92 resultados para ESR dating

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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Study on the structural coupling relationship between basin and range is not only helpful to recognize the basin formation and evolution systematically, but also to guide petroleum exploration in the basin. As a late Paleozoic Orogen, the South Tianshan Mountains reactivated and uplifted rapidly during the Cenozoic, and led to the Mesozoic-Cenozoic considerable thick deposits in the Kuqa Depression. The researches of the dissertation were carried out in the Kuqa depression-South Tianshan M ountain s ystem, a nd t he b rittle m icrotectonics w. ere c hosen as t he m ost important object. Based on observations and measurements of the field, we made detailed investigations on the geometry and kinematics of this area, and analyzed the abutting and cutting relationships and relative sequence of many brittle structures, such as joint, shear fractures, faults and some small-scale structures related to them closely. According to those brittle fractures' relationships with stress, the nature and variation of regional palaeostress field during the Cenozoic were studied through inversion of fault slip data and inferring stress state from joint sequences. And the deformation time was estimated primarily via ESR dating of faulting. Results show that the stress field varies as well in times as in space. The maximal principal stress direction shifted from the vertical to the horizontal, and stress regime from weak extension to strong compression from the Paleogene to the Neogene regionally. During the late Neogene, the structural deformation of the South Tianshan and the basin-range boundary was dominated by near N-S extension, while near N-S compressive deformation in the interior of the Kuqa Depression. There exits obvious differential stress state from the north to the south. ESR dating of the faulting during the Cenozoic indicates that, the normal faulting in the north edge of the Kuqa Depression have been active all along from the Miocene to the early Pleistocene, but the thrusting and reverse faulting in the interior only been active from the Pliocene to the early Pleistocene. On the base of those geological data and some geophysical information and theoretical calculation results, we infer that, the different stress regime the basin-range system is ascribed to the vertical uplift of the Tianshan Mountain. It was the vertical uplift that lead to the gravity-driven gliding of thick layers lying on the faulted basement from the South Tianshan Mountain to the Kuqa depression, and to folding and thrusting in the interior and frontal of the Kuqa depression. Combining the structural evolution with petroleum geological conditions of the Kuqa Depression, we think that the strong compressive deformation of the Kuqa Depression during rapid uplifting of the Tianshan Mountains from the Pliocene to the early Pleistocene play crucial role in the structural trap formation and proliferous gas accumulation.

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本文采用电子自旋共振ESR方法,结合运用自旋捕捉技术(Spin Trapping-ESR)和时间分辨手段(TRESR),针对某些与生命能量代谢体系电子传递及其化学模拟反应的研究相关的几个重要问题(包括高等植物光系统II颗粒内超氧阴离子自由基(O2-)的产生机制、光合作用模型体系电子传递和跨膜电子传递反应动力学、传统中药有效成分提取物抗氧化分子机理与构效关系),从分子设计、实验方法、分子结构理论、反应机理与动力学分析等几个角度进行了较为系统的探索性研究,并获得以下几点新颖的研究成果: 1.光系统II颗粒内光抑制过程中O2-生成的分子机制 (1).首先,发展了新Spin Trapping-ESR技术,研制一系列性能优良的新型磷酰基取代的吡咯啉类活性氧自旋捕捉剂,并通过对比研究其捕捉性能,证明磷酰基取代的吡咯啉类捕捉剂比常用的DMPO捕捉剂的捕捉能力强、速度快,自由基加合物稳定性高,适合于光系统II体系中活性氧的研究。 (2).在PSII颗粒的光抑制过程中成功地检测到了O2-,并探讨了影响O2-产生的诸多因素。包括氧分子的浓度、1O2增强剂与淬灭剂、pH值效应、电子传递链阻断剂的影响。首次提出了O2-生成的分子机制:PSII颗粒中产生的O2-是光系统II中反应中心产生的1O2与次级电子受体QA形成的质子化半醌自由基反应的产物。此外,设计了一套化学模拟体系,进一步证明了02-的生成的分子机制。 2. 中国传统性中药的酚类提取物抗氧化剂的抗氧化分子机理与构效关系研究 用理论计算与实验结合的手段,研究了酚类抗氧化剂与02的反应。探讨了酚类抗氧化物的分子结构与其抗氧化活性的构效关系,为评价抗氧化剂的抗氧化能力提供了一定的依据。 3.有关光合作用模型体系电子传递和跨膜电子传递反应动力学的探索性基础研究 (1).对原有的电子自旋共振谱仪进行改造,自行设计并研制一套时间分辨ESR装置,时间分辨率达到准微秒级。 (2).利用时间分辨ESR装置,对C60及其环加成衍生物分子间和分子内光诱导电子转移反应的自由基复合过程动力学进行了研究,从分子结构角度分析了影响电荷分离态稳定性的因素。 (3).初步探讨了TPP/DODAC与HA/DODAC两种单层囊泡间的光诱导电子转移反应,获得了长寿命的电荷分离态,为光合作用模拟提供有价值的模型。 (4).通过对比研究mes-卟啉Ⅱ/苯醌/CH。OH的化学诱导动态核自旋态极化( CIDNP)和ESR波谱,提出一个激发态苯醌与质子给体间的光诱导氢转移自由基反应新机理。

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Relative paleointensity records from the northern South China Sea, northwest Pacific Ocean were studied in two gravity piston cores. Continuous mineral magnetic and paleomagnetic measurements were made using discrete sediment samples. Detailed rock magnetic parameters, such as thermomagnetic and high-field hysteresis data, indicate that pseudo-single domain magnetite in a narrow range of grain-size and concentration is the main contributor to the remanent magnetization. The uniform magnetic mineralogy meets the commonly accepted criteria for establishing relative paleointensity records. The relative paleointensity (RPI) curves were constructed by normalizing the natural remanent magnetization (NRM) with isothermal remanent magnetization (IRM), both in the 20-60 mT demagnetization state. Dating constraints have been provided by radiocarbon ages in the upper 400 cm of both cores. Furthermore, we have correlated our paleointensity records with NAPIS-75, S.Atlantic-1089, Sint-200 and NOPAPIS-250 to determine the chronological RPI framework for the South China Sea (SCS-PIS). Although some temporal offsets of paleointensity features between the different records have been recognized, their similar shape suggests that relative paleointensity on the 10(3)-10(4) year scale is globally coherent and can provide an age framework for sediments independent of delta O-18 ages.

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本论文侧重用现场及非现场的光谱电化学方法研究导电聚合物的电聚合过程及聚合物薄膜修饰甲极的氧化-还原行为。用现场的ESR电化学研究了二苯胺的电聚合过程;用现场的可见光谱电化学及非现场的低温ESR研究了同多酸及杂多酸掺杂的聚吡咯薄膜的氧化-还原行为,同时对磷铜酸掺杂的聚吡咯薄膜电极的制备方法及聚合物薄膜修饰电极的电催化性能作了较为细致研究。