波长为515nm的氩离子激光器的频率稳定

用声光晶体对氩离子激光作频率调制,获得了碘分子的差拍饱和吸收信号。将得到的斜率极陡的—阶微商形式的饱和吸收信号作为鉴频曲线把氩离子频率激光稳定到~(127)I_2分子的p(13)43—0的a_3超精细分量上。通过与一稳定到相同精细分量的稳频氩离子激光拍频,给出激光频率稳定性优于±6.5×10~(-12),重复性优于±3.4×10~(-11)。     

Prevention of marital distress: Results of a German prospective longitudinal study.

This article reports on the development and long-term evaluation of a marital distress prevention program for German couples, the Ein Partnerschaftliches Lernprogramm (EPL, A Couple's Learning Program). The EPL is a 6-session program designed to teach couples effective communication and problem-solving skills. In the current article, the EPL is evaluated in a prospective, quasi-experimental, controlled trial. The results of the 3-year follow-up are reported, contrasting 55 EPL couples with a control group of 17 couples. Significant differences emerged with regard to the couples' dissolution rates, relationship satisfaction, and positive and negative communication behavior favoring the EPL couples. These results demonstrate the utility of the EPL program in assisting happy couples who are preparing for marriage. The implications of the findings for prevention research and for the dissemination of prevention programs are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preview benefit and parafoveal-on-foveal effects from word n + 2.

Using the gaze-contingent boundary paradigm with the boundary placed after word n, the experiment manipulated preview of word n + 2 for fixations on word n. There was no preview benefit for 1st-pass reading on word n + 2, replicating the results of K. Rayner, B. J. Juhasz, and S. J. Brown (2007), but there was a preview benefit on the 3-letter word n + 1, that is, after the boundary but before word n + 2. Additionally, both word n + 1 and word n + 2 exhibited parafoveal-on-foveal effects on word n. Thus, during a fixation on word n and given a short word n + 1, some information is extracted from word n + 2, supporting the hypothesis of distributed processing in the perceptual span. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Online Communication and Adolescent Well-Being: Testing the Stimulation Versus the Displacement Hypothesis

The aim of this study was to contrast the validity of two opposing explanatory hypotheses about the effect of online communication on adolescents' well-being. The displacement hypothesis predicts that online communication reduces adolescents' well-being because it displaces time spent with existing friends, thereby reducing the quality of these friendships. In contrast, the stimulation hypothesis states that online communication stimulates well-being via its positive effect on time spent with existing friends and the quality of these friendships. We conducted an online survey among 1,210 Dutch teenagers between 10 and 17 years of age. Using mediation analyses, we found support for the stimulation hypothesis but not for the displacement hypothesis. We also found a moderating effect of type of online communication on adolescents' well-being: Instant messaging, which was mostly used to communicate with existing friends, positively predicted well-being via the mediating variables (a) time spent with existing friends and (b) the quality of these friendships. Chat in a public chatroom, which was relatively often used to talk with strangers, had no effect on adolescents' well-being via the mediating variables.     

An Asymptotic Preserving Method for Linear Systems of Balance Laws Based on Galerkin’s Method

We apply the concept of asymptotic preserving schemes (SIAM J Sci Comput 21:441–454, 1999) to the linearized \(p\) -system and discretize the resulting elliptic equation using standard continuous Finite Elements instead of Finite Differences. The fully discrete method is analyzed with respect to consistency, and we compare it numerically with more traditional methods such as Implicit Euler’s method.     

Measurement-based modeling of contact forces and textures for haptic rendering

Haptic texture represents the fine-grained attributes of an object's surface and is related to physical characteristics such as roughness and stiffness. We introduce an interactive and mobile scanning system for the acquisition and synthesis of haptic textures that consists of a visually tracked handheld touch probe. The most novel aspect of our work is an estimation method for the contact stiffness of an object based solely on the acceleration and forces measured during stroking of its surface with the handheld probe. We establish an experimental relationship between the estimated stiffness and the contact stiffness observed during compression. We also measure the height-displacement profile of an object's surface enabling us to generate haptic textures. We show an example of mapping the textures on to a coarse surface mesh obtained with an image-based technique, but the textures may also be combined with coarse surface meshes obtained by manual modeling.     

Dynamic control mechanisms for revenue management with flexible products

Revenue management with flexible products has experienced a growing interest in the academic literature within the last few years. Flexible products allow supply-side substitution between resources and can therefore help to maximize overall revenue as well as capacity utilization in markets with highly uncertain demand. This paper addresses the question of how the mathematical models which have been developed for capacity control with flexible products should be used over time to exploit the substitution opportunities, while keeping practical applicability in mind. Several dynamic control mechanisms are proposed, each of which makes use of the flexibility to a different extent. A comprehensive computational study shows the potential of the different approaches by revealing their strengths and weaknesses.     

Psychosocial causes and consequences of pathological gaming

Pathological use of computer and video games has been associated with indicators of psychosocial well-being, such as loneliness, low self-esteem, low social competence, and low life satisfaction. However, few studies have decisively demonstrated whether these indicators of psychosocial well-being are causes or consequences of pathological gaming. To address this gap in the literature, we conducted a two-wave panel study among 851 Dutch adolescents (543 gamers). Causal relations were analyzed using autoregressive structural equation models. These analyses indicated that social competence, self-esteem, and loneliness were significant predictors of pathological gaming six months later. Thus, lower psychosocial well-being can be considered an antecedent of pathological gaming among adolescent gamers. Our analyses further indicated that loneliness was also a consequence of pathological gaming. This suggests that displacement of real-world social interaction resulting from pathological use of video games may deteriorate existing relationships, which could explain the increase in adolescent gamers’ feelings of loneliness.