Diameter dependence of ferromagnetic spin moment in Au nanocrystals

Au nanoparticles exhibit ferromagnetic spin polarization and show diameter dependence in magnetization. The magnetic moment per Au atom in the particle attains its maximum value at a diameter of about 3 nanometer (nm) in the Magnetization-Diameter curve. Because Au metal is a typical diamagnetic material, its ferromagnetic polarization mechanism is thought to be quite different from the ferromagnetism observed in transition metals. The size effect strongly suggests the existence of some spin correlation effect at the nanoscale. The so-called ``Fermi hole effect'' is the most probable one given in the free electron gas system. Ferromagnetism in Au nanoparticles is discussed using this model.Comment: 5 pages, 6 figures, to appear in Phys. Rev.

Photochemical Behavior of Type-II Semiconductor Heterodimers

Type-II semiconductor heterodimers with a staggered alignment of band edges at the heterointerface can promote spatial charge separation of the electron and hole in different parts of the heterodimer for photocatalytic and photovoltaic applications. In this paper, the two kinds of CdS-based type-II semiconductor heterodimers were successfully synthesized. Type-II CdS-CdTe heterodimers without any defects exhibited clear photo-induced electron transfer, whereas CdS-Cu31S16 heterodimers showed dominant consumption of photogenerated carries via vacancy-induced decay processes. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3517

Multiple-valued logic-in-memory VLSI based on a floating-gate-MOS pass-transistor network

科研費報告書収録論文(課題番号:09558027・基盤研究(B)(2)・H9～H12/研究代表者:羽生, 貴弘/1トランジスタセル多値連想メモリの試作とその応用

Photochemical Behavior of Type-II Semiconductor Heterodimers

Type-II semiconductor heterodimers with a staggered alignment of band edges at the heterointerface can promote spatial charge separation of the electron and hole in different parts of the heterodimer for photocatalytic and photovoltaic applications. In this paper, the two kinds of CdS-based type-II semiconductor heterodimers were successfully synthesized. Type-II CdS-CdTe heterodimers without any defects exhibited clear photo-induced electron transfer, whereas CdS-Cu31S16 heterodimers showed dominant consumption of photogenerated carries via vacancy-induced decay processes. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3517

Photoacoustic Signal Enhancement by Localized Surface Plasmon of Gold Nanoparticles

Photoacoustic imaging has been widely studied as a deep biological tissue imaging modality combining optical absorption and ultrasonic detection. It enables multi-scale high resolution imaging of optical absorbing intrinsic molecules as well as exogenous molecules. Gold nanoparticles have the primary advantages of large absorption cross section and bioconjugation capability for the imaging contrast agents. In order to design the photoacoustic imaging agents for enhancing the contrast with high specificity to targeted molecules and / or cell, we measured and analyzed time-of-flight photoacoustic signals of aqueous solutions of various shapes and sizes of gold nanoparticles. The signal intensities were sensitive to the shapes and sizes of the gold nanoparticles. We found a strong photoacoustic signal of the polyhedral gold nanoparticle due to the localized surface plasmon resonance. The experimental results derive the strategy of designing the optimum photoacoustic contrast agents. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3543

Direct evidence for ferromagnetic spin polarization in gold nanoparticles

We report the first direct observation of ferromagnetic spin polarization of Au nanoparticles with a mean diameter of 1.9 nm using X-ray magnetic circular dichroism (XMCD). Owing to the element selectivity of XMCD, only the gold magnetization is explored. Magnetization of gold atoms estimated by XMCD shows a good agreement with the results obtained by conventional magnetometry. This result is evidence of intrinsic spin polarization in nano-sized gold.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Let

Magnetic shielding properties of GdBCO bulks with different crystal orientation

AbstractHigh-temperature bulk superconductors have significant potential for superconductivity applications. For this paper, the magnetic shielding properties of GdBCO bulk with different crystal orientations were investigated at different temperatures for the purpose of determining its application as field concentrators. Four discs with a diameter of 20mm and thickness of 5mm were cut from the GdBCO single domain. In two discs, the c-axis of crystal was parallel to the disc radius, and, in the others, the c-axis was perpendicular to it. The magnetic shielding effects in a couple of bulks with a gap of 2mm were measured in background fields up to 11 T. The magnetic fields were measured at the center and edge points between the two bulks at LN2, LHe, and temperatures controlled with a cryocooler. In LHe, the discs whose c-axes were parallel to the external magnetic fields maintained a zero field up to 11 T. Even in LN2, the field was shielded to 1 T. The results confirmed the strong magnetic shield effects of GdBCO bulk and can be used for the design of a field concentrator

A Racial Reckoning: Anti-Asian racism and exclusion in higher education

The Atlanta massacre on March 16, 2021, spurred a series of solidarity statements with the broader Asian and Asian American1 community from higher education institutions across the nation. While many colleges and universities have expressed their grief and support with the larger Asian and Asian American community, the same institutions have yet to reflect and reckon with their own history of exclusion, which has omitted Asian and Asian American students from larger conversations of diversity, equity, and inclusion. The purposes of this brief are to name the forms of anti-Asian racism that already exist in higher education institutions and to propose a series of recommendations to address the foreseeable forms of overt and covert anti-Asian violence that may occur when students return to campuses in fall 2021 and beyond. We recommend that institutions of higher education: create effectual task forces to think strategically about racism and xenophobia towards Asian and Asian American students; increase funding for ethnic studies, specifically, Asian American Studies Departments, Programs, and Centers; and collect and report disaggregated data on diverse subgroups of Asian and Asian American students

Anti-Asian Bullying and Harassment: Symptoms of racism in K-12 schools during COVID-19

The COVID-19 pandemic has posed many challenges for K-12 students. However, these challenges have not been experienced equally across student groups. There has been a significant increase in mainstream media coverage of anti-Asian racism, but very little attention has been given to Asian American youth, who are not immune from incidents of bullying and harassment in our K-12 schools. This brief discusses how Asian American and Pacific Islander (AAPI)1 students face unique challenges associated with bullying and harassment because of their racial and ethnic identity. We examine the historical context of bullying and harassment of Asian Americans and how that persists as anti-Asian racism today. Finally, we propose policy solutions to create a more positive learning environment and address racist attitudes towards this specific community. Notably, we propose that K-12 leaders disaggregate data by ethnic subgroup, collect more comprehensive data on school bullying, harassment, and victimization disaggregated by AAPI ethnic subgroups, and invest in culturally sustaining mental health resources and curriculum