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71.
Ho Seong Hwang † Myung Gyoon Lee 《Monthly notices of the Royal Astronomical Society》2009,397(4):2111-2122
We present the results of a study of galaxy activity in two merging binary clusters (A168 and A1750) using the Sloan Digital Sky Survey (SDSS) data supplemented with the data in the literature. We have investigated the merger histories of A168 and A1750 by combining the results from a two-body dynamical model and X-ray data. In A168, two subclusters appear to have passed each other and to be coming together from the recent maximum separation. In A1750, two major subclusters appear to have started interaction and to be coming together for the first time. We find an enhanced concentration of the galaxies showing star formation (SF) or active galactic nuclei (AGN) activity in the region between two subclusters in A168, which were possibly triggered by the cluster merger. In A1750, we do not find any galaxies with SF/AGN activity in the region between two subclusters, indicating that two major subclusters are in the early stage of merging. 相似文献
72.
尼日尔Termit盆地上白垩统储层岩石学特征及控制因素分析 总被引:1,自引:0,他引:1
本文对尼日尔Termit盆地17口井218个井壁取芯样品开展普通薄片、阴极发光、X衍射、扫描电镜及重矿物分析,研究上白垩统储层的岩石学特征,并探讨其控制因素。实验分析结果表明,Termit盆地上白垩统储层的岩石类型主要为石英砂岩,成分成熟度高,以石英为主,含量达86%以上,钾长石、方解石及斜长石等含少量,占比约5%,这种岩石类型对原生孔隙的保存比较有利;填隙物主要为粘土杂基,含量为7%左右,矿物成分以高岭石为主,利于对晶间孔的保留;岩石中发育硅质、方解石和铁质等胶结类型,胶结物的含量占比较小,对储层的破坏作用不大;重矿物类型为磁铁矿、赤铁矿、锆石、磷灰石,推测物源区的母岩类型主要为花岗岩;以细粒结构和少量的不等粒结构为主,分选中等-差,磨圆度一般为次棱角-次圆状,磨圆差。与国内石英砂岩沉积于高能的滨浅海环境不同,研究区石英砂岩成分成熟度高,但分选程度和磨圆度较低,一方面反映了物源区母岩富含石英,同时也反映了这种石英砂岩沉积于近源的河流-三角洲环境。影响研究区上白垩统储层物性的主要因素是岩石类型及成岩作用,由于储层的岩石类型为石英砂岩,压实作用对储层的破坏作用较一般岩石类型偏小。砂岩埋深小于2500m时,主要发育原生孔隙,面孔率大于15%。溶蚀作用对本区储层产生一定的影响,最常见的为长石的溶蚀,溶蚀作用形成粒内溶孔和粒间溶孔,还会扩大原生孔隙形成混合孔,改善了砂岩的储集性能。 相似文献
73.
Acta Geochimica - In this study, we investigated the chemical composition of dissolved solids in the Ca River basin, North-Central Vietnam. Water samples were collected from August 2017 to July... 相似文献
74.
75.
I. INTRODUCTION Bordering the SW margin of the Red Basin of Szechuan runs a roughly N-S mountain range which includes such mountains as Washan, Omeishan and Talliangshan (Pl. I) and for the sake of convenience is designated with the name of Liangshan Range. Among these mountains only the geology of the Omeishan region is fairly well known in consequence of the works done by many a geologist; of the Washan region, though had been visited by 相似文献
76.
77.
苏州富铌钽花岗岩的物质组成及钽的赋存状态研究 总被引:1,自引:0,他引:1
苏州富含铌钽花岗岩 (A型 )由富黑云母花岗岩和富钠长石花岗岩组成。主要副矿物为铌钽铁矿、锆石、细晶石、磷钇矿、黄玉和黄铁矿。钽元素主要形成铌钽铁矿系列单矿物 ,少量分散于长石、石英、黑云母、黄铁矿及萤石中 相似文献
78.
The presence of the minimum salinity and oxygen-rich East Sea Intermediate Water (ESIW) off Korean coast has raised many questions
about its origin and movement. This study attempts to answer these questions in the context of numerical model. For this,
the Miami Isopycnic Coordinate Ocean Model is used with surface and inflow boundary conditions based on available data. Model
results show that the ESIW forms most distinctly off Vladivostok, where the center of doming structure is observed, and moves
southward along Korean coast forming a large cyclonic gyre around the doming. The renewed ESIW has the character of minimum
potential vorticity common to usual mode waters. These results are compatible with various indications made in previous observational
and theoretical studies. However, it is not known whether the doming structure is a result of convection or the latter is
favored by the former.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
79.
80.
Large agricultural fields in South Korea are located mostly on alluvial plains, where a significant amount of groundwater is used for heating of water‐curtain insulated greenhouses. Such greenhouses are commonly used for crop cultivation during the winter dry season from November to March. After use the groundwater is discharged directly into streams, causing groundwater depletion. A hydrogeological study was carried out in a typical agricultural area of this type, located on an alluvial aquifer near the Nakdong River. Groundwater levels, chemical characteristics, and temperatures from 68 observation wells were analyzed to determine the impacts of seasonal groundwater pumping on the groundwater system and stream‐aquifer interactions. Our results show that the groundwater system has not yet reached a state of dynamic equilibrium. Decades of excessive seasonal pumping have caused a gradual decline of groundwater levels, leading to groundwater depletion, especially in areas further from the river. Seasonal pumping has also significantly affected groundwater quality in the aquifer near the river. Groundwater temperature is decreasing (in this case a disadvantage), and saline groundwater is being diluted by induced recharge. The results of this study provide a basic outline for effective integrated water management that is widely applicable in South Korea. 相似文献