摘要:
A system, method, and device for analyzing a sample using spectroscopy. The system includes a spectroscope, a sample vial with a swab removably sealable within a transparent enclosure, the swab including an absorbent collection substrate. The system further includes a sample vial adaptor configured to affix to the spectroscope, and a sample vial receptacle that receives the sample vial. The adaptor is configured to position the sample vial such that the transparent portion of the enclosure is between the swab and the laser of the Raman instrument, and such that the swab is positioned at the focal distance of the laser.
摘要:
A high gain antenna for direction finding in the Ka-band. The antenna consists of a lens antenna fed by two micro strip patch antennas. The printed patch antennas are fed by a 180 degree hybrid coupler having four ports, with two ports connected to the feeds of the patch antennas and the other two ports connected to the receiver/exciter. The hybrid sums the signals from the patches and subtracts the signals from the patches to form sum and difference channels. By comparing the sum and difference channels, a user can determine whether the signal entered through the main beam. For example, if the sum signal is greater than the difference signal, the signal is in the main beam. If not, the signal came from another angle.
摘要:
A nucleic acid tag comprising a nucleotide-support platform attached to a nucleic acid molecule, an odorant, and an encapsulant. Unique nucleic acid-containing tags containing an odorant are seeded at one or more geographic locations. Using odorant-detection systems, the person or object of interest is examined for the presence of one or more of the odorant, thereby revealing the presence of the seeded nucleic acids and eliminating the expense and time associated with unnecessary screening. The geographic location associated with each detected nucleic acid is used to backtrack the item's path or extrapolate a probable point of origin.
摘要:
Methods and systems for detecting chemical and biological agents using oligonucleotide aptamers. A sensor includes a detection complex between an aptamer that has a binding domain for the chemical or biological agent, and a first oligonucleotide with a sequence complementary to a region of the aptamer. In the absence of the agent, the aptamer and the first oligonucleotide form an intermediate combination. In the presence of the agent, the intermediate combination dissociates. The sensor further includes a second oligonucleotide with a sequence that interacts with a region of the first oligonucleotide to form a duplex structure only when the first oligonucleotide is dissociated from the aptamer. When the duplex structure is formed, it can interact with a reporter molecule which in turn initiates a signal reporting detection of the chemical or biological agent.
摘要:
A radar system includes a transmit antenna array having subarrays disposed at predetermined positions. An orthogonal waveform signal is directed to a corresponding one of the subarrays. On receive, an adaptive processor derives a plurality of adaptive weight factors from a plurality of receive signals and applies them to the receive signals to obtain a jammer cancelled signal. That signal is separated into its orthogonal waveform components by passing it through a bank of correlators. The correlator system provides a plurality of unique receive signals substantially corresponding one-to-one to the unique transmit subarrays. The receive beamformer derives an angular estimate of at least one target relative to boresight from the unique receive signals.
摘要:
A radar system includes a transmit antenna array having subarrays disposed at predetermined positions. An orthogonal waveform signal is directed to a corresponding one of the subarrays. On receive, an adaptive processor derives a plurality of adaptive weight factors from a plurality of receive signals and applies them to the receive signals to obtain a jammer cancelled signal. That signal is separated into its orthogonal waveform components by passing it through a bank of correlators. The correlator system provides a plurality of unique receive signals substantially corresponding one-to-one to the unique transmit subarrays. The receive beamformer derives an angular estimate of at least one target relative to boresight from the unique receive signals.
摘要:
Methods, systems, and devices for the detection and notification of chemical, biological, radiological, nuclear, and/or explosive agent. The detection and notification system uses aptamers bound to a catalyst that is activated when the aptamer binds to the agent. The activated catalyst acts on a substrate to create a signal that is detected, indicating the presence of the agent. For example, the system can be a glove worn by a user that includes a catalyst/substrate pair that, in the presence of the target agent, produces a colorimetric and/or fluorescent signal in a time-efficient manner.
摘要:
Methods and systems for injecting a wireless message in a cellular communication system. The attacking system receives a synchronization waveform from a base station and synchronizes in time and frequency. The attacking system transmits the correct time and frequency, and also transmits one or more attack messages. The mobile transceiver receives the one or more attack messages and responds. The attacking system then transmits a first wireless message configured to alter a characteristic of a physical layer of the mobile station.
摘要:
A system for adaptively generating a sidelobe null in a radar transmit antenna pattern by positioning a small air vehicle along the radial of the sidelobe to be suppressed. The air vehicle is fitted with a receiver and antenna facing the radar, as well as a GPS device for maintaining the designated position. The vehicle further includes a communication link to the processor of the main radar transmitter to form a closed loop that enables adjustment of the attenuators and phase shifters of the auxiliary channel(s) to suppress signals transmitted in the sidelobe to be nulled. The com link may be replaced by a suitable transponder.
摘要:
The present invention is directed to a method for use in a cognitive radio. A Fourier transform of a time domain signal is performed to obtain a series of frequency domain samples covering substantially the entire predetermined RF spectrum, the time domain signal corresponding to the RF waveform, each frequency domain sample being characterized by a predetermined waveform characteristic. The predetermined waveform characteristic of each frequency domain sample is evaluated in each subcarrier block to obtain a subcarrier block activity level for each subcarrier block. A subcarrier block is selected when its subcarrier block activity level is greater than a predetermined threshold.