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Nitrogen and oxygen isotopic signatures of subsurface nitrate seaward of the Florida Keys reef tract
Nitrogen oxygen isotopic signatures subsurface nitrate seaward Florida Keys reef tract
2014/4/22
Hydrographic and nutrient structure and the nitrogen and oxygen isotopic compositions (d15N and d18O) of the nitrate pool seaward of the Florida Keys reef tract were measured in Summer 2003. Nitrate a...
Anaerobic ammonium oxidation in the Peruvian oxygen minimum zone
Anaerobic ammonium oxidation Peruvian oxygen minimum zone
2014/4/22
We investigated the microbial pathways of nitrogen (N) loss in an April 2005 transect through the Peruvian oxygen minimum zone (OMZ) at 12°S latitude using short anaerobic incubations with 15N-labeled...
Dissolved oxygen response to wind–inflow interactions in a stratified reservoir
Dissolved oxygen response wind–inflow interactions
2014/4/22
Results of a field campaign and numerical simulations are used to show how physical mechanisms impose
length scales and timescales that determine the dominant biogeochemical process. As an example, t...
The oxygen-18 isotope approach for measuring aquatic metabolism in high productivity waters
The oxygen-18 isotope approach measuring aquatic metabolism high productivity waters
2014/4/22
We examined the utility of δ18O2 measurements in estimating gross primary production (P), community respiration (R), and net metabolism (P : R) through diel cycles in a productive agricultural stream ...
Oxygen as a control on sea floor biological communities and their roles in sedimentary carbon cycling
Oxygen sea floor biological communities sedimentary carbon cycling
2014/4/22
13C tracer experiments were conducted at sites spanning the steep oxygen, organic matter, and biological community gradients across the Arabian Sea oxygen minimum zone, in order to quantify the role t...
Effects of progressive oxygen depletion on sediment diagenesis and fluxes: A model for the lower St. Lawrence River Estuary
progressive oxygen depletion sediment diagenesis fluxes A model for the lower St. Lawrence River Estuary
2014/4/21
We applied a diagenetic model to examine the effects of a decadal-timescale progressive decrease in bottomwater oxygen concentration on sediment geochemistry and fluxes across the sediment-water inter...
The presence of ladderane lipids in the oxygen minimum zone of the Arabian Sea indicates nitrogen loss through anammox
The presence of ladderane lipids oxygen minimum zone Arabian Sea indicates nitrogen loss through anammox
2014/4/23
Distributions of ladderane lipids, which are characteristic of membranes of bacteria performing anaerobic ammonium oxidation (anammox), were determined in the northwestern Arabian Sea with respect to ...
碳载体预处理对CoTMPP/BP电催化剂氧还原性能的影响（Effect of Pretreatment of Carbon Supports on Activity of CoTMPP Electrocatalysts for the Reduction of Oxygen）
CoTMPP/BP电化学催化剂 化学预处理 碳载体 氧还原反应
2010/8/18
采用微波加热合成法制备了CoTMPP/BP电化学氧还原催化剂。采用旋转圆盘电极(RDE)研究了BP2000碳载体经30% H2O2或6 mol·L-1 HNO3化学预处理后对催化剂氧还原催化活性的影响，并且在PEM燃料电池工作站上测试了不同CoTMPP/BP催化剂的燃料电池单电池性能。结果表明，碳载体经过化学预处理后催化剂性能有显著的提高，并且30% H2O2处理效果更好。采用IR、XRD和XPS...
Geobiologists Solve "Catch-22 Problem" Concerning the Rise of Atmospheric Oxygen（图）
Environmental Changes green plants carbon dioxide
2006/12/8
November 29, 2006，PASADENA, Calif.--Two and a half billion years ago, when our evolutionary ancestors were little more than a twinkle in a bacterium's plasma membrane, the process known as photosynthe...
Oxygen Ion Implantation in Strontium Bismuth Tantalate Thin Films
Ferroelectric Thin films SBT Oxygen implantation Plasma focus
2010/9/29
Strontium Bismuth Tantalate (SBT) ferroelectric thin films have attracted considerable attention for the development of non-volatile ferroelectric random access memories (NV-FRAMs). These films, howev...
Anaerobic ammonium oxidation in the oxygen-deficient waters off northern Chile
Anaerobic ammonium oxidation oxygen-deficient waters off northern Chile
2014/5/5
We investigated the pathways of N2 production in the oxygen-deficient water column of the eastern tropical South Pacific off Iquique, Chile, at 20°S, through short anoxic incubations with 15N-labelled...
Spatial and temporal patterns of mineralization rates and oxygen distribution in a permeable intertidal sand flat (Sylt, Germany)
Spatial and temporal rates oxygen distribution
2014/5/5
Oxygen distribution and benthic mineralization rates were investigated in a permeable intertidal sand flat
(permeability: 3.9 3 10211 m2
) in a transect from the low toward the high waterline. At al...
A time series investigation of the oxygen isotopic composition of dissolved inorganic phosphate in Monterey Bay, California
oxygen isotopic composition dissolved inorganic phosphate Monterey Bay California
2014/5/5
We present a 2-yr time series of the oxygen isotopic composition of dissolved inorganic phosphate (δ18Op) in Monterey Bay, California. δ18Op can serve as a proxy for phosphate utilization because its ...
Short-term variation of triple oxygen isotopes and gross oxygen production in the Sagami Bay, central Japan
Short-term variation triple oxygen isotopes gross oxygen production Sagami Bay central Japan
2014/5/4
We studied diurnal and daily variations in triple oxygen isotopes in the euphotic zone of the Sagami Bay during summer 2003 and 2004. There were sharp changes in physical processes, driven by changes ...
Long-term changes in the areal hypolimnetic oxygen deficit (AHOD) of Onondaga Lake: Evidence of sediment feedback
Long-term changes areal hypolimnetic oxygen
2014/4/30
Long-term trends in the rate of depletion of hypolimnetic dissolved oxygen (DO) are documented for ionically
enriched hypereutrophic Onondaga Lake, New York, for the 1978–2002 interval. Depletion rat...