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91.
Summary Aluminum alkoxides carrying functional alkoxy groups are effective initiators for the-caprolactone polymerization in toluene and tetrahydrofuran. The coordination-insertion type of polymerization is living and yields exclusively linear polyesters of a predictable molecular weight with a narrow molecular weight distribution within the period of time required for the total monomer conversion. The functional group associated to the active alkoxy group of the initiator is selectively attached to one chain-end, and the second end-group is systematically a hydroxyl function resulting from the hydrolysis of the living growing site. Asymmetric telechelic polyesters are thus obtained in a perfectly controlled way, including macromonomers. Beside (meth)acrylic double bond, the functional end-group derived from the initiator can be, for instance, an unsaturation, a halogen and a tert-amine. Coupling the asymmetric telechelic polymer via the OH end-group (or the precursor Al alkoxide end-group) is a direct way to the related symmetric telechelic of a twofold increased molecular weight.The authors are indebted to IRSIA for a fellowship to one of them (Ph. Dubois) and to the Services de la Programmation de la Politique Scientifique for financial support. NMR spectra were recorded at the CREMAN facility of the University of Liège which has been funded by a grant from the Fonds National de la Recherche Scientifique. The helpful assistance of Dr. Warin has been very much appreciated. They are very greatful to G. Broze (Colgate Palmolive) who initiated this research. 相似文献
92.
93.
Presents a brief history of the development of the Lamaze childbirth preparation training regimen and critically examines the few empirical studies that have been conducted. Because explanations for the efficacy of the preparation, if it exists, are equivocable, literature on the explicit components of the training (e.g., respiration techniques, conditioned relaxation, cognitive restructuring) in situations other than child delivery are reviewed and their implications for the Lamaze method discussed. However, because there exist several, more implicit factors that may affect the type of child delivery a prepared woman experiences, the literature concerning social comparison, the effects of commitment and conformity, perceived control, and endorphin secretion are also discussed as they may apply to psychoprophylactic preparation. (113 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
94.
Various aspects of the benthos and fish populations living within a kraft pulp mill effluent channel were monitored from June, 1974 to September, 1975. Chironomid larvae dominated the benthos, and were distributed within the channel in relation to bottom type and current characteristics. Yearly abundance of chironomid larvae was correlated with measured flow through the channel.A total of 25 species of fish were taken from the channel. Many of these were collected seasonally and did not appear to be permanent residents of the channel. Food habits for warmouth, Lepomis gulosus, revealed chironomid larvae and mosquitofish, Gambusia affinis to be major food items, occurring in 50 and 40% of the stomachs respectively. A gradual feeding shift from chironomid larvae to mosquitofish and coleopterans occurred as warmouth increased in length. Mosquitofish appeared to be utilized more heavily in the winter months. White catfish, Ictalurus catus, and brown bullhead, Ictalurus nebulosus, had similar feeding habits, with chironomid larvae occurring in 96 and 95% of stomachs respectively. All fish examined for food habits utilized other aquatic insects to a greater extent in the summer, as they became more abundant with vegetational increases in the channel. The growth of warmouth and white catfish in the channel appears to equal or possibly surpass some natural waters. 相似文献
95.
The pull tension and sidewall bearing pressure experienced by cables during installation determine the lengths of cable installed and splices needed, if any, and influence the cost of installation. For the first time, personal computer software exists which not only estimates these forces, but enhances confidence in the results by showing the user his raceway on the CRT in any of the four (4) standard views. Typically, the installer /estimator uses the estimated forces to determine what kind of pull he can expect - easy or hard - and to consequently exercise any options he may have in the design/bid/installation of the system. He can then quickly input alternate raceways or cable changes, and rerun the program. Twenty-five (25) help screens and ten (10) data libraries aid the user. 相似文献
96.
Considers that the progressive selection of a distinctive pattern of immaturity in primate evolution has enabled the more flexible adaptation of the human species. The most distinctive feature of that adaptation is culture-using: changing the amplifiers and transformers for man's sense organs, muscles, and reckoning posers, and changing the properties of his habitat. Characteristics of the maturing process in the human species include (a) evolution of educability and existence of fixed limits for the primate young; (b) emergence of a more flexible form of social bonding among primates accompanied by new capacity for observational learning; (c) interaction between, and effects of, the function of play and learning to use tools; and (d) instructional interaction between adults and young, especially in the symbolic meaning of language. Man's natural mode of adapting should be used to render change as intelligent and stable as possible. (103 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
97.
This article discusses the move of the American Psychological Association headquarters to Twelve Hundred Seventeenth Street. It also announces that on Saturday, October 16,1965, the headquarters building will be dedicated by Dr. Donald F. Hornig, Special Assistant to the President for Science and Technology. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
98.
Truax Charles B.; Wargo Donald G.; Frank Jerome D.; Imber Stanley D.; Battle Carolyn C.; Hoehn-Saric Rudolf; Nash Earl H.; Stone Anthony R. 《Canadian Metallurgical Quarterly》1966,30(5):395
A study aimed at cross-validating previous research suggesting that the levels of the therapist's accurate empathy, nonpossessive warmth, and genuineness were causally related to the degree of patient improvement or deterioration. An equal number of "good" or "poor" therapy prospects were randomly assigned to 4 resident psychiatrists (10 patients each) for 4 mo. of psychotherapy. Results tended to confirm the importance of the 3 therapeutic conditions in combination and of empathy and genuineness separately. Negative findings for separate analysis of therapist's warmth were interpreted in terms of its negative correlation with empathy and genuineness in the present sample. On the overall measure for all patients, therapists providing high therapeutic conditions had 90% patient improvement while those providing lower conditions had 50% improvement. (17 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
99.
Panayiotis Papadopoulos Reese E. Jones Jerome M. Solberg 《International journal for numerical methods in engineering》1995,38(15):2603-2617
This article advocates a new methodology for the finite element solution of contact problems involving bodies that may undergo finite motions and deformations. The analysis is based on a decomposition of the two-body contact problem into two simultaneous sub-problems, and results naturally in geometrically unbiased discretization of the contacting surfaces. A proposed two-dimensional contact element is specifically designed to unconditionally allow for exact transmission of constant normal traction through interacting surfaces. 相似文献
100.
Gibson Janet M.; Brooks John O.; Friedman Leah; Yesavage Jerome A. 《Canadian Metallurgical Quarterly》1993,8(4):481
The experiments reported here investigated whether changes of typography affected priming of word stem completion performance in older and younger adults. Across all experiments, the typeface in which a word appeared at presentation either did or did not match that of its 3-letter stem at test. In Exp 1, no significant evidence of a typography effect was found when words were presented with a sentence judgment or letter judgment task. However, subsequent experiments revealed that, in both older and younger adults, only words presented with a syllable judgment task gave rise to the typography effect (Exps 2–4). Specifically, perforance was greater when the presentation and test typeface matched than when they did not. Exp 5, which used stem-cued recall, did not reveal a difference between syllable and letter judgment tasks. These findings highlight the complex nature of word stem completion performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献