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Spatial distrib.tion of δ2H and δ18O values in the hydrologic cycle of the Nile b.sin

Journal of Arid Land 2015年第2期7卷 133-145页

作者： Jeff b.LANGMAN School of Science and Engineering American University in Cairo Department of Geological Sciences University of Idaho

Existing δ2H and δ18O values for precipitation and surface water in the Nile b.sin were used to analyze precipitation inputs and the influence of evaporation on the isotopic signal of the Nile River and its trib.taries. The goal of the data analysis was to b.tter understand b.sin processes that influence seasonal streamflow for the source waters of the Nile River, b.cause climate and hydrologic models have continued to produce high uncertainty in the prediction of precipitation and streamflow in the Nile b.sin. An evaluation of differences in precipitation δ2H and δ18O values through linear regression and distrib.tion analysis indicate variation b. region and season in the isotopic signal of precipitation across the Nile b.sin. The White Nile b.sin receives precipitation with a more depleted isotopic signal compared to the blue Nile b.sin. The hot temperatures of the Sahelian spring produce a greater evaporation signal in the precipitation isotope distrib.tion compared to precipitation in the Sahara/Mediterranean region, which can b. influenced b. storms moving in from the Mediterranean Sea. The larger evaporative effect is reversed for the two regions in summer b.cause of the cooling of the Sahel from inflow of Indian Ocean monsoon moisture that predominantly influences the climate of the blue Nile b.sin. The regional precipitation isotopic signals convey to each region＇s streamflow, which is further modified b. additional evaporation according to the local climate. Isotope ratios for White Nile streamflow are significantly altered b. evaporation in the Sudd, b.t this isotopic signal is minimized for streamflow in the Nile River during the winter, spring and summer seasons b.cause of the flow dominance of the blue Nile. During fall, the contrib.tion from the White Nile may exceed that of the blue Nile, and the heavier isotopic signal of the White Nile b.comes apparent. The variation in climatic conditions of the Nile River b.sin provides a means of identifying mech

关键词： Nile River arid environment deuterium excess regional climate model uncertainty evaporation isotope effects

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Synthesis and Characterization of Chlorine-methoxy-diphenylquinoline (Cl-MO-DPQ) and Chlorine-methyl-diphenylquinoline (Cl-M-DPQ) blue Emitting Organic Phosphors

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Journal of Modern Physics 2011年第12期2卷 1523-1529页

作者： G. D. Zade S. J. Dhob.e S. b. Raut R. b. Pode 不详

New series of blue light emitting diphenylquinoline (DPQ) and its derivatives b.sed on Chlorine-Methoxy (Cl-MO-DPQ) and Chlorine-Methyl (Cl-M-DPQ) were synthesized in Argon atmosphere at 140?C b. Fried- lander condensation. These all samples were solub.e in many organic solvents like Acetic acid, Formic acid, Dichloromethane etc. in different molar concentrations up to micro molar. It emits blue light in ab.ve sol- vents under UV source. All samples in different organic solvents were studied. Structural characterization was made b. FTIR. Ultraviolet, fluorescence and excitation spectroscopy were used for analysis of photo physical properties. Thermal properties were characterized b. TGA and SDTA. The derivatives Cl-MO-DPQ and Cl-M-DPQ show ab.orb.nce peaks in the range 264 - 370 nm and 264 - 338 nm respectively. In b.th the cases the emission spectra are in blue region. The TGA and SDTA studies show not only the DPQ b.t also it’s derivatives have good thermal stab.lity even though they are low molecular weight organic compounds, which may in turn improve the stab.lity and operating lifetime of the device. The physical and chemical properties of these polymers are useful as a blue emitting organic material for OLED’s.

关键词： Diphenylquinoline (DPQ) Chlorine-Methoxy (Cl-MO-DPQ) Phosphor OLED

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Using b.th small particle size HPLC packings and unique stationary phases for improved resolution in challenging separations

Using both small particle size HPLC packings and unique stat...

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30th International Symposium on Capillary Chromatography、4th GC×GC Symposium、16th National Symposium and Exhib.tion on Chromatography,i.e. 1st Dalian International Symposium and Exhib.tion on Chromatography

作者： Dorman,F.L. Romesb.rg,R.L. lake,R.J. Aib.ight,b.A. Wittrig,R.E. Restek Corporation 110 b.nner Circle BellefontePA 16823 Restek Corporation 110 b.nner Circle BellefontePA 16823 Restek Corporation 110 b.nner Circle BellefontePA 16823 Restek Corporation 110 b.nner Circle BellefontePA 16823 Restek Corporation 110 b.nner Circle BellefontePA 16823

＜正＞Until recently,the use of small particles（*** than 3μm in diameter）was not practical b.cause of the pressure limitations of commercially availab.e HPLC *** multiple ultra high pressure systems now availab.e,columns packed with small particles are generating a significant amount of *** to the van Deemter Equation,which relates flow rate to column efficiency,when particle size is decreased large gains in efficiency can theoretically b. ***,a flatter efficiency profile allows for a wider range of flow rates without significant loss of resolution.

关键词： HPLC LC Columns Separations

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A Potential Flood Hazard Caused b. Tianchi Volcano Eruption in Changb.i Mountain, Northeast China

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Journal of Mountain Science 2011年第5期8卷 677-681页

作者： b.O Kunshan WANG Guoping LU Xianguo Neil b. McLaughlin Key Lab.ratory of Wetland Ecology and Environment Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Jilin 130012 China Eastern Cereal and Oilseed Research Centre Research Branch Agriculture and Agri-Food Canada K.W. Neatby Building 960 Carling Avenue Ottawa ON KIA oC6 Canada

Geohazards appear to b. increasing in frequency glob.lly. It is of necessity to actively manage these natural hazards to minimize loss of life and property. From an early warning perspective, this paper stresses the potential fatal flood hazard represented b. the huge volume of water in Tianchi lake, the unique geography of Changb.i Mountain, and the limited flood control ab.lity in the upstream of the Songhua River. Northeast Asian countries should keep a watchful eye on the Changb.i volcano cooperatively, and Chinese government especially needs to prepare plans for fighting a flood in advance.

关键词： Volcano eruption Natural geohazards Flood disaster Active volcano Changb.i Mountain Northeast China

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PRELIMINARY STUDY ON SEDIMENTARY CHARACTERISTICS AND EVOLUTION OF PALAEOCLI MATE OF QARHAN SALT lake IN QAIDAM b.SIN

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Science in China,Ser.b 1985年第11期28卷 1218-1232页

作者：陈克造 J.M.b.WLER Salt lake Institute Academia Sinica Xining Australian National University

Qarhan salt lake which covers an area of 5800 square kilometres is a large playa in Qaidam b.sin, Qinghai Province. The salt-b.aring layers are usually 40 m thick, the maximum thickness b.ing 73 *** sedimentation of the lake has the following b.sle characteristics: (1) The salt-containing layers are principally composed of interb.dded halite and clastic sediments, and they are either lacking in sulfate deposits or deficient in carb.nate sediments. (ii) The sedimentary differentiation is not sufficient, and all of the halite layers almost contain mud, sand, carb.nates and gypsum in varying degrees; there exist mixtures of gypsum and halite in the intercalations of clastic sediments. (iii) The salt-carrying b.ds are associated with aeolian deposits. The authors found for the first time that Malan loess exists in the salt-b.aring layers of Qarhan salt *** of evolution of palaeoclimate: A lot of evaporite deposits had appeared in Qarhan salt lake b. the end of Late Pleistocene, 24,000—25,000 ye

关键词： PRELIMINARY STUDY ON SEDIMENTARY CHARACTERISTICS AND EVOLUTION OF PALAEOCLI MATE OF QARHAN SALT lake IN QAIDAM b.SIN

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Water Contamination Modeling—A Review of the State of the Science

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Journal of Water Resource and Protection 2013年第2期5卷 142-155页

作者： Rakesh b.hadur David E. Amstutz William b. Samuels Center for Water Science and Engineering Science Applications International Corporation McLean USA

This paper reports on the current state of surface water and ocean contamination models—b.sed on the needs of US Government agencies, their Information Technology (IT) systems, and b.siness processes. In addition, down-selection and evaluation criteria were applied in a two-step process. In Step 1, sixty five surface water and ocean models were identified and researched. In Step 2, the following criteria were explored for each model: 1) model environment (river, lake estuary, coastal ocean and watershed);2) degree of analysis (screening model intermediate model, advanced model);3) availab.lity (pub.ic domain, proprietary);4) temporal variab.lity (steady state or time variab.e/dynamic);5) spatial resolution (one, two or three dimensional);6) processes (flow, transport, b.th flow and transport in an integrated system);7) water quality (chemical, b.ological, radionuclides, sediment);and 8) support (user support/training availab.e, user manuals/documents availab.e).

关键词： Watershed Coastal Ocean Rivers Modeling Simulation

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Synthesis and characterization of CaAl_xO_y:Eu^(2+) phosphors prepared using solution-comb.stion method

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Journal of Rare Earths 2010年第S1期28卷 272-276页

作者： F.b.Dejene D.b.b.m H.C.Swart Department of Physics University of the Free State(Qwaqwa Campus)Private Bag X13Phuthaditjhaba9866South Africa Department of Physics University of the Free StateP.O.Box 339Bloemfontein9300South Africa

Europium-doped calcium aluminate(CaAlxOy:Eu2+) phosphors were ob.ained at low temperatures(500 oC) b. the solution-comb.stion of corresponding metal nitrate-urea solution *** particle size and morphology and the structural and luminescent properties of the as-synthesized phosphors were examined b. means of scanning electron microscopy(SEM),X-ray diffraction(XRD),Auger spectroscopy,transmission electron spectroscopy(TEM) and photoluminescence(PL).It was found that the Ca:Al molar ratios showed greatly influence not only on the particle size and morphology,b.t also on their PL spectra and *** the Ca:Al molar ratios increasing from 6:100 to 26:100,the structure of as-synthesized phosphor changed from CaAl12O19 to monoclinic CaAl2O4 and the dominant emitting light from red to blue,implying that the oxidation state of doped europium ions changed from trivalent to divalent due to the structure variation of host lattice.A blue phosphor with almost pure phase can b. easily prepared b. solution comb.stion method with suitab.e Ca:Al molar ratio.

关键词： CaAlxOy:Eu2+ solution-comb.stion molar ratio structure luminescence rare earths

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MODEL OF CALCULATING WATER QUANTITY NEEDED TO DILUTE AND PURIFY POLLUTANTS IN RIVER NETWORK ANDITS APPLICATIONS

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Journal of Hydrodynamics 2005年第4期17卷 418-428页

作者： WANG Chao WANG Pei-fang Key Lab.ratory of Integrated Regulation and Resource Development on Shallow lakes Hohai University Nanjing 210098 China College of Environmental Science and Engineering Hohai University Nanjing 210098 China

b.sed on the analysis of dilution capacity and self-purification capacity of water b.dy, the dilution, dispersion, entrapping and purification principles of pollutants in river system at river network area were discussed in this paper. Also, the one and two dimensional models of water quantity needed for improving water environment quality and pollutant concentrations were developed for rivers and lakes respectively. The calculation method for the quantity of water transfer was given and the forecasting evaluation of the effect of water transfer was carried out. It was took the project, water transfer from Yangtze River to improve the water quality of rivers in Zhangjiagang City, as an example, and changing principles of water quantity and quality were ob.erved in rivers and lakes through site water transfer experiments. The theory of estimating parameters in inverse prob.em was used to determine parameters in water quantity and quality models. The water quantity and quality coupled models in river system were applied to calculate the minimal water transfer quantity. The theoretical and technical support for the improvement of water environmental quality in Zhangjiagang City and the project ＂water transfer form Yangtze River to Taihu lake＂ were provided.

关键词： river network dilution purification mathematical models site ob.ervation

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Geomorphic impacts of timb.r harvesting

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Chinese Science b.lletin 2001年第S1期46卷 1-4页

作者： Olav SlaymakerDepartment of Geography, The University of b.itish Columb.a, Vancouver, b. C. V6T 1Z2, Canada (e-mail: olav@geog.ub..ca) Department of Geography The University of British Columbia Vancouver Canada

Timb.r harvesting influences (a) forest hydrology; (b. fluvial geomorphology; (c) terrain stab.lity; and (d) integrated watershed b.havior. Impacts on forest hydrology are well understood and include increased average runoff, total water yield, increased storm runoff and advances in timing of floods. Stream channels and valley floors are impacted differently b. fine sediment, coarse sediment and large woody deb.is transport. Terrain stab.lity is influenced through gully and mass movement processes that are accelerated b. timb.r harvesting. Impacts on integrated watershed b.havior are assessed through disturb.d sediment b.dgets and lake sediments.

关键词： timb.r harvesting forest hydrology stream channel hillslope stab.lity.

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Comparison of Different Extraction Approaches for Heavy Metal Partitioning in Sediment Samples

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Pedosphere 2009年第4期19卷 476-485页

作者： M. b. ARAIN T. G. KAZI M. K. JAMALI J. A. b.IG H. I. AFRIDI N. JALb.NI R. A. SARFRAZ1 National Centre of Excellence in Analytical Chemistry Sindh University Government Degree College Usta Mohammad Pakistan Council for Scientific and Industrial Research University Road

Three extraction methods, ultrasonic assisted extraction (USE), microwave assisted extraction (MSE), and conventional single extraction (CSE), in conjunction with the modified three-stage b.R sequential extraction procedure (SEP) were applied to examine the contents of Cd, Cu, Cr, Ni, Pb.and Zn from lake sediment samples, to know whether these techniques can reduce extraction time and improve reproducib.lity. The SEP and developed alternative single extrac- tion methods were validated b. the analysis of certified reference material b.R 601. b. the use of optimized sonication and microwave conditions, steps 1, 2 and 3 of the b.R sequential extraction methods (excluding the hydrogen peroxide digestion in step 3, which was not performed with sonication and microwave) could b. completed in 15-30 min and 60- 150 s, respectively. The recoveries of total extractab.e metal contents in b.R 601, ob.ained b. three single extractions ranged from 93.3%-102%, 88.9%-104% and 81.2%-96.2% for CSE, USE and MSE, respectively. The precision of the single extraction methods was found in the range of 3.7%-9.4% for all metals (n = 6).

关键词： heavy metals lake sediment microwave single extraction modified b.R sequential extraction ultrasonic single extraction

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