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浅谈中国后奥运时期选择性旅游的发展 总被引:4,自引:0,他引:4
大众旅游一直追求经济利益最大化给旅游接待地造成了严重的生态环境破坏,因此人们开始寻求新的旅游形式,选择性旅游应运而生。选择性旅游积极倡导真正意义上的生态旅游。该文研究的主要内容是中国在后奥运这样的特殊时期如何开展选择性旅游,选择性旅游一方面能尽量避免大众旅游所带来的生态环境破坏,另一方面能更好地适应各个国家不同旅游者到中国旅游求新求异的特点。通过对后奥运时期旅游趋势以及旅游市场的分析,中国在后奥运时期开展选择性旅游具有可行性。优先开展选择性旅游,可促进旅游的可持续性发展。 相似文献
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The dynamic response of tall civil structures due to earthquakes is very important to civil engineers. Structures exposed to earthquakes experience vibrations that are detrimental to their structural components. Structural pounding is an additional problem that occurs when buildings experience earthquake excitation. This phenomena occurs when adjacent structures collide from their out‐of‐phase vibrations. Many energy dissipation devices are presently being used to reduce the system response. Tuned mass dampers (TMD) are commonly used to improve the response of structures. The stiffness and damping properties of the TMD are designed to be a function of the natural frequency of the building to which it is connected. This research involves attaching adjacent structures with a shared tuned mass damper (STMD) to reduce both the structures vibration and probability of pounding. Because the STMD is connected to both buildings, the problem of tuning the STMD stiffness and damping parameters becomes an issue. A design procedure utilizing a performance function is used to obtain the STMD parameters to result in the best overall system response. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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宝兴岩体位于华北板块北缘陆缘活动带东段,岩性为花岗闪长岩,LA-ICP-MS锆石~(206)Pb/~(238)U年龄加权平均值为235.0±1.3Ma,属于中三叠世。岩石的K_2O/Na_2O平均值为1.07,属高钾钙碱性系列;富集大离子亲石元素,亏损高场强元素,具有活动陆缘钙碱性岩系特征;稀土元素总量平均值为147×10~(-6),稀土元素配分曲线右倾,属具中等负Eu异常的轻稀土元素富集、重稀土元素亏损型。通过岩石学、岩石地球化学及年代学研究,结合邻区构造演化研究,认为中三叠世研究区在伸展作用下岩石圈进行拆沉,从而形成大规模的岩浆活动。 相似文献
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JIN Mingming SHI Jiuxin LU Yong CHEN Jianfang GAO Guoping WU Jingfeng ZHANG Haisheng 《海洋学报(英文版)》2005,24(6):88-96
The phenomenon of nutrient maximums at 70~200 m occurred only in the region of the Canada Basin among the world oceans. The prevailing hypothesis was that the direct injection of the low-temperature high-nutrient brines from the Chukchi Sea shelf (<50 m) in winter provided the nutrient maximums. However, we found that there are five problems in the direct injection process. Formerly Jin et al. considered that the formation of nutrient maximums can be a process of locally long-term regeneration. Here we propose a regeneration-mixture process. Data of temperature, salinity, oxygen and nutrients were collected at three stations in the southern Canada Basin during the summer 1999 cruise. We identified the cores of the surface, near-surface, potential temperature maximum waters and Arctic Bottom Water by the diagrams and vertical profiles of salinity, potential temperature, oxygen and nutrients. The historical 129Ⅰ data indicated that the surface and near-surface waters were Pacific-origin, but the waters below the potential temperature maximum core depth was Atlantic-origin. Along with the correlation of nutrient maximums and very low oxygen contents in the near-surface water, we hypothesize that, the putative organic matter was decomposed to inorganic nutrients; and the Pacific water was mixed with the Atlantic water in the transition zone. The idea of the regeneration-mixture process agrees with the historical observations of no apparent seasonal changes, the smooth nutrient profiles, the lowest saturation of CaCO3 above 400 m, low rate of CFC-11 ventilation and 3H-3He ages of 8~18 a around the nutrient maximum depths. 相似文献
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