Microstructure and domain configurations in ferroelectric PbTiO3 and Pb(Zr,Ti)O3 thin fims

Ferroelectric domain configurations in PbTiO₃ and Pb(Zr_xT_1−x)O₃ (PZT, x = 0.3 or 0.5) thin films have been studied by transmission electron microscopy. The PbTiOg and PZT thin films have been deposited by the ionized cluster beam technique and radio frequency sputtering, respectively. The grain size in these thin films is typically less than 0.5 μm. Lamellar 90°-domain features have been observed in both PbTiO₃ and PZT (30/70) samples. The domain walls correspond to the {011} twin boundaries. La-doping and Ca-modification are shown to affect the microstructure of the PZT films. No clear domain feature occurs in the PZT thin film that has composition near the morphotropic phase boundary. The effects of grain sizes are briefly discussed.     

Digit pipelined arithmetic on fine-grain array processors

In this paper, we present a novel scheme for performing fixed-point arithmetic efficiently on fine-grain, massively parallel, programmable architectures including both custom and FPGA-based systems. We achieve anO(n) speedup, wheren is the operand precision, over the bit-serial methods of existing fine-grain systems such as the DAP, the MPP and the CM2, within the constraints of regular, near neighbor communication and only a small amount of on-chip memory. This is possible by means of digit pipelined algorithms which avoid broadcast and which operate in a fully systolic manner by pipelining at the digit level. A base 4, signed-digit, fully redundant number system and on-line techniques are used to limit carry propagation and minimize communication costs. p ]Although our algorithms are digit-serial, we are able to match the performance of the bit-parallel methods, while retaining low communication complexity. Reconfigurable hardware systems built using field programmable gate arrays (FPGA's) can share in the speed benefits of these algorithms. By using the organization of logic blocks suggested in this paper, problems of placement and routing that exist in such systems can be avoided. Since the algorithms are amenable to pipelining, very high throughput can be obtained.     

Addiction to altruism? Opponent-process theory and habitual blood donation.

Explores the possibility that one of undoubtedly several interacting motives behind commitment to regular blood donation is the development of an affective "addiction" to the behavior, based on initial anxiety, through the mechanisms postulated by opponent-process theory. Pre- and post-donation responses to 1,846 blood donation experiences were subjected to correlational and regression analyses. Support was found for the relevance of opponent-process theory to the development of positive affective responses to donation. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dependence of electrical properties of polycrystalline cvd si films on grain size and impurity doping concentrationa,b

The electrical properties of sets of simultaneously grown p-type polycrystalline Si films, deposited by SiH₄ pyrolysis on polycrystalline high-purity alumina substrates and B-doped during growth, were determined by Hall-effect measurements in the temperature range 77-420K as functions both of impurity doping concentration N (~10^l5 to ~10²⁰cm⁻³) and average grain size (≈1 to ≈125μm) in the film. Room temperature data showed rapidly increasing resistivities and rapidly decreasing free-carrier concentrations for doping below a critical concentration N_m and distinct mobility minima at that concentration, with the value of N_m being larger the smaller the average grain size. Measurements as a function of sample temperature showed the intergrain barrier height E_b, decreasing from a maximum value of ~0.4eV at the critical concentration to very small values (~0.01eV) for concentrations above 10¹⁹cm⁻³, with a functional dependence close to E_b ∝l/N^1/2 and E_b for any given concentration being larger the smaller the average grain size. Results are interpreted in terms of the grain-boundary trapping model. Trapped carrier densities in the grain boundaries were calculated to range from ~5×l0¹¹cm⁻² at N≈N_m to ~5×l0¹²cm⁻² for N>10¹⁹cm⁻³, the density being higher the smaller the grain size, and evidence was found for an energy distribution of traps in the Si bandgap, rather than a fixed density at a single discrete energy level. The observed relationship between N_m and average grain size nearly coincides with that of the model for films with ~lμm grain size but sharply departs from it for larger grain sizes, indicating probable applicability of the model for grain sizes up to that range. ^aThis work was supported by the U.S. Department of Energythrough its San Francisco Operations Office under Contract DE-AC03-79ET23045 and monitored by the Solar Energy Research Institute, Golden, CO. bThese results were first described at the 22nd Electronic Materials Conference, Ithaca, NY, June 21–27, 1980, Paper No. M4.     

Sex differences in children's response to training on a visual-spatial test.

In a study with 133 children in Grades 1, 3, and 5, a brief training procedure designed to improve performance on the Children's Embedded Figures Test, a test of visual ability, resulted in significant improvement for girls but not for boys. No sex difference was observed among children receiving this training. The implications for theories of sex differences in visual–spatial ability are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimizing Leakage Energy Consumption in Cache Bitlines

As technology scales down into deep-submicron, leakage energy is becoming a dominant source of energy consumption. Leakage energy is generally proportional to the area of a circuit and caches constitute a large portion of the die area. Therefore, there has been much effort to reduce leakage energy in caches. Most techniques have been targeted at cell leakage energy optimization. Bitline leakage energy is critical as well. To this end, we propose a predictive precharging scheme to reduce bitline leakage energy consumption. Results show that energy savings are significant with little performance degradation. Also, our predictive precharging is more beneficial in more aggressively scaled technologies.     

Individual differences and autonomic control: Absorption, hypnotic susceptibility, and the unilateral control of skin temperature.

Proposed to (a) replicate earlier findings that human Ss could voluntarily control peripheral skin temperature, (b) test the hypothesis that hypnotic susceptibility and the capacity for absorbed, imaginative attention would enhance autonomic learning and performance, and (c) demonstrate a learning effect, if one exists. A comparison was made with 7 Ss who scored high and 7 Ss who scored low on both a modified version of the Harvard Group Scale of Hypnotic Susceptibility and the Tellegen Absorption Scale. Auditory feedback was used to train Ss to produce a difference in skin temperature in one hand relative to the other in a direction specified by the E. Large and reliable performance and learning effects were found, but they were unrelated to hypnotic susceptibility or the capacity for absorbed, imaginative attention. Variables that might account for individual differences in learning and performance are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Finance, Policy and Industrial Dynamics—The Rise of Co-productions in the Film Industry

This paper explores the growing phenomenon of international co-productions in the film industry. We argue that the rise of co-productions is part of a wider narrative of financial and institutional innovation shaping industrial organization in the film industry. This narrative centres on film finance as a central risk distribution mechanism, and discusses how changes in film support policy, increased tax competition, the search for finance and an abundance of inflowing capital are increasingly driving industrial dynamics in the film industry.     

Students’ linguistic behaviour in online discussion groups: Does gender matter?

This research examined students’ language use and interaction styles in text-based, computer-mediated discussion groups. The contributions of 197 introductory psychology students (149 females, 48 males) participating in asynchronous computer-mediated communication (CMC) were collated. Both quantitative and qualitative methods were used, under the methodological framework of qualitative content analysis [Mayring, P. (2000). Qualitative Content Analysis. Forum Qualitative Sozialforschung/Forum: Qualitative Social Research [online] 1. http://qualitative-research.net/fqs-e/2-00halt-e.htm Accessed 10.06.2001]. A coding system, which incorporated the creation of ‘supercodes’, was developed using Atlas.ti 4.2 and used to code 699 student postings in total. The frequencies of coded categories were analysed using χ² statistics in SPSS 10. It was found that males and females were similar regarding use of individual linguistic variables, with the exception of intensifiers as more females used them than males. However, significant gender differences were found in use of many of the stylistic variables and the supercode analysis showed overall gender-related patterns in interaction styles. Males were more likely to use authoritative language and to respond negatively in interactions, than females. On the other hand, females were more likely to explicitly agree and support others and make more personal and emotional contributions, than males. The results suggest that gendered power differentials may carry over into online contexts, which has implications for the use of CMC in education.