采煤矿区不同塌陷塘水域生态环境特征分析   总被引：2，自引：0，他引：2  

王振红  桂和荣  张晓勇 《安徽农业科学》2006,34(16):4072-4073,4087

通过对淮南矿区不同塌陷年龄的采煤塌陷塘的水生态环境监测,分析了不同塌陷年龄塌陷塘的主要限制性因子和塘内浮游植物种类组成及其生长的限制性因子,结果表明:不同塌陷年龄的塌陷塘中主要限制因子各不相同,但TP在各塘中均占据主要的限制性因子地位,塌陷塘主要为P限制型;浮游植物组成方面绿藻和蓝藻均占据优势地位,但各塌陷塘浮游植物组成与主成分因子间的关系并不一致,其受限因子也有所不同。  相似文献   

Prediction of dissolved oxygen in pond culture water based on K-means clustering and gated recurrent unit neural network     

《Aquacultural Engineering》2020

Dissolved oxygen in water is an important ecological factor in ensuring the healthy growth of aquatic products, as hypoxic stress is known to restrict the growth of aquatic products. The accurate monitoring and prediction of dissolved oxygen is the key to precise regulation and control of pond aquaculture water quality. The current dissolved oxygen prediction model has some limitations, such as a short prediction period and inadequate prediction accuracy for actual production demands. Therefore, a prediction model of dissolved oxygen in pond culture was proposed based on K-means clustering and Gated Recurrent Unit (GRU) neural network. Firstly, the key factors affecting the changes in dissolved oxygen were selected by principal component analysis (PCA). The dissolved oxygen time series was then subjected to K-means clustering, and the dissolved oxygen prediction model was constructed using GRU. To improve the clustering effect, we enhanced the similarity calculation for the time series based on the variation of dissolved oxygen. This process combined the Euclidean distance with the dynamic time-warping distance. The proposed method can predict the dissolved oxygen content of aquaculture water over different time intervals according to the demands of real-world scenarios. The average absolute error of the 30-min interval model was 0.264, and the mean absolute percentage error was 3.5 %. Experimental results indicated that the proposed method achieves higher prediction accuracy and flexibility than the conventional approach.  相似文献   

古莲花池的造园特点及其复建   总被引：2，自引：1，他引：1  

齐秀静  刘桂林王茜 张娜张芳  冀亚伟 《中国农学通报》2010,26(23):267-270

古莲池对于中国古典园林的研究具有重要的意义。文章简要介绍古莲池的发展历程,重点从规划布局、理水手法、建筑营制几个方面分析古莲池的造园特点,以及人们对其复建后产生的一些争议。  相似文献   

棕点石斑鱼池塘人工育苗技术研究   总被引：2，自引：0，他引：2  

董杨  冯永勤  梁盛  刘璐 《安徽农业科学》2010,38(17):9043-9044

[目的]利用对虾养殖高位池进行棕点石斑鱼人工育苗试验,探索棕点石斑鱼大水体育苗技术,提高育苗的成活率并培育出健壮苗种,缓解当前棕点石斑鱼养殖苗种匮乏问题。[方法]先利用微生物在池中建立稳定平衡的生态系统,然后进行棕点石斑鱼受精卵的孵化和鱼苗培育。[结果]2007和2008年2年中共进行5批育苗试验,共购买棕点石斑鱼受精卵5 kg,其中每批购受精卵量均为1 kg,平均孵化率为91.5%,5批共孵出仔鱼593.5万尾。5批孵化的仔鱼育苗均取得成功,共培育出体长2.0~3.5 cm的鱼苗82.3万尾,仔鱼平均育苗成活率为13.9%。[结论]利用对虾养殖高位池进行棕点石斑鱼仔、稚鱼培育能有效提高鱼卵的孵化率、育苗的成活率和减少互相残食,因此该育苗技术是可行的。  相似文献   

水产养殖过程水质模糊综合评价系统的设计     

马从国  赵德安 《安徽农业科学》2011,(17):10497-10498,10502

以池塘水产养殖水质为研究对象,在综合分析池塘水质各影响因子的基础上,提出了水质评价指标体系和评价标准,建立了渔业水质模糊综合评价模型,设计和实现了池塘养殖水质模糊综合评价系统。将该系统应用于某企业养殖池塘水质的评价,取得了较好效果。大量试验结果表明,该模糊综合评价系统对渔业水质的综合评价结果客观、合理,使用简便,提高了水产养殖业的经济和社会效益。  相似文献   

人力资本专用性视角下的农村池塘闲置研究(英文)     

余乙兵  宗刚 《农业科学与技术》2012,(5):1086-1088

池塘资源是农村地区的重要经济和生态资源,对于发展农村地区经济和维系生态平衡起着重要的作用,但是现今农村地区池塘资源日益闲置,拥塞荒废现象严重。本文对某县域地区池塘资源进行了详尽的调查研究,并利用不完全契约理论的 GHM 模型框架对池塘资源闲置进行了经济学分析。本文表明随着市场经济日益深化,不完全契约下的人力资本专用性扭曲了对池塘治理的投资激励,需要进行相应的制度安排来治理池塘闲置问题。  相似文献   

Interactions between climate, beaver activity, and pond occupancy by the cold-adapted mink frog in New York State, USA     

Viorel D. Popescu  James P. Gibbs   《Biological conservation》2009,142(10):2059-2068

Mink frogs (Rana septentrionalis) are cold-adapted, climate-sensitive amphibians occurring above the 43rd parallel in North America. We conducted repeated night call surveys at 46 ponds near the southern edge of the species’ range to collect presence/absence data and used information-theoretic models to relate pond occupancy to historical climate and habitat factors. Mink frog occurrence was strongly and positively influenced by pond size (>1.5 ha) and the presence of beavers (Castor canadensis). Presence of calling mink frogs decreased sharply at sites with historical mean July air temperatures >19.5 °C. Our results suggest that predicted changes in temperature over the next century might reduce the range of mink frogs in New York, yet we hypothesize that any such reductions could be mitigated by generation of suitable breeding habitat associated with future expansion of beaver populations.  相似文献   

Distribution, species composition and management implications of seed banks in southern New England coastal plain ponds     

Christopher Neill  Maira Ometto Bezerra  Richard McHorney 《Biological conservation》2009,142(7):1350-1361

Buried seeds that germinate during periods of low water or water level drawdown can play important roles in shaping plant community composition, community dynamics and species richness in ecosystems with fluctuating water levels. Northeastern US coastal plain ponds have fluctuating water levels and contain a characteristic shoreline flora that contains many rare plants. The objectives of this study were to: (1) test whether geographically distant ponds in Cape Cod and Martha’s Vineyard had distinct seed banks, (2) determine if hydrologic status as permanent and ephemeral ponds led to differences in seed banks, and (3) examine seed diversity and seed abundance across gradients of shoreline elevations and sediment characteristics. Viable seeds of 45 plant species were identified from nine ponds. Native species dominated pond-shore seed banks and made up 89-100% of all species. There was high overlap in seed bank composition across hydrological classes and geographic regions. One hydrological class captured 73-76% of total species and one geographical region captured 69-78% of the total species recovered from the entire suite of seed bank samples. Seeds were relatively evenly distributed along the shorelines of ephemeral ponds but seed diversity and abundance were lower at low elevations in permanent ponds. Results suggest that strategies to protect pond shorelines to capture maximum diversity of coastal plain pond plants contained in pond sediment seed banks should be implemented across pond hydrologic classes and across a wide geographic area. Shoreline seed distributions indicate that ground-water withdrawals or climate changes that lower pond water levels in permanent ponds will reduce the diversity and abundance of plants recovered from seed banks by shifting water levels to a shoreline zone of high sediment organic matter where seed densities are lower. This effect will be much less in ephemeral ponds where seed diversity and abundance on pond bottoms was high.  相似文献   

池养尖吻鲈人工繁殖的研究   总被引：3，自引：0，他引：3  

陈永乐  陈奋昌  胡隐昌  叶星  梁幼嫦  曾素梅  王文派 《水产科技情报》1992,(3)

尖吻鲈(Lates Calcarifer)在华南地区的池塘饲养条件下,可以从鱼苗培育成性腺成熟的亲鱼,其强化培育主要措施是在适当的放养密度下掌握好饲料的日常投喂和季节性调整,并注意池塘水质和盐度等。成熟亲鱼的外观特征与其它池养鱼类的性成熟特征基本相似。本试验于1990年9月初进行催产,共五批,计19组次,其中受精率较高的两批分别为89.94%和96.6%,孵化率为83.94%和88.0%,总计获苗409万尾,达到了批量生产的规模。通过比较,催产剂以使用LRH-A+DOM较好;结合生产试验,对尖吻鲈的胚胎发育亦作了观察。  相似文献   

古莲花池的造园艺术赏析     

袁晓宏  杜鸿云  张辉  刘小宁  刘桂林 《河北林果研究》2006,21(2):209-211

古莲花池位于河北省保定市,是我国现存最古老的古典园林之一。据考证它始建于元代,起初为私家园林,后成为衙署园林,清代又辟为皇家园林,成为京南第一行宫,此时的古莲花也达到了造园的鼎盛时期。进入20世纪80年代,古莲花池又以其高超的造园艺术被评为国内十大名园。本文对其建园艺术进行了剖析,以供借鉴。  相似文献