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纳米SiO2粒子具有许多新的特征,利用它对聚合物进行改性,可以得到具有特殊性能或性能更加优异的聚合物/纳米SiO2复合材料。本文介绍了纳米SiO2特性、聚合物/纳米SiO2复合材料的制备方法以及我国聚合物/纳米SiO2复合材料的研究进展。 相似文献
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聚合物改性沥青可以有效地提升沥青路面的各项性能,因此近年来得到越来越广泛的应用,其中食用废油的再生利用也受到国内众多学者的关注。文章研究了一种新的含食用废油的聚合物改性沥青结合料的制备方法,并开展试验对含食用废油聚合物改性沥青的相关性能进行分析和评估。老化试验结果表明:在沥青中加入食用废油和聚合物能显著提升沥青的抗老化性能;温度扫描试验结果表明:含有食用废油和聚合物的沥青具有较好的高温性能,但食用废油降低了改性沥青的复数模量和车辙因子,不利于改性沥青的高温性能;频率扫描试验结果表明:含有食用废油的聚合物改性沥青具有更低的温度敏感性,这与食用废油含有与沥青相似的轻质组分相关。文章的研究结果可为食用废油在聚合物改性沥青中的应用提供参考。总体而言,食用废油有利于降低聚合物改性沥青的温度敏感性和提升沥青的抗老化性能,但不利于改性沥青的高温性能。 相似文献
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随着我国陆上老油田开发的持续,综合含水较高,油气产量下降难以避免,以聚合物驱油为代表的三次采油技术得到了广泛的应用。原有的可采储量预测多基于天然能量开发或者注水开发所进行的,而注聚合物驱替在机理上与常用的注水开发有着较大的不同,注聚合物后的新增储量需要重新评价。文章应用动态资料,从驱替特征曲线特征研究入手,建立了不同渗透率级差、不同聚驱控制程度、不同聚合物用量、不同聚合物粘度与原油粘度比情况下注聚机理模型,应用数值模拟得到的非均质油藏注聚后驱替特征曲线变化趋势,然后根据已经结束注聚区块注聚增加可采储量递推校正,以得出注聚合物新增可采储量的预测方法,并对聚驱控制程度、聚合物用量、渗透率变异系数等对聚合物驱效果影响进行分析,评价精度较高,效果真实可信。 相似文献
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原油是现代社会发展中必需的能源材料,在原油的开采中,需要尽量避免严重的浪费现象的出现,因此,提高原油的采收率是非常重要的。大庆油田作为我国主要的原油开采油田之一,在开采的过程中对原有采收率的问题实际为关注的,聚合物驱油技术是提高采收率的有效方法,但是该技术如何才能够在大庆油田这一地理环境下进行科学运用是非常关键的。文中对聚合物驱油的原理进行了研究,对其适合条件进行了分析,并针对大庆油田整体环境,对聚合物驱油技术的实际应用进行了探究。 相似文献
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《聚合物合成工艺学》是高分子材料专业的必修课程,本文针对课程特点进行了详尽的分析,阐述了课程的重难点,讨论了授课方式的改进方法,旨在为本课程的内容进行规划,建立合理的课程体系进行探讨和分析。 相似文献
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通过对形状记忆功能高分子材料制作和表征方法方面,以及国内外发展现状进行研究总结,得出形状记忆聚合物的发展趋势。 相似文献
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本文以Artificial Muscle Inc.开发的一款电活性聚合物作动器为原本,探讨了电聚合物薄膜圆环模型在受到集中力作用时的大变形问题。通过该模型变形的平衡方程和边界条件进行数值计算。结果表明,电活性聚合物薄膜的变形是非常不均匀的,这说明作为该种模型的作动器,电活性聚合物薄膜变形时材料的利用率并不高。 相似文献
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在自制的电解槽中,采用电絮凝法处理含聚合物的采油污水,分别研究了不同因素对污水处理效果的影响,确定了最佳电絮凝条件.在此条件下对污水进行处理,处理后COD和聚合物的去除率分别为69.3%和51.4%. 相似文献
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本文运用文献资料法、专家访谈法、问卷调查法、实地考察法、数理统计法等方法,依据分层抽样的原则,以陕西省8所高校1600名大学生为调查对象。探寻陕西省大学生参加课外体育活动的影响因素,充分研究如何发挥高校体育功能,努力促使大学生积极参加课外体育锻炼,促进学生全面素质发展。并为我省高校课外体育锻炼的改革和管理提供参考依据和建议。 相似文献
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The flowshop scheduling problem with no intermediate storage (NIS problem) was studied in this research. This problem, a modification of the classical flowshop scheduling problem, arises when a set of jobs, once started, must be processed with no wait between consecutive machines. By eliminating the need for intermediate storage, reduction of capital investment in work-in-process inventory can be achieved. This approach can be practically applied to a steel mill, in which the metal should be continuously processed in order to maintain high temperature, as well as many other similar processes.To provide insight into selecting an appropriate scheduling technique for solving the NIS problem, six methods were compared in terms of the quality and efficiency of the scheduling solutions they produced. The quality of solution was measured by makespan and the efficiency of solution was measured by the computational time requirements. The six methods examined in this study included: the Gupta algorithm, the Szwarc algorithm, an integer linear programming method, the Campbell et al. algorithm, the Dannenbring rapid access with extensive search algorithm, and a mixed integer linear programming procedure.The problem factors considered in this study were number of jobs, number of machines, and range of processing times. Relatively small-sized problems were tested with up to ten jobs, five machines, and 1–100 processing time units. Six solution techniques were selected and compared, with respect to makespan and computational time requirements, for multiple combinations of the three problem variables.The resulting test data were investigated using graphical procedures and formal statistical analyses. Initially, plots of mean values were used to graphically compare the six solution methods for the two performance criteria. Next, a multivariate analysis of variance study was conducted to investigate the quality and efficiency of the algorithms with respect to the problem factors. Then, a multiple comparison procedure was employed to analyze treatment mean differences among the six solution techniques. Results from the statistical analyses are summarized in this article.It was concluded that the two mathematical programming methods, the integer linear programming procedure and the mixed integer linear programming methods, produced the best performance in terms of makespan. These two methods, however, used a far greater amount of computational time than the other four solution techniques. Producing moderately good results as far as quality of performance, the Gupta and the Szwarc algorithms were comparable with the Campbell et al. and the Dannenbring algorithms in terms of computational efficiency. By comparison, the Campbell et al. and the Dannenbring algorithms produced the poorest performance with respect to the quality of solutions.Certain limitations were imposed for this study. The problem size considered was relatively small and the sample size was also limited to ten problems per cell. In addition, a uniform distribution function was used for generating processing times within certain ranges. These limitations were necessary in order to allow the various scheduling problems to be solved within a reasonable amount of computer time.Finally, some suggestions were provided for future research in the NIS problem area. The integer linear programming method was recommended as a standard of evaluation, owing to its best overall performance. A possible area for future research would involve the improvement of the Gupta and the Szwarc algorithms through the use of backtracking procedures within the branch-and-bound technique, so that they might be competitive with the mathematical programming methods with respect to quality of performance. Other distribution functions could be investigated in terms of the influence of the distribution of processing times on the performance measures. 相似文献
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A metropolitan community was faced with the problem of locating areas of the community in terms of more or less need for leisure-time services. The authors developed a set of methods and techniques to solve this problem. It was noted that these methods differed in some ways from prior efforts of this sort. The advantages of the methods were that they could use readily available data, did not require the use of a computer, and presented a relative level of need that was more than a simple ranking of planning areas. Further, the methods could be used to locate any number of conditions in which one might be interested. In addition to spelling out the details of the original effort, an attempt is made to show how factor analysis could be used as an alternate approach to the first effort. The pros and cons of factor analysis as a substitute method are discussed. The major disadvantage would be if the particular community did not have a large computer available. This is outweighed by the higher levels of accuracy, predictability and comparability provided by factor analysis. 相似文献
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COGNITIVE MAPPING AND REPERTORY GRIDS FOR QUALITATIVE SURVEY RESEARCH: SOME COMPARATIVE OBSERVATIONS 总被引:2,自引:0,他引:2
A study of business strategy was carried out in 86 organizations in the crop protection industry. A multi-operational approach was used to enable validation of data by triangulation, including cognitive mapping used in an unusual way. This provided an unintended opportunity to conduct a comparative evaluation of interactive investigational methods in a relatively controlled, if unsophisticated manner. Results were interesting enough to suggest that further investigation is needed into the impact of various subject-generated factors such as face validity on methodological effectivness, as well as more traditional criteria such as construct validity of particular methods. Accordingly, process issues affecting repertory grids, cognitive mapping and software for the analysis of cognitive maps (COPE) are described and discussed. Recommendations are made for improvements to mapping and software and further studies suggested. 相似文献
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汽车轻量化是当前汽车工业的发展方向之一。内高压成形技术作为汽车轻量化的重要途径之一,近几年得到了快速发展,本文就内高压成形工艺过程及特点做了一定的探讨。 相似文献
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This paper first briefly discusses six alternative methods that have been applied to financial failure prediction: linear discriminant analysis, logit analysis, recursive partitioning, survival analysis, neural networks and the human information processing approach. The main objective was to study empirically whether the results stemming from the use of alternative methods differ from each other. This was conducted using the Finnish data one, two and three years prior to failure in empirical analysis. The results indicated that there was a statistically significant difference in prediction accuracy only between logistic analysis and survival analysis one year prior to failure. Two and three years prior to failure statistically significant differences were not found. The results indicate, with the three variables employed in this study, that no superior method has been found. Even one of the latest applications, neural networks, is in its present form only as effective as discriminant analysis was as early as thirty years ago. 相似文献
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大学生心理健康问题日益严峻,本文采用UPI和SCL-90两种方法测评了湖南某高校大学生心理健康状况,结果问题严重。然后着重对两种方法进行了检验,结果发现存在显著的相关性。接着对两种方法进行了回归分析,构建了相应的回归模型,表明了UPI和SCL-90两种方法具有相应的替代性与互补性。建议高校在大学生心理测评与干预工作上,将两种方法有机地结合运用。 相似文献
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从工程实际出发,介绍了在英文AutoCAD中输入汉字、修改汉字文本方法,较好地解决了AutoCAD与中文Word的图形变换,及用打印机输出大幅面纸的问题。 相似文献
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随着我国高速公路的快速发展,贝雷梁在公路桥梁中得到广泛的应用,本文以隐形盖梁施工为例进行详细分析,同时给出了相应的施工方法与施工工序,并提出质量控制以及安全控制的措施。 相似文献