气象参数对成都地区办公建筑能耗的影响及预测

气象参数是影响建筑热环境和供暖空调能耗的主要因素之一。基于成都地区1971—2000年共30 a的历史观测数据,生成了建筑能耗模拟软件EnergyPlus所需要的逐时气象数据文件。比较分析了该地区30 a干球温度、太阳辐射等各气象参数月均值的变化,模拟分析了该地区建筑的采暖、制冷及总能耗,利用多元回归建立了建筑能耗与气象参数之间的关系式,并检验了该关系式的准确性。结果表明：成都地区办公建筑能耗变化与各气象参数没有呈现明显的规律性;建筑月总能耗与各气象参数呈纯二次多项式关系,月采暖能耗、月制冷能耗与各气象参数呈交叉二项式关系;建筑月能耗回归模型能够较准确地预测建筑月能耗与各气象参数的关系,且月采暖能耗和月制冷能耗回归模型预测的准确性优于月总能耗模型。     

Application of Leslie's model on a population of common dolphins (Delphinus delphis): Sensitivity study

The rapid development of the albacore tuna (Thunnus alalunga) driftnet fishery in the Bay of Biscay (Atlantic ocean, France) has incited European management authorities to ask for a study of its ecological impact on populations of common dolphins and striped dolphins. A programme with onboard observers has been led during 1992 and 1993, and a sighting survey has allowed the evaluation of the abundances of fractions of populations in the studied area. For the population of common dolphins, the biological parameter estimation has allowed the building of a discrete age-structured model based on a Leslie matrix. Sensitivity studies have been conducted using four model parameters (age of first reproduction, interval between births, juvenile and adult survival rates). Results show that the increase rate of the population presents the highest sensitivity versus adult survival rate and, in second place versus the interval between births.     

Constraining release of pollutants from anoxic bottom sediment via water-lifting aeration in a source water reservoir,East China

Journal of Soils and Sediments - Seasonal hypoxia in water bodies can increase levels of reduced chemical species in the hypolimnion as they are released from anoxic bottom sediments. Water-lifting...     

辽东半岛海岸侵蚀分布规律及其发育特征

为了探明辽东半岛海岸侵蚀的分布规律和发育特征,结合海岸侵蚀的现场调查资料,对辽东半岛海岸蚀淤状况和侵蚀发育特征进行了研究。结果表明,辽东半岛海岸可划分为严重侵蚀、强侵蚀、侵蚀、微侵蚀、稳定共5种侵蚀等级。其中,沙质海岸侵蚀较重的区域主要分布在绥中和鲅鱼圈一带,基岩海岸侵蚀较重的区域主要分布在大连金石滩一带,粉沙淤泥质海岸侵蚀较重的区域分布在庄河一带。河流入海泥沙的减少是近年来辽东半岛海岸侵蚀的主要原因,气候变暖引起的海平面上升对辽东半岛海岸侵蚀起一定的控制作用。此外,人为采砂和不合理的海岸工程进一步加剧了局部海岸侵蚀的程度。     

不同人工林凋落叶混合分解速率及其C,N释放动态

对岷江上游连香树、糙皮桦、云南松和云杉4种主要人工林凋落叶进行了凋落叶混合分解试验,探讨了凋落叶混合分解过程中的残留率以及分解过程中C,N含量和C,N释放率的动态变化,为试验区最佳混交树种的选择提供理论指导.结果表明,不同凋落叶分解速率存在显著差异.糙皮桦与云杉,糙皮桦与云南松,连香树与云南松凋落叶混合后对分解过程具有明显的促进作用,连香树与云杉凋落叶的混合对分解的促进作用不明显.放置于阔叶林地的针阔混合凋落叶分解速率较之放置于针叶林地快,且针阔混交有益于凋落叶的分解.在分解过程中凋落叶C含量呈减小趋势,但其释放率反之;N含量在分解过程中,连香树、云杉、云南松凋落叶表现为增加(富集)减小(释放)趋势,糙皮桦表现为减小—增大—减小的变化趋势.针阔林地凋落叶混合后促进了针叶林地凋落叶C和N的释放.     

Nitrogen reduction in a eutrophic river canal using bioactive multilayer capping (BMC) with biozeolite and sand

Purpose

Nitrogen reduction in a eutrophic river canal using bioactive multilayer capping (BMC) with biozeolite and sand was examined through laboratory incubation experiments over 121 days.

Materials and methods

Biofilm formation on zeolite was cultivated by a mixed culture containing isolated heterotrophic nitrifiers (Bacillus sp.) and aerobic denitrifiers (Acinetobacter sp.). Two combination methods of biozeolite and sand (with two grain sizes) were used in the experiments: combination I had biozeolite on top of sand, while combination II had sand on top of biozeolite.

Results and discussion

BMC not only completely inhibited ammonium release from sediment but also reduced total nitrogen (TN) in the overlying water and sediment. On day 24, the reduction efficiencies of TN in overlying water by BMC were 60–82 %. After day 24, the long-term effectiveness of nitrogen reduction by BMC using combination II was found to be significantly better than that using combination I. Fine sand used for BMC was found to be superior to coarse sand in nitrogen reduction. Fine sand on the upper layer could strengthen biological denitrification of the biozeolite layer. The optimal BMC could reduce the amount of biozeolite and thus the costs of the technique. The TN reduction efficiency of sediment by the optimal BMC was up to 13 %.

Conclusions

BMC with biozeolite under the fine sand was found to be a feasible technique to reduce N in a eutrophic river canal.     

园林景观设计中生态标识设计初探——以长安区商业步行街为例

生态标识是通过植物物种建立的具有地域生态及文化特征的标识系统。通过调查,对长安步行街在园林景观设计中的植物种类及生态特征进行了分析。结果表明:其绿化植物应用形式多样,乔、灌、草共52种,植物搭配得当,美化街景效果较好;考虑到乡土树种的应用,符合生态设计的基本要求;但缺乏绿量较大的乔木树种,特别是没有把体现长安历史文化内涵和地域生态特征的标志性植物加以突现,其生态识别性较差。针对这种情况,提出了长安商业步行街植物配置中生态标识设计的建议。     

水、氮调控对夏玉米根系特性的影响

采用土柱模拟试验研究了水、氮调控措施对夏玉米根系生长状况及其与籽粒产量之间的关系.结果表明:水分对根系干重、根系活力、根系表面积的影响较氮肥大;根系干重随土层深度增加而减小,0～ 10 cm土层尤为明显;0～20 cm根系密度较高,根系密度随土层深度增加先减小后上升;根干重和根系密度随施氮量增加而降低,根冠比基本呈减小趋势;氮肥能提高玉米根系活力.根干重、根系密度、根表面积和根系活力与籽粒产量和玉米地上部分干物质量均呈极显著相关关系;根冠比只与地上部分相关;根表面积和根系活力之间呈极显著相关关系;根系活力和根系吸氮能力对玉米生长和籽粒的形成有很重要的作用,存在显著正相关性.     

县域旅游资源评价及开发对策——以陕西省柞水县为例

以陕西省柞水县为例,在介绍其旅游资源基本情况和旅游资源及其分布特征的基础上,构建评价指标体系,运用模糊聚类法对柞水县13个镇的旅游资源进行了聚类评价分析,并得出最佳聚类为3类,分为A区（乾佑镇、下梁镇、小岭镇、凤凰镇、红岩寺镇、曹坪镇、蔡玉窑镇、杏坪镇、柴庄镇、瓦房口镇、丰北河镇）、B区（营盘镇）和C区（石瓮镇）。研究结果表明,C区的资源综合品质最高,其次为B区,而A区资源分布不均,配套建设落后。最后提出了相应的开发对策。     

张掖市道路绿化设计研究

道路绿化设计是城市道路系统中重要的组成部分。张掖市道路绿化设计依托总体规划思路,即＂以水带绿,以绿融城＂的绿色框架,强调生态环境和谐发展,对城市的主干道、次干道、支路进行绿化设计,对类似的工程设计具有一定借鉴意义。