Aging and the Detection of Contingency in Causal Learning.

Young and older participants' ability to detect negative, random, and positive response-outcome contingencies was evaluated using both contingency estimation and response rate adaptation tasks. Age differences in contingency estimation were consistently greater for negative than positive contingencies, and these differences, though still present, were smaller when response rate adaptation was used as the measure of contingency learning. Detecting causal contingency apparently becomes more difficult with age, especially when an oven numerical estimate of contingency must be provided and when the relationship between a causal event and an outcome is negative. A model that incorporates features of both associative and rule-based approaches to contingency learning (e.g., P. C. Price & J. F. Yates, 1995; D. R. Shanks, 1995) provides the best explanation for this pattern of findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

ТДГ3．15万kVA主变压器经济运行分析

根据电力变压器功率损耗的分析，找到ТДГ3．15万kVA2台主变压器的功率损耗与负荷率β的函数关系，并对该2台主变压器的经济运行进行了探讨，计算出了经济运行点。     

Qualitative Differences Between Conscious and Nonconscious Processing? On Inverse Priming Induced by Masked Arrows.

In general, both consciously and unconsciously perceived stimuli facilitate responses to following similar stimuli. However, masked arrows delay responses to following arrows. This inverse priming has been ascribed to inhibition of premature motor activation, more recently even to special processing of nonconsciously perceived material. Here, inverse priming depended on particular masks, was insensitive to contextual requirements for increased inhibition, and was constant across response speeds. Putative signs of motor inhibition in the electroencephalogram may as well reflect activation of the opposite response. Consequently, rather than profiting from inhibition of primed responses, the alternative response is directly primed by perceptual interactions of primes and masks. Thus there is no need to assume separate pathways for nonconscious and conscious processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Influence of Rapid Annealing Cycles on the Recrystallisation Behaviour of Cold Rolled Ultra Low Carbon and Low Carbon Steel

For ultra low carbon (ULC) and low carbon steel (LC), the influence of heating rate, annealing temperature, and holding time on the recrystallisation behaviour and the resulting grain size was investigated. For ULC smallest grain sizes of about 9 μm were obtained at the lowest heating rate whereas for LC significant smaller grain sizes of about 5 μm were determined at the highest heating rate. Furthermore, the evolution of the grain size distribution with varying heating rate, annealing temperature, and holding time was studied in dependence of the rolling and normal direction. The state of the as‐hot rolled microstructure as well as the precipitation state exert a strong influence on the development of the recrystallised microstructure along the different directions for both steel grades. The inherent prolonged microstructure due to the cold rolling process is still obvious just after recrystallisation. With ongoing annealing and grain growth, the aspect ratio approaches the equiaxed state. This change proceeds faster for the ULC steel grade. With increasing annealing temperature, the bimodal character of the grain size distribution disappears and the distribution becomes more homogeneous.     

Parallel and Systolic Solution of Normalized Explicit Approximate Inverse Preconditioning

A new class of normalized approximate inverse matrix techniques, based on the concept of sparse normalized approximate factorization procedures are introduced for solving sparse linear systems derived from the finite difference discretization of partial differential equations. Normalized explicit preconditioned conjugate gradient type methods in conjunction with normalized approximate inverse matrix techniques are presented for the efficient solution of sparse linear systems. Theoretical results on the rate of convergence of the normalized explicit preconditioned conjugate gradient scheme and estimates of the required computational work are presented. Application of the new proposed methods on two dimensional initial/boundary value problems is discussed and numerical results are given. The parallel and systolic implementation of the dominant computational part is also investigated.     

Solid particle erosion behaviour of hardfacing deposits on cast iron—Influence of deposit microstructure and erodent particles

Solid particle erosion (SPE) behaviour of different hardfacing electrodes deposited on gray cast iron (ASTM 2500) was studied using quartz sand and iron ore as erodent particles. Erosion test was carried out as per ASTM G76 test method. Considerable differences in erosion rates were found among different hardfacing electrodes at normal impact. Both volume fraction of carbides and type of carbides played an important role in the erosion behaviour of the deposits when quartz sand was used as erodent particles. On the other hand, only volume fraction of carbides irrespective of carbide type mainly controlled the erosion rate of the same deposits when iron ore was used as erodent particles. Such difference is attributed due to difference in metal removal mechanisms by the two erodent particles used. Hard quartz sand particles were capable of causing damage to most of the carbides while relatively softer iron ore particles were unable to fracture any carbides present in the microstructures. Furthermore, relatively brittle matrix led to high erosion rate which is significant in case of quartz sand as erodent, but not in case of iron ore particles. Like abrasion resistance, hardness is not a true index of erosion resistance of hardfacing deposits.     

润滑油混入气泡后对滑动轴承耗油量的影响

滑动轴承的耗油量是一项重要的特性参数。本文在引入气油两相流粘度模型的基础上，建立了一套适用于气油两相流工况下径向滑动轴承的数值计算理论，计算研究了气油两相流对滑动轴承耗油量的影响     

基于非时序模型的新能源消纳能力评估方法

随着风电和光伏装机容量的快速增长,弃风和弃光问题日益突出,开展新能源消纳能力研究,建立消纳能力量化评估体系对电网调度的运行和控制工作有着重要的意义。文中提出了一种基于非时序分析模型的新能源消纳能力量化评估方法。该方法基于概率分析理论,首先利用阿基米德Copula函数构建了新能源理论出力的概率分布,通过负荷特性构建了系统新能源消纳空间的概率分布,进而得到了系统新能源弃电功率的概率分布。然后,再通过新能源弃电功率的概率分布计算得到新能源弃电率,评估系统的新能源消纳能力。最后,基于EPRI 36机组系统验证了所提方法的正确性和有效性,并分析了负荷、新能源装机容量、常规机组调峰率以及备用水平对弃电率的影响。     

Comments on the sliding wear of metals

The author reviews selected experimental results which have contributed to improved understanding of sliding wear processes. The emphasis is on the chemical and structural changes which occur at and near the surface of metallic materials during sliding in different environments. The importance of plastic deformation, fracture, transfer, mechanical mixing, phase transformations and oxidation is discussed. Examples of transitions are described, and interesting correlations noted. In selecting the content of this paper, the author includes controversial results and conclusions and raises questions about the development of wear equations, interpretations of the wear coefficient, the importance of adhesion, the roles of hardness, the causes of transitions and the location of debris-producing cracks.     

基于功率变化率的刀具破损监测系统

介绍一种以刀具切削功率变化率为信号，利用单片机进行处理与判断，实现加工过程刀具破损在线监测的系统组成和工作原理，讨论了提高刀具破损报警准确性的措施。