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461.
Ridgeia piscesae是唯一一种存在于东北太平洋Juan de Fuca Ridge热液区的管状蠕虫,我们成功通过RACE PCR获得Ridgeia piscesae TAK1(Rp TAK1)基因全长c DNA序列.为深入研究TAK1基因在管状蠕虫中的作用,本文通过显微注射获得Rp TAK1转基因果蝇,并在果蝇体内成功过表达Rp TAK1基因.我们发现由Rp TAK1编码的氨基酸序列具有一定保守性,可能暗示其功能上的保守性,同时也暗示TAK1蛋白在物种进化中的保守性.而过表达突变体果蝇的眼睛出现变异,包括眼睛变得粗糙、单眼排列不整齐及整体形状变小,可以看出Rp TAK1基因影响果蝇的机体发育,我们猜测在Rp TAK1基因在管状蠕虫的生长发育过程中也可能起到重要作用. 相似文献
462.
Cheng Yinhe Zhou Shengqi Wang Dongxiao Lu Yuanzheng Huang Ke Yao Jinglong You Xiaobao 《中国海洋湖沼学报》2016,34(3):619-628
The observed characteristics of lower atmospheric ducts over the South China Sea(SCS) were analyzed based on Global Position Systerm(GPS) radiosonde data collected four times daily during autumn open cruises from 2006 to 2012.Duct occurrence,thickness,and strength over the SCS were about 40%,150-m thick,and 8 M units,respectively,which were larger than during the summer monsoon period.Most ducts occurred at heights 1 500 m and these ducts easily trap electromagnetic wave clusters with wavelengths 2 m.Diurnal variation of the SCS ducts appeared evident.They occurred more often at midnight at higher altitudes(about 1 100 m),with a thickest layer of about 145 m and less frequently during the evening at lower altitudes(about 800 m),with a thinnest layer of about 125 m.Moreover,ducts during the daytime at a mean height of about 900 m,with the greatest strength of about 10 M units.Furthermore,all duct variables observed over the SCS in autumn decreased from north to south.These findings are useful not only in the design of radar and communication systems,but also for evaluating possible effects of anomalous propagation on meteorological radar and military applications. 相似文献
463.
ZHENG Tingting BAI Yi WANG Qiang ZHU Xufeng FANG Kaiyong YAO Yuan ZHAO Yongqiang WANG Xiaolin 《《地质学报》英文版》2018,92(3):897-903
A new ootype collected from the Upper Cretaceous Lijiacun Formation in the Shangdan Basin, Shaanxi Province is described in this paper. Based on general external shape, size, eggshell thickness and honeycomb‐like eggshell microstructure, eggs are referable to the oofamily Faveoloolithidae. Compared with other members of Faveoloolithidae, specimens described in this paper show special characteristics: adjacent pores are usually separated by two eggshell units between which often develop interspaces; columnar eggshell units are relatively closely arranged in radial view. According to these characteristics, we erect a new oogenus and a new oospecies: Duovallumoolithus shangdanensis oogen. et oosp. nov. The new discovery expands the diversity of Faveoloolithidae. 相似文献
464.
The Jiangaidarina granitic mass(JM) is an important part of the magmatic belt in Longmu CoShuanghu Suture Zone(LSSZ) in the central Tibetan Plateau. An integrated research involving wholerock geochemistry, zircon LA-ICP-MS U-Pb ages and Hf isotopic compositions was carried out to define the timing, genesis and tectonic setting of the JM. Zircon LA-ICP-MS U-Pb ages have been obtained ranging from 210 to 215 Ma, rather than the Early Jurassic as previously thought. Fifteen granite samples contain hornblendes and show a negative correlation between P_2 O_5 and SiO_2, indicating that the JM is an I-type granite. All the granites are enriched in LREE relative to HREE, with negative Eu anomalies(Eu/Eu*=0.56-0.81), and have similar trace elements patterns, with depletion of Ba, Nb, Sr and P. These suggest that the JM was fractionated, and this is also proved by the characteristic of negative correlations between oxide elements(TiO_2, MgO, FeOt, MnO, CaO) and SiO_2. Almost all ε_(Hf)(t) values of the granites are between-10.3 and-5.8, implying that the JM has a crustal source intimately related with the South Qiangtang Block(SQB), except for one(+10.2), showing a minor contribution from mantle source.Moreover, relatively low Na_2 O/K_2 O ratios(0.42-0.93) and high A/CNK values(0.91-1.50) reflect that the JM was predominately derived from the medium-high potassium basaltic crust, interacted with greywacke. Our new geochemical data and geochronological results imply that the Late Triassic magmas were generated in a post-collisional tectonic setting, probably caused by slab break-off of the Longmu Co-Shuanghu Tethyan Ocean(LSTO). This mechanism caused the asthenosphere upwelling, formed extension setting, offered an enormous amount of heat, and provided favorable conditions for emplacement of voluminous felsic magmas. Furthermore, the LSTO could be completely closed during the Middle Triassic, succeed by continental collision and later the slab broke off in the Late Triassic. 相似文献
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内蒙古科尔沁右翼中旗协和尔斯德一带出露一套中生代地层,岩石组合主要为酸性火山碎屑岩、火山碎屑沉积岩夹碎屑沉积岩及酸性火山熔岩。1∶50000区调依据在该套地层上部层位发现的木化石组合确定其时代为中—晚侏罗世,结合岩石组合,将该套地层划分为上侏罗统满克头鄂博组。为了准确厘定该套地层时代,为木化石延限研究及区域生物地层划分对比提供依据,本次研究在低于产木化石层位的酸性火山碎屑岩中采取了锆石测年样品(LA-ICP-MS),获得锆石U-Pb年龄(165±1)Ma,时代为中侏罗世。同时采取了侵入该套地层的斑状细晶闪长岩测年样品,获得锆石年龄(131±1)Ma,限定了地层形成的上限年龄。根据岩性组合的区域对比、测年结果、木化石组合时限、地层产状特征,认为该套地层应划为中侏罗统新民组,是突泉火山-沉积盆地充填物的一部分。 相似文献
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469.
近几年,随着四川盆地海相碳酸盐岩储层勘探的不断加强,碳酸盐岩储层强的非均质性已成为制约礁滩气藏勘探开发的现实问题。以川东宣汉盘龙洞长兴组典型台缘礁滩剖面为研究对象,通过对典型台缘礁滩野外剖面的精细观察,结合镜下薄片及岩矿资料分析,重点探讨了盘龙洞礁滩储层纵向非均质性特征及成因。剖面上礁滩体垂向上存在很强的旋回性和储层非均质性,其储集岩分布、储层厚度、白云岩化程度、溶蚀作用等受海平面周期性的升降变化影响而呈现周期性变化。礁滩储层非均质性受高能相带、海平面升降变化和建设性成岩作用的共同控制,高能相带控制储层原生孔隙的发育,决定了储层的沉积非均质性,白云岩化和溶蚀作用有利于礁滩体储层的形成,大气淡水淋滤改造对于优化储层具有关键作用,海平面升降变化决定了礁滩体旋回性发育,而建设性成岩作用的选择性改造深化了储层非均质性。 相似文献
470.
松桃大屋锰矿是贵州省地矿局103地质队于上世纪70年代勘查评价的中型锰矿床。锰矿产于南华系大塘坡组第一段黑色岩系底部,矿体呈层状、似层状产出,矿层走向北东约70°,矿体平均厚1. 42 m,平均品位18. 85%。矿区从北西向南东,含锰岩系、锰矿体从无到有。大屋锰矿床只保留了古天然气渗漏沉积成矿系统中的过渡相和边缘相,中心相应在齐公坡一带,但已被剥蚀殆尽。通过构造古地理恢复分析,推测南华纪大屋地堑盆地长大于14 km、宽约4 km,沿北东70°方向展布。预测盆地北东柳树塘、大坳至孟溪一带还具有发现中-大型规模锰矿床的潜力。 相似文献