Log-normal nanograin-size distributions in nanostructured composites

A key challenge in the fabrication of superhard nanocomposite films is how to control the distribution of grain sizes in these materials. High-resolution transmission electron microscopy has been used to measure nanograin-size distributions in the Ti–B–N films with various B contents. The results show that the mean grain size decreases with increase of B content and the grain-size distribution conforms to a log-normal function when the hardness approaches a maximum value. The transition from normal to log-normal distributions can be determined by analysis in terms of a minimum information criterion. The origin of a log-normal size distribution probably results from heterogeneity arising from a diffusion-drift process.     

Design strategy for microalloyed ultra-ductile magnesium alloys

This article describes a design strategy deployed in developing ultra-ductile Mg alloys based on a microalloying concept, which aims to restrict grain growth considerably during alloy casting and forming. We discuss the efficiency of the design approach, and evaluate the resulting microstructural and mechanical properties. After processing, the so-designed alloys ZQCa3 (Mg–3Zn–0.5Ag–0.25Ca–0.15Mn, in wt.%) and ZKQCa3 (Mg–3Zn–0.5Zr–0.5Ag–0.25Ca–0.15Mn, in wt.%) reveal very fine grains (<10 µm), high ductility (elongation to fracture of up to 30%) at moderate strength or high strength (ultimate tensile strength of up to 350 MPa) at reasonable ductility. These properties are explained based on thermodynamic modelling, microstructure analysis including transmission electron microscopy studies, and microstructural and mechanical testing after annealing, and are compared to a related commercial alloy (ZK31).     

Thirty Years Later: An Oncologist Reflects on Kubler-Ross's Work

As compared with conventional vaccine production systems, plant-made vaccines (PMVs) are said to enjoy a range of advantages including cost of production and ease of storage for distribution in developing countries. In this article, we introduce the science of PMV production, and address ethical issues associated with development and clinical testing of PMVs within three interrelated domains: PMVs as transgenic plants; PMVs as clinical research materials; and PMVs as agents of global health. We present three conclusions: first, while many of the ethical issues raised by PMVs are familiar, PMVs add a new dimension to old issues, and raise some novel issues for ethicists and policy-makers; secondly, it is premature to promise broad applicability of PMVs across the developing world without having demonstrated their feasibility; thirdly, in particular, proponents of PMVs as a solution to global health problems must, as a condition of the ethical conduct of their research, define the commercial feasibility of PMVs for distribution in the developing world.     

Protecting God from Science and Technology: How Religious Criticisms of Biotechnologies Backfire

Many religious critics argue that biotechnology (such as cloning and genetic engineering) intrudes on God's domain, or plays God, or revolts against God. While some of these criticisms are standard complaints about human hubris, I argue that some of the recent criticism represents a "Promethean" concern, in which believers unreflectively seem to fear that science and technology are actually replicating or stealing God's special deity–defining powers. These criticisms backfire theologically, because they diminish God, portraying God as an anthropomorphic superbeing whose relevance and special nature are increasingly rivaled by human power.     

基因工程药物发展的历史及启示

基因工程诞生20余年,运用于医药行业,研制和开发工程药物,已取得长足进展,迄今为止,已有近100个基因工程新药上市,并有数百种正在研制和开发中,可以预计,基因工程药物的发展具有无比强大的生命力。就基因工程药物发展史进行概述,会从中得到许多启示。     

Miscarriages of psychoanalytic treatment with suicidal patients2

The author describes a particularly perilous frontier on the psychoanalytic landscape‐ namely, the treatment of suicidal patients with serious personality disorders. Using a clinical example of egregious boundary violations by an analyst, he describes specific countertransference pitfalls that lead to mishandling the patients' expressions of suicidal despair. These include disidentification with the aggressor, failure of mentalization, collapse of the analytic play space, reactions to loss in the analyst's personal life, omnipotence, envy of the patient and masochistic surrender. The author emphasizes the unique vulnerabilities that accompany analytic treatment of such patients.     

When worlds collide: Engineering students encounter social aspects of production

To design effective and socially sensitive systems, engineers must be able to integrate a technology-based approach to engineering problems with concerns for social impact and the context of use. The conventional approach to engineering education is largely technology-based, and even when additional courses with a social orientation are added, engineering graduates are often not well prepared to design user- and context-sensitive systems. Using data from interviews with three engineering students who had significant exposure to a socially-oriented perspective on production systems design, this paper argues that engineering students may have difficulty integrating in their own practice the technology-based and the socially-oriented perspectives on production. To enhance engineering students' ability to create systems that integrate both perspectives, and to relieve the intense cognitive and emotional pain that can be experienced by students exposed to both perspectives but unable to reconcile them, this paper reinforces the importance of teaching students the meta skill, design. A design perspective can help students integrate varied, sometimes conflicting, perspectives, and reach beyond customer-defined constraints to consider workplace and social impact.     

Group boundary permeability moderates the effect of a dependency meta‐stereotype on help‐seeking behaviour

Previous studies have found that when low‐status group members are aware that their in‐group is stereotyped as dependent by a specific out‐group (i.e. a dependency meta‐stereotype is salient), they are reluctant to seek help from the high‐status out‐group to avoid confirming the negative meta‐stereotype. However, it is unclear whether low‐status group members would seek more help in the context of a salient dependency meta‐stereotype when there is low (vs. high) group boundary permeability. Therefore, we conducted two experiments to examine the moderating effect of permeability on meta‐stereotype confirmation with a real group. In study 1, we manipulated the salience of the dependency meta‐stereotype, measured participants' perceived permeability and examined their help‐seeking behaviour in a real‐world task. Participants who perceived low permeability sought more help when the meta‐stereotype was salient (vs. not salient), whereas participants who perceived high permeability sought the same amount of help across conditions. In study 2, we manipulated the permeability levels and measured the dependency meta‐stereotype. Participants who endorsed a high‐dependency meta‐stereotype sought more help than participants who endorsed a low‐dependency meta‐stereotype; this effect was particularly strong in the low‐permeability condition. The implications of these results for social mobility and intergroup helping are discussed.