90 . 95 . the phase transformation temperature of the natural cryptomelane was about 635 . 5 examined by tga and dta and the cryptomelane was changed to bixbyite at a higher temperature . these studies reveal the significant features of cryptomelane for the potential application in the environmental materials science K 3 . 37 % 4 . 17 %差热热重分析表明天然锰钾矿的结构热稳定性较好， 635 . 5时相转变为方铁锰矿。
According to the electron probe analyses and other data , some conclusions have been reached as follows : the modes of occurrence of associated silver include minerals of stephanite , bromargyrite , ag - sb - tetrahedrite , electrum etc . , which occur as small grains among or between fe - mn minerals 利用电子探针等测试方法对锰矿石中伴生银的赋存状态进行研究，初步查明银主要是以脆银矿、溴角银矿、银锑黝铜矿、银金矿等矿物形式存在，呈微小颗粒状被包裹于铁锰矿物内或矿物间隙里。
The intense eluviation and weathering of soil with groundwater and run - off result in the enhancing of capacity of transference of some elements , such as si , al , fe , mn . the chemical reactions of the colloid particles in the soil water make those crannies or holes filled by some epigenetic clay minerals and quartz . then a great deal of white reticulate clay comes into being in the quaternary laterite of the dongting basin 地下水和地表水强烈的淋溶作用使土壤中硅铝铁锰等元素的迁移能力增强，土壤胶体粒子之间的化学反应，使得这些孔隙空间在后期逐渐被次生黏土矿物和石英所充填，最终，在洞庭盆地第四系红土地层中形成大量的蠕虫状和根状白色网纹。
Deferrizers and demaganizers are series of products designed by our company for underground water with comparatively high iron and managanese content according to aerating oxidation priciple . in these prducts , packed natural manganese sand in filter is applied as filtering materials , and oxygen in air is applied as oxidants , to make ferrous iron in water oxidized into ferric iron , in a same time , oxidation reaction makes its produced its produced substances left in filtering materials for purposes of deferrization and deman - ganization 除铁锰装置是我公司针对铁、锰较高的地下水，按曝气氧化法的原理而设计的系列产品，它是利用过滤器内装填城然锰砂为滤料，利用空气中的氧化剂，使水中的二价铁，同时发生氧化反应使其物进截留在滤料中，从而达到除，除锰的目的。
Apart from geochemists from western countries , which paid a particular attention on amorphous iron - manganese oxides extracted by enzyme or 0 . 1 ~ 0 . 25m nh2oh ? hc1 , our results show that the extraction of metals adsorbed by clay and bound to the carbonate in soil is most useful to identify the concealed mineralizations in the semiarid and loess covered terrains , northern china 但与国外重点关注非晶质铁锰氧化物如酶、盐酸羟氨提取结果不同，在我国北方半干旱黄土覆盖景观区，粘土吸附和碳酸盐结合态金属元素的提取为最有效的提取步骤。而游离态、有机结合态的提取效果则受景观控制变化较大。
The study mainly introduced some aspets as follow : the reduction of the soil acidity , the eli mination of toxicity of al , fe and mn to the root system , the improvement on acidic soil , the effect on crops yield , as well as the agricultural application of lime in home and abroad and the calculational methods of the required quantity of acidic soil in application 摘要主要介绍了生石灰降低土壤酸度、消除铝铁锰对根系毒害作用、对酸性土壤的改良作用、对作物产量的影响等方面，以及生石灰在农业生产上的国内外应用情况和酸性土壤施用生石灰需要量的计算方法。
