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41.
X-ray absorption spectroscopy studies of the polycrystalline SrRu0.5Mn0.5O3 have been performed at Ru, Mn-L2,3 edges. The 2p-->t2g related peak at the Ru-L2 edge is more intense than the Ru-L3 edge and a shift of the 2p-->eg related peak by approximately 0.8 eV to higher energy than that of the Ru(IV) compound, SrRuO3 is observed. In combination with a crystal field multiplet calculation approach, a possible anomalous change in the spectral features is explained based on the existence of a redox ionic pair involving Ru(IV)/Ru(v)<-->Mn(III)/Mn(IV). 相似文献
42.
Single-mode plane-polarized ytterbium-doped large-core fiber laser with 633-W continuous-wave output power 总被引:3,自引:0,他引:3
Jeong Y Nilsson J Sahu JK Soh DB Dupriez P Codemard CA Baek S Payne DN Horley R Alvarez-Chavez JA Turner PW 《Optics letters》2005,30(9):955-957
We demonstrate a cladding-pumped single-mode plane-polarized ytterbium-doped fiber laser generating 633 W of continuous-wave output power at 1.1 microm with 67% slope efficiency and a polarization extinction ratio better than 16 dB. The laser is end pumped through both fiber ends and shows no evidence of roll-over, even at the highest output power, which is limited only by the available pump power. 相似文献
43.
Single-frequency, single-mode, plane-polarized ytterbium-doped fiber master oscillator power amplifier source with 264 W of output power 总被引:10,自引:0,他引:10
Jeong Y Nilsson J Sahu JK Soh DB Alegria C Dupriez P Codemard CA Payne DN Horley R Hickey LM Wanzcyk L Chryssou CE Alvarez-Chavez JA Turner PW 《Optics letters》2005,30(5):459-461
We present a single-frequency, single-mode, plane-polarized ytterbium-doped all-fiber master oscillator power amplifier source at 1060 nm generating 264 W of continuous-wave output power. The final-stage amplifier operated with a high gain of 19 dB and a high conversion efficiency of 68%. There was no evidence of rollover from stimulated Brillouin scattering even at the highest output power, and the maximum output was limited only by the available pump power. 相似文献
44.
We have constructed a class of plane symmetric macro models in Barber's second self-creation theory, when the source of the gravitational field is a macro matter field representing perfect fluid and satisfying the gamma-law equation of state p=(-1), where =4/3 and 3/2. The solutions of the field equations are derived and their physical aspects are studied. 相似文献
45.
In this article, the novel (G ′/G)-expansion method is successfully applied to construct the abundant travelling wave solutions to the KdV–mKdV equation with the aid of symbolic computation. This equation is one of the most popular equation in soliton physics and appear in many practical scenarios like thermal pulse, wave propagation of bound particle, etc. The method is reliable and useful, and gives more general exact travelling wave solutions than the existing methods. The solutions obtained are in the form of hyperbolic, trigonometric and rational functions including solitary, singular and periodic solutions which have many potential applications in physical science and engineering. Many of these solutions are new and some have already been constructed. Additionally, the constraint conditions, for the existence of the solutions are also listed. 相似文献
46.
Vaisakh Mohan A. Nijamudheen Sudhir Kumar Das Prabhat K. Sahu Usha Pallabi Kar Dr. Abdur Rahaman Dr. Moloy Sarkar 《Chemphyschem》2012,13(17):3882-3892
A new multi‐component chemosensor system comprising a naphthalimide moiety as fluorophore is designed and developed to investigate receptor–analyte binding interactions in the presence of metal and non‐metal ions. A dimethylamino moiety is utilized as receptor for metal ions and a thiourea receptor, having acidic protons, for binding anions. The system is characterized by conventional analytical methods. The absorption and fluorescence spectra of the system consist of a broad band typical for an intramolecular charge transfer (ICT). The effects of various metal‐ion additives on the spectral behavior of the present sensor system are examined in acetonitrile. It is found that among the metal ions studied, alkali/alkaline earth‐metal ions and transition‐metal ions modulate the absorption and fluorescence spectra of the system. As an additional feature, the anion signaling behavior of the system in acetonitrile is studied. A decrease in fluorescence efficiency of the system is observed upon addition of fluoride and acetate anions. Fluorescence quenching is most effective in the case of fluoride ions. This is attributed to the enhancement of the photoinduced electron transfer from the anion receptor to the fluorophore moiety. Hydrogen‐bond interactions between the acidic NH protons of the thiourea moiety and the F? anions are primarily attributed to the fluoride‐selective signaling behavior. Interestingly, a negative cooperativity for the binding event is observed when the interactions of the system are studied in the presence of both Zn2+ and F? ions. NMR spectroscopy and theoretical calculations are also carried out to better understand the receptor–analyte binding. 相似文献
47.
Sensing of Phosphates by Using Luminescent EuIII and TbIII Complexes: Application to the Microalgal Cell Chlorella vulgaris 下载免费PDF全文
Sandeep Nadella Jashobanta Sahoo Dr. Palani S. Subramanian Abhishek Sahu Dr. Sandhya Mishra Prof. Dr. Markus Albrecht 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(20):6047-6053
Phenanthroline‐based chiral ligands L1 and L2 as well as the corresponding EuIII and TbIII complexes were synthesized and characterized. The coordination compounds show red and green emission, which was explored for the sensing of a series of anions such as F?, Cl?, Br?, I?, NO3?, NO2?, HPO42?, HSO4?, CH3COO?, and HCO3?. Among the anions, HPO42? exhibited a strong response in the emission property of both europium(III) and terbium(III) complexes. The complexes showed interactions with the nucleoside phosphates adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP). Owing to this recognition, these complexes have been applied as staining agents in the microalgal cell Chlorella vulgaris. The stained microalgal cells were monitored through fluorescence microscopy and scanning electron microscopy. Initially, the complexes bind to the outer cell wall and then enter the cell wall through holes in which they probably bind to phospholipids. This leads to a quenching of the luminescence properties. 相似文献
48.
Sharma M Sahu K Dube A Gupta PK 《Journal of photochemistry and photobiology. B, Biology》2005,81(2):107-113
Effect of varying extracellular pH on mode of cell death induced by photodynamic action of chlorin p6 was investigated in human colon carcinoma (Colo-205) cells. At an extracellular pH of 7.4, compared to cells treated with chlorin p6 in dark, the photodynamically treated cells showed reduction in mitochondrial membrane potential, an increase in ADP/ATP ratio (1:2) and a large percentage of cells with chromatin condensation. In contrast, when photodynamic treatment and post irradiation incubation was carried out in acidic medium (pH 6.5), total loss of mitochondrial membrane potential, a marked increase in ADP/ATP ratio (1:33) and increased damage to plasma membrane were observed. Further, cells subjected to photodynamic treatment in a medium of pH 7.4 showed twofold increase in caspase-3 activity as compared to photodynamic treatment at pH 6.5. These results suggest that chlorin p6 mediated photodynamic action induces apoptotic cell death when extracellular pH is 7.4 whereas necrosis is more predominant under condition when extracellular pH is 6.5. 相似文献
49.
We investigate certain classes of normal completely positive (CP) maps on the hyperfinite II1 factorA. Using the representation theory of a suitable irrational rotation algebra, we propose some computable invariants for such
CP maps.
Dedicated to Professor K B Sinha 相似文献
50.
We analyze the spectra of pions and protons in heavy-ion collisions at relativistic energies from 2 A GeV to 65+65 A GeV by
using a jet-implemented hadron-string cascade model. In this energy region, hadron transverse mass spectra first show softening
until SPS energies, and re-hardening may emerge at RHIC energies. Since hadronic matter is expected to show only softening
at higher energy densities, this re-hardening of spectra can be interpreted as a good signature of the quark-gluon plasma
formation 相似文献