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111.
112.
Based on results from eigenspace and residual assignment a closed-form parameterization of all transfer function matrices obtainable by state feedback is given. 相似文献
113.
Per Brinch Hansen 《Software》1989,19(6):553-578
This paper defines a programming language for distributed processing called Joyce. Joyce is based on CSP and Pascal. A Joyce program defines concurrent agents which communicate through synchronous channels. The agents may be recursive. 相似文献
114.
Two coupling agents based on trichloro-s-triazine with different terminal unsaturated groups were synthesized in order to improve the bonding between cellulose fibers and an unsaturated polyester matrix. The products of the reactions between hydroxyl groups of cellulose and reactive species of coupling agents were analysed by Fourier-transform infrared spectroscopy (FTIR) and by elemental microanalyses. ESCA was used for surface characterization of treated fibers. The coupling agents were found to be concentrated on the fiber surface. Polymerization of styrene was carried out in the presence of treated fibers. That the unsaturated groups of the treated fibers were able to copolymrize with styrene was shown by FTIR. Further evidence of the presence of grafted polystyrene on the surfaces of the cellulose fibers was provided by ESCA measurements. 相似文献
115.
Although effective therapies for pathological gambling exist, their uptake is limited to 10% of the target population. To lower the barriers for help seeking, the authors tested an online alternative in a randomized trial (N = 66). The participants were pathological gamblers not presenting with severe comorbid depression. A wait-list control was compared with an 8-week Internet-based cognitive behavior therapy program with minimal therapist contact via e-mail and weekly telephone calls of less than 15 min. Average time spent on each participant, including phone conversations, e-mail, and administration, was 4 hr. The Internet-based intervention resulted in favorable changes in pathological gambling, anxiety, depression, and quality of life. Composite between-group effect size (Cohen's d) at posttreatment was 0.83. Follow-ups carried out in the treatment group at 6, 18, and 36 months indicated that treatment effects were sustained (ds = 2.58, 1.96, and 1.98). This evidence is in support of Internet-delivered treatment for pathological gamblers. However, it is not clear how effective the treatment is for more severely depressed individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
116.
0-18 nm-thick titanium, zirconium and tantalum oxide films are thermally evaporated on Nafion 117 membranes, and used as thin spacer electrolyte layers between the Nafion and a 3 nm Pt catalyst film. Electrochemical characterisation of the films in terms of oxygen reduction activity, high frequency impedance and cyclic voltammetry in nitrogen is performed in a fuel cell at 80 °C and full humidification. Titanium oxide films with thicknesses up to 18 nm are shown to conduct protons, whereas zirconium oxide and tantalum oxide block proton transport already at a thickness of 1.5 nm. The performance for oxygen reduction is higher for a bi-layered film of 3 nm platinum on 1.5 or 18 nm titanium oxide, than for a pure 3 nm platinum film with no spacer layer. The improvement in oxygen reduction performance is ascribed to a higher active surface area of platinum, i.e. no beneficial effect of combining platinum with zirconium, tantalum or titanium oxides on the intrinsic oxygen reduction activity is seen. The results suggest that TiO2 may be used as electrolyte in fuel cell electrodes, and that low-temperature proton exchange fuel cells could be possible using TiO2 as electrolyte. 相似文献
117.
网络拱桥──一种适合中国的桥梁 总被引:1,自引:0,他引:1
阐述了网络拱桥的特点,设计原理,节点形式及架设安装。对中国大跨度简支架桥的发展有一定的借鉴作用. 相似文献
118.
In timber exposed to moisture variations, drying distortions is a serious problem that might result into sawn timber and other wood products unsuitable for construction purposes. Two characteristics of wood are that its behaviour is strongly orthotropic and that it is very sensitive to variations in moisture content. In addition, wood is characterised by variation in its properties from pith to bark. A further important property of wood, which affects its behaviour, is its spiral grain. For timber containing much compression wood the drying distortions are also highly dependent upon where the compression wood is located in the sawn boards. The present study concerns an experimental investigation of density, grain angles, shrinkage parameters and longitudinal elastic modulus in a number of spruce boards containing much compression wood. On the basis of the data obtained, numerical simulations have been carried out in order to determine the deformations that developed in the boards during changes in moisture content. 相似文献
119.
Observed parental interactive patterns in the presence (a triadic setting) and in the absence (a dyadic setting) of the spouse in 44 families with 16 female and 28 male early adolescents (approximately 13 yrs old). Findings indicate that in accordance with hypotheses, the presence of the father enhanced the quality of mother–son relations, whereas the presence of the mother reduced the quality of father–son relations. The presence of the spouse influenced the extent to which parents treated girls and boys differently: Mothers differentiated more between girls and boys in the presence of the spouse, whereas fathers differentiated more between girls and boys in the absence of the spouse. Relative to the dyad, parental role differentiation increased in the triad but only in families of boys. In demonstrating interdependencies among family relationships and the responsivity of parental behaviors to the interpersonal structure of interaction settings, the results support a systems model of family processes. Implications for the study of family relations and sex typing at early adolescence are discussed. (60 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
120.
In 1956, the Swedish office equipment company Facit embarked on a plan to produce large-scale computers for the Swedish and Western European markets. The plan involved recruiting several top engineers known as the BESK Boys, who developed a computer for Facit that briefly was the world's fastest. Circumstances, however, ultimately worked against Facit. 相似文献