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31results about How to "Guaranteed reversibility" patented technology

Omni-directional prediction error histogram modification-based reversible image watermarking algorithm

The invention discloses an omni-directional prediction-based reversible image watermarking algorithm comprising the steps of watermark embedding and watermark detection, wherein the watermark embedding process comprises the following steps of: firstly, dividing an image into two mutually-disjointed pixel sets of S1 and S2; secondly, sequentially predicting the pixel sets of S1 and S2 with an omni-directional prediction method to obtain the predication error; and finally, modifying the prediction error histogram to embed the watermark. The watermark extraction process comprises the following steps of: firstly, dividing the image into two mutually-disjointed pixel sets of S1 and S2; secondly, sequentially predicting the pixel sets of S1 and S2 with the omni-directional prediction method according to the sequence opposite to the embedding sequence to obtain the predication error; and finally, extracting the watermark from the predication error, modifying the histogram and restoring the image. According to the invention, by adopting the sequentially-embedded and reversibly-extracting mode, the embedded watermark image can be restored after the watermark is extracted and the reversibility of the watermark of the image can be realized; by adopting the omni-directional prediction method to predict, the prediction error histogram has high centrality and the higher embedded capacity can be realized; and by using the histogram modification in the embedding process, the influence on the image is little and the image embedded with the watermark has favorable visual quality.
Owner:BEIHANG UNIV

Reversible video frequency watermark method based on interframe forecast error histogram modification

The invention relates to a reversible video frequency watermark method based on interframe forecast error histogram modification, comprising watermark embedding and watermark detection. The watermarkembedding process is carried out according to a video frequency negative sequence: firstly, utilizing the previous frame to carry out motion estimation to obtain an interframe forecast error, and thencarrying out the histogram modification on the interframe forecast error so as to embed a watermark. An extracting process is carried out according to a video frequency sequence mode: similarly, utilizing the previous frame to carry out the motion estimation to obtain a forecast error, and then extracting a watermark from the forecast error, and modifying a histogram to carry out the frame imagerecovery. The invention uses the mode of negative sequence embedding and sequence extracting, thereby an embedded video frequency frame can be recovered after the watermark is extracted, and the reversibility of the video frequency watermark is realized; the motion estimation is used according to the content relation of adjacent interframes to carry out prediction so as to enable the forecast error histogram to have the height centrality, and realize the bigger embedding content; in the embedding process, using the histogram modification enables that the influence on the frame image is small,and a watermark-embedded video frequency has high visual quality.
Owner:BEIHANG UNIV

Multistage sub-array focusing MVDR wave beam forming method

The invention relates to a multistage sub-array focusing MVDR wave beam forming method. According to the multistage sub-array focusing MVDR wave beam forming method, a common rapid frequency-domain broadband wave beam forming algorithm and a sub-array focusing MVDR algorithm are combined, a target orientation is firstly and roughly measured through the rapid frequency-domain broadband wave beam forming algorithm, then sub-arrays are divided, finally the target orientation is accurately measured through the sub-array focusing MVDR algorithm, and rapid and high-accuracy wave beam forming is achieved. The multistage sub-array focusing MVDR wave beam forming method includes the steps of 1, firstly completing rapid frequency-domain broadband wave beam forming on data received by a linear array sonar device through one-time time-domain FFT and airspace phase compensation, and completing initial estimation of the target orientation; 2, then carrying out peak detection on a common wave beam forming curve, after a target is found, carrying out sub-array dividing on a frequency-domain array signal, carrying out sub-array focusing MVDR wave beam forming on the orientation nearby the target, carrying out secondary orientation detection, and obtaining the more accurate target orientation. By means of the multistage sub-array focusing MVDR wave beam forming method, the performance of a whole sonar positioning system is improved, and meanwhile the requirements for the real-time performance, the high resolution and the tolerance are met.
Owner:INST OF ACOUSTICS CHINESE ACAD OF SCI

High-fidelity H.264/AVC video three-coefficient reversible steganography method

The invention discloses a high-fidelity H.264 / AVC video three-coefficient reversible steganography method which comprises two parts of an embedding method and an extraction method. The embedding method comprises the steps of: according to an H.264 / AVC video standard, carrying out coding operation on a YUV video sequence frame by frame to obtain quantized residual DCT coefficients of all macro blocks in a current coded frame; sequentially traversing a plurality of macro blocks in the current coded frame according to a sequence from top to bottom and from left to right, and selecting 4*4TU sub-blocks of which texture-complexity is greater than or equal to a set threshold; and according to a three-coefficient embedding strategy, completing embedding, and carrying out entropy coding to obtaina compressed video after embedding. According to the invention, a three-coefficient modulation strategy combines information of a vacuum value, a coefficient translation path and the like, the quantized residual DCT coefficients which do not need to be modified are filtered out, useless modification of a carrier is reduced, embedding efficiency of an algorithm is improved, and video quality and algorithm safety are ensured.
Owner:SOUTH CHINA UNIV OF TECH

Convolutional neural network system and convolutional neural network quantification method

The invention provides a convolutional neural network system and a convolutional neural network quantization method, and the system comprises: a quantization module which is used for carrying out thequantization of the input data of an ith convolution layer of the system and the weight and bias of the ith convolution layer, and wherein i is a positive integer; and a convolution module that is used for carrying out convolution calculation on the quantized input data of the ith convolution layer, the quantized weight and the quantized bias to obtain a convolution result of the ith convolution layer. According to the convolutional neural network system provided by the invention, the weight and bias of the convolutional layer needing to be quantized in the convolutional layer and the input data input into the convolutional layer are quantized, and convolution calculation is performed by using the quantized input data, the quantized weight and the quantized bias so as to obtain the calculation result of each convolutional layer. The calculation amount of the convolutional neural network is reduced, and the quantization precision of the convolutional neural network is improved.
Owner:HUAWEI TECH CO LTD

Method and system of obtuse angle prediction based on reversible information hiding

The present invention belongs to the data hiding technology field, and provides a method and system of obtuse angle prediction based on reversible information hiding. The method comprises: obtaining a carrier image and auxiliary information, wherein the auxiliary information comprises watermark information and a position map, performing preprocessing, determining the size of the scanning block and the image roughness, performing predication of the target pixel according to the maximum predicated angle, the reference pixel quantity and the location of the target pixel, obtaining the prediction error of the target pixel, embedding the watermark information into the carrier image according to the predication error of the target pixel and the storage information of the auxiliary information, forming a secret carrying image, identifying the auxiliary information in the secret carrying image, extracting the watermark information from the secret carrying image, restoring the pixel having correcting the pixel gray value and restoring the carrier image. The method and system of obtuse angle prediction based on reversible information hiding can improve the embedding capacity and the peak signal to noise ratio of the reversible information hiding technology and enhance the predication performance.
Owner:NORTH CHINA ELECTRIC POWER UNIV (BAODING)

Dynamic covalent bond cross-linked oil displacement polymer and preparation method thereof

The invention relates to a dynamic covalent bond cross-linked oil displacement polymer and a preparation method thereof. According to the invention, acrylamide is used as a main monomer to increase the length of molecular chains, so that the frictional resistance between the molecular chains is increased to improve the viscosity of a solution, diacetone acrylamide is used as a functional monomer to copolymerize with acrylamide to introduce keto-carbonyl into a polymer chain to realize crosslinking with adipic dihydrazide, and thus the nonionic polymer cross-linked by the dynamic acylhydrazone bonds is obtained. The polymer chain does not have ions, so that charge shielding and flocculation effects of various salt ions are avoided, and relatively high viscosity can be kept in hypersalinity water. The polymer takes an acylhydrazone bond which can be dynamically formed and dissociated as a chemical crosslinking point, and the acylhydrazone bond is used as a stimulus-responsive dynamic chemical bond, so that the reversibility of physical crosslinking is maintained, the strength of chemical crosslinking is also realized, and reversible formation and fracture can be realized under the stimulation of an external environment so as to overcome the defect of poor shear resistance of a traditional polymer.
Owner:SHANDONG UNIV

Medical image wavelet-domain real-time encryption and decryption algorithm based on multi-chaos system

The invention provides a medical image wavelet-domain real-time encryption and decryption algorithm based on a multi-chaos system. The medical image wavelet-domain real-time encryption and decryptionalgorithm based on the multi-chaos system includes the following steps of decomposing a medical image, encrypting wavelet coefficients, obtaining the encrypted medical image, and decrypting the medical image. Compared with related technologies, the medical image wavelet-domain real-time encryption and decryption algorithm based on the multi-chaos system adopts LeGaII5 / 3 integer wavelet transform to conduct three-grade wavelet grading on the initial medical image, and thus the relevance among pixels of the medical image is fully reduced; the medical image wavelet-domain real-time encryption anddecryption algorithm based on the multi-chaos system has high time efficiency and high security at the condition that an initial chaos value and system parameters are unknown.
Owner:COLLEGE OF APPLIED SCI JIANGXI UNIV OF SCI & TECH

Digital audio reversible watermarking algorithm based on side information prediction and histogram shifting

The invention discloses a digital audio reversible watermarking algorithm based on side information prediction and histogram shifting. The algorithm includes the following steps that the prediction coefficient of audio data and the prediction value of a sample are calculated; the prediction value is subtracted from the sample value to obtain a prediction error, two different histograms are constructed according to two modes of the side information prediction algorithm, and then watermarking information is embedded in the prediction error to obtain the prediction error containing a watermark; the prediction error containing the watermark is embedded in a next sample value of the current sample to obtain an audio value containing the watermark; an audio signal containing the watermark is received at the receiving end, the prediction value is subtracted from the sample value, an embedded signal is extracted by means of prediction error histogram shifting characteristics, and an original audio signal is restored in a lossless mode. Compared with an original prediction algorithm, the algorithm improves prediction performance; non-causality and histogram shifting are combined, so the algorithm has good embedability and low distortion rate when the embedding rate is low.
Owner:JINAN UNIVERSITY

Steam turbine oil product online monitoring and analyzing system and method for nuclear power

ActiveCN110397476ALow safety impactReduce retrofit riskFlow propertiesMachines/enginesNuclear powerFuel tank
The invention discloses a steam turbine oil product online monitoring and analyzing system and method for nuclear power. The system comprises an oil product online monitoring cabinet, a DCS system anda monitoring center, wherein the oil product online monitoring cabinet is used for making an analysis test on the lubricating oil of a steam turbine oil tank so as to generate steam turbine lubricating oil product online monitoring data. The DCS system is used for sending the steam turbine lubricating oil product online monitoring data to the monitoring center. The monitoring center comprises a basic data analysis module, an early warning module and a fault diagnosis module, wherein the basic data analysis module is used for conducting calculation and analysis on the steam turbine lubricatingoil product online monitoring data. The early warning module is used for monitoring results from the basic data analysis module, and when the steam turbine lubricating oil product online monitoring data is abnormal, the early warning module can generate alarm information. The fault diagnosis module is used for generating a preliminary diagnosis result through using a fault tree according to abnormal monitoring data. According to the online monitoring and analyzing system and method, the improved risk is small, abnormal parameters can be timely informed, and the primary diagnosis result can beaccurately provided.
Owner:SUZHOU NUCLEAR POWER RES INST +2

Sodium metal battery and electrochemical device

ActiveCN113451546AEnsure deposition uniformityLower deposition overpotentialNegative electrodesSecondary cellsElectrical batteryPole piece
The invention relates to a sodium metal battery and an electrochemical device. The battery comprises a positive pole piece and a negative pole piece; the negative pole piece is a negative current collector; the thickness of a sodium layer deposited in situ on the negative current collector after the battery is charged and discharged for the first time is larger than or equal to 30 nm. By utilizing the first irreversible capacity of a positive electrode material and the design optimization of a battery cell, after the battery cell is charged and discharged for the first time, the amount of residual sodium metal is enough, so that the sodium deposition layer with a certain thickness can be uniformly formed on the surface of the negative current collector; and therefore, higher nucleation energy required by deposition of sodium to the surface of the current collector in the subsequent charge-discharge cycle process is avoided, the overall deposition overpotential is reduced, and the deposition uniformity of sodium metal and the reversibility of the charge-discharge process are ensured.
Owner:CONTEMPORARY AMPEREX TECH CO

High-capacity encrypted image information hiding method based on block capacity label

The invention discloses a high-capacity encrypted image information hiding method based on a block capacity label, which comprises the following steps of: in a secret data hiding stage, processing predicted pixel points in an original image, partitioning an area formed by all the predicted pixel points by a content owner, scrambling all image blocks, and then hiding the image blocks by the content owner; obtaining a block capacity label of each scrambled image block; then correcting the absolute value of the prediction error value of each prediction pixel point in each scrambled image block, and then performing encryption; embedding first additional information and second additional information in the encrypted image according to the block capacity label; the data hider extracts a tag original value sequence from the encrypted image embedded with the additional information, and embeds secret data according to the tag original value sequence; in the secret data extraction and image restoration stage, the receiver extracts the first additional information, the second additional information and the secret data and restores the image; the method has the advantages that the original image can be restored in a lossless manner while the larger embedding capacity is obtained.
Owner:NINGBO UNIVERSITY OF TECHNOLOGY

Data storage method and device, computer readable storage medium and electronic equipment

The invention relates to a data storage method and device, a computer readable storage medium and electronic equipment. The method comprises the steps of obtaining original sensitive data in a data warehouse; backing up the original sensitive data to obtain backup sensitive data, independently storing the backup sensitive data into a data warehouse, and enabling the backup sensitive data not to flow in the data warehouse; and performing desensitization operation on the original sensitive data. Therefore, the risk of leakage of the sensitive data in the data warehouse circulation process can bereduced. Besides, the original sensitive data is backed up (namely backup sensitive data) and is independently stored, and the backup sensitive data does not flow in the data warehouse, so that the reversibility and uniqueness of the data can be ensured, and the requirements of a user on reversible operation of the sensitive data and table association operation based on sensitive fields are met.Moreover, the backup sensitive data does not flow in the data warehouse, so that the risk of sensitive data leakage can be reduced, and subsequent auditing of the sensitive data and tracing of the sensitive data leakage are facilitated.
Owner:BEIJING SANKUAI ONLINE TECH CO LTD

Whole-course multi-section synergetic sterilization and fresh-keeping method for shredded Qiongzhuea tumidinoda Hsueh bamboo shoots

The invention discloses a whole-course multi-section synergistic sterilization and fresh-keeping method of shredded Qiongzhuea tumidinoda Hsueh bamboo shoots, which comprises the following steps: blanching the Qiongzhuea tumidinoda Hsueh bamboo shoots with shells, removing the shells, putting the blanched Qiongzhuea tumidinoda Hsueh bamboo shoots into a blanching fixation machine, carrying out steaming fixation, carrying out color protection and brittleness protection on the whole or half cut Qiongzhuea tumidinoda Hsueh bamboo shoots, wherein the composite color protection agent is prepared bydissolving vitamin C, D-isoascorbic acid, sodium chloride and citric acid in water according to a certain proportion,the crispness-keeping agent is prepared by dissolving calcium chloride, sodium alginate and pectin in water according to a certain proportion; and then shredding, pickling to remove bitter taste, mixing, packaging in vacuum, then carrying out ultrahigh pressure treatment, precooling and liquid nitrogen quick-freezing treatment, and carrying out low-temperature freezing storage to realize long-term storage. According to the method, the storage time of the shredded Qiongzhuea tumidinoda Hsueh bamboo shoots can be prolonged to 2 years, the fresh-keeping effect is improved, original functional components of the raw materials are well preserved, the color and hardness are closeto those of fresh bamboo shoots, the taste is good, the product is safe, and no sulfur is left.
Owner:宜宾西华大学研究院 +1

Infrared and visible light image fusion method combining potential low-rank representation and convolutional neural network

The invention relates to the technical field of computer information, and discloses an infrared and visible light image fusion method combining potential low-rank representation and a convolutional neural network, and the method comprises the steps: carrying out the preprocessing of a visible light image and an infrared image, decomposing the image into a significant part and a low-rank part through the potential low-rank representation, and fusing the salient part and the low-rank part by using two full convolution models, and finally adding the fused salient part and the fused low-rank part to obtain a final fused image. The fusion result obtained through fusion is rich in detail information, and compared with an original low-illumination image, the scene target is clearer, and the contrast ratio of the image is improved.
Owner:SICHUAN UNIV

Supporting-anchoring composite reinforcing structure and method for rammed earth wall

The invention discloses a supporting-anchoring composite reinforcing structure and method for a rammed earth wall. The supporting-anchoring composite reinforcing structure comprises an opposite penetrating anchoring structure, a repairing structure and a supporting frame structure which are arranged on a ruin wall, wherein the supporting frame structure is supported on a ruin wall body, the opposite penetrating anchoring structure penetrates through the ruin rammed earth wall body and is fixedly connected with a supporting-anchoring connecting piece of the supporting frame structure, gap grouting bodies are injected into gaps of the ruin wall body through the repairing structure, adobe brick masonry is repaired and built on the missing part of the ruin rammed earth wall body, and composite reinforcement of the ruin rammed earth wall body is achieved. The supporting-anchoring composite reinforcing structure is a composite reinforcing structure integrating anchoring, repairing and building and supporting technologies, and the local and overall stability problem caused by earthen ruins longitudinal cracks and foundation erosion diseases is solved; and on the premise of meeting the cultural relic protection principle, the local safety of the ruins is improved, stress concentration is relieved, and meanwhile the overall stability and the anti-overturning capacity of the wall are greatly improved.
Owner:陕西建工第十三建设集团有限公司

Sodium metal battery and electrochemical device

ActiveCN114824167AEnsure deposition uniformityLower deposition overpotentialSecondary cellsNegative electrodesConductive coatingElectrical battery
The invention relates to a sodium metal battery and an electrochemical device, the battery comprises a positive pole piece and a negative pole piece, the negative pole piece is a negative current collector, and the thickness of a sodium layer deposited in situ on the negative current collector after the battery is charged and discharged for the first time is greater than or equal to 30nm, the first charge capacity of a positive active material in the positive pole piece is QC mAh / g, the first discharge capacity is QDmAh / g, the coating mass of the positive active material is CW g / cm < 2 >, and the theoretical volume gram capacity of sodium metal is X mAh / cm < 3 >, so that a conductive coating is arranged on at least part of the surface of the negative current collector, and the thickness of the conductive coating is 1-10 microns.
Owner:CONTEMPORARY AMPEREX TECH CO LTD

A system and method for on-line monitoring and analysis of steam turbine oil for nuclear power

ActiveCN110397476BLow safety impactReduce retrofit riskFlow propertiesMachines/enginesNuclear powerIndustrial engineering
The invention discloses an online monitoring and analysis system for steam turbine oil used in nuclear power, which includes an online oil monitoring cabinet, a DCS system and a monitoring center. Online monitoring data of lubricating oil products; DCS system is used to send the online monitoring data of steam turbine lubricating oil products to the monitoring center; the monitoring center includes basic data analysis module, early warning module and fault diagnosis module, and the basic data analysis module is used The online monitoring data of oil and oil products is calculated and analyzed; the early warning module is used to monitor the analysis results of the basic data analysis module, and when the online monitoring data of steam turbine lubricating oil products is abnormal, an alarm message is generated; the fault diagnosis module is used to use the The fault tree generates preliminary diagnostic results. The present invention has little modification risk, can timely notify abnormal parameters, and can accurately provide preliminary diagnosis results.
Owner:SUZHOU NUCLEAR POWER RES INST +2

Satellite transmission physical characteristic self-fusion type compression encryption algorithm for CTD marine observation data

The invention belongs to the field of ocean big data communication transmission, and provides a satellite transmission physical property self-fusion type compression encryption algorithm for CTD (Conductivity-Temperature-Depth) observation data. By extracting an initial value secret function, first-layer physical self-fusion encryption is realized, and 33% of data volume is reduced. Time is eliminated through mutual correction of time and pressure, second-layer physical self-fusion encryption is achieved, and the data size is reduced by 20%. New parameters are generated by performing cross coding on the water temperature and the conductivity of core data, so that third-level physical self-fusion encryption is realized, and the numerical value is reduced. And then the new sequence is fixed,sliced and recombined, a string of decimal numbers is provided as secret keys by the user, and offset replacement is performed on each element data bit by bit according to the secret keys. And finally, the data is converted into a binary system, bit splicing is performed, and overall compression is performed by using an LZW (Lempel-Ziv-Welch) compression algorithm. Therefore, the security problemand data volume control of CTD observation data satellite transmission are effectively solved.
Owner:CHINA NAT OFFSHORE OIL CORP +3

Obtuse angle prediction method and system based on reversible information hiding

The present invention belongs to the data hiding technology field, and provides a method and system of obtuse angle prediction based on reversible information hiding. The method comprises: obtaining a carrier image and auxiliary information, wherein the auxiliary information comprises watermark information and a position map, performing preprocessing, determining the size of the scanning block and the image roughness, performing predication of the target pixel according to the maximum predicated angle, the reference pixel quantity and the location of the target pixel, obtaining the prediction error of the target pixel, embedding the watermark information into the carrier image according to the predication error of the target pixel and the storage information of the auxiliary information, forming a secret carrying image, identifying the auxiliary information in the secret carrying image, extracting the watermark information from the secret carrying image, restoring the pixel having correcting the pixel gray value and restoring the carrier image. The method and system of obtuse angle prediction based on reversible information hiding can improve the embedding capacity and the peak signal to noise ratio of the reversible information hiding technology and enhance the predication performance.
Owner:NORTH CHINA ELECTRIC POWER UNIV (BAODING)

Digital Audio Reversible Watermarking Algorithm Based on Side Information Prediction and Histogram Shift

The invention discloses a digital audio reversible watermarking algorithm based on side information prediction and histogram shifting. The algorithm includes the following steps that the prediction coefficient of audio data and the prediction value of a sample are calculated; the prediction value is subtracted from the sample value to obtain a prediction error, two different histograms are constructed according to two modes of the side information prediction algorithm, and then watermarking information is embedded in the prediction error to obtain the prediction error containing a watermark; the prediction error containing the watermark is embedded in a next sample value of the current sample to obtain an audio value containing the watermark; an audio signal containing the watermark is received at the receiving end, the prediction value is subtracted from the sample value, an embedded signal is extracted by means of prediction error histogram shifting characteristics, and an original audio signal is restored in a lossless mode. Compared with an original prediction algorithm, the algorithm improves prediction performance; non-causality and histogram shifting are combined, so the algorithm has good embedability and low distortion rate when the embedding rate is low.
Owner:JINAN UNIVERSITY

Reversible video frequency watermark method based on interframe forecast error histogram modification

The invention relates to a reversible video frequency watermark method based on interframe forecast error histogram modification, comprising watermark embedding and watermark detection. The watermark embedding process is carried out according to a video frequency negative sequence: firstly, utilizing the previous frame to carry out motion estimation to obtain an interframe forecast error, and then carrying out the histogram modification on the interframe forecast error so as to embed a watermark. An extracting process is carried out according to a video frequency sequence mode: similarly, utilizing the previous frame to carry out the motion estimation to obtain a forecast error, and then extracting a watermark from the forecast error, and modifying a histogram to carry out the frame imagerecovery. The invention uses the mode of negative sequence embedding and sequence extracting, thereby an embedded video frequency frame can be recovered after the watermark is extracted, and the reversibility of the video frequency watermark is realized; the motion estimation is used according to the content relation of adjacent interframes to carry out prediction so as to enable the forecast error histogram to have the height centrality, and realize the bigger embedding content; in the embedding process, using the histogram modification enables that the influence on the frame image is small, and a watermark-embedded video frequency has high visual quality.
Owner:BEIHANG UNIV

A Real-time Encryption and Decryption Algorithm in Wavelet Domain of Medical Image Based on Multiple Chaos System

The invention provides a real-time encryption and decryption algorithm in the medical image wavelet domain based on multiple chaotic systems. The real-time encryption and decryption algorithm in the wavelet domain of medical images based on multiple chaotic systems includes the following steps: decomposing medical images, encrypting wavelet coefficients, obtaining encrypted medical images and decrypting medical images. Compared with related technologies, a real-time encryption and decryption algorithm of medical image wavelet domain based on multiple chaotic systems provided by the present invention proposes to use LeGall5 / 3 integer wavelet transform to perform three-level wavelet classification on the original medical image, which fully reduces the distance between medical image pixels. Correlation, which has high time efficiency and high security when the initial value of chaos and system parameters are unknown.
Owner:COLLEGE OF APPLIED SCI JIANGXI UNIV OF SCI & TECH

Sodium metal batteries, electrochemical devices

ActiveCN113451546BEnsure deposition uniformityLower deposition overpotentialSecondary cellsNegative electrodesElectrical batteryEngineering
The present application relates to a sodium metal battery and an electrochemical device. The battery includes a positive pole piece and a negative pole piece. The negative pole piece is a negative current collector. The thickness of the deposited sodium layer is ≥30nm. The present invention utilizes the first irreversible capacity of the positive electrode material and the design optimization of the battery cell. After the battery cell is charged and discharged for the first time, the amount of residual sodium metal is large enough to uniformly form a layer of sodium deposition layer with a certain thickness on the surface of the negative electrode current collector. Avoid the higher nucleation energy required for sodium to deposit on the surface of the current collector during the subsequent charge-discharge cycle, reduce the overall deposition overpotential, and ensure the uniformity of sodium metal deposition and the reversibility of the charge-discharge process.
Owner:CONTEMPORARY AMPEREX TECH CO

Electric actuator connected to a gearbox selector shaft by stepdown gearing

An electric actuator, in particular for driving a gearbox selector shaft, the actuator comprising a coil guided in rotation between two flat permanent magnets carried by yoke plates, the coil being centered on the rotary spindle and having an angular stroke lying in the range 90° to 180°, its rotary spindle being connected by stepdown gearing to the gearbox selector shaft.
Owner:TELEFLEX AUTOMOTIVE FRANCE

A vertical disassembly and assembly equipment for hydraulic support columns

ActiveCN105328440BRealize the problem of automatic switching of actionsRealize automatic switchingMetal working apparatusElectrical controlControl system
The invention discloses a novel vertical disassembly and assembly device of a hydraulic support hydraulic cylinder. The novel vertical disassembly and assembly device comprises a double-vehicle double-station operation process, a synchronous lifting frame structure, plug pin locating devices, a synchronous hydraulic cylinder body supporting mechanism, mechanical hydraulic cylinder supporting devices and an intelligent electrical control system. According to the novel vertical disassembly and assembly device, the performance of the integral device is complete, and the efficiency can be improved by on time by virtue of double-station circulating operation; the locating accuracy of the mechanical automatic hydraulic cylinder supporting devices is high, the synchronous lifting frame structure is adopted, and the locating of the plug pin locating devices is accurate and reliable, so that the operation problem about disassembling and assembling guide sleeves and pulling out and pressing in a piston rod on one device at the same time is overcome; an emulsion is prevented from polluting the environment on a disassembly site; particularly, the operation manner of manual hydraulic cylinder supporting is replaced by the mechanical hydraulic cylinder supporting devices, so that the hidden danger of security accidents is eliminated from the source; the intelligent electrical control system is adopted, so that the operation manner is simplified, the operation accuracy is improved, the service life of the machinery is prolonged, the maintenance cost is reduced, and the market popularization prospect is wide.
Owner:焦作欣扬程煤矿设备有限公司 +2

A kind of dynamic covalent bond cross-linked oil displacement polymer and preparation method thereof

The invention relates to a dynamic covalent bond cross-linked oil-displacing polymer and a preparation method thereof. In the present invention, acrylamide is used as the main monomer to increase the length of the molecular chain, thereby increasing the frictional resistance between the molecular chains to improve the viscosity of the solution, and diacetone acrylamide is used as the functional monomer to copolymerize with acrylamide to introduce the ketone carbonyl group into the polymer chain Cross-linking with adipic hydrazide is achieved, resulting in nonionic polymers cross-linked with dynamic hydrazone bonds. The absence of ions in the polymer chain avoids charge shielding and flocculation of various salt ions, and can maintain high viscosity in high salinity water. And the polymer uses the acylhydrazone bond that can be dynamically formed and dissociated as the chemical cross-linking point. As a stimulus-responsive dynamic chemical bond, it not only maintains the reversibility of physical cross-linking, but also has the strength of chemical cross-linking. Reversible formation and breakage can be achieved under external environmental stimuli to overcome the disadvantages of poor shear resistance of traditional polymers.
Owner:SHANDONG UNIV

Binary image reversible information hiding method based on image enlargement strategy

The present invention relates to the field of digital forensics and information security, and more particularly to a binary image reversible information hiding method based on an image enlargement strategy, which is capable of recovering an original image without loss after information extraction. The method comprises: using a cross-shaped mode block to enlarge the original image to achieve the purpose of reversible information hiding; analyzing and classifying 32 types of cross-shaped mode blocks, and selecting the appropriate mode block as the reference mode block to obtain a reference picture with better visual quality; after determining the reference mode block, analyzing the type of the cross-shaped mode block centered on each pixel in the original picture, and using the designed enlargement strategy to enlarge each pixel point into a 2 x 2 block to obtain a reference picture; and finally, using a selection strategy of invertible pixels within a type of block to flip the pixels, and performing information imbedding. The method provided by the present invention can be used for information security, especially for binary image secret information transmission.
Owner:SUN YAT SEN UNIV
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