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21.
《Marine Policy》2015
Substandard vessels that fail to comply with international maritime regulations are the target of Port State Control inspections. Despite their significant costs, many inspections do not lead to any detentions and, in a significant number of cases, no deficiencies are detected. In this paper, quantile regressions for count data are used to estimate the likelihood of having a high number of deficiencies of a specific type. The purpose is to complement existing practices focusing on detention with the objective to improve the selection process. Similar factors influence the likelihood of having a vessel detained and that of having a vessel recording a high number of deficiencies. However, quantile regressions applied to the number of deficiencies help improving the identification of factors influencing the likelihood of finding some specific types of deficiencies, which is the focus of Concentrated Inspection Campaigns. The paper concludes that the selection process for such campaigns should be improved using this new methodology. 相似文献
22.
The proportional contributions of stream bank and surface sources to fine sediment loads in watersheds in New York State were quantified with uncertainty analysis. Eroding streamside glacial drift, including glaciolacustrine deposits, were examined to help explain variations in the proportional contributions made by bank erosion. Sediment sources were quantified by comparing concentrations of the bomb‐derived radionuclide 137Cs in fluvial sediment with sediment from potential source areas such as agricultural soils, forest soils and stream banks. To compare sediment sources in streams containing abundant deposits of fine‐grained glacial drift with watersheds that lacked moderate or extensive streamside deposits, samples were taken from 15 watersheds in the region. The mean contribution of bank erosion to sediment loads in the six streams with glaciolacustrine deposits was 60% (range 46–76%). The proportional contribution of bank erosion was also important in one stream lacking glaciolacustrine deposits (57%) but was less important in the remainder, with contributions ranging from 0 to 46%. Data from this study on the varying contributions of bank erosion and data from past studies of sediment yield in 15 watersheds of New York State suggest that eroding streamside glacial deposits dominate sediment yield in many watersheds. In other watersheds, past impacts to streams, such as channelization, have also resulted in high levels of bank erosion. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
23.
《Geoforum》2015
In Malaysia, second largest palm oil producer worldwide, logging companies, palm oil corporations, and even responsible citizens can now compensate their biodiversity impacts by purchasing Biodiversity Conservation Certificates in an emerging new biodiversity market: the Malua BioBank. Biodiversity markets are part of a wider trend of marketisation and neoliberalisation of biodiversity governance; introduced and promoted as (technical) win–win solutions to counter biodiversity loss and enable sustainable development. The existing neoliberalisation and nature literature has tended to analyse these processes as consequences of an inherent drive of capital to expand accumulation and submit ever more areas of nature to the neoliberal market logic.In contrast, I aim (a) to problematise the agency and the “work” behind marketisation of biodiversity, challenging the story of (corporate-driven) neoliberalisation as the realisation of an inherent market-logic (based on the a false conceptual state–market divide, often prevalent even in activist academic circles working on neoliberalisation of nature) and to see the state not only as regulator, but driving force behind, and part of “the market”; (b) to question the myth of neoliberalisation as state losing control to the market and to show how the state is using the biodiversity market as mode of governing; re-gaining control over its forests and its conservation policy; and (c) to demonstrate empirically the distinction between neoliberal ideology and practice, and to show that marketisation was based on pragmatic decisions, not ideology-driven political action. My analysis is based on 35 qualitative interviews with actors involved in the BioBank. 相似文献
24.
I. D. Lewis 《Australian Journal of Earth Sciences》2019,66(6):785-792
South Australia’s State Heritage Register contains 2294 listed places, the majority of which are from the ‘Built’ environment, ranging from settlers’ huts, community buildings, historical industrial sites to magnificent stone mansions. Only 96 places are linked to the ‘Natural’ environment. The Register listings protect heritage places from alteration, damage or removal without formal prior consultation, compulsory under the South Australian Development Act. ‘Natural’ environments are landscape-based and oriented towards Geological, Archaeological, Palaeontological and Speleological heritage (‘GAPS heritage’). A process to provide a greater balance between ‘Natural’ and ‘Built’ listings has initiated a series of State Heritage ‘Natural’ environment assessments, mostly of single sites. Two individual caves in the Naracoorte Caves National Park are already entered in the State Heritage Register as single sites. However, an innovative broader multiple-site nomination has focused on the many different but significant GAPS features contained within the 25 caves of the Naracoorte Caves National Park, providing a further level of protection for the land and the caves’ exteriors and interiors. The example of the Naracoorte Caves draws attention to the number of important land and coastal karst (limestone) features across South Australia that were generated by steady geological uplift of three large sections of Oligocene–Miocene limestone—the Nullarbor Plain, the Murray Basin and the Gambier Karstfield (which includes Naracoorte and Mount Gambier), resulting in specific karst forms worthy of a broader coordinating management approach across South Australian karst parks. 相似文献
25.
Paleoproterozoic volcanic rocks in the southern margin of the North China Craton,central China:Implications for the Columbia supercontinent 总被引:1,自引:0,他引:1
The volcanic rocks of the Xiong'er Group are situated in the southern margin of the North China Craton(NCC).Research on the Xiong er Group is important to understand the tectonic evolution of the NCC and the Columbia supercontinent during the Paleoproterozoic.In this study,to constrain the age of the Xiong'er volcanic rocks and identify its tectonic environment,we report zircon LA-ICP-MS data with Hf isotope,whole-rock major and trace element compositions and Sr-Nd-Pb-Hf isotopes of the volcanic rocks of the Xiong'er Group.The Xiong'er volcanic rocks mainly consist of basaltic andesite,andesite.dacite and rhyolite,with minor basalt.Our new sets of data combined with those from previous studies indicate that Xiong'er volcanism should have lasted from 1827 Ma to 1746 Ma as the major phase of the volcanism.These volcanics have extremely low MgO.Cr and Ni contents,are enriched in LREEs and LILEs but depleted in HFSEs(Nb,Ta,and Ti),similar to arc-related volcanic rocks.They are characterized by negative zircon ε_(Hf)_(t) values of-17.4 to 8.8,whole-rock initial ~(87)Sr/~(86)Sr values of 0.7023 to 0.7177 andε_(Nd)(t) values of-10.9 to 6.4.and Pb isotopes(~(206)Pb/~(204)Pb =14.366-16.431,~(207)Pb/~(204)Pb =15.106-15.371,~(208)Pb/~(204)Pb= 32.455-37.422).The available elemental and Sr-Nd-Pb-Hf isotope data suggest that the Xiong'er volcanic rocks were sourced from a mantle contaminated by continental crust.The volcanic rocks of the Xiong'er Group might have been generated by high-degree partial melting of a lithospheric mantle that was originally modified by oceanic subduction in the Archean.Thus,we suggest that the subduction-modified lithospheric mantle occurred in an extensional setting during the breakup of the Columbia supercontinent in the Late Paleoproterozoic,rather than in an arc setting. 相似文献
26.
Hospital service area (HSA) and hospital referral region (HRR), known as a hierarchical HSA system, have been used as analysis units in a growing body of large‐scale studies of healthcare spending, utilization, and outcome in the United States. However, the popular Dartmouth HSAs and HRRs were produced more than two decades ago and are unable to represent contemporary healthcare markets. This research uses a revised Huff Model to delineate two levels of hospital service areas in Florida, resulting in sixty‐four HSAs nested in twenty‐one HRRs. Three elements distinguish our method from existing work. First, a best‐fitting distance‐decay function derived from the actual travel pattern of hospitalization is embedded in the Huff Model to strengthen the model's theoretical foundation in individual spatial behavior. Secondly, the hierarchal central place structure is supported by the differing travel‐friction coefficients for general versus specialized patients; general patients experience a steeper gradient and thus a shorter average travel range that supports delineating more HSAs of smaller area size, and specialized patients exhibit a flatter gradient and thus a longer average travel range that leads to fewer HRRs of large‐sized areas. Finally, the delineation method automated in geographic information systems (GIS) can be easily replicated in other regions to define large‐scale and consistent hierarchical HSA systems. 相似文献
27.
ABSTRACTBased on a large-scale household survey conducted in six large Chinese cities, this study is among the first attempts to juxtapose factors related to institution, market, and demography to examine the complex patterns and mechanisms of housing differentiation and housing poverty in low-income neighborhoods, which are conventionally conceived as homogenous substandard settlements. Results of Theil indices and multivariate regression models convey several interesting findings. First, the forces of the market and the State have projected different impacts on various aspects of housing status. Institutional factors had significant impacts on some costly and durable housing indicators such as housing tenure and housing area, while market forces have swiftly transformed the most malleable aspects of housing conditions, such as housing facilities, and will eventually replace some institutional legacies. Second, within-group housing differentiation is more palpable than between-group housing differentiation, suggesting that low-income neighborhoods in large Chinese cities are fluid and heterogeneous. Third, different institutional elements have different impacts on housing poverty. The well-functioning market remuneration system helps reduce the risk of housing poverty, yet working poor remains a severe problem. These findings can inform policies promoting social mix and housing affordability. 相似文献
28.
Groundwater exploitation is an essential aspect of the numerous processes of transforming the urban natural environment for human gains. We use the political ecology of borehole exploitation in Nigeria’s urban environment to understand the micro-and macro-level processes mediating the transformation and changes in urban “groundwater scape”. The fieldwork processes depend on field counting of borehole distribution, in-depth and semi-structured interviews, and a review of secondary literatures. We argue that the social and environmental changes arising from the exploitation of groundwater bespeak the active and continual manifestation of the interplay of combustible interests and power friction among institutional agents within the permissible range of the natural environment. Such dynamic power relations engender a pattern of socio-natural transformation consistent with Swyngedouw’s notion of urban metabolism- “a series of interconnected heterogeneous and dynamic but contested and contestable processes of continuous quantitative and qualitative transformations that re-arranges humans and non-humans in new and often unexpected ways”. 相似文献
29.
30.
用磁力浮沉子密度测量装置,在15 ~25 ℃之间的三个温度下测定了珠江口20 个水样的密度。结果表明,测定值皆高于相应条件下国际标准海水状态方程的计算值,在海水盐度范围0.08~33 .446 ,密度平均偏差范围为2 .4 ~54.0 ×10 - 3kg/m3 。测定密度和计算密度的偏差随盐度的降低而增大,与盐度的变化成直线相关:与(Ca2 + )/S、SO42 - /S比和比碱度之间皆呈指数曲线相关。珠江口水样(Ca2 + )/C1 、SO42 - /C1 和比碱度平均值分别超出大洋水平均值17 .8 % 、8 .21 % 和152 % ,其余的Na + /C1、K+ /C1 和Sr2 + /C1 比值与大洋水无明显差别,基本类同。珠江口海水的高碱度、高(Ca2 + )/C1 和高SO42 - /C1 是造成其海水密度正偏差的主要因素。经计算机拟合,首次导出了珠江口海水密度的状态方程,该方程计算值与实验值的平均标准偏差为±2.5×10- 3kg/m3 。 相似文献