基于梯形模糊综合分析法的弹药维修安全风险评估

针对弹药维修的复杂性和特殊性,提出了一种基于梯形模糊综合分析法的弹药维修安全风险评估的方法.从环境、管理、人员、设备和物资等5个方面考虑,建立了弹药维修安全风险评估指标体系;鉴于人判断的模糊性和判断矩阵一致性检验要求,采用了基于梯形模糊数期望值的层次分析法确定指标的权重系数;建立了基于梯形模糊综合分析法的弹药维修安全风险评估模型.通过对某弹药维修工厂的实例分析证明,所建立的弹药安全风险评估模型合理、科学、有效,能够为制定相应的法规提供理论的支撑.     

Bold graph drawings

When a graph is drawn in a classical manner, its vertices are shown as small disks and its edges with a positive width; zero-width edges and zero-size vertices exist only in theory. Let r denote the radius of the disks that show vertices and w the width of edges. We give a list of conditions that make such a drawing good and that apply to not necessarily planar graphs. We show that if r<w, a vertex must have constant degree for a drawing to satisfy the conditions, and if r?w, a vertex can have any degree. We also give an algorithm that, for a given drawing and values for r and w, determines whether the bold drawing satisfies the conditions. Furthermore, we show how to maximize r and/or w without violating the conditions in polynomial time.     

权值不确定的模糊多属性格序决策方法

针对权值是区间数且指标值以三角模糊数形式给出的模糊多属性决策问题,基于格序决策的理论,提出一种新的格序决策办法.方法通过计算梯形模糊数的中心将TOPSIS方法推广到了模糊数的领域,进而给出一种新的方案排序方法.     

梯形直觉模糊数排序方法及在多属性决策中应用

基于梯形直觉模糊数的值和模糊度两个特征,一类梯形直觉模糊数的排序方法被研究.首先,给出了梯形直觉模糊数的定义、运算法则和截集.其次,定义了梯形直觉模糊数关于隶属度和非隶属度的值和模糊度,以及值的指标和模糊度的指标.最后,给出了梯形直觉模糊数的排序方法,并将其应用到属性值为梯形直觉模糊数的多属性决策问题中.     

Experimental Investigation of Laminar Heat Transfer Inside Trapezoidal Duct Having Different Corner Angles

In this study, steady-state laminar forced flow and heat transfer in a horizontal smooth trapezoidal duct having different corner angles were experimentally investigated in the Reynolds number range from 10² to 10³. Flow is hydrodynamically fully developed and thermally developing under a uniform surface temperature condition. Based on the present experimental data of laminar flow in the thermal entrance region, new engineering correlations were presented for the heat transfer and friction coefficients for each corner angle. The results have shown that as the Reynolds number increases heat transfer coefficient increases but Darcy friction factor decreases. Also, it is observed that average Nusselt number increases while average Darcy friction factor decreases with increasing corner angle of the duct.     

虚拟现实系统中水体绘制技术的研究与应用

在虚拟现实系统实现过程中,水体的模拟是非常重要的部分。本文通过对水体特点进行剖析,比较、借鉴总结大量国内外研究成果及文献,深入地分析和研究了不同场景中的水体实时模拟绘制方法,提出了具有较高绘制效率和视觉效果的能够在PC机上实现的不同水体模型的绘制方法。     

探讨CAD绘图中“图块”的智能化应用

计算机技术与工程设计结合产生的CAD技术,不仅绘图速度快、精度高,而且在绘制过程中能够重用图形,更易于交流和管理。本文着重对CAD绘图中能实现“重用图形”的图形设计辅助工具--“图块”进行了深度探究,详细介绍了“属性块”、“动态块”的智能化应用。     

Surface Textured Polymer Fibers for Microfluidics

This article introduces surface textured polymer fibers as a new platform for the fabrication of affordable microfluidic devices. Fibers are produced tens of meters‐long at a time and comprise 20 continuous and ordered channels (equilateral triangle grooves with side lengths as small as 30 micrometers) on their surfaces. Extreme anisotropic spreading behavior due to capillary action along the grooves of fibers is observed after surface modification with polydopamine (PDA). These flexible fibers can be fixed on any surface—independent of its material and shape—to form three‐dimensional arrays, which spontaneously spread liquid on predefined paths without the need for external pumps or actuators. Surface textured fibers offer high‐throughput fabrication of complex open microfluidic channel geometries, which is challenging to achieve using current photolithography‐based techniques. Several microfluidic systems are designed and prepared on either planar or 3D surfaces to demonstrate outstanding capability of the fiber arrays in control of fluid flow in both vertical and lateral directions. Surface textured fibers are well suited to the fabrication of flexible, robust, lightweight, and affordable microfluidic devices, which expand the role of microfluidics in a scope of fields including drug discovery, medical diagnostics, and monitoring food and water quality.     

浅谈 AutoCAD 在有线电视网络中的应用

为适应有线电视数字化和双向业务的发展趋势,探讨了新型的有线电视信息化管理方式,分析了AutoCAD软件在有线电视网络工程图纸绘制方面的可行性与重要性,阐述了AutoCAD在有线电视网络中的应用范围,并介绍了AutoCAD制图中的基本操作和规范。