Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《材料研究学报》
Abstract： C-TaC coatings with different C contents (in mass fraction) were deposited on pure graphite by chemical vapor deposition technique with a gas mixture of TaCl5-Ar-C3H6. The tribological properties of the as-prepared coatings were characterized by multifunctional tribometer. The microstructures of the coatings and then the morphologies of the friction surface were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results show that the addition of an appropriate amount of Ta to a pure carbon coating can increase the content of sp2 bonds in the carbon coatings, and can improve the degree of graphitization of the carbon based coatings. When the mass fraction of C in the coatings was 86.4%, the coating show a nano composite structure with the pyrolytic carbon matrix embedded with nanometersized TaC crystallites and among others, which shows the smallest friction coefficient of 0.13. The wear mechanism may mainly concern with adhesive wear, fatigue wear and abrasive wear. By controlling the carbon content and the size of the crystallites in the coating, the friction coefficient of the coating can be adjusted effectively.
Subjects: Geosciences >> Geography submitted time 2018-01-11 Cooperative journals: 《智库理论与实践》
Abstract：[目的/意义] 中国是世界遗产最多的国家之一，传承保护好这些珍贵的历史文化遗产是中国人民，也是世界人民的共同责任，但是如何处理好文化遗产保护利用与城乡改造开发的关系却是一个重大的现实问题。[方法/过程] 采用实地调研、案例分析、对比研究等方法，分析了美国黑石河峡谷遗产廊道、日本纪伊山脉胜地的基本概况，总结了上述两个案例的成功经验，提出了对北京西山文化带的建设启示。[结果/结论] 研究表明，国际上山岳型遗产地保护发展有不少成功经验，可以概括为重视文化遗产保护，自然景观与人文景观相协调；因势利导发展旅游业，促进文化遗产保护与利用相结合；完善规划管理体系，政府管理与民众意愿相统一；成立专门机构，促进国家、地方、民众相联合。这启示北京应进一步凝练西山文化带的文化特色和内涵、切实保护和利用好自然和文化资源、成立专门机构进行统一管理、加强规划引导和功能定位。
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