Kinetics of diffusion via divacancies in a concentrated random fcc alloy

The diffusion kinetics in a concentrated fcc alloy are described by means of divacancies. The model chosen is the random alloy model with bound divacancies. We show that for the fcc structure the Manning formalism developed originally for monovacancies can be used intact to describe diffusion via divacancies. Monte Carlo simulation results for both tracer and collective correlation factors are in good agreement with the results of the formalism for a wide range of the component atom exchange frequencies with the divacancy except for the slower-moving component.     

Nd2O3 : Eu3+ nanocrystalline phosphor–a new potential thermoluminescing material for dosimetry

Nanoparticles of trivalent Eu³⁺-doped Nd₂O₃ phosphors have been prepared using a low-temperature solution combustion method with metal nitrate as precursor and oxalyldihydrazide as a fuel at a fairly low temperature (<500°C) and in a very short time (<5 min). A powder X-ray diffraction pattern reveals that cubic Nd₂O₃ : Eu³⁺ crystallites are directly obtained without the requirement of further calcinations. The crystallite size, evaluated from Scherer's formula, was found to be in the range of 20–30 nm. The microstructure and morphology were studied by scanning electron microscopy, which showed the phosphor to be foamy and fluffy in nature. Thermoluminescence characteristics of the Nd₂O₃ : Eu³⁺ have been studied using gamma irradiation. These demonstrate that the phosphor is suitable for use as a dosimeter.     

Replication of the Self-Concept and Identity Measure (SCIM) Among a Treatment-Seeking Sample

Identity distress occurs within a variety of psychiatric conditions. Reliable tools for assessing identity-related functioning among clinical populations are greatly needed. The Self-Concept and Identity Measure (SCIM) is a brief self-report scale designed to assess healthy and disturbed identity dimensions. This measure has been validated within normative but not treatment-seeking samples. The present study used an a priori confirmatory approach to replicate the SCIM’s factor structure among disadvantaged women enrolled in treatment for chemical dependence (N = 216). The original three-factor structure and item loadings generally replicated within this diagnostically diverse, significantly impaired sample. Higher SCIM scores were also associated with other problems, such as emotion dysregulation and depression. Results support the SCIM’s use and scoring with clinical populations.     

What can we learn from psychoanalysis and prospective studies about chemically dependent patients?

Despite the common occurrence of drug abusers in the psychoanalytic clinic, contemporary literature on the subject, particularly among publications in the IJP, is sparse. This paper aims to review the most important psychoanalytic contributions on drug dependency in the past 100 years, then attempts to compare their postulations to the findings ofpertinent prospective studies. In these patients, a persistent symbiotic object relationship is found, which ties them to narcissistic functioning, where drug use is viewed in the light of both pleasure without object and omnipotently controlled need. The author also discusses the possible contribution of the mother and father in the genesis of this condition, focusing on the compromise of the paternal function as the deciding factor. The theoretical and technical implications of this approach are illustrated by clinical material.     

高中学生解决计算类化学问题的表征及其与策略关系的研究

在国内外关于问题解决中表征和策略研究的基础上,本研究提出了高中学生解决计算类化学问题的五个表征层次和四种解决策略,并用出声思维法对15位典型被试学生进行了详尽的个案分析.研究结果表明:高中学生在解决计算类化学问题时的表征程度(包括表征时间的长短和表征正确率的高低)决定了其问题解决策略的选取,表征程度高的学生倾向于选择相对优化的策略.     

The functional state of the central nervous system in chemical stress

The psychosocial and physical factors, including chemical ones, which affect the human organism are considered by some authors to be stress factors which affect the functional state (FS) of the central nervous system (CNS). We calculated correlations among the clinical, psychological/psychometric, and quantitative electropsychological (QEEG) variables of the functional changes of the CNS in chemical stress. These data were based on occupational contact with lead as experienced by 402 workers, with styrene by 96, with shale-oil products by 252, with organic solvents by 77 workers, and a control group of 145 workers in different age groups. The QEEG data of 77 patients were analyzed to determine the chronic neurotoxic effects of industrial chemical substances by diagnosing the functional changes at the syndrome level. We concluded that occupational chemical factors impact the functional state of the CNS. During chemical stress -activity and total cerebral bioelectrical activity (BA) decreases. The use of psychometric/ psychological and QEEG methods makes it possible to diagnose the changes of the CNS as hypersthenic, hyposthenic, and organic psychosyndromes.     

On the Escaig obstacle hypothesis for cross-slip in face-centered-cubic materials

There is a significant body of literature wherein a linear approximation of Escaig's model is used to justify the large experimentally measured activation-volumes for cross-slip in face-centered-cubic copper. Here, by examining the error between the linear approximation and the original theory, we show that this explanation is not satisfactory. The calculated value for activation volume in copper, using Escaig's original equations, yields ～60b ³ (b?=?Burgers vector) while the linear approximation yields 200b ³, the latter result fortuitously matching the experimental values.     

Synthesis and characterization of nanocrystalline MoBi2Te5 thin films for photoelectrode applications

Molybdenum bismuth telluride thin films have been prepared on clean glass substrate using arrested precipitation technique which is based on self-organized growth process. As deposited MoBi₂Te₅ thin films were dried in constant temperature oven at 110°C and further characterized for their optical, structural, morphological, compositional, and electrical analysis. Optical absorption spectra recorded in the wavelength range 300–800?nm showed band gap (E _g) 1.44?eV. X-ray diffraction pattern and scanning electron microscopic images showed that MoBi₂Te₅ thin films are granular, nanocrystalline having rhombohedral structure. The compositional analysis showed close agreements in theoretical and experimental atomic percentages of Mo⁴⁺, Bi³⁺, and Te^2? suggest that chemical formula MoBi₂Te₅ assigned to as deposited molybdenum bismuth telluride new material is confirmed. The electrical conductivity and thermoelectric power measurement showed that the films are semiconducting with n-type conduction. The fill factor and conversion efficiency was characterized by photoelectrochemical (PEC) technique. In this article, we report the optostructural, morphological, compositional, and electrical characteristics of nanocrystalline MoBi₂Te₅ thin films to check its suitability as photoelectrode in PEC cell.     

Psychoendocrine and physical performance responses in male Tunisian rugby players during an international competitive season

The aim was to investigate a follow-up study based on hormonal, physical, and psychological parameters among rugby players who trained during a whole season interspersed with competitions on an international level. Fitness or reciprocally tiredness as well as competitive anxiety were evaluated, respectively, using the French Society for Sports Medicine (SFMS) and the sport competition anxiety test (SCAT) questionnaires. In this study, SFMS and SCAT scores increased respectively over the competitive season. The SFMS score revealed a state of relative tiredness at the end of the season, highlighted by a slight decrement in physical performances. The SCAT score changes are related to the competition context and therefore increased accordingly to the importance of the competition stake. We analyzed the corticotrope and the gonadotrope axis before (T(1)), and at the end of the national and international rugby season (T(2)). Training did not affect the resting salivary cortisol (Csal) levels, but induced a decrease in resting testosterone (Tsal) values, resulting in a dropped T/C ratio. Competition, in both periods (T(1)-T(2)), provoked a significant increase in Csal levels, but the Tsal responses depended on the match stake. Their concentrations increased when the competition generated an important stress and decreased when the psychological conditions remained relatively stable. SFMS is preferentially correlated with resting Csal levels and T/C values measured at 08:00 hr but not with Tsal. SCAT is highly correlated with competitive Csal and Tsal concentrations measured before and after the matches.     

心理弹性儿童的压力/逆境认知

心理弹性儿童是如何看待其曾经历的或正在经历的严重压力/逆境的?解读这一问题或可促进对聚焦于儿童自身的心理弹性机制的探查。为考察心理弹性儿童压力/逆境认知特点,利用Visual FoxPro 8.0平台自编计算机程序和故事测验法,分别从压力/逆境的敏感程度、觉知到的压力/逆境严重程度、觉知到的压力/逆境影响持久程度和觉知到的压力/逆境可应对程度四个方面对心理弹性组儿童和缺乏心理弹性组儿童进行测量。结果发现:(1)心理弹性儿童的压力/逆境敏感程度高于缺乏心理弹性儿童,表现为前者在压力/逆境指标回忆量、压力/逆境再认敏感性指标和模糊情境下压力/逆境偏向性上的得分均比后者高,而且,前者的压力/逆境指标再认击中平均反应时比后者短,反应标准亦比后者宽松。(2)心理弹性儿童在觉知到的压力/逆境严重程度、影响持久程度和可应对程度上两亚类实验任务(你认为主人公如何看?和若你是主人公如何看?)上的得分与反应时,除设身处地的压力/逆境影响持久程度认知外,其余与缺乏心理弹性儿童之间差异均不显著,提示,心理弹性儿童所觉知到的严重压力/逆境影响远没有缺乏心理弹性儿童所认为的更为持久。文章探讨了儿童更为敏感的压力/逆境觉知和相对而言认为严...