Anisotropic magnetic field responses of ferroelectric polarization in a trigonal multiferroic CuFe1-xAlxO2 (x=0.015)

We have investigated magnetic field dependences of a ferroelectric incommensurate-helimagnetic order in a trigonal magneto-electric (ME) multiferroic CuFe1-xAlxO2 with x=0.015, which exhibits the ferroelectric phase as a ground state, by means of neutron diffraction, magnetization and dielectric polarization measurements under magnetic fields applied along various directions. From the present results, we have established the H-T magnetic phase diagrams for the three principal directions of magnetic fields; (i) parallel to the c axis, (ii) parallel to the helical axis, and (iii) perpendicular to the c and the helical axes. While the previous dielectric polarization (P) measurements on CuFe1-xGaxO2 with x=0.035 have demonstrated that the magnetic field dependence of the `magnetic domain structure' results in distinct magnetic field responses of P [S. Seki et al., Phys. Rev. Lett., 103 237601 (2009)], the present study have revealed that the anisotropic magnetic field dependence of the ferroelectric helimagnetic order `in each magnetic domain' can be also a source of a variety of magnetic field responses of P in CuFe1-xAxO2 systems (A=Al, Ga).Comment: 11 pages, 9 figures, accepted for publication in Phys. Rev.

A randomized controlled trial of a bidirectional cultural adaptation of cognitive behavior therapy for children and adolescents with anxiety disorders

Background: Cognitive behavior therapy (CBT) programs with ethnic and cultural sensitivity are scarce. This study was the first randomized controlled trial of cognitive behavior therapy for children and adolescents with anxiety disorders using bidirectional cultural adaptation. Methods: The Japanese Anxiety Children/Adolescents Cognitive Behavior Therapy program (JACA-CBT) was developed based on existing evidence-based CBT for anxious youth and optimized through feedback from clinicians in the indigenous cultural group. Fifty-one children and adolescents aged 8–15 with anxiety disorders were randomly allocated to either a cognitive behavioral treatment (CBT: 122.08 days, SD = 48.15) or a wait-list control condition (WLC: 70.00 days, SD = 11.01). Participants were assessed at pre-treatment and post-treatment as well as 3 and 6 months after completion of treatment (92.88 days, SD = 17.72 and 189.42 days, SD = 25.06) using a diagnostic interview, self-report measures of anxiety, depression, cognitive errors, and a parent-report measure of anxiety. Results: A significant difference was found between the CBT and WLC at post-treatment, specifically 50% of participants in the treatment condition were free from their principal diagnoses compared to 12% in the wait-list condition, χ2 (1, N = 51) = 8.55, η2 = 0.17, p <.01. In addition, participants in the treatment condition showed significant improvement in clinical severity and child-self reported depression, F (1, 49) = 12.38, p <.001, F (1, 47.60) = 5.95, p <.05. At post-treatment, Hedge's g between the conditions was large for clinical severity, 1.00 (95% CI = 0.42–1.58), and moderate for the self-report anxiety scale, 0.43 (0.19–1.04), two depression scales, 0.39 (0.22–1.00), 0.48 (0.14–1.09), and the cognitive errors scale, 0.38 (0.24–0.99). Finally, significant improvements in diagnostic status were evident at the 3 and 6-month follow-up assessments when combining the CBT and WLC, ps <.001. Conclusion: The current results support the transportability of CBT and the efficacy of a bidirectional, culturally adapted cognitive behavior therapy in an underrepresented population

Magnetization plateaux of S = 1/2 two-dimensional frustrated antiferromagnet Cs2_2CuBr4_4

The field induced magnetic phase transitions of Cs$_2$CuBr$_4$ were investigated by means of magnetization process and neutron scattering experiments. This system undergoes magnetic phase transition at Ne\'{e}l temperature $T_\mathrm{N}=1.4$ K at zero field, and exhibits the magnetization plateau at approximately one third of the saturation magnetization for the field directions $H\parallel b$ and $H\parallel c$. In the present study, additional symptom of the two-third magnetization plateau was found in the field derivative of the magnetization process. The magnetic structure was found to be incommensurate with the ordering vector $\boldsymbol{Q}=(0, 0.575, 0)$ at zero field. With increasing magnetic field parallel to the c-axis, the ordering vector increases continuously and is locked at $\boldsymbol{Q}=(0, 0.662, 0)$ in the plateau field range $13.1 \mathrm{T} < H < 14.4 \mathrm{T}$. This indicates that the collinear \textit{up-up-down} spin structure is stabilized by quantum fluctuation at the magnetization plateau.Comment: 6 pages, 4 Postscript figures, uses iopams.sty and IOPART.CL

Electronic structure of pristine and K-doped solid picene: Non-rigid-band change and its implication for electron-intramolecular-vibration interaction

We use photoemission spectroscopy to study electronic structures of pristine and K-doped solid picene. The valence band spectrum of pristine picene consists of three main features with no state at the Fermi level (EF), while that of K-doped picene has three structures similar to those of pristine picene with new states near EF, consistent with the semiconductor-metal transition. The K-induced change cannot be explained with a simple rigid-band model of pristine picene, but can be interpreted by molecular orbital calculations considering electron-intramolecular-vibration interaction. Excellent agreement of the K-doped spectrum with the calculations points to importance of electron-intramolecular-vibration interaction in K-doped picene.Comment: This article is accepted by Physical Review

Quadrupolar Kondo Effect in Non-Kramers Doublet System PrInAg2

We performed ultrasonic measurement on the rare-earth intermetallic compound PrInAg_2 to examine the quadrupolar Kondo effect associated with the non-Kramers Gamma_3 doublet ground state. The characteristic softening of the elastic constant (c_{11}-c_{12})/2 below 10 K in PrInAg_2 is attributed to a Curie term in quadrupolar susceptibility for the quadrupole O_2^2=J_x^2-J_y^2 of the stable Gamma_3 ground state. (c_{11}-c_{12})/2 turns to a slight increase with the -lnT dependence below 0.1 K, which suggests the quenching of the quadrupolar moment in the quadrupolar Kondo state. Under applied magnetic fields of 10 T and 15 T above 8.7 T corresponding to the Kondo temperature T_K of ~ 0.86 K, the behavior of (c_{11}-c_{12})/2 is described in terms of quadrupolar susceptibility for the stable 4f^2 state.Comment: PDF, 10pages + 5figures, Strongly Correlated Electron

Geological structure of an arsenic-contaminated aquifer at Sonargaon, Bangladesh

ArticleJOURNAL OF GEOLOGY. 116(3):288-302(2008)journal articl

An English-to-Turkish interlingual MT system

This paper describes the integration of a Turkish generation system with the KANT knowledge-based machine translation system to produce a prototype English-Turkish interlingua-based machine translation system. These two independently constructed systems were successfully integrated within a period of two months, through development of a module which maps KANT interlingua expressions to Turkish syntactic structures. The combined system is able to translate completely and correctly 44 of 52 benchmark sentences in the domain of broadcast news captions. This study is the first known application of knowledge-based machine translation from English to Turkish, and our initial results show promise for future development. © Springer-Verlag Berlin Heidelberg 1998

Anomalous heavy-fermion and ordered states in the filled skutterudite PrFe4P12

Specific heat and magnetization measurements have been performed on high-quality single crystals of filled-skutterudite PrFe_4P_{12} in order to study the high-field heavy-fermion state (HFS) and low-field ordered state (ODS). From a broad hump observed in C/T vs T in HFS for magnetic fields applied along the direction, the Kondo temperature of ~ 9 K and the existence of ferromagnetic Pr-Pr interactions are deduced. The {141}-Pr nuclear Schottky contribution, which works as a highly-sensitive on-site probe for the Pr magnetic moment, sets an upper bound for the ordered moment as ~ 0.03 \mu_B/Pr-ion. This fact strongly indicates that the primary order parameter in the ODS is nonmagnetic and most probably of quadrupolar origin, combined with other experimental facts. Significantly suppressed heavy-fermion behavior in the ODS suggests a possibility that the quadrupolar degrees of freedom is essential for the heavy quasiparticle band formation in the HFS. Possible crystalline-electric-field level schemes estimated from the anisotropy in the magnetization are consistent with this conjecture.Comment: 7 pages and 7 figures. Accepted for publication in Phys. Rev.