This study investigated location-, movement-, and directional-selectivity of action potential discharges of hippocampal neurons in awake rats subjected to passive displacements in order to estimate vestibular contributions to this activity. Water-deprived rats were habituated to being restrained in a sling mounted on a moving robot. The extracellular activity of single complex-spike cells in area CA1 of the hippocampus was recorded with glass micropipettes in the rats during passive translations, rotations, and immobility. The robot made a standardized series of trajectories starting from each of four corners of a square enclosure surrounded by black curtains. A drop of water was delivered to the rat each time the robot arrived at one designated corner of the arena. The activities of 29 neurons were investigated in 45 recording sessions (16 of which were in total darkness) in four rats. Hippocampal neurons recorded in 31 sessions (9 sessions in the dark) had significant location-selective increases or decreases in firing rate as the rat was passively displaced or immobile within the experimental arena. In 20 sessions (6 in the dark) direction-selective discharges were found when the rat was in the corners. In six sessions, cells discharged selectively during movement initiation or termination. These data suggest that information essential for path integration is present in the hippocampus and that inertial cues could play a vital role in hippocampal spatial functions. These results resemble those of O'Mara et al. ([1994] J Neurosci 14:6511) using the same protocol in macaques, suggesting similarities in hippocampal processing and function.
В статье изложены термодинамические основы и методика уточненного расчета характеристик выделения теплоты при горении по экспериментальным индикаторным диаграммам, введен термин «располагаемая теплота». Предложено оценивать продолжительность сгорания по положению «квазиадиабатной точки» на характеристике располагаемой теплоты. Исследованы некоторые причины погрешностей в исходных данных для анализа индикаторных диаграмм, в частности, описаны неточности в определении цикловой подачи топлива и измерении текущего давления в цилиндре двигателя при регистрации индикаторной диаграммы. С целью учёта указанных погрешностей предложены и обоснованы способы корректировки указанных исходных данных. Утверждается, что использование на практике предложенной методики и соответствующей программы анализа индикаторных диаграмм обеспечивает требуемое качество результатов исследования влияния различных факторов на процесс горения топлива в дизеле и способствует высокому качеству его диагностирования.Ключевые слова: рабочий процесс дизеля, выделение теплоты при горении, характеристики тепловыделения, погрешности регистрации индикаторных диаграмм, учёт погрешностей.
The quality of the diesel engine largely depends on the consistency constructive and controllable parameters of fuel equipment and combustion chamber. The specified line is provided by this combination of parameters, which are complex processes of flow of fuel into the cylinders, distribution of the sprayed fuel jets and their interaction with the surfaces of the combustion chamber, the process heat from fuel combustion provides excellent fuel economy with acceptable environmental characteristics of the engine. The method of selecting combinations of parameters should be based on adequate description and quantification of the main processes in the engine cylinder with process heat from the combustion. To solve the problem solely according to the calculations is currently not possible. This is because, given the extreme complexity and very high processes, researchers have not yet created an adequate mathematical model. The problem solved by calculation and experiment, combining physical simulation of processes of fuel injection, the movement of the spray of fuel, their interaction with each other, with the surfaces of the combustion chamber and heat dissipation as the result of the analysis of indicator diagrams of diesel. The result of applying this method is the refinement of perception that occurs in the diesel process, in particular the temporal change of the geometrical and mass properties of fuel jets, what are the dates of deposition of fuel on the surface of the piston and the cylinder head, which factors cause changes to the shape of the fuel characteristics during combustion. The application of this methodology gives an opportunity to outline such ways of organizing processes in the cylinder, which provide high economic and environmental performance of the engine during its creation and exploitation. Keywords: working process of diesel fuel, the movement of the fuel jets, interaction of jets with the surface of the combustion chamber, heat release during combustion.
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