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11.
广东省大宝山钼多金属矿区岩浆岩成岩时代研究 总被引：2，自引：0，他引：2
大宝山钼多金属矿区位于南岭成矿带中段。区内主要分布有次英安斑岩、花岗闪长斑岩;钼多金属矿床受NW、E-W、NE等方向断裂组成的构造格架控制,矿体分布与岩浆岩有密切关系。通过对大宝山钼多金属矿区丘坝次英安斑岩和船肚花岗闪长(斑)岩单颗锆石LA-ICP-MS测试,得出丘坝次英安斑岩单颗锆石U-Pb法206Pb/238U表面年龄(419~496 Ma)、花岗闪长(斑)岩单颗锆石U-Pb法206Pb/238U表面年龄(410~489 Ma),反映二者形成时代一致,可能为同一来源岩浆的产物;大宝山强蚀变次英安斑岩锆石SHRIMP U-Pb法206Pb/238U表面年龄有两组,一组为145~168 Ma,另一组为412~420 Ma;认为大宝山钼多金属矿区大面积分布的次英安斑岩和花岗闪长(斑)岩为加里东末期形成的岩浆岩,而紧贴钼多金属矿体分布的岩浆岩为燕山早期岩浆活动形成产物。 相似文献
12.
Toll样受体是一类重要的蛋白质分子,参与固有免疫系统,在哺乳动物在受到细菌感染的时候,TLR1和TLR2基因可以形成异源二聚体,进而启动宿主的固有免疫。本文应用实时荧光定量PCR的技术,检测了TLR1和TLR2基因在牙鲆健康组织以及牙鲆腹腔注射迟缓型爱德华氏菌(Edwardsiella tarda)后各组织中的表达变化,并探讨了它们与牙鲆(Paralichthys olivaceus)固有免疫反应的关系。结果表明,TLR1和TLR2基因广泛表达于健康牙鲆的各种组织中,其中,TLR1在脾脏组织中表达量最高,其次是心脏、肌肉;TLR2在小肠组织中表达量最高,其次是肝脏、心脏。免疫刺激实验表明,多数组织在感染病原6h后TLR1基因表达达到峰值,其中脾脏中基因的表达量最大,是0时间点的290倍(P0.01)。TLR2基因在感染病原1h后在脾脏中表达量最高,为0时间点的17.8倍(P0.01),在感染病原1d后心脏组织中基因的表达量为对照组的14倍(P0.01),其余时间点表达变化不明显。结果表明TLR1和TLR2参与了牙鲆对迟缓型爱德华氏菌的免疫应答反应。实验结果还显示,在牙鲆感染迟缓型爱德华氏菌后,MyD88、TNF-α和IL-1基因的表达也都同步上调,暗示迟缓型爱德华氏菌有可能通过TLR1通路上调MyD88的表达,并最终导致炎症因子TNF-α和IL-1的基因表达上调,以应答病原菌的感染。 相似文献
13.
Chang-Guang Qi Jin-Hui Zheng Dian-Jun Zuo Geng Chen 《Geotechnical and Geological Engineering》2017,35(3):983-990
The physical and mechanical properties of bubble mixed light-weight soil (BMLS) were studied through laboratory penetration test, soak test and unconfined compressive strength test, and a method to treat vehicle bump at bridge approach of open expressway was put forward based on the condition, in which the BMLS was used to replace parts of road embankment by horizontally drilling holes on both sides of the embankment. Analyses show that the water absorption of BMLS can reach 25% maximally and its initial unit-weight cannot be restored after drying; after using BMLS horizontal drilling replacement, the surface subsidence and sedimentation rate gradually approach zero; and finally, satisfactory treatment performance for vehicle bump at bridge approach of open expressway has been obtained. 相似文献
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为揭示虎龙杂交斑(Epinephelus fuscoguttatus♀×E. lanceolatus♂)和斜带石斑鱼(Epinephelus coioides)肠道微生物群落的结构及功能差异, 利用16S rDNA高通量测序技术对其肠道微生物群落进行分析。结果表明: (1) 虎龙杂交斑肠道微生物群落以变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)和放线菌门(Actinobacteria)为主, 斜带石斑鱼中以变形菌门、梭杆菌门(Fusobacteria)和厚壁菌门为主。(2) 在属水平, 虎龙杂交斑和斜带石斑鱼肠道中均含有高丰度的弧菌属(Vibrio)。鲸杆菌属(Cetobacterium)、发光杆菌属(Photobacterium)和丙酸菌属(Propionigenium)是斜带石斑鱼肠道中的标志微生物, 而虎龙杂交斑肠道中的标志微生物为棒状杆菌属1 (Corynebacterium 1)、变形杆菌属(Proteus)、葡萄球菌属(Staphylococcus)和类香菌属(Myroides)。(3) 网络分析显示, 变形菌门在两种石斑鱼肠道中均占主导地位。(4) 功能预测表明, 虎龙杂交斑肠道微生物群落中抗坏血酸与糖醛酸代谢、植物-病原体相互作用和胰岛素信号通路显著高于斜带石斑鱼, 斜带石斑鱼肠道微生物群落的功能在万古霉素类抗生素和链霉素生物合成、亚油酸代谢、双酚降解以及类黄酮生物合成的相关途径中显著富集。研究结果有望加深对石斑鱼肠道微生物群落的认识, 为选择合适的石斑鱼养殖品种, 提高石斑鱼养殖产业的经济效益提供科学参考。 相似文献
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Qiu-Li Li Xian-Hua Li Yu Liu Fu-Yuan Wu Jin-Hui Yang R.H. Mitchell 《Chemical Geology》2010,269(3-4):396-405
Perovskite, a common Th- and U-enriched accessory mineral crystallised from kimberlitic magmas, has long been thought to be an important geochronometer for dating the emplacement of kimberlite. However, it also contains variably high levels of common Pb, which makes it difficult to obtain a precise measurement of radiogenic Pb/U and Pb/Th isotopic compositions using microbeam techniques such as SIMS and LA-ICP-MS. We present calibration protocols for in situ U–Pb and Th–Pb age determination of kimberlitic perovskite using the large double-focusing Cameca IMS 1280. Linear relationships are found between ln(206Pb?+/U+) and ln(UO2+/U+), and between ln(208Pb?+/Th+) and ln(ThO+/Th+), based on which the inter-element fractionation in unknown samples during SIMS analyses can be precisely calibrated against a perovskite standard. The well-characterized Ice River perovskite is chosen as the U–Pb and Th–Pb age standard in this study. The 204Pb-correction method was used to estimate the fraction of common Pb, which is consistent with the results obtained using the 207Pb-based correction method for the dated perovskites of Phanerozoic age.A Tazheran perovskite with unusually high U but rather low Th yielded a Concordia U–Pb age of 462.8 ± 2.5 Ma and a Th–Pb age of 462 ± 4 Ma. Two perovskite samples from the Iron Mountain kimberlite have identical Concordia U–Pb ages of 410.8 ± 3.4 Ma and 411.0 ± 2.6 Ma, which are consistent within errors with their corresponding Th–Pb ages of 409.2 ± 7.2 Ma and 412.3 ± 3.3 Ma, respectively. Two perovskite samples from the Wesselton Mine of South Africa yielded indistinguishable 206Pb/238U ages of 91.5 ± 2.2 Ma and 90.3 ± 2.9 Ma, and Th–Pb ages of 90.5 ± 0.8 Ma and 88.4 ± 1.6 Ma, respectively. Accuracy and precision of 1–2% (95% confidence level) for these measurements have been demonstrated by the consistency of their U–Pb and Th–Pb ages with the recommended U–Pb ages of previous works. 相似文献
16.
利用常规观测资料、数值预报物理量场和NCEP/NCAR每日4次全球再分析网格点资料,对2010年03月28日发生在克州境内的一场罕见大风、沙尘暴天气过程进行了诊断分析,探讨了这次强风沙天气的成因,结果表明：高空低压槽和地面冷锋及锋后强冷平流、高空急流的加强及高空形成的次级环流使高空动量有效下传到地面起到了积极的动能作用,大风沙尘上空螺旋度上负下正的垂直分布与大风沙尘的出现有很好的对应关系,大风沙尘发生前后压、温、湿要素出现的剧烈突变对预报也有很好的指示意义。 相似文献
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18.
The Heilongjiang Group: A Jurassic accretionary complex in the Jiamusi Massif at the western Pacific margin of northeastern China 总被引：45，自引：0，他引：45
Fu-Yuan Wu Jin-Hui Yang Ching-Hua Lo Simon A. Wilde De-You Sun Bor-Ming Jahn 《Island Arc》2007,16(1):156-172
Abstract The tectonic setting of the Eastern Asian continental margin in the Jurassic is highly controversial. In the current study, we have selected the Heilongjiang complex located at the western margin of the Jiamusi Massif in northeastern China for geochronological investigation to address this issue. Field and petrographic investigations indicate that the Heilongjiang complex is composed predominately of granitic gneiss, marble, mafic‐ultramafic rocks, blueschist, greenschist, quartzite, muscovite‐albite schist and two‐mica schist that were tectonically interleaved, indicating they represent a mélange. The marble, two‐mica schist and granitic gneiss were most probably derived from the Mashan complex, a high‐grade gneiss complex in the Jiamusi Massif with which the Heilongjiang Group is intimately associated. The ultramafic rocks, blueschist, greenschist and quartzite (chert) are similar to components in ophiolite. The sensitive high mass‐resolution ion microprobe U‐Pb zircon age of 265 ± 4 Ma for the granitic gneiss indicates that the protolith granite was emplaced coevally with Permian batholiths in the Jiamusi Massif. 40Ar/39Ar dating of biotite and phengite from the granitic gneiss and mica schist yields a late Early Jurassic metamorphic age between 184 and 174 Ma. Early components of the Jiamusi Massif, including the Mashan complex, probably formed part of an exotic block from Gondwana, affected by late Pan‐African orogenesis, and collided with the Asian continental margin during the Early Jurassic. Subduction of oceanic crust between the Jiamusi block and the eastern part of the Central Asian Orogenic Belt resulted in the formation of a huge volume of Jurassic granites in the Zhangguangcai Range. Consequently, the collision of the Jiamusi Massif with the Central Asian Orogenic Belt to the west can be considered as the result of circum‐Pacific accretion, unrelated to the Central Asian Orogenic Belt. The widespread development of Jurassic accretionary complexes along the Asian continental margin supports such an interpretation. 相似文献
19.
长江口表层水体的生态遗传毒性初步研究 总被引：1，自引：1，他引：1
采用Ames试验方法,结合浮游动物多样性数据和一些水质理化参数的分析,对长江口表层水体的生态遗传毒性进行初步研究。结果表明,长江口南支的水样有明显的遗传毒性,而河口外海滨区的部分样品在加入S9活化后也表现出一定的遗传毒性,口外海区样品没有遗传毒性。浮游动物的调查结果显示,长江口南支水样中浮游动物的密度及多样性都较低,口外海区较高。统计分析也表明,遗传毒性数据和生物多样性数据存在着一定的线形关系。这说明长江口表层水体污染物的毒性效应在分子水平和生物群落水平上有相关性。而二者与水质参数的相关分析表明,遗传毒性与多数所测水质理化因子之间没有相关性,但浮游动物多样性与部分理化参数有一定的相关性。同时,本文也从实践上证明,在河口、近岸海域的环境监测中开展遗传毒性检测具有可行性和必要性。 相似文献
20.
琼州海峡夏季三塘潮流谱分析和余流特征研究 总被引：3，自引：0，他引：3
无论潮流矢量是反时针旋转(f>0)还是顺时针旋转(f<0),全日潮谱峰都高于半日潮谱峰。2个半日潮周期分别为12、12.4h;2个日潮周期分别为23.9和25.8h;在半日潮和全日潮分量中,反时针分量是主要的:顺时针的半日潮能谱只有反时针的84%;顺时针的日潮能谱只有反时针的65%;浅水分潮6.2、8h和超过24h的3、4.2和5.5d等也有明显表现,但是都未通过显著性检验;夏季余流流速在5～10cm/s范围内变化,方向以南偏西为主。造成这种现象的首要的因素是夏季琼州海峡水交换基本态势和三塘附近海底地形,风对流向变化也有重要影响。 相似文献