Limnology of Lake Ngahewa,North Island,New Zealand     

D. I. Forsyth  R. H. S. McColl 《新西兰海洋与淡水研究杂志》2013,47(3):311-332

The water chemistry, flora, and fauna of Lake Ngahewa are described. Its waters are coloured by humic material from a flax swamp and the mean carbon: nitrogen ratio of the sediments lies in the range for dystrophic lakes. Thermal stratification is very weak or absent during summer, although deoxygenation occurs at depths below 3 m in late summer. The lake is highly productive and has a diverse phytoplankton and zooplankton population, which is different in species composition from other nearby eutrophic lakes; some algal species common in nearby eutrophic lakes are absent, and there is a high ratio of rotifers to cladocerans and copepods.

The high levels of dissolved phosphorus (42.2 mg.m^‐3) and nitrogen (up to 36.1 mg.m^‐3 NO3‐N) in the lake waters, and the differences in the flora and fauna compared with neighbouring lakes give only weak support to its tenuous classification as a dystrophic lake on the basis of water colour and sediment carbon values. The concept of dystrophy is discussed.  相似文献   

A new species of eucypris (ostracoda) from wellington     

Stephen H. Eagar 《新西兰海洋与淡水研究杂志》2013,47(2):195-202

Eucypris pratensis sp. nov. is described from Wellington. It is considered conspecific with the one previous record of the genus from North Island, New Zealand.  相似文献   

高斯投影与横墨卡托投影等价性证明     

李忠美  于金星  李厚朴  边少锋 《海洋测绘》2013,33(3):17-20

为探寻球面高斯与横墨卡托投影间的内在联系,将墨卡托投影中的圆柱旋转90°,与某一子午线相切,并根据球面三角形定理得到横墨卡托投影的一般表达式;考虑到高斯投影实数型级数展开式不易于进行公式变换,推导出球面高斯投影复变函数表示式;根据复变函数及常用初等函数的定义,从高斯投影复变函数表示出发,经过一系列数学分析过程,给出球面高斯投影与横轴墨卡托投影等价性的严格证明。  相似文献