缺水传感器改进设计

针对一种煤矿用本安型缺水传感器在现场安装及维护难度大,以及抽采泵供水状态下管道内有水但传感器检测显示为无水,或抽采泵停止工作时传感器检测显示有水问题,分析原产品中磁体及探头感应装置结构。改进其结构形式,并优化安装,使检测稳定可靠。实现抽采泵管道用缺水传感器的可靠性设计和轻量化设计。     

Reduced‐scale test to assess the effect of fire barriers on the flaming combustion of cored composites: An upholstery‐material case study

Herein, we describe a reduced‐scale test (“Cube” test), measuring the fire performance of specimens including a fire barrier (FB) and a flammable core material, which acts as the main fuel load. The specimen is intended to reproduce a cross‐section of a composite product where heat/mass transfer occurs primarily in a direction perpendicular to the FB. The Cube test procedure and benefits are discussed in this work by adopting residential upholstery furniture as an exemplary study. One flexible polyurethane foam, one polypropylene cover fabric, and 10 commercially available FBs were selected. They were used to compare the fire performance of FBs, measured in terms of peak of heat release rate, in the ASTM E1474‐14 standard test and the newly developed Cube test. Edge effects severely affected the performance of FBs in the ASTM E1474‐14 standard test but not in the Cube test. Furthermore, appropriate test conditions were determined in the Cube test to measure the so‐called “wetting point,” that is, the time and value of heat release rate measured when flammable liquid products were first observed on the bottom of the specimen. The relevance of the “wetting point” in terms of full‐scale fire performance and failure mechanism of FBs is discussed.     

The influence of textese on adolescents’ perceptions of text message writers

Text messages are characterised by a casual language style, ‘textese’ (e.g., c u on thurs). This study investigated adolescents’ perceptions of the use of different levels of textese in digital messages which varied in their intended recipient (friend, teacher). Grade 8 students in Australia (N = 90, aged 13–14 years) each read six text messages purportedly written by a fellow student, and rated the extent to which they agreed (on a 7-point Likert scale) that the message writer was intelligent, paid attention to detail, used an appropriate writing style, and was friendly. Overall, participants rated message senders most favourably on all measures when they used no textese, and least favourably when they used high levels of textese. This pattern was even stronger when messages were addressed to teachers rather than same-aged friends. The findings suggest that adolescents are sensitive to both writing style and recipient when considering digital messages.     

Effects of upholstery materials on the burning behavior of real‐scale residential upholstered furniture mock‐ups

Fire spread and growth on real‐scale four cushion mock‐ups of residential upholstered furniture (RUF) were investigated with the goal of identifying whether changes in five classes of materials (barrier, flexible polyurethane foam, polyester fiber wrap, upholstery fabric, and sewing thread), referred to as factors, resulted in statistically significant changes in burning behavior. A fractional factorial experimental design plus practical considerations yielded a test matrix with 20 material combinations. Experiments were repeated a minimum of two times. Measurements included fire spread rates derived from video recordings and heat release rates (HRRs). A total of 13 experimental parameters (3 based on the videos and 10 on the HRR results), referred to as responses, characterized the measurements. Statistical analyses based on Main Effects Plots (main effects) and Block Plots (main effects and factor interactions) were used. The results showed that three of the factors resulted in statistically significant effects on varying numbers of the 13 responses. The Barrier and Fabric factors had the strongest main effects with roughly comparable magnitudes. Foam was statistically significant for fewer of the responses and its overall strength was weaker than for Barrier and Fabric. No statistically significant main effects were identified for Wrap or Thread. Multiple two‐term interactions between factors were identified as being statistically significant. The Barrier*Fabric interaction resulted in the highest number of and strongest statistically significant effects. The existence of two‐term interactions means that it will be necessary to consider their effects in approaches designed to predict the burning behavior of RUF.     

Ergonomic mismatch between students anthropometry and university classroom furniture

University students spend most of their time in classrooms, mostly in a sitting position. Prolonged sitting on ill-fitted furniture and the resulting bad posture is making students suffer from different musculoskeletal disorders (MSDs). This study evaluates the potential mismatch between furniture dimensions and anthropometric measurements. To determine potential mismatch, 13 anthropometric measurements of 550 students and 11 dimensions of two types of classroom furniture (mounted-desktop and chair-with-table) were measured and then compared. Additionally, chi-square test was performed to compare the relation between anthropometry and relevant furniture dimensions. Results showed that a significant number of mismatches emerged between anthropometric measurements and furniture dimensions. For both types of furniture, seat height was too high and seat depth was too deep. Moreover, for mounted desktop, desk height is almost appropriate for all students whereas for chair and table, it was too high for the males. These circumstances may lead to increase discomfort and increase MSDs problems among all students. It can be concluded that the dimensions of both types of classroom furniture were not appropriate for users according to anthropometric measurements. This analysis recommends the measurements of furniture dimensions based on participants’ anthropometric measurements to avoid or minimise discomfort and MSDs problems.     

Chemical exposures from upholstered furniture with various flame retardant technologies

Upholstered furniture is often manufactured with polyurethane foam (PUF) containing flame retardants (FRs) to prevent the risk of a fire and/or to meet flammability regulations, however, exposure to certain FRs and other chemicals have been linked to adverse health effects. This study developed a new methodology for evaluating volatile organic compound (VOC) and FR exposures to users of upholstered furniture by simulating use of a chair in a controlled exposure chamber and assessing the health significance of measured chemical exposure. Chairs with different fire-resistant technologies were evaluated for VOC and FR exposures via inhalation, ingestion, and dermal contact exposure routes. Data show that VOC exposure levels are lower than threshold levels defined by the US and global indoor air criteria. Brominated FRs were not detected from the studied chairs. The organophosphate FRs added to PUF were released into the surrounding air (0.4 ng/m³) and as dust (16 ng/m²). Exposure modeling showed that adults are exposed to FRs released from upholstered furniture mostly by dermal contact and children are exposed via dermal and ingestion exposure. Children are most susceptible to FR exposure/dose (2 times higher average daily dose than adults) due to their frequent hand to mouth contact.     

基于第三方物流的家具配送开放式车辆路径问题

为了降低家具配送成本,提高物流效率,基于第三方物流配送模式,构建了以总行驶距离最短和车辆数最少为最优目标的开放式车辆路径问题(open vehicle routing problem,OVRP)数学模型,并设计了一个改进的两阶段禁忌搜索算法进行求解,第1阶段求解包含所有客户的TSP(traveling salesman problem)路径来作为第2阶段划分OVRP路径的基础.设计了一个随机动态禁忌表,并将"邻域算子编号"和"邻域交换点对"同时作为禁忌对象,避免了过度禁忌的情况.另外,对5个邻域算子进行了测试,表明采用由点交换、分序点插入、点逆序和前点前向插入这4个算子组成的多邻域结构体效果最佳.经算例测试和文献对比,验证了设计算法的有效性,采用第三方物流配送比自营物流配送更节省成本.     

中国古瓷中的明青花牡丹纹的艺术特征

牡丹纹作为为元明清青花瓷中重要的装饰之一最晚出现瓷器不过宋代,布局和绘画方式变化多样。主要特点为枝叶舒展或是多枝相交,花朵怒放被枝头环抱。明朝时期也是青花瓷发展的一个重要阶段,本文通过对现存明朝时期的青花牡丹纹饰例,分别分析不同风格和技法的青花牡丹纹饰,从而论证其艺术特色,以及对后期造成的影响。     

屏边苗式建筑风格及建设初探

考察屏边建筑特色风貌,总结了屏边在打造特色风貌县城建设方面的成功经验,对县城风貌建设提出合理化建议。     

一种使用多维度直方图匹配的图像风格迁移算法

在传统的基于直方图匹配的图像风格迁移算法的基础上，提出一种新的基于多维度直方图匹配的图像风格迁移算法。通过构建关于原图像的不同维度的直方图，然后进行原图像和目标图像的匹配，分别得到原图像在不同维度直方图下的风格迁移图像，最后对这些风格迁移后的图像进行融合生成最终的结果。在保持原图像与目标图像整体风格上尽量相似的情形下，同时又使原图像的局部细节尽可能保留，实现整体风格相似却又保留局部细节的平衡。