黑龙江嘉荫地区白垩系与古近系界线附近的古气候分析

本文在前人应用古生物及锆石测年资料确定的黑龙江嘉荫地区白垩系与古近系界线附近,用地球化学指标分析了该区在该时段的气候变化趋势。作者主要是应用电感耦合等离子发射光谱仪（ICP—AES）测定了界线附近全岩样品的部分元素含量,从中提取能指示气候变化的常规气候指标CaO／MgO、Sr／Ba,并用因子分析的方法综合探讨该区在界线附近的古气候变化。分析结果显示,嘉荫地区在白垩纪末到古近纪初,气候整体上呈气温下降、降水增多的趋势,这一趋势与前人在该区从古生物方面得出的结果以及当时的生态相似区（北美）的气候变化基本一致。     

Spatial modelling of sprinkler irrigation suitability in a Central Brazilian Cerrado region

Sprinkler irrigation, an agricultural production system that is causing increasing conflict among water resource users, is expanding quickly in the Central Western Cerrado regions of Brazil. To subsidize watershed management and concession of water rights, GIS-based spatial modelling was applied to spatially predict relative likelihood of the installation of centre sprinkler irrigation systems. Interpretation of multitemporal Landsat Thematic Mapper and Enhanced Thematic Mapper imagery was conducted to map spatial distribution of centre-pivot sprinkler systems. Multi-source data layers on environmental conditions and infrastructure were elaborated to test their predictive power in an Ecological Niche Factor Analysis, a spatial modelling technique for presence-only data. Underpinned by an exploratory analysis of spatial autocorrelation of irrigation systems, suitability predictions were found to be accurate on landscape scale and improved when the model includes underlying ecogeographical factors (EGV) such as farming suitability, soil groupings and distance to the hydrographic network and a density layer of existing irrigations.     

甘肃省若干地段强震地面运动特征

以甘肃、陕西等地历年来获得的强震记录,主要是汶川大震的强震记录,研究了甘肃省强震地面运动的特征以及不同场地的地震反应。注意到本地地震动具有大陆板内地震的特点,与强震记录最多的美国西部地震动有较大的差别。甘肃的场地类型大致可以分为四个区域:河西走廊、黄土地区、陇南山区和甘南高原区,强震地面运动特征各自具有其自身的特点,又和地震动的特性有密切的关系。认为有必要对汶川大震的强震记录作全面而系统的研究,进而应用到我国的地震安全性评价中去。     

会昌地震台相同测点倾斜固体潮观测之对比分析

通过对会昌地震台2007-07～2011-06相同测点倾斜固体潮资料的对比分析,可以看出垂直摆资料质量稍优于水管仪资料,两种资料存在着一定的可比性。其主要的相同之处表现在于年变趋势动态、日变形态和降雨、强远震波动、潮汐因子的时间同步性上;而NS向线性倾变、潮汐因子定量化和高频信号频谱等方面存在一定差异。这种差异主要可能为观测山洞的环境条件和仪器工作特性的不同。为改善地倾斜资料高频信息记录能力,建议提高仪器采样率和改进仪器频率响应设计。     

Integrated urban and rural water affairs management reform in China: Affecting factors

The institutional evolution is often induced by some factors. This paper intends to analyze the affecting factors in integrated urban and rural water affairs management reform in China. The integrated urban and rural water affairs management reform is to restructure the governmental organizational setting in water management by forms of water affair bureau or re-designing functions of current water resources bureau to incorporate part or all functions of resources management, service regulation and environment management in water sector. The analyses selected some natural and socio-economic factors. The results point out that the integrated urban and rural water affairs management reform is a factor-induced institutional evolution. The factors promoting this reform include occasional drought events, higher central water investment percentage; but the data from the urban sector do not provide the support to the reform.     

从影响因素相互作用关系分析岩石边坡的稳定性

从区域上影响岩石边坡稳定性的地质和工程两方面因素相互作用出发建立关系矩阵,进一步得到它们各自权重,并求得岩体不稳定性指数（ＲＭＩＩ）;通过观察实际变形边坡影响料大的地质因素是同现及其作用程度计算出可预报性估值（ＰＲ）。结合实验对两者结果进行了比较。     

安顺市2015—2019年冰雹时空特征 及雷达临近预警指标研究

利用安顺市2015-2019年降雹个例、Micaps常规观测资料以及贵阳雷达资料,分析总结了安顺市冰雹时空分布特征及雷达临近预警指标。结果表明：安顺市冰雹以直径20 mm以下的小冰雹为主,冰雹站次呈北多南少特征;冰雹天气主要发生在春季,4月最多,5月次之;2015—2019年期间,2019年安顺市冰雹站次最多,2017年最少。直径10 mm以上与直径10mm以下冰雹对应的雹云相比,其强回波值更强、降雹概率更高、强回波中心平均升降次数更多、上升幅度及最高上升高度更高（须在0 ℃层高度以上）、对应的径向速度场有明显特征（逆风区、辐合/辐散、旋转）的比例更高、径向速度特征（逆风区、辐合/辐散、旋转）出现时间较降雹时间提前量更多。此外,强回波中心上升高度（0 ℃层高度以上）越高,冰雹直径越大。以上雷达回波特征均可作为安顺市冰雹预警指标,有利于提高安顺市冰雹预警准确率及提前量。     

北京地区“环流－降水－谷物”系统的短期振动研究

文章用因子分析方法提取北京地区小麦气象产量主要特征及代表序列，并对该序列和北京地面气象要素的关系用交叉谱进行研究。发现它们在前期秋冬季中的４－６年的周期振荡（中心周期为４．５年）中有显著的相关，当前期秋季和冬季的降水量和气温在振荡中处于正距平时，当年的气象产量为丰年，反之为欠年；进一步对该序列与大气环流的静力和动力物理量之间关系研究发现它们在同样的周期振荡中有十分强烈的表现，尤其表现在与动力物理量上。研究结果进一步证实“环流－降水－谷物”系统的存在，并揭示在短期气候振动（４－６年）上的规律性。      

Determination of the critical failure surface for slope stability analysis using ant colony optimization

Slope stability analysis of any natural or artificial slope aims at determining the factor of safety of the slip surface that possesses the lowest factor of safety. In this study, an ant colony optimization (ACO) algorithm is developed to solve this factor-of-safety minimization problem. Factors of safety of slip surfaces are found by using the Morgenstern–Price method, which satisfies both force and moment equilibrium. Nonlinear equations from the Morgenstern–Price method are solved numerically by the Newton–Raphson method. In the proposed ACO algorithm, the initiation point and the shape of the slip surface are treated as the search variables. The proposed heuristic algorithm represents slip surfaces as piecewise-linear curves and solves for the optimal curve yielding the minimum factor of safety. To demonstrate its applicability and to investigate the validity and effectiveness of the algorithm, four examples with varying complexity are presented. The obtained results are compared with the available literature and are found to be in agreement.     

辽宁中部城市群夏季大气能见度的观测研究

利用2009年6—8月辽宁中部4个城市的观测资料,分析了辽宁中部城市群夏季的季、月、日能见度分布,并探讨了能见度的日变化特征及其影响因子。结果表明:辽宁中部城市群内各城市夏季大气能见度月际变化趋势基本一致,天气系统和大气环境比较均一,具有明显的区域性特征;各城市大气能见度日变化呈明显的单周期谷、峰形分布,06时前后能见度最差,15—16时最好;大气细粒子、水汽和风速都对城市群能见度有一定的影响,其中,大气细粒子是主要影响因子;城市群夏季的低能见度时次,仅有一小部分是由轻雾引发的,而大部分则是由霾天气造成的。