摘要:
An apparatus and method for rotating an optical element, such as a diffraction grating or mirror, utilizes a moving coil actuator and an optical encoder to provide precise element position control. The moving coil actuator, which is coupled to the optical element, is comprised of a coil immersed in a magnetic field created by a pair of magnets. Current flowing in the coil windings causes the coil, and ultimately the optical element, to rotate. An optical encoder monitors the rotation of the element and provides rotation signals representative of the instantaneous element position to an actuator control circuit. The actuator control circuit phase shifts the rotation signals and compares the phase shifted rotation signals to a desired reference signal to generate position and velocity error signals. In a track follow mode, the position error signal is applied to the moving coil actuator via a loop compensator. When the apparatus is operating in an optimal seek mode, a trajectory generator receives the velocity error signals and generates an optimum velocity signal based on a preprogrammed velocity curve. The optimum velocity signal is then applied to the moving coil actuator via the loop compensator.
摘要:
In one aspect, the present invention provides methods of determining whether an agent is more like a partial agonist of a target molecule than a full agonist of the same target molecule. In another aspect, the present invention provides methods to select a candidate compound that may reduce blood plasma glucose concentration in a mammal. Populations of genes are provided that are useful in the practice of the present invention.
摘要:
Substituted 2-aminopyridine compounds of Formula (I) and pharmaceutically acceptable salts which have been found useful in the treatment of nitric oxide synthase mediated diseases and disorders. ##STR1##
摘要:
Disclosed is an improved viscous oil recovery method employing the injection of a thermal recovery fluid which may be steam or a mixture of steam and additives, and cycles of pressurization and drawdown. First the thermal recovery fluid is injected and production is restricted in order to increase the pressure in the reservoir. Injection is then terminated or decreased and production is increased in order to effect a pressure drawdown in the reservoir. Thereafter the production rate is decreased or production wells are shut in completely and non-condensable gas is injected to raise the pressure in the reservoir to a value which is from 50 to 90 percent of the final target pressure, after which the thermal recovery fluid is again injected into the formation to rebuild reservoir pressure with restricted production. Finally, production rate is increased and thermal recovery fluid injection is reduced or terminated in order to accomplish another reservoir drawdown cycle. Additional cycles of partial repressuring with non-condensable gas followed by steam injection followed by pressure drawdown production cycles may be employed.