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Pt-ceO_2/SiO_2 catalyst for cO oxidation in humid air at ambient temperature

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chinese j.urnal of catalysis 2017年第3期38卷 475-488页

作者： Shirish S.Punde Bruce j.Tatarchuk 奥本大学化学工程系美国亚拉巴马州奥本市

cO self-poisoning and slow surface kinetics pose maj.r challenges to a cO oxidation catalyst that should work at ambient ***,the presence of moisture would cause passivation of the catalyst A highly active ceria promoted Pt catalyst（4%Pt-12%ceO_2/SiO_2;conversion≥99%at low（ 500 ppm） and high（ 2500 ppm） cO concentrations was developed for cO oxidation at ambient temperature in humid *** preparation variables such as Pt and ceO_2 loading,ceria deposition method,drying and calcination conditions for the ceria and Pt precursors were optimized *** activity was correlated with surface properties using cO/H_2 chemisorption,O_2-H_2 titration,X-ray diffraction and BET surface area *** method of ceO_2 deposition had a significant impact on the catalytic ***_2 deposition by impregnation resulted in a catalyst that was three times more active than that prepared by deposition precipitation or ceO_2grafting.O_2-H_2 titration results revealed that the close association of ceria and Pt in the case of ceO_2deposition by impregnation resulted in higher *** catalyst support used was also crucial as a silica supported catalyst was five times more active than an alumina supported *** particle size and pore structure of the catalyst support were also crucial as the reaction was diffusion *** drying and calcination conditions of the ceria and Pt precursors also played a crucial role in determining the catalytic *** Pt-ceO_2/SiO_2 catalysts with Pt 2.5 wt%and ceO_2 15 wt%were highly active（TOF 0.02 s^（-1）） and stable（conversion 99%after 15 h） at ambient conditions.

关键词： carbon monoxide oxidation catalyst Platium ceria Silica Precursor O_2-H_2 titration chemisorption Temperature-programmed reduction

Systematic Biological Upgrade of a Urea Fertilizer Effluent Treatment Plant Using GPS

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Open j.urnal of Applied Sciences 2023年第8期13卷 1457-1477页

作者： Isyaku Ahmad j.seph T. Akintola Regina j. Patinvoh Wilson F. Ekpotu Martins c. Obialor Philemon chukwuebuka Udom Process (Urea) Department Dangote Fertiliser Limited Lagos Nigeria Department of Research & Development Vitapur Nigeria Limited Lagos Nigeria Department of chemical Engineering Faculty of Engineering Lagos State University Lagos Nigeria Department of chemical & Petroleum Engineering University of Uyo Akwa Ibom Nigeria Department of chemical Engineering Federal University of Owerri Owerri Nigeria

The use of modeling and simulation has developed into a critical tool for the sustainable management of wastewater, especially when it comes to replicating the complex biochemical procedures required for fertilizer effluent treatment, which calls for a significant amount of wastewater-related data. The biological improvement of a urea fertilizer effluent via GPS* simulation was carried out in this work using a methodical process. Using established analytical techniques, temperature, total suspended solids (TSS), biochemical oxygen demand (BOD), total phosphorus (T/), chemical oxygen demand (cOD), total nitrogen (TN), total nitrate (NO3), electric conductivity (Ec), turbidity, residual chlorine, urea, NH3, and heavy metals (cu, cd, cr, Pb, Ni, and Fe) were assessed. The research revealed that the measured values from the fertilizer factory outfall effluent had high concentrations of all the physicochemical water quality indicators, with the exception of TSS, PO4-, SO4-, and NO3-. These concentrations are higher compared to the authorized limits or suggested values by the Federal Environmental Protection Agency (FEPA). To improve the therapy biologically, however, a modeling and simulation program (GPS-X, version 8.0) was used with the physicochemical information gathered from the studied sample. The results of the treated water simulation showed that the concentrations of BOD5 and cOD had been significantly reduced by 35% and 44%, respectively. Additionally, it was discovered that total phosphorus (TP), nitrate (N), and total nitrogen (TN) were all within the permitted FEPA limit. The results revealed good treatment performance of the wastewater with increasing concentration of acetic acid and sodium hydroxide. Hence, the results of this research work identify the need for proper treatment of fertilizer industry effluents prior to their release into the environment.

关键词： Fertilizer Wastewater Effluent Discharge Basin Outfall Basin Physiochemical Analysis GPS* Modelling & Simulation

Lc-MS/MS Method for the Quantitation of cefotetan in Human Plasma and Its Application to Pharmacokinetic Study

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chemical Research in chinese Universities 2014年第6期30卷 900-904页

作者： SHI Meiyun YIN Lei cAI Lanlan WANG can LIU Xidong ZHAO Sen SUN Yantong FAWcETT j. Paul ZHAO Limei YANG Yan GU j.ngkai college of Life Science Jilin University Changchun 130012 t~ R. China clinical Pharmacology center Research Institute of Translational Medicine the First Hospital of Jilin University Changchun 130061 1~ R. China" School of Pharmaceutical Sciences dilin University Changchun 130021 P. R. China School of Pharmacy University of Otago Dunedin 9054 New Zealand The Second clinical Hospital Affiliated to chinese Medical University Shenyang 110004 P. R. China

A rapid and sensitive liquid chromatography-tandem mass spectrometry（Lc-MS/MS） method for the de- termination of cefotetan in human plasma was developed and validated. After the protein precipitation of sample with acetonitrile, the analyte and internal standard（IS）, tramadol, were separated on a Zorbax XDB c8 column using ace- tonitrile/1%（volume fraction） formic acid（volume ratio 35：65, pH=2.5） as mobile phase at a flow rate of 1.0 mL/min with a 1 ： 1 split. The detection was performed by electrospray ionization with positive ion mode, followed by multiple reaction monitoring of the transitions for cefotetan at m/z 576.3→460.2（quantifier） and m/z 576.3→432.2（qualifier） and for IS at m/z 264.1→58.1. cefotetan and IS were eluted at 1.86 and 1.87 rain, respectively. The assay was linear over the concentration range of 0.1-100 gg/mL for 20 μL of human plasma only with intra- and inter-day preci- sions（expressed as the relative standard deviation） of less than 6.62% and accuracies（as relative error） of ＋1.31%. The method was applied to the pharmacokinetic study of a l-h intravenous infusion of 1.0 g of cefotetan disodium for human volunteers（n=6）.

关键词： cefotetan Liquid chromatography-tandem mass spectrometry(Lc-MS/MS) Pharmacokinetics Humanplasma

The controlling factors of high suspended sediment concentration in the intertidal flat off the Huanghe River Estuary

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Acta Oceanologica Sinica 2020年第10期39卷 96-106页

作者： Bowen Li Yonggang j.a j.Paul Liu j.anfeng Su Xiaolei Liu Mingzheng Wen Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of ChinaQingdao 266100China Laboratory for Marine Geology Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China Department of Marine Earth and Atmospheric SciencesNorth Carolina State UniversityRaleighNC 27695USA State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092China Tianj.n center China Geological SurveyTianjin 300170China

The Huanghe River(Yellow River)is known by its high suspended sediment concentration(SSc)in its river mouth tidal ***,the factors controlling the high SSc over there are not well ***,we conducted 7-d hydrodynamic observations(water depth,wave height,and current velocity)and SSc measurements on the tidal flat off the Huanghe River *** data shows that in most of time,under the calm sea condition,the SSc ranges 0.1–3.5 g/L,and sediment discharge from the river is the main ***,when hydrodynamics are enhanced in a tidal cycle and large-scale erosion occurs on the seafloor,resuspended sediment becomes the main source,and the SSc in the water column reaches 17.3 g/*** find the suspended sediment flux is mainly controlled by the tidal current and Stokes drift,while the wave-induced shear stress could also affect the variation of suspended sediment *** the observation period,when sea under calm-rippled conditions,the current-induced resuspended sediment concentration(RSc)was greater than the wave-induced *** contrast,in smooth-wavelet sea conditions,the wave-induced RSc was greater than the current-induced RSc,for instance,a single wave event was found to cause 11.8 cm seabed erosion within 6 *** study reveals different controlling factors for the high SSc near a river-influenced tidal flat,and helps us get a better understanding of a delta's depositional and erosional mechanisms.

关键词： Huanghe River(Yellow River) sediment re-suspension sediment transport wave current in-situ observation

Thermodynamic analysis of a photoelectrochemical hydrogen production system

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Thermodynamic analysis of a photoelectrochemical hydrogen pr...

Vegetative Rhombic Pattern Formation Driven by Root Suction for an Interaction-Diffusion Plant-Ground Water Model System in an Arid Flat Environment

第九届全国氢能学术会议

作者： c.j.Tseng.c.L.Tseng National central University

Hydrogen is regarded as a potential energy carrier for the *** exist several methods to produce hydrogen from various *** promising method is photoelectrochemical(PEc) decomposition of water into hydrogen and *** this study, the thermodynamic analysis of PEc hydrogen production is performed for air mass 1.5 *** irradiation is separated into long and short wavelength parts depending on

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American j.urnal of Plant Sciences 2015年第8期6卷 1278-1300页

作者： Inthira chaiya David j. Wollkind Richard A. cangelosi Bonni j. Kealy-Dichone chontita Rattanakul Department of Mathematics Faculty of Science Mahidol University Bangkok Thailand Department of Mathematics Washington State University Pullman USA Department of Mathematics Gonzaga University Spokane USA

A rhombic planform nonlinear cross-diffusive instability analysis is applied to a particular interaction-diffusion plant-ground water model system in an arid flat environment. This model contains a plant root suction effect as a cross-diffusion term in the ground water equation. In addition a threshold-dependent paradigm that differs from the usually employed implicit zero-threshold methodology is introduced to interpret stable rhombic patterns. These patterns are driven by root suction since the plant equation does not yield the required positive feedback necessary for the generation of standard Turing-type self-diffusive instabilities. The results of that analysis can be represented by plots in a root suction coefficient versus rainfall rate dimensionless parameter space. From those plots regions corresponding to bare ground and vegetative patterns consisting of isolated patches, rhombic arrays of pseudo spots or gaps separated by an intermediate rectangular state, and homogeneous distributions from low to high density may be identified in this parameter space. Then, a morphological sequence of stable vegetative states is produced upon traversing an experimentally-determined root suction characteristic curve as a function of rainfall through these regions. Finally, that predicted sequence along a rainfall gradient is compared with observational evidence relevant to the occurrence of leopard bush, pearled bush, or labyrinthine tiger bush vegetative patterns, used to motivate an aridity classification scheme, and placed in the context of some recent biological nonlinear pattern formation studies.

关键词： Leopard Bush Tiger Bush Pearled Bush Root Suction Nonlinear Stability Analyses Threshold-Dependent Pattern Formation

Water Balance of Two Maj.r Soil Types of the Texas High Plains: Implications for Dryland crop Production

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Open j.urnal of Soil Science 2020年第7期10卷 274-297页

作者： Robert j. Lascano Gary R. Leiker Timothy S. Goebel Steven A. Mauget Dennis c. Gitz III Wind Erosion and Water conservation Research Unit USDA-ARS Lubbock TX USA Department of Plant and Soil Science Texas Tech University Lubbock TX USA

crop production in the Texas High Plains is shifting from irrigated to dryland due to the increase of the depth to the water table from the Ogallala aquifer in regions where the saturated thickness of 9 m, the minimum to sustain irrigation, has been reached. Our obj.ctive was to use the mechanistic model ENWATBAL to evaluate the daily and annual water balance for three scenarios of rainfall in this region, a dry (189 mm), an average (449 mm) and a wet (669 mm) year. These three scenarios were applied to two maj.r soil series of this region, Pullman and Amarillo. In all simulations, we used hourly input weather data for a location near Lubbock, Texas and used measured soil hydraulic properties to simulate the water balance for each soil series and the three rainfall scenarios. Results showed that in years with average and wet rain, storage of rainfall occurred in the Pullman but not in in the Amarillo soil series. However, storage of water could be enhanced by combining furrow dikes with minimum tillage along with crop covers that provide a surface residue. The implications of our results for dryland crop production in the semiarid climate of the THP suggest that for years with average and wetter rainfall soils in the Pullman series could store water that would be available for crop use. However, this was not the case for the Amarillo soil series and these soils represent a higher risk for dryland crop production.

关键词： Irrigation Water Use Efficiency Simulation Rainfall Ogallala Aquifer

control of Glyphosate-Resistant Giant Ragweed (Ambrosia trifida L.) with Isoxaflutole and Metribuzin Tankmix

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American j.urnal of Plant Sciences 2016年第6期7卷 916-927页

作者： Scott Ditschun Nader Soltani Darren E. Robinson François j. Tardif Allan c. Kaastra Peter H. Sikkema Department of Plant Agriculture University of Guelph Guelph Canada University of Guelph Ridgetown campus Ridgetown Canada Bayer crop Science canada Guelph Canada

Five field trials were conducted over a two-year period (2013, 2014) to determine the control of glyphosate-resistant (GR) giant ragweed with isoxaflutole (IFT) and metribuzin (MTZ) applied alone and in combination. Treatments were designed to assess the dose response of an IFT plus MTZ tank-mix as well as each chemical applied alone to classify the response using Flint’s adaptation of colby’s equation. Two factor factorial experiments were performed in the growth room to ascertain the response of IFT versus glyphosate, IFT versus MTZ, and IFT plus MTZ versus glyphosate on single plants. Field experiments evaluated the control of GR giant ragweed with IFT plus MTZ in tank-mix in a 1:4 ratio. The rate of IFT plus MTZ for 80% control of GR giant ragweed at 4 and 8 weeks after application (WAA) was 518 (104 g a.i. ha-1 IFT + 414 g a.i. ha-1 MTZ) and 631 g a.i. ha-1 (126 g a.i. ha-1 IFT + 505 g a.i. ha-1 MTZ), respectively. A rate of 668 and 467 g a.i. ha-1 was required to reduce GR giant ragweed density and biomass by 80%, respectively. Field experiments evaluating the control of GR giant ragweed with tank-mixes of IFT plus MTZ, where glyphosate was a constant tank-mix partner, were mostly synergistic. However, the low tank-mix rate (52.5 + 210 g a.i. ha-1) had an additive response for GR giant ragweed biomass reduction. When tested in the greenhouse and growth room, glyphosate susceptible (GS) giant ragweed showed some antagonism with glyphosate and isoxaflutole tank-mixes at rates less than commercial field rates. GR giant ragweed showed an additive response across all treatments in the growth room. Greenhouse experiments evaluating IFT versus MTZ and IFT plus MTZ versus glyphosate revealed all tank-mix treatments to be synergistic at 2 WAA.

关键词： Additive Antagonistic Giant Ragweed Glyphosate Herbicide Resistance Soybean Synergistic Yield

NANO cOMPOSITE AND NANO REPLIcATION TEcHNIQUES IN DIREcT METHANOL FUEL cELL

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NANO COMPOSITE AND NANO REPLICATION TECHNIQUES IN DIRECT MET...