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71.
为探讨高原牌70kN和进口120,210kN瓷绝缘子的成分和结构性能,中采用原子吸收光谱(AAS)和X射线衍射(XRD)方法,对三类产品进行了检测。结果表明,有效成分除K2O外,70kN和210kN的SiO2,Al2O3,Fe2O3含量接近,主晶相基本相同,有刚玉,莫来石、石英和长石等;结晶相总量:70kN35%,120kN40%,210kN48%,这表明机械强度愈大,结晶相含量愈高,只需调整70kN原样的部分成分,粒度和工艺,即生产出高等级(如210kN)瓷绝缘子。  相似文献   
72.
Abstract. Several epithermal gold deposits occur in the Hoshino area, which is located in the western end of the late Cenozoic Hohi volcanic zone, north‐central Kyushu, Japan. The area is characterized by intermediate to felsic extrusive rocks of Pliocene age. In the Hoshino area, the shallow manifestation of the hydrothermal activity is exposed on the surface. Several outcrops of sinter are still preserved on the top of hydro thermally altered volcanic rocks, and high‐grade gold‐bearing quartz veins occur on the surface at lower levels. The hydrothermal alteration resulted into well‐developed alteration zones. The zonal alteration pattern, primarily of near‐neutral pH type, is characterized by the outer smectite zone of a lower temperature, and the inner mixed layer minerals zone of a higher temperature. Quartz vein‐related or fracture‐controlled alteration, is represented by the occurrence of interstratified illite/smectite and K‐feldspar, suggesting a potassium‐enriched alteration. The mineralization in the Hoshino area is recognized on the surface by the occurrence of gold‐bearing quartz veins distributed mainly in the mixed layer minerals zone. The fracture system related to the gold mineralization is mainly characterized by NW‐SE trend. The alteration pattern and the mineralogical composition of the veins suggest that the mineralizing fluids had near‐neutral pH and the mineralization is of low‐sulfidation‐type. Fluid inclusion data and textures observed in quartz veins indicate that gold precipitated during boiling. The chemical composition of quartz veins shows that high‐grade gold‐bearing quartz veins are characterized by higher content of Al2O3, K2O and Rb. Several outcrops of silica‐sinters are distributed on the top of the mixed layer minerals zone. Although their structures are not very well preserved, because of later silicification, the Hoshino sinters still show characteristic textures identical to those observed in modern sinters, such as the presence of plant fossil incorporated into the sinters, the strongly developed depositional laminations and the columnar structures perpendicular to the depositional surfaces. Quartz is the only silica mineral constituting the Hoshino sinters presently. The conversion of amorphous silica into quartz was probably governed by higher temperatures resulting from later hydrothermal activity. This later hydrothermal activity is reflected by the intense silicification affecting mainly the lower parts of the sinters and also by the presence of quartz veins cutting the sinters. The distribution of sinters in the Hoshino area is very significant. The presence beneath the sinters of concealed high‐grade gold‐bearing quartz veins should be highly considered and exploration work is strongly suggested.  相似文献   
73.
The reservoir quality of Jurassic and Triassic fluvial and lacustrine-deltaic sandstones of the Yanchang Oil Field in the Ordos Basin is strongly influenced by the burial history and facies-related diagenetic events. The fluvial sandstones have a higher average porosity (14.8%) and a higher permeability (12.7×10?3 ?m2) than those of the deltaic sandstones (9.8% and 5.8 ×10?3 ?m2, respectively). The burial compaction, which resulted in 15% and 20% porosity loss for Jurassic and Triassic sandstones, respectively, is the main factor causing the loss of porosity both for the Jurassic and Triassic sandstones. Among the cements, carbonate is the main one that reduced the reservoir quality of the sandstones. The organic acidic fluid derived from organic matter in the source rocks, the inorganic fluid from rock-water reaction during the late diagenesis, and meteoric waters during the epidiagenesis resulted in the formation of dissolution porosity, which is the main reason for the enhancement of reservoir-quality.  相似文献   
74.
Quadrupole mass spectrometer (QMS) is an instrument for effectively determining gaseous composition of fluid inclusion. The gaseous component is extracted from inclusions with thermal decrepitation method and then determined with the sensitive QMS instrument. The method is characterized by high sensitivity and high accuracy with the relative standard deviation (RSD,n=6) of less than 3%. It has been successfully used for analyzing fluid inclusions. The analytical results meet the requirement of geological study.  相似文献   
75.
长江巨洪前期物理因子的配置   总被引:4,自引:4,他引:4  
冯利华 《地理科学》2002,22(4):504-507
提出了长江巨洪前期物理因子配置的概念,在每一次巨洪发生之前,影响巨洪的主要物理因子之间一般都会表现出相似的特征,即出现一些固有的配置,这些配置正是长江发生巨洪的强信号,对长江巨洪的预测研究具有重要的指示作用。  相似文献   
76.
A diatom study of lacustrine sediments in the southern part of the Bolivian Altiplano (Salar of Coipasa) provides a continuous record of the period 21,000–17,500 14C yr BP. Constrained by seven AMS 14C dates, this record provides evidence that the Coipasa basin was filled by a shallow body of water during this time. Diatom/salinity and diatom/ionic composition transfer functions indicate that the lake was saline, dominated by sodium-chloride throughout all the period.A comparison with regional data shows that Lake Titicaca could not have overflowed towards the southern Bolivian Altiplano at that time. As this dry phase was not registered in Lake Coipasa, this lake was probably supplied by winter precipitation originating from the Pacific. But, recent data from the deep basin of Lake Titicaca show that the lake-level was higher during this time interval, and the question arises whether precipitation from Atlantic and Amazonia sources could have played an important role on the Altiplano during the Last Glacial Maximum (LGM). This hypothesis needs to match other available paleoclimatic data from the lowlands of tropical South America, where there is evidence that during the LGM, conditions were drier than today. Global climate simulations suggest a positive P-E on the Altiplano, due to a strong cooling, reducing evaporative demand more than any increase in precipitations. An increase of winter precipitation from the Pacific is in agreement with data from the Chilean coast showing a northward locations of the Westerlies during the LGM. This paleoclimatic hypothesis is also in agreement with a coupled ocean-atmosphere model, which indicates weaker summer precipitation and stronger winter precipitation in the tropical areas.  相似文献   
77.
78.
某地石英矿砂通过磁选分离法、稀酸浸泡法处理后,矿砂不同程度地降低了铁、铝、钙镁的含量;采用磁选分离 稀酸浸泡法联合处理后,使该地石英砂的化学成分达到了优质的生产平板玻璃用硅质原料的国家标准。  相似文献   
79.
依据镜泊湖地区水体的同位素、水化学及微量元素中子活化分析资料,详细阐述了各采样点水体的来源、补给相对高程和它们之间可能的水力联系,以及有关的地热信息;分析了区内地热资源的有利地质背景条件研究区地处深大断裂及岩浆喷发带,火山喷发一直延续至第四纪全新世,有充分的热源供给;区内上部为较厚的玄武岩覆盖,有利于储存地热;下部白垩系上统为主要含水层,发现有广泛分布的典型木/岩热蚀变产物——斜发沸石,进而证明存在地下热水的可能性。  相似文献   
80.
泥炭藓是贫营养泥炭类型中的建群植物,由于生态水环境主要靠大气降水补给,少受其他水源的污染,可自然反映古降水、古湿度的情况,所以是古气候研究最理想的纤维素同位素测试材料之一。因此,弄清我国贫营养泥炭沉积的物质组成及水化学环境特征,具有重要意义。笔根据多年来的国内外野外调查,结合收集到的资料,以东北大小兴安岭山地的泥炭辞贫营养泥炭地为基础,与美国、加拿大以及俄罗斯等国家的同类泥炭地相比较,对我国贫营养泥炭沉积的物质组成、理化特性及水化学环境做了系统的分析研究,并就此讨论了湿地保护中的一些实际问题,以及相应的对策。  相似文献   
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