Effect of heating ramp rates on transient enhanced diffusion in ion-implanted silicon

\u3cp\u3eBoron marker-layer structures have been used to analyze the heating ramp-rate dependence of transient enhanced dopant diffusion (TED) during rapid thermal annealing of Si implantation damage. The study uses short anneals with heating ramp rates in the range 0.1-350°CVs, and peak temperatures in the range 900-1100°C. Increasing the ramp rate is found to reduce the amount of profile broadening caused by TED, as well as reducing the smaller amount of normal thermal-equilibrium diffusion which is related to thermal budget. The results show why high ramp rates lead to improved B-implant activation and junction-depth control in Si devices. An Ostwald ripening model of interstitial-cluster evolution describes the detailed trends in the data and predicts further improvements in the case of ultrarapid annealing.\u3c/p\u3

Near-death experience: Out-of-body and out-of-brain?

During the last decades, several clinical cases have been reported where patients described profound subjective experiences when near-death, a phenomenon called "near-death experience" (NDE). Recurring features in the accounts involving bright lights and tunnels have sometimes been interpreted as evidence of a new life after death; however the origin of such experiences is largely unknown, and both biological and psychological interpretations have been suggested. The study of NDEs represents one of the most important topics of cognitive neuroscience. In the present paper the current state of knowledge has been reviewed, with particular regard to the main features of NDE, scientific explanations and the theoretical debate surrounding this phenomenon

Z-Selective Metathesis Homocoupling of 1,3-Dienes by Molybdenum and Tungsten Monoaryloxide Pyrrolide (MAP) Complexes

Molybdenum or tungsten monoaryloxide pyrrolide (MAP) complexes that contain OHIPT as the aryloxide (hexaisopropylterphenoxide) are effective catalysts for homocoupling of simple (E)-1,3-dienes to give (E,Z,E)-trienes in high yield and with high Z selectivities. A vinylalkylidene MAP species was shown to have the expected syn structure in an X-ray study. MAP catalysts that contain OHMT (hexamethylterphenoxide) are relatively inefficient.National Science Foundation (U.S.) (CHE-0841187)National Science Foundation (U.S.) (CHE-1111133)National Institutes of Health (U.S.) (Grant GM-59426)National Science Foundation (U.S.) (CHE-0946721