Abstract: A method for increasing the difficulty for attackers to launch keyword guessing attacks, which uses a time-delay encryption with a keyword search based on a public key that generates searchable ciphertexts and/or files ciphertexts for keywords of at least one file that uploaded by time-delay encryption from a cloud server. A system for implementing the method is also described.

Abstract: Disclosed are a non-singular finite-time control method and system for prescribed performance dynamic positioning of unmanned boat, which belong to the field of automatic control of unmanned boats. The method includes obtaining a difference between the actual measured position and the desired position of the unmanned boat to obtain a position error of the unmanned boat; performing prescribed performance transformation on the unmanned boat position error; constructing a non-singular finite-time virtual velocity law as a reference velocity for unmanned boats; obtaining the difference between the reference speed and the actual measured speed to obtain the speed tracking error; calculating the fuzzy supervisory saturation compensated law and adaptive fuzzy approximation term; constructing a non-singular finite-time dynamical controller to output control commands; applying a force or moment to the unmanned boat to adjust the propeller speed of the unmanned boat, thereby realizing positioning of the unmanned boat.

Abstract: The disclosure discloses a large-aperture infrared metalens camera, which belongs to the technical field of infrared imaging and micro-nano photonics, including a large-aperture metalens, an infrared focal plane array detector, a metalens mechanical assembly and a housing. The large-aperture metalens has an aperture greater than 50 mm and a thickness less than 2 mm, and the distance between the large-aperture metalens and the infrared focal plane array detector is greater than 30 mm. The metalens mechanical assembly uses a buffer structure to fix, adjust and protect the metalens from shocks. The housing is sealed through a thermal insulation coating, thus providing heat insulation and waterproof protection for the lens.

Abstract: A multimodal medical image fusion method based on a DARTS network is provided. Feature extraction is performed on a multimodal medical image by using a differentiable architecture search (DARTS) network. The network performs learning by using the gradient of network weight as a loss function in a search phase. A network architecture most suitable for a current dataset is selected from different convolution operations and connections between different nodes, so that features extracted by the network have richer details. In addition, a plurality of indicators that can represent image grayscale information, correlation, detail information, structural features, and image contrast are used as a network loss function, so that the effective fusion of medical images can be implemented in an unsupervised learning way without a gold standard.

Abstract: The present invention relates a method for ensuring search completeness of searchable public key encryption, applicable to a blockchain network formed by a plurality of computer nodes. The method at least comprises: the blockchain network receiving a keyword ciphertext and a corresponding file-identifier ciphertext generated by a transmitting end based on the public key encryption, and at least one miner storing the ciphertexts in a ciphertext table; the blockchain network receiving a search trapdoor Tw transmitted by a receiving end, generated according to a private key and a keyword w to be searched; the at least one miner in the blockchain network performing a secure search based on information of a state table and the search trapdoor Tw, and outputting a search result to the blockchain network; and the blockchain network feeding the search result back to the receiving end.

Abstract: The present invention provides a preparation method of a bipolar gating memristor and a bipolar gating memristor. The preparation method includes: preparing a lower electrode; depositing a resistive material layer on the lower electrode; and depositing an upper electrode on the resistive material layer by using a magnetron sputtering manner to deposit the upper electrode, controlling upper electrode metal particles to have suitable kinetic energy by controlling sputtering power, controlling a vacuum degree of a region where the upper electrode and the resistive material layer are located, such that a redox reaction occurs spontaneously between the upper electrode and the resistive material layer during the deposition of the upper electrode to form a built-in bipolar gating layer; and continuously depositing the upper electrode on the built-in bipolar gating layer .

Abstract: A three-dimensional ultrasound tomography method and system based on spiral scanning are provided. The method includes the following. (1) Collecting raw data: an emission array element is switched while a probe maintains a uniform linear motion, so that changes in trajectory with time of a position of an equivalent emission array element in a three-dimensional space show a spiral or a partial spiral, and echo data is received. (2) Pre-processing data. (3) Calculating coordinates of each equivalent emission array element. (4) Calculating coordinates of an imaging focus point. (5) Performing synthetic aperture focusing on each imaging focus point. (6) Post-processing data. The disclosure improves the principle of the imaging method, the design of the overall process, etc. Volume data containing information of continuous tissue layers is obtained through spiral scanning.

Abstract: A phase change memory device based on a nano current channel is provided. A nano current channel layer structure is adopted and configured to limit the current channel. As such, when flowing through the layer, the current enters the phase change layer from nano crystal grains with high electrical conductivity, and the current is thereby confined in the nano current channels. By using the nano-scale conductive channels, the contact area between the phase change layer and the electrode layer is significantly decreased, the current density at local contact channel is significantly increased, and heat generation efficiency of the current in the phase change layer is improved. Moreover, an electrically insulating and heat-insulating material with low electrical conductivity and low thermal conductivity prevents heat in the phase change layer from being dissipated to the electrode layer, and Joule heat utilization efficiency of the phase change layer is thereby improved.

Abstract: A Cu-doped Sb2Te3 system phase change material, a phase change memory, and a preparation method thereof belonging to the technical field of micro-nano electronics are provided. A Sb—Te system phase change material is doped with Cu element to form Cu3Te2 bonds with both tetrahedral and octahedral structures in the case of local enrichment of Cu. The strongly bonded tetrahedral structure improves the amorphous stability and data retention capability of the Sb—Te system phase change material, and the octahedral structure of the crystal configuration improves the crystallization speed of the Sb—Te system phase change material. A phase change memory including the phase change material and a preparation method of the phase change material are also provided. Through the phase change material provided by the invention, both the speed and amorphous stability of the device are improved, and the comprehensive performance of the phase change memory is also enhanced.

Abstract: The disclosure discloses a method for constructing a TFDMA random self-organizing ad hoc network: the total spectrum bandwidth W is divided into N=W/?f sub-channels, and ?f represents the bandwidth of one sub-channel. 24 hours a day is divided into U epochs, V time frames, S time slots, and E time chips. In an epoch of sub-channel bandwidth ?f, the last time slot is connected to the first time slot to form a time-frequency loop net. The N epoch-ring net corresponding to the N sub-channels are stacked together in a manner of time slot alignment to form a cylindrical web. A web is reused U times to cover the full spectrum bandwidth W and 24 hours a day, forming a time-frequency division multiple access self-organizing network.

Abstract: A compression-molding method for a permanent includes: providing a drive coil to generate an electromagnetic force when a transient current is passed into the drive coil, so as to apply a molding compression force to magnetic powder under compression, and providing an orientation coil to generate an orientation magnetic field when a transient current is passed into the orientation coil, thereby providing the magnetic powder under compression with an anisotropic property; and synchronously passing the transient currents to the drive coil and the orientation coil to synchronously generate the electromagnetic force and the orientation magnetic field, thereby completing compression-molding of the permanent magnet, wherein a magnitude of the electromagnetic force and an intensity of the orientation magnetic field are respectively changed by changing peak values of the transient currents.

Abstract: The disclosure relates to the field of heavy metal adsorbents, and a heterogeneous agglomeration adsorbent for heavy metal adsorption, a method for preparing the same, and applications are provided. The heterogeneous agglomeration adsorbent includes the following components according to percentage by weight: 0.005% to 0.01% of polyacrylamide, 0.0005% to 0.001% of calcium chloride, 0.001% to 0.01% of coconut oil fatty acid diethanolamide, and a balance is water.

Abstract: The disclosure belongs to the technical field of powered drive devices, and discloses an acceleration control method for a load on a powered backpack based on a disturbance observer. The method includes: S1 setting the desired acceleration of the load on the powered backpack, presetting the initial motor drive current that regulates the movement of the load according to the desired acceleration, measuring the actual acceleration of the load; S2 establishing the disturbance observer for controlling acceleration the load on the powered backpack, using the disturbance observer to calculate the motor drive current that makes the actual acceleration of the load equal to the desired acceleration, so as to realize the acceleration control of the load on the powered backpack.

Abstract: Disclosed is an efficient recycling system for exhaust energy of an internal combustion engine. Firstly, a thermoelectric generation device recycles high-temperature waste heat energy in the exhaust of the internal combustion engine and recycles high-temperature heat that originally radiates into the ambient atmosphere on the surface of the volute (24). Secondly, pressure energy in the exhaust of the internal combustion engine is efficiently recycled by using a turbocharging device, and the efficiency of the turbocharging device is improved through the graphite sealing device. Finally, low-temperature waste heat energy in the exhaust of the internal combustion engine is efficiently recycled by using an organic Rankine cycle device. The risk of decomposition caused by the fact that the working medium used by organic Rankine cycle works in a high-temperature environment is avoided, thereby ensuring the cycle efficiency and the working reliability of the organic Rankine cycle.

Abstract: Disclosed herein is a wide-range temperature electrolyte, a preparation thereof and a lithium ion battery. The wide-range temperature electrolyte includes a glycerin segment, a diisocyanate segment and a segment containing at least two terminal hydroxyl groups and one disulfide bond, and the self-healing electrolyte has a three-dimensional cross-linked network structure. The wide-range temperature electrolyte introduces a large number of repetitive disulfide bond groups and self-complementary hydrogen bond structures into molecules of an electrolyte base material having self-complementary hydrogen bond structures, so as to form the three-dimensional cross-linked network structure. An intermolecular exchange reaction of the disulfide bonds realizes a cross-scale (molecular, micro, and macro-scale) damage sensing response of the electrolyte and a rapid self-healing of the material, and further achieves a multi-level (molecule-component-device-system) self-healing repair function.

Abstract: The disclosure discloses a testing device and a testing system for testing high-pressure and large-scale gap dynamic sealing performance of a plunger sleeve. The testing device includes two cylinders, first and second plunger rods and a piston rod. A first chamber is formed between an end of the first plunger rod and a first cylinder, and a second chamber is formed between an end of the second plunger rod and a second cylinder. The first chamber and the second chamber are provided with high-pressure liquid, and the two chambers communicate with each other. When being driven by a driving device, the piston rod drives the first and second plunger rods to reciprocate left and right. The plunger sleeve and a locking plunger sleeve are disposed outside each of the first and second plunger rods. The locking plunger sleeve has a leakage port. When the first and second plunger rods reciprocate, the high-pressure liquid in the chambers leaks from the leakage port.

Abstract: A method for optimizing a mobile phone terminal based on a probability of an energy consumption-related interruption is disclosed. The method includes: S1. predicting a probability of an energy consumption-related interruption in real time; and S2. adjusting an operating frequency of a baseband chip of a mobile phone terminal according to the predicted probability of an energy consumption-related interruption.

Abstract: A topological rotary engine includes a first transmission mechanism, a second transmission mechanism, a valve mechanism, a rotor, and a cylinder. The rotor is arranged in an inner chamber of the cylinder. A cross section of the rotor is a curved-side topological polygon having n sides. A cross section of the inner chamber of cylinder is a curved-side topological polygon having n+1 sides, and n is an even number greater than or equal to 4. An outer topological curved surface of the rotor is meshed with an inner topological curved surface of the cylinder. The rotor reversely revolves around an axis of the cylinder with an eccentricity as a radius while rotating, and divides the cylinder into n+1 independent chambers. The cylinder is provided with n+1 fuel injection nozzles and n+1 spark plugs, which cooperate with the rotor and the valve mechanism.

Abstract: The disclosure belongs to the technical field of solid fuel utilization and discloses a gasification reactor adaptable for feedstock with wide particle size distribution, including a reactor body. The reactor body is composed of a first reaction chamber, a second reaction chamber, and a third reaction chamber, which are connected with each other. The side wall of the first reaction chamber is provided with a first vent for introducing a gasification agent to fluidize the fine feedstock particles in the first reaction chamber and the gasification reaction occurs. The bottom of the second reaction chamber is provided with a second vent for introducing an oxidant to react with the coarse feedstock particles in the second reaction chamber. The bottom of the third reaction chamber is provided with a third vent for introducing a gasification agent to fluidize and gasify the incompletely reacted particles in the third reaction chamber.

Abstract: The present invention relates a method for high-performance traceability query oriented to multi-chain data association, comprising: identifying a target transaction needing the traceability query; searching out all corresponding target chains based on cross-chain transaction data association; making query requests parallelly; and executing the query among the target chains according to a key value of the target transaction and returning query results. The blockchain traceability query method proposed by the present invention is different from serialized block data query conducted in the chain-type structure, and the disclosed cross-chain query operation can be parallelly executed, leading to improved efficiency of traceability query. Opposite to the conventional blockchain where blocks are used as nodes of chains, the present invention directly uses sub blockchains as nodes of the SRB.