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991.
Flexion-extension moments acting at the L5/S1 level and hip joints were calculated using three different techniques; a pure static analysis, a static analysis including the inertial force of the load, and a dynamic analysis. Ten subjects participated in the study and were asked to lift a box weighing either 50 N or 150 N, using a freestyle technique. The lifts were performed at normal and fast speed. The intra-subject lifting techniques were consistent when lifting the same loads. The moments predicted by the dynamic analysis and the static analysis were the same when holding weights in static postures. When performing the lifts, differences in the peak moments occurred between static and dynamic analyses. These differences were influenced by external load and by lifting speed. Taking the effect of the inertia of load into account in the static analysis resulted in an increase in the moment magnitude, but the predicted moment was still much less than in the dynamic analysis which yielded the largest moment magnitudes. The difference between dynamic and static analysis was greatest when lifting 50 N at fast speed; an 87% increase in L5/S1 moment and a 95% increase in hip moment was observed when replacing the pure static with a dynamic analysis. 相似文献
992.
Memory reallocation is used to construct a run-time data structure for fast/efficient storage of information during collection and analysis. The data structure presented uses dynamic memory but does not require the use of pointers to link nodes of information together. It allows for simple and efficient access to data via array indexing rather than through the use of lists or tree structures and it provides flexibility for competing storage requirements that are determined dynamically. The data structure is developed in the C programming language and a suite of ANSI standard C subroutines that make up a run-time data structure management system is provided. 相似文献
993.
V. I. Belousov G. G. Denisov N. Yu. Peskov 《Journal of Infrared, Millimeter and Terahertz Waves》1991,12(9):1035-1043
The article presents results of theoretical and experimental investigation of quasioptical multiplexer based on reflecting diffraction grating. Diffraction losses caused by reflection into mirror harmonic, and by angle divergence of wave beams are calculated. In an experimental multiplexer, wave beams with the frequencies 70 GHz and 79 GHz were mixed with power losses less than 1%. 相似文献
994.
Institute of Geology Siberian Branch, Academy of Sciences of the USSR, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 106–109, January-February, 1992. 相似文献
995.
The temperature and bias dependence of the carrier multiplication M(I/sub bulk//I/sub drain/) in submicrometre pMOS transistors has been characterised and studied over the temperature range of 30-300 K. In addition, a model which reproduces the bias dependence of M over the measured range of temperature can be extrapolated down to 4.2 K to predict the internal bulk potential and its related 'kink effect'. The agreement between data and the prediction of the model confirms that the gate voltage and temperature dependence of the mean free path plays the key role in determining the carrier multiplication characteristics of submicrometre pMOS transistors, operating in the temperature range of 4.2-300 K.<> 相似文献
996.
997.
The dynamic interaction, through the underlying or surrounding soil, between three-dimensional structures has been investigated, by coupling finite and boundary elements. The structures are discretized by finite elements, and the infinite soil is represented by boundary elements. A harmonic force is applied on both mass-lumped structures and mass-distributed structures. On the basis of our numerical studies, we further indicate the effects of distance, direction of alignment between two foundations, bedrock, natural frequency of the system and the location of load on the dynamic responses of structure-soil-structure interaction systems. 相似文献
998.
Adherent and pin-hole free amorphous Sb2Te3 thin films have been obtained by vacuum evaporation at substrate temperatures ≤25 °C. The films have been crystallized by thermal and laser annealing, and the crystallization processes monitored as a function of annealing temperature and laser scan speed. A comparative study of topography reveals disk-shaped crystallized areas in thermal crystallization and dendrite growth in the laser induced process. The crystallized films in both cases contain a single Sb2Te3 phase. Activation energy of 2 eV for crystallization, determined using differential scanning calorimetery indicates good room temperature stability of the amorphous states. 相似文献
999.
1000.
Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 1, p. 25, January, 1992. 相似文献