旅游及城市化影响下的避暑山庄植被及其生态规划研究

避暑山庄是现存我国最大的皇家园林。由于种种原因，避暑山庄植被从建庄至今，发生了很大的变化，原始植被破坏殆尽，仅留下少数古树，现状植被多为五十年代大搞绿化时所植，植物配冤出现了与这一历史名园不相协调的矛盾;近几十年来旅游及城市的发展对避暑山庄植被有一定的冲击，要求有相应的对策。 我有从生态学的观点出发，首先对避暑山庄的历史及现状植被进行了研究，然后研究了旅游与城市化对避暑山庄植被的影响，最后，对避暑山庄不同游览区的生境优劣(土壤肥力及小气侯因子)及环境污染(S、Pb)的现状进行了观测与分析。根据上述研究，我们进进了避暑山庄植被生态规划。结果如下: 1、避暑山庄盛期的主要植被是以油松、栎类为主的针(阔)叶林或混交林，尚有以白榆、国槐、旱柳、元宝械等组成的混合林等10个植物群落。 2、避暑山庄现状植被可划分为14个植物群落，以油松群落面积最大。 3、旅游及城市化对避暑山庄植被的影响，主要表现在对土壤的影响及对植被的直接影响，主要方式有机械破坏及造成的环境污染的危害等，这些影响与避暑山庄古松死亡(26.5棵/年)有很大关系。 4、山庄各游览区环境污染的大小顺序是:宫殿区>湖洲区>平原区>山峦区。其中避暑山庄S污染严重是北京北京植物园的2.1倍。 5、避暑山庄各游览区生境优劣:山峦区优予胡洲区，湖洲区优于平原区，平原区优于宫殿区;在山峦区，沟谷优于阴坡，阴坡优于阳坡。 6、避暑山庄湖水出现了富营养化污染，总N及总P含量超过国家标准3倍多。 7、基于上述分析，提出了以旅游为主的避暑山庄植被生态规划原则，根据这一原则，规划出11个植物群落。 8、共编绘了1:10000的避署山庄历史、现状及规划植被图3幅。

Learning large-scale spatial relationships in a maze and effects of MK-801 on retrieval in the rhesus monkey

Monkeys have strong abilities to remember the visual properties of potential food sources for survival in the nature. The present study demonstrated the first observations of rhesus monkeys learning to solve complex spatial mazes in which routes were guid

碧塔海自然保护区科考旅游开发探讨

Based on analyses of the natural characteristics and exploitation advantageous conditions of Bita lake reserve, this paper recommended that the goal of scientific exploration tour was considered as a core program of ecotourism. The concrete exploitation plans, including science interpretation, tourism items, signs explanation systems, guide training and guidebook establishment, were suggested. In addition, how to implement the plan and solve some problems that would be encountered were discussed in the article.

Simultaneous determination of four phases of copper in geological samples

According to the specific property of respective phases in copper ore, optimal extracting condition for, tour phases of copper with five infusion was examined. After a series of experiments, for example, different weight Of sample, artificial mixed single phases sample and repeated experiment, the extracting ratio constants foil all phases in different infusions were obtained. The mathematical model which is on the basis of the stable extracting constant is established. Based on the purpose-control genetic algorithms, we only need to determine the total copper in the sample in different infusions under the selected condition, then the value of respective phase could be calculated. The-relative standard deviation are (%) free oxidized copper phase:1.5, conjunction oxidized copper phase: 17.6,, secondary copper sulfide phase: 1.9, primary copper sulfide phase : 2.7,total copper: 0.8.