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91.
Marcelo M. Cavalcanti Ammar Khemmoudj Mohamed Medjden 《Journal of Mathematical Analysis and Applications》2007,328(2):900-930
In this paper, the uniform stabilization of the Cauchy-Ventcel problem with variable coefficients is considered, and the uniform energy decay rate for the problem is established by Riemannian geometry methods. 相似文献
92.
We evaluate the inter-channel crosstalk in a semiconductor optical amplifier when injecting a high optical power continuous wave, as assist light, inside its active region around the gain transparency wavelength. In this work, the crosstalk of signal1 (1535 nm) modulated at 2.5 Gb/s, has been induced by signal2 (1560 nm) modulated at 2.5 Gb/s as well and having an optical input power of −7.5 dBm to simulate a multi-channel transmission. By measuring the bit error rate of signal1, we show that the pattern penalty induced by the cross-gain modulation can be significantly reduced or even in certain conditions suppressed by the assist light. 相似文献
93.
Ammar R Baringer P Coppage D Davis R Haas P Kelly M Kwak N Lam H Ro S Kubota Y Nelson JK Perticone D Poling R Schrenk S Crawford G Fulton R Jensen T Johnson D Kagan H Kass R Malchow R Morrow F Whitmore J Wilson P Bortoletto D Brown DN Dominick J McIlwain RL Miller DH Modesitt M Ng CR Schaffner SF Shibata EI Shipsey IP Battle M Kroha H Sparks K Thorndike EH Wang C Alam MS Kim IJ Li WC Nemati B Romero V Sun CR Wang P Zoeller MM Goldberg M Haupt T Horwitz N Jain V Kennett R Mestayer MD Moneti GC 《Physical review D: Particles and fields》1991,44(11):3383-3393
94.
Ammar R Baringer P Coppage D Davis R Kelly M Kwak N Lam H Ro S Kubota Y Lattery M Nelson JK Perticone D Poling R Schrenk S Wang R Alam MS Kim IJ Nemati B Romero V Sun CR Wang P Zoeller MM Crawford G Fulton R Gan KK Kagan H Kass R Lee J Malchow R Morrow F Sung MK Whitmore J Wilson P Butler F Fu X Kalbfleisch G Lambrecht M Skubic P Snow J Bortoletto D Brown DN Dominick J McIlwain RL Miller DH Modesitt M Shibata EI Schaffner SF Shipsey IP Battle M Ernst J Kroha H Roberts S Sparks K Thorndike EH 《Physical review D: Particles and fields》1992,45(11):3976-3985
95.
Muhammad Akmal Kamarudin Ammar A. Khan Suhana Mohd Said Malik M. Qasim Timothy D. Wilkinson 《Liquid crystals》2018,45(1):112-121
The doping of polymer electrolytes (PEs) with liquid crystal (LC) materials has been shown to improve the performance of dye-sensitised solar cells (DSSCs). This is achieved by promoting ionic conduction and increasing optical path length through multiple-light scattering within the photovoltaic devices. In LCs, it is well known that the length of the alkyl chain plays an important role since the LC morphology and mesophase stabilisation depend strongly on the alkyl group. In this work, liquid crystal-polymer composite electrolytes (LC-PEs) are prepared using nematic LCs with different alkyl chain lengths. The morphology of the LC-PEs is investigated and correlated with their electrical properties. Subsequently, DSSCs are prepared using the LC-PEs as a direct example of its application. It is shown that increasing the alkyl chain length of the LCs reduces the efficiency of the solar devices. The longer alkyl chains are speculated to intertwine, thus trapping the mobile ions and reducing the bulk ionic conductivity. For the same reason, longer alkyl chain LCs are thought to be unable to passivate the TiO2 surface through the adsorption of cyanobiphenyl groups and hence the higher probability of back recombination reaction between the electrons in TiO2 and PE. 相似文献
96.
In this study, combined technique of solid-phase extraction based on multi-walled carbon nanotubes with bio-coacervation extraction (SPE-MWCNT-BCAE) has been developed as a new sample preparation method for the determination of atrazine from water samples. The proposed method involves two steps: analyte enrichment on the solid sorbent and subsequently elution of the analyte by an appropriate solvent. Multi-walled carbon nanotubes (MWCNTs) were used as the sorbent. They have high specific surface area, nano-scale structure and high diffusion rate. The second step is based on the use of bioaggregates for analyte re-enrichment, which consists of biosurfactants and ionic liquid. This method follows the principles of green chemistry. Parameters affecting the extraction efficiency were optimized. Under optimum conditions, the enrichment factor was 176. The linear dynamic range (LDR) and limit of detection (LOD) were 2–100 µg L?1 and 0.66 µg L?1, respectively. The relative standard deviation (RSD) for six replicate measurements was 3.8%. The method was applied to the determination of ultratrace levels of atrazine in environmental water samples with satisfactory results. 相似文献
97.
Abdelhafid Jouini Abdelmadjid Maali Mustapha Benssalah Ammar Mesloub Genevieve Baudoin Mhamed Hamadouche 《International Journal of Communication Systems》2021,34(1)
In this paper, a new robust auto‐adaptive approach for pseudo‐noise (PN) code acquisition is proposed. It is applied to the generalized multi‐carrier direct‐sequence code‐division multiple‐access (MC DS‐CDMA) systems communicating over frequency‐selective multipath Rayleigh fading channels. This new approach is based on the constant false alarm rate (CFAR) detection algorithm, referred here as automatic selection partial sum ordered statistics (ASPSOS)‐CFAR. The proposed approach does not require any prior information about the background environment and uses maximum likelihood estimation (MLE) method to detect the interfering signals group in the ranked cells for the full reference window. Once this group is identified and censored, the remaining smaller ranked cells are combined to form an estimate of the background noise level to compute the adaptive threshold. Through simulations, the performance of the proposed detector is analyzed and compared with traditional CFAR detectors based on fixed or automatic censoring algorithms. The obtained results show that the proposed detector eliminates the drawbacks of the previously related detectors and offers a robust detection performance to enhance the acquisition process in heterogeneous background environments. 相似文献
98.
Alexander J Artuso M Bebek C Berkelman K Browder T Cassel DG Cheu E Coffman DM Crawford G DeWire JW Drell PS Ehrlich R Galik RS Gittelman B Gray SW Halling AM Hartill DL Heltsley BK Kandaswamy J Katayama N Kreinick DL Lewis JD Ludwig GS Mistry NB Mueller J Nandi S Nordberg E O'Grady C Peterson D Pisharody M Riley D Sapper M Selen M Silverman A Stone S Worden H Worris M Sadoff AJ Avery P Besson D Garren L Yelton J Bowcock T Kinoshita K Pipkin FM Procario M Wilson R Wolinski J Xiao D Zhu Y 《Physical review letters》1990,65(13):1531-1534
99.
Bowcock T Kinoshita K Pipkin FM Procario M Wilson R Wolinski J Xiao D Ammar R Baringer P Coppage D Haas P Lam H Jawahery A Park CH Kubota Y Nelson JK Perticone D Poling R Chen W Dominick J McIlwain RL Miller DH Ng CR Schaffner SF Shibata EI Yao W Sparks K Thorndike EH Alam MS Kim IJ Li WC Lou XC Sun CR Fulton R Hempstead M Jensen T Johnson DR Kagan H Kass R Morrow F Whitmore J Bortoletto D Goldberg M Horwitz N Mestayer MD Moneti GC Sharma V Shipsey IP Skwarnicki T Csorna SE Letson T Alexander J 《Physical review D: Particles and fields》1990,41(3):805-808
100.
1,3-Diphenyl-5-imino-2-imidazolidinone-4-thione (II) was treated with diazomethanes to give (III-V). Interaction of (II) with amino compounds furnished the corresponding 4-substituted imino derivatives (VIa-m). Imidazoquinoxaline derivatives (VIIIb, c) were obtained through interaction of (II) with o-phenylenediamines. Condensation of (II) with hydrazines afforded the hydrazones (IX, Xa, b). Semicarbazone and thiosemicarbazone derivatives (XIIa-d) were prepared from the reaction of (IX) with isocyanates and isothiocyanates. Again (II) was allowed to react with n-butylmagnesium bromide and HgCl2 to give (XIII) and (XIV) respectively. 相似文献