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51.
Brian N. Tissot Barbara A. Best Eric H. Borneman Andrew W. Bruckner Cara H. Cooper Heather D’Agnes Timothy P. Fitzgerald Amanda Leland Susan Lieberman Amy Mathews Amos Rashid Sumaila Teresa M. Telecky Frazer McGilvray Brian J. Plankis Andrew L. Rhyne Glynnis G. Roberts Benjamin Starkhouse Todd C. Stevenson 《Marine Policy》2010
As the world’s largest importer of marine ornamental species for the aquaria, curio, home décor, and jewelry industries, the United States has an opportunity to leverage its considerable market power to promote more sustainable trade and reduce the effects of ornamental trade stress on coral reefs worldwide. Evidence indicates that collection of some coral reef animals for these trades has caused virtual elimination of local populations, major changes in age structure, and promotion of collection practices that destroy reef habitats. Management and enforcement of collection activities in major source countries such as Indonesia and the Philippines remain weak. Strengthening US trade laws and enforcement capabilities combined with increasing consumer and industry demand for responsible conservation can create strong incentives for improving management in source countries. This is particularly important in light of the March 2010 failure of the parties to the Convention on International Trade in Endangered Species (CITES) to take action on key groups of corals. 相似文献
52.
Melissa M. Foley Benjamin S. Halpern Fiorenza Micheli Matthew H. Armsby Margaret R. Caldwell Caitlin M. Crain Erin Prahler Nicole Rohr Deborah Sivas Michael W. Beck Mark H. Carr Larry B. Crowder J. Emmett Duffy Sally D. Hacker Karen L. McLeod Stephen R. Palumbi Charles H. Peterson Helen M. Regan Mary H. Ruckelshaus Paul A. Sandifer Robert S. Steneck 《Marine Policy》2010
The declining health of marine ecosystems around the world is evidence that current piecemeal governance is inadequate to successfully support healthy coastal and ocean ecosystems and sustain human uses of the ocean. One proposed solution to this problem is ecosystem-based marine spatial planning (MSP), which is a process that informs the spatial distribution of activities in the ocean so that existing and emerging uses can be maintained, use conflicts reduced, and ecosystem health and services protected and sustained for future generations. Because a key goal of ecosystem-based MSP is to maintain the delivery of ecosystem services that humans want and need, it must be based on ecological principles that articulate the scientifically recognized attributes of healthy, functioning ecosystems. These principles should be incorporated into a decision-making framework with clearly defined targets for these ecological attributes. This paper identifies ecological principles for MSP based on a synthesis of previously suggested and/or operationalized principles, along with recommendations generated by a group of twenty ecologists and marine scientists with diverse backgrounds and perspectives on MSP. The proposed four main ecological principles to guide MSP—maintaining or restoring: native species diversity, habitat diversity and heterogeneity, key species, and connectivity—and two additional guidelines, the need to account for context and uncertainty, must be explicitly taken into account in the planning process. When applied in concert with social, economic, and governance principles, these ecological principles can inform the designation and siting of ocean uses and the management of activities in the ocean to maintain or restore healthy ecosystems, allow delivery of marine ecosystem services, and ensure sustainable economic and social benefits. 相似文献
53.
Taiwan and China have a long history of sharing marine resources in the China Seas. However, due to political issues, the two sides have yet to formalize collaboration and interaction despite such a close geographical relationship. The lack of formal collaboration means they cannot manage fisheries or conserve resources as a team. The lack of collaboration in the regional fisheries management organizations also means a mutually beneficial situation for the two sides is yet to be achieved. Recognizing this, the two sides began negotiations in 2008 and have since signed agreements on fisheries co-operation projects. This paper discusses the unique fisheries relationship between Taiwan and China, and the characteristics of their fishing industries. The paper also presents the latest update on the collaboration between the two sides. Finally, this paper proposes practical solutions for resolving outstanding issues between the two sides’ fishing industries. 相似文献
54.
盆地形成及成矿与地幔流体间的成因联系 总被引:11,自引:0,他引:11
文中共讨论以下5个问题:(1)盆地起源于幔壳溃变和膨隆,后者是地幔流体(超临界态(>375℃)HACONS流体,简称幔汁)上涌、渗入、交代、富化、致熔的产物。地幔流体造成油气盆地深部的高热流、异常超高压、伊利水云母化、硅化和地层有机碳的加氢成油作用。(2)盆地成矿可分两大阶段,先是沉积时的同生成矿;地层沉积后还有众多的后生成矿。两者组成“盆地矿套”(杜乐天,2002)。成矿无论同生还是后生,其分布均受断裂控制,都和地幔流体活动有关。(3)黑色页岩的实质是碳-硅-泥三元岩系,和热液成矿中的碳酸盐-硅质-泥质蚀变三元完全相当。此类岩系中总是有几十种亲壳亲幔亲气元素的特殊富集。奇异的是,石油、油页岩、沥青及砂岩型铀矿彼此有完全类似的继承性元素特殊富集。此等元素群不可能都是来自盆地之外蚀源区岩体的风化。研究证明,相当多的元素是地幔流体携带上来的。(4)盆地地层中广泛发育由地幔流体衍生的热液作用。(5)盆地实质上是气盆,全盆地排气。许多气田是地幔流体排气形成的。沙漠(原地型)和天然气田的共生很值得注意,两者皆源于地球强烈排气,导致地下和大气增温,过度蒸发,不易降雨,长期干旱而形成沙漠。 相似文献
55.
This paper presents a new procedure to transform an SSI system into an equivalent SDOF system using twice equivalence. A pushover analysis procedure based on the capacity spectrum method for buildings with SSI effects (PASSI) is then established based on the equivalent SDOF system, and the modified response spectrum and equivalent capacity spectrum are obtained. Furthermore, the approximate formulas to obtain the dynamic stiffness of foundations are suggested. Three steel buildings with different story heights (3, 9 and 20) including SSI effects are analyzed under two far-field and two near-field historical records and an artificial seismic time history using the two PASSI procedures and the nonlinear response history analysis (NLhRHA) method. The results are compared and discussed. Finally, combined with seismic design response spectrum, the nonlinear seismic response of a 9-story building with SSI effects is analyzed using the PASSI procedures, and its seismic performance is evaluated according to the Chinese 'Code for Seismic Design of Buildings. The feasibility of the proposed procedure is verified. 相似文献
56.
James L. Foster Gail Skofronick‐Jackson Huan Meng James R. Wang George Riggs Paul J. Kocin Benjamin T. Johnson Judah Cohen Dorothy K. Hall Son V. Nghiem 《水文研究》2012,26(22):3459-3471
The snowfall in the Baltimore/Washington metropolitan area during the winter of 2009/2010 was unprecedented and caused serious snow‐related disruptions. In February 2010, snowfall totals approached 2 m, and because maximum temperatures were consistently below normal, snow remained on the ground the entire month. One of the biggest contributing factors to the unusually severe winter weather in 2009/2010, throughout much of the middle latitudes, was the Arctic Oscillation. Unusually high pressure at high latitudes and low pressure at middle latitudes forced a persistent exchange of mass from north to south. In this investigation, a concerted effort was made to link remotely sensed falling snow observations to remotely sensed snow cover and snowpack observations in the Baltimore/Washington area. Specifically, the Advanced Microwave Scanning Radiometer onboard the Aqua satellite was used to assess snow water equivalent, and the Advanced Microwave Sounding Unit‐B and Microwave Humidity Sounder were employed to detect falling snow. Advanced Microwave Scanning Radiometer passive microwave signatures in this study are related to both snow on the ground and surface ice layers. In regard to falling snow, signatures indicative of snowfall can be observed in high frequency brightness temperatures of Advanced Microwave Sounding Unit‐B and Microwave Humidity Sounder. Indeed, retrievals show an increase in snow water equivalent after the detection of falling snow. Yet, this work also shows that falling snow intensity and/or the presence of liquid water clouds impacts the ability to reliably detect snow water equivalent. Moreover, changes in the condition of the snowpack, especially in the surface features, negatively affect retrieval performance. Copyright © 2011. This article is a U.S. Government work and is in the public domain in the USA. 相似文献
57.
Current designs for nuclear-waste repositories rely primarily upon subsurface geologic barriers for long-term containment. Because water and air are generally considered to be the mechanisms most likely to transport radioactivity to the surface environment, flow and transport models are important tools in repository assessment. Most models assume that the geologic medium can be treated as a continuum. A substantial body of recent work has focused on applying these models to difficult-to-solve problems, such as the simulation of variably dense or variably saturated flow and transport, large and complex flow systems, sharp solute concentration fronts, and fractured rock systems. The complex chemical interactions between the transport fluid and solid particles within the system have been analyzed using geochemical flow models, most of which assume that the system is at chemical equilibrium. The role of colloids in contaminant transport is a relatively new area of research. The large-scale effects of small-scale variability within the geologic system have been the subject of intense investigation. Inherent limitations of the continuum approach have prompted the design of models in which the flow occurs in discrete fractures. The difficulty and complexity of simulating transport has led to the development of network transport models, which represent the flow field as a series of 1-D path segments. The widespread use of models for prediction and analysis has prompted investigations of their reliability and relative merits. 相似文献
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60.
Geophysical analysis of zonal tidal signals in length of day 总被引:5,自引:0,他引:5
Benjamin Fong Chao James B. Merriam Yoshiaki Tamura 《Geophysical Journal International》1995,122(3):765-775