瞬间液相连接的过冷连接新工艺

提出了瞬间液相(TLP)连接的新工艺--过冷连接工艺,即首先将待连接区域加热至某高温进行短时保温,然后再降至一定温度进行长时保温连接.由于液相经历了一次温度过冷,在液/固界面前沿就形成了成分过冷区,破坏了平衡状态下的界面稳定性,形成胞状界面.随着凝固过程的完成,界面消失,形成跨界面连续晶粒,实现冶金接合.以Fe-Ni基非晶合金为中间层,进行了低碳钢过冷TLP连接实验,并与传统的TLP连接工艺进行了比较.结果表明,过冷TLP连接工艺产生了非平面状界面,并且随着凝固的完成界面消失,形成无界面的组织均匀接头.与传统TLP连接工艺接头相比,过冷TLP连接工艺可大大提高接头冲击韧性,其数值达到母材水平.     

Oxidative Stress and Chemoradiation-Induced Oral Mucositis: A Scoping Review of In Vitro,In Vivo and Clinical Studies

Chemoradiation-induced mucositis is a debilitating condition of the gastrointestinal tract eventuating from antineoplastic treatment. It is believed to occur primarily due to oxidative stress mechanisms, which generate Reactive Oxygen Species (ROS). The aim of this scoping review was to assess the role of oxidative stress in the development of Oral Mucositis (OM). Studies from the literature, published in MEDLINE and SCOPUS, that evaluated the oxidative stress pathways or antioxidant interventions for OM, were retrieved to elucidate the current understanding of their relationship. Studies failing inclusion criteria were excluded, and those suitable underwent data extraction, using a predefined data extraction table. Eighty-nine articles fulfilled criteria, and these were sub-stratified into models of study (in vitro, in vivo, or clinical) for evaluation. Thirty-five clinical studies evaluated antioxidant interventions on OM’s severity, duration, and pain, amongst other attributes. A number of clinical studies sought to elucidate the protective or therapeutic effects of compounds that had been pre-determined to have antioxidant properties, without directly assessing oxidative stress parameters (these were deemed “indirect evidence”). Forty-seven in vivo studies assessed the capacity of various compounds to prevent OM. Findings were mostly consistent, reporting reduced OM severity associated with a reduction in ROS, malondialdehyde (MDA), myeloperoxidase (MPO), but higher glutathione (GSH) and superoxide dismutase (SOD) activity or expression. Twenty-one in vitro studies assessed potential OM therapeutic interventions. The majority demonstrated successful a reduction in ROS, and in select studies, secondary molecules were assessed to identify the mechanism. In summary, this review highlighted numerous oxidative stress pathways involved in OM pathogenesis, which may inform the development of novel therapeutic targets.     

真空电弧镀膜中金属液滴的热过程研究

本文建立了真空电弧镀膜中液滴热过程的理论模型，求解了沉积ＴｉＮ膜过程中液滴的温度与粒径变化。计算表明，液滴在飞行过程中温度和粒径不断减小；粒径较小的液滴温度降低较大，甚至可能发生凝固。计算实例能较好解释早期ＴｉＮ膜的电镜分析结果，揭示液滴在薄膜中引起两种不同微孔的机理。     

Böhler Edelstahl

Böhler Edelstahl produces high performance tool and high speed steels via an optimised powder metallurgy/hot isostatic pressing route, as part of a high value special alloys portfolio.     

四合一天线合路器的控制与实现

介绍了一种基于FPGA控制的四合一天线合路器,该合路器能够根据4部电台的不同频率选择正确的通信信道,并将其信息传送到一路天线上进行通信。文中介绍了该合路器的硬件结构,软件控制算法以及工程上的实现方法。测试表明,该天线合路器能够满足4部电台同时在一路天线上进行接收与发送的要求,具有广泛的实用价值。     

电力设备全寿命周期成本中故障成本的估算

针对全寿命周期成本中故障成本难预测的问题,根据电力设备累积失效概率符合威布尔(Weibull)模型的特点,运用最小二乘法对Weibull模型参数进行估计,计算出设备的期望寿命,从而建立故障成本估算模型。通过比较分析不可修复设备和可修复设备故障成本的计算方式,针对可修复设备平均寿命的特殊性,引进等劣化理论来揭示可修复设备平均寿命之间的关系,并计算出可修复设备的故障成本。算例验证了该方法的有效性。     

Life Prediction Based on Transient Dynamics Analysis of Van Semi-trailer with Air Suspension System

The early fatigue damage in the van-body of the semi-trailer is often caused by the unique mechanical characteristics and the dynamic impact of the loads.The traditional finite element method with static strength analysis cannot support the fatigue design of van-body;thus,the dynamics analysis should be adopted for the endurance performance.The accurate dynamics model to describe the transient impacts of all kinds of uneven road and the proper system transfer functions to calculate the load transfer effects...     

Theoretical calculations of the surface tension of Ag(1−x)-Cu(x) liquid alloys

The surface tension of silver-copper binary liquid alloys is calculated, in the frame work of Eyring theory. The calculations were made for different compositions (mole fraction, x_Cu = 0, 0.2, 0.4, 0.6, 0.8 and 1), in the temperature range 1100-1800 K. The surface tension decreases with temperature increase, at a fixed copper fraction x_Cu, and increases with increasing copper content. The calculated results are appropriately compared with existing literature data.     

因需而型,应需为变——豫西南地区村镇住宅优化设计研究

研究豫西南农村的住宅设计模式,借助计算机数字化分析,探讨投入低、舒适度高的村镇住宅设计思路,并提出该因需而型,应需为变的优化设计策略。     

The cognitive differentiation-integration effort hypothesis: A synthesis between the fitness indicator and life history models of human intelligence.

This article presents a potential synthesis between the fitness indicator and life history models of human intelligence through consideration of the phenomena of ability differentiation and integration. The cognitive differentiation-integration effort hypothesis proposes that these effects result from a life history tradeoff between cognitive integration effort, a mating effort component associated with strengthening the positive manifold amongst abilities; and cognitive differentiation effort, a somatic effort component associated with the cultivation of specific abilities. This represents one of two largely independent sources of genetic variance in intelligence; the other is mediated by general fitness and mutation load and is associated with individual differences in levels of 'genetic g'. These two sources (along with a common source of environmental variance) combine to give rise to a variety of cognitive phenotypes characterized by different combinations of high or low levels of 'genetic g' and cognitive specialism or generalism. Fundamental to this model is the assumption that measures of life history speed (K) and g are essentially independent, which is demonstrated via meta-analysis of 10 studies reporting correlations between the variables (ρ = .023, ns, n = 2056). The implications of the model are discussed in an evolutionary, ecological, and developmental context. Seven key predictions are made in the discussion which if tested could provide definitive evidence for the hypothesis. (PsycINFO Database Record (c) 2011 APA, all rights reserved)