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991.
In this study, we detail procedures to synthesise inclusions of fluids of known composition under diagenetic conditions – low temperatures (50–180 °C) and pressures (2–25 MPa) – hosted by quartz. Pre‐existing microcavities in polished quartz chips were used, decrepitated and rinsed before being healed in an autoclave. Each synthesis required around 4 weeks. A range of biphase liquid–vapour inclusions in the H2O–CH4–NaCl system, similar to natural ones, were synthesised in quartz, varying the content of all three components. The quartz chips were checked before and after synthesis by optical microscopy, microthermometry and Raman spectroscopy. The method was used to build a series of calibration curves relating methane‐to‐water count ratios to the methane content of aqueous fluid inclusions. Good correlation was obtained between Raman band area ratios and the expected CH4 solubilities from equations of state. The chosen procedure's main advantages, compared with other published methods, are as follows: quicker healing of the microfractures at lower temperatures, larger inclusions, simple quartz sample preparation, control of fluid inclusion composition and the use of commercial reactors. Such reference material inclusions allow the calibration of Raman microspectrometers with the objective of PTX reconstruction of palaeofluid migration in petroleum reservoirs.  相似文献   
992.
苏里格大气田多成因河道砂体的分布模式研究   总被引:1,自引:0,他引:1  
以鄂尔多斯盆地苏里格大气田二叠系下石盒子组盒8段河道砂体为研究对象,开展盒8段河道砂体成因类型及分布模式的研究。详细的岩心观察和相标志研究表明,盒8下段为辫状河砂体,盒8上段为曲流河砂体,局部发育网状河砂体。岩性、岩相与砂体的含气性的关系密切,含气砂体与砂岩中的粗岩相单元有良好的对应关系,粗岩相主要发育在高能辫状水道、心滩及曲流河下部边滩内。河道砂体分布模式研究表明,盒8下段发育高能辫状河砂体与低能辫状河砂体模式,盒8上段具有北部网状河、南部曲流河的分布模式。  相似文献   
993.
1980年以来,中国对南极的气象观测和研究已取得了显著进展.1985年2月在乔治王岛建立了南极长城气象站,国际站号为89058,此后一直进行天气观测,并向世界天气监视网发出报告.近年来,根据观测资料并结合南极和南半球其他资料,开展了极区气旋、影晌南极半岛的天气系统、大气化学、高层大气、辐射特点、南极海冰状态与气候变化关系等项目研究.这些研究对了解南极当地气候的形成、发展和变化及其对全球气候的影响提供了重要资料.  相似文献   
994.
Autumn living coccolithophores in the Yellow Sea and the East China Sea   总被引:1,自引:0,他引:1  
An investigation was carried out on living coccolithophores(LCs) distribution in the Yellow Sea and the East China Sea from October 17 to November 24, 2011. A total of 223 samples from different depths were collected at 48 stations. Totally 18 taxa belonging to coccolithophyceae were identified using a polarized microscope at the 1 000× magnification. The maximum species abundance was found at the outside of Transect P. The dominated species were Gephyrocapsa oceanica, Emiliania huxleyi, Helicosphaera carteri, and Algirosphaera robusta. The abundance of coccoliths and cells ranged 0–2 965.73 coccoliths/mL, and 0–119.16 cells/mL, with the average values of 471.00 coccoliths/mL and 23.42 cells/mL, respectively. The LCs in surface layer were mainly observed on the coastal belt and middle part of the survey area. The comparison among Transects A, F, P and E indicated lower species diversity and less abundance in the Yellow Sea than those of the East China Sea. The highest abundance of LCs was found in transect F and P. The coccolith abundance increased slightly from surface to bottom in the water column, but the highest value of the cell abundance was observed in the depth of 10–30 m. Temperature, depth and nutrient concentration were suggested as the major environmental factors controlling the distribution and species composition of LCs in the studying area based on canonical correspondence analysis(CCA).  相似文献   
995.
资源三号影像质量评价及海岸带地物识别能力分析   总被引:1,自引:0,他引:1       下载免费PDF全文
为了检验资源三号(ZY-3)影像质量,利用印度的IRS P5和德国的RapidEye影像,采用主观和客观评价相结合的评价方法,对ZY-3传感器校正产品进行了质量评价。主观评价结果表明,ZY-3影像表观质量优于IRS P5和RapidEye影像,地物的纹理、边界更加清晰,影像所反映的细节信息更加丰富,在海岸带地物识别方面表现更好。在客观评价方面:ZY-3全色影像灰度动态范围和信息熵等指标均优于IRS P5影像;ZY-3多光谱影像的灰度范围和信息熵等指标与RapidEye影像相比稍差,但各波段之间的独立性要优于RapidEye影像。总的来说,ZY-3影像成像质量较高,海岸带地物识别能力强,在海岸带遥感研究与应用领域具有巨大潜力。  相似文献   
996.
天气学的发展概要——关于锋面气旋学说的四个阶段   总被引:1,自引:1,他引:0  
参照流体力学发展的4个阶段,以锋面气旋模型为例将天气学也分为:"古代"、经典、近代和现代4个发展阶段。"古代"天气学的代表是1863年航海家Fitz-Roy绘制的第一个风暴概念模型,它是对实践经验的总结,但不失其科学性;100年前挪威气象学派锋面气旋模型是基于牛顿力学的经典天气学代表,确立了斜压性是天气变化机理的核心,但将锋面视为物质面是其有悖流体连续性原则的重大缺陷;50年前芝加哥学派的锋面气旋三维模型是基于对准地转动力学理论深刻物理洞察力的近代天气学代表;20世纪末暖锋后弯卷入爆发性气旋模型是高科技时代基于大规模数值计算的现代天气学代表。在大数据时代,现代天气学需要学习和继承近代天气学用深刻的物理洞察力来分析天气学问题。  相似文献   
997.
The growth, biochemical content and bioaccumulation quantity of 2,2’,4,4’-tetrabromodiphenyl ether (BDE-47) in Skeletonema costatum were studied under different N:P ratios (1, 4, 16, 64 and 128). All cellular biochemical contents of S. costatum presented decreasing trend over cultivation time. At early stage of cultivation, the cellular protein, carbohydrate and lipid in S. co-statum presented higher values in treatments of N:P=4 and 16. However, they were lower in these treatments at the late stage, but higher in treatments N:P=1 and 128. Similarly, BDE-47 levels per cell of S. costatum were higher in treatments of N:P=4 and 16 at early stage of cultivation, which were 3.8 and 3.7 ng (106 cells)-1, respectively. At the middle stage of cultivation, the BDE-47 level per S. costatum cell lowered;and it further reduced in the treatments of N:P=4 and 16 at the late stage with the values 0.6 and 0.5 ng (106 cells)-1, respectively. However, it rose in N:P=128, reaching up to 2.3 ng (106 cells)-1. Compared with BDE-47 per cell, BDE-47 per algal volume under different N:P ratios did not present obvious difference. The quantity BDE-47 accumulated per cell of S. co-statum was positively correlated with protein, carbohydrate and lipid per cell; meanwhile, the BDE-47 per volume had a positive correlation with biochemical content per volume. The variation of bioaccumulation ability of BDE-47 in S. costatum can be ex-plained by biochemical changes due to N:P ratios.  相似文献   
998.
本研究预测naa cluster中的naaB基因负责催化烟酸到6-羟基烟酸的反应。通过对NaaB的蛋白序列进行分析,发现该酶含有三个亚基,分别由naaBL1、naaBS、naaBL2基因编码,其中naaBL1和naaBL2分别编码2个含有钼辅因子结合结构的大亚基,naaBS基因编码一个含有[2Fe-2S]簇的小亚基。本研究对naaB基因进行了克隆,将构建的重组质粒pME6032-naaBL1SL2分别转化到无色杆菌(Achromobacter sp.)和大肠杆菌(Escherichia coli)中,通过HPLC和LC-MS检测验证了NaaB负责催化烟酸到6-羟基烟酸,并且在无色杆菌和大肠杆菌中NaaB均能够转化烟酸,这与之前报道烟酸羟化酶不能在大肠杆菌表达的结果不同,说明NaaB的基因编码和催化功能具有独特性。通过序列分析推测NaaB的这一特性可能跟该酶同时含有两个钼结合结构域的大亚基有关。  相似文献   
999.
Determining the foliar N:P ratio provides a tool for understanding nutrient limitation on plant production and consequently for the feeding patterns of herbivores. In order to understand the nutrient limitation at landscape scale, remote sensing techniques offer that opportunity. The objective of this study is to investigate the utility of field spectroscopy and a potential of hyperspectral mapper (HyMap) spectra to estimate foliar N:P ratio. Field spectral measurements were undertaken, and grass samples were collected for foliar N and P extraction. The foliar N:P ratio prediction models were developed using partial least square regression (PLSR) with original spectra and transformed spectra for field and the resampled field spectra to HyMap. Spectral transformations included the continuum removal (CR), water removal (WR), first difference derivative (FD) and log transformation (Log(1/R)). The results showed that CR and WR spectra in combination with PLSR predicted foliar N:P ratio with higher accuracy as compared to FD and R, using field spectra. For HyMap spectral analysis, addition to CR and WR, FD achieved higher estimation accuracy. The performance of FD, CR and WR spectra were attributed to their ability to minimize sensor and water effects on the fresh leaf spectra, respectively. The study demonstrated a potential to predict foliar N:P ratio using field and HyMap simulated spectra and shortwave infrared (SWIR) found to be highly sensitive to foliar N:P ratio. The study recommends the prediction of foliar N:P ratio at landscape level using airborne hyperspectral data and could be used by the resource managers, park managers, farmers and ecologists to understand the feeding patterns, resource selection and distribution of herbivores (i.e. wild and livestock).  相似文献   
1000.
An Oracle8i-based approach is proposed to manage the integrated databases of large CyberCity. This approach consists of three schemes: ? a special R+-tree index is designed to accelerate spatial retrieving, in which the bounding boxes of local regions have no intersection and all leaf nodes of the R+-tree (geometry records) have no repetition; ∪ different data compression algorithms are adopted to compress the digital elevation models, 3D vector models and images, such as LZ77 lossless compression algorithm for compression of vector data and JPEG compression algorithms for texture images; ? in order to communicate with Oracle8i database, a CyberCity GIS spatial database engine (SDE) is designed. On the basis of this SDE prototype a case study is done.  相似文献   
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