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Seasonal variations and sources of mass and chemical composition for PM_(10) aerosol in Hangzhou,china

Particuology 2009年第3期7卷 161-168页

作者： Junji cao Zhenxing Shen Judith c. chow Guowei Qi john G. Watson State Key Lab of Loess and Quaternary Geology - SKLLQG. Institute of Earth Environment ChineseAcademy of Sciences Xi'an. Shaanxi 710075 China Department of Environmental Science and Engineering. xi'an Jiaotong University. Xi'an 710049. china Division of Atmospheric Sciences. Desert Research Institute. Reno. USA Hangzhou Municipal Environmental Monitoring center Hangzhou 310007 China

Aerosol observation was conducted for four seasons from September 2001 to August 2002 at five sampling sites in Hangzhou, South china, on PM10 mass, 22 elements （Na, Mg, AI, Si, P, S, K, ca, Ti, V, cr, Mn, Fe, Ni, cu, Zn, As. Se, Br, cd, Ba, and Pb）, 5 major ions （F^-, cl^ , NO3^-, SO4^2- , and NH4^＋）, and organic and elemental carbon （Oc and Ec）, showing that PM10 mass ranged from 46.7 to 270.8 μg/m^3, with an annual average of 119.2 μg/m^3. Na, AI, Si, S, K, ca, and Fe were the most abundant elements in PM10, most of S being in the form of SO4^2- . SO4^2-, NO3^-, and NH4^＋ were the major ions, which contributed to about 20% of the PM10 mass. The mean seasonal concentrations for SO4^2- , averaged over all sites, were found to be 18.0, 18.5, 24,Z and 21.4 μg/m^3, for spring, summer, autumn, and winter, respectively, while the corresponding loadings for NO3^- were 7.2, 4.7, 7.1, and 11.2 μg/m^3, and for NH4^＋ were 6.0, 5.9, 8.2, and 9.3 μg/m^3, in the form mostly of NH4NO3 in spring, autumn, and winter, and mostly of （NH4）2SO4 in summer. The low NO3^-/SO4^2- ratio found indicates coal combustion as the major source throughout the year. The mean annual concentrations of Oc and Ec in PM10 were found to be 21.4, and 4.1 μg/m^3, respectively. Material balance calculation indicated that fugitive dust, the secondary aerosol, and carbonaceous matter were the most abundant species in PM10 for the four seasons, as is characteristic for cities in South china.

关键词： PM10 Elements lons carbon Material balance

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Global Agricultural Trade and Developing countries

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丛书名： Trade and Development Series

2005年

作者： Aksoy Mtaman Beghin john c.

ISBN: (纸本)0821358634

Global Agricultural Trade and Developing countries presents research findings based on a series of commodity studies of significant economic importance to developing countries. First, the book sets the stage with background chapters and investigations of cross-cutting issues. Trade and domestic policy regimes affecting agricultural and food markets are described, and the resulting patterns of production and trade are assessed. The book follows with an analysis of product standards and costs of compliance and their effects on agricultural and food trade. An investigation of the impact of preferences given to selected countries and their effectiveness is next. The evidence on the attempts to decouple agricultural support from agricultural output is then reviewed. The last background chapter explores the robustness of the global gains of multilateral agricultural and food trade liberalization. Given this context, the book presents detailed commodity studies for coffee, cotton, dairy, fruits and vegetables, groundnuts, rice, seafood products, sugar, and wheat. These markets feature distorted policy regimes among industrial or middle-income countries.; The studies analyze current policy regimes in key producing and consuming countries document the magnitude of these distortions and estimates the distributional impacts -winners and losers- of trade and domestic policy reforms. By bringing the key issues and findings together in one place, Global Agricultural Trade and Developing countries aids policy makers and researchers, both in their approach to global negotiations and in evaluating their domestic policies on agriculture. This book also complements the recently published Agriculture and the WTO that focuses primarily on the agricultural issues within the context of the WTO negotiations.

关键词： International economic relations.

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Effect of adding a smart potassium ion-responsive copolymer into polysulfone support membrane on the performance of thin-film composite nanofiltration membrane

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Frontiers of chemical Science and Engineering 2019年第2期13卷 400-414页

作者： Meibo He Zhuang Liu Tong Li chen chen Baicang Liu john c.crittenden Institute of New Energy and Low-carbon Technology Sichuan UniversityChengdu 610207China college of Architecture and Environment Sichuan UniversityChengdu 610065China School of chemical Engineering Sichuan UniversityChengdu 610065China Research center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China Litree Purifying Technology co. LtdHaikou 571126China Brook Byers Institute for Sustainable Systems School of Civil and Environmental EngineeringGeorgia Institute of TechnologyAtlantaGA 30332USA

Thin-film composite (TFc) nanofiltration (NF) membranes were fabricated via the interfacial polymerization of piperazine (PIP) and 1,3,5-benzenetricart)oiiyl trichloride on polysulfone (PSf) support membranes blended with K^+-responsive poly(N-isopropylacryamideco- acryloylamidobenzo-15-crown-5)(P(NIPAM-co- AAB15c5)). Membranes were characterized by attenuated total reflection Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, atomic force microscope, scanning electron microscope, contact angle, and filtration tests. The results showed that:(1) Under K^+-free conditions, the blended P(NIPAM-co-AAB15c5)/PSf supports had porous and hydrophilic surfaces, thereby producing NF membranes with smooth surfaces and low MgSO4 rejections;(2) With K^+ in the PIP solution, the surface roughness and water permeability of the resultant NF membrane were increased due to the K^+-induced transition of low-content P(NIPAM-co-AAB15c5) from hydrophilic to hydrophobic;(3) After a curing treatment at 95℃, the improved NF membrane achieved an even higher pure water permeability of 10.97 L·m^-2·h^-1 - bar1 under 200 psi. Overall, this study provides a novel method to improve the performance of NF membranes and helps understand the influence of supports on TFc membranes.

关键词： nanofiltration interfacial polymerization support membrane potassium ion-responsive thin-film composite

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chemical poison and regeneration of ScR catalysts for NOx removal from stationary sources

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Frontiers of Environmental Science & Engineering 2016年第3期10卷 413-427页

作者： Junhua LI Yue PENG Huazhen cHANG Xiang LI john c. cRITTENDEN Jiming HAO State Key Joint Laboratory of Environment Simulation and Pollution control School of Environment Tsinghua University Beijing 100084 China School of civil and Environmental Engineering and the Brook Byers Institute for Sustainable Systems Georgia Institute of Technology 800 West Peachtree Street Suite 400 F-H Atlanta GA 30332-0595 United States School of Environment and Natural Resource Renmin University of China Beijing 100872 China

Selective catalytic reduction （ScR） of NOx with NH3 is an effective technique to remove NOx from stationary sources, such as coal-fired power plant and industrial boilers. Some of elements in the fly ash deactivate the catalyst due to strong chemisorptions on the active sites. The poisons may act by simply blocking active sites or alter the adsorption behaviors of reactants and products by an electronic interaction. This review is mainly focused on the chemical poisoning on V2O5-based catalysts, environmental-benign catalysts and low temperature catalysts. Several common poisons including alkali/alkaline earth metals, SO2 and heavy metals etc. are referred and their poisoning mechanisms on catalysts are discussed. The regeneration methods of poisoned catalysts and the development of poison-resistance catalysts are also compared and analyzed. Finally, future research directions in developing poisoning resistance catalysts and facile efficient regeneration methods for ScR catalysts are proposed.

关键词： flue gas DeNOx ScR catalyst poison and regeneration

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Growth, Development and Yield of Kenaf as Affected by Planting Dates and N Fertilization

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Open Journal of Applied Sciences 2024年第3期14卷 707-720页

作者： Julius Yirzagla Peter Quandahor Iddrisu Yahaya Olivia Aguriboba Akanbelum Listowell Aditwin Akologo john Bokaligidi Lambon Abdul-Wahab M. Imoro Kwadwo Gyasi Santo cSIR-SARI Nyankpala Ghana St Vincent college of Education Yendi Ghana Gbewaah college of Education Pusiga-Bawku Ghana cSIR-Head Office Accra Ghana c.K. Tedam University of Technology and Applied Sciences Navrongo Ghana University of Energy and Natural Resources Sunyani Ghana

Kenaf (Hibiscus cannabinus L) consists of various beneficial components like stalks, seeds, leaves, fibers, oils, proteins, allelopathic chemicals, and fiber strands, among other things. Despite the numerous uses of the crop, there is little or no information on optimum agronomic practices such as planting date and N fertilization of the crop in the Upper East Region (UER) of Ghana where the crop is widely cultivated by smallholder farmers. Field experiments were therefore carried out in 2020 and repeated during the 2021 cropping season in the study area. The objective of the study was to determine appropriate planting date and N fertilization for increased kenaf productivity. In each year, the treatments consisted of 3 × 5 factorial combinations of three planting dates (1st July, 7th July and 14th July) and five levels of N (0, 20, 40, 60 and 80 kg/ha) replicated three times. The design of the experiment was a split-plot with the N fertilizer as the main plot and the planting date assigned to sub plot. The results showed that, planting kenaf in early (1st) July or N fertilization at the rate of 60 kg/ha increased plant density, stem height, stem diameter, dry bast and core yields in both cropping seasons.

关键词： Growth Fibres Bast Yield core Yield

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A cAScADIc MULTIGRID ALGORITHM FOR cOMPUTING THE FIEDLER VEcTOR OF GRAPH LAPLAcIANS

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Journal of computational Mathematics 2015年第2期33卷 209-226页

作者： john c. Urschel Jinchao Xu Xiaozhe Hu Ludmil T. Zikatanov Department of Mathematics Penn State University Pennsylvania USA Department of Mathematics Tufts University Medford MA 02155 Department of Mathematics Penn State University Pennsylvania USA Institute of Mathematics and Informatics Bulgarian Academy of Sciences Sofia Bulgaria

In this paper, we develop a cascadic multigrid algorithm for fast computation of the Fiedler vector of a graph Laplacian, namely, the eigenvector corresponding to the second smallest eigenvalne. This vector has been found to have applications in fields such as graph partitioning and graph drawing. The algorithm is a purely algebraic approach based on a heavy edge coarsening scheme and pointwise smoothing for refinement. To gain theoretical insight, we also consider the related cascadic multigrid method in the geometric setting for elliptic eigenvalue problems and show its uniform convergence under certain assumptions. Numerical tests are presented for computing the Fiedler vector of several practical graphs, and numerical results show the efficiency and optimality of our proposed cascadic multigrid algorithm.

关键词： Graph Laplacian cascadic Multigrid Fiedler vector Elliptic eigenvalue prob-lems.

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Polarization variability arising from clumps in the winds of Wolf-Rayet stars

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chinese Journal of Astronomy and Astrophysics 2009年第5期9卷 558-576页

作者： Qing-Kang Li Joseph E cassinelli john c. Brown Richard Ignace Department of Astronomy Beijing Normal University Beijing 100875 China Department of Astronomy University of Wisconsin-Madison 53711 USA Department of Physics and Astronomy University of Glasgow Glasgow G12 8QQ Scotland UK Department of Physics and Astronomy Eastern Tennessee State University USA

Polarimetric and photometric variability of Wolf-Rayet （WR） stars as caused by clumps in the winds is revisited. In our model, which is improved from Li et al., radial expansion of the thickness is accounted for, but we retain dependence on the β velocity law and stellar occultation effects. We again search for parameters that can yield results consistent with observations in regards to the mean polarization p, the ratio R = σp/σphot of polarimetric to photometric variability and the volume filling factor fV. clump generation and spatial distribution are randomized by the Monte carlo method so as to produce clumps which are, in the mean, distributed uniformly in space and have time intervals that obey a Gaussian distribution. The generated clumps move radially outward with a velocity law determined by a β index, and the angular size of clumps is assumed to be fixed. By fitting the observed σp/σphot and the volume filling factor fv, clump velocity taw index β （- 2） and clump ejection rate .N （- 1） are inferred, and are found to be well constrained. In addition, the subpeak features of broad emission lines seem to support the clump ejection rate. Meanwhile, the fraction of total mass loss rate that is contained in clumps is obtained by fitting observed polarization. We conclude that this picture of the clumps＇ properties produces a valuable diagnostic of WR wind structure.

关键词： stars mass loss -- stars Wolf-Rayet -- stars winds, outflows

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Investigation of Terminal Group Effect on Electron Transport Through Open Molecular Structures

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communications in Theoretical Physics 2013年第5期59卷 649-654页

作者： c. Preferencial Kala P. Aruna Priya D. john Thiruvadigal Department of Physics and Nano Technology Center for Materials Science and NanodevicesSRM University Department of Electronics and communication Engineering Center for Materials Science and NanodevicesSRM University

The effect of terminal groups on the electron transport through metal-molecule-metal system has been investigated using nonequilibrium Green’s function (NEGF) formalism combined with extended Huckel theory (EHT). Au-molecule-Au junctions are constructed with borazine and BcN unit structure as core molecule and sulphur (S), oxygen (O), selenium (Se) and cyano-group (cN) as terminal groups. The electron transport characteristics of the borazine and BcN molecular systems are analyzed through the transmission spectra and the current-voltage curve. The results demonstrate that the terminal groups modifying the transport behaviors of these systems in a controlled way. Our result shows that, selenium is the best linker to couple borazine to Au electrode and oxygen is the best one to couple BcN to Au electrode. Furthermore, the results of borazine systems are compared with that of BcN molecular systems and are discussed. Simulation results show that the conductance through BcN molecular systems is four times larger than the borazine molecular systems. Negative differential resistance behavior is observed with borazine-cN system and the saturation feature appears in BcN systems.

关键词： molecular electronics extended Huckel theory (EHT) nonequilibrium Green’s function (NEGF) quantum transport

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Lipopolysaccharide immune stimulation but not β-mannanase supplementation affects maintenance energy requirements in young weaned pigs

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Journal of Animal Science and Biotechnology 2018年第4期9卷 901-916页

作者： Nichole F.Huntley c.Martin Nyachoti john F.Patience Department of Animal Science Iowa State University Department of Animal Science University of Manitoba

Background: Pathogen or diet-induced immune activation can partition energy and nutrients away from growth,but clear relationships between immune responses and the direction and magnitude of energy partitioning responses have yet to be elucidated. The objectives were to determine how β-mannanase supplementation and lipopolysaccharide(LPS) immune stimulation affect maintenance energy requirements(MEm) and to characterize immune parameters, digestibility, growth performance, and energy ***: In a randomized complete block design, 30 young weaned pigs were assigned to either the control treatment(cON; basal corn, soybean meal and soybean hul s diet), the enzyme treatment(ENZ; basal diet + 0.056% β-mannanase),or the immune system stimulation treatment(ISS; basal diet + 0.056% β-mannanase, chal enged with repeated increasing doses of Escherichia coli LPS). The experiment consisted of a 10-d adaptation period, 5-d digestibility and nitrogen balance measurement, 22 h of heat production(HP) measurements, and 12 h of fasting HP measurements in indirect calorimetry chambers. The immune chal enge consisted of 4 injections of either LPS(ISS) or sterile saline(cON and ENZ), one every48 h beginning on d 10. Blood was collected pre-and post-challenge for complete blood counts with differential,haptoglobin and mannan binding lectin, 12 cytokines, and glucose and insulin ***: Beta-mannanase supplementation did not affect immune status, nutrient digestibility, growth performance,energy balance, or MEm. The ISS treatment induced fever, elevated proinflammatory cytokines and decreased leukocyte concentrations(P ct nitrogen balance or nutrient digestibility(P > 0.10),but increased total HP(21%) and MEm(23%), resulting in decreased lipid deposition(-30%) and average daily gain(-18%)(P conclusions: This experiment provides novel data on β-mannanase supplementation effects on immune parameters and energy balance i

关键词： Acute phase proteins β-Mannan cytokines Digestibility Feed induced immune response Heat production Inflammation Lipopolysaccharide Nitrogen balance Swine

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XFEL data analysis for structural biology

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Frontiers of Electrical and Electronic Engineering in china 2016年第3期4卷 159-176页

作者： Haiguang Liu john c. H. Spence complex Systems Division Beiiin.q Computational Science Research Center Beijing 100193 China Physics Department Arizona State University Tempe AZ 85287 USA

X-ray Free Electron Lasers （XFELs） have advanced research in structure biology, by exploiting their ultra-short and bright X-ray pulses. The resulting ＂diffraction before destruction＂ experimental approach allows data collection to outrun radiation damage, a crucial factor that has often limited resolution in the structure determination of biological molecules. Since the first hard X-ray laser （the Linac coherent Light Source （LcLS） at SLAc） commenced operation in 2009, serial femtosecond crystallography （SFX） has rapidly matured into a method for the structural analysis of nano- and micro-crystals. At the same time, single particle structure determination by coherent diffractive imaging, with one particle （such as a virus） per shot, has been under intense development. In this review we describe these applications of X-ray lasers in structural biology, with a focus particularly on aspects of data analysis for the computational research community. We summarize the key problems in data analysis and model reconstruction, and provide perspectives on future research using computational methods.

关键词： X-my Free Electron Laser single particle scattering serial crystallography phase retrieval orientationrecovery

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