古风化壳孔隙与裂缝发育特征及其油气地质意义

通过总结前人研究结果,利用数据整理、薄片观察等方法对古风化壳中孔隙和裂缝的发育规律进行了分析,并探讨了古风化壳结构的油气地质意义。研究结果表明,发育完全的古风化壳具有风化黏土层和半风化岩石的分层结构;半风化岩石中部孔隙和裂缝较发育,向上向下规模逐渐减小,至风化黏土层大孔隙和裂缝不发育。通过实例汇总认为,影响半风化岩石孔缝系统发育程度的主要因素包括风化基岩的岩性、风化的时间和强度、风化壳形成时期的剥蚀厚度和古风化壳的埋藏深度以及裂缝孔隙的充填特征。风化黏土层岩性致密,对油气的保存具有建设性作用;半风化岩层中部的孔缝连通体,既为油气运移的良好通道,也可作为油气聚集的有效储层。     

洞庭湖区水系格局及连通性优化

江湖关系演变及强烈人类活动改变了洞庭湖区的水系格局与连通性,加剧了湖区水环境与水生态的恶化形势,开展水系格局与连通性研究是洞庭湖区水系综合整治和河湖生态修复的重要内容。基于景观生态学中网络连通度分析方法,建立了水系格局与连通性评价指标体系,包括河频率、河网密度、水系环度（α）、节点连接率（β）和网络连接度（γ）等,分析评价了洞庭湖不同片区现状及规划水系格局与连通性的差异以及合理性,提出了水系连通规划的优化方案。结果表明:现状洞庭湖区水系格局和连通性总体较好,但各个片区存在较大差异,湘-资水尾闾地区的现状水系格局和连通性良好,北部地区和松澧地区的现状水系格局与连通性较差。松澧地区水系规划方案改善了该地区的水系格局与连通性,但北部地区的规划方案并不合理。经过比选与优化,北部地区的α、β、γ指标比现状提高了13.2%、6.9%和4.7%,比原规划方案提高26.0%、9.4%和9.4%。     

干旱区绿洲扩展过程中的景观变化分析

绿洲化过程中的景观变化和尺度效应是景观生态学研究的热点之一。针对这一目标以黑河中游张掖绿洲为研究区域,应用“3S”技术的缓冲分析方法,以绿洲标志景观类型农田、林地和湿地为核心,确定了不同时期绿洲范围并划分了老绿洲区和新增绿洲区。在此基础上,从景观组成动态和斑块连通度的尺度依赖特征两个方面分析了绿洲化过程中的景观变化机制和尺度效应。研究结果表明,绿洲化过程是以农田和建设用地斑块动态为主要特点。主要表现为：在不同的分区中,农田斑块以总面积和最大斑块指数增加为特点,说明农田斑块趋向集中连片分布;建设用地斑块总面积、斑块密度和最大斑块指数等3个指标都为增加,在景观上呈星点状扩张分布。老绿洲与新增绿洲的比较分析显示,新增绿洲的建设用地面积增加速率小于老绿洲,而农田面积的增加速率大于老绿洲。从景观斑块连通度的尺度依赖特点来看,在老绿洲中景观斑块类型的空间尺度依赖规律明显,但在时间尺度上的变化不显著;在新增绿洲内,林地、水域和建设用地的尺度依赖性比老绿洲高,其中林地、建设用地的空间变化规律明显,在时间尺度上无明显的差异;而水域斑块的尺度依赖性1985年高于2006年。     

柴北缘油气运移优势通道特征及其控油气作用

油气运移优势通道研究对于追踪油气运移方向和预测有利勘探目标具有重要意义, 在对柴北缘地区输导层砂体展布、主要成藏期古流体势、断层倾角和区域盖层分割槽等地质条件综合研究的基础上, 分别阐述了级差优势、流向优势、流压优势和分割槽优势等4种类型优势通道的分布特征以及对油气运移的单因素控制作用, 然后进行多因素叠加, 综合分析在4种优势通道共同作用下柴北缘地区的油气优势运移方向, 进而优选勘探目标.结果表明: 冷湖-南八仙构造带具有阿尔金斜坡、赛什腾、鱼卡-南八仙3个大规模沉积体系的级差优势通道, 同时流压优势通道、分隔优势通道和流向优势通道分布范围广, 并且处于昆特依凹陷和伊北凹陷油气的运移指向区, 使得该构造带成为最有利的油气聚集带, 其次是鄂博梁Ⅰ号-葫芦山构造带; 冷湖七号东、西高点深层构造和葫芦山构造为最有利的勘探目标, 有望取得新的突破.      

盘龙铅锌矿浮选铅中矿工艺矿物学特征研究

针对广西盘龙铅锌矿选矿厂铅浮选指标较差的现状,以现场产出的铅中矿1为研究对象,采用化学多元素分析、物相分析、光学显微镜鉴定、解离度统计等技术手段,对盘龙铅锌矿浮选铅中矿的化学组成、物相组成、目的矿物的嵌布粒度及嵌布特征进行了详尽的工艺矿物学特征研究。研究结果表明,铅中矿1含Pb 2. 03%,主要赋存于方铅矿中;方铅矿整体嵌布粒径细小,经筛分分级后,不同粒径的分级产品中方铅矿的嵌布特征差异性极大,+74μm及-74～+39μm部分含铅矿物颗粒基本为铅-锌-硫复杂连生的集合体,这两个粒级金属总占有率达56%以上,是影响盘龙铅锌矿铅浮选指标的关键所在。根据以上研究结果,推荐采用对铅中矿1进行分级磨矿工艺流程改造,提高铅中矿1中方铅矿的单体解离度,实现铅精矿中铅金属回收率的进一步提升。     

基于历史资料和Argo资料的印尼贯通流次表层和中层水起源与路径探讨

利用Argo资料和《世界海洋数据集2001版》(WOD01)温盐历史资料,通过对代表性等位势面上盐度分布的分析,探讨了次表层和中层等不同层次上印尼贯通流(ITF)的起源与路径问题.分析结果表明,ITF的次表层水源主要来自北太平洋,中层水源地既包括北太平洋、南太平洋,同时也不能排除有印度洋的可能性.在印度尼西亚海域西部,ITF的次表层和中层水源分别为北太平洋热带水(NPTW)和中层水(NPIW),经苏拉威西海、望加锡海峡到达弗洛勒斯海,层次越深特征越明显.在印度尼西亚海域东部,发现哈马黑拉-新几内亚水道附近存在次表层强盐度锋面,阻隔了南太平洋热带水(SPTW)由此进入ITF海域;中层水具有高于NPIW和来自南太平洋的南极中层水(AAIW)的盐度值,既可能是AAIW和SPTW在当地发生剧烈垂直混合而形成,也可能是来自印度洋的AAIW向北延伸进入ITF的结果.     

Monitoring ephemeral headwater streams: a paired‐sensor approach

This paper introduces a paired‐sensor approach to monitoring ephemeral streamflow. Part of this approach includes the design of a new flow detection sensor. This flow detection sensor addresses the limitation of previous electronic resistance sensors that use water presence as a proxy for flow for assessing hydrological connectivity, by explicitly measuring flow presence. Using paired electronic resistance and flow detection sensors, this paper evaluates the performance of each sensor individually, and as a pair. Individually, the sensors were tested for the amount of noise they contain and the types of errors they were prone to committing. As a paired set, the sensors were analysed by the percent of time they were in valid states versus invalid states. Valid states included when water was present but flow was absent, when water and flow were both present and when water and flow were both absent during a storm. One invalid case existed, where the sensors recorded flow presence but not water presence. These valid and invalid cases were assessed using data collected from sensor networks established at two study sites in southern Ontario. This analysis was completed for the overall corroboration at each site, for each storm at each site and based on the relative position of the sensors in the channel at each site. The sensors were in valid states 83% and 94% of the time at each respective study site. Differences in local site conditions were found to affect the performance of the sensor network; however, no significant correlation was found between storm characteristics and sensor performance. Particularly, bed roughness was found to be a factor as it restricted the placement of the sensors. Despite this, the paired‐sensor network helps to increase the understanding of the flow dynamics within headwater streams by explicitly separating the two hydrological characteristics. A discussion of the challenges, limitations and opportunities of monitoring ephemeral flow is presented, and insights into how to address those limitations are provided. Copyright © 2015 John Wiley & Sons, Ltd.     

Using geomorphic understanding of catchment-scale process relationships to support the management of river futures: Macaé Basin,Brazil

Impacts of colonial settlement upon catchment-scale fluvial geomorphic relationships are reported for a relatively small catchment in northern Rio de Janeiro State, Brazil. Structural controls have induced the type and patterns of rivers in Macaé Basin. Fault block activity has resulted in steep, incised headwater streams above the escarpment. Confined and partly confined rivers in mid-catchment reaches of the rounded foothills have limited potential for geomorphic adjustment. Fluvial, estuarine and marine sediments in low relief landscapes of the lowland plain have supported the development of meandering sand bed rivers, with many cut-and-fill (intact valley fill) deposits in tributary systems. Indigenous people exerted relatively minor, localized impacts upon the geomorphology of this river system. Portuguese settlement since the sixteenth century brought about clearance of much of the Atlantic Forest of lowland reaches, and subsequent establishment of sugar cane and coffee plantations. Lowland reaches were channelized from the 1940s-1980s for flood protection and to support the expansion of pastoral agriculture. Significant adjustments have occurred to these geomorphologically sensitive reaches. In contrast, although rivers in the rounded foothills were impacted by forest clearance, the limited availability of sediment stores along these reaches has limited the extent of geomorphic responses to human disturbance. Relatively inaccessible upland reaches were even less impacted, and are now major conservation areas. Building on principles of the River Styles framework, catchment-scale evolutionary trajectories of rivers in the Macaé Basin are assessed based on analysis of patterns of river types, their capacity for adjustment and connectivity relationships, and responses to disturbance events. From this, three future scenarios of prospective evolutionary traits are developed: a ‘steady as she goes’ scenario, an optimistic (effective, proactive management) scenario, and a ‘doomsday’ scenario.     

中国沿海陆地自然保护区景观连接度评价

人类社会发展进入人新世时期,以人类活动为主导的高频率干扰和自然资源的高强度开发对生态环境造成严重威胁,提升自然保护区的景观连接度是缓解和应对外界干扰的关键手段之一。传统意义上景观连接度研究侧重于景观基质对物种迁徙的累积负向阻碍作用,评价体系中忽略了生物多样性对物种迁徙的正向支持作用。本文以中国沿海省份作为研究区域,将生物多样性空间分布作为生态系统关键功能的表征,并将其纳入景观连接度评价体系,构建了生态廊道的连通适宜性及生态支持力二维评价新方法,进一步分析人类活动干扰和物种空间分布对自然保护区景观连接度的影响。研究结果表明沿海地区人类活动对景观连接度的影响存在明显的边缘效应,即自然保护区边缘地带的人类干扰范围（46.46%）明显高于其内部区域,人类活动干扰使保护区面积减少约720.25 km²,且造成廊道起点和终点位置的改变。自然保护区边缘地带人类干扰导致了研究区域内95条廊道的连通适宜性下降;78条廊道的生态支持力有明显提升,“一降一升”的评价结果能有效地衡量景观基质对物种迁移的支持能力变化。基于景观基质阻碍和促进作用的二维评价可为中国未来自然保护区连通性和生物多样性保护提供更为全面的时空格局动态变化模拟,为优化自然保护区空间布局提供更为完善的景观连接度评估新方法。     

主要发达经济体从碳达峰到碳中和的路径及启示

随着气候变化影响加剧,全球气候治理进程加速,实现碳达峰已经成为全球气候行动的核心,各国也相继制定碳中和目标并开展行动。中国在第75届联合国大会一般性辩论上提出了碳达峰碳中和目标,部分已实现碳达峰的发达经济体也提出了各自的碳中和承诺。文中从“整体-阶段”及“焦点-公平”视角分析了欧盟和美国等主要发达经济体碳达峰的历程和特点,以及其碳中和目标和规划。研究发现,发达经济体在碳达峰过程中普遍经历了较长的爬坡期（58~136年）和平台期（4~20年),在碳达峰时,发达经济体的能源结构以油气为主,油气占一次能源消费比重为57%~77%,其人均排放量、历史累计排放以及人均GDP也都处于较高水平,在碳达峰前后总体处于经济与碳排放脱钩状态。各发达经济体的碳中和路径均以能源转型为重点,采用了多元化的政策工具,并且注重低碳和负碳技术的革新。根据发达经济体的政策展望,在实现碳中和时,均难以将绝对排放量降为零,都需要通过碳移除手段进行抵消。通过对比分析,发现中国的碳达峰和碳中和目标是具有雄心的气候承诺,相较其他发达经济体需要付出更大努力。建议运用全面综合的政策工具支撑碳中和目标的有效落实,加快中国的气候立法,在兼顾公正转型的同时推动能源结构调整,注重可再生能源和能效方面的新技术开发应用。