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991.
Lueger Robert J.; Howard Kenneth I.; Martinovich Zoran; Lutz Wolfgang; Anderson Eric E.; Grissom Grant 《Canadian Metallurgical Quarterly》2001,69(2):150
The dosage model provides a normative estimate of the overall pattern of patient improvement in psychotherapy. The phase model further specifies patterns of change in the domains of subjective well-being, symptom remediation, and functioning. The expected treatment response (ETR) approach uses patient characteristics to predict an expected path of progress for each patient. With repeated measures of mental health status, the treatment progress of an individual patient can be assessed against the patients ETR to support decisions that would enhance the quality of a clinical service while it is being delivered. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
992.
Two series of polyisocyanurates were prepared from polymeric 4,4′‐diphenylmethane diisocyanate (MDI) and soy‐based or polypropylene oxide polyols by varying isocyanate indexes from 105 to 350. Increasing isocyanate index gave polyisocyanurates with increased thermal stability, flame resistance, tensile strength, modulus, and glass transition. Impact was lower. Soy‐based polyisocyanurates displayed better thermal stability, higher rigidity (modulus), and higher strength than those based on the propylene oxide polyols of the same molecular weight and functionality. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3333–3337, 2003 相似文献
993.
994.
Juliana Nanclares Zoran S. Petrović Ivan Javni Mihail Ionescu Franklin Jaramillo 《应用聚合物科学杂志》2015,132(36)
Novel segmented polyurethane elastomers were successfully synthesized by a nonisocyanate route using dicyclic carbonates as precursors for both soft and hard segments. The hard segment was prepared from the dicyclic carbonate of bisphenol A and m‐xylylenediamine as chain extender. The soft segment was poly(tetramethylene ether) glycol of molecular weight 1000. Three polyurethanes with different morphologies were made with soft segment concentration of 70, 50, and 30%. Method of synthesis consisted in preparation of dicyclic carbonate of bisphenol A from a commercial epoxy resin and carbon dioxide, while dicyclic carbonate of poly(tetramethylene ether) glycol (PTMEG) was made from previously prepared diglycidyl ether of PTMEG and carbon dioxide. Polymers were prepared by reacting dicyclic carbonates with m‐xylylenediamine by one‐pot process. The monomers and polymers were characterized by Fourier transform infrared spectroscopy, differential scanning chromatography, thermogravimetric analysis, 1H NMR, 13C NMR, scanning electron microscopy, and mechanical measurements. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42492. 相似文献
995.
Nowadays, the airline industry and worldwide companies in the aerospace industry have been forced to find new ecological alternatives to traditional fuels to substitute as aviation fuels and kerosene. In aero turbo engines, rubber seals based on nitrile–butadiene rubber (NBR) with different contents of acrylonitrile are the most commonly used for the production of seals. This NBR is characterized by excellent physical and mechanical properties. In this article, we present the effects of critical operating conditions and the addition of the methyl ester of rapeseed oil to aviation fuel in relation to seals for aircraft engines. In this study, we evaluated changes in the physical and mechanical properties of rubber blends that were produced from NBR rubber. The exact composition and material properties were obtained from the producer. Static immersion tests in B10 (10% biodiesel in diesel), B50 (50% biodiesel in diesel), B75 (75% biodiesel in diesel), and B100 (100% biodiesel) were carried out at a higher temperature (100°C) for 500 h and at laboratory temperature (23 ± 2°C) for 3000 h. At the end of the immersion test, the degradation behavior was investigated by the measurement of the relative changes in the weight, hardness, tensile strength, and elongation. The change in the rubber surface morphology was studied by optimal microscopy and with a digital camera. The results show that the extent of rubber blend degradation was observed for samples that were exposed to a higher concentration of biodiesel and to a higher temperature. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42254. 相似文献
996.
997.
The aim of this work was to investigate the leaching of chalcopyrite concentrate in hydrochloric acid with hydrogen peroxide as a strong oxidizing agent. The effects of the leaching variables on metal extraction, such as stirring speed, solid-to-liquid ratio, temperature and HCl and H2O2 concentrations, were studied. The maximum final copper extraction of 33% was attained with 3.0 mol/L H2O2 in 0.5 mol/L HCl at room temperature after 180 min of the reaction. The results showed that the copper extraction was increased in the first 60 min of reaction, after which it essentially ceased due to the fast catalytic decomposition of hydrogen peroxide. Further, solid-to-liquid ratio affected the copper extraction significantly and the highest copper extraction was obtained in the most dilute suspension (i.e., S/L ratio of 1:100). The dissolution process was described by the first order kinetics equation. The apparent activation energy of 19.6 kJ/mol suggested that the dissolution process was under diffusion control. The reaction orders for HCl and H2O2 were established to be 0.30 and 0.53, respectively. The results of the XRD and SEM/EDS analysis of the leaching residue indicated the generation of the elemental sulphur on mineral surfaces which tended to inhibit the leaching rate. 相似文献
998.
999.
Blends of two biocompatible polymers: thermoplastic polyester‐urethane (TPU) and polylactic acid (PLA) were studied. The effect of the blending ratio on blend morphology and properties was examined by running a series of blends from 10 to 80 wt % of PLA. Increasing TPU concentration in the blends lowered the glass transition and melting point of PLA indicating that the components were compatible and partially miscible. The blends with 10–40 wt % PLA are hard, reinforced elastomers, while those with 60–80 wt % PLA are tough plastics. Cocontinuous morphology was suggested in samples with 40 and 50 wt % PLA. Inversion points between 30 and 40 wt % PLA (from globular phase is dispersed in the matrix to a cocontinuous morphology) and between 50 and 60 wt % PLA (a transition from cocontinuous to TPU dispersed in the PLA matrix) were observed. Elastomers with higher PLA content and intermediate morphology displayed a combination of high tensile strength, hardness, relatively high elongation and modulus. New materials have potential applications in the medical field. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41104. 相似文献
1000.
Stefano Gottardi Kathrin Müller Juan Carlos Moreno‐Lpez Handan Yildirim Ute Meinhardt Milan Kivala Abdelkader Kara Meike Sthr 《Advanced Materials Interfaces》2014,1(1)
The self‐assembly of cyano‐substituted triarylamine derivatives on Au(111) is studied with scanning tunneling microscopy and density functional theory calculations. Two different phases, each stabilized by at least two different cyano bonding motifs are observed. In the first phase, each molecule is involved in dipolar coupling and hydrogen bonding, while in the second phase, dipolar coupling, hydrogen bonding and metal‐ligand interactions are present. Interestingly, the metal–ligand bond is already observed for deposition of the molecules with the sample kept at room temperature leaving the herringbone reconstruction unaffected. It is proposed that for establishing this bond, the Au atoms are slightly displaced out of the surface to bind to the cyano ligands. Despite the intact herringbone reconstruction, the Au substrate is found to considerably interact with the cyano ligands affecting the conformation and adsorption geometry, as well as leading to correlation effects on the molecular orientation. 相似文献