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用RT-PCR方法从1个H5N1亚型禽流感病毒分离株A/Chicken/Guangdong/DH/1997扩增NA基因cDNA片段,将其克隆至pMD18-T载体,获得重组质粒pMD-NA,并对其核苷酸序列进行测定和分析。结果表明,该毒株的NA基因长度为1350bp,编码449个氨基酸,与其它H5N1亚型AIV分离株的核苷酸序列同源性为97.0%～99.4%,氨基酸序列同源性为97.7%～99.1%,提示禽流感病毒NA基因保守性较高。NA基因氨基酸序列的聚类分析表明该毒株与来自香港的A/Pheasant/HK/FY155/01和A/Ch/HK/FY150/01两个分离株处于同一进化枝,亲缘关系较近。 相似文献
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西秦岭厂坝、黄渚关岩体的锆石U-Pb年龄、Hf同位素组成及其地质意义 总被引：1，自引：1，他引：0
厂坝及黄渚关岩体位于商丹缝合带和勉略缝合带之间的秦岭微板块,主要由花岗闪长岩及二长花岗岩组成。LA-MC-ICP-MS锆石U-Pb定年显示,黄渚关及厂坝岩体的演化可划分为中三叠世(229 Ma)和晚三叠世(215~209 Ma)2期。黄渚关中心部位的年龄((229.2±1.0)Ma)老于边部岩体((215.8±0.8)Ma),厂坝岩体中心部位年龄((218.3±1.2)Ma),老于边部年龄((209.4±0.8)Ma),结合岩体中心相和边缘相渐变的特征,说明2个岩体是由中心部位侵位,边部岩体的侵位冷却时间较晚造成的。黄渚关岩体的ε_(Hf)(t)为-3.13~-14.51,集中于-10~-6;厂坝岩体的ε_(Hf)(t)为-5.17~-14.51,集中于-12~-6。在ε_(Hf)(t)-t图解中,ε_(Hf)(t)均在球粒陨石之下和古元古地壳演化线之上;二阶段模式年龄黄渚关岩体主要集中在1.8~2.1 Ga,厂坝岩体主要集中在2.0~2.2Ga,结合继承锆石年龄1932 Ma、2039 Ma,表明古元古代地层可能为岩体的源区之一,在黄渚关岩体发现的暗色包体说明岩浆在上升的过程中发生了壳-幔岩浆的混合。因此,笔者认为黄渚关、厂坝岩体起源于古老地壳重熔,并在上升的过程中与幔源岩浆发生一定比例混合。 相似文献
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甘肃西成矿集区是西秦岭最重要的多金属成矿区之一,以铅锌矿床为主,其次发育有金、铜、钼等矿床(点)。厂坝黑云母二长花岗岩体位于西成矿集区中东部,岩体南缘接触带部位发育石英脉型钼矿,辉钼矿呈中粗粒半自形团块状产于粗粒石英脉内。Re-Os同位素年代学研究表明,其模式年龄范围为207.7±3.0~209.8±2.8Ma,加权平均年龄为208.9±1.1 Ma,等时线年龄为209±15 Ma,指示钼矿化发生于晚三叠世。辉钼矿的铼含量介于18.82×10~(-6)~21.97×10~(-6)之间,平均19.65×10~(-6),表明成矿物质主要为壳幔混合来源,可能以壳源为主。钼矿化与区域岩浆活动以及金、铅锌成矿作用时代相近,是印支期区域构造-岩浆-流体活动的产物。钼矿化年龄的厘定为区内找矿提供了新的思路。 相似文献
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根据GenBank中发表的H5亚型禽流感病毒HA基因序列设计2对引物,用RT-PCR方法从禽流感病毒广东分离病毒株(A/Chicken/Guangdong/1997)中扩增HA基因cDNA片段,并将其克隆至pMD-18T载体进行核苷酸序列测定。结果表明:用2对引物所扩增的片段大小分别约为1300 bp和800 bp,经序列拼接获得的HA基因cDNA长度约为1601 bp,编码533个氨基酸,与国内己发表的11个代表株的核苷酸和氨基酸序列同源性为分别为96.9%~99.9%和86.5%~93.0%;HA基因编码的氨基酸序列的系统进化树也表明A/Chicken/Guang-dong/1997、A/Goose/Huadong/01/2000、A/Ck/Hk/37.4/2002、A/Chicken/Zhoukou/2/02、A/Duck/Guangxi/53/2002、A/Duck/Fujian/01/2002等毒株处于同一进化枝,亲缘关系较近;而与A/Silly/Chicken/Hongkong/SF189/01株处于不同进化枝,亲缘关系较远。 相似文献
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Abstract The metallogeny of Japan can be grouped into four environments: (1) Paleozoic-Mesozoic stratiform Cu and Mn deposits within accretionary complexes, (2) Cretaceous-Paleogene post-accretionary deposits related to felsic magmatism in a continental-margin are environment, (3) Miocene epigenetic and syngenetic deposits related to felsic magmatism during back-arc opening, and (4) late Miocene-Quaternary volcanogenic deposits in an island-are environment. Group (1) deposits were a major source of Cu and Mn for the Japanese mining industry, and this style of mineralization is reviewed here. The stratiform Cu and Mn deposits were formed on the sea floor during the late Paleozoic to Mesozoic, and were subsequently accreted to active continental margins mainly in Jurassic to Cretaceous age. The Cu sulfide deposits, termed Besshi type, are classified into two subtypes: the Besshi-subtype deposit is related to basaltic volcanism, probably at a mid-oceanic ridge or rise; the Hitachi subtype is related to bimodal volcanism, probably in a back-arc or continental rift. Most of the Besshisubtype deposits occur in the Sanbagawa metamorphic belt, with some occurrences in weakly metamorphosed Jurassic and Cretaceous accretionary terrains. This subtype is divided into two groups: the sediment-barren group is hosted by basalt-chert sequences; whereas the sedimentcovered group is hosted by basalt-shale sequences. Both subtypes are characterized by S isotope trends similar to those of sea-floor sulfide deposits now forming at mid-oceanic ridges. The Hitachi-subtype deposits occur in late Paleozoic volcanic-sedimentary sequences and lack pelagic sediments. These deposits are characterized by association of sphalerite- and barite-rich ores. The Mn deposits occur mainly in Middle Jurassic to Early Cretaceous accretionary complexes containing abundant chert beds of Triassic to Jurassic age. Their locations are well separated from those of the Cu sulfide deposits. The Mn deposits are divided into two types: the Mn type, hosted by chert, and the Fe-Mn type, sandwiched between chert and basaltic volcanic rocks. The Mn-type ores appear to have deposited on the deep-sea floor further from the site of hydrothermal activity than the Fe-Mn type. Primary Mn precipitates may have been transformed to rhodochrosite and other Mn-minerals during diagenesis. Many of the Mn deposits were significantly metamorphosed during intrusion of Cretaceous granitoids, resulting in a very complex mineralogy. 相似文献
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Li Jianzhong Gansu Institute of Geology for Non-Ferrous Metals CNNC Lanzhou Gansu He Dianren North west Institute of Geology for Non-Ferrous Metals CNNC Xi''an Shaanxi Wu Jianmin Research Institute of Geology for Mineral Resources CNNC Guilin Guangxi 《《地质学报》英文版》1993,67(1)
Qinling-type Pb-Zn deposits are located in the Qinling fold belt, occurring in the fine-clastic and carbonate rocks of the Devonian marine facies. They are reformed sedimentary deposits originating from hydrothermal waters, and may be subdivided into 2 subtypes: hydrothermal sedimentary deposits (Changba subtype) and reformed hydrothermal sedimentary deposits (Bijiashan-Qiandongshan subtype). In comparison with some of the famous Palaeozoic Pb-Zn deposits in the world, the Qinling-type Pb-Zn deposits constitute an independent type, which possesses some characteristics of both hydrothermal sedimentary deposits (Meggen type) and reformed hydrothermal deposits (Mississippi Valley type). 相似文献
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借助GIS以内蒙古自治区呼和浩特市5713km2为研究区域,将土壤中镉的空间分布规律与相关统计规律相结合,确定了研究区内4种典型的土壤亚类表层中重金属镉的基准值,通过对933个样品的分析,得到以下结论:呼和浩特市表层土壤中镉的基准值在洪积新积土中最高,达0.117mg/kg;在淡栗褐土中最低,仅为0.084mg/kg。本研究为制订内蒙古自治区地方土壤环境质量标准提供了基础资料。 相似文献
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小武当断陷红盆位于浰源岩体北部,该岩体位于大东山—贵东岩浆岩带东段,属南岭产铀岩体,二者呈断裂接触,断陷盆地位于该断裂带上盘。该处成矿地质条件与岩体上覆盆地亚类型铀矿床极为相似,从成矿背景、盆地类型、盆地年代、沉积环境、含铀建造等多方面与黄子洞矿床这一典型的岩体上覆盆地亚类铀矿床进行类比分析,认为岩体北部小武当断陷红盆深部具有较大的找矿潜力,为研究区新型铀矿床的勘探提供新的找矿方向和找矿思路。 相似文献
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拉果错盐湖位于西藏阿里地区改则县麻米乡境内,盐湖水体类型为硫酸钠亚型地表卤水,氯化锂资源储量232万吨,是西藏重要锂盐湖之一。前人对拉果错盐湖的研究集中在锂元素来源、成矿规律,不同温度下盐类矿物析出序列等,对盐湖中含硼盐类矿物并未相关研究。本次工作对拉果错盐田中采集的5件样品进行X射线衍射实验和扫描电镜分析,发现盐田中盐类矿物组合为三方硼砂、石盐、钾石盐、钾芒硝、无水芒硝、硫酸锂钾。三方硼砂呈他形-半自形的短柱状集合体,长约36μm,宽约30μm,含量在5.94%-84.51%。三方硼砂为首次在硫酸盐型盐湖卤水盐类结晶矿物中被发现,由先析出的硼砂脱水形成,属次生三方硼砂。 相似文献
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