不同饵料、密度和池底对锯缘青蟹大眼幼体蜕皮变态的影响

实验观察了不同饵料、池底、密度对锯缘青蟹大眼幼体蜕皮变态率和残杀率的影响.实验结果表明:投喂裸腹蚤时,大眼幼体蜕皮变态率最高,3种池底大眼幼体蜕皮变态率平均为 78.1%,残杀率最低平均为 11.4%;海泥池底大眼幼体蜕皮变态率最高,投喂3种饵料的大眼幼体蜕皮变态率平均为84.8%,残杀率最低平均为7.6%;裸腹蚤是青蟹大眼幼体培育适宜的饵料,而海泥则是大眼幼体变态适宜的池底.不同培育密度对青蟹大眼幼体蜕皮变态率和残杀率的实验结果表明:当大眼幼体的培育密度为3 尾/dm3 时,其蜕皮变态率最高,而残杀率与大眼幼体培育密度的关系不明确. 【英文摘要】 Effects of different dietary,densities and substrata on metamorphosis rate and cannibalistic rate from protozoea 1 (PZ1) to postlarvae 1(PL1) stages of Scylla serrata megalopae were studied in two separate experiments.In the first experiment,three dietary:Monia mongolica,minced meat of Ruditapes philippinaram which filted through mesh and haima 0 shrimp stuff and three substrata:sea mud,sand and cement were investigated.It showed that the metamorphosis rate of megalopae was higher when it was fed Monia mong...国家海洋 863 项目“锯缘青蟹大规模人工育苗技术”(2002AA603013)资

Reviews on Ecosystem Services Valuation and GIS-Based Mapping

生态系统服务价值评估是当前生态经济学领域的研究热点,为解决生态系统对人类的重要性提供了量化参考。文章论述了国内外生态系统服务价值的评估方法,分别从静态评估、动态评估和gIS技术应用三大方面进行了归纳分析,提出今后应重点关注生态系统服务价值的时空动态模型开发、评价指标体系与评价方法的标准化制订和生态系统综合管理与应用等方面的研究。Ecosystem services valuation has become one of the hotspots in the field of ecological economics,and provides quantitative evidence concerning the importance of the ecosystem for human-beings.In this paper,we first discussed ESV method in static,dynamic and GIS based respectively.We pointed out that scientific community should focus on several topics in the near future to deepen the understanding of the values of ecosystems.These topics include the development of spatially and temporarily explicit dynamic valuation models,standardization of valuation methods and payment for ES and meeting the requirements of regional ecosystem management and decision making.北京市科学技术委员会“永定河生态修复目标体系研究”(D090409004009003);北京市生态学重点学科项

U型拱梁失稳有限元分析

U型拱梁在隧道支护和矿山巷道支护中应用广泛,实际工程中的地压作用以及注浆加固过程中产生的集中力都可能引起支架的失稳破坏。本文利用有限元数值分析软件ANSYS采用我们提出的瞬态分析计算失稳临界载荷方法对不同对称位置受径向集中力作用的U型钢拱梁的稳定性进行了研究,并分别采用特征值屈曲分析和几何非线性分析方法进行了分析,将得到的失稳临界荷载值进行了对比分析。研究结果为工程应用提供了可行方法和理论依据

Studies on the Energy Budgets of Juvenile Pseudosciaena crocea (Richardon) During Starvation

研究了饥饿状态下大黄鱼幼鱼的能量收支 .结果表明 ,其排泄能及代谢能与体质量均成指数关系 ,排泄能与温度正相关 ,代谢能与温度之间为二次函数关系 .体质量对饥饿状态下的能量分配模式没有显著影响 ,其平均能量收支方程为 :30 .2 3U +6 9.77R - 10 0G =0 .能量分配模式随温度的变化而呈显著的变化Energy budgets of starvaed juvenile Pseudosciaena crocea (Richardon) under different sizes ( 7.4 ～21.9) and temperature(15～30 ℃) were investigated. Results showed that, excretion and metabolism were power functions of body mass. Excretion were positively linearly correlated with temperature. The fish body mass seemed not to have significant effects on the energy allocation models, however, the energy allocation models changed remarkably with temperature.福建省水产饲料研究会和厦门大学自选课 题 (Y0 70 0 9)资

Effects of Diets,Densities and Substrata on Metamorphosis Rate to Postlarvae of Scylla serrata Megalopae

实验观察了不同饵料、池底、密度对锯缘青蟹大眼幼体蜕皮变态率和残杀率的影响.实验结果表明:投喂裸腹蚤时,大眼幼体蜕皮变态率最高,3种池底大眼幼体蜕皮变态率平均为 78.1%,残杀率最低平均为 11.4%;海泥池底大眼幼体蜕皮变态率最高,投喂3种饵料的大眼幼体蜕皮变态率平均为84.8%,残杀率最低平均为7.6%;裸腹蚤是青蟹大眼幼体培育适宜的饵料,而海泥则是大眼幼体变态适宜的池底.不同培育密度对青蟹大眼幼体蜕皮变态率和残杀率的实验结果表明:当大眼幼体的培育密度为3 尾/dm3 时,其蜕皮变态率最高,而残杀率与大眼幼体培育密度的关系不明确. 【英文摘要】 Effects of different dietary,densities and substrata on metamorphosis rate and cannibalistic rate from protozoea 1 (PZ1) to postlarvae 1(PL1) stages of Scylla serrata megalopae were studied in two separate experiments.In the first experiment,three dietary:Monia mongolica,minced meat of Ruditapes philippinaram which filted through mesh and haima 0 shrimp stuff and three substrata:sea mud,sand and cement were investigated.It showed that the metamorphosis rate of megalopae was higher when it was fed Monia mong...国家海洋 863 项目“锯缘青蟹大规模人工育苗技术”(2002AA603013)资

基于GDEM–GAVA的白羊城沟泥石流成灾风险数值分析

降雨型泥石流是一个降雨–洪水–泥沙输运–推移质运动的多过程耦合过程。本文借助颗粒碎屑流仿真系统（GDEM–GAVA），对白羊城沟泥石流的成灾风险进行了分析。首先通过历史灾情数据反分析出了沟道物源的力学参数，而后基于该参数分析了不同降雨强度下该泥石流的成灾临界降雨时长。计算结果表明，白羊城沟泥石流物源的饱和黏聚力为0.5～1 kPa，饱和内摩擦角为5°～10°；降雨强度为65 mm/h时，沟道形成泥石流的时间为3.6 h；降雨强度为78 mm/h时，沟道形成泥石流的时间为2.8 h；降雨强度为88 mm/h时，沟道形成泥石流的时间为2.3 h。上述泥石流成灾风险的分析结果可为白羊城沟泥石流的科学预警提供必要的依据