27 resultados para 15201
Resumo:
本书系统地介绍了微/纳米力学测试技术中最常用的压入和划入技术及其典型应用。全书共分13章。测试技术方面,内容涉及接触力学、测试原理、方法、校准、仪器、力学参量、影响因素。典型应用方面,内容涉及在表面工程、微机电系统、生物、高聚物和金属玻璃等领域内的微/纳米力学行为的测试。本书可供力学、材料、物理、电子、机械、生物和化学等领域的研究人员、工程技术人员以及大专院校相关专业的师生参考。
目录
前言
第1章 绪论
1.1硬度的定义和分类
1.2纳米压入和划入技术的发展
1.3纳米压入和划入技术的特点
参考文献
第2章 压入接触力学
2.1弹性接触
2.1.1 Soeddon解
2.1.2锥形压针
2.1.3球形压针
2.1.4圆柱压针
2.2弹塑性接触
2.2.1塑性发生
2.2.2完全塑性
2.2.3材料响应
参考文献
第3章 纳米压入测试原理
3.1压入硬度和模量
3.2连续刚度测量
3.3载荷一深度数据确定的材料参数
3.3.1马氏硬度
3.3.2压入蠕变
3.3.3压入松弛
3.3.4压入弹性功和塑性功
参考文献
第4章 纳米压入测试方法
4.1压针类型
4.1.1玻氏压针
4.1.2立方角压针
4.1.3维氏压针
4.1.4努氏压针
4.1.5圆锥压针
4.1.6球形压针
4.1.7圆柱压针
4.1.8楔形压针
4.1.9考虑因素
4.2测试环节
4.2.1样品准备
4.2.2环境控制
4.2.3间距选择
4.2.4表面探测
4.2.5驱动方式
4.2.6测试步骤
4.2.7测试报告
参考文献
第5章 纳米压入的确认和校准
5.1直接确认和校准
5.2间接校准
5.3测试和校准的实例
参考文献
第6章 纳米压入和划入的测量仪器
6.1仪器技术指标的定义
6.2美国Mrs公司
6.3美国Hysitmn公司
6.4瑞士CSM公司
6.5英国MML公司
6.6澳大利亚CSIRO公司
6.7测量仪器的发展趋势
参考文献
第7章 力学参量的测量
7.1压入方式
7.1.1硬度和模量
7.1.2断裂韧度
7.1.3蠕变和粘弹行为
7.1.4压入应力??应变曲线
7.1.5加卸载曲线涉及的
部分现象
7.2划人方式
7.2.1块体材料
7.2.2薄膜材料
7.2.3粗糙度
7.3弯曲方式
7.3.1微悬臂梁静载弯曲
7.3.2微桥静载弯曲
7.3.3微结构疲劳
7.4吸引方式
7.5声发射测试
7.6温度测试
参考文献.
第8章 影响纳米压入测试的因素
8.1测试仪器的影响
8.1.1压针缺陷
8.1.2测试方法
8.1.3接触零点的确定
8.1.4载荷和位移的分辨力
8.2样品的表面状态和性质
8.2.1表面吸湿
8.2.2表面粗糙度
8.2.3残余应力
8.2.4凹陷和凸起变形
8.3纳米压入和划入测试所面临的问题
参考文献
第9章 在表面工程中的应用
9.1金属材料表面激光强化的力学表征
9.2硬质膜的力学和摩擦学性能评估
9.2.1显微硬度测试
9.2.2纳米压人测试
9.2.3纳米划入测试
9.2.4膜材的影响
参考文献
第10章 在微机电系统中的应用
10.1薄膜测试
10.1.1典型薄膜材料的硬度和模量
10.1.2薄膜疲劳
10.1.3淀积工艺对二氧化硅薄膜力学性质的影响
10.2微结构弯曲
10.2.1微结构的静态弯曲
10.2.2微结构的动态弯曲
参考文献
第11章 在生物及其相关材料中的应用
11.1人工林杉木管胞细胞壁
11.2人体腰椎骨
11.3存储液对人体牙齿微力学性能的影响
参考文献
第12章 在高聚物中的应用
12.1PMMA单轴拉伸和弯曲力学行为
12.2划入测试的理论分析
12.3韧性行为的描述
12.4脆性行为的描述
12.4.1温度效应
12.4.2应变率效应
参考文献
第13章 在金属玻璃中的应用
13.1硬度和屈服应力的关系
13.2不连续的塑性变形
13.3压痕形貌和微结构变化
13.4应变率效应
13.5钕基金属玻璃的变形行为
参考文献
附录 常见问题的回答
1测试数量
2压入间距
3压入深度
4泊松比的选择
5典型材料的参数
6断裂韧度测试压针的选择
7纳米薄膜的测试
8典型材料的压入变形行为
9显微硬度和纳米压入硬度的关系
10压入影响区及其边界效应
10.1压入影响区的有限元模拟
10.2边界距离影响的有限元模拟
10.3压人间距影响的测试
参考文献
Resumo:
Cap. 1. La reinvención del museo etnológico. Xavier Roigé i Ventura Cap. 2. La mise en patrimoine du catharisme. Enjeux de territoire, enjeux d’identité. Marie-Carmen Garcia. Cap. 3. Más allá del museo. Las activaciones económicas del patrimonio: de los parques naturales a las fiestas temáticas. Agustí Andreu i Tomàs. Cap. 4. La patrimonialización de un territorio a través de los museos etnográficos: el caso de Extremadura. Aniceto Delgado Méndez. Cap. 5. La situación de los museos, colecciones, centros de interpretación y otros equipamientos patrimoniales del Alto Pirineo catalán. Jordi Abella Pons. Cap. 6. Patrimonio, conocimiento y dinamización. Una experiencia de trabajo en el Priorat (Catalunya). Salvador Palomar. Cap. 7. Experiencias de desarrollo local en el Pirineo aragonés basadas en la valorización del patrimonio. Aurelio García Gállego. Cap. 8. Las dimensiones sociales y culturales del patrimonio edificado: una propuesta para su estudio. Iñaki Arrieta Urtizberea.
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The stomachs of 819 Atlantic bluefin tuna (Thunnus thynnus) sampled from 1988 to 1992 were analyzed to compare dietary differences among five feeding grounds on the New England continental shelf (Jeffreys Ledge, Stellwagen Bank, Cape Cod Bay, Great South Channel, and South of Martha’s Vineyard) where a majority of the U.S. Atlantic commercial catch occurs. Spatial variation in prey was expected to be a primary influence on bluefin tuna distribution during seasonal feeding migrations. Sand lance (Ammodytes spp.), Atlantic herring (Clupea harengus), Atlantic mackerel (Scomber scombrus), squid (Cephalopoda), and bluefish (Pomatomus saltatrix) were the top prey in terms of frequency of occurrence and percent prey weight for all areas combined. Prey composition was uncorrelated between study areas, with the exception of a significant association between Stellwagen Bank and Great South Channel, where sand lance and Atlantic herring occurred most frequently. Mean stomach-contents biomass varied significantly for all study areas, except for Great South Channel and Cape Cod Bay. Jeffreys Ledge had the highest mean stomach-contents biomass (2.0 kg) among the four Gulf of Maine areas and Cape Cod Bay had the lowest (0.4 kg). Diet at four of the five areas was dominated by one or two small pelagic prey and several other pelagic prey made minor contributions. In contrast, half of the prey species found in the Cape Cod Bay diet were demersal species, including the frequent occurrence of the sessile fig sponge (Suberites ficus). Prey size selection was consistent over a wide range of bluefin length. Age 2–4 sand lance and Atlantic herring and age 0–1 squid and Atlantic mackerel were common prey for all sizes of bluefin tuna. This is the first study to compare diet composition of western Atlantic bluefin tuna among discrete feeding grounds during their seasonal migration to the New England continental shelf and to evaluate predator-prey size relationships. Previous studies have not found a common occurrence of demersal species or a pre-dominance of Atlantic herring in the diet of bluefin tuna.
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The optical and structural properties of anodized AlxGa1-xAs films were investigated by using optical reflectance, X-ray photoemission and Auger electron spectroscopy (XPS and AES). II was found that the anodization process occurs progressively from the surface to the bulk of AlxGa1-xAs and the formed oxidation film comprises mainly oxides of Al and Ga together with a relatively small amount of As. The refractive indexes of the anodized Al0.8Ga0.2As film and Al0.8Ga0.2As film itself were deduced to be about 1.80 and 3.25, respectively, indicating that the anodization film is desirable for anti-reflection coating of the surface of AlxGa1-xAs/GaAs solar cells. (C) 1997 Elsevier Science S.A.
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本文报道了两种具有稳定的低熔体黏度的有望用树脂转移模塑成形工艺的聚酰亚胺基体树脂,讨论了树脂的高温流变行为以及黏度与温度、时间的关系.
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1923/10/16 (Numéro 15201).
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UANL
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Resumen basado en el del autor en catalán
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The combination of model predictive control based on linear models (MPC) with feedback linearization (FL) has attracted interest for a number of years, giving rise to MPC+FL control schemes. An important advantage of such schemes is that feedback linearizable plants can be controlled with a linear predictive controller with a fixed model. Handling input constraints within such schemes is difficult since simple bound contraints on the input become state dependent because of the nonlinear transformation introduced by feedback linearization. This paper introduces a technique for handling input constraints within a real time MPC/FL scheme, where the plant model employed is a class of dynamic neural networks. The technique is based on a simple affine transformation of the feasible area. A simulated case study is presented to illustrate the use and benefits of the technique.
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Aqüicultura orgânica certificada (comercialização de camarões e ostras orgânicas). Localização: Goianinha (RN)
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The reconfiguration of a distribution network is a change in its topology, aiming to provide specific operation conditions of the network, by changing the status of its switches. It can be performed regardless of any system anomaly. The service restoration is a particular case of reconfiguration and should be performed whenever there is a network failure or whenever one or more sections of a feeder have been taken out of service for maintenance. In such cases, loads that are supplied through lines sections that are downstream of portions removed for maintenance may be supplied by the closing of switches to the others feeders. By classical methods of reconfiguration, several switches may be required beyond those used to perform the restoration service. This includes switching feeders in the same substation or for substations that do not have any direct connection to the faulted feeder. These operations can cause discomfort, losses and dissatisfaction among consumers, as well as a negative reputation for the energy company. The purpose of this thesis is to develop a heuristic for reconfiguration of a distribution network, upon the occurrence of a failure in this network, making the switching only for feeders directly involved in this specific failed segment, considering that the switching applied is related exclusively to the isolation of failed sections and bars, as well as to supply electricity to the islands generated by the condition, with significant reduction in the number of applications of load flows, due to the use of sensitivity parameters for determining voltages and currents estimated on bars and lines of the feeders directly involved with that failed segment. A comparison between this process and classical methods is performed for different test networks from the literature about networks reconfiguration
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)