Abstract: The present application relates to an LED epitaxial structure and the preparation method and application thereof. The LED epitaxial structure comprises a first multiple-quantum-well light-emitting layer and a second multiple-quantum-well light-emitting layer. The first multiple-quantum-well light-emitting layer comprises a first shoes layer, a first well layer, a first cap layer, and a first Barrier layer epitaxially grown from bottom to top in sequence. The second multiple-quantum-well light-emitting layer comprises a second shoes layer, a second well layer, a second cap layer, and a second Barrier layer epitaxially grown from bottom to top in sequence. The technical solutions disclosed in the present application can solve the problem that the 365 nm to 375 nm wave band LED would emit yellow light.

Abstract: Embodiments of the present invention disclose a matrix multiplier, and relate to the field of data computing technologies, so as to divide two matrices into blocks for computation. The matrix multiplier includes: a first memory, a second memory, an operation circuit, and a controller, where the operation circuit, the first memory, and the second memory may perform data communication by using a bus; and the controller is configured to control, according to a preset program or instruction, a first matrix and a second matrix to be divided into blocks, and control the operation circuit to perform a multiplication operation on corresponding blocks in the first memory and the second memory based on block division results of the controller. The matrix multiplier may be configured to perform a multiplication operation on two matrices.

Abstract: A method for preparing an active catalyst for high-efficiency denitration is disclosed. The method includes: a catalyst raw material is charged into a denitration reactor, NH3 and an inert gas are introduced and then heating is performed, and the temperature is held and then natural cooling is performed, thereby obtaining the catalyst. The active catalyst can greatly improve the denitration activity in low temperature range, and can not only improve the denitration efficiency under the condition without SO2 and H2O, but also can improve the denitration efficiency under the condition with both SO2 and H2O. The service life of the catalyst is prolonged under the premise of not changing the existing catalyst preparation process, and the economic benefit is significant. The denitration efficiency of a powder catalyst can be increased by 25%, and the denitration efficiency of a honeycombed catalyst or a corrugated catalyst can be increased by 20%.

Abstract: A method for preparing an active catalyst for high-efficiency denitration is disclosed. The method includes: a catalyst raw material is charged into a denitration reactor, NH3 and an inert gas are introduced and then heating is performed, and the temperature is held and then natural cooling is performed, thereby obtaining the catalyst. The active catalyst can greatly improve the denitration activity in low temperature range, and can not only improve the denitration efficiency under the condition without SO2 and H2O, but also can improve the denitration efficiency under the condition with both SO2 and H2O. The service life of the catalyst is prolonged under the premise of not changing the existing catalyst preparation process, and the economic benefit is significant. The denitration efficiency of a powder catalyst can be increased by 25%, and the denitration efficiency of a honeycombed catalyst or a corrugated catalyst can be increased by 20%.

Abstract: A security check method includes: pre-creating at least four concurrently operating threads, one thread being responsible for movement control and data acquisition, one thread being responsible for imaging processing, one thread being responsible for interface displaying, and one thread being responsible for target detection and recognition; then the four concurrently operating threads divide original echo data of a human body to be checked into data of a plurality of adjacent overlapped azimuthal segments during data processing and perform individual processing on the data of each azimuthal segment. The security check system includes a thread creating unit, a first thread parallel unit, a second thread parallel unit, a third thread parallel unit, a fourth thread parallel unit, and a thread loop control unit. Because subsequent data processing is not required to be performed after the acquisition of all data is completed, the time for a security check process is reduced.

Abstract: The invention provides a series of halogenated tetracyclic triterpene derivatives and their preparation and application. It is represented by the following general structural formula: R1 is halogen, R2 is H, and the halogen is selected from fluorine, chlorine, bromine or iodine; or R1 and R2 are each fluorine, and R3 is an amine, alcohol, amino acid, peptide or phosphate linked to oxygen through an acyl group. The derivatives are relatively stable in rat whole blood through pharmacokinetic studies. The absolute bioavailability after a single intragastric administration for male and female rats was 15.6% and 28.4% respectively. The mean bioavailability was 22%. The derivatives showed better in vivo activities compared with the existing standard drugs enalapril and sacubitril valsartan sodium. Meanwhile, hydrophilic prodrugs of the tetracyclic triterpenoid derivatives in the present invention were prepared. The derivatives of the present invention can be used for preparing cardiovascular medicines.

Abstract: A security check method includes: pre-creating at least four concurrently operating threads, one thread being responsible for movement control and data acquisition, one thread being responsible for imaging processing, one thread being responsible for interface displaying, and one thread being responsible for target detection and recognition; then the four concurrently operating threads divide original echo data of a human body to be checked into data of a plurality of adjacent overlapped azimuthal segments during data processing and perform individual processing on the data of each azimuthal segment. The security check system includes a thread creating unit, a first thread parallel unit, a second thread parallel unit, a third thread parallel unit, a fourth thread parallel unit, and a thread loop control unit. Because subsequent data processing is not required to be performed after the acquisition of all data is completed, the time for a security check process is reduced.

Abstract: A nematic phase liquid crystal compound with negative dielectric constant has a structure represented by wherein R1 represents a hydrogen atom or linear alkyl having 1 to 8 carbon atoms or linear alkenyl having 1-8 carbon atoms, or an alkoxy or alykenoxy formed by substituting one or nonadjacent two CH2 in the linear alkyl or alkenyl with oxygen atom, wherein 0 to 4 hydrogen atoms of R1 group can be substituted with fluorine; R2 represents a hydrogen atom or linear alkyl having 1 to 8 carbon atoms, or R2 represents a linear fluoroalkyl having 1 to 8 carbon atoms, in which group 1 to 4 hydrogens can be substituted with fluorine atoms; A represents a benzene ring or 1,4-cyclohexane ring, if A is a benzene ring 0 to 4 hydrogen atoms on the benzene ring may be substituted with fluorine; n=1 to 2, and m=0 to 2.

Abstract: A nematic phase liquid crystal compound with negative dielectric constant has a structure represented by wherein R1 represents a hydrogen atom or linear alkyl having 1 to 8 carbon atoms or linear alkenyl having 1-8 carbon atoms, or an alkoxy or alykenoxy formed by substituting one or nonadjacent two CH1 in the linear alkyl or alkenyl with oxygen atom, wherein 0 to 4 hydrogen atoms of R1 group can be substituted with fluorine; R2 represents a hydrogen atom or linear alkyl having 1 to 8 carbon atoms, or R2 represents a linear fluoroalkyl having 1 to 8 carbon atoms, in which group 0 to 4 hydrogens can be substituted with fluorine atoms; A represents a benzene ring or 1,4-cyclohexane ring, if A is a benzene ring 0 to 4 hydrogen atoms on the benzene ring may be substituted with fluorine; n=1 to 2, and m=0 to 2.