摘要:
The present invention relates to a method enabling precise determination of the elevation of a projectile following a ballistic trajectory by use of a conventional Doppler surveillance radar. The method includes calculating first the estimate {circumflex over (Γ)}ρ of the value of the radial component Γρ of the acceleration of the projectile from the quantities {dot over (d)} and {umlaut over (d)}, respectively representing the first derivative and the second derivative with respect to time of the Doppler velocity d of the projectile, then calculating the estimate {circumflex over (V)} of the speed V of the projectile from d, {dot over (d)} and {circumflex over (Γ)}ρ, and finally calculating the estimate Ê of its angle of elevation E from d and {circumflex over (V)}. The method according to the invention may apply to the protection of sensitive areas against the firing of ballistic projectiles.
摘要:
The present invention relates to a method enabling precise determination of the elevation of a projectile following a ballistic trajectory by use of a conventional Doppler surveillance radar. The method includes calculating first the estimate {circumflex over (Γ)}ρ of the value of the radial component Γρ of the acceleration of the projectile from the quantities {dot over (d)} and {umlaut over (d)}, respectively representing the first derivative and the second derivative with respect to time of the Doppler velocity d of the projectile, then calculating the estimate {circumflex over (V)} of the speed V of the projectile from d , {dot over (d)} and {circumflex over (Γ)}ρ, and finally calculating the estimate Ê of its angle of elevation E from d and {circumflex over (V)}. The method according to the invention may apply to the protection of sensitive areas against the firing of ballistic projectiles.
摘要:
The invention relates to novel basic architecture for helicopter autopilots, transforming the conventional objective of maintaining fuselage trim to an objective of maintaining airspeed, and without making use of coupler techniques. On each of the pitch and roll control systems, a known fraction of the output signal (24S) from the flight control is injected by being summed with the standard fuselage trim input (1S). The signal (4S) formed in this way possesses the novel static and dynamic properties required for the control loop to make the helicopter statically stable in speed throughout its flight envelope. The novel architecture makes it possible to replace the conventional fuselage trim signal (1S) with an accelerometer signal. The signal (4S) is displayed in particular on a standard "artificial horizon" type instrument (33), thereby making it possible simultaneously to monitor rapid variations of fuselage trim and to control airspeeds.
摘要:
The present invention relates to an aerodynamic or hydrodynamic profile (1) which can be deformed in a continuous and controlled manner, essentially consisting of a shell mounted on an infrastructure. The profile is characterized in that said infrastructure comprises a core (2) extending along the longitudinal axis of the cross section of the profile (1), and in that this core (2) has at least one active section made of composite material having continuous and controlled deformation under the effect of an adjustable temperature variation in at least one active layer of said composite material which, in the regions of the shell of the profile (1) corresponding to said active section, induces a deformation of corresponding direction and amplitude.
摘要:
A process is provided for the synthesis for metal oxides of high specific surface area and high porosity which are particularly useful as catalyst supports. The process comprises forming a mixture of a salt of at least one metal and a molten salt medium comprising at least one alkali metal salt having an oxidizing effect, maintaining this mixture at the reaction temperature for the time necessary to convert the salt to oxide and thereafter isolating the metal oxide formed.
摘要:
A method for producing an aortic or mitral heart valve prosthesis and the resulting aortic or mitral heart valve. The method is characterized in that it essentially consists in producing the prosthesis by shaping a textile material. The invention is more particularly applicable in the field of medicine, in particular repair surgery, and especially in heart surgery, more particularly heart prostheses.
摘要:
A method for producing an aortic or mitral heart valve prosthesis and the resulting aortic or mitral heart valve. The method is characterized in that it essentially consists in producing the prosthesis by shaping a textile material. The invention is more particularly applicable in the field of medicine, in particular repair surgery, and especially in heart surgery, more particularly heart prostheses.
摘要:
A laboratory device and method are adapted to subject a same rock sample to successive liquid treatments without any intermediary handling of the sample. The device combines a chamber comprising a first part fitted with an inlet for introducing a rock sample and liquid reagents into the chamber; a heater for regulating the temperature in the chamber and a plug fitted within an open port for protecting the chamber from an overpressure. The first part also comprises means for stirring the contents of the chamber including a liquid by introducing gas as bubbles into the liquid. A second part of the chamber is located under the first part and a selective filtering unit is interposed between the first and second parts of the chamber, the filter has a porosity selected for retaining organic material contained in the sample. A gas bubbling inlet is provided for introducing the gas into the liquid contained in the chamber and a valve controlled discharge opening is also provided for draining off liquid from the chamber.
摘要:
The invention relates to a valve endoprosthesis, characterised in that it substantially comprises an extensible stent or frame (1) made of several parts, i.e. an upper cylinder (11), a lower bearing portion (21) having the shape of a truncated cone and a maximum diameter higher than that of the aortic ring and decreasing down to the diameter of the extensible stent or frame (1) in the direction of the proximal end, and arches (31), the upper cylinder (11) being connected to the lower bearing portion (21) via mounts (41) and by a valve (2) connected to said stent (1) by stitches, staples or clips. The invention can particularly be used in the field of medicine, in particular in plastic surgery, and particularly in cardiac surgery, in particular for cardiac prostheses.
摘要:
The present invention relates to a method of preparing ceramics based on lanthanum-doped barium titanate, which comprises the following steps: (a) flash sintering of lanthanum-doped barium titanate powders; and (b) heat treatment of the material thus obtained, in an air atmosphere or in an oxidising atmosphere. The invention also relates to ceramics based on lanthanum-doped barium titanate, possessing a very high real part of the relative dielectric permittivity, and to their use for obtaining capacitors of high capacitance and high capacitance per unit volume for high-voltage withstand capability.