Observations of T‐peel behavior of flexible polymers using digital image correlation

This work investigates the T‐peel behavior of a flexible polymer using digital image correlation (DIC). In particular, the method enabled the direct observation of the full‐field strain of the T‐peel system in fabrics coated with thermoplastic polyurethane elastomers. The strain field is divided into three parts defined as the high‐strain zone, low‐strain zone, and far‐field zone. The correlation between the strain variation and the load‐displacement curve can be used to identify the full‐field beginning of the peeling process, which is defined as the “peel initiation.” Furthermore, a model is developed to predict the strain variation as a function of the load. To validate this model, the calculated strain in the root region is compared with the experimental results measured by DIC and is found to be in excellent agreement. Finally, to address the inhomogeneity of the strain distribution, an engineering index based on the relative displacement of the upper and lower peeling arms is proposed to evaluate the deformation inhomogeneity. It is found that the index increases exponentially near the welded zone. POLYM. ENG. SCI., 55:196–204, 2015. © 2014 Society of Plastics Engineers     

Mutagenicity and Safety Evaluation of Ethanolic Extract of Prunus mume

ABSTRACT:  The ethanolic extract of  Prunus mume  (EPM) is a novel polyphenol preparation derived from branches (with leaves) of  Prunus mume , which could be used as a functional ingredient for antioxidant and antiobesity therapy. The purpose of this study was to evaluate the safety of EPM. An EPM was prepared and evaluated for oral acute and subacute toxicity in  Sprague–Dawley  rats, while its mutagenic potential was assessed by a reverse mutation test using  Salmonella typhimurium , by a bone marrow cell micronucleus test using ICR mice, and by a sperm abnormality test using ICR mice. The results showed no acute lethal effects at the maximal tested EPM dose of 20 g/kg bw in either rats or mice, suggesting that EPM can be regarded as virtually nontoxic. Administration at levels of 0.84, 1.67, and 3.33 g/kg bw to rats for 30 d did not induce any significant hematological, clinical, chemical, or histopathological changes. No mutagenicity evidence was detected in any of the 3 mutagenic tests. The level of "no observed adverse effect" (NOAEL) for EPM was above 3.33 g/kg bw for the subacute toxicity study.     

融合多特征的最大熵汉语命名实体识别模型

最大熵模型能有效整合多种约束信息,对于汉语命名实体识别具有很好的适用性,因此,将其作为基本框架,提出一种融合多特征的最大熵汉语命名实体识别模型,该模型集成局部与全局多种特征,同时为降低搜索空间并提高处理效率,而引入了启发式知识,基于SIGHAN 2008命名实体评测任务测试数据的实验结果表明,所建立的混合模式是一种组合统计模型与启发式知识的有效汉语命名实体识别模式,基于不同测试数据的实验说明,该方法针对不同测试数据源具有一致性.     

抽油机偏磨井防偏磨综合技术

根据抽油机井出现管杆偏磨的原因和机理，制定出减缓偏磨的综合防治措施和方法：即采用弹性抽油杆抗磨扶正器及多功能自由式抽油杆扶正器对杆柱进行有效的扶正，减少杆柱受压；采用抽油杆旋转装置，使杆柱均匀磨损，延长杆柱寿命；采用油管锚定技术及安装油管旋转装置，防止管柱弯曲，减少油管磨损；采用合理的防偏磨抽油泵及合理工作制度等措施进一步提高防偏磨能力。现场应用证明，制定的综合防偏磨措施能有效减轻油井偏磨。     

光电稳定平台变论域模糊自抗扰控制器设计

为了提高线性自抗扰控制(LADRC)应用下的光电稳定平台稳定精度及抗干扰能力,提出一种变论域模糊自抗扰控制(VFADRC)方法.在系统模型未知的情况下,在线性自抗扰的设计中引入不依赖模型信息的模糊控制器,使用伸缩因子函数实现变论域设计,并将VFADRC与线性自抗扰及模型辅助自抗扰(MLADRC)方法进行仿真对比.仿真结...     

UML技术在零部件资源协同管理系统中的应用

组建计算机支持的网络化协同设计平台,需要建立起支持协同设计的基于Web零部件管理系统。UML作为一种目前被广泛应用的面向对象软件建模语言,正好满足了零部件管理系统在设计与开发阶段的需求。首先简要概括了UML软件建模技术的内容和步骤;然后结合零部件管理系统的实际需求,给出了UML系统建模的详细设计应用实例,并在文章的最后介绍了系统实施开发的方案。     

预测天然气斜井临界携液流量新方法

目的 Turner模型和李闽模型是现场应用比较广泛的气井携液模型,二者是以直井为基础建立的,且假定曳力系数为定值,没考虑井斜角和曳力系数对临界携液流量的影响。为了准确预测天然气斜井临界携液流量,分析了天然气斜井中液滴的受力情况,建立了预测天然气斜井临界携液流量新模型。方法 该模型考虑了雷诺数变化对曳力系数的影响,对比不同曳力系数计算模型的精确度,优选出Barati模型计算天然气斜井中液滴的曳力系数,推导了该模型相对于Turner模型的修正系数,并给出了修正系数表。结果 通过实例将新模型与Belfroid模型、杨文明模型和李丽模型进行比较,结果表明,新模型计算结果与现场数据吻合最好,准确率为94.6%。结论 新模型可用于对天然气斜井积液的判断。     

疏浚排泥管道磨损研究及开发方向

文章通过对塑料管道两种磨损类型产生破坏原因的分析,得出耐磨性并非材料的固有特性,而是与疏浚工况中输送介质的特性、工艺参数紧密相关的结论,进而针对不同疏浚工况提出了相应的排泥管道的开发方向。     

Scatter search for the stochastic travel-time vehicle routing problem with simultaneous pick-ups and deliveries

In parallel with the growth of both domestic and international economies, there have been substantial efforts in making manufacturing and service industries more environmental friendly (i.e., promotion of environmental protection). Today manufacturers have become much more concerned with coordinating the operations of manufacturing (for new products) and recycling (for reuse of resources) together with scheduling the forward/reverse flows of goods over a supply chain network. The stochastic travel-time vehicle routing problem with simultaneous pick-ups and deliveries (STT-VRPSPD) is one of the major operations problems in bi-directional supply chain research. The STT-VRPSPD is a very challenging and difficult combinatorial optimization problem due to many reasons such as a non-monotonic increase or decrease of vehicle capacity and the stochasticity of travel times. In this paper, we develop a new scatter search (SS) approach for the STT-VRPSPD by incorporating a new chance-constrained programming method. A generic genetic algorithm (GA) approach for STT-VRPSPD is also developed and used as a reference for performance comparison. The Dethloff data will be used to evaluate the performance characteristics of both SS and GA approaches. The computational results suggest that the SS solutions are superior to the GA solutions.     

应用永久式井下压力计压降曲线计算油藏动态储量

海上某油田的湖相碳酸岩油藏沉积范围小、厚度薄、横向变化快、地震资料品质差、储层难以识别,致使常规容积法计算储量的准确度受到了限制。利用永久式井下压力计监测井底压力,在不影响油井正常生产的情况下,应用压降曲线法计算油藏动态储量,取得了较好效果,为该油田下一步调整提供可靠的储量基础。