秦巴地区矿产资源和成矿分布规律

对秦巴地区的成矿地质构造进行了分区和分期,定量地论述了区域矿产资源的特色和组成总貌,全面系统地总结论述了7种矿床类型及其成矿特征,阐述了区域成矿分布规律,反映了该区矿产地质的研究现状。     

吉林省夹皮沟金矿带几个重要地质问题的讨论

夹皮沟金矿带位于吉林省东南部桦甸地区。自1820 年发现以来,已累计探明黄金地质储量150 吨左右。该金矿带位于中朝古板块北缘东段与布列亚-佳木斯地块南缘的碰撞对接部位附近。区内发育5 条平行的NW 向含矿构造带,其北端均以锐角交汇于挥发河断裂。有别于前人的研究成果,本文提出夹皮沟金矿带恰好位于高级区与夹皮沟花岗-绿岩带的接触部位,形成以夹皮沟金矿化带为中心的矿化分带。夹皮沟金矿带为中生代成矿,夹皮沟NW 向弧形构造片理化带及其上盘扇状断裂系控制着金矿床的分布。在主要NW 构造带之间,还存在一系列与之平行的次级构造,它们与扇状断裂的交汇点及扇状构造系中的横向应力集中带是金矿化定位的有利部位。     

一步彩虹全息术的成象位置分析

本文从标量衍射理论出发,结合一定的物理意义,直接导出了一步彩虹全息术的成象位置公式;并根据可观察再现象的条件,从理论上导出了较为完整的成象位置关系表;并从中选出一部分成象位置关系进行了实验验证。     

签到位置数据的密度峰值快速搜索与聚类方法

位置签到数据蕴含了城市居民活动变化。由于客户端位置候选问题,不同的签到行为以同一候选位置签到时会产生位置重复现象。针对现有密度聚类方法在签到数据聚类上存在的问题,以快速搜索和查找密度峰值聚类算法(CFSFDP)为基础,提出了签到位置数据的密度峰值快速搜索与聚类方法。首先,引入位置重复频率来表达签到位置重复,然后,对原始签到位置数据点统计位置重复频率并重新设计数据结构,以新的空间点要素为研究对象寻找密度峰值点;最后,构建了峰值点密度簇聚类算法,在点要素集聚类过程中考虑密度连通性来保证峰值密度簇的连续与完整。试验表明,所提出的聚类方法有效避免了重复度较高的离群位置对象选为峰值并聚类的情况,并具有良好的空间适应性。所提取的密度峰值点不仅可以用来表示热区的中心,还能够反映热区的集中趋势,进而可以帮助探索热区的动态变化情况。     

1951—2009年东亚副热带夏季风北边缘位置的地域特征

利用1951—2009年中国662个气象台站逐日降水资料和NCEP/NCAR逐日再分析资料,分析了东亚副热带夏季风北边缘地理位置的年际、年代际变化以及夏季风影响北边缘的时间演变特征。结果表明:基于过程透雨量定义的夏季风北边缘能很好地反映边缘带降水特点,东亚副热带夏季风北边缘带大致呈东北-西南走向,在110°E处,北边缘带南界大致位于36°N,北界大致位于41°N。边缘带宽度与其南界纬度具有很好的负相关,且有逐年变宽的趋势。边缘带存在显著的准3年和9年的周期特征。夏季风平均在6月28日开始影响北边缘带,9月21日南撤离开北边缘带。110°E是夏季风边缘带中南风分量最大的经度,与偏南年相比,偏北年夏季风影响边缘带时间开始早,结束迟。     

1951—2015年进入东海的台风频数及登陆点的变化

利用日本气象厅提供的西北太平洋台风最佳路径观测资料,选取东海海区为研究范围,统计处理1951—2015年台风各要素资料,研究进入东海海区的台风频数、台风登陆点位置、台风频数及登陆点位置与太平洋年代际振荡（Pacific Decadal Oscillation,PDO）及ENSO的关系、影响台风生成和移动的因素等。结果表明：1）每年的7—9月为东海海区的台风高发季,其中8月最高,登陆台风也有相似趋势。2）进入东海海域的台风频数存在较明显的年际和年代际变化趋势。当PDO处于暖位相时,台风频数较小且有上升趋势,反之亦然。El Niño年进入东海海区的台风频数较常年减少,反之亦然。Niño3.4指数与台风频数整体上为负相关关系,相关系数为-0.32且通过90%置信度检验。3）进入东海海域的台风登陆点纬度变化较大,处于24~36°N之间,且有年代际变化特征。当PDO处于暖（冷）位相时,台风登陆点偏北（偏南）且有向北（南）移动的趋势。而登陆点纬度与ENSO的关系较为复杂。4）西北太平洋副热带高压的位置和强度是引起台风频数及登陆点位置变化的主要原因之一。当PDO处于冷位相时,西北太平洋副热带高压强度偏弱,且副高中心向东向北方向移动,导致进入东海的台风频数偏多,且台风登陆点偏北,反之亦然。     

The marker quantification of the Shared Socioeconomic Pathway 2: A middle-of-the-road scenario for the 21st century

Studies of global environmental change make extensive use of scenarios to explore how the future can evolve under a consistent set of assumptions. The recently developed Shared Socioeconomic Pathways (SSPs) create a framework for the study of climate-related scenario outcomes. Their five narratives span a wide range of worlds that vary in their challenges for climate change mitigation and adaptation. Here we provide background on the quantification that has been selected to serve as the reference, or ‘marker’, implementation for SSP2. The SSP2 narrative describes a middle-of-the-road development in the mitigation and adaptation challenges space. We explain how the narrative has been translated into quantitative assumptions in the IIASA Integrated Assessment Modelling Framework. We show that our SSP2 marker implementation occupies a central position for key metrics along the mitigation and adaptation challenge dimensions. For many dimensions the SSP2 marker implementation also reflects an extension of the historical experience, particularly in terms of carbon and energy intensity improvements in its baseline. This leads to a steady emissions increase over the 21st century, with projected end-of-century warming nearing 4 °C relative to preindustrial levels. On the other hand, SSP2 also shows that global-mean temperature increase can be limited to below 2 °C, pending stringent climate policies throughout the world. The added value of the SSP2 marker implementation for the wider scientific community is that it can serve as a starting point to further explore integrated solutions for achieving multiple societal objectives in light of the climate adaptation and mitigation challenges that society could face over the 21st century.     

Child health outcomes in sub-Saharan Africa: A comparison of changes in climate and socio-economic factors

We compare changes in low birth weight and child malnutrition in 13 African countries under projected climate change versus socio-economic development scenarios. Climate scenarios are created by linking surface temperature gradients with declines in seasonal rainfall sea along with warming values of 1 °C and 2 °C. Socio-economic scenarios are developed by assigning regionally specific changes in access to household electricity and mother's education. Using these scenarios, in combination with established models of children's health, we investigate and compare the changes in predicted health outcomes. We find that the negative effects of warming and drying on child stunting could be mitigated by positive development trends associated with increasing mothers’ educational status and household access to electricity. We find less potential for these trends to mitigate how warming and drying trends impact birth weights. In short, under warming and drying, the risk of more malnourished children is greater than the risk of more children with low birth weights, but increases in child malnutrition could be averted in regions that increase access to educational resources and basic infrastructure.     

Linking regional stakeholder scenarios and shared socioeconomic pathways: Quantified West African food and climate futures in a global context

The climate change research community’s shared socioeconomic pathways (SSPs) are a set of alternative global development scenarios focused on mitigation of and adaptation to climate change. To use these scenarios as a global context that is relevant for policy guidance at regional and national levels, they have to be connected to an exploration of drivers and challenges informed by regional expertise.In this paper, we present scenarios for West Africa developed by regional stakeholders and quantified using two global economic models, GLOBIOM and IMPACT, in interaction with stakeholder-generated narratives and scenario trends and SSP assumptions. We present this process as an example of linking comparable scenarios across levels to increase coherence with global contexts, while presenting insights about the future of agriculture and food security under a range of future drivers including climate change.In these scenarios, strong economic development increases food security and agricultural development. The latter increases crop and livestock productivity leading to an expansion of agricultural area within the region while reducing the land expansion burden elsewhere. In the context of a global economy, West Africa remains a large consumer and producer of a selection of commodities. However, the growth in population coupled with rising incomes leads to increases in the region’s imports. For West Africa, climate change is projected to have negative effects on both crop yields and grassland productivity, and a lack of investment may exacerbate these effects. Linking multi-stakeholder regional scenarios to the global SSPs ensures scenarios that are regionally appropriate and useful for policy development as evidenced in the case study, while allowing for a critical link to global contexts.