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61.
分析了1997年11~12月在广东台山市三合镇附近发生的最大震级为41级小震群的活动特征、地质构造背景和震源机制解,并将其与1970年7~12月发生的最大震级为40级的台山震群进行了对比,计算了两次小震群的序列特征参数,结果表明,1997年震群具有前兆震群的某些特征。  相似文献   
62.
In this study, we determined the cytotoxicity and genotoxicity of carbamate insecticide carbaryl to flounder gill(FG) cells and its teratogenicity to zebrafish embryos. The cytotoxicity of carbaryl to FG cells was determined with methods including MTT and neutral red uptaking(NRU), lactate dehydrogenase(LDH) releasing and Hoechst 33342 and propidium idodide(PI) double staining. Moderate cytotoxicity in a concentration-dependent manner was observed. The 24 h-IC50 value of 53.48 ± 1.21, 59.13 ± 1.19 and 46.21 ± 1.24 mg L-1 carbaryl was obtained through MTT, NRU and LDH assays, respectively. Double fluorescence staining demonstrated that carbaryl induced the death of FG cells mainly through necrosis. There was no significant genotoxicity found in the FG cells exposed to the highest testing concentration of carbaryl(20 mg L-1, P 0.05) as was demonstrated by Comet assay. Zebrafish embryos exposed to carbaryl at concentrations ≥10 mg L-1 displayed moderate toxic effects on the survival, spontaneous movement, hatching, heart rates of the embryos and their development, which were evidenced by yolk and pericardial sac edemas, body length reduction and tail flexure in time- and concentration-dependent manners at specific stages. The 24 h-, 48 h- and 96 h-LC50 values of carbaryl to zebrafish embryos were 41.80 ± 1.10, 17.80 ± 1.04 and 14.46 ± 1.05 mg L-1, respectively. These results suggested that carbaryl is moderately toxic to FG cells cultured in vitro and zebrafish embryos, and the FG cells were similar to zebrafish embryos in their sensitivity to carbaryl as 24 h-IC50 and LC50 indicated.  相似文献   
63.
塔里木盆地晚寒武世台地沉积区发育大量的白云岩,其中蕴涵着大量白云岩储层。以柯坪地区肖尔布拉克剖面为例,首次提出了以地层单层厚度为划分依据划分层序地层的方法,结合岩石学分析结果,确定了肖尔布拉克剖面寒武系下丘里塔格组白云岩的层序地层四分方案,塔中地震资料表明该四分方案可能适用于塔里木盆地整个西部台地区。根据肖尔布拉克剖面下丘里塔格组白云岩的岩石学分析,埋藏岩溶作用产生的溶蚀空间为该白云岩段的主要储集空间,因此可将下丘里塔格组白云岩储层定义为"埋藏岩溶型白云岩储层",该储层发育位置与层序界面有密切关系,一般沿层序界面之下发育。根据上寒武统白云岩的层序地层四分方案,与层序地层对储层的控制作用,提出了塔里木盆地西部台地区上寒武统"埋藏岩溶型复式白云岩储层"概念,并给予了阐释。  相似文献   
64.
塔里木盆地寒武系发育层状硅质岩和硅化岩,层状硅质岩主要发育于塔东下寒武统深水沉积相区;硅化岩发育于塔东上寒武统斜坡沉积区与西部台地区寒武系白云岩中。根据显微结构特征,可将硅化岩分为放射状硅化岩与交代残余结构硅化岩两种。分析结果表明,层状硅质岩在Al—Fe-Mn三元图中位于正常海水沉积硅质岩区内,在微量元素平均地壳标准化图解上显示平缓右倾的特征;层状硅质岩Si同位素组成护。δ30Si为0.99‰~1.4‰,O同位素组成δ18O为21.4‰~24.4‰,与沉积型硅质岩相吻合,指示了正常海水沉积成因。硅化岩区别于层状硅质岩的典型特征是具有高U异常的特征;罗西斜坡放射状硅化岩具有较高的微量元素和稀土元素含量(∑REE为18.8~96.9μg/g)与较低的Si、O同位素值(δ18O和δ30Si值分别为15.8‰和1.7‰);西部台地区交代残余结构硅化岩具有较低微量元素和稀土元素含量(∑REE为0.58~2.61μg/g)与较高的δ30Si(1.0‰~3.8‰)、δ18O(21.6‰~27.0‰)值特征。盆地东西部硅化岩的地球化学差异可能与硅化流体的温度差异有关,罗西斜坡放射状硅化岩硅化温度相对更高;另一方面,硅化过程对h430SiO4选择性较高,因而形成的交代石英具有较高的铲勘值。根据古城4井硅化岩包裹体均一温度与交代石英的O同位素值计算得到交代流体的δ18O值为9.1‰,该值与酸性岩浆水的δ18O值相似,指示了硅化流体可能来自于岩浆或变质水;以δ18O值(9.1‰)作为西部台地区硅化流体的O同位素值,计算得到西部台地区硅化岩硅化流体温度为101.3~158.5℃。根据石英O同位素温度计计算的硅化流体温度呈东高西低的趋势,指示了硅化流体可能来自台地东部。  相似文献   
65.
The physics behind the spectral energy distribution (SED) of blazars remains open. We assembled 36 blazars to tackle the factors that control their SED. Now, many blazar spec- tra have the "double hump" feature in the radio and far-IR frequencies. For these a parameter, , is created to characterize the behavior of the SED. We found a significant correlation be- tween the broad-line luminosity (LBLR) and . Because LBLR is an indicator of the accreting power of the source in blazars, we derived a linear correlation, ∝ M˙1/3.18, which suggests that the SED of blazars may depend on the accretion rate, like that of BL Lac objects. We also found a significant correlation between ■ and for a sample of 11 blazars (out of one of 36) with available black hole masses. This implies the Eddington accretion ratio may influence the shape of the SED of blazars.  相似文献   
66.
There are many reports that cells (protoplasts) separated from the thallus of Porphyra by enzyme can develop to normal leafy thalli in the same way as monopores. But there are few investigations on the subcellular structure of the isolated vegetative cell for ccmparison with the subcellular structure of monospores. To clarify whether the separated and cultured cells undergo the same or similar ultrastructure changes during culture and germination as monospores undergo in their formation and germination, we observed their ultrastructure, ccxnpared them with those of the monospore and found that the ultrastructure of separated and cultured cells did not have the characteristic feature as that of monospore formarion, such as production of small and large fibrous vesicles, but was acccxnpanied by vacuolation andstarch mobilization like that in monospore germination. The paper also discusses the relations between monospores and separated and cultured cells.  相似文献   
67.
为了监视北京地区的地壳稳定性,北京测绘院对10多个基岩点和北京市区进行了多次沉降观测,结果表明香山点近10多年来高程变化只有几毫米,其重力效应可略而不计,但测点东北和东南方有两个较大的下沉区。用线积分法计算了两个局部沉降的重力效应,在沉降区中心其影响可达0.38μms^-2,但对香山点的重力效应非常小,完全可以忽略。因此得出如下结论:香山点观测到的重力变化不是地壳变形引起的。  相似文献   
68.
Lacustrine turbidite of Chang-7 Member in the studied area consists of sihstone and fine sandstone with respect to grain size, which is feldspathic lithie sandstone, syrosem arkose and arkose with respect to mineral constitution affected by provenance. There are such apparent signatures as lithology, sedimentary structure, sedimentary sequence and well logs, to recognize turbidite. During the paleogeographic evolution of Chang-7 Member, lake basin and deep lake are both at their maximum extent during Chang-73 stage, resulting in the deposition of Zhangjiatan shale with widespread extent and of turbidite with fragmental-like. Deep lake line is gradually moving toward lake center and turbidite sand bodies are gradually turning better with better lateral continuity, connectivity and more thickness, from stages of Chang-73, Chang-72 and Chang-7t, which can be favorable reservoir in deep-water.  相似文献   
69.
编辑部 《地质论评》2022,68(5):2003-2004
《地质论评》、《地质学报》是中国地质学会主办的地质科学学术刊物。《地质论评》主要登载各种探讨、争鸣、评述类论文和新技术、新方法论文。《地质学报》反映地质科学各分支学科及边缘学科中最新、最高水平的基础理论研究和基本地质问题研究成果。《地质学报》(中文版)和《地质学报》(英文版)分别独立刊载论文。自2001年起,《地质学报》(中文版)和《地质论评》均改版为大16开(210 mm×297 mm)。《地质论评》和《地质学报(英文版)》为双月刊;2006年起,《地质学报》(中文版)改为月刊。《地质论评》2014年起每期页码增加至236页; 2016年起每期页码为256页。  相似文献   
70.
The optical observations of the type Ic supernova(SN Ic) SN 2012 ap in NGC 1729 are presented. A comparison with other SNe Ic indicates that SN 2012 ap is highly reddened(with E(B- V)host~0.8 mag) and may represent one of the most luminous SNe Ic ever observed, with an absolute V-band peak magnitude of ~-19.3±0.5 mag after extinction correction. The near-maximum-light spectrum shows wide spectral features that are typical of broad-lined SNe Ic. One interesting feature in the spectrum is the appearance of some narrow absorption features that can be attributed to the diffuse interstellar bands, consistent with the large reddening inferred from the photometric method. Based on the light curves and the spectral data, we estimate that SN 2012 ap produced a56 Ni mass of ~ 0.3 ± 0.1M in the explosion, with an ejecta mass of 2.4+0.7-0.7M and a kinetic energy of E5K= 1.1+0.4-0.4× 102 erg. The properties of its progenitor are also briefly discussed.  相似文献   
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