968 resultados para 8.2 ka event,


Relevância:

100.00% 100.00%

Publicador:

Resumo:

[ES] La creación de empresas desde las universidades no sólo es una vía de transferencia de tecnología sino que además contribuye al desarrollo de la economía regional. Sin embargo, debido al carácter relativamente reciente del fenómeno de las spin-offs universitarias, no abundan los estudios empíricos sobre el tema. En este trabajo analizamos qué factores presentes en las universidades influyen en la creación de spin-offs desde la óptica de la teoría de los recursos. Los resultados indican que los recursos financieros e institucionales se encuentran relacionados positivamente con el emprendimiento universitario.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

[ES] Este trabajo analiza la relación entre el desarrollo regional y la creación de empresas desde una perspectiva micro del enfoque institucional, a partir de los stakeholders más relevantes que intervienen en el proceso. La contribución de los emprendedores al crecimiento económico regional viene siendo objeto de especial atención por los poderes públicos, para lo que se necesita un sistema de referencias que permita evaluar la adecuación de los programas públicos de fomento de la actividad emprendedora.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

[ES] A pesar de que los economistas han dedicado enorme esfuerzo a examinar la racionalidad de los contratos en agricultura, pocos estudios se han llevado a cabo en viticultura. Sin embargo, se observan diferencias contractuales en la producción de uva y vino. En el presente trabajo se analizan las estructuras contractuales actualmente utilizadas en varias regiones vitivinícolas. Independientemente de las características inherentes en los contratos, se obtiene que estos mecanismos permiten a las bodegas articular sus requisitos con respecto a la calidad de las uvas producidas por los agricultores.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

[ES] El objetivo de este trabajo es establecer en qué medida los índices de riesgo país más utilizados por la comunidad económica y financiera internacional, en concreto, el índice de Euromoney y el ICRG, recogen las variables relevantes en el desencadenamiento de las crisis monetarias y financieras externas, como un aspecto básico en la evaluación de su capacidad para medir adecuadamente el riesgo de los diferentes países.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

[ES] Uno de los motivos de mayor peso que inducen a las organizaciones a la implantación de sistemas de gestión medioambiental es la presión ejercida por los grupos de interés. La investigación aporta resultados sobre cuál es la influencia de los grupos de interés sobre la gestión medioambiental. Con este fin hemos analizado 142 centros de negocio españoles, poseedores de los certificados ISO 14000 y/o EMAS, estableciendo la relación de los grupos de interés y su influencia con el modo en que se realiza en dichas organizaciones la gestión medioambiental.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

(Document pdf contains 193 pages) Executive Summary (pdf, < 0.1 Mb) 1. Introduction (pdf, 0.2 Mb) 1.1 Data sharing, international boundaries and large marine ecosystems 2. Objectives (pdf, 0.3 Mb) 3. Background (pdf, < 0.1 Mb) 3.1 North Pacific Ecosystem Metadatabase 3.2 First federation effort: NPEM and the Korea Oceanographic Data Center 3.2 Continuing effort: Adding Japan’s Marine Information Research Center 4. Metadata Standards (pdf, < 0.1 Mb) 4.1 Directory Interchange Format 4.2 Ecological Metadata Language 4.3 Dublin Core 4.3.1. Elements of DC 4.4 Federal Geographic Data Committee 4.5 The ISO 19115 Metadata Standard 4.6 Metadata stylesheets 4.7 Crosswalks 4.8 Tools for creating metadata 5. Communication Protocols (pdf, < 0.1 Mb) 5.1 Z39.50 5.1.1. What does Z39.50 do? 5.1.2. Isite 6. Clearinghouses (pdf, < 0.1 Mb) 7. Methodology (pdf, 0.2 Mb) 7.1 FGDC metadata 7.1.1. Main sections 7.1.2. Supporting sections 7.1.3. Metadata validation 7.2 Getting a copy of Isite 7.3 NSDI Clearinghouse 8. Server Configuration and Technical Issues (pdf, 0.4 Mb) 8.1 Hardware recommendations 8.2 Operating system – Red Hat Linux Fedora 8.3 Web services – Apache HTTP Server version 2.2.3 8.4 Create and validate FGDC-compliant Metadata in XML format 8.5 Obtaining, installing and configuring Isite for UNIX/Linux 8.5.1. Download the appropriate Isite software 8.5.2. Untar the file 8.5.3. Name your database 8.5.4. The zserver.ini file 8.5.5. The sapi.ini file 8.5.6. Indexing metadata 8.5.7. Start the Clearinghouse Server process 8.5.8. Testing the zserver installation 8.6 Registering with NSDI Clearinghouse 8.7 Security issues 9. Search Tutorial and Examples (pdf, 1 Mb) 9.1 Legacy NSDI Clearinghouse search interface 9.2 New GeoNetwork search interface 10. Challenges (pdf, < 0.1 Mb) 11. Emerging Standards (pdf, < 0.1 Mb) 12. Future Activity (pdf, < 0.1 Mb) 13. Acknowledgments (pdf, < 0.1 Mb) 14. References (pdf, < 0.1 Mb) 15. Acronyms (pdf, < 0.1 Mb) 16. Appendices 16.1. KODC-NPEM meeting agendas and minutes (pdf, < 0.1 Mb) 16.1.1. Seattle meeting agenda, August 22–23, 2005 16.1.2. Seattle meeting minutes, August 22–23, 2005 16.1.3. Busan meeting agenda, October 10–11, 2005 16.1.4. Busan meeting minutes, October 10–11, 2005 16.2. MIRC-NPEM meeting agendas and minutes (pdf, < 0.1 Mb) 16.2.1. Seattle Meeting agenda, August 14-15, 2006 16.2.2. Seattle meeting minutes, August 14–15, 2006 16.2.3. Tokyo meeting agenda, October 19–20, 2006 16.2.4. Tokyo, meeting minutes, October 19–20, 2006 16.3. XML stylesheet conversion crosswalks (pdf, < 0.1 Mb) 16.3.1. FGDCI to DIF stylesheet converter 16.3.2. DIF to FGDCI stylesheet converter 16.3.3. String-modified stylesheet 16.4. FGDC Metadata Standard (pdf, 0.1 Mb) 16.4.1. Overall structure 16.4.2. Section 1: Identification information 16.4.3. Section 2: Data quality information 16.4.4. Section 3: Spatial data organization information 16.4.5. Section 4: Spatial reference information 16.4.6. Section 5: Entity and attribute information 16.4.7. Section 6: Distribution information 16.4.8. Section 7: Metadata reference information 16.4.9. Sections 8, 9 and 10: Citation information, time period information, and contact information 16.5. Images of the Isite server directory structure and the files contained in each subdirectory after Isite installation (pdf, 0.2 Mb) 16.6 Listing of NPEM’s Isite configuration files (pdf, < 0.1 Mb) 16.6.1. zserver.ini 16.6.2. sapi.ini 16.7 Java program to extract records from the NPEM metadatabase and write one XML file for each record (pdf, < 0.1 Mb) 16.8 Java program to execute the metadata extraction program (pdf, < 0.1 Mb) A1 Addendum 1: Instructions for Isite for Windows (pdf, 0.6 Mb) A2 Addendum 2: Instructions for Isite for Windows ADHOST (pdf, 0.3 Mb)

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

During the summer of 1997, we surveyed 50 waterbodies in Washington State to determine the distribution of the aquatic weevil Euhrychiopsis lecontei Dietz. We collected data on water quality and the frequency of occurrence of watermilfoil species within selected watermilfoil beds to compare the waterbodies and determine if they were related to the distribution E. lecontei . We found E. lecontei in 14 waterbodies, most of which were in eastern Washington. Only one lake with weevils was located in western Washington. Weevils were associated with both Eurasian ( Myriophyllum spicatum L.) and northern watermilfoil ( M. sibiricum K.). Waterbodies with E. lecontei had significantly higher ( P < 0.05) pH (8.7 ± 0.2) (mean ± 2SE), specific conductance (0.3 ± 0.08 mS cm -1 ) and total alkalinity (132.4 ± 30.8 mg CaCO 3 L -1 ). We also found that weevil presence was related to surface water temperature and waterbody location ( = 24.3, P ≤ 0.001) and of all the models tested, this model provided the best fit (Hosmer- Lemeshow goodness-of-fit = 4.0, P = 0.9). Our results suggest that in Washington State E. lecontei occurs primarily in eastern Washington in waterbodies with pH ≥ 8.2 and specific conductance ≥ 0.2 mS cm -1 . Furthermore, weevil distribution appears to be correlated with waterbody location (eastern versus western Washington) and surface water temperature.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Biological control of exotic plant populations with native organisms appears to be increasing, even though its success to date has been limited. Although many researchers and managers feel that native organisms are easier to use and present less risk to the environment this may not be true. Developing a successful management program with a native insect is dependent on a number of critical factors that need to be considered. Information is needed on the feeding preference of the agent, agent effectiveness, environmental regulation of the agent, unique requirements of the agent, population maintenance of the agent, and time to desired impact. By understanding these factors, researchers and managers can develop a detailed protocol for using the native biological control agent for a specific target plant. . We found E. lecontei in 14 waterbodies, most of which were in eastern Washington. Only one lake with weevils was located in western Washington. Weevils were associated with both Eurasian ( Myriophyllum spicatum L.) and northern watermilfoil ( M. sibiricum K.). Waterbodies with E. lecontei had significantly higher ( P < 0.05) pH (8.7 ± 0.2) (mean ± 2SE), specific conductance (0.3 ± 0.08 mS cm -1 ) and total alkalinity (132.4 ± 30.8 mg CaCO 3 L -1 ). We also found that weevil presence was related to surface water temperature and waterbody location ( = 24.3, P ≤ 0.001) and of all the models tested, this model provided the best fit (Hosmer- Lemeshow goodness-of-fit = 4.0, P = 0.9). Our results suggest that in Washington State E. lecontei occurs primarily in eastern Washington in waterbodies with pH ≥ 8.2 and specific conductance ≥ 0.2 mS cm -1 . Furthermore, weevil distribution appears to be correlated with waterbody location (eastern versus western Washington) and surface water temperature.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Executive Summary: The western National Coastal Assessment (NCA-West) program of EPA, in conjunction with the NOAA National Ocean Service (NOS), conducted an assessment of the status of ecological condition of soft sediment habitats and overlying waters along the western U.S. continental shelf, between the target depths of 30 and 120 m, during June 2003. NCA-West and NOAA/NOS partnered with the West Coast states (Washington (WA), Oregon (OR), and California (CA)), and the Southern California Coastal Water Research Project (SCCWRP) Bight ’03 program to conduct the survey. A total of 257 stations were sampled from Cape Flattery, WA to the Mexican border using standard methods and indicators applied in previous coastal NCA projects. A key study feature was the incorporation of a stratified-random sampling design with stations stratified by state and National Marine Sanctuary (NMS) status. Each of the three states was represented by at least 50 random stations. There also were a total of 84 random stations located within NOAA’s five NMSs along the West Coast including the Olympic Coast NMS (OCNMS), Cordell Bank NMS (CBNMS), Gulf of Farallones NMS (GFNMS), Monterey Bay NMS (MBNMS), and Channel Islands NMS (CINMS). Collection of flatfish via hook-and-line for fish-tissue contaminant analysis was successful at 50 EMAP/NCA-West stations. Through a collaboration developed with the FRAM Division of the Northwest Fisheries Science Center, fish from an additional 63 stations in the same region and depth range were also analyzed for fish-tissue contaminants. Bottom depth throughout the region ranged from 28 m to 125 m for most stations. Two slightly deeper stations from the Southern California Bight (SCB) (131, 134 m) were included in the data set. About 44% of the survey area had sediments composed of sands (< 20% silt-clay), about 47% was composed of intermediate muddy sands (20-80% silt-clay), and about 9% was composed of muds (> 80% silt-clay). The majority of the survey area (97%) had relatively low percent total organic carbon (TOC) levels of < 2%, while a small portion (< 1%) had high TOC levels (> 5%), in a range potentially harmful to benthic fauna. Salinity of surface waters for 92% of the survey area were > 31 psu, with most stations < 31 psu associated with the Columbia River plume. Bottom salinities ranged only between 31.6 and 34.4 psu. There was virtually no difference in mean bottom salinities among states or between NMS and non-NMS stations. Temperatures of surface water (range 8.5 -19.9 °C) and bottom water (range 5.8 -14.7 °C) averaged several degrees higher in CA in comparison to WA and OR. The Δσt index of watercolumn stratification indicated that about 31% of the survey area had strong vertical stratification of the water column. The index was greatest for waters off WA and lowest for CA waters. Only about 2.6 % of the survey area had surface dissolved oxygen (DO) concentrations ≤ 4.8 mg/L, and there were no values below the lower threshold (2.3 mg/L) considered harmful to the survival and growth of marine animals. Surface DO concentrations were higher in WA and OR waters than in CA, and higher in the OC NMS than in the CA sanctuaries. An estimated 94.3% of the area had bottom-water DO concentrations ≤ 4.8 mg/L and 6.6% had concentrations ≤ 2.3 mg/L. The high prevalence of DO from 2.3 to 4.8 mg/L (85% of survey area) is believed to be associated with the upwelling of naturally low DO water across the West Coast shelf. Mean TSS and transmissivity in surface waters (excluding OR due to sample problems) were slightly higher and lower, respectively, for stations in WA than for those in CA. There was little difference in mean TSS or transmissivity between NMS and non-NMS locations. Mean transmissivity in bottom waters, though higher in comparison to surface waters, showed little difference among geographic regions or between NMS and non-NMS locations. Concentrations of nitrate + nitrite, ammonium, total dissolved inorganic nitrogen (DIN) and orthophosphate (P) in surface waters tended to be highest in CA compared to WA and OR, and higher in the CA NMS stations compared to CA non-sanctuary stations. Measurements of silicate in surface waters were limited to WA and CA (exclusive of the SCB) and showed that concentrations were similar between the two states and approximately twice as high in CA sanctuaries compared to OCNMS or nonsanctuary locations in either state. The elevated nutrient concentrations observed at CA NMS stations are consistent with the presence of strong upwelling at these sites at the time of sampling. Approximately 93% of the area had DIN/P values ≤ 16, indicative of nitrogen limitation. Mean DIN/P ratios were similar among the three states, although the mean for the OCNMS was less than half that of the CA sanctuaries or nonsanctuary locations. Concentrations of chlorophyll a in surface waters ranged from 0 to 28 μg L-1, with 50% of the area having values < 3.9 μg L-1 and 10% having values > 14.5 μg L-1. The mean concentration of chlorophyll a for CA was less than half that of WA and OR locations, and concentrations were lowest in non-sanctuary sites in CA and highest at the OCNMS. Shelf sediments throughout the survey area were relatively uncontaminated with the exception of a group of stations within the SCB. Overall, about 99% of the total survey area was rated in good condition (<5 chemicals measured above corresponding effect range low (ERL) concentrations). Only the pesticides 4,4′-DDE and total DDT exceeded corresponding effect range-median (ERM) values, all at stations in CA near Los Angeles. Ten other contaminants including seven metals (As, Cd, Cr, Cu, Hg, Ag, Zn), 2-methylnaphthalene, low molecular weight PAHs, and total PCBs exceeded corresponding ERLs. The most prevalent in terms of area were chromium (31%), arsenic (8%), 2-methylnaphthalene (6%), cadmium (5%), and mercury (4%). The chromium contamination may be related to natural background sources common to the region. The 2-methylnaphthalene exceedances were conspicuously grouped around the CINMS. The mercury exceedances were all at non-sanctuary sites in CA, particularly in the Los Angeles area. Concentrations of cadmium in fish tissues exceeded the lower end of EPA’s non-cancer, human-health-risk range at nine of 50 EMAP/NCA-West and nine of 60 FRAM groundfish-survey stations, including a total of seven NMS stations in CA and two in the OCNMS. The human-health guidelines for all other contaminants were only exceeded for total PCBs at one station located in WA near the mouth of the Columbia River. Benthic species richness was relatively high in these offshore assemblages, ranging from 19 to 190 taxa per 0.1-m2 grab and averaging 79 taxa/grab. The high species richness was reflected over large areas of the shelf and was nearly three times greater than levels observed in estuarine samples along the West Coast (e.g NCA-West estuarine mean of 26 taxa/grab). Mean species richness was highest off CA (94 taxa/grab) and lower in OR and WA (55 and 56 taxa/grab, respectively). Mean species richness was very similar between sanctuary vs. non-sanctuary stations for both the CA and OR/WA regions. Mean diversity index H′ was highest in CA (5.36) and lowest in WA (4.27). There were no major differences in mean H′ between sanctuary vs. nonsanctuary stations for both the CA and OR/WA regions. A total of 1,482 taxa (1,108 to species) and 99,135 individuals were identified region-wide. Polychaetes, crustaceans and molluscs were the dominant taxa, both by percent abundance (59%, 17%, 12% respectively) and percent species (44%, 25%, 17%, respectively). There were no major differences in the percent composition of benthic communities among states or between NMSs and corresponding non-sanctuary sites. Densities averaged 3,788 m-2, about 30% of the average density for West Coast estuaries. Mean density of benthic fauna in the present offshore survey, averaged by state, was highest in CA (4,351 m-2) and lowest in OR (2,310 m-2). Mean densities were slightly higher at NMS stations vs. non-sanctuary stations for both the CA and OR/WA regions. The 10 most abundant taxa were the polychaetes Mediomastus spp., Magelona longicornis, Spiophanes berkeleyorum, Spiophanes bombyx, Spiophanes duplex, and Prionospio jubata; the bivalve Axinopsida serricata, the ophiuroid Amphiodia urtica, the decapod Pinnixa occidentalis, and the ostracod Euphilomedes carcharodonta. Mediomastus spp. and A. serricata were the two most abundant taxa overall. Although many of these taxa have broad geographic distributions throughout the region, the same species were not ranked among the 10 most abundant taxa consistently across states. The closest similarities among states were between OR and WA. At least half of the 10 most abundant taxa in NMSs were also dominant in corresponding nonsanctuary waters. Many of the abundant benthic species have wide latitudinal distributions along the West Coast shelf, with some species ranging from southern CA into the Gulf of Alaska or even the Aleutians. Of the 39 taxa on the list of 50 most abundant taxa that could be identified to species level, 85% have been reported at least once from estuaries of CA, OR, or WA exclusive of Puget Sound. Such broad latitudinal and estuarine distributions are suggestive of wide habitat tolerances. Thirteen (1.2%) of the 1,108 identified species are nonindigenous, with another 121 species classified as cryptogenic (of uncertain origin), and 208 species unclassified with respect to potential invasiveness. Despite uncertainties of classification, the number and densities of nonindigenous species appear to be much lower on the shelf than in the estuarine ecosystems of the Pacific Coast. Spionid polychaetes and the ampharetid polychaete Anobothrus gracilis were a major component of the nonindigenous species collected on the shelf. NOAA’s five NMSs along the West Coast of the U.S. appeared to be in good ecological condition, based on the measured indicators, with no evidence of major anthropogenic impacts or unusual environmental qualities compared to nearby nonsanctuary waters. Benthic communities in sanctuaries resembled those in corresponding non-sanctuary waters, with similarly high levels of species richness and diversity and low incidence of nonindigenous species. Most oceanographic features were also similar between sanctuary and non-sanctuary locations. Exceptions (e.g., higher concentrations of some nutrients in sanctuaries along the CA coast) appeared to be attributable to natural upwelling events in the area at the time of sampling. In addition, sediments within the sanctuaries were relatively uncontaminated, with none of the samples having any measured chemical in excess of ERM values. The ERL value for chromium was exceeded in sediments at the OCNMS, but at a much lower percentage of stations (four of 30) compared to WA and OR non-sanctuary areas (31 of 70 stations). ERL values were exceeded for arsenic, cadmium, chromium, 2- methylnaphthalene, low molecular weight PAHs, total DDT, and 4,4′-DDE at multiple sites within the CINMS. However, cases where total DDT, 4,4′-DDE, and chromium exceeded the ERL values were notably less prevalent at CINMS than in non-sanctuary waters of CA. In contrast, 2-methylnaphthalene above the ERL was much more prevalent in sediments at the CINMS compared to non-sanctuary waters off the coast of CA. While there are natural background sources of PAHs from oil seeps throughout the SCB, this does not explain the higher incidence of 2-methylnaphthalene contamination around CINMS. Two stations in CINMS also had levels of TOC (> 5%) potentially harmful to benthic fauna, though none of these sites exhibited symptoms of impaired benthic condition. This study showed no major evidence of extensive biological impacts linked to measured stressors. There were only two stations, both in CA, where low numbers of benthic species, diversity, or total faunal abundance co-occurred with high sediment contamination or low DO in bottom water. Such general lack of concordance suggests that these offshore waters are currently in good condition, with the lower-end values of the various biological attributes representing parts of a normal reference range controlled by natural factors. Results of multiple linear regression, performed using full model procedures to test for effects of combined abiotic environmental factors, suggested that latitude and depth had significant influences on benthic variables regionwide. Latitude had a significant inverse influence on all three of the above benthic variables, i.e. with values increasing as latitude decreased (p< 0.01), while depth had a significant direct influence on diversity (p < 0.001) and inverse effect on density (p <0.01). None of these variables varied significantly in relation to sediment % fines (at p< 0.1), although in general there was a tendency for muddier sediments (higher % fines) to have lower species richness and diversity and higher densities than coarser sediments. Alternatively, it is possible that for some of these sites the lower values of benthic variables reflect symptoms of disturbance induced by other unmeasured stressors. The indicators in this study included measures of stressors (e.g., chemical contaminants, eutrophication) that are often associated with adverse biological impacts in shallower estuarine and inland ecosystems. However, there may be other sources of humaninduced stress in these offshore systems (e.g., bottom trawling) that pose greater risks to ambient living resources and which have not been captured. Future monitoring efforts in these offshore areas should include indicators of such alternative sources of disturbance. (137pp.) (PDF contains 167 pages)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Presentación (p. 9-27). Index Verborum (p.65-89). Letra "P" (extraido del CD-Rom, p.1-184)

Relevância:

100.00% 100.00%

Publicador:

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

Relevância:

100.00% 100.00%

Publicador:

Resumo:

  本书系统地介绍了微/纳米力学测试技术中最常用压入和划入技术及其典型应用。
全书共分13章。测量技术方面,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
2.2 弹塑性接触
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-深度数据确定的材料参数
参考文献
第4章 纳米压入测试方法
4.1 压针类型
4.2 测试环节
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MTS公司
6.3 美国Gysitron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
7.2 划入方式
7.3 弯曲方式
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
8.2 样品的表面状态和性质
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
第10章 在微机电系统中的应用
第11章 在生物及其相关材料
第12章 在高聚物中的应用
第13章 在金属玻璃中的应用
附录