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<正> 1 前言玻璃钢渔船长期在水中作业,受力状态比较复杂。不同规格的渔船和船体不同部位所要求性能也不同,船体要求耐水性,强度、刚度高,耐冲击性能好;甲板在满足强度和刚度要求外,还要求受热时变形小;上层建筑必须承受大气老化;水舱应符合卫生要求等等。玻璃钢的耐水性对玻璃钢渔船船体来说具有特别重要的意义。在水的浸泡下玻璃钢性能会发生变化,玻璃钢受水的作用与金属不同,不是表面发生电化学腐蚀,而是水渗透到内部起浸蚀作用,且内部组分也会扩散到水中。水对玻璃钢的影响很复杂,主要表现是对UP树脂、玻璃纤维与界面的浸蚀作用。玻璃钢耐水性与树脂和玻璃纤维制品的性能及玻璃钢成型质量有 相似文献
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陈廷炳 《玻璃钢/复合材料》1985,(6)
在玻璃钢产品中,不同结构件之间需要连接。连接方法很多,其中应用最普遍的是粘合剂粘接。在产品应用中,不仅玻璃钢会老化,粘合剂也会老化,特别是钢与玻璃钢粘接时,粘接寿命如何,是人们十分关心的问题。我们对JF-1粘合剂和HYJ-6粘合剂粘接的玻璃钢/普通碳钢试样进行了大气老化试验。 1.粘合剂配方及试样制备 JF-1和HYJ-6粘合剂粘接玻璃钢/普通碳钢,试样形式如下图: 相似文献
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针对高温太阳能热管接收器中高温热管的启动特性进行理论分析,计算其过渡状态和连续流动状态下的转变温度分别为273和419℃,并对V形沟槽与金属纤维毡复合吸液芯钠热管在不同加热方式、不同输入功率和不同倾角下的启动性能进行试验研究.试验结果表明,半周受热高温热管启动过程与全周受热的启动过程相似,均符合前端启动模型,不同加热方式下转变温度相同且绝热段转变温度与理论计算值吻合,半周受热高温热管启动时间稍短于全周受热启动时间.随输入功率增加,高温热管启动时间缩短,倾斜角度变化对启动性能无明显影响. 相似文献
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基于平行热线法结合镜像热源原理,提出了一种新的固体材料热物性参数测算模型,在热线法测试原理的基础上,以试样绝热边界为界线,设与真实热源对称位置处存在虚拟镜像热源,以此消除绝热边界造成的热积聚效应影响,测试时可不需再限制实验时间和试样厚度. 当相邻时刻材料的热物性参数计算结果大于判别准则时,引入镜像热源对计算温度进行修正. 为防止修正过程所用热物性参数对实验初期计算值的依赖,模型对实测温度进行两次修正. 以石棉板为研究对象,理论分析结合计算结果表明,两次修正结果不同,但差异不大,且第二次修正后各组热物性参数计算结果更稳定. 对石棉板、大理石、硼硅玻璃、硅砖等4种材料的薄板和厚板进行了热物性测定,结果与文献值较吻合,最大误差均小于5%,验证了本测定方法适用于薄板和厚板试样,有效提升了热线法测定精度,扩大了应用范围. 相似文献
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为了研究浇注料烘烤过程中其内部状态变化与其弹性模量变化的相关性,将纯铝酸钙水泥结合的刚玉质浇注料振动成型,自然养护24 h后脱模,部分脱模后试样继续在烘箱中于110℃干燥48 h,部分干燥后试样继续在500℃热处理3 h,采用弯曲共振法检测试样在不同加热过程中的弹性模量变化:1)对脱模后试样,以5℃·min-1的速率升温,并在50℃及其整数倍温度点保温60~90 min,检测试样在加热过程中的弹性模量变化;2)对干燥后试样,以5℃·min-1的速率连续升温至500℃,检测试样在加热过程中的弹性模量变化;3)对500℃热处理后试样,以15℃·min-1的速率连续升温至500℃后保温35 min,检测试样在保温过程中的弹性模量变化。结果表明:1)自由水的排出使试样的弹性模量增大,结合水的排出则使其弹性模量减小;2)在连续升温的加热过程中,自由水和结合水的排出滞后于设置保温的加热过程,试样弹性模量的变化也出现相应的滞后现象;3)快速连续升温过程中试样内部存在热应力,温度和热应力的存在会影响试样的弹性模量;4)浇注料烘烤过程中弹性模量的变化可综合反映其内部状态变化尤其是水分排出情况的变化。 相似文献
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操作参数和流体物性参数对水力旋流器的迁移率的影响 总被引:3,自引:0,他引:3
在迁移率计算模型的基础上,本文对水力旋流器的迁移率与分流比、流量及物性参数之间的关系进行了分析与计算。结果表明,在分流比不变的条件下,流量和物性参数对迁移率的影响只表现在改变分割尺寸d50上,流量、物性参数及分割尺寸的变化遵循旋流器数Hy=const.的规律。当分流比改变时,分割尺寸略微变化,但迁移率MP'与无因次液滴直径△=d/d50之间的关系不变。这两点与Thew的回归结果略有区别。在分流比、流量及物性参数同时变化时,本文根据计算结果给出了迁移率及旋流器数与分流比之间的关联式,据此可预估不同操作参数与物性参数下的迁移率。 相似文献
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采用采样分析法,对投用10年的不同管径失效样件现场截取试样,与同时期、同厂家生产的未投用试样进行对比试验,对其拉伸强度、巴氏硬度、玻璃化转变温度、树脂含量、不可溶分含量等进行测定,分析玻璃钢管道在役期间的性能变化和失效原因。测试结果表明:服役10年左右的玻璃钢综合性能都较未投用玻璃钢管有所降低,其中树脂含量降低最为严重,由树脂老化降解引起的玻璃钢管道玻璃化转变温度降低是造成其失效的主要原因。 相似文献
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本文论述了通过静态浸泡实验 ,观察玻璃钢试样的外观、介质外观变化及试样力学性能的变化 ,研究了制品中加入不同类型、不同比例的无机矿物填料对玻璃钢制品防腐性能和力学性能的影响 相似文献
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A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases. 相似文献
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P. P. Budnikoff 《Journal of the American Ceramic Society》1924,7(11):817-820
The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO3 and determination of CaO by KMnO4 titration, the SO3 by Andrews method of titration of BaCrO4 has been found to give very reliable results with the least consumption of time. 相似文献
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面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。 相似文献
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ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l/3为氧气,2/3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中:A一混… 相似文献
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A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.
Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology. 相似文献
Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology. 相似文献
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用两个形状指数表征粉煤灰颗粒形貌的研究 总被引:5,自引:0,他引:5
引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。 相似文献
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本文以三种典型煤的碳燃烧为研究对象,分别采用简单一维沉降燃烧方式和等温加热燃烧方式,实验研究了煤在快速加热条件下,其碳的初期和中,后期燃烧过程。以实验为基础,建立了煤的碳燃烧模型,变工况数值模拟了煤的碳燃烧过程,揭示了煤不同条件下的单颗粒碳燃烧特性。 相似文献
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归纳了当今卫生陶瓷工业的发展现状和水平 ,对窑炉产业提出了的新要求 ,分析了某一新型窑炉的特点 ,对发展我国陶瓷窑炉产业提出了建议 相似文献
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ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES 总被引:5,自引:0,他引:5
Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log10 viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log10 viscosity as a function of soda content are smooth up to 50% Na2O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO2, 2Na2O) due to Molecular Substitution of CaO, MgO and Al2O3 for Na2O The effect is clearly brought out by plotting (from the results of English) the change of log10η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature Ta. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log10η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A12O3) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al2O3) per 100°. At the aggregation temperature the change of log10η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al2O3. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log10η due to substitution of an oxide for Na2O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na2O-CaO-SiO2. Change of Viscosity of Glass (4SiO2, 2Na2O) due to of Substitution of B2O3 for SiO2 The change of log10η (from the results of English) is plotted as a function of temperature, and also the change of log10η per per cent B2O3. The curves are more complex than for the substitution for Na2O. 相似文献