Dendroclimatic response of Picea jezoensis along an altitudinal gradient in Changbai Mountains

We investigated the effects of climate on Yeddo spruce (Picea jezoensis) radial growth along altitudinal gradients in the subalpine forests of Changbai Mountains using dendroclimatic analyses. Yeddo spruce at its lower and upper distribution limits was more sensitive to the climate. Despite precipitation being generally considered sufficient, we found that precipitation significantly affected Yeddo spruce radial growth. Yeddo spruce at its lower distribution limit was much more affected by precipitation while Yeddo spruce at its upper distribution limit was much more affected by minimum temperature. Yeddo spruce at its medial altitude was affected by sunshine ratio. These results demonstrated that climate affected Yeddo spruce growth differently depending on its altitudinal distributions in the Changbai Mountains. Both temperature and precipitation in the annualization period significantly correlated with Yeddo spruce radial growth. However, warmer signals were not reflected in radial growth trend during the past 20 years because annual total precipitation declined during the same period. It appeared that the climate affected tree rings growth by altering soil moisture availability.

     

A variable pressure method for characterizing nanoparticle surface charge using pore sensors

A novel method using resistive pulse sensors for electrokinetic surface charge measurements of nanoparticles is presented. This method involves recording the particle blockade rate while the pressure applied across a pore sensor is varied. This applied pressure acts in a direction which opposes transport due to the combination of electro-osmosis, electrophoresis, and inherent pressure. The blockade rate reaches a minimum when the velocity of nanoparticles in the vicinity of the pore approaches zero, and the forces on typical nanoparticles are in equilibrium. The pressure applied at this minimum rate can be used to calculate the zeta potential of the nanoparticles. The efficacy of this variable pressure method was demonstrated for a range of carboxylated 200 nm polystyrene nanoparticles with different surface charge densities. Results were of the same order as phase analysis light scattering (PALS) measurements. Unlike PALS results, the sequence of increasing zeta potential for different particle types agreed with conductometric titration.     

Phase Equilibria in the System “FeO”-CaO-SiO<Subscript>2</Subscript>-Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-MgO at Different CaO/SiO<Subscript>2</Subscript> Ratios

The “FeO”-containing slags play an important role in the operation of an ironmaking blast furnace (BF), in particular the primary slags such as the system “FeO”-CaO-SiO₂-Al₂O₃-2 mass pct MgO with CaO/SiO₂ weight ratios of 1.3, 1.5, and 1.8 saturated with metallic iron. To investigate the characteristics of such a slag system and its behavior in BF, the phase equilibria and liquidus temperatures in the slag system have been experimentally determined using the high-temperature equilibration and quenching technique followed by an electron probe X-ray microanalysis (EPMA). Isotherms between 1553 K and 1603 K (1280 °C and 1330 °C) were determined in the primary phase fields of dicalcium silicate, melilite, spinel, and monoxide [(Mg,Fe²⁺)O]. Pseudo-ternary phase diagrams of (CaO + SiO₂)-Al₂O₃-“FeO” with a fixed MgO concentration at 2 mass pct and at CaO/SiO₂ ratios of 1.3, 1.5, and 1.8 have been discussed, respectively, simplifying the complexity of the slag system for easy understanding and applying in BF operation. It was found that the liquidus temperatures increase in melilite and spinel primary phase fields, but decrease in dicalcium silicate and monoxide primary phase fields with increasing Al₂O₃/(CaO + SiO₂) ratio. In addition, the liquidus temperatures decrease with increasing “FeO” concentration in dicalcium silicate and melilite primary phase fields, while showing an increasing trend in the spinel and monoxide primary phase fields. The data resulted from this study can be used to improve and optimize currently available database of thermodynamic models used in FactSage.     

Effect of object onset on the distribution of visual attention.

There now exists considerable evidence to suggest that the appearance of a new object in the visual field captures visual attention. One of the consequences of this attentional capture is that the object initiates a redistribution of attentional resources across visual space. This is classically observed in the precuing paradigm in which the onset of an abrupt cue influences the processing of a subsequently presented target. The present research describes a new phenomenon that occurs as a result of a new object appearing in the visual field. A stimulus presented in a region of space adjacent to a comer of an onsetting object receives an enhancement of processing relative to a stimulus presented adjacent to one of the object's straight edges. With the use of 2 converging methods, evidence is presented that suggests that the effect is a higher order attentional phenomenon whereby greater resources become directed to the comers of objects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Examining the relationship between free recall and immediate serial recall: The effects of list length and output order.

In 4 experiments, participants were presented with lists of between 1 and 15 words for tests of immediate memory. For all tasks, participants tended to initiate recall with the first word on the list for short lists. As the list length was increased, so there was a decreased tendency to start with the first list item; and, when free to do so, participants showed an increased tendency to start with one of the last 4 list items. In all tasks, the start position strongly influenced the shape of the resultant serial position curves: When recall started at Serial Position 1, elevated recall of early list items was observed; when recall started toward the end of the list, there were extended recency effects. These results occurred under immediate free recall (IFR) and different variants of immediate serial recall (ISR) and reconstruction of order (RoO) tasks. We argue that these findings have implications for the relationship between IFR and ISR and between rehearsal and recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling of Droplet Generation in a Top Blowing Steelmaking Process

Metallurgical and Materials Transactions B - Quantification of metal droplets ejected due to impinging gas jet on the surface of liquid metal is an important parameter for the understanding and for...     

Designing emergent cooperation: a pursuit–evasion game case study

This research concerns a comparison of two neuroevolution approaches for the design of cooperative behavior in a group of simulated mobile robots. The first approach, termed single pool (SP), was characterized by robot neural controllers that were derived from a single genotype. The second approach, termed multiple pools (MP), was characterized by robot neural controllers that were derived from many different genotypes. The application domain implemented a pursuit–evasion game in which teams of robots of various sizes, termed predators, collectively worked to capture (immobilize) other robots, termed prey. The MP and SP approaches were tested, with and without lifetime learning, for the design of cooperative prey capture behavior within teams of predators. Results indicated that the MP approach was superior to the SP approach in terms of measures defined for prey-capture performance. Specifically, the MP approach facilitated behavioral specializations in the predator team facilitating emergent cooperative prey capture strategies that proved effective for the various team sizes tested.