仿射变换法在航天MSS数据变换中的应用     

华瑞林  潘涛 《地理研究》1988,7(2):81-86

航天MSS数据数字纠正、MSS图象复盖地图资料、遥感图象配置区界的模拟试验等结果表明,仿射变换法可分别满足平地与山区1:25万和1:100万的地理制图的精度要求。  相似文献   

The Reference Manure Concept for Transformation Tests of Veterinary Medicines and Biocides in Liquid Manure     

Robert Kreuzig 《洁净——土壤、空气、水》2010,38(8):697-705

Veterinary medicines and biocides are frequently applied in animal houses of livestock husbandry. Due to these application patterns, they reach liquid manure. So far these substances are not transformed during manure storage, they enter soil by the application of manure as organic fertilizer. Therefore, biodegradability of veterinary medicines and biocides in manure is in the focus of regulatory procedures of environmental risk assessment. Since the representative and reproducible sampling of manures from high volume tanks is considered impossible due to high matrix variabilities, the reference manure concept was developed to utilize liquid bovine and pig manures for reproducible laboratory testing. Accordingly, excrement samples of cattle and pigs individually kept at experimental and conventional animal houses were taken. Tap water was added to matrix characterized excrements in order to prepare bovine and pig reference manures of 10 and 5% dry substance contents, respectively. Subsequently, the long‐term transformation of selected ¹⁴C‐labeled test substances was investigated under strictly anaerobic conditions. The application of different batches of bovine or pig reference manures indicated that extrapolation of transformation rates within the same animal species was possible. However, results cannot be transferred from bovine to pig manure because of substance specific interactions with the different manure matrices. The dependency of metabolic dynamics on different dry substance contents (2.5, 5, 10%) was additionally investigated in both manure matrices. These tests clearly showed that the dry substance content of the reference manure is one of the most relevant factors affecting the transformation of veterinary medicines and biocides. In contrast to highly variable tank manures, the reference manure concept allows for the exact adjustment of this parameter to guarantee reproducible laboratory testing.  相似文献   

Situated adaptation: Tackling the production of vulnerability through transformative action in Sri Lanka’s Dry Zone     

《Global Environmental Change》2021

Drawing attention to the production of vulnerability across scales in Sri Lanka, we contribute to knowledge of why certain people and social groups are vulnerable. We build our contribution on the theoretical application of ‘situated adaptation’. A situated analytical approach identifies, assesses, and responds to the everyday realities and politics of those living in climate changed environments. It highlights uneven geographies of vulnerability and opportunity, while identifying new imaginations and possibilities for transformative action that counter the production of vulnerability. We illustrate the utility of ‘situated adaptation’ by filling an empirical gap relating to experiences of political-economic and environmental change in Sri Lanka’s Dry Zone. We detail situated experiences by drawing on field research in the Anuradhapura District, revealing how the lives and livelihoods of farmer participants are structured by a productivity-vulnerability paradox. We demonstrate how a prevalent adaptation-development paradigm (whereby development and adaptation programs co-exist in theory and practice) is unable to address the structural drivers of vulnerability in Sri Lanka’s Dry Zone. A situated adaptation approach both explains why this is the case and highlights opportunities for alternative transformative actions, potentially identifying a more democratic and egalitarian politics of co-determining socionatural change.  相似文献   

DLT方法在遥感相机几何定标中的应用     

郑逢杰  余涛  陈兴峰  谢东海  袁国体  兰进京 《测绘与空间地理信息》2011,34(2):26-29

为建立适用于遥感相机定标的实验室,需要有几何标定的算法和软件对摄影图像进行计算.使用近景摄影测量中基于3维控制场的定标方法,对单CCD四波段遥感相机进行了几何定标,研究并自主编程实现了直接线性变换DLT(Direct Linear Transformation)算法,与基于空间后方交会算法的定标结果进行了精度对比.结论...  相似文献   

我国夏季高温极值的概率分布特征及其演变   总被引：2，自引：0，他引：2       下载免费PDF全文

周云  钱忠华  何文平  封国林 《应用气象学报》2011,22(2):145-151

针对夏季高温极值分布存在偏态性,利用Box-Cox变换,得到一种偏态概率分布拟合函数。基于偏态分布函数中的偏态指数和最概然高温极值,揭示了我国夏季高温极值的概率分布特征及其在20世纪80年代前后的变化规律,发现我国夏季高温极值的概率分布主要呈正偏分布型,最概然高温极值变化较好地反映了分布型的改变。研究不同时间尺度内极值对偏态指数和最概然高温极值的影响发现,最概然高温极值较为稳定,10年尺度内受极值影响较小,而偏态指数所受影响随着时间尺度的增大而越发显著。  相似文献   

The role of adaptive capacity in incremental and transformative adaptation in three large U.S. Urban water systems     

《Global Environmental Change》2023

Urban water systems need to serve increasing numbers of people under a changing climate. Studies of systems facing extreme events, such as drought, can clarify the nature of adaptive capacity and whether this might support incremental (marginal changes) or transformative adaptation (fundamental system shifts) to climate change. We conducted comparative case studies of three major metropolitan water systems in the United States to understand how actions taken in response to drought affected adaptive capacity and whether the adaptive capacity observed in these systems fosters the preconditions needed for transformative adaptation. We find that while there is ample evidence of existing and potential adaptive capacity, this can be either enabled or diminished by the specific actions taken and their cascading effects on other parts of the system. We also find social dimensions, such as public acceptance, learning, trust, and collaboration, to be as critical as physical elements of adaptive capacity in urban water systems. Finally, we suggest that changes in practices initiated during drought, combined with sustained engagement, collaboration, and education, can lead to substantial and long-lasting changes in values around water, a precursor to transformative adaptation.  相似文献   

322矿田花岗岩与铀矿床的同位素研究     

沈吉  赵乙英 《铀矿地质》1990,6(4):213-219

本文应用同位素地质方法研究322矿田内花岗岩的年龄和成因、成矿热液和成矿物质来源等问题。研究表明,矿田内的成矿母岩为改造型花岗岩,其Rb-Sr同位素年龄为198.8Ma,成矿热液来自花岗岩结晶矿物颗粒间和裂隙中的溶液以及大气降水。成矿物质主要来自花岗岩,部分也来自岩体周围的寒武系地层。  相似文献   

An ecosystem approach to small-scale fisheries through participatory diagnosis in four tropical countries     

《Global Environmental Change》2016

Participatory diagnosis is an approach to identify, prioritize and mobilise around factors that constrain or enable effective governance and management in small-scale fisheries. Diagnostic frameworks are mostly designed and used for systematic scientific analysis or impact evaluation. Through participation they also have potential to guide contextually informed improvements to management in practice, including transitions to contemporary forms of governance like the ecosystem approach to fisheries (EAF)—the focus of our study. We document and critically reflect on participatory diagnosis processes and outcomes at sites in Indonesia, Philippines, Solomon Islands and Tanzania. These sites were part of an international project on the implementation of the EAF and differed widely in institutional and operational contexts. The Participatory Diagnosis and Adaptive Management framework and the “issue radar” diagnosis map were used to identify, evaluate and address factors associated with navigating management transitions towards the EAF. We found that many challenges and priority actions identified by participants were similar across the four study countries. Participants emphasized habitat restoration, particularly mangrove rehabilitation, and livelihood enhancement. The importance of strengthening governance entities, networks and processes (e.g., harmonization of policies, education and awareness of policies) was also a prominent outcome of the diagnosis. Site-specific factors were also explored together with the differing views among stakeholders. We conclude that diagnosis frameworks are indeed useful tools for guiding management transitions in fisheries, particularly where they enable flexibility in approaches to diagnosing problems and applying solutions to local contexts.  相似文献   

Resurrecting vintage paper seismic records     

Peter R. Miles  Marc Schaming  Raúl Lovera 《Marine Geophysical Researches》2007,28(4):319-329

Marine seismic data has been collected for several decades in both academia and industry. Early single channel acquisitions were often, if at all, recorded on magnetic media that are generally no longer supported for replay. Although seismic data over 10 years old has limited quality compared to modern acquisition, thousands of survey km of hard copy records remains world wide in areas with no recent coverage. In addition, many processed multi-channel datasets are now not available as digital files for a variety of reasons. Rising interest in continental margin geology in response to climate change priorities and the UNCLOS submission requirements of maritime states has created a demand to re-use these older records where the cost of new or re-acquisition is not pragmatic. Through creating digital SEG-Y files from images of these records they can be reprocessed and re-interpreted. This paper investigates the practicalities of paper seismic record re-use and measures the performance of a typical conversion option as an indicator of the validity of the concept. Examples of applications of the process illustrate what can be achieved and the limitations that exist so that users can make an informed choice of whether to resurrect their information.  相似文献   

耐盐基因转化蓝藻Synechococcus sp. PCC 7942研究     

刘广发  张会永  楼士林  周克夫 《海洋科学》2002,26(10):43-46

将从极端耐盐的假单胞杆菌中克隆得到的3个基因，即转录调控因子基因，NADH脱氢酶Ⅱ基因和磷酸甘油磷酸酯酶基因转入淡水蓝藻Synechococcus sp.PCC 7942中，使受体藻对NaCl的耐受性从低于2．5％显著提高到4．5％，进一步证明了这3个基因确定与生物的耐盐性密切相关。本实验为进一步培育耐盐经济作物奠定了基础。  相似文献