Habituation may contribute to within-session decreases in responding under high-rate schedules of reinforcement

2001 ◽  
Vol 29 (1) ◽  
pp. 79-91 ◽  
Author(s):  
Kenjiro Aoyama ◽  
Frances K. McSweeney
Author(s):  
L. E. Murr ◽  
G. Wong

Palladium single-crystal films have been prepared by Matthews in ultra-high vacuum by evaporation onto (001) NaCl substrates cleaved in-situ, and maintained at ∼ 350° C. Murr has also produced large-grained and single-crystal Pd films by high-rate evaporation onto (001) NaCl air-cleaved substrates at 350°C. In the present work, very large (∼ 3cm2), continuous single-crystal films of Pd have been prepared by flash evaporation onto air-cleaved (001) NaCl substrates at temperatures at or below 250°C. Evaporation rates estimated to be ≧ 2000 Å/sec, were obtained by effectively short-circuiting 1 mil tungsten evaporation boats in a self-regulating system which maintained an optimum load current of approximately 90 amperes; corresponding to a current density through the boat of ∼ 4 × 104 amperes/cm2.


Author(s):  
A. Elgsaeter ◽  
T. Espevik ◽  
G. Kopstad

The importance of a high rate of temperature decrease (“rapid freezing”) when freezing specimens for freeze-etching has long been recognized1. The two basic methods for achieving rapid freezing are: 1) dropping the specimen onto a metal surface at low temperature, 2) bringing the specimen instantaneously into thermal contact with a liquid at low temperature and subsequently maintaining a high relative velocity between the liquid and the specimen. Over the last couple of years the first method has received strong renewed interest, particularily as the result of a series of important studies by Heuser and coworkers 2,3. In this paper we will compare these two freezing methods theoretically and experimentally.


2001 ◽  
Author(s):  
Z. Steel ◽  
J. Jones ◽  
S Adcock ◽  
R Clancy ◽  
L. Bridgford-West ◽  
...  

2010 ◽  
Author(s):  
Nicholas Commons-Miller ◽  
Michael Commons ◽  
Robin Gane-McCalla ◽  
Alex Pekker ◽  
Michael Woodford

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