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硅酸盐和氧化物矿物的溶解速率，在远未达到平衡的条件下，其实验活化能随ｐＨ值的变化达几十个ｋｊ／ｍｏｌ。在远比零净质子电荷点更酸性或更碱性的ｐＨ条件下，实测的Ｅｅｘｐ值从大于５０ｋｊ／ｍｏｌ变化到在ＰＺＮＰＣ附近但未必在ＰＺＮＰＣ点的很小的值。我们通过经验的溶解速率定律与产生正表面电荷的质子吸附的条件平衡常数相结合的方法，解释了这种矿物溶解速率随ｐＨ值发生的变化。利用条件平衡常数中的静电势项，对矿物 相似文献
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景色美丽气候宜人的南加州是2000多万人口的家园,而且对国民经济非常重要。遗憾的是,该地区也纵横分布着许多可产生强烈地震的活断层。来自一些科研院所的科学家正在探索一种研究高危险性大都市地区地震灾害的新方法。 SCIGN(南加州综合全球定位系统台 相似文献
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Frey WH 《International journal of population geography : IJPG》1995,1(1):51-67
"This article presents newly-available migration data from the 1990 U.S. census to assess immigration and internal migration components as they affect state poverty populations. New immigrant waves are heavily focused on only a few 'port-of-entry' states. It is suggested that these immigrants have begun to impact upon internal migration into and out of these 'high immigration states', and have also altered the national system of internal migration patterns. This article addresses three questions: How do the magnitudes of poverty population out-migration from high immigration states compare with those of other states? Is this out-migration selective on particular social and demographic groups? Is immigration a significant determinant of internal migration of the poor population? The results of this analysis are consistent with the view that recent, focused immigration is associated with out-migration among a state's poor longer-term residents." 相似文献
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