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121.

Principal components analysis of fracture trace and sinkhole characteristics near 33 wells drawing water from the Ocala aquifer identified three hydrogeologically significant components. Multiple regression analysis using these components as independent variables showed that the flow of water to a well bore is influenced in order of importance by (1) proximity to a zone of high secondary permeability; (2) average aquifer transmissivity near the well; and (3) degree of cavity development in the closest zone of high secondary permeability.  相似文献   
122.
【目的】探索波吉卵囊藻胞外滤液对铜绿微囊藻的抑制机理。【方法】采用Illumina平台,对使用BG11培养基(对照组)和波吉卵囊藻胞外滤液(实验组)培养的铜绿微囊藻(Microcystis aeruginosa)进行转录组测序,筛选差异表达基因并进行通路富集分析,并对部分差异表达基因进行qRT-PCR验证。【结果】与对照组相比,波吉卵囊藻胞外滤液处理后的铜绿微囊藻组中筛选1483个表达差异显著的基因,其中上调表达基因788个,下调表达基因695个。GO功能分析将差异基因划分为35个子类别,包括催化活性、结合、代谢过程、细胞过程、膜、膜部分等。KEGG通路分析中,所有差异基因聚集在108个通路,其中84个差异基因注释在代谢功能类别中,而氧化磷酸化通路富集最显著。氧化磷酸化通路中,相关基因表达以上调为主(26个DEGs,20个上调,6个下调)。qRT-PCR验证结果与转录组测序结果的表达变化趋势一致。【结论】波吉卵囊藻滤液引起铜绿微囊藻氧化磷酸化途径上基因表达上调,ATP合成效率提高。  相似文献   
123.
The modal pushover analysis (MPA) procedure, presently restricted to one horizontal component of ground motion, is extended to three‐dimensional analysis of buildings—symmetric or unsymmetric in plan—subjected to two horizontal components of ground motion, simultaneously. Also presented is a variant of this method, called the practical modal pushover analysis (PMPA) procedure, which estimates seismic demands directly from the earthquake response (or design) spectrum. Its accuracy in estimating seismic demands for very tall buildings is evaluated, demonstrating that for nonlinear systems this procedure is almost as accurate as the response spectrum analysis procedure is for linear systems. Thus, for practical applications, the PMPA procedure offers an attractive alternative whereby seismic demands can be estimated directly from the (elastic) design spectrum, thus avoiding the complications of selecting and scaling ground motions for nonlinear response history analysis. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
124.
流体包裹体成分物理化学参数的NET2.0C#语言计算程序   总被引:1,自引:0,他引:1  
王真光  王莉娟 《矿床地质》2011,30(4):754-758
根据地球化学热力学原理,利用流体包裹体成分测试数据和有关热力学原理,在原有基础上采用NET2.0 C#语言进行修编,编制成目前切实可行的计算机处理程序——矿物包裹体成分、物理化学参数的计算程序.其目的是方便广大地质工作者将这些参数用于地质找矿和科学研究中.  相似文献   
125.
太平洋侧花海葵的营养成分分析   总被引:1,自引:0,他引:1  
本文测定了太平洋侧花海葵中的蛋白质、脂肪和无机元素等营养成分,分析了太平洋侧花海葵中构成蛋白质的17种常见氨基酸和主要脂肪酸含量。结果表明,太平洋侧花海葵是一种高蛋白、低脂肪的海产品;必需氨基酸和鲜味氨基酸的含量较高,但必需氨基酸之间的比值不太符合人体的氨基酸平衡,宜与其他食物搭配食用。各类脂肪酸中,油酸(18∶1)含量最高,其次为C22∶2。无机元素丰富,尤其是Zn,含量可达254.4 mg/kg。  相似文献   
126.
Wharf embankment and strengthening program at the Port of Oakland   总被引:1,自引:0,他引:1  
The wharf and embankment strengthening program (WESP) is a structural modification project involving approximately 12,000 linear feet of pile-supported, marginal wharf structures. WESP is necessary because the Port of Oakland plans to deepen its berths from −42′ mean lower low water (MLLW) to −52′ MLLW, in conjunction with a Federal Government-sponsored channel dredging project. Unless they are structurally reinforced prior to the dredging, the waterfront components (i.e. wharves and embankments) will be weakened by the berth deepening project. WESP is a three-phase program that establishes the existing structural and seismic capacities of waterfront components, develops designs for improvements necessary to maintain these capacities after the berth deepening, and constructs the improvements. WESP also includes consideration of seismic upgrade improvements. The Port is currently completing the first phase of the WESP program. This paper will describe the design criteria, project phasing, construction type of waterfront components, project organization, and results to date for WESP.  相似文献   
127.
The study of groundwater hydrogeochemistry of the Paleozoic Basses-Laurentides sedimentary rock aquifer system in Québec produced a large geochemical dataset. Groundwater samples were collected at 153 sites over a 1500 km2 study area and analyzed for major and minor ions. The large number of data can lead to difficulties in the integration, interpretation and representation of the results. Two multivariate statistical methods, hierarchical cluster analysis (HCA) and principal components analysis (PCA), were applied to a subgroup of the dataset to evaluate their usefulness to classify the groundwater samples, and to identify geochemical processes controlling groundwater geochemistry. This subgroup consisted of 144 samples and 14 parameters (Ca2+, Mg2+, Na+, K+, , Cl, , Fe2+, Mn2+, Br, Sr2+, F, Ba2+, HS). Seven geochemically distinct clusters, C1–C7, resulted from the HCA. Samples from clusters C3, C4, C6 and C7 are mostly located in preferential recharge areas. The majority of these samples have Ca–Mg–HCO3 recharge groundwater (C3, C6, C7) and Na–HCO3 evolved groundwater (C4). Samples from the other three clusters (C1, C2, C5) are characteristic of an aquifer system under confined conditions. The majority of these samples have Na–HCO3 evolved groundwater (C1, C5) and Na–Cl ancient groundwater that exhibits elevated concentrations in Br (C2). In addition to recognizing the importance of hydrogeological conditions on groundwater geochemistry, the distribution of clusters also showed the importance of the geological formations on minor and trace elements, such as Fe2+, Mn2+, Sr2+, F and Ba2+. The first five components of the PCA account for 78.3% of the total variance in the dataset. Component 1 is defined by highly positive loadings in Na+, Cl and Br and is related to groundwater mixing with Champlain Sea water and solute diffusion from the marine clay aquitard. The high positive loadings in Ca2+ and Mg2+ of component 2 suggest the importance of dissolution of carbonate rocks in this aquifer system. From their characteristic loadings, the first two components are defined as the “salinity” and “hardness” components, respectively. Components 3–5 are related to more local and geological effects. The integration of the HCA and the PCA, with conventional classification of groundwater types, as well as with the hydrogeological and geological contexts, allowed the division of the region into four main geochemical areas, providing an improved regional picture of the aquifer system dynamics and hydrogeochemical evolution of groundwater. The following factors were recognized as influencing the evolution of groundwater identified in every geochemical area: (1) geological characteristics including sedimentary rock type and till mineralogy; (2) hydrogeological characteristics represented by the level of confinement and the hydraulic gradient; and (3) the geological history including the latest glaciation and the Champlain Sea invasion. With its integrated approach, this hydrogeochemical study contributes to the characterization and understanding of complex groundwater flow systems, and provides an example of the long-term geochemical evolution of hydrogeological systems after a major perturbation, in this case seawater invasion.  相似文献   
128.
The thermal maturity and organofacies sensitivity of polycyclic aromatic compound (PAC) distributions was explored by examination of the aromatic fractions of solvent extracts from a diverse set of 53 shales, coals and kerogen macerals which have undergone either natural or artificial maturation and which represent all three principal sedimentary organic matter (OM) types. Systematic changes with maturation were observed in the following groups of isomers: tri- and tetramethylnaphthalenes, methyl- and dimethylphenanthrenes, methyl- and dimethyldibenzothiophenes, methylpyrenes, and methylchrysenes. The maturity differences were quantified by mathematical ratios of the relative concentrations of the more thermally stable isomers to the less stable, on the basis of theoretical considerations and empirical observations. The PAC maturity parameters, unlike those derived from saturated biomarker stereoisomers, are typically effective across the entire oil generation window. To compensate for the effects of OM type on the maturity parameters, they were combined using principal components analysis. The resulting first principal component was in good agreement with independent indicators of maturity. The relative distributions of C0–C3 alkylphenanthrenes, dibenzothiophene, methyldibenzothiophenes and methyldibenzofurans were evaluated by a separate principal components analysis. The results permitted an independent grouping of the samples by OM type and suggested additional, simple molecular ratios that allow graphical recognition of OM type, including the ratio of dibenzothiophenes to dibenzofurans and a ratio using C2-alkylphenanthrene isomers.  相似文献   
129.
附有条件的参数平差模型的有偏估计   总被引:1,自引:0,他引:1  
讨论附有条件的参数平差模型参数的有偏估计问题。提出了约束岭估计和约束主成分估计,并证明了它们的优良性质,最后给出了一个算例,验证了所得结果。  相似文献   
130.
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