华北型煤田奥陶系岩溶水水文地球化学特征及其对地热的指示意义

华北型煤田奥陶系岩溶水是集水、热于一体的绿色能源,明确受煤层开采影响其补给来源、热储赋存环境、径流与循环等形成演化特征对于地热资源的勘探与开发具有重要意义。在充分了解典型华北型煤田-淮北煤田地质、水文地质及地热地质条件的基础上,采集区内岩溶地热水样品进行水化学及同位素测试并收集相关成果进行数据补充,揭示了岩溶地热水水化学成分特征及水-岩作用类型,明确了地热水补给来源,评估了岩溶热储温度及地热水循环深度,提出了研究区地热水形成演化模式。结果表明:淮北煤田岩溶地热水主要来源于大气降水补给,北部闸河矿区以直接入渗补给为主,水化学表现为HCO_(3)-Ca型,水-岩作用以溶滤溶解为主,指示该区地热水更新速率较快、循环路径短;南部宿县和临涣矿区仅在部分区域接受大气降水蒸发入渗补给并与古地下水混合明显,水化学类型多样,包括SO_(4)-Ca、SO_(4)-Ca·Mg、HCO_(3)·SO_(4)-Ca·Mg、SO_(4)-Ca·Na、Cl·SO_(4)-Na、Cl-Na等,水-岩作用类型以溶滤溶解及阳离子交替吸附(正反向)为主并伴有脱白云石化作用,指示该区地热水滞留时间久、循环路径长,热储环境更为封闭。选用石英温标及改进的SiO_(2)温标估算该区热储温度范围34.8~69.1℃,地热水循环深度881~2281 m。淮北煤田岩溶地热水形成演化受构造控制明显,地热水循环更新能力、热储温度、循环深度以及水化学环境均存在显著空间差异,岩溶地热资源的开发和利用应综合考虑区域特点。

Quantum Entanglement and Nonlocality Properties of Two-Mode Squeezed Thermal States in a Common-Reservoir Model

We study a system consisting of two identical non-interacting single-mode cavity fields coupled to a common vacuum environment and provide general, explicit, and exact solutions to its master equation by means of the characteristic function method. We analyze the entanglement dynamics of two-mode squeezed thermal state in this model and show that its entanglement dynamics is strongly determined by the two-mode squeezing parameter and the purity. In particular, we find that two-mode squeezed thermal state with the squeezing parameter r ≤ -（1/2） In √u is extremely fragile and almost does not survive in a common vacuum environment. We investigate the time evolution of nonlocality for two-mode squeezed thermal state in such an environment. It is found that the evolved state loses its nonlocality in the beginning of the evolution, but after a time, the revival of nonlocality can occur.