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Journal of Natural Gas Chemistry 2006年第1期15卷 1-10页

作者： John P. Collins Joep J. H. M. Font Freide Barry Nay bp Exploration America Inc. bp Exploration Operating Company

Conversion of Fischer-Tropsch wax into high quality synthetic crude or finished transportation fuels such as premium diesel has been studied over the past 15 years within bp. Catalyst screening and selection was carried out in dedicated micro-reactors and pilot plants, whose designs are critical to the performance selection. Variation in catalyst composition and defining the gas to oil feed ratios with the operating temperature are a few of the parameters studied. Product selection and maximizing diesel yield combined with stability （catalyst life） were the ultimate drivers. The selected catalyst was then tested under commercial conditions in a dedicated 300 barrel per day demonstration plant. The products were also tested in engines to assess their combustion characteristics.

关键词： Fischer-Tropsch wax upgrading hydrocracking synthetic crude diesel naphtha engine emission

Plasma Formed in Argon,Acid Nitric and Water Used in Industrial ICP Torches

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Plasma Science and Technology 2012年第8期14卷 683-692页

作者： F.BENDJEBBAR P.ANDRE M.BENBAKKAR D.ROCHETTE S.FLAZI D.VACHER LGEO Oran UniversityBP1505El Mnaouer ORANAlgerie Blaise Pascal University LAEPTBP 10448F-63000 CLERMONT-FERRANDFrance Blaise Pascal University LMVBP 10448F-63000 CLERMONT-FERRANDFrance

Inductively coupled plasmas （ICPs） are used in spectrochemical analyses. The introduction of the sample by means of an aerosol are widely used. The introduction and the total evaporation of the aerosol is required in order to obtain a good repeatability and reproducibility of analyses. To check whether the vaporization of the aerosol droplets inside the plasma is completed, a solution could be used to compare the experimental results of the emission spectral lines with theoretical results. An accurate calculation code to obtain monatomic spectral lines intensities is therefore required, which is the purpose of the present paper. The mixtures of argon, water and nitric acid are widely used in spectrochemical analyses with ICPs. With these mixtures, we calculate the composition, thermodynamic functions and monatomic spectral lines intensities of the plasma at thermodynamic equilibrium and at atmospheric pressure. To obtain a self sufficient paper and also to allow other researchers to compare their results, all required data and a robust accurate algorithm, which is simple and easy to compute, are given.

关键词： inductively coupled plasmas argon plasma monatomic spectral lines ther-modynamic properties thermal plasma

Arabic Word Recognition by Classifiers and Context

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Journal of Computer Science & Technology 2005年第3期20卷 402-410页

作者： NadirFarah LabibaSouici MokhtarSellami ComputerScienceDepartment AnnabaUniversityBP12Annaba23000Algeria

Given the number and variety of methods used for handwriting recognition, ithas been shown that there is no single method that can be called the ''best''. In recent years, thecombination of different classifiers and the use of contextual information have become major areasof interest in improving recognition results. This paper addresses a case study on the combinationof multiple classifiers and the integration of syntactic level information for the recognition ofhandwritten Arabic literal amounts. To the best of our knowledge, this is the first time either ofthese methods has been applied to Arabic word recognition. Using three individual classifiers withhigh level global features, we performed word recognition experiments. A parallel combination methodwas tested for all possible configuration cases of the three chosen classifiers. A syntacticanalyzer makes a final decision on the candidate words generated by the best configuration *** effectiveness of contextual knowledge integration in our application is Arabicconfirmed by theobtained results.

关键词： handwriting recognition multiclassifier systems contextual knowledge literal amounts

Numerical Methodology for Metal Forming Processes Using Elastoplastic Model with Damage Occurrence

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Journal of Materials Science & Technology 2006年第2期22卷 279-283页

作者： A.Cherouat H.Borouchaki K.Saanouni P.Laug LASMIS-CNRS FRE 2719 University of Technology of Troyes BP 2060-10010TroyesFrance LASMIS-CNRS FRE 2719 University of Technology of Troyes BP 2060-10010Troyes France LASMIS-CNRS FRE 2719 University of Technology of Troyes BP 2060-10010 Troyes France INRIA Rocquencourt bp 105-78153 Le ChesnayFrance

Ductile damage often occurs during metal forming processes due to the large thermo-elasto （visco） plastic flow Iocalisation. This paper presents a numerical methodology, which aims to virtually improve any metal forming processes. The methodology is based on elastoplastic constitutive equations accounting for nonlinear mixed isotropic and kinematic hardening strongly coupled with isotropic ductile damage. An adaptive remeshing scheme based on geometrical and physical error estimates including a kill element procedure is used. Some numerical results are presented to show the capability of the model to predict the damage initiation and growth during the metal forming processes.

关键词： Finite elastoplasticity Ductile damage Error estimation Adaptive remeshing Metal forming processes

Large magnetocaloric effect in Er_(2)O_(3) compounds at cryogenic temperature

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Journal of Rare Earths 2021年第10期39卷 1232-1237,I0003页

作者： A.Elouafi S.Derkaoui R.Moubah A.Tizliouine A.Charkaoui H.Lassria LPMMAT Faculty of Science Ain ChockBP 5366Maarif20100CasablancaMorocco LMPC1 Ecole Superieure de TechnologieBP 8012OuasisCasablancaMorocco

We investigated the magnetocaloric effect in commercial Er_(2)O_(3) powders which presents almost no hysteresis losses at low *** a magnetic field change of 5 T,it displays large magnetic entropy change(-ΔSM)max of 15.02 J/(kg·K)and a refrigerant capacity(RC)of 311 J/K at Neel temperature TN=3.32 *** magnetic transition was found to be of a *** maximum values of adiabatic temperature change(ΔTad)max reach 0.70 K for a magnetic field change of 1 *** large value,of(-ASM)max as well as no hysteresis loss,makes Er_(2)O_(3) a promising material as a magnetic refrigerant at low temperature.

关键词： Magnetic refrigeration Hysteresis losses Second-order magnetic transition Magnetocaloric effect Rare earths

Using Timed Petri Net to Model Instruction-Level Loop Scheduling with Resource Constraints

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Journal of Computer Science & Technology 1994年第2期9卷 128-143页

作者：王剑苏伯珙 INRIARocquencourt DomainedeVoluceauBP10578158LeChesnayCedexFrance

This paper uses timed Petri net to model and analyze the problem of instructionlevel loop scheduling with resource constraints, which has been proven to be an NP complete problem. First, we present a new timed Petri net model to integrate functional unit allocation, register allocation and spilling ilno a unified theoretical *** we develop a state subgraph, called Register Allocation Solution Graph, which can effectively describe the major behavior of our new model. The maill property of this state subgraph is that the number of all its nodes is polynomial. Finally we present and prove that the optimum loop schedules can be found with polynomial computation complexity, for almost all practical loop prograrns. Our work lightens a new idea of finding the optimum loop schedules.

关键词： Instruction level parallelism loop scheduling register allocation and spilling Petri net timed Petri net

On the effectiveness of dry drainage in soil salinity control

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Science China(Technological Sciences) 2009年第11期52卷 3328-3334页

作者： VINCENT Bernard BOUARFA Sami VIDAL Alain Cemagref BP 44 92163 Antony Cedex France Cemagref 361 rue Jean-Franois Breton BP 5095 34196 Montpellier Cedex 5 France

Dry drainage is thought to be a potential approach to control soil salinity. This study took the Hetao Irrigation District as an example and evaluated the effectiveness of dry drainage by using remote sensing, a conceptual model and a field experiment. Archived remote sensing images from 1973―2006 were used to delineate the temporal and spatial change of soil salinity. The conceptual water and salt balance model was used to evaluate the role of dry drainage in removing excess salt from the irrigated land. The field experiment was performed to get field validation and give more accurate estimation. The results show that dry drainage did contribute to remove excess salt from the irrigated land and succeed in controlling soil salinity in the Hetao Irrigation District. It can be taken as an alternative approach in (semi-)arid area where artificial drainage is not applicable.

关键词： soil salinity dry drainage remote sensing conceptual model field experiment

Picard Dimension of Signed Radial Kato Measures

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Acta Mathematica Sinica,English Series 2009年第11期25卷 1805-1818页

作者： Allami BENYAICHE Aiad ELGOURARI IBN TOFAIL University Faculty of Science Kenitra BP: 133 MOROCCO

The Picard dimension dimμ of a signed local Kato measure μ on the punctured unit ball in R^d, d ≥ 2, is the cardinal number of the set of extremal rays of the convex cone of all continuous solutions u ≥ 0 of the time-independent SchrSdinger equation Δu -- uμ = 0 on the punctured ball 0 〈｜｜x｜｜〈 1, with vanishing boundary values on the sphere ｜｜x｜｜ = 1. Using potential theory associated with the Schrodinger operator we prove, in this paper, that the dimμ for a signed radial Kato measure is 0, 1 or ＋∞. In particular, we obtain the Picard dimension of locally Holder continuous functions P proved by Nakai and Tada by other methods.

关键词： Schrodinger equation Kato measure Picard dimension

Depth factors for undrained bearing capacity of circular footing by numerical approach

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第4期9卷 761-766页

作者： Sadok Benmebarek Insaf Saifi Naima Benmebarek NMISSI Laboratory Biskra University BP 145 Biskra 07000 Algeria

The undrained vertical bearing capacity of embedded foundation has been extensively studied using analytical and numerical *** comparing the results of a circular embedded foundation in the literature,a significant difference between the bearing capacity factors and depth factors is *** on the previous research findings,numerical computations using FLAC code are carried out in this study to evaluate the undrained bearing capacity of circular foundations with embedment ratios up to five for different base and side foundation roughness *** the foundation base,the roughness of the foundation side has a significant effect on the bearing *** comparison of the present results with numerical studies available in the literature shows that the discrepancy is related to the procedures used to simulate the foundation side interface conditions and to the estimation of the bearing capacity.

关键词： Circular footing Bearing capacity Embedment depth Numerical modeling Plasticity

Robust SVM-direct torque control of induction motor based on sliding mode controller and sliding mode observer

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Frontiers in Energy 2020年第4期14卷 836-849页

作者： Abdelkarim AMMAR Amor BOUREK Abdelhamid BENAKCHA LGEB Laboratory Department of Electrical EngineeringUniversity of BiskraBiskraBP 145Algeria

This paper proposes a design of control and estimation strategy for induction motor based on the variable structure *** describes a coupling of sliding mode direct torque control(DTC)with sliding mode flux and speed *** algorithm uses direct torque control basics and the sliding mode approach.A robust electromagnetic torque and flux controllers are designed to overcome the conventional SVM-DTC draw・backs and to ensure fast response and full reference tracking with desired dynamic behavior and low ripple *** sliding mode controller is used to generate reference voltages in stationary frame and give them to the controlled motor after modulation by a space vector modulation(SVM)*** second aim of this paper is to design a sliding mode speed/flux observer which can improve the control performances by using a sensorless algorithm to get an accurate estimation,and consequently,increase the reliability of the system and decrease the cost of using *** effectiveness of the whole composed control algorithm is investigated in different robustness tests with simulation using Matlab/Simulink and verified by real time experimental implementation based on dS pace 1104 board.

关键词： induction motor direct torque control(DTC) space vector modulation(SVM) sliding mode control(SMC) sliding mode observer(SMO) dS1104