Studies on synthesis esterified zirconium glyphosates and their hydrophobic properties

A series of new organic-modified zirconium glyphosate compounds were synthesized based on the reactions between esterified glyphosates and ZrOCl₂. FT-IR spectra, solid-state ³¹P MAS NMR and elementary analysis proved the formation of these new compounds. Powder X-ray diffraction (PXRD) patterns and transmission electron microscope (TEM) images proved these compounds had lamellar structures. Scanning electronic microscope (SEM) images showed that solvents used in synthesis had great influence on the morphologies of products. Water contact angle measurements showed that the hydrophobic property of the products was a function of the number of carbon in esterified glyphosates, increased from 0° of zirconium glyphosate to 133° of dodecyl zirconium glyphosate. The present study offered a new route to synthesize organic-modified α-Zr(HPO₄)₂·H₂O (α-ZrP) materials with various morphology and controllable hydrophobic property.     

A dinuclear pyrazolato-N:N′-bridged dinickel(II) complex of 1,3-bis(5-chlorosalicylideneamino)propan-2-ol

The title compound, μ-[1,3-bis(5-chloro-2-oxidobenzyl­idene­amino)­propan-2-olato(3−)]-O,N,O′:O′,N′,O′′-μ-(3,5-di­methyl­pyrazolato)-N:N′-dinickel(II), [Ni₂(C₁₇H₁₃Cl₂N₂O₃)(C₅H₇N₂)], has crystallographic mirror symmetry. The Ni atoms in the dinuclear structure are linked symmetrically by the N atoms of the 3,5-di­methyl­pyrazole group and by the alkoxo O atom. Each Ni^II ion is coordinated by two N atoms and two O atoms, forming a square plane with trans-N₂O₂ geometry.     

The insertion of 1-phenyl-1-propyne into the ruthenaborane cluster HRu4(CO)12BH2 and the isolation and molecular structure of 1-phenyl-2,3-dimethylazulene

Photolysis of the tetraruthenaborane butterfly cluster HRu₄(CO)₁₂BH₂ with 1-phenyl-1-propyne yields the cluster product HRu₄(CO)₁₂B(H)C(Ph)CMeH. Interestingly, 1-phenyl-2,3-dimethylazulene has also been isolated from the reaction mixture. The formation of this substituted azulene is an example of a novel cyclodimerisation of the alkyne. The crystal structure of 1-phenyl-2,3-dimethylazulene has been determined.     

Tetraethylammonium (diorgano)halogeno-(2, 6-pyridinedicarboxylato)stannates: Synthesis,characterization and in vitro antitumour activity

The synthesis and characterization of tetraethylammonium (diorgano)halogeno(2, 6-pyridinedicarboxylato)stannates are described. The solution structures of these complexes in CDCl₃ and DMSO are discussed on the basis of ¹¹⁹Sn and ¹⁹F NMR data. Their in vitro antitumour activities against two human tumour cell lines, MCF-7 and WiDr, are presented.     

A framework for the value of information in inventory replenishment

Technological advances and changes in supply chain management practices have combined to draw attention to the value of information sharing in inventory replenishment. Academic research has produced seemingly conflicting results due to differences in the type of information that is shared, the supply chain structure, and the selection and parameterization of performance goals. This research provides a framework to help explain apparent differences in the extant literature. Our purpose is to understand what determines the value of information. With this specific view, we establish a set of research questions and suggest directions for future research.     

The p-hub center allocation problem

The p-hub center problem is to locate p hubs and to allocate non-hub nodes to hub nodes such that the maximum travel time (or distance) between any origin–destination pair is minimized. We address the p-hub center allocation problem, a subproblem of the location problem, where hub locations are given. We present complexity results and IP formulations for several versions of the problem. We establish that some special cases are polynomially solvable.     

How to Inflate in the Right Places-An Analysis of Design Characteristics to Cope with Variations in Gas Transmission Networks

This paper considers how much margin to allow when designing a large pipe network based on predictions of future gas supply and demand. Thus it deals with forecasting from the engineering aspect of how to cope with variations from the predicted pattern of events.The subject of the paper is the British Gas National Transmission System. The detail of the paper concerns some of the margins used to design the system, in particular their purpose, size and application.The methods used to analyse the margins are: simulation, regression, distribution fitting, convolution and risk analysis.The conclusion of the work is that different parts of the network require different sizes of margin to retain the same level of security, since the impact of localized forecasting errors and predicted plant failures varies significantly across the grid.     

Ab initio calculation of distortion and bonding energy components of the cis-trans conversion energy for formic,thiolformic and thionformic acids

The energy change in the formation of the intramolecular hydrogen-bonded ring conformers of formic, thiolformic and thionformic acids from the chain conformers has been divided up into distortion and bonding energy components, following the treatment of Smit, Derissen, and van Duijneveldt for the formation of the formic acid dimer.     

Experimental and theoretical investigation of the isotope shift of the 4D level in atomic potassium

Doppler-free two-photon laser spectroscopic measurements in the deep red spectral region have been performed on the transition 4² S _1/2→4² D _J in the naturally abundant isotopes 39 and 41 of atomic potassium. The 4D level isotope shift, ?81±12 MHz was obtained by combining the current results with data from Rydberg-state spectroscopy. Many-body perturbation theoretical calculations of the specific mass shift in the measured state are also presented. With the use of Brueckner orbitals the value ?70 MHz was obtained in substantial agreement with the experimental result.