Effect of heat treatment on the NO2-sensing properties of sputter-deposited indium tin oxide thin films

Transparent conducting indium tin oxide (ITO) films were deposited onto glass substrates by radio-frequency magnetron sputtering at 648?K, under an oxygen partial pressure of 1?Pa. The effect of annealing on the electrical properties of the films was studied. Characterization of the coatings revealed an electrical resistivity below 6.5?×?10^??3?Ω?cm. The ITO films deposited at 648?K were amorphous, while the crystallinity improved after annealing at 700?K. The surface morphology examined by scanning electron microscopy appears to be uniform over the entire surface area after annealing. The NO₂-sensing properties of the ITO films were investigated and showed sensitivity at concentrations lower than 50?ppm, at a working temperature of 600?K.     

Effect of cooling rate on size-dependent atomic ordering of CoPt nanoparticles

We report on the effect of cooling rate on the size-dependent atomic ordering of CoPt nanoparticles using aberration corrected high-resolution transmission electron microscopy. It was found that cooling rate plays a crucial role in promoting atomic ordering during the cooling process after annealing. Nanoparticles of ≈3?nm in diameter show the A1-disordered phase after annealing at 873?K for 1?h followed by rapid cooling (110?K/min), while the L1₀-ordered phase is obtained when the cooling rate is slow (1.5?K/min). The disordered phase is also obtained by rapid cooling after annealing at 973?K for 1?h. These results unambiguously indicate that the order–disorder transformation temperature is reduced to a temperature at least lower than 873?K for CoPt nanoparticles smaller than 3?nm in diameter. The slow cooling process promotes the atomic ordering, which resulted in an enhancement of magnetic coercivity as high as 2200?Oe. This study demonstrates that hard magnetic properties of the CoPt nanoparticles can be improved by controlling the cooling rate after heat treatments.     

Microstructures and tensile properties of 304 steel with dual nanocrystalline and microcrystalline austenite content prepared by aluminothermic reaction casting

The microstructures of 304 stainless steels with different amounts of nanocrystalline and microcrystalline austenite prepared by an aluminothermic reaction casting, without and with annealing at 1073?K for 8?h, have been investigated by X-ray diffraction, an electron probe micro-analyser, a transmission electron microscope and a scanning electron microscope. The steels, both without and with annealing, consisted of different dual nanocrystalline and microcrystalline austenite combinations and a little nanocrystalline δ ferrite, while the average grain size of the nanocrystalline austenite increased from 19 to 26?nm and volume fraction of the microcrystalline austenite increased from 17 to 30% after annealing. The tensile strength of the steel was dramatically increased from 500 to 1000?MPa and the tensile elongation ratio increased from 8 to 12% after annealing. However, the tensile strength was decreased to 600?MPa and the tensile elongation ratio increased from 12 to 22% after an annealing at 1273?K. The combination of dual nanocrystalline and microcrystalline austenite obtained after the annealing at 1073?K results in the best tensile properties.     

Motivation gains in performance groups: paradigmatic and theoretical developments on the Köhler effect

In contrast to many demonstrations of social loafing, relatively few studies have documented group motivation gains. One such exception was O. K?hler's (1926, 1927) finding that team members working together did better at a taxing persistence task than would be expected from their individual performances, particularly when there was a moderate discrepancy in coworkers' capabilities. In Experiment 1, we developed a paradigm within which K?hler's overall motivation gain effect could be replicated, although the discrepancy in coworkers' capabilities did not moderate these motivation gains (after statistical artifacts were taken into account). Experiment 2 indicated that this motivation gain occurred under conjunctive but not under additive task demands, suggesting that the instrumentality of one's contribution to valued outcomes is a more likely explanation of the K?hler effect than social comparison processes.     

Mechanical spectroscopy of a high-Nb-bearing γ-TiAl-based alloy with near-gamma and fully lamellar microstructure

Intermetallic γ-TiAl sheet material of composition Ti–46?at.%Al–9?at.%Nb and two different microstructures (fine-grained near-gamma and coarse-grained fully lamellar) was studied by mechanical-loss (internal-friction) measurements using two frequency ranges: (I) 0.01–10?Hz and (II) around 2?kHz. The mechanical spectra in range I show (i) a loss peak of Debye type at T?≈?1000?K, which occurs only in fully lamellar samples; and (ii) a high-temperature damping background above?≈?1100?K. The values of the activation enthalpy H of the high-temperature background, 4.3?eV (near-gamma) and 4.2?eV (fully lamellar), which were determined from the frequency shift, are distinctly higher than those obtained for TiAl sheet material with low Nb content. The high-temperature damping background is assigned to diffusion-assisted climb of dislocations, and the 1000?K peak (H?=?2.9?eV) to local (reversible) glide of dislocation segments anchored between lamella interfaces. From measurements of the eigenfrequency in range II, the variation of Young's modulus in the temperature range 300–1000?K was determined.     

Dynamic properties of edge dislocations decorated by interstitial loops in α-iron and copper

Clusters of self-interstitial atoms (SIAs) in the form of parallel crowdions are created directly in high-energy displacement cascades produced in metals by neutron irradiation. They are equivalent to small perfect dislocation loops and, in isolation in pure metals, undergo fast thermally-activated glide in the direction of their Burgers vector. Their strain field and ability to glide allows long-range interaction with other extended defects. Indeed, dislocations decorated by dislocation loops are commonly observed after neutron irradiation. Dislocations gliding under applied stress also encounter these mobile defects. These effects influence mechanical properties and require further investigation. This paper presents results from an atomic-scale study of copper and α-iron at either 0?K or 300?K. Loop drag and breakaway effects are investigated for an edge dislocation under applied stress interacting with a row of SIA loops below its glide plane. The maximum speed at which a loop is dragged is lower in copper than iron, and the applied stress at which this occurs is also lower. These differences in the dynamics of cluster-dislocation interaction are determined by the atomic structure of the defects and cannot be investigated by continuum treatment.     

Crossover from bulk to surface diffusion in the fluctuations of step edges on Pt(111)

Using low-energy electron microscopy we explore the fluctuations of step edges on Pt(111) in the temperature range 1190?K<T<1520?K. Below 1400?K the relaxation times vary with wave vector q as q ³, and above 1400?K as q ², while the observed activation energy changes from 1.25 to 2.75?eV. A discussion shows that surface diffusion is responsible for the rates at low temperatures, and that bulk vacancy diffusion becomes dominant above 1400?K. We infer that a similar crossover must occur for steps on most metal surfaces. The step stiffness is determined as 175 ± 20?meV?nm^?1 at 1500?K.     

Influence of test temperature on the size effect in molybdenum small-scale compression pillars

Previous research has shown that body-centred cubic (bcc) metals exhibit a smaller size dependence of strength than what is commonly observed in face-centred cubic (fcc) metals. This work investigates compression testing of focused ion beam-manufactured molybdenum pillars ranging in size from 300?nm to 5?μm, both above and below its critical temperature at 300 and 500?K. At 500?K the size effect is found to be consistent with what is observed in fcc metals, owing to the increased mobility of screw dislocations.     

Giant electrocaloric effect of highly (1 0 0)-oriented 0.68PbMg1/3Nb2/3O3–0.32PbTiO3 thin film

PbZr_0.95Ti_0.05O₃ thin film has the highest electrocaloric properties of all the oxide thin films (0.48?K?V^?1). Here, it is shown giant electrocaloric properties in 200?nm (1?0?0)-oriented PMN–PT 68/32 film near the ferroelectric Curie temperature of 146?°C. The results indicate the significance of this system to achieve electrocaloric entropy change and temperature change, up to 32.21?J/kg?°C and 14?K, respectively, in 12?V (i.e. 1.155?K?V^?1) near the Curie point. This exceeds the previous best results obtained in PbZr_0.95Ti_0.05O₃ thin film.     

Implicit sound symbolism in lexical access: evidence from an interference task

K?hler (1929) reported anecdotally that, when asked to choose, subjects were much more likely to attach the name 'takete' to a spiky abstract object, and the name 'baluma' (or, by 1947, 'maluma') to a curvy abstract object. Follow-up work has suffered from the same three weaknesses as K?hler's original anecdotal study: a reliance on small number of stimuli carefully selected by the experimenter; the use of manipulations that were transparent to the subject; and the use of overtly semantic tasks. This paper reports two experiments that replicate and extend K?hler's claims using an implicit interference task that allows for multiple measures per subject, and does not require subjects to make explicit decisions about the relation between visual form and meaning. Subjects undertook a lexical or letter decision task with the stimuli presented inside spiky or curvy frames. Reaction times show interference patterns consistent with K?hler's claims. This demonstrates that the effect is pre-semantic. Neurological reasons for these word/shape and character/shape interference phenomena are discussed.     

Knowledge of partner's ability as a moderator of group motivation gains: an exploration of the Köhler discrepancy effect

O. K?hler (1926, 1927) found that less able performers tried harder as team members under conjunctive task demands (Kohler motivation gain effect) and that the greatest gain occurred with moderately discrepant coworker abilities (K?hler discrepancy effect). Recent investigations have reproduced K?hler's overall motivation gain but not the discrepancy effect. The present research examined whether workers' foreknowledge of task abilities--present in Kohler's research, absent in contemporary studies--moderates the discrepancy effect. Participants worked alone or in 2-person teams under conjunctive task demands. Experiment 1 manipulated foreknowledge of ability. Experiment 2 manipulated discrepancy: a (confederate) teammate performed slightly, moderately, or substantially better. Both experiments found (a) overall motivation gains and (b) discrepancy moderation under foreknowledge conditions. Implications for understanding group motivation gains are discussed.     

A randomized, controlled trial of virtual reality-graded exposure therapy for post-traumatic stress disorder in active duty service members with combat-related post-traumatic stress disorder

Abstract Virtual reality (VR)-based therapy has emerged as a potentially useful means to treat post-traumatic stress disorder (PTSD), but randomized studies have been lacking for Service Members from Iraq or Afghanistan. This study documents a small, randomized, controlled trial of VR-graded exposure therapy (VR-GET) versus treatment as usual (TAU) for PTSD in Active Duty military personnel with combat-related PTSD. Success was gauged according to whether treatment resulted in a 30 percent or greater improvement in the PTSD symptom severity as assessed by the Clinician Administered PTSD Scale (CAPS) after 10 weeks of treatment. Seven of 10 participants improved by 30 percent or greater while in VR-GET, whereas only 1 of the 9 returning participants in TAU showed similar improvement. This is a clinically and statistically significant result (χ(2)?=?6.74, p?相似文献   

A Prospective Investigation of Changes in Avoidant and Active Coping and Posttraumatic Stress Disorder Symptoms among Military Veteran

The present investigation utilized a prospective design to investigate associations between changes in self-reported avoidant and active coping occurring during residential treatment for posttraumatic stress disorder (PTSD) and PTSD symptom severity at treatment discharge. Participants were 636 military Veteran patients (91.4?% male; M _age?=?51.7?years) admitted to a Veterans Affairs (VA) residential rehabilitation program for PTSD, between 2000 and 2008. Results indicated that increases in avoidant coping and decreases in active coping from treatment intake to discharge were simultaneously and incrementally predictive of total PTSD symptom severity at treatment discharge, after accounting for PTSD symptom severity at treatment intake. These findings hold particular relevance for treatment-seeking populations with severe PTSD and researchers and clinicians attempting to understand and treat these populations.     

The Role of Visual Cues in Movement Control and Motor Memory

3 groups of 12 Ss performed an index finger letter-writing task with visual information but without kinesthetic cues (+V?K), followed immediately by repeating the same letters without vision (?V?K). All groups performed 6 test trials of + V?K, then ?V?K writing. Group 1 had no experience with the task prior to the test trials, Group 2 practiced the letters without vision with kinesthetic cues (?V+K), while Group 3 had visual and kinesthetic practice (+V+K). Visual cues efficiently guided performance in the absence of kinesthesis, and visual memory traces had a marked reinforcing effect. Further, learned reliance on kinesthetic cues was present even in +V?K performance, but reliance on visual cues did not develop.     

Treating Survivors of Terrorism While Adversity Continues

Abstract

The current situation in Israel of continuous terrorist attacks poses unique challenges to the treatment of Posttraumatic Stress Disorder (PTSD). This article addresses issues that arise when treating survivors of ongoing terrorism. These include: (a) Is PTSD treatable during ongoing adversity? (b) When should treatment be offered? (c) Is avoidance maladaptive or adaptive? (d) How does one deal with re-exposure? (e) How to define the end of treatment? and (f) What are the effects on the therapist when conducting treatment during ongoing adversity? Case studies are provided to illustrate these issues when treating clients with PTSD during ongoing terror.     

Microstructure and superconductivity of bulk BPSCCO/LPMO composite

Bulk superconducting (SC) ceramics containing BPSCCO and LPMO (Lanthanum/Lead – manganite phase) have been produced. The initial components were prepared by a low-temperature Pechini method. The submicron powders in weight ratio 90/10 Bi_1.6Pb_0.4Sr₂Ca₂Cu₃O_z/La_0.6Pb_0.4MnO₃ (nominal composition) were heat treated at 840°C. The duration of the heat treatment effect (60 and 100?h) of the composite on the transformation of the microstructure was studied. The obtained composites were analyzed by scanning electron microscopy (SEM) and by the method of energy-dispersive X-ray spectroscopy (EDX). They contain several phases. It was established that the SC 2212 phase is predominate in the composite. The phase La_0.6Pb_0.4MnO₃ transforms in solid solution with preliminary composition La_0.5(Sr?+?Ca)_0.5Mn_{1? z} Cu _z O₃, which after full replacement of the La and Mn ions leads to the appearance of phases with nominal composition Sr_{1? x} Ca _x CuO _y . AC and DC magnetization measurements were used to study the SC and magnetic properties of the samples. Both samples are SC with critical temperatures 75 and 77?K, respectively. It was concluded that the SC and magnetic phases stably coexist in the composite sintered at 60?h heat treatment at 840°C.     

Deformation structure after fracture-toughness test of Mg–Al–Zn alloys processed by equal-channel-angular extrusion

Fracture toughness and deformation structures have been investigated using an AZ31 magnesium alloy processed by equal-channel-angular extrusion (ECAE). The ECAE-processed alloy (as-ECAE) was annealed at 573?K for 24?h (annealed-ECAE). The average grain sizes of as-ECAE and annealed-ECAE alloys were 4.0 and 16.3?µm, respectively. The plane-strain fracture toughness K _IC, obtained by stretched-zone analysis in as-ECAE and annealed-ECAE, were estimated to be 27.3 and 23.5?MPa/m^1/2, respectively. From optical microstructural observations in samples after the fracture-toughness tests, deformation twins were observed in annealed-ECAE. No deformation twins were observed in as-ECAE. In addition, dislocations on basal planes, as well as on non-basal planes, were activated in as-ECAE. It is concluded that the enhancement of the fracture toughness in the fine-grain structure was related to a reduction of deformation twins and dislocation movement in non-basal planes.     

Solid and liquid thermal expansion and structural observations in the quasicrystalline Cd84Yb16 compound

The structure of single-grain Cd₈₄Yb₁₆ samples aligned along the twofold and fivefold axes has been followed from 300 to 1050?K using high-energy synchrotron X-rays. The quasicrystal phase is stable up to its melting temperature of 914?K and has a large linear thermal expansion of 37.1?ppm?K^?1 over this temperature range. The samples melt congruently over a temperature range of less than 1?K. The liquid is 7% less dense than the solid and, upon cooling from the melt, the quasicrystal phase directly solidifies within a 1?K interval. The amount of undercooling achieved, about 5–25?K, was dependent on the cooling rate. The total scattering function of the liquid is consistent with a dilute liquid Cd structure. These results agree with suggestions that the structure of the liquid must undergo reordering in order to form the solid phases. However, there is no compelling evidence for icosahedral short-range order in the liquid prior to the formation of the quasicrystalline structure.     

Traumatic stress, perceived global stress, and life events: prospectively predicting quality of life in breast cancer patients.

The authors investigated the relationship between stress at initial cancer diagnosis and treatment and subsequent quality of life (QoL). Women (n = 112) randomized to the assessment-only arm of a clinical trial were initially assessed after breast cancer diagnosis and surgery and then reassessed at 4 months (during adjuvant treatment) and 12 months (postadjuvant treatment). There were 3 types of stress measured: number of stressful life events (K. A. Matthews et al., 1997), cancer-related traumatic stress symptoms (M. J. Horowitz, N. Wilner, & W. Alvarez, 1979), and perceived global stress (S. Cohen, T. Kamarck, & R. Mermelstein, 1983). Using hierarchical multiple regressions, the authors found that stress predicted both psychological and physical QoL (J. E. Ware, K. K. Snow, & M. Kosinski, 2000) at the follow-ups (all ps < .03). These findings substantiate the relationship between initial stress and later QoL and underscore the need for timely psychological intervention.     

Wittgenstein on K?hler and Gestalt psychology: a critique.

Wittgenstein's objections to K?hler and gestalt psychology are critically examined. Principal features of K?hler's Gestalt Psychology are discussed that are relevant to Wittgenstein's views. They include K?hler's concepts of "subjective" and "objective" experiences, "sensory organization," and "empiristic theory." Wittgenstein's objections, which focus on the concept of sensory organization, are examined. Wittgenstein employs the term "aspect," which is derived from the findings of gestalt psychology, as a replacement for K?hler's term "sensory organization." After tracing his uses of aspect, it is shown that aspect is a superordinate entity distinct from 'sensory content' (colors and shapes). This dualism of aspect and sensory content is of the same kind that prevailed in the empiristic theory of visual perception. Wittgenstein's adherence to the empiristic theory is discussed. Finally, the difference between Wittgenstein's aspect and K?hler's sensory organization is examined.