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.     

有机海水围塘养殖生态系统能量收支与利用效率研究

对连云港市宋庄镇有机海水养殖基地的海水围塘南美白对虾—缢蛏—梭鱼混养系统和南美白对虾单养系统的能量收支与利用效率进行了研究。结果表明,在有机水产养殖方式下,混养系统中能量输入、输出分别为10.54和8.37MJ/m2,单养系统能量输出、输入分别为13.45和10.72MJ/m2。混养系统的光能利用率、光合能转换效率、生物能转换效率、总能转化率和底泥沉积率分别为0.18%、34.51%、48.11%、16.89%和62.41%,单养系统相对应的数据分别为0.19%、24.95%、24.04%、11.17%和68.54%。混养系统除光能利用率外,其他指标均优于单养系统,底泥沉积率亦小于单养系统。从综合生态经济指标来看,混养系统也优于单养系统,但2者综合生态经济指标(EY)均小于1,混养和单养系统都具有提高经济效益和生态效益的潜力。     

高寒温带干旱区农牧业生态系统的能值分析——以柴达木盆地为例

能值理论是综合分析生态经济系统的各种能量流的转换机理,并定量研究生态效益与经济效益及其相互关系的重要理论。本文以柴达木盆地(青海海西州)的农牧生态经济系统为例,通过一系列的能值指标的建立和能值的投入产出分析,定量分析海西州农牧业生态系统的特点,并发现该地区农牧业生产中存在的问题,从而为本地区和相似区域农牧业的可持续发展提供科学依据。     

鲢鱼糜与淀粉复合系统的微波糊化特性

在2 450 MHz频率的微波处理条件下,为了考察添加鲢鱼糜对小麦粉面团糊化的影响,将小麦粉、鲢鱼糜、NaCl和去离子水按比例混合制成鲢鱼糜面团,面团中鲢鱼糜含量分别为0%,10%,20%和30%(w/w,质量百分比),对样品面团中淀粉的介电特性和糊化特性进行研究。结果表明,对于相同尺寸的面团样品,添加鲢鱼糜可改善面团样品在电磁场中的加热均匀性。随着温度的升高,面团的介电常数和介电损失率分别在20~23和9~12内波动并呈下降趋势,微波的穿透深度因淀粉的糊化略有上升。淀粉的糊化速率随温度的升高而下降。降低样品中淀粉的含量,会使面团糊化活化能由113.54 kJ/mol下降至59.96 kJ/mol。     

可再生生物质燃料的研究与应用

文章对碳水化合物制备生物沼气、生物乙醇和生物汽油的研究与应用进展进行了综述,同时讨论了新能源的拓展思路,并对生物质能未来的发展趋势进行了展望.     

欧洲木质颗粒燃料产业发展现状与启示

欧洲是全球木质颗粒燃料产业发达地区.文中介绍欧洲木质颗粒燃料市场总体情况、生产特征、消费特征和价格体系, 分析其为规范和引导发展木质颗粒燃料产业而在原料收集、燃料燃烧、能源服务等3个环节采取的政策措施, 从统筹环境保护与经济发展角度提出对我国发展木质颗粒燃料产业的启示.     

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.     

Experimental Analysis on Energy Dissipation Mechanism and Seismic Performance of Steel Truss Coupling Beam-Coupled Shear Wall Structure

Pseudo-dynamic tests and low cyclic reversed loading tests on two-floor coupled shear wall planar structures were conducted, and one is arranged with two steel truss coupling beams, the other is arranged with a steel coupling beam and a RC coupling beam. The shear walls’ seismic response under different earthquake intensity was deliberated, Their failure mechanism, bearing capacity, hysteretic ductility, energy dissipation mechanism, and stiffness and strength degradation mechanism were analyzed as well. The results show that the shear wall with two steel truss coupling beams has reasonable stiffness distribution. Its energy dissipation mechanism, stiffness and strength degradation mechanism can fulfill the demands of coupled shear wall’s seismic design: under rare earthquake, it can maintain good bearing capacity and stiffness, and keep restraining the walls. Its seismic performance is superior to RC coupling beams-coupled shear wall system.     

智能通风技术在保水降温通风中的实践应用

智能通风系统自动采集大气温湿度和监控粮情变化,按构建模型进行智能分析,自动捕捉通风时机进行通风;通风过程中,根据流出气体温湿度等反馈的即时粮情、大气温湿度等数据,判断是否继续通风,从而避免了低效通风、无效通风和有害通风,取得了在降温通风中减少水分损耗、节能降耗的良好效果。     

马铃薯红外干燥特性研究

以马铃薯为原料,研究其红外干燥特性及数学模型。通过试验收集了不同切片厚度和干燥温度下马铃薯水分比(MR)随干燥时间(t)的变化数据,得到了马铃薯的干燥曲线,并计算了干燥过程中的有效水分扩散系数(Deff)和干燥活化能(Ea)。结果表明,干燥温度(T)与切片厚度(L)对马铃薯红外干燥特性有较大影响,干燥温度越高,切片厚度越薄,马铃薯的干燥速率(DR)越快,干燥时间越短;同时,通过拟合计算发现,在10种干燥模型中Modified Henderson and Pabis的预测值与实测值比较吻合,能够更好地反映干燥过程。在试验条件下,Deff在0.238 4×10-10~12.557 3×10-10m~2·s-1之间,且随着干燥温度和切片厚度的增加而增大。1、3、5、7 mm厚的马铃薯片红外干燥活化能分别为34.386 0、31.041 8、28.783 2、30.060 1 k J/mol。