共查询到20条相似文献，搜索用时 15 毫秒
1.
本研究综述了国际上海洋环境辐射质量评价方面的研究进展,结合我国海洋管理的实际需求,提出将海洋环境辐射质量分为4个级别(1~4级分别表示环境放射性水平处于本底范围、超出本底范围但无危害、所致公众辐射剂量超出限值和所致海洋生物辐射剂量超出限值),并提出了各级导出活度浓度限值的确定原则。其中,确定第1级导出活度浓度限值的依据为我国的放射性本底调查数据,采用统计分析的方法,取绝大多数本底值的上限值,作为分级阈值。确定第2级导出活度浓度限值的依据为公众辐射剂量限值、鱼类对不同核素的浓集系数、不同核素的剂量转换因子、海产品消费量等参数,原则是确保在正常摄入海产品的情况下,对公众造成的辐射剂量不超过国家标准规定的年剂量限值。确定第3级导出活度浓度限值的依据为国际上有关海洋生物发生辐射效应阈值的研究成果,原则是保护海洋生物种群不受辐射伤害。最后,本研究将根据各级的分级阈值与现行国家标准限值进行比较。本研究成果有助于国内工作在一线的海洋监测人员对常规监测数据进行评价,亦为海洋管理决策提供技术支持和参考依据。 相似文献
2.
本文针对目前海洋观测网业务化运行的海洋站（点）缺少评价体系的现状,首次应用层次分析法进行海洋站（点）观测能力、运行质量等综合能力评价的研究。通过构建评价指标层次结构,结合定性和定量分析,构建判断矩阵,建立了层次分析法模型。对海洋站（点）的特点和影响其运行质量的主要因素进行分析,从海洋站（点）的布局、观测环境代表性、仪器设备、基础设施和运行管理等方面,设计了海洋站（点）综合评价体系,评价指标权重合理准确,可为海洋站（点）的综合评价和分级管理提供理论依据。 相似文献
3.
发展海洋碳汇对于建设人与自然和谐共生的美好世界具有重要意义,红树林作为海洋碳汇的重要来源,拥有强大的固碳和储碳能力,具有较高的生态价值和经济价值,因此,加快开发红树林碳汇是应对气候变化的重要战略选择。本文基于三角模糊数和结构方程构建红树林碳汇项目风险测度模型,选取湛江红树林造林项目这一我国的代表性项目,采用净现值方法和肯定当量法对其进行实证对比分析,测度风险因素对项目价值及其投资决策的影响,从而助力红树林碳汇的高质量发展。结果表明：（1）红树林碳汇项目的开发存在一定的风险,各阶段风险按照影响由高到低,依次为核查备案阶段、决策阶段、施工阶段、运营维护阶段和设计阶段,核查备案阶段的技术风险、决策阶段的政策风险、施工阶段的市场风险、运营维护阶段的市场风险和设计阶段的人类行为风险是各阶段中影响较大的风险种类;（2）风险的发生会使红树林碳汇项目的价值降低,相比传统净现值法,肯定当量法更符合红树林碳汇项目的开发和运行情况。 相似文献
4.
运行状态下由叶轮旋转效应产生的气动阻尼对海上风电结构振动影响显著,然而当前的数值模拟方法受到计算能力与施加气动阻尼方式的限制,无法真实高效地表征气动力对振动的影响,使得模拟结果与实际工程存在偏差。针对上述问题,以某海上风电场内1台筒型基础整机为研究对象,考虑气动阻尼效应搭建了整机顺风向振动的简化理论模型,研究气动阻尼对运行状态下整机振动的折减效果,并以折减系数形式引入到数值模型计算中再与原型观测结果进行对比。研究表明：所建理论模型与数值模型的一阶自振频率与实测数据反馈值均相差较小,两类模型对实际工程的适用性良好;理论模型与数值模型同风速下的振动差值稳定,两者动力学上具有很好的同步性;停机工况与运行工况下,模拟塔筒顶部振动位移均方根值与原型观测均方根值平均误差分别为 12.19%与7.99%,说明基于考虑气动阻尼效应的振动理论模型对数值模拟结果进行折减是可行的,模拟精度可以满足工程需求。 相似文献
5.
实际用海效益包括海域资源在生产过程中产生的直接经济收益和生态环境系统的负面效应,文章通过建立海洋高质量用海效益评估模型反映和量化实际用海效益,并将该模型在台州市海域应用,研究结果发现,台州市涉海县、市、区中椒江区实际单位用海效益最高为68.85万元/hm2,玉环市最低为4.02万元/ hm2。原因在于椒江区不仅其海域资源价值表现良好,而且生态环境损害程度得到了有效控制。从而得出,海洋经济高质量发展绝对不是海域资源过度使用,也不是海洋生态环境的绝对保护,两者是相互统一、相互协调的,保证海域资源使用价值保值增值是海洋经济合理运行的基础,保护海洋生态环境系统是海域资源使用价值保值增值的根本,这是引导海洋经济高质量发展的重要路径。 相似文献
6.
G-880G海洋磁力梯度仪的改装与使用 总被引：2，自引：2，他引：0
将海洋磁力梯度仪用于海洋磁力总场测量是常见的实际需求,以G-880G海洋磁力梯度仪为例,分析了其结构及电流、电压情况,提出了一种将G-880G海洋磁力梯度仪改装用于地磁总场测量的方案,并论证了其可行性。 相似文献
7.
目前,由于串靠外输方式具有对船舶吨位差异及装载状况要求小、海况适应力强、系泊力小、解脱迅速等优点,而被广泛运用于浮式生产储卸油平台(FPSO)外输作业中。串靠提油作业时,位于穿梭油轮尾部的拖轮能够提供的最大有效拖力直接影响到了作业的安全性。为完善串靠提油作业时所需拖轮拖力的研究,提出更加合理的拖轮选型理论依据,就需要对拖力进行数值计算。首先,对FPSO与穿梭油轮串靠外输系统绕系泊单点旋转时所受风、浪、流等环境载荷进行全面考虑,建立了准动态受力平衡模型;然后,运用经验公式及AQWA软件计算出环境载荷大小,并依据计算结果拟合出环境载荷曲线;最后,配合受力平衡方程求解出能够保障作业安全进行所需的最小拖力。依照此方法计算所得拖力选取的拖轮能够兼顾作业安全性和使用经济性。 相似文献
8.
This paper reviews the last two years operational deep-water performance record of two manned/unmanned tethered ROV Mantis vehicles. Deviations of the system as compared to conventional submersibles and remotely operated vehicles (ROV's) are discussed and evaluated. Applications and advantages of this system in support of deep-water operations are appraised. Results and observations concluded in this paper deal with the importance of having a man in the water, or at least available to go in the water, and also those circumstances which require a remotely operated system either for safety or total bottom time requirement. The significance of each mode of operation is examined. Observations and conclusions have been compiled from operational data collected during over 250 actual dives in deep-water work to depths of 2000 ft (sim 600 m). 相似文献
9.
超声波萃取-高效液相色谱法在海洋沉积物样品多环芳烃分析中的运用 总被引：6，自引：0，他引：6
建立用超声波萃取-高效液相色谱法同时检测海洋沉积物中16种优先监控的多环芳烃(PAH s)的方法。本方法采用丙酮作为萃取溶剂,在超声波作用下萃取出泥样中的PAH s,萃取液经浓缩后直接进行高效液相色谱分析。经对色谱条件和萃取条件进行优化后,各PAH组分的线性范围为1~500 ng之间,相关系数0.9921~0.999,检出限0.1~4.6 ng,达到海洋沉积物PAH s的检测要求。运用本法对粤东大规模增养殖区柘林湾表层沉积物PAH s进行检测,各PAH组分加标回收率为69.2%~108%,总平均达89.2%,相对标准偏差为0.5%~10.3%。本方法只需要萃取、浓缩和定容三个步骤,具有简便、迅速、高效、分析成本低的特点。 相似文献
10.
Maintenance and repair at the operational level is a critical function to comply with the standard of competence for officers in charge of an engineering watch in a manned/unmanned ship engine room. The human factor in ship maintenance especially deals with fulfilling of the required competency about dismantling, inspecting, repairing and reassembling equipment in accordance with manuals and good practice stated in STCW Code, as amended in 2010. This study extends the shipboard operation human reliability analysis (SOHRA) through the marine auxiliary machinery maintenance operations. The approach involves the determined marine-specific error producing conditions (EPC) and generic task type parameters to quantify generic error probability (GEP) values along with the subtasks of the maintenance operation. To acquire the EPC and GEP values, the real case study on heavy fuel oil (HFO) purifier overhauling considers different operating conditions on-board selected five ships in a dry bulk fleet. The case study shows that human error probability (HEP) values of tasks in maintenance operation change in regard to ship operating conditions. Consequently, the study contributes to the marine engineering field in improving the human factor in ship repair and maintenance operations. This approach is further extended by incorporating maintenance 4.0 requirements into ship operating environment to conduct scenario-based task analysis. 相似文献
11.
在全球气候变化的背景下，现代化海洋牧场是我国应对近海生态环境恶化和渔业资源衰退、实现海洋生态文明和海洋强国战略的重要手段。而海洋牧场观测网是科学指导现代化海洋牧场建设，并进行科学管理的重要基础。为了保障现代化海洋牧场的可持续健康发展，山东省于2015年底开始在各海洋牧场建设生态环境海底观测站，并组网建成世界先进的海洋牧场观测网，目前已覆盖23处海洋牧场。设立观测网预警中心，负责海洋牧场观测网的日常运行和维护，同时开展水域多学科耦合过程的基础研究和业务化辅助决策的应用服务。海洋牧场观测网的建立和业务化运行初步实现了海洋牧场生态环境和渔业资源的"可测"、"可视"、"可控"和"可预警"。目前，我国现代化海洋牧场观测网的科学发展仍面临诸多挑战，建议进一步增强观测设备的自主研发能力和长期在线监测的稳定性，跨介质立体组网、实现海洋牧场的全方位立体监测，深化多学科耦合过程的基础研究并提供多元业务化辅助决策应用服务，为现代化海洋牧场的高质量发展保驾护航。 相似文献
12.
《Marine Policy》2013
This study proposes a hybrid operational model to manage marine activities. This approach combines cost-benefit analysis (CBA), the analytic hierarchy process (AHP), and the Dempster–Shafer theory (DST), and retains the advantages of CBA as well as facilitating the incorporation of incomplete information into the evaluation process. A particular advantage of this hybrid approach is that it can synthesize evaluation results into an easily understood unit: namely, utility. Conflicts between marine resource users (user–user conflicts) and between users and marine environment (user-environment conflicts) can easily be evaluated using this hybrid operational model. A sea use management system is proposed, which incorporates a permitting process and elements of marine spatial planning (MSP). In the proposed system, marine activities are grouped into three clusters based on their potential environmental impacts and exclusive use, then assigned to competent authorities, a panel of experts or government agencies for review and permit approval. This study suggests that the central and local governments share responsibility for approving permits for marine activities. More importantly, it suggests that the integration of marine activities needs to be handled by the central government. A numerical example is used to illustrate the application of the hybrid operational model. 相似文献
13.
When using self-propelled ship models, it is necessary to observe and record a trajectory of actual movement and also to determine a current value of velocity and acceleration. An optoelectronic system for determining and recording the trajectory of the model has been developed. It operates over an 150 m×150 m area with a fundamental error of less than 0.1 m and consists of an optical transmitter aboard the model and two stations ashore connected to a computer placed in a remote operational room. The directional angles are measured by two receiving telescopes (one for each station ashore), which are rotating with an angular velocity ~15 rad/s. The coordinates of the model are obtained by simple arithmetic. Errors of measurements and the maximum range of operation are also discussed 相似文献
14.
The operability of marine operations, that is, the estimation of their weather downtime and duration, is traditionally determined either by means of risk analysis or Monte Carlo simulation techniques. The work presented herein establishes analytically the probability distribution and statistical parameters of the duration of individual activities of a marine project based on the theory of Markov chains. According to the proposed Markov model the distribution of the duration of an activity is associated with certain statistical properties of the return time, that is the period between two successive passages from the non-operable state. Information about individual activities is then combined according to the PNET methodology, as proposed by Ang, A. H. S., Abdelnour, J. & Chaker, A. A., Analysis of activity networks under uncertainty. J. Engng Mech. Div., ASCE, 101 (EM4) (1975) 373–387 which considers the sequence of the execution of the activities, as defined by the operations scenario of the project, in order to establish analytically the probability distribution of the duration of the project.
The statistical analysis distinguishes between activities which do not require a weather window for their execution and those which do. Policies which affect the execution of an activity are incorporated into the analysis by taking into consideration secondary tasks which are performed before or after its temporary suspension. Furthermore, performance efficiency factors are also introduced in order to reflect the influence of the prevailing sea state/vessel responses on the ability of the crew to carry out the activity.
The Markov model is applied for a range of uninterrupted durations to activities which do or do not require a weather window and the results are compared with those from a Monte Carlo simulation. Good agreement is obtained for the mean durations but significant deviation is evident for the second order moments. This behaviour is attributed to the length of the record and also to the distribution of the return times. Agreement between the results of the two models is generally better for activities of low uninterrupted duration which do not require a weather window.
Finally, the combined Markov/PNET methodology is illustrated with an example for a hypothetical project and results are compared with those from a Monte Carlo simulation. Similar conclusions to those mentioned above are drawn. 相似文献
15.
海洋垂直剖面水温实时监测浮标系统研制与应用 总被引：3，自引：1，他引：2
为了实时、连续地监测獐子岛海洋牧场养殖区域不同深度的温度状况,为海洋牧场构建和运行提供数据支持,项目组自行研制了海洋垂直剖面水温实时监测浮标系统,可以在水深≤50 m、风速≤60m/s、波高≤15 m的环境下应用。该浮标系统主要包括水面浮标载体子系统和剖面链观测子系统两部分,浮标载体子系统提供了安全可靠的工作平台;而剖面链子系统上的不同位置挂有多个水下传感器,用于测量相应位置的海水温度。耐压试验、温度标定、室内拷机、现场比测、海上拷机的检定数据表明该系统无渗漏、误差小、数据接收率100%。海上运行18个月的结果同样表明,浮标系统运行稳定,数据采集和接收率高,浮标电压稳定。实践表明该浮标系统具有测温精度高、结构简单、使用方便的优点,具有广泛的应用前景。 相似文献
16.
《Marine Policy》2016
Seeing the ocean through the eyes of seabirds could help meet the challenges of managing common-pool marine resources both in protected and unprotected areas. First, seabirds are top-predators, exposed to all threats affecting the oceans, and this makes them ideal sentinel organisms for monitoring changes within marine ecosystems. Second, seabirds cross both ecological and political boundaries, and following their movements should help making interdependencies within and between marine ecosystems more visible. Third, seabirds are conspicuous and often charismatic animals, which interact differently with different groups of stakeholders and provide the opportunity to acknowledge and discuss each other's values and interests. In this paper, we present these research avenues using a seabirds’ view, for tackling marine conservation and management issues, and we give operational examples of implementation based on our work in the English Channel. 相似文献
17.
海上单道地震与浅地层剖面数据海浪改正处理研究 总被引：2，自引：1，他引：1
因受海面大风浪与涌浪等影响,海上单道地震与浅地层剖面数据反射同相轴常出现波浪状起伏,造成剖面反射层位错乱,分辨率与信噪比降低。根据海浪噪声与海底反射地层在横向上的相关性与变化频率等特性,以及综合前人的研究成果,采用陆上地震数据剩余静校正处理中的统计模型道互相关方法来实现对剖面反射同相轴的海浪改正处理;为减少强能量噪声对相关运算的影响,采用中值滤波、光滑滤波技术对反射同相轴曲线进行滤波处理,以进一步减少残留海浪的影响及相关运算改正误差。将这些方法综合运用于海上实际调查资料处理后,大风浪与涌浪影响下的波浪状反射同相轴变得连续、光滑,海底下混乱模糊的反射层位变得清晰、连续,剖面信噪比与分辨率得到了极大的提高。 相似文献
18.
The dearth of generally available, failure data that can be directly applied to marine energy converters (MECs) has been commented on for some years. The advancement of the industry will be fundamentally linked to proven reliability assessments, which is difficult on an industry wide basis. This paper describes how targeted component reliability testing could enable the establishment of relevant failure rate data for the marine renewable energy industry. The necessity of dedicated component testing is briefly reviewed for the wave energy sector together with the experience from other industries. A generic procedure used in test intensive industries for service simulation testing is outlined and applied to wave tank mooring tests. By means of a rainflow analysis procedure and the Palmgren–Miner rule the most severe load cycles, largely contributing to the fatigue damage are identified and reproduced for a possible component test signal. The application of the suggested generic test approach will assist marine energy stakeholders in obtaining evidence of component reliability under simulated operational conditions much more rapidly than can be achieved with prototypes under normal service conditions. Importantly, this would also allow a more accurate estimate of field failure rates and could reveal possible failure modes/design weaknesses ahead of field deployments. 相似文献
19.
F.N. Spiess 《Ocean Engineering》1974,2(6):243-249
Three aspects of marine technology are discussed. First is the unsolved problem of how to monitor the condition of a multi-strand strain wire. Second is the development of a piece of hardware for picking wire up off the sea floor and third is the conduct of an actual instrument retrieval operation at sea. 相似文献