Improving National Park Service and Nonprofit Partnerships—Lessons from the National Trail System

Federal land management agencies are increasingly relying on collaborative partnerships for managing national trails, heritage areas, scenic rivers, and recreation areas. For agencies such as the National Park Service, these joint approaches are significantly different from traditional management approaches. This article uses a case study of the Juan Bautista De Anza National Historic Trail to identify partnership lessons for this case and other protected areas that rely on public–private partnerships. The research highlights partnership issues with nonprofit capacity and mission alignment, project momentum, and leadership dilemmas. We suggest that agencies such as the National Park Service need to assess the mission and capacity of community and nonprofit groups to determine their partnership approach. This is a significant shift, from agencies simply needing to find organizations willing to partner on collaborative management efforts, to a role in assessing, forming, and developing nonprofit partners.     

纹理特征与视觉注意相结合的建筑区提取

提出一种有效提取高分辨率遥感影像建筑区的算法。通过模拟人类视觉系统感知环境的过程,引入视觉注意机制,提出基于自信息最大化视觉注意机制的建筑区显著指数。根据建筑区在高分辨率遥感影像中的特点,基于时/频域的纹理分析,提出一种针对建筑区的纹理特征描述方法,实现了建筑区的高效提取。通过对8组高分辨率遥感影像进行试验,验证了本文算法的有效性。     

关于山区道路工程控制网布设方案研究

对于贵州山区而言,多数道路工程测区中通常是山峦起伏、荆棘丛生,致使通视、通行条件差,因此,建立满足工程施工需要和符合控制精度要求并能尽量减少工作量的测量控制网是很有研究价值的。从通视性分析和网形优化的角度提出控制网的布设方案,希望对今后的此类项目实施起到一定的借鉴作用。     

北京市绿化隔离地区信息化管理的研究

为了实现北京绿化隔离地区的信息化管理,本文通过现有的绿地的相关数据,结合ArcGIS Server、ASP.NET以及数据库技术,提出了一种结合WebGIS技术进行绿地动态监测的方法,来完善绿化隔离地区信息化管理;据此设计技术方案,进而建立动态监测系统,实现北京市绿化隔离地区的动态监测、动态管理以及统计分析,为政府的规...     

不同农村居民点整理模式下的耕地潜力评价模型

设计了农村居民点整理复耕流程,划分了农村居民点城镇化、内部改造与迁村并点3种整理模式,统筹区域农户意愿与经济条件两大影响因子,分标准定量评价不同整理模式下的现实整理潜力。综合考虑坡度、耕作半径、耕地连片度、居耕比等影响因子,以GIS空间分析为平台,构建了不同农村居民点整理模式下的耕地潜力评价模型。     

秦安县农村居民点空间分布景观格局分析

基于RS与GIS技术,以2008年甘肃省秦安县SPOT遥感影像为数据源,主要选职斑块面积、斑块数、平均斑块面积、斑块大小变异系数、斑块大小标准偏差、平均形状指数、平均周长．面积比、平均斑块分维数8个景观指数,从居民点用地、规模、形态、分布等方面进行景观空间格局分析。结果表明：秦安县农村居民点分布特点受坡度、坡向、高程、...     

中国西部及邻区百年尺度周期的地震活动及其和太阳活动之间的负相关性

利用小波变换分析中国西部及邻区1700年以来M≥7级和M-T图分析1700年以来M≥7.8级地震活动,除了得到和其他学者研究基本一致的几个十年尺度周期结果外,还得到百年左右尺度的地震活动周期结果,再与太阳黑子活动进行比较,发现地震活动与太阳黑子数在百年左右尺度周期上具有负相关性,地震高活动时段对应太阳黑子低值时段.此外...     

复合隔震墩隔震性能的振动台试验研究

通过对农村民居特点的研究,提出一种新型、经济、简单、可靠的隔震技术—钢筋-沥青复合隔震墩.根据相关理论设计了相应的隔震墩试件.通过地震模拟振动台试验输入E1 Centro和Taft地震动与结构地震反应的对比,研究了钢筋-沥青复合隔震墩模型的振动特性.试验结果表明,隔震墩加速度折减系数在0.34 ～ 0.55之间,可有效...     

山东东部及近海地区中等以上震例前地震活动性参数群体异常研究

对1975年以来山东东部及近海地区16次ML≥4.7级地震前的地震学参数群体异常进行了研究.回顾性检验表明,地震活动性单项参数中,反映地震强度、频度及与强度、频度有关的地震参数异常在本区的中强地震预测中较为有效.参数的时程曲线中Et、QP和η值一般表现为低值或由高值转为下降异常形态,其余参量多数显示为高值异常.在20余...     

Chemical characterization of naturally weathered oil residues in the sediment from Yellow River Delta, China

With its close proximity to Shengli Oilfield, China’s second largest oilfield, the Yellow River Delta is at high risk for crude oil contamination. The massive oil discharge in oilfield may offer a chance for a natural experiment to investigate compositional changes of oil residues and study the stability of source- and weathering-dependent molecular parameters in oil residues after spills. The results demonstrate that the conventional diagnostic ratios, such as C₂₉20S/(20S + 20R), C₂₉/C₃₀H, C₃₀βα/αβ, C₃₁22S/(22S + 22R), C₂-DBTs/C₂-PHENs, C₃-DBTs/C₃-PHENs, DBT/MCHRY, CHRY/PHENs, are also valid for oil source identification even after extensive weathering of spilled oils in terrestrial environment, although some exceptions were encountered for extensively weathered sample. Moreover, the ratios of selected specific biomarkers (the oleanane index, the gammacerane index) have been developed and assessed as source indicators. Finally, we find that some maturity parameters based on alkyl naphthalenes and methyl phenanthrenes in petroleum geochemistry, such as the methylnaphthalene ratios (TMNr, TeMNr, PMNr), the methylphenanthrene ratios (MPI-1, MPDF), can be applied for the source identification and correlation at their lightly to moderately weathered stage.