A comparative study of thin film insulation techniques for gold electrodes

The increasing use of microelectrodes in small sample volumes and biological environments require the use of thin film insulators. The insulating ability of the thin film insulators electrophoretic paint, polyimide, allylphenol phenol copolymer and an epoxy dip coat have been assessed using gold wires coated in the relevant film. Insulation was assessed by recording the current from the wires in a solution of known redox couple. The effect of prolonged storage in aqueous solutions was also investigated. The most successful insulating approach, with regards to insulative ability, prolonged use in aqueous environments and speed of application, was the combination of cathodic electrophoretic paint followed by polyimide.     

Psychopathy and alexithymia in female offenders.

Determined the comorbidity of psychopathy and alexithymia in 37 female inmates of a medium-security prison. The authors also investigated the association between psychopathy and alexithymia with the use of affective language in response to questions about an emotional event, and with their propensity for violence. The extent of psychopathy and alexithymia were assessed with the Hare Psychopathy Checklist—Revised (PCL-R) and the Toronto Alexithymia Scale (TAS), respectively. Using standard cutoff scores, 30% were identified as psychopaths, and 32% as alexithymics. Three Ss were both psychopaths and alexithymics. The correlation between PCL-R and TAS total scores was not significant, but the socially deviant impulsive factor of the PCL-R significantly correlated with the TAS items that reflect inability to discriminate feelings and bodily sensations. Alexithymia, but not psychopathy, was negatively related to measures of affective speech content. Both psychopathy and alexithymia were associated with a history of violence. In spite of several manifest similarities, psychopathy and alexithymia appear to be different clinical constructs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

英国银匠大师Paul de Lamerie

Paul de Lamene是18世纪早期英国银器鼎盛时期一颗耀眼的明星，他也是那个时代英国最多产的银匠。     

How to find Steiner minimal trees in euclideand-space

This paper has two purposes. The first is to present a new way to find a Steiner minimum tree (SMT) connectingN sites ind-space,d >- 2. We present (in Appendix 1) a computer code for this purpose. This is the only procedure known to the author for finding Steiner minimal trees ind-space ford > 2, and also the first one which fits naturally into the framework of backtracking and branch-and-bound. Finding SMTs of up toN = 12 general sites ind-space (for anyd) now appears feasible.We tabulate Steiner minimal trees for many point sets, including the vertices of most of the regular and Archimedeand-polytopes with <- 16 vertices. As a consequence of these tables, the Gilbert-Pollak conjecture is shown to be false in dimensions 3–9. (The conjecture remains open in other dimensions; it is probably false in all dimensionsd withd 3, but it is probably true whend = 2.)The second purpose is to present some new theoretical results regarding the asymptotic computational complexity of finding SMTs to precision .We show that in two-dimensions, Steiner minimum trees may be found exactly in exponential time O(C ^N ) on a real RAM. (All previous provable time bounds were superexponential.) If the tree is only wanted to precision , then there is an (N/)^O(N)-time algorithm, which is subexponential if 1/ grows only polynomially withN. Also, therectilinear Steiner minimal tree ofN points in the plane may be found inN ^O(N) time.J. S. Provan devised an O(N ⁶/⁴)-time algorithm for finding the SMT of a convexN-point set in the plane. (Also the rectilinear SMT of such a set may be found in O(N ⁶) time.) One therefore suspects that this problem may be solved exactly in polynomial time. We show that this suspicion is in fact true—if a certain conjecture about the size of Steiner sensitivity diagrams is correct.All of these algorithms are for a real RAM model of computation allowing infinite precision arithmetic. They make no probabilistic or other assumptions about the input; the time bounds are valid in the worst case; and all our algorithms may be implemented with a polynomial amount of space. Only algorithms yielding theexact optimum SMT, or trees with lengths (1 + ) × optimum, where is arbitrarily small, are considered here.     

On the study of creep feed grinding of alumina

Several issues involved in creep feed grinding of alumina with diamond wheels were studied. Influences of variables on responses were investigated. Off-line optimization was performed by formulating the grinding process as a multi-objective nonlinear mixed integer problem. The dominant mechanism of material removal was determined. The grinding process was simulated to obtain the number of active cutting edges and the grinding parameters such as cutting length, maximum undeformed chip thickness, etc. Unit load distribution was characterized and then used to estimate the percentage of cutting edges that fracture or plastically cut the material and to derive the probability distribution function for substance cracks. Fractal concept was applied to characterize wheel profiles. Findings from these studies are reported in this paper. These studies are definitely not complete, but surely shed some light on the creep feed grinding process of ceramic materials.     

Aging Behavior of xPb(Fe2/3W1/3)O3· (1 –x)Pb(Fe1/2Nb1/2)O3 Ceramic

The aging behavior of a series of lead perovskite dielectrics with the compositions x Pb(Fe_2/3W_1/3)O₃·(1 – x )Pb(Fe_1/2-Nb_1/2)O₃, where 0 ≤ x ≤ 1, and the effect of dopants were studied. Below the Curie temperature ( T _c), the capacitance and the dissipation factor (tan δ) decrease approximately linearly with logarithmic time. The aging rate depends on the temperature difference, Δ T , between the aging temperature and T _c, and on the dopant concentration, but is independent of the measurement frequency between 1 and 1000 kHz. The maximum aging rate is about 3% per decade of time for capacitance and 5% per decade for tan δ at 1 mol% dopant concentration, and increases to 6.3% for capacitance and 8.5% for tan δ at 0.7 mol% dopant concentration. These results are consistent with an aging mechanism caused by changing ferroelectric domain structure with time, as proposed for BaTiO₃.