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101.
Using a random sample of 389 grade 11 science students, the factor structure of the Longeot test (a measure of logical thinking) is investigated and some psychometric properties of the test items are determined. Varimax rotation on six principal component factors resulted in a simple structure. An attempt is made to interpret the obtained orthogonal factors. Implications of the findings on the “unity hypothesis” of the Piagetian construct of logical thinking and, consequently, on grade 11 science education are discussed.  相似文献   
102.
This paper seeks to explain why an acquiring organization was unable to leverage the expertise of the acquired organization even though both organizations were highly successful in their own right prior to the acquisition. It offers a knowledge-based perspective by teasing out the essential knowledge attributes pertinent to acquisitions. The research was carried out using an interpretative case study methodology at a Singapore-based multinational organization in the semi-conductor industry. The main data collection method used was face-to-face interviews with some 28 staff from October 2006 to December 2006, almost 2 years after the acquisition exercise. The findings suggest that the lackluster outcome could be traced to three knowledge attributes, namely, accessibility, applicability and cumulativeness. In conclusion, a number of practical and research implications are highlighted.  相似文献   
103.
中国委陵菜属植物研究   总被引:2,自引:0,他引:2  
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With the growing interest in the concept of free radicals in the pathogenesis of myocardial ischemia, it was thought worthwhile to study the changes in lipid peroxides and antioxidant enzyme glutathione peroxidase (GPx) in ischemic heart disease (IHD). The study was carried out on 76 patients of IHD-38 of acute myocardial infarction (AMI) and 38 of stable ischemic heart disease (SIDH). They were age and sex matched with 38 normal healthy controls. A significant increase (p<0.001) in lipid peroxides as malondialdehyde (MDA) (5.9±0.7 mmol/L) and a decrease in GPx (24.6±2.2 U/gmHb) was found in patients of AMI when compared with controls. There was no significant difference in these values in SIHD. Thus this study confirms the earlier findings that MDA and GPx are useful parameters in IHD and their magnitude is dependent on severity and/or duration of ischemia. We suggest that these tests would be of use in smaller institutions with limited facilities.  相似文献   
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Abstract

The purpose of this study was to determine the minimum and maximum velocity of the tennis ball for selected heights of contact and angles of projection and wall impact points during the tennis serve. By use of a ballistics formula, a number of variables which determine the trajectory of the tennis ball were programed for the computer. Tables were tabulated and are available for all data gathered. Angles of projection from the horizontal were selected to range from ?5° to 15° in increments of 1°. Velocity of the serve ranged from a low of 30 ft. per second to a high of 176 ft. per second. Finally, the height of the contact point ranged from a low of 6.0 ft. to a high of 9.0 ft. in increments of .5 ft. Height of the ball when crossing the net (impact point on the practice court) ranged from a low of 3.01 ft. to a high of 8.47 ft. The minimum height at crossing was achieved at 6.5 ft. service height, a ?3° angle of projection and time from baseline of .30 sec. This is a relatively high velocity serve. In contrast, the maximum height over the net of 8.47 ft. was achieved at an 8.5 ft. service height, a 15° angle of projection, and time of .79 sec. to point of impact. These data indicate that at higher service heights and slower velocities, a ball can hit the impact area as much as 8.47 ft. from the floor, 4.47 ft. above the net and still remain in the service court.  相似文献   
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Exact solutions, based on couple-stresses plane strain theory of elasticity, are presented for the normal, shear and couple-stresses, displacements and rotations of an infinite-length (in z-axis) rectangular thin plate simply supported at two opposite edges (i.e.xL) and bent by a uniform load. Exact solutions reduce to classical values as l→0. Here l is defined as the new elastic material constant taking account of couple stresses.  相似文献   
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