Phase Reversal Diffraction in incoherent light

Phase reversal occurs in the propagation of an electromagnetic wave in a negatively refracting medium or a phase-conjugate interface. Here we report the experimental observation of phase reversal diffraction without the above devices. Our experimental results and theoretical analysis demonstrate that phase reversal diffraction can be formed through the first-order field correlation of chaotic light. The experimental realization is similar to phase reversal behavior in negatively refracting media.Comment: 8 pages, 5 figure

3-Benzyl-1-butyl­imidazo[1,2-a]benzo­thieno[3,2-d]pyrimidine-2,5(1H,3H)-dione

In the crystal structure of the title compound, C23H21N3O2S, all ring atoms of the imidazo[1,2-a]benzothieno[3,2-d]pyrimidine system are essentially coplanar and the phenyl ring is twisted with respect to it [dihedral angle = 72.60 (9)°]. The crystal packing is mainly governed by C—H⋯π hydrogen bonds and inter­molecular π–π inter­actions, with inter­planar distances of 3.54 (1) and 3.56 (1) Å, and with distances between adjacent ring centroids of 3.72 (1) and 3.80 (1) Å. The three terminal C atoms of the butyl group are disordered over two positions; the site occupancy factors are ca 0.6 and 0.4

Experimental Observation of Classical Sub-Wavelength Interference with Thermal-Like Light

We show the experimental observation of the classical sub-wavelength double-slit interference with a pseudo-thermal light source. The experimental results are in agreement with the recent theoretical prediction shown in quant-ph/0404078 (to be appeared in Phys. Rev. A).Comment: 4 pages, 6 figure

Spatial Interference: From Coherent To Incoherent

It is well known that direct observation of interference and diffraction pattern in the intensity distribution requires a spatially coherent source. Optical waves emitted from portions beyond the coherence area possess statistically independent phases, and will degrade the interference pattern. In this paper we show an optical interference experiment, which seems contrary to our common knowledge, that the formation of the interference pattern is related to a spatially incoherent light source. Our experimental scheme is very similar to Gabor's original proposal of holography[1], just with an incoherent source replacing the coherent one. In the statistical ensemble of the incoherent source, each sample field produces a sample interference pattern between object wave and reference wave. These patterns completely differ from each other due to the fluctuation of the source field distribution. Surprisingly, the sum of a great number of sample patterns exhibits explicitly an interference pattern, which contains all the information of the object and is equivalent to a hologram in the coherent light case. In this sense our approach would be valuable in holography and other interference techniques for the case where coherent source is unavailable, such as x-ray and electron sources.Comment: 8 pages, 5 figure

Phase Control on Surface for the Stabilization of High Energy Cathode Materials of Lithium Ion Batteries.

The development of high energy electrode materials for lithium ion batteries is challenged by their inherent instabilities, which become more aggravated as the energy densities continue to climb, accordingly causing increasing concerns on battery safety and reliability. Here, taking the high voltage cathode of LiNi0.5Mn1.5O4 as an example, we demonstrate a protocol to stabilize this cathode through a systematic phase modulating on its particle surface. We are able to transfer the spinel surface into a 30 nm shell composed of two functional phases including a rock-salt one and a layered one. The former is electrochemically inert for surface stabilization while the latter is designated to provide necessary electrochemical activity. The precise synthesis control enables us to tune the ratio of these two phases, and achieve an optimized balance between improved stability against structural degradation without sacrificing its capacity. This study highlights the critical importance of well-tailored surface phase property for the cathode stabilization of high energy lithium ion batteries

Detection of STAT2 in early stage of cervical premalignancy and in cervical cancer

AbstractObjectiveTo measure the expression pattern of STAT2 in cervical cancer initiation and progression in tissue sections from patients with cervicitis, dysplasia, and cervical cancer.MethodsAntibody against human STAT2 was confirmed by plasmids transient transfection and Western blot. Immunohistochemistry was used to detect STAT2 expression in the cervical biopsies by using the confirmed antibody against STAT2 as the primary antibody.ResultsIt was found that the overall rate of positive STAT2 expression in the cervicitis, dysplasia and cervical cancer groups were 38.5%, 69.4% and 76.9%, respectively. The STAT2 levels are significantly increased in premalignant dysplasia and cervical cancer, as compared to cervicitis (P< 0.05). Noticeably, STAT2 signals were mainly found in the cytoplasm, implying that STAT2 was not biologically active.ConclusionsThese findings reveal an association between cervical cancer progression and augmented STAT2 expression. In conclusion, STAT2 increase appears to be an early detectable cellular event in cervical cancer development

Is the nature of magnetic order in copper-oxides and in iron-pnictides different?

We use the results of first-principles electronic structure calculations and a strong coupling perturbation approach, together with general theoretical arguments, to illustrate the differences in super-exchange interactions between the copper-oxides and iron-pnictides. We show that the two magnetic ground states can be understood in a simple manner within the same theoretical foundation. Contrary to the emerging view that magnetic order in the iron-pnictides is of itinerant nature, we argue that the observed magnetic moment is small because of frustration introduced by the electrons of the Fe orbitals as they compete to impose their preferred magnetic ordering.Comment: 5 pages, 5 figure