Abstract: The present invention related to the field of power system protection and control, presents a voltage travelling wave differential protection method considering the influence of frequency-dependent parameters, which provides more accurate and rapid fault identification. The technical scheme of the present invention is as follows: a calculation method of voltage travelling-wave differential protection for VSC-HVDC transmission lines, taking the influence of the frequency-dependent parameters into consideration, the steps are as follows: calculating a characteristic impedance and propagation coefficient of the frequency-dependent transmission line in time domain, collecting voltage and current signals at the both ends of the transmission line and then calculating the forward and backward voltage travelling wave, respectively, comparing a differential value of voltage travelling wave with a preset threshold value to determine whether the internal fault occurs.

Abstract: A superhydrophobic polypropylene porous film, including a polypropylene porous film substrate, titanium dioxide layers and a surface modifier layer, is disclosed. The titanium dioxide layers are deposited on the surface of the polypropylene porous film substrate by atomic deposition technology; a surface modifier is coated on the titanium dioxide layers; hydrophobic bonds are formed between the titanium dioxide layers and the surface modifier layer; the superhydrophobic polypropylene porous film has a water contact angle greater than 150 degrees, a rolling angle less than 10 degrees, an aperture of 0.1-0.4 ?m, a porosity of 50%-80%, a tensile strength of 30-50 MPa, and an elongation at break of 10%-30%.

Abstract: The present disclosure provides a method for correcting a light intensity measurement value is provided. The method includes: emitting detection light into a measured object; measuring a light intensity measurement value at a measurement position, and measuring light intensity of photons at a benchmark position as a light intensity reference value. A sensitivity of the light intensity of photons to a concentration change of a specific substance in the measured object is less than or equal to a preset threshold, and a change rate of the light intensity at the measurement position with a concentration of the specific substance in the measured object is greater than a change rate of the light intensity at the benchmark position with the concentration of the specific substance; correcting the light intensity measurement value by using the light intensity reference value. The present disclosure further provides a concentration measurement device.

Abstract: A large-particle spherical salt with a particle size of 400-950 ?m and a sphericity of 0.5-1.0 is disclosed, which overcomes the existing difficulty in this field for larger particle size as well as higher sphericity. A preparation method of the large-particle spherical salt is also disclosed, wherein in one preparation process, 2% of gum arabic (based on the mass percentage of solute sodium chloride in a sodium chloride saturated solution) is added, and under conditions of an evaporating temperature of 60° C. a stirring rate of 350 rpm, and an evaporating time of 8 hours, a large-particle spherical salt with a particle size of 921.593 ?m and an average sphericity of 0.904 is successfully prepared. The large-particle spherical salt prepared by the method has a uniform particle size distribution and good appearance, can be combined with other substances, adding some extra value to the salt. Meanwhile, the large-particle spherical salt prepared by the method has a high safety grade (e.g.

Abstract: The present disclosure discloses a visual relationship detection method based on adaptive clustering learning, including: detecting visual objects from an input image and recognizing the visual objects to obtain context representation; embedding the context representation of pair-wise visual objects into a low-dimensional joint subspace to obtain a visual relationship sharing representation; embedding the context representation into a plurality of low-dimensional clustering subspaces, respectively, to obtain a plurality of preliminary visual relationship enhancing representation; and then performing regularization by clustering-driven attention mechanism; fusing the visual relationship sharing representations and regularized visual relationship enhancing representations with a prior distribution over the category label of visual relationship predicate, to predict visual relationship predicates by synthetic relational reasoning.

Abstract: A supported core-shell bimetallic catalyst with high selectivity, and preparation method and an application thereof are provided. SBA-15 is used as support, platinum (Pt) is used as active component, 3d transition metal is used as cocatalysts. In the core-shell bimetallic catalyst formed by the 3d transition metal and Pt, in one aspect, by the addition of the 3d metal in the core, the d-band center of surface Pt atoms is down shifted, and the absorption of propylene is weakened, thereby improving the selectivity for propylene. In another aspect, the use of Pt is reduced by the addition of the 3d transition metal, improving the utilization of Pt. The catalyst is applicable in a hydrogen atmosphere, has a good effect on the preparation of propylene by propane dehydrogenation and causes high dehydrogenation activity under high temperature conditions. The total selectivity for propylene may reach 85%, which achieves high propylene selectivity.

Abstract: An Aureobasidium pullulans recombinant strain with high-yield heavy oil and a construction method and application thereof are provided. The Aureobasidium pullulans recombinant strain is obtained by knocking out a pullulan synthetase PUL gene while overexpressing an ACL gene. The obtained Aureobasidium pullulans recombinant strain can significantly increase the yield of heavy oil. After 7-day fermentation with xylose as carbon source, the yield of the heavy oil of the recombinant strain reaches 19.4372 g/L, while the yield of the heavy oil of the original strain is 10.0325 g/L, i.e. the recombinant strain improves the yield by 93.74% compared with the original strain.

Abstract: The invention relates to a grounding fault protection method for a high-voltage capacitor of a direct-current filter. The method comprises the following steps of acquiring a head end voltage u and an unbalanced current iT2 of a direct-current filter, and acquiring a discrete head end voltage and unbalanced current sequence; calculating a virtual capacitance Czd; determining a protection setting value Cset according to the bridge arm capacitance of the high-voltage capacitor, and when the virtual capacitance Czd is larger than the protection setting value Cset, protecting and judging to be an internal fault; otherwise, protecting and judging to be an external fault.

Abstract: A lignocellulose nanofibril material, a stable foam system based thereon, a preparation method and an application thereof are provided. The lignocellulosic nanofibril material includes the following components: 0.5-20 wt % of wood flour, 0.1-10 wt % of (2,2,6,6-tetramethylpiperidin-1-yl)oxidanyl, 2-25 mmol/g of an oxidant, 6-15 wt % of NaBr, and the remaining is water. The stable foam system based on the lignocellulosic nanofibril material includes: 0.1-1.0 wt % of the lignocellulosic nanofibril material, 0.2-1.0 wt % of a surfactant, 0.1-10 wt % of sodium chloride, 0.1-1.0 wt % of calcium chloride, 0.1-1.0 wt % of magnesium chloride, 0.1-1.0 wt % of sodium sulfate, and a balance of water.

Abstract: The present application relates to use of Prussian blue nanoparticles in the preparation of a medicament for the prevention, delay or treatment of neurodegenerative disease. The present application finds that Prussian blue nanoparticles have significant effects in the prevention, delay or treatment of neurodegenerative disease. Cell test results show that Prussian blue nanoparticles can reduce the level of ROS in nerve cells stimulated by hydrogen peroxide and increase the proportion of living cells in nerve cells stimulated by hydrogen peroxide. Animal test results show that Prussian blue nanoparticles can significantly reduce the expression level of oxidative stress markers in the hippocampus of mouse models of neurodegenerative disease, and significantly improve the learning and memory abilities and ameliorate motor dysfunction of mouse models of neurodegenerative disease.

Abstract: The present disclosure discloses a method for fast determining a time-delay stability margin of a power system, which focuses on three steps, i.e., Jordan standardization, Taylor separation and Schur simplification, to reconstruct a new time delay system and reduce the system dimension. In this method, firstly, a time delay model is Jordan standardized; further, Taylor expansion is applied in a process for separating state variables with time delay from stage variables without time delay; then, balanced model reduction is realized by Schur simplification; and finally, a WSCC 3-generator-9-bus power system with multiple delays will be used to validate the proposed method via several typical criteria.

Abstract: The present invention discloses a three-component mixed working fluid for an ICE waste heat recovery power cycle, wherein the three-component mixed working fluid consists of carbon dioxide, pentane and a refrigerant, the refrigerant is a high-performance environment-friendly refrigerant with GWP value which is lower than 1000 and ODP value which is 0, and the refrigerant is one selected from a group consisting of difluoromethane, fluoroethane and 1,1-difluoroethane; according to the selected refrigerants, the mass percentage of each component is as follow: the mass percentage of CO2, pentane and difluoromethane are 30-70, 10-20, and 10-60; the mass percentage of CO2, pentane and fluoroethane are 30-70/10-20/10-50; the mass percentage of CO2, pentane and 1,1-difluoroethane are 10-70/10-30/10-60.

Abstract: The present invention discloses a visual relationship detection method based on a region-aware learning mechanism, comprising: acquiring a triplet graph structure and combining features after its aggregation with neighboring nodes, using the features as nodes in a second graph structure, and connecting in accordance with equiprobable edges to form the second graph structure; combining node features of the second graph structure with features of corresponding entity object nodes in the triplet, using the combined features as a visual attention mechanism and merging internal region visual features extracted by two entity objects, and using the merged region visual features as visual features to be used in the next message propagation by corresponding entity object nodes in the triplet; and after a certain number of times of message propagations, combining the output triplet node features and the node features of the second graph structure to infer predicates between object sets.

Abstract: A method of using lactase for generating galactooligosaccharide as well as the preparation and an application of the lactase are provided. Lactase (BglD305 derived from Bacillus circulans B2301 and BglD derived from Bacillus circulans ATCC 31382) molecules from two sources are taken as the basis for molecular evolution, so as to obtain new lactase enzyme molecules with high galactooligosaccharide synthesis efficiency and good expression performance. The high-producing strain lactase is further constructed, the lactase can be efficiently synthesized during the submerged fermentation, and the enzyme molecule is secreted into the culture medium, the high-activity enzyme preparation is directly prepared from the fermentation supernatant, and the lactase expression level can achieve 2208 U/mL. As the result, the fermentation manufacturing cost of lactase is reduced, the fermentation manufacturing process is simplified, and the quality of the lactase preparation is improved.

Abstract: The present invention discloses a modular multilevel dynamic switching DC-DC transformer, which consists of N DC-DC sub-modules connected in series. Each of the DC-DC sub-modules is of a symmetrical structure capable of realizing bidirectional power flow, which consists of two half-bridge sub-modules and isolating switches S1, S2 between capacitors C1, C2 of the two half-bridge sub-modules. The capacitors C1, C2 are disposed in parallel between the half-bridge sub-modules and the isolating switches. Assuming that the power flows in the primary side of the DC-DC transformer and flows out from the secondary side; the half-bridge sub-module located on the primary side of the DC-DC transformer is referred to as a primary-side sub-module; and, the half-bridge sub-module located on the secondary side of the DC-DC transformer is referred to as a secondary-side sub-modules.

Abstract: The present invention discloses a method for detecting the mechanical response of a mechanical component by an organic mechanoresponsive fluorescent material, comprising the following steps of: selecting an organic mechanoresponsive fluorescent material; preparing an organic mechanoresponsive fluorescent material solution; forming a film on a metal surface; calibrating fluorescence intensity and obtaining the fluorescence intensity and distribution in a crack tip area; observing the fluorescence signal generated at cracks to monitor the occurrence of fatigue cracks, and predict a propagation pathway of fatigue cracks by using the fluorescence intensity distribution in the crack tip area.

Abstract: The present disclosure relates to a non-silane polymeric coupler. The non-silane polymeric coupler may include a dendritic polymer core having at least one reactive end group. The at least one reactive end-group may be selected from the group consisting of thiol, thioester, thioether, sulfanyl, mercapto, sulfide, and disulfide.

Abstract: An electromagnetic braking system and control method, with the system having a CCU, a braking cylinder, a push rod, an electromagnetic braking ring, an electromagnetic braking piston fixed to the push rod, a first shading plate and a second shading plate, a photoelectric sensor fixed near the push rod, and an electromagnetic braking control circuit, and the control method including following the steps: initial estimating of the braking distance (l) according to the current magnitude, electromagnetic force between the two electromagnetic coils and initial velocity (v) of the push rod, arranging a restoration distance (?l) between the top dead center and the piston after braking, installing two shading plates and the photoelectric sensor; and setting the distance between the two electromagnetic coils to when the starts braking.

Abstract: The present invention relates to an embedded shaking table with heavy load capacity and extensible test frequency and area, comprising a shaking table body; the shaking table body is arranged in a building foundation in which a long-stroke groove is formed, a plurality of long-stroke servo actuators are horizontally and vertically hinged in the shaking table; a short-stroke groove being formed on the upper end of the shaking table body; an excitation platform being arranged in the short-stroke groove; a plurality of short-stroke servo actuators are horizontally and vertically hinged in the shaking table. The present invention is aimed at providing a large-scale and heavy-load embedded shaking table that can meet the test requirements of realizing long stroke and high-frequency loading.

Abstract: The present invention relates to a modular shaking table with heavy load capacity and extensible test frequency and area, comprising a shaking table body; the shaking table body is arranged in a building foundation in which a long-stroke groove is formed, long-stroke servo actuators are horizontally and vertically hinged in the modular shaking table; and an integration foundation is fixedly arranged on the upper end face of the shaking table body; an excitation platform is arranged in a short-stroke groove that is formed in the integration foundation, short-stroke servo actuators are horizontally and vertically hinged in the modular shaking table. The present invention is aimed at providing a large-scale and heavy-load modular shaking table that can meet the test requirements of realizing long stroke and high-frequency loading.