40 results about "Diffusion theory" patented technology

The present invention provides systems and methods for obtaining a three-dimensional (3D) representation of one or more light sources inside a sample, such as a mammal. Mammalian tissue is a turbid medium, meaning that photons are both absorbed and scattered as they propagate through tissue. In the case where scattering is large compared with absorption, such as red to near-infrared light passing through tissue, the transport of light within the sample is described by diffusion theory. Using imaging data and computer-implemented photon diffusion models, embodiments of the present invention produce a 3D representation of the light sources inside a sample, such as a 3D location, size, and brightness of such light sources.

The invention discloses a river and lake bottom sludge pollutant flux test method and a river and a device based on a diffusion theory. The method comprises the following steps of: A, acquiring a bottom sludge sample; B, putting the bottom sludge into a base of an experimental device, and enabling the sludge surface to be horizontal; C, slowly injecting water to a column port along a column wall; D, injecting running water into the experimental device without the bottom sludge; E, standing for a certain time; F, measuring the pollutant concentration of the taken water sample; G, calculating a degrading coefficient of the pollutant in the water; H, calculating an initial concentration value of the bottom sludge water; and I, calculating a pollutant exchange flux of a water-sludge interface. A base plate is fixed at the bottom of a constant-temperature water tank; a base wall is arranged on the base plate; a lower flange disk is arranged on the upper part of the base wall; an upper flange disk is arranged at one end of a column body; and an upper flange disk fixing bolt flange hole is formed in the upper flange disk. The method is feasible, and is convenient to operate; the experimental device has a rational and simple structure; operations of accommodating deposits, sampling water samples and the like are extremely convenient; and outstanding economic benefit is achieved.

This invention discloses a new type of flow field uniform diffuser. Apart from the new design to the diameter of the tube, it utilizes the turbulent flow diffusion theory of the flow field to build up an idea of setting a first and a second uniform flow boards with rectangular holes in the diffusion tube on the basis of the current inlet, outlet and diffusion tubes which has the advantages of short uniform flow length, uniform flows and small occupied space.

The invention provides a window fusion method based on the heat diffusion theory. The method includes the steps that each initial detection window corresponds to one position in a thermodynamic system; a heat conduction coefficient between positions, corresponding to any two initial detection windows, in the thermodynamic system is calculated; a linear anisotropy heat diffusion equation which is in a discrete version under a steady state is established by using of the heat conduction coefficient between any two positions; K positions are selected in the system as heat sources to enable the temperature sum of the whole system to reach the maximum under the condition of heat diffusion; the repeated initial detection windows are eliminated through a non-maxima suppression method because duplicate detection of the corresponding K detection windows still possibly exists after the K positions of the heat resources are determined. According to the window fusion method based on the heat diffusion theory, the method of maximizing the temperature sum of the system under the condition of linear anisotropy heat diffusion is utilized for simulating an objective law of the initial detection windows, and therefore precision of target detection can be greatly improved.

Gas chromatography separation simulation method based on random diffusion theory: the establishment of the cylindrical structure of the column and its internal energy barrier; the target separation particles do free random diffusion motion in the cylinder, and their velocity has distribution characteristics; the target separation particles are outside the energy barrier The area also performs directional diffusion motion. The driving force of directional diffusion is the carrier gas, and its diffusion speed and direction are the same as the flow rate of the carrier gas. To simulate the diffusion and separation process of a large number of particles in the chromatographic column, the time distribution of the particles flowing out of the chromatographic column is for the detection signal. The advantage of the invention is that the key information that restricts the diffusion behavior is retained, the interaction between particles is simplified, the calculation amount is reduced, the operation efficiency is improved, and the dynamic simulation of the whole process of gas chromatography is realized.

The invention relates to the technical field of films, in particular to an adatom diffusion model for adjusting and controlling the coarsening rate. An adatom diffusion theory is used for guiding practice, complex diffusion is simplified, uphill diffusion and downhill diffusion which influence the surface coarsening rate are only considered, the 'adatom diffusion' model is established, and the relationship between microcosmic adatom diffusion and macroscopic surface coarsening is quantitatively revealed; and according to the adatom diffusion model for controlling the coarsening rate, experiments can be guided to prepare films with various surface roughness in situ, the changing degree of the surface roughness of the films can further be predicted, and the adatom diffusion model is widely applied to various sedimentation preparation methods.