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271.
根据地层与古生物、沉积构造、岩性特征、成岩作用,结合微量元素组分含量和某些元素的比值、饱和烃气相色谱地球化学参数,综合研究额济纳旗雅干地区二叠系哈尔苏海组的沉积环境,为研究区石炭系—二叠系油气地质条件评价提供依据。研究结果表明,银-额盆地中二叠世末期发生过大范围的海退,晚二叠世哈尔苏海组海相沉积主要发育于额济纳旗—雅干—杭乌拉一带,以火山碎屑岩-碎屑岩夹少量碳酸盐岩沉积为主。说明额济纳旗雅干地区二叠系哈尔苏海组形成于半咸水的浅海-滨海-海陆交替的环境。  相似文献   
272.
A huge filament eruption of 12 September 2000 associated with a two-ribbon spotless flare is described. During the acceleration phase the shape of the filament changed, and signatures of topological restructuring of large-scale coronal magnetic fields were inferred by tracking changes of nearby coronal holes. At the same time electron beams associated with the flare impulsive phase escaped into interplanetary space. Based on the time–spatial relationships a hypothesis is put forward, according to which the reconnection between the arcade magnetic field and the ambient field provides a temporary link between the open field lines and the flare energy release site, enabling the escape of electron beams into interplanetary space.  相似文献   
273.
A frequency-analysis of the broadbandUBV photometric observations of the interacting binary star KX And has been performed in order to disclose claimed rapid periodic variations. Our analysis confirms existence of rapid variability, but disagrees with the period. In discussion we rejected rotations as possible cause of the rapid photometric variations, and found that some kind of pulsations offer plasusible explanation.  相似文献   
274.
深部粘性土的微观结构与力学性质试验研究分析   总被引:2,自引:0,他引:2  
采用扫描电镜、X-射线衍射方法研究了拟建矿井龙固矿深部粘性土的微观结构,并进行了力学强度的测试,初步探讨了其工程地质特征及影响因素,其结果可为微观结构和宏观力学性质的研究提供参考依据。  相似文献   
275.
复合型含油气系统的特征与描述 : 以塔中含油气系统为例   总被引:2,自引:0,他引:2  
通过对塔中含油气系统的研究,发现它难以用传统的含油气系统方法来描述。它主要有二个油源区三套生油岩,发育有三套储层;不同油源在不同时期生成的油气在储层内共生、甚至相互混合,使油气成因复杂。据此提出了它是一个复合型含油气系统。在此基础上,进一步指出复合型含油气系统的特点是多油源、多期成烃、油气成因复杂,出现在迭合型盆地。并针对这些特点,初步提出了工作思路及描述方法。  相似文献   
276.
中亚古生代造山带成矿作用基本特征   总被引:3,自引:0,他引:3  
中亚成矿域是与环太平洋成矿域、特提斯成矿域媲美的巨型成矿域。其成矿作用带有鲜明的古生代造出带成矿作用特点,在中亚各古生代造山带发展的拉张型过渡壳-洋壳-汇聚型过渡壳-古生代新陆壳的各阶段,形成特定的矿床成矿系列类型,矿床成矿系列类型本身也随着地壳发展,地壳成熟度的提高而有规律地演化。  相似文献   
277.
全球升温1.5℃和2.0℃情景下淮河上游干流径流量研究   总被引:1,自引:0,他引:1  
基于ISI-MIP(The Inter-Sectoral Impact Model Inter-comparison Project)推荐使用的5个全球气候模式数据(HadGEM2-ES,GFDL-ESM2M,MIROC-ESM-CHEM,Nor-ESM1-M,IPSL-CM5ALR),驱动SWIM(Soil and Water Integrated Model)水文模型,研究全球升温1.5℃和2.0℃情景下淮河上游干流径流量变化,得出结论:(1)淮河上游干流径流量年际变化在2种升温情景下均呈先减小后增加趋势。全球升温1.5℃时年径流量较基准期(1986—2005年)增长9.5%,而升温2.0℃情景下涨幅更明显,高达17%。(2) 4个季节径流量在2种升温情景下较基准期均有增长,其中春季涨幅最明显,达24.4%,夏、秋、冬季涨幅分别为7.1%、16.1%、13.5%。全球升温2.0℃时淮河上游干流径流量在4个季节较基准期增长率均大于全球升温1.5℃时。(3)不同气候模式输出日径流量最大值相差较大而平均值相差较小。未来2种升温情景日径流量超过王家坝闸设计流量的日次较基准期均有增加,尤其升温2.0℃情景较基准期增多22次,较升温1.5℃情景多5.8次,表明未来升温2.0℃情景下淮河上游出现极端径流事件的可能性进一步增大。  相似文献   
278.
We present observations of the flare of May 14, 1981, which can be classified as a three-ribbon flare. After a detailed analysis in metric, decimetric, microwave, optical, and X-ray ranges we propose that the event was caused by a reconnection process driven by erupting filament. The energy was liberated in the current sheet above the filament in the region between the erupting flux and the overlying field. It is shown that plasma microinstabilities develop as the plasma enters the current sheet. The observations indicate that during the precursor phase a certain low-frequency turbulence, such as ion-accoustic turbulence had to be present.The reconnection rate was growing due to the increasing tension of the stretched overlying field. It is shown that the reconnection proceeded in the Sonnerup-Petschek regime during the precursor, and changed to the pile-up regime in the fast reconnection phase, when the maximal lateral expansion (50 km s–1) of the H ribbons was observed. The proposed process of reconnection driven by an erupting filament can be applied to three- and four-ribbon flares.  相似文献   
279.
The general behaviour of the circular polarization at dm-m wavelengths during the evolution of five two-ribbon flares is investigated. The changes of polarization, if present, occurred 10 to 20 min after the impulsive phases. Increases of the radio and X-ray fluxes occurred at the moments when the H ribbons started to extend over spot umbrae.Proceedings of the Workshop on Radio Continua during Solar Flares, held at Duino (Trieste). Italy, 27–31 May, 1985  相似文献   
280.
The prominence which erupted at the SE limb on August 18, 1980 is one of the best observed disparition brusque events: high-resolution monochromatic ground-based observations in the H line were supplemented by the SMM and Solwind satellite coronographic observations; the radio wavelength range was well covered by single-frequency and spectral observations, and the prominence magnetic fields were measured two days before the eruption.The prominence showed a helical-like internal structure from the pre-eruptive phase, up to the late phases of eruption. The pitch angles of the helical-like threads were measured at several positions 31 along the prominence axis, and the evolution of twist was followed during the eruption. These measurements provide an estimate of the parameters which are directly comparable with theoretical models. The pitch angles of the helical threads decreased during the eruption. A redistribution of twist along the prominence axis could not be detected within the accuracy of measurements, although there are indications that the twist was partly transformed into an external kink-type screw of the prominence axis. The value of the total twist did not change during the eruption within the accuracy of the measurements.The kinematics of the process was followed, and accompanying events in the radio-range and soft X-rays are listed. Measurements of the magnetic field vector in the prominence are reviewed briefly. The observations were compared with predictions of cylindrical models, considering the forces acting at the prominence summit. Observational implications and constraints are discussed, and the decrease of the axial electric current and the mass loss are inferred.  相似文献   
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