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81.
82.
83.
S. Kumar T. Ramanathan K. Subramanian Thomas Steiner 《Journal of chemical crystallography》1998,28(12):931-933
The X-ray crystal structure of 7-hydroxyflavone monohydrate, C14H10O3 · H2O, is determined. The compound crystallizes in the monoclinic space group, P21/n with a = 3.801(3), b = 19.665(4), c = 16. 039(6), = 93.69(3)°, and = 0.68 mm–1 for Z = 4. The phenyl ring of the flavone moiety is rotated 18.6(1)° out of the penzopyran plane, which is a typical value for flavones. In the crystal lattice, there are wide channels which are lined mainly by C–H groups. The water molecules enclosed in these channels are severely disordered. 相似文献
84.
We identify conditions under which correlations resulting from quantum measurements performed on macroscopic systems (systems composed of a number of particles of the order of the Avogadro number) can be described by local realism. We argue that the emergence of local realism at the macroscopic level is caused by an interplay between the monogamous nature of quantum correlations and the fact that macroscopic measurements do not reveal properties of individual particles. 相似文献
85.
Ramanathan A Wright KC Muniz SR Zelan M Hill WT Lobb CJ Helmerson K Phillips WD Campbell GK 《Physical review letters》2011,106(13):130401
We have created a long-lived (≈40 s) persistent current in a toroidal Bose-Einstein condensate held in an all-optical trap. A repulsive optical barrier across one side of the torus creates a tunable weak link in the condensate circuit, which can affect the current around the loop. Superflow stops abruptly at a barrier strength such that the local flow velocity at the barrier exceeds a critical velocity. The measured critical velocity is consistent with dissipation due to the creation of vortex-antivortex pairs. This system is the first realization of an elementary closed-loop atom circuit. 相似文献
86.
Nazikian R Berk HL Budny RV Burrell KH Doyle EJ Fonck RJ Gorelenkov NN Holcomb C Kramer GJ Jayakumar RJ La Haye RJ McKee GR Makowski MA Peebles WA Rhodes TL Solomon WM Strait EJ Vanzeeland MA Zeng L 《Physical review letters》2006,96(10):105006
Evidence is presented for a multitude of discrete frequency Alfvén waves in the core of magnetically confined high-temperature fusion plasmas. Multiple diagnostic instruments confirm wave excitation over a wide spatial range from the device size at the longest wavelengths down to the thermal ion Larmor radius. At the shortest scales, the poloidal wavelengths are comparable to the scale length of electrostatic drift wave turbulence. Theoretical analysis confirms a dominant interaction of the modes with particles in the thermal ion distribution traveling well below the Alfvén velocity. 相似文献
87.
L. F. Miranda A. B. Lugo L. D. B. Machado L. V. Ramanathan 《Radiation Physics and Chemistry》1999,55(5-6):709-712
Swelling was performed on dried membranes, normal ones and dried gel to unravel the role of crosslinking and degradation on polymeric structure during drying and hydration process. The comparison of the swelling results suggested that the network were formed only by PVP molecules. The complex mixture of macromolecules showed a irreversible behavior upon drying and hydration, probably as a function of PEG and/or agar entangling in effective physical crosslink. The best network regularity and useful properties was found at 20–30 kGy. 相似文献
88.
89.
A sugar-based photoresponsive supergelator, N-glycosylazobenzene that shows selective gelation of aromatic solvents is described. The partial trans-cis isomerization of the azobenzene moiety allows photoinduced chopping of the entangled gel fibers to short fibers, resulting in controlled fiber length and gel-sol transition. The gelator is useful for the selective removal of toxic aromatic solvents from water. 相似文献
90.
The aim of this study is to investigate the antitumour and antioxidant activities of the ethanol extract of Scutia myrtina (EESM) against Ehrlich's ascites carcinoma (EAC) in mice. Twenty-four hours after tumour inoculation, EESM was administered at doses 100, 200 and 300?mg?kg?1 bodyweight/mice/day for 21 days. EESM caused a significant (p?0.01) decrease in ascites volume, packed cell volume and viable cell count, and also prolonged the life span of EAC tumour-bearing mice. Haematological profiles reverted to near-normal levels in extract-treated mice (p?0.01). EESM also produced protective effects by significantly decreasing the activity of serum enzymes and bilirubin and increasing the protein and uric acid levels (p?0.05). EESM significantly (p?0.05) decreased the levels of lipid peroxidation, while it significantly (p?0.05) increased the levels of enzymatic and non-enzymatic antioxidants. The results indicate that EESM exhibited significant antitumour and antioxidant activities in EAC-bearing mice. 相似文献