Origin and Evolution of Aquitard Porewater in the Western Coastal Plain of Bohai Bay,China

High‐salinity paleowater from low‐permeability aquitards in coastal areas can be a major threat to groundwater resources; however, such water has rarely been studied. The chemical and isotopic compositions of porewater extracted from a 200‐m‐thick Quaternary sedimentary sequence in the western coastal plain of Bohai Bay, China, were analyzed to investigate the salinity origin and chemical evolution of porewater in aquitards. Porewater samples derived at depths shallower than 32 m are characterized by Cl‐Na type saline water (total dissolved solids [TDS], 10.9–84.3 g/L), whereas those at depths greater than 32 m comprise Cl·SO₄‐Na type brackish water (TDS, 2.2–6.3 g/L). Saline porewater is interpreted as evaporated seawater prior to halite saturation, as evidenced by Cl‐Br relationships. Although substantial dilution of saline porewater with meteoric water is supported by a wider Cl^? range and δ²H‐δ¹⁸O covariance, the original marine waters were not completely flushed out. The deeper brackish porewater is determined to be a mixture of fresher porewater and brine groundwater and had a component of old brine of less than 10%, as indicated by a mixing model defined using δ²H and Cl^? tracers. Porewater δ²H‐δ¹⁸O relationships and negative deuterium excess ranging from ?25.9‰ to ?2.9‰ indicate the existence of an arid climate since Late Pleistocene in Tianjin Plain. The aquitard porewaters were chemically modified through water‐rock interactions due to the long residence time.     

基于自由振动响应的基础隔震建筑减震能力评估方法研究

目前国内外已修建完成了大量隔震建筑,但仅有少量经受了地震检验,绝大部分隔震结构减震能力能否达到设计目标尚存疑问.本文针对基础隔震建筑,提出了一种基于自由振动响应的减震能力评估方法.首先,对隔震建筑进行多级幅值初位移自由振动原位试验,获取结构的抗震能力曲线;其次,根据地震反应谱建立地震需求曲面,进而确定隔震结构性能点;最...     

天然闪锌矿原位高温X射线衍射研究

对天然闪锌矿进行了原位高温X射线衍射实验研究,结果表明：闪锌矿受热膨胀,27～675℃温度范围内其膨胀系数为25.61×10-6℃-1;随着温度的升高,在543℃时产生中间物相Zn3O（SO4）2,并分解产生红锌矿ZnO;在797℃时中间物相完全消失,同时出现尖晶石结构的ZnFe2O4;加热至1160℃时的产物为ZnO和ZnFe2O4。实验表明,天然闪锌矿的热改性可产生一定比例的红锌矿（ZnO）,其与闪锌矿一起形成二元复合半导体。在光的激发下,该半导体体系产生的光生载流子由一种半导体注入另一种半导体,降低了光生电子-空穴对的复合几率,提高其光催化活性。本文的研究可为热改性提高天然闪锌矿光催化活性提供理论依据。     

裙带菜配子体基因工程选择标记的研究

研究了裙带菜(Undaria pinnatifida)配子体对除草剂草丁膦的敏感性以及温度对草丁膦处理效果的影响。结果表明,裙带菜配子体对草丁膦敏感;统计学分析得出了草丁膦在不同温度条件下处理裙带菜配子体的半致死浓度(LD50)及95%可信限;温差达到10℃时,相同处理时间各组内不同处理温度样品的LD50之间呈现显著差异,第6天的LD50由10℃组的15.78 mg/L降为20℃组的11.56 mg/L和25℃组的10.33 mg/L。研究发现可以尝试采用草丁膦作为裙带菜配子体遗传转化的选择试剂。     

Hydrothermal plume mapping as a prospecting tool for seafloor sulfide deposits: a case study at the Zouyu-1 and Zouyu-2 hydrothermal fields in the southern Mid-Atlantic Ridge

Seafloor hydrothermal polymetallic sulfide deposits are a new type of resource, with great potential economic value and good prospect development. This paper discusses turbidity, oxidation–reduction potential, and temperature anomalies of hydrothermal plumes from the Zouyu-1 and Zouyu-2 hydrothermal fields on the southern Mid-Atlantic Ridge. We use the known location of these vent fields and plume data collected in multiple years (2009, 2011, 2013) to demonstrate how real-time plume exploration can be used to locate active vent fields, and thus associated sulfide deposits. Turbidity anomalies can be detected 10 s of km from an active source, but the location precision is no better than a few kilometers because fine-grained particles are quasi-conservative over periods of many days. Temperature and oxidation–reduction potential anomalies provide location precision of a few hundred meters. Temperature anomalies are generally weak and difficult to reliably detect, except by chance encounters of a buoyant plume. Oxidation–reduction potential is highly sensitive (nmol concentrations of reduced hydrothermal chemicals) to discharges of all temperatures and responds immediately to a plume encounter. Real-time surveys using continuous tows of turbidity and oxidation–reduction potential sensors offer the most efficient and precise surface ship exploration presently possible.     

厚层覆盖区综合物化探方法找金试验研究——以广西兴安金石金矿为例

在兴安金石金矿外围 4号分散流异常区 ,通过地电化学提取金测量法 ,查明测区存在 5个走向规模小于 5 0 m的金异常区 ,W( Au) 最大值为 72 .4× 10 - 9,高出背景值十几倍 ,并藉综合土壤吸附汞测量 ,高精度磁测和激发极化法等多种物化探方法来确定这些异常区的地质、地球化学和地球物理特征 ,提出金矿成矿的有利部位在金的地电提取高异常区、高汞量异常区、高磁性异常区、低视电阻率异常区和中等视极化率异常区的“三高一低一中”的找矿模式。确定测区的北北东角 (右下角 )一带具备有利的金矿成矿条件     

热球菌HJ21高温α-淀粉酶基因克隆、表达及性质研究

通过简并引物扩增热球菌(Thermococcus siculi)HJ21高温α-淀粉酶保守区域之间的序列,再利用Site-finding技术获得两端未知序列.构建了在N端添加了His6标签的表达载体pEt-28a-His6-THJA后转化E.coli,在IPTG诱导下表达.进一步纯化后SDS-PAGE电泳检测达到电泳纯...     

Orinoco地层油的开发特征及组分研究

Orinoco地层油具有较高的气油比和沥青质含量,在模拟油藏开发状况时,使用油罐油和天然气配制的模拟油。利用大直径长岩心模型进行压力衰竭实验,得到Orinoco地层油的流动特点及模拟开发效果。结果显示：(1)高于泡点压力阶段,模拟油显现弹性驱动特征,采收率很低;(2)在泡点和“拟泡点”之间的降压阶段,模拟油表现出缓慢的膨胀性能,采收率近似线性增加,斜率接近1,此时具有最大的开采效益;(3)低于拟泡点压力阶段,产气量增大,采收率增加缓慢。实验测定了Orinoco地层油的详细组分,并以此为依据配制模拟油。对模拟油PVT性质进行分析,结论是：气油比和少量的轻质组分对相对体积的影响很小,沥青等重质组分对气体保持稳定状态起主要作用;脱气状态的地层油在60 ℃时粘度仍高达6 194 mPa·s,而较高的气油比使地层油粘度陡降,特别在压力降低至泡点压力后,仍存在一个粘度缓慢变化的阶段,显示了Orinoco地层油的独特之处。     

华北山地多成因壶穴初步研究——对华北山地“冰臼”等“冰川地貌”的讨论

华北山地"距今二、三百万年"的"冰臼"绝大部分位于第四纪河谷内,"距今1～2万年"的"冰川壶穴"位于全新世河谷内,与华北山地地貌演化相矛盾;所谓的"冰川地貌"组合不是真正的地貌组合,而是不同时代、不同成因地貌的混合,因此,华北山地不存在冰臼。所谓的"冰臼"是不同时代、多种成因的壶穴——距今2.50Ma前后的河蚀壶穴,距今10～20ka的雪蚀壶穴,距今10ka以来的溶蚀穴、溶蚀—河蚀壶穴、风化—风蚀壶穴、现代壶穴和水潭。     

生物气CO2还原途径中碳同位素分馏作用研究及应用

地质历史中,CO2/H2还原产甲烷作用对生物气的形成具有十分重要的意义。中国柴达木盆地第四系生物气主要为CO2/H2还原型生物气。笔者以CO2/H2还原生气理论为指导,进行不同初始碳同位素值和不同赋存状态碳源的生物模拟实验,研究CO2/H2还原产气过程中发生的碳同位素分馏作用。实验结果表明,产物中δ13CH4值与底物的δ13C值呈很好的正相关关系;在反应母质过量的情况下,碳源的赋存状态可以影响产物甲烷的碳同位素组成。以游离形式CO2还原产生的甲烷δ13C值,相对于以HCO3-、CO23-离子形式产生的甲烷δ13C值轻。通过柴达木盆地东部第四系生物气田实例分析,探讨了该区生物气的主要底物CO2的来源及赋存状态,对评价盆地生物气资源和有利勘探区预测有重要的参考价值。