16 results about "Mean free path" patented technology

The invention discloses a non-uniform and conformal grid-oriented electromagnetic particle adaptive simulation method and system, and relates to the technical field of electromagnetic particle simulation. The method comprises the following steps: performing non-uniform right-angle mesh generation based on a charged particle average free path, and identifying conformal mesh units; carrying out initialization by adopting macro particles; executing electromagnetic field propulsion, field interpolation, particle propulsion, charge current backfilling and collision simulation in each time step; and accelerated calculation is realized through a CPU and GPU hybrid parallel architecture. Through the method, the numerical simulation precision can be improved, the adaptability of complex geometry is enhanced, the coupling stability of the electromagnetic field and the particles is ensured, the information interaction between the field and the particles is improved, and the large-scale calculation efficiency is improved.

The invention discloses a dynamic calculation method and system for a radiation field in the cutting process of an activity non-uniform radioactive source, and belongs to the field of radiation field calculation. The method comprises the following steps: acquiring three-dimensional activity distribution data of a radioactive source; constructing a voxelization model and coupling the voxelization model with an activity grid to distribute activity; establishing an LBVH hierarchical structure of the shielding body; a point kernel is generated in a self-adaptive mode through ray tracing and average free path comparison; carrying out radiation field calculation by adopting point nuclear integration, and realizing multilayer ray tracing in the radioactive source, between the sources and a shield in the process; on-line cutting and moving operation of the voxel model is supported, and the radiation field is dynamically updated. According to the method, the cutting operation of the activity non-uniform radioactive source can be simulated, the problem that the radioactive activity of each cutting product cannot be represented after cutting by a traditional method is solved, the radiation field dynamic calculation in the activity non-uniform radioactive source cutting process can be simulated, initial modeling of the radiation environment only needs to be carried out once, and the efficiency is improved. And repeated modeling is not needed.

A substrate processing method with improved etching selectivity includes: a first operation for forming a film on a stepped structure having a top surface, a bottom surface, and side surfaces connecting the top surface and the bottom surface, wherein a first atmosphere is set to shorten the mean free path of plasma ions and make the plasma ions non-directional; and a second operation for changing the bonding structure of a part of the film, wherein a second atmosphere is set to make the plasma ions directional, wherein the first operation is repeated multiple times, the second operation is performed for a predetermined period of time, the first operation and the second operation form a set of cycles, and the set of cycles is repeated multiple times.

To provide a pressure sensor capable of preventing deterioration of measurement accuracy due to a deposition film with a structure to be easily manufactured.SOLUTION: A pressure sensor includes: a diaphragm 28 for partitioning between a fluid chamber to which measured fluid is introduced and an inner space; a sensor element 22 for detecting pressure based on a displacement of the diaphragm 28; and a tabular structure 21 opposing to the diaphragm 28 at a predetermined interval. The structure 21 includes a plurality of above-structures 23 aligned with penetration areas 33 in a surface direction orthogonal to a thickness direction. The above-structure 23 has a surface which is not vertical to the diaphragm 28 at a distance equal to or less than a mean free path from a pressure reception surface 34 of the diaphragm 28.SELECTED DRAWING: Figure 2

The application discloses a sensor structure and a simulation method for distinguishing different molecular weight gases, the sensor structure comprising a semiconductor nanotube array and an electrode, the electrode being in contact with the top and bottom of the semiconductor nanotube array, and the nanotube diameter being smaller than the mean free path of the gas to be detected; the simulation method comprising: establishing an axisymmetric two-dimensional section geometric model of a single nanotube structure in the semiconductor nanotube array by using a finite element simulation software, adding a semiconductor and a free molecule flow physical field interface, setting material properties and boundary conditions, dividing a grid and analyzing the diffusion of different molecular weight gases and the sensor response process by using a transient solver; and the application realizes the distinction of the sensor to different molecular weight gases through different diffusion processes in the nanotube with a diameter smaller than the mean free path of the gas to be detected and different response results of the sensor, and solves the problem of poor gas distinguishing ability of the semiconductor gas sensor in the prior art.

The invention discloses a speckle pumping microscopic system for measuring the average free path of a photon-generated carrier. The speckle pumping microscopic system comprises a laser light source, a pumping light path, a detection light path, a signal acquisition module and an image processing module, the laser light source is used for outputting pump light and probe light with selected wavelengths, and the pump light and the probe light are combined to the signal acquisition module through a pump light path and a probe light path respectively; a beam shaping module is arranged on the pump light path and comprises two objective lenses and a diffusion sheet placed at the focal points of the two objective lenses; the signal acquisition module is used for exciting a signal on the surface of the sample and shooting a signal returned from the sample; and the image processing module is in communication connection with the camera and is used for performing Fourier amplitude spectrum processing on the shot signal to obtain the average free path, the service life and the bipolar diffusion coefficient of the photon-generated carrier of the sample. According to the invention, the pump light is shaped into speckles, so that the measurement covers a ballistic region and a diffusion region, and the technical problem of measuring the average free path in a non-equilibrium state by an experiment is solved.

A method of ion mobility spectrometry and an ion mobility spectrometer. The method includes introducing a sample ion packet into a chamber, the sample ion packet containing ions for analysis and the chamber containing a drift region and a deflection region. The sample ions are transferred toward the deflection region on a drift trajectory passing through the drift region, wherein the sample ions are separated according to their ion mobility when passing through the drift region. The sample ions received from the drift region are then transferred on a deflection trajectory passing through the deflection region, while changing the direction of the sample ions on the deflection trajectory to move toward the same drift region or another drift region. The chamber is maintained at a pressure that is substantially uniform throughout the chamber, the pressure being such that the mean free path of the ions for analysis is greater than the length of the deflection trajectory and less than the length of the drift trajectory.

The application discloses a simulation method for tokamak neutral beam injection and fast ion deposition. In the numerical simulation of the neutral beam particle injection and ionization process in a tokamak device, the physical parameters of the neutral beam injection device are determined first, then the injection source is simplified by using a narrow particle beam model, the neutral beam particle density of a reference point given under geometric conditions is calculated, the average free path of the neutral beam particle ionization is calculated after the parameters of the position of the reference point in the plasma interior are obtained, the ions in different regions are divided by using a non-uniform grid and are given different weights, and finally the simulation process of the neutral beam injection is realized. The application realizes the simulation of the injection process of the neutral beam particles by using the narrow particle beam model, can obtain the neutral particle and fast ion distribution at any position in the plasma, has high calculation efficiency and strong numerical stability, and is a stable and efficient numerical simulation method.

A method for patterning a substrate includes providing a substrate, and depositing a multi-layer stack including N layers on the substrate. N is an integer greater than one. The N layers include N mean free paths for secondary electrons, respectively. The method includes depositing a photoresist layer on the multi-layer stack, wherein the N mean free paths converge in the photoresist layer. Another method for patterning a substrate includes providing a substrate and depositing a layer on the substrate. The layer includes varying mean free paths for secondary electrons. The method includes depositing a photoresist layer on the layer. The varying mean free paths for secondary electrons converge in the photoresist layer.

The E×B thermoelectric effect is based on the E×B drift, a CPT phenomenon that biases the velocity distribution of charged particles and transports them along cycloids perpendicularly to the E and B fields. This transport mechanism relies on the configuration of the electromagnetic fields, not on phonon drag and temperature difference. The resulting downstream carrier concentration produces a voltage that drives a current through a load. To close the electrical loop, the drift is turned on in the forward channel by increasing mobility and decreasing concentration, and off in the return channel by decreasing mobility and increasing concentration. Power is maximized when the Hall resistivity is matched to the sum of the Drude resistivity of the semiconductor and the equivalent load resistivity. It is also maximized at the thermodynamic threshold, where the mean free path equals the size of the cycloids. This threshold is a powerful design optimization tool.

A lighting device (10) is provided comprising a first light emitting element (11); an envelope (20) enclosing the first light emitting element (11), the envelope (20) being translucent, the envelope (20) having a wall thickness TE and a mean free path. A second light emitting element (12) arranged in connection with the envelope (20), such that the envelope (20) is arranged to act as a light guide for light emitted by the second light emitting element (12). The envelope (20) comprises a matrix material in which scattering particles are dispersed in a concentration such that the mean free path is larger than the wall thickness TE. The matrix material has a matrix material refractive index RIM and the scattering particles have a scattering particle refractive index RISP, and 0.5 ≤ |RIM - RISP| ≤ 1.5.

The invention discloses a heating element and a preparation method thereof and an electronic atomization device, the heating element comprises a base body, a metal heating body and a plurality of vacancy clusters distributed in the metal heating body, the density of the vacancy clusters is 1 * 10 < 18 > cm <-3 >-5 * 10 < 19 > cm <-3 >, and the resistivity of the heating element is not lower than 160 mu omega.cm. The heating element provided by the invention contains the vacancy clusters with proper density, and the vacancy clusters can be used as scattering centers of electrons to generate a strong scattering effect on the average free path of current carriers, so that the resistivity of the heating element is improved.

The application discloses a method for single-shot imaging of an internal target of a scattering medium based on near-infrared light. The method utilizes statistical characteristics of speckle and a conclusion that a square root of a covariance of the speckle is equal to an amplitude of autocorrelation of the target, realizes single-shot imaging of the internal target of the thick scattering medium based on the near-infrared light, and can realize imaging of an internal target of fresh chicken breast tissue with a maximum of 20 mean free paths and a maximum imaging resolution of 150 microns. The method only needs to shoot a speckle corresponding to the target to clearly reconstruct the image, which greatly reduces a calculation amount in scattering imaging; the near-infrared light is used as a light source to improve imaging depth, the maximum imaging depth can reach 20 mean free paths, and the method provides a new thought for applications in the fields of biomedicine and the like.

The application discloses a high-throughput calculation method of electric transport performance based on deformation potential approximation. In the method, the electron relaxation time involved in the calculation of the electric transport performance is only considered as the electric-acoustic interaction, and the electric-acoustic interaction is described by using the deformation potential approximation. A high-throughput calculation method of the deformation potential constant is developed, the average value of the first band is used as a reference state, and the obtained deformation potential constant dataset is used for high-throughput electric transport performance calculation. Compared with the constant relaxation time approximation and the constant mean free path approximation method, the method has higher precision, and compared with the precise electric-acoustic coupling method, the method is more suitable for high-throughput calculation in terms of cost and time. The method is based on the MatHub-3d database, 11993 semiconductor materials are screened from the database, the deformation potential constants of the 11993 semiconductor materials are high-throughput calculated, and the electric transport performance of 10195 semiconductor materials is high-throughput predicted by using the deformation potential constant dataset.

A method of depositing a material on a substrate is provided, the method comprising: generating a plasma remote from one or more sputtering targets adapted for plasma sputtering, wherein at least one different region of the one or more targets comprises an alkali metal, an alkaline earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, or a combination thereof; generating a sputtered material from the one or more targets using the plasma; and depositing the sputtered material on a substrate, the working distance between the target and the substrate being within + / - 50% of the theoretical mean free path of the system.

This invention discloses a method for selective epitaxy of the SiGe:C base region in high-speed silicon-germanium (HBT), comprising: providing a patterned substrate having a base region growth window; performing RCA cleaning on the patterned substrate; forming a low-pressure environment in the epitaxial chamber; and forming the SiGe:C base region in the base region growth window of the patterned substrate through selective epitaxy. In this invention, optimized pretreatment of the patterned substrate surface effectively suppresses the etching damage caused by highly reactive carbon atoms and their uncontrollable migration on the dielectric surface; thereby significantly widening the process window for selective SiGe:C epitaxy and improving process stability and repeatability; conducting the reaction under low pressure increases the mean free path of gas molecules and facilitates surface reaction control, strengthening the dependence of growth / etching on surface chemical properties and enhancing selectivity.