标准号: NF E52-615-2009

摘要： La présente Norme européenne traite des exigences techniques permettant de minimiser les risques dus aux phénomènes dangereux énumérés à l'article 4, susceptibles d'apparaître lors de l'installation 1>, du fonctionnement et de la maintenance des dispositifs et systèmes installés de manière permanente pour le stationnement motorisé des véhicules automobiles, tels que définis de 3.1 à 3.4 ci-dessous. Cette norme fournit également des exigences concernant la disposition d'informations pour l'utilisation comportant des exigences relatives à la rédaction des instructions. Les exigences concernant la compatibilité électromagnétique sont également traité*** présente Norme européenne s'applique aux dispositifs et aux systèmes de stationnement motorisé des véhicules automobiles à quatre roues, dont l'envergure maximale est de 5,30 m de long par 2,30 m de large et 2,20 m de haut, et dont le poids est inférieur à 2 500 kg. Les dispositifs peuvent être à commande manuelle ou automatique.

关键词： 机械手臂   动力学   拉格朗日方程   仿真  

摘要： 动力学的计算在机械手臂设计阶段和运动控制阶段都有实际意义。本文对空间五自由度机械手进行动力学分析并采用拉格朗日动力学方法建立理想情况下,即没有考虑摩擦影响下的动力学模型并结合相应计算机算法完成该机械手的动力学逆解仿真计算研究。

关键词： 混合动力   工程机械   多能源  

摘要： 介绍混合动力技术在工程机械领域的应用,混合动力的关键技术、知识产权、典型产品和我国混合动力工程机械研发现状。

关键词： Protein folding   Folding/unfolding kinetics   Chevron plot   Chevron rollover   Contact order   Long-range interaction  

摘要： The folding/unfolding kinetics of a three-dimensional lattice protein was studied using a simple statistical mechanical model for protein folding that we developed earlier. We calculated a characteristic relaxation rate for the free energy profile starting from a completely unfolded structure (or native structure) that is assumed to be associated with a folding rate (or an unfolding rate). The chevron plot of these rates as a function of the inverse temperature was obtained for four lattice proteins, namely, proteins a1, a2, b1, and b2, in order to investigate the dependency of the folding and unfolding rates on their native structures and amino acid sequences. Proteins a1 and a2 fold to the same native conformation, but their amino acid sequences differ. The same is the case for proteins b1 and b2, but their native conformation is different from that of proteins a1 and a2. However, the chevron plots of proteins a1 and a2 are very similar to each other, and those of proteins b1 and b2 differ considerably. Since the contact orders of proteins b1 and b2 are identical, the differences in their kinetics should be attributed to the amino acid sequences and consequently to the interactions between the amino acid residues. A detailed analysis revealed that long-range interactions play an important role in causing the difference in the folding rates. The chevron plots for the four proteins exhibit a chevron rollover under both strongly folding and strongly unfolding conditions. The slower relaxation time on the broad and flat free energy surfaces of the unfolding conformations is considered to be the main origin of the chevron rollover, although the free energy surfaces have features that are rather complicated to be described in detail here. Finally, in order to concretely examine the relationship between changes in the free energy profiles and the chevron plots, we illustrate some examples of single amino acid substitutions that increase the folding rate. (C) 2009 Elsevie

关键词： Hamiltonian vector fields   Homogeneous polynomial potentials   Global flow  

摘要： This paper is devoted to analyze certain dynamical aspects of the planar mechanical system associated to the potential V = ax (4) + cx (2) y (2) as a function of the real parameters a and c.

关键词： Thiol-ene   Photopolymerization   Thio-Michael addition   Networks  

摘要： Thio-acrylate networks were prepared using two methods. The first method involved the in-situ photopolymerization of a multifunctional thiol mixed with a multifunctional acrylate in the presence of a photoinitiator (photo-cure only), while the second method utilized an extremely efficient thio-acrylate Michael reaction followed by the photopolymerization of unreacted acrylate functional groups (amine catalysis/photo-cure). The thio-acrylate Michael reaction was catalyzed by a primary amine that promoted a rapid 1-to-1 Michael addition reaction of thiol to acrylate. Kinetic analysis via real-time infrared (RTIR) spectroscopy verified the 1-to-1 addition, the rates of the thio-acrylate Michael reaction and the total incorporation of the thiol into the networks at various concentrations when the amine catalyst was used. Differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) data show very narrow glass transition temperatures for the networks prepared when the amine catalysis/photo-cure sequence was used. The two step sequential process can be used to target network films that can be tailored to have high energy damping properties at a given temperature, e.g., room temperature. Finally, in all cases, whether the photo-cure only or the amine catalysis/photo-cure process was used, the glass transition temperature increased with the initial acrylate feed concentration. (C) 2009 Published by Elsevier Ltd.

关键词： Fluid structure interaction  

摘要： Bileaflet mechanical heart valves (BMHVs) are widely implanted to replace diseased heart valves but still suffer from complications such as hemolysis and platelet activation. These complications are closely related to both flow characteristics through the valves and leaflet dynamics. In this study, a fluid-structure interaction (FSI) simulation is performed to investigate the characteristics of physiological flow interacting with moving leaflets in a BMHV. The present FSI model uses both a finite volume computational fluid dynamics code and a finite element structure dynamics code to solve the governing equations for fluid flow and leaflet dynamics. In addition, a structural analysis is performed with the forces acting on the leaflet surfaces. From the analysis, detailed flow information and leaflet behavior are quantified for a cardiac cycle. The results show that the present FSI model performs well at predicting the overall flow patterns interacting with the moving leaflets and leaflet behavior in the BMHV. ASAIO journal 2009;55:428-437.

关键词： Bread baking   Crumb   Texture   Staling   Amylopectin  

摘要： This paper presents a study on the impact of baking conditions on crumb staling. Breads were baked at 220 degrees C, 200 degrees C and 180 degrees C corresponding to 6, 8 and 10 min to rise the temperature to 98 degrees C in the crumb (heating rates 13, 9.8 and 7.8 degrees C/min respectively with an initial temperature of 20 degrees C). A new protocol has been developed, consisting in baking a slab of degassed dough in a miniaturized oven to mimic the baking conditions of conventional bread making. Texture tests were done during staling on degassed crumb and on conventional crumb. Calorimetry tests showed that during storage, amylopectin recrystallisation occurred before crumb stiffening. A first order kinetics model was used to fit the evolution of the crumb texture (Young's modulus) and of the recrystallisation of amylopectin. The results showed that the hardening of the crumb during staling occurred after retrogradation of amylopectin. In addition, the staling rate was faster for faster baking kinetics. A mechanical model showed that the relative Young modulus is proportional to the square of the relative density of the crumb. (C) 2009 Published by Elsevier Ltd.

关键词： ACETYLENE   HYDROCHLORIC acid   PALLADIUM   VINYL chloride   DYNAMICS  

摘要： The catalyst for acetylene hydrochlorination with gaseous HCl at room temperature is prepared by mechanical pretreatment of K2PdCl4 in an acetylene atmosphere. The rate-determining step of the reaction is the chloropalladation of pi-coordinated acetylene involving an HCl molecule. As a consequence, the replacement of HCl with DCl brings about a kinetic isotope effect of 2.8 +/- 0.4, which differs substantially from that observed in the protodemetalation of the intermediate palladium(II) chlorovinyl derivative yielding vinyl chloride (6.8 +/- 0.6).

关键词： Cl + CH2FCl   Dual level dynamics   Minimum energy path (MEP)  

摘要： Theoretical investigations are carried out on the reaction Cl + CH2FCl by means of direct dynamics method. The minimum energy path (MEP) is obtained at the MP2/6-311G(d, p) level. The energetic information is further improved by single-point energy calculations using QCISD(T)/6-311++G(d, p) method. The kinetics of this reaction are calculated by canonical variational transition state theory incorporating with the small-curvature tunneling correction over a wide temperature range of 220–3,000 K, and rate constant expression are found to be k( T) = 1.48 × 10−17 T2.04exp(−913.91/ T). For the title reaction, H-abstraction reaction channel is the major channel at the lower temperatures. At higher temperatures, the contribution of Cl-abstraction reaction channel should be taken into account. [ABSTRACT FROM AUTHOR]