基于符号有序二叉决策图的装配序列生成技术

为提高装配序列规划求解效率和自动化水平,给出了装配体联结图模型、干涉向量和接触向量模型的有序二叉决策图描述,建立了基于符号有序二叉决策图模型及操作的可行装配序列生成技术.结合实例验证了基于有序二叉决策图的装配体模型和可行装配序列生成技术的正确性和可行性.     

Modeling motivation and habit in driving behavior under lifetime driver's license revocation

The purpose of the present study was to verify the motivational factors underlying the theory of planned behavior (TPB) predicting the driving behavior of lifetime driving license revoked offenders. Of a total of 639 drivers whose licenses had been permanently revoked, 544 offenders completed a questionnaire constructed to measure attitudes toward behaviors, subjective norms, perceived behavioral control, behavioral intentions (the key constructs of the TPB), and previous driving habit strength. The finding of the study revealed that an offenders’ driving behavior after a lifetime license revocation was significantly correlated to behavioral intention (R = 0.60, p < 0.01), perceived behavioral control (R = 0.61, p < 0.01), previous driving habit (R = 0.44, p < 0.01), and attitude (R = 0.41, p < 0.01). There was no evidence that subjective norms including road regulation, society ethics, and people important to offenders had an influence on driving behavior (R = 0.03). Low driving habit strength offenders are motivated to drive because of behavioral intention, whereas strong driving habit strength offenders are motivated to drive because of perceived behavioral control. Previous driving habit strength is a moderator in the intention–behavior relationship. The model appeared successful when previous habits were weak, but less successful when previous habits were strong.     

A spatial generalized ordered response model to examine highway crash injury severity

This paper proposes a flexible econometric structure for injury severity analysis at the level of individual crashes that recognizes the ordinal nature of injury severity categories, allows unobserved heterogeneity in the effects of contributing factors, as well as accommodates spatial dependencies in the injury severity levels experienced in crashes that occur close to one another in space. The modeling framework is applied to analyze the injury severity sustained in crashes occurring on highway road segments in Austin, Texas. The sample is drawn from the Texas Department of Transportation (TxDOT) crash incident files from 2009 and includes a variety of crash characteristics, highway design attributes, driver and vehicle characteristics, and environmental factors. The results from our analysis underscore the value of our proposed model for data fit purposes as well as to accurately estimate variable effects. The most important determinants of injury severity on highways, according to our results, are (1) whether any vehicle occupant is ejected, (2) whether collision type is head-on, (3) whether any vehicle involved in the crash overturned, (4) whether any vehicle occupant is unrestrained by a seat-belt, and (5) whether a commercial truck is involved.     

Plasmonic Amplifiers: Engineering Giant Light Enhancements by Tuning Resonances in Multiscale Plasmonic Nanostructures

The unique ability of plasmonic nanostructures to guide, enhance, and manipulate subwavelength light offers multiple novel applications in chemical and biological sensing, imaging, and photonic microcircuitry. Here the reproducible, giant light amplification in multiscale plasmonic structures is demonstrated. These structures combine strongly coupled components of different dimensions and topologies that resonate at the same optical frequency. A light amplifier is constructed using a silver mirror carrying light‐enhancing surface plasmons, dielectric gratings forming distributed Bragg cavities on top of the mirror, and gold nanoparticle arrays self‐assembled into the grating grooves. By tuning the resonances of the individual components to the same frequency, multiple enhancement of the light intensity in the nanometer gaps between the particles is achieved. Using a monolayer of benzenethiol molecules on this structure, an average SERS enhancement factor <EF> ～10⁸ is obtained, and the maximum enhancement in the interparticle hot‐spots is ～3 × 10¹⁰, in good agreement with FDTD calculations. The high enhancement factor, large density of well‐ordered hot‐spots, and good fidelity of the SERS signal make this design a promising platform for quantitative SERS sensing, optical detection, efficient solid state lighting, advanced photovoltaics, and other emerging photonic applications.     

基于水滴模板法构筑可溶性聚酰亚胺规整多孔膜

采用实验室自制的以二苯甲酮四羧酸二酐(BTDA)和3,3-二甲基-4,4-二氨基二苯甲烷(DMMDA)为单体合成的可溶性聚酰亚胺BTDA-DMMDA为成膜材料制备蜂窝状有序多孔膜,研究不同湿气氛围、相对湿度大小以及固体基板等因素对膜孔形态的影响,并探讨多孔膜表面被剥离前后的亲疏水性变化.结果表明,通过改变环境的相对湿度实现了膜孔径从400nm到2μm的动态调控;亲水性好的固体基板更有利于规整多孔膜的构筑;多孔膜表层剥离后其表面接触角得以大大提高,在超疏水表面有潜在的应用前景.     

Fuelwood as an energy source for the commercial cooking sector – An overview analysis focused in the city of São Paulo,Brazil

This paper provides an overview analysis of fuelwood utilization in the commercial cooking sector. Cultural, market and logistic factors that may weaken the explanatory power of the energy ladder hypothesis are highlighted. Additionally, gender issues and health and environmental aspects related to fuelwood use in cities are explored. The analysis is developed as from the viewpoint of the use of different fuels for cooking in urban areas, focusing on commercial establishments. Evidences were observed in the pizza market in the city of São Paulo, Brazil, demonstrating that consumer expectations, expressed by means of classical market pressure mechanisms, can markedly influence this commercial cooking niche and consist in an important driving force for its energy choice. The city has the second largest pizza market in the world, characterized by the commercialization of 40 million units of the product per month in over 5000 commercial establishments. Interviews conducted in 270 of these establishments reveal that 88% use fuelwood ovens despite its lower practicality and wide availability of modern energy options such as electricity and liquefied petroleum gas (LPG). The work validates the fuel stacking model, according to which energy diversification – and not substitution –, results from economic development, urbanization and/or a population income growth.     

L12相间有序畴界成分的微观相场研究

利用微观相场模型研究了有序畴界结构、合金成分和弹性应变能对Ni75AlxV25-x合金中L12-Ni3Al相间有序畴界成分的影响规律。结果表明:L12相间形成的3种有序畴界中,在(100)//(200)·[001]处,Ni的贫化程度最小,Al的贫化程度最大,V的偏聚程度最大;在(200)//(200)处,Ni的贫化程度最大,Al的贫化程度最小,V的偏聚程度最小。随着合金中Al浓度的增加,3种有序畴界处Ni的浓度降低,Al的浓度升高,V的浓度降低。弹性应变能使得L12相间3种有序畴界处Ni和Al的浓度升高,V浓度降低。但弹性应变能对(200)//(200)·[001]和(100)//(200)·[001]成分的影响较大,对(200)//(200)成分的影响则相对较小。     

含长周期堆垛有序结构Mg94Zn2Y4挤压态合金的显微组织与力学性能

采用SEM和TEM等分析方法研究包含长周期堆垛有序结构的挤压态Mg94Zn2Y4合金的显微组织和力学性能。结果表明：铸态Mg94Zn2Y4合金由18R-LPSO和α-Mg两相组成。挤压后,长周期相分层,并形成宽度为50~200 nm的α-Mg 薄片。合金经498 K时效处理36 h后达到时效峰值,在其组织中析出β′相,该析出相的出现显著提高了α-Mg基体的显微硬度,从HV108.9增加到HV129.7;而LPSO结构的显微硬度稳定在HV145左右。TEM分析及其电子衍射花样表明,β′相与α-Mg和LPSO结构具有独特的位相关系,其原子最密排面的堆垛方向垂直于α-Mg和LPSO相最密排面的堆垛方向。由于β′相和18R-LPSO相的共同存在,处于时效峰值态的Mg94Zn2Y4合金的抗拉强度达到410.7 MPa。