摘要:
A citizens band transmitter employing negative overall envelope feedback in the final RF stage obtains the feedback signal from a filter in the antenna coupling network which has a phase shift of 90 degrees or an odd multiple thereof at the radio frequency. A pair of detector diodes have their cathodes connected to opposite ends of filter and their anodes connected to a low pass filter to provide an envelope of the higher of the two voltages at either end of the filter in the coupling circuit in negative feedback to the modulating signal.
摘要:
A system comprising inexpensive composite panels and a configuration that holds them, all components of which are man portable. Select embodiments protect assets against external force and impacts from airborne projectiles. An open box-like stackable frame module holds thin panels along a longitudinal axis of the frame. Multiple frames a reconnected to construct a protective barrier, such as a wall. The panels may be formulated of a very high strength portland cement-based concrete with one side, both sides, or both sides and all edges, covered with elastic material, the combination of which significantly reduces penetration of projectiles. A panel may be covered with specially formulated elastic material comprising multiple layers, each layer of a different type or thickness of elastic material. The elastic material may include reinforcing material such as fabric woven from available COTS high-strength fibers. The panels may be fabricated using basic means available in rural locations. A method of installing is also provided.
摘要:
An ultracapacitor having two porous organic membrane electrodes is made from microporous polymer substrates (10). The surface of the polymer substrate and the walls of the micropores (30) are coated with metal oxides. Both sides of the substrate can be coated with the conductive materials. The film can be a carboxylic ion-exchange material dispersed in a microporous copolymer matrix, and the film can be supported on a woven nylon substrate. The two electrodes (82, 84) are situated substantially parallel to each other, with the coated surface of one electrode facing the coated surface of the other electrode. An ionic electrolyte solution (89) fills the gap (86) between the electrodes.
摘要:
A method of forming electrode patterns on a substrate. A transparent substrate (10) is patterned with a photoresist layer (14) on the front side so that portions (18) of the substrate are revealed. A metal oxide layer (12) is deposited on the patterned photoresist layer and the revealed portions of the substrate. The patterned photoresist layer is then exposed to actinic radiation (19) through the back side (25) of the transparent substrate. The photoresist pattern (20) is removed, carrying with it those portions of the metal oxide layer deposited on the photoresist layer, forming an electrode pattern (22) by a lift-off technique.
摘要:
An electrode for a rechargeable electrical energy storage device has a substrate and an electrochemically active material deposited on the substrate. The electrochemically active material provides electron transfer between itself and an electrolyte. The electrochemically active material is a mixed-valence complex containing at least two metal atoms and at least one ligand attached to the metal atoms, and has metal-to-metal bonds where the metals exist in multiple oxidation states such that electron transfer between the metal atoms in the complex or between discrete complexes occurs. A rechargeable electrical energy storage device (20) has two electrodes (28, 36) constructed from a mixed-valence complex (30), and the electrodes are electrically connected by an ion carrying electrolyte (32). The electrodes are also physically separated from each other by a barrier (34) that will pass ions but not electrons.
摘要:
Solder pastes having vehicles including formic acid-soluble organic acids as fluxing agents are described. Fluxing agents may be compounds of the formula: ##STR1## where R is an electron withdrawing group. In one embodiment, R is selected from the group consisting of fluorine, chlorine, bromine, iodine, sulfur, hydroxyl, nitrile, and benzyl. Other suitable formic-acid fluxing agents include, but are not limited to, adipic acid, acrylic acid, polyacrylic acid, methacrylic acid and polymethacrylic acid. The compounds clean oxides from the printed circuit boards (PCBs) under assembly and then volatilize leaving a residue to be cleaned away. The cleaning step involves rinsing with formic acid. No undesired residue remains indicating that the organic acids of the invention are effective in cleaning boards. Such acid fluxing agents can be used mixed with typical solder components, such as lead/tin solder pastes, or applied topically to solders, such as solder balls; both techniques permit the assembly of PCBs more easily with high quality bonds, and with little or no residue. Malic acid is a preferred organic acid fluxing agent. The formic acid cleaning step may be followed by a water rinse.
摘要:
Solder pastes having vehicles including blends of low boiling point alcohols and relatively high boiling point alcohols are described which leave residues which may be cleaned using only water are described. The low boiling point alcohols have a boiling point range of between about 65.degree. and about 150.degree. C. whereas the high boiling point alcohols have a boiling point in rhe range of about 150.degree. to about 270.degree. C. The solder pastes also use water-soluble organic acids as fluxing agents such as compounds of the formula: ##STR1## where R is an electron withdrawing group such as fluorine, chlorine, bromine, iodine, sulfur, hydroxyl, nitrile, and benzyl. Other suitable formic-acid fluxing agents include, but are not limited to, adipic acid, polyacrylic acid, methacrylic acid and polymethacrylic acid. The compounds clean oxides from the printed circuit boards (PCBs) under assembly and then volatilze leaving a residue to be cleaned away. The cleaning step involves rinsing with water. No undesired residue remains indicating that the organic acids of the invention are effective in cleaning boards. Malic acid is a preferred organic acid fluxing agent.
摘要:
A ceramic article is treated to increase the adhesion of metals to the ceramic article by placing the ceramic article under at least a partial vacuum. A thin film of metal is then deposited on the ceramic article by sputtering or evaporating. The metallized ceramic article is further bombarded by high energy ions, resulting in the formation of a metal-ceramic compound that renders the article more receptive to further metal deposition.
摘要:
A digital filter for use with a randomly generated variable, such as in a radioactive densometer, is provided and includes a microprocessor and timing clock for sampling the random variable over a specific time interval. The microprocessor utilizes a weighting factor based upon a first confidence factor and computes the mean value of a first sample of the random variable and compares the number of standard deviations that a subsequent sample is from the mean value of the previous sample and uses a probability related factor to determine if the subsequent sample represents an actual change in density. Further, the microprocessor uses a second confidence factor in determining the weighting factor which counts the number of consecutive times that the subsequent samples are greater than, or less than the mean value and again determines a probability related factor to determine if a change in density is actually occurring. As both the first and second confidence factors increase, so does the weighting factor and the probability that an actual change in fluid density has occurred.
摘要:
A control system for a gas-coupled gas turbine engine particularly directed to control of the setting angle of the power turbine nozzle of the engine and to correlation of the power turbine nozzle setting with fuel supply and with operating parameters of the engine. The control provides for operation of the engine from closed to full open throttle, with closed throttle calling for idle speed of the engine. The initial stage of opening the throttle develops an increasing nozzle reference temperature signal which is matched with a turbine temperature signal to control a servo which varies the setting, and therefore area, of the turbine nozzle. After the initial stage of throttle opening, the reference temperature signal increases with engine speed, which increases in response to an increasing throttle signal. The actual level of the nozzle reference temperature is also a function of engine inlet temperature up to a given level of this temperature. Throttle position generates a speed reference signal which is matched with actual gas generator speed to control fuel supply to the engine. The speed reference signal is coordinated with the nozzle reference temperature signal so that there is a smooth transition from the increasing nozzle reference temperature over the initial range of throttle movement to the increasing engine speed reference signal over the remainder of the travel of the throttle up to or near 100% rated power output signal.The control also responds to acceleration of the gas generator to vary the nozzle reference signals turbine inlet temperature with an acceleration reference temperature signal responsive to engine inlet air temperature, which signal is used to limit engine fuel flow during acceleration. Upon occurrence of an engine acceleration above idle, the opening of the turbine nozzle is limited to improve energy division between the gas generator and power turbines. In one embodiment this limitation is maintained during the duration of acceleration; in another the limitation of nozzle opening is progressively relaxed during the acceleration.The nozzle opening limitation is overridden during starting of the engine and acceleration to idle, specifically by an override responsive to operation of the starter to crank the gas generator.