New coupled Liouville system: Prolongation structure,soliton solution,and complete integrability

We suggest a new coupled Liouville equation which is exactly solvable. We obtain the Lax pair through a prolongation analysis and also obtain the exact one-soliton-like solution by a direct procedure. We confirm our result through a Painlevé analysis of the similarity reduced systems.     

Two manganese(II) coordination polymers driven by (iso)nicotinoyl-hydrazone blocks and pseudohalide ancillary ligands: syntheses,structural features,and magnetic properties

Two coordination polymers, [Mn₂(μ-L¹)₂(μ-N₃)₂]_n (1) and [Mn(μ-HL²)(SCN)₂]_n (2), were assembled in a single-pot from MnCl₂·4H₂O, HL¹ (2-acetylpyridine isonicotinoylhydrazone) or HL² (2-acetylpyridine nicotinoylhydrazone) and ancillary ligand sources (NaN₃ or NH₄NCS). The products were fully characterized, including by single-crystal X-ray diffraction, which revealed a 2-D metal–organic layer in 1 and a 1-D zigzag coordination chain in 2. Both 1 and 2 are constructed from six-coordinate Mn(II) nodes that adopt distorted octahedral (MnN₅O) environments; the adjacent nodes are driven by the μ-L¹ and μ-N₃ linkers in 1 or μ-HL² linkers in 2 to form different metal–organic networks. Their topological classification was performed, disclosing the hcb and 2C1 topology in 1 and 2, respectively. Different weak non-covalent interactions promote dimensionality extension. Variable-temperature magnetic susceptibility measurements were carried out, revealing weak ferromagnetic and antiferromagnetic interactions in 1 and 2, respectively.     

A Spirocyclohexyl Nitroxide Amino Acid Spin Label for Pulsed EPR Spectroscopy Distance Measurements

Site‐directed spin labeling and EPR spectroscopy offer accurate, sensitive tools for the characterization of structure and function of macromolecules and their assemblies. A new rigid spin label, spirocyclohexyl nitroxide α‐amino acid and its N‐(9‐fluorenylmethoxycarbonyl) derivative, have been synthesized, which exhibit slow enough spin‐echo dephasing to permit accurate distance measurements by pulsed EPR spectroscopy at temperatures up to 125 K in 1:1 water/glycerol and at higher temperatures in matrices with higher glass transition temperatures. Distance measurements in the liquid nitrogen temperature range are less expensive than those that require liquid helium, which will greatly facilitate applications of pulsed EPR spectroscopy to the study of structure and conformation of peptides and proteins.     

Structural Characterization of Coordination Polymers of Nickel(II) and Zinc(II) with Polycarboxylate Ligands

Abstract  

The structural aspects of one-dimensional coordination polymer (1) of nickel(II) with 1,3,5-benzene tricarboxylate and a three-dimensional interpenetrating coordination polymer (2) of zinc(II) with 1,4-benzenedicarboxylate ligand are studied by single crystal X-ray diffraction analysis. Coordination polymer (1) forms a hydrogen bonded three dimensional network structures. The coordination polymer 1 having a composition [Ni₃(TMA)₂(H₂O)₁₂] _n where (TMA = trimesate anion), crystallizes in monoclinic crystal system with C2 space group and has a/?, 17.3387(4); b/?, 12.8748(4); c/?, 6.5302(2); β/°111.620(2); V/?³, 1355.20(7). The zinc coordination polymer 2 crystal system is orthorhombic, with space group Pbca. It has a/?, 14.5049(3); b/?, 17.1616(3); c/?, 18.1389(4); V/?³, 4515.27(16). The 1,4-benzenedicarboxylate three dimensional coordination polymer of zinc(II) comprises of novel hydroxo bridged tetranuclear zinc(II) secondary building units and has a composition [Zn₂(C₆H₄C₂O₄)_1.5{(CH₃)₂SO}₂(OH)] _n . Topological analysis of the three dimensional coordination polymer 2 shows that it has a two fold interpenetrating net topology.     

Synthesis and photo physical properties of Au @ Ag (core @ shell) nanoparticles disperse in poly vinyl alcohol matrix

Synthesis of core @ shell (Au @ Ag) nanoparticle with varying silver composition has been carried out in aqueous poly vinyl alcohol (PVA) matrix. Core gold nanoparticle (~15 nm) has been synthesized through seed-mediated growth process. Synthesis of silver shell with increasing thickness (~1–5 nm) has been done by reducing Ag⁺ over the gold sol in the presence of mild reducing ascorbic acid. Characterization of Au @ Ag nanoparticles has been done by UV–Vis, High resolution transmission electron microscope (HRTEM) and energy dispersive X-ray (EDX) spectroscopic study. The blue shift of surface plasmon resonance (SPR) band with increasing mole fraction of silver has been interpreted due to dampening of core, i.e. Au SPR by Ag. The dependence of nonlinear optical response of spherical core @ shell nanoparticles has been investigated as a function of relative composition of each metal. Simulation of SPR extinction spectra based on quasi-static theory is done. A comparison of our experimental and the simulated extinction spectra using quasi-static theory of nanoshell suggests that our synthesized bimetallic particles have core @ shell structure rather than bimetallic alloy particles.     

Maximal Contractive Tuples

Maximality of a contractive tuple of operators is considered. A characterization for a contractive tuple to be maximal is obtained. The notion of maximality for a submodule of the Drury–Arveson module on the \(d\) -dimensional unit ball \({\mathbb {B}}_d\) is defined. For \(d=1\) , it is shown that every submodule of the Hardy module over the unit disc is maximal. But for \(d\ge 2\) we prove that any homogeneous submodule or submodule generated by polynomials is not maximal. A characterization of maximal submodules is obtained.     

Small secret exponent attack on RSA variant with modulus N=p^rq

We consider an RSA variant with Modulus \(N=p^rq\) . This variant is known as Prime Power RSA. In PKC 2004, May proved when decryption exponent \(d<N^{ \frac{r}{(r+1)^2}}\) or \(d< N^{\left( \frac{r-1}{r+1}\right) ^2}\) , one can factor \(N\) in polynomial time. In this paper, we improve this bound when \(r \le 5\) . We provide detailed experimental results to justify our claim.     

On the formation of shock and soliton in a dense quantum dusty plasma with cylindrical geometry

Excitation of nonlinear waves in a quantum dusty plasma with various effects is analyzed when the geometry is cylindrical.This introduces the effect of finite boundary conditions on the solitary waves so generated. it is observed that the nonlinear equation deduced is cylindrical KP–Burger type leading to the generation of Shock Wave. Different situations which arises in various parameter regions are considered separately and the form of the nonlinear excitations are obtained explicitly.