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1.
The structural, elastic and phonon properties of the quaternary CoFeCrZ (Z = Al, Si, Ga and Ge) Heusler alloys have been investigated using the generalized gradient approximation method within density functional theory. The ground-state properties, including, lattice constant and bulk modulus are in good agreement with the available theoretical and experimental data. The elastic constants Cij are computed using the stress–strain technique. The calculated results indicate that CoFeCrZ (Z = Al, Si, Ga and Ge) alloys are ductile materials. Debye temperatures are predicted from calculated elastic constants. The phonon dispersion relations of CoFeCrZ (Z = Al, Si, Ga and Ge) alloys are calculated for the first time using the density functional theory and the direct method with 2 × 2 × 2 supercell.  相似文献   

2.
We have studied the structural, elastic, electronic, phonon and thermodynamic properties of Ir3Ta and Rh3Ta alloys, using ab initio calculations. For the L12 phase, we report the calculated lattice constants, bulk modulus and elastic constants, and these values are compared with previously published values. We also derive the elastic constants from the values of the slopes of the acoustic branches in the phonon dispersion curves. The band structures show that both materials are metallic. The phonon dispersion curves, and their corresponding total and projected densities of states, are obtained using a linear response in the framework of the density functional perturbation theory. The specific heat capacity at constant volume and different temperatures is calculated, and this aspect is discussed using the quasi-harmonic approximation.  相似文献   

3.
The magnetic, mechanical and thermodynamic properties of LaMO3 (M = Ti~Fe) have been systematically investigated using the first-principles calculations. The total magnetic moments of LaMO3 are mainly from the M atom, and the contributions from La and O are very small. For LaTiO3, LaVO3, LaCrO3 and LaMnO3 the total magnetic moments agree well with experiment, while with somewhat larger disagreement for LaFeO3. Using the GGA + U (U = 5.6 eV), the calculated magnetic moment of LaFeO3 is 4.98μB, which is in agreement with experiment data. The elastic constants and Vickers hardness suggest that LaMO3 are mechanically stable and soft materials. The B/G ratios indicate that all of LaMO3 are ductile except LaVO3 and LaCrO3.The LaCrO3 has the highest Debye temperature, while LaVO3 has the lowest Debye temperature.  相似文献   

4.
Neurodevelopmental delays are known to occur in children with metopic synostosis, but it is presently unclear whether the cognitive, behavioral and psychological outcomes of children with metopic synostosis differ to those of their healthy peers. This meta-analysis consolidated data from 17 studies (published prior to August 2017) that examined the cognitive, behavioral and psychological outcomes of children (n = 666; aged ≤19 yrs) with metopic synostosis. Hedges’g (gw) effect sizes compared the outcomes of samples with metopic synostosis (unoperated, operated) to healthy controls or normative data and, where available, the prevalence of problems/disorders was calculated. Children with unoperated metopic synostosis performed significantly worse than their healthy peers on measures of: general cognition (gw = ?.38), motor functioning, (gw = ?.81), and verbal (gw = ?.82) and visuospatial (gw = ?.92) abilities. Children with operated metopic synostosis performed significantly worse on measures of motor functioning (gw = ?.45), visuospatial skills (gw = ?.32), attention (gw = ?.50), executive functioning (gw = ?.36), arithmetic ability (gw = ?.37), and behavior (gw = ?.34). Cognitive, behavioral, and psychological problems were prevalent, but variable. Overall, the cognitive, behavioral, and psychological outcomes of children with metopic synostosis are generally worse than their healthy peers, regardless of surgical status. However, research is sparse, samples small, controls are rarely recruited, and the severity of metopic synostosis often not stated. Nevertheless, the findings suggest that children with metopic synostosis are likely to experience a variety of negative outcomes and should therefore receive ongoing monitoring and support.  相似文献   

5.
ABSTRACT

We present results for the structural, electronic, vibrational, and electron-phonon coupling properties of LaSn3 and CaSn3 adopting the simple cubic AuCu3-type structure obtained using the the generalised gradient approximation of the density functional theory and plane wave ab initio pseudopotential method. Our electronic results show that both materials display metallic character with several bands, which have mainly Sn 5p character, crossing the Fermi level. The calculated phonon spectrum of LaSn3 accords very well with reported experimental measurements. The weights of the peaks in the Eliashberg spectral function of both compounds are enhanced with the use of experimental lattice constant in our electron-phonon calculation, increasing the value of average electron phonon coupling parameter from 0.876 to 0.937 for LaSn3 (by 7%) and from 0.642 to 0.725 for CaSn3 (by 13%). The use of experimental lattice constant also improves the agreement between theoretical and experimental values of the superconducting temperature for both compounds.  相似文献   

6.
Although college campuses represent strategic locations to address mental health disparity among minorities in the US, there has been strikingly little empirical work on risk processes for anxiety/depression among this population. The present investigation examined the interactive effects of acculturative stress and experiential avoidance in relation to anxiety and depressive symptoms among minority college students (n = 1,095; 78.1% female; Mage = 21.92, SD = 4.23; 15.1% African-American (non-Hispanic), 45.3% Hispanic, 32.5% Asian, and 7.1% other races/ethnicities. Results provided empirical evidence of an interaction between acculturative stress and experiential avoidance for suicidal, social anxiety, and anxious arousal symptoms among the studied sample. Inspection of the significant interactions revealed that acculturative stress was related to greater levels of suicidal symptoms, social anxiety, and anxious arousal among minority college students with higher, but not lower, levels of experiential avoidance. However, in contrast to prediction, there was no significant interaction for depressive symptoms. Together, these data provide novel empirical evidence for the clinically-relevant interplay between acculturative stress and experiential avoidance in regard to a relatively wide array of negative emotional states among minority college students.  相似文献   

7.
The effects of pressure on the mechanical and dynamical stability of NaAlSi have been fully investigated by first-principles calculations within the generalised gradient approximation (GGA). The obtained results show that the optimised lattice constants, atomic positions and elastic constants at ambient pressure are in good agreement with the available experimental and theoretical data. The lattice constants decrease monotonically with increasing pressure. The elastic constant C11, C12, C13, C33 and C66 increase while C44 decreases with increasing pressure. It is found that NaAlSi is mechanically unstable when the pressure is above 25.97?GPa. The phonon-dispersion curves along several high symmetry lines are obtained. The phonon frequencies at the Z point decrease with increasing pressure and completely soften to zero at 27.52?GPa, further confirming the structural instability of NaAlSi.  相似文献   

8.
The construct of authenticity is thought of as an expression of individuality and eudaimonic well-being. Yet, previous research has related state authenticity more to positive affect and pleasant behavior. We examine the extent to which feeling authentic is a reflection of personally held standards of worth (values) and authenticity’s relationship with affective states. We also examine whether feelings of authenticity are facilitated by dispositional authenticity. Study 1 had participants debate benevolent behavior (N = 199). In study two (N = 124) and three (N = 146), participants described memories where they acted in concordance or against their values, in both pleasant and unpleasant contexts. We found a relationship between acting in accordance with one’s values and experiencing authenticity, thus demonstrating that authenticity is a form of eudaimonic well-being, which is closely related to, but distinct from, affective states. We found less consistent associations between dispositional authenticity and momentary authentic feelings.  相似文献   

9.
Despite growing evidence that conversation on inner states fosters gains in children’s social cognition, this mechanism has yet to be tested with toddlers. To address this gap, we examined whether an intervention based on conversing about mental states with small groups of 2-year-old children at nursery had a significant effect on toddlers’ theory of mind (ToM) and emotion understanding (EU). Participants were 68 children (Mage at pre-test: 29.9 months) who were assigned to either an experimental or a control condition. Measures of verbal ability, ToM and EU were administered at pre-test, post-test and follow-up stages. Over a one-month intervention, all children were read a series of brief illustrated stories. After listening to the stories, the experimental group (n = 34) was involved in conversations on mental states, whereas the control group (n = 34) was engaged in conversation regarding the material entities and actions featured in the storybook. The experimental group significantly outperformed the control group on measures of both ToM and EU, independently of gains in verbal ability. Furthermore, these positive effects remained stable over time. We discuss the theoretical and practical implications of these findings.  相似文献   

10.
There is growing recognition of the importance of understanding the nature of the associations between anxiety and cardiovascular disease (CVD), although limited research has examined mechanisms that may explain the anxiety-CVD link. Anxiety sensitivity (fear of anxiety-relevant somatic sensations) is a cognitive-affective risk factor implicated in the development of anxiety psychopathology and various behavioral risk factors for CVD, although has not been examined among individuals with CVD. Adult daily smokers (n = 619; 50.9% female; Mage = 44.0, SD = 13.67) completed an online survey that included the Anxiety Sensitivity Index-3 (ASI-3) and the Patient Health Questionnaire (PHQ). The presence of CVD was assessed via the presence of ≥1 of the following: heart attack, heart murmur, positive stress test, heart valve abnormality, angina, and heart failure. Smokers with CVD indicators (n = 66, 10.7%) had significantly higher scores on the ASI-3 (M = 33.5, SD = 22.15), relative to smokers without CVD (M = 22.0, S= 17.92; Cohen’s d = .57). Those with CVD were significantly more likely to have moderate or high anxiety sensitivity (66.7%) relative to those without CVD (49.4%). Physical and social concerns about the meaning of somatic sensations were common among smokers with CVD.  相似文献   

11.
Exposure to secondhand smoke (SHSe) can compound an already challenging set of health problems for youth with Sickle Cell Disease (SCD). Exposure to electronic cigarettes may also impact SCD symptomology and respiratory functioning. This study built on these previous findings by a) utilizing two objective measures of SHSe, salivary cotinine and exhaled carbon monoxide and b) examining the association of SHSe with emergency department utilization, physician-reported sickle cell crises, and pulmonary functioning. Caregivers (= 31 dyads; Mage = 37.6 years; SD = 8.5 years) of youth with SCD (Mage = 9.0 years; SD = 4.5 years) completed self-report measures of tobacco/nicotine use. Youth provided a saliva sample to assess cotinine levels, and performed pulmonary function tests. Dyads provided breath samples for measurement of eCO. A chart review was conducted to obtain medical history and utilization. Majority of youth (88%) were exposed to SHS via salivary cotinine. Interestingly, no significant associations were observed between youth cotinine levels and emergency department utilization, physician-reported sickle cell crises, or pulmonary functioning. Present findings indicate a need to assess for SHSe using objective assessment measures. Future research should investigate which specific factors contribute to increase SHSe/SHVe in youth with SCD.  相似文献   

12.
Work-anxieties are costly and need early intervention. The perception of being able to cope with work is a basic requirement for work ability. This randomized controlled trial investigates whether a cognitive behavioural, work-anxiety-coping group (WAG) intervention leads to better work-coping perception than an unspecific recreational group (RG). Heterogeneous people in medical rehabilitation, who were due to return to work, were interviewed concerning their work-anxieties, and either randomly assigned to a WAG (n = 85) or a RG (n = 95). The participants (with an average of 50 years old [range 23–64]; 51% women; 70% workers or employees, 25% academics, 5% unskilled) followed the group intervention for four or six sessions. The perceived work-coping was assessed by self-rating (Inventory for Job-Coping and Return Intention JoCoRi) after each group session. Although participants had a slight temporary decrease in work-coping after group session two (from M1 = 2.47 to M2 = 2.28, dCohen = ?.22), the WAG led to the improvement of perceived work-coping over the intervention course (from M1 = 2.47 to M6 = 2.65, dCohen = .18). In contrast, participants from the RG reported lower work-coping after six group sessions (from M1 = 2.26 to M6 = 2.02, dCohen = ?.18). It is considered that people with work-anxieties need training in work-coping. By focusing on recreation only, this may lead to deterioration of work-coping. Indeed, intervention designers should be aware of temporary deterioration (side effects) when confronting participants with work-coping.  相似文献   

13.
The experiences in close relationships revised (ECR-R) is widely used to assess romantic attachment dimensions. Investigating cultural limitations in its applicability is imperative. This study aims to examine the instrument’s: (1) factor structure in two large and normative samples of Greek (N = 1706, M age = 16.16; SD = 2.16; 49.7% male) and Cypriot (N = 1279; M age = 15.54; SD = 0.65; 44.9% male) adolescents; (2) measurement invariance between these groups, accounting for potential gender and age effects. Results supported the two-factor structure and indicated partial invariance of the constructs between Greek and Cypriot adolescents. Findings support limitations in the use of instruments adapted for Greece in Cyprus.  相似文献   

14.
Residents experience severely high levels of stress, depression and burnout, leading to perceived medical errors, as well as to symptoms of impairment, such as chronic anger, cognitive impairment, suicidal behavior and substance abuse. Because research has not yet provided a psychometrically robust population-specific tool to measure the level of stress of medicine residents, we aimed at building and validating such a measure. Using an inductive scale development approach, a short, pragmatic measure was built, based on the interviews of 17 medicine residents. The Internal Medicine Residency Stress Scale (IMRSS) was then administered in a sample of 259 internal medicine residents (199 females, 60 males, MAge = 25.6) along with the Hospital Anxiety and Depression Scale, Maslach Burnout Inventory, Satisfaction With Life Scale and Ways of Coping Checklist. The IMRSS showed satisfactory internal reliability (Cronbach’s α = .86), adequate structural validity – studied through Confirmatory Factor Analysis (χ2/df = 2.51, CFI = .94; SRMR = .037, RMSEA = .076) – and good criterion validity – the IMRSS was notably strongly correlated with emotional exhaustion (r = .64; p < .001) and anxiety (r = .57; p < .001). Because of its short length and robust psychometric qualities, the use of the IMRSS is recommended to quickly and frequently assess and monitor stress among internal medicine residents.  相似文献   

15.
Previous research has shown that individuals with generalized anxiety disorder (GAD) report elevated anger compared with nonanxious individuals; however, the pathways linking GAD and anger are currently unknown. We hypothesized that negative beliefs about uncertainty, negative beliefs about worry and perfectionism dimensions mediate the relationship between GAD symptoms and anger variables. We employed multiple mediation with bootstrapping on cross-sectional data from a student sample (N = 233) to test four models assessing potential mediators of the association of GAD symptoms to inward anger expression, outward anger expression, trait anger and hostility, respectively. The belief that uncertainty has negative personal and behavioural implications uniquely mediated the association of GAD symptoms to inward anger expression (confidence interval [CI] = .0034, .1845, PM = .5444), and the belief that uncertainty is unfair and spoils everything uniquely mediated the association of GAD symptoms to outward anger expression (CI = .0052, .1936, PM = .4861) and hostility (CI = .0269, .2427, PM = .3487). Neither negative beliefs about worry nor perfectionism dimensions uniquely mediated the relation of GAD symptoms to anger constructs. We conclude that intolerance of uncertainty may help to explain the positive connection between GAD symptoms and anger, and these findings give impetus to future longitudinal investigations of the role of anger in GAD.  相似文献   

16.
Do graphics on clothing drive perceptions? We used a between group design to test if athletic, academic, or suggestive graphics on clothing differentially influence perceptions and behavioral intentions. In study 1, participants (= 199) rated five female t-shirt models, and in study 2 and 3, participants rated five male t-shirt models (= 120) or university students (= 50). Analyses of variance controlling for sex (ANCOVA) showed participants were least likely to want to interact with models/students wearing sexually suggestive graphics: Study 1, F(3,165) = 30.263, < .001, ηp 2  = .30, power = 1.00; Study 2, F (3,119) = 11.630, p < .000, ηp = .234, and Study 3, F(1, 42) = 12.578, p < .000. Participants did not rate models in the academic and athletic graphic shirts differently from models with plain white shirts. Results support the concept that people form different perceptions based upon the clothing a person wears, changing behavioral intentions. Neither sex role ideation (Study 1) or sexism (Study 2) were significant covariates of perceptions and intentions.  相似文献   

17.
The present study examined the impact of thin-ideal media exposure on Chinese women’s drive for thinness, attitudes towards body shape, and eating attitude. Women were assigned to one of two video conditions, which portrayed the thin-ideal (experimental) or was neutral (control group), in terms of content. A total of 83 young women from Hong Kong (N = 38) and Shanghai (N = 45), aged between 18 and 25 years (Mage = 22.7) participated in the study. A significant interaction was observed between the experimental video condition and location. Hong Kong women in the experimental group experienced greater levels of body dissatisfaction than Shanghai women exposed to the same condition. Exposure to thin-ideal media produced an increase in drive for thinness, body dissatisfaction and problematic eating attitudes regardless of location, with a greater immediate impact shown in Hong Kong women.  相似文献   

18.
This study aimed to examine the psychometric properties of Beck Hopelessness Scale (BHS) in Greek patients with a recent suicide attempt, the predictive ability of BHS especially in terms of age and the possible effect of the financial crisis on hopelessness as it has been identified as a significant suicide risk factor. The study included a total of 510 individuals, citizens of Athens, Greece. Three hundred and forty individuals (170 attempted suicide patients, and 170 -age and gender- matched healthy individuals used as controls) completed BHS before the financial crisis onset (from 2009 to 2010). A sample of 170 healthy individuals also completed the BHS after the financial crisis onset (from 2013 to 2014), when the impact of the austerity measures was being felt by the Greek society. The Greek BHS version demonstrated good psychometric properties and a sufficient degree of internal consistency. Attempted suicide patients (M = 9) presented higher hopelessness than the controls (M = 3). The patients’ age positively correlated with hopelessness (rs = .35, p < .001), and the ROC curve revealed that the BHS ability to discriminate the individuals with pathological rates of hopelessness from those without, strengthened as age increased. No significant differences were found between the individuals evaluated before (M = 3) and after (M = 3, p > .05) the crisis onset. Nevertheless, regarding the latter group, the women, the younger individuals, the less educated, the unemployed and the participants with low or mediocre self-reported financial status presented increased hopelessness. Our findings suggest that BHS could be a useful instrument especially when screening for suicide risk in people of older age, and that the financial crisis in Greece had a greater impact on subgroups of the population regarding hopelessness.  相似文献   

19.
Ethnic minority children bear a disproportionate amount of the US asthma burden. We compared asthma morbidity and pulmonary function (%FEV1) in two Caribbean groups living in the Bronx, NY: Puerto Rican and Afro-Caribbean children. Caregiver-child dyads (Puerto Rican: n = 113, M age = 9.89 ± 2.05; Afro-Caribbean: n = 47, Mage = 10.35 ± 2.08) responded to sociodemographic and asthma-related questions, and children’s %FEV1 was measured. Puerto Rican children had significantly greater (past year) asthma morbidity, yet there were no significant differences in %FEV1. This discrepancy between objective pulmonary function and asthma morbidity suggests the importance of considering sociocultural factors in pediatric asthma care.  相似文献   

20.
ABSTRACT

Children at ages 7 (N = 24, M age = 6.96, SD age =.20), 9 (N = 29, M age = 8.76, SD age =.44), and 11 (N = 25, M age = 10.76, SD age =.66), and adults (N = 30) made judgements about the obligation to help when it conflicts with a personal desire. Across ages, the obligation to help was judged to be strongest when there were positive or neutral past interactions with the person in need of help, compared to mean past interactions. Expectation of a future friendship predicted the obligation to help, even after controlling for age and sex. However, we found no effect of children helping gender in-group members more. Evidence for altruism was not found: expected positive emotions did not predict the obligation to help. We conclude that an expectation of future relationship is the strongest predictor of helping obligation.  相似文献   

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