新疆准噶尔含煤盆地基本构造格架与认识

基于盆地煤田构造与赋煤特征的综合分析,辅以准噶尔盆地西北、东北、东部和南部典型构造剖面的解析分析,厘清了准噶尔盆地的基本构造形态,呈现出如下规律:一是准噶尔现今构造格局于喜山运动中晚期定格,长期处于近南北向构造挤压应力场环境,总体具隆坳相间、南北分带、东西分块的构造格局;二是盆缘四周构造变形强烈,向盆内逐渐减弱且层次变浅,整体呈"环带"构造,反映出准噶尔盆地主体受控于周缘造山带和自盆缘向盆内挤压应力场的动力学、运动学和几何学特征;三是准噶尔盆地大规模聚煤作用是在早中侏罗世短暂的引张或弱挤压的区域构造应力场背景下完成的;四是准噶尔盆地周缘推覆带为可能的煤炭资源勘查开发远景区。     

Locating the Multiple Failure Surfaces for Slope Stability Using Monte Carlo Technique

Owing to the complicated slope stratigraphy (e.g., multiple soil layers and multiple benches or gradients in side slopes), multiple failure surfaces for slope stability have been recognized in geotechnical discipline. This paper aims to develop a systematic and probabilistic approach to locate the multiple failure surfaces combining the traditional limit equilibrium method with Monte Carlo Simulation. Each of the multiple failure surfaces is selected from a large pool of failure surfaces and the correlation coefficient between two failure surfaces in factor of safety (FS) is adopted to characterize the extent to which two failure surfaces are correlated. After eliminating those highly correlated failure surfaces, the multiple failure surfaces can be gradually identified. The number of failure samples and the number of exclusive failure samples corresponding to each of multiple failure surfaces are determined within the proposed methodology. These data are reanalyzed to find the critical failure surface with the maximum failure probability, the critical failure surface with maximum simplified risk, and those failure surfaces dominating the risk of slope failure. The proposed approach is illustrated through two examples excerpted from the literature and validated against the results from the commercial software package and literature. The comparative study manifests that the critical failure surface with the minimum FS does not always coincide with that with the maximum failure probability and with the maximum simplified risk. In addition to FS, the failure surfaces should be received much attention. The proposed methodology provides an effective tool in decision making for slope stabilization and rehabilitation process.     

Target setting and allocation of carbon emissions abatement based on DEA and closest target: an application to 20 APEC economies

Regarded as an effective method for treating the global warming problem, carbon emissions abatement (CEA) allocation has become a hot research topic and has drawn great attention recently. However, the traditional CEA allocation methods generally set efficient targets for the decision-making units (DMUs) using the farthest targets, which neglects the DMUs’ unwillingness to maximize (minimize) some of their inputs (outputs). In addition, the total CEA level is usually subjectively determined without any consideration of the current carbon emission situations of the DMUs. To surmount these deficiencies, we incorporate data envelopment analysis and its closest target technique into the CEA allocation problem. Firstly, a two-stage approach is proposed for setting the optimal total CEA level for the DMUs. Then, another two-stage approach is given for allocating the identified optimal total CEA among the DMUs. Our approach provides more flexibility when setting new input and output targets for the DMUs in CEA allocation. Finally, the proposed approaches are applied for CEA target setting and allocation for 20 Asia-Pacific Economic Cooperation economies.     

新疆卡特巴阿苏金矿床矿体特征及金赋存状态研究

新疆卡特巴阿苏金矿床是那拉提-红柳河金-铜-镍-铅锌-玉石-白云母成矿带内近几年发现的特大型金矿之一。在野外地质调查和室内综合整理基础上,利用显微镜鉴定、扫描电镜观察和X射线能谱仪测试分析等手段和方法,对金矿石中金的赋存状态进行了研究。结果表明,卡特巴阿苏金矿床金矿物主要以自然金和含银自然金的形式存在,自然金成色为764.5‰~1 000‰;主要载金矿物为黄铁矿,有少量黄铜矿及脉石矿物;金的嵌布类型有裂缝金、晶间金和相对较少的包裹金3种形式;矿石中自然金均为粒度小于40μm的显微粒金。     

Adjoint sensitivity study on idealized explosive cyclogenesis

The adjoint sensitivity related to explosive cyclogenesis in a conditionally unstable atmosphere is investigated in this study.The PSU/NCAR limited-area,nonhydrostatic primitive equation numerical model MM5 and its adjoint system are employed for numerical simulation and adjoint computation,respectively.To ensure the explosive development of a baroclinic wave,the forecast model is initialized with an idealized condition including an idealized two-dimensional baroclinic jet with a balanced three-dimensional moderateamplitude disturbance,derived from a potential vorticity inversion technique.Firstly,the validity period of the tangent linear model for this idealized baroclinic wave case is discussed,considering different initial moisture distributions and a dry condition.Secondly,the 48-h forecast surface pressure center and the vertical component of the relative vorticity of the cyclone are selected as the response functions for adjoint computation in a dry and moist environment,respectively.The preliminary results show that the validity of the tangent linear assumption for this idealized baroclinic wave case can extend to 48 h with intense moist convection,and the validity period can last even longer in the dry adjoint integration.Adjoint sensitivity analysis indicates that the rapid development of the idealized baroclinic wave is sensitive to the initial wind and temperature perturbations around the steering level in the upstream.Moreover,the moist adjoint sensitivity can capture a secondary high sensitivity center in the upper troposphere,which cannot be depicted in the dry adjoint run.     

山东省农业干旱脆弱性区划研究

选取山东省17个地级市为研究对象,根据影响山东农业旱灾的自然环境、经济环境、社会环境3方面因素确定了指标体系,构建了山东省农业干旱脆弱性区划层次分析模型,建立了判断矩阵,对山东省农业干旱脆弱性情况作了评估研究,并绘制出山东省17地市农业干旱脆弱性区划图。结果表明:在2000—2013年的14年间,山东省农业干旱脆弱性评价为不脆弱的城市有5个,轻微脆弱的城市有4个,脆弱的城市有4个,强脆弱的城市有3个,极端脆弱的城市有1个。山东省农业干旱脆弱性空间分布格局,全省大致是东南与西北方向低,中部与西南方向高,脆弱性区划的结果反映出山东省农业干旱风险程度的地域性差异,脆弱性较高的地市应作为农业干旱灾害防御的重点区域。     

The Effects of Spatial Scale and Aggregation on Food Access Assessment: A Case Study of Tucson,Arizona

Adequate access to healthy food has become a social issue due to the recent Great Recession and heightened levels of unemployment. Geographers have focused their attention on how to accurately evaluate food access and how to identify and delineate food deserts; that is, low-income neighborhoods where affordable and healthy food is lacking or limited. Findings of recent food access studies are, however, dramatically inconsistent. We argue that spatial scale and the level of aggregation used in constructing food access measures could account for a major portion of the varying results. We draw on an empirical study in the Tucson, Arizona, metropolitan area, to examine how varying geographic scales and aggregation methods affect food access assessment. We also provide an analysis to show how spatial scale and aggregation practices lead to inconsistent conclusions about food access and designation of food deserts.