Effect of salinity on growth and energy budget of red and green colour variant sea cucumber Apostichopus japonicus (Selenca)

Sea cucumber, Apostichopus japonicus (Selenca), tolerates salinity fluctuations inhabiting intertide zone. This study deals with growth, food intake, food conversion and the bioenergetic responses of the red variant (wet weight of 2.60 ± 0.11g) and green variant (wet weight of 2.56 ± 0.08 g) A. japonicus to different salinities of 22, 26, 30, 34, and 38 psu at 16.5 ± 0.5°C. The results showed that salinity had a significant effect on specific growth rate (SGR) of both green and red variants A. japonicus (P < 0.05). Both colour variants of sea cucumber had highest SGR at 30 psu, and then decreased when salinity below or above this point. Maximum SGR (the green 1.07 ± 0.08% day^?1, the red 1.14 ± 0.09% day^?1 respectively) is related with maximum food intake (FI) and highest food conversion efficiency (FCE) (P < 0.05) occurring at 30 psu. Only under 22 psu, the green variant grew faster than the red variant (P < 0.05), and under other four salinity treatments there was no significant difference between SGR of two colour variant holothruians (P > 0.05). Values of adaptable salinity scope for green and red variants sea cucumber survival are 18.5~39 psu and 20.9~38.6 psu respectively. The average energy budget formula of sea cucumber at 30 psu was: 100C = 6G +42F +3U+49R (C, energy ingested; G, energy for growth; F, energy loss as faeces; U, energy used for ammonia excretion; R, energy loss for respiration). The sea cucumber had maximum energy ingested (C) and highest proportion of energy for growth (G) at 30 psu, and then decreased when salinity is above or below this salinity. Both red and green variants of A. japonicus deposited for growth were very low, and the energy loss in faeces and energy for respiration accounted for the majority of assimilation energy. The result clearly showed that the optimum condition for farming green and red variants A. japonicus, both with respect growth and energy allocation, is the salinity scope of 26 ~ 30 psu.     

冬季黑穗醋栗叶绿素含量及影响因素的初步研究

冬季黑穗醋栗（Ｒｉｂｅｓ　ｎｉｇｒｕｍ　Ｌ．）枝条树皮中叶绿素含量不断下降，仲冬（１月份）时达最低点，叶绿素含量变化与月平均气温相吻合．叶绿素含量下降与冰冻低温有关，更与冰冻低温结合日照有关．冰冻能直接引起叶绿素含量下降，其中ａ的下降率低于ｂ的下降率，因而ａ／ｂ比值增大．叶绿素含量下降能导致组织细胞电解质渗出率加大，所以冬季冰冻低温及其与光照相结合会造成树皮组织细胞的伤害，其向阳面更重．     

51个木麻黄地理种源对星天牛抗虫序列的调查研究

本文报道51个木麻黄(Casuarina spp.)地理种源对星天牛(Anoplophora chinensis(Forster))抗性调查和分析的结果。调查获得数据应用IBM—PC计算机进行逐步聚类分析,将51个木麻黄地理种源划分为高感、中抗、高抗和绝抗4个类群,并进行方差分析,结果表明4个类群木麻黄对星天牛的抗性达极显著差异,因此在星天牛发生严重地区可以选择既抗虫、又抗风,生长较好的C_(33)、C_(39)、C_(44)等种源造林。     

Effects of diatom concentration in prepared feeds on growth and energy budget of the sea cucumber Apostichopus japonicus (Selenka)

Eight test diets were used in the experiment: seven fresh diatom (Cylindrotheca fusiformis) diets in which diatom occupied 100%, 83.3%, 50%, 33.3%, 20%, 14.3% and 11.1% in dry matter of the feeds (marked as D100, D83, D50, D33, D20, D14 and D11), and a formulated diet (70% Sargassum thunbergii powder, 20% sea mud and 10% fish meal, based on dry weight, marked as ST). The results showed that the specific growth rates (SGRs) of the animals fed diets D33, D20, D14 and D11 were not significantly different from the SGR of those fed diet ST. However, the energy allocated to growth for the animals fed with diet D14 was twice that of diet ST. For sea cucumbers fed diet D14 the largest expenditure part was allocated to respiration (55.4%), but for those fed diet ST, the largest part was allocated to faeces (62.7%). The organic content of diet D14 was also much lower than that of diet ST. Frozen diatom diets containing 14% (dry matter weight) fresh diatom could be an environmentally friendly feed as an alternative option for macroalgae powder.     

表面油流法显示螺旋离心泵内部流动的研究

对螺旋离心泵叶轮、进水节和进水节与蜗壳交界处的部分端面做了表面油膜、油点试验。通过流谱分析，揭示了表面奇点、分离线与再附着线等流动特征，研究了螺旋离心泵内部流动规律，进而提出了改进螺旋离心泵结构的设想。     

基于粒子群算法的发动机悬置系统稳健优化设计

应用稳健优化设计理论,考虑设计变量的变差对优化设计结果的影响,建立了稳健优化设计模型.以发动机悬置系统能量解耦为目标,悬置刚度参数为设计变量,考虑目标函数和约束函数均值μ和标准差σ的变化,构造了发动机悬置系统的稳健优化模型.采用粒子群优化算法对发动机悬置系统的悬置刚度参数进行了稳健优化设计,并用Monte Carlo方法进行了分析.设计应用表明,优化方法可以有效降低系统解耦度对悬置刚度参数的敏感性,系统解耦度分布更合理.比遗传算法的计算效率高.     

Beneficial co‐culture of jellyfish Rhopilema esculenta (Kishinouye) and sea cucumber Apostichopus japonicus (Selenka): implications for pelagic‐benthic coupling

This study investigated monthly changes of sedimentation and sediment properties in three different culture systems (ponds) – i.e. jellyfish Rhopilema esculenta monoculture (J), sea cucumber Apostichopus japonicus and jellyfish co‐culture (SJ) and sea cucumber monoculture (S) – to verify the feasibility of co‐culturing jellyfish and sea cucumbers. Results showed that jellyfish culture accelerated the settling velocity of total particulate matter (TPM). Average TPM settling velocities in the SJ (75.6 g m^?2 day^?1) and J (71.1 g m^?2 day^?1) ponds were significantly higher than that in the S pond (21.7 g m^?2 day^?1) from June to September during the jellyfish culture period. Average settling velocities of organic matter (OM), total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) in the SJ pond increased significantly by 3.0, 2.9, 3.3 and 3.8 times, respectively, compared with those in the S pond. Sediment contents of OM, TOC, TN and TP in the SJ and J ponds were significantly higher than those in the S pond during the jellyfish culture season. The specific growth rate of sea cucumbers feeding on SJ sediment was significantly higher than that of those feeding on S sediment. Co‐culturing sea cucumbers with jellyfish may help alleviate benthic nutrient loading due to the jellyfish and provide a secondary cash crop.     

不同铁肥品种对苹果叶片叶绿素、铁含量及光合速率的影响

采用断根输液法对缺铁失绿症的苹果树分别施用不同浓度的柠檬酸铁、螯合铁和邻啡罗啉铁3种铁肥,试验结果表明,断根输液能在较短时间内提高叶片的叶绿素和铁的含量,提高叶片的光合速率,从而获得较好的复绿效果。邻啡罗啉铁是适合根系输液矫正苹果树缺铁失绿症的铁肥品种。     

消费者食品安全信息分享行为影响因素分析

研究基于ELM理论和多元有序Logit回归模型,考察消费者食品安全信息的需求偏好现状并分析其食品安全信息分享行为影响因素.结果表明,消费者主要通过社交媒体、亲友同事间耳口相传、搜索引擎或门户网站获取食安信息,对政府监管部门、消费者协会、主流新闻媒体信任程度较高,消费者性别、婚姻状况、收入水平、购买频率等个体特征显著影响...     

市场中不合格烟剂农药的调查与分析

本文对79份不合格烟剂样品进行比较,发现不合格烟剂主要是杀虫烟剂与杀菌烟剂,多数不合格烟剂中且违规添加了未登记的农药成分。本文通过调查分析提出了对烟剂农药市场管理的几点建议。