养殖网箱清洗设备的实验研究

在网箱养殖业中,网箱网衣的清洗是亟待需解决的一个问题.本文主要对自行研制涡旋式网箱清洗设备的使用效率进行研究.通过对4种不同规格的毛刷进行实验分析,评估涡旋式网箱清洗设备的实际清洗效率、清洗时间.通过对耐清洗生物种和对污染性生物再生长的研究,为以后的工作指明方向.最终确定自行研制的涡肇式网箱清洗设备的最佳毛刷长度为15～20 cm,设备的清洗效率为30%以上,最佳清洗时间为下海后2周,实验区耐清洗的生物主要为紫贻贝和牡蛎.同时要根据海区及附着物的不同,选择不同的毛刷材料.在实际养殖过程中,采取机械清洗和其他清洗措施相结合的方法,来解决养殖网箱网衣的清洗问题.     

菲律宾蛤仔清洗分级整机设计及参数优化

针对捕捞后菲律宾蛤仔清洗不彻底、分级精度低、破损率高、效率缓慢等难题，本研究设计了一种菲律宾蛤仔清洗分级一体机以实现菲律宾蛤仔清洗与分级作业。确定了毛刷辊配合高压喷淋的清洗方法、滚筒式筛分的分级方式，完成了滚筒筛筛分机构、高压水喷淋结构等关键部件设计、选型。开展了清洗分级一体机作业参数的EDEM离散元仿真分析。仿真结果显示：当毛刷辊转速3 r/min、滚筒筛转速15 r/min、滚筒筛倾角3°时，分级精度为91%。经过样机作业测试，在此参数下分级精度达到91%,蛤仔破损率在1%～2%之间，其壳体附着泥沙冲洗干净。研究表明，该清洗分级一体机实现了对菲律宾蛤仔的高效率、高品质的清洗分级。     

新型滚筒式贻贝清洗设备设计

为了提高贻贝清洗工序的自动化程度和清洗效果,降低工人劳动强度,设计了一种集打散和清洗工序为一体的新型滚筒式贻贝清洗设备,利用摩擦清洗方式代替当前使用的振动清洗方式,清洗后的贻贝表面附着物和足丝连接更少,该设备提高清洗加工自动化程度和降低加工人员配置的同时,设备占地面积更小。采用Solidworks软件和Simulation模块对设备进行三维建模和相关零部件的有限元仿真,并对该设备进行样机制作和相关试验。结果显示:清洗过程中,贻贝破损数量和滚筒转速成正比,清洗所用时间和滚筒转速成反比,结合破损数量和清洗时间两曲线,确定滚筒最佳转速为30 r/min,最佳清洗时间为32s,清洗速度为375颗/min(约25 kg/min)。该设备对发展贻贝船上加工模式具有借鉴意义。     

鲜活海参清洗工艺试验研究

为了解决海参前处理加工环节中的清洗问题,通过引入气泡清洗技术,研发一种新型的适用于鲜活海参清洗新工艺。试验研究发现,气泡清洗能对海参周身体表进行有效的、低损伤、全方位的洗涤,而清洗强度（通入清洗水体的气流量）与清洗时间是海参清洗的重要工艺参数,并与气泡清洗后海参的洗净率和损伤率呈正线性关系。通过试验初步确定：当清洗强度为15 m^3/h,清洗1 min,海参的洗净率可达90%,而损伤率仅为5%。     

贻贝高压水射流清洗关键参数建模及试验

为解决贻贝传统清洗方式劳动强度高、清洗效果差的问题，搭建了贻贝高压水射流清洗平台。以射流压力、靶距、入射角为变量，射流打击力和射流冲击压力为评价指标，对贻贝外壳进行高压水射流清洗试验；通过Design-Expert软件设计多因素组合试验，建立射流打击力和射流冲击压力的数学模型，使用Box-Behnken响应面寻优得出贻贝高压水射流清洗参数的最优组合；采用最优清洗参数进行射流清洗试验，以验证参数的有效性。结果显示：使用喷射角为65°,内径为2 mm的扇形喷嘴，在射流压力为9.66 MPa,靶距为99.88 mm,入射角为75.38°进行高压水射流清洗时，射流冲击压力为0.011 MPa射流冲击压力远小于贝壳整体曲面的承压能力，清洗后的贻贝表壳完整无裂纹，表壳附着的各类顽固污物基本去除，清洗效果相较于传统清洗方式得到显著提升。高压水射流技术应用于贻贝的清洗，能有效提高贝源的洁净程度和工业化精细处理水平，同时对其他双壳纲贝类的清洗也具有一定的借鉴意义。     

改性牡蛎壳粉的制备及其对Cd~(2+)的吸附

以十二烷基磺酸钠(SDS)为改性剂,制备了有机改性牡蛎壳粉,并以Cd2+的去除率为指标进行正交实验分析,确定最佳改性工艺。通过红外光谱(FTIR)、扫描电镜(SEM)、能谱(EDS)对有机牡蛎壳粉进行表征,并进行了其对Cd2+的吸附动力学研究。正交实验结果表明,最佳改性工艺条件为:SDS用量为牡蛎壳粉质量的15%,改性时间为120 min,改性温度为60℃,改性p H值为7。FTIR、SEM和EDS图谱表明SDS对牡蛎壳粉的改性是成功的。动力学研究表明改性牡蛎壳粉对Cd2+的吸附符合准二级动力学方程。     

近江牡蛎的超声波辅助自溶及酶解条件研究

超声波和蛋白酶可以破坏蛋白质结构,提高短肽的得率。本试验以近江牡蛎为原料,在适度水解、控制挥发性盐基氮在合理范围的前提下,以短肽含量为主要目标,首先通过研究超声波功率、时间对牡蛎自溶酶解的影响,优化超声波辅助酶解工艺,然后采用单因素试验研究碱性蛋白酶对超声波—自溶酶解液酶解效果的影响。结果显示,440 W超声波处理牡蛎10min后自溶酶解,短肽含量为(88.75±1.16)mg/mL,是对照组的2.12倍;水解度为(30.38±0.05)%;挥发性盐基氮为(79±2)μg/g。采用碱性蛋白酶对超声波-自溶酶解液进行进一步酶解,优化的酶解条件是:加酶量5kU/g,酶解温度55℃,酶解时间4h,此时短肽含量达到100mg/mL以上,水解度为(35.95±0.05)%;挥发性盐基氮为(178±6)μg/g,处在可接受范围。试验结果表明,超声波预处理后自溶,再进行外源蛋白酶酶解可显著提高酶解效率。     

壳聚糖固定化胰蛋白酶制备牡蛎肽的研究

以壳聚糖为载体固定化胰蛋白酶,制备牡蛎肽,然后以肽得率为指标,分别研究了pH值,酶加量,酶解时间和温度等单因子对固定化胰蛋白酶酶解牡蛎蛋白质的影响。实验结果表明,酶解牡蛎蛋白的最佳工艺条件是:底物浓度为200μg/mL,加固定化胰蛋白酶量7mg/3mL,酶解时间3h,pH 8.0,温度40℃。在此条件下水解牡蛎蛋白,肽得率可达到20.39%。     

响应面优化酶法提取牡蛎糖原工艺条件研究

为研究制备牡蛎(Crassostrea angulata)糖原的最佳工艺条件,通过比较分析了碱性蛋白酶、木瓜蛋白酶、胃蛋白酶、中性蛋白酶和胰蛋白酶等5种不同蛋白酶对牡蛎进行酶解提取糖原的效果,以碱性蛋白酶为最优酶制剂。在对碱性蛋白酶酶解工艺条件进行单因素实验的基础上,应用Box-Bhenken中心组合设计3因素3水平试验方案,通过响应面分析,建立数学模型优化牡蛎糖原的提取条件,以p H、酶解温度和加酶量为自变量,牡蛎糖原提取率为指标,获得碱性蛋白酶水解牡蛎提取糖原的最佳工艺条件,即加酶量4%、p H9、水解温度50℃,此时牡蛎糖原的提取率可达(48.55±0.01)%。试验结果表明,响应面法对牡蛎糖原提取条件的优化方案合理可行,该研究为牡蛎糖原的开发利用提供了理论依据。     

青岛西海岸新区开展养殖牡蛎清洗分拣机推广工作

牡蛎的清洗作为牡蛎生产加工的必经工序,目前国内通常还是采用人工高压冲洗的作业模式,不仅生产效率低,而且产品品质的稳定性相对较差,严重制约牡蛎养殖产业的发展。为改进养殖牡蛎传统的清洗分拣模式,2019年底,青岛西海岸新区积极推广牡蛎全自动清洗分拣加工技术,鼓励养殖企业从外地引进牡蛎全自动清洗分拣加工机设备,开展牡蛎销售前的清洗及分拣工作。     

高压射流式水下洗网机喷嘴的设计

为解决深水网箱养殖过程中因网衣附着生物而影响水体交换,并给换网及网衣清洗带来极大困难等问题,开发水下洗网机并提高水下洗网机的清洗效率,是深水网箱养殖的重要配套装备与技术。通过对高压射流水下洗网机工作原理的分析,基于能量方程,推导出洗网机关键部件喷嘴的结构几何参数计算表达式。合理选择高压水发生系统的压力和流量,计算出喷嘴的孔径与长径比。在此基础上计算高压射流水下洗网机的水力参数,为进一步优化洗网机结构提供理论依据。     

船舶水下液压清洗设备研究

在船舶不进坞的情况下,有效地清除附在其外表面上的海生物,有利于延长船舶坞修时间和提高船舶使用寿命.船舶水下液压清洗设备由回转机构、清洗机构、磁路机构等关键部件组成,通过摇杆摆动和叶片旋转来清除海生物,通过控制定位系统使叶片始终与船体保持一定距离以保护油漆,后续有高频超声波震荡来清除残余海生物.所研制的设备具有体积小、调节方便、功率大、清洗简单可靠等特点,具有一定的应用推广价值.     

基于ANSYS的水下洗网机流场模拟仿真

建立了水下洗网机内部流动的CFD计算模型,用计算流体力学软件ANSYS—FLOTRAN对水下洗网机内部的流场进行了模拟分析,得到了洗网机内部流体的速度分布曲线及压力分布曲线。分析结果为研究洗网机结构参数的优化设计提供了重要参考。     

Cleaner fishes and shrimp diversity and a re‐evaluation of cleaning symbioses

Cleaning symbiosis has been documented extensively in the marine environment over the past 50 years. We estimate global cleaner diversity comprises 208 fish species from 106 genera representing 36 families and 51 shrimp species from 11 genera representing six families. Cleaning symbiosis as originally defined is amended to highlight communication between client and cleaner as the catalyst for cooperation and to separate cleaning symbiosis from incidental cleaning, which is a separate mutualism preceded by no communication. Moreover, we propose the term ‘dedicated’ to replace ‘obligate’ to describe a committed cleaning lifestyle. Marine cleaner fishes have dominated the cleaning symbiosis literature, with comparatively little focus given to shrimp. The engagement of shrimp in cleaning activities has been considered contentious because there is little empirical evidence. Plasticity exists in the use of ‘cleaner shrimp’ in the current literature, with the potential to cause significant confusion. Indeed, this term has been used incorrectly for the shrimp Infraorder Stenopodidea, involving three families, Stenopodidae, Palaemonidae and Hippolytidae, and to represent all members of Lysmata and Stenopus. Caution is expressed in the use of grey literature and anecdotal observations to generate data on cleaning interactions, due to the presence of species complexes. Interest in cleaning organisms as biological controls in aquaculture is increasing due to their value as an alternative to various chemical ectoparasite controls. Reports of the importance of cleaner organisms in maintaining a healthy reef ecosystem has also been increasing and we review the current biological knowledge on cleaner organisms, highlighting areas that are understudied.     

Triploidy induction by hydrostatic pressure in the pearl oyster, Pinctada martensii Dunker

Triploidy of the pearl oyster, Pinctada martensii Dunker, was induced with hydrostatic pressure shock. The efficiency of inductions changed with the time of initiation of treatment, the duration of treatment and the intensity of pressure. The most effective procedure for inducing triploidy was the treatment of eggs at 200–250 kg/cm² 5–7 min (for the first polar body retention) and 17–19 min (for the second polar body retention) after insemination for 10 min duration, which resulted in 76% triploid embryos. Under this optimal treatment, high hatchability was also obtained.     

养殖网箱网衣清洗设备喷嘴的设计及力学特性分析

以提升清洗设备喷嘴清洗清洁度为目的,采用k-kl-w三方程湍流模型及有限元理论方法分析3类喷嘴孔内压强分布特性、速度分布特性和空化程度情况。结果显示:1)与锥型截面喷嘴和圆弧型截面喷嘴相比,突变型截面喷嘴在结构缩颈处有单位时间最大速度变化量224.13 m/s,具有更大的概率发生空化效应;2)锥型截面喷嘴与圆弧型截面喷嘴的空化区域远小于突变型喷嘴,其最大气相体积分数约为同等条件下突变型截面喷嘴的37.5%;3)高压流体作用下突变型截面喷嘴的流体状态为湍流,与锥型截面喷嘴和圆弧型截面相比湍流动能和湍流强度最大;4)圆弧型截面喷嘴湍流动能和湍流强度均趋于零,流体状态为层流,与突变型和锥型截面喷嘴相比,圆弧型截面喷嘴对保持流体层流性有较好的稳定性。喷嘴优化分析结果显示,通过增加突变型截面的喷嘴结构能显著提升喷嘴的空化强度。     

Comparison of environmental conditions in two representative oyster farming areas: Hiroshima Bay,western Japan and Oginoham a Bay (a branch of Ishinomaki Bay), northern Japan

ABSTRACT:   Sea water environmental conditions over annual cycles were investigated and compared between two oyster farming areas, western Hiroshima Bay and Oginohama Bay (a branch of Ishinomaki Bay) in Miyagi Prefecture, to appropriately manage oyster culture or more efficiently utilize farming areas. The environmental parameters of temperature, salinity, nutrient concentrations (NO₂–N, NO₃–N, NH₄–N, PO₄–P, and SiO₂–Si) and size-fractionated chlorophyll- a (<0.2, 2–20, >20µm), and abundances of microzooplankton were measured in each bay at the surface, and 2 and 5 m depth layers. Differences in the annual mean values and results with monthly paired Student's t -tests showed that salinity was lower, and temperature, nutrient (especially PO₄–P) and chlorophyll- a concentrations, and abundance of microzooplankton, were higher in Hiroshima Bay than in Oginohama Bay. Differences in environmental conditions between inshore and offshore areas of each bay suggest that inflows of river water in western Hiroshima Bay and sea water from offshore had the most significant effects on the environmental conditions. It is concluded that such oceanographic and biological differences strongly affect the oyster farming system, especially regarding the optimum usage of offshore areas in Summer under clean, cold and stable seawater conditions, rather than food quantity in Hiroshima Bay, and under more abundant food conditions in Oginohama Bay.     

Seasonal Fouling Stress on the Farmed Pearl Oyster,Pinctada fucata,from Southeastern Arabian Sea

Biofouling on the periostracum of pearl oysters and on the cages has been considered as a stress factor causing mortality of the farmed stock, reducing growth rates and also affecting pearl quality. In farming experiments using the pearl oyster, Pinctada fucata, at Kollam Bay (India), biofouling was found to be a problem. This study was conducted to understand the effect of fouling on the mortality of pearl oysters kept in suspended culture, to identify the main foulers, the seasonal variation in biofouling and species successions in the community with reference to abiotic factors. The average monthly mortality rate (MR) was estimated as 0.117 ± 0.002 and the monthly variations were significantly different (P < 0.01). The total fouling (0.163 ± 0.002 g/g oyster) and biofouling weights (0.166 ± 0.007 g/g oyster) were high in December when the fouling community was composed of several species and dominated by the ascidian, Didemnum sp. December was also the period when the MRs peaked indicating that this organism was the main cause of mortality in pearl farms in Kollam Bay. A clear seasonality in the fouling community (25 species belonging to nine phyla) has been observed in the present study. On the basis of this study, monthly cleaning of oysters is advocated except during December, January, and March when the cleaning should be fortnightly.     

牡蛎肉的醒酒作用机理初探

以小鼠血清中乙醇浓度为指标,对牡蛎肉中含有的蛋白质、糖原以及牛磺酸等生理活性成分的醒酒效果进行了初步探讨,旨在阐明牡蛎肉的醒酒作用机理.实验结果表明,牡蛎肉中的糖原和牛磺酸均具有明显的醒酒效果,最佳醒酒效果的剂量分别为0.8、0.05 mg/ml,与阳性对照组比较,小鼠血清的乙醇浓度分别下降了49.4%和43.74%,牡蛎肉蛋白质无醒酒作用,糖原和牛磺酸为牡蛎肉醒酒作用的主要有效成分.