柴达木盆地察尔汗古湖贝壳堤剖面粒度特征及其沉积环境

通过对柴达木察尔汗盐湖贝壳堤剖面沉积物粒度、碳酸盐和磁化率的对比,结合沉积物粒度频率曲线与多种粒度参数分析,详细讨论了研究剖面形成过程中物质搬运和沉积作用以及所反映的环境变化。结果表明沉积物粒度特征指示了湖泊水位的相对变化。在距今约38.2 ka BP（14-C年代,未校正。下同）左右,沉积记录指示古湖泊的范围和水位已达到剖面位置,之后湖泊继续扩张、水位波动上升;在距今约35.5 ka BP,粒径有一突然变细又变粗的过程,可能为一次较快速的湖面波动;在距今约35.5 ～ 33.3 ka BP之间,沉积物颗粒较粗,碳酸盐含量和磁化率值低,揭示湖泊水位较低。距今约33.3 ～ 27.1 ka BP之间,沉积物颗粒较细,碳酸盐含量较前一阶段高,表明此阶段湖泊水位相对较深,但粒度、碳酸盐和磁化率等指标也记录了三次较明显的湖泊快速但短暂的退缩过程;在距今约29.7～28.3 ka BP,沉积物颗粒最细,指示了此时期可能为湖泊水位最高期。从距今约27.1 ka BP开始,沉积积物颗粒明显变粗,揭示湖泊进入到退缩期,距今约18.1 ka BP,粒度指标的变化和上层的盐壳指示湖泊进入快速盐化阶段,之后湖泊退出剖面所在的位置,此后研究区湖泊水位再也没有达到这个高度。     

鄂尔多斯盆地西南缘泾河油田长7-长8古流向及 沉积相分析

对泾河油田三维地震前积反射、钻井取芯砂岩轻重矿物分离测试和砂体剖面结构对比,并结合前人研究结果认为,泾河油田长8-长7砂岩碎屑主要来自于西南部陇西古陆,部分来自于南部秦岭物源,不受北东物源影响。结合物源、岩芯特征和测井相分析结果认为,泾河油田整个长8₁自下而上是河流-三角洲-半深湖的水进沉积过程,发育3条北东向和1条南北向河道。长8₁2为滨浅湖相-三角洲-河流相沉积,发育（水下）分流河道砂岩;长8₁1储层为浅湖-半深湖背景中水进三角洲水下分流河道砂岩。长7₂为浊积砂岩储层,发育9个北东向浊积水道。     

松辽盆地古龙凹陷白垩系青山口组储集空间与油态研究

松辽盆地古龙凹陷有丰富的页岩油气资源.但是目前对古龙凹陷页岩油储层的岩石学特征和页岩油的状态,尤其是储集空间的类型及其组合关联性认识不清.通过对古龙凹陷白垩系青山口组岩芯的精细描述及其薄片分析和电子显微镜观察及三维CT深入研究,发现古龙青山口组页岩油的储集空间具有多样性和多尺度性.除了纳米孔缝外,还有页理缝.根据页理缝...     

汉江上游安康东段古洪水事件光释光测年研究

通过对汉江上游河谷广泛的野外考察,结合粒度和磁化率分析,证明汉江上游安康东段阶地剖面夹有两层典型的古洪水滞流沉积层,其记录了两期古洪水事件。选择该河段LSC两个剖面进行系统采样,对其进行了年代学和沉积学研究。应用单片再生法（SAR）光释光测年技术,获得其光释光年龄值,结合地层对比,确定这两期古洪水事件分别发生在距今13050~12270 a（对应BL+AL事件向着YD气候恶化事件转折阶段）和发生在距今1000~900 a左右,相当于我国历史上的北宋时代后期（A.D. 1000~1100）。通过与国内外多种高分辨率气候变化记录的对比分析,揭示了古洪水事件的发生与气候恶化转折时期,季风气候格局突变、气候波动不稳定、降水变率增大有密切关系,这对汉江上游水资源综合开发利用以及防洪减灾有着重要的意义。     

实验室条件下微生物降解原油的地球化学特征研究

通过对胜利油田四个正常原油样品微生物作用前后的族组分及饱和烃色谱质谱分析,发现实验室条件下微生物对原油有明显的降解作用。微生物作用以后的原油族组分其饱和烃相对含量降低,饱/芳比也明显降低,而芳烃、非烃和沥青质的相对含量都不同程度的升高。通过饱和烃色谱-质谱分析,发现微生物作用以后原油正构烷烃被严重降解,姥/植(Pr/Ph)比值和∑C_21-/∑C₂₂₊比值都明显降低。微生物作用原油后能产生表面活性剂,造成了培养基表面张力的降低。     

曹岘黄土和小良山红土剖面磁化率解释机制的差异

磁化率因其磁测方法快捷、简便和没有破坏性的优点,作为一种研究手段以利用环境物质的磁性来恢复古环境,分析磁性矿物在环境系统中的迁移、转化和组合规律等方面,得到了快速而广泛的应用,取得了一系列研究成果。事实上影响沉积物磁化率的因素是多种多样的,因此在具体应用磁化率分析古环境上要持慎重态度,并结合其他实验结果进行解释,尤其要注意沉积类型的差别对解释磁化率结果的影响。为进一步分析磁化率对古环境的指示意义,本文选取黄土和红土两种沉积类型进行磁化率测试,了解不同类型沉积物的磁化率指示意义,为正确解析磁化率提供依据。     

松嫩平原典型黑土分布区土壤呼吸研究

在松嫩平原典型黑土分布区,选择耕地、休耕地、自然荒地3种土地利用方式进行土壤CO₂呼吸研究。采用壕沟隔断法,探讨了植物根系呼吸在不同土地利用方式下的差异,采用温度敏感系数Q10分析了不同土地利用方式下土壤呼吸对温度的敏感性。结果表明: 土壤呼吸受多方面因素影响,包括土壤温度、湿度、植被类型、农业生产活动等。土壤呼吸日变化过程中,温度是影响土壤呼吸速率的决定性因素。在夏季植物根系呼吸所占的比例最大,超过了50％,春秋两季根系呼吸所占的比例相对较少。受植物种类及植物根系呼吸在土壤呼吸中所占比例大小的影响,在3种不同的土地利用方式下根系自养呼吸所占的比例大小顺序依次为荒地>休耕地>耕地。有根系的土壤呼吸对土壤温度升高的反应要敏感些。     

Cultivated land change in the Belt and Road Initiative region

The Belt and Road Initiative (BRI)–a development strategy proposed by China – provides unprecedented opportunities for multi-dimensional communication and cooperation across Asia, Africa and Europe. In this study, we analyse the spatio-temporal changes in cultivated land in the BRI countries (64 in total) to better understand the land use status of China along with its periphery for targeting specific collaboration. We apply FAO statistics and GlobeLand30 (the world’s finest land cover data at a 30-m resolution), and develop three indicator groups (namely quantity, conversion, and utilization degree) for the analysis. The results show that cultivated land area in the BRI region increased 3.73×10⁴ km² between 2000 and 2010. The increased cultivated land was mainly found in Central and Eastern Europe and Southeast Asia, while the decreased cultivated land was mostly concentrated in China. Russia ranks first with an increase of 1.59×10⁴ km² cultivated land area, followed by Hungary (0.66×10⁴ km²) and India (0.57×104 km2). China decreased 1.95×10⁴ km² cultivated land area, followed by Bangladesh (–0.22×10⁴ km²) and Thailand (–0.22×10⁴ km²). Cultivated land was mainly transferred to/from forest, grassland, artificial surfaces and bare land, and transfer types in different regions have different characteristics: while large amount of cultivated land in China was converted to artificial surfaces, considerable forest was converted to cultivated land in Southeast Asia. The increase of multi-cropping index dominated the region except the Central and Eastern Europe, while the increase of fragmentation index was prevailing in the region except for a few South Asian countries. Our results indicate that the negative consequence of cultivated land loss in China might be underestimated by the domestic- focused studies, as none of its close neighbours experienced such obvious cultivated land losses. Nevertheless, the increased cultivated land area in Southeast Asia and the extensive cultivated land use in Ukraine and Russia imply that the regional food production would be greatly improved if China’ “Go Out policy” would help those countries to intensify their cultivated land use.     

内蒙古黄旗海不同粒级湖泊沉积物Rb、Sr组成与环境变化

Based on the geochemical elements Rb and Sr in sediments with three different grain size fractions from profile H3 on the northern lacustrine bottomland 13 m above the Huangqihai Lake surface in 1986,the paper investigates the record of palaeolake stand state, sedimentary environmental evolution,and winter monsoon change.First,these samples are separated into three different grain size fractions,i.e.,total sediments,77-20μm and〈20μm. Second,the chemical elements-Rb and Sr-of the grain size separation were tested and analyzed systematically in this paper.Then the elements compositions of these samples are measured using VP-320 mode fluorescence spectrum instrument,respectively.The magnetic susceptibility of these samples is measured using Kappabridge KLY-3 mode instrument made in Czech AGICO Company.The results showed the elements and the ratios varied regularly with the grain size.But the ratio of Rb/Sr in the sediments〈20μm correlates positively with the magnetic susceptibility of these samples.Therefore,the ratio of Rb/Sr in the fraction〈20 μm from the lake sediments reflected the strengthening of the weathering in the deposition sites.It is a good indicator of the summer monsoon-induced weathering and pedogenesis fluctuations and can be used to reconstruct the conditions of the paleoclimate and paleoenvironment.     

旅游地生态安全测度分析——以九寨沟自然保护区为例

从人地关系安全、旅游生态伦理以及全球气候变化的视角,提出广义与狭义的旅游地生态安全概念,建立基于生态足迹的旅游地生态安全测度与评价模型,并以九寨沟为例,探讨旅游消费对旅游地区内与区际生态安全影响的特性。结果表明:(1)2004年九寨沟游客的旅游生态足迹总值为163514.0248hm²,人均旅游生态足迹为0.105190274hm²,居民的人均本底生态足迹为0.994925 hm²,同2002年比较,旅游生态足迹总值增加115.10%,人均旅游生态足迹增加72.44%,居民人均本底生态足迹增加3.47%。(2)2004年九寨沟旅游废弃物生态足迹总量为46960.5678hm²,约占旅游生态足迹总值的42.35%,其中旅游业的CO₂排放量高达309455.66t,占旅游废弃物生态足迹的99.84%,加强旅游业发展对区域乃至全球气候变化影响的研究十分紧要。(3)2004年九寨沟的生态安全系数处于1.093158~1.159388之间,处于可持续发展的生态安全状态,九寨沟自然保护区发展旅游业对自身生态安全的影响小于对区际(全球)的生态安全影响。(4)未来游客量的增加、旅行市场半径的拓展、受旅游消费示范效应的影响而引起的居民消费方式的转变以及居民对自然环境资源依赖程度的加强态势,是影响九寨沟生态安全的主要因素。