KNO3溶液结构:密度泛函理论和分子动力学研究

基于密度泛函理论,采用ωB97XD方法和6-311++G(d,p)基组,系统研究了[K(H₂O)_n]⁺,[NO₃(H₂O)_n]-和KNO₃(H₂O)_n水合团簇的结构和性质;并结合经典分子动力学、OPLS-AA全原子力场以及SPC/E水模型模拟了不同水盐比(WSR) KNO₃溶液,目的在于深入理解KNO₃溶液中K⁺和 NO-₃的微观水合结构,以及K⁺-NO-₃离子间缔合作用特征。研究发现,对于KNO₃(H₂O)_n (n=6,8,10和12)水合团簇,K⁺第一水合层稳定结构为四、五和六水合结构,其中五水合结构最稳定。K⁺和NO-₃主要以溶剂共享离子对形式存在。随着团簇尺寸减小,直接接触离子对(CIP)物种出现。同时,分子动力学模拟证实KNO₃溶液中形成了直接接触K⁺-NO-₃离子对,且随着溶液浓度增加,CIP物种形成需越过更大能垒。以上结果表明在KNO₃稀溶液中主要存在物种为水合K⁺和NO-₃,随浓度增大,单齿直接接触离子对(MCIP)逐渐出现。在高浓溶液或过饱和溶液中,K⁺-NO-₃离子缔合主要以单齿CIP和少量双齿CIP结构存在。     

基于AIS信息校准的双频地波雷达的船只融合跟踪

高频地波雷达（HFSWR）和自动船只确认系统（AIS）是船只跟踪的重要传感器。高频地波雷达可以用来跟踪探测区域的所有船只,而AIS只能用来确认合作船只的信息。由于海杂波的干扰,使用单频率地波雷达的船只跟踪会淹没在布拉格峰值的盲区里,改变探测频率是克服这一缺点的有效手段。在这种背景下,我们提出一种基于AIS校准的双频雷达融合探测算法。因为不同频率的地波雷达测量与AIS的测量值存在系统误差,所以AIS信息可以用来估计和校准地波雷达的每个频率的系统误差。首先,将合作目标的点迹测量与地波雷达的点迹测量通过JVC分配算法进行点迹关联。从合作船只的点迹关联结果中,双频雷达的系统误差可以估计和校准。其次,基于校准的双频雷达数据,使用融合JPDA-UKF算法进行船只跟踪。通过真实探测的数据的实验结果显示所提算法可以实时跟踪船只,相比单频率跟踪可以进一步提高跟踪能力和跟踪精度。     

小洋山邻近海域主要游泳动物生态位及种间联结性

根据2014年秋季和2015年秋季在小洋山邻近海域调查获得的渔业资源资料,运用生态位测定、聚类分析、W检验、基于2×2列联表的χ2检验、联结系数（AC）和共同出现百分率（PC）等方法分析主要游泳动物间的生态关系。结果表明,该海域主要游泳动物共24种,其中优势种为龙头鱼（Harpodon nehereus）、三疣梭子蟹（Portunus trituberculatus）和安氏白虾（Exopalaemon annandalei）,这3个种类的生态位宽度较宽;通过生态位宽度聚类分析,可将主要游泳动物分为3组,分别为广生态位种、中生态位种和狭生态位种;种对间生态位重叠值介于0~0.96之间,表明物种利用资源的能力具有相似性,种对间存在一定竞争性;W检验分析得出主要游泳动物总体呈显著正关联;χ2检验显示有150个种对的联结性显著（χ2 ≥ 3.841）;联结系数（AC）和共同出现百分率（PC）表明种间联结性较强,总体趋于正相关。     

The rise and fall of factory trawlers: An eclectic approach

Factory trawlers are the most controversial vessel group in Norwegian fisheries. At the time the fleet emerged, stern trawling in combination with on-board processing of cod fillets was regarded as a major innovation. However, the deep-sea fleet was intended to be a stable supplier of fish to the land-based industry. Factory trawlers were not a part of the political project. On the contrary, the vessels represented a serious departure from the traditional employment system for the fisheries’ dependent districts. Factory trawlers have, since the seventies, been regarded as the main enemy to the coastal vessels and the land-based industry. The vessels have been subject to a profound debate about several built-in contradictory goals for the fisheries policy, such as the ideal of employment for all and the need for a profitable sector without state subsidies. Despite a series of policy-driven initiatives to remove the factory trawlers, the fleet has been one of the most profitable vessel groups in the Norwegian fisheries. Nonetheless, the fleet is now marginalised in the number of vessels and transformed into an obedient supplier of round fish to the land-based industry. In this article, we outline the history of the Norwegian factory trawlers and how the fleet was subject to a series of critical changes reflecting the complexity of the vessels.     

Fishing for social realities—Challenges to sustainable fisheries management in the Cape Horn Biosphere Reserve

Social-ecological complexity challenges conservation-oriented interventions even in settings with a small number of actors and conflicts involved. This article examines the development and trajectory of King and Snow Crab fisheries in the Cape Horn Biosphere Reserve (BR), the highly remote but globally connected Southern tip of the Americas. The feasibility of the Chilean legal instrument of Marine Management Areas (MMA) is assessed as a tool for mitigating impacts of overfishing in the area. Examining the local fishers’ perspectives in complement to a context analysis we find that external management models such as the MMA are not suited to make Cape Horn fisheries sustainable. Instead, efforts should be dedicated to a continuous process of stakeholder collaboration for developing site-specific management concepts and structures. These should be embedded in the larger BR initiative. Considering the area's particular conditions, several recommendations for such a process are formulated.     

Participatory practices in fisheries across Europe: Making stakeholders more responsible

Drawing on an EU-funded project titled “Sharing responsibilities in fisheries management” this paper assesses the institutional landscape of fisheries management in a number of European countries, with a particular emphasis on stakeholder involvement in regulatory decision-making. What are their roles and responsibilities in the chain of governance? What are the specific characteristics of each country, and what is similar and what is different as compared with other sectors? Although there is a move towards devolvement and decentralisation in some European countries, there is quite an ambivalence regarding such reforms in other countries. These differences in stakeholder involvement are partly a result of institutional traditions within each country, but also a reflection of how management authorities struggle with the dilemmas pertaining to such reforms of participatory practices. Thus, we argue that even within a reformed fisheries management system that allows greater participation of stakeholder groups, there can hardly be one European model that fits all.     

Fishing capacity management in China: Theoretic and practical perspectives

The Food and Agriculture Organization (FAO) Committee on Fisheries (COFI) adopted an International Plan of Action for the Management of Fishing Capacity, which calls for all member states to achieve efficient, equitable and transparent management of fishing capacity by 2005. Based on the theoretical review of fishing capacity management, this paper examines the major practices made by China's government in managing the fishing capacity of its marine capture fisheries. Finally, it categorizes the main practices and then analyses and evaluates their effects.     

Management responses to the problem of incidental catch in fishing: A comparative analysis of the EU,Norway, and the Faeroe Islands

The article addresses incidental catch as a two-level management problem for systems that regulate fish catches. The first level is legal and concerns the problem of establishing clear and legitimate criteria for criminal liability. The second level is environmental and concerns the efficacy of chosen liability criteria in resource conservation. The article compares and explains the solutions chosen by Norway, the Faeroe Islands, and the EU. Each solution constitutes a distinct form of fisheries management. It is argued that national choices are determined by administrative capacity for implementation and political autonomy in the distribution of fishing rights.     

Governing fisheries as complex adaptive systems

Fisheries are complex human-in-nature systems. The conventional approach to fisheries systems has been to treat them as predictable and controllable. As complex systems they are neither of the two and have to be approached differently. Complex systems often exhibit the capacity to self-organize or adapt, even without outside influence. If this is true of fisheries, it should lead to a radically different approach to management of fisheries systems that places much emphasis on enabling self-organization, learning and adaptation. Conceptual and practical frameworks for enabling activities are needed.     

The exclusive economic zone and economic development in the Pacific island countries

The exclusive economic zone (EEZ) became accepted internationally in the 1970s. This transferred resource wealth to the coastal states establishing such zones. The history of the EEZ is reviewed, and its impact on the economic development of the Pacific island states considered. The growth performance and the tuna fishery development of these states are reviewed and possible causes of limited success discussed. The use of trust funds to increase the resource wealth of the Pacific island states is briefly considered.