"中国马克思主义哲学"理论体系的实存应予肯定--兼答徐素华先生

徐素华先生文章把我提出的“中国马克思主义哲学”等同于他所说的“党的指导思想形态”,“在中国的马克思主义哲学”等同于他所说的“学术研究形态”,这不符合我的本意。“马克思主义哲学合法性问题”的讨论确实存在。“中国马克思主义哲学”是在中国实践中学习、运用,在总结实践经验、发扬中国优秀哲学文化、升华人民群众智慧的基础上发展了的马克思主义哲学。它是中国哲学的一个现代形态。它既是一个创新的哲学理论体系,又是党的指导思想的哲学基础。     

The dynamics of perceptual learning: an incremental reweighting model

The mechanisms of perceptual learning are analyzed theoretically, probed in an orientation-discrimination experiment involving a novel nonstationary context manipulation, and instantiated in a detailed computational model. Two hypotheses are examined: modification of early cortical representations versus task-specific selective reweighting. Representation modification seems neither functionally necessary nor implied by the available psychophysical and physiological evidence. Computer simulations and mathematical analyses demonstrate the functional and empirical adequacy of selective reweighting as a perceptual learning mechanism. The stimulus images are processed by standard orientation- and frequency-tuned representational units, divisively normalized. Learning occurs only in the "read-out" connections to a decision unit; the stimulus representations never change. An incremental Hebbian rule tracks the task-dependent predictive value of each unit, thereby improving the signal-to-noise ratio of their weighted combination. Each abrupt change in the environmental statistics induces a switch cost in the learning curves as the system temporarily works with suboptimal weights.     

Traditional and modern characteristics across the generations: similarities and discrepancies

The authors examined, through an analysis of self-construals and beliefs about social interaction, the traditional and modern orientations of younger and older generations of Taiwanese people. The authors surveyed 169 pairs of parent-child dyads with a battery of structured questionnaires. Within-subjects analyses revealed high generational correlations as well as discrepancies in both traditional and modern characteristics. Between-subjects analyses further indicated that individual traditional and modern characteristics were affected by age and gender and by their interactions. The authors discuss (a) the pattern of generational similarities and discrepancies in the framework of culture stability and change and (b) the coexistence of traditional and modern characteristics in a rapidly changing society.     

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.     

Nanoindentation-induced elastic–plastic transition and size effect in α-Al2O3(0001)

The mechanical properties of α-Al₂O₃(0001) have been investigated using the technique of nanoindentation with a Berkovich indenter. Coupled with the Hertzian contact theory, a theoretical shear strength of 28?±?2?GPa was determined from the onset of pop-in events on load–displacement curves during loading, and the intrinsic hardness 30?±?3?GPa was obtained by analysis of the so-called indentation size effect, based on the concept of geometrically necessary dislocations. The predicted values of the shear strength, hardness and elastic modulus are in good agreement with available experimental data. The importance of experimentally calibrating the area function over the contact depth range prior to nanoindentation tests is emphasized.     

Vacancy-decomposition-induced lattice instability and its correlation with the kinetic stability limit of crystals

Vacancy decomposition kinetics in crystals at elevated temperatures is analysed. It is found that lattice instability is induced by a significantly enhanced vacancy decomposition at a critical temperature (T?*). The critical temperature coincides with the kinetic instability limit (kinetic limit of superheating) of crystals in a variety of metals determined from the homogeneous nucleation catastrophe model.     

Myelin breakdown mediates age-related slowing in cognitive processing speed in healthy elderly men

Background

To assess the hypothesis that in a sample of very healthy elderly men selected to minimize risk for Alzheimer’s disease (AD) and cerebrovascular disease, myelin breakdown in late-myelinating regions mediates age-related slowing in cognitive processing speed (CPS).

Materials and methods

The prefrontal lobe white matter and the genu of the corpus callosum myelinate later in brain development (late-myelinating white matter; LMWM) and are more vulnerable to breakdown due to the effects of normal aging. An in vivo MRI biomarker of myelin integrity (transverse relaxation rates; R₂) of LMWM was obtained for 38 very healthy elderly adult men (mean age = 66.3 years; SD = 6.0; range = 55–76). To evaluate regional specificity, we also assessed a contrasting early-myelinating region (splenium of the corpus callosum; SWM), which primarily contains axons involved in visual processing. CPS was assessed using the Trail Making Test.

Results

LMWM R₂ and CPS measures were significantly correlated (r = .515, p = .0009), but no significant association between R₂ and CPS was detected in the splenium (p = .409). LMWM R₂, but not SWM R₂, was a significant mediator of the relationship between age and CPS (p = .037).

Conclusions

In this very healthy elderly sample, age-related slowing in CPS is mediated by myelin breakdown in highly vulnerable late-myelinating regions but not in the splenium.     

工作记忆表征引导视觉注意选择的眼动研究

工作记忆表征能否引导视觉注意选择？目前实验结果尚不一致。有研究者认为能否观察到注意引导效应取决于视觉搜索类型。研究采用工作记忆任务与视觉搜索任务相结合的双任务范式, 结合眼动追踪技术, 对不同视觉搜索类型下的注意引导效应进行验证。实验1结果发现, 不管视觉搜索任务的靶子是否变化, 在早期的眼动指标上都发现了显著的注意引导效应, 但注意引导效应在靶子固定的视觉搜索任务下表现得更强。实验2在平衡两种视觉搜索任务中的工作记忆负载后发现, 两种视觉搜索任务下都出现了显著的注意引导效应, 但没有发现实验1中所出现的任务间差异。实验结果否定了视觉搜索类型对注意引导效应的决定性影响, 同时也提示工作记忆负载可能在注意引导效应中起重要作用。     

Qualitative Exploration of Acculturation and Life‐Span Issues of Elderly Asian Americans

Awareness of aging issues across diverse populations begins the journey toward counselors becoming culturally competent across client life spans. Understanding the life‐span experiences of cultural groups is important for helping professionals. The purpose of this research was to gain insight into the qualitative experiences of Asian American elders. The authors conducted semistructured interviews with 8 participants between September 2010 and March 2011 and analyzed the data using the Consensual Qualitative Research method. Findings indicate unique patterns in life‐span development with this population.