The Enrichment Process of Groundwater Fluorine in Sea Water Intrusion Area of Gaomi City,China

A typical area, Gaomi City in China, was chosen to discuss the enrichment process of groundwater fluorine in sea water intrusion area. The groundwater had fluorine levels of 0.09–10.99 mg/L, with an average concentration of 1.38 mg/L. The high-fluorine groundwater was mainly distributed in the unconsolidated Quaternary sediments, where concentrations in 83.6% of the samples exceeded the national limit of 1.0 mg/L. The groundwater in the Quaternary sediments also had higher levels of Cl⁻, TDS, Mg²⁺, and pH and lower levels of Ca²⁺, Co, Ni, and Cu than that in the bedrock. The groundwater fluorine levels in the Quaternary sediments are positively correlated with Cl⁻, TDS, Mg²⁺, pH, and negatively correlated with Ca²⁺, γCa²⁺/γMg²⁺, Co, Ni, Cu. Geochemical indices of Cl⁻ and TDS indicate sea water intrusion in the Quaternary high-fluorine groundwater area (F⁻ > 1.0 mg/L), while they do not indicate any intrusion in the bedrock area. The chemical weathering of minerals was intensified with the intrusion of sea water. Cation exchange was confirmed to occur in the Quaternary sediments and was promoted by sea water intrusion. Cation exchange consumes part of groundwater Ca²⁺ and permits more F⁻ dissolving. Consequently, in the Quaternary sediments, the groundwater was supersaturated with CaF₂ minerals and undersaturated with MgF₂ minerals when F⁻ > 1.0 mg/L, while CaF₂ and MgF₂ minerals both are undersaturated when F⁻ < 1.0 mg/L. Thus, the chemical weathering of minerals and cation exchange caused by sea water intrusion are the crucial processes controlling the groundwater fluorine levels, which should be considered when the groundwater fluorine enrichment mechanism is discussed along coastal zones.     

地球磁场对太阳风的加卸载响应与地震

将磁暴过程作为地球磁场对太阳风的加卸响应，计算分析了北京地磁台１９６５．１－１９７９．１２和１９８９．１－１９９１．１２共１８年垂直分量Ｚ的暴时场Ｄｓｔ加卸载响应比值ｆＤ（Ｚ）的变化。     

青岛城区土壤重金属现状评价及趋势预测

通过对青岛城区土壤进行调查取样,运用单因子评价和内梅罗指数法对青岛表层土壤8种重金属元素(As,Cd,Cr,Cu,Ni,Hg,Pb和Zn)的测试结果进行评价,查明了土壤环境质量现状及其污染程度:青岛市土壤环境质量总体较高,绝大部分地区土壤环境保持在清洁水平;污染区域以孤岛状零星分布于青岛市内,区内胶州湾入海口污染指数偏高,很可能是由于河流上游污水排放导致的。通过对未来20年城区土壤在大气降尘影响下重金属Cd,Zn的累积情况进行了预测,结果表明:随着时间的推移,土壤有害元素含量会有所增高。其中,大气降尘中Zn元素对青岛市区土壤影响明显。该研究对于正确认识青岛区域地球化学特征和地质环境具有一定的指导意义。     

Zircon U-Pb Ages of Bottom and Top Parts of the Zhangjiakou Formation in Lingyuan Area （West Liaoning Province） and Luanping Area （North Hebei Province） and Their Significance

Thecharacteristicsofthetectonics,stratigraphy, paleontologyandvolcanicpetrologyoftheMesozoicin NorthHebeiandWestLiaoningaresimilarinmanyas pects,butthetworegionsalsohavesomeobvious differences.Thetworegionshavebeen“hotspots”inthegeologicalworldforafewy…     

农业气象指数保险研究及其应用进展

全球气候变化背景下，极端天气事件和自然灾害频发，农业生产面临着巨大的气象灾害风险。新疆农区各类气象灾害呈现多发、频发的趋势，以合同中约定的天气指数作为触发值进行赔付的农业气象指数保险，是转移农业灾害风险的重要途径。分析农业气象指数保险的发展历程与研究进展，讨论其在新疆农业生产中的应用现状，提出新疆农业气象指数保险的研究重点及发展方向，以期为气象指数保险服务于农林业安全生产提供思路和参考。     

近50a石河子棉区≥10℃积温时空变化特征

利用石河子棉区4个气象站1971—2020年逐日气象资料，采用气候倾向率、累积距平、均方差、Mann-Kendall突变检验等方法，分析了石河子棉区≥10℃积温的变化特征。结果表明：石河子棉区≥10℃初日呈显著提前趋势，终日略微推迟，持续日数显著延长，积温明显增多；≥10℃积温及持续日数均在1994年发生了由少到多的突变；≥10℃积温正常年份的概率超过64%，依次向两端递减；≥10℃积温偏低地区主要在莫索湾，偏高地区主要在乌兰乌苏。气候变化背景下，石河子棉区热量条件有较好的改善，棉花延迟型低温冷害有所减轻，石河子棉区品种布局应以早熟棉为主。