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391.
We propose and experimentally realize a new scheme for universal phase-insensitive optical amplification. The presented scheme relies only on linear optics and homodyne detection, thus circumventing the need for nonlinear interaction between a pump field and the signal field. The amplifier demonstrates near optimal quantum noise limited performance for a wide range of amplification factors. 相似文献
392.
Selecting the most suitable registry alternative for shipping fleets has become a highly complex strategic activity for ship owners in the maritime transportation industry, and necessitates consideration of both internal and external environmental factors, which can be both qualitative and quantitative. The aim of this paper is to propose an originally structured multi-methodological approach based on the systematic application of the SWOT analysis, the AHP and the TOPSIS methods to support the critical decision process on shipping registry selection under multiple criteria. In the proposed approach, the SWOT analysis is utilized to determine the key assessment factors on the shipping registry decision and to structure the decision hierarchy. While the AHP is used to measure the relative importance of evaluation criteria in this decision hierarchy, the TOPSIS is applied to rank the shipping registry alternatives. As a case study, major open registries are analyzed to select the most suitable of them for the fleet that is operated by a worldwide ship owner. The results show that the proposed multi-methodological approach takes the advantages of the SWOT analysis, the AHP and the TOPSIS to select the most suitable shipping registry. The proposed approach also provides a relatively simple and very well suited decision-making tool for this type of strategic decision making problem. 相似文献
393.
Algin O Ozmen E Metin MR Ozcan MF Sivaslioglu AA Karaoglanoglu M 《Magnetic resonance imaging》2012,30(5):734-739
Urinary fistulas and leakages of lower urinary tract are serious complications of various surgical procedures. Radiologists need to have enough information about these situations to perform precise diagnosis and treatment. Various techniques [such as intravenous pyelography, ultrasound, computed tomography (CT), CT urography, cystoscopy, cystography and magnetic resonance (MR) imaging] are used for the diagnosis of these conditions. Application of all these techniques reduces the comfort and cooperation of the patients and increases the cost. Here we present four postoperative patients with lower urinary tract fistula or leakage. To the best of our knowledge, there is no report regarding the use of contrast-material-enhanced MR urography (CE-MRU) in the demonstration of postoperative lower urinary tract fistulae and leakages. In conclusion, CE-MRU could show the existence and location of the urinary fistulae and leakages clearly without the need for another investigation technique, as described in our patients. Also, CE-MRU is a safe and relatively inexpensive technique that avoids exposure to radiation as well as nephrotoxic and more allergic contrast-material administration. 相似文献
394.
A base‐catalyzed condensation of diacetamido sulfides [(RNHCOCH2)2S)] with glyoxal affording thiophene‐2,5‐dicarboxylic acid bis‐aryl(alkyl)amides has been accomplished under mild conditions. Excellent results were readily obtained when R was a substituted 3‐nitrophenyl, 4‐nitrophenyl, 4‐chlorophenyl group, but the yield was poor when R was cyclohexyl. Unknown compounds were characterized by elemental analyses, IR, 1H, and 13C NMR techniques. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:503–506, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20153 相似文献
395.
Silk fibroin, which has many characteristic properties such as low inflammation reaction, biodegradation, suppleness, good antithrombogenic details, biocompatibility and high tensile strength is a very good candidate for biomedical applications. Electrospinning procures high surface area, porous, nanofiber dimension fiber generation, which is a plain method. An experimental study was carried out to produce nanofiber structure from silk fibroin by electrospinning and the electrospinning parameters for the spinning of uniform, continuous and silk fibroin fibers were optimized. As a result, the effect of variables of concentration, distance and applied voltage on the strength, thickness, surface structure, fiber diameter of nanomaterial was investigated. Then, in vitro cell viability of the silk fibroin mat was analyzed. It was seen that the strength, mat thickness, and fiber diameter increased with solution concentration rise. It was found that the values of the fiber diameter and tensile strength decreased with increasing distance. It was determined that the effect of distance varies depending on the concentration in the mat thicknesses. The tensile strength was affected inversely proportional the applied voltage rises and distance. It was found that the fiber diameter values decreased together with increasing applied voltage. At cell viability of silk fibroin mat was occurred high cell viability after 24 h, but it was obtained low cell viability at the 48th h. 相似文献
396.
The chemical reactivity of syn‐ 3 was investigated. The experimental results showed that the central double bond of this system is inert toward chemical reactions. To determine the reactivity of this central double bond, we synthesized syn‐ and anti‐ 7 and recorded their photoelectron spectra. Low first‐ionization potentials of syn‐ and anti‐ 7 (7.6 eV) clearly indicated that these compounds should be highly reactive. 相似文献
397.
Nihal Kan Kaynar Erbil Ağar Hasan Tanak Songul Sahin Orhan Büyükgüngör Metin Yavuz 《Crystallography Reports》2018,63(3):372-374
The molecular structure of the title compound, C14H11ClN2O4, was determined by single crystal X-ray diffraction. The compound crystallizes in the monoclinic sp. gr. P21/c with Z = 4. The title compound, C14H11ClN2O4, is a Schiff base which adopts the phenol-imine tautomeric form in the solid state.The molecule is almost planar and the dihedral angle between the planes of two aromatic ring is 2.2(1)°. The molecular structure is stabilized by intramolecular O–H···N hydrogen bond which generates a six-membered ring. In the crystal structure, the molecules are linked together by intermolecular C–H···O interactions. 相似文献
398.
Nihal Kan Kaynar Metin Yavuz Hasan Tanak Songul Şahin Orhan Büyükgüngör Erbil Ağar 《Crystallography Reports》2018,63(3):375-378
The molecular structure of the title compound, C21H15Br1N2O2, was characterized by single crystal X-ray diffraction. The compound crystallizes in the triclinic sp. gr. \(P\bar 1\) with Z = 2. The molecule is not planar: the dihedral angle between the planes of two aromatic rings [C1/C6] and [C16/C21] is 84.9(2)°. The other dihedral angle between two aromatic rings [C9/C14] and [C16/C21] is 88.8(2)°. The title compound exists as a phenol-imine tautomer, in which a strong intramolecular O–H···N hydrogen bond is formed. This study verifies the preference of the phenol-imine tautomeric form in the solid state. A π–π stacking interactions are also observed, which may influence crystal stability: the distance between centroids is 3.702(2) Å. 相似文献
399.
A general and convenient route for the synthesis of 2,5-di[1-methyl-1-arylcyclobutane-3-yl]- thiophenes 4a–c and bis[1-methyl-1-arylcyclobutane-3-yl]-2-(2-oxyethtylamido)thiazole sulfides 7a–c is reported. The characterization of these compounds was obtained by elemental analyses, IR, 13C, and 1H NMR techniques. © 2003 Wiley Periodicals, Inc. 15:26–31, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.hc10207 相似文献
400.
Ahsen Sare Yalın Buse Sündü Melek Sermin Özer Ayoub Abdelkader Mekkaoui Soufiane El Houssame Önder Metin 《应用有机金属化学》2023,37(1):e6943
A facile wet-chemical protocol for the synthesis of bimetallic CuPd alloy nanoparticles (NPs) anchored on mesoporous graphitic carbon nitride (m-gCN), serving as both stabilizer and support material, was presented herein. The presented protocol allowed to synthesize nearly monodisperse CuPd alloy NPs with an average particle size of 3.9 ± 0.9 nm without use of any additional surfactants and to prepare CuPd/m-gCN nanocatalysts with different Cu/Pd compositions (Cu25Pd75/m-gCN, Cu35Pd65/m-gCN, Cu16Pd74/m-gCN, Cu32Pd68/m-gCN, Cu10Pd90/m-gCN, and Cu50Pd50/m-gCN). After the detailed characterization of CuPd/m-gCN nanocatalysts, they were utilized as catalysts in the dehydrogenation of terpenes. Among all tested nanocatalysts, Cu50Pd50/m-gCN showed the highest activity in terms of the product yields within the same reaction time. Various parameters influencing the catalytic activity of Cu50Pd50/m-gCN were studied using himachalene as a model substrate and the optimum conditions were determined. Under the optimized reaction conditions, the catalytic application of Cu50Pd50/m-gCN nanocatalysts was extended to nine different terpenes and the corresponding products were obtained in high conversion yields (>90%) under mild conditions. A reusability test showed that Cu50Pd50/m-gCN nanocatalysts can be re-used up to four cycles without significant loss in their initial activity. 相似文献