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11.
Based on analyses of the components of crude oil hydrocarbons and carbon isotopes, the content of normal alkane de-creased from 49.00% to 20.10% when moving from the No.3 to No.5 tectonic belt of the Lenghu area of the Qaidam Basin, while cycloalkanes increased from 30.00% to 52.20% and aromatic and branch chain alkanes increased gradually as well. The maturity of sterane in crude oil is higher than that of its source-rock, which shows that the hydrocarbons were generated from a deep source-rock of high maturity around the tectonic belts of the Lenghu area. The analysis of the characteristics of carbon isotopes also shows that these isotopes of hydrocarbon compounds in the No.4 and No.5 tectonic belt are apparently heavier than those in the No.3 belt. The results of our research show that the hydrocarbons in the No.3 tectonic belt are mainly from a relatively rich sapropelic substance, while the hydrocarbons in the No.4 and No.5 tectonic belt originated mainly from organic matter of a rela-tively rich humic type substance.  相似文献   
12.
An aerial distance sampling survey of double-crested cormorants (Phalacrocorax auritus) was conducted in the northern region of Lake Huron (North Channel; four largest lakes of Manitoulin Island; South Shore of Manitoulin Is. facing the main body of the lake) to assess the relative distribution, abundance and prey demand by cormorants on inland lake vs. coastal habitat. On a per area basis, the density (approx. 1-2 cormorants ? km− 2) and prey demand (approx. 1.2 kg ha− 1) of cormorants in the four inland lakes matched that of the North Channel. The South Shore had approximately half the density and prey demand as the other two areas. Cormorants on the inland lakes of Manitoulin Island represented 13% early in the season and a high of 33% of the total population for this region of Lake Huron later in the summer. Estimating regional distributions of cormorants within the Great Lakes basin is important because mapped nest colonies and nest counts are not representative of the actual distribution of foraging cormorants during and after the nesting season. There are two general conclusions to emerge from this survey. First, aquatic productivity from both Great Lakes coast and inland lakes contributes to trends in population and distribution of cormorants in the northern region of Lake Huron and perhaps elsewhere. Second, inland aquatic ecosystems are important throughout a season for foraging cormorants from the Great Lakes and may become more important as Great Lake productivity trends downward.  相似文献   
13.
This paper presents a new technique for mapping regional salt sources that has major implications for salinity management in southeastern Australia. This was achieved by analyzing a regional mosaic of airborne gamma-ray emission derivatives and verified by existing airborne electromagnetic and drilling data. A significant correlation was found between aeolian (windblown) materials, upland salts and gamma-ray signatures. This is consistent with the conceptual model that much of the salt in the upland areas of the Murray-Darling Basin is sourced from deposited aeolian materials that have been derived from deflationary events in salt-bearing landscapes in the western arid part of the basin. From gamma-ray emissions, and based on an observed relationship with borehole salinity, concentrated aeolian salt source deposits contained about 0.7% potassium and 10 ppm thorium. Using this signature on normalized data, an Euclidean distance algorithm provided mapping and information relating to salt-mobility pathways over a wide region. The resulting gamma-ray salt source model (GSM) facilitates focussed management of salinity infiltration zones in catchments across the basin.  相似文献   
14.
太湖流域水灾害应急对策研究   总被引:1,自引:0,他引:1  
吴浩云  金科 《中国水利》2012,(13):40-43
太湖流域是我国经济社会高度发达的地区之一,发生水灾害时往往会造成重大经济损失。对发生各类水灾害时的应急对策展开研究总结,以减轻水灾害,避免人员伤亡,保障经济社会可持续健康稳定发展,并通过分析典型案例的实际应对过程,为今后开展类似工作提供参考。  相似文献   
15.
根据岩心、测录井、地震以及分析化验资料,运用沉积学原理和方法,对西丁家地区沙河子组—营城组时期沉积相和沉积体系进行综合研究。研究表明该区域在早白垩世主要发育湖泊、辫状河三角洲相等四大类沉积相及其亚相和微相。结合研究区"西断东超"型箕状断陷的构造演化特征,在沉积相认识的基础上组合出两大类沉积体系:从沙河子组沉积期至营城组沉积期,北部斜坡带由扇三角洲—水下扇沉积体系演化为辫状河三角洲—湖泊沉积体系;西部断阶带主要发育扇三角洲—水下扇沉积体系。  相似文献   
16.
在环鄱阳湖区域实施污染净化型农业的产业化是控制湖区面源污染,实现经济转型的重要策略。本文论述了污染净化型农业特点及其在鄱阳湖实施产业化的有利条件,提出了适合鄱阳湖区域特色的污染净化型农业产业化模式。  相似文献   
17.
Stress and anxiety are common phenomena that contribute to many nervous system dysfunctions. More and more research has been focusing on the importance of the gut–brain axis in the course and treatment of many diseases, including nervous system disorders. This review aims to present current knowledge on the influence of psychobiotics on the gut–brain axis based on selected diseases, i.e., Alzheimer’s disease, Parkinson’s disease, depression, and autism spectrum disorders. Analyses of the available research results have shown that selected probiotic bacteria affect the gut–brain axis in healthy people and people with selected diseases. Furthermore, supplementation with probiotic bacteria can decrease depressive symptoms. There is no doubt that proper supplementation improves the well-being of patients. Therefore, it can be concluded that the intestinal microbiota play a relevant role in disorders of the nervous system. The microbiota–gut–brain axis may represent a new target in the prevention and treatment of neuropsychiatric disorders. However, this topic needs more research. Such research could help find effective treatments via the modulation of the intestinal microbiome.  相似文献   
18.
渤海湾盆地喜马拉雅运动幕次划分及演化特征   总被引:2,自引:0,他引:2  
从构造运动的一致性入手,运用构造运动与沉积环境、火山喷发之间的关系,综合各油田对所在坳陷或凹陷的认识,提出渤海湾盆地喜马拉雅运动划分为侯镇幕、济阳幕、东营幕、渤海幕的新观点.指出其在四大沉积期内存在孔二段、沙河街组四-三段、沙河街组一段-东营组三套烃源岩,相比而言沙河街组四-三段的烃源岩分布范围大生烃能力强,整体上具有沉降中心由南向北和由西向东迁移的沉积演化特征.  相似文献   
19.
刚果盆地钾盐矿床沉积特征及成因探讨   总被引:2,自引:0,他引:2  
刚果盆地是低纬度重要的成盐盆地,主要由白垩系、新近系和第四系组成。含盐地层赋存于白垩纪地层中部,其下伏陆相碎屑岩沉积,上覆海相碎屑—碳酸盐岩沉积。盐层包括5种沉积层序,盐类矿物析出顺序是:硬石膏—石盐—光卤石—水氯镁石—溢晶石。研究区钾盐矿和石盐矿共生,钾盐矿层有20层,累计平均厚度259.61m,KCl品位大于15%。矿石类型主要为光卤石型,次为钾石盐型。矿石为滨海—泻湖相沉积蒸发岩,其沉积与大西洋裂谷的演化发展密切相关,是白垩纪裂谷发育期间,由初始浓缩沉积的富含卤化物海水运移至次级盆地进一步蒸发沉积形成。  相似文献   
20.
Major depressive disorder (MDD) is characterized by a high risk of recurrence, especially among individuals whose initial episode occurs during adolescence. Identifying predictors of recurrence of MDD among young samples is therefore of paramount clinical importance. Survival analytic models were used to evaluate the effects of dysfunctional cognitions and Axis II personality pathology on MDD recurrence in a sample of 130 previously, but not currently, depressed young adults. Participants were initially assessed for depression, dysfunctional attitudes, and personality pathology during their first semester in college and then reevaluated via the Longitudinal Interval Follow-up Evaluation interview every 6 months for 18 months. Baseline level of depressive symptoms significantly (HR-1.07, p = .002) predicted recurrence of MDD. In the survival analyses with baseline level of depression serving as a current mood state covariate, overall personality pathology (HR-1.04, p DSM–IV personality disorder cluster scores uniquely predicted recurrence. We discussed the theoretical, empirical, and clinical implications of these findings, and we noted the limitations of the study. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
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