A cubic, 12-connected, microporous metal-organometallic phosphate framework sustained by truncated tetrahedral nodes

A rare example of a microporous metal-organic phosphate, [Co(12)(L)(6)(μ(3)-PO(4))(4)(μ(3)-F)(4)(μ-H(2)O)(6)][NO(3)](2) (1), is synthesized by the reaction of a [(η(5)-C(5)H(5))Fe(II)](+)-functionalized terephthalate ligand with Co(NO(3))(2)·6H(2)O and phosphate and fluoride ions generated from the in situ hydrolysis of hexafluorophosphate. 1 is a cubic, 12-connected, face-centered cubic framework sustained by the linear connection of unprecedented, dodecanuclear truncated tetrahedral coordination clusters.     

A point‐input,point‐output forest as a microprototype for capital accounting

The point‐input, point‐output, plantation forest was first studied by Martin Faustmann in the mid‐19th century. The exploitation of a Faustmannian forest involves decisions concerning investments and receipts over time that are qualitatively different from the smooth, convex flows that are usually studied in the economics of accounting. The simple, well understood analysis of the forest has implications for the concept of income in forestry as well as in other industries that are typified by nonconvex decisions. A forest is a salient example of the importance of discrete, irreversible investment, and of the role of price effects (capital gains) in income accounting and, more fundamentally, of perceptions of the “right prices” in economic analysis.     

A new formula for winding number

We give a new formula for the winding number of smooth planar curves and show how this can be generalized to curves on closed orientable surfaces. This gives a geometric interpretation of the notion of winding number due to B. Reinhart and D.R.J. Chillingworth.     

Improvements in ion-trap chemical-ionization performance.

Ion-trap chemical-ionization performance has been improved by application of a modified scan function for the rejection of the undesired electron-ionization-like (EI-like) ions formed at the beginning of the reaction ionization period. The net effect of this software modification to the automatic reaction control is to produce chemical ionization (CI) spectra that are no longer adulterated with concentration-dependent EI-like ions. Under such improved conditions, CI spectra from an ion trap can now be directly compared with CI spectra produced on conventional quadrupole and magnet-scanning instruments.     

The synthesis of l-alkyl-1,4-dihydro-4-quinolone-2-carboxylic acids

A general method tor the preparation of 1,4-dihydro-4-quinolone-2-carboxylic acids, especially those which carry alkyl substituents on the ring N-atom, is described.     

31P chemical shifts in N-aryliminotriphenylphosphoranes

³¹P chemical shifts in N-aryliminotriphenylphosphoranes and the corresponding N-methylated phosphonium salts are presented. They can be correlated with those theories of the bonding in phosphorus-nitrogen ylides which involve partial double bonding as a result of p^π–d^π overlap.     

Synergistic inhibition effect of 2-mercaptobenzothiazole and Tween-80 on the corrosion of brass in NaCl solution

The corrosion inhibition of brass in 0.2 M NaCl in the presence of 2-mercaptobenzothiazole (MBT) and polyoxyethylene sorbitan monooleate (Tween-80) has been investigated using potentiodynamic polarization, X-ray photoelectron spectroscopy and inductively coupled plasma analysis. Analysis of the results revealed that the addition of MBT and Tween-80 inhibits the corrosion of brass in 0.2 M NaCl. Potentiodynamic polarization measurements showed that MBT acts as a mixed-type inhibitor and Tween-80 as an anodic inhibitor. Corrosion inhibition occurs through adsorption of the inhibitor on brass surface without modifying the corrosion mechanism. The adsorption of MBT and Tween-80 both follow Langmuir adsorption isotherm. Potentiodynamic polarization results suggested that the mixture of MBT and Tween-80 acts as a mixed-type inhibitor. Inhibition efficiency of 79.0 and 62.5% were obtained in the presence of optimum concentration of MBT and Tween-80, respectively. The addition of the mixture of MBT and Tween-80 enhanced the inhibition efficiency to 94.0% and showed a synergism of inhibition. XPS analysis indicated that MBT adsorbed on brass surface along with Tween-80 in the presence of the mixture of MBT and Tween-80. The results of solution analysis using ICP showed that the mixture of MBT and Tween-80 effectively controlled the dezincification of brass.