渔业资源评估中声学方法的应用

介绍了渔业资源声学评估的国内外研究现状，基本工作原理，声学仪器，声学评估的主要工作过程，其中重点介绍了声学调查与评估，它包括调查设计，数据采集，目标强度确定、映像分析，数据处理，生物量计算等。最后指出了目前渔业资源声学评估工作中尚待解决的若干问题，例如在各鱼种积分值分配问题上，很大程度取决于生物学取样网次中渔获物的组成比例，以及各个水层中存在不同的非生物或者非调查种类的生物将影响回波信号以及探鱼仪映像的形成，这些都需要渔业工作者在对经研究的基础上予以辨别后，再对数据和映像进行预处理等，并提出了未来发展方向的展望。     

Regulating the global fisheries: The World Wildlife Fund, Unilever, and the Marine Stewardship Council

This analysis uses an analytical frameworkgrounded in political economy perspectives of theglobalization of the agro-food sector combined with acase study approach focusing on the Marine StewardshipCouncil (MSC) to inform discussions regarding thecharacteristics of societal regulation in thepost-Fordist era. More specifically, this analysisuses the case of the emergence of the MSC toinvestigate propositions regarding the existence of,and location of, nascent forms of a transnationalState. The MSC proposes to regulate the certificationof sustainable fisheries at the global level throughan eco-labeling program. The MSC was created in 1996by the transnational environmental organization theWorld Wildlife Fund and the transnational corporationUnilever. The emergence of the MSC has generatedheated discussion in fisheries management circles thatis in general divided along North/South lines. Thisanalysis indicates that the case of the MSC providesvaluable insights into the possible characteristics ofsupranational regulatory mechanisms that might emulatethe role of the nation-State in the post-Fordist era.     

RELEVANCE OF SONOGRAPHIC ARTIFACTS OBSERVED DURING IN VITRO CHARACTERIZATION OF UROCYSTOLITH MINERAL COMPOSITION

Nine pure mineral type canine uroliths (bladder or urethral origin only) were imaged ultrasonographically using 3.5 MHz, 5.0 MHz, and 7.5 MHz fixed focus, mechanical sector transducers in a urinary bladder phantom. The uroliths studied were those composed of 100% magnesium ammonium phosphate, calcium oxalate monohydrate, calcium oxalate dihydrate, calcium phosphate appatite, and calcium hydrogen phosphate dihydrate (brushite), ammonium acid urate, sodium acid urate, cystine, and silica. The occurrence of both reverberation/streak and acoustic shadowing artifacts were compared to urocystolith mineral type (classified by effective atomic number), urocystolith width, urocystolith height (thickness), and ultrasonographic imaging frequency. No predictable relationship was found between either of the artifacts seen beyond the urocystolith (reverberation/streak or the acoustic shadowing) and urocystolith mineral type. There was no statistical relationship between the occurrence of reverberation/streak artifact and the size (width or height) of the urocystolith or the ultrasonographic frequency. There was, however, a statistically relevant relationship between ultrasonographic imaging frequency and the occurrence of acoustic shadowing and between urocystolith height (thickness) and the occurrence of acoustic shadowing. However, regardless of ultrasound frequency, acoustic shadowing was observed less than 35% of the time in any of the urocystolith mineral types examined. Based on the imaging of the bladder phantom supporting apparatus (7.0 mm bolts covered by plastic), the accurate characterization of a curved object surface directly facing the transducer was found to be directly related to the frequency of sound used for imaging and at best predictably limited to curved vs flat. Accurate measurement of the maximum transverse dimension of an echogenic curved object or accurate characterization of the lateral borders of such an object was considered unlikely with general ultrasonographic equipment of the frequencies studied. Therefore, detailed architectural characterization of urocystoliths suitable for mineral composition prediction is considered highly unlikely with general pulse-echo ultrasonographic techniques.     

应用Kaiser效应测定某水电站右坝肩地应力

介绍了岩石声发射Kaiser效应的理论及其在室内进行地应力测试的方法与过程,并证实了与现场实测值的一致性.     

Migration and escapement of silver eel males,Anguilla anguilla,from a southwestern European river

The catadromous life cycle of the European eel encompasses a spawning migration to the Sargasso Sea. Prior to their migration, eels develop a silver coloration being referred to as “silver eels.” Due to the dramatic European eel recruitment decline, it is crucial to quantify silver eel escapement to evaluate the success of measures taken under Eel Management Plans (Regulation EC (1100/2007)). Thus, the percentage of silver eels escaping from the River Mondego (Portugal) was estimated during two consecutive spawning seasons (2014–2016) and their migratory behaviour was studied. Thirty-six male silver eels were tagged with acoustic transmitters and their downstream migration was tracked using automatic receivers deployed at four locations along the river course, from the first impassable obstacle up to the river mouth (67 km). Among the tagged eels, 15 (42%) escaped to the sea. In both years, individuals displayed faster migration speed in the downstream reaches of the river. BRT (“Boosted Regression Trees”) models were used to explain downstream migration and escapement of silver eels. The analyses revealed that the downstream migration is triggered by several environmental variables with water conductivity as the most influential predictor. Escapement of eels from the estuary occurred a few hours after their arrival and was primarily explained by the offshore wind intensity, which promotes a current in the coast that may favour their transport to the open sea. These findings contribute to a better understanding of silver eel migration in southern latitudes and highlight and reinforce the need to monitor spawner escapement.     

基于绿视率的校园景观感知视听耦合特征分析

深入认识视觉和听觉耦合下人们对景观的感知规律，对景观资源评价和宜居环境设计尤为关键。以福建农林大学金山校区校园景观为对象，结合样地监测和问卷调查等方法，比较分析夏季（7月）不同绿视率呈现的视觉信息与声音感受特征结合下人们对景观环境感知特征的差异。结果表明:1）校园声景观不同时段的声音类型频率与声级无明显相关关系（P＞0.05），声级大小与空气温度、湿度等环境因子亦无显著相关性；2）景观中10、30 m和50 m的3个圆形缓冲区内的道路面积占比与声级呈中等强度正相关（0.577＜r＜0.689），且林地面积占比与声级呈中等强度负相关（r=-0.591），其他景观要素与声级均无显著相关性；3）声音的存在会影响人们对景观美感度和景观自然度感知，但在高和低绿视率景观中表现相反，即:在高绿视率景观中为正向效应，而在低绿视率组中产生负向效应。女性对声景观感知的好感度显著高于男性；4）无论景观绿视率高低与否，受访者对声音响度与视听匹配度的感受都会对景观美感度和自然度产生显著影响，但影响作用各异。     

海洋环境污染现状及对渔业的影响

随着大规模地对海洋进行开发利用,海洋环境污染日趋严重,在此通过叙述目前海洋环境污染的现状以及存在的问题,从环境保护和渔业行政执法角度对解决海洋环境污染提出几点建议.     

基于超声波传播特性的液态食品质量检测系统研制

研制了一个适用于液态食品超声波传播特性检测的装置，利用超声脉冲发射和接收测定液态食品的超声传播速度、声衰减和声阻抗。声速检测采用比较法，相对误差小于0.5%。利用声传播途径通过方程计算声衰减和声阻抗，计算中考虑了传播过程的声反射和声透射，结果具有一定的准确性。利用该装置研究发现苹果汁饮料中原果汁浓度与声速有良好的线性相关，具较好的实用性，可以应用于食品质量的超声检测。     

Estimating incidental takes of shearwaters in driftnet fisheries: lessons for the conservation of seabirds

We consider estimation of the magnitude of incidental fisheries ‘bycatch’ for two petrel species, sooty shearwaters (Puffinus griseus) and short-tailed shearwaters (Puffinus tenuirostris). There are clear statistical advantages in estimating bycatch for abundant species such as these, and our results may also guide the conservation and management of rarer species. We used fisheries statistics and observer data to estimate retrospectively the total numbers of sooty and short-tailed shearwaters bycatch in seven large-scale pelagic North Pacific driftnet fisheries between 1952 and 2001. Sensitivity analysis greatly simplified estimation of uncertainty by identifying four driftnet fisheries to be of particular importance in determining the magnitude and precision of the estimated bycatch totals. We estimated that between 1.0 and 12.8 million (95% CI) sooty shearwaters were killed by driftnets between 1952 and 2001. For short-tailed shearwaters we estimated between 4.6 and 21.2 million (95% CI) over the same period. More precise estimation was hampered by the paucity of available observer data, lack of reported detail and inconsistencies among data sources. Estimates may be strongly biased because some dead birds are misidentified or drop out of nets before hauling, or because some records were of live captures that were subsequently released. Improved estimation of overall take and its impact on populations of seabirds requires standardisation of reporting, allowance for potential sampling bias, as well as a clearer definition of the sampling unit and underlying bycatch probability distribution model, and knowledge of potential compensatory changes in population parameters.     

车削刀具磨损声发射信号的云特征分析

针对刀具磨损状态监测和磨损量预测研究中特征提取这一关键技术,该文提出了基于云理论的信号特征提取方法。首先,采用小波包分析对声发射信号进行信号分解和重构,滤除噪声对提取特征参数的影响;其次根据重构信号的统计分布特性,利用逆向云算法提取信号敏感频带的期望值、熵及超熵云特征参数,定量分析刀具在不同切削条件下3种云特征参数随磨损量增大所呈现的变化规律;最后,通过散点图分析3种特征参数表征刀具磨损声发射信号的有效性。结果表明:刀具磨损声发射信号具有明显的云特性,3种云特征参数与刀具磨损状态具有明显的对应关系,可作为刀具磨损状态监测、磨损量预测的特征参数;云理论在刀具磨损监测领域的应用,扩大了知识的表示范围。