A rapid method of synthesizing the layered titanosilicate JDF-L1

A rapid procedure for synthesis of highly crystalline and pure samples of JDF-L1 without using organics are reactants or templates is described and indexation of the powder X-ray diffraction pattern of this phase is presented.     

Photoreactions on finely divided semiconductors

Photoreactions on finely divided semiconductors are discussed. Experimental results on photo-oxidation of CO, isobutane, and NH₃ over UV -irradiated n-TiO₂ (anatase) particles of different size are discussed. The possibility of using size-quantized films for spectroscopy of adsorbates is also considered.     

Weak measurements are universal

It is well known that any projective measurement can be decomposed into a sequence of weak measurements, which cause only small changes to the state. Similar constructions for generalized measurements, however, have relied on the use of an ancilla system. We show that any generalized measurement can be decomposed into a sequence of weak measurements without the use of an ancilla, and give an explicit construction for these weak measurements. The measurement procedure has the structure of a random walk along a curve in state space, with the measurement ending when one of the end points is reached. This shows that any measurement can be generated by weak measurements, and hence that weak measurements are universal. This may have important applications to the theory of entanglement.     

Hysteresis of dielectric properties of Li-Ti-Ferrite ceramics

Field dependences of Li-Ti ferrite ceramics polarization are obtained. When related to temperature, these dependences exhibit either non-linear behavior or non-linearity and hysteresis. Electric Barkhausens pulses are revealed. Temperature dependences of the electric pulse heights are obtained after re-polarization of the specimens in the electric fields of different strengths. The results provide evidence on the presence of ferroelectric properties in Li-Ti ferrite ceramics.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 97–99, October 2004.     

Temperature Dependences of the Electrophysical Parameters of a Li–Ti Ferrite

Temperature dependences of real and imaginary parts of the complex permeability of a Li–Ti ferrite were obtained by measuring its capacitance and total electrical conductivity by the bridge method at temperatures lying in the range 77–500 K. The measurements were carried out at a frequency of 1 MHz and a standard signal voltage of 250 mV. Dipoles of two types are identified. The static permittivity, activation energy, and pre-exponential factors characterizing the reorientation time constants of each dipole and also of the quantities describing the charge-carrier transfer in an electric field are estimated by the method of regression analysis of the obtained dependences.     

Di­methyl 2‐{[2‐(methoxy­carbonyl)‐1‐(methoxy­carbonyl­methyl)pyrrol‐4‐yl]­methyl­ene}propane­dioate

The title compound, C₁₅H₁₇NO₈, is a pyrrole–ethene derivative with potential biological activity. Although a large part of the mol­ecule is planar, there is no structural evidence for any conjugation push–pull effect across the ethyl­enic bond, which is usually observed for substituted ethyl­enes; π‐electron delocalization appears to be restricted to the 2‐(methoxy­carbonyl)­pyrrole moiety.     

Anomalies of dielectric properties in a polycrystalline lithium-titanium ferrite

For the first time a dielectric hysteresis is observed in a polycrystalline lithium-titanium ferrite in the temperature range 475–575 K. A thermal Barkhausen effect is detected during heating and cooling of ferrite specimens prepolarized in an electric field. The results provide evidence on the formation of properties similar to ferroelectric ones in lithium-titanium ferrites under certain conditions. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 59–61, February, 2007.