952 resultados para Evans, Herbert M


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The principal objective of this study was to determine if additional net benefits can be derived from the sub-regional longline fishery by the introduction of a new management agreement that would centre on the provision of licensing arrangements that would allow access by eligible longline vessels to multiple Exclusive Economic Zones, i.e. Multi-zone Access. [90pp.]

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Health advisories are now posted in northern Florida Bay, adjacent to the Everglades, warning of high mercury concentrations in some species of gamefish. Highest concentrations of mercury in both forage fish and gamefish have been measured in the northeastern corner of Florida Bay, adjacent to the dominant freshwater inflows from the Everglades. Thirty percent of spotted seatrout (Cynoscion nebulosus Cuvier, 1830) analyzed exceeded Florida’s no consumption level of 1.5 μg g−1 mercury in this area. We hypothesized that freshwater draining the Everglades served as the major source of methylmercury entering the food web supporting gamefish. A lack of correlation between mercury concentrations and salinity did not support this hypothesis, although enhanced bioavailability of methylmercury is possible as freshwater is diluted with estuarine water. Stable isotopes of carbon, nitrogen, and sulfur were measured in fish to elucidate the shared pathways of methylmercury and nutrient elements through the food web. These data support a benthic source of both methylmercury and nutrient elements to gamefish within the eastern bay, as opposed to a dominant watershed source. Ecological characteristics of the eastern bay, including active redox cycling in near-surface sediments without excessive sulfide production are hypothesized to promote methylmercury formation and bioaccumulation in the benthos. Methylmercury may then accumulate in gamefish through a food web supported by benthic microalgae, detritus, pink shrimp (Farfantepenaeus duorarum Burkenroad, 1939), and other epibenthic feeders. Uncertainty remains as to the relative importance of watershed imports of methylmercury from the Everglades and in situ production in the bay, an uncertainty that needs resolution if the effects of Everglades restoration on mercury levels in fish are to be modeled and managed.

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(PDF contains 3 pages.)

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Trata da questão da comercialização e doação de sangue e de órgãos. Uma Lei Complementar será criada para que a doação seja de livre e espontânea vontade.

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Supporting slides from the Janet network end to end performance initiative workshop

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 mg style="width: 261px; height: 221px" src="http://ec4.images-amazon.com/images/I/41869IowBoL._SL500_AA300_.jpg" border="0" alt="" width="300" height="300" align="left" />本书的目的是把一般性概括性的理论和实际工程经验很好地结合起来,对工程技术各个系统的自动控制和自动调节理论作一个全面的探讨。它一方面奠定了工程控制论这门技术科学的理论基础,另一方面指出这门新学科今后的几个研究方向。
本书最初是用英文写的。现在的汉文版是在钱学森先生的指导下,翻译英文版并且参照俄文译本略加修改和补充而成。
本书曾荣获中国科学院1956年度一等科学奖金。
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目录

汉文版序
原序
第一章 引言
 1.1 常系数线性系统
 1.2 变系数线性系统
 1.3 非线性系统
 1.4 工程近似的问题
第二章 拉氏变换法
 2.1 拉氏变换和反转公式
 2.2 用拉氏变换法解常系数线性微分方
 2.3 拉氏变换的“字典”(拉氏变换表)
 2.4 关于正弦式的驱动函数的讨论
 2.5 关于单位冲量驱动函数的讨论
第三章 输入、输出和传递函数
 3.1 一阶系统
 3.2 传递函数的表示法
 3.3 一阶系统的一些例子
 3.4 二阶系统
 3.5 确定频率特性的方法
 3.6 由多个部件组成的系统
 3.7 超越的传递函数
第四章 反馈伺服系统
 4.1 反馈的概念
 4.2 反馈伺服系统的设计准则
 4.3 乃氏(Nyquist)法
 4.4 艾文思(Evans)法
 4.5 根轨迹的流体力学比拟
 4.6 伯德(Bode)法
 4.7 传递函数的设计
 4.8 多回路伺服系统
第五章 不互相影响的控制
 5.1 单变数系统的控制
 5.2 多变数系统的控制
 5.3 不互相影响的条件
 5.4 反应方程
 5.5 涡轮螺旋桨发动机的控制
 5.6 有补充燃烧的涡轮喷气发动机的控制
第六章 交流伺服系统与振荡控制伺服系统
 6.1 交流系统
 6.2 把直流系统变为交流系统时传递函数的变化方法
 6.3 振荡控制伺服系统
 6.4 继电器的频率特性
 6.5 利用固有振荡的振荡控制伺服系统
 6.6 一般的振荡控制伺服系统
第七章 采样伺服系统
 7.1 一个采样线路的输出
 7.2 施梯必茨?申南(Stibitz?Shannon)理论
 7.3 采样伺服系统的乃氏准则
 7.4 稳态误差
 7.5 F*2(s)的计算
 7.6 连续作用伺服系统与采样伺服系统的比较
 7.7 F2(s)在原点有极点的情形
第八章 有时滞的线性系统
第九章 平稳随机输入下的线性系统
第十章 继电器伺服系统
第十一章 非线性系统
第十二章 变系数线性系统
第十三章 利用摄动理论的控制设计
第十四章 满足指定积分条件的控制设计
第十五章 自动寻求最优运转点的控制系统
第十六章 噪声过滤的设计原理
第十七章 自行镇定和适应环境的系统
第十八章 误差的控制
俄文文献
索引
附录
工程控制论简介
现代化、技术革命和控制论
编后记

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(PDF contains 3 pages.)

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(PDF contains 3 pages.)

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Commonly adopted approaches to managing small-scale fisheries (SSFs) in developing countries do not ensure sustainability. Progress is impeded by a gap between innovative SSF research and slower-moving SSF management. The paper aims to bridge the gap by showing that the three primary bases of SSF management--ecosystem, stakeholders’ rights and resilience--are mutually consistent and complementary. It nominates the ecosystem approach as an appropriate starting point because it is established in national and international law and policy. Within this approach, the emerging resilience perspective and associated concepts of adaptive management and institutional learning can move management beyond traditional control and resource-use optimization, which largely ignore the different expectations of stakeholders; the complexity of ecosystem dynamics; and how ecological, social, political and economic subsystems are linked. Integrating a rights-based perspective helps balance the ecological bias of ecosystem-based and resilience approaches. The paper introduces three management implementation frameworks that can lend structure and order to research and management regardless of the management approach chosen. Finally, it outlines possible research approaches to overcome the heretofore limited capacity of fishery research to integrate across ecological, social and economic dimensions and so better serve the management objective of avoiding fishery failure by nurturing and preserving the ecological, social and institutional attributes that enable it to renew and reorganize itself. (PDF contains 29 pages)

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Diagnosis and adaptive management can help improve the ability of small-scale fisheries (SSF) in the developing world to better cope with and adapt to both external drivers and internal sources of uncertainty. This paper presents a framework for diagnosis and adaptive management and discusses ways of implementing the first two phases of learning: diagnosis and mobilising an appropriate management constituency. The discussion addresses key issues and suggests suitable approaches and tools as well as numerous sources of further information. Diagnosis of a SSF defines the system to be managed, outlines the scope of the management problem in terms of threats and opportunities, and aims to construct realistic and desired future projections for the fishery. These steps can clarify objectives and lead to development of indicators necessary for adaptive management. Before management, however, it is important to mobilize a management constituency to enact change. Ways of identifying stakeholders and understanding both enabling and obstructive interactions and management structures are outlined. These preliminary learning phases for adaptive SSF management are expected to work best if legitimised by collaborative discussion among fishery stakeholders drawing on multiple knowledge systems and participatory approaches to assessment. (PDF contains 33 pages)

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During June 1974 the California Department of Fish and Game, in cooperation with the Sea Grant program at Moss Landing Marine Laboratories, conducted an exploratory fishing cruise that extended from La Jolla to Santa Cruz and included the Channel Islands, concentrating on inshore waters. The cruise was preliminary to the initiation of a major program of squid research and had six objectives: 1) To gather samples of market squid (Lo1igo opa1escens) for population, growth, aging and food chain studies. 2) To locate potential new fishing grounds. 3) To investigate methods for determining spawning intensity. 4) To gather data on oceanographic parameters of the spawning grounds. 5) To make incidental collections as requested by other investigators. 6) To familiarize Sea Grant personnel with the capabilities of the Department's largest research vessel, ALASKA, with respect to squid. Especially good weather and oceanographic conditions persisting throughout the cruise enabled us to make 66 night1ight stations, 17 midwater trawls and eight bottom trawls. Fishable concentrations of squid were discovered in the areas between Cape San Martin and Partington Point, between Pfeiffer Point and Point Sur, and in Carmel Bay, heretofore unfished. Squid spawning off Santa Cruz Island was observed utilizing an underwater observation chamber aboard the vessel. Mating and feeding behavior were observed in shipboard aquaria. PDF contains 28 pages)

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This synopsis of the literature was designed to summarize the biological and biochemical studies involving Pandalus borealis as well as to provide a summary of the literature regarding the fisheries data published before early 1984. Included are many unpublished observations, drawn from studies at the State of Maine Department of Marine Resources Laboratory in West Boothbay Harbor, Maine. (PDF file contains 63 pages.)