Field investigation of siltation at a tidal harbor: North Port of Incheon,Korea     

Lee  Guan-hong  Shin  Hyun-Jung  Kim  Young Taeg  Dellapenna  Timothy M.  Kim  Kuk Jin  Williams  Joshua  Kim  Seok-Yun  Figueroa  Steven Miguel 《Ocean Dynamics》2019,69(9):1101-1120

Ocean Dynamics - To understand siltation processes within the North Port of Incheon, Korea, this study estimated the sedimentation rate and then determined the dominant mechanisms for the...  相似文献   

Effects of Solid Organic Wastes on Soil Particulate Organic Carbon Structure Under Different Water Conditions     

Xiaojing Qu  Jinggui Wu  Jinghong Zhao  Jianming Li  Juan Hu  Opoku‐Kwanowaa Yaa 《洁净——土壤、空气、水》2019,47(8)

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Moringa‐Seed‐Based Coagulant Removes Microcystins Dissolved in Water     

Selma Gouvea‐Barros  Maria d. C. Bittencourt‐Oliveira  Jos E. S. Paterniani 《洁净——土壤、空气、水》2019,47(6)

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Analysis of Stock Market Development and CO2 Emissions on OECD Countries via an Empirical Model     

Zhigang Li  Wei‐Ting Chen  I‐Chia Chang  Joe‐Ming Lee 《洁净——土壤、空气、水》2020,48(4)

Accompanying economic growth, CO₂ emissions have polluted the natural environment worldwide. This study highlights the special problems with stock market development and CO₂ emissions in 25 Organization for Economic Cooperation and Development (OECD) countries during 1971–2007 to trace the trend of CO₂ emissions while countries grow their economies. A panel‐data model is applied to analyze the relationships between stock market (SM) development, energy consumption, gross domestic product (GDP), and CO₂ emissions in 25 OECD countries. Low‐GDP countries show different results from high‐GDP countries in the trends of SM development and CO₂ emissions, and dynamic effects occur in SM development and CO₂ emissions under various GDP conditions. There is a negative relationship between SM development and CO₂ emissions if countries enjoy high economic growth, which means that these countries avoid CO₂ emissions through SM development. However, a positive relationship is found between SM development and CO₂ emissions if countries experience low economic growth, which means that SM development does not show the boycott‐effect relationship with CO₂ emissions when countries experience low levels of economic development. This study shows a correlation between SM development and CO₂ emissions among OECD countries.  相似文献   

Evaluation of Sludge Digester Effluent as Feeding Solution for the Enrichment of Anammox Bacteria     

&#x;pek elen‐Erdem 《洁净——土壤、空气、水》2020,48(3)

The aim of this study is to evaluate the feasibility of sludge digester effluent as feeding solution to enrich anaerobic ammonium oxidation (anammox) bacteria. The performance of the two parallel pilot scale‐upflow packed bed anammox reactors (UPBAn1 and UPBAn2) are examined in terms of the enrichment of anammox bacteria. The control experiment is set up conducting synthetic wastewater as feeding solution in the UPBAn1 reactor whereas, the sludge digester effluent is fed to the nitritation reactor and then the partially nitrated digester effluent to the UPBAn2 reactor. Anammox activities are evaluated by mass balances based on ammonium (NH₄⁺), nitrite (NO₂^?), and nitrate (NO₃^?) analysis and NRR. Microbial community of anammox bacteria is analyzed using real‐time polymerase chain reaction (PCR). The results demonstrate that UPBAn 1 and UPBAn2 reactors are successfully enriched on days 64 and 40 with NRRs of 19.54 and 19.43 g N m^?3 per day, respectively. This study reveals that both synthetic wastewater and digester effluent are suitable for the enrichment of anammox bacteria; however, digester effluent as feeding solution for enrichment of anammox bacteria based on the ease of process control and process stability is more advisable.  相似文献   

Geochemical correlations between effusive and explosive silicic volcanics in the Saraykent region (Yozgat), central Anatolia,Turkey     

Gonca Genaliolu‐Kucu  Peter A. Floyd 《Geological Journal》2002,37(2):143-165

Two main volcanic events are distinguished between Saraykent and Akçakışla in the Yozgat province of central Anatolia: (1) early Late Cretaceous–Palaeocene effusive activity, that produced a sequence of intermediate to felsic ‘basal lavas’; and (2) marginally later Palaeocene explosive activity that formed a series of covering ignimbrite flows. Due to their close temporal and spatial relation, geochemical comparisons were made between the silicic members of the lavas and ignimbrites, to identify chemical groups and their relative petrogenesis. The basal lavas range from calc‐alkaline basaltic andesites to dominant rhyolites. Based on trace element correlations three main geochemical groups were identified: the Akçakışla rhyolites (present as domes); Akçakışla rhyodacites‐dacites (lava flows); and Ozan‐Saraykent rhyolites (lava flows). Large‐ion lithophile elements have been mobile in all the groups, but mainly in the Akçakışla rhyolites. Rare earth element (REE) patterns show marked similarity between the Ozan and Saraykent basal lavas. The Akçakışla dome rhyolites are more fractionated with lower La_N/Yb_N ratios (c.10), whereas the Akçakışla basal lavas have much higher La_N/Yb_N ratios (c.30). The chemical coherence and petrographic similarities between the Saraykent and Ozan lavas suggest a single suite related via fractionation. Three geochemical groups were also established for the ignimbrites: Saraykent ignimbrite; Bağlıca ignimbrite‐Toklu‐Kızıldağ crystal tuffs; and Keklikpınar ignimbrite. The ignimbrites, like the basal lavas, display a pronounced depletion in Ba on ORG‐normalized plots. Relative to the basal lavas, chondrite‐normalized patterns for the ignimbrites are different in displaying negative Eu anomalies that indicate feldspar fractionation. The lack of geochemical overlap or coherence between any of the lava and ignimbrite groups suggests that they represent distinct eruptive events and are not related in any simple volcanic development and cogenetic sense. Two geochemical features are common to all the volcanic rock groups: (1) the presence of a Nb‐Ta anomaly, which is generally accepted as a crustal signature; and (2) the relatively low Y abundances which appear characteristic for the region as a whole. These fundamental features of the local silicic volcanism largely reflect source composition and effects. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

A semi‐distributed parallel‐type linear reservoir rainfall‐runoff model and its application in Taiwan     

Lung‐Sheng Hsieh  Ru‐Yih Wang 《水文研究》1999,13(8):1247-1268

The main purpose of this paper is to introduce a semi‐distributed parallel surface rainfall‐runoff conceptual model. In this paper, a general solution of the instantaneous unit hydrograph (IUH) has been derived successfully for N linearly connected reservoirs, each having a different storage constant. The solution is a function of geomorphologic parameters, meteorologic factors and roughness coefficients. The model also takes into account the hydrologic response which is influenced by outflow downstream of a reservoir. For calibration, the shuffled complex evolution (SCE) algorithm is used to search for the global optimal parameters of the model. Because of the parallel structure, the mean roughness parameter of the channel becomes a “conceptual” parameter without a real physical meaning. To evaluate the adaptability of the model adopted, three watersheds around the city of Taipei in Taiwan were chosen to test the effectiveness of the model. The study provides an appropriate rainfall‐runoff model for planning flood mitigation in Taiwan. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

Coleopteran evidence for a mosaic of environments at high altitude in the eastern Pyrénées,France, during the climatic transition between the Allerød and Younger Dryas     

Philippe Ponel  G. Russell Coope  Valrie Andrieu‐Ponel  Maurice Reille 《第四纪科学杂志》1999,14(2):169-174

Late‐glacial environmental and climatic implications are inferred from an insect fauna from organic sediments infilling a palaeochannel on the banks of the River Têt, eastern Pyrénées, France. A pine cone in association with the insect fauna has been radiocarbon dated to 10 920 ± 60 yr BP, namely close to the Allerød – Younger Dryas boundary. Two distinct insect associations appear to be recognisable here. One is an assemblage typical of the high altitude forest and a second is characteristic of an alpine grassland. The close coexistence of these two assemblages is attributed to the climatic cooling towards the start of the Younger Dryas Stadial, when the forest cover broke up into remnant patches interspersed by alpine grassland. It is suggested that in a region of such high relief a mosaic of habitats may have been caused by patchy differences in insolation aspect, especially during a period of climatic deterioration. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

Fugacity analysis of polycyclic aromatic hydrocarbons between microplastics and seawater     

Hwang Lee  Sein Chang  Seung-Kyu Kim  Jung-Hwan Kwon 《Ocean Science Journal》2017,52(1):43-55

Recently, the accumulation of plastic debris in the marine environment has become a great concern worldwide. Although plastics are biologically and chemically inert, plastic debris has been suspected of causing adverse effects on ecosystems due to the increase in reactivity by size reduction and/or micropollutants associated with plastics. Because of the high sorption capacity of microplastics toward organic micropollutants, it is suspected that microplastics may play roles in the distribution and fate of micropollutants. In order to quantitatively evaluate the “net flow” of environmental contaminants in water-plastic-organism systems, a fugacity analysis was conducted using concentrations of polycyclic aromatic hydrocarbons (PAHs) in open oceans and in polyethylene as a representative material of plastic debris. Ratio of fugacity in polyethylene to that in seawater showed a decreasing trend with increasing partition coefficient between polyethylene and seawater (K_PE/sw). This indicates that phase equilibrium between polyethylene and seawater is not attained for higher molecular weight PAHs. Disequilibrium of high molecular weight PAHs suggests that transfer from seawater to plastic debris is thermodynamically driven and the role of plastic debris as a vector to transfer them to living organisms would be minimal. However, additives may slowly migrate from plastics into the environment causing potentially serious effects on ecosystems.  相似文献   

Three-dimensional topography corrections of magnetotelluric data     

Myung Jin Nam  Hee Joon Kim  Yoonho Song †  Tae Jong Lee  Jung Hee Suh 《Geophysical Journal International》2008,174(2):464-474

Topographic effects due to irregular surface terrain may prevent accurate interpretation of magnetotelluric (MT) data. Three-dimensional (3-D) topographic effects have been investigated for a trapezoidal hill model using an edge finite-element method. The 3-D topography generates significant MT anomalies, and has both galvanic and inductive effects in any polarization. This paper presents two different correction algorithms, which are applied to the impedance tensor and to both electric and magnetic fields, respectively, to reduce topographic effects on MT data. The correction procedures using a homogeneous background resistivity derived from a simple averaging method effectively decrease distortions caused by surface topography, and improve the quality of subsurface interpretation. Nonlinear least-squares inversion of topography-corrected data successfully recovers most of structures including a conductive or resistive dyke.  相似文献