聚氨酯热熔体用于纺织品多层复合--更快、更强、更可靠

介绍了多层复合织物的使用范围和要求,以及溶剂型和非溶剂型粘合剂的性能、工艺要求。     

Multiprocessor modeling of parallel Particle Swarm Optimization applied to nuclear engineering problems

Particle Swarm Optimization (PSO) is a population-based metaheuristic (PBM), in which solution candidates evolve through simulation of a simplified social adaptation model. Putting together robustness, efficiency and simplicity, PSO has gained great popularity. Many successful applications of PSO are reported, in which PSO demonstrated to have advantages over other well-established PBM. However, computational costs are still a great constraint for PSO, as well as for all other PBMs, especially in optimization problems with time consuming objective functions. To overcome such difficulty, parallel computation has been used. The default advantage of parallel PSO (PPSO) is the reduction of computational time. Master-slave approaches, exploring this characteristic are the most investigated. However, much more should be expected. It is known that PSO may be improved by more elaborated neighborhood topologies. Hence, in this work, we develop several different PPSO algorithms exploring the advantages of enhanced neighborhood topologies implemented by communication strategies in multiprocessor architectures. The proposed PPSOs have been applied to two complex and time consuming nuclear engineering problems: i) reactor core design (CD) and ii) fuel reload (FR) optimization. After exhaustive experiments, it has been concluded that: i) PPSO still improves solutions after many thousands of iterations, making prohibitive the efficient use of serial (non-parallel) PSO in such kind of real-world problems and ii) PPSO with more elaborated communication strategies demonstrated to be more efficient and robust than the master-slave model. Advantages and peculiarities of each model are carefully discussed in this work.     

Composite gel-filled giant vesicles: Membrane homogeneity and mechanical properties

We further investigate the properties of composite Poly(NIPAM) (poly(N-isopropylacrylamide)) gel-filled giant vesicles, focusing here on i) the homogeneity of the membrane, ii) its coupling to the inner gel under strong suction pressures, and iii) the relation between the final elastic modulus of the vesicles and the amount of crosslinker in the pre-gel medium. We show that whereas the photo-polymerization process induces a decrease of the membrane homogeneity at the micrometer size range, the membrane still remains strongly coupled to the internal gel network. The vesicles studied here display average moduli in the range [0.5–25] kPa, confirming their potential as biomimetic mechanical systems.     

One‐Pot Synthesis of Functional Helicoidal Hybrid Organic–Inorganic Nanofibers with Periodically Organized Mesoporosity

The one‐pot synthesis and properties of multifunctional hybrid mesoporous organosilica fibers with helical shapes are described. These hybrid mesoporous fibers are prepared without chiral elements and functionalized with a large variety of organic R functions (R = alkylthiols, phenylsulfonates, alkylphosphonates, dansyl, aminopropyl, fluoroalkyl, etc.). The resulting nanomaterials are thoroughly characterized by a variety of techniques. The use of a synergetic combination of achiral molecules as co‐directing structuring agents, a surfactant, and an organofunctional silica precursor R‐Si(OR)₃ allows, via carefully tuning of the main synthesis parameters and processing conditions, to control the shape, which is the anisotropic factor, of the hybrid nanofibers. The functionalization of the hybrid materials with fluorescent molecules (dansyl) and gold nanoparticles opens possibilities for sensor and catalytic applications, respectively. Moreover, these hybrid nanofibers can be easily transferred in organic solvents or in a “green” solvent such as water to make stable colloidal dispersions. This tunable functionality of nanofibers also allows their transferability into a variety of polymeric hosts (PVDF, PVBu, and PVP) allowing the formation of functional homogeneous nanocomposite hybrid membranes.     

New membranes for reverse osmosis I. Characteristics of the base polymer: sulphonated polysulphones

Within the scope of our research programme on new materials for the preparation of reverse osmosis membranes, we have studied the specific characteristics and performance of a new polymer which is a sulphonated aromatic polysulphone.Film properties were determined in reverse osmosis, permeability constants were calculated from measurements carried out at 52 bars and 20°C on a 35 g/l NaCl solution:Water permeability D₁C₁ = 2.8 × 10^-7 g/cm/sSalt permeability D₂K = 1.9×10^-10 cm²/sThere the ratio (D₁C₁/D₂K) = 1.470 g/cm³Under the same conditions, a cellulose acetate film allows a ratio D₁C₁:D₂K of 1,200 g/cm³ which is in agreement with results in the literature.     

Motivational variables in second language acquisition: A study of Francophones learning English.

Assessed the motivational characteristics of Francophones learning English as a 2nd language. A total of 304 Grade 10 and 11 Montreal Francophone students responded to a battery of attitude and motivation scales (e.g., attitudes toward English Canadians, parental encouragement, and opportunity to use English). The correlations among these scales were factor analyzed together with indices of intelligence, and achievement in French, mathematics, and English. Results tend to support the generalization that an individual's motivation to learn a 2nd language is dependent upon favorable attitudes toward the 2nd language community (i.e., an integrative motive). However, while Ss' intentions to continue studying English were related to an integrative motive, actual competence in the 2nd language seemed to be more closely related to a dimension of motivation which is best described as self-confidence derived from prior experience with the language. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)