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1.
Estuarine ecosystems are largely influenced by watersheds directly connected to them. In the Mobile Bay, Alabama watersheds we examined the effect of land cover and land use (LCLU) changes on discharge rate, water properties, and submerged aquatic vegetation, including freshwater macrophytes and seagrasses, throughout the estuary. LCLU scenarios from 1948, 1992, 2001, and 2030 were used to influence watershed and hydrodynamic models and evaluate the impact of LCLU change on shallow aquatic ecosystems. Overall, our modeling results found that LCLU changes increased freshwater flows into Mobile Bay altering temperature, salinity, and total suspended sediments (TSS). Increased urban land uses coupled with decreased agricultural/pasture lands reduced TSS in the water column. However, increased urbanization or agricultural/pasture land coupled with decreased forest land resulted in higher TSS concentrations. Higher sediment loads were usually strongly correlated with higher TSS levels, except in areas where a large extent of wetlands retained sediment discharged during rainfall events. The modeling results indicated improved water clarity in the shallow aquatic regions of Mississippi Sound and degraded water clarity in the Wolf Bay estuary. This integrated modeling approach will provide new knowledge and tools for coastal resource managers to manage shallow aquatic habitats that provide critical ecosystem services.  相似文献   
2.
杨静 《环境与发展》2020,(1):238-239
在第二次全国污染源普查的基础上,利用污染源普查期间配置的软硬件,开发市级区域环境污染源管理平台,进行污染源数据的年度更新,拓展污染源普查软件应用,实现环境管理及环境执法移动终端的应用。拓展二污普一张图的功能,利用移动客户端机动实时及地定位导航等为环境管理执法和环境突发事件应急处置提供技术支持。  相似文献   
3.
Apps are small task-orientated programs with the potential to integrate the computational and sensing capacities of smartphones with the power of cloud computing, social networking, and crowdsourcing. They have the potential to transform how humans interact with nature, cause a step change in the quantity and resolution of biodiversity data, democratize access to environmental knowledge, and reinvigorate ways of enjoying nature. To assess the extent to which this potential is being exploited in relation to nature, we conducted an automated search of the Google Play Store using 96 nature-related terms. This returned data on ~36 304 apps, of which ~6301 were nature-themed. We found that few of these fully exploit the full range of capabilities inherent in the technology and/or have successfully captured the public imagination. Such breakthroughs will only be achieved by increasing the frequency and quality of collaboration between environmental scientists, information engineers, computer scientists, and interested publics.  相似文献   
4.
This study characterizes the composition of plastic frames and printed circuit boards from end-of-life mobile phones. This knowledge may help define an optimal processing strategy for using these items as potential raw materials. Correct handling of such a waste is essential for its further “sustainable” recovery, especially to maximize the extraction of base, rare and precious metals, minimizing the environmental impact of the entire process chain. A combination of electronic and chemical imaging techniques was thus examined, applied and critically evaluated in order to optimize the processing, through the identification and the topological assessment of the materials of interest and their quantitative distribution. To reach this goal, end-of-life mobile phone derived wastes have been systematically characterized adopting both “traditional” (e.g. scanning electronic microscopy combined with microanalysis and Raman spectroscopy) and innovative (e.g. hyperspectral imaging in short wave infrared field) techniques, with reference to frames and printed circuit boards. Results showed as the combination of both the approaches (i.e. traditional and classical) could dramatically improve recycling strategies set up, as well as final products recovery.  相似文献   
5.
研究了用流动注射分析技术测定水体中高锰酸盐指数。使用新发明的耐腐蚀恒流泵、低记忆高效混合器、不存留气泡流通池等部件,通过高温高压,缩短消解时间,从而建立了一种可用于无人值守的自动在线快速监测水体中高锰酸盐指数的分析方法。  相似文献   
6.
广州市区公交车站PM_(2.5)与CO暴露水平研究   总被引:1,自引:1,他引:0  
用便携式颗粒物浓度测定仪(DustTrak Model8520)和CO测定仪(Q-Trak Model8551),于2008年9月至2009年1月对广州市区11个代表性公交车站的PM2.5和CO暴露水平进行了测定。结果表明,公交车站7:00~19:00时间段PM2.5的平均浓度范围为206~348μg/m3,总体均值达288μg/m3,显示公交车站PM2.5污染问题突出;CO平均浓度范围1.5~4.0mg/m3,总体平均2.8mg/m3,有六个站点平均浓度超过了我国环境空气质量标准限值(4.0mg/m3或3.2mg/m3)。大多数站点工作日与非工作日PM2.5与CO水平差异不大,部分站点则受车流量和客流量变化影响呈现差异。同一站点PM2.5日变化特征不如CO明显,一次污染物CO变化受交通高峰影响呈双峰特征,而PM2.5水平影响因素复杂,一般白天较低,夜晚21:00出现峰值。不同站点CO与车流量未见显著相关性,表明车流量并不是决定公交站点CO水平的唯一因素,而扩散条件及公交车排放可能也是重要影响因素;与CO不同,不同站点PM2.5与车流量表现出显著相关(p0.05),可能侧面反映路面扬尘对公交车站PM2.5水平的影响和贡献。  相似文献   
7.
In the meerkat (Suricata suricatta), a cooperative mongoose, pups follow potential feeders while the group is foraging and emit incessant calls when soliciting food from them. In contrast to a ’stationary’ brood of chicks, in which nestlings are fed at a fixed location, meerkat pups are ’mobile’ and become spread out. The question arises whether meerkat pups that experience different constraints to those facing chicks have evolved similar begging strategies. This paper describes the vocalisations that meerkat pups emit in the context of begging and investigates the influence of these calls on food allocation by older group members and on the behaviour of littermates. Meerkat pups use two types of calls when soliciting food from a potential feeder. The most common is a ’repeat’ call, which pups emit continuously when following an older forager over several hours a day. In addition, when a potential feeder finds a prey item, the pups next to it emit a bout of calls with increased calling rate, amplitude and fundamental frequency, termed ’high-pitched’ calls. Observations, together with playback experiments, showed that more prey was allocated to pups that called longer and more intensely. The pup closest to a feeder was almost always fed. The probability of emitting high-pitched calls did not depend on the time since a pup had received food, and the change from repeat to high-pitched calls occurred suddenly. The main function of the high-pitched call, therefore, does not appear to be to signal a pup’s hunger state. More likely, the two calls, in the context of begging, may be an adaptation to energetic constraints in a mobile feeding system. Pups, which are dispersed during foraging, may emit repeat calls over long periods to prevent potential feeders from eating all the prey themselves. At the moment a potential feeder finds prey, pups may give the more intense high-pitched calls to direct feeders to bring the food item to them and not to a littermate. Therefore, unlike the stationary feeding system where chicks emit one type of begging call when the feeder approaches the nest, meerkats, with a mobile feeding system, have evolved two discrete types of vocalisations in the context of begging. Received: 22 November 1999 / Revised: 1 July 2000 / Accepted: 17 July 2000  相似文献   
8.
南京市通讯辐射环境调查   总被引:1,自引:0,他引:1  
通过对南京市区进行网格式布点监测,并重点监测典型区域和典型基站,采用基于MapInfo构建的电磁辐射环境评价系统进行现状评价。结果表明,南京市电磁辐射水平总体较低,处于安全水平,部分电磁辐射水平相对较高的区域主要受电视发射塔和广播电台的影响,是南京市电磁辐射环境保护和移动通信基站建设应关注的重点。  相似文献   
9.
Accurately quantifying the concentration and transport flux of atmospheric fine particulate matter (PM2.5) is vital when attempting to thoroughly identify the pollution formation mechanism. In this study, the mobile lidar measurements in Beijing on heavily polluted days in December from 2015 to 2018 are presented. The lidar was mounted on a vehicle, which could perform measurements along designated routes. On the basis of mobile lidar measurements along closed circuits of the 6th Ring Road around Beijing, the spatial distribution and transport flux of PM2.5 in Beijing were determined with information of wind field. In the spatial distribution, both the concentration and transport of PM2.5 were revealed to be more significant in the southern section of Beijing. The regional transport layer at heights < 1.3 km plays an important role in pollution formation. The maximum transport flux reached 1600 μg/(m2*sec) on 11 December 2016. With the aerosol boundary layer height determined from the image edge detection (IED) method, the inter-annual variations of the aerosol boundary layer height (ABLH) were also analysed. The ABLH decreased from 0.73 to 0.46 km during the same heavy pollution period from 2015 to 2018. Increasingly adverse aerosol boundary layer (ABL) meteorological factors, including lower ABLH, light winds, temperature inversions, and accumulated moisture, have become necessary for pollution formation in Beijing.  相似文献   
10.
This study examined the effectiveness of a Global Positioning System (GPS)-based mobile navigation system in comparison to paper maps and direct experience of routes, by focusing on the user's wayfinding behavior and acquired spatial knowledge. Based on information received from one of these three media, participants walked six routes finding the way to goals. Results showed that GPS users traveled longer distances and made more stops during the walk than map users and direct-experience participants. Also, GPS users traveled more slowly, made larger direction errors, drew sketch maps with poorer topological accuracy, and rated wayfinding tasks as more difficult than direct-experience participants. Characteristics of navigation with these three learning media and possible reasons for the ineffectiveness of the GPS-based navigation system are discussed.  相似文献   
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