荒漠草原2种植物群落土壤微生物及土壤酶特征

测定和分析了甘肃省金昌市金川区荒漠草原土壤微生物数量、微生物生物量和土壤酶活性。结果表明：同层土壤3大类微生物（真菌、细菌和放线菌）数量、土壤微生物量碳和氮含量及4类土壤酶（蔗糖酶、脲酶、磷酸酶和过氧化氢酶）活性均表现为盐爪爪（Kalidium foliatum）群落大于骆驼刺（Alhagi sparsifolia）群落,而土壤微生物量磷含量相反;同一植物群落,不同层土壤微生物数量（除骆驼刺群落中的真菌亚表层最高外）、土壤微生物量碳、氮、磷含量及土壤酶活性（除骆驼刺群落中脲酶呈现高-低-高-低趋势外）均呈现随土层的加深而降低的趋势;金川区荒漠草原不同植物群落不同空间层次土壤微生物数量、微生物生物量和各种酶之间有不同程度的相关性。     

基于指数模型的郑州—洛阳地区史前聚落遗址空间分布

为了探究郑州—洛阳地区史前人类聚落遗址空间分布规律,在GIS 支持下,主要使用高程分析、坡度坡向分析和缓冲区分析等空间数据分析方法,分别获取4个史前文化时期聚落遗址分布与高程、坡度、坡向、离水距离4种环境因子的关系。在此基础上构造适宜性指数评价系统,建立聚落遗址指数模型,将模型结果与遗址具体分布情况进行比较,阐述遗址分布的特征和原因,并据此解读史前人地关系演变。研究结果表明:① 史前人类遗址选址对上述4 因子具有强烈的选择倾向:地势较低的地区更有利于人类生活、交通和农作物种植;坡度较小的平原地带受地表径流势能作用相对较小,有利于建造房屋和抵御自然灾害;阳坡(朝南)不仅可在一定程度上抵挡风寒,也适宜植被和作物生长,有利于人类获得更多的生产、生活资料;而河流湖泊则可为人类提供充足的水源。② 在4个史前文化时期中,裴李岗时期的人类生存能力较弱,对环境依赖性较强,为谋求生存,必须尽可能占据环境最优区域;在仰韶前期和仰韶后期,人类适应和改造自然的能力逐步提高,不仅能够选择条件较优的居住点,还开始扩展新的生存领域;龙山时期人类按自由意志活动的能力进一步增强,体现在遗址数量大幅增长,并开始出现社会分化现象,部分人群凭借某种特权得以优先占据条件最好的区域。     

不同施工机械碾压下矿区复垦土壤物理性质的变化

以国家自然科学基金为依托建立模拟实验区,探究不同施工机械和碾压次数下的土壤物理指标(压实度、容重、孔隙度、含水量、电导率和温度)的变化。研究结果表明:随土层深度的增加,压实度、容重和电导率逐渐递增,孔隙度、含水量和温度逐渐递减;随碾压次数的增加,压实度和容重逐渐递增,孔隙度逐渐递减,土壤含水量、电导率和温度先增加后降低,其中使用自卸汽车时,3次碾压指标值最高,使用履带式推土机时,5次碾压指标值最高,而使用履带式推土机的处理效果要好于使用自卸汽车;通过对各处理与对照间的拟合度分析发现,使用履带式推土机碾压5次的土壤中各指标与对照拟合度最高,表明采用"履带式推土机×碾压5次"的组合,复垦土壤中物理性质与正常土壤最为接近。     

Industrial structure,technological progress and CO<Subscript>2</Subscript> emissions in China: Analysis based on the STIRPAT framework

The application of facility location problems in choosing the best location of relief distribution centers plays a salient role in emergency operations of large-scale disasters. On the premise that the service recipients are uniformly distributed along the network edges, this study investigates a combined mobile and immobile pre-earthquake facility location problem. A predefined number of locations are to be selected among a set of potential locations. Each facility is used in the relief distribution operation. It is incontrovertible that due to earthquakes, some network edges collapse and corresponding areas may lose their accessibility. Thus in this study, it is assumed that people on intact and accessible edges travel to the location of the distribution centers to receive the relief. For those who are located on collapsed or inaccessible network edges, the medium-scale unmanned aerial vehicle (UAV) helicopters are utilized in the relief distribution operation. This study aims to develop a mathematical model which minimizes the aggregate traveling time for both people and UAVs over a set of feasible scenarios. Since the network problems are NP-hard, some metaheuristic algorithms are developed to solve the proposed model. In order to demonstrate the applicability of developed model, a case study based on feasible earthquake scenarios in Tehran is presented.     

互联网众源照片的三维重建定位技术

随着电子产品的普及和互联网发展,人们习惯性地将照片上传到主流图片分享网站和社交媒体。这些照片很多都没有地理坐标或者仅有模糊的位置信息。如果互联网上任意来源的电子照片能被恢复出真实地理位置,它们将可以应用在城市建设、城市景观分析和犯罪追踪等很多方面。本文提出了一种互联网众筹照片的三维重建定位技术,该技术将结构化组织的街景数据作为参考数据集,使用三步走策略：图像检索粗定位、图像匹配细筛选和三维重建精定位,来给不明来源的众筹照片附上精确的地理标签。本文通过摄影测量原理恢复待查询照片周围的三维空间信息,较之前Zamir和Shah的方法,定位精度中值从256.7 m提升到69.0 m,平均值从350.4 m提升到206.0 m,在50 m精度要求下的照片数量占比从17.2%提升到43.2%。另一个发现是在重建误差成因方面,待查询照片的相机距离主拍摄目标越近,定位总误差越小。本文所提出的照片定位技术提供了灵活的参数,使其应用范围不仅仅局限于小区域,也可以扩大至城市、国家尺度。     

Large-scale estimates of gross primary production on the Qinghai-Tibet plateau based on remote sensing data

Vegetation gross primary production (GPP) is an important variable for the carbon cycle on the Qinghai-Tibetan Plateau (QTP). Based on the measurements from 12 eddy covariance flux sites, we validated a light use efficiency model (i.e. EC-LUE) to evaluate the spatial-temporal patterns of GPP and the effect of environmental variables on QTP. In general, EC-LUE model performed well in predicting GPP at different time scale over QTP. Annual GPP over the entire QTP ranged from 575 to 703 Tg C, and showed a significantly increasing trend from 1982 to 2013. However, there were large spatial heterogeneities in long-term trends of GPP. Throughout the entire QTP, air temperature increase had a greater influence than solar radiation and precipitation (PREC) changes on productivity. Moreover, our results highlight the large uncertainties of previous GPP estimates due to insufficient parameterization and validations. When compared with GPP estimates of the EC-LUE model, most Coupled Model Intercomparison Project (CMIP5) GPP products overestimate the magnitude and increasing trends of regional GPP, which potentially impact the feedback of ecosystems to regional climate changes.     

Multi-objective Emergency Scheduling for Geological Disasters

Natural Hazards - Because of the specific time and distance constraints, emergency management departments usually build multiple depots (resource centers) to serve the widely dispersed customers...     

热活化过硫酸盐降解氧氟沙星特性及响应面优化

为了探究热活化过硫酸盐（PS）技术对水中氧氟沙星（OFX）的氧化降解作用,考察了反应温度、体系的初始pH、PS的初始浓度、OFX的初始浓度对OFX降解效果的影响;并在单因素实验的基础上,选取反应时间、体系的初始pH、PS的初始浓度和OFX的初始浓度4个因素进行了响应面优化实验。结果表明：最佳降解条件为,反应温度60℃、PS初始浓度4.0 mmol/L、pH=4.7、OFX初始浓度0.03 mmol/L、反应时间60 min,此时OFX的降解率为81.29%;4个因素对热活化PS降解OFX均有影响,其影响显著性从大到小为反应时间、OFX的初始浓度、PS的初始浓度、初始pH。利用响应曲面法模拟出反应体系的最佳条件,经实验验证,OFX降解率为93.78%,与预测最佳结果95.00%基本相符,表明模型可靠有效。     

马达加斯加索菲亚省BINARA地区铬铁矿遥感找矿预测

马达加斯加北部地区地广人稀、交通不便、植被稀疏、矿产资源丰富,利用遥感技术提取矿化蚀变信息具有独特的优势和较好的效果。为了对BINARA地区铬铁矿进行遥感找矿预测,文章首先利用Landsat 8遥感数据2、4、5、6波段进行主成分分析提取研究区内基性-超基性岩信息;然后基于实测高光谱数据,采用偏最小二乘回归法建立Fe含量定量反演模型,并利用该模型对Hyperion高光谱遥感数据进行计算,提取研究区内Fe含量异常信息;最后根据综合遥感异常信息以及野外调查验证结果,确定研究区内的Fe含量为一级异常的区域作为预测区。     

GeoGraphViz: Geographically constrained 3D force-directed graph for knowledge graph visualization

Knowledge graphs are a key technique for linking and integrating cross-domain data, concepts, tools, and knowledge to enable data-driven analytics. As much of the world's data have become massive in size, visualizing graph entities and their interrelationships intuitively and interactively has become a crucial task for ingesting and better utilizing graph content to support semantic reasoning, discovering hidden knowledge discovering, and better scientific understanding of geophysical and social phenomena. Despite the fact that many such phenomena (e.g., disasters) have clear spatial footprints and geographic properties, their location information is considered only as a textual label in existing graph visualization tools, limiting their capability to reveal the geospatial distribution patterns of the graph nodes. In addition, most graph visualization techniques rely on 2D graph visualization, which constrains the dimensions of information that can be presented and lacks support for graph structure examination from multiple angles. To tackle the above challenges, we developed a novel 3D map-based graph visualization algorithm to enable interactive exploration of graph content and patterns in a spatially explicit manner. The algorithm extends a 3D force directed graph by integrating a web map, an additional geolocational force, and a force balancing variable that allows for the dynamic adjustment of the 3D graph structure and layout. This mechanism helps create a balanced graph view between the semantic forces among the graph nodes and the attractive force from a geolocation to a graph node. Our solution offers a new perspective in visualizing and understanding spatial entities and events in a knowledge graph.