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针对松散破碎巷道控制问题,普通水泥注浆存在诸多缺陷,且水泥颗粒不能注入半径小于0.2 mm的孔隙或者裂隙中。本文采用碳纤维、聚合物以及超细水泥制备试块,通过单轴压缩试验及巴西劈裂试验确定注浆材料的最佳配合比。试验结果表明,当碳纤维掺量为水泥掺量的1.0%(质量分数)时,水泥砂浆试块性能最佳。采用电子扫描显微镜(SEM)确定试块微观结构,结合聚合物成膜的Ohama模型和Konietzko模型,分析其微观结构形成过程及碳纤维失效模式,揭示碳纤维增强聚合物水泥注浆材料微观增强机理。本文为降低深部破碎煤岩巷道维护成本,实现深部开采可持续发展提供了技术支撑。 相似文献
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聚合物材料的宏观力学性能与其微观结构具有密切的关系,计算机模拟是研究这种结构与性能关系的重要手段之一,近年来国内外学者已经发展了多种模拟方法并从不同尺度来模拟聚合物材料的力学性能。本文综述了不同方法在聚合物材料力学性能模拟研究中的应用,重点介绍了Monte Carlo模拟、分子动力学模拟和基于弹簧格子模型的多尺度模拟这3种常见模拟方法的应用情况,如在分子动力学模拟中重点关注无定形聚合物玻璃态、结晶聚乙烯和部分非均质体系,而在多尺度模拟中则重点关注复杂的非均质聚合物体系,并讨论了各种方法的应用前景及亟待解决的问题。 相似文献
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综述了基于聚合反应机理、面向聚合物链结构的聚合反应过程模型化方法。分别介绍了聚合物分子量及其分布、共聚物组成以及序列结构分布的模型,回顾比较了各模型发展历程与应用。指出在规模化聚合物生产过程中面向链结构建模的重要性,面向序列结构分布建模是烯烃聚合反应过程模型化领域的重要发展方向。 相似文献
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本文评述了关于纤维增强复合材料和结构阻尼的研究现状,特别是聚合物基复合材料和结构阻尼的研究现状.首先叙述了复合材料的阻尼机理和适宜的阻尼分析方法学,而后提出了关于阻尼的研究包括宏观力学、微观力学、粘弹性研究方法、复合材料中的界面阻尼模型、阻尼与破坏模型,某些重要工作涉及到已经改进了的厚的层压制品结构阻尼模型,对层压制品阻尼的改进以及纤维增强复合材料/结构阻尼的优化进行了评价。 相似文献
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SBS改性沥青化学交联过程的微观结构和性能研究 总被引:2,自引:0,他引:2
研究了SBS改性沥青在反应性改性过程中的微观相态结构变化,以及交联剂对改性沥青性能的影响.结果表明:化学交联反应可以改变石油沥青的胶体结构,从而显著改善改性沥青的储存稳定性、高温稳定性和感温性;反应性改性沥青的微观相态结构不但与聚合物的品种有关,也与基质沥青的化学组成密切相关,在高速剪切过程中逐渐由沥青为连续相、聚合物为分散相的"海""岛"型结构,转变为聚合物相和沥青相互相贯穿网络的双连续相结构,SBS在高温储存过程中分散更加均匀,不发生离析现象. 相似文献
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本文介绍了生化过程的两类主要的数学模型——非结构模型和结构模型的结构和建模方法。并在分析两者特点的同时。提出了今后有关这类过程模型化的对策之设想。 相似文献
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介绍了三元催化转化器的结构及工作原理,论述了目前开发出的催化转化器的各种数学模型,包括温度模型,二维模型,多维模型,及动力学模型等。对今后催化转化器数学模型的研究方向做了展望。 相似文献
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Hybrid modeling has attracted increasing attention in order to take advantage of the additional data to improve process understanding. Current practice often adopts mechanistic models to predict process behaviors. These mechanistic models are based on physical understandings and experimental studies, but they sometimes lead to plant-model mismatch (PMM) as they may be inaccurate to fully describe real processes. Black-box models can serve as an alternative, but they often suffer from poor generalization and interpretability. To combine the two techniques, hybrid models are developed to make use of process data while maintaining a degree of physical understanding. In this work, we implement a framework of identification of PMM using partial correlation coefficient and mutual information, followed by introducing and comparing serial, parallel, and combined structures of hybrid models. The framework is applied and tested with a simulated reactor model and two pharmaceutical unit operation case studies. 相似文献
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A model consisting of three partial non-linear differential equations for describing the humidity and temperature of a thin sheet of material and of the temperature of the air flow as a function of time and position in an infrared dryer was reduced to a model more adaptable to direct digital control. To begin with the original model was discretized along the length of the dryer and then linearized. Models of orders ranging from 12 to 72 were analyzed for controllability and observability. Using Moore's method, the models thus obtained were further reduced to a controllable state space model of order 5 that produced satisfactory results and for which stability was preserved. Simulated open loop responses of the reduced model to discrete perturbations in emitter electrical power, inlet humidity and velocity of the web, produced satisfactory dynamic and steady-state responses when compared to responses of the original model subjected to similar perturbations. The steady-state responses showed absolute errors for humidity and temperature of the web less than 1.3% [g water/100 g] and 2.2°C, respectively. 相似文献
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电解质NRTL模型的发展及应用 总被引:1,自引:0,他引:1
综述了电解质NRTL模型从最初的用于处理单一电解质、单一溶剂体系的两贡献模型发展成为能处理多电解质组分、混合溶剂体系的热力学模型,介绍了模型在电解质溶液相平衡计算中的应用。最后指出了此模型的优缺点和模型参数的发展方向。 相似文献
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This paper combines grey model with time series model and then dynamic model for rapid and in-depth fault prediction in chemical processes. Two combination methods are proposed. In one method, historical data is in-troduced into the grey time series model to predict future trend of measurement values in chemical process. These predicted measurements are then used in the dynamic model to retrieve the change of fault parameters by model based diagnosis algorithm. In another method, historical data is introduced directly into the dynamic model to re-trieve historical fault parameters by model based diagnosis algorithm. These parameters are then predicted by the grey time series model. The two methods are applied to a gravity tank example. The case study demonstrates that the first method is more accurate for fault prediction. 相似文献
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Abstract. We consider fitting a parametric model to a time series and obtain the maximum likelihood estimates of unknown parameters included in the model by regarding the time series as a Gaussian process satisfying the model. We evaluate the asymptotic value of the conditional quasi-likelihood function when the number of observations tends to infinity. We show what properties of the time series we can find by examining the behaviour of the conditional quasi-likelihood function, even when the time series does not necessarily satisfy the model and is not necessarily Gaussian. 相似文献