中国高技能劳动力与一般劳动力的空间分布格局及其影响因素

基于2000和2010年全国人口普查分县数据和地级行政单元数据,采用不均衡指数和空间自相关分析等方法,刻画中国高技能劳动力和一般劳动力的空间分布格局及其变化,并采用空间滞后模型,识别高技能劳动力与一般劳动力空间分布的决定因素及其变化。结果表明：① 两类劳动力总体的空间特征均为东南密集,西北稀疏;② 2000—2010年,高技能劳动力在空间分布上呈集中化的趋势,而一般劳动力呈分散化的趋势;③ 十年间高技能劳动力集聚区虹吸作用加强,其分布越发集中于沿海特大城市群,而一般劳动力集聚区回波作用加强,其分布越发均衡;④ 空间回归分析结果表明,职工平均工资、是否直辖市或省会、每万人在校高校学生、是否沿海城市、常住人口数和空间溢出效应在十年中一直都是决定高技能劳动力和一般劳动力空间分布的主要因素,而失业率、中学生师比、二氧化硫排放量和绿地率在2010年也成为影响两类劳动力空间分布的主要因素。对比两类劳动力的模型结果可得,高技能劳动力的空间分布受行政因素、高校因素和地区生活舒适度的影响更大,而一般劳动力的空间分布受劳动力市场因素的影响更大。     

Robustness of the holistic seismic risk evaluation in urban centers using the USRi

The Urban Seismic Risk index (USRi) published in a previous article (Carreño et al., Nat Hazards 40:137–172, 2007) is a composite indicator that measures risk from an integrated perspective and guides decision-making for identifying the main interdisciplinary factors of vulnerability to be reduced or intervened. The first step of the method is the evaluation of the potential physical damage (hard approach) as a result of the convolution of the seismic hazard with the physical vulnerability of buildings and infrastructure. Subsequently, a set of social context conditions that aggravate the physical effects is also considered (soft approach). According to this procedure, the physical risk index is evaluated for each unit of analysis from existing loss scenarios, whereas the total risk index is obtained by multiplying the former index by an impact factor using an aggravating coefficient, based on variables associated with the socio-economic conditions of each unit of analysis. The USRi has been developed using the underlying holistic and multi-hazard approach of the Urban Risk Index framework proposed for the evaluation of disaster risk in different megacities worldwide. This article presents the sensitivity analysis of the index to different parameters such as input data, weights and transformation functions used for the scaling or normalization of variables. This analysis has been performed using the Monte Carlo simulation to validate the robustness of this composite indicator, understanding as robustness how the cities maintain the ranking as well as predefined risk level ranges, when compared with the deterministic results of risk. Results are shown for different cities of the world.     

玉米秸秆带状覆盖对西北旱地土壤温度及马铃薯产量的影响

设黑膜大垄（M1）、玉米秸秆带状平覆（M2）、玉米秸秆带状垄沟覆杆（M3）和不覆盖露地平作（CK）4个处理进行田间小区试验,对比研究不同覆盖方式对西北旱地土壤温度及马铃薯产量的影响。结果表明：M1较CK提高全生育期土壤温度0.98℃,主要提高了块茎膨大期5 cm土层（2015年）及淀粉积累期10 cm土层（2016年）的土壤温度;M2、M3较CK降低全生育期土壤温度1.06℃、0.59℃,主要降低了块茎形成期10 cm土层的土壤温度。两年M1、M2、M3分别平均较CK增产11.68%、21.74%、16.88%。产量与淀粉积累期至收获期单株结薯数、单株产量正相关（r=0.064~0.766）,覆盖处理显著较CK提高淀粉积累期单株结薯数及单株产量,平水年以M1最好,偏旱年以M2最好。     

基于R树索引的三维可视化查询方法

针对应用日益广泛的最近邻查询,提出了一种基于R树广度遍历和优化排序原理的最近邻查询算法,能适应不同空间分布的目标数据集。同时,提出了多细节层次（LOD）目标查询方法。实验证明,此方法支持多尺度场景逼真描述,查询结果准确,满足当前三维GIS的功能需求。     

赣南北部黄陂河流域离子型稀土矿地区水质与健康风险评价

水质安全和健康是保障中国赣南老区乡村振兴发展的重要因素。赣南离子型稀土矿长期开发利用,导致浸矿剂和矿体中重金属元素等危害人体健康的物质进入水循环系统,给周边乡村饮用水卫生安全带来了潜在风险。目前,针对当地复垦后稀土矿及周边地区水质和健康风险缺乏系统调查评价,本文以《生活饮用水卫生标准》(GB 5749—2006)为评价依据,选择赣南北部黄陂河流域典型离子型稀土矿及周边的水体开展调查研究,采用电感耦合等离子体发射光谱/质谱等技术测定锰、镉等元素含量,采用水质指数(WQI)、危害商(HQ)、致癌风险(CR)评价了锰和铅等9种指标及其健康风险。结果表明：地表水中的异常指标有氨氮(平均值750μg/L)、锰(平均值207μg/L),地下水中的异常指标有氨氮(平均值4533μg/L)、锰(平均值4009μg/L);世界卫生组织(WHO)公布的Ⅰ类致癌物砷在地表水及地下水均未见异常。WQI显示研究区内85.7%的地表水适宜饮用。地表水及地下水中氨氮的HQ平均值<1,对人类健康没有不良影响;地下水中锰的HQ平均值>1,可能会对人类健康产生不良影响。地表水及地下水中致癌元素砷的CR值分布区...     

Geochemistry,Paleoenvironment and Mechanism of Organic-Matter Enrichment in the Lower Silurian Longmaxi Formation Shale in the Sichuan Basin,China

To investigate the mechanism of the organic-matter enrichment in the Lower Longmaxi Formation shale, the geochemistry and total organic carbon(TOC) of the Longmaxi Formation black shales in the Jiaoshiba, Zhaotong, and Weiyuan areas of the Sichuan Basin were analyzed. Paleoproductivity proxy parameters(Babio, Siex, and Ni/Al), clastic influx proxies(TiO_2 and Ti/Al), redox indices(V/Cr, Ni/Co, V/(V+Ni), and U/Th), and hydrothermal indicators(Fe, Mn,and Y concentrations; Fe/Ti ratio and a Ni-Zn-Co diagram) were employed to decipher the paleoenvironment of the Lower Longmaxi Formation shales. TiO_2 and Ti/Al indicated low terrigenous detrital influx in all three areas. However, Babio, Siex,and Ni/Al indicated high productivity in the Jiaoshiba area. V/Cr, Ni/Co, and U/Th indicated higher oxygen content with larger fluctuations in the Zhaotong and Weiyuan areas. Fe, Mn, and Y concentrations and the Fe/Ti ratio implied greater active hydrothermal activity in the Weiyuan area. These heterogeneities were considered to be closely related to the paleoenvironment and paleogeography, and the large basement faults that developed during the Chuanzhong paleo-uplift could have provided vents for deep-hydrothermal-fluid upwelling. The redox indices(V/Cr, Ni/Co, and U/Th) and a paleoproductivity proxy(Ni/Al) displayed a significant correlation with the TOC, suggesting that both excellent preservation conditions and high paleoproductivity were the controlling factors for the enrichment of organic matter in the Longmaxi Formation shale. There was no obvious correlation between the clastic influx proxy(Ti/Al) and the TOC due to the extremely low supply of terrigenous debris. The hydrothermal indicator(Fe/Ti) was negatively correlated with the TOC in the Weiyuan area, indicating that hydrothermal activity may have played a negative role in the accumulation of organic matter. This study suggests that the enrichment of organic matter in the Longmaxi Formation marine shale varied according to the paleogeography and sedimentary environment.     

Drought assessment in a south Mediterranean transboundary catchment

ABSTRACT

Predicting the impacts of climate change on water resources remains a challenging task and requires a good understanding of the dynamics of the forcing terms in the past. In this study, the variability of precipitation and drought patterns is studied over the Mediterranean catchment of the Medjerda in Tunisia based on an observed rainfall dataset collected at 41 raingauges during the period 1973–2012. The standardized precipitation index and the aridity index were used to characterize drought variability. Multivariate and geostatistical techniques were further employed to identify the spatial variability of annual rainfall. The results show that the Medjerda is marked by a significant spatio-temporal variability of drought, with varying extreme wet and dry events. Four regions with distinct rainfall regimes are identified by utilizing the K-means cluster analysis. A principal component analysis identifies the variables that are responsible for the relationships between precipitation and drought variability.     

河南夏季高温日数的时空分布特征及500 hPa环流型

对河南省40个代表站1961-2005年夏季≥35℃高温日数进行经验正交函数(EOF)展开分析,结果显示,前3个典型场基本能反映河南夏季高温日数分布的主要特征,前3个模态的累积方差贡献率达85%.据此,得出河南夏季≥35℃高温日数的时空分布类型为全省一致型、西北至东南差异型和西南至东北差异型.第一模态对应的时间系数序列的变化幅度最大,第二模态对应的时间系数序列的变化幅度比前一个时间序列要小.第一模态的时间系数演变显示,河南夏季高温日数平均呈减少趋势,且存在2～4 a、8～14 a的周期变化,目前河南夏季高温日数正处于偏多状态中.应用逐日20时500 hPa ECMWF北半球格点资料,对1991-2005年河南典型的大面积持续高温下的环流形势进行普查、分类,分别求各种类型下的环流平均场,从而得到河南省高温的两种环流型,即贝加尔湖高压型和副热带高压型.     

风云卫星数据服务评价指标的验证分析

简述了目前我国风云卫星数据服务以及气象服务效益评估业务的现状,利用层次分析法提出风云卫星数据服务评价的6个1级指标和19个2级指标。设计了风云卫星数据服务评测量表,并采用分半信度、因子分析等方法对量表作信度和效度分析,结果表明所设计的评测量表具有良好的信度和效度,确定了包括服务平台易用性、服务流程规范性、服务响应及时性、服务内容完整性、服务工作主动性、服务宣传广泛性等6个方面的风云卫星数据服务评价指标。     

不均匀地表产生的中尺度通量的数值试验

采用北京大学三维的复杂地形中尺度模式,结合陆面过程模式(SiB),模拟了草原和沙漠并存的下垫面的边界层大气运动.利用SiB模式计算了地表辐射、感热、潜热通量,并且预报地表温度.中尺度模式则模拟了沙漠地区受热抬升,形成的辐合运动,垂直速度的分布,不同高度上水平流场的变化以及中尺度动量和热量通量,把中尺度通量跟湍流通量进行了比较,以确定这种中尺度运动在GCM模式的参数化过程中的重要性.试验表明中尺度通量尤其是热量通量要比湍流通量大很多.