Increase in available soil phosphorus at depth in some north Queensland krasnozems

Lack of response to phosphate application of an established pasture on a soil with a low surface content of available phosphorus is attributed to the high content of available phosphorus at greater depth

Leaching and residual value of superphosphate and rock phosphate under high rainfall conditions

Leaching of superphosphate and of rock phosphate ran fairly parallel. Residual phosphorus after 3 years from the application of 200 lb. P205 per acre was appreciable, but there was little retention from amounts of 100 lb and lower

Effect of Centrosema pubescens Benth on soil fertility in the humid tropics

The present paper covers an investigation of soils under grazed guinea grass (Panicum maximum var. typica) and guinea grass/centro pastures of various ages. Comparisons of these soils with each other and with a soil under tropical rain-forest are reported. From investigations of 16-yr-old swards, it is concluded that Guinea grass/centro pastures can play an important part in the tropics in maintaining soil-N and OM in the better soils and in improving these constituents in the poorer soils

The laboratory estimation of the phosphorus status of soil. 1. Choice of extraction method

The extractants 0.01N H2SO4 (Kerr and von Stieglitz) and 0.03 N NH4F in 0.1 N HCl (Bray and Kurtz) gave results which were approximately linearly related. The Kerr and von Stieglitz method would be suitable for routine use

Cumulant ratios and their scaling functions for Ising systems in strip geometries

We calculate the fourth-order cumulant ratio (proposed by Binder) for the two-dimensional Ising model in a strip geometry L x oo. The Density Matrix Renormalization Group method enables us to consider typical open boundary conditions up to L=200. Universal scaling functions of the cumulant ratio are determined for strips with parallel as well as opposing surface fields.Comment: 4 pages, RevTex, one .eps figure; references added, format change

Understanding person acquisition using an interactive activation and competition network

Face perception is one of the most developed visual skills that humans display, and recent work has attempted to examine the mechanisms involved in face perception through noting how neural networks achieve the same performance. The purpose of the present paper is to extend this approach to look not just at human face recognition, but also at human face acquisition. Experiment 1 presents empirical data to describe the acquisition over time of appropriate representations for newly encountered faces. These results are compared with those of Simulation 1, in which a modified IAC network capable of modelling the acquisition process is generated. Experiment 2 and Simulation 2 explore the mechanisms of learning further, and it is demonstrated that the acquisition of a set of associated new facts is easier than the acquisition of individual facts in isolation of one another. This is explained in terms of the advantage gained from additional inputs and mutual reinforcement of developing links within an interactive neural network system. <br/

Valence Band Dependent Charge Transport in Bulk Molecular Electronic Devices Incorporating Highly Conjugated Multi-[(Porphinato)Metal] Oligomers

Molecular electronics offers the potential to control device functions through the fundamental electronic properties of individual molecules, but realization of such possibilities is typically frustrated when such specialized molecules are integrated into a larger area device. Here we utilize highly conjugated (porphinato)metal-based oligomers (PMn structures) as molecular wire components of nanotransfer printed (nTP) molecular junctions; electrical characterization of these "bulk" nTP devices highlights device resistances that depend on PMn wire length. Device resistance measurements, determined as a function of PMn molecular length, were utilized to evaluate the magnitude of a phenomenological β corresponding to the resistance decay parameter across the barrier; these data show that the magnitude of this β value is modulated via porphyrin macrocycle central metal atom substitution [β(PZnn; 0.065 Å-1) &lt; β(PCun; 0.132 Å-1) &lt; β(PNin; 0.176 Å-1)]. Cyclic voltammetric data, and ultraviolet photoelectron spectroscopic studies carried out at gold surfaces, demonstrate that these nTP device resistances track with the valence band energy levels of the PMn wire, which were modulated via porphyrin macrocycle central metal atom substitution. This study demonstrates the ability to fabricate "bulk" and scalable electronic devices in which function derives from the electronic properties of discrete single molecules, and underscores how a critical device function - wire resistance - may be straightforwardly engineered by PMn molecular composition

Various spin-polarization states beyond the maximum-density droplet: a quantum Monte Carlo study

Using variational quantum Monte Carlo method, the effect of Landau-level mixing on the lowest-energy--state diagram of small quantum dots is studied in the magnetic field range where the density of magnetic flux quanta just exceeds the density of electrons. An accurate analytical many-body wave function is constructed for various angular momentum and spin states in the lowest Landau level, and Landau-level mixing is then introduced using a Jastrow factor. The effect of higher Landau levels is shown to be significant; the transition lines are shifted considerably towards higher values of magnetic field and certain lowest-energy states vanish altogether.Comment: 4 pages, 2 figures. Submitted to Phys. Rev.

Stereotype priming in face recognition: interactions between semantic and visual information in face encoding

The accuracy with which previously unfamiliar faces are recognised is increased by the presentation of a stereotype-congruent occupation label (Klatzky, Martin, & Kane, 1982a, b). For example, providing the label ‘criminal’ both during encoding and test improves recognition for previously unfamiliar faces that look like the stereotypical criminal. Experiments 1 and 2 both replicate this effect and show that the label exerts its influence during the encoding of stereotypical faces and has little influence at test. These findings indicate that semantic information that is congruent with novel stereotypical faces facilitates their encoding