Chemical sensors based on vertically aligned p-type CuO nanowire arrays have been fabricated by in situ micromanipulation in a scanning electron microscope. The sensors are capable of detecting air-diluted H 2 S to the parts per billion level. Different mechanisms have been proposed for the detections of low and high concentrated H 2 S. The recoverable detection for low concentrations can be explained by an oxygen adatom related process, while an interface reaction model fits for the high concentration detection, which also explains the exponential sensing response. Furthermore, selective detection for H 2 S has also been investigated. The sensor demonstrated strong selectivity for H 2 S, as compared with the responses to high concentrations of H 2 , CO, and NH 3 .

Quantum mechanical studies point to the importance of polarization and charge transfer (CT) in zinc binding. A new CT force field is used to study these effects in ion-water dimers and in aqueous solution. Quantum mechanics calculations are carried out to determine amounts of CT. Models for zinc and magnesium are parametrized to reproduce solvation structure, hydration free energy, and CT properties. The new models are subjected to energy decomposition, in which the effects of polarization and CT are investigated. The importance of these multibody interactions in the liquid is also considered. We find that, for divalent cations, polarization and charge transfer both strongly affect binding to water. Though polarization increases the internal (self) energy of water and ions, this is more than compensated for by a stronger ion-water interaction energy. The direction of the charge transfer from the water to the cation weakens the ion-water interaction; this increase in energy is counteracted by a decrease in the system energy due to electron delocalization.

PurposeThis paper aims to redefine the peer reference model – using student assistants to staff the reference desk – by expanding it to include upper‐level undergraduate students from various disciplines providing full reference service with minimal supervision as well as performing paraprofessional‐level duties.Design/methodology/approachSet within a backdrop of budget cuts, severe time and staffing limitations, and increasing demands for library services, the paper assesses the processes and results of implementing this new model of peer reference at a medium‐sized academic library.FindingsThe findings suggest that undergraduate students are not only capable but perhaps optimal at providing high‐quality reference service to their peers.Originality/valueThis paper redefines the peer reference model, using a case study carried out in a US university library.

The Forest and Rangeland Renewable Resources Planning Act of 1974 (RPA), P.L. 93-378, 88 Stat. 475, as amended, directed the Secretary of Agriculture to prepare a Renewable Resources Assessment by December 31, 1975, with an update in 1979 and each loth year thereafter. This Assessment is to include "an analysis of present and anticipated uses, demand for, and supply of the renewable resources offorest, range, and other associated lands with consideration of the international resource situation, and an emphasis of pertinent supply, demand and price relationship trends" (Sec. 3 .(a)). The 1989 WA Assessment is the third prepared in response to the RPA legidation. It is composed of 12 documents, including this one. The summary Assessment document presents an overview of analyses of the present situation and the outlook for the land base, outdoor recreation and wilderness, wildlife and fish, forest-range grazing, minerals, timber, and water. Complete analyses for each of these resources are contained in seven supporting technical documents: There are also techni-USDA Forest Service General