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101.
102.
多媒体课件在开放实验室中的应用 总被引:2,自引:0,他引:2
介绍了制作多媒体课件的必要性,及所制作课件的特点。该课件与实验室管理系统配合起来,有利于实现实验室的全面开放。 相似文献
103.
S. M. Fitzpatrick D. Miller I. Weatherston J. N. McNeil 《Journal of chemical ecology》1985,11(2):207-215
Levels of benzaldehyde recovered from virginPseudaletia unipuncta (Haw.) males were not influenced by (1) the time hairpencils remained in the solvent (1-72 hr), (2) anesthetization or agitation of males prior to excision of hairpencils, or (3) the time (photophase or scotophase) that hairpencils were excised. Thus the interindividual variability observed is not a methodological artifact. Most males had similar concentrations in both hairpencils, although in some cases only one hairpencil contained pheromone. In one case, a male with partially extruded hairpencils had no benzaldehyde at all. Neither pupal weight nor hairpencil length proved to be reliable indicators of pheromone content.Contribution No. 373, Département de biologie, Université Laval. 相似文献
104.
105.
106.
T. D. M. Weijers H. Timmers R. G. Elliman 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2002,190(1-4):397-401
The impact of the pulse height deficit effect in gas ionization detectors on the accurate extraction of depth information from heavy ion elastic recoil detection spectra has been investigated. Thin GaN films and GexSi1−x/Si heterostructures have been analyzed with a 200 MeV 197Au beam. Employing an empirical parameterisation of the pulse height deficit, a global energy calibration of the detector can be achieved. Energy spectra have been compared, calibrated with either a constant or a full energy-dependent compensation for the deficit. A constant compensation results in significant distortion of the extracted depth profile for heavier ions, whereas an energy-dependent compensation yields true concentration–depth profiles. 相似文献
107.
A new method for characterization of stratified thermal energy stores (TES) that integrates both the first law and the second law concerns is presented here. The first law concern is incorporated into a quantity called energy response factor and the second law concern into an entropy generation ratio. A product of these two quantities is at the heart of the TES efficiency definitions. This approach removes the overemphasis of the existing methods either on the first or the second law of thermodynamics which often biases the characterization results. The information about the evolution of the temperature field of the system in time is the prerequisite of the new method. It may be obtained from experiments or from suitable numerical simulations. The current method can be easily integrated into computational fluid dynamic (CFD) simulations and thus facilitate CFD-based design analysis. As an example of such CFD-integrated analysis, a large-scale hot water seasonal heat store is numerically studied to identify the effects of aspect ratio, containment shape, internal structures, and containment size on their efficiency. The results suggest the effectiveness of the new method in deriving useful design insights. 相似文献
108.
Johan M. Thevelein 《Yeast (Chichester, England)》1994,10(13):1753-1790
109.
提出了由一个变迹IDT叉指换能器和一个均匀IDT组成的SAW滤波器简化衍射频响的计算方法,即将均匀IDT简化成单根指计算其衍射频响。该方法与未简化衍射频响的计算方法相比,计算量大为减小,前者约为后者的(N为均匀IDT的指对数)。并给出了一个实例,用未简化与简化方法分别计算了其衍射频响,结果表明,两者符合得较好。 相似文献
110.
T.A. Wyatt 《Journal of Wind Engineering & Industrial Aerodynamics》2004,92(5):359-374
The classical spectral analysis of structural response to a gusty wind is applied to the prediction of fatigue damage as expressed by the rate of accumulation of Miner's quotient, using the rainflow algorithm to establish stress-range cycle counts. A general solution in chart form is given for the effect of the broad-band (quasi-static) part of the response spectrum, together with an algebraic formulation for its combination with the effect of narrow-band (quasi-resonant) response.A procedure for integration of the long-term expectation of Miner's quotient is indicated. It is concluded that quasi-static response alone is unlikely to pose a serious fatigue problem. With generally anticipated levels of dynamic response, fatigue damage is greatly increased, but can be controlled at acceptable levels by care to avoid features especially sensitive to fatigue. 相似文献