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排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
G. A. Baranov A. A. Belyaev A. V. Zemlyanoĭ S. B. Onikienko S. A. Smirnov V. V. Khukharev 《Technical Physics》2007,52(7):927-933
A cavitation flow in an expanding nozzle is numerically simulated. The cavitation activation of cells is studied experimentally. 相似文献
992.
J. M. Criado L. A. Pérez-Maqueda M. J. Diánez P. E. Sánchez-Jiménez 《Journal of Thermal Analysis and Calorimetry》2007,87(1):297-300
The SCTA method implies to control the temperature in such a way that
the reaction rate changes with the time according to a function previously
defined by the user. Constant Rate Thermal Analysis (CRTA) is one of the most
commonly used SCTA methods and implies achieving a temperature profile at
which the reaction rate remains constant all over the process at a value previously
selected by the user. This method permits to minimize the influence of heat
and mass transfer phenomena on the forward reaction. The scope of this work
is to develop a universal CRTA temperature controller that could be adapted
to any thermoanalytical device. The thermoanalytical signal is programmed
to follow a preset linear trend by means of a conventional controller that
at the time controls a second conventional temperature programmer that forces
the temperature to change for achieving the trend programmed for the thermoanalytical
signal. Examples of the performance of this control system with a Thermobalance
and a Thermomechanical Analyser (TMA) are given. 相似文献
993.
994.
A group of machines for processing a set of jobs in a manufacturing system is often located in a serial line. An efficient strategy for locating these machines such that the total travel distance or the cost of transporting the jobs is minimized is desired. In this research, the assumption of a linear line with equally spaced machine location is relaxed. This research addressed problems of locating unique machines. It is found that the machine distances possess unique properties in this type of a problem. Utilizing these properties, heuristic strategies are proposed to obtain efficient solution where optimal methods are expected to be computationally prohibitive. A lower bound for the optimum solution is also proposed. Results are encouraging. 相似文献
995.
J M Squirrell R D Schramm A M Paprocki D L Wokosin B D Bavister 《Microscopy and microanalysis》2003,9(3):190-201
We employed multiphoton laser scanning microscopy (MPLSM) to image changes in mitochondrial distribution in living rhesus monkey embryos. This method of imaging does not impair development; thus, the same specimen can be visualized multiple times at various developmental stages. Not only does this increase the amount of information that can be gathered on a single specimen but it permits the correlation of early events with subsequent development in the same specimen. Here we demonstrate the utility of MPLSM for determining changes in mitochondrial organization at various developmental stages and show that rhesus zygotes possess a distinct accumulation of mitochondria between the pronuclei prior to syngamy. We present evidence that suggests that this pronuclear accumulation may be positively correlated with development to the blastocyst stage-in the same embryo-thereby illustrating how MPLSM can be used to correlate cellular dynamics of primate oocytes and early embryos with their developmental potential. Understanding the relationship between mitochondrial distribution and the subsequent development of mammalian embryos, particularly primates, will increase our ability to improve embryo culture technologies, including those used for human assisted reproduction. 相似文献
996.
B. Velázquez-Martí C. Gracia-López 《International Journal of Infrared and Millimeter Waves》2004,25(7):1109-1122
The thermal treatment by millimeter waves for the soil disinfection can be one possible alternative to chemical treatments. This physical method is based on incrementing the soil temperature and its pathogens irradiating with high frequency electromagnetic waves. So the previous knowledge of the temperature distribution in the irradiated soil is essential for achieving an effective bad microorganism and weed seeds elimination. This report analyse the heating kinetic and spatial distribution of the maximum temperatures reached by the soil. It is presented a mathematic model about how are distributed the reached temperatures in the depth of the irradiated soil. This model concludes that when an orchard soil is irradiated superficially by microwaves, the microwaves have a big attenuation due to the soil dielectric properties and the water located in the pores of the most superficial layer. This fact causes a shield effect blocking the waves penetration in few centimetres. The heating by radiation is reduced to the superficial layer. The heating propagation in the depth is occurred by conduction following the Fourier equations. 相似文献
997.
998.
Kjeld B. Laursen Michael M. Neumann 《Rendiconti del Circolo Matematico di Palermo》1991,40(3):325-341
We extend the automatic continuity theory for linear operators θ:X→Y which intertwine two given bounded linear operatorsT∈L
X andS∈L
Y on Banach spacesX andY, respectively. This is done both by relaxing the intertwining conditionSθ=θT and by enlarging the classes of operatorsT, resp.S, well beyond the decomposable operators. Among the operatorsS captured by these extensions are multipliers on commutative semi-simple Banach algebras.
dedicated to George Maltese on his 60th birthday 相似文献
999.
G. Bouwmans B. Ségard P. Glorieux P. A. Khandokhin N. D. Milovsky E. Yu. Shirokov 《Radiophysics and Quantum Electronics》2004,47(10-11):729-742
This paper is devoted to the polarization dynamics of a longitudinally monomode bipolarized Nd:YAG laser: the low-frequency polarization dynamics of a microchip laser is studied experimentally and theoretically. The intensities and the relaxation oscillation spectrum of orthogonally polarized modes versus the direction of pump polarization is observed. A phase-sensitive model of a longitudinally monomode bipolarized solid-state laser with linear polarized diode laser pump is developed to account for the experimental observations. 相似文献
1000.
For an innovative product characterized by short product lifecycle and high demand uncertainty, investment in capacity buildup has to be done cautiously. Otherwise either the product’s market diffusion is impeded or the manufacturer is left with unutilized capacity. Using the right information for making capacity augmentation decisions is critical in facing this challenge. In this paper, we propose a method for identifying critical information flows using the system dynamics model of a two-echelon supply chain. The fundamental premise of system dynamics methodology is that (system) structure determines (its) behavior. Using loop dominance analysis method we study the feedback loop structure of the supply chain system. The outcome is a set of dominant loops that determine the dynamics of capacity growth. It is revealed that the delivery delay information has little effect while the loop that connects retail sales with production order affects the dynamics significantly. Modifying this loop yields appropriate capacity augmentation decisions resulting in higher performance. What-if analyses bring out effects of modifying other structural elements. In conclusion, we claim that the information feedback based methodology is general enough to be useful in designing decision support systems for capacity augmentation. The limitations of the model are also discussed and possible extensions identified. 相似文献