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81.
82.
A series of statistical copolymers derived from 2‐(dimethylamino)ethyl methacrylate with four different hydrophobic comonomers (ethyl, butyl, cyclohexyl, and octyl methacrylates) have been prepared via conventional free radical copolymerization under bulk conditions. The copolymers have been subsequently modified, with 1,3‐propanesultone to yield the corresponding polysulfoproylbetaine derivatives. Those copolymers exhibiting the requisite aqueous solubility have been screened with respect to their antimicrobial activity against two common and notorious pathogens, namely Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). We show that certain copolymers do indeed exhibit antimicrobial activity. The extent of activity is related to the molecular characteristics of the materials such as the molar composition and structure of the hydrophobic comonomer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1036–1041, 2006 相似文献
83.
介绍了水杨醛在农药、医药、香料等方面的应用,对水杨醛不同的合成方法进行了分类和比较,并且介绍了作者在利用Reimer-Tiemann反应合成水杨醛方面所作的改进和创新,产品收率达到58.6%。 相似文献
84.
聚四甲撑醚二醇聚氨酯弹性体性能和应用 总被引:1,自引:0,他引:1
聚四甲撑醚二醇(PTMG)和异氰酸酯合成的聚氨酯是一类具有广泛开发前景的材料,可用以制成各种类型的泡沫,纤维,涂料,粘合剂,弹性体等产品,阐述了PTMG型聚氨酯弹性体的合成及其性能,特点和应用,PTMG型PU有热固型和热塑型两种,可用浇注、叶涂、注射、挤出等方法成型加工,且都具有优异的性能,如良好的耐低温性能、耐生物降解性、耐水性、高回弹性,以及优良的动力学性能,所有这些使其相对于其它低聚物多元醇合成的PU,具有广泛的优越性,现在PTMG型PU已应用于冶金、矿山、纺织、造船和造纸等工业,有报道说在运动和医学领域也已开始使用。 相似文献
85.
木/塑复合材料的发展趋势 总被引:15,自引:0,他引:15
本文介绍了木/塑复合材料的生产技术及应用状况,指出其与原木材料和纯塑料制品的性能对比优势,开发厂商的开发及发展动态。 相似文献
86.
木材液化及其在高分子材料中的应用 总被引:9,自引:1,他引:9
木材通过液化可转化为具有反应活性的液态产物,进一步反应可以制备胶粘剂、聚氨酯材料等新型高分子材料。文章从方法、机理以及其产物在制备高分子材料等方面对木材液化的研究进展进行了评述。 相似文献
87.
《International journal of human-computer studies》2014,72(3):337-348
The last 2 decades have seen a constantly increasing interest in mindfulness, due to its positive effects on health and well-being. Recently, a number of mobile applications aimed at supporting people in practicing mindfulness techniques have appeared, but their efficacy has not been formally evaluated yet. In this paper, we first introduce the reader to mindfulness techniques, traditional as well as computer-based. Then, we propose and evaluate a mobile application (called AEON) aimed at helping users in practicing thought distancing, i.e. a mindfulness technique that requires one not to react in response to his/her thoughts but to be aware of them and observe them while they go away. AEON allows the user to enter his/her thoughts and visualize them as written in ink on a parchment placed under water. By touching the screen, the user can interact with the water and produce waves that progressively dissolve each written thought. We evaluate AEON on a sample of naive meditators (i.e. people with no or minimal experience with meditation), contrasting it with two traditional thought distancing techniques that are not computer-based. The first traditional technique requires users to mentally visualize their thoughts as printed on clouds and observe them as they pass by, while the second requires users to write their thoughts on cards, then pick up the cards one at a time, look at them and toss them into a wastepaper basket. AEON obtained better results in terms of achieved mindfulness, perceived level of difficulty and degree of pleasantness. Since practicing mindfulness tends to be difficult for naive meditators, these results suggest that AEON can be a novel and effective way to help them approach mindfulness. 相似文献
88.
This paper deals with the problem of piecewise auto regressive systems with exogenous input(PWARX) model identification based on clustering solution. This problem involves both the estimation of the parameters of the affine sub-models and the hyper planes defining the partitions of the state-input regression. The existing identification methods present three main drawbacks which limit its effectiveness. First, most of them may converge to local minima in the case of poor initializations because they are based on the optimization using nonlinear criteria. Second, they use simple and ineffective techniques to remove outliers. Third, most of them assume that the number of sub-models is known a priori. To overcome these drawbacks, we suggest the use of the density-based spatial clustering of applications with noise(DBSCAN) algorithm. The results presented in this paper illustrate the performance of our methods in comparison with the existing approach. An application of the developed approach to an olive oil esterification reactor is also proposed in order to validate the simulation results. 相似文献
89.
Design of video encoders involves implementation of fast mode decision (FMD) algorithm to reduce computation complexity while maintaining the performance of the coding. Although H.264/scalable video coding (SVC) achieves high scalability and coding efficiency, it also has high complexity in implementing its exhaustive computation. In this paper, a novel algorithm is proposed to reduce the redundant candidate modes by making use of the correlation among layers. A desired mode list is created based on the probability to be the best mode for each block in base layer and a candidate mode selection in the enhancement layer by the correlations of modes among reference frame and current frame. Our algorithm is implemented in joint scalable video model (JSVM) 9.19.15 reference software and the performance is evaluated based on the average encoding time, peak signal to noise ration (PSNR) and bit rate. The experimental results show 41.89% improvement in encoding time with minimal loss of 0.02 dB in PSNR and 0.05% increase in bit rate. 相似文献
90.
Considering gravity change from ground alignment to space applications, a fuzzy proportional-integral-differential (PID) control strategy is proposed to make the space manipulator track the desired trajectories in different gravity environments. The fuzzy PID controller is developed by combining the fuzzy approach with the PID control method, and the parameters of the PID controller can be adjusted on line based on the ability of the fuzzy controller. Simulations using the dynamic model of the space manipulator have shown the effectiveness of the algorithm in the trajectory tracking problem. Compared with the results of conventional PID control, the control performance of the fuzzy PID is more effective for manipulator trajectory control. 相似文献