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41.
Cubature formulae of degree 11 with minimal numbers of knots for the integral $$\int\limits_{ - 1}^1 { \int\limits_{ - 1}^1 {(1 - x^2 )^\alpha } } (1 - y^2 )^\alpha f(x,y) dxdy \alpha > - 1$$ which are invariant under rotation over an angle π/2 are determined by a system of 18 nonlinear equations in 18 unknowns. We start with a known solution for this system for α=0. By varying α smoothly, the knots and weights of the cubature formula vary smoothly except in the singular solutions such as turning points and bifurcation points where new solutions branches arise. We use for this purpose the program AUTO. We obtain surprisingly many branches of cubature formulae. 相似文献
42.
Contends that Freud discovered transference in connection with material derived from his treatment of Emma Eckstein. The last chapter of Studies on Hysteria by J. Breuer and S. Freud (1895) in which Freud's 1st published use of the term transference occurs, can be read as a working through of the crisis that occurred when Eckstein nearly died. This concept, it is argued, explained Freud's patient's disturbed feelings toward him as a "false connection" and thereby helped to free him of feelings of personal involvement in her libidinal demands. The story of the troubled circumstances under which Freud discovered transference provides insight into the defensive nature of the concept. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
43.
Dana G. Miloaga Hazel‐Ann A. Hosein Manjusri Misra Lawrence T. Drzal 《应用聚合物科学杂志》2007,106(4):2548-2558
Poly(3‐hydroxybutyrate) (PHB) has been shown to be efficiently nucleated by exfoliated graphite nanoplatelets (xGnP). The nucleating effect of xGnP was investigated using differential scanning calorimetry, optical microscopy and atomic force microscopy. Nonisothermal crystallization of PHB from the melt required lower activation energies for PHB containing 1 wt % and 3 wt % xGnP (?214 and ?102 kJ/mol respectively) than for pure PHB (?60 kJ/mol). A kinetic study of the PHB/xGnP crystallization employing a modified form of the Avrami equation revealed that the presence of xGnP increased the PHB crystallization temperature, as well as the crystallization rates, and generated smaller and more numerous spherulites. Optical microscopy and atomic force microscopy confirmed the incorporation of xGnP into the lamellar structure of the PHB spherulites and provided insight into the influence of xGnP on spherulite size and lamellae thickness. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 相似文献
44.
Allard A. Cossé Julie L. Todd Jocelyn G. Millar Lee Ann Martínez Thomas C. Baker 《Journal of chemical ecology》1995,21(11):1823-1836
We have identified five compounds from the headspace of calling male Mediterranean fruit flies (medfly),Ceratitis capitata (Wiedemann), and three compounds from the headspace of ripe mango (Mangifera indica L). using coupled gas chromatographic-electroantennographic (GC-EAG) recordings, coupled gas chromatographic-mass spectrometric (GC-MS) analysis, and electroantennographic (EAG) assays of standards. The male-produced volatiles eliciting responses from female antennae were ethyl-(E)-3-octenoate, geranyl acetate, (E,E)--farnesene, linalool, and indole. An EAG dose-response test of linalool enantiomers and indole with female medfly antennae showed relatively strong EAG activities, but no significant difference between (R)-(-)-linalool and (S)-(+)-linalool. The three mango volatiles were identified as (1S)-(-)--pinene, ethyl octanoate, and-caryophyllene. In addition, a strong antennal response was recorded from a contaminant,-copaene, present in a commercial sample of-caryophyllene. The EAG response amplitudes from both male and female antennae to the above three mango volatiles were significantly greater than to a hexanol control. For both male and female medfly antennae, the greatest EAG responses were elicited by-caryophyllene followed by ethyl octanoate. The mean EAG responses of female antennae to-caryophyllene and (1S)-(-)--pinene were significantly greater than those of male antennae. 相似文献
45.
The reactions of a variety of activated vinyl compounds with cotton cellulose fabric containing quaternary ammonium hydroxide substituents were explored. Each reaction, catalyzed by the basic groups in the cellulose, was followed to or near the point of leveling off. The results are analyzed and discussed in terms of accessibility of the cellulosic compositions and in terms of the efficiency of the quaternary ammonium substituents as catalysts for the addition reactions. Estimates of relative forward rate constants (kf) and equilibrium constants (K) for the reactions were made. The values of kf for reactions of the vinyl compounds with the quaternary ammonium celluloses show a relative order which is similar to that for the reactions of the vinyl compounds with simple alcohols. Evidence is presented to indicate that, in some cases, the addition of vinyl compounds is accompanied by anionic-catalyzed graft polymerization. 相似文献
46.
In drug delivery systems that use silicone elastomers as a diffusion matrix for the active drug, it is common to crosslink the material by the hydrosilylation reaction. In this platinum‐catalyzed reaction, vinyl groups on a polymer add to the methyl siloxane hydride (MHS) groups on a low molecular mass crosslinker. With an excess of crosslinker, a fast curing is achieved and a fully crosslinked material is formed. Unreacted MHS groups were shown to remain in the elastomer after curing because of the excess crosslinker. In this work, a simple procedure was developed to eliminate the unreacted MHS groups from the final product. We found that storage of the product at +40°C and 75% relative humidity for a few weeks will effectively destroy the residual MHS groups in the elastomer. The effects of varying levels of humidity, oxygen, and temperature on this postcuring procedure were studied. The amount of MHS groups was measured with NMR and IR spectroscopy. We also found that the hardness of the material increased by approximately 25% as a consequence of this postcuring treatment. This increase is probably due to a secondary crosslinking reaction between MHS and silanol groups. Heat treatment at higher temperatures led to an even further increase in the hardness and compression modulus. Because no MHS groups remained in the elastomer when this heat treatment was started, it is apparent that another secondary crosslinking reaction is occurring, probably silanol condensation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2254–2264, 2002 相似文献
47.
AbstractThis article introduces a case study undertaken in the indigenous Penan community of Long Lamai, Upper Baram, Sarawak, Malaysia. In this community, there is concern about the negative image other cultural groups hold of the Penan. This case study explores co-design as a means to invite community members, together with a designer, to explore the identity that they would like to present to people outside the community. In preparing for an exhibition to challenge perceptions, it turned out to be important to embrace the culture of the community to facilitate self-expression, introducing new concepts such as technological interventions and design probes to stimulate reflection and creativity. However, it was indigenous material culture, when actively and encouragingly supported by the designer, that had a key role in developing the co-design and, with it, empathic understanding between designer and community. 相似文献
48.
Priyadarshini R. Pennathur Ann M. Bisantz Rollin J. Fairbanks Colin G. Drury Li Lin 《Cognition, Technology & Work》2014,16(4):565-584
A hospital emergency department (ED) is a complex cognitive work system. ED providers routinely create, process and share various kinds of information in their work. They may constantly transform information using technological artifacts such as an electronic patient information system. The functionality in the technology, however, limits their tasks and activities. So, they create their own artifacts (such as handwritten notes on a post-it note), to share and process information. The goal of the paper is to illustrate how health providers in EDs create, process, transform and share information to achieve work goals. We present the information trail model in the ED to illustrate various facets of information creation activity and generate insights for health information technology design. 相似文献
49.
Gudrún V. Skúladóttir Du Shi-Hua Ann E. Brodie Donald J. Reed Rosemary C. Wander 《Lipids》1994,29(5):351-357
Weanling male Sprague-Dawley rats were fed diets for four weeks which differed in their content of n−6 (corn oil; CO) and
n−3 fatty acids (fish oil; FO), but were similar in their content of saturated and monounsaturated fatty acids and vitamin
E. At the end of the four-week feeding period, each dietary group was subdivided into two groups. One group received a single
placebo injection of α-tocopherol-stripped corn oil (TSCO); the other group received a single injection of the free radical
generator, methyl ethyl ketone peroxide (MEKP), in TSCO. Twenty-four hours after injection, the effect of dietary oil and
MEKP treatment on endogenous lipid peroxide (LPO) production (measured as methylene blue formed by the “Determiner LPO” assay),
glutathione (GSH) and vitamin E content, and fatty acid composition of phosphatidylcholine and phosphatidylethanolamine in
heart and liver from unfasted animals were measured. FO-fed rats had significantly heavier hearts and livers, increased levels
of n−3 fatty acids in membrane phospholipids, and higher liver LPO levels than CO-fed rats. MEKP treatment resulted in significantly
lower body weights and liver GSH levels. The data indicate that dietary n−3 fatty acids increase lipid peroxidation in liver
somewhat more than in heart. The study also demonstrates that the effect of induced oxidative stress due to a single dose
of MEKP on lipid peroxide formation and antioxidant status in tissues from unfasted animals was independent of the dietary
oils. 相似文献
50.
Robin A. Henderson Robert G. Jensen Carol J. Lammi-Keefe Ann M. Ferris Kenneth R. Dardick 《Lipids》1992,27(11):863-869
To examine the effect of fish oil supplementation on the fatty acid (FA) composition of human milk and maternal and infant
erythrocytes, five lactating women were supplemented with 6 g of fish oil daily for 21d. Usual maternal diets contained 1,147
mg of total n−3 FA, with 120 mg from very long-chain (>C18) n−3 FA. Supplementation increased dietary levels to 3,092 mg of total n−3 FA and 2,006 mg of very long-chain n−3 FA. Milk
samples were collected daily, prior to fish oil ingestion, and at 4-h intervals on days 1, 7, 14 and 21. Milk n−3 FA content
increased within 8 h and reached steady state levels within one week. The n−6 fatty acid content decreased. Erythrocyte eicosapentaenoic
acid content increased from 0.24% to 1.4% (P<0.01) in mothers and from 0.11% to 0.70% (P<0.05) in infants. Docosapentaenoic acid increased from 1.4% to 2.2% (P<0.05) in mothers and from 0.30% to 0.78% (P<0.01) in infants. There was no significant change in docosahexaenoic acid or n−6 fatty acid content. Maternal platelet aggregation
responses were variable. No differences in milk or plasma tocopherol levels were noted.
Based on a paper presented at the Symposium on Milk Lipids held at the AOCS Annual Meeting, Baltimore, MD, April 1990. 相似文献