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101.
Ahmad M. Farag Kamal M. Dawood Hatem A. Abdel‐Aziz Nehal A. Hamdy Issa M. I. Fakhr 《Journal of heterocyclic chemistry》2011,48(2):355-360
Reaction of E‐3‐(N,N‐dimethylamino)‐1‐(3‐methylthiazolo[3,2‐a]benzimidazol‐2‐yl)prop‐2‐en‐1‐one ( 1 ) with some N‐nucleophiles, such as anilines 2a , 2b , 2c , 4‐amino‐N‐pyridin‐2‐yl‐benzenesulfonamide ( 4a ), 4‐amino‐N‐pyrimidin‐2‐yl‐benzenesulfonamide ( 4b ), hydrazine, hydroxylamine, thiourea, and guanidine afforded the corresponding arylaminoprop‐2‐en‐1‐one derivatives 3a , 3b , 3c , 5a , 5b , the pyrazole, isoxazole, pyrimidinethione and aminopyrimidine derivatives 7a , 7b , 9a , and 9b , respectively. The utility of compound 1 , as a versatile building block, for the synthesis of the pyranone 13 , benzo[b]furan 17a , and naphtho[1,2‐b]furan 17b was also explored via its reaction with 2‐benzamidoacetic acid ( 10 ), 1,4‐benzoquinone ( 14a ), and 1,4‐naphthoquinone ( 14b ), respectively. J. Heterocyclic Chem., (2011). 相似文献
102.
Hatem Oueslati Salah Ben Mabrouk Abdelkader Mami 《Mathematical and Computer Modelling of Dynamical Systems: Methods, Tools and Applications in Engineering and Related Sciences》2013,19(2):130-145
The work presented in this article focuses on the analysis and modelling of heat and mass transfers in the tunnel dryer during the drying of agricultural products. The main objective of this work is to establish a global modelling of the studied system based on the bond graph methodology. The pseudo-bond graph methodology was used in modelling the system. Such methodology was very suitable for this thermal process since it allows good management of the nonlinearity present in the system.The thermal performance of the proposed dryer is analysed by solving the various energy balance equations. An application of drying tomatoes was achieved and a fair agreement was observed between predicted and experimental results. 相似文献
103.
Theophilos Maltezopoulos Manuel Mittenzwey Armin Azima Jörn Bödewadt Hatem Dachraoui Marie Rehders Christoph Lechner Michael Schulz Marek Wieland Tim Laarmann Jörg Roßbach Markus Drescher 《Applied physics. B, Lasers and optics》2014,115(1):45-54
Direct seeding with a high-harmonic generation (HHG) source can improve the spectral, temporal, and coherence properties of a free-electron laser (FEL) and shall reduce intensity and arrival-time fluctuations. In the seeding experiment sFLASH at the extreme ultraviolet FEL in Hamburg FLASH, which operates in the self-amplified spontaneous emission mode (SASE), the 21st harmonic of an 800 nm laser is refocused into a dedicated seeding undulator. For seeding, the external light field has to overcome the noise level of SASE; therefore, an efficient coupling between seed pulse and electron bunch is mandatory. Thus, an HHG beam with a proper divergence, width, beam quality, Rayleigh length, pointing stability, single-shot pulse energy, and stability in the 21st harmonic is needed. Here, we present the setup of the HHG source that seeds sFLASH at 38.1 nm, the optimization procedures, and the necessary diagnostics. 相似文献
104.
The false vacuum decay in field theory from a coherently oscillating initial state is studied for φ6 potential. An oscillating bubble solution is obtained. The instantaneous bubble nucleation rate is calculated. 相似文献
105.
This work deals with a reliability assessment of springback problem during the sheet metal forming process. The effects of operative parameters and material properties, blank holder force and plastic prestrain, on springback are investigated. A generic reliability approach was developed to control springback. Subsequently, the Monte Carlo simulation technique in conjunction with the Latin hypercube sampling method was adopted to study the probabilistic springback. Finite element method based on implicit/explicit algorithms was used to model the springback problem. The proposed constitutive law for sheet metal takes into account the adaptation of plastic parameters of the hardening law for each prestrain level considered. Rackwitz-Fiessler algorithm is used to find reliability properties from response surfaces of chosen springback geometrical parameters. The obtained results were analyzed using a multi-state limit reliability functions based on geometry compensations. 相似文献
106.
Tej-Eddine Ghoul Van Tien Nguyen Hatem Zaag 《Annales de l'Institut Henri Poincaré (C) Analyse Non Linéaire》2018,35(6):1577-1630
We consider the following parabolic system whose nonlinearity has no gradient structure: in the whole space , where and . We show the existence of initial data such that the corresponding solution to this system blows up in finite time simultaneously in u and v only at one blowup point a, according to the following asymptotic dynamics: with and . The construction relies on the reduction of the problem to a finite dimensional one and a topological argument based on the index theory to conclude. Two major difficulties arise in the proof: the linearized operator around the profile is not self-adjoint even in the case ; and the fact that the case breaks any symmetry in the problem. In the last section, through a geometrical interpretation of quantities of blowup parameters whose dimension is equal to the dimension of the finite dimensional problem, we are able to show the stability of these blowup behaviors with respect to perturbations in initial data. 相似文献
107.
Hatem Elmarami Hanno Meyer Gudrun Massmann 《Isotopes in environmental and health studies》2017,53(2):184-197
Stable isotopes of hydrogen and oxygen are often used for water balance calculations of lakes. We present an approach combining the lake water balance with an isotope mass balance to constrain the sources and sinks of the water of a small dimictic lake subjected to eutrophication. Meteorological and hydraulic data in combination with measured isotope signatures of the different water compartments enabled to assess the degree of surface water/groundwater interaction and the amount of overland flow into the lake. Groundwater could be excluded as a lake water source, as its water level was always below the lake water level. In the absence of a channelled inflow, precipitation and overland flow were the remaining options, whereby the latter was only active during periods of exceptionally high rainfall. While the groundwater signatures adjacent to the lake showed an influence of lake water, the lake water balance itself indicated that the associated volumetric water loss to groundwater is rather negligible. In the present case, only a combined assessment of hydrological and isotopic data allowed for an accurate characterization of the studied lake and a quantification of its water sources and sinks, highlighting the importance of using more than one methodological approach for such a purpose. 相似文献
108.
This paper proposes solution approaches to the belief linear programming (BLP). The BLP problem is an uncertain linear program where uncertainty is expressed by belief functions. The theory of belief function provides an uncertainty measure that takes into account the ignorance about the occurrence of single states of nature. This is the case of many decision situations as in medical diagnosis, mechanical design optimization and investigation problems. We extend stochastic programming approaches, namely the chance constrained approach and the recourse approach to obtain a certainty equivalent program. A generic solution strategy for the resulting certainty equivalent is presented. 相似文献
109.
Summary: Colloidal particles are largely used in biomedical applications as a solid support, as a carrier, as nanoreactors and as labels for target molecule detection. With the recent development of bionanotechnology, more appropriate colloidal particles should be elaborated. In this direction, new specification are listed in order to develop reactive nanoparticles to be use in microsystems, microfluids and all combined systems in which we can conduct sample preparation, specific capture, purification, concentration and detection in small volume (generally less than 100 µl). Then the aim of this short review is to give to the readers some recent orientations of reactive magnetic latex particles for in vitro bionanotechnology applications. 相似文献
110.
Hatem Hadda Najoua Dridi Sonia Hajri-Gabouj 《4OR: A Quarterly Journal of Operations Research》2010,8(1):87-99
In this paper, we deal with the two-machine flow shop scheduling problem having an unavailability interval on the first machine,
and nonresumable jobs. We first present an enhancement procedure that, once applied to any arbitrary solution, produces a
schedule that is at most equal 2 times the optimal makespan. We then develop an improved heuristic, with a relative worst-case
error of 3/2. 相似文献