鄂尔多斯盆地安塞地区长6油层沉积相研究

文章选取长6油层组这一典型的曲流河三角洲作为例案,分析该地区发育的微相类型:水上分流河道、分流间沼泽、水下分流河道、河口坝、分流间湾等,其中以三角洲前缘水下分流河道为主。研究表明了相是沉积物形成条件的物质表现。(1)曲流河三角洲平原弯度大的分流河道与平原相近,分流河道许多向外延展;(2)曲流河三角洲前缘水下分流河道河道短,由于水体浅所以导致了大量的堆积物沉积,河口处冲击力变大,水携带者冲积物缓慢运移,多在水下分流河道的两侧堆积成指状;(3)受曲流河三角洲平原的影响,在其末端垂向沉积上,上粗下细在沉积粘土沉积之上,形成河口坝等厚度的砂体富集体。在沉积相砂体展布中体现了砂体长61发育最强,对于长6油层的开发有指示意义。     

Water and sediment transport mechanisms in a large river‐connected lake

Using the finite volume method, a 2‐D water‐sediment coupled model was developed to investigate the transport mechanisms of water and sediment in Poyang Lake, the largest river‐connected lake in China. Simulating water and sediment transport processes in an average water year revealed that the total volume of water and the amount of suspended sediment transported from the five main rivers upstream of Poyang Lake were approximately 1.56 × 10¹¹ m³ and 1.25 × 10⁷ t, respectively. The outputs of water and sediment from the lake to the downstream Yangtze River were approximately 2.17 × 10¹¹ m³ and 1.53 × 10⁷ t, respectively. During the wet season, especially between July and September, nearly 1.06 × 10¹⁰ m³ of water and 1.89 × 10⁶ t of suspended sediment were transported upstream from the Yangtze River into the lake due to the high external water levels, which accounted for 4.88% and 12.35%, respectively, of the total annual transport from the lake into the Yangtze River.     

避暑山庄宫墙外引水水系探究

承德避暑山庄为中国现存最大皇家园林,以自然山水见胜,山庄理水将形式与功能完美融合,具有极高的营建智慧。以往对于避暑山庄理水的研究大都基于以围墙为界,多探讨宫墙内洲渚河湖交错的匠心巧思,而对于宫墙外这一智慧营建的起点鲜有关注,为数不多的相关经典研究尚有值得商榷之处。利用清代文档、舆图等文献信息,基于水文学原理,结合实地调研,论证了避暑山庄宫墙外所引之水是来自于武烈河,梳理了舆图"热河城外河山图"的河工信息,重新绘制了避暑山庄早期引水水系示意图,分析了武烈河与狮子沟交汇口河道演变过程。避暑山庄宫墙外引水水系的梳理有助于园林理水系统性的认识。     

A mixing‐length‐scale‐based analytical model for predicting velocity profiles of open‐channel flows with submerged rigid vegetation

In open‐channel flows with submerged vegetation, the vertical velocity profile can often be described by two layers: the vegetation layer in the lower region and the surface layer in the upper non‐vegetated region. In this paper, a new mixing‐length scale of eddy is proposed for predicting the vertical velocity profile of flow in an open‐channel with submerged rigid vegetation. The analytical model of velocity profile is based on the momentum equation of flow where the turbulent eddy viscosity is assumed to have a linear relationship with the local velocity. The proposed model was tested against different datasets from the literature. The 22 datasets used cover a range of submergence [flow depth (H)/vegetation height (h) = 1.25 ~ 3.38], different vegetation densities of ah = 0.11 ~ 1.85 (a defined as the frontal area of the vegetation per unit volume) and bed slopes (S_o = 1.8 × 10^?6 ~4.0 × 10^?3). This study showed that the proposed model can predict the velocity profiles well against all datasets, and that the mixing length scale of eddies (λ) is well related with both vegetation height (h) and flow depth of surface layer (i.e. the height of non‐vegetation layer, H–h). Close examination of λ in the proposed model showed that when λ = 0.03, the model predicts vertical velocity profiles well for all datasets used except for very shallow submergence (i.e. H/h < 1.5).     

Electro‐oxidation of phenol in petroleum wastewater using a novel pilot‐scale electrochemical cell with graphite and stainless‐steel electrodes

This work investigated the removal of phenol from petroleum wastewater by the electro‐oxidation process. The experimental design was developed on a pilot‐scale electro‐oxidation system equipped with a cylindrical shape of graphite electrodes as an anode and stainless‐steel electrodes as a cathode. An initial study was performed based on operating variables such as current density and time on real petroleum wastewater. The optimum conditions were obtained as a current density of 3 mA/cm² and time 15 min. Under these applied optimum conditions, complete phenol removal from an initial concentration of about 6.8 mg/L was achieved. Also, 50–60% removal of organic matter in terms of chemical oxygen demand (COD) and biological oxygen demand (BOD). The removal of organic matter using electro‐oxidation requires a long reaction time. Also, the economic study indicated that the energy consumption was determined to be 0.79 kWh/m³ and the operating cost was 0.051 $/m³ which is very economical compared with conventional methods.     

Erneuerung der Eisenbahnüberführung in Fulda‐Horas über die Fulda

A new rail bridge crosses the River Fulda in Fulda‐Horas. The rail connection between Gießen and Fulda crosses the Fulda River in the town of Fulda‐Horas. It replaces the three‐span tressle bridge design that was over 100 years old. The new bridge consists of only two spans, broadening each span. The following article describes the key visible construction features of the steel superstructure. The new bridge was built at an elevation of approximately 10 meters and parallel to the old one. A critical review of the design assisted in a faster‐than‐planned construction and lower costs.     

Treatment of chromium‐bearing wastewaters with constructed wetlands

Chromium can have detrimental effects on most organisms, including humans. The present study focused on the effect of treating chromium‐bearing, organic‐rich wastewater on constructed wetland performance. Eight laboratory‐scale systems were used to study organic matter and chromium removals, with three features tested in duplicate: media with proven chromium sorption capacity, vegetation presence and intermittent influent loading. A set of two wetlands acted as the base design. Average BOD₅ and chromium removal rates were 13.4 g/m² day and 135 mg Cr/m² day, respectively. From an influent chromium concentration of 5 mg/L, <0.5 mg/L could be detected at the outlet during the study in all systems. Chromium removal efficiencies were statistically different for all systems (P<0.01), except when comparing the base design against the intermittent feed systems (P>0.05). Overall treatment performance of all systems was remarkably good in spite of significant chromium content and salinity.     

Die Wupper‐Talbrücke Oehde – eine moderne Verbundbrücke

The Wupper River valley bridge – a state‐of‐the‐art composite bridge. The German motorway Autobahn A 1 is one of the nation's most important and frequently traveled highways, connecting the country's northern and southern regions. The road currently has two lanes in each direction, which do not provide enough capacity to carry the traffic volume without daily traffic jams and heavy delays. Therefore, the federal government and the Northrhine‐Westfalia Department of Transportation decided to ease the situation by adding one lane in each direction. This total of 6 lanes fits into the master plan of widening major highways around the Ruhr River region. North of Cologne, the Autobahn A 1 crosses mountainous terrain, so several bridges with total lengths between 240 and 420 meters have had to be widened, replaced, or, most commonly, supplemented by a new bridge. Such supplementation was used on the Wupper River Valley Bridge, called Oehde, close to the city of Wuppertal. The bridge illustrates an example of modern composite bridges adopting new methods in construction and design, and also marks an outstanding example of current composite structures in Germany.     

Ausbau des Stichkanals nach Salzgitter von SKS‐km 3,550 bis 14,918

Expansion of the branch channel to Salzgitter from SKS‐km 3,550 to 14,918 The branch channel to Salzgitter will be extended to the waterway category Vb in the next years. This will enable inland waterway vessels with a width of 11,45 m and a loaded draft of 2,80 m to run it without limitations. The reaches Wedtlenstedt and Üfingen will be extended in most areas to a trapezoidal cross section with a width at water level of 36,90 m and a water depth of 4,00 m. The exit basins of the locks will be extended on one side. Overall about 1 000 000 m² of soil will be moved. About 300 000 m² of clay sealing and 460 000 m² of rip‐rap will be installed. Three culverts have to be replaced by new constructions to adapt to the new cross section of the channel. In addition two bridges will be modified to allow for a clearance of 5,25 m. At present the plan approval procedure is carried out. It is expected to achieve the plan approval order in 2017. The construction is planned to start in 2018. Completion is scheduled for 2024.     

Spatio‐temporal characterization of Korean drought using severity–area–duration curve analysis

In this study, the depth–area–duration (DAD) analysis for characterizing an extreme precipitation event provides a basis for analysing drought events when storm depth is replaced by an appropriate measure of drought severity. Monthly precipitation is probabilistically transformed into standardized precipitation index (SPI) and SPI time series are decomposed into a mutually independent data set by the empirical orthogonal function (EOF) analysis. All EOFs are spatially expanded to a 6 × 6 km resolution by kriging, for which a commercial package, SuRFER^?, is used. Twenty main drought events from the grid‐based SPI time series are identified to construct the drought severity–effective area–drought duration (SAD) curves. The shape of SAD curves is similar to that of the rainfall DAD curves in the sense that drought severity and effective area are out of phase and that drought severity and duration are also out of phase. However, the severity reduction rate in SAD curves is much smaller than the corresponding rate in DAD analysis.     

Human‐influenced streamflow during extreme drought: identifying driving forces,modifiers, and impacts in an urbanized catchment in central Poland

This study investigates the response of the streamflow to an extremely hot and dry summer 2015 in the urbanized catchment of the Utrata River in central Poland. The objectives were to: reveal changes in the flow regime, assess anomalies in summer river flows, estimate the natural and wastewater effluent contribution and provide an ecological context for the in‐stream conditions. The mean annual flow rate in the period 1996–2015 increased by 0.61 m³/s as compared to 1951–1970. The mean annual wastewater inflow rate to the river in 2015 was approximately 0.770 m³/s, constituting 39% of the observed flow. Almost the entire period of August this contribution approached 100%. The optimum river water temperature threshold for warm‐water fish species was exceeded. Streamflow modifications are attributed to an increase of wastewater discharge, urban impact through an increase in imperviousness, and the variability of climatic driving forces.     

Fundamental period of masonry infilled moment‐resisting steel frame buildings

It is known to be a necessary practice to study the effect of infill walls on fundamental period and revise the equations included in the current building codes. In this research, the fundamental period of vibration, by modeling an infill wall as a compression strut in three‐dimensional numerical models of moment‐resisting steel frames, was studied. Areas studied in the present research were structures of symmetric infill wall arrangements wherein the effects of various infill percentage, various moduli of elasticity of masonry wall materials, and different numbers of spans were investigated. The mean fundamental period obtained by the formula provided in FEMA450 was 1.3 times greater than the value resulted from the numerical modeling of infilled moment‐resisting steel frames. Moreover, the corresponding coefficient of determination, R², of the curve fitted to numerically obtained periods was found to be 0.65 when the fundamental period of the infilled frames was only estimated based on the height of buildings, indicating a great deal of variation within the results. A new formula was proposed to estimate the fundamental period based on the structure height, infill wall percentage, and modulus of elasticity, at an acceptable level of accuracy so that the R² coefficient was determined to be 0.99 for the results of the proposed formula.     

Effects of operational parameters on the treatment of nitrate‐rich wastewater by autohydrogenotrophic denitrifying bacteria

The effects of the C/N ratio, as well as hydrogen gas and substrate concentrations, on the treatment of nitrate‐rich wastewater by autohydrogenotrophic denitrifying bacteria in sequencing batch reactors were investigated. Among the various C/N ratios applied in this study, a C/N ratio of 4 was found to be the most suitable ratio that resulted in faster growth and adaptation. The denitrification rate improved with less accumulation of nitrite with increasing H₂ sparging time. Moreover, an increase in nitrate concentration resulted in high nitrite accumulation. The nitrite accumulated to 601 mg/L NO₂‐N when the nitrate concentration was 1000 mg/L NO₃^– ‐ N. The specific degradation rates for nitrate and nitrite were found to be 27.8 mg NO₃^?‐N/g MLVSS/d and 50 mg NO₂^?‐N/g MLVSS/d, respectively, when the C/N ratio was 2, and H₂ as electron donor was sparged for 1 min with 2 h interval.     

Fish tissue quality in the lower Mississippi River and health risks from fish consumption

Between 1990 and 1994, samples of three shellfish species (i.e. blue crab, Callinectes sapidus;crayfish, Procambarus acutis; and river shrimp, Macrobrachium ohionii) and 16 fish species and were collected at six sites along the lower Mississippi River by the Louisiana Department of Environmental Quality, Office of Water Resources in coordination with the US Environmental Protection Agency. The fish species included: bigmouth buffalo (Ictiobus cyanellus); blue catfish (Ictalurus furcatus); carp (Cyprinus carpio); channel catfish (Ictalurus punctatus); cobia (Rachycentron canadum); flathead catfish (Pylodictis olivaris); freshwater drum (Aplodinotus grunniens); largemouth bass (Micropterus salmoides); long nose gar (Lepisosteus osseus); red drum (Sciaenops ocellatus); red snapper (Lutjanus campechanus); smallmouth buffalo (Ictiobus bubalus); spotted gar (Lepisosteus oculatus); striped bass (Morone saxatilis); white bass (Morone chrysops); and white crappie (Pomoxis annularis). Organic compound and heavy metal concentrations were measured in 161 composite fish tissue samples where each composite included three to 10 individual fish. Nineteen chemicals, found at measurable levels in sample tissues, were used in calculations of lifetime excess cancer and non-cancer risks due to fish consumption. We calculated: 574 chemical-specific cancer risks; 41 total cancer risks; and 697 margins of exposure based on a consumption rate of one 8-ounce meal per week (0.032 kg/day), a body weight of 70 kg and reported cancer potency factors and reference doses. We identified nine species of concern (blue catfish, carp, channel catfish, cobia, crayfish, flathead catfish, red drum, spotted gar and striped bass) based on total cancer risk greater than 10(-4) or margin of exposure greater than 1, and whether or not samples collected in subsequent years resulted in lower risks. The compounds primarily responsible for the elevated risks were aldrin, dieldrin, alpha-benzene hexachloride, gamma-benzene hexachloride, heptachlor epoxide, arsenic and mercury.     

Prediction of residential radon exposure of the whole Swiss population: comparison of model‐based predictions with measurement‐based predictions

Radon plays an important role for human exposure to natural sources of ionizing radiation. The aim of this article is to compare two approaches to estimate mean radon exposure in the Swiss population: model‐based predictions at individual level and measurement‐based predictions based on measurements aggregated at municipality level. A nationwide model was used to predict radon levels in each household and for each individual based on the corresponding tectonic unit, building age, building type, soil texture, degree of urbanization, and floor. Measurement‐based predictions were carried out within a health impact assessment on residential radon and lung cancer. Mean measured radon levels were corrected for the average floor distribution and weighted with population size of each municipality. Model‐based predictions yielded a mean radon exposure of the Swiss population of 84.1 Bq/m³. Measurement‐based predictions yielded an average exposure of 78 Bq/m³. This study demonstrates that the model‐ and the measurement‐based predictions provided similar results. The advantage of the measurement‐based approach is its simplicity, which is sufficient for assessing exposure distribution in a population. The model‐based approach allows predicting radon levels at specific sites, which is needed in an epidemiological study, and the results do not depend on how the measurement sites have been selected.     

Analysis of UK river restoration using broad‐scale data sets

This paper uses data from the UK River Restoration Centre's National River Restoration Inventory (NRRI) and the UK Environment Agency's River Habitat Survey (RHS) to analyse the relationship between restoration technique and the physical catchment context in which they have been implemented. Specifically we tested the relationship between categories of restoration technique and energy conditions, the relationship between restoration project and degree of channel modification, and whether the associations between restoration and physical catchment attributes have changed over time. Significant associations between categories of restoration technique and catchment variables were found, with direct morphological interventions needed in lower energy conditions; however, the analysis shows no change over time. This work shows that analysis of existing data sets can provide useful information to support the science and practice of river restoration and suggests that further analysis of existing ecological and geomorphological data sets provides an important learning opportunity to strengthen river restoration.     

Einfluß der Auflagerpositionen auf die 1. Eigenfrequenz beim Euler‐Bernoulli‐Balken

Influence of the support locations on the 1^st angular frequency of an Euler‐Bernoulli‐Beam. A closed form solution for the 1^st angular frequency of an Euler‐Bernoulli‐Beam of constant length with variable support locations is introduced. Based on the assumption, that the kinetic energy of the mode shape is independent of the support locations, the angular frequency is determined from a Rayleigh‐Coefficient. The approximation quality is assessed by comparison to a numerical solution.     

Grundlagen und Ergebnisse der Ableitung von axialen Pfahlwiderständen aus Erfahrungs‐werten für die EA‐Pfähle

Background and results of derivation of axial pile resistances based on empirical values for “EA‐Pfähle”. The basics of the derivation of axial pile capacity based on empirical values and selected results are presented, which are already integrated in the national German recommendations for piles “EA‐Pfähle”. The study provides to a large extent a secured range of empirical values for the base resistance and the skin friction for different pile systems as a function of the soil strength. Based on comparative statistical analysis of pile load tests of different pile systems, it becomes possible to derive a consistent analysis of bearing behaviour of pile systems, which provides a safe and an economical pile bearing capacity depending on the expense of pre‐liminary soil investigations.     

The Wansbeck Barrage Scheme: Twenty-One Years of Environmental Impact

The Wansbeck barrage (in Northumberland), which was completed in 1975, was envisaged as a means of removing unsightly saltmarsh and creating an amenity lake and country park. This study examines the effect of the scheme on the estuarine environment and focuses on (a) the nature of the habitat, (b) the rate of sedimentation, (c) the control on water quality within the impoundment, and (d) amenity use.     

A study of optimum aeration efficiency of a lab‐scale air‐diffused system

Up to now, tremendous efforts have been devoted to modelling the oxygen transfer coefficient (k_La) for diffused aeration systems, while not considering the corresponding energy consumption. Enhancing k_La is favorable for an exemplary oxygenation process, but may come at the cost of greater energy withdrawal, an unwelcome tradeoff. Assessing the aeration efficiency (the rate of oxygen delivered per unit energy) reflects the overall effectiveness of an aeration process and guarantees a superior system performance. Presented here is a lab‐scale study that investigates the effect of the orifice diameter, the airflow rate and the water column on the aeration efficiency. Various combinations of the studied parameters were tested using a cylindrical tank with a single orifice for air injection. An optimal performance of the aeration efficiency was observed at an orifice diameter of 0.3 mm when tested under 0.91 m water column and an airflow rate of 0.05 SLPM. Furthermore, a new empirical formula of aeration efficiency was established with a high correlation index (R² = 0.97) to allow preliminary prediction of aeration efficiency.