High-temperature nanoindentation behavior of Al/SiC multilayers

Nanoscale Al/SiC composite laminates have unique properties, such as high strength, high toughness, and damage tolerance. In this article, the high-temperature nanoindentation response of Al/SiC nanolaminates is explored from room temperature up to 300°C. Selected nanoindentations were analyzed postmortem using focused ion beam and transmission electron microscopy to ascertain the microstructural changes and the deformation mechanisms operating at high temperature.     

Microstructure and mechanical behavior of nanostructured composite Cu60Fe40 alloy

In this study, bulk nanostructured composite Cu₆₀Fe₄₀ alloy is prepared by a combustion synthesis technique. The prepared Cu₆₀Fe₄₀ alloy consists of Cu(Fe) solid solution and Fe(Cu) solid solution phases. The large-scaled compositional segregation in the Cu-rich and Fe-rich phases is not observed, respectively. A few micron-sized dendrite (Fe(Cu) solid solution) is embedded into the nanostructured matrix (Cu(Fe) solid solution). The grain size of the matrix is in the range 50–300?nm. The yield and fracture strength of the Cu₆₀Fe₄₀ alloy are 540 and 1050?MPa, respectively, and the fracture strain obtained from the compression test is about 20.9%. The Cu₆₀Fe₄₀ alloy displays notable work hardening in the compressive deformation.     

Microstructure evolution and hardness variation of pack-rolled nanocrystalline nickel

The microstructure evolution and hardness of nanocrystalline nickel during pack rolling at room temperature have been investigated. It was found that the roll-bonding side (R) and non-roll-bonding side (NR) behaved quite differently. The hardness of side R is higher than that of side NR. No obvious work softening was observed in either side R or side NR until the strain reached ~ 0.611. Quantitative X-ray diffraction analysis indicated that the grain size in side NR increases faster than that in side R, a result confirmed by transmission electron microscopy. Texture analysis showed that (2 0 0) preferred orientation first strengthens but then weakens in both sides NR and R, while a strong (2 2 0) preferred orientation emerges, particularly in side R. Further texture analysis suggests that dislocation slip is responsible for the texture discrepancy between side NR and side R. The dislocation activity, grain rotation and grain growth are discussed based on the experimental results.     

Thermal behaviour of poly(methyl methacrylate)/fullerene composite films

ABSTRACT

Poly(methyl methacrylate) films and poly(methyl methacrylate)/fullerene composite films were fabricated by casting from toluene solutions. The mass fraction of fullerene (C₆₀) was varied from 0.05–3?wt. %. The effect of the fullerene (C₆₀) content on the thermal degradation parameters of the composite films was evaluated by thermogravimetric (TG) analysis. It was found that the incorporation of C₆₀ improved the thermal stability of the polymers. The films eventually decomposed in three stages. Incorporation of fullerene caused a change in the distribution of mass loss over the stages of degradation in comparison with the pristine polymer. Using differential scanning calorimetry (DSC), the phase transitions from the glassy state to the elastic one was studied for the examined polymeric materials. New data relating to the effect of C₆₀ on the glass transition temperature of composites with low weight fractions of filler were obtained. Specifically, for films containing up to 0.1 wt. % of C₆₀, a single glass transition temperature was found, whereas for composites with a higher concentration of filler, two glass transition temperatures were recorded.     

Chemistry (intrinsic) and inclusion (extrinsic) effects on the toughness and Weibull modulus of Fe-based bulk metallic glasses

Systematic changes in composition were employed to increase the notch toughness of a variety of Fe-based Bulk Metallic Glasses (BMGs). The Fe₅₀Mn₁₀Mo₁₄Cr₄C₁₆B₆ BMG possessed very high hardness (e.g. 12 GPa) but very low notch toughness (e.g. 5.7 MPa m^1/2) at room temperature, consistent with fracture surface observations of brittle features. Many of the other Fe-BMG variants, created to change the Poisson's ratio via systematic changes in alloy chemistry, exhibited higher toughness but more scatter in the data, reflected in a lower Weibull modulus. SEM examination revealed fracture initiation always occurred at inclusions in samples exhibiting lower toughness and/or Weibull modulus for a given chemistry. Implications of these observations on reliability of BMGs are discussed.     

Changes of hardness and electronic work function of Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass on annealing

The hardness and electronic work function (EWF) of a bulk metallic glass, namely Zr_41.2Ti_13.8Cu_12.5Ni₁₀Be_22.5, have been studied experimentally, with an emphasis on the effect of heat treatments. The glass was annealed at different time and temperatures, and its hardness and EWF measured using the Rockwell indentation technique and a scanning Kelvin probe system, respectively. It is found that the EWF decreases with annealing time and temperature, whereas the hardness increases. This study shows a close relationship between hardness and EWF, indicating that the EWF could be a sensitive parameter for characterising and investigating the mechanical behaviour of BMG at the electronic level.     

The relationship between perception and production of /w/, /r/, and /l/ by three-year-old children

Twenty-one normally developing 3-year-old children were tested on two approximant consonant contrasts, rake-lake and wake-rake, and a control contrast, wake-bake. Perception was assessed in a two-choice picture identification paradigm; stimuli were (1) natural and computer synthesized “clear cases” of the minimal pairs, and (2) synthetic stimulus series which interpolated on acoustic dimensions that differentiate the minimal pairs. As a group, the children showed very accurate perception of the minimal pairs. Performance on the synthetic series yielded consistent identification of the endpoint stimuli and monotonic functions with abrupt crossovers at the phoneme boundary. Children who did not yet articulate /r/ and /l/ appropriately showed somewhat less consistent perception than children who produced all phonemes correctly.     

Strengthening of a thin austenitic stainless steel coil by cold wavy rolling with no magnetic and dimensional changes

A comparison of the effects of wavy rolling and cold rolling on microstructure variation, phase evolution, tensile and magnetic properties of a thin coil of Fe-18.47Cr-8.10Ni-0.94Mn austenitic stainless steel was made at room temperature. Wavy rolling led to strengthening with no change in magnetic property and thickness, unlike the conventional cold rolling that changed all these properties by deformation induced martensitic transformation, in addition to substructure evolution. The yield strength of 413 MPa and magnetic saturation 3.7 emu/g under mill-annealed condition increased, respectively, to 1208 MPa and 11.8 emu/g, upon four cycles of wavy rolling. While the maximum yield strength of 1790 MPa could be achieved by combining this stage of four cycles of wavy rolling with subsequent 50% conventional cold rolling, the magnetic saturation increased to 73.3 emu/g by deformation induced martensitic transformation caused by the latter.     

MRA和无创FAIR灌注成像在早期脑缺血中的诊断价值

为了探讨3D—TOFMRA脑血管成像及流动敏感交互式反转恢复（FAIR）MR灌注成像在早期（发病2h-7d）脑缺血中的诊断价值,对27例早期脑缺血患者行3D—TOFMRA和FAIR检查。结果显示,MRA异常27例,表现为血管闭塞、狭窄、硬化;FAIR异常27例,表现为缺血区血流灌注的减低,患侧和对侧灰、白质信号强度的差异均有统计学意义（P〈0．005）,患者患侧与志愿者灰、白质信号强度的差异亦均有统计学意义（P〈0．005）。FAIR灌注技术无需注射造影剂,能够提供早期脑缺血患者血流动力学受损情况,FAIR与3D—TOF法MRA联合运用,对早期脑缺血的诊断、血流灌注评价会更全面、更准确。     

Phase transformation of germanium by processing through high-pressure torsion: strain and temperature effects

Germanium has been processed by high-pressure torsion (HPT) under a nominal pressure of 24 GPa at room temperature and cryogenic temperature. The samples processed at room temperature were composed of a diamond-cubic Ge-I phase and a metastable tetragonal Ge-III phase. The formation of Ge-III was significantly suppressed and Ge-I and an amorphous phase, in addition to a small amount of body-centred-cubic Ge-IV, appeared in the case of cryogenic HPT processing at 100 K. The Ge-IV phase gradually disappeared at room temperature. These results indicated that shear strain and thermal energy are important for promoting the formation of Ge-III.     

Comparison between BALB/cJ and BALB/cByJ mice in tests of social behavior and resident-intruder aggression

The behavior of male mice from two BALB strains, the BALB/cJ strain and the BALB/cByJ strain, was examined with a social behavior test and a resident-intruder paradigm. Prior to testing, the animals were isolated for 0, 2, 5, or 10 days. In the social behavior test the pairs of BALB/cJ mice spent more time in active social interaction than pairs of BALB/cByJ mice, although the latter strain showed more locomotor activity. BALB/cJ mice isolated for 5–10 days, when tested in a familiar environment were more aggressive than mice from the BALB/cByJ strain. In the resident-intruder paradigm, in which a resident BALB mouse was confronted with an intruder NIH Swiss mouse, the BALB/cByJ mice showed more social investigation in their home cage towards the intruders, but there were no significant differences between the two strains in the amounts of aggressive behavior exhibited. The results of these experiments suggest that there are some differences in the social behavior of the genetically related BALB/cJ and BALB/cByJ mice. However, the differences appear subtle and paradigm-specific.     

A kinematic approach to the conceptual representations of this and that

The Italian demonstrative pronouns questo/a (‘this_[mas/fem]’) and quello/a (‘that_[mas/fem]’) implicitly convey information about objects’ distance with respect to the speaker. Our study investigated the referents of questo/a (‘this_[mas/fem]’) and quello/a (‘that_[mas/fem]’) by analysing their influence on reach-to-grasp actions towards objects located near to (12 cm) or far from (30 cm) the participant. Upon acoustic instruction containing one or the other pronoun, participants had to reach for and grasp a target object. Results showed an effect of pronoun on movement planning. When the object was in the far position, reaction times were faster for the congruent pronoun quello/a, whereas when it was in the near position they were faster for the congruent pronoun questo/a. Interactions between implied and real target distance suggest that the conceptual spaces of questo/a and quello/a do not map onto a strict distinction between peripersonal and extrapersonal space.     

Antecedents of educational/career preferences and choices

The primary purpose of this study was to investigate the influence of social reinforcement, modeling, direct reinforcement, and words and images on the acquisition of career-related preferences. The study also examined the mediating role of career decision-making skills (CDMS) on the factors influencing preference. Finally, the combined influence of career-related preferences and CDMS on certainty about career choices was investigated. A total of 47 college students completed a questionnaire describing antecedent factors influencing their preference for a major or a career and evaluating the degree of influence of each factor. Students' scores on a vocational maturity inventory were the basis for dividing them in high and low groups. Students identified social reinforcement as the most important antecedent for their career preference. Results indicated that CDMS mediate the influence of models and direct reinforcement on career preference. Career-related preference was a better predictor of career certainty among low than high maturity students. Findings support and extend a social learning theory of career development.     

Hostility and quality of life among Hispanics/Latinos in the HCHS/SOL Sociocultural Ancillary Study

Objective: The purpose of this study was to determine if hostility is associated with physical and mental health-related quality of life (QoL) in US. Hispanics/Latinos after accounting for depression and anxiety.

Methods: Analyses included 5313 adults (62% women, 18–75 years) who completed the ancillary sociocultural assessment of the Hispanic Community Health Study/Study of Latinos. Participants completed the Center for Epidemiological Studies Depression Scale, Spielberger Trait Anxiety Scale, Spielberger Trait Anger Scale, Cook–Medley Hostility cynicism subscale and Short Form Health Survey. In a structural regression model, associations of hostility with mental and physical QoL were examined.

Results: In a model adjusting for age, sex, disease burden, income, education and years in the US., hostility was related to worse mental QoL, and was marginally associated with worse physical QoL. However, when adjusting for the influence of depression and anxiety, greater hostility was associated with better mental QoL, and was not associated with physical QoL.

Conclusions: Results indicate observed associations between hostility and QoL are confounded by symptoms of anxiety and depression, and suggest hostility is independently associated with better mental QoL in this population. Findings also highlight the importance of differentiating shared and unique associations of specific emotions with health outcomes.     

Neurophysiology and neuroanatomy of reflexive and volitional saccades: evidence from studies of humans

This review provides a summary of the contributions made by human functional neuroimaging studies to the understanding of neural correlates of saccadic control. The generation of simple visually guided saccades (redirections of gaze to a visual stimulus or pro-saccades) and more complex volitional saccades require similar basic neural circuitry with additional neural regions supporting requisite higher level processes. The saccadic system has been studied extensively in non-human (e.g., single-unit recordings) and human (e.g., lesions and neuroimaging) primates. Considerable knowledge of this system’s functional neuroanatomy makes it useful for investigating models of cognitive control. The network involved in pro-saccade generation (by definition largely exogenously-driven) includes subcortical (striatum, thalamus, superior colliculus, and cerebellar vermis) and cortical (primary visual, extrastriate, and parietal cortices, and frontal and supplementary eye fields) structures. Activation in these regions is also observed during endogenously-driven voluntary saccades (e.g., anti-saccades, ocular motor delayed response or memory saccades, predictive tracking tasks and anticipatory saccades, and saccade sequencing), all of which require complex cognitive processes like inhibition and working memory. These additional requirements are supported by changes in neural activity in basic saccade circuitry and by recruitment of additional neural regions (such as prefrontal and anterior cingulate cortices). Activity in visual cortex is modulated as a function of task demands and may predict the type of saccade to be generated, perhaps via top-down control mechanisms. Neuroimaging studies suggest two foci of activation within FEF - medial and lateral - which may correspond to volitional and reflexive demands, respectively. Future research on saccade control could usefully (i) delineate important anatomical subdivisions that underlie functional differences, (ii) evaluate functional connectivity of anatomical regions supporting saccade generation using methods such as ICA and structural equation modeling, (iii) investigate how context affects behavior and brain activity, and (iv) use multi-modal neuroimaging to maximize spatial and temporal resolution.     

对消化道菌群的探索进展及启示

在人类的消化道中寄居着大量的茵群,它们对人类的生长、发育、消化、吸收、营养和免疫等多方面产生着影响.随着现代科学技术的进步与发展,对消化道茵群的培养和鉴定取得了丰硕成果.目前已了解到消化道茵群失调有可能导致多种疾病,而益生菌能够起到维护人类健康的作用.对消化道菌群的探索将带给我们更多深刻的启示.     

Queering gender: anima/animus and the paradigm of emergence

An exploration into the world of the queer others of gender and sexuality moves us beyond the binary opposition of male/masculinity and female/femininity in our understanding of gender and expands the meaning of gender and sexuality for all humans. A revision of Jungian gender theory that embraces all genders and sexualities is needed not only to inform our clinical work but also to allow us to bring Jungian thought to contemporary gender theory and to cultural struggles such as gay marriage. The cognitive and developmental neurosciences are increasingly focused on the importance of body biology and embodied experience to the emergence of mind. In my exploration of gender I ask how gender comes to be experienced in a developing body and how those embodied gender feelings elaborate into a conscious category in the mind, a gender position. My understanding of emergent mind theory suggests that one's sense of gender, like other aspects of the mind, emerges very early in development from a self-organizing process involving an individual's particular body biology, the brain, and cultural environment. Gendered feeling, from this perspective, would be an emergent aspect of mind and not an archetypal inheritance, and the experiencing body would be key to gender emergence. A revised Jungian gender theory would transcend some of the limitations of Jung's anima/animus (A/A) gender thinking allowing us to contribute to contemporary gender theory in the spirit of another Jung; the Jung of the symbolic, the mythic, and the subtle body. This is the Jung who invites us to the medial place of the soul, bridging the realm of the physical body and the realm of the spirit.     

Augustine's Ethics of Belief and AvoidingViolence in Religious Disputes

This article is a study of how Augustine's ethics of belief shaped his arguments against unbelief and its legacy in using coercion to settle disputes. After considering the arguments for belief presented by Augustine, the article studies how these were shaped by his understanding of the problem of evil and how the Fall influenced free will. What is noted to be of benefit in Augustine is that he offers arguments in favor of belief, and is convinced that he has shown unbelief to be based on unsound reasoning. By way of contrast, a number of theologians (such as Tertullian, John Calvin, and those under the heading of Reformed Epistemology) are considered who do not believe that arguments are necessary to support belief or reject unbelief. These are contrasted with Augustine and it is argued that they have significant shortcomings in this respect. However, the article concludes that Augustine could have gone farther in supporting the claim that it is clear that God exists, and his own shortcomings have been used to justify coercion in religious belief. If common ground is to be achieved this problem must be corrected and an adequate foundation for clarity must be established.     

Relative contribution of perception/cognition and language on spatial categorization

This study investigated the relative contribution of perception/cognition and language-specific semantics in nonverbal categorization of spatial relations. English and Korean speakers completed a video-based similarity judgment task involving containment, support, tight fit, and loose fit. Both perception/cognition and language served as resources for categorization, and allocation between the two depended on the target relation and the features contrasted in the choices. Whereas perceptual/cognitive salience for containment and tight-fit features guided categorization in many contexts, language-specific semantics influenced categorization where the two features competed for similarity judgment and when the target relation was tight support, a domain where spatial relations are perceptually diverse. In the latter contexts, each group categorized more in line with semantics of their language, that is, containment/support for English and tight/loose fit for Korean. We conclude that language guides spatial categorization when perception/cognition alone is not sufficient. In this way, language is an integral part of our cognitive domain of space.