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Effects of pH on rheological characteristics and stability of petroleum coke water slurry

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Petroleum science 2016年第4期13卷 782-787页

作者： Fu-Yan Gao Eric-j.Hu Ningbo Institute of Technology Zhejiang University school of Mechanical Engineering University of Adelaide

In this study, the effects of pH on slurrying properties of petroleum coke water slurry（PCWs） were investigated. The slurrying concentration, rheological characteristics and stability of PCWs were studied with four different types of additives at pH varying from 5 to *** results showed that the slurrying concentration, rheological characteristics and stability of PCWs all increased at first and then decreased with increasing pH from 5 to 11,and a pH of around 9 was found to be the most favorable acid–alkali environment to all these three slurrying properties. It was also indicated that only in a moderate alkaline environment can the additives be active enough to react with particle surfaces sufficiently to obtain good slurrying concentration and form a stable three-dimensional network structure, which can support strong pseudoplastic characteristics and good stability. An acid environment was a very unfavorable factor to the slurrying properties of PCWs.

关键词： Petroleum coke Petroleum coke water slurry pH slurrying concentration Rheological characteristics stability

AGWO-CNN Classification for Computer-Assisted Diagnosis of Brain Tumors

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Computers, Materials & Continua 2022年第4期71卷 171-182页

作者： T.jeslin j.Arul Linsely Department of Electronics and Communication Engineering Universal College of Engineering and TechnologyVallioor627117India Department of Electrical and Electronics Engineering Noorul Islam Centre for Higher EducationKumarakovil629180India

Brain cancer is the premier reason for cancer deaths all over the *** diagnosis of brain cancer at an initial stage is mediocre,as the radiologist is *** experiments have been conducted and demonstrated clearly that the algorithms for nodule segmentation are ***,the research has consolidated incremental clustering focused on superpixel segmentation as an appropriate optimization approach for the accurate segmentation of pulmonary *** key aim of the research is to refine brain CT images to accurately distinguish tumors and the segmentation of small-scale anomalous nodules in the brain *** the beginning stage,an anisotropic diffusion filters(ADF)method with un-sharp intensification masking is utilized to eliminate the noise discernment in *** the following stage,within the improved nodule image sequence,a superpixel segmentation Based Iterative Clustering(ssBIC)algorithm is proposed for irregular brain tissue ***,the brain nodule samples are captured using deep learning methods:Advanced Grey Wolf Optimization(AGWO)with ONN(AGWO-ONN)and Advanced GWO with CNN-based(AGWOCNN).The proposed technique indicates that the sensitivity is increased and the calculation time is ***,the proposed methodology manifests that the advanced Computer-Assisted Diagnosis(CAD)system has outstanding potential for automatic brain tumor *** average segmentation time of the nodule slice order is 1.06s,and 97%of AGWO-ONN and 97.6%of AGWO-CNN achieve the best classification reliability.

关键词： Advanced GWO with ONN(AGWO-ONN) Advanced GWO with CNN(AGWO-CNN) brain cancer superpixel segmentation based iterative clustering(ssBIC)algorithm

To forage or hide？ Threat-sensitive foraging behaviour in wild, non-reproductive passerine birds

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Current Zoology 2014年第6期60卷 719-728页

作者： shaun TURNEY jean-Guy j. GODIN Department of Biology Carleton University Ottawa ON K1 S 5B6 Canada Department of Biology McGill University Montreal QC H3A 1B 1 Canada

Because antipredator behaviours are costly, the threat-sensitive predator avoidance hypothesis predicts that individual animals should express predator-avoidance behaviour proportionally to the perceived threat posed by the predator. Here, we experimentally tested this hypothesis by providing wild passerine birds supplemental food （on a raised feeding platform） at either 1 or 4 m from the edge of forest cover （potential refuge）, in either the presence or absence of a nearby simulated predation threat （a sharp-shinned hawk Accipiter striatus model）. Compared with the control treatment, we observed proportionally fewer bird visits to the food patch, and the birds took longer to re-emerge from forest refuge and return to feed at the food patch, after the hawk presentation than before it. The observed threat-sensitive latency-to-return response was stronger when the food patch was further away from the nearest refuge. Overall, our results are consistent with the predictions of the threat-sensitive predator avoidance hypothesis in that wild passerine birds （primarily black-capped chickadees Poecile atricapillus） exhibited more intense antipre- dator behavioural responses with increasing level of apparent threat. The birds were thus sensitive to their local perceived threat of predation and traded-off safety from predation （by refuging） and foraging gains in open habitat in a graded, threat-sensitive manner [Current Zoology 60 （6）： 719-728, 2014].

关键词： Foraging Predation risk Threat sensitivity Risk taking Distance-to-refuge Birds

Harmonic aspects of wind power integration

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journal of Modern Power systems and Clean Energy 2013年第1期1卷 14-21页

作者： Math H.j.BOLLEN Kai YANG Electric Power Engineering Lulea University of Technology93187 SkellefteaSweden

This paper discusses a number of ways in which wind power installations can impact the harmonic levels in the power *** turbines are an additional source of harmonic emission,especially when it concerns"non-characteristic harmonics."Parallel resonances can amplify the emission from individual turbines.A mathematical model is developed to quantify this *** resonances can result in high currents,driven by the background voltage distortion in the transmission grid,flowing into thewind *** of the transmission grid will increase lower order harmonics but reduce higher order harmonics.

关键词： Power quality Power system harmonics Wind power

Inhibitory effects of interferons on pancreatic stellate cell activation

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World journal of Gastroenterology 2006年第6期12卷 896-901页

作者： jan-TidoBaumert Giselasparmann j rgEmmrich stefanLiebe Robertjaster Department of Me-dicine Division of GastroenterologyMedical FacultyUniversity of RostockE-Heydemann-Str.618057 Rostock Germany

AIM： To analyze and to compare the effects of interferon （IFN）-α, IFN-β, and IFN-γ on pancreatic stellate cell （PsC） activation/n vitro and to elucidate the molecular basis of IFN action. METHODs： PsCs were isolated from rat＇s pancreatic tissue, cultured and stimulated with recombinant rat IFNs. Cell proliferation and collagen synthesis were assessed by measuring the incorporation of 5-bromo-2＇ -deoxyuridine （BrdU） into DNA and [^3H]-proline into acetic acid-soluble proteins, respectively. Apoptotic ceils were determined by FACs analysis （sub-G1 peak method）. Exhibition of the myofibroblastic PsC phenotype was monitored by immunoblot analysis of （α-smooth muscle actin （α-sMA） expression. To assess the activation of signal transducer and activator of transcription （sTAT）, Western blots using phospho- sTAT-specific antibodies were performed. In studies on sTAT1 function, expression of the protein was inhibited by siRNA. REsULTs： IFN-β and IFN-γ, but not IFN-α significantly diminished PsC proliferation and collagen synthesis. IFN-γ, was the only IFN that clearly inhibited α-sMA expression. Under the experimental conditions used, no enhanced rate of apoptotic cell death was observed in response to any IFN treatment. IFN-β and IFN-γ, induced a strong increase of sTAT1 and sTAT3 tyrosine phosphorylation, while the effect of IFN-α was much weaker. Inhibition of sTAT1 expression with siRNA was associated with a significantly reduced growth-inhibitory effect of IFN-γ. CONCLUsION： IFN-β and particularly IFN-γ, display inhibitory effects on PsC activation in vitro and should be tested regarding their in vitro efficiency. Growth inhibition by IFN-γ action requires sTAT1.

关键词： Interferons Pancreatic stellate cell Apoptosis

ON THE UNIQUENEss OF THE WEAK sOLUTIONs OF A QUAsILINEAR HYPERBOLIC sYsTEM WITH A sINGULAR sOURCE TERM

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Chinese Annals of Mathematics,series B 2002年第3期23卷 317-324页

作者： j.P.DIAs M.FIGUEIRA Dedicated to the memory of jacques-Louis Lions Dedicated to the memory of Jacques-Louis Lions

This paper is a continuation of the authors' previous paper [1]. In this paper the authors prove, assuming additional conditions on the initial data, some results about the existence and uniqueness of the entropy weak... 详细信息

关键词： Cauchy problem Weak solution Quasilinear hyperbolic system

Determination of Time-Dependent Coefficients for a Weakly Degenerate Heat Equation

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Computer Modeling in Engineering & sciences 2020年第5期123卷 475-494页

作者： M.j.Huntul D.Lesnic Department of Mathematics Faculty of ScienceJazan UniversityJazanSaudi Arabia Department of Applied Mathematics University of LeedsLeedsLS29JTUK

In this paper,we consider solving numerically for the first time inverse problems of determining the time-dependent thermal diffusivity coefficient for a weakly degenerate heat equation,which vanishes at the initial moment of time,and/or the convection coefficient along with the temperature for a one-dimensional parabolic equation,from some additional information about the process(the so-called over-determination conditions).Although uniquely solvable these inverse problems are still ill-posed since small changes in the input data can result in enormous changes in the output *** finite difference method with the Crank-Nicolson scheme combined with the nonlinear Tikhonov regularization are *** resulting minimization problem is computationally solved using the MATLAB toolbox routine *** both exact and noisy input data,accurate and stable numerical results are obtained.

关键词： Inverse problem weakly degenerate heat equation Tikhonov’s regularization

A statistical study of the interdependence of solar wind parameters

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Chinese journal of Astronomy and Astrophysics 2009年第4期9卷 485-493页

作者： shollykutty john P. j. Kurian Department of Physics St Joseph’s CollegeAlappuzha.Kerala-688012 India Physics Research Centre St.Berchmans’ CollegeChanganacherry Kerala-686101 India

Correlation analysis of solar wind parameters, namely solar wind velocity, proton density, proton temperature and mean interplanetary magnetic field （IMF） from the ACE spacecraft data near Earth, was done. To our best knowledge, this study is a novel one since we consider here only the parameters inside the solar wind, including the mean IMF and, hence, the solar wind is a self consistent system. We have proposed a Multiple Linear Regression （MLR） model for the prediction of the response variable （solar wind velocity） using the parameters proton density, proton temperature and mean IMF measured as daily averages. About 60% of the observed value can be predicted using this model. It is shown that, in general, the correlation between solar wind parameters is significant. A deviation from the prediction at the solar maximum is interpreted. These results are verified by a graphical method.

关键词： solar wind-statistical model-correlation-solar wind parameters

Forecasting the development of boreal paludified forests in response to climate change: a case study using Ontario ecosite classification

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Forest Ecosystems 2015年第1期2卷 45-55页

作者： Benoit Lafleur Nicole j Fenton Yves Bergeron Institut de recherche sur les forêts Université du Québec en Abitibi-Témiscamingue 445 boul. de l’Université Rouyn-Noranda QC J9X 5E4 Canada Centre d’étude de la forêt Université du Québec à Montréal 141 Avenue du Président-Kennedy Montréal QC H2X 1Y4 Canada

Background：successional paludification,a dynamic process that leads to the formation of peatlands,is influenced by climatic factors and site features such as surficial deposits and soil *** boreal regions,projected climate change and corresponding modifications in natural fire regimes are expected to influence the paludification process and forest *** objective of this study was to forecast the development of boreal paludified forests in northeastern North America in relation to climate change and modifications in the natural fire regime for the period 2011–***：A paludification index was built using static（*** deposits and soil texture）and dynamic（*** regime and soil organic layer thickness）stand scale factors available from forest *** index considered the effects of three temperature increase scenarios（i.e.＋1°C,＋3°C and＋6°C）and progressively decreasing fire cycle（from 300 years for 2011–2041,to 200 years for 2071–2100）on peat accumulation rate and soil organic layer（sOL）thickness at the stand level,and paludification at the landscape ***：Our index show that in the context where in the absence of fire the landscape continues to paludify,the negative effect of climate change on peat accumulation resulted in little modification to sOL thickness at the stand level,and no change in the paludification level of the study area between 2011 and ***,including decreasing fire cycle to the index resulted in declines in paludified ***,the index predicts a slight to moderate decrease in the area covered by paludified forests in 2100,with slower rates of ***：slower paludification rates imply greater forest productivity and a greater potential for forest harvest,but also a gradual loss of open paludified stands,which could impact the carbon balance in paludified ***,as the thick sphagnum layer typical of paludified forests may protect soil organic layer from dr

关键词： Boreal forest Canada Carbon sequestration Paludification Peat forests Forest harvest