基于WoS和Citespace的应急避难场所知识图谱和进展分析

以近30 年Web of Science 核心数据库收录的2472 篇应急避难场所相关文献为基础,首先统计发文数量时间分布和期刊分布,然后利用Citespace可视化软件,从发文作者、机构、国家、关键词和学科方向5个方面分别进行知识图谱分析。结果表明：近30年来应急避难场所研究发文呈现由缓慢探索、稳步发展向高速发展的阶段;发文期刊主要为自然灾害类、紧急医学类、工程技术类;研究作者群较多,学术交流较为紧密;美国和中国为发文量最多的国家;路易斯安那州立大学和中国科学技术大学是主要的发文机构;从关键词发现应急避难场所目标人群主要围绕灾害救援和社会弱势群体,研究视角从单一问题和事件开始向综合系统演变,研究方法从定性的方法模型转向动力机制和信息系统开发,研究内容则注重多学科交叉和微观尺度、重视案例实证和信息共享和强调应急避难场所管理;学科方向主要为工程学和公共环境与健康两个学科。在建设韧性城市的背景下,可借鉴国际经验来构建中国应急避难场所研究体系和管理。     

基于近底原位观测的小尺度海底沙波地形小波分解

浅海海床发育着不同尺度的活动性砂体,在大型活动性砂体上常叠加发育着大量小尺度沙波(纹),分析这些小尺度沙波(纹)有助于揭示活动性砂体的成因机制。但它们的尺度较小,常规分析方法往往将其作为高频噪声滤除,难以对该尺度海底沙波(纹)进行分离量化研究。为了解决这个问题,本文设计并实现了一种基于小波分析的小尺度海底沙波地形分解方法,并以台湾浅滩典型区域的高精度近底原位观测数据为例,实现了小尺度海底沙波地形的分解和定量分析,分解出背景地形、小型沙波和沙波纹(波长小于0.6 m)3种地貌类型。本文提出的小尺度海底沙波地形分解量化方法,可广泛应用于浅海高活动性地貌发育演化和海底边界层沉积动力过程研究,对评估海洋工程的稳定性也具有一定的实用价值。     

Climate change at the monsoon/Westerly boundary in Northern Mexico

Northern Mexico lies close to the present day boundary between mid-latitude (Westerly) and tropical (monsoonal) sources of moisture. Studies from the adjacent southwest USA have shown major changes in lake levels and vegetation distributions over the late Quaternary which have been interpreted in terms of significant variations in the relative strengths and positions of these climate systems. Palaeoclimatic data from this area have, however, left a number of unresolved questions which can only be answered by extending work into northern Mexico, closer to the major source of summer (monsoonal) rain, the Gulf of Mexico. Studies of palaeolake sediments from a series of hydrologically closed lake basins across a range of altitudes (1280 to 2200 m a.s.l.) in northern Chihuahua are in progress using geochemical, mineral magnetic, diatom and plant microfossil analyses. Preliminary results are presented from the Alta Babícora and Encinillas basins. The sites provide records of lacustrine deposition between >11000 and about 2500 yr BP. The diatom record from Babíora provides clear evidence for a deep water lake in this basin in the late glacial which persisted into the early Holocene. A dry episode coinciding with the timing of the Younger Dryas is recorded in Alta Babícora. Conditions wetter than present are indicated up to at least 7000 yr BP.     

Volunteer health and emotional wellbeing in marine protected areas

Citizen science monitoring programs in the marine environment frequently focus on volunteer collected data precision for conservation and resource use of marine biota. Few studies have examined the social science aspects of volunteer engagement in marine monitoring programs in a quantifiable manner. This research focuses on emotional attitudes of Sea Search volunteers who monitor Marine National Parks and Marine Sanctuaries in Victoria, Australia. Volunteers responded that their participation in Sea Search activities made them feel good emotionally and mentally, with active learning, such as remembering names of marine biota, stimulating brain activity and memory. Volunteer monitoring efforts generated personal satisfaction through their contributions, feelings of enjoyment, and socialising with others. Sea Search volunteers gain a sense of want to protect and conserve the marine environment through positive behaviour change. By understanding and having a sense of meaning towards the marine environment, the volunteers felt a sense of pride in themselves. The concepts of volunteer connection to the natural environment and positive mental and emotional health are important for any citizen science monitoring program and should be used in the program’s aims and strategies as an effective means to attract volunteers. A functional framework which clearly communicates and assesses not only the scientific expectations from a citizen science program, but also the health and wellbeing connections to nature, need to be addressed in Government marine and coastal strategies.     

The heavy element mixture and the stellar cluster age

Recent analyses of solar spectroscopic data (see Asplund, Grevesse & Sauval 2005 and references therein) suggest a significative variation of the heavy element abundance. The change of the heavy mixture might affect the determination of the cluster ages for two different reasons: the change of theoretical isochrones at fixed metallicity and the variation of the inferred cluster metallicity from the observed [Fe/H]. The first point is analyzed discussing the effects of updating the metal distribution on theoretical evolutionary tracks and isochrones for metallicities suitable for the galactic globular and open clusters and for the bulk population of the Large Magellanic Clouds. The maximum variation of the estimated age is of the order of 10%. The second point is addressed by comparing present theoretical predictions with the very precise observational data of the Hyades cluster from the Hypparcos satellite.     

Flare SOL2012-07-06: On the Origin of the Circular Polarization Reversal Between 17 GHz and 34 GHz

The new generation of multiwavelength radioheliographs with high spatial resolution will employ microwave imaging spectropolarimetry to recover flare topology and plasma parameters in the flare sources and along the wave propagation paths. The recorded polarization depends on the emission mechanism and emission regime (optically thick or thin), the emitting particle properties, and propagation effects. Here, we report an unusual flare, SOL2012-07-06T01:37, whose optically thin gyrosynchrotron emission of the main source displays an apparently ordinary mode sense of polarization in contrast to the classical theory that favors the extraordinary mode. This flare produced copious nonthermal emission in hard X-rays and in high-frequency microwaves up to 80 GHz. It is found that the main flare source corresponds to an interaction site of two loops with greatly different sizes. The flare occurred in the central part of the solar disk, which allows reconstructing the magnetic field in the flare region using vector magnetogram data. We have investigated the three possible known reasons of the circular polarization sense reversal – mode coupling, positron contribution, and the effect of beamed angular distribution. We excluded polarization reversal due to contribution of positrons because there was no relevant response in the X-ray emission. We find that a beam-like electron distribution can produce the observed polarization behavior, but the source thermal density must be much higher than the estimate from to the X-ray data. We conclude that the apparent ordinary wave emission in the optically thin mode is due to radio wave propagation across the quasi-transverse (QT) layer. The abnormally high transition frequency (above 35 GHz) can be achieved reasonably low in the corona where the magnetic field value is high and transverse to the line of sight. This places the microwave source below this QT layer, i.e. very low in the corona.     

新疆农村贫困化空间分布及影响因素探究——以荒地镇为例

在国家大力推进精准扶贫的政策背景下,分析不同地区贫困成因的差异性具有重要意义。本文以新疆维吾尔自治区莎车县荒地镇为研究区,通过地理探测器和地理加权回归模型探究该区贫困人口和状态的空间分布及其影响因素,研究结果表明：1)荒地镇农村贫困化呈现一定范围内集聚分布的特征,镇域中部和北部地区的贫困发生率明显高于其周边地区,中部的贫困地区由中心向四周扩散,北部的贫困发生率低于中部。2)导致贫困的主要因素包括距主干道距离、人口密度和男性人口所占比例。3)距离主干道的距离与贫困发生率呈现出明显的正向相关的关系,距离镇中心的距离与贫困发生率呈现出一定的负相关关系,人口密度与贫困发生率呈现出明显的负相关关系。4)依据不同地区贫困形成的主导因素,贫困地区可以划分为道路制约型和人口制约型,其中道路制约性主要分布在荒地镇的东南地区,而人口制约性主要分布在北部地区。针对不同成因的农村贫困,本文提出应该采用不同策略的扶贫措施。