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81.
对青蛤(Cyclina sinensis)转录组文库筛选并克隆得到青蛤TRAF6(Cs TRAF6)基因的c DNA序列,其开放阅读框为2337bp,编码778个氨基酸,分子量为86.59k Da。Cs TRAF6蛋白包含RING型锌指结构,两个TRAF型锌指结构,coiled-coil结构域以及MATH结构域。经生物信息学及分子系统学分析表明Cs TRAF6属于TRAF6家族的一员。利用实时荧光定量PCR方法检测了Cs TRAF6基因在青蛤各个组织以及在Poly I:C侵染下在血淋巴中的时序性表达情况。结果表明,Cs TRAF6基因在青蛤血淋巴、闭壳肌、鳃、性腺、外套膜和肝脏中普遍表达,其中在血淋巴中的表达水平最高。在Poly I:C刺激后的3h,青蛤血淋巴中Cs TRAF6的表达量迅速升高,在6h达到最大值,说明青蛤的Cs TRAF6基因参与了病毒类似物侵染下的免疫应答反应。  相似文献   
82.
针对岩石颗粒边缘模糊、结构复杂的特点,为了更有效地识别颗粒边缘,在基于特征值的C3相干算法的基础上,融合多尺度和多角度的特征表达,提出了一种改进的C3相干算法。该算法综合考虑岩石薄片图像角度域光学特征、空间尺度信息和各向异性信息,能更有效地表征颗粒边缘特征,表现出对复杂矿物结构的适应能力。在采集的岩石薄片正交偏光图像上验证提出的算法,实验结果表明,与原生C3相干算法相比,改进后的C3相干算法在全局图像上的方差和灰度差分乘积分别提升了68.41%和22.91%,信息熵下降了21.61%。  相似文献   
83.
Machine learning algorithms are an important measure with which to perform landslide susceptibility assessments,but most studies use GIS-based classification methods to conduct susceptibility zonation.This study presents a machine learning approach based on the C5.0 decision tree(DT)model and the K-means cluster algorithm to produce a regional landslide susceptibility map.Yanchang County,a typical landslide-prone area located in northwestern China,was taken as the area of interest to introduce the proposed application procedure.A landslide inventory containing 82 landslides was prepared and subse-quently randomly partitioned into two subsets:training data(70%landslide pixels)and validation data(30%landslide pixels).Fourteen landslide influencing factors were considered in the input dataset and were used to calculate the landslide occurrence probability based on the C5.0 decision tree model.Susceptibility zonation was implemented according to the cut-off values calculated by the K-means clus-ter algorithm.The validation results of the model performance analysis showed that the AUC(area under the receiver operating characteristic(ROC)curve)of the proposed model was the highest,reaching 0.88,compared with traditional models(support vector machine(SVM)=0.85,Bayesian network(BN)=0.81,frequency ratio(FR)=0.75,weight of evidence(WOE)=0.76).The landslide frequency ratio and fre-quency density of the high susceptibility zones were 6.76/km2 and 0.88/km2,respectively,which were much higher than those of the low susceptibility zones.The top 20%interval of landslide occurrence probability contained 89%of the historical landslides but only accounted for 10.3%of the total area.Our results indicate that the distribution of high susceptibility zones was more focused without contain-ing more"stable"pixels.Therefore,the obtained susceptibility map is suitable for application to landslide risk management practices.  相似文献   
84.
The Powder River Basin (PRB) of Wyoming and Montana contains significant coal and coal bed natural gas (CBNG) resources. CBNG extraction requires the production of large volumes of water, much of which is discharged into existing drainages. Compared to surface waters, the CBNG produced water is high in sodium relative to calcium and magnesium, elevating the sodium adsorption ratio (SAR). To mitigate the possible impact this produced water may have on the quality of surface water used for irrigation, the State of Montana passed water anti‐degradation legislation, which could affect CBNG production in Wyoming. In this study, we sought to determine the proportion of CBNG produced water discharged to tributaries that reaches the Powder River by implementing a four end‐member mixing model within a Bayesian statistical framework. The model accounts for the 87Sr/86Sr, δ13CDIC, [Sr] and [DIC] of CBNG produced water and surface water interacting with the three primary lithologies exposed in the PRB. The model estimates the relative contribution of the end members to the river water, while incorporating uncertainty associated with measurement and process error. Model results confirm that both of the tributaries associated with high CBNG activity are mostly composed of CBNG produced water (70–100%). The model indicates that up to 50% of the Powder River is composed of CBNG produced water downstream from the CBNG tributaries, decreasing with distance by dilution from non‐CBNG impacted tributaries from the point sources to ~10–20% at the Montana border. This amount of CBNG produced water does not significantly affect the SAR or electrical conductivity of the Powder River in Montana. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
85.
变差函数的研究在地质统计学中具有十分重要作用,本文运用界面图形图像处理强的C ̄(++)语言实现了界面友好汉化人机对话变差函数的拟合,主要包括管理菜单的生成,实验变差值的求解,变差图的图形显示,标准函数模型的计算及变差函数人机对话求解等部分。最后对比一下回归分析与人机对话拟合结果。  相似文献   
86.
Chevkinite specimen from a rare-earth mineral deposit in Sichuan,southwest ofChina have been studied in detail by means of transmission electron microscope(TEM).The selected area electron diffraction(SAED)and convergent beam electron diffraction(CBED)patterns,obtained from different crystal zone axis direction,proved coineidently that the space group of chevkinite is C2/m.Fringe lattice image obser-vation showed the mineral crystal is structurally uniform in microscale,and it is anideal specimen for electron diffraction analysis.The mineral studied here is similar to theone from Bayan Obo,Inner Mongolia,China,in chemical composition and REE distri-bution.The chemical formula of the crystal is(Ce,La,…,Ca)_4 Fe~2-(Fe,Ti,Nb)_2O_8 (Si_2O_7)_2 .From our study,we come to the conclusion that the space group of the natu-ral chevkinite is C2/m,instead of P2_1/a as synthetic one.Up to now,chevkinitecompositionally similar to the synthetic one,in which the complete replacements of Ce,La by Nd and Fe by Mg or Co o  相似文献   
87.
通过对独山子地区荒漠土碳酸盐淀积层的 ̄14C年龄测定,探讨了碳酸盐淀积层碳的来源及其 ̄14C年龄的可靠性问题。提出了根据碳酸盐淀积层的无机碳年龄,对确定土壤的年龄是有意义的  相似文献   
88.
Immature Torbanite and the resistant biopolymer (PRB A) isolated from extant B. braunii were previously compared using bulk spectroscopic methods. In the present work, analysis of 400°C pyrolysis products and pyrolysis residues provided further information on their structure and possible relationships. It appears that such polymers are based upon unbranched, saturated, cross-linked hydrocarbon chains up to C31. In addition to these bridging structures, a substantial part of the alkyl chains is singly bound, as esters of unbranched, saturated or cis unsaturated, even fatty acids. These esters are sterically protected, against chemical degradations, by the network of the bioand geopolymer.Quantitative and qualitative observations derived from 400°C pyrolysis confirm that the chemical structure of PRB A and immature Torbanite are closely related. The pyrolysis residues show a similar evolution and numerous common features are noted, with respect to the nature and the distribution of the major constituents of the pyrolysates (hydrocarbons and fatty acids). Accordingly, Botryococcus provides what seems to be the first example of a close structural relationship between a biopolymer produced in large amounts by an extant alga and the geopolymer of an immature kerogen. The essential role of PRB A in Torbanite formation is ascertained. Moreover, it is found that the resistant biopolymer does not undergo important structural changes during the first stages of diagenesis. Thus, owing to steric protection, the esters of immature Torbanite show a distribution quite close to the one of PRB A esters, with exclusively even constituents and a large contribution of unsaturated acids.Recent observations pointed to the possible genesis of some algal kerogens principally by selective preservation of resistant macromolecules. Such a type of formation is clearly predominant in Torbanite, where the bulk of the fossil organic matter corresponds to a selectively preserved and weakly altered, resistant biopolymer, while incorporation of lipids into the kerogen structure during diagenesis seems to play a minor role.  相似文献   
89.
成层介质中交流电测井响应   总被引:27,自引:10,他引:27       下载免费PDF全文
本文给出了纵向成层、径向不均匀介质中轴对称电磁波的反射阵和透射阵的递推公式.用这些阵可以计算交流电测并响应,包括感应测并和深探测电磁波传播测井(DPT).同时还给出了幅度基函数和斜度基函数,它们分别"支撑"起结点上函数的幅度和斜度.  相似文献   
90.
中国西北C-3植物的碳同位素组成与年降雨量关系初探   总被引:2,自引:0,他引:2  
 本文对不同年降雨量环境下生长的藜、独行菜、魁蓟和平车前这4种常见C-3植物的δ13C进行了分析,发现这4种C-3植物的δ13C组成都表现出随年降雨量减少而变重的趋势,其中藜和独行菜的碳同位素组成对降水变化的响应相对要较其它2种植物强烈得多。藜、独行菜和魁蓟的δ13C组成与年降雨量有显著的线性关系,平车前碳同位素组成与年降雨量没有显著的相关性,表明藜、独行菜和魁蓟的δ13C组成可作为年降雨量的替代性指标,平车前的δ13C组成不能作为年降水的替代性指标。  相似文献   
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