Color image segmentation: advances and prospects

Image segmentation is very essential and critical to image processing and pattern recognition. This survey provides a summary of color image segmentation techniques available now. Basically, color segmentation approaches are based on monochrome segmentation approaches operating in different color spaces. Therefore, we first discuss the major segmentation approaches for segmenting monochrome images: histogram thresholding, characteristic feature clustering, edge detection, region-based methods, fuzzy techniques, neural networks, etc.; then review some major color representation methods and their advantages/disadvantages; finally summarize the color image segmentation techniques using different color representations. The usage of color models for image segmentation is also discussed. Some novel approaches such as fuzzy method and physics-based method are investigated as well.     

关于大学物理实验教学改革的思考

针对大学物理实验教学现状,分析了问题存在的原因,提出了相应的建议。并对提高学生物理实验的兴趣,培养创新能力,提高实验教学水平提出了自己的看法,从根本上提高大学生的科学素养,培养学生的实践能力和创新能力,以适应现代社会发展的需要。     

虚拟原型技术在机电产品开发中的应用

从我国机电产品开发面临的挑战入手,阐述了虚拟原型技术及其在机电产品开发中的应用现状和发展趋势。研究表明,采用该方法能够有效缩短产品开发周期,提高设计质量,实现产品开发周期和成本的最小化。     

WC—8（Fe／Ni／Co）R硬质合金的研究

用Ｆｅ、Ｎｉ部分取代ＷＣ－８Ｃｏ合金（牌号ＹＧ８）中的粘结剂Ｃｏ,再添加微量稀土Ｒ制得ＷＣ－８（Ｆｅ／Ｎｉ／Ｃｏ）Ｒ硬质合金,测试了其物理机械性能,研究了粘结剂各种成份比例及烧结温度对硬质合金的影响。结果表明：ＷＣ－８（Ｆｅ／Ｎｉ／Ｃｏ）Ｒ硬质合金的性能可以达到ＹＧ８的性能标准。利用扫描电镜（ＳＥＭ）及Ｘ射线衍射（ＸＲＤ）对其作了显微结构分析,同时探讨了影响ＷＣ－８（Ｆｅ／Ｎｉ／Ｃｏ）Ｒ合金性能的     

微观材料学的两个基本方程和三个基础概念

本文应用逻辑学、系统分析、物理学的进化论述了微观材料学中三个基础概念——结构 (S)、环境 (e)、性能 (性质 ) (P) ,以及它们所组成的两个基本方程 :P=f(e,S)和 S={ E,R} ,式中 E为系统中组元的集合 ,R为组元间关系的集合。比较了因果关系的各种学说 ,扩展第一方程 ,增加了第四个基础概念——揭示事物秘密的“过程”;应用数量学、生物进化论等讨论无生物、生物及人类各种过程的目的。这些论述 ,为《材料学的方法论》的广泛应用 ,打下理性基础。     

近代物理多媒体教学软件的开发

以Windows Multimedia ToolBook平台开发的《近代物理》多媒体教学软件具有系统性、资料性等特点,软件包括狭义相对论、量子力学、物理学名人、测试题四个模块,介绍了辅教型、助学型《近代物理》多媒体教学软件的物理意义、设计思想、技术要点,分析了超文本导航、对象提示、回退一步、交互性动画、交互性习题等制作过程。     

谈物理教学中的类比方法

主要介绍物理教学中的类比方法及作用。     

Effect of SiC nanowires on the high-temperature microwave absorption properties of SiCf/SiC composites

SiC-nanowire-reinforced SiC_f/SiC composites were successfully fabricated through an in situ growth of SiC nanowires on SiC fibres via chemical vapour infiltration. The dielectric and microwave absorption properties of the composites were investigated within the frequency range of 8.2–12.4 GHz at 25–600 °C. The electric conductivity and complex permittivity of the composites displayed evident temperature-dependent behaviour and were enhanced with increasing temperature. The composites exhibited superior microwave absorption abilities with a minimum reflection loss value of ?47.5 dB at 11.4 GHz and an effective bandwidth of 2.8 GHz at 600 °C. Apart from the contribution of the interconnected SiC nanowire network and multiple reflections, the excellent microwave absorption performance was attributed to dielectric loss that originated from SiC nanowires with abundant stacking faults and heterostructure interfaces. Results suggested that the composites are promising candidates for high-temperature microwave absorbing materials.     

Designing and transforming yield-stress fluids

We review progress in designing and transforming multi-functional yield-stress fluids and give a perspective on the current state of knowledge that supports each step in the design process. We focus mainly on the rheological properties that make yield-stress fluids so useful and the trade-offs which need to be considered when working with these materials. Thinking in terms of “design with” and “design of” yield-stress fluids motivates how we can organize our scientific understanding of this field. “Design with” involves identification of rheological property requirements independent of the chemical formulation, e.g. for 3D direct-write printing which needs to accommodate a wide range of chemistry and material structures. “Design of” includes microstructural considerations: conceptual models relating formulation to properties, quantitative models of formulation-structure-property relations, and chemical transformation strategies for converting effective yield-stress fluids to be more useful solid engineering materials. Future research directions are suggested at the intersection of chemistry, soft-matter physics, and material science in the context of our desire to design useful rheologically-complex functional materials.