中文摘要：

采取化学分析和Tessier连续提取法，对西宁市6个功能区城市土壤重金属cu、zn、Pb和cd的含量及形态进行研究。结果表明：西宁市各功能区土壤的cu、zn、Pb和cd的全量分别是全国土壤相应重金属几何平均值的1．9。5．2，1．9～6．9，0．8-4．0，7．4～11．1倍，4种重金属污染比较严重。6个功能区的重金属cu、zn、Pb和cd含量进行差异显著性分析，结果是广场区cu的含量与风景区的差异不显著（P〉0．05），但与其他4个功能区差异显著（P〈0．05）；风景区与开发区差异显著（P〈0．05），但与其他4个功能区差异不显著（P〉0．05）；开发区zn的含量与商业区和居民区的差异显著（JP〈0．05），而其他各功能区间差异均不显著（P〉0．05）；各功能区Ph和cd的含量均无显著差异（P〉0．05）。研究土壤中重金属的化学形态有较大的差异，Cu以残渣态和有机结合态为主；Zn以残渣态和铁锰氧化物结合态为主；Pb和cd以残渣态为主。Cu活性相对较高的土壤出现在风景区、矿冶区和居民区，zn活性相对较高的土壤出现在风景区和广场区，Pb活性相对较高的土壤出现在风景区和居民区，cd活性相对较高的土壤出现在矿冶区和开发区，研究土壤中4种重金属均具有一定的生物有效性和潜在的生态危害性。

英文摘要：

Decalcification using hydrochloric acid is an important pretreatment in the process of the analysis of soil particle-size distribution from calcareous soil samples. Decalcification procedure is characterized by complex operations, time consuming and low accuracy. To analyze differences and convert relationships for soil particle-size distribution between decalcification and non-decalcification, 368 soil samples were determined by the Mastersizer 2000 laser particle-size analyzer. Results showed that there was a difference in soil particle-size distribution between decalcifica tion and non-decalcification. For coarse sand and clay contents, the samples of the ~〈 3% difference value accounted for 97.28% and 98.91%, respectively. For fine sand and silt contents, the samples of the ~ 3% difference value accounted for 70.65% and 76.63%, respectively. The changes in soil particle-size distribution were mainly influenced by calcium carbonate contents. The correlation of soil particle-size distribution was very significant between decalcification and non-decalcification. The conversion equations of data between the two cases were established so that soil particle-size distribution by the decalcification method could be calculated using the data obtained by the non-decalcification one.