Formation of the Yazi Spring Stream and its significance on tectonics-climate on the northern slope of Kunlun Mountains

IEECAS SKLLQG

Radiolarian fauna in surface sediments of the northeastern East China Sea

Radiolarian abundance and species composition have been determined in 72 surface: sediment samples from the northeastern East China Sea. The results are compared with chemical and physical properties of the overlying water masses, and with sediment conditions. In the study area, radiolarian abundance and species number increase markedly from northwest to southeast, and their distributions can be divided into three provinces: the low-density zone corresponding to the shelf, the middle-density zone corresponding to the western slope of the Okinawa Trough and the high-density zone corresponding to the central part of the Okinawa Trough. The distribution of radiolarians correlates well with modem sea surface temperature and sea surface salinity, but shows a negative relation with nutrients and primary productivity of the overlying water. This distribution pattern is also strongly affected by the sediment type and terrigenous material input. Also, the Kuroshio Current has an important effect on controlling the distribution and species composition of radiolarian fauna in this area. Based on three Q-mode factors (accounting for 90.2% of the variance), three radiolarian assemblages have been distinguished, and their distributions are clearly correlated with oceanographic current patterns in the region. The mixed water assemblage dominated by Tetrapyle circularis, Tetrapyle quadriloba and Ommatartus tetrathalamus tetrathalamus is restricted to the area of the Mixed Water, but mainly influenced by the Shelf Water. The Kuroshio Water assemblage, which is dominated by Lithelius minor, Dictyocoryne profunda, Stylodictya multispina, Acrosphaera spinosa, Dictyocoryne truncatum, Spongaster tetrars, Stylodictya arachnia and Ommatartus tetrathalamus tetrathalamus, is basically controlled by the Kuroshio Surface Water. And the transition assemblage dominated by Tetrapyle quadriloba and Monozonium pachystylum is associated with the Tsushima Warm Current Water. The boundaries among these assemblages approximately coincide with the oceanographic front. And the changes in the distribution of these assemblages could be,regarded as-not only modifications of the water masses, but also indicators of the possible movements of the oceanic front. (C) 2003 Elsevier Science B.V. All rights reserved.

Sea surface height and transport stream function of the South China Sea from a variable-grid global ocean circulation model

A fine-grid model (1/6degrees) covering the South China Sea (SCS), East China Sea and Japan/East Sea, which is embedded into a coarse-grid (3degrees) global model, was established to study the SCS circulation. In the present paper, we report the model-produced monthly and annual mean transport stream functions and sea surface heights(SSH) and their anomalies of the SCS. Comparison to the TOPEX/Poseidon data shows that the model-produced monthly sea surface height anomalies (SSHA) are in good agreement with altimeter measurements. Based on the results, the circulation of the SCS, especially the upper layer circulation, is discussed. In the surface layer, the western Philippine Sea water intrudes into the SCS through the Luzon Strait in autumn, winter and spring, but not in summer. However, as far as the whole water column is concerned, the water intrudes into the SCS through the Luzon Strait all the year round. This indicates that in summer the water still intrudes into the SCS in the subsurface and intermediate layers. The area near the northern continental slope of the SCS is dominated by a cyclonic circulation all the year round. The SCS Southern Anticyclonic Gyre, SE Vietnam Off-Shore Current in summertime and SCS Southern Cyclonic Gyre in wintertime are reproduced reasonably. The difference between the monthly averaged SSH and SSHA is significant, indicating the importance of the mean SSH in the SCS circulation.

Metodologia para avaliação experimental da atividade da fauna bentônica.

2007

Stream segregation on a single electrode as a function of pulse rate in cochlear implant listeners.

While cochlear implants (CIs) usually provide high levels of speech recognition in quiet, speech recognition in noise remains challenging. To overcome these difficulties, it is important to understand how implanted listeners separate a target signal from interferers. Stream segregation has been studied extensively in both normal and electric hearing, as a function of place of stimulation. However, the effects of pulse rate, independent of place, on the perceptual grouping of sequential sounds in electric hearing have not yet been investigated. A rhythm detection task was used to measure stream segregation. The results of this study suggest that while CI listeners can segregate streams based on differences in pulse rate alone, the amount of stream segregation observed decreases as the base pulse rate increases. Further investigation of the perceptual dimensions encoded by the pulse rate and the effect of sequential presentation of different stimulation rates on perception could be beneficial for the future development of speech processing strategies for CIs.

Constructal dendritic configuration for the radiation heating of a solid stream

Here we show that the configuration of a slender enclosure can be optimized such that the radiation heating of a stream of solid is performed with minimal fuel consumption at the global level. The solid moves longitudinally at constant rate through the enclosure. The enclosure is heated by gas burners distributed arbitrarily, in a manner that is to be determined. The total contact area for heat transfer between the hot enclosure and the cold solid is fixed. We find that minimal global fuel consumption is achieved when the longitudinal distribution of heaters is nonuniform, with more heaters near the exit than the entrance. The reduction in fuel consumption relative to when the heaters are distributed uniformly is of order 10%. Tapering the plan view (the floor) of the heating area yields an additional reduction in overall fuel consumption. The best shape is when the floor area is a slender triangle on which the cold solid enters by crossing the base. These architectural features recommend the proposal to organize the flow of the solid as a dendritic design, which enters as several branches, and exits as a single hot stream of prescribed temperature. The thermodynamics of heating is presented in modern terms in the Sec. (exergy destruction, entropy generation). The contribution is that to optimize "thermodynamically" is the same as reducing the consumption of fuel. © 2010 American Institute of Physics.

Chemically tagging the Hyades stream: does it partly originate from the Hyades cluster?

The Hyades stream has long been thought to be a dispersed vestige of the Hyades cluster. However, recent analyses of the parallax distribution, of the mass function, and of the action-space distribution of stream stars have shown it to be rather composed of orbits trapped at a resonance of a density disturbance. This resonant scenario should leave a clearly different signature in the element abundances of stream stars than the dispersed cluster scenario, since the Hyades cluster is chemically homogeneous. Here, we study the metallicity as well as the element abundances of Li, Na, Mg, Fe, Zr, Ba, La, Ce, Nd and Eu for a random sample of stars belonging to the Hyades stream, and compare them with those of stars from the Hyades cluster. From this analysis: (i) we independently confirm that the Hyades stream cannot be solely composed of stars originating in the Hyades cluster; (ii) we show thatsomestars (namely 2/21) from the Hyades stream nevertheless have abundances compatible with an origin in the cluster; (iii) we emphasize that the use of Li as a chemical tag of the cluster origin of main-sequence stars is very efficient in the range 5500K ≤Teff≤ 6200K, since the Li sequence in the Hyades cluster is very tight, while at the same time spanning a large abundance range; (iv) we show that, while this evaporated population has a metallicity excess of ~0.2 dex with respect to the local thin-disc population, identical to that of the Hyades cluster, the remainder of the Hyades stream population has still a metallicity excess of ~0.06-0.15 dex, consistent with an origin in the inner Galaxy and (v) we show that the Hyades stream can be interpreted as an inner 4:1 resonance of the spiral pattern: this then also reproduces an orbital family compatible with the Sirius stream, and places the origin of the Hyades stream up to 1kpc inwards from the solar radius, which might explain the observed metallicity excess of the stream population. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.