基于曲边梯形面积刻画毕达哥拉斯模糊数的排序方法

毕达哥拉斯模糊集（Pythagorean fuzzy set,PFS）是传统直觉模糊集（intuitionistic fuzzy set,IFS）的扩展,能在更广泛区域处理多属性信息决策问题。首先,针对某文献毕达哥拉斯模糊数（Pythagorean fuzzy number,PFN）排序方法存在的错误,分析了其产生原因。其次,在毕达哥拉斯模糊环境下,基于可靠信息量所对应的曲边梯形面积（curved trapezoidal area,CTA）提出了新的得分函数公式,进而给出了PFN的排序准则,并讨论了该得分函数的基本性质。最后, 用实例说明给出的排序方法克服了其他方法的某些缺陷,具有一定优势。     

T型缝隙结构表面等离子波导的基本特性研究

An air channel inside a silver metal film is usually used as a typical Channel Plasmon Polariton （CPP） waveguide. This paper presents research on the basic properties of this waveguide using the Finite Difference Time Domain（FDTD） method. The relationship between transmission power and structure of the waveguide is investigated. The simulation results show that the subwavelength trapezoidal CPP waveguide is superior to the rectangle CPP waveguide for controlling SPP radiation loss and enhancing the transmitted power. As a result, if the rectangle CPP waveguide is replaced by a trapezoidal CPP waveguide in certain integrated optical devices, their performance may be improved.     

高职港口与航道专业工程制图教学改进研究

随着国家"一带一路"倡议的提出, 国内外港口与航道工程急需大量专业技术管理人员。就我国目前的高职高专港口与航道工程制图教学内容及方法而言, 还存在着教材内容滞后, 实践教学缺乏, 考核方法落后等诸多问题。要改变这种现状, 就必须改进传统的教学方式, 引入图形科学与图形技术, 制定新的教学管理内容与方法, 完善课程考核制度。通过课程教学改革, 促进高职港口与航道专业制图教学内容和方式的创新, 提高港口与航道专业工程制图课程的教学质量。     

低偶然符合效应的高脉冲分辨能力数字化X荧光能谱仪研制

在X荧光能谱测量中,当两个事例发生间隔较短时,存在脉冲前沿或后沿堆积的情况.如果能谱仪的脉冲分辨能力不足,在事例发生间隔小于能谱仪脉冲分辨能力时,发生了偶然符合效应.当堆积发生在信号的上升沿时,后端电子学无法识别堆积脉冲,并将堆积脉冲当成1个脉冲,从而在测量能谱中会产生虚假能峰;当堆积出现在下降沿时,堆积信号间隔小于通...     

Recent developments in oriented polymers for biomedical and engineering applications

A review is presented of recent research at Leeds University which has been directed at devising novel methods for the production of oriented polymer structures. First, the new hot compaction process for oriented fibre and tapes is described, together with its applications to polyethylene and polypropylene where there are a number of practical developments. Secondly, there is the use of hydrostatic extrusion to make load bearing oriented products from hydroxyapatite filled polyethylenes. The production routes include the application of high pressure annealing prior to hydrostatic extrusion and the preparation of high modulus polyethylene fibre/hydroxyapatite billets as the starting point. Finally, recent progress on die-drawing as a means to producing oriented monofilaments and biaxially oriented tubes is described, where the applications include polymer ropes, pipes for gas and water distribution and transparent cans for packaging.     

Nb 管增强Cu-Nb 复合线材的结构及力学性能研究

Cu-Nb 复合材料兼具高强度、 高电导率以及高热稳定性等优势, 已成为脉冲磁体和电磁线圈导体材料的首选. 本文通过集束拉拔技术成功制备出了 Nb 管增强 Cu-Nb 三次复合线材. 综合利用 TEM/HRTEM、EBSD 等表征和测试手段分析了冷拉变形后材料的微观组织, 揭示了大塑性变形后 Nb 管增强 Cu-Nb 复合线材的微结构演变特征. 并基于线材强度与 Nb 芯丝的量化关系分析, 探讨了 Nb 管增强 Cu-Nb 复合线材的强化机理.     

High frequency doubling efficiency THz GaAs Schottky barrier diode based on inverted trapezoidal epitaxial cross-section structure

A high-performance terahertz Schottky barrier diode (SBD) with an inverted trapezoidal epitaxial cross-sectional structure featuring high varactor characteristics and reverse breakdown characteristics is reported in this paper. Inductively coupled plasma dry etching and dissolution wet etching are used to define the profile of the epitaxial layer, by which the voltage-dependent variation trend of the thickness of the metal-semiconductor contact depletion layer is modified. The simulation of the inverted trapezoidal epitaxial cross-section SBD is also conducted to explain the physical mechanism of the electric field and space charge region area. Compared with the normal structure, the grading coefficient M increases from 0.47 to 0.52, and the capacitance modulation ratio (C_max/C_min) increases from 6.70 to 7.61. The inverted trapezoidal epitaxial cross-section structure is a promising approach to improve the variable-capacity ratio by eliminating the accumulation of charge at the Schottky electrode edge. A 190 GHz frequency doubler based on the inverted trapezoidal epitaxial cross-section SBD also shows a doubling efficiency of 35% compared to that 30% of a normal SBD.