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In order to study the effect of low temperature environment on the fatigue crack growth performance of high-speed train brake disc materials, the tensile and fatigue crack growth rate tests of special cast steel materials of high-speed railway brake disc at-40℃,-20℃, 0℃ and room temperature（20℃）were carried out. The mechanical properties, fatigue crack growth rate and fracture morphology of high-speed railway brake disc materials at different temperatures were analyzed. The results show that the decrease of temperature has a significant effect on the mechanical properties and fatigue crack propagation of high-speed railway brake disc. Compared with room temperature, the elastic modulus, Poisson′s ratio, yield strength, tensile strength and other mechanical properties of high-speed railway brake disc materials increase with the decrease of temperature. In the stable stage of fatigue crack growth, the fatigue crack growth rate decreases with the decrease of temperature, but the inhibition effect of low temperature on the fatigue crack growth rate decreases with the increase of ΔK. The fracture analysis shows that with the decrease of temperature, the fatigue crack propagation is likely to change from ductile fracture to brittle fracture.

This paper introduces an innovative cooperative model for energy efficiency retrofitting that incorporates carbon emission rights, addressing critical financial constraints in Energy Performance Contracting (EPC). By employing the fuzzy analytic hierarchy process (F-AHP) to evaluate risk assessment indicators and stakeholder contributions and utilizing the enhanced Shapley method for equitable benefit distribution, the model demonstrates significant improvements in financing and efficiency for energy conservation projects. The findings are as follows: (1) the energy efficiency retrofit model, which integrates carbon emission rights, effectively alleviates the financial constraints and fosters energy conservation and emission reduction in guaranteed-savings EPC projects; (2) the enhanced Shapley method is deemed appropriate for the equitable distribution of energy-saving benefits among stakeholders; (3) when compared with the traditional model and the benefit allocation-absent carbon rights, the energy-saving benefits of the energy efficiency retrofit model incorporating carbon emission rights are higher in individual and overall terms. The findings of this study offer a viable solution to financing challenges faced by stakeholders in such projects and delineate a pragmatic approach for enterprises to enhance energy efficiency and reduce emissions. [ABSTRACT FROM AUTHOR]

The reliability of a pressurized water reactor power plant's control rod drive mechanism (CRDM) is affected by many factors, such as operation states, unit performance, and dynamic environments. Multiple sources of uncertainties, including random, interval, and fuzzy, exist when analyzing the reliability of CRDMs. Modeling reliability without considering the fusion of multisource uncertainties may result in model distortion and may not provide realistic assessment results. This paper proposes a multisource uncertainty fusion method powered by the margin-based variable transformation and the Bayesian network propagation. The interval and fuzzy variables are transformed into random variables to obtain the corresponding generalized probability density function of the CRDM's feature parameters. After that, the CRDM's reliability can be evaluated via probability quantization of the Bayesian network inference result through sampling algorithms. A magnetic-jack type CRDM case is presented to verify the proposed method, and the results show that this method can fuse three types of uncertainty variable in a unified way and effectively obtain reliability evaluation results. [ABSTRACT FROM AUTHOR]

Susanna, a young girl from a low-income Chinese immigrant family, develops her oral language proficiency quickly in Head Start and kindergarten; however, she needs more support in her reading and writing. This case study examines an unusual journey of Susanna's learning to read and write in English. Observations in her home indicate a home with limited print, whereas Head Start and kindergarten provide not only print rich environment but also teachers' and peers' support so that she moves from an English language observer to an English language user. However, she still struggles with the use of decontextualized language. Susanna's difficulties are explained from a social-cultural and psycholinguistic perspective. Instructional implications are drawn from the findings.

Examines how second-language knowledge is integrated with the first, noting elements of native language development that are most resistant to influence from second languages and those that are most permeable. Discusses how the process of integration and influence can be universal or different depending on the language, using data from native speakers of Slavic, Chinese, and Navajo. (SM)

This article discusses the system and practice of performance assessment (PA) in academic libraries both conceptually and practically. A descriptive analysis of an existing PA system used in a university library is conducted. Three system-inherent problems, i.e., weighting of criteria, the immediate supervisor as the rater, and the purpose of PA, are illustrated. It is concluded that, as a managerial means, the PA system can directly reflect the social and cultural environment of a work place as well as the managerial standards of that administration. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this study is to promote a better understanding of performance assessment (PA) as a managerial means via analyses and discussion of the system and practice in an academic library. Design/methodology/approach – One existing PA system of a university library is presented. Descriptive analyses of two specific system-inherent problems, respectively: weighting scheme of the evaluated criteria and disqualification of the immediate supervisor as rater, are conducted. The purpose of PA is addressed with reference to PA and pay linkage. Circular supervision as an effective element to ultimately eliminate individual errors in an administration is discussed. Findings – The PA system and practice of CL are flawed. First, the weighting scheme of the evaluated categories is so allocated that the least measurable category has the overriding power. Second, the most qualified evaluator (the direct supervisor) is deprived of the numeric rating vote. Third, the end ratings from the PA lead to unfair merit compensation decisions and salary inequity. Finally, the system lacks a circular supervision mechanism to eliminate undefeatable power in the administration. Originality/value – With concrete examples and data, this study brings to light some serious problems that exist in a PA system. Via in-depth analyses and discussion of specific issues, it touches upon circular supervision, a core element in a sound administration that needs to be adequately addressed. [ABSTRACT FROM AUTHOR]

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