A statistical model of cleavage fracture in structural steels with power-law distribution of microcrack size

Based on the well-accepted physical understanding that cleavage fracture of structural steels is preceded by plastic deformation, a critical flaw in the Beremin model and its modifications is proposed, and a new statistical model with the power-law distribution of microcracks is obtained to describe the cumulative probability of cleavage fracture. A set of cleavage fracture toughness data of a nuclear pressure vessel steel is used to highlight the difference between the new model and the Beremin model.     

Influencing surface plastic flow in metals using common chemical media

We demonstrate a unique mechanochemical effect – change in surface plastic flow by action of chemical media such as inks and glues – in large-strain deformation of metals. Unlike other well-known phenomena such as stress corrosion cracking and liquid metal embrittlement, the effect is not catastrophic and is largely material independent. High-speed in situ imaging shows that the media influence the flow by effecting a local ductile-to-brittle transition – from unsteady, large-amplitude, plastic folding, to repeated fracture and segmentation – with large decrease in deformation forces. The benign nature of the media offers opportunities for enhancing performance of metal cutting and deformation processes.     

Influence of plastic strain localisation on the mechanical properties of metal matrix composites

The aim of the present study is to reveal the most critical underlying factor influencing the mechanical properties of metal matrix composites (MMCs). It is shown that the mechanical properties of MMCs are essentially governed by the degree of strain localisation during plastic deformation. In other words, the MMCs exhibit superior mechanical performance only if the strain localisation is obviously inhibited and the accumulated stresses can be effectively transferred out. The work provides a new perspective in guiding the design of next-generation high-performance MMCs by suppressing the strain localisation as far as possible.     

Distribution of Cr atoms in a strained and strain-relaxed Fe89.15Cr10.75 alloy: a Mössbauer effect study

An Fe_89.15Cr_10.75 alloy in a heavily strained (by cold rolling) state and in strain-relaxed states was studied by means of conversion electrons Mössbauer spectroscopy. Analysis of the spectra in terms of a two-shell model revealed significant differences between the studied samples, particularly in values of the hyperfine field and the distribution of Cr atoms within the first two neighbour shells. The latter is quantified in terms of short-range order parameters.     

Why do residents accept a demanding rule?: Fairness and social benefit as determinants of approval of a recycling system1,2

Abstract: This study examined why people accepted a demanding rule in a recycling system that was newly introduced in Nagoya City. We focused on two social psychological topics: social dilemmas and fairness. While the new system succeeded in reducing waste, it imposed a burden on citizens without providing incentives and sanctions. In a research survey, 1442 responses from a sample of 3000 (48% response rate) were obtained using a stratified sampling method. The results showed that the new recycling system was approved despite the demands placed on citizens, with a preference for more strict rules such as penalties and surveillance for noncompliance. The main determinants of approval of the new recycling system were social benefit and procedural fairness, whereas the main determinant of preference for strict rules was outcome fairness. We argue that (a) social benefit should be emphasized to facilitate cooperative behavior in a social dilemma situation and (b) the government should ensure sufficient discussion with citizens and acknowledgment of their opinions.     

躯体变形障碍与美容整形术前心理评估

躯体变形障碍是一种并不罕见的精神障碍,其临床表现的特殊性使大多数患者以普通求术者的身份出现在美容整形科医生面前。然而,关容整形手术非但不能解决患者的心理问题,更可能引发复杂的医疗纠纷。基于躯体变形障碍在美容整形科呈高发生率的特点,文章对美容整形术前心理评估的必要性和现状进行分析,并列举了有效的评估工具以提高心理评估的准确性。     

整形外科的临床治疗决策分析

在生物心理社会医学模式下,以循证医学为基础的共享型临床决策成为主导。整形外科疾病有着诊断容易、治疗方法多样、效果不一、患者年龄小、心理脆弱、大众认知有一定误区等特点,更需要在情感和实践上体现对患者的理解和尊重,真正实现医生患者共同参与的共享型临床决策。     

Development and analysis of a community-based resource recovery program

Five studies were conducted over a 10-month period to determine the effectiveness of specific procedures in encouraging recycling among residential neighborhoods. Results indicated that: (a) initial levels of participation in neighborhoods were frequently related to housing values; (b) weekly recycling pick-ups that coincided with garbage collection days resulted in higher levels of participation than pick-ups that occurred at other times; (c) notifying homes about the recycling program through distributed door-to-door brochures was more effective than soliciting participation through newspaper ads; (d) distributing containers to help residents separate recyclable from nonrecyclable material proved to be an effective procedure, especially when combined with frequent prompting (prompting alone did not have much effect); and (e) procedures that facilitated the greatest levels of participation were not always cost-effective. The subsequent combination of these procedures into a package program resulted in high levels of neighborhood participation that were cost-effective and maintained over a 6-month period.     

Parent-like spokesperson for campaigning an anti-plastic straw movement to young adults: Is it effective?

Parental communication is still relatively meaningful in Asian families with hierarchical, vertical, and authoritative relationships. Meanwhile, children's pro-environmental behaviour in emerging Asian nations tends to be passive, leading to a need for intervention from the closest parties, often the parent, whose familial role in green communication has not been examined. This study uses social learning theory to examine the interplay of parent-like spokespeople and message appeals in affecting young adults' cognitive and emotional responses, which is expected to influence the ad liking and believability of green advertisements and switching intention to green products, such as eco-friendly straws. A laboratory experiment was conducted with 240 subjects. The results showed that the frame of a father-like figure conveying a hope appeal generated the greatest enthusiasm and argument quality for young adults. Mother-like figures speaking a fearful message frame were the best generator for young adults' anger and threat appraisal. Ad liking was significantly impacted only by a mother-like spokesperson who spoke a fearful appeal mediated by anger and a father-like spokesperson who delivered a hope appeal mediated by argument quality. Young adults' willingness to switch to eco-friendly straws was indirectly influenced by the interaction effect of a mother-like spokesperson and fear appeal type mediated by ad believability.     

Plastic stability of bimetals composed of Ti-based metallic glass composite and pure titanium

The plastic stability of bimetals composed of a Ti-based metallic glass composite (MGC) and a pure titanium (PT) under tension has been investigated. The results reveal that the plastic stability of the MGC/PT bimetal is strongly dependent on the thickness fraction of the MGC: when the thickness fraction of the MGC decreases to a critical value, a homogeneous plastic deformation occurs in the MGC/PT bimetals, i.e. the strain localization and necking of the MGC is effectively suppressed. This unique phenomenon is explained using the normalized strain-hardening rate, and the quantitative relationship between the normalized strain-hardening rate of the MGC/PT bimetals and the thickness fraction of the MGC is thereby established.