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1.
Based on deep-sea pollen results (512-76 m) from ODP Site 1143 in the southern South China Sea (SCS),the climate and vegetation evolution sequence on the surrounding islands and the exposed continental shelf are discussed. The pollen records show that the pollen influx was quite low before 8.15 Ma and increased dramatically afterwards. The influx changes can be ascribed,on one side,to tectonics deformations around the southern SCS resulting in rapid uplift of islands and subsequent increase of the sediment rates and pollen influx and on the other side to climate cooling and monsoon enhancement. Around 2.63 Ma was another obvious boundary,the increasing of pollen and spores influx since this time was mainly related to global climate cooling. Spectrum analysis of pollen influx values shows that 2 Ma,0.67 Ma,and 0.19-0.17 Ma cycles existed during 12-3.0 Ma,while 0.1 Ma and 46.9 ka cycles existed during 3.0-2.0 Ma.  相似文献   
2.
七氟丙烷替代三氟溴甲烷灭火剂性能比较   总被引:3,自引:0,他引:3  
七氟丙烷具有良好的灭火性能 ,由于它不含溴氯 ,它对臭氧层的耗损潜能值(ODP)为零 ,具有良好的环保性 ,是哈龙灭火剂很好的替代品 ,由于七氟丙烷与三氟溴甲烷在物理和化学性质的区别 ,它们在灭火使用时对环境的要求仍有所区别。  相似文献   
3.
As the third summary report of ODP Leg 184 to the South China Sea (SCS), this paper discusses the evolution of the East Asian monsoon and the SCS basin. A multi-proxy approach, involving geochemistry, micropale-ontology, pollen and other analyses, was adopted for reconstructing the evolutionary history of the East Asian monsoon, which was characterized by a series of paleo-climate events especially at 8, 3.2, 2.2 and 0.4 Ma. The new record indicates similar stages in the development of the East and South Asian monsoons, with an enhanced winter monsoon over East Asia being the major difference. The rich spectrums of monsoon variability from the southern SCS also reveal other characteristic features of the low latitude ocean. Evidence for the evolution of the SCS includes the hemipelagic Oligocene sediments, implying the existence of deep water environments during the early seafloor spreading stage of the SCS basin. The four major unconformities and some remarkabl ediagenetic features in upper Oligocene deposits indicate the strongest tectonic events in the region. From a careful comparison of lithologies and sedimentation rates, we conclude that the prominent differences in sedimentary environments between the southern and northern SCS were established only by ~3 Ma.  相似文献   
4.
The most prominent cooling event of the Earth surface during Cenozoic in the long-term transition from a non-glaciated planet, or “green-house world”, to a polar, glaciated planet, or “ice-house world”, is the Earliest Oligocene Glacial Maximum (EOGM) above the Eocene/Oligocene boundary at about 33.7 Ma. Planktonic and benthic foraminiferal oxygen and carbon isotopes, carbonate content, and coarse fraction, along with high-resolution color reflectance and magnetic susceptibility records during 35-30 Ma, from deep-water Sites 1262 and 1265, Ocean Drilling Program (ODP) Leg 208 in South Atlantic, reveal the global cooling event occurring in both surface and deep oceans. The results show that the earliest Oligocene δ^18O values during 33.5-33.1 Ma represent the magnitude of continental ice sheets on east Antarctica and indicate the large decrease in both surface and deep water temperatures of worldwideoceans. The δ^13C records show the large excursion during the period of EOGM event and indicate some types of shift in global carbon reservoir, probably demonstrating the sudden increase in organic carbon burial rates and the changes in the distribution and timing of production. At the same time, lithologic composition, carbonate content, color reflectance, and coarse fraction brought about significant changes close to the Eocene/Oligocene boundary, reflecting the abrupt deepening in the carbonate compensation depth (CCD). Changes in carbonate content were revealed from the color reflectance identify periodicities associated with eccentricity of the Earth‘s orbit (100 and 400 ka), further indicating orbitally forced global climate variations in the Early Oligocene.  相似文献   
5.
中国冰箱行业淘汰CFCs 的环境效益分析   总被引:2,自引:0,他引:2  
以无《蒙特利尔议定书》的情景为基线情景, 从消耗臭氧层物质排放、温室气体排放及冰箱耗电量角度分析中国冰箱行业履约淘汰 CFCs 产生的环境效益。结果表明,截至2008年底,中国冰箱行业淘汰 CFCs已实现减排 273.5 MtCO2-eq 和 4.7×104t ODP; 2008 年后还将减排 619.8 MtCO2-eq 和 1.0×105t ODP;通过采用更加节能的制冷剂,截至 2008 年底累计节电 2.8×1010 kWh, 折合减排 24.2MtCO2-eq,对中国节约资源和节能减排具有十分重要的现实意义。  相似文献   
6.
基于氟利昂制冷剂的ODP和GWP问题,运用热力学方法,分别对环境友好性的自然工质CO2和三种常规氟利昂制冷剂R22、R134a及R152a的比热、导热系数、表面张力等物性参数进行了对比,并对相应的循环性能进行了分析,为高效、节能的CO2跨临界循环热泵热水器的研究提供了基础资料。  相似文献   
7.
在较佳的合成条件下合成了十八碳醇磷酸酯(ODP)表面活性剂,并以其作为改性剂对碳酸钙进行原位表面改性.同时利用透射电镜TEM、XRD、红外光谱(IR)等测试手段对产品的形貌、晶型等方面进行表征.实验结果表明,磷酸酯改性后的碳酸钙具有纺锤形,当其用量达到2%时,活化指数可达到0.99,这充分说明了改性碳酸钙表面由亲水变为疏水,达到了很好的改性效果.  相似文献   
8.
对分布式网络管理系统中对象的抽象程度进行分类,提出了分布式网络管理的对象组织模型,把对象划分为任务对象、子任务对象和被管对象,应用开放式分布处理(ODP)的信息和计算视点进行描述,刻画了各类对象的基本特点,形式化地描述了对象间的约束关系,并给出了IDL接口描述,使得系统结构清晰,便于构建。  相似文献   
9.
提出了ODP环境的全局安全系统的格模型,给出了其中安全域的表示和构造;在这一格模型的基础上,悍出了多安全级的全局安全系统的模型,该模型将安全系统中的安全域划分成了不同的安全级,并结合层次结构对安全系统进行组织和管理。  相似文献   
10.
Shallow marine sequences of the northern South China Sea (SCS) are uplifted and exposed by plate convergence in the Taiwan mountain belt. These deposits provide detailed geological information about the rifting event, stratigraphy, sedimentology, paleoclimate and paleoceanography of the shallow SCS to compare with what are recorded in the ODP 1148 deep-sea core. Seismic surveys and marine micropalentological studies show that Eocene sequences in the offshore Taiwan Strait and onland Taiwan mountain belt are all deposited in rifting basins and are covered unconformably by the Late Oligocene-Neogene post-rifting strata. Between syn-rifting and post-rifting sequences, there is a regional break-up unconformity throughout the island. Early Oligocene and Late Eocene strata are missing along the break-up unconformity equivalent to the T7 unconformity in the Pearl River Mouth Basin off south China. This may suggest that the SCS oceanic crust could have initiated between 33 and 39 Ma. Neither obvious stratigraphic gap nor slumping features are found in the Oligocene-Miocene transition interval of Taiwan. This observation highly contrasts with what has been documented from the ODP 1148 deep-sea core. This suggests that the stratigraphic gap and slumping features could only be recorded in the SCS deep sea region, but not in the shallow shelf near Taiwan. Compared to the Middle Miocene paleoceanographic re-organization events in the SCS deep sea, the geological history of the Taiwan shallow sequence shows changes of in sedimentation and faunal composition. Due to the Antarctic glacial expansion at~14 Ma, Middle to late Miocene strata of the Western Foothills show progressive regression sedimentations associated with a decrease of benthic foraminif-eral abundance and a sharp faunal turnover event. Many Early-Middle Miocene endemic benthic foraminifers were extinct in 14-13 Ma and new benthic foraminifers of the Kuroshio Current fauna appeared from 10.2 Ma, comparable with new occurrence of Modern benthic foraminifers at 9 Ma in the Java Sea area. This reveals that the Western Boundary Kuroshio Current in the North Pacific could initiate from 10-9 Ma due to closures of the Indo-Pacific seaways by convergent tectonics between the Australian Continent and the Indonesian Arc in 12-8 Ma. Subduction of the SCS oceanic lithosphere since the Middle Miocene resulted in formation of the Hengchun Ridge accretionary prism and the North Luzon Arc. Occurrence of these two bathymetric highs ( 2400 m) since the Middle Miocene and closures of the inter-arc passages in the North Luzon arc in the last 3.5 Ma would control the water exchanges between the West Pacific and the deep SCS. Accordingly, the tectonic evolution in the Central Range-Hengchun Peninsula accretionary prism and the arc-forearc Coastal Range not only control directly the route for water exchanges between the West Pacific and the SCS, but also indirectly shows a great influence on the geochemistry of deep SCS waters. The latter is best shown by much negative carbon isotope values of benthic foraminifers in the ODP 1148 deep-sea core than the West Pacific records in the last 14 Ma.  相似文献   
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