The district attorney's dilemma: Experimental games and the real world of plea bargaining.

The lack of effectiveness of the prisoner's dilemma (PD) game is attributed to the departure from the original model involving 2 suspects and a district attorney. PD research is examined in the light of an actual murder case that involved its basic constituents. Suggestions are made for shifting the focus of PD research back to the original paradigm to widen the range of issues covered and increase its relevance to the criminal justice system. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Problematik und Systematik der Verfahren zur Prüfung des Verhaltens von Holz und Holzwerkstoffen im Feuer

Ohne Zusammenfassung Nach einem Vortrag, gebalten auf der Dreil?uder-Holz-tagung in Baden-Baden am 23. Juni 1956.     

Formation mechanism and growth of MNbO3, M=K,Na by in situ X‐ray diffraction

Hydrothermal synthesis is a well‐established method to produce complex oxides, and is a potential interesting approach to synthesize stoichiometric lead‐free piezoelectric K_0.5Na_0.5NbO₃. Due to challenges in obtaining the desired stoichiometry of this material, more knowledge is needed on how the end‐members, KNbO₃ and NaNbO₃, are nucleating and growing. Here, we report on the formation mechanisms and growth during hydrothermal synthesis of KNbO₃ and NaNbO₃ by in situ synchrotron powder X‐ray diffraction. We show that tetragonal KNbO₃ crystallites form from dissolved T‐Nb₂O₅ at 250°C‐300°C and 250 bar while orthorhombic NaNbO₃ forms via several crystalline intermediate phases at 225°C‐325°C and 250 bar. The crystallite size of KNbO₃ is decreasing while the crystallite size of NaNbO₃ is increasing with increasing temperature, demonstrating that the presence of intermediate phases is highly important for the nucleation and growth of the final product. The different crystallization schemes explain the challenge in obtaining stoichiometric K_0.5Na_0.5NbO₃ by hydrothermal synthesis.     

Panel 3: PVC extrusion: Single vs multi-screw

Pros and cons—single or twin screw for pipe, profile, siding, foamed PVC, compounding flexibles; profile and film; capital investment for equivalent output; formulation cost differences; dimensional control, sizing flow and hot strength; power consumption; screw and barrel wear; replacement costs and frequency; differences in end product physical properties; effect of newer, longer L/D single screw extruders; differences in maintenance costs; future developments extrusion technology.     

The tensile properties of strain‐crystallizing vulcanizates. II. Stress relaxation and hysteresis

Stress relaxation on cessation of extension and hysteresis were examined in conventional and peroxide vulcanizates over a range of crosslink densities at room temperature and at 90°C. The rate of relaxation decreases with an increase in temperature and is attributed to slower nucleation of strain‐induced crystallites. The decrease in the volume fraction of extendable material as a result of strain‐induced crystallites has only a small effect on the rate at which the slope of the stress–strain curve rises. Crystallites that form on cooling, melt on heating, leaving an unaltered network, but when strain‐induced crystallites are melted by heating, they do not reform on cooling. The relaxed network now extends further before failure than a network in which extension was not interrupted by a heating–cooling cycle. This supports proposals in the preceding article that strain‐induced crystals increase tensile properties by altering the network deformation pattern and not by the deflection of propagating flaws, whose mechanism would require the heated sample to fail earlier due to its lower crystalline content. Hysteresis increases sharply at strains at which crystallization in the network becomes possible. The hysteresis ratio reaches a plateau value at higher strains. Relaxation affects both the extension and retraction stress–strain curves and it is proposed that hysteresis is determined by differences in the crystallinity during extension and retraction. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2423–2430, 2006     

被忽视的传统?——作为图像学的艺术史

本文指出,能容纳所有形象的"图像学"研究原本就是艺术史自身的一个传统,而今天艺术史学界将艺术史研究仅限于"高级艺术"的领域,而将对摄影与电影等"低级艺术"的研究称为"视觉文化研究"并视之为异端的倾向,是一种数典忘祖的表现.由此作者重新梳理了作为图像学的艺术史的兴起与摄影及电影等新媒体的密切关系,指出在19世纪的德国,最重要的艺术史家都对这两种新媒体给予了敏锐而充分的重视,由此形成了一种通向图像学的全新视角.而像瓦尔堡、潘诺夫斯基与本雅明这样的艺术学巨擘,他们最有创造性的研究成果也都集中在摄影与电影的领域中.