固体支撑剂普遍存在运移能力差、刚性结构易堵塞裂缝等缺陷,可以液相注入的支撑剂成为主要发展方向。基于乳化热固性树脂体系研发一种相变支撑剂并对其进行评价。相变支撑剂体系基于双酚A型环氧树脂,采用二亚乙基三胺与丁基缩水甘... 常规固体支撑剂普遍存在运移能力差、刚性结构易堵塞裂缝等缺陷,可以液相注入的支撑剂成为主要发展方向。基于乳化热固性树脂体系研发一种相变支撑剂并对其进行评价。相变支撑剂体系基于双酚A型环氧树脂,采用二亚乙基三胺与丁基缩水甘油醚的加成物作为固化剂,树脂质量1%的SiO_(2)固体颗粒作为乳化剂,随后分别加入树脂质量1.25%的中空玻璃微球和树脂质量25%的无水乙醇用于降低树脂密度和稀释树脂。通过工艺优化,得到粒径为4.5、3、2~2.5、2、1和0.5 mm的支撑剂颗粒。对所得支撑剂进行评价,结果表明:由于材料的低密度和高强度,支撑剂的运移能力和导流能力可充分满足针对高闭合压力的非常规储层的开采需要。 展开更多
关键词 相变支撑剂 乳化热固性树脂 体系优选 工艺优化 性能评价
下载PDF
Rate of Phase Difference Change Estimation in Single Airborne Passive Locating System 被引量:5
20
作者 王军虎 王永生 +2 位作者 郭涛 王洪浩 王强 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2009年第2期184-190,共7页
As an important parameter in the single airborne passive locating system, the rate of phase difference change contains range information of the radio emitter. Taking single carrier sine pulse signals as an example, th... As an important parameter in the single airborne passive locating system, the rate of phase difference change contains range information of the radio emitter. Taking single carrier sine pulse signals as an example, this article illustrates the principle of passive location through measurement of rates of phase difference change and analyzes the structure of measurement errors. On the basis of the Cramér-Rao lower bound (CRLB), an algorithm associated with time-chips is proposed to determine the rates of pha... 展开更多
关键词 LOCATION rate of phase difference change Cramér-Rao lower bound phase discrimination multi-chip processing
原文传递
上一页 1 2 9 下一页 到第
使用帮助 返回顶部