Cordless-Microscope
All about Cordless-Microscope.Relation between peak structures of loss functions of single double-walled carbon nanotubes and interband transition energies
Relation between peak structures of loss functions of single double-walled carbon nanotubes and interband transition energies
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Electron energy-loss spectra of single double-walled carbon nanotubes (DWCNTs) were compared with calculated joint density of states (jDOSs) obtained by a simple tight-binding (STB) and an extended tight-binding (ETB) method. From the comparisons, interband transition energies of ETB calculations show better agreement with peak positions of the experimental spectra than those of STB results. From a further comparison among calculated jDOS, real and imaginary parts of a dielectric function and a loss function Im[–1/], it was confirmed that the peak energies in a spectrum of single DWCNTs are almost equal to those of the optical absorption spectrum 2.
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Other Articles:
| • | Luminescence Database I—Minerals and Materials |
| Research Articles Colin M. MacRae, Nicholas C. Wilson, Microscopy and Microanalysis, Volume 14 Issue 02 , pp 184-204 Abstract A luminescence database for minerals and materials has been complied from the literature, the aim being to create a resource that will aid in the analysis of luminescence spectral of ionic species in minerals and materials. The database is based on a range of excitation techniques and records both major and minor lines, and their activators. The luminescence techniques included in the database are cathodoluminescence, ion luminescence, and photoluminescence. When combined with other traditional X-ray measurements collected on the same region, use of the luminescence database will give additional insight into the chemistry of minerals and materials. |
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| • | Patterns of Local Recurrence After Intraoperative Radiotherapy for Advanced Neuroblastoma |
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The purpose of this study was to retrospectively evaluate local recurrence patterns after intraoperative radiation therapy (IORT) combined with total or subtotal resection and intensive chemotherapy for advanced neuroblastoma. The outcomes of 27 patients (14 boys and 13 girls) with advanced-stage neuroblastoma who received IORT as part of multimodality therapy between November 1988 and December 2006 were reviewed in order to evaluate the impact of IORT. Of particular interest was the local recurrence patterns observed. Six patients relapsed in the abdominal area: three out of six relapsed adjacent to the radiation fields. Other three relapsed in the field of electron ports. Among them, one relapsed in paraspinal lymph nodes, which are behind the irradiated volume but out of the reach of the electron beam, while another relapsed in the lymph nodes of the mesocolon, which had been displaced outside the irradiation field at the time of IORT. The last case relapsed beside the vertebral column near the left ureter, which had been shielded by a lead plate. These three ‘in-field’ recurrences would have been irradiated if external opposite two-beam radiations had been performed, instead of electron beams. In spite of a complete tumor control in the treated volume, some ‘marginal’ recurrences were observed. Further investigation—for example, a combination of IORT and external-beam radiotherapy—should be considered to achieve higher local control and decrease complication rates. |
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| • | Unforeseen problems with prospective moon dwellers |
NASA research on the Earth's magnetic field has uncovered a bit of a problem for future moon dwellers. It turns out that during the full moon, the moon is strongly whipped by the Earth's magnetotail, causing violent dust storms and electromagnetic activity which could have serious consequences for any surface dwellers or at best will require careful planning and a lot more cost to deal with than has been considered up to now.  At full moon, the moon passes through an oscillating "plasma sheet" — hot ionised gas particles trapped in the tail. Being hot, the electrons are fast moving with high kinetic energy and these electrons impact all over the moon's surface giving the moon a net negative charge. On the moon's dayside this effect is mitigated by the photoelectric effect due to sunlight, where photons release electrons from the surface, reducing the negative charge. But on the night side, the electronic charge stays built up and can accumulate to a relative potential of thousands of volts. You may ask how did NASA not know this? Well it had been seen before but it seems none of the Apollo missions never landed at full moon so there's been no direct experience of the effect to date. The effect was first noticed in 1968, when the Surveyor 7 lander photographed a strange glow on the horizon after dark, but nobody knew what it was. See Space.com. |
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| • | Legos Teach Fairness |
| I came across this article (via Digg) from a 2006 Rethinking Schools journal. The authors lead a before- and after-school program, and their story is about a teachable moment regarding ownership and society. The classroom Lego collection became a battleground as some kids claimed ownership of certain pieces, so the teachers developed a set of exercises and discussion opportunities to help resolve the issue. Over time, this evolved into a better understanding of how rules are formed and how societies function. I think out-of-school programs play a critical role in helping young people understand society. Because there is less formal structure, there is some room to let the kids form the rules. There is also time to reflect on how changes in those rules affect everyone. Open discussion and free choice cannot go as far in the classroom because there is a necessary structure there. (Of course, there are your "Dead Poet Society" exceptions, but how would those kids have done on their standardized tests??) One could read the Rethinking Schools article and worry that these teachers are preaching a form of communism - see James Clavell's The Children's Story for a fictional account. However, it is exercises in free thought and debate that allow the students to grow into adults who can appreciate the value of the world they live in without forgetting that it is imperfect. On a related note, the Afterschool Math PLUS curriculum includes a unit on the built environment which includes a design charette similar to the activity described in the article (building Pike Place Market from Legos). However, the kids using Math PLUS probably have instructors who are promoting cooperation and fair play more directly, since this is a deliberate part of this curriculum. The results that I have seen are great - the kids design wonderful communities (to scale - it is math after all!) and most have social justice built in. So, here is food for thought: is it better to deliberately teach our kids to be fair or better to conduct exercises that let them discover fairness on their own? |
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| • | The Osteogenic Potential of Pseudoarthrosis Tissue and Bone from Human Scaphoid Non-Unions |
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Scaphoid fractures have the highest prevalence of non-union in the human body, but little is known about the osteogenic potential of cells at the pseudoarthrosis. It was our goal to determine whether cells isolated from non-unions could be stimulated to differentiate into osteoblasts and produce bone in vitro. Fifteen human scaphoid non-unions were excised during surgery and bone from either side of the non-union and the fibrocartilagenous central regions were harvested. Osteoblastic populations were subcultured from these. The number of bone nodules (colonies of osteoblast cells that produced bone) from all three regions was similar to the number of nodules derived from iliac bone cultures from the same patients. Treatment of cells with rhBMP-2 resulted in a 3- to 10-fold increase in bone nodule formation in vitro from cells derived from the non-unions. These data demonstrate that cells at the pseudoarthrosis have osteogenic capability and can be stimulated by rhBMP-2, possibly increasing the ability to heal. |
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