Directional motion of Gallium-based liquid metal induced by asymmetric chemical surrounding

Interfacial, or surface tension, is a significant topic in chemical education. This paper describes the directional motion of gallium-based liquid metal drops, resulting from a difference of interfacial tension across the drop. This demonstration can engage students in discovering the underlying chemical principles. A mechanism for the drop’s directional motion is proposed to provide insight into this intriguing phenomenon. It appears that unbalanced chemical environments cause different physical or chemical processes to occur on each hemisphere of the drop, such as a pH difference, redox reactions, galvanic replacement, or adsorption. As a result, a difference in the interfacial tension across the drop is generated, providing the driving force that acts on the drop. This demonstration can be used to introduce the fundamental principles in chemical reactions, such as redox activity, electrical double-layer formation, and interfacial tension

Amplified spontaneous emission-based technique for simultaneous measurement of temperature and strain by combining active fiber with fiber gratings

This article reports on an optical fiber-based sensing system for carrying out the simultaneous measurement of temperature and strain. The sensor design is based on the combination of active dopedoptical fiber and fiber gratings. Erbium/ytterbium co-doped fiber is used to meet the requirements for both high temperature responsivity and small sensor size to address smart structure applications. The temperature dependence of the amplified spontaneous emission power under different pump wavelengths is used as the basis of the sensor and an optical reference to enhance the measurement resolution is discussed. The feasibility of this technique for simultaneous measurement of temperature and strain is demonstrated

The relationship between SNPS in the genes of TLR signal transduction pathway downstream elements and rheumatoid arthritis susceptibility

Toll-like receptors (TLRs) play an important role in the induction and regulation of the innate immune system or adaptive immune responses. Genetic variations within human TLRs have been reported to be associated with rheumatoid arthritis (RA). This study was conducted to investigate correlation between SNP of downstream mononucleotide in signal transduction of Toll-like receptors and predisposing genes of RA. There was obviously correlative between single nucleotide polymorphism and predisposing genes of RA. G-type of IL-1RAP rs766442 may be protecting genes of RA, while T-type alleles of IL-6R rs11265618 and IL-1RAP rs766442 may be susceptible genes of RA. In conclusion, the studies on the nucleis acid polymorphism in TLRs signal pathway contribute to disclose genes’ influence on the attack mechanism of RA, early diagnosis and treatment of RA.Толл-подобные рецепторы (TLRs) играют важную роль в индукции и регуляции врожденной иммунной системы или адаптивных иммунных ответах. Показано, что что генетическая изменчивость TLRs человека связана с ревматоидным артритом (РА). Целью настоящей работы было изучение корреляций между однонуклеотидным полиморфизмом в сигнальной трансдукции TLRs и генами предрасположенности к РА. G-тип IL-1RAP rs766442 могут быть генами, предохраняющими от РА, в то время как аллели T-типа IL-6R rs11265618 и IL-1RAP rs766442 могут быть генами чувствительности к РА. Изучение полиморфизма нуклеиновых кислот в сигнальном пути TLRs может внести вклад в выявление участия генов в механизмах приступов РА, раннюю диагностику и лечение РА.The study was supported by Shandong Province young scientist in incentive fund (Grant № 2006BS03018) and National Natural Science Foundation of China (Grant № 30801025)

Analytical results on quantum interference and magnetoconductance for strongly localized electrons in a magnetic field: Exact summation of forward-scattering paths

We study quantum interference effects on the transition strength for strongly localized electrons hopping on 2D square and 3D cubic lattices in the presence of a magnetic field B. These effects arise from the interference between phase factors associated with different electron paths connecting two distinct sites. For electrons confined on a square lattice, with and without disorder, we obtain closed-form expressions for the tunneling probability, which determines the conductivity, between two arbitrary sites by exactly summing the corresponding phase factors of all forward-scattering paths connecting them. An analytic field-dependent expression, valid in any dimension, for the magnetoconductance (MC) is derived. A positive MC is clearly observed when turning on the magnetic field. In 2D, when the strength of B reaches a certain value, which is inversely proportional to twice the hopping length, the MC is increased by a factor of two compared to that at zero field. We also investigate transport on the much less-studied and experimentally important 3D cubic lattice case, where it is shown how the interference patterns and the small-field behavior of the MC vary according to the orientation of B. The effect on the low-flux MC due to the randomness of the angles between the hopping direction and the orientation of B is also examined analytically.Comment: 24 pages, RevTeX, 8 figures include

A tunable radiation source by coupling laser-plasma-generated electrons to a periodic structure

Near-infrared radiation around 1000 nm generated from the interaction of a high-density MeV electron beam, obtained by impinging an intense ultrashort laser pulse on a solid target, with a metal grating is observed experimentally. Theoretical modeling and particle-in-cell simulation suggest that the radiation is caused by the Smith-Purcell mechanism. The results here indicate that tunable terahertz radiation with tens GV=m field strength can be achieved by using appropriate grating parameter

Implicações das prioridades de gasto do estado sobre a dinâmica econômica brasileira

XX Encontro Nacional de Economia Política: desenvolvimento Latino-Americano, Integração e Inserção Internacional - UNILA, Foz do Iguaçu, 26 a 29 de maio de 2015A sociedade brasileira tem passado, nas últimas décadas, por transformações importantes em seu contexto político e econômico. Este artigo trata principalmente de dois fatos que ainda, atualmente, impactam na dinâmica do gasto público. O processo de redemocratização, em fi nais dos anos de 1980 e a globalização econômica com a consequente fi nanceirização dos mercados. Estas transformações infl uenciam a forma de atuação do Estado na economia, principalmente no que se refere à defi nição de alocação de recursos públicos. Assim, este artigo aprofunda o entendimento da evolução das despesas públicas na esfera federal, pela análise dos gastos sociais bem como da dívida pública, constatando os impactos econômicos destas despesas e levantando conclusões sobre a viabilidade de determinados gastos governamentais sob a dinâmica econômica e social do país. A realização deste estudo contribui para o debate sobre as estratégias de política fi scal que vêm sendo adotadas e o impacto de priorização de determinados gastos, sobre o crescimento econômico do paísBanco Nacional de Desenvolvimento Econômico e Social (BNDES); Usina Hidrelétrica de Itaipu (ITAIPU); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) e Universidade Federal da Integração Latino-Americana (UNILA

Dispersion of a single hole in the t-J model

The dispersion of a single hole in the t-J model obtained by the exact result of 32 sites and the results obtained by self-consistent Born approximation and the Green function Monte Carlo method can be simply derived by a mean-field theory with d-RVB and antiferromagnetic order parameters. In addition, it offers a simple explanation for the difference observed between those results. The presence of the extended van Hove region at (pi,0) is a consequence of the d-RVB pairing independenct of the antiferromagnetic order. Results including t' and t" are also presented and explained consistently in a similar way.Comment: LaTex file, 5 pages with 5 embedded eps figure