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81.
Researchers explain a model of navigation that proposes that local guidance and global awareness are better supported by more, and less, egocentric displays, respectively. Greater egocentrism is created by perspective viewing, map rotation, and viewpoint positions that correspond to the axis of control. The model was tested in an experiment in which 40 pilots flew simulated landings with displays that varied the degree of egocentrism between a fully egocentric viewpoint, 3 distances of exocentric 3-dimensional viewpoints, and a 2-dimensional planar display. The results generally supported model predictions: The egocentric viewpoint supported best guidance, whereas the mid-distance exocentric viewpoint supported best global awareness. Implications of the model for the design of flight displays in particular, and navigational displays in general, are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
82.
Ginger V. Shultz Orion B. Berryman Lev N. Zakharov David R. Tyler 《Journal of Inorganic and Organometallic Polymers and Materials》2008,18(1):149-154
ADMET was evaluated as a method for preparing organometallic polymers with metal–metal bonds in the main chain. The Cp2Mo2CO4(Ph2P(CH2)6CH=CH2)2 complex was synthesized, and the X-ray crystal structure is reported. The molecule did not undergo ADMET polymerization with
Grubbs’ or Schrock’s catalysts. In a control experiment to test if the Ph2P(CH2)6CH=CH2 ligand was interfering with the ADMET reaction, the phosphine was reacted with Grubbs’ 2nd generation catalyst. The dimerized
metathesis product Ph2P(CH2)6CH=CH(CH2)6PPh2 was obtained with no observed degradation or deactivation of the catalyst. To test the inherent ADMET reactivity of the Ph2P(CH2)6CH=CH2 ligand when it is bonded to a metal center, the mononuclear cis-Mo(CO)4(Ph2P(CH2)6CH=CH2)2 complex was synthesized and polymerized using Grubbs’ 2nd generation catalyst. These control experiments suggest that the
inability of Cp2Mo2CO4(Ph2P(CH2)6CH=CH2)2 to polymerize is not due to electronic effects pertaining to the C=C unit of the Ph2P(CH2)6CH=CH2 ligand. Accordingly, steric effects are implicated in the inability of the Cp2Mo2CO4(Ph2P(CH2)6CH=CH2)2 to polymerize by ADMET. 相似文献
83.
The traditional methods used for the identification and assessment of hazards in the chemical industry are based on experience, but increased economic and environmental restrictions on its operations have required the development of other methods to ensure that an acceptable level of safety is maintained. The present paper briefly reviews the traditional methods, describes in mire detail the basis of the newer methods, namely hazard and operability studies and hazard analysis, and considers how they might be more widely used in assessing fire hazards. 相似文献
84.
BD Astill R Gingell D Guest J Hellwig JR Hodgson K Kuettler W Mellert SR Murphy RL Sielken TR Tyler 《Canadian Metallurgical Quarterly》1996,31(1):29-41
An increasing number of studies, both experimental and epidemiologic, have provided evidence that filtering glaucoma surgery may be less effective than initially described. Of a number of risk factors for failure, duration and number of antiglaucoma drugs prior to surgery seem to play a critical role and highly accumulated antiglaucoma topical treatments significantly reduce success rates. Histopathological studies have confirmed that topically applied drugs may exert toxic effects to the corneoconjunctival surface, and induce chronic infraclinical inflammation, as shown by the presence of immune and inflammatory infiltrates in multitreated eyes. The origin of topical inflammation has not yet been clearly determined, but a common component of ophthalmic drugs, the benzalkonium chloride used as preservative in almost all antiglaucoma preparations, has shown strong evidence of toxicity. A number of questions remain to be investigated, but suppression of preservatives from chronically applied drugs should be a critical issue in the near future. 相似文献
85.
Discusses articles by D. E. Polkinghorne (see record 1985-07630-001), G. S. Howard (see record 1985-07626-001), and M. J. Patton (see record 1985-07629-001), who recommended that counseling research be reoriented. The accepted definition of science, based primarily on the work of pre-20th-century physical scientists, does not fit in with the current advanced thinking about the philosophy of science. Similarities and differences in the 3 articles are considered, and problems that arise from the inadequacy of available psychometric and statistical techniques for the new kinds of research envisaged are discussed. It is concluded that the rethinking of some assumptions with regard to determinism and the way counseling is defined are necessary. (4 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
86.
The development of the competent self in adolescence, the interrelationship of psychotherapeutic and psychoeducational change, and the role of the high school counselor as a mental health gatekeeper were explored in a pre–post experimental–control design study of group counseling. 147 exemplary ("getting their lives together well and handling school well") and marginal ("having trouble getting their lives together and managing school") high school students participated. Precounseling assessments and patterns of change over the counseling period supported the 1st author's hierarchical competence configuration model of psychosocial functioning, consisting of self-attitudes, world-attitudes, and relevant behavioral attributes. Overall effectiveness of counseling was indicated at multiple levels by significant goal attainment (Kiresuk-Sherman Goal Attainment Scale) and by increased self-efficacy (Rotter's Internal–External Locus of Control Scale). The impact of counseling was significantly different for exemplary than for marginal students and for students from different race and sex subgroups. These findings confirm the interrelation of change patterns at behavioral and personality levels, the importance of sociocultural factors in individual psychosocial change patterns, and the potential therapeutic impact of relatively brief psychoeducational-psychotherapeutic interventions. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
87.
Plasmas or ionized gases, existing at temperatures as high as 50,000°C, constitute the highest controlled temperatures known. At these temperatures, reactions occur about which we have little or no knowledge. This paper explores. the various possibilities of using plasma devices for extractive metallurgy. 相似文献
88.
The performances of 1 g h?1 and 20 kg h?1 flash pyrolysers are compared for three Australian coals: Loy Yang brown coal (Victoria), Liddell bituminous coal (New South Wales), and Millmerran sub-bituminous coal (Queensland). The two reactors gave comparable yields of tar, char and C1–C3 hydrocarbon gases over a range of operating conditions for each particular coal. The yield of total volatile matter from Millmerran coal was similar from both reactors, as were the compositions of chars from Loy Yang coal and tars from the Liddell and Millmerran coals. For Millmerran coal, the yields of tar, C1–C3 gases and volatiles from the large reactor below 650 °C, were slightly lower than for the small reactor, possibly owing to a shorter retention time of Millmerran coal particles in the large-scale reactor. At a temperature near 600 °C tar yields were independent of tar concentration in the effluent gas, over a range 0.0025–0.1 kg m?3 for Liddell coal, 0.005–0.26 kg m?3 for Millmerran coal and 0.0045–0.09 kg m?3 for Loy Yang coal. The tar yields from Millmerran and Liddell coals at 600 °C in the large reactor, correlate directly with the atomic ratio of the parent coal, in the same manner as that found for a wider range of bituminous coals in the small-scale reactor. 相似文献
89.
Using a national sample of hospital discharges, we found identical seasonal patterns for spontaneous abortions and conceptions but no significant seasonal variation in the rate of spontaneous abortions per 1,000 conceptions. The differences between our findings and those of previous investigators of spontaneous abortion may reflect our more comprehensive definition of spontaneous abortion, our more complete estimate of the monthly number of conceptions, and our more rigorous statistical analysis. The periodic regression analysis (PRA) reported in our study may be useful in other studies that monitor short-term trends. 相似文献
90.
The Cartter Report and Roose-Andersen Reports (sponsored by the American Council of Education) on quality of graduate education in American universities have been used as a basis for national policy and funding judgments, and for institutional, academic discipline, and student applicant uses. It is argued that instead of serving the public purposes for which they were intended, these reports serve more directly private guild interests of the participating disciplines, particularly psychology. Reasons include the fact that psychology has become increasingly technician-oriented, and the sampling procedure used to select raters and the questions asked were biased. These issues could be better approached by defining appropriate models of excellent graduate programs, developing scales for rating the variables considered to contribute to excellence, and then assessing the validity of those measures. The consequences of present biased rating procedures are far too significant for society and students for psychologists to continue to ignore. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献