Effective base point free theorem for log canonical pairs--Koll\'ar type theorem

We prove Koll\'ar's effective base point free theorem for log canonical pairs.Comment: 9 pages, v2: Appendix was added, minor revisions, v3: minor modifications, title changed, v4: minor modifications, to appear in Tohoku Math.

Structure and Electrochemical Properties of a Mechanochemically Processed Silicon and Oxide-Based Nanoscale Composite as an Active Material for Lithium-Ion Batteries

Si is essential as an active material in Li-ion batteries because it provides both high charge and optimal cycling characteristics. A composite of Si particles, Cu particles, and pure H2O was realized to serve as an anode active material and optimize the charge–discharge characteristics of Li-ion batteries. The composite was produced by grinding using a planetary ball mill machine, which allowed for homogenous dispersion of nanoscale Cu3Si as Si–Cu alloy grains and nanoscale Si grains in each poly-Si particle produced. Furthermore, some Si particles were oxidized by H2O, and oxidized Si was distributed throughout the composite, mainly as silicon monoxide. As a result, each Si particle included silicon monoxide and conductive Cu3Si materials, allowing for effective optimization of the recharging and charge-discharge characteristics. Thus, a new and simple process was realized for synthesizing a Si active material composited with silicon oxides, including silicon monoxide. This Si-rich conductive material is suitable as an anode for Li-ion batteries with high charge and optimized cycling properties

Magnetic properties of mechanically milled Sm-Co permanent magnetic materials with the structure

The magnetic properties of Sm(Co,Fe,Cu,Zr) 7 compound with the TbCu 7 structure are studied for the mechanically milled samples. The coercivity could be varied, without affecting the saturation magnetization, from 44 kA/m for the micron sized particles to 280 kA/m by reducing the particle size to sub-micron size (600-900 nm) using high-energy ball milling. The enhancement in the coercivity is attributed to the particles approaching single domain size. The presence of dipolar coupling suggests that the grain sizes are well above the exchange length for the milled samples. The thermal measurements indicate that the compound with the TbCu 7 structure is not stable at high temperatures beyond 743 K

Water Dynamics

xix, 246 ha.; ill.; 25c