We investigated the effects of seawater equilibrated with CO 2 -enriched air (2000 ppm, pH 7.4) on the early development of the mussel Mytilus galloprovincialis. Mussel embryos were incubated for 144 h (6 d) in control and high-CO 2 seawater to compare embryogenesis, larval growth and morphology with ordinary light, polarized light, and scanning electron microscopy. Embryogenesis was unaffected by exposure to high-CO 2 seawater up to the trochophore stage, but development at the trochophore stage was delayed when the shell began to form. All veliger larvae of the high-CO 2 group showed morphological abnormalities such as convex hinge, protrusion of the mantle and malformation of shells. Larval height and length were 26 ± 1.9% and 20 ± 1.1% smaller, respectively, in the high-CO 2 group than in the control at 144 h. These results are consistent with our previous findings of CO 2 effects on early development of the oyster Crassostrea gigas, although the severity of CO 2 damage appears to be less in M. galloprovincialis, possibly due to differing spawning seasons (oyster: summer; mussel: winter). Results from this and the previous study indicate that high CO 2 (2000 ppm) interferes with early development, particularly with larval shell synthesis, of bivalves; however, vulnerability to high CO 2 differs between species. Taken together with recent studies demonstrating negative impacts of high CO 2 on adult mussels and oysters, results imply a future decrease of bivalve populations in the oceans, unless acclimation to the predicted environmental alteration occurs.

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The optical properties of colored dissolved organic matter (CDOM) in the Changjiang (Yangtze River) plume water were investigated during the summer of 2009 and 2010. The absorption coefficient of CDOM at 325 nm (aCDOM) increased inversely with decreasing sea-surface salinity (SSS), implying that aCDOM can be used as a natural tracer of Changjiangdiluted water (CDW). This aCDOM vs. SSS relationship, however, differed between 2009 and 2010. For mapping the CDW plume, the aCDOM was retrieved from an ocean-color satellite. Values of SSS were also derived from the satellite-retrieved aCDOM using field-based SSS vs. aCDOM relationships. Satellite observations revealed the temporary variable eastward extension of a high aCDOM, low SSS CDW plume in the central East China Sea (ECS) during the summer. The CDW plume during the summer of 2010 extended southeastward from the mouth of the Changjiang (Yangtze River) to almost 26°N. Moreover, the branch of this southeastward CDW plume was seen to extend northeastward to the eastern ECS where the Kuroshio Current flows northeastward along the shelf break. Subsequently, this branch was distributed around southern Kyushu. Satellite observations revealed this unique dispersal of the CDW plume, which illustrates that the aCDOM and SSS from oceancolor satellite data are useful for monitoring the dispersal of this river-water plume.

The coupling of the waves launched from a 4.6 GHz lower hybrid (LH) system into PBX-M plasmas has been studied for both L mode and H mode plasmas. The characteristics of the plasma in front of the LH coupler have been measured with a fast Langmuir probe. The reflected power of the coupler has been measured across the transition to the H mode as a function of phase and the distance between the coupler and the separatrix. A transient rise in the LH reflection coefficient was observed near the L-H transition under some conditions. Coupling depends primarily on the electron density in the vicinity of the coupler, and proper positioning of the coupler can compensate for changes in the plasma edge due to H mode transitions. Good coupling can be maintained throughout the H mode.

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It has been said that connecting MOSFETs in parallel makes power consumption reduce without concentrating current on one of MOSFETs easily, because the resistance of MOSFET have a positive temperature characteristic. But switching MOSFETs under low voltage and high current condition causes concentration of switching loss owing to unbalance of avalanche characteristics of MOSFETs and the concentration of switching loss leads a MOSFET to thermal destruction. In this paper, a novel gate drive circuit dividing the switching loss equally between MOSFETs connected in parallel is proposed. The surge energy at turn-off time is not consumed by the avalanche characteristic of MOSFETs, but by the channel resistance of the MOSFET, because the new circuit controls the gate voltage. The switching loss in the new circuit hardly increases compared to the conventional one, because its switches operate with a high-speed response.MOSFET