现代高尔夫草坪科学发展史研究

通过实地调研和资料搜集等多种手段,研究了高尔夫球场的起源、发展及高尔夫草坪管理和利用历史,认为高尔夫球场起源于苏格兰东海岸海滨沙地。高尔夫球场发展应该包括3个阶段:Links、石楠丛及现代阶段。高尔夫草坪的管理也包括3个阶段:初期高尔夫草坪管理、中期高尔夫草坪管理和现代高尔夫草坪管理。高尔夫草坪不但遍布全世界各种地理环境中,而且已经成为一种产业并影响着人类的生活。人类对高尔夫草坪的利用过程就是高尔夫草坪历史发展和发生的过程。     

湘西桐油中脂肪酸分析方法的研究

主要研究目的是为了检测出湘西各地区桐油中所含脂肪酸的种类及含量,据此来判断湘西桐油的品质特性。采用的方法是将湘西各地的桐油与氢氧化钾-甲醇溶液发生质酯交换反应,进行衍生甲酯化,使符合气相色谱法的检测要求,在适合的检测条件下进行气相色谱法的检测。结果发现湘西桐油的主要组分为:棕榈酸、油酸、亚油酸、α-桐酸、β-桐酸,其中影响桐油品质的成分桐酸的含量达到了73%~80%,其中α-桐酸含量远远大于β-桐酸的含量。这说明湘西的桐油具有优良的品质,特别是张家界市永定区的桐油样品中β-桐酸的含量非常低,只有2.01%,这不仅有利于桐油的长时间的保存及运输,而且使湘西桐油具有良好干性油的特性。     

抗菌肽的研究现状及应用前景

抗菌肽是一类广泛存在于生物界的活性多肽,具有广谱抗菌性、热稳定性好、抗菌机理独特等优点,成为医药、食品、畜牧业的研究热点。综述了抗菌肽膜损伤型和非膜损伤型的抗菌机理,不同来源获得抗菌肽及其在医药领域和食品领域的应用前景和存在问题。天然抗菌肽的推广及应用关键在于能否高效获得,并降低其生产成本。     

Electromechanical coupling experimental analysis of permanent magnet AC servo precision drive system

To research the dynamic characteristics of the permanent magnet AC servo precision drive system coupled with multi-factors, the experiment system is constructed with PMAC as the core and IPC as the support platform. Through software prototype system, response signals such as the current, speed and torque are acquired when the system is in the no-load and in the loading operating state, then the theoretical analysis results are compared with the experimental results. So the experiment validates that the electromechanical coupling analysis of the system is correct. This research helps to analyze the influence mechanism and law that the design parameters and electromechanical coupling parameters exerted on the system performance. At the same time, the research is beneficial for dynamic design of the permanent magnet AC servo precision drive system.     

Electromechanical coupling dynamic analysis of permanent magnet AC servo system

Electromechanical coupling effect is considered in the dynamic analysis on permanent magnet AC servo precision derive system. Using electromechanical energy conversion and according to the global coupling analysis and the local coupling analysis, the relation diagrams of global electromechanical coupling and local electromechanical coupling between the permanent magnet synchronous motor precision transmission subsystem are established. Applying Lagrange Maxwell equation, a physical model and a mathematic model of the subsystem are built up, the dynamic equations of the subsystem were derived, and the mathematic model is analyzed. The results show that the mathematic model is correct which provides theoretical basis for experimental study.