The influence of water on reproductive success and chemical composition of laboratory reared populations of Daphnia magna

The purpose of this study was to examine the effect of two types of natural water and one processed water on the reproductive success of Daphnia magna. It was also of interest to discover whether the chemical composition of the water or that of the food was more important in determining the chemical composition of the organisms. To achieve this purpose 50 neonates per water type were reared to maturity. Their progeny were enumerated every other day. The study lasted 4 weeks. In addition, neonates were batch cultured in each water for 4 weeks. These random aged populations, with no individual older than 28 days, were analyzed for their elemental content. Sodium, K, Cu, Mg, Ca, Zn, P, S, Se, Mo, Cl, Fe, Mn, Co and Ni were measured in random populations of D. magna grown in each of the three waters, neonates and adults reared in processed and one natural water and finally, in the three waters themselves. Linear correlation coefficients were calculated among all the variables. Partial correlation coefficients showed that the chemical composition of the organisms is determined by the chemical composition of the rearing water. The largest number of broods, the greatest total number of neonates, the largest mean brood size, the greatest number of neonates per female, occurred among populations reared in lake water. The poorest demographic results were obtained from daphnids reared in processed water. Suggestions are offered for ways in which processed water could be improved as a rearing medium for daphnids.     

太湖流域农村生活污水治理运营机制及适宜技术

从行政管理的角度出发,对太湖流域农村生活污水治理、运营管理模式进行了有益探索,筛选出一批适合太湖流域农村生活污水治理的新工艺、新技术。针对目前太湖流域农村生活污水治理过程中存在的问题进行了分析,并提出了相应对策。     

杭州西湖世界文化景观遗产的物质表象与精神内涵

杭州西湖是历史上最能体现中国传统文化价值的审美实体之一,在第35届世界遗产大会上,西湖的成功申遗证明了西湖文化景观作为世界文化景观遗产的历史原真性、独特性和唯一性。在研究西湖文化景观物质表象与精神内涵的构成要素、本质特征的基础上,提出西湖文化景观是以物质表象传达文化精神、因文化精神彰显景观深度、依题词点景实现意境升华,并通过分析其中的内在关系来解读西湖的普世价值,为后申遗时代的西湖文化景观建设提供借鉴。     

西湖湖滨景区古香樟保护效果分析

香樟是杭州市市树,古香樟在杭州市的古树名木中占有较大比重。通过去除树冠下硬铺装、根际土壤消毒、施缓释肥、夏季喷叶喷干、树体修补等保护措施,对西湖湖滨景区复壮前后古香樟叶片叶绿素、SOD、POD活性和MDA含量进行测定。结果表明:经过复壮与抢救,古香樟生长状况有所好转,叶绿素含量、SOD、POD活性都有所增加,而导致植物衰老的MDA含量有所下降,说明复壮与抢救效果较明显,实际观察也表明经过复壮与抢救后,香樟整体生长势都有所好转,叶色也明显变绿。     

Lake responses following lanthanum-modified bentonite clay (Phoslock) application: An analysis of water column lanthanum data from 16 case study lakes

Phoslock^® is a lanthanum (La) modified bentonite clay that is being increasingly used as a geo-engineering tool for the control of legacy phosphorus (P) release from lake bed sediments to overlying waters. This study investigates the potential for negative ecological impacts from elevated La concentrations associated with the use of Phoslock^® across 16 case study lakes. Impact-recovery trajectories associated with total lanthanum (TLa) and filterable La (FLa) concentrations in surface and bottom waters were quantified over a period of up to 60 months following Phoslock^® application. Both surface and bottom water TLa and FLa concentrations were <0.001 mg L⁻¹ in all lakes prior to the application of Phoslock^®. The effects of Phoslock^® application were evident in the post-application maximum TLa and FLa concentrations reported for surface waters between 0.026 mg L⁻¹–2.30 mg L⁻¹ and 0.002 mg L⁻¹ to 0.14 mg L⁻¹, respectively. Results of generalised additive modelling indicated that recovery trajectories for TLa and FLa in surface and bottom waters in lakes were represented by 2nd order decay relationships, with time, and that recovery reached an end-point between 3 and 12 months post-application. Recovery in bottom water was slower (11–12 months) than surface waters (3–8 months), most probably as a result of variation in physicochemical conditions of the receiving waters and associated effects on product settling rates and processes relating to the disturbance of bed sediments. CHEAQS PRO modelling was also undertaken on 11 of the treated lakes in order to predict concentrations of La³⁺ ions and the potential for negative ecological impacts. This modelling indicated that the concentrations of La³⁺ ions will be very low (<0.0004 mg L⁻¹) in lakes of moderately low to high alkalinity (>0.8 mEq L⁻¹), but higher (up to 0.12 mg L⁻¹) in lakes characterised by very low alkalinity. The effects of elevated La³⁺ concentrations following Phoslock^® applications in lakes of very low alkalinity requires further evaluation. The implications for the use of Phoslock^® in eutrophication management are discussed.     

污水提标技术在炼化污水处理中的应用

大型桥梁工程由于两岸通视困难,用传统测量方法直接布设大桥工程控制网及进行大桥施工测量非常困难,因此GPS定位技术在大型桥梁工程的施工控制网测量中应用广泛。本文详细介绍了荆岳铁路洞庭湖大桥施工控制网的测量方案及实施情况,在测量中采用了GPS定位技术来建立施工控制网,整个施工控制网的测量包括施工平面控制网测量和施工高程控制网测量。结果表明获得的平面和高程控制测量成果精度均优于二等精度,可满足工程定测和施工测量应用的需要。     

Hydrological analysis as a technical tool to support strategic and economic development: A case study of Lake Navaisha,Kenya

Effective integrated water resources management requires reliable estimation of an overall basin water budget and of hydrologic fluctuations between groundwater and surface‐water resources. Seasonal variability of groundwater‐surface water exchange fluxes impacts on the water balance. The long term lake water balance was calculated by Modflow using the stage‐volume rating curve of Lake Package LAK3. The long term average storage volume change is 8.4 × 10⁸ m³/month. The lake water balances suggests that the lake is not in equilibrium with the inflow and outflow terms. Using field abstraction data analysis and model simulation, the combined volume of lake‐groundwater used for industrial abstraction since the last three decades was estimated. This requires an average abstraction amount of 7.0 × 10⁶ m³/month with a long term trend of abstraction ratio 30% (groundwater) and 70% (lake water) since 1980. The amount resulted in a lake which might have been 4.8 m higher than was observed in the last stress period (2010). A long term regional groundwater budget is calculated reflecting all water flow in to and out of the regional aquifer. The model water balance suggests that lake Navaisha basin is in equilibrium with a net outflow about 1% greater than the inflow over the calibrated period of time (1932–2010). The regional model is best used for broad‐scale predictions and can be used to provide a general sense of groundwater to surface water and groundwater to groundwater impacts in the basin. A basin wide water resource management strategy can be designed by integrating the lake/wetland within the regional groundwater model to increase the level of sustainable production and good stewardship in Lake Navaisha. Such hydrological analysis is crucial in making the model serve as simulator of the response of lake stage to hydraulic stresses applied to the aquifer and variation in climatic condition.     

察尔汗盐湖地区盐渍土微观结构及其力学特性

为探明察尔汗盐湖区盐渍土的微观结构特征及其力学特性,对原状氯盐渍土进行电镜扫描、力学强度试验,从微观结构上分析了盐渍土的力学特性,提出了察尔汗盐湖区盐渍土微结构的连结形式,并将研究结果与新疆板块状盐渍土相关研究成果进行了对比。结果表明: (1)盐渍土微结构连结有三种形式:①点接触,②堆叠接触,③晶体胶结;(2)不同含盐量的盐渍土微观结构形式不同。盐晶体的胶结作用是影响其力学特性的显著因素;(3)无侧限抗压强度显著变化的含盐量拐点为45.74%;(4)青海察尔汗盐湖盐渍土属细粒土,其颗粒胶结作用随含盐量的增加而增强,其力学特性也在不断提高。而新疆板块状盐渍土属粗粒土,土颗粒胶结作用和力学强度随着含盐量的增加先增加后减小,存在一个最佳含盐量峰值,这是两地区盐渍土微结构和强度变化特性最显著的区别。     

文化景观遗产的空间格局演进分析：以杭州西湖为例

文化景观类遗产是自然与人联合的工程,是有机演进的持续性景观。作为一种新类型遗产,目前的研究往往偏重于识别、保护等环节。本文试图以文化景观类遗产的活态特征及演进逻辑为着眼点,以杭州西湖世界遗产为例,结合历史图文资料与现场测绘数据,还原及分析西湖空间格局及空间要素在千年内的演化与成型过程,最终揭示出此类遗产的基于人群行为的空间尺度生成,并以此来建立场所秩序的动态发展机制。     

湖泊公园的人性化设计策略研究--以翡翠湖为例

本文主要介绍了人性化设计在湖泊公园中的应用,并结合翡翠湖公园具体分析,在对公园主要使用人群的活动和行为特征进行调查总结的基础上,从滨湖景观的水上活动开发及驳岸设计,环湖绿地的设施配套和空间营造等方面提出了具体的人性化设计策略。