Energy-Based Land Use Predictors of Proximal Factors and Benthic Diatom Composition in Florida Freshwater Marshes

The Landscape Development Intensity index (LDI), which is based on non-renewable energy use and integrates diverse land use activities, was compared to other measures of LU (e.g., %agriculture, %urban) to determine its ability for predicting benthic diatom composition in freshwater marshes of peninsular Florida. In this study, 70 small, isolated herbaceous marshes located along a human disturbance gradient (generally agricultural) throughout peninsular Florida were sampled for benthic diatoms and soil and water physical/chemical parameters (i.e., TP, TKN, pH, specific conductance, etc.). Landscape measures of percent agriculture, percent urban, percent natural, and LDI index values were calculated for a 100 m buffer around each site. The strongest relationships using Mantel's r statistic, which ranges from −1 to 1, were found between benthic diatom composition, the combined soil and water variables, and LDI scores (r=0.51, P<0.0001). Although similar, soil and water variables alone (r=0.45, P<0.0001) or with percent agriculture or percent natural were not as strongly correlated (both Mantel's r=0.46, P<0.0001). Little urban land use was found in the areas surrounding the study wetlands. Diatom data were clustered using flexible beta into 2 groups, and stepwise discriminant analysis identified specific conductance, followed by LDI score, soil pH, water total phosphorus, and ammonia, as cluster-separating variables. The LDI explained slightly more of the variation in species composition than either percent agriculture or percent natural, perhaps because the LDI can combine disparate land uses into a single quantitative value. However, the ecological significance of the difference between land use metrics and diatom composition is controvertible, and additional tests including more varied land uses appear warranted.     

滤后水中NOM经臭氧氧化产生的小分子醛、酮和酮酸

以富集、分离得到的滤后水中6种不同特性的天然有机物(NOM)为对象,测定了臭氧氧化NOM各组分后小分子醛、酮及酮酸的生成情况.NOM各组分臭氧氧化后甲醛和丙酮酸产量最大,特别是憎水中性物质(HON)的甲醛产率是其醛、酮总产率的70.58%,单位DOC丙酮酸的产率达103.2 μg/mg;憎水性NOM组分的小分子醛、酮、酮酸产率比亲水性组分的高,特别是憎水中性物质(HON)和憎水酸(HOA)的小分子醛、酮及酮酸类总产率最高,二者之和分别占NOM各组分的醛酮总产率及酮酸总产率的55.56%和60%; NOM碱性组分的醛、酮、酮酸产量最低.用小分子醛、酮、酮酸总量折算DOC占氧化后NOM的DOC的百分比作为衡量氧化后各组分可生物降解性的参考,则臭氧氧化后HON和HOA的可生物降解性比其他组分高得多.     

电解-水生植物-软隔离带复合技术治理重污染河流的中试研究

为了探索重污染河流的治理技术,2011年3月在无锡市新区鸿山镇徐塘桥河开展生态治理示范工程,通过电解技术、种植高等水生植物和构建软隔离带复合工程技术改善河流水质。实验结果表明,通过电解技术,可以迅速降低TP、氨氮（NH4＋-N）和COD;但较难减少TN。通过软隔离带可以有效隔离外源污染,在较短时间内改善河流TN、TP、COD的平均水平,但是难以提高河流的生态系统稳定性。电解能够有效的降解大分子有机物,为水生植物提供良好的生长环境,之后再种植水生植物,能够进一步降低的TN、TP。通过电解一水生植物一软隔离带复合技术不仅能够全面改善河流水质的平均水平,而且能够修复水生生态系统,提高生态系统稳定性。     

THE APPLICATION OF HYDROLOGIC MODELS TO SMALL WATERSHEDS HAVING MILD TOPOGRAPHY1

ABSTRACT: The application of hydrologic models to small watersheds of mild topography is not well documented. This study evaluates the applicability of hydrologic models described by Huggins and the Soil Conservation Service to small watersheds by comparing the simulated and actual hydrograph for both gaged and ungaged situations. The annual maximum rainfall events plus storms exceeding 2.5 inches from 25 years of rainfall and runoff data for two small watersheds were selected for the model evaluations. These storms had a variety of patterns and occurred on many different watershed conditions. Simulated and actual hydrographs were compared using a parameter which contained volume, peak, and shape factors. One-half of the selected storms were used to calibrate the models. For both models, there were no significant differences between the simulated and actual runoff volumes and peak runoff rates. Parameters obtained during the calibration process and relationships developed to estimate antecedent moisture and to modify tabulated runoff curve numbers were used to simulate the runoff hydrograph from the remaining storms. These remaining storms or test storms were simulated only once in order to imitate an ungaged situation. In general, both the Huggins and SCS model performed similarly on the test storms, but the level of model performance was lower than that for the calibration storms. For both models, the two-day antecedent rainfall was more important than the five-day in determining antecedent moisture and modifying tabulated curve numbers. The time of concentration which resulted in good hydrograph simulations was about three times larger than that estimated using published empirical relationships.     

Intraventricular haemorrhage in a fetus with cerebral cytomegalovirus infection

Cytomegalovirus (CMV) is the leading infectious cause of prenatal neurological damage, which is particularly severe when primary maternal infection occurs during the first 16 weeks of gestation, at the time of organ development and neuronal migration. Vascular involvement has been suggested to be among thepossible pathogenic mechanisms of virus-induced pathology, in addition to direct viral effects. We report on a fetus with cerebral CMV infection, which had intraventricular haemorrhage, together with oligohydramnios and hyperechogenic bowel, following maternal primary CMV infection. Copyright © 2002 John Wiley & Sons, Ltd.     

Demographic Consequences of Terrestrial Habitat Loss for Pool‐Breeding Amphibians: Predicting Extinction Risks Associated with Inadequate Size of Buffer Zones

Abstract: Much of the biodiversity associated with isolated wetlands requires aquatic and terrestrial habitat to maintain viable populations. Current federal wetland regulations in the United States do not protect isolated wetlands or extend protection to surrounding terrestrial habitat. Consequently, some land managers, city planners, and policy makers at the state and local levels are making an effort to protect these wetland and neighboring upland habitats. Balancing human land‐use and habitat conservation is challenging, and well‐informed land‐use policy is hindered by a lack of knowledge of the specific risks of varying amounts of habitat loss. Using projections of wood frog (Rana sylvatica) and spotted salamander (Ambystoma maculatum) populations, we related the amount of high‐quality terrestrial habitat surrounding isolated wetlands to the decline and risk of extinction of local amphibian populations. These simulations showed that current state‐level wetland regulations protecting 30 m or less of surrounding terrestrial habitat are inadequate to support viable populations of pool‐breeding amphibians. We also found that species with different life‐history strategies responded differently to the loss and degradation of terrestrial habitat. The wood frog, with a short life span and high fecundity, was most sensitive to habitat loss and isolation, whereas the longer‐lived spotted salamander with lower fecundity was most sensitive to habitat degradation that lowered adult survival rates. Our model results demonstrate that a high probability of local amphibian population persistence requires sufficient terrestrial habitat, the maintenance of habitat quality, and connectivity among local populations. Our results emphasize the essential role of adequate terrestrial habitat to the maintenance of wetland biodiversity and ecosystem function and offer a means of quantifying the risks associated with terrestrial habitat loss and degradation.     

钝化剂对轻中度镉污染农田的安全利用效果

为研究酸性镉（Cd）污染土壤安全利用问题,以陕西商洛轻中度Cd污染农田为研究对象,分别施加生石灰、生物炭和钙镁磷肥,通过小麦-玉米轮作试验,探究不同用量钝化剂对Cd污染土壤的安全利用效果,筛选出最佳的钝化剂配比.结果表明：①通过钝化剂的施加,能不同程度地改善土壤质量.②施用钝化剂后,小麦和玉米的籽粒产量均有不同程度地提高.③3种钝化剂可有效地提升土壤pH值和降低土壤有效态Cd含量,生石灰2 340 kg·hm^-2（C3）处理效果最佳,分别增加小麦和玉米土壤pH 1.453和1.717单位,减少有效态Cd含量34.38%和30.20%.④施加生物炭1 800 kg·hm^-2（B2）处理对降低小麦根系、秸秆和籽粒Cd含量效果最好,较CK分别显著降低了53.60%、38.86%和52.96%,其小麦籽粒ω（Cd）降低至0.09 mg·kg^-1,低于《食品安全国家标准 食品中污染物限量》（GB 2762-2017）中规定的小麦Cd限量值（0.1 mg·kg^-1）;施加生物炭1 260 kg·hm^-2（B1）处理对降低玉米根系、秸秆和籽粒Cd含量综合效果最佳,较CK分别显著降低43.74%、53.20%和94.57%,其玉米籽粒ω（Cd）降低至0.001 9 mg·kg^-1,远低于《食品安全国家标准 食品中污染物限量》（GB 2762-2017）中规定的玉米Cd限量值（0.1 mg·kg^-1）.因此,在田间试验条件下,综合考虑各项指标的影响,生物炭在轻中度Cd污染的小麦-玉米轮作区农田土壤效果最好.     

复合动力灾害条件下孤岛工作面区段煤柱宽度留设研究

孤岛工作面覆岩空间结构复杂多变,受开采和地质等因素的影响在开采过程中面临冲击地压、煤与瓦斯突出、自燃发火以及采空区突水等复合动力灾害。留设合理宽度的区段煤柱是确保工作面安全开采的关键,以陕西某矿特厚煤层孤岛工作面开采为工程案例,通过分析工作面覆岩空间结构,理论计算了工作面应力分布;采用应力动态监测等方法确定了该工作采空区侧向覆岩运动,并综合考虑冲击地压灾害防治、次生灾害控制以及巷道支护等因素,确定了该工作面区段煤柱的合理宽度为5~7 m。     

Intelligent power supply management of an autonomous hybrid energy generator

ABSTRACT

This work deals with the optimization of an hybrid energy system used to supply an isolated site. The proposed system combines a wind turbine, a photovoltaic panel, a diesel generator and a battery bank to electrify atypical home. An energy cost-effectiveness approach is adopted in accordance with meteorological data, time profile of energy consumption, and the cost of different alternative systems. A variety of performances is obtained through simulations within the Homer Pro environment. The selection of an optimal combination is based on the maximum integration of renewable energy in the suggested system with a minimum of gas emission. According to the obtained results, the overall cost of the selected installation is about 72,900 €, with 0.415€ the unit cost of a kWh electric energy provided with a contribution of renewable energy of around 86%. Simulations show a technical and financial benefits of the different configurations obtained to supply the target site. To control the proposed hybrid energy system, a supervision algorithm is developed and implemented on TMS320F28027 DSP platform. The proposed energy system aims to take advantages of renewable energy sources and shift to conventional sources only when necessary in order to ensure source autonomy and service continuity.