计量学主题词表词间关系构建方法探析

为了防止叙词性汉语主题词表可能存在的词义模糊甚至歧义的问题,防止在应用中出现“误检”“漏检”的现象。在构建计量学主题词表时,本文通过“前方一致”、“后方一致”等方法对专业术语进行排序,并针对不同特征进行归纳演绎,有效的获得了词间关系,提高了实际应用中“查准率”和“查全率”。     

去噪后单晶硅表面形貌的反射率分析

针对单晶硅表面在制绒时会有“凹坑”缺陷出现的现象,利用双正交提升小波bior4.4进行分段处理,将“凹坑”缺陷等价为“类三角形”的金字塔模型去噪。通过对去噪后的单晶硅绒面建立反射率的估计计算模型,进行反射率的估计计算。结果表明,将“凹坑”缺陷等价处理后能有效地降低反射率,同时得出单晶硅绒面的平均反射率与绒面的一致性存在一定的关系,有必要进一步控制绒面制造工艺因素,提高微结构的一致性。     

涡轮设计方法改进研究

首先从涡轮总体设计性能要求出发,运用流线曲率法设计涡轮子午流道,并获得设计所需的气流速度三角形;然后运用课题组开发的“十四”参数法【1】进行二维叶栅设计,由参数曲面完成三维叶片造型以及构建涡轮特征模块化体系进行网格划分;最后得到可直接用于计算的网格。设计过程表明,经过改进后的设计方法可方便、快捷的完成涡轮设计。     

曲面围成区域的简图作法

为了能快速作出多个曲面围成区域的简图,手工作图有时候很有必要.手工作曲面围成的立体图的难点是画出曲面的交线.先化简联立方程,结合投影和平行截割法,准确地描出交线.给出了作简图的数学原理和一般步骤.学生作图效果表明这种作图法操作性强,便于学生掌握.     

运用表面肌电信号对山西省射箭运动员技术特征分析初探

表面肌电图是从肌肉表面通过电极引导、记录下来的神经肌肉系统活动时的生物电信号。文章测定了山西省12名射箭运动员在日常训练时6块肌肉的肌电信号,并与国家队队员肌电信号进行对比分析和探索山西省射箭运动员技术特征。     

机械加工表面形貌的分形特性表征

为了表征机械加工表面形貌分形特征,介绍了用结构函数计算加工表面分形维数的方法.以车削加工和镗削加工作为算例,分别给出了粗糙度Ra为1.6μm和3.2μm的四种表面形貌图片和形貌曲线,应用结构函数法表征了表面形貌的分形维数.计算结果表明,同种加工方法的不同粗糙度下表面形貌具有较强相似性.     

沥青路面除冰雪技术研究(英文)

为降低路面和冰雪之间的黏结力,用有机硅憎水材料作为道路表面涂层.有机硅憎水涂层技术的除冰效果用接触角实验和剪切实验来表征,其耐久性用加速加载磨耗实验来评价,而其抗滑性能则用摆式摩擦法和铺砂法来评价.接触角实验结果表明,有机硅憎水涂层材料与水的接触角为100.2°,具有很好的憎水性能.其次,通过剪切实验可以得出:在涂有有机硅憎水材料的情况下,冰层与试件表面的最大剪切应力仅为0.06 MPa,低于没有进行表面涂层处理的最大剪切力3.5 MPa;剪切之后,冰层能够很完整地从试件表面脱落.加速加载磨耗实验表明,在经过一定时间的磨耗之后,残留在沥青路面构造深度里的有机硅涂层材料仍然具有除冰雪的效果.表面涂层后的道路表面的BPN值和构造深度值均有所降低,但是其仍然远远大于规范的要求,确保了安全性.研究表明,沥青道路表面涂层技术能有效地降低沥青路面与冰层的黏结,从而解决冬季道路结冰影响行车安全的问题.     

Constructive,collaborative, contextual,and self‐directed learning in surface anatomy education

Anatomy education often consists of a combination of lectures and laboratory sessions, the latter frequently including surface anatomy. Studying surface anatomy enables students to elaborate on their knowledge of the cadaver's static anatomy by enabling the visualization of structures, especially those of the musculoskeletal system, move and function in a living human being. A recent development in teaching methods for surface anatomy is body painting, which several studies suggest increases both student motivation and knowledge acquisition. This article focuses on a teaching approach and is a translational contribution to existing literature. In line with best evidence medical education, the aim of this article is twofold: to briefly inform teachers about constructivist learning theory and elaborate on the principles of constructive, collaborative, contextual, and self‐directed learning; and to provide teachers with an example of how to implement these learning principles to change the approach to teaching surface anatomy. Student evaluations of this new approach demonstrate that the application of these learning principles leads to higher student satisfaction. However, research suggests that even better results could be achieved by further adjustments in the application of contextual and self‐directed learning principles. Successful implementation and guidance of peer physical examination is crucial for the described approach, but research shows that other options, like using life models, seem to work equally well. Future research on surface anatomy should focus on increasing the students' ability to apply anatomical knowledge and defining the setting in which certain teaching methods and approaches have a positive effect. Anat Sci Educ 6: 114–124. © 2012 American Association of Anatomists.     

Optimization of extraction of phenolics from leaves of Ficus virens

In this research, the conditions for extraction of phenolics from leaves of Ficus virens were optimized using response surface methodology (RSM). The extraction abilities of phenolics (EAP) and flavonoids (EAF), the 2,2-diphenyl-1-pierylhydrazyl (DPPH) free-radical scavenging potential, and the ferric reducing/antioxidant power (FRAP) were used as quality indicators. The results of single-factor experiments showed that temperature, ethanol concentration, extraction time, and the number of extraction cycles were the main influencing variables, and these provided key information for the central composite design. The results of RSM fitted well to a second degree polynomial model and more than 98% of the variability was explained. The ideal extraction conditions for EAP, EAF, DPPH free-radical scavenging potential, and FRAP were obtained. Considering the four quality indicators overall, the ideal extraction conditions were 58% ethanol at 57 °C for 37 min with three extraction cycles. At the ideal extraction conditions, the values of EAP, EAF, DPPH free-radical scavenging potential, and FRAP were 5.72%, 3.09%, 58.88 mg ascorbic acid equivalent (AAE)/g dry weight (DW), and 15.86 mg AAE/g DW, respectively. In addition, linear correlations were observed between EAP, EAF, and antioxidant potential.     

基于贪心蚁群算法的无人水面艇全局路径规划

为解决无人水面艇(unmanned surface vessel,USV)在地型较复杂小型水域内的全局路径规划问题,提出一种以贪心算法、蚁群算法、栅格法建模为基础,通过加入双向搜索算法来解决传统贪心算法搜索时易陷入局部最优解等问题的贪心蚁群算法。该算法利用贪心算法规划基础路线,利用蚁群算法的信息素机制摆脱局部收敛状态,并通过双向搜索算法降低局部收敛概率。仿真结果表明:该算法搜索时间较传统蚁群算法减少70%以上,迭代次数较传统蚁群算法减少约85%;该算法在处理USV的全局路径规划问题中具有一定的有效性、合理性。