海底表层土导热系数变化规律的试验研究

基于热探针法原理,测试了在杭州湾以东陆架区取得的28个海底表层柱状样0.2、1.0和1.8 m处的导热系数,结合激光粒度分析结果,比较了研究区6种土导热系数的大小,发现含砂量大于10%的粗粒土拥有较大的导热系数。土质类型相同时,含水量和干密度对其导热系数影响显著。杭州湾沉积区、混合沉积区,陆架砂质沉积区表层土导热系数的平均值分别是:1.25、1.45 和1.46 W·m^-1·K^-1,呈现出由近岸向外海增大的趋势。而土样导热系数在垂向的变化表明:水深、埋深等空间分布因素对海洋土的热物性没有直接影响。     

New equation to decipher the relationship between carbon isotopic composition of methane and maturity of gas source rocks

The identification of the origin and source of natural gas is always a difficult and hot issue.Hereinto,the maturity identification is one of the most important scientific problems.Many empirical equations have been established to decipher the relationship between the maturity of gas source rocks and the carbon isotopic composition of natural gas.However,these equations proposed often fail to identify the maturity of the source rocks correctly,which in turn prevents the identification of genetic types and source rocks of the natural gas because the petroliferous sedimentary basins in China are complex and diverse,with multiple sets of source rocks and different thermal history.In this paper,the oil-associated gas from the Permian lacustrine source rocks and the coal-derived gas from the Jurassic source rocks in Junggar and Turpan-Hami basins have been investigated to decipher the relationship between the maturity(vitrinite reflectance)of gas source rocks and the carbon isotopic composition of methane.The equations established areδ¹³C₁=25lgR_o-42.5 for oil-associated gas,andδ¹³C₁=25lgR_o-37.5 for coal-derived gas.These new equations are suitable for the maturity identification of source rocks in most petroliferous basins,and favorable for the identification of the genetic type and source of natural gas,which is very important to improve the geological theory of natural gas.     

河西走廊地质历史中宋辽干冷期灾变事件及其影响

宋辽寒冷干旱期的急剧降温,使河西地区降水量迅速减少,气候变得更为干旱。植被枯萎,风暴、沙暴、尘暴、火灾、旱灾、饥荒等灾害事件频繁发生,从而引发了一系列生态环境问题和战争动乱,对中国政治、社会、经济、文化产生重大影响。依据历史资料和考古研究成果及地质记录中“事件标志层”层位、年代,确定宋辽寒冷干旱期发生于公元1000~1050年,发展于公元1050~1100年,强盛于公元1100~1320年,消亡于公元1320~1335年。     

遥感技术在黑竹沟风景旅游资源调查分类与评价中的应用

随着信息技术的发展,遥感成为了旅游资源调查评价的新手段。阐述了运用遥感新技术对四川省乐山市黑竹沟风景旅游区旅游资源进行调查的过程,并结合现场调研和相关资料对其旅游资源进行了分类和评价。首先对黑竹沟风景旅游区2003年的ETM影像数据遥感图像进行了处理,然后建立了解译标志进行旅游资源信息的提取和分析,最后对黑竹沟风景旅游区的旅游资源进行了客观全面的分类和评价。黑竹沟的旅游资源可分为2大类、7亚类、21个基本类型,是一处景源内容丰富、景象多变的旅游区,发展潜力巨大。     

基于双隐层ANN模型的叶绿素a浓度智能预报方法

利用2019年5月WZ02生态浮标监测数据,建立了两种不同隐层人工神经网络(ANN)模型的叶绿素a(Chl-a)智能预报方法,并对单隐层和双隐层模型的预测结果做了对比.结果表明:双隐层结构预测结果精度更高,泛化能力更强,一定程度上说明了深层学习比浅层学习对信息的主要特征提取能力更有优势.同时,对数据样本集合进行了系统预...     

多种降阻材料搭配在变电站接地网改造中应用

在北海市三塘110KV变电站接地网系统改造工程实践中,通过不等长接地体技术及多种将阻材料搭配使用,克服了原接地网接地电阻值增大因素,并对变电站接地网改造和施工工艺进行设计。     

Impacts of native vegetation on the hydraulic properties of the concentrated flows in bank gullies

To quantify the impacts of native vegetation on the spatial and temporal variations in hydraulic properties of bank gully concentrated flows, a series of in situ flume experiments in the bank gully were performed at the Yuanmou Gully Erosion and Collapse Experimental Station in the dry-hot valley region of the Jinsha River, Southwest China. This experiment involved upstream catchment areas withone-and two-year native grass(Heteropogon contortus) and bare land drained to bare gully headcuts, i.e., Gullies 1, 2 and 3. In Gully 4, Heteropogon contortus and Agave sisalana were planted in the upstream catchment area and gully bed, respectively. Among these experiments, the sediment concentration in runoff in Gully 3 was the highest and that in Gully 2 was the lowest, clearly indicating that the sediment concentration in runoff obviously decreased and the deposition of sediment obviously increased as the vegetation cover increased. The concentrated flows were turbulent in response to the flow discharge. The concentrated flows in the gully zones with native grass and bare land were sub-and supercritical, respectively. The flow rate and shear stress in Gully 3 upstream catchment area were highest among the four upstream catchment areas, while the flow rate and shear stress in the gully bed of Gully 4 were lowest among the four gully beds, indicating that native grass notably decreased the bank gully flow rate and shear stress. The Darcy–Weisbach friction factor(resistance f) and flow energy consumption in the gully bed of Gully 4 were notably higher than those in the other three gully beds, clearly indicating that native grass increased the bank gully surface resistance and flow energy consumption. The Reynolds number(Re), flow rate, shear stress, resistance f, and flow energy consumption in the gully beds and upstream areas increased over time, while the sediment concentration in runoff and Froude number(Fr) decreased. Overall, increasing vegetation cover in upstream catchment areas and downstream gully beds of the bank gully is essential for gully erosion mitigation.     

微波照射下火成岩升温特性和升温预测模型研究

微波辅助破岩可有效降低刀具磨损,提高破岩效率,具有广阔的发展前景.文章选取了10种火成岩进行微波加热试验,发现岩石的升温速率主要与岩石所含矿物的种类、含量,及岩石中的Fe元素含量有关.岩石所含矿物越敏感、含量越多,岩石中的Fe元素含量越大时,其升温速率越高.整体而言,火成岩中基性岩的升温速率最高、中性岩次之、酸性岩最低...     

国家统一的地理学解释——以东西德统一为例

国家的统一问题一直是关乎区域稳定发展、民族复兴乃至世界和平的大事,然而在地理学领域系统讨论该命题的研究尚不多见。事实上,地理学拥有比政治学和法学更为综合的理论分析体系,尤其是随着政治地理学的快速崛起,从地理学视角解析国家统一的发生机理和影响机制已经日渐成熟。本文从国家主权学说、地缘政治学、后殖民主义、新帝国主义等理论出发,试图构建“国家统一地理学”的分析框架,将国家统一分解为地缘政治重构、经济一体化和文化认同重建3个不同的阶段;并通过东西德国统一的案例分析,深入诠释了德国统一过程中政治版图和地缘格局变化,德国统一后漫长的经济一体化和原西德资本主义的野蛮扩张,以及由于长时间受到不同文化帝国主义渗透带来的民族身份认同分歧问题。德国案例很好地展示了从地理学视角探讨国家统一问题的优越性,同时德国的案例分析可为其他国家的统一问题提供参考与借鉴。     

1978年改革开放以来中国工业地理格局演变

回顾改革开放40年,在深刻的制度变革环境下,中国工业实现快速发展,中国工业地理格局也在经济转型中得到重塑。中国工业总体上经历了从内陆扩散到沿海地区集聚,再向内陆转移的过程。但不同类型产业地理格局及变化受制于不同力量,显现出一定的行业差异性。与改革开放之初相比,中国工业在不同地理尺度上呈现出明显的集聚趋势,但集聚程度较欧盟和美国低。产业的聚集与分散驱动不同尺度下的产业迁移,导致区域产业频繁进入和退出,促使地方产业呈现多样化态势,推动中国工业地理格局演变。从经济转型的视角出发,改革开放可概括为市场化、全球化和分权化三个过程,这些过程创造市场力量,激活地方力量,引入全球力量,共同重塑了中国工业地理格局。