240 resultados para 338.8


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128 samples from Ocean Drilling Program (ODP) Site 1143 in the southern South China Sea were analyzed for grain size, clay minerals, biogenic opal content and quartz in order to reconstruct changes in East Asian monsoon climate since 8.5 Ma. An abrupt change of terrigenous mass accumulation rate (MAR), clay mineral assemblage, median grain size and biogenic opal MAR about 5.2 Ma suggests that between 8.5-5.2 Ma the source of terrigenous sediment was mainly in the region of surface uplift and basaltic volcanism in southern Vietnam. A simple model of East Asian summer monsoon evolution was based on the clay/feldspar ratio, kaolinite/chlorite ratio and biogenic opal MAR. The summer monsoon has two periods of maximum strength at 8.5-7.6 Ma and 7.1-6.2 Ma. Subsequently, there was a relatively stable period at 6.2-3.5 Ma, continued intensification about 3.5-2.5 Ma, and gradually weakening after 2.5 Ma. Since I Ma the monsoon has intensified, with remarkable high-frequency and amplitude variability. Simultaneous increase in sedimentation rates at ODP Sites 1143, 1146 and 1148, as well as in MAR of terrigenous materials, quartz, feldspar and clay minerals at ODP Site 1143 at 3.5-2.5 Ma, may be the erosional response to both global climatic deterioration and the strengthening of the East Asian summer monsoon after about 3-4 Ma. (c) 2006 Elsevier B.V. All rights reserved.

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随着全球变暖和各种极端天气事件发生频率的增加,气候变化已成为全世界关注的焦点问题,ENSO事件是年际尺度上气候变化的最强信号,它的影响波及到世界各地,所以,对ENSO事件进行深入研究,弄清其发生机制,具有重要的科学意义。虽然,目前对ENSO事件的研究已经取得了巨大成果,但仍不能对其发生发展的全过程进行准确的预测,因此,仍需要对其进行深入研究,本文正是从热带太平洋次表层温度场和流场的变化着手,对ENSO循环过程中的相关机理进行研究。 通过对TOGA/TAO、SODA和NCEP等海洋大气实测和再分析资料的分析,研究了热带太平洋次表层海温和流场的变化特征,分析了它们的变化机理,进而深入探讨了它们与ENSO事件的相互关系,并利用全球海洋数值模式的敏感性试验,探讨了大气风场的变化对海洋次表层要素的影响,主要得到以下结论: 1. 上世纪70年代末的气候突变之后,用28℃定义西太平洋暖池(WPWP),已不能合理的描述WPWP的基本特征。我们通过对比分析提出,用28.5℃来定义WPWP更合理,这一定义即可以充分反映WPWP突变前的特征,又能够合理的反映WPWP突变后的特征;对新定义的WPWP区域不同深度的海温距平的分析表明,次表层(148m)海温距平的变化趋势和变化幅度与表层和深层的变化差异较大,次表层海温的变化幅度最大并且年代际变化趋势与上下层正好相反;进一步的研究表明,WPWP次表层海温的年代际变化与PDO的变化有一定关系。 2. 利用热带太平洋次表层海温的变化特征,定义了表征ENSO事件的新指数——赤道太平洋温跃层海温振荡指数(EPOI),与其它ENSO指数相比,EPOI将东、西太平洋次表层海温的变化信息都包括在内,能够较全面的反映出ENSO事件的变化特征,特别是EPOI可以较好的反映出ENSO循环的年代际变化特征。另外,EPOI的变化比ONI的变化超前2个月,更有利于对ENSO事件的提前预报。由于EPOI主要反映海洋次表层的变化特征,因此能够更好的满足对ENSO机理研究的需要。 3. 赤道潜流距平场的EOF分析表明,其前两个模态的方差贡献较大,第一模态方差贡献为30.75%,主要反映东太平洋赤道潜流的变化特征;第二模态方差贡献为16.18%,主要反映中太平洋赤道潜流的变化特征。赤道潜流前两个模态与ENSO指数的变化有很好的相关关系,其中东太平洋潜流在滞后ENSO指数1个月时,二者达到最大负相关(r=-0.74)。中太平洋赤道潜流的变化对“东部型”和“中部型”El Niño事件的形成有一定影响。“东部型”El Niño事件发生前,中太平洋赤道潜流异常增强,次表层异常海温信号随着潜流中心迅速向东移动到达东太平洋,使得“东部型”El Niño事件爆发;而“中部型”El Niño事件发生前,中太平洋赤道潜流则异常减弱,西太平洋异常海温信号不能迅速向东传播,而是在中西太平洋堆积并向上扩展,使得异常海温首先在中太平洋出现,“中部型”El Niño事件爆发。 4. ENSO循环过程中,异常冷(暖)信号之所以在8ºN-10ºN附近向西传播的原因较多,其中温跃层深度在8ºN-10ºN的特殊分布特征对其有一定贡献,具体表现为在北半球8ºN-10ºN正好是温跃层深度较浅的区域,该区域的温跃层相当于从东到西的一个海下“山脊”,使得来自南北两侧的异常信号都很难穿过这一区域,而只能沿该纬度向西传播;而南半球的温跃层对来自赤道地区的异常信号没有阻挡作用,使其可以直接传播到高纬度地区。ENSO信号的强度在传播过程中发生了明显的变化,主要是ENSO事件爆发后,4-5年的周期信号并没有传到东太平洋10ºN附近,在从东到西的传播过程中,4-5年的周期信号有所增加,但增加的幅度较小。在西太平洋有来自南、北半球中高纬度异常信号的补充,从而使得ENSO循环得以维持。 5. 数值模拟表明,不同区域风应力的变化对海洋的影响各不相同。赤道地区风应力对海洋的影响主要通过纬向分量的变化来产生作用,它的变化主要对赤道次表层海温的变化产生影响,并且东西太平洋呈现反位相变化趋势;而对流场的影响则是上下层反位相变化。北太平洋副热带地区风应力的变化对海洋的影响与赤道有明显不同,对温度场的影响表现为东西太平洋次表层海温的变化一致,而对流速的影响则是东西太平洋反位相变化。

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本研究利用AFLP和微卫星标记,以海湾扇贝杂交F1为作图群体,构建了海湾扇贝的遗传连锁图谱,并对壳色决定基因和与生长性状相关的QTL进行了定位。 共用55对AFLP引物组合对亲本和88个子代个体进行扩增,共得到了2424个位点,多态性位点为392个,占所有标记的16.17%。其中,母本标记121个,父本标记196个,共有标记75个。经卡方检验,共有331个标记(84.4%)符合孟德尔分离比,61个标记(15.6%)出现偏分离现象。偏分离标记中,36个(59%)为纯合子缺失。从35对微卫星引物中筛选出了10对多态性引物,得到了5个母本标记和6个父本标记。另外,将表现为质量性状的壳色标记作为形态标记一同进行连锁图谱构建。 分别利用母本和父本标记构建了海湾扇贝雌性和雄性连锁图谱。其中,共有包括109个AFLP标记、5个微卫星标记和1个壳色标记组成了雌性图谱的框架图,分布于16个连锁群。图谱总长度为338.8cM,平均间隔为5.29cM,图谱覆盖率为65.82%。雄性连锁图谱框架图共定位了186个标记,包括181个AFLP标记、5个微卫星标记,壳色标记未实现定位。图谱包括17个连锁群,总长度为780.3cM,平均间隔为6.56cM,图谱覆盖率为78.11%。通过SSR12位点的定位结果,可以将雌性图谱第7连锁群与雄性图谱17连锁群对应起来。 壳色标记定位在了雌性图谱第九连锁群上,说明橙色基因位点为杂合。我们将壳色基因命名为Orange1,两个标记——F1f335和D8f420与这一基因之间图距为0。在家系和群体中初步验证,这两个标记与壳色基因紧密或完全连锁。 共定位了16个与生长相关的QTL,它们分布于雌性图谱的2、3、5连锁群和雄性图谱的4、5、6、7、8连锁群上。每个QTL均发现了与其图距非常接近的分子标记(0.01-2.51%)。其中壳长、壳高、壳宽三个长度指标QTL成簇分布或部分重叠,可一同作为选择性指标,壳重和全湿重QTL位点也比较相近。只有软体部重位点单独分布,可能具有相对独立的遗传基础。

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C16H15Br2O7.5, orthorhombic, P2(1)2(1)2 (no. 18), a = 18.483(2) angstrom, b = 9.413(1) angstrom, c = 10.072(1) angstrom, V = 1752.3 angstrom(3), Z = 4, R-gt(F) = 0.083, wR(ref)(F-2) = 0.202, T= 293 K.

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A new lead(II) phosphonate, Pb[(PO3)(2)C(OH)CH3]center dot H2O (1) was hydrothermally synthesized and characterized by IR, elemental analysis, UV, TGA, SEM, and single crystal X-ray diffraction analysis. X-ray crystallographic study showed that complex 1 has a two-dimensional double layered hybrid structure containing interconnected 4- and 12-membered rings and shows an unusual (5,5)-connected (4(7) . 6(3)) (4(8) .6(2)) topology. (C) 2008 Elsevier B.V. All rights reserved.

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根据野外样方调查资料,对青海湖西部布哈河下游地区8种植物群落进行了研究。结果表明:群落的多样性随丰富度的降低而呈下降趋势,均匀度的变化受物种丰富度的影响不大,群落的物种多样性指数与丰富度指数和均匀度指数均表现出极显著的正相关性(P〈0.01),相关系数分别为0.912和0.684;群落的均匀度与丰富度相关性不显著,说明物种多样性主要为物种丰富度所推动。

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本文报道了我国西部高山上的8种龙胆属植物的染色体数目。其中宽街龙胆(Gentianaampla)的染色体数目为Zn=48,提钟龙胆(G.stipitataSubsp.timensis)的染色体数目为2n=26)小齿龙胆(G.microdonta)和四数龙胆(G.lineolata)的染色体数目为2n=24,南山龙胆(G.grumil)的染色体数目为2n=18,上述5种植物的染色体数目为首次报道。其余蓝玉簪龙胆(G.veitchiorum)的染色体数目为2n=24,线叶龙胆(G.lawrenci Burk.var.farrei)的染色体数目为2n=48,钻叶龙胆的染色体数目为2n=18。

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8位单片机仍是当前应用的主流辽宁省单片微机学会理事长 中科院沈阳自动化研究所马喜顺 在半世纪之交,基于半导体集成技术的突飞猛进的发展,各种类型的单片机正日新月异地涌向市场,为单片机技术的应用人员提供了极大的方便。1975年美国德州仪器(TI)公司推出…。

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The exploration in recent years shows that the Yanchang Formation in the southwest of Ordos Basin is of great resource potential and good exploration and exploitation prospect. In the thesis ,sedimentary source analysis,sedimentary system,sedimentary microfacies,sandstones distribution and reservoir characteristic are studied and favorable oil area are forecasted in Chang6-Chang8 of Yanchang formation in HuanXian region, by mainly study on the data of field section observation ,core observation, well logging explaination and routine microscope slice identification,scanning Electron Microscope and reservoir analysis of lithology and physical property , Under the guidance of such advanced theories and methods as sedimentology,reservoir sedimentology,lithological oil pool and so on. The stratum of Chang6-Chang8 of Yanchang formation could be divided into pieces of member following the principles that firstly contrasting the big segments, then contrasting the small segments, being controlled by cycle and consulting the thickness etc.And the characteristic of stratum are detailed discussed , respectively. Based on the source direction of the central basin, heavy and light minerals are used to analyse source direction of Chang6 and Chang8 member, in HuanXian area. Research result shows that the source of Chang6 and Chang8 member is mixed provenance,including west-south,west and east-north. By the study of rock types、 sedimentary conformation、lithology and electromotive curve combination and palaeo-biology,lake、delta and braided delta mianly developed in study area are recognized, Subaqueous distributary channels in delta front and in braided delta front, and sand body in deep-lake turbidite, are the main reservoir.forthermore,the characteristic of depositional system and sandy body in space are discussed. Applied with routine microscope slice identification, Scanning Electron Microscope, reservoir lithology and physical property analysis and other analytic machinery, Feldspar-lithic fine-sandstone and feldspar fine-sandstone are mainly sandstone of Y Chang6-Chang8 in Huanxian area, small pore and tiny pore are the main pore types, tiny throat type and micro-fine throat type are widely developed , secondary dissolution porosity, intercrystal porosity, tiny pore and micro-crack are main pore types.Intergranular porosity and dissolution porosity secondary is the main pore secondary. The dominant diagenesis types in the area are compaction, cementation, replacement and dissolution. Chlorite films cementation facies, carbonate cementation facies ,mud cementation compaction facie, compaction 、pressure solution facies are the main diagenetic facies,in which Chlorite films cementation facies is the best diagenetic facies in study area. Reservoir influence factor analysis ,rock types are the main factor forming this low-pore and low-permeability of Chang6-Chang8 member in study area,and relatively higher permeability area are cortrolled by sedimentary facies distribution, diagenesis improved reservoir physical property. According to the distributing of sedimentary micro-facies and sandy body , and the test oil, favorable region in Chang6-Chang8 are forecasted.

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Migration carriers act as the “Bridges” connecting source rock and traps and play important roles in petroleum migration and accumulation system. Among various types of carriers, sandstone carrier constitutes the basis of carrier system consisting of connected sandstone bodies, of sand-bodies connected with other carriers, such as faults and/or unconformities. How do we understand sandstone carrier beyond the traditional reservoirs concept? How could we characterize quantitatively this kind of carriers for petroleum migration? Such subjects are important and difficult contents in dynamic studies on hydrocarbon migration and accumulation. Sandstone carrier of Chang 8 member in Longdong area of Ordos Basin is selected as the research target in this thesis. Through conducting integrated reservoir analysis on many single wells, the correlation between single sandstone thickness and oil thickness seems good. Sketch sandstone is defined in this thesis as the principal part of carrier based on systematical analysis on lithology and sandstone thickness. Geometry connectivity of sandstone bodies was identified by the spatial superposition among them and was proved by the oil property features in oilfields. The connectivity between sandstone carriers is also hydrodynamically studied by observing and analyzed various diagenetic phenomena, especially the authigenic minerals and their forming sequence. The results were used to characterize transporting capability of sandstone carriers during the key petroleum migration periods. It was found that compaction and cementation are main causes to reduce pore space, and resolution may but not so importantly increases pore space after the occurrence of first migration. The cements of ferrocalcite and kiesel seem like the efficient index to demonstrate the hydraulic connection among sandy bodies. Diagenetic sequence and its relationship with petroleum migration phases are analyzed. Sandstone carrier of Chang 8 member was then characterized by studying their pore space and permeable properties. The results show an average porosity and permeability of Chang 8 carriers are respectively 8% and 0.50md, belongs to low porosity - low permeability reservoirs. Further, the physical properties of Chang 81 member are commonly better than those of Chang 82 member. Methods to reconstruct property of sandstone carrier during petroleum migration phase (late Jurassic) are built based on diagenetic sequence. Planal porosity, porosity and permeability of sandstone carrier in this period are statistically analyzed. One combining index - product of thickness and ancient porosity - is selected as the idea parameter to characterize sandstone carrier of late Jurassic after contrast with other parameters. Reservoirs of Chang 8 member in Longdong area are lithological reservoir controlled by sand body in which oil layers in middle part are clamped with dry layers in upper and lower parts, in a sandwich way. Based a newly proposed “migration-diagensis-remigration” model in low permeability sandstone of Chang 8 member in Longdong area, oil migration and accumulation processes during different periods are simulated with the reconstructed sandstone carriers system. Results match well with current reservoir distributions. Finally, suggestions for next favorable exploration areas are given based on all research achievements.

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Sulige gas field is located in Northwest of Yi-Shan Slope of the Ordos Basin. The Shan 1 Member of the Shanxi Formation and He8 Member of the ShiHeZi Formation are not only objective strata of research but also main producing strata of the Sulige Field. From core and wireline log data of 32 wells in well Su6 area of Sulige field, no less than six lithofaice types can be recognised. They are Gm,Sl,Sh,Sm,Sp,Fl,Fm. Box-shaped, bell-shaped, funnel-shaped and line-segment-shaped log are typcial gamma-ray log characters and shapes. The Depositonal system of the Shan1-He8 strata in research area have five bounding-surface hierarchies and was composed of six architectural elements, CH, LS,FF(CH),SB,LA,GB. The depositional model of Shan 1 was the type of a sandy meandering river with natural levee, abandoned channels and crevasse splay. Channel depth of this model maybe 7-12 m and the fullest-bank flow can reach 14 m high. Based on analysis of depositional causes, a sandy braided river model for the depositional system of He 8 can be erected. It consists of active main channels, active chute channels, sheet-like sand bars, abandoned main channels and abandoned chute channels. Channel depth of this model can be 3-4 m with 9 m of highest flow. Six gamma-ray log cross sections show that the connectivity of sandbodies through Shan 1 Member is lower than He 8. Influenced by occurrence of mudy and silty deposits, vertical connectivity of sandbodies through He 8 is not high.

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为了解高温高压条件下,α-β石英相变过程中的弹性性质,在0.7~1.8GPa,室温~1120℃条件下,利用多顶砧波速测量装置,采用脉冲反射-透射法,测量了α石英以及相变为β石英的纵波速度,弹性纵波穿过单晶α石英的方向为平行结晶轴X方向。实验结果表明,随温度升高,α石英的纵波速度开始非线性降低,之后,快速升高,这一现象是由于α-β石英相变引起的,依据晶体对称性与弹性参数的关系确定了α石英的弹性参数(C_(11)),及其随温度和压力的变化关系,同时获得了β石英的弹性参数(C_(11)),实验证实,测量α-β石英相变时的纵波速度,不仅是确定α-β石英相变温度和压力的一种方法,也是校正高压腔体温度和压力的有力手段.