ABSTRACT
The arrays of metallic nanowires are considered as promising precursors for 1D semiconductor nanostructures after appropriate treatment at temperatures close to the melting point. Therefore the melting behaviour of the metallic structures in oxide templates is a key parameter for the subsequent conversion process. The present paper focuses on understanding of the effect of mechanical stress generated during heating on the melting point of the metal nanowires deposited into the pores of anodic alumina. Extremely high local compressive stress appears due to the difference in the thermal coefficients of the oxide template and nanowires inside the pores. The effect of the composite structural parameter that may be related to the concentration of nanowires on the melting temperature has been investigated. A numerical model predicting the melting point has been developed for composites with indium, tin, and zinc nanowires. The simulation results obtained using the suggested model were compared with the experimental data.
ABSTRACT
At the ion source test bench in Institute for Theoretical and Experimental Physics the program of ion source development for semiconductor industry is in progress. In framework of the program the Metal Vapor Vacuum Arc ion source for germanium and rhenium ion beam generation was developed and investigated. It was shown that at special conditions of ion beam implantation it is possible to fabricate not only homogenous layers of rhenium silicides solid solutions but also clusters of this compound with properties of quantum dots. At the present moment the compound is very interesting for semiconductor industry, especially for nanoelectronics and nanophotonics, but there is no very developed technology for production of nanostructures (for example quantum sized structures) with required parameters. The results of materials synthesis and exploration are presented.
Subject(s)
Conditioning, Classical , Time Perception , Animals , Dogs , Macaca mulatta , Mental Recall , Rabbits , Reinforcement ScheduleABSTRACT
The study of changes in the precision of evaluating different time intervals by animals (monkeys, rabbits) showed that the value of error in time evaluation delta and the value of confidential interval of time evaluation delta, characterizing differential thresholds of time perception, depend on the duration of signal interval, which is in maximal conformity with Weber's law. The revealed dependence is considered as a sign of the increase with time of the intensity of excitatory process, used by the nervous system as a substratum for time counting. Assumed nature of neurodynamic processes underlying this relation is discussed.
Subject(s)
Time Perception/physiology , Animals , Conditioning, Classical/physiology , Differential Threshold , Food , Macaca mulatta , Papio , Rabbits , Species SpecificityABSTRACT
Switching over of simple reflexes and of a system of reflexes to "pure" time was studied on 12 rabbits, 2 dogs and one monkey. Instrumental conditioned reflexes (pulling a ring or pressing a pedal) were elaborated in response to 5; 4, 2 and 1.5 minutes time intervals; a system of conditioned reflexes was elaborated to different time intervals: 1.5--2.5--3.5 min and 4--2 min. Switching over agents were a metronome (300 beats/min), noise of a ventilator plus light of an electrical bulb, as well as different quantities or qualities of alimentary reinforcement. Turning in of the one and turning out of the other agents caused switching over of the food-procuring activity from one rhythm to another. The mechanisms of this complex form of integrative brain activity are discussed.
Subject(s)
Conditioning, Operant/physiology , Cues , Transfer, Psychology , Animals , Dogs , Food , Haplorhini , Humans , Light , Macaca mulatta , Rabbits , Sound , Species Specificity , Stereotyped Behavior/physiology , TimeABSTRACT
The object of the study was the formation of systems of conditioned food-procuring reflexes to time intervals of different duration (from 1,5 to 4 min) integrated into a stereotype in monkeys (macaques and baboons). It has been shown that unlike rabbits, monkeys more readily form such systems and reproduce them more distinctly. The greater capacity of monkeys for complicate forms of orientation in time as compared with rabbits is more manifest in the elaboration of complex systems (five-interval in the present experiments) of conditioned reflexes to time.
Subject(s)
Conditioning, Operant/physiology , Cues , Time Perception , Animals , Food , Haplorhini , Macaca , Papio , Rabbits , Species Specificity , TimeABSTRACT
Experiments on rabbits carried out by the food-procuring conditioned reflex method have shown that conditioned reflex systems to "pure" time can be elaborated, provided that conditioned stimulus is presented at regular, though different time intervals, following one another in a fixed sequence. The complexity of elaborating such systems to time is determined by the number of signal time intervals in the system, their different length, and their sequence. The formation of conditioned reflex systems to time is characterized by definite stages.
