Although previous research indicates that Japanese speakers' second language (L2) perception ... more Although previous research indicates that Japanese speakers' second language (L2) perception and production of English /see symbol/ may improve with increased L2 experience, relatively little is known about the fine phonetic details of their /see symbol/ productions, especially during the early phase of L2 speech learning. This cross-sectional study examined acoustic properties of word-initial /see symbol/ from 60 Japanese learners with a length of residence of between one month and one year in Canada. Their performance was compared to that of 15 native speakers of English and 15 low-proficiency Japanese learners of English. Formant frequencies (F2 and F3) and F1 transition durations were evaluated under three task conditions--word reading, sentence reading, and timed picture description. Learners with as little as two to three months of residence demonstrated target-like F2 frequencies. In addition, increased LOR was predictive of more target-like transition durations. Although...
The current project aimed to investigate the potentially different linguistic correlates of compr... more The current project aimed to investigate the potentially different linguistic correlates of comprehensibility (i.e., ease of understanding) and accentedness (i.e., linguistic nativelikeness) in adult second language (L2) learners’ extemporaneous speech production. Timed picture descriptions from 120 beginner, intermediate, and advanced Japanese learners of English were analyzed using native speaker global judgments based on learners’ comprehensibility and accentedness, and then submitted to segmental, prosodic, temporal, lexical, and grammatical analyses. Results showed that comprehensibility was related to all linguistic domains, and accentedness was strongly tied with pronunciation (specifically segmentals) rather than lexical and grammatical domains. In particular, linguistic correlates of L2 comprehensibility and accentedness were found to vary by learners’ proficiency levels. In terms of comprehensibility, optimal rate of speech, appropriate and rich vocabulary use, and adequat...
To investigate the pedagogical effectiveness of oral corrective feedback (CF) on target language ... more To investigate the pedagogical effectiveness of oral corrective feedback (CF) on target language development, we conducted a meta-analysis that focused exclusively on 15 classroom-based studies (N = 827). The analysis was designed to investigate whether CF was effective in classroom settings and, if so, whether its effectiveness varied according to (a) types of CF, (b) types and timing of outcome measures, (c) instructional setting (second vs. foreign language classroom), (d) treatment length, and (e) learners' age. Results revealed that CF had significant and durable effects on target language development. The effects were larger for prompts than recasts and most apparent in measures that elicit free constructed responses. Whereas instructional setting was not identified as a contributing factor to CF effectiveness, effects of long treatments were larger than those of short-to-medium treatments but not distinguishable from those of brief treatments. A simple regression analysis...
This article reports on an increasing number of SLA studies showing that interactional feedback p... more This article reports on an increasing number of SLA studies showing that interactional feedback plays a significant role in improving classroom learners' use of the target language. Whereas the provision of feedback has proven more effective than no feedback, there are still many variables that mediate the effectiveness of interactional feedback. This article synthesizes a set of classroom studies about interactional feedback taking into account four mediating variables: (a) feedback types, (b) instructional setting, (c) learners' age, and (d) linguistic targets. The synthesis leads to the conclusion that prescriptions to use only "implicit negative feedback" at the expense of other more overt types of interactional feedback are not supported by classroom research. The article closes with a recommendation for teachers to adopt a wide variety of interactional feedback techniques in accordance with a range of contextual, individual, and linguistic variables.
The dependence of magnetotransport on field orientation is an important issue in spintronics-rela... more The dependence of magnetotransport on field orientation is an important issue in spintronics-related devices where the applied field is not necessarily in the ideal field-in-plane (FIP) geometry. In this study, we perform tunneling magnetoresistance (TMR) measurements on Co-Al 2 O 3 -CoFe-NiFe spin-dependent tunnel (SDT) junctions prepared at different conditions with varying field orientation ranging from FIP to field-perpendicular-to-plane (FPP). The TMR ratio decreases drastically, whereas the switching field of Co increases when the field direction is set close to FPP. Furthermore, in a situation near FPP, a peculiar TMR looping behavior is observed for one set of samples. Interface effect is thought to be related.
Configurational entropy due to structural disorder in complex crystals is considered in some deta... more Configurational entropy due to structural disorder in complex crystals is considered in some details. It is reminded that motional correlation and equivalence of plural entities (such as molecule or group) have potentially serious effects on the entropy. Possible appearance of entropy plateaus in its temperature dependence is suggested.
Yasuhisa Yamamura†, Kazuya Saito†, Isao Ikemoto‡ and Michio Sorai† † Microcalorimetry Research Ce... more Yasuhisa Yamamura†, Kazuya Saito†, Isao Ikemoto‡ and Michio Sorai† † Microcalorimetry Research Centre, Faculty of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan ‡ Department of Chemistry, Faculty of Science, Tokyo Metropolitan University, Hachioji, Tokyo ...
ABSTRACT The heat capacity of crystalline p-quinquephenyl was measured by adiabatic calorimetry b... more ABSTRACT The heat capacity of crystalline p-quinquephenyl was measured by adiabatic calorimetry below room temperature. A broad hump was detected around 264 K and attributed to a phase transition. through which an average molecular conformation changes from the planar to the twisted one on cooling. A similar anomaly was also detected for crystalline p-sexiphenyl around 295 K by chopped-light ac calorimetry. The broad shape of the thermal anomalies arising from the twist transitions are discussed in relation to the number of possible intramolecular twisting modes. Properties of the twist transition in polymer are discussed on the basis of those of oligomers. Standard thermodynamic functions are tabulated for p-quinquephenyl.
ZrV(2)O(7) and HfV(2)O(7), which show negative thermal expansion (NTE) in the high-temperature ph... more ZrV(2)O(7) and HfV(2)O(7), which show negative thermal expansion (NTE) in the high-temperature phase, were investigated using X-ray diffraction and heat capacity calorimetry. Two sharp anomalies due to successive phase transitions were observed in the temperature dependence of heat capacity at 345.5 K and 373.4 K for ZrV(2)O(7) and 341.8 K and 370.3 K for HfV(2)O(7). The smallness of their combined entropies of transition suggested that the phase transitions are of displacive type. Effective phonon densities of states (DOS) described by a simple model, and mode-Grüneisen parameters of the low-temperature phase were obtained through the spectrum analyses of heat capacities of ZrV(2)O(7) and HfV(2)O(7). Their effective phonon DOS's show the three features common to NTE compounds: low-energy phonon mode, high-energy phonon mode, and a wide phonon gap in between. The mode-Grüneisen parameter of low-energy modes corresponding to translational and librational vibrations of the constituent polyhedra is negative but with a small absolute value due to the distortion of V(2)O(7) group in the low-temperature phase, resulting in positive thermal expansion. It is revealed that the release of the structural distortion upon the successive phase transitions with large volume increase leads to the NTE of ZrV(2)O(7) and HfV(2)O(7) in the high-temperature phase.
Heat capacity of a hydrogen-bonded organic-inorganic hybridconductor, [Pd(H2-xedag)(Hedag)]·TCNQ ... more Heat capacity of a hydrogen-bonded organic-inorganic hybridconductor, [Pd(H2-xedag)(Hedag)]·TCNQ (x≈1/3), has been precisely measured by adiabatic calorimetry below room temperature. A very broad but definite anomaly was detected around 170 K and attributed to a metal-insulator transition. The enthalpy and entropy of transition were determined and discussed in relation to a possible order-disorder mechanism of protons in the hydrogen bonds between the Pd complexes and a possible Peierls mechanism. The analysis shows the latter is more likely. It is suggested that the long superstructure appearing below the metal-insulator transition originates in two potential periodicities arising from the non-stoichiometry x. Standard thermodynamic functions are tabulated.
Organic conductors, (DMET)2BF4, (DMET)2CIO4 and (DIMET)zBF4 (DMET=dimethyl(ethylenedithio)diselen... more Organic conductors, (DMET)2BF4, (DMET)2CIO4 and (DIMET)zBF4 (DMET=dimethyl(ethylenedithio)diselenadithiafulvalene), have two types of donor columns, which are almost perpendicular to each other. Resistivity and thermopower were measured along the two types of columns under ambient pressure between 4.2 and 300 K. All the salts show metal-insulator transition at about 30 K. Unusual stepwise increases in resistivity and corresponding changes in thermopower were found for the salts below 30 K. The stepwise changes suggest that a few transitions occur in the semiconducting state.
Although previous research indicates that Japanese speakers' second language (L2) perception ... more Although previous research indicates that Japanese speakers' second language (L2) perception and production of English /see symbol/ may improve with increased L2 experience, relatively little is known about the fine phonetic details of their /see symbol/ productions, especially during the early phase of L2 speech learning. This cross-sectional study examined acoustic properties of word-initial /see symbol/ from 60 Japanese learners with a length of residence of between one month and one year in Canada. Their performance was compared to that of 15 native speakers of English and 15 low-proficiency Japanese learners of English. Formant frequencies (F2 and F3) and F1 transition durations were evaluated under three task conditions--word reading, sentence reading, and timed picture description. Learners with as little as two to three months of residence demonstrated target-like F2 frequencies. In addition, increased LOR was predictive of more target-like transition durations. Although...
The current project aimed to investigate the potentially different linguistic correlates of compr... more The current project aimed to investigate the potentially different linguistic correlates of comprehensibility (i.e., ease of understanding) and accentedness (i.e., linguistic nativelikeness) in adult second language (L2) learners’ extemporaneous speech production. Timed picture descriptions from 120 beginner, intermediate, and advanced Japanese learners of English were analyzed using native speaker global judgments based on learners’ comprehensibility and accentedness, and then submitted to segmental, prosodic, temporal, lexical, and grammatical analyses. Results showed that comprehensibility was related to all linguistic domains, and accentedness was strongly tied with pronunciation (specifically segmentals) rather than lexical and grammatical domains. In particular, linguistic correlates of L2 comprehensibility and accentedness were found to vary by learners’ proficiency levels. In terms of comprehensibility, optimal rate of speech, appropriate and rich vocabulary use, and adequat...
To investigate the pedagogical effectiveness of oral corrective feedback (CF) on target language ... more To investigate the pedagogical effectiveness of oral corrective feedback (CF) on target language development, we conducted a meta-analysis that focused exclusively on 15 classroom-based studies (N = 827). The analysis was designed to investigate whether CF was effective in classroom settings and, if so, whether its effectiveness varied according to (a) types of CF, (b) types and timing of outcome measures, (c) instructional setting (second vs. foreign language classroom), (d) treatment length, and (e) learners' age. Results revealed that CF had significant and durable effects on target language development. The effects were larger for prompts than recasts and most apparent in measures that elicit free constructed responses. Whereas instructional setting was not identified as a contributing factor to CF effectiveness, effects of long treatments were larger than those of short-to-medium treatments but not distinguishable from those of brief treatments. A simple regression analysis...
This article reports on an increasing number of SLA studies showing that interactional feedback p... more This article reports on an increasing number of SLA studies showing that interactional feedback plays a significant role in improving classroom learners' use of the target language. Whereas the provision of feedback has proven more effective than no feedback, there are still many variables that mediate the effectiveness of interactional feedback. This article synthesizes a set of classroom studies about interactional feedback taking into account four mediating variables: (a) feedback types, (b) instructional setting, (c) learners' age, and (d) linguistic targets. The synthesis leads to the conclusion that prescriptions to use only "implicit negative feedback" at the expense of other more overt types of interactional feedback are not supported by classroom research. The article closes with a recommendation for teachers to adopt a wide variety of interactional feedback techniques in accordance with a range of contextual, individual, and linguistic variables.
The dependence of magnetotransport on field orientation is an important issue in spintronics-rela... more The dependence of magnetotransport on field orientation is an important issue in spintronics-related devices where the applied field is not necessarily in the ideal field-in-plane (FIP) geometry. In this study, we perform tunneling magnetoresistance (TMR) measurements on Co-Al 2 O 3 -CoFe-NiFe spin-dependent tunnel (SDT) junctions prepared at different conditions with varying field orientation ranging from FIP to field-perpendicular-to-plane (FPP). The TMR ratio decreases drastically, whereas the switching field of Co increases when the field direction is set close to FPP. Furthermore, in a situation near FPP, a peculiar TMR looping behavior is observed for one set of samples. Interface effect is thought to be related.
Configurational entropy due to structural disorder in complex crystals is considered in some deta... more Configurational entropy due to structural disorder in complex crystals is considered in some details. It is reminded that motional correlation and equivalence of plural entities (such as molecule or group) have potentially serious effects on the entropy. Possible appearance of entropy plateaus in its temperature dependence is suggested.
Yasuhisa Yamamura†, Kazuya Saito†, Isao Ikemoto‡ and Michio Sorai† † Microcalorimetry Research Ce... more Yasuhisa Yamamura†, Kazuya Saito†, Isao Ikemoto‡ and Michio Sorai† † Microcalorimetry Research Centre, Faculty of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan ‡ Department of Chemistry, Faculty of Science, Tokyo Metropolitan University, Hachioji, Tokyo ...
ABSTRACT The heat capacity of crystalline p-quinquephenyl was measured by adiabatic calorimetry b... more ABSTRACT The heat capacity of crystalline p-quinquephenyl was measured by adiabatic calorimetry below room temperature. A broad hump was detected around 264 K and attributed to a phase transition. through which an average molecular conformation changes from the planar to the twisted one on cooling. A similar anomaly was also detected for crystalline p-sexiphenyl around 295 K by chopped-light ac calorimetry. The broad shape of the thermal anomalies arising from the twist transitions are discussed in relation to the number of possible intramolecular twisting modes. Properties of the twist transition in polymer are discussed on the basis of those of oligomers. Standard thermodynamic functions are tabulated for p-quinquephenyl.
ZrV(2)O(7) and HfV(2)O(7), which show negative thermal expansion (NTE) in the high-temperature ph... more ZrV(2)O(7) and HfV(2)O(7), which show negative thermal expansion (NTE) in the high-temperature phase, were investigated using X-ray diffraction and heat capacity calorimetry. Two sharp anomalies due to successive phase transitions were observed in the temperature dependence of heat capacity at 345.5 K and 373.4 K for ZrV(2)O(7) and 341.8 K and 370.3 K for HfV(2)O(7). The smallness of their combined entropies of transition suggested that the phase transitions are of displacive type. Effective phonon densities of states (DOS) described by a simple model, and mode-Grüneisen parameters of the low-temperature phase were obtained through the spectrum analyses of heat capacities of ZrV(2)O(7) and HfV(2)O(7). Their effective phonon DOS's show the three features common to NTE compounds: low-energy phonon mode, high-energy phonon mode, and a wide phonon gap in between. The mode-Grüneisen parameter of low-energy modes corresponding to translational and librational vibrations of the constituent polyhedra is negative but with a small absolute value due to the distortion of V(2)O(7) group in the low-temperature phase, resulting in positive thermal expansion. It is revealed that the release of the structural distortion upon the successive phase transitions with large volume increase leads to the NTE of ZrV(2)O(7) and HfV(2)O(7) in the high-temperature phase.
Heat capacity of a hydrogen-bonded organic-inorganic hybridconductor, [Pd(H2-xedag)(Hedag)]·TCNQ ... more Heat capacity of a hydrogen-bonded organic-inorganic hybridconductor, [Pd(H2-xedag)(Hedag)]·TCNQ (x≈1/3), has been precisely measured by adiabatic calorimetry below room temperature. A very broad but definite anomaly was detected around 170 K and attributed to a metal-insulator transition. The enthalpy and entropy of transition were determined and discussed in relation to a possible order-disorder mechanism of protons in the hydrogen bonds between the Pd complexes and a possible Peierls mechanism. The analysis shows the latter is more likely. It is suggested that the long superstructure appearing below the metal-insulator transition originates in two potential periodicities arising from the non-stoichiometry x. Standard thermodynamic functions are tabulated.
Organic conductors, (DMET)2BF4, (DMET)2CIO4 and (DIMET)zBF4 (DMET=dimethyl(ethylenedithio)diselen... more Organic conductors, (DMET)2BF4, (DMET)2CIO4 and (DIMET)zBF4 (DMET=dimethyl(ethylenedithio)diselenadithiafulvalene), have two types of donor columns, which are almost perpendicular to each other. Resistivity and thermopower were measured along the two types of columns under ambient pressure between 4.2 and 300 K. All the salts show metal-insulator transition at about 30 K. Unusual stepwise increases in resistivity and corresponding changes in thermopower were found for the salts below 30 K. The stepwise changes suggest that a few transitions occur in the semiconducting state.
Uploads
Papers by Kazuya Saito