动起来的礼物

成为“Jumper（心灵传输者）”必定是每个人曾有过的梦想。没有关系，即使你不能倚靠心灵的力量而遍游世界，那些有趣的礼物同样能带来移动的快感。     

Analysis of the theaflavin composition in black tea (Camellia sinensis) for predicting the quality of tea produced in Central and Southern Africa

A parameter of black tea that correlates with quality is highly desired. Twenty good and 20 poor quality tea clones were selected from the breeding programme at the Tea Research Foundation (Central Africa) (TRF(CA)). The theaflavin (TF) composition of the black tea manufactured from each clone was analysed by capillary electrophoresis and correlated with total scores and valuation from two tea tasters with regression analysis. The significance of the differences between the 20 good and 20 poor quality tea clones was determined with the Student t‐test and the distribution‐free Kruskal–Wallis test. The sum of the TFs of the black tea correlated well (r = 0.785, P = 0.0002) with the value of the tea. Of the individual TFs determined in the black tea, the highest correlation was obtained with TF‐3′‐monogallate (TF‐B) (r = 0.788, P = 0.0016), TF‐3‐monogallate (TF‐A) (r = 0.741, P = 0.0004) and free TF (TF‐f) (r = 0.705, P = 0.0002). TF‐B (m = 24.90) followed by TF‐A (m = 12.48) showed the steepest slopes against value, making them good indicators for value. The TF‐digallate (TF‐dg) content did not show significant correlation with value (r = 0.316, P = 0.358). The individual TF content thus can be used for optimising the black tea manufacturing process in Central and Southern Africa. © 2002 Society of Chemical Industry     

Porous silicon-based rugate filters

We report an experimental study of porous silicon-based rugate filters. We performed filter apodization, following a half-apodization approach, which successfully attenuated the sidelobes at both sides of the photonic stop band. We achieved successful reduction of interference ripples through the insertion of index-matching layers on the first and last interfaces. An apodized dielectric mirror and a rugate filter are compared: Appreciable differences in the harmonic presence and stop-band performance were observed and are commented on. Bandwidth control when index contrast is modified is also demonstrated. Finally, the possibility of combining different rugate filter designs to attain more complex responses is demonstrated by the achievement of a multi-stop-band filter. Numerical calculations for design optimization and comparison with experimental data are reported too.     

Mother-child emotional availability in ecological perspective: Three countries, two regions, two genders.

This study used a cross-national framework to examine country, region, and gender differences in emotional availability (EA), a prominent index of mutual socioemotional adaptation in the parent-child dyad. Altogether 220 Argentine, Italian, and U.S. mothers and their daughters and sons from both rural and metropolitan areas took part in home observations when the children were 20 months old. In terms of country, Italian mothers were more sensitive and optimally structuring, and Italian children were more responsive and involving, than Argentine and U.S. dyads. In terms of region, rural mothers were more intrusive than metropolitan mothers, and boys from metropolitan areas were more responsive than boys from rural areas. In terms of gender, mothers of girls were more sensitive and optimally structuring than mothers of boys, and daughters were more responsive and involving than sons. Understanding how country, region, and gender influence EA exposes forces that shape child development, parent-infant interaction, and family systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Out-of-plane reflection and refraction of light by anisotropic optical antenna metasurfaces with phase discontinuities

Experiments on ultrathin anisotropic arrays of subwavelength optical antennas display out-of-plane refraction. A powerful three-dimensional (3D) extension of the recently demonstrated generalized laws of refraction and reflection shows that the interface imparts a tangential wavevector to the incident light leading to anomalous beams, which in general are noncoplanar with the incident beam. The refracted beam direction can be controlled by varying the angle between the plane of incidence and the antenna array.     

Explaining the user experience of recommender systems

Research on recommender systems typically focuses on the accuracy of prediction algorithms. Because accuracy only partially constitutes the user experience of a recommender system, this paper proposes a framework that takes a user-centric approach to recommender system evaluation. The framework links objective system aspects to objective user behavior through a series of perceptual and evaluative constructs (called subjective system aspects and experience, respectively). Furthermore, it incorporates the influence of personal and situational characteristics on the user experience. This paper reviews how current literature maps to the framework and identifies several gaps in existing work. Consequently, the framework is validated with four field trials and two controlled experiments and analyzed using Structural Equation Modeling. The results of these studies show that subjective system aspects and experience variables are invaluable in explaining why and how the user experience of recommender systems comes about. In all studies we observe that perceptions of recommendation quality and/or variety are important mediators in predicting the effects of objective system aspects on the three components of user experience: process (e.g. perceived effort, difficulty), system (e.g. perceived system effectiveness) and outcome (e.g. choice satisfaction). Furthermore, we find that these subjective aspects have strong and sometimes interesting behavioral correlates (e.g. reduced browsing indicates higher system effectiveness). They also show several tradeoffs between system aspects and personal and situational characteristics (e.g. the amount of preference feedback users provide is a tradeoff between perceived system usefulness and privacy concerns). These results, as well as the validated framework itself, provide a platform for future research on the user-centric evaluation of recommender systems.     

The dirty dozen: Twelve failures of the Hurricane Katrina response and how psychology can help.

This comprehensive analysis addresses the United States' alarming lack of preparedness to respond effectively to a massive disaster as evidenced by Hurricane Katrina. First, a timeline of problematic response events during and after Hurricane Katrina orients readers to some of the specific problems encountered at different levels of government. Second, a list of the "Dirty Dozen"--12 major failures that have occurred in prior disasters, which also contributed to inadequate response during and after Hurricane Katrina--is presented. Third, this article encourages expanding psychology's role beyond the treatment of trauma to encompass disaster planning and mitigation efforts from a broader public health perspective. Finally, areas for important interdisciplinary research in human behavior that will influence our nation's overall preparedness for future catastrophes are identified, and ways psychologists can become personally involved beyond treating casualties are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

独特的爱情礼物

这个情人节，带给对方什么样的惊喜呢？首饰或者花束或者巧克力缓缓一缓吧，让我们精心挑选最独特，最前卫的礼品，让情侣和他/她身边的一切都是独特的。