因埠而兴的湖北古镇--阳新龙港

阳新龙港是一个因埠头而兴的湖北古镇,大革命时期曾为湘鄂赣革命根据地中心,被誉为"小莫斯科".她以"三山·两河·一新城·一老街"的古镇空间结构、"背河式"生长的街道形态、富有节奏的街道界面以及亲切宜人的转角空间勾勒出龙港古镇的空间特色,天井、亮斗的灵活运用体现其建筑特色.     

The Ribble/Wyre observatory: major, minor and trace elements in rivers draining from rural headwaters to the heartlands of the NW England historic industrial base

Information on a new observatory study of the water quality of two major river basins in northwestern England (the Ribble and Wyre) is presented. It covers upland, intermediate and lowland environments of contrasting pollution history with sufficient detail to examine transitional gradients. The upland rivers drain acidic soils subjected to long-term acidic deposition. Nonetheless, the acidic runoff from the soils is largely neutralised by high alkalinity groundwaters, although the rivers retain, perhaps as colloids, elements such as Al and Fe that are mobilised under acid conditions. The lowland rivers are contaminated and have variable water quality due to variable urban/industrial point and diffuse inputs reflecting local and regional differences in historic and contemporary sources. For most determinands, pollutant concentrations are not a major cause for concern although phosphate levels remain high. Set against earlier studies for other regions, there may be a general decline in pollutant levels and this is most clearly observed for boron where effluent inputs have declined significantly due to reductions in household products that are flushed down the drain. High concentrations of sodium and chloride occurred briefly after a severe cold spell due to flushing of road salts.A major inventory for water quality within rural, urban, industrial and agricultural typologies is provided within data summary attachments for over 50 water quality determinands. Within the next year, the full dataset will be made available from the CEH website. This, with ongoing monitoring, represents a platform for water quality studies across a wide range of catchment typologies pertinent to environmental management of clean and impacted systems within the UK. The study provides a base of research “from source to sea” including extensions to the estuary and open sea for a semi-confined basin, the Irish Sea, where there are many issues of pollution inputs and contamination.     

天然气掺氢技术发展现状及相关标准体系

新一轮能源革命条件下,大力发展清洁能源、优化能源结构是实现"碳中和"的普遍做法.氢气是清洁、高效、可再生的二次能源,可实现电、气、热等不同能源形式的相互转化,但氢气的输送一直是制约氢能产业链发展的难题.将氢气与天然气掺混,利用在役天然气管道及其输配管网进行输送,是目前可实现安全、高效、大规模和长距离输氢至终端用户的最佳...     

Water quality in Scotland: the view of the regulator

Water quality in Scotland has progressively improved over the past 50 years as the environmental damage, which resulted from the industrial revolution, has been addressed. This paper provides an overview of current water quality in rivers, lochs, estuaries and coastal waters and describes the limited information available on groundwater. The main factors affecting water quality are reviewed, with sewage, diffuse agricultural pollution, acidification and urban drainage identified as the most important. Trends in pollution pressure and levels of investment in pollution control have been used to predict the condition of Scotland's surface water over the next 10 years. Major improvements are expected. However, progress will be slowed by the increased relative importance of diffuse sources of pollution, which are less amenable to legislative controls. Future changes in environmental monitoring are also expected to move the emphasis away from point source pollution. The current freshwater classification schemes are based upon a relatively narrow measure of water quality and are expected to expand to include a wider range of ecological parameters. This will result in an increase in the waters defined as impacted as the effects of other environmental pressures are taken into account. Finally the implications of these changes for the future management of the aquatic environment are assessed.     

城市河流从“边缘界线”回归“公共纽带”的探索——以川杨河生态绿廊建设规划研究为例

城市河流曾是城市发展的重要依赖,承载着城市的兴衰使命。而当前许多城市中,城市河流在规划中逐渐被忽视,尤其是具有区域性意义的主干河流,成为无人问津的"边缘界线",沦为封闭而消极的廊道空间。以川杨河生态绿廊的建设研究为例,从城市河流的角色演变和现状问题出发,分析城市河流被边缘化的深层原因,并从"公共纽带"的视角来探讨城市河流功能复兴和回归城市生活的规划实践。     

粉粒夹层对饱和砂土液化特性影响的试验研究

为了能更好地反映粉粒夹层对自然界中沉积或吹填土层动力特性的影响,将土颗粒进行筛分后制备含粉粒夹层的饱和土样。采用应变控制加载方式进行一系列动三轴试验,分析了粉粒夹层对饱和砂土的抗液化强度和动孔隙水压力发展规律的影响。研究结果表明,粉粒夹层的存在对循环荷载作用下饱和砂土抗液化强度和动孔隙水压力的发展规律有显著影响,若忽视粉粒夹层对饱和砂土抗液化强度的影响,将会使液化判别得到偏于不利或保守的结论。     

Nationwide monitoring of selected antibiotics: Distribution and sources of sulfonamides, trimethoprim, and macrolides in Japanese rivers

We report the results of a nationwide survey of commonly used human and veterinary antibiotics (7 sulfonamides, trimethoprim, and 4 macrolides) in 37 Japanese rivers. Concentrations of the sum of the 12 target antibiotics ranged from undetectable to 626 ng/L, with a median of 7.3 ng/L for the 37 rivers. Antibiotics concentrations were higher in urban rivers than in rural rivers and were correlated with those of molecular markers of sewage (crotamiton and carbamazepine). Macrolides were dominant over sulfonamides in urban rivers. Sulfonamides, especially sulfamethazine (used in animals), were dominant in a few rivers in whose catchment animal husbandry is active. However, these signals of veterinary antibiotics were overwhelmed by those of human antibiotics in lower reaches of most rivers. The analysis of the antibiotics in all 88 samples showed that the target antibiotics in Japanese rivers are derived mainly from urban sewage, even though larger amounts of antibiotics are used in livestock. Most of the livestock waste-derived antibiotics are unlikely to be readily discharged to surface waters.     

Evaluation of correlations between absorbance at 254 nm and COD of river waters

Correlations between the absorbance module at 254 nm (A_{254 nm}^{1 cm}) and COD by the permanganate and dichromate methods in rivers in the lower part of the Odra river basin are given. For the purpose of the conducted study a clean reach of the river, two short reaches with medium and high pollution, especially with lignin and humic substances and phenolic wastes below industrial waste outfalls have been selected. Investigation results from 1973 to 1978 have been evaluated mathematico-statistically: regression equations and empirical relations with average conversion factors and variation coefficient are presented. Relationships between absorbance and COD are also given graphically. Close relations have been found and the absorbance module at 254 nm has been recommended to be used as indicator of organic pollution in selected reaches of the river. The method is suitable for laboratory work as well as automatic monitoring of concentration changes in dissolved organic matter. This work is in relation with the results of many authors who carried out investigations in various localities.     

试论中国的能源结构与空调冷热源的选择取向

分析了我国能源结构尤其是发电能源以煤炭为主的事实,指出电力空调会带来大气污染和温室气体排放的严重负面影响。电力空调的普及加大了供电峰谷差,进一步加剧了对环境的破坏。在我国,电力不能算是清洁能源。随着世界能源革命的发展,以氢能源和可再生能源代替碳能源是２１世纪的必然趋势。天然气将成为我国经济发达的大城市和特大城市的主要能源。在空调冷热源的选择上,应加大燃气空调的比例,实现建筑空调冷热源的多元化。     

Levels Of Linear Alkylbenzenesulfonates (LAS) In Sediments Of The Berre Lagoon (FRANCE)

A method is described to extract, concentrate and determine trace levels of linear alkylbenzenesulfonates (LAS) (a major anionic surfactant) from sediment samples. It consists of an ultrasonic extraction, followed by clean up and enrichment with C18 mini-columns cartridges and determination by HPLC. Both efficiency and accuracy of the method are high, i.e. mean recovery of 85% and repeatability of 2.8% relative standard deviation for five-replicate LAS analyses. The spatial distribution of LAS and their composition of homologues in sediments of the Berre lagoon, the widest lagoon of the Mediterranean littoral, have been studied. The levels of total LAS in sediments range from 0.21 to 5.00?mg=g (dry weight). Results show that LAS principally associated with solids in suspension, and originating from industrial and urban wastewaters, are principally discharged into the Arc and Cadière Rivers then decant in the mouths of these rivers. The maximum concentrations have been monitored in three zones of the site: the Bolmon lagoon, the Vaine lagoon and the northeast part of the Berre lagoon. The distribution of the LAS homologues in the sediments is not the same as that of the commercial LAS. A great percentage of C13-LAS has been observed (>50%).     

还河流以生命,给城市以活力——城市中河流整治与两岸建设

历史上河流与城市往往存在着唇齿相依的关系,城市中的河流哺育了灿烂的历史文明,承载着两岸繁衍生息的芸芸众生.而今我们却常常看到城市与河流相背离,相排斥,城区河段是臭河,滨河城区是死角.当河流没落为城市的下水道时,当滨河城区衰退并边缘化时,我们难免产生疑问:应如何对待河流,如何建设河流两岸?重新认识城市中河流的价值,重新恢复城市滨水地区活力,对于滨河城市发展而言无疑有着重要的战略意义.     

Measuring the severity of transboundary freshwater conflict: structural vs. behavioural indices in Africa

In the global crisis over access to clean, adequate freshwater, Africa is a special case. Not only are many African states under severe water stress, but the continent is one of the most hydrologically interconnected regions on the planet. With 113 rivers, lakes and aquifers that cross an international border, over 60% of Africa’s territory falls into a transboundary watershed. Africa’s hydrology is interdependent, and mass poverty and political volatility heighten the risk of conflict over freshwater resources. This paper compares two approaches to understanding the severity of transboundary freshwater conflict; one based in behavior and the other based on structural factors unique to each water resource and its users. The goal is to identify Africa’s water hot spots, or those areas where violence over water resources is most likely. The broader aim is to better understand how the way we measure severity affects our understanding of freshwater conflict, and how policy-makers might best approach water politics in Africa.     

福州市厦坊溪黑臭水体污染成因分析及治理方案

厦坊溪是典型的城郊结合脏乱差河道,水体污染情况严重。通过对河道水体的黑臭指标检测并结合民意调查及现场踏勘,对厦坊溪黑臭水体进行识别和原因分析。厦坊溪重度黑臭河段位于城中村及建成区,是点源污染、内源污染及面源污染等多种因素综合作用的结果。针对厦坊溪黑臭水体具体情况,结合河道周边用地情况、排水体制、排水系统现状条件及支流汇入情况,选择针对性较强的水体污染整治措施,通过控源截污、内源治理、生态修复、清水补给和岸带修复等多项措施,解决河道黑臭问题,实现水质改善目标。     

How green is my river? A new paradigm of eutrophication in rivers

Although the process of eutrophication is reasonably well understood in lakes, there is currently no conceptual understanding of how eutrophication develops in rivers. This issue is addressed here. A review of the main processes controlling the development of eutrophication in lakes has been carried out as a precursor to considering the effect in rivers. The importance of hydraulic flushing in controlling algal growth suggests that short-retention-time rivers will show different effects compared to long retention-time, impounded rivers. The latter are likely to operate like lakes, moving from macrophyte domination to phytoplankton domination whereas the former move to benthic and filamentous algal domination. Subsequently, a conceptual model of the development of eutrophic conditions in short-retention-time rivers is developed. Although there is general agreement in the literature that an increase in nutrients, particularly phosphorus, is a pre-requisite for the eutrophic conditions to develop, there is little evidence in short-retention-time rivers that the plant (macro and micro) biomass is limited by nutrients and a good case can be made that the interaction of hydraulic drag with light limitation is the main controlling factor. The light limitation is brought about by the development of epiphytic algal films on the macrophyte leaves. The implications of this conceptual model are discussed and a series of observable effects are predicted, which should result if the model is correct.     

Nitrate concentrations in river waters of the upper Thames and its tributaries

The spatial and temporal patterns of in-stream nitrate concentrations for the upper Thames and selected tributaries are described in relation to point and diffuse sources for these rural catchments. The rivers associated with catchments dominated by permeable (Cretaceous Chalk) bedrock show a smaller range in nitrate concentrations than those associated with clay and mixed sedimentary bedrock of lower permeability. The differences reflect the contrasting nature of water storage within the catchments and the influence of point and diffuse sources of nitrate. Nitrate concentrations often increase in a gradual way as a function of flow for the rivers draining the permeable catchments, although there is usually a minor dip in nitrate concentrations at low to intermediate flow due to (1) within-river uptake of nitrate during the spring and the summer when biological activity is particularly high and (2) a seasonal fall in the water table and a change in preferential flow-pathway in the Chalk. There is also a decrease in the average nitrate concentration downstream for the Kennet where average concentrations decrease from around 35 to 25 mg NO(3) l(-1). For the lower permeability catchments, when point source inputs are not of major significance, nitrate concentrations in the rivers increase strongly with increasing flow and level off and in some cases then decline at higher flows. When point source inputs are important, the initial increase in nitrate concentrations do not always occur and there can even be an initial dilution, since the dilution of point sources of nitrate will be lowest under low-flow conditions. For the only two tributaries of the Thames which we have monitored for over 5 years (the Pang and the Kennet), nitrate concentrations have increased over time. For the main stem of the Thames, which was also monitored for over 5 years, there is no clear increase over time. As the Pang and the Kennet river water is mainly supplied from the Chalk, the increasing nitrate concentrations over time clearly reflect increasing nitrate concentrations within the groundwater. It primarily reflects long-term trends for agricultural fertilizer inputs and significant aquifer storage and long water residence times. The results are discussed in terms of hydrogeochemical processes and the Water Framework Directive and are compared with data from other eastern UK rivers. The importance of diffuse sources of nitrate contamination is highlighted. On a flow weighted basis, the average diffuse component of nitrate is around 95% for the Thames Basin rivers draining Chalk and for the corresponding rivers draining less permeable strata, there is a more significant but not major point source component (at least in terms of flux); the average diffuse component is 79% in this case. These data fit well with earlier assessments of agricultural sources to UK surface waters. Under baseflow conditions the diffuse sources remain dominant for the Chalk fed Thames Basin rivers, but point sources can be dominant for the low permeability cases. On a proportionate basis, the Thames Basin rivers are similar to the rural rivers of the Tweed and Humber Basins in terms of percentage diffuse components although the lower intensity agriculture occurring for the rivers monitored means that the average nitrate concentrations are lower for the rural rivers of central and northern England and the borders with Scotland: the Humber and Tweed.     

Calcite saturation in eastern UK rivers

Calcite saturation in eastern UK rivers is assessed in relation to the potential kinetic inhibition of calcite precipitation. Two well established inhibitors are considered: soluble reactive phosphorus (SRP, i.e. inorganic monomeric phosphorus); and dissolved organic carbon (DOC). The rivers show a range of calcite saturation levels from approximately 1 hundredth to approximately 100-fold. The greatest range occurs for the northernmost river considered, the Tweed, where the waters range from highly unsaturated to highly oversaturated. The lowest range occurs for the most southerly rivers (the Great Ouse and the Thames) where the waters are consistently oversaturated with respect to calcite. The contrasting patterns relate to a greater diversity of water quality within the northern regions. Thus, during the winter, the main waters are derived from the upland areas with acidic soils and low weathering rates. During the summer baseflow periods, groundwater inputs are more important and high photosynthesis results in particularly high pHs and calcite oversaturation. In contrast, for the southern rivers, the main source of water during both the summer baseflow and the winter highflow periods comes from calcium carbonate rich aquifer sources. Statistical analysis of pH vs. the logarithm of the calcite saturation index for each river indicates strong linear features with individual gradients of approximately 1. This linearity results from an autocorrelation (the logarithm of the saturation index is calculated from the pH) and this indicates that calcite solubility controls are not operative in any of the rivers examined. A comparison of calcite saturation levels and SRP and DOC concentrations show a pattern inconsistent with kinetic hindrance, although some structure is observed, probably due to the mixing reactions between point and diffuse sources of water with contrasting chemistry.     

Sewage-effluent phosphorus: a greater risk to river eutrophication than agricultural phosphorus?

Phosphorus (P) concentrations from water quality monitoring at 54 UK river sites across seven major lowland catchment systems are examined in relation to eutrophication risk and to the relative importance of point and diffuse sources. The over-riding evidence indicates that point (effluent) rather than diffuse (agricultural) sources of phosphorus provide the most significant risk for river eutrophication, even in rural areas with high agricultural phosphorus losses. Traditionally, the relative importance of point and diffuse sources has been assessed from annual P flux budgets, which are often dominated by diffuse inputs in storm runoff from intensively managed agricultural land. However, the ecological risk associated with nuisance algal growth in rivers is largely linked to soluble reactive phosphorus (SRP) concentrations during times of ecological sensitivity (spring/summer low-flow periods), when biological activity is at its highest. The relationships between SRP and total phosphorus (TP; total dissolved P+suspended particulate P) concentrations within UK rivers are evaluated in relation to flow and boron (B; a tracer of sewage effluent). SRP is the dominant P fraction (average 67% of TP) in all of the rivers monitored, with higher percentages at low flows. In most of the rivers the highest SRP concentrations occur under low-flow conditions and SRP concentrations are diluted as flows increase, which is indicative of point, rather than diffuse, sources. Strong positive correlations between SRP and B (also TP and B) across all the 54 river monitoring sites also confirm the primary importance of point source controls of phosphorus concentrations in these rivers, particularly during spring and summer low flows, which are times of greatest eutrophication risk. Particulate phosphorus (PP) may form a significant proportion of the phosphorus load to rivers, particularly during winter storm events, but this is of questionable relevance for river eutrophication. Although some of the agriculturally derived PP is retained as sediment on the river bed, in most cases this bed sediment showed potential for removal of SRP from the overlying river water during spring and summer low flows. Thus, bed sediments may well be helping to reduce SRP concentrations within the river at times of eutrophication risk. These findings have important implications for targeting environmental management controls for phosphorus more efficiently, in relation to the European Union Water Framework Directive requirements to maintain/improve the ecological quality of impacted lowland rivers. For the UK rivers examined here, our results demonstrate that an important starting point for reducing phosphorus concentrations to the levels approaching those required for ecological improvement, is to obtain better control over point source inputs, particularly small point sources discharging to ecologically sensitive rural/agricultural tributaries.     

微波暗室空调设计研究

针对微波暗室的温湿度特点、产尘情况,分别介绍了洁净和非洁净微波暗室的空调设计要点,并以洁净度9级的某高大微波暗室为工程实例,从送风量的计算、风口的布置以及空调系统的确定进行了论述。     

延安红色根据地主要建筑特点及类型浅析

通过对凤凰山革命旧址的分析.得出延安20世纪30年代～40年代建筑的特点,从而深入系统地认识延安革命时期建筑的历史、艺术及科学价值,为研究延安革命时期的建筑起到一定的积极作用.     

Children's perceptions of river landscapes and play: what children's photographs reveal

The insights that children's photography can provide into children's perceptions of river landscapes and play opportunities are focused upon, based on an analysis of over 500 photographs and comments generated during visits to two London rivers by children aged nine to eleven from three nearby schools. In their photographs, the children recognized the aesthetic appeal of specific natural features of the river landscapes, particularly trees. Some also appreciated broader river landscape 'views'. The rivers themselves were seen as littered and polluted. Dangers were identified, but these were not seen as unmanageable. The children recognized the special character of the rivers as play places affording varied, adventurous and manipulable play opportunities, but wanted cleaner, safer, more accessible and managed rivers. Some differences were found in the responses of boys and girls and in the children's responses to the two rivers. The urban children taking part in the study showed little understanding of the functions that living and decaying riverside vegetation might have in river ecology, indicating a need for more environmental education.