2979results about How to "Avoid difficulties" patented technology

The invention relates to the technical field of solar energy thermal power generation and discloses a tower-typed solar energy thermal power generation system with two-stage thermal storage. The system at least comprises a photo-thermal conversion subsystem, a two-stage thermal storage subsystem and a power subsystem; wherein, the photo-thermal conversion subsystem is used for receiving and converging solar radiation energy, converting the received solar radiation energy into heat energy, and transmitting the heat energy to the power subsystem or the two-stage thermal storage subsystem; the two-stage thermal storage subsystem is used for storing the heat energy input by the photo-thermal conversion subsystem and providing the heat energy for the power subsystem when the solar radiation energy is not enough; the power subsystem is used for converting the received heat energy into electrical energy and outputting the electrical energy. By adopting the invention, the problem that the steam is difficult to store is solved, and the difficulty that the running of a steam turbine in the previous tower-typed solar energy thermal power generation proposal by taking the steam as heat absorption working substance is influenced by the unstable and discontinuous solar radiation is overcome.

The invention relates to an electric-vehicle power battery quick replacing system, which comprises a quick dismounting mechanism and a transferring mechanism. The quick-dismounting mechanism comprises a vacuum sucker and an electromagnetic sucker, which can pull the battery case out from the electric vehicle body or push the battery case into the electric vehicle body. The transferring mechanism adopts the work module of three-coordinate translational and rotational motion, thus transferring the dismounted battery case to a charging support and / or inserting the battery case taken from the charging support in the electric vehicle, thus completing the mechanical quick loading and replacing of electric-vehicle power battery.

The invention discloses an in-hole drilling tool integrating drilling, slotting and punching a coal seam and a using method thereof. The in-hole drilling tool comprises a water supple device or an air supple device, a high-pressure sealing drill pipe, a slotting and punching valve and a drill bit. The water supply device and the air supply device are connected with the high-pressure sealing drill pipe at an orifice. The slotting and punching valve is installed between the high-pressure sealing drill pipe and the drill bit. The in-hole drilling tool is essentially used for drilling and anti-reflective outburst eliminating after drilling of soft outburst coal seam. The using method is as follows: after the drilling construction is finished, a water supplier with a pressure release valve is used for starting a high-pressure pumping station to improve the pressure and the flux for water supply; high-pressure water current at the pumping station drives the slotting and punching valve to act for closing an axial liquid passage and opening a radial liquid passage; and high-pressure jet current realizes slotting or punching through a cutting nozzle or a punching nozzle. The invention has novel design and easy operation, is safe and reliable, improves the outburst elimination efficiency and realizes the integrated operation of drilling, slotting or punching and outburst eliminating.

The invention discloses a method for tracing the track of a wheeled mobile robot based on a quantum-behaved particle swarm algorithm. The method sets a coordinate system within a motion range first, establishes a kinematic model of the wheeled robot, utilizes an inversion design method to decompose the kinematic model, obtains an error propagation equation of a reference pose and an actual pose through the track generated by path planning, takes the equation as a target function, utilizes the quantum-behaved particle swarm optimization algorithm to obtain parameters of a controller with quick speed and strong global solving capacity, designs the controller through the group of parameters, and further guarantees that the robot can be stably and quickly converged on the target track, namely the target function value is close to or less than an allowable value within a limited time period. The method solves the problems of high nonlinearity and non-integrity of track tracing of the wheeled mobile robot, and can quickly realize track tacing of the wheeled mobile robot and improve the tracing control effect of the mobile robot.

The present invention relates to a distributed optical-fibre sensing detection method for cast-in-place pile foundation. It is characterized by that it utilizes the sensing property of optical fibre for strain, so that the optical fibre can be implanted in the cast-in-place pile. When the concrete is solidified or loaded externally, said concrete and its peripheral concrete can produce synchronous deformation, its produced strain extent is the strain valve of said pile-body concrete. The invented sensing technique is a distributed data acquisition, namely, it can obtain the strain data of every point of pile-body. Said invention can utilize these data to implement detection and analysis of cast-in-place pile.

The invention discloses a voice recognition method facing a specific crowd. The method comprises the following steps of: first, sampling a voice signal and converting the voice signal to a digital signal from an analogue signal; then, pre-weighting, windowing, en-framing and performing front-end processing of endpoint detection on the digital voice signal; later on, performing feature extraction on the voice signal by adopting discrete wavelet transform; and finally, performing voice recognition on the feature-extracted voice signal by adopting a discrete hidden Markov model after training a sample. In the processes of performing the front-end processing and the feature extraction on the voice signal, spectrum features and pronunciation characteristics of different target crowds are fully taken into consideration and the process of extracting voice information is optimized, so that a processing process and an information extracting process can be simplified; and therefore, recognition precision is ensured, simultaneously calculation amount and information storage capacity in the recognition process are greatly reduced, and the voice recognition on an embedded platform is realized.

The invention discloses an online cognitive assessment system and an assessment method, and belongs to the field of assessment systems. The online cognitive assessment system comprises a terminal platform, wherein the terminal platform comprises a processor module, a power supply module, a man-machine interaction module, a communication module, a recording module, an assessment module, a storage module, a calculation module and an output module; the power supply module, the man-machine interaction module, the communication module, the recording module, the assessment module, the storage module, the calculation module and the output module are connected with the processor module respectively. Online cognitive diagnosis is carried out through reading and processing information of each module. By adopting the online cognitive assessment system and the assessment method, rapid and accurate assessment and good accuracy can be realized, and information is updated in real time.

The invention relates to a direct prestack time migration method for the seismic data acquired under the undulant ground surface. The method is applied to reflection seismic data processing during earthquake exploration and is a prestack migration imaging method aiming at the seismic data acquired under the undulant ground surface. The method can be directly applied to the seismic data which is acquired under the undulant ground surface and is acquired at shot points and demodulation points of different heights. Accordingly, the method can avoid errors caused by field static correction processing as well as correct the speed of a speed reducing belt in a migration process. The method can self-adaptively determine time-varying migration aperture and can correctly compensate geometric spreading effect of seismic waves during an imaging process so as to obtain an amplitude-preserved common reflection point gather. The core of the method is to use a one-way wave theory and a stable phase point principle to analyze so that the travel time and the amplitude of the seismic waves, which depend on the speed and thickness of the speed reducing belt, the heights of the shot points and the demodulation points, and stacking speed based on a floating datum plane, are obtained. The method has important application value for the explorations of oil, gas and mineral resources in areas with complex ground surfaces.

The invention discloses a high-speed rail large-scale bridge performance evaluation method based on health monitoring data, which relates to the field of bridge engineering detection. The high-speed rail large-scale bridge performance evaluation method comprises the steps of arranging an automatic sensor hardware equipment system on a high-speed rail bridge in an optimized manner, achieving automatic data acquisition, carrying out denoise processing, time domain statistical processing, frequency domain processing and the like on measured data in sequence, and evaluating bridge running safety performance based on the health monitoring data. The high-speed rail large-scale bridge performance evaluation method meets the actual requirements of high-speed rail bridge detection and evaluation, can reflect the running safety of the high-speed rail bridge accurately and timely, and provides important guarantee for the safe running of high-speed trains; the evaluation results obtained through adopting the method are unified with the high-speed rail conventional detection and evaluation results, thereby facilitating the actual application of the method for the bridge managers; and decision-making suggestions for targeted bridge maintenance and repair are made on the basis of the evaluation results obtained through adopting the method, thereby being conductive to implementing timely maintenance and dynamic maintenance, and greatly improving the bridge overhaul efficiency.

The present invention discloses a method and device for recommending boarding locations. The method includes the following steps that: the current position of a passenger, the current position of a driver and an initial agreed boarding point are obtained; a plurality of recommended boarding locations within the preset range of the initial agreed boarding point are obtained; time for the passenger to arrive at each recommended boarding location and time for the driver to arrive at the same recommended boarding location are calculated according to current traffic information and the respective modes of transportation of the passenger and driver; total travel time for arriving at each recommended boarding location is calculated accord to the time for the passenger and the driver to arrive at the same recommended boarding location; the recommended boarding locations are sequined according to the small-to-large order of the corresponding total travel time; recommended boarding locations which rank before a preset place are selected as preferred recommended boarding locations; and the preferred recommended boarding locations are sent to a passenger client and a driver client. With the method and device adopted, when the passenger and driver need to change an agreed boarding location, they can select the preferred recommended boarding locations on the corresponding clients.

The invention discloses an organic / inorganic compound fertilizer taking biomass charcoal as a matrix, a preparation method of the organic / inorganic compound fertilizer and a preparation method of fine straw biomass charcoal powder, relates to a compound fertilizer, a preparation method thereof and a preparation method of biomass charcoal and aims to solve the problems that the compound fertilizer is high in raw material cost, poor in granulation, capable of causing straw resource waste and low in utilization ratio and the energy consumption in the production process of the fine straw biomass charcoal powder is high. The fertilizer disclosed by the invention is prepared from fine straw biomass charcoal powder, a nitrogen fertilizer, a phosphate fertilizer, a potassium fertilizer, bentonite, a binder and trace elements; the preparation method of the fertilizer disclosed by the invention comprises the steps: firstly, preparing biomass charcoal; and secondly, smashing and screening; and the preparation method of the fertilizer disclosed by the invention comprises the steps: firstly, weighting the fine straw biomass charcoal powder and other raw materials; secondly, pretreating an inorganic fertilizer raw material; thirdly, mixing; and fourthly, granulating and drying to obtain organic / inorganic compound fertilizer grains taking the biomass charcoal as the matrix. The preparation method of the organic / inorganic compound fertilizer is applied to the technical field of fertilizer production.

The invention provides a method and a system for processing factoring information based on a blockchain. The method for processing the factoring information comprises the following steps: receiving afactoring request transmitted by a user; forming a corresponding factoring smart contract according to the factoring request; identifying user information related to the factoring smart contract on the blockchain; carrying out endorsement verification on the factoring smart contract by an endorsement verification node corresponding to the user information, on the blockchain; when the factoring smart contract passes the endorsement verification, changing ownership information corresponding to the factoring request by the factoring smart contract. The method and the system for processing the factoring information based on the blockchain, provided by the invention, provide fidelity and traceability of service data for all parties participating in factoring service by applying the characteristics of non-deletability, temper resistance, multi-maintenance, account book sharing and the like of blockchain data. Besides, the fulfillment of factoring service is finished by the factoring smart contract, service data cannot be tempered, and the difficulty of information mutual recognition of all the parties participating in the factoring service in the prior art is overcome.

The invention discloses a method in a boat control field and especially relates to the sliding mode-reverse step double loop trace tracking control method of an underactuated unmanned surface vehicle.The method comprises the following steps of firstly, establishing a three-degree-of-freedom motion mathematical model of the heading, the surging and the swaying of the unmanned surface vehicle; then, through an integrated pose sensor, measuring the current position information of the unmanned surface vehicle, combining the real-time position and the reference trace of the unmanned surface vehicle, calculating an error under a boat body coordinate system; and then, designing a kinematic loop trace tracking controller based on a backstepping method, and designing a dynamic loop trace trackingcontroller based on a sliding mode control algorithm. Through a sliding mode-reverse step double loop trace tracking controller, the trace tracking control of the unmanned surface vehicle Is realized,the unmanned surface vehicle can track a linear trace, and the stability and accuracy of unmanned surface vehicle navigation can be increased.

The invention belongs to the field of computer vision and relates to a quantified evaluation method of image mosaic algorithms. The method comprises the following steps: carrying out mosaic on mosaic sequence images by adopting different mosaic algorithms to be evaluated so as to obtain mosaic composite images; carrying out overall statistics on the mosaic composite images and computing a global evaluation index; selecting corresponding mosaic sequence images as reference images in allusion to local mosaic composite images so as to carry out reference image quality evaluation and compute a local evaluation index; and constructing image mosaic evaluation index system levels by adopting a multi-index comprehensive evaluation method, determining the weighting coefficients of the indexes according to the mosaic requirement and purpose, normalizing the evaluation indexes and carrying out weighted aggregation step by step to finally obtain a comprehensive evaluation result. Through the quantified evaluation method of the image mosaic algorithms, the difficulties existing in the current mosaic evaluation algorithms are overcome; and the evaluation result fits the subjective judgment results of people and has objectivity, consistency and stability. The quantified evaluation method of the image mosaic algorithms can also be used for the quantified comprehensive evaluation of the algorithms such as image fusion and the like.

The invention discloses a life prediction method of accelerated life test based on grey RBF neural network. An original curve of reliability and failure time is constructed by collecting test data; class ratio test is conducted on failure time data; a curve of reliability and accumulated failure time is constructed; three layers of RBF artificial neural network are established; RBF artificial neural network is trained; the well-trained neural network is used for prediction; and finally the prediction value of the dummy accumulated failure time obtained by prediction is reduced so as to obtain the life information of the products under normal stress. The method has no need of establishing physical accelerator model and resolving complex multivariate likelihood equation set, thereby avoiding the introduction of system error in the life prediction, solving the problem of needing a large number of training samples for artificial neural network modeling in accelerated life test, also being applied to small sample test data, and facilitating the application in actual engineering. Compared with the existing BP neural network prediction method, the life prediction precision is obviously improved.

A heat exchanger tube having an integral restricting and turbulating structure consisting of dimples formed by confronting indentations pressed into the sides of the heat exchanger tube. The dimples are comprised of indentations disposed in pairs which extend into the tube to such a depth as is necessary to significantly reduce the cross sectional area of the heat exchanger tube. The dimples of a pair are staggered or offset, longitudinally with respect to each other such that a restrictive passage is defined between each pair of offset dimples. The turbulence characteristics of the tube can be controlled by varying the depth to which the dimples project into the tube and the longitudinal spacing between the dimples that comprise the pair. Adjacent pairs of dimples may be rotated 90° with respect to each other or alternately can be arranged in a helix pattern.

The invention relates to a multi-resolution medical image registration method based on the quantum-behaved particle swarm optimization, which is characterized in that the method comprises the following step of: firstly removing the backgrounds of the two images to be registered to keep the images off the interference of noise; next obtaining the images with low resolution from the two background-removed images via the wavelet transform, using the low resolution to be the object, taking the normalized mutual information as the objective function, using the quantum-behaved particle swarm optimization, then the images with the high resolution to be the object, and obtaining the rotation amount and the translation amount between the two images to be registered to finish the image registration by using the Powell method. With solving a plurality of local extrema based on the objective function of the mutual information, the invention greatly improves the registration precision and speed, reaching up to the sub-pixel level; and is widely applicable to the fields of the image discrimination of the clinical diagnosis, the framing of the radiation treatment, the image guided surgical, etc.

The invention discloses a rotary Fourier transform interference imaging spectrometer, which includes a front collimation objective, a cube corner reflector, a beamsplitter, a rear imaging objective, a detector and a control and processing module, aims to reduce the light energy loss of a target, and has the characteristics of high luminous flux and detection sensitivity. The traditional rectilinear motion scanning manner of a moving mirror is substituted by the rotary scanning manner of the beamsplitter or the cube corner reflector, so as to avoid series of technical difficulties brought by precise rectilinear scanning of the moving mirror; a lateral shear interferometer based on the Michelson interference principle is adopted, and the characteristic of common path is obtained, so that the interference effect cannot be influenced even if the beamsplitter slightly shakes during the rotation; a planemirror in the traditional Fourier transform imaging spectrometer is substituted by the cube corner reflector, so that the problem brought by the inclined planemirror is avoided; therefore, the stability, reliability and vibration and impact resistance of the instrument are improved, and the structure of the spectrometer is more compact.

The invention discloses an inclination-angle-constraint-based kinematic calibration method for a Stewart parallel robot. The method comprises the following steps of: firstly, theoretically establishing a novel kinematic constraint, which is an inclination angle constant constraint, namely keeping two inclination angles of a motion platform of the Stewart parallel robot relative to a horizontal plane constant group by group; secondly, using a servo regulating way to physically realize the established kinematic constraint in a high-precision way; thirdly, establishing a calibration model on the basis of a principle of least square according to the kinematic constraint; and finally, identifying a model parameter by solving a nonlinear least square optimizing problem and compensating for the model parameter in a robot control software. By making full use of a characteristic that a repeating precision of a measuring instrument is superior to a position measuring precision of the measuring instrument, the method has the advantages of good calibration effect, simple measurement, high automatism in the calibrating process and the like.

The invention discloses a method for automatically testing parameters of a millimeter wave power amplifier and a system. The system comprises the structure that a millimeter wave excitation signal power control unit of a piece to be tested is connected with a millimeter wave excitation signal power generation unit of the piece to be tested; a millimeter wave excitation signal power detection unit of the piece to be tested is connected with the millimeter wave excitation signal power control unit of the piece to be tested; the input end of the piece to be tested is connected with the millimeter wave excitation signal power detection unit of the piece to be tested; the output end of the piece to be tested is connected with the millimeter wave excitation signal power detection unit of the piece to be tested; a direct current signal supply unit of the piece to be tested is connected with the piece to be tested; and a test system control unit is respectively connected with the millimeter wave excitation signal power generation unit of the piece to be tested, the millimeter wave excitation signal power detection unit of the piece to be tested, the direct current signal supply unit of the piece to be tested and an output signal detection unit of the piece to be tested. According to the method and the system disclosed by the invention, the automatic test of multiple millimeter wave power parameters is realized; the difficulty in lacking of test equipment is overcome; and the defects of manual test efficiency, low accuracy, uncertain factors and the like are avoided.

The invention discloses a rotational molding wear-resistant polyolefin resin and a preparation method thereof. In the rotational molding wear-resistant polyolefin resin, raw materials commonly used in the rotational molding process, namely linear low-density polyethylene, high-density polyethylene or polypropylene is taken as a matrix material; and by adding components of an inorganic filler, ultrahigh molecular weight polyethylene and a lubricant, the wear resistance of the matrix resin is improved. The rotational molding wear-resistant polyolefin resin consists of the following components in percentage by mass: 70 to 80 percent of matrix resin, 10 to 15 percent of inorganic filler subjected to surface treatment, 4 to 13 percent of ultrahigh molecular weight polyethylene and 1.5 to 2 percent of lubricant, wherein the matrix resin is the linear low-density polyethylene, the high-density polyethylene or the polypropylene; and a range of a melt flow rate of the matrix resin is between 2g / 10min and 15g / 10min.

The invention provides a division and evaluation method for fracture and hole type reservoir flow units. The division and evaluation method for the fracture and hole type reservoir flow units comprises the steps that the standards for dividing flow unit types in an underground reservoir body are determined according to the changing rate of the hurst index after water appears in an oil well and the storage characteristics of the underground reservoir body of a fracture and hole type reservoir; the statistical result of weighted average porosity of the underground reservoir body of all the flow unit types is used as the unified standard for dividing the flow unit types, and the flow unit type division on a whole fracture and hole type reservoir area is carried out by utilizing the unified standard; characteristic parameters reflecting oil well productivity contribution are selected according to flowing laws of fluid of each flow unit type, and the flow units belonging to the corresponding flow unit types are evaluated by utilizing the characteristic parameters. According to the division and evaluation method for the fracture and hole type reservoir flow units, the fact that the units with identical storage characteristics and the flowing laws of the fluid can be divided as the same flow unit is facilitated, the evaluation standard is beneficial for forming efficient developing modes aiming at different flow units for researching the distribution characteristics of remaining oil.

The invention discloses a prediction method of multi-functional parameter accelerated degradation testing product life based on multivariate hybrid time sequence analysis, belonging to the technical field of accelerated test evaluation, comprising the steps of test data acquisition and pretreatment; multi-functional parameter time sequence modeling; multi-functional parameter degradation failure prediction; multi-functional parameter degradation accelerated modeling and multi-functional parameter product life prediction; the problem that the prediction is inaccurate since the mutual influence among a plurality of property parameter degradation processes of the product is unconsidered in the single property parameter degradation prediction of the product is solved; a multivariate hybrid time sequence model is put forward in considering monotonicity degradation trend, randomness and cyclical fluctuation in the product multi-functional parameter degradation process and the relativity of the characteristics among the property parameter; a failure criterion of the product multi-functional parameter degradation is put forward; the description to the multi-functional parameter degradation process is more comprehensive and the accuracy of the prediction result of multi-functional parameter accelerated degradation testing life is improved.

The invention relates to a space truss structure aerial pairing integral slide installation method, which belongs to the installation technical field of an aerial steel structure. The invention relates to an aerial space truss steel structure installation method. Scaffolds are arranged outside a house to pair a platform, after each pairing, the pair of platforms slide into the house, the splicing continues until all platforms slide in place, and slide rails are disassembled after supports are installed. The method has the advantages that the difficulty that the span of the space truss is large and no large-sized hoisting device exists on the spot can be solved; during the construction period of the roof space truss, the lower part of the civil work can be alternatively carried out; the expense for establishing the spliced platform is saved by 60 percent or more compared to an all-round scaffold aerial scattered installation method; and moreover, the peripheral land occupation of the building is less, and only one construction field is required.

The invention discloses a method for estimating unknown object grabbing positions and posture on the basis of mixed information input network models, and belongs to the field of autonomous grabbing ofrobots. By the aid of the method, unknown objects can be quickly and effectively grabbed by robots. The method include preprocessing image mixed information in training image data sets; constructinginformation fusion mechanisms on the basis of mixed information input and building neural network models; training network model parameters with the mixed information fusion mechanisms to obtain optimized mixed information input network models; segmenting objects capable of being grabbed for scene images by the aid of object segmentation technologies on the basis of RGB-D (red, green and blue-depth) images; searching the optimal grabbing regions on the objects by the aid of candidate region generation mechanisms on the basis of feedback information; estimating grabbing positions and grabbing posture of the robots in the optimal grabbing regions by the aid of depth information and further acquiring the grabbing positions and posture when the objects are grabbed. The scene images are acquired by sensors. The method has the advantage that the unknown objects can be advantageously quickly and accurately autonomously grabbed by the robots.

The invention discloses a device and a method for testing a low-permeability core starting pressure gradient at the high temperature and the high pressure with an unsteady state method. The method comprises steps as follows: a to-be-tested low-permeability core sample is prepared and placed in a core holder; an automatic water pump is used for providing required confining pressure and return pressure for the core holder; a third valve is closed, and a gas pressurization device is used for pressurizing a standard bottle; after a second pressure sensor stably reads, the third valve is opened, and gas in the standard bottle permeates an inlet of the core holder; a controller records a pressure value, changing over time, read by the second pressure sensor and stops recording until the change rate of a reading number of the second pressure sensor is lower than a threshold value; and the core starting pressure gradient is calculated according to the reading number, changing over time, of the second pressure sensor. According to the device and the method, all that is required is to add a high-precision pressure sensor at an outlet of the standard bottle for recording pressure of the outlet, the high-precision pressure sensor has characteristics of low cost, high test precision, large range and the like, and the measurement problem of low flow speed is solved.

The invention discloses a single-wall and double-wall combined steel cofferdam construction method and a single-wall and double-wall combined steel cofferdam. The single-wall and double-wall combined steel cofferdam construction method includes the following steps: firstly, assembling the bottom segment side plate of the cofferdam at an assembly field; then floating to the position of a pier; after that, injecting concrete into the foot blade and assembling the top segment of cofferdam and the top segment inclined strut; then positioning, cleaning up the pedestal, building a boring platform, installing a steel casing and stacking the sandbags sequentially; after that, injecting bottom seal concrete, and boring the pier for injection; finally, after the pier pedestal is constructed, pumping the water, cutting off the steel casing, chiseling off the laitance at the head of the pier and beginning the construction of a bearing board. The bottom segment side plate of the cofferdam is composed of circular external and internal wall panels, and the top segment side plate of the cofferdam is fixed on the circular external wall panel. The invention has the advantages of fast engineering speed, small construction difficulty and small cost investment, and the top segment side plate can be used repeatedly and is high in recovery rate; the invention overcomes the difficulties at the time of no bottoming concrete thickness; the circular sealing concrete between the bearing board and the cofferdam also has the effect of resisting water.

The invention relates to a brain electric and eye electric signal decision fusion method for identifying control intention, comprising the following steps: extracting relative wavelet packet energy of pre-processed EEG (electroencephalogram) as motor imagery feature and taking typical variable of pre-processed EOG (electrooculogram)as motor imagery feature; applying the constructed state classifier based on the motor imagery feature of the EEG to obtain state classification result; and applying the constructed motor imagery multi-class classifier based on the motor imagery feature of the EOG to obtain motor imagery classification result; finally, and using the state classification result obtained by the EEG and the motor imagery classification result obtained by the EOG to perform decision fusion so as to obtain identification result of the control intention represented by the motor imagery. The method of the invention can effectively solve interference for identification result of the control intention caused by eye movement irrelevant to the control intention and improve accuracy of the motor imagery identification and reliability of the control intention information.

The invention discloses a method for preparing spider silk protein / polylactic acid composite nano-fiber yarn. The method comprises the following steps of preparing a spinning solution, preparing a bath solution and then adopting an improved electrostatic spinning method to guide, heat, wind and shape bunched fibers, so as to obtain the spider silk protein / polylactic acid composite nano-fiber yarn. The composite nano-fiber yarn of the invention can be continuously spun for more than 10 hours and have no broken ends, and a certain amount of spider silk protein effectively reduces the diameter of the fibers and improves the strength of the yarn. In addition, the fracture strength and flexibility of the composite nano-fiber yarn can be further improved through secondary stretching and combined twisting, so that the composite nano-fiber yarn can be applied in biomedical materials and other fields better.

The invention relates to a steel truss hoisting construction method, in particular to a multilayer steel truss fragmented reverse hoisting construction method in an arc-shaped frame. The multilayer steel truss fragmented reverse hoisting construction method comprises the steps of firstly performing modeling and checking calculation to all of hoisting conditions, utilizing brackets at two ends and a portal frame in the middle as lifting points of an arc-shaped main truss, hoisting the arc-shaped main truss by combining a hydraulic synchronous hoisting technology, connecting sub trusses above two roof trusses and steel beams to form a trapezoid fragmented truss, utilizing the temporality-fixed main truss hoisted in position and the hydraulic synchronous hoisting technology to install roof layer fragmented trusses, dismounting the lifting point of the portal frame of the arc-shaped main truss after the arc-shaped main truss is stabilized, sequentially and inversely lifting multilayer fragmented sub trusses to a bottom layer downward, and then utilizing the main truss, the sub trusses, a truck-mounted crane, a tower crane and leading chains to install other members and finish hoisting of a multilayer steel structure of the arc-shaped frame. The multilayer steel truss fragmented reverse hoisting construction method in the arc-shaped frame has the advantages of achieving hoisting operation in a narrow field or on a building surface, ensuring quality and safety, saving expenses, shortening a construction period and being free of pollution and good in environmental-protection benefit.