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41.
When timber is to be used in the form of furniture it must be dried. Green timber contains many times more water than wood and if it is placed indoors the water will slowly evaporate. When the fibre saturation point is reached the wooden parts start to shrink and the shape of the details will change. If the wood is dried before it is used for furniture parts this calamity is reduced because shrinking has occurred already in the drying kiln when the raw material was in the form of lumber. This drying process uses a lot of heat which is produced by electricity or by firing wood chips or oil in boilers. The cost for these energy sources varies during the season or, for electricity, also during the day. This paper describes how to optimize the use of energy in two drying kilns located at a small carpentry factory in the south of Sweden. Monitored values from the factory are used in order to describe the process in close detail. These values are then used as a basis for a mathematical model which is designed in the form of a mixed integer linear program. The method makes it possible to optimize the operating schemes for the two dryers. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
42.
泥园     
水清则无蛙In clean water Iives no frog "刘海戏蟾"是中国的民间故事.金蟾是民间传说中能吞吐金钱的灵物.刘海捉金蟾的方法是根据金蟾的"习性",以一串金钱引诱并钓住它,即民间所谓"刘海戏金蟾,步步钓金钱".其行为的目的也由除蟾祟演化为获取金钱,刘海遂成一位财神,蟾蜍也成为财富、沃土和长寿的象征.  相似文献   
43.
The introduction of in situ techniques has had a vast impact on research and development in the area of heterogeneous catalysis as emphasized in many reviews and monographs. Recently, the number of in situ techniques that can give information at the atomic scale has increased significantly and new possibilities exist for making the measurements under industrially relevant conditions. In order to fully exploit the results from the in situ and operando studies, it has also become increasingly gainful to combine the experimental studies with theoretical methodologies based on, for example, Density Functional Theory (DFT). This has allowed one to extract more detailed atomic-scale information from the measurements and it has also allowed the establishment of detailed structure-activity relationships. Furthermore, the interplay between in situ techniques and theory has helped bridging the pressure gap such that in situ information obtained at conditions far from industrial ones may be used in a more relevant manner. Here, we will illustrate how microscopy-, spectroscopy- and X-ray-based techniques in combination with experimental and theoretical surface science methods can aid industrial catalyst developments. We will do this by presenting examples of our current understanding and latest developments in the areas of heterogeneous nano-particle catalysts for methanol synthesis, steam reforming and hydrotreating.  相似文献   
44.
Results from an experimental investigation of the simultaneous temperature and velocity fields above an evenly heated horizontal cylinder with a Rayleigh number of 9.4E7 is presented. Ensemble averaged two-dimensional velocity and temperature fields, velocity fluctuations, temperature variance, and velocity–temperature correlations are computed from 2700 instantaneous data sets from simultaneous laser-induced fluorescence (LIF) and particle image velocimetry (PIV). The vertical velocity and temperature field in the plume are compared with similarity solutions from turbulent planar plumes. The production of turbulent kinetic energy (TKE) due to mean shear and buoyancy is evaluated and shows that the production of TKE is dominated by velocity shear.  相似文献   
45.
Though many cognitive abilities exhibit marked decline over the adult years, individual differences in rates of change have been observed. In the current study, biometrical latent growth models were used to examine sources of variability for ability level (intercept) and change (linear and quadratic effects) for verbal, fluid, memory, and perceptual speed abilities in the Swedish Adoption/Twin Study of Aging. Genetic influences were more important for ability level at age 65 and quadratic change than for linear slope at age 65. Expected variance components indicated decreasing genetic and increasing nonshared environmental variation over age. Exceptions included one verbal and two memory measures that showed increasing genetic and nonshared environmental variance. The present findings provide support for theories of the increasing influence of the environment with age on cognitive abilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
46.
The factor structure of health locus of control (Form A; K. A. Wallston, B. S. Wallston, & R. DeVellis, 1978) was examined in 420 octogenarians (M age?=?83.2 years), and the contributions of genetic and environmental factors to health-control beliefs in 141 octogenarian twin pairs (71 identical, 70 same-sex fraternal) were estimated. Factor analyses reproduced previously proposed factors (Internal, Chance, and Powerful Others). Associations between health-control beliefs and life satisfaction, depression, and other health-related measures (e.g., self-rated health, outpatient contacts, and hospitalization), were modest. Quantitative genetic analyses revealed significant shared environmental influence on the Chance subscale, and significant familiarity (attributable to a combination of genetic and shared environmental influences) on the Powerful Others subscale; there was no evidence of familiarity on the Internal subscale. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
47.
Self-reflections of age and aging are predictors for key outcomes such as mortality, but little is known about the nature and potential antecedents of subjective age in very old age. We used cross-sectional data from the Swedish OCTO study (N = 267; B. Johansson & S. H. Zarit, 1995) and found that almost two thirds of the 84- to 90-year-olds reported not feeling old. Multinomial logistic regression analyses indicated that younger age and better physical functioning as well as higher well-being and mastery beliefs were all related to not feeling old. In multivariate analyses, however, mastery beliefs emerged as the most consistent and robust predictor of subjective age. Our findings suggest that adaptive capacities may be preserved into advanced age and highlight the pivotal role of perceived control for successful aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
48.
Structure-activity relationships for 6-, 7-, 8-, and 9-alkyl substituted analogs of (Z)-5-decenyl acetate, a pheromone component of the turnip moth,Agrotis segetum, have been studied by electrophysiological single-sensillum recordings, and interpreted in terms of a receptor-interaction model. The compounds were prepared by alkenyl cuprate reactions with,-unsaturated carbonyl derivatives or alkyl halides. The electrophysiological results indicate steric repulsive interactions between the alkyl groups and the receptor in all the positions studied. This demonstrates a high complementarity between the receptor and the terminal alkyl chain.Schiff., Lepidoptera: Noctuidae.  相似文献   
49.
The present study investigated sense of coherence (SOC) as a protective factor among targets of workplace bullying. A hypothesis that strong SOC lessens the relationship between exposure to bullying and symptoms of posttraumatic stress was tested in a cross-sectional sample of 221 self-labeled targets of workplace bullying. The findings showed that SOC offers most protective benefits to targets exposed to low levels of bullying, whereas the benefits of SOC diminish as bullying becomes more severe. The results support previous findings that workplace bullying is a traumatic experience for those exposed to it, regardless of the target's available coping resources. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
50.
There is a great deal of variation in the encoding of spoken texts in electronic form, both with respect to the types of features represented and the way particular features are rendered. This paper surveys problems in the electronic representation of speech and presents the solutions proposed by the Text Encoding Initiative. The special tags needed for the encoding of spoken texts are discussed, including a mechanism for temporal alignment. Further work is needed on phonological aspects, parallel representation, and on the development of software which connects the systematic underlying representation with a workable format for input and display.  相似文献   
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