Explosives concealed within electronic devices, such as smartphones and tablet PCs, are detected using NQR spectroscopy. For example, a suspect electronic device can be placed inside a NQR scanner and be subject to interrogation electromagnetic radiation at varying frequencies. The electronic device is exposed to interrogation electromagnetic radiation at frequencies that correspond to chemical components of various explosives. In the event that an explosive chemical component is present inside the electronic device, irradiating the electronic device with interrogation electromagnetic radiation at the specific NQR frequency of that explosive chemical component will cause the explosive chemical component to emit feedback electromagnetic radiation at that frequency. Consequently, the NQR scanner can measure the feedback electromagnetic radiation and determine that the frequency of the feedback electromagnetic radiation indicates the presence of the explosive chemical component inside the electronic device.

Explosives concealed within electronic devices, such as smartphones and tablet PCs, are detected using NQR spectroscopy. For example, a suspect electronic device can be placed inside a NQR scanner and be subject to interrogation electromagnetic radiation at varying frequencies. The electronic device is exposed to interrogation electromagnetic radiation at frequencies that correspond to chemical components of various explosives. In the event that an explosive chemical component is present inside the electronic device, irradiating the electronic device with interrogation electromagnetic radiation at the specific NQR frequency of that explosive chemical component will cause the explosive chemical component to emit feedback electromagnetic radiation at that frequency. Consequently, the NQR scanner can measure the feedback electromagnetic radiation and determine that the frequency of the feedback electromagnetic radiation indicates the presence of the explosive chemical component inside the electronic device.

A system for magnetic detection includes a magneto-optical defect center material including at least one magneto-optical defect center that emits an optical signal when excited by an excitation light; a radio frequency (RF) exciter system configured to provide RF excitation to the magneto-optical defect center material; an optical light source configured to direct the excitation light to the magneto-optical defect center material; and an optical detector configured to receive the optical signal emitted by the magneto-optical defect center material.

A system for magnetic detection includes a magneto-optical defect center material including at least one magneto-optical defect center that emits an optical signal when excited by an excitation light; a radio frequency (RF) exciter system configured to provide RF excitation to the magneto-optical defect center material; an optical light source configured to direct the excitation light to the magneto-optical defect center material; and an optical detector configured to receive the optical signal emitted by the magneto-optical defect center material.

A method for determining depth of a material is disclosed. The method includes transmitting a signal from an antenna at a location. The signal includes a fundamental frequency and the signal penetrates ground under the location. The location is selected to locate a material at a depth under the location. The fundamental frequency matches a known resonant frequency of a resonant atom of a molecule of the material. The method includes detecting a reflected wave on the antenna, determining a time difference between transmission of the signal and detection of the reflected wave on the antenna, and determining the depth to the material based on the time difference and a reflected velocity corresponding to the resonant atom.

A method for determining depth of a material is disclosed. The method includes transmitting a signal from an antenna at a location. The signal includes a fundamental frequency and the signal penetrates ground under the location. The location is selected to locate a material at a depth under the location. The fundamental frequency matches a known resonant frequency of a resonant atom of a molecule of the material. The method includes detecting a reflected wave on the antenna, determining a time difference between transmission of the signal and detection of the reflected wave on the antenna, and determining the depth to the material based on the time difference and a reflected velocity corresponding to the resonant atom.

Described here are systems and methods for reconstructing images of a subject using a magnetic resonance imaging (“MRI”) system. As part of the reconstruction, synthesized data are estimated at arbitrarily specified k-space locations from measured data at known k-space locations. In general, the synthesized data is estimated using a convolution operation that is based on measured or estimated covariances in the acquired data. The systems and methods described here can thus be referred to as Convolution Operations for Data Estimation from Covariance (“CODEC”).

An anti-saturation device for a ground magnetic resonance signal amplifying circuit has a receiving coil connected with a band-pass filter circuit through a pre-amplifying circuit and a programmable amplifying circuit. The programmable amplifying circuit is connected with an AD acquisition card through the band-pass filter circuit. The band-pass filtering circuit is connected with a computer through the AD acquisition card, and the AD acquisition card is connected with an emitting system through the computer. An automatic amplification factor adjusting module is embedded into a nuclear magnetic resonance detector, and can also directly replace a receiving amplification circuit of the nuclear magnetic resonance detector to work independently.

An anti-saturation device for a ground magnetic resonance signal amplifying circuit has a receiving coil connected with a band-pass filter circuit through a pre-amplifying circuit and a programmable amplifying circuit. The programmable amplifying circuit is connected with an AD acquisition card through the band-pass filter circuit. The band-pass filtering circuit is connected with a computer through the AD acquisition card, and the AD acquisition card is connected with an emitting system through the computer. An automatic amplification factor adjusting module is embedded into a nuclear magnetic resonance detector, and can also directly replace a receiving amplification circuit of the nuclear magnetic resonance detector to work independently.

A method and device for detection of solid organic matter and fluids in a shale rock by means of low field Nuclear Magnetic Resonance (NMR) in a single measurement, by submitting a rock sample to a 2D NMR assay comprising applying a 2D pulse sequence with a saturation-recovery, or inversion-recovery, in an indirect dimension and an FID-CPMG in a direct dimension. The method can be used as an analytical technique for rock samples from unconventional hydrocarbon reservoirs.