中美地理学近百年发展脉络的比较研究——基于《地理学报》和Annals of the Association of American

基于《地理学报》和Annals of the Association of American Geographers学术论文的统计,对比近百年中美两国地理学的发展脉络,着重从总体特征、重点研究内容及其变化、理论—实践关系三方面对比异同,获得经验和借鉴。美国地理学经过初期发展、高速发展后,目前进入持续发展阶段;中国地理学在曲折中崛起,目前正处在高速发展时期。美国地理学中人文地理学一直居主导地位,中国则从重视自然地理开始逐渐向自然、人文、方法三足鼎立方向迈进;美国地理学家非常重视微观、中观实践,但在国家宏观决策中远没有中国地理学家发挥作用更直接。美国地理学研究水平高于中国,但这种差距正在缩小,研究方向的变化相差3~5年。世界地理研究中心有向亚太地区、向中国转移的可能,中国地理学家要勇于创建具有中国特色的地理学派。     

南华北盆地阜阳区块古生代地震层序划分及地震相研究

阜阳区块位于南华北盆地的周口坳陷东部,面积约11000km^2,占坳陷面积的三分之一;该盆地按照中、新生界构造特征将其划分为六凹四凸;随着油气勘探的深入和地质研究的深化,笔者利用该区地震剖面进行地震层序研究与划分,并进一步进行了沉积相的研究,为该区古生代的油气勘探提供科学依据。     

义煤集团西部四矿奥灰水防治技术研究

2006年曹窑东井27080工作面突然发生大型奥灰滞后突水,最大涌水量达到1693m^3／h,通过矿井水文地质条件分析,曹窑东井及相邻西部四矿大部分区域已处于“突水危险区”。为避免奥灰突水灾害再次发生,提出了“以防为主”的预防奥灰突水的技术手段和方法步骤,以探索深部煤炭开采的防治水工作。     

我国暴雨形成机理及预报方法研究进展

本文分别从华南前汛期暴雨、江淮流域梅雨锋暴雨、华北和东北暴雨以及暴雨预报方法等方面回顾了我国近年来在三大主要雨带的观测、数值模拟、动力机理及诊断分析和预报方法方面取得的进展,指出了华南前汛期暴雨、江淮梅雨锋暴雨及华北东北暴雨研究取得的新认识,认为华南前汛期暴雨的形成机理主要是发生在低空南风向北推进过程中,由海岸线及地形抬升而产生位势不稳定造成强上升运动,以及由于南风低空急流向北发展时产生急流前部的辐合而发生流线分叉使低层低涡发展,促进垂直运动加强或使正涡度集中促使垂直运动发展而造成暴雨;江淮暴雨生成机制主要与对称不稳定、涡度场变化及β中尺度对流线有关;而华北东北暴雨过程中的非均匀饱和引起的局部湿度集中特点较为明显,中高层干冷空气入侵引起的不稳定和动量下传及高空中尺度急流增强引发的高层局地辐散增强对暴雨发生有重要作用。目前,新型探测资料已经用到暴雨研究和预报中,具有自主知识产权的GRAPES-MESO和GRAPES-GFS系统已经实现业务化,并在集合数值预报方面取得显著进步,且动力因子暴雨预报方法在很多省市气象台得到推广应用。虽然暴雨机理研究和预报已经取得以上诸方面的长足进步,但是也还存在不少问题,需要加强基于观测的暴雨中尺度系统的理论研究、数值模式动力框架和物理过程描述的改进、资料同化理论技术的发展及人工智能技术如何用到大气科学的研究和业务应用等,以期在我国暴雨中尺度系统的三维精细结构、发生发展机理和预报理论和方法研究方面取得更大进步。     

南极海洋保护区设立的适宜性评价研究

南大洋海域因其特殊的地理位置、极端的气候环境和丰富的资源,具有重要的科学和经济意义。当今世界各国力争国家权益,积极参与南极海洋保护区设立的国际事务,然而我国虽对此持续关注,但相关研究甚少,在南极海洋保护区设立的适宜性评价指标和区划方法研究方面几近空白。在此背景下,通过对现有各国南极海洋保护区的提案分析,尝试构建南极海洋保护区设立的适宜性评价的多级指标体系,并基于我国南极科学考察数据,运用层次分析法和加权叠加分析,对普里兹湾海洋保护区设立的适宜性进行案例研究,以期为我国南极海洋保护区的设立和相关研究提供参考。     

The Lingering Effects of Neighborhood Appraisal: Evaluating Redlining's Legacy in Pittsburgh

Place-based classifications can create long-standing influences on neighborhood fortunes. Redlining is a classic example of these unintended effects. The Federal Home Loan Bank Board developed housing appraisal standards subsequently codified in Residential Security Maps. By georeferencing the 1937 map of Pittsburgh, we evaluated the spatial legacies of neighborhood appraisals. We identify persistent neighborhood conditions by comparing neighborhood evaluations with normalized census data from 1970 to 2000. Contemporary conditions correspond with security grades from the 1937 map. Concentrations of poverty, people of color, and vacancy persist in historically redlined areas. Concentrations of high incomes, home values, and homeownership persist elsewhere.     

共水平轴双叶轮海流机水动力学性能的实验研究

针对水平轴单叶轮海流机在低流速时启动性能差、获能少的缺点,采用共水平轴同向旋转双叶轮水轮机进行了水动力学性能的水槽试验.由实验结果研究了共水平轴单叶轮和双叶轮水轮机的功率特性和启动特性,分析了不同上、下游叶轮安装角和叶轮轴向间距对叶轮启动水流速度以及发电机获得功率的影响,并对单叶轮和双叶轮水轮机的运行情况进行了比较.结果表明,共水平轴双叶轮水轮机的启动水流速度较单叶轮低很多,而且能从水流中获得更多的能量.因此,共水平轴双叶轮水轮机能改进一般水平轴单叶轮水轮机难以启动和获能少的不足,更适合于我国低海流流速的实际海况.     

Quantifying and modelling urban stream temperature: a central US watershed study

Hydrologic models that rely on site specific linear and non‐linear regression water temperature (T_w) subroutines forced solely with observed air temperature (T_a) may not accurately estimate T_w in mixed‐use urbanizing watersheds where hydrogeological and land use complexity may confound common T_w regime assumptions. A nested‐scale experimental watershed study design was used to test T_w model predictions in a representative mixed‐use urbanizing watershed of the central USA. The linear regression T_w model used in the Soil and Water Assessment Tool (SWAT), a non‐linear regression T_w model, and a process‐based T_w model that accounts for watershed hydrology were evaluated. The non‐linear regression T_w model tested at a daily time step performed significantly (P < 0.01) better than the linear T_w model currently used in SWAT. Both regression T_w models overestimated T_w in lower temperature ranges (T_w < 10.0 °C) with percent bias (PBIAS) values ranging from ?28.2% (non‐linear T_w model) to ?66.1% (linear regression T_w model) and underestimated T_w in the higher temperature range (T_w > 25.0 °C) by 3.2%, and 7.2%, respectively. Conversely, the process‐based T_w model closely estimated T_w in lower temperature ranges (PBIAS = 4.5%) and only slightly underestimated T_w in the higher temperature range (PBIAS = 1.7%). Findings illustrate the benefit of integrating process‐based T_w models with hydrologic models to improve model transferability and T_w predictive confidence in urban mixed‐land use watersheds. The findings in this work are distinct geographically and in terms of mixed‐land use complexity and are therefore of immediate value to land‐use managers in similarly urbanizing watersheds globally. Copyright © 2015 John Wiley & Sons, Ltd.     

2003年南极威德尔海至普里兹湾之间海冰分布研究

Ship-based sea ice observation data (concentrations,ice thickness,topography and overlying snow cover) were collected from Middle Weddell Sea to Prydz Bay,Antarctic during the period of 4 to 17 Jan 2003.Antarctic ice chart of first week of Jan 2003 was derived from National Ice Center (NIC).The compared analysis of sea ice concentrations and thickness distributions were conducted though in situ data and NIC chart.Results from sea ice concentration-analysis indicated the presence of large-scale open water between 2000 and 4100 km along transit route resulted from sea ice drifting.We describe the existence of mostly smooth first-year sea ice in study region ranged between 30 and 120 era.We also display the derived overlying snow coverage.Our results reveal the strong correspondence between ship-based observations and remotely sensed ice charts whatever in ice concentrations and ice thickness distributions.