摘要:
An electrical stimulation system is provided for electrically stimulating target nerve tissue in a person's brain using a stimulation lead having a tip electrode, having at least five electrodes, or both. The system includes a stimulation lead adapted for implantation into the brain for electrical stimulation of target nerve tissue in the brain. The stimulation lead may include a tip electrode located at a distal tip of the stimulation lead and adapted to be positioned proximate the target nerve tissue in the brain and to deliver electrical stimulation pulses to the target nerve tissue in the brain. The stimulation lead may include at least five electrodes, one or more of which are adapted to be positioned proximate the target nerve tissue in the brain and to deliver electrical stimulation pulses to the target nerve tissue in the brain. The system also includes a stimulation source operable to generate the electrical stimulation pulses for transmission to the one or more electrodes, possibly including a tip electrode, of the stimulation lead to cause the one or more electrodes to deliver the electrical stimulation pulses to the target nerve tissue in the brain.
摘要:
A molecular species is covalently attached to elemental carbon by exposing the carbon to a reaction mixture containing a strong base and a compound of the formula (I) or (II) in which X denotes a covalently attached atom or group capable of forming an X− anion and each Z is a moiety comprising a plurality of atoms, but which does not have a hydrogen atom directly attached to the atom which itself is directly attached to the —CH2X or —CHX group. The carbon substrate may be graphite or carbon nanotubes.
摘要:
Catalytic hydrogenation of a double bond, notably a C═C or C═N double bond, is carried out using a homogenous catalyst which is a complex of rhodium or other transition metal containing at least one ligand which is a nitrogenous organic base. Preferably the complex is phosphorus-free and the ligand is a bicyclic base having formula where R1 and R4 are hydrocarbon chains. R1 preferably is a saturated chain of two carbon atoms and R4 preferably is a saturated chain of three to five carbon atoms.
摘要:
A wirelessly controlled motorized vehicle system may be utilized to facilitate operation of a motorized vehicle. The wirelessly controlled motorized vehicle system may comprise a motorized vehicle and a wireless communications system. The motorized vehicle may comprise a drive system operable to operate the motorized vehicle and a controller in communication with at least a portion of the drive system. The controller may be configured to receive a command from a user. The wireless communications system may be configured to allow wireless communication between the controller and the portion of the drive system. The wireless communications system may comprise one or more transmitters in communication with the controller and one or more receivers in communication with the portion of the drive system. Alternate embodiments may comprise a gauge and/or a central display unit in combination with one or more of the elements listed above.
摘要:
A method of monitoring gas in a downhole environment is discussed which provides downhole a mid-infrared light emitting diode, operates the diode to transmit respective infrared signals on a first optical path extending from the diode through a downhole gas sample and a second optical path extending from the diode through a reference gas sample, detects the transmitted infrared signals, and determines the concentration of a component of the downhole gas sample from the detected signals.
摘要:
This invention relates to an actuator and has particular reference to linear and rotary actuators, particularly those for use in the control of robotic arms. The invention provides a relatively low cost means of achieving substantially backlashfree rotary and/or linear motion. There is provided an actuator (10) comprising: a first drive pulley (28); a second drive pulley (29), the first drive pulley and the second drive pulley being interconnected to rotate together; a first driven pulley (52; 70); a second driven pulley (53; 72); an endless drive belt (40) engaging the first and second drive pulleys and the first and second driven pulleys; a motor (19) connected to drive the first and second drive pulleys to rotate and drive the endless drive belt; a driven member (50; 88; 71, 73) carrying at least one of the driven pulleys; the first and second drive pulleys being arranged so that upon rotation thereof the circumferential speed of the first drive pulley is different from the circumferential speed of the second drive pulley, the endless drive belt being looped around the drive pulleys and the driven pulleys so that the difference between the circumferential speed of the first drive pulley and the circumferential speed of the second drive pulley causes movement of the driven member.
摘要:
A scale dissolver fluid for dissolving scale in a subterranean hydrocarbon-bearing formation comprises an effective amount of a scale dissolver formulation and an effective amount of a surfactant for controlling the viscosity of the fluid. In use, formation hydrocarbons act on the surfactant to reduce the viscosity of the fluid so that the fluid selectively invades a hydrocarbon-bearing zone of the formation.
摘要:
This invention relates to methods and apparatus for determination of ion concentrations, particularly in downhole water from hydrocarbon wells, aquifers etc. It is useful in a wide range of applications, including predicting the formation of scale and fingerprinting waters from different sources. More particularly, the invention relates to the use of ligands whose electronic configuration is altered by the binding of the scaling ions within a water sample. These alterations are detected, for example by electrochemical means, and are indicative of the concentration of scaling ions in the sample.