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根据对中美两国海洋生态类教材的调查,并与新版海洋类通识教材相比较,两国有关海洋通识教材的共同点是两国都着重基础知识的开发,教材编写已有一定体系。存在的差异是国外教材主张激发学生兴趣为主,国内海洋类教材主张完善知识体系为主。建议我国海洋通识教材编写注意加入海洋权益及海洋意识知识,并使之教材内容联系实际,以激发学生兴趣,并且裨益于日常生活。 相似文献
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针对实时动态定位(RTK)技术在物探测量领域中存在的问题,在介绍物探测量相关知识的基础上,对RTK技术原理及网络RTK技术原理进行了介绍,对应用网络RTK技术在物探测量施工中的关键环节进行了分析说明,分析了应用网络RTK技术的优点及存在的主要问题,并对网络RTK技术发展方向进行了探讨。 相似文献
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Tidal current energy is prominent and renewable. Great progress has been made in the exploitation technology of tidal current energy all over the world in recent years, and the large scale device has become the trend of tidal current turbine (TCT) for its economies. Instead of the similarity to the wind turbine, the tidal turbine has the characteristics of high hydrodynamic efficiency, big thrust, reliable sealing system, tight power transmission structure, etc. In this paper, a 1/5th scale horizontal axis tidal current turbine has been designed, manufactured and tested before the full scale device design. Firstly, the three-blade horizontal axis rotor was designed based on traditional blade element momentum theory and its hydrodynamic performance was predicted in numerical model. Then the power train system and stand-alone electrical control unit of tidal current turbine, whose performances were accessed through the bench test carried out in workshop, were designed and presented. Finally, offshore tests were carried out and the power performance of the rotor was obtained and compared with the published literatures, and the results showed that the power coefficient was satisfactory, which agrees with the theoretical predictions. 相似文献
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研究了四种氨基酸(赖氨酸、谷氨酸、甘氨酸、组氨酸)化合物在改性黏土的吸附特征, 考察了改性剂PACl 添加比例、介质pH 及离子强度对吸附过程的影响, 并探讨了吸附机制。结果表明, 在一定比例的PACl 改性能促进氨基酸在高岭土上的吸附, 最佳改性比例为5%, 赖氨酸、谷氨酸、甘氨酸、组氨酸的最大吸附量分别为827、712.56、723.14、732.56 μmol/g; 氨基酸在改性黏土上的吸附动力学符合伪二阶动力学模型; 利用Weber-Morris 模型测定四种氨基酸内部粒子扩散常数, 5%改性条件下赖氨酸、谷氨酸、甘氨酸、组氨酸的内部粒子扩散常数分别为0.847、0.567、0.780、0.603。热力学研究表明, 氨基酸在改性黏土上的吸附等温线是C 型等温线, 5%改性条件下四种氨基酸(赖氨酸、谷氨酸、甘氨酸、组氨酸)的热力学自由能分别为?1.99、?2.41、?3.16、?2.94 kJ/mol, 说明氨基酸在改性黏土上的吸附是一个自发的吸附过程。介质pH 及离子强度对吸附过程具有重要影响。 相似文献