Helan shan is located in the northwest of china , 37 . 0 - 3 9 . 6 n . and 105 . 3 - 106 . 8 e . . its altitude ranges from 1 600m to 3 556m . the cosmo politan genera and species of higher fungi from helan shan amount to 64 . 1 % and 1 9 . 8 % respectively . most of them are saprophytic taxa of broad physiological adap tability . the genera belonging to the boreal areal type make up 35 . 9 % , and species 52 . 7 % , which indicates that the higher fungi flora of the helan shan are dominan ted by boreal elements . no tropical genera and species have been found there . the elements of europe - asia add up to 11 . 5 % , while the elements of east asia - north america amount to 9 . 9 % which shows close relationship of fungi between the helan shan and the above two regions . the elements of china - japan amount to 3 . 1 % , whic h reflects some relations of higher fungi between china and japan . few elements e ndemic to helan shan were found but with further investigation and study , it is p ossible to find some considering its isolated geographic location and varied top ography 贺兰山高等真菌区系地理成分中,世界性分布属占64 . 1 % 、种占19 . 5 ,他们多为适应性强的腐生菌类;欧亚北美分布属占35 . 9 % 、种占52 . 7 % ,未发现热带分布的属或种,充分显示出该地区真菌以北温带分布成分为主的特点;欧亚分布种占11 . 5 % ,东亚北美分布种占9 . 9 % ,表明该地区真菌区系与欧洲、北美洲的密切联系;中国&日本分布种占3 . 1 % ,可见本地区和日本在真菌区系上也有着联系;本地区特有成分较少,但从贺兰山特殊的地理位置、相对孤立的山体和复杂的地形分析,随研究工作的深入,很可能有一些山的分布的特有成分被发现.贺兰山真菌区系成分与邻近的内蒙古大青山相比较,共有种多达57种,而与地处亚热带向热带过渡的湖南莽山相比较,共有种仅有12种,更进一步说明本地区深居北温带,真菌区系以泛北极成分为主的特色
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The specific methods : 1 . to ascertain five control indications including suspended solid content , grain diameter median , oil content , iron bacteria and saprophytic bacteria by carrying out the experiment of core flow ; 2 . to ascertain indications of sulfate reducing bacteria and average corrosion rate by carrying out the experiment of revolving corroded test pieces ; 3 . to ascertain indications of average scaling rate and total mineralization degree by carrying out the experiment of scaling prediction and sensibility 具体的做法是：采用岩心流动试验确定悬浮固体含量、颗粒直径中值、含油量、铁细菌和腐生菌五项控制指标；采用旋转腐蚀挂片实验确定硫酸盐还原菌和平均腐蚀率指标；采用结垢预测和敏感性实验确定平均结垢率和总矿化度指标。
