不同培养方式及换水频率对坛紫菜(Porphyra haitanensis)自由丝状体生长及藻胆蛋白含量的影响

本实验以坛紫菜自由丝状体为材料,研究不同培养方式(静置、摇床、通气)和换水频率(5d、7d、10d、20d)对丝状体生长及藻胆蛋白(PE、PC)含量变化的影响。研究结果表明:坛紫菜自由丝状体在摇床培养条件下生长较好,特定生长速率可达10.832 7%~10.891 5%;摇床培养下的丝状体PE含量相对静置培养的较高一些,通气培养的相对较低,最高为36.816 8mg/g;静置条件下培养的丝状体PC含量最高,摇床培养次之,通气培养最低,最低为1.082 4mg/g。相同培养方式下,换水频率对丝状体特定生长速率影响不大;除通气培养外,换水频率20d其PE、PC含量较高。方差分析结果表明:实验范围内的培养方式及换水频率对丝状体特定生长速率大小、PE和PC含量不存在交互作用。本文实验结果对坛紫菜自由丝状体产业化应用于食品加工、色素提取等产业提供了实验理论和依据。     

Stated preferences for size and bag limits of Alaska charter boat anglers

Over the last several years, significant regulatory changes related to Pacific halibut Hippoglossus stenolepis have occurred in the for-hire recreational charter boat fishing sector in Alaska. In addition to limited entry restrictions and adoption of a catch sharing plan that provides a formal means of determining allocation between the commercial and charter boat fishing sectors, more restrictive harvest regulations were placed on anglers fishing from charter boats. This article provides insights into how the value anglers place on charter boat fishing is affected by these regulations, principally bag and size limits. Such information is helpful in assessing the trade-offs in economic benefits associated with different regulatory tools used to manage angler harvest levels. Stated preference choice experiment data from a 2012 survey are analyzed using a panel rank-ordered mixed logit model to estimate the economic value, or willingness to pay (WTP), non-resident anglers place on saltwater charter boat fishing trips in Alaska and to assess how changes in characteristics of fishing trips, particularly harvest restrictions related to Pacific halibut, affect this value. The model specification accounts for a wide array of size and bag limit restrictions that have been recently implemented or are under consideration by Pacific halibut fishery managers. The results indicate that very strict harvest restrictions have the effect of driving WTP to zero, while allowing at least one (potentially) large fish to be caught is valuable to anglers. The results also suggest that WTP for fishing trips with bag limits that allow two or more fish to be harvested with no size restrictions on the first fish harvested are not statistically different from the value for trips for larger bag limits or for the case where all the fish in the limit can be any size. This suggests that fishery managers can restrict the size of the second fish in a two-fish bag limit and still maintain economic values for fishing trips.     

GNSS-R海洋遥感监测技术综述

介绍了GNSS-R海洋遥感的发展过程、技术原理和理论模型,进一步研究了GNSS-R在海洋遥感各应用领域的主要研究内容,探讨了GNSS-R海洋测风、测高、海冰监测、溢油检测和移动目标探测的技术途径,概述了GNSS-R海洋遥感监测技术所涉及的反演理论和信息提取方法,并根据现有研究成果和海洋遥感的应用需要,提出今后需解决的关键技术和未来的发展方向。     

多波束海底地形数据空值区域的插值填补方法分析

由于边界误差剔除、测线布设过于稀疏等因素影响,利用多波束数据生成高分辨率DEM时,常常会存在一些水深空值单元或区域。为了对这些数据空值区域进行可靠填补,在考虑地形特征及空值单元大小的情况下,利用IDW、Spline、Kriging、TIN四种插值方法对某区域多波束海底DEM空值区域进行直接内插填补试验,结果表明插值算法的选取不仅受地形类型限制,而且与空值区域的大小也密切相关。     

A review of the assessments of the major fisheries resources in South Africa

The waters off South Africa's coastline boast a rich mix of commercially fished species. Quantitative assessments of these marine resources have developed from simple methods first applied in the 1970s, to models that encompass a wide range of methodologies. The more valuable resources have undergone regular assessments in recent decades, with frequencies closely related to the management approach employed for each fishery. Many of these assessments form the operating models used to simulation-test candidate management procedures. This paper provides a comprehensive review of the assessments of 11 of the most important fisheries resources in South Africa. Some assessments use simple biomass dynamics models, whereas others are a hybrid of age- and length-based models, each designed to model the specific characteristics of the resource and fishery concerned. Many of the assessments have been disaggregated by species/stock and/or area as related multispecies/stock/ distribution hypotheses have arisen. This paper explores the similarities and differences in the data available and the methods applied. The review indicates that, whereas the status of three of these resources cannot be estimated reliably at present, the status of six resources is considered to be reasonable to good, whereas that of abalone Haliotis midae and West Coast rock lobster Jasus lalandii remains poor.     

基于三轴加速度的波浪测量技术研究

以浮标为载体,以TMS320C6416型DSP处理器、三轴加速度传感器、电子罗盘为硬件电路核心,利用加速度频域二次积分的波高计算方法以及三轴加速度倾角补偿电子罗盘的波向测量方式,进行海洋波浪要素测量技术研究,获取了某一海域不同时段的波浪特征值。     

“陆态网络”Ⅱ期西部绝对重力测定结果分析

介绍了2013~2014中国大陆构造环境监测网络的基本情况及西部地区绝对重力观测的情况,并对观测结果进行分析。结果表明,成果稳定性良好,89.5%的成果观测精度优于±5.00μGal,能够满足"陆态网络"的技术要求。     

GRACE时变重力数据后处理方法评价

针对GRACE Level2卫星时变重力数据后处理方法如何评价的问题,该文以中国数字地震观测网络获得的青藏高原地区地面重力变化图像为参考,基于平均结构相似性等图像相似度指标,研究了与该区域地面重力观测同期、不同后处理方法得到的GRACE卫星重力变化图像的可靠性。结果显示,GRACE卫星重力和地面重力观测结果具有一定的可比性,滑动窗口去相关滤波和高斯400 km滤波的组合方法可以获得最优的处理效果。本文的方法和结论对GRACE及GRACE Follow-On卫星重力数据应用中后处理方法和参数的选取有一定的借鉴意义。     

车载移动测量在大比例尺DOM质检中的应用实践

以一个大比例尺DOM质检项目为应用实例,利用车载移动测量系统进行了点云采集、数据处理、检测点提取、精度统计等。在此基础上,检测分析了系统平面数学精度,以及在几种测区类型下的误差特性,并与传统GPS RTK方法在精度、数据量、时间效率上进行了比较,指出了车载移动测量应用于大比例尺DOM质检的优化方向。     

无人机航空摄影测量技术在矿区地形测量中的应用研究

无人机摄影测量是中小面积地形测绘的重要手段,具有低成本、高效率、高精度、信息量大、产品可以重复使用的优点,弥补了传统方法的不足。本文简要介绍了无人机航空摄影测量技术,从工程实例中,进一步论述了利用无人机,搭载非量测型相机,在地形复杂的高山矿区进行地形测量的过程和方法,评估了点位精度误差,希望能为相关领域研究人员提供借鉴。