The Dajing Cu-Sn-polymetallic ore deposit is famous for its large scale, abundant associated elements, narrow and closely-spaced development of ore veins and high grade, but exploration within the mining district and ...The Dajing Cu-Sn-polymetallic ore deposit is famous for its large scale, abundant associated elements, narrow and closely-spaced development of ore veins and high grade, but exploration within the mining district and its deeper parts has revealed no Yanshanian rockbody. Therefore, there have been proposed a diversity of hypotheses on the genesis of the deposit. The authors, from the angle of mantle-branch structure, provided evidence showing that the mining district is located in the core of the Da Hinggan Ling mantle-branch structure, the multi-stage evolution of mantle plume paved the way for the ascending of deep-source ore fluids and these fluids extracted part of the ore-forming materials. Then, these ore-forming materials were concentrated in the favorable structural loci (e.g. structural fissures) to form ores. The orientation of ore-forming and ore-controlling fissures is closely related to the regionally structural stress field at the metallogenic stage. The zonation of Sn, Cu, Au, Ag, Pb, and Zn within the mining district appears to be related to metallogenesis and the crystallization temperature of ore-forming materials. Mineralization of Sn, Cu, Au, etc. which require relatively high crystallization temperature and pressure is in most cases recognized in the central part of the mining district, while that of Ag, Pb, Zn, etc. which require relatively low crystallization temperature and pressure is, for the most part, produced in the periphery of the mining district.展开更多
文摘左束支阻滞(left bundle branch block,LBBB)时心室激动顺序发生改变,左室除极位于QRS波后半部,因此,当LBBB合并急性心肌梗死(acute myocardial infarction,AMI)时,可干扰心电图诊断。本文介绍了Sgarbossa、Smith和巴塞罗那诊断标准,并比较其诊断敏感性及特异性。1996年提出的Sgarbossa标准根据ST段同向改变及过度反向抬高等指标诊断LBBB合并AMI,特异性高,但敏感性低。Smith标准将Sgarbossa标准中的"过度反向抬高≥0.5 m V"修订为考量ST段反向偏移幅度与S(R)波的比值,提高了诊断的敏感性。巴塞罗那标准提出,LBBB时任意导联ST段同向偏移≥0.1 m V,或低电压导联反向偏移≥0.1 m V时,即可诊断AMI,显著提高了诊断敏感性及特异性。Cabrera及Chapman征对LBBB合并AMI也具有辅助诊断价值。
基金This research was jointly granted by the Key Scientific Research Project of Inner Mongolia Geological Survey(2004-05)the National Natural Science Foundation of China(Grant No.40272088).
文摘The Dajing Cu-Sn-polymetallic ore deposit is famous for its large scale, abundant associated elements, narrow and closely-spaced development of ore veins and high grade, but exploration within the mining district and its deeper parts has revealed no Yanshanian rockbody. Therefore, there have been proposed a diversity of hypotheses on the genesis of the deposit. The authors, from the angle of mantle-branch structure, provided evidence showing that the mining district is located in the core of the Da Hinggan Ling mantle-branch structure, the multi-stage evolution of mantle plume paved the way for the ascending of deep-source ore fluids and these fluids extracted part of the ore-forming materials. Then, these ore-forming materials were concentrated in the favorable structural loci (e.g. structural fissures) to form ores. The orientation of ore-forming and ore-controlling fissures is closely related to the regionally structural stress field at the metallogenic stage. The zonation of Sn, Cu, Au, Ag, Pb, and Zn within the mining district appears to be related to metallogenesis and the crystallization temperature of ore-forming materials. Mineralization of Sn, Cu, Au, etc. which require relatively high crystallization temperature and pressure is in most cases recognized in the central part of the mining district, while that of Ag, Pb, Zn, etc. which require relatively low crystallization temperature and pressure is, for the most part, produced in the periphery of the mining district.
