73 results about "Drift velocity" patented technology

The invention discloses a gallium-nitride-based heterostructure field effect transistor with composite barrier layers. The composite barrier layers are formed by AlInGaN material with different polarization intensities. When the AlInGaN composite barrier layer with low polarization intensity is located at a grid drain terminal, the density of two-dimensional electron gas (2DEG) of the channel below the barrier layer is smaller than that of the 2DEG at other positions of the channel drain terminal, an LDD structure is formed, and the electric field distribution of the channel is modulated to increase voltage endurance capability; when the AlInGaN composite barrier layer with low polarization intensity is located right below a grid, a below-grid gallium nitride (GaN) channel guide strip bottom is distributed in a stepped manner, the drift speed of a below-grid channel carrier is increased due to barrier descending, electric field peak is generated between AlInGaN composite barrier layer with two different elemental components, and more potential is distributed at the grid drain terminal instead of the whole grid to restrain drain induced barrier lowering (DIBL).

A method for fast and accurate recognition of species contained in trace amounts in complex mixtures such as ambient air or biological fluids is taught based on the use in tandem of one or several differential mobility analyzers (DMAs) and possibly also a mass spectrometer (MS), all arranged in series. The two DMAs operate in different regions of the ion drag versus drift velocity curve (for instance, linear versus nonlinear regions), hence separating according to more than one independently discriminating parameters of the ion. Very high discrimination can be achieved even with a single stage of mass spectrometric separation by selecting a narrow range of ions with the DMA, and analyzing them in the MS, first without fragmentation, and then with fragmentation. This process does not require necessarily a tandem MS when fragmentation takes place in the inlet region of the MS. Fast and accurate discrimination is possible in single ion monitoring mode (SIM) for a large number of targeted species, even with relatively inexpensive and light single quadrupole MS systems, where the various filters placed in series would open pre-configured narrow windows suitable for passage of each ion in a list.

A method for raising the resolving power, specificity, and peak capacity of conventional ion mobility spectrometry is disclosed. Ions are separated in a dynamic electric field comprising an oscillatory field wave and opposing static field, or at least two counter propagating waves with different parameters (amplitude, profile, frequency, or speed). As the functional dependencies of mean drift velocity on the ion mobility in a wave and static field or in unequal waves differ, only single species is equilibrated while others drift in either direction and are mobility-separated. An ion mobility spectrum over a limited range is then acquired by measuring ion drift times through a fixed distance inside the gas-filled enclosure. The resolving power in the vicinity of equilibrium mobility substantially exceeds that for known traveling-wave or drift-tube IMS separations, with spectra over wider ranges obtainable by stitching multiple segments. The approach also enables low-cutoff, high-cutoff, and bandpass ion mobility filters.

The present invention relates to a novel process for the remote plasma surface treatment of substrate particles at atmospheric pressure. The invention is motivated by the urge to overcome major drawbacks of particle treatment in low pressure plasmas and in-situ particle treatment at atmospheric pressure. The former requires complex and mostly expensive vacuum installations and vacuum locks usually prohibiting continuous processing. Independent of the system pressure, in-situ plasma treatment causes particle charging and therefore undesirable interaction with the electric field of the discharge, which is seen to contribute to the process of reactor clogging. Additionally, the filamentary discharges modes of atmospheric pressure plasmas are inflicted with inhomogeneous surface treatment. Furthermore, short radical lifetimes at elevated pressures complicate a remote plasma treatment approach as widely used in low pressure applications. The key-element of the invention is that by reducing the dimension of the atmospheric discharge arrangement to the micrometer range, transonic flow conditions can be achieved in the discharge zone while maintaining moderate flow rates. The resulting superimposition of high drift velocity in the gas flow and the inherent diffusion movement is to prolong the displacement distance of activated species, thus making a remote plasma treatment of substrate particles feasible and economically interesting. The circumferential arrangement of e.g. micro discharge channels around the treatment zone of variable length allows a remote plasma treatment independently of the discharge mode and benefits additionally from the aerodynamic focusing of a particle-gas stream to the centre, reducing reactor clogging. Furthermore, taking advantage of non-thermal discharges, there is no restriction of the concept of the outlined invention in the material properties of the particulate solids especially not with regard to the treatment of temperature sensitive materials as often encountered in polymer or pharmaceutical industries. In conclusion, atmospheric pressure plasma treatment close to ambient gas temperature as well as continuous processing is a specialty of the invention disclosed here.

A method for fast and accurate recognition of species contained in trace amounts in complex mixtures such as ambient air or biological fluids is taught based on the use in tandem of one or several differential mobility analyzers (DMAs) and possibly also a mass spectrometer (MS), all arranged in series. The two DMAs operate in different regions of the ion drag versus drift velocity curve (for instance, linear versus nonlinear regions), hence separating according to more than one independently discriminating parameters of the ion. Very high discrimination can be achieved even with a single stage of mass spectrometric separation by selecting a narrow range of ions with the DMA, and analyzing them in the MS, first without fragmentation, and then with fragmentation. This process does not require necessarily a tandem MS when fragmentation takes place in the inlet region of the MS. Fast and accurate discrimination is possible in single ion monitoring mode (SIM) for a large number of targeted species, even with relatively inexpensive and light single quadrupole MS systems, where the various filters placed in series would open pre-configured narrow windows suitable for passage of each ion in a list.

The invention relates to an angle-modulation type real-time on-line offshore oil spill detection system employing a miniature surface plasma resonance technique. The system comprises six parts, namely an optical module, a sensing module, a detection module, a regeneration module, a power supply module and a control module, wherein the optical module adopts a semiconductor laser module and has a relatively large divergence angle to meet the angle control on a light source; the sensing module comprises a prism which is made of a high-refractive index heavy flint glass material and a gold film sensing slide which is made of the same material with the prism; and the detection module is used for collecting an image by virtue of a wireless transmission mode linear array CCD detector and transmitting the image to a computer data collection part of the control module, and carrying out data and image processing. According to the miniature real-time on-line oil spill detection system, detection is carried out mainly aiming at small-area early offshore oil spill which cannot be easily found out; multi-sensor data fusion is realized by system encapsulation positioning and distributed network arrangement; and monitoring on real-time tracking and information display of the oil spill position, drift speed, direction and track are carried out, so that important information is provided for judgment of oil spill places.

A plasma accelerating apparatus and a plasma processing system, which efficiently elevate a drift velocity of a plasma beam and are simple to manufacture and simple in construction. A channel includes an outlet port opening at an end of the channel. A gas supply portion supplies a gas in the channel. A plasma generator provides ionization energy to the gas in the channel to generate a plasma beam. A plasma accelerating portion includes a plurality of grids transversely arranged spaced apart from each other by a predetermined distance in the channel for accelerating the plasma beam generated by the plasma generator to the outlet port of the channel with an electric field. The plasma accelerating apparatus and the plasma processing system elevate a drift velocity of the plasma beam more efficiently than conventional accelerating apparatuses that use an electromagnetic force induced by a magnetic field and a secondary current.

A method for presenting the current drift values of an aircraft on a display device in which the drift values are presented in a vector presentation. The length of the drift vector above a predefined threshold value is presented in a manner proportional to the current drift velocity, and the length of the drift vector below the threshold value is presented in a manner disproportionate to the current drift velocity. There is a continuous transition between the two ways of presentation at the threshold value.

A method for raising the resolving power, specificity, and peak capacity of conventional ion mobility spectrometry is disclosed. Ions are separated in a dynamic electric field comprising an oscillatory field wave and opposing static field, or at least two counter propagating waves with different parameters (amplitude, profile, frequency, or speed). As the functional dependencies of mean drift velocity on the ion mobility in a wave and static field or in unequal waves differ, only single species is equilibrated while others drift in either direction and are mobility-separated. An ion mobility spectrum over a limited range is then acquired by measuring ion drift times through a fixed distance inside the gas-filled enclosure. The resolving power in the vicinity of equilibrium mobility substantially exceeds that for known traveling-wave or drift-tube IMS separations, with spectra over wider ranges obtainable by stitching multiple segments. The approach also enables low-cutoff, high-cutoff, and bandpass ion mobility filters.

A manual controller commands a telescope mount to automatically track a specific bright star after the image of the star is located to center of an electronic eyepiece and a timer is started. The average moving speed of the bright star is calculated after a predetermined elapsed time to acquire the right ascension (RA) and the declination (DEC) coordinates of this bright star. Subsequently, the RA and DEC coordinates are compared with pre-stored data contained within a database used to identify the bright star. The celestial sphere coordinates of the telescope can be determined after a minimum of one bright star is identified. In the auto-tracking procedure, the manual controller controls movement of telescope by feedbacks of the drifting speed and direction of the specific bright star in an electronic eyepiece for the purpose of keeping the specific bright star in the center of the electronic eyepiece.