排序方式: 共有45条查询结果,搜索用时 343 毫秒
1.
Veysel T. Yilmaz Eda Soyer Orhan Buyukgungor 《Journal of organometallic chemistry》2009,694(20):3306-3311
Two new silver(I) complexes [Ag(barb)(pym)]·H2O (1) and [Ag(barb)(dmpy)]·1.5H2O (2) (barb = 5,5-diethylbarbiturate, pym = pyridine-2-ylmethanol and dmpy = 2,6-dimethoxypyridine) have been synthesized and characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction. In both complexes, the silver(I) ions are linearly coordinated by the N atoms of a barb anion and a pym or a dmpy ligand, forming mononuclear species. The molecules of 1 and 2 are doubly bridged by N–HO hydrogen bonds involving the barb moieties and these hydrogen-bonded dimers are assembled into two-dimensional layered networks through weak AgCpy (η1) interactions of ca. 3.3 Å. Additionally, the thermal and fluorescent properties of these complexes are also investigated. 相似文献
2.
Laux S Lureau F Radier C Chalus O Caradec F Casagrande O Pourtal E Simon-Boisson C Soyer F Lebarny P 《Optics letters》2012,37(11):1913-1915
Transverse parasitic lasing is well known for limiting the signal gain and the pulse energy that can be extracted from Ti:sapphire petawatt amplifiers. We have developed a technique for suppressing these parasitic lasing modes based on perfect refractive index-matching liquid doped with a broad-bandwidth absorber to suppress the transverse lasing while ensuring proper heat removal from the Ti:sapphire crystal. The 800 nm laser output with a bandwidth of 41 nm (FWHM) and peak energy of 22.7 J at a repetition rate of 1 Hz is demonstrated. 相似文献
3.
Atilla Evcin Nalan iek Bezir Refik Kayal Mehmet Ar Deniz Belks Kepeki 《Crystal Research and Technology》2014,49(5):303-308
Nine sets of (3 × 3) InP nanofiber samples have been successfully prepared at three different voltages (20, 25, 30 kV) and at three separate heights (5, 7, 10 cm) by electrospinning with a constant precursor flow rate of 0.3 mLh−1. The crystalline structure, thermal, morphologies and nanostructure, electrical, and optical properties of the samples are characterized by X‐ray powder diffractometer (XRD) and thermal gravity‐differential scanning calorimeter (TG‐DSC), scanning electron microscopy (SEM), by Four‐Point Probe Technique (FPPT,) and ultraviolet/visible spectrometry (UV/VIS), respectively. From these measurements, we have found the formation of stoichiometric nanostructured InP with zinc‐blende structure and having lattice parameter of a = 5.874 Å, weight loss of 64.59% and crystallization temperature of 500°C, average fiber diameter of 65.82 nm, the activation energies, Ea, of the samples, and band gap energy, Eg, of the nanofibers developed at constant applied voltage 30 kV. The band gap energies determined at different distances 5, 7, and 10 cm are found to be as 1.29, 1.37, and 1.30 eV, respectively. 相似文献
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Ab initio calculations on the different associated structures of 2-pyrrolidinone with water and with itself were carried out using 3-21G and 6-31G* basis sets at the Hartree–Fock level, including electron correlation using second-order Møller–Plesset perturbation theory. The calculated free energy changes for the intermolecular hydrogen bonded dimer and hydrated species indicated that the molecular systems with cyclic dimerization and association with two water molecules are dominant. The results are compared to the available experimental data in the literature. 相似文献
6.
J. Gomez C. Bruneau N. Soyer A. Brault 《Journal of Analytical and Applied Pyrolysis》1985,7(4):307-313
The pyrolysis of amphetamine sulphate was studied in a laboratory flow reactor in the range 350–1000°C. The identifications and quantitative determinations of most gaseous and condensed products by means of gas chromatography and mass spectrometry made possible the suggestion of a thermal degradation scheme. The presence of sulphate in the initial molecule led to oxidation reactions in addition to the usual thermal reactions that occur during the pyrolysis of organic materials. 相似文献
7.
Yanling Li Amina Benchohra Buqin Xu Benoît Baptiste Keevin Bneut Paraskevas Parisiades Ludovic Delbes Alain Soyer Kamel Boukheddaden Rodrigue Lescouëzec 《Angewandte Chemie (International ed. in English)》2020,59(39):17272-17276
A key challenge in the design of magnetic molecular switches is to obtain bistability at room temperature. Here, we show that application of moderate pressure makes it possible to convert a paramagnetic FeIII2CoII2 square complex into a molecular switch exhibiting a full dia‐ to paramagnetic transition: FeIICoIII ? FeIIICoII. Moreover, the complex follows a rare behavior: the higher the pressure, the broader the magnetic hysteresis. Thus, the application of an adequate pressure allows inducing a magnetic bistability at room temperature with predictable hysteresis width. The structural studies at different pressures suggest that the pressure‐enhanced bistability is due to the strengthening of intermolecular interactions upon pressure increase. An original microscopic Ising‐like model including pressure effects is developed to simulate this unprecedented behavior. Overall, this study shows that FeCo complexes could be very sensitive piezo switches with potential use as sensors. 相似文献
8.
In this study, we determine when the Diophantine equation x 2?kxy+y 2?2 n = 0 has an infinite number of positive integer solutions x and y for 0 ? n ? 10. Moreover, we give all positive integer solutions of the same equation for 0 ? n ? 10 in terms of generalized Fibonacci sequence. Lastly, we formulate a conjecture related to the Diophantine equation x 2 ? kxy + y 2 ? 2 n = 0. 相似文献
9.
R. Muzaffer MusalRefik Soyer Christopher McCabeSamer A. Kharroubi 《European Journal of Operational Research》2012,218(2):538-547
In this paper we consider the health utility index mark II for quantifying and describing a population’s health related quality of life over health states composed of multiple attributes. This measure can be used for various purposes such as evaluating the severity of the effect of a disease or comparing different treatment methods. We present a Bayesian framework for population utility estimation and health policy evaluation by introducing a probabilistic interpretation of the multi-attribute utility theory (MAUT) used in health economics. In doing so, our approach combines ideas from the MAUT and Bayesian statistics and provides an alternative method of modeling preferences and utility estimation. 相似文献
10.
S. Soyer Uzun S. Sen C.J. Benmore C.A. Tulk B.G. Aitken 《Journal of Physics and Chemistry of Solids》2008,69(9):2336-2340
Structural mechanisms of densification of a molecular chalcogenide glass of composition Ge2.5As51.25S46.25 have been studied in situ at pressures ranging from 1 atm to 11 GPa at ambient temperature as well as ex situ on a sample quenched from 12 GPa and ambient temperature using high-energy X-ray diffraction. The X-ray structure factors display a reduction in height of the first sharp diffraction peak and a growth of the principal diffraction peak with a concomitant shift to higher Q-values with increasing pressure. At low pressures of at least up to 5 GPa the densification of the structure primarily involves an increase in the packing of the As4S3 molecules. At higher pressures the As4S3 molecules break up and reconnect to form a high-density network with increased extended-range ordering at the highest pressure of 11 GPa indicating a structural transition. This high-density network structure relaxes only slightly on decompression indicating that the pressure-induced structural changes are quenchable. 相似文献