Abstract: The present disclosure discloses a method for producing raw cotton of machine-harvested long-staple cotton with a modal length of greater than or equal to 35 mm, including the steps: planting sea-island long-staple cotton and machining seed cotton, wherein planting the sea-island long-staple cotton includes preparation before machine harvesting, defoliation and ripening, choosing a cotton variety, etc.; and machining the seed cotton includes preparation before seed cotton ginning, mechanical separation of cotton seeds and raw cotton, and finishing the separated raw cotton. Raw cotton fibers obtained by the method of the present disclosure have main quality indexes that: a fiber length is 36.5-38.4 mm, a specific strength is 42.3-46.1 cN/tex, a uniformity is 86.2-87.0%, a foreign-fiber content is 0.2-0.4 g/t, and an impurity content is 2.6-3.4%.

Abstract: A handheld MPI system and method based on field free line (FFL) rotation is provided. The handheld MPI system includes: a gradient module configured to construct a gradient field with an FFL; a cooling module configured to cool the gradient module; an excitation module configured to excite magnetic particles in a region of the FFL; a detection module configured to receive an excitation response signal of the magnetic particles and counteract an excitation signal directly induced by a reception coil; a rotation module configured to control the gradient module and the cooling module to rotate around an axis of an excitation coil; a control and signal processing module configured to control each module to operate as needed, and process a received magnetic particle induction signal; and an image reconstruction module configured to reconstruct a magnetic particle distribution into a two-dimensional image.

Abstract: In a magnetic particle imaging reconstruction method based on a neural network constrained by a forward model, a system matrix is obtained through calibration, voltage data generated by a specimen is measured, collected data are transformed into a frequency-domain by Fourier transform, frequency features of data are screened by a signal-to-noise ratio threshold, a reconstruction network is built by a Pytorch to realize mapping from one-dimensional voltage data to a multi-dimensional magnetic particle concentration distribution, the system matrix is used as the forward model of magnetic particle imaging, and simulated voltage data is generated according to a reconstructed multi-dimensional magnetic particle concentration distribution, a difference between the simulated voltage data and input voltage data is calculated as a loss function for network parameter updating, a total variation regularization term is added to the loss function, and training parameters and regularization parameters are adjusted to achie

Abstract: An MPI reconstruction method, device, and system based on a RecNet model include obtaining a one-dimensional (1D) MPI signal on which imaging reconstruction is to be performed, taking the 1D MPI signal as an input signal, and inputting the input signal and a velocity signal of an FFP corresponding to the input signal into a trained magnetic particle reconstruction model RecNet for image reconstruction to obtain a two-dimensional (2D) MPI image, where the magnetic particle reconstruction model RecNet is constructed based on a domain conversion network and an improved UNet network. The MPI reconstruction method, device, and system obtain a high-quality and clear magnetic particle distribution image without obtaining the system matrix.

Abstract: An MPI reconstruction method, device, and system based on a RecNet model include obtaining a one-dimensional (1D) MPI signal on which imaging reconstruction is to be performed, taking the 1D MPI signal as an input signal, and inputting the input signal and a velocity signal of an FFP corresponding to the input signal into a trained magnetic particle reconstruction model RecNet for image reconstruction to obtain a two-dimensional (2D) MPI image, where the magnetic particle reconstruction model RecNet is constructed based on a domain conversion network and an improved UNet network. The MPI reconstruction method, device, and system obtain a high-quality and clear magnetic particle distribution image without obtaining the system matrix.

Abstract: A method and system for reconstructing a magnetic particle distribution model based on time-frequency spectrum enhancement are provided. The method includes: scanning, by a magnetic particle imaging (MPI) device, a scan target to acquire a one-dimensional time-domain signal of the scan target; performing short-time Fourier transform to acquire a time-frequency spectrum; acquiring, by a deep neural network (DNN) fused with a self-attention mechanism, a denoised time-frequency spectrum; acquiring a high-quality magnetic particle time-domain signal; and reconstructing a magnetic particle distribution model. The method learns global and local information in the time-frequency spectrum through the DNN fused with the self-attention mechanism, thereby learning a relationship between different harmonics to distinguish between a particle signal and a noise signal.

Abstract: An apparatus and a method for magnetic particle imaging and thermotherapy fusion based on field-free line inertial scanning comprises a magnetic body group, an induction coil, a living body bed, a control device, a display device, an image processing device and a cooling system. The magnetic body group comprises a long curved magnetic body pair and a cylindrical magnetic body. The control device is used to scan and image the target living body and perform thermotherapy on a preset area.

Abstract: A hysteresis effect-based Field Free Point-Magnetic Particle Imaging (FFP-MPI) method includes the following steps: acquiring a hysteresis loop model of Superparamagnetic Iron Oxide Nanoparticles (SPIOs); calculating to obtain a Point Spread Function (PSF) of the SPIOs on the basis of a sinusoidal excitation magnetic field and the hysteresis loop model of the SPIOs; acquiring an original reconstructed image of FFP-MPI on the basis an FFP moving track and a voltage signal; performing deconvolution on the original image with respect to the PSF considering an hysteresis effect, so as to obtain a final reconstructed image; the artifacts and phase errors of image reconstruction caused by the hysteresis effect of the SPIOs with large particle sizes are reduced, the deficiency in reconstruction by the traditional reconstruction method that ignores the hysteresis effect is overcome, the reconstruction speed and the resolution are greatly improved, and the application range of the SPIOs is expanded.

Abstract: A fluorescence molecular tomography reconstruction method includes: obtaining an MPI three-dimensional tomographic image, a body surface near-infrared fluorescence two-dimensional image, and a CT image; constructing an SIS capable of accommodating the ROI, and discretizing the SIS by using a finite element method; performing data mapping to obtain detected surface fluorescence signals, a prior of the anatomical structure of tissues and organs around the tumor and a prior of the tumor; performing forward model calculation to obtain a system matrix and constructing an objective function; iteratively solving the objective function based on the Laplacian regularization matrix to obtain a fluorescence molecular tomography reconstruction result; the present invention adopts MPI to guide the FMT, achieving complete morphology and structure, clear tissue edges, and high accuracy of spatial position.

Abstract: The present disclosure belongs to a field of biomedical imaging technology, and in particularly to a non-uniform excitation field-based method and system for performing a magnetic nanoparticle imaging. The present disclosure includes: separating the non-uniform excitation field into independent space and current time functions by a spatialtemporal separation method; calculating a normalized signal peak through the current time function; constructing a reconstruction mathematical model based on the normalized signal peak and an imaging subunit volume; and quantitatively reconstructing a spatial distribution of a nanoparticle by combining the normalized signal peak, a non-uniform spatial function of the excitation field and the reconstruction mathematical model, so as to achieve the magnetic nanoparticle imaging of a to-be-reconstructed object.

Abstract: The present disclosure provides a light-weight flexible high-thermal-conductivity nano-carbon composite film and a method for preparing same. The nano-carbon composite film includes a plurality of composite units laminated sequentially. The composite unit includes flexible adhesive layers and a graphene film layer, and the flexible adhesive layers are disposed on both sides of the graphene film layer. The preparation method includes sequentially laminating the composite units and hot pressing to obtain the nano-carbon composite film. The nano-carbon composite film has the characteristics of high thermal conductivity, light weight and flexibility, and has an in-plane thermal conductivity of up to 500 W/m·K or higher, a density of 2.0 g/cm3 or less, and still a thermal conductivity of 500 W/m·K or higher after the nano-carbon composite film is repeatedly bent by 180° for 50 times while there is no peeling of graphene from the surface.

Abstract: A movable platform includes one or more propulsion units configured to provide a driving force to the movable platform and a control unit operatively coupled to the one or more propulsion units. The control unit is configured to: communicate with a plurality of batteries adapted to supply current to the one or more propulsion units; obtain one or more electrical characteristics of each of the plurality of batteries; and determine, based on the electrical characteristics, a controlling signal to set a power supply state for at least one of the plurality of batteries.

Abstract: The present disclosure belongs to a field of biomedical imaging technology, and in particularly to a non-uniform excitation field-based method and system for performing a magnetic nanoparticle imaging. The present disclosure includes: separating the non-uniform excitation field into independent space and current time functions by a spatialtemporal separation method; calculating a normalized signal peak through the current time function; constructing a reconstruction mathematical model based on the normalized signal peak and an imaging subunit volume; and quantitatively reconstructing a spatial distribution of a nanoparticle by combining the normalized signal peak, a non-uniform spatial function of the excitation field and the reconstruction mathematical model, so as to achieve the magnetic nanoparticle imaging of a to-be-reconstructed object.

Abstract: A multi-color quantitative magnetic nanoparticle imaging method and system based on trapezoidal wave excitation solves the problem that the existing technology cannot implement multi-color quantitative magnetic particle imaging. The method includes: constructing, based on hysteresis effect and hysteresis inertial growth differences of n superparamagnetic iron oxide nanoparticles (SPIOs) under trapezoidal wave excitation, an equation set of quality of n SPIOs in a to-be-tested sample formed by any composition of n SPIO standard products; solving the equation set to obtain the quality distribution of the to-be-tested sample at position r; and performing rearrangement, color assignment, and image merging on the quality distribution to implement multi-color quantitative imaging of various particles in magnetic particle imaging (MPI). The method broadens the functions of MPI to realize multi-color quantitative imaging, such that MPI has greater potential for application in the medical field.

Abstract: A hysteresis effect-based Field Free Point-Magnetic Particle Imaging (FFP-MPI) method includes the following steps: acquiring a hysteresis loop model of Superparamagnetic Iron Oxide Nanoparticles (SPIOs); calculating to obtain a Point Spread Function (PSF) of the SPIOs on the basis of a sinusoidal excitation magnetic field and the hysteresis loop model of the SPIOs; acquiring an original reconstructed image of FFP-MPI on the basis an FFP moving track and a voltage signal; performing deconvolution on the original image with respect to the PSF considering an hysteresis effect, so as to obtain a final reconstructed image; the artifacts and phase errors of image reconstruction caused by the hysteresis effect of the SPIOs with large particle sizes are reduced, the deficiency in reconstruction by the traditional reconstruction method that ignores the hysteresis effect is overcome, the reconstruction speed and the resolution are greatly improved, and the application range of the SPIOs is expanded.

Abstract: The present disclosure includes: transforming a time-domain voltage signal collected by an MPI system device to a frequency domain; calculating a square root of a square sum of a real part and an imaginary part at each frequency point of a frequency domain signal; arranging acquired amplitudes in a descending order, and acquiring a screening threshold by an amplitude ratio method; screening an amplitude through the screening threshold and constructing frequency domain signal data; acquiring a row vector of a system matrix corresponding to each frequency point of the data, so as to construct an update system matrix; and solving, based on the frequency domain signal array and the update system matrix, an inverse problem in a form of a least square based on an L2 constraint to obtain a three-dimensional magnetic particle concentration distribution result, so as to achieve a fast reconstruction of the MPI system.

Abstract: The present invention relates to a method for a non-specific amplification of a natural short-fragment nucleic acid, comprising the following steps: (1) performing end repair on the natural short-fragment nucleic acid to obtain an end-repaired nucleic acid; (2) connecting the end-repaired nucleic acid to a double-stranded linker to obtain a ligation product, in which each strand of the double-stranded linker contains only three bases; (3) performing PCR amplification on the ligation product using a PCR primer labeled with deoxyuridine to obtain a PCR product, in which the PCR primer is completely or partially complementary to a strand of the double-stranded linker and contains only three bases; and (4) digesting the PCR product by using an enzyme having a deoxyuridine cleavage function, followed by digesting the PCR product by using an enzyme with both 5??3? polymerase activity and 3??5? exonuclease activity in the presence of a deoxynucleotide solution to obtain a non-specific amplification product of the na

Abstract: A magnetic particle imaging method based on a non-ideal Field Free Point (FFP), including the following steps: setting external magnetic field conditions of a non-ideal FFP and an ideal FFP, and obtaining a magnetization vector M of Superparamagnetic Iron Oxide Nanoparticles (SPIOs) and a Point Spread Function (PSF) in combination with a Langevin function; obtaining a signal feature on basis of a voltage signal of a detection coil of a Magnetic Particle Imaging (MPI) instrument; performing integral transformation on the voltage signal collected by the detection coil of the MPI instrument to obtain a voltage signal of an equivalent ideal FFP; averaging the moving speed of an FFP of the MPI instrument to obtain a moving speed of the equivalent ideal FFP; obtaining an equivalent Three-Dimensional concentration reconstruction image on basis of the voltage signal of the equivalent ideal FFP and a moving speed of the equivalent ideal FFP.

Abstract: Disclosed are a control method and system for a parallel converter system, including a common AC voltage controller and a separate current controller for each converter; the AC voltage controller generates an active current, a wattless current, and a system voltage phase reference value and, by means of communication, sends same to the current controller of each converter in island control mode to be a converter control signal; the active and wattless current outputted by each converter, along with the corresponding current reference value, accomplish the objective of the parallel converter system collectively controlling the amplitude and frequency of an AC bus voltage. The method and system are highly reliable and effectively ensure the synchronization of a plurality of converters.

Abstract: A magnetron sputtering scanning method for manufacturing a silicon carbide optical reflector surface modification layer and improving surface profile includes (1) for a silicon carbide plane mirror to be modified, first utilizing diamond micro-powders to grind and roughly polish an aspherical silicon carbide reflector with a conventional polishing or CCOS numerical control machining method; (2) after the surface profile precision of the silicon carbide reflector satisfies a modification requirement, utilizing a strip-shaped magnetron sputtering source to deposit a compact silicon modification layer on the surface of the silicon carbide reflector; (3) then, utilizing a circular sputtering source to modify and improve the surface profile of the reflector; and (4) finally, finely polishing the modification layer, and achieving the requirements for machining the surface profile and roughness of the reflector.