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141.
M. Sakhawat Hussain Mazhar-ul-Haque Sk. A. Ali 《Journal of chemical crystallography》1999,29(1):33-38
The title compound crystallizes in the monoclinic space group P21/n, with a = 6.225(1), b = 14.612 (1), c = 15.520 (1) Å, = 96.6(3)°, Z = 4 and V = 1402.4Å3. The stereochemistry of the 7/5-fused ring system is trans, the 7-membered and the 5-membered rings are found to be in the chair and envelope conformations, respectively. This represents the first study of a compound containing the 7/5-ring skeleton shown in (3) below. 相似文献
142.
This work focuses on the universal scaling laws, which relate scaled diffusivity to excess entropy in fluids and their mixtures. The derivation of the new scaling law for diffusivity proposed recently [A. Samanta, Sk. M. Ali, and S. K. Ghosh, Phys. Rev. Lett. 92, 145901 (2004)] is discussed in details highlighting the nature of approximations involved. Also the applicability of the scaling law is extended to a new class of liquids, viz., liquid metals. The results calculated based on the scaling laws are shown to be in very good agreement with the simulation results for liquid Rb and Cs metals along the liquid-vapor coexistence curve corresponding to a wide variation of temperature and density. The new universal scaling law discussed here is superior to the earlier empirically proposed scaling laws and provides a very simple route to calculate a dynamical quantity such as diffusivity from an equilibrium property such as the radial distribution function. 相似文献
143.
Kim HK Park JA Kim KM Nasiruzzaman SM Kang DS Lee J Chang Y Kim TJ 《Chemical communications (Cambridge, England)》2010,46(44):8442-8444
We report the synthesis of macrocyclic DTPA conjugates of 1,1'-bis(amino)ferrocenes (1a-b) and their Gd-complexes [Gd(L)(H(2)O)] (2a-b, L = 1a-b) for use as new MRI blood-pool contrast agents. High R(1) relaxivity in HSA as well as high thermodynamic and kinetic stabilities is observed for 2a. 相似文献
144.
An efficient plant regeneration protocol through indirect somatic embryogenesis pathway via callus had been developed from the leaf explant of an ornamental bulbaceous plant Drimiopsis kirkii. Optimum friable calli were induced on Murashige and Skoog (MS) basal medium supplemented with 3.0 mg/l of 2,4-dichlorophenoxyacetic acid and 1.0 mg/l of α-naphthalene acetic acid (NAA). On subculturing the callus on MS medium supplemented with 2.5 mg/l of thidiazuron (TDZ), 73.3 % of the cultures responded with 20.4?±?0.3 somatic embryos (SEs) per 500 mg callus at different stages of development after 6 weeks of culture. The highest response of 86.7 % with 28.3?±?0.5 embryos per 500 mg callus was observed on MS medium supplemented with 2.5 mg/l TDZ and 1.0 mg/l NAA. SEs were encapsulated in calcium alginate beads for the production of synthetic seeds (SSs) and their storability was investigated. The highest SS germination (93.3 %) was observed in 1.0 % sodium alginate followed by 86.7 % germination with 2.5 % sodium alginate. The SSs were stored at three different temperatures (4, 15, and 24?ºC) up to 6 months. The SSs kept at 15 °C showed 64.4 % germinability even after 4 months of storage. Both nonencapsulated and encapsulated SE-derived plants were successfully transferred to soil with 93.3 and 88.3 % survival rate accordingly. Randomly amplified polymorphic DNA (RAPD) analysis revealed that there were no somaclonal variations among the plants produced via somatic embryogenesis and they are true-to-type to their parental plant. These results confirmed the most reliable methods, which can be further used for genetic transformation studies as well as for mass propagation of ornamental D. kirkii at a commercial level. 相似文献
145.
146.
S. Priya Arijit Sengupta Sk. Jayabun 《Journal of Radioanalytical and Nuclear Chemistry》2016,309(3):1049-1057
147.
Iva Matolínová Viktor Johánek Josef Mysliveček Kevin C. Prince Tomáš Skála Michal Škoda Nataliya Tsud Mykhailo Vorokhta Vladimír Matolín 《Surface and interface analysis : SIA》2011,43(10):1325-1331
Methanol adsorption on ion‐sputtered Pt(111) surface exhibiting high concentration of vacancy islands and on (2 × 1)Pt(110) single crystal were investigated by means of photoelectron spectroscopy (PES) and thermal desorption spectroscopy. The measurements showed that methanol adsorbed at low temperature on sputtered Pt(111) and on (2 × 1)Pt(110) surfaces decomposed upon heating. The PES data of methanol adsorption were compared to the data of CO adsorbed on the same Pt single crystal surfaces. In the case of the sputtered Pt(111) surface, the dehydrogenation of HxCO intermediates is followed by the CO bond breakage. On the (2 × 1)Pt(110) surface, carbon monoxide, as product of methanol decomposition, desorbed molecularly without appearance of any traces of atomic carbon. By comparing both platinum surfaces we conclude that methanol decomposition occurs at higher temperature on sputtered Pt(111) than on (2 × 1)Pt(110). Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
148.
Nondissipative Josephson current through nanoscale superconducting constrictions is carried by spectroscopically sharp energy states, the so-called Andreev states. Although theoretically predicted almost 40 years ago, no direct spectroscopic evidence of these Andreev bound states exists to date. We propose a novel type of spectroscopy based on embedding a superconducting constriction, formed by a single-level molecule junction, in a microwave QED cavity environment. In the electron-dressed cavity spectrum we find a polariton excitation at twice the Andreev bound state energy, and a superconducting-phase-dependent ac Stark shift of the cavity frequency. Dispersive measurement of this frequency shift can be used for Andreev bound state spectroscopy. 相似文献
149.
Silicon-incorporated diamond like carbon (Si-DLC) films were deposited via DC plasma-enhanced chemical vapor deposition (PECVD) on glass and alumina substrates at a substrate temperature of 473 K. The precursor gas used was acetylene and for silicon incorporation tetraethyl orthosilicate dissolved in methanol was used. Silicon atomic percentage in the films was varied from 0% to 19.3% as measured from energy dispersive X-ray analysis. Fourier transformed infrared spectroscopy studies depicted the presence of Si-C, Si-H and Si-H2 bonding within the films. The binding energies of C 1s, Si 2s and Si 2p were determined from X-ray photoelectron spectroscopic studies. UV-vis-NIR spectroscopic studies were used to determine the optical gaps as well as the Urbach parameters of the samples. Room temperature photoluminescence study showed a broad peak centered at around 467 nm. Also the peak intensity was found to increase monotonically with Si percentages. The results are discussed in terms of the electronic structure of a-C:H, the doping induced defect states and the enhanced carbon dangling bonds via the formation of more sp3 hybridized carbon network. 相似文献
150.
Effect of temperature and aspect ratio on the field emission properties of vertically aligned carbon nanofiber and multiwalled carbon nanotube thin films were studied in detail. Carbon nanofibers and multiwalled carbon nanotube have been synthesized on Si substrates via direct current plasma enhanced chemical vapor deposition technique. Surface morphologies of the films have been studied by a scanning electron microscope, transmission electron microscope and an atomic force microscope. It is found that the threshold field and the emission current density are dependent on the ambient temperature as well as on the aspect ratio of the carbon nanostructure. The threshold field for carbon nanofibers was found to decrease from 5.1 to 2.6 V/μm when the temperature was raised from 300 to 650 K, whereas for MWCNTs it was found to decrease from 4.0 to 1.4 V/μm. This dependence was due to the change in work function of the nanofibers and nanotubes with temperature. The field enhancement factor, current density and the dependence of the effective work function with temperature and with aspect ratio were calculated and we have tried to explain the emission mechanism. 相似文献