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31.
The ecosystem approach to fisheries (EAF) is a holistic paradigm that considers stocks of exploitable species, marine ecosystems and stakeholders. Management agencies must strike a balance between their capacity constraints and the requisites of management measures. Most small-scale sea cucumber fisheries of Pacific Islands have been plundered while others are being opened to commercial exploitation. Data from fishery managers and a regional workshop were used to assess the current problems, institutional constraints and solutions to the management of sea cucumber fisheries in 13 Pacific Island countries (PICs). Technical capacity was often strong for some management actions such as developing marine reserves but weak for others, such as enforcement. Using multi-disciplinary indicators, half of the fisheries were diagnosed by their managers as being overfished or depleted, despite evidence of optimistic bias. Fishery governance varied greatly among the PICs, and co-management frameworks were not typical of any cultural region. Management objectives were prioritised differently among managers but most highly ranked was to protect ecological resilience. The fishery managers proposed different sets of regulatory measures and various management actions, such as surveys to collect socio-economic and fishery-dependent data, support for local governance and strong enforcement – all widely under-practised. Pacific sea cucumber fisheries exemplify how the transition to an EAF by management institutions must involve reorganisation of their technical and human-resource capacities among management tasks. Levies on exports need to be internalised to fund improved management. Management agencies should consider a shift in resources from developing marine reserves, conducting underwater surveys and aquaculture-based restocking to strengthening enforcement capacity, stakeholder involvement and communication with fishers. In concert with these actions, short fishing seasons, shortlists of allowable species and tighter enforcement at export points may serve to turn the tide on boom-and-bust exploitation and safeguard biodiversity.  相似文献   
32.
ITQs offer environmental and economic benefits, including better conservation of a fish stock and greater profitability for fishers. With some limitations, they achieve fairly good alignment between the profit incentive and stewardship objectives. Nevertheless, critics have objected to ITQ schemes because of such factors as the “armchair fishing” phenomenon, unfairness to the public (the owner of the fish), economic and social damage to remote communities, and increased concentration within the fishery. Economists generally dismiss these as distributional issues rather than matters of efficiency or economics, but economic principles are clearly not the only factors that may require attention or action from a government or regulator. This paper proposes an intervention that addresses these concerns within the context of an ITQ scheme. The intervention does not reduce the permanence or values of ITQs, and therefore retains the benefits that ITQs are designed to deliver. Nevertheless, the intervention addresses the criticisms identified above. Modifications of the intervention may enable additional goals and benefits to be achieved as well.  相似文献   
33.
Governance failures associated with top-down management have spawned a myriad of institutional arrangements to engage resource users in decision-making through co-management. Although co-management can take many forms and may not always lead to positive outcomes, it has emerged as a promising governance option available to meet social and ecological goals. Recent research on co-management of small-scale fisheries has used comparative approaches to test factors associated with social and ecological success. Less is known however, about how co-management institutional arrangements emerge and persist in the face of socioeconomic and environmental change. Here, we examine the emergence of co-management governance using a case study from coral reef fisheries in the Hawaiian Islands. We used a mixed methods approach, combining a robust policy analysis and a set of key respondent interviews to trace the evolution of this co-management arrangement. Our research uncovers a set of linked drivers and social responses, which together comprise the emergence phase for the evolution of co-management in this case study. Drivers include resource depletion and conflict, and social responses comprise self-organization, consensus building, and collective action. We share insights on key factors that affect these phases of emergence, drawing on empirical findings from our policy review and key respondent interviews. We conclude by describing ways that our findings can directly inform policy and planning in practice, including the importance of documenting the ‘creation story’ that spawned the new institutional arrangement, ensuring that enabling conditions are present, the complexity of defining community, the connection between process legitimacy and outcomes, and understanding the costs and timelines associated with co-management governance transitions.  相似文献   
34.
Abstract

The Ninth Conference of the Parties (COP-9) decided to adopt an accounting system based on expiring carbon credits to address the problem of non-permanent carbon storage in forests established under the Clean Development Mechanism (CDM). This article reviews and discusses carbon accounting methods that were under consideration before COP-9 and presents a model which calculates the minimum area that forest plantation projects should reach to be able to compensate CDM transaction costs with the revenues from carbon credits. The model compares different accounting methods under various sets of parameters on project management, transaction costs, and carbon prices. Model results show that under current carbon price and average transaction costs, projects with an area of less than 500 ha are excluded from the CDM, whatever accounting method is used. Temporary crediting appears to be the most favorable approach to account for non-permanent carbon removal in forests and also for the feasibility of smaller projects. However, lower prices for credits with finite lifetimes may prevent the establishment of CDM forestry projects. Also, plantation projects with low risk of unexpected carbon loss and sufficient capacity for insuring or buffering the risk of carbon re-emission would benefit from equivalence-adjusted average carbon storage accounting rather than from temporary crediting.  相似文献   
35.
大尺度断层往往控制了沉积盆地的形成和油气成藏,而小尺度断层则影响着注水开发效果和剩余油分布.大尺度断层可以通过二维或三维地震资料识别,而小尺度断层的识别则特别困难.本文提出了一种基于断层分形生长模式和三维地质力学模拟相结合来确定小尺度断层的数量、发育位置和方位的方法,并根据油田开发动态资料来确定小尺度断层对注水开发和剩余油分布的影响.将地震上识别的大尺度断层引入到三维数值力学模型中,模拟大尺度断层形成时期断裂带附近的应力扰动作用,然后结合破裂准则来建立最易发生破裂的方位和最大库伦剪切应力网格,以这两套网格和断层尺度的幂律分布确定的小尺度断层数量为约束条件来确定随机模型,对小尺度断层的密度、产状和发育位置进行定量预测.研究表明:利用分形理论和三维地质力学模拟可以对大尺度断层伴生小尺度断层进行有效预测;小尺度断层对注水开发效果和剩余油分布的影响取决于小尺度断层的规模(断距)以及小尺度断层方位和注采方向的关系.  相似文献   
36.
在前人研究成果和野外调查基础上,对新资深大断裂变质带特征进行系统总结,从宏观构造、显微构造与组构、岩石矿物学、年代学和地球化学等多学科角度综合研究,分析了新资断裂带各类岩石组构成因,并建立了其活动演化期次。新资深大断裂变质带构造岩主要包括定向组构系列岩石和块状系列岩石,主要是由早期的韧性变形变质作用阶段和晚期的脆性破碎作用阶段先后作用形成。越城岭岩体西侧规模巨大的花岗片麻岩带应属新资深大断裂变质带的一部分,属早期活动的产物,其原岩为越城岭岩体,为断裂变质和动力热流变质作用形成。韧性剪切系列岩石按变形变质强度可分为高温高压韧性剪切带和中温高压韧性剪切带,表明韧性剪切作用具有多期性。新资断裂带活动演化主要经历了四个阶段,始于加里东期,至喜山期均有活动,现在的新资断裂带是经过多个阶段不同类型变质作用由东向西不断迁移和相互叠加的结果。  相似文献   
37.
The dynamics of stably stratified stellar radiative zones is of considerable interest due to the availability of increasingly detailed observations of Solar and stellar interiors. This article reports the first non-axisymmetric and time-dependent simulations of flows of anelastic fluids driven by baroclinic torques in stably stratified rotating spherical shells – a system serving as an elemental model of a stellar radiative zone. With increasing baroclinicity a sequence of bifurcations from simpler to more complex flows is found in which some of the available symmetries of the problem are broken subsequently. The poloidal component of the flow grows relative to the dominant toroidal component with increasing baroclinicity. The possibility of magnetic field generation thus arises and this paper proceeds to provide some indications for self-sustained dynamo action in baroclinically-driven flows. We speculate that magnetic fields in stably stratified stellar interiors are thus not necessarily of fossil origin as it is often assumed.  相似文献   
38.
39.
This paper identifies three management initiatives in New Zealand's Individual Transferable Quota system that facilitated consolidation of the processing sector and limited market access for fishers, even those with quota rights. They are: (1) the placement of responsibility onto a Māori trust in 1992 and tribes (iwi) in 2004 to manage a limited amount of quota to benefit all Māori, fishers and non-fishers, which increased the use of quota as an investment asset; (2) the creation of Annual Catch Entitlement (ACE) as a fish access right separate from the quota ownership right, which made it possible to overcome consolidation limits by leasing ACE; (3) the 1997 Licensed Fish Receiver Act that made it illegal for fishers to sell fish off the boat without food safety certification. This account of the fishery policy environment in New Zealand explains why, despite owning significant portions of New Zealand's fishing quota, few Māori are fishing, processing, or selling fish caught by Māori quota.  相似文献   
40.
This article presents the first bottom-up analysis of the proportion of global marine fisheries subsidies to small-scale fisheries (SSF). Using existing data, the reported national subsidy amounts are split into the fraction that goes to small- and large-scale fishing sectors. Results reveal a major imbalance in subsidy distribution, with SSF receiving only about 16% of the total global fisheries subsidy amount of $35 billion in 2009. To bring this into perspective, a person engaged in large-scale fishing received around 4 times the amount of subsidies received by their SSF counterparts. Furthermore, almost 90% of capacity-enhancing subsidies, which are known to exacerbate overfishing go to large-scale fisheries, thus increasing the unfair competitive advantage that large-scale fisheries already have. The developmental, economic and social consequences of this inequity are huge and impair the economic viability of the already vulnerable small-scale fishing sector. Conclusions indicate that taxpayers' money should be used to support sustainable fishing practices and in turn ocean conservation, and not to foster the degradation of marine ecosystems, often a result of capacity-enhancing subsidies. Reducing capacity-enhancing subsidies will have minimal negative effects on SSF communities since they receive very little of these subsidies to begin with. Instead, it will help correct the existing inequality, enhance SSF economic viability, and promote global fisheries sustainability.  相似文献   
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