基于增强式学习的仿生机器鱼避障控制

研究了仿生机器鱼的自主避障控制,提出了一种集成超声和红外传感器的仿生机器鱼系统设计方案,为机器鱼安装了3个超声传感器和3个红外传感器.针对此仿生机器鱼系统,提出了一种基于增强式学习的仿生机器鱼自主避障控制策略,给出了状态集和行为集,采用当场奖励和延时奖励相结合的方法,通过学习获得了有效的状态行为组合.仿真实验验证了学习结果的有效性.     

Short-Term Immune Responses of Gilthead Seabream (Sparus aurata) Juveniles against Photobacterium damselae subsp. piscicida

Photobacteriosis is a septicaemic bacterial disease affecting several marine species around the globe, resulting in significant economic losses. Although many studies have been performed related to the pathogen virulence and resistance factors, information regarding the host defence mechanisms activated once an infection takes place is still scarce. The present study was designed to understand innate immune responses of farmed juvenile gilthead seabream (Sparus aurata) after Photobacterium damselae subsp. piscicida (Phdp) infection. Therefore, two groups of seabream juveniles were intraperitoneally injected with 100 µL of PBS (placebo) or 100 µL of exponentially growing Phdp (1 × 10⁶ CFU/mL; infected). The blood, plasma, liver, and head kidney of six fish from each treatment were sampled immediately before infection and 3, 6, 9, 24 and 48 h after infection for the broad screening of fish immune and oxidative stress responses. Infected animals presented marked anaemia, neutrophilia and monocytosis, conditions that are correlated with an increased expression of genes related to inflammation and phagocytic activity. Similar studies with different fish species and bacteria can be useful for the definition of health biomarkers that might help fish farmers to prevent the occurrence of such diseases.     

基于鱼体回声图像的鱼类识别算法

以图像处理技术理论为前提,使用Matlab中的DIP(Digtal Image Process)工具箱和GUI(Graph User Interface)工具,对鱼体回声图像进行处理,匹配专家数据库,成功实现了对单体鱼的识别.介绍了对单体鱼的识别方法,详细阐述了鱼体回声图像的预处理方法、单体鱼的体态及长度参数的提取方法、通过建立专家数据库来实现目标识别的方法.引入了自适应图像窗的概念,提出了对鱼群的识别算法.     

鱼油脂肪酸乙酯化工艺研究

比较三种不同鱼油原料脂肪酸组成、含量和各项品质指标,选取步鱼油用碱催化法进行乙酯化反应。通过单因素实验和响应面分析,步鱼油乙酯化工艺最优条件为:无水乙醇/鱼油反应物摩尔比为6:1,反应温度为75℃～77℃,反应时间2小时,碱催化剂浓度为0.8N～1.0N,由分子蒸馏得到乙酯化得率为96％。     

Use of β-hydroxyacyl-CoA-dehydrogenase (HADH) activity to differentiate frozen from unfrozen fish and shellfish

 Further work on an enzymic method to differentiate frozen from unfrozen fish and shellfish is reported. The method is based on the release of the β-hydroxyacyl-CoA-dehydrogenase (HADH) from mitochondria during freezing. Enzymic activity was evaluated in fresh and frozen thawed samples from sole (Solea solea), sea bream (Pagellus centrodontus), hake (Merluccius merluccius), gilt headed bream (Sparus aurata), sea bass (Dicentrarchus labrax), salmon (Salmo salar), prawn (Penaeus japonicus) and Norwegian lobster (Nephrops norvegicus). Changes in the HADH activity of fresh and frozen thawed samples were compared after freezing at –196  °C for 15 min. Two values were obtained: U (by dividing: HADH activity of samples frozen at –196  °C, then thawed/HADH activity of unfrozen samples) and F (by dividing: HADH activity of samples frozen at –18  °C, thawed, then frozen at –196  °C /HADH activity of samples frozen at –18  °C, then thawed). Statistical analysis showed significant differences (P≤0.05) between both quotients for gilt headed bream, salmon, sea bream, sole and prawn, and an arbitrary limit was set at 2 to differentiate frozen thawed from unfrozen samples. The application of this limit made it possible to discriminate the unfrozen from the frozen thawed state of around 90% of the total samples analysed. Best results were obtained for prawn (100% of samples differentiated). In the present paper, a laboratory routine is proposed based on the comparison of the HADH activity of a sample analysed straight away and that of a sample frozen at –196  °C and then thawed. The reported method is simple and fast. The entire laboratory procedure can be performed in 45 min. Received: 20 July 1998 / Revised version: 2 November 1998     

Effects of feeding an aquatic weed Lemna trisulaca as partial replacement of fish meal on the performance of growing ducklings

Growing ducklings were fed diets containing an aquatic weed Lemna trisulaca meal (LTM) replacing, on a protein basis, either 40, 60 or 80 g kg^?1 of the fish meal (FM) from a control diet which contained 120 g FM kg^?1. Partial replacement of FM (40 and 60 g kg^?1 of the FM) by LTM on a protein basis showed good growth and low food consumption but food conversion efficiency was found to be comparable. It was concluded that LTM could be considered as a protein feed supplement for growing ducklings and also as a part replacement of animal protein (FM) in the nutrition of growing ducklings without deleterious effect on performance.     

鱼肉鲜度测定方法研究进展

综述了用于鱼肉鲜度测定的几类不同方法 ,包括感官评价方法、微生物学方法、物理和化学方法和生物传感器方法等 ,并比较了不同测定方法的特点 ,阐明了鱼肉鲜度测定方法的未来发展趋势。     

低值鱼蛋白磷酸化改性对酶解影响研究

对低值鱼蛋白磷酸化改性,并进行体外酶解,研究了磷酸化鱼蛋白的酶解特性(酶解物氨态氮得率、TCA可溶性肽得率及肽分子量分布)。结果表明,磷酸化低值鱼蛋白酶解物中TCA-N得率与对照样相近,约46%,磷酸化对其酶解程度影响很小。     

酶法制取龙头鱼水解蛋白及海鲜风味料的研究

研究了酶法水解龙头鱼的工艺及其水解液脱苦的适宜条件。通过正交试验确定了以水解龙头鱼蛋白为基料制备复合调味料的较优配方 ,获得口感丰富、具有浓郁海鲜风味的产品。     

超临界二氧化碳富集提纯鱼油中EPA和DHA的研究进展（Ⅱ）鱼油的预处理和实验装置

综述了近年来人们用超临界二氧化碳（ＳＣ－ＣＯ_２）从鱼油中富集提纯ＥＰＡ（廿碳五烯酸）和ＤＨＡ（廿二碳六烯酸）的各类实验装置。讨论了鱼油的预处理方法、萃取操作条件对ＳＣ－ＣＯ_２提纯ＥＰＡ和ＤＨＡ的纯度和收率的影响。介绍了一个工业化双塔连续逆流萃取模拟流程。对我国鱼油资源的利用进行了分析。