179 research outputs found

    Cooper Pair Formation in U(1) Gauge Theory of High Temperature Superconductivity

    Full text link
    We study the two-dimensional spin-charge separated Ginzburg-Landau theory containing U(1) gauge interactions as a semi-phenomenological model describing fluctuating condensates in high temperature superconductivity. Transforming the original GL action, we abstract the effective action of Cooper pair. Especially, we clarify how Cooper pair correlation evolves in the normal state from the point of view of spin-charge separation. Furthermore, we point out how Cooper pair couples to gauge field in a gauge-invariant way, stressing the insensitivity of Cooper pair to infrared gauge field fluctuation.Comment: 4 pages, 5 figures included, submitted to J. Phys. Soc. Jp

    Phase Separation Based on U(1) Slave-boson Functional Integral Approach to the t-J Model

    Full text link
    We investigate the phase diagram of phase separation for the hole-doped two dimensional system of antiferromagnetically correlated electrons based on the U(1) slave-boson functional integral approach to the t-J model. We show that the phase separation occurs for all values of J/t, that is, whether 0<J/t<10 < J/t < 1 or J/t1J/t \geq 1 with J, the Heisenberg coupling constant and t, the hopping strength. This is consistent with other numerical studies of hole-doped two dimensional antiferromagnets. The phase separation in the physically interesting J region, 0<J/t0.40 < J/t \lesssim 0.4 is examined by introducing hole-hole (holon-holon) repulsive interaction. We find from this study that with high repulsive interaction between holes the phase separation boundary tends to remain robust in this low JJ region, while in the high J region, J/t > 0.4, the phase separation boundary tends to disappear.Comment: 4 pages, 2 figures, submitted to Phys. Rev.

    “The Continuing Imperative of Value Theory”, translated into Turkish

    Get PDF
    This paper addresses two important, conspicuous topics for the understanding of contemporary capitalism: the world market and the knowledge economy. By locating these within Marx’s value theory, its authors take issue with other interpretations that explicitly reject or misinterpret Marx’s value theory in light of these themes. More general, these exercises point to the need for value theory and the fact that it should and can move beyond its traditional terrain, collaborating with other strands of critical thought in understanding developments within contemporary societ

    Stripes due to the next-nearest neighbor exchange in high-Tc cuprates

    Full text link
    We propose a possible mechanism of the charge stripe order due to the next-nearest neighbor exchange interaction J' in the two-dimensional t-J model, based on the concept of the phase separation. We also calculate some hole correlation functions of the finite cluster of the model using the numerical diagonalization, to examine the realization of the mechanism. It is also found that the next-nearest neighbor hopping t' suppresses the stripe order induced by the present mechanism for t'0.Comment: 4 pages, Revtex, with 5 eps figures, to appear in Phys. Rev. B Rapid Communications (April 1, 2001

    Розвиток духовності особистості в процесі фахової підготовки майбутніх учителів образотворчого мистецтва

    Get PDF
    (uk) У статті наголошується, що вчитель образотворчого мистецтва виступає носієм не лише спеціальних знань та умінь, але і носієм духовних цінностей. Духовне збагачення і вдосконалення кожної особистості відбувається протягом всього життя в тому числі і в процесі навчання. Гуманізація освіти та естетичне виховання спрямовано на формування гармонійної цілісної особистості, загальнокультурний її розвиток. Засобами естетичного виховання в мистецтві виступає художній образ. Художній образ є відображенням дійсності яке містить в собі не лише суб’єктивний досвід автора, його розуміння та відношення до об’єктів дійсності, але і відбитки культурно-історичного досвіду, естетичних цінностей, але і відбитки культурно-історичного досвіду, естетичних цінностей соціуму загалом. На їх базі і формується всебічно та гармонійно розвинута особистість із вищими моральними цінностями, естетичними канонами та ідеалами.(ru) В статье делается акцент на то, что учитель изобразительного искусства выступает носителем не только специальных знаний и умений, но и носителем духовных ценностей. Духовное обогащение и совершенствование каждой личности происходит на протяжении всей жизни в том числе и в процессе обучения. Гуманизация образования и эстетическое воспитание направлены на формирование гармоничной целостной личности и ее общекультурное развитие. Средством эстетического воспитания в искусстве выступает художественный образ. Художественный образ является отражением действительности, которое содержит в себе не только субъективный опыт автора, его понимание и отношение к объектам действительности, но и отпечатки культурно-исторического опыта, эстетических ценностей социума в целом. На их базе и формируется всесторонне и гармонично развитая личность с высокими моральными ценностями, эстетическими канонами и идеалами.(en) Importance of education in society is determined by the need to raise the national consciousness of the saved and nurturing genuine citizen. Spiritual enrichment and improvement of each individual occurs throughout life including during training. Spirituality determines the direction of all mental, emotional, sensual, strong-willed human qualities and its ability to self yourself as a person. Master of Fine Arts acting carrier not only specialized knowledge and skills, but also a bearer of spiritual values. Humanizing education and aesthetic education aims at forming a harmonious whole person, her general cultural development. Art is an integral part of spiritual culture, a reflection of the artistic representations of the human form of the world of reality. The means of aesthetic education in the art of acting artistic image. Artistic image is a reflection of reality, which contains not only the subjective experience of the author, and understanding related to the objects of reality, but the prints are of cultural and historical experience, the aesthetic values of society as a whole. At their base is formed fully and harmoniously developed personality with higher moral values, aesthetic canons and ideals

    Boundary degrees of freedom in fractional quantum Hall effect: Excitations on common boundary of two samples

    Full text link
    Using the Carlip's method we have derived the boundary action for the fermion Chern-Simons theory of quantum Hall effects on a planar region with a boundary. We have computed both the bulk and edge responses of currents to the external electric field. From this we obtain the well-known anomaly relation and the boundary Hall current without introducing any ad hoc assumptions such as the chirality condition. In addition, the edge current on the common boundary of two samples is found to be proportional to the difference between Chern-Simons coupling strengths.Comment: 20 pages, uses revte

    Non-Fermi liquid behavior and scaling of low frequency suppression in optical conductivity spectra of CaRuO3_3

    Full text link
    Optical conductivity spectra σ1(ω)\sigma_1(\omega) of paramagnetic CaRuO3_3 are investigated at various temperatures. At T=10 K, it shows a non-Fermi liquid behavior of σ1(ω)1/ω12\sigma_1(\omega)\sim 1/{\omega}^{\frac 12}, similar to the case of a ferromagnet SrRuO3_3. As the temperature (TT) is increased, on the other hand, σ1(ω)\sigma_1(\omega) in the low frequency region is progressively suppressed, deviating from the 1/{\omega}^{\frac 12%}-dependence. Interestingly, the suppression of σ1(ω)\sigma_1(\omega) is found to scale with ω/T\omega /T at all temperatures. The origin of the % \omega /T scaling behavior coupled with the non-Fermi liquid behavior is discussed.Comment: 4 pages, 3 figure

    Mutation analysis of SDHB and SDHC: novel germline mutations in sporadic head and neck paraganglioma and familial paraganglioma and/or pheochromocytoma

    Get PDF
    BACKGROUND: Germline mutations of the SDHD, SDHB and SDHC genes, encoding three of the four subunits of succinate dehydrogenase, are a major cause of hereditary paraganglioma and pheochromocytoma, and demonstrate that these genes are classic tumor suppressors. Succinate dehydrogenase is a heterotetrameric protein complex and a component of both the Krebs cycle and the mitochondrial respiratory chain (succinate:ubiquinone oxidoreductase or complex II). METHODS: Using conformation sensitive gel electrophoresis (CSGE) and direct DNA sequencing to analyse genomic DNA from peripheral blood lymphocytes, here we describe the mutation analysis of the SDHB and SDHC genes in 37 patients with sporadic (i.e. no known family history) head and neck paraganglioma and five pheochromocytoma and/or paraganglioma families. RESULTS: Two sporadic patients were found to have a SDHB splice site mutation in intron 4, c.423+1G>A, which produces a mis-spliced transcript with a 54 nucleotide deletion, resulting in an 18 amino acid in-frame deletion. A third patient was found to carry the c.214C>T (p.Arg72Cys) missense mutation in exon 4 of SDHC, which is situated in a highly conserved protein motif that constitutes the quinone-binding site of the succinate: ubiquinone oxidoreductase (SQR) complex in E. coli. Together with our previous results, we found 27 germline mutations of SDH genes in 95 cases (28%) of sporadic head and neck paraganglioma. In addition all index patients of five families showing hereditary pheochromocytoma-paraganglioma were found to carry germline mutations of SDHB: four of which were novel, c.343C>T (p.Arg115X), c.141G>A (p.Trp47X), c.281G>A (p.Arg94Lys), and c.653G>C (p.Trp218Ser), and one reported previously, c.136C>T, p.Arg46X. CONCLUSION: In conclusion, these data indicate that germline mutations of SDHB and SDHC play a minor role in sporadic head and neck paraganglioma and further underline the importance of germline SDHB mutations in cases of familial pheochromocytoma-paraganglioma

    Is PTEN loss associated with clinical outcome measures in human prostate cancer?

    Get PDF
    Inactivating PTEN mutations are commonly found in prostate cancer, resulting in an increased activation of Akt. In this study, we investigate the role of PTEN deletion and protein expression in the development of hormone-refractory prostate cancer using matched hormone-sensitive and hormone-refractory tumours. Fluorescent in situ hybridisation and immunohistochemistry was carried out to investigate PTEN gene deletion and PTEN protein expression in the transition from hormone-sensitive to hormone-refractory prostate cancer utilising 68 matched hormone sensitive and hormone-refractory tumour pairs (one before and one after hormone relapse). Heterogeneous PTEN gene deletion was observed in 23% of hormone sensitive tumours. This increased significantly to 52% in hormone-refractory tumours (P=0.044). PTEN protein expression was observed in the membrane, cytoplasm and the nucleus. In hormone sensitive tumours, low levels of cytoplasmic PTEN was independently associated with shorter time to relapse compared to high levels of PTEN (P=0.028, hazard ratio 0.51 (95%CI 0.27–0.93). Loss of PTEN expression in the nucleus of hormone sensitive tumours was independently associated with disease-specific survival (P=0.031, hazard ratio 0.52, 95%CI 0.29–0.95). The results from this study demonstrate a role for both cytoplasmic and nuclear PTEN in progression of prostate cancer to the hormone-refractory state
    corecore