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81.
G. V. Prosser 《Instructional Science》1978,7(4):359-383
Both active questions i.e. questions asked by subjects, and provided (or passive) questions i.e. offered to subjects as problems for solution, had been found to facilitate learning and retention of prose material when subjects were faced with a task of sufficient difficulty to challenge their competence. With difficult prose, boys and low ability subjects had gained most from active questions. These effects were more pronounced in the long term. In this study, the effects of relevant active questions i.e. questions which subjects can put alongside answers, are investigated and compared with those of active and provided questions, over a series of six presentations for both the short and the long term (i.e. after ten months). In the short term, although active questions give greater help than provided questions on the first presentation, and relevant active questions give the greatest improvement between the first and second presentations, provided questions are the most helpful overall. In the long term, however, both the active questions treatments prove to be as effective as provided questions. For low ability boys, the difference between treatments is negligble even in the short term; under the relevant active questions treatment the number of questions asked is greater; and the decline in inspection time over presentations is negligible.This study formed part of a Schools' Council Research project (Director: Dr. W. P. Robinson) in the Department of Psychology, University of Southampton. 相似文献
82.
83.
V.K. Zworykin 《Journal of The Franklin Institute》1934,217(1):1-37
This paper gives an outline of a new television system developed in the laboratories of RCA Victor Company, in Camden, N. J.The system is truly electrical and employs only electronic devices, without a single mechanically moving part.The translation of the visual image is accomplished by means of a vacuum tube called the iconoscope. This tube is a virtual electric eye and consists of a photo-sensitive mosaic corresponding to the retina of the human eye, and a moving electron beam representing the nerve of the eye. The image is projected optically on the mosaic and transformed within the tube into a train of electrical impulses, representing the illumination of individual points of the image.The reproduction of the image is accomplished by means of another vacuum tube, the kinescope, which transforms the electrical impulses back into the variation of light intensity through the bombardment of a fluorescent screen by the moving electron beam.The movement of the electron beams in both tubes, which is responsible for both transformations, is linear and divides the picture into a series of parallel lines. The movements are synchronized so that the instantaneous position of the beams with respect to a point in the picture is always identical. The synchronization is transmitted together with the picture signals, and operation of the receiver is completely automatic.The sensitivity of the iconoscope, at the present time, is approximately equal to that of a photographic film operating at the speed of a motion picture camera, permitting the transmission of outdoor scenes. The resolution is high, much higher than necessary for television images of the highest quality.The paper describes the theory of the system, its characteristics, mode of operation, and includes photographs of images obtained on the fluorescent screen of the receiver. 相似文献
84.
Anurag Srivastava L. D. Joshi S. P. Singh 《Indian journal of clinical biochemistry : IJCB》1989,4(1):50-57
Normal and alloxan induced diabetic guinea pigs were kept on whole seed diet of green gram for 4 weeks. Serum total lipids
were found to be significantly decreased in both normal and diabetic guinea pigs (P <0.001)—Both free and esterified fractions
of cholesterol were found to be lowered significantly in diabetic animals (P<0.05; <0.01, respectively), whereas only esterified
fraction was reduced significantly in case of normals (P<0.05). Significant lowering of triglyceride levels (P<0.01) was also
noticed in both normal as well as diabetic guinea pigs while phospholipids remained almost unaffected. Green gram feeding
decreased the total cholesterol / phospholipid ratio from 0.630 to 0.625 in normal and from 1.039 to 0.850 in diabetic guinea
pigs indicating its antiatherogenic nature. 相似文献
85.
H.C. Reddy C.P. Reddy M.N.S. Swamy V. Ramachandran 《Journal of The Franklin Institute》1982,313(4):197-206
In this paper a method for the realization of RC transfer immittance functions with an unsymmetrical lattice is presented. The method yields minimal capacitor realizations for Z12(s) with no pole at s = 0 and ?y12(s) having no pole at s = ∞. The number of resistors needed are only two more than the minimum needed. 相似文献
86.
87.
The difficulties in solving Fredholm integral equations of the first kind are well known. A classical method has been to convert the equation into a set of m linear algebraic equations in n unknowns (m?n). For computational convenience, it is customary to force m = n and solve the resulting ill-conditioned system using one technique or other. In the general case, a feasible solution, if it exists, can be found by determining the generalized inverse of the coefficient matrix. One method of finding the generalized inverse is to reformulate the problem and observe the steady state response of a system of ordinary differential equations with prescribed initial conditions. Results obtained from this reformulation are found to be comparable in quality to those obtained earlier by other methods. Analog and digital computer implementations are discussed. 相似文献
88.
A. Bhise P. V. Krishnan R. Aggarwal M. Gaiha J. Bhattacharjee 《Indian journal of clinical biochemistry : IJCB》2005,20(2):4-9
The present study comprised 100 patients of essential hypertension who were screened for fasting hyperinsulinemia, which was
detected in 77% cases. Twenty such hyperinsulinemic cases were subjected to 4 weeks of dietary control phase followed by 6
weeks of omega-3 fatty acids substitution [either 0.6 g/d (group 1) or 1.2 g/d (group 2)]. The mean basal fasting plasma insulin
levels were significantly higher (p<0.001) in patients of hypertension when compared to normal controls (126.51±80.36 and
19.35±12.61 μU/ml respectively). At the end of 4 weeks of diet control only, no significant change was observed in any parameter.
After substitution of omega-3 fatty acid, a significant reduction of fasting plasma insulin levels in both group 1 (29%) and
group 2 (22.8%) was observed (p<0.001). Significant reduction of systolic and diastolic blood pressure (16.4% and 25% respectively),
serum cholesterol, triglycerides and low density lipoprotein was also noted in both groups (p<0.001), while high density lipoprotein
increased by ∼8 mg% in both groups. Thus omega-3 fatty acid substituion in low dose along-with curtailment of dietary omega-6
fatty acid may be used as an adjunctive measure in the management of essential hypertension. 相似文献
89.
J Heyrovsky’s invention of polarography in which a dropping mercury electrode is used in the electrochemical cell revolutionised
electroanalysis, study of electrode kinetics and adsorption studies on mercury electrodes. Polarography has also directly
contributed to the development of new and innovative ideas in electrochemical techniques, instrumentation and applications 相似文献
90.
M. V. Stegaeva 《Scientific and Technical Information Processing》2016,43(1):28-35
This paper considers the history of the emergence and development of cooperative cataloging in Russia and abroad and presents the first projects and programs in the field of cooperative cataloging: CONSER, NACO, BIBCO, and PCC. It elucidates the activity of the OCLC Center and Consortium of European Scientific Libraries, which are the first-rate international cooperative associations, as well as the ARBIKON Association and LIBNET centers which are Russian centers of cooperative cataloging. 相似文献