摘要:
A microwave imaging system uses microwave radiation provided by a microwave source to image targets. The system includes an array of antenna elements that are capable of being programmed with a respective direction coefficient to direct the microwave illumination from the microwave source toward a position on the target. The antenna elements are further capable of being programmed to receive reflected microwave illumination reflected from the position on the target. A processor is operable to measure an intensity of the reflected microwave illumination to determine a value of a pixel within an image of the target. Multiple beams can be directed towards the target to obtain corresponding pixel values for use by the processor in constructing the image.
摘要:
An illumination device provides light to a flowing gaseous sample. The device includes a structure including a cavity configured to have a microplasma disposed therein. The cavity substantially encircles a cross-section of a channel that is configured to pass the flowing gaseous sample therethrough. The cavity is defined in part by an interior wall of the structure separating the cavity from the channel. The interior wall includes at least one orifice passing therethrough configured to provide to the flowing gaseous sample light generated by the microplasma. At least one electrode is configured to supply energy to the microplasma within the cavity.
摘要:
Grating lobe free scanning in a phased array with sparse element spacing is obtained by restricting the maximum scan angle for elements in the array, and arranging the elements in a convex form. One convex form is a paraboloid, which may be continuous, or piecewise in nature, tiled with flat segments.
摘要:
A microwave imaging system captures a microwave image of a target and minimizes noise in the microwave image using phase differentiation. A reflector antenna array is provided including a plurality of antenna elements for reflecting microwave radiation towards the target and for reflecting microwave radiation reflected from the target towards a microwave receiver. A processor programs the antenna elements with respective first phase shifts to capture a first microwave image of the target, and programs the antenna elements with respective second phase shifts to capture a second microwave image of the target. The first phase shift of each antenna element is 180 degrees different than the second phase shift for that antenna element. The processor minimizes noise from a combination of the first microwave image and the second microwave image.
摘要:
A method to convert surplus nitroarene explosives into trinitrophloroglucinol and triaminotrinitrobenzene (TATB) is described. Picric acid is directly aminated to diaminopicric acid, which is converted to trinitrophloroglucinol and triaminotrinitrobenzene.
摘要:
A high-speed, high-resolution superconducting counting A/D converter providing greatly increased conversion speeds with a low device count. The superconducting counting A/D converter includes includes a double-junction SQUID quantizer and a bidirectional binary counter having n stages of floating four-junction SQUID flip-flops, where n is the number of bits of accuracy of the counter. The quantizer continuously tracks an analog signal, generating up-count and down-count voltage pulses of the same polarity on two different output lines for increasing and decreasing values of the analog current, respectively. The bidirectional binary counter algebraically counts the voltage pulses, increasing the binary count when up-count pulses are received and decreasing the binary count when down-count pulses are received. Several techniques for reading the contents of the bidirectional binary counter at the end of each sampling interval are also disclosed.