Octopus as predators of abalone on a sea ranch

This study examined the occurrence of octopus across an abalone, Haliotis laevigata, Donovan, sea ranch in south‐western Australia, to understand how octopus may be impacting abalone production. Commercial divers removed 654 octopus and 17,666 empty abalone shells during regular, 2 to 4‐weekly surveys over 27 months. A negative binomial generalised linear model estimated a 78% increase in empty shells per artificial abalone habitat per day, when octopuses were present, after adjusting for location and season. Of the 408 shells examined for evidence of predation, 19% had a small, slightly ovoid hole consistent with those made by octopus. The mean (± 1 SE) length of shells with boreholes (70.3 ± 2.2 mm) was significantly longer than those without (59.8 ± 0.5 mm), and boreholes were concentrated over the adductor, respiratory organs and heart. This study provides important insights into the adaptable feeding regimes of octopus and their potential to impose strong top‐down controls on sea ranching operations.     

Social and political barriers to the use of Marine Protected Areas for conservation and fishery management in Melanesia

Abstract: In this paper we examine the strengths and weaknesses of state‐supported Customary Marine Tenure (CMT) systems in two independent Melanesian states (Solomon Islands and Papua New Guinea) in the context of the management of rapidly intensifying commercial and subsistence fisheries. We focus particularly on the proposed use of permanent no‐take Marine Protected Areas (MPAs), which are at present strongly favoured by scientists and environmentalists around the world, as the most versatile marine fishery management tool, especially in poor developing countries. We argue that, with some exceptions, typical Melanesian CMT regimes make MPAs difficult to establish, primarily due to issues of scale. We look closely at the ecological rationale for no‐take MPAs, for different coral‐reef based species, and assess the likelihood that populations of these species are self‐replacing on the same scale as CMT territories for most of coastal PNG and Solomon Islands. We argue that with some exceptions (mainly species with short‐lived larvae), the dynamics and scale of population replacement processes for most fished species make no‐take permanent closures largely incompatible with traditional CMT systems, and therefore unlikely to prove a successful management tool in this socio‐political context.     

自然水域无土栽培水稻的生态适应性研究

 为探明自然水域浮床无土栽培水稻（简称水上种稻，下同）技术应用于大型水库等水域的可行性，1991～1993年，在浙江省境内的5种水域类型上进行了生态适应性试验。累计试种双季和单季稻4.33 hm2，均经受住了不同生态环境和不同年份气候条件的考验。其中，除连作早稻单产低于水田水稻对照外，其他两季的单产均超过了水田水稻对照。最高的双季连作稻和单季晚稻单产分别达14 985和10 065　kg/hm2。 从而证明，在各类型水域上进行水上种稻不但可行，且能取得与水田水稻相仿甚至更高的产量。     

Nutritive value of copra cake meal fermented with Rhizopus spp. and its use as a protein source in practical diets for rabbitfish (Siganus javus)

The aims of this study were to evaluate fermentation of copra cake meal with Rhizopus spp. to enhance its nutritive value and to determine the optimum supplementation levels of the fermented meal on the growth performance and feed utilization of the rabbitfish, Siganus javus. Copra cake meal was fermented with Rhizopus spp. and included in four iso-nitrogenous diets at 0, 150, 300, and 450 g/kg. Rabbitfish (88.3 ± 1.7 g initial body mass) were fed with the test diets at 2.5%–3.0% of biomass/d for 12 weeks. After fermentation, the crude protein content of copra cake increased significantly (P < 0.05) from 218 ± 16 g/kg (mean ± SD) to 293 ± 4 g/kg, while lipid decreased from around 127 ± 4 g/kg to 60 ± 11 g/kg. Total amino acid content of copra cake meal increased after fermentation from 176 ± 12 g/kg to 207 ± 18 g/kg. Based on the third-order (cubic) polynomial regression, inclusion of fermented copra cake meal (FCCM) in test diets had significant (P < 0.05) effects on all parameters observed except for feed intake and survival rate. Fish fed the FCCM0 and FCCM150 diets had a similar protein retention (PR) but significantly differed (P < 0.05) from the diets containing higher FCCM inclusion rates. The breakpoint of two regressions fitted to specific growth rate (SGR) determined that the optimum inclusion rate is 137 g FCCM /kg diet, and at this level, protein from soybean meal can be included at approximately 315 g/kg diet for grow-out of rabbitfish, S. javus, in floating net cages.     

基于GSM的蔬菜漂浮育苗监控系统研制

根据漂浮育苗环境要求,结合农户育苗投资少和操作方便等经济性要求,研制出一种造价低、能够实现对漂浮育苗大棚内的环境温度、湿度、营养液深度和pH值等参数进行监测的系统。利用LPC2131进行数据处理,实现对温度、湿度、营养液添加和pH值在一定范围内的自动调整与手动调整相结合,给漂浮育苗提供稳定的环境条件。现场调试表明:该监控系统能够很好地满足蔬菜漂浮育苗要求,对蔬菜育苗具有促进作用。     

基于风洞平台实验的内浮顶罐油气泄漏扩散数值模拟

研究内浮顶罐油气泄漏扩散规律,对于加强环境污染控制、保障罐区安全具有重要意义。建立风洞实验平台,测试小型内浮顶罐风速及浮盘位置对蒸发损耗速率的影响,并考察了风场、浓度场分布规律。基于CFD数值模拟,使用UDF导入环境风,建立了内浮顶罐油气泄漏扩散的数值模型,并通过风洞实验数据验证其模拟的可行性。重点讨论了内浮顶罐外风场及风压分布规律、风速对内浮顶罐油气流场分布及油气扩散浓度的影响。结果表明:浮盘位置越低、风速越大,蒸发速率越快;罐壁的静压力分布规律为迎风侧最大、背风侧居中、罐两侧最小;不同风速下,罐内油气分布整体呈现对称状态;风速越小,油气质量浓度越高,浮盘缝隙处的油气质量浓度最高,并存在安全和环境污染隐患。研究成果对于内浮顶罐设计及运行维护、环保安全管理具有参考价值。     

黄河小北干流浮体泵站拦污设施探索

结合山西省运城市夹马口灌区吴王水源泵站的实际情况，从理论分析入手，提出了导污浮体的实用方案，为黄河流域水源泵站拦污设施提供了一条新的设计思路。     

立式内浮顶油罐瘪罐现象分析

针对立式内浮顶油罐遭受热带风暴侵袭后瘪罐事故屡有发生的现象,采用ANSYS软件建立有限元模型,对立式油罐进行了几何非线性分析,计算得出风压导致的变形量较小,表明风压对瘪罐事故的影响较小。同时,对呼吸阀的输送能力进行了分析,结果表明,温度骤降时机械呼吸阀换气量不足是导致事故的主要原因。根据分析结果,提出了提高储罐安全性的建议。     

试析物权法中浮动抵押与我国企业担保法制的完善

该文在对英美法系浮动抵押制度的主要特征及其利弊进行评析的基础上,对新《物权法》中的浮动抵押规定加以阐述,提出浮动抵押制度对完善我国企业担保制度的意义和在实际运用中应注意的问题。     

城市流动人口合理规模的层次分析模型

以成都市为例,根据成都市的经济社会发展现状和2000年的战略纲要,通过分析影响城市流动人口合理规模的诸因素并在此基础上对指标加以选择、修正,建立起成都市流动人口合理规模的层次分析(AHP)模型,并最终判断选出最佳方案.