The odd-even shifts in odd-odd deformed nuclei based on residual interaction studies

Residual interaction calculations have been made for predicting the sign and the magnitude of the odd-even shifts observed in the rotational levels of theK=0 bands in the doubly-odd rare earth nuclei. It is shown that, contrary to the conclusions reached in earlier studies, the same zero-range spin-dependent residual interaction can reproduce the odd-even shifts as well as the GM splitting energies. This has been made possible with the inclusion of the phase factors for the total intrinsic spin and the total parity of the two-quasi-particle states in the Newby matrix elements. Predictions are made for the odd-even shifts for otherK=0 bands arising from several configurations not confirmed or observed so far.     

Structure of 3,6-di(p-methoxyphenyl)-2,7-dihydro-1,4,5-thiadiazepine

The title compound C₁₈H₁₈N₂O₂S is monoclinic with unit-cell dimensionsa=8.849(10),b=9.185(11),c=20.257(9) Å,=109.28(10)°. The space group isP2₁/c, withZ=4. Data were measured by photographic methods. The structure was solved by direct methods. A full-matrix least-squares refinement converged toR=0.10. All atoms except sulfur were assigned individual isotropic thermal parameters. The conformation of the thiadiazepine ring system is distorted boat shaped, as indicated by torsion angle studies.     

All‐Inorganic CsPb1−xGexI2Br Perovskite with Enhanced Phase Stability and Photovoltaic Performance

Compared with organic‐inorganic perovskites, all‐inorganic cesium‐based perovskites without volatile organic compounds have gained extensive interests because of the high thermal stability. However, they have a problem on phase transition from cubic phase (active for photo‐electric conversion) to orthorhombic phase (inactive for photo‐electric conversion) at room temperature, which has hindered further progress. Herein, novel inorganic CsPb_1?xGe_xI₂Br perovskites were prepared in humid ambient atmosphere without a glovebox. The phase stability of the all‐inorganic perovskite was effectively enhanced after germanium addition. In addition, the highest power conversion efficiency of 10.8 % with high open‐circuit voltage (V_OC) of 1.27 V in a planar solar cell based on CsPb_0.8Ge_0.2I₂Br perovskite was achieved. Furthermore, the highest V_OC up to 1.34 V was obtained by CsPb_0.7Ge_0.3I₂Br perovskite, which is a remarkable record in the field of all‐inorganic perovskite solar cells. More importantly, all the photovoltaic parameters of CsPb_0.8Ge_0.2I₂Br perovskite solar cells showed nearly no decay after 7 h measurement in 50–60 % relative humidity without encapsulation.     

Gelation of aqueous pectin solutions: a dynamic light scattering study

We report the dynamic light scattering study of the gelation of aqueous solutions of the biopolymer, pectin, induced by the addition of calcium chloride. The time correlation function data are analyzed under the framework of the coupling model. As the solution enters the semidilute regime where gelation sets in, the relaxation process shows a stretched exponential behavior. The stretching exponent decreases and the characteristic time of the stretched exponential diverges as the system evolves to a gel. Aqueous pectin solutions in the presence of 0.1 M NaCl show similar behavior. Thus, the molecular relaxation modes of pectin solutions can be well described by the coupling model.     

IAEA activities for the production and utilization of isotopes: Some examples of recent work

The paper gives a brief overview of typical IAEA activities which contribute to the production of isotopes in nuclear reactors and accelerators, as well as their use. The areas touched upon include (1) isotope production in research reactors and accelerators, (2) quality control and quality assurance in radioanalytical measurements, (3) neutron activation analysis, (4) nuclear methods for land mine detection, (5) radiopharmaceuticals and nuclear medicine, (6) isotope techniques of water resource management and (7) soil management and crop nutrition.     

B \bar B widths of the diquoniums based on quark potential model

A detailed and systematic study is carried out of the \(B\bar B(N\bar N, N\bar \Delta , \Delta \bar \Delta )\) widths of the “True” (colour \(3 \times \bar 3\) ) diquoniums making use of the quark pair creation model supplemented by the idea of a quark-quark potential. The widths, which continue to be of the order of 10 MeV, help confirm our hypothesis of avoiding the need for the “Mock” (colour \(6 \times \bar 6\) ) diquoniums to explain the narrow width resonances observed in the production experiments. Another outcome concerns the criterion to select out the dominant ones among the numerous diquonium trajectories. It is proposed to replace the one based on “peripherality” withR～1/m _π with another more natural one based on the width pattern itself.     

Phase behavior of concentrated aqueous solutions of cetyltrimethylammonium bromide (CTAB) and sodium hydroxy naphthoate (SHN)

We have characterized the phase behavior of mixtures of the cationic surfactant cetyltrimethylammonium bromide (CTAB) and the organic salt 3-sodium-2-hydroxy naphthoate (SHN) over a wide range of surfactant concentrations using polarizing optical microscopy and X-ray diffraction. A variety of liquid crystalline phases, such as hexagonal, lamellar with and without curvature defects, and nematic, are observed in these mixtures. At high temperatures the curvature defects in the lamellar phase are annealed gradually on decreasing the water content. However, at lower temperatures these two lamellar structures are separated by an intermediate phase, where the bilayer defects appear to order into a lattice. The ternary phase diagram shows a high degree of symmetry about the line corresponding to equimolar CTAB/SHN composition, as in the case of mixtures of cationic and anionic surfactants.     

A new colorimetric method for the determination of carbon disulphide and its application to the analysis of some dithiocarbamate fungicides

A new and convenient colorimetric method for determination of carbon disulphide, based on its transformation into bright yellow potassium benzyl trithiocarbonate through reaction with benzyl mercaptan and potassium hydroxide in tert.-butyl alcohol, has been successfully applied to determination of some dithiocarbamate fungicides in their formulations. The method possesses a distinct advantage in that it is free from all sources of errors/problems which are associated with the xanthate method for the analysis of these materials. The proposed method is precise and accurate and hence recommended for routine analysis of technical formulations containing dithiocarbamate fungicides.     

Thin-Layer Chromatographic Determination of Alpha-Amyrin in the Bark of Mallotus philippensis Lamk

JPC – Journal of Planar Chromatography – Modern TLC - A simple, precise, and accurate high-performance thin-layer chro-matographic method has been established for determination of...