飞机涂层老化模式及日历寿命预测

介绍一种评估飞机结构防护涂层老化的方法—当量法。这种方法利用涂层大气幕寡试验和加速试验数据,建立统一的老化模型,从而确定涂层自然老化与加速试验老化的当量关系,并且给出了涂层老化当量关系的计算结果,进而得到了涂层使用寿命。通过试验结果与计算结果的比较所建立的老化模型描述飞机结构涂层老化是合适的。现已用于评估某飞机涂层的老化。     

典型大气环境玻璃钢天线罩聚氨酯涂层工艺老化行为研究

通过南海海洋大气环境、海南万宁湿热乡村大气环境、西藏拉萨高原大气环境户外大气暴露对玻璃钢基灭线罩聚氨酯涂层工艺进行了老化试验，运用光泽、颜色、粉化率、SEM等手段测试了涂层在户外大气暴露的性能变化和表面形貌，并进行对比分析。结果表明，在相同大气环境中，工艺玻璃钢板／雷达罩底漆／浅灰航天聚氨酯涂层耐候性能优于工艺玻璃钢板／环氧聚酰胺／弹性聚氨酯磁漆涂层的耐侯性能；对于同种工艺，西沙海洋大气环境对其耐侯性的影响最大，其次是万宁湿热乡村环境，拉萨高原环境影响较小；光照、温度、湿度是涂层老化的主要原因。     

不同颜色油漆试板的耐光老化性能分析

汽车工业的发展的和汽车工艺的进步,推动了汽车外观、颜色等方面的多样化发展。消费者通常以高安全性、高保值率、视觉美观等为主要依据选择车漆颜色,较少考虑车漆的耐光老化性,这种消费心理导致很多生产厂家对车漆的耐光老化性缺少重视。本文通过研究两家油漆厂家制作的不同颜色油漆试板,分析其耐光老化性能优劣,为生产厂家提高不同颜色油漆耐光老化性能及其研究方向的选择提供参考。     

应用于高盐高辐照环境下的钢结构涂层防护行为研究

为研究在严酷环境下涂层对钢结构的防护性能,本文通过对应用于钢结构外表面、内表面以及钢支架的涂层进行了1年的现场暴露试验以及2000h的模拟加速腐蚀试验,积累了涂层在钢结构的老化数据,获取了涂层的腐蚀等级评级。结果表明：现场暴露1年后,载荷尚未产生明显的影响,所有涂层均未出现失光、变色、粉化、开裂、起泡等老化现象;经过2000h盐雾试验后,涂层表面形貌未发生明显变化,涂层未出现起泡、开裂和出锈等现象,表明涂层具有良好抗盐雾和水汽的渗透能力;经过2000h紫外老化试验后,涂层均未出现严重的老化现象,但都出现了不同程度的变色和粉化现象。     

汽车皮革耐候性测试研究

分析汽车皮革老化的原理,然后列举汽车皮革常用氙灯试验条件,引用GMW 14444内饰件自然老化试验条件,比较加速试验与自然老化试验的异同点;比较汽车皮革老化后性能数据变化趋势,获得黄色指数和颜色数据更适合皮革材料老化趋势分析。     

丙烯酸聚氨酯涂层在我国典型大气环境下的老化历程

本文采用交流阻抗测试技术、傅立叶红外测试技术研究了丙烯酸聚氨酯涂层在我国典型大气环境(武汉、拉萨)下户外降解规律,分析了其降解机理,比较了不同地区的环境老化强度,并探讨了丙烯酸聚氨酯涂层降解过程中电化学等效回路模型的转换问题.结果表明:(i)随曝露时间的延长,涂层的孔隙率增加、孔隙结构增大,体系由一个时间常数特征转为两个时间常数特征,涂层内逐渐形成了腐蚀性离子通往基底金属的通道,基底金属发生腐蚀,随金属腐蚀产物的增加,金属/溶液双电层电容逐渐被具有弥散效应的电容元件替换;(ii)丙烯酸聚氨酯涂层抗蚀性能的降低主要由涂层内高分子链节的断裂所致,随曝露时间的延长,在仲酰胺处发生断裂,生成了新的基团伯酰胺;(iii)丙烯酸聚氨酯涂层在拉萨地区的降解速率较武汉地区快.     

基于EIS的航空涂层老化研究

选用当量加速试验0~9周期的聚氨酯涂层试样进行电化学阻抗(EIS)测试。通过聚氨酯涂层的电化学信息,判断涂层表面、内部和金属基体的腐蚀状况,研究聚氨酯涂层的老化失效机制。     

基于色差的航空涂层老化失效当量加速关系研究

针对飞机结构涂覆的航空涂层老化失效问题,基于色差的失效标准分析了涂层老化行为规律,并建立了自然曝晒条件与实验室加速条件下航空涂层色差失效的当量加速关系。结果表明,同类涂层试验件在自然曝晒试验与老化加速试验下的色差变化总体趋势基本一致,得到的两类涂层试样的加速老化当量关系函数可为研究实验室加速老化试验和自然曝晒试验之间的当量加速关系提供一定基础。     

我国典型气候环境下塑料老化严酷度表征模型研究

太阳辐照、温度、湿度是影响塑料老化的最主要的环境因素。基于以上的三种环境因素,分别建立模型进行量化分析,形成环境条件对塑料老化的严酷度表征模型。应用模型可以通过两个地点的环境条件推测塑料在两地老化的严酷度,并进行比较。通过开展高分子参考材料(聚苯乙烯和聚碳酸酯)在我国典型气候环境的自然老化试验,采用塑料老化过程的光学性能数据对严酷度模型进行验证,表明严酷度模型能够反应塑料在我国典型气候的老化严酷度。     

三种涂层在模拟热带海洋大气环境中的性能退化研究

为了考核评价舰船、舰载机等装备用三种涂层在热带海洋大气环境中的性能退化情况，设计了涂层在实验室模拟热带海洋大气环境中太阳辐射试验、湿热试验和盐雾试验的组合循环试验方法。通过实验室组合循环试验，分别检测了试验前后涂层的形貌、失光率、色差、附着力和电化学阻抗等数据。试验结果表明，随着试验时间的延长，三种涂层均出现不同程度的老化，失光率和色差呈增大趋势，附着力降低；但试验前后其老化机理未发生明显变化，电化学交流阻抗值基本保持在109Ω以上，涂层的厚度基本保持不变。综合三种涂层的性能退化对比，在工程实际应用中推荐优先选用4号或10号涂层。     

Land use change and carbon exchange in the tropics: I. Detailed estimates for Costa Rica,Panama, Peru,and Bolivia

Our group, composed of modelers working in conjunction with tropical ecologists, 3 has produced a simulation model that quantifies the net carbon exchange between tropical vegetation and the atmosphere due to land use change. The model calculates this net exchange by combining estimates of land use change with several estimates of the carbon stored in tropical vegetation and general assumptions about the fate of cleared vegetation. In this report, we use estimates of land use and carbon storage organized into sixlife zone (sensu Holdridge) categories to calculate the exchange between the atmosphere and the vegetation of four tropical countries. Our analyses of these countries indicate that this life zone approach has several advantages because (a) the carbon content of vegetation varies significantly among life zones, (b) much of the land use change occurs in life zones of only moderate carbon storage, and (c) the fate of cleared vegetation varies among life zones. Our analyses also emphasize the importance of distinguishing between temporary and permanent land use change, as the recovery of vegetation on abandoned areas decreases the net release of carbon due to clearing. We include sensitivity analysis of those factors that we found to be important but are difficult to quantify at present.     

两种常用高分子材料外观颜色评价方法的比较

产品外观颜色的评价一直是高分子材料及制品质量检验中的一个重要项目.目前,关于颜色测试的方法主要有1976年国际照明协会(CIE)推荐的CIE LAB色差公式法和纺织品色牢度试验评定变色用灰色样卡法,两种方法在纺织印染、涂料、高分子材料加工、化工等行业中均得到了广泛的应用,本文详细分析了两种方法的原理、应用和特点.     

航空聚氨酯涂层老化分析

随着飞机服役时间的增长,其结构表面的有机涂层逐渐老化失效,最终导致机体金属结构的腐蚀。基于某沿海机场的严酷环境条件,依据编制的适用于有机涂层的加速试验谱,开展涂层加速老化试验,分析涂层老化规律。     

Carbon dynamics and land-use choices: building a regional-scale multidisciplinary model

Policy enabling tropical forests to approach their potential contribution to global-climate-change mitigation requires forecasts of land use and carbon storage on a large scale over long periods. In this paper, we present an integrated modeling methodology that addresses these needs. We model the dynamics of the human land-use system and of C pools contained in each ecosystem, as well as their interactions. The model is national scale, and is currently applied in a preliminary way to Costa Rica using data spanning a period of over 50 years. It combines an ecological process model, parameterized using field and other data, with an economic model, estimated using historical data to ensure a close link to actual behavior. These two models are linked so that ecological conditions affect land-use choices and vice versa. The integrated model predicts land use and its consequences for C storage for policy scenarios. These predictions can be used to create baselines, reward sequestration, and estimate the value in both environmental and economic terms of including C sequestration in tropical forests as part of the efforts to mitigate global climate change. The model can also be used to assess the benefits from costly activities to increase accuracy and thus reduce errors and their societal costs.     

油漆涂层老化黄变分析

汽车涂装后形成的涂层,既要具备较好的外观装饰效果,又必须具有优良的防护性能,而在实际使用过程中,常因涂层老化而发生的黄变,严重影响了其原有的性能要求。文章分析了涂层老化黄变的原因,对比分析了几种面漆的耐老化性能,并提出提高涂层耐黄变性能的措施。     

GROUND WATER/SURFACE WATER RESPONSES TO GLOBAL CLIMATE SIMULATIONS,SANTA CLARA‐CALLEGUAS BASIN,VENTURA, CALIFORNIA1

ABSTRACT: Climate variations can play an important, if not always crucial, role in successful conjunctive management of ground water and surface water resources. This will require accurate accounting of the links between variations in climate, recharge, and withdrawal from the resource systems, accurate projection or predictions of the climate variations, and accurate simulation of the responses of the resource systems. To assess linkages and predictability of climate influences on conjunctive management, global climate model (GCM) simulated precipitation rates were used to estimate inflows and outflows from a regional ground water model (RGWM) of the coastal aquifers of the Santa Clara‐Calleguas Basin at Ventura, California, for 1950 to 1993. Interannual to interdecadal time scales of the El Niño Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) climate variations are imparted to simulated precipitation variations in the Southern California area and are realistically imparted to the simulated ground water level variations through the climate‐driven recharge (and discharge) variations. For example, the simulated average ground water level response at a key observation well in the basin to ENSO variations of tropical Pacific sea surface temperatures is 1.2 m/°C, compared to 0.9 m/°C in observations. This close agreement shows that the GCM‐RGWM combination can translate global scale climate variations into realistic local ground water responses. Probability distributions of simulated ground water level excursions above a local water level threshold for potential seawater intrusion compare well to the corresponding distributions from observations and historical RGWM simulations, demonstrating the combination's potential usefulness for water management and planning. Thus the GCM‐RGWM combination could be used for planning purposes and — when the GCM forecast skills are adequate — for near term predictions.