208results about How to "No mutation" patented technology

The present invention provides an S-shaped acceleration and deceleration control method for changing speed and position of an object on line. The method comprises the acceleration phase speed planning, the deceleration phase speed planning, the constant speed phase speed planning, the real speed reduction point predication, the maximum speed processing, the surplus distance compensation, the online object speed changing algorithm and the online object position changing algorithm. An acceleration and deceleration discretization speed planning method is employed and the user input parameters are combined to calculate the operation time of a seven-phase speed planning phase. It is determined whether the maximum acceleration and the maximum speed can reach the criterion or not, the integration problem of a sampling period Ts according to the acceleration / deceleration acceleration, the acceleration / deceleration speed and the final position L after discretization is considered, and the real reachable acceleration / deceleration acceleration, the acceleration / deceleration speed and the feed rate are corrected. The S-shaped acceleration and deceleration control method for changing speed and position of the object on line greatly simplifies an original calculation formula and saves lots of operation time of a computer, and the surplus distance employs a one-time compensation method in the speed reduction process.

The invention discloses a transmitter and a transmitter signal processing method. The transmitter comprises a pre-distortion processing unit, a digital-analog conversion unit, a radio frequency unit, a power amplifier, a coupler, a feedback radio frequency unit, an analog-digital conversion unit, an adaptive tracking algorithm unit, a lookup table storage unit and a lookup table control unit; the lookup table control unit is used for detecting input digital baseband signals, and sending an update signal to the pre-distortion processing unit when a predestinated frame of input digital baseband signals ends; the pre-distortion processing unit takes a digital pre-distortion parameter out of the lookup table storage unit according to the update signal, and carries out pre-distortion on the input digital baseband signal according to the taken out digital pre-distortion parameter. The transmitter and the transmitter signal processing method ensure that signals output by the pre-distortion processing unit can not generate jumps, thus improving the pre-distortion effect of the input digital baseband signal, namely stability and reliability.

The invention discloses a method for adjusting running speed of a robot in real time. Movement elements are analyzed through a demonstrating track, track planning and interpolation are carried out, and an interpolation command is corrected by inputted speed adjusting parameters to achieve the purpose of adjusting the speed in real time. According to the control command corrected by the method, a curve can be changed smoothly and continuously, so that stress on a mechanical system is not impacted or changed suddenly, a control effect is soft, and loss on moving parts is reduced. Meanwhile, the method is simple in control logic and small in calculated amount, and meets control requirements on instantaneity of a robot control system. When the speed is adjusted, only a standard process requires to be demonstrated according to actual working conditions, then a monitoring terminal is debugged to transmit different speed adjusting commands, a robot control system responds the received speed adjusting parameters so that the effect of changing the running speed of the robot can be achieved, work complexity of operators is greatly simplified, the field processing efficiency is improved, and standardized operation of the robot is facilitated.

The invention discloses an ultrahigh-strength steel plate local quenching and hardening forming die. The die comprises an upper die base, a female die fixed on the upper die base, a lower die base and a male die fixed on the lower die base, and the male die and the female die are of splicing type structures, composed of heating inserts and cooling inserts and used for heating and cooling different regions of the die. A plurality of electric heating tubes are embedded into the heating inserts, and cooling water holes are arranged inside the cooling inserts and connected with a cooling water circulating system. Portioned cooling and pressure maintaining quenching of paths after ultrahigh-strength steel plate hot forming can be achieved, and further parts with customized mechanical properties are obtained. The forming die is simple and reliable in structure, deformation of the parts is small as the whole process is completed with the die closed, and the parts are excellent in size precision.

The invention discloses a special foaming agent for a hard PVC (polyvinyl chloride) low-foaming material and a preparation method thereof. The special foaming agent comprises the following materials in parts by weight: 20-80 parts of azodicarbonamide (ADC), 20-80 parts of auxiliary foaming agent, 1-20 parts of activating agent, 0.2-10 parts of dispersing agent and 0.2-5 parts of processing agent. The preparation method comprises the steps: adding the dispersing agent and the processing agent in a mixer, mixing for 3-7 minutes, and sequentially uniformly mixing the ADC, the auxiliary foaming agent and the activating agent in the mixer to prepare the special foaming agent. The special foaming agent is suitable for hard PVC low-foam materials such as PVC crushing and low-foaming sectional bars, tubular products and sheets, a wood-plastics low-foaming material and the like. The special foaming agent has the positive effects that 1, the decomposition temperature is 160-190 DEG C, and is within a processing temperature range of the hard PVC low-foaming material; 2, the foaming process is short in induction period, the decomposition is performed without mutation, and the foaming process is easily controlled; 3, the hard PVC low-foaming material is used on a hard PVC low-foaming product, and has a smooth surface and has no discoloring and ageing phenomena; and 4, the special foaming agent is low in cost and good in comprehensive performance, and accords with the use requirement.

The invention discloses a robot trajectory planning method based on a genetic chaos optimization algorithm. The method comprises the following steps: performing interpolation in a starting point and an ending point in Cartesian space to obtain a series of middle position points; establishing a D-H parametric model and solving angle values of joints of a robot corresponding to the position points in joint space; initializing a time interval sequence between every two nodes in the joint space; constructing values of angles passed by polynomial interpolation joint space and controlling themotion form of each joint; constructing a time optimal fitness function, optimizing the time interval sequences with the robot trajectory planning method based on the genetic chaos optimization algorithm until end conditions are met, and outputting the optimal time interval sequence; planning a motion trajectory and finishing set motion. With adoption of the method, the optimal running time of the robot can be obtained, the working efficiency of the robot is increased, curves of the motion trajectory, speed and acceleration are smooth without sudden change, and the service life of the robot is prolonged.

A method for planning trajectories of an industrial robot based on NC (numerical control) codes relates to a robot trajectory planning method, in particular to a robot trajectory planning method using universal NC codes as a working language. In order to overcome complexity and non-universality of traditional robot working languages, the NC codes are used as the working language to realize basic functions of the industrial robot, such as carving, painting and the like. The concept of 'vertical tool' is adopted so as to quickly convert each NC code into inverse solution required parameters for the robot. Cubic-quintic compound interpolation is used to plan a continuous trajectory for the robot, and an accurate trajectory is obtained.

The invention discloses an adopted technical proposal, namely, an image-data fusion method. The method comprises the following steps: (1) re-sampling is conducted to a color image with low resolution to cause the size of pixels of the color image to resemble that of a black-white image with high resolution; (2) precise correction is adopted to lead the color image with low resolution and the black-white image with high resolution to be overlapped; (3) three wave bands of each pixel of the color image after re-sampling are all multiplied by a respective brightness ratio of the black-white image; and (4) a resulting image is output. The data fusion method not only completely integrates spatial information of the original black-white image and spectral information of the color image, without loss in the spectral information and differentiation in image color, but also is comparatively simple with less operation, fast processing and extremely high application value.

The invention relates to a rubber thin sheet grinding wheel and a preparation method thereof. The rubber thin sheet grinding wheel comprises the following raw materials in part by weight: 4 to 6 parts of natural rubber emulsion, 0.5 to 1.5 parts of zinc oxide, 4 to 6 parts of sulfur, 0.5 to 2.5 parts of epoxy resin, 0.4 to 0.6 part of anti-ager, 0.3 to 0.7 part of accelerant, 6 to 8 parts of silicon carbide, 2 to 4 parts of diamantane, 2 to 4 parts of chromium corundum, 1 to 3 parts of resin powder, 0.5 to 1.5 parts of resin liquid and 3 to 5 parts of coagulator. The rubber thin sheet grinding wheel of the invention has the advantages of high wear resistance, heat resistance, self-sharpening property, heat conductivity, corrosion resistance, toughness, hardness and working efficiency and long service life; in addition, the rubber thin sheet grinding wheel prepared by the preparation method of the rubber thin sheet grinding wheel of the invention is very thin and has low loss and high accuracy during cutting.

The invention provides an automatic grinding and polishing process for a titanium alloy annular casting. An automatic grinding and polishing system for the titanium alloy annular casting mainly comprises a base, an outer cover, an industrial robot, an electric main shaft, a rotating workbench, a positioning clamp, a water tank, a cooling chip removal machine, a PLC and a display screen. The titanium alloy annular casting is positioned and clamped on the surface of the rotating workbench through the clamp; the robot clamps the electric main shaft to move according to a certain trajectory so that the grinding and polishing work of the titanium alloy annular casting is realized, moreover, multiple kinds of sensors are adopted for cooperation to adjust a machining path so as to adapt to the complicated contour and shape difference of a part, therefore, the automatic grinding and polishing system for the titanium alloy annular casting has a wide application prospect in titanium alloy annular casting machining, the production efficiency can be improved, and considerable benefits can be brought to enterprises.

The present invention discloses an automatic exposure control method of a digital camera and a device. Based on the method, when a target subject is detected in an image, brightness control information is generated according to target subject average brightness, the imaging effect of the target subject can be ensured pointedly, when the target subject is not detected in the image, brightness control information is generated according to a whole frame average brightness and the first weighted value of a whole frame calibration brightness, since the weighted proportion of the whole frame average brightness in the first weighted value and the frame cumulative value of target subject continuous detection failures are in a monotonically increasing relationship, when the target subject has a fluctuation phenomenon sometimes in the multiple continuous frames of images, the first weighted value is changed in a gradual manner and does not change suddenly, thus the transition amplitude of the brightness control information can be weakened, and thus the brightness smoothness and birghtness stability of exposure are improved.

The invention discloses a medical hyperbaric oxygen chamber therapy system, which comprises a hyperbaric oxygen chamber, and an oxygen supply system, an air supply system and a waste oxygen exhaust system which are connected with the hyperbaric oxygen chamber, and also comprises a computer monitoring and control system, wherein the computer monitoring and control system comprises a controller and a computer terminal which is connected with the controller and controls the controller, and the controller is respectively connected with the hyperbaric oxygen chamber, the oxygen supply system, the waste oxygen exhaust system and the air supply system. The oxygen supply system, the air supply system and the waste oxygen exhaust system of the hyperbaric oxygen chamber are controlled by the computer monitoring and control system, and oxygen pressure, air pressure, pressurization rate, exhaust rate, temperature and other parameters in the hyperbaric oxygen chamber are precisely monitored, so that the hyperbaric oxygen environment in which a patient is positioned smoothly changes, and does not suddenly change, and thus the possibility of generating barotrauma is reduced, and an oxygen concentration sensor controls intake and outtake pneumatic diaphragm valves to regulate the environment in the chamber based on actual pressure and temperature so as to achieve the best therapeutic effect.

The invention discloses a method for rapidly simplifying and drawing a complex leaf. The method comprises the following steps of: inputting a tree model and extracting leaf information so as to complete first-time simplification on the complex leaf in leafage; iteratively combining the leaves so as to complete second-time simplification; iteratively combining the leaves in a crown so as to complete third-time simplification; calculating the density of the leaves; respectively storing leaf geometric information and simplification information in two arrays and reading the information; according to a current viewpoint and a pixel error, secondarily searching for the arrays storing simplification information; and determining a proper detail level model drawing image of a canopy. The invention is fit for simplifying the complex leaves of different shapes. The simplification speed can be promoted by using distance limitation so as to realize efficiently abstracting and drawing of the detail level model of the canopy. The drawing speed can be improved by establishing a multi-resolution con-existing model of the crown by using density factors. The method of the invention can maintain the shape of the crown, efficiently overcome the deformation phenomenon and finally realize real-time roaming in a forest of tens of thousands of plants.

The invention discloses a porous magnesium alloy three-dimensional reinforced absorbable medical compound material and a preparation method thereof. The compound material is prepared by compounding a porous magnesium alloy structural member which has a three-dimensional mesh structure and serves as a reinforcing body and absorbable high polymer material polylactic acid which is compounded and filled into the holes of the porous magnesium alloy reinforcing body and serves as a substrate. Degradable polymer substrates such as polylactic acid and the like are mixed with the wild phase of the porous magnesium alloy structural member, are molded or extruded into bars or plates under certain pressures, and are treated with subsequent machining, so that various degradable biological medical compound materials can be obtained. The method has the characteristics of mild processing condition and easiness for operating; the product has high mechanical performance, high biocompatibility and wide application prospect, and is suitable for orthopedic internal fixation products of various shapes; the production degradation is safe, stable and controllable; and the pain to a patient caused by secondary operation or advanced invalidation of the conventional orthopedic product is avoided.

The invention relates to an indoor robot positioning algorithm based on Kalman filtering. The indoor robot positioning algorithm comprises the following steps: 1) a distance model is created; 2) an indoor robot positioning model is arranged based on Kalman filtering: 2.1) iterative execution of a Kalman filtering process is achieved; 2.2) Kalman filtering work is carried out; and 3) filtering parameters are optimized by a Kalman filtering indoor robot positioning algorithm, the corresponding parameters which are input of a feedback system are read after the network is initialized, then an observation value is solved, the Kalman filtering algorithm is executed and finally an optimal state estimation value is outputted. According to the Kalman filtering algorithm, a proper state error matrixand a proper observation error matrix are selected, the positioning precision is optimized, and the positioning performance of the indoor robot is improved.

The invention provides a method for correcting a lithium battery SOC according to dynamic voltage. The method comprises the following steps of S1, obtaining the corresponding relation between dynamicend voltage and SOC of a battery under different temperatures and different multiplying powers through experiments; S2, according to the characteristics of the battery, selecting calibrated points inthe charging process and the discharging process; S3, in the traveling car discharging process, when it is judged that the continuous setup frequency that the current is smaller than a set threshold value and the voltage is smaller than a threshold value corresponding to the current temperature reaches a set threshold value in real time, if the current SOC is larger than the SOC corresponding to the calibrated point, calibrating the current SOC to the SOC corresponding to the calibrated point; S4, in the charging process, when it is judged that the current is smaller than the set threshold value, and the voltage is smaller than the threshold value corresponding to the current temperature in real time, if the current SOC is smaller than the SOC corresponding to the calibrated point, calibrating the current SOC to the SOC corresponding to the calibrated point. In the traveling car process, algorithm operation is performed in real time, a program does not reply on the special standing working condition, and in the SOC calibration process, it is ensured that SOC smoothness changes cannot change suddenly.

The embodiment of the invention discloses a robot smooth obstacle avoiding movement scheduling method based on tangent recursion. The method is suitable for a super-redundancy robot. The method includes the following steps of firstly, establishing a spherical obstacle in a task space, forming a recursion tangent for the obstacle to intersect with a safety distance circle so as to obtain obstacle avoiding non-collision route points; secondly, obtaining the position inverse solution of the super-redundancy robot through a ridgeline modal method so as to obtain joint space postures correspondingto the non-collision route points; thirdly, conducting seven times of B spline interpolation on the postures to obtain a robot smooth obstacle avoiding movement route. The obtained robot movement route is smooth, and the speeds, accelerations and jerks of all driving joints of the robot in the movement process are continuous without sudden changes. When the redundancy of the robot is increased, the method has the more remarkable advantage of being small in computation amount.

The invention relates to a pig pseudorabies virus natural low-virulent C strain and a heatproof preservation method thereof. The microbe collection registry number of the strain is CCTCC NO: V201114. According to the invention, various cryoprotectant substrates are mixed and blended according to a certain ratio; the cryoprotectants are respectively subject to aseptic processing; cryoprotectant components that can be subject to high-pressure sterilization are dissolved in bi-distilled water, and are sterilized for 15-30min under a temperature of 108-121 DEG C; cryoprotectant components that can not be subject to high-pressure sterilization are dissolved in bi-distilled water according to a certain formula, and are sterilized by using a filter membrane with a size of 0.22mum; all the cryoprotectant components are then mixed into a heatproof cryoprotectant; the heatproof cryoprotectant is mixed with a pseudorabies virus liquid according to a ratio of 1:1-1.2; and the mixture is lyophilized with a corresponding lyophilization curve. Compared to prior arts, the C strain provided by the invention has good stability. In a fifth generation animal of continuous back-procreation, the genetic sequence is stable, and no mutation is found. Therefore, the strain provided by the invention provides a good resource for the researches of pig pseudorabies low-virulent vaccines. The strain can bepreserved for 24 months under a temperature of 2-8 DEG C, and the virus titer is reduced by no more than 1 titer.

A cationic branched-chain starch wood adhesive and its production are disclosed. The process is carried out by adding cross-linking agent, etherifying agent and oxidant into branched-chain starch, cross-linking reacting, etherification reacting and low-degree oxidation reacting. Its advantages include excellent adhesion, water-resistance, fluidity and anticoagulant performance, long storage period and fast dry speed.

The invention relates to a skirt and frame of a tank container. The skirt comprises a box body and two rear sealing plates. The box body comprises a top straight-barrel arc section, a bottom straight-barrel arc section, a first connection section and a second connection section. One end of the top straight-barrel arc section is connected with one end of the bottom straight-barrel arc section through the first connection section. The other end of the top straight-barrel arc section is connected with the other end of the bottom straight-barrel arc section through the second connection section. The outer diameter of the top straight-barrel arc section and the outer diameter of the bottom straight-barrel arc section are both the same as the outer diameter of a tank body. The upper arc section and the lower arc section are both connected with the tank body through butt joint welding seams. By means of the design of the structure of the skirt, the longitudinal impact force borne by the tank container can be uniformly dispersed and transmitted through multiple routes, each transmission route is simple and direct, the whole frame is reasonable in force bearing, no large stress concentration can be generated, and the railway transportation working conditions can be completely met.

A port plate for a plunger pump belongs to a port plate for a hydraulic plunger pump, and aims at reducing cavitation corrosion, vibration and noise of the plunger pump during the distribution process, and improving the work stability of a pump. The port plate is circular, wherein a low pressure zone kidney slot and a high pressure zone kidney slot which are symmetrical relative to a cross shaft and are mutually isolated are arranged in a circular ring, the low pressure zone kidney slot and the high pressure zone kidney slot are respectively formed by kidney-shaped through holes which are divided into N segments, the inlets of the low pressure zone kidney slot and the high pressure kidney slot are respectively provided with a low pressure zone vibration-damping groove and a high pressure zone vibration-damping groove, the front end of the high pressure zone vibration-damping groove or the high pressure zone vibration-damping groove is a circular structure, the tail end is a V shape or an arc-shaped gradually-opened structure, the middle portion is an arc transition structure provided with a reducing hole, and the depths of all portions are different. The port plate has excellent cavitation resistance, small vibration, low noise and excellent work stability, and is suitable for plunger pump sport plates which utilize seawater, fresh water, high water base, mineral oil and the like as work medium, and is simultaneously also suitable for oil-pressure plunger pumps which utilize mineral oil as work medium.

The invention discloses a negative voltage slope control circuit for controlling erasing voltage of a nonvolatile memory. The negative voltage slope control circuit comprises an oscillator, a first switch tube, a benchmark constant-current source, a mirror image constant-current source, a transient control capacitor and a second switch tube. The oscillator is used for generating periodic wave; the first switch tube is connected with the oscillator and is used for obtaining control periodic wave to control the connection and disconnection of the first switch tube; the benchmark constant-current source is connected with the first switch tube; the mirror image constant-current source is connected with the first switch and is used for mirroring the current of the benchmark constant-current source; the transient control capacitor is connected with the mirror image constant-current source; the second switch tube is connected between the transient control capacitor and the mirror image constant-current source; and the erasing voltage is output through the second switch tube. The erasing voltage obtained by the negative voltage slope control circuit avoids generating abrupt change to form ripple wave, thereby the defects in the prior art are overcome.

According to a switching power supply frequency reduction control circuit and a control method of the invention, a frequency control circuit generates a first current signal associated with a compensation control signal, and the first current signal changes the size of a first current source so as to make a first clock signal for controlling switching of a power switch tube change with the compensation control signal, and therefore, the switching frequency of the power switch tube is controlled by the compensation control signal. When the compensation control signal is greater than a threshold voltage signal, the switching frequency of the power switch tube is a preset switching frequency; and when the compensation control signal is smaller than the threshold voltage signal, the switching frequency of the power switch tube changes with the difference between the compensation control signal and the threshold voltage signal. The threshold voltage signal in the embodiment is set to represent the output voltage under a light-load or no-load state. The switching power supply makes the switching frequency of the power switch tube not change suddenly, and the output voltage is highly stable.

The invention discloses a medical hyperbaric oxygen cabin therapy system integrated with a computer monitoring system, comprising a hyperbaric oxygen cabin, an oxygen supply system which is connected to the hyperbaric oxygen cabin, an air supply system and a waste oxygen discharging system, wherein the system further comprises the computer monitoring system. The computer monitoring system comprises a controller and a computer terminal which is used for connecting and controlling the controller. The controller is respectively connected with the hyperbaric oxygen cabin, the oxygen supply system, the waste oxygen discharging system and the air supply system. The invention controls the oxygen supply system, the air supply system and the waste oxygen discharging system of the hyperbaric oxygen cabin through the computer monitoring and controlling system, accurately monitors and adjusts various parameters in the hyperbaric oxygen cabin, such as the oxygen, the air pressure, the pressurizing speed rate, the air discharging rate and the temperature, so the hyperbaric oxygen environment in which the patient stands can be stably changed and has no mutation, the possibility of aural barotraumas are reduced, and the best curative effect can be realized through controlling the inlet and outlet pneumatic film valves and adjusting the environment in the cabin by an oxygen concentration sensor according to the actual pressure and the temperature.

The invention discloses a balance valve. The balance valve comprises a valve seat, a valve housing, a valve sleeve, a balance valve element, a one-way valve element, a retaining ring, a first spring,a compensating plunger, a second spring and a reverse-proportional overflow valve. The balance valve disclosed by the embodiment of the invention is simple to machine, prevents abrupt changes in an open area, can quickly achieve a safety protection function and saves energy.

The present invention provides a 3D NAND memory and a formation method thereof. In the formation method, the density of a channel through hole formed in a channel through hole regulation region is smaller than that of the channel through hole formed in a core region outside the channel through hole regulation region to reduce the difference between the density of a dummy channel through hole formed in a dummy channel through hole regulation region and the density of the channel through hole formed in the channel through hole regulation region, correspondingly, the density of a storage structure in the channel through hole in the channel through hole regulation region is smaller than that of a storage structure in the channel through hole in the core region outside of the channel through hole regulation region, so that the difference of the stress of a film in stack structures at the two sides of or near the junction of a step region and the core region, when the stack structures at thejunction of the step region and the core region are etched to form a gate isolation groove, the side walls of the gate isolation groove at the junction of the step region and the core region cannot be inclined or the inclination degree is greatly reduced, and it is avoided that the gate isolation groove is in short circuit with the channel through hole.

The invention discloses a stator of an automobile power steering pump and a method for designing a stator curve. The cross section of the outer surface of the stator is of a regular round structure; the circumferential curve of the cross section of the inner surface of the stator, namely the stator curve of the stator, consists of a big circular arc ala2, a big circular arc a3a4, a small circular arc b1b2, a small circular arc b3b4 and four sections of transition curves for connecting the four circular arcs; and the transition curves consist of simple harmonic trapezoidal subsection combined motion law curves. The designing method comprises optimization of optimized target function acceleration Am, simulation solution and final obtaining of the optimized simple harmonic trapezoidal subsection combined motion law curves. The stator curve designed with the method does not generate 'hard impact' or 'rigid impact', does not cause 'soft impact' or 'flexible impact' due to the abrupt change of the acceleration, meets the requirements of the stator curve on no vibration impact and low noise, effectively eliminates the steering noise in a cab, and prolongs the service life of the power steering pump.

The present invention discloses a kind of indoor air smell-cleaning agent, including two portions of component A and component B. The compount A is a solid active agent formed from one or several kinds of oxalic acid, tartaric acid, amino acid, citric acid, aminosulfonic acid, isonicotinic acid and camphoric acid, and the component B is a stable solution formed from one or several kinds of potassium chlorate, sodium chlorate, magnesium chlorate, sodium hypochlorite, calcium hypochlorite, sodium chlorite, sodium perchlorate, potassium perchlorate, sodium dichloroisocyanurate and sodium trichloroisocyanurate. The component A can be added in the component B. The substances of nascent state oxygen, nascent state chlorine or chlorinedioxide can be released so as to eliminate harmful smell pollution due to building, decoration and furniture in the room.

The invention discloses an incremental steady-state layout method for time-varying network data. The incremental steady-state layout method comprises the following steps: loading network structure data; preprocessing the data; generating an initial static graph by adopting a multi-level method; initializing node positions for newly added nodes; adjusting the length of the edge for the newly-addededge; calculating the level attribute of the node; partitioning the nodes, calculating the repulsive force in the form of pseudo nodes, and simplifying the layout updating process of the force guidingalgorithm. According to the invention, a stable layout method for time-varying network data is designed as a starting point; a force guide graph is used as a basic visual presentation mode; network structure characteristics such as'node level 'are introduced, it is guaranteed that focus of interest of a user does not change suddenly in the large-range change process of the network topology structure, the stability and continuity of the cognitive process of the user are kept, the user is helped to understand the topology structure of a complex network more effectively, and the understanding difficulty of the time-varying network topology structure is reduced.

The invention provides an electronic expansion valve comprising a valve body having a valve port and a valve needle matched with the valve prot to adjust flows for the electronic expansion valve. The electronic expansion valve is characterized in that the valve port orderly comprises a first conical surface part, a straight section part and a second conical surface part, wherein the height of the first conical surface part and the height of the straight section part are in a relationship of =<d1 / d2=<10; d1 represents the height of the first conical surface part; and d2 represents the height of the second conical surface part. When the valve needle leaves the valve port to a position with at least 250 pulse, a flow path with an annular cross section is formed between the first conical surface of the valve needle and the first conical surface part of the valve port; the annular ring area is gradually increased from the valve port to the inner cavity of the valve seat, so circulation area from the valve port to the inner cavity of the valve seat is smoothly changed; and when fluid flows through the valve port, jumping changes of the circulation area can be avoided, so bubbles can be prevented and noise can be reduced.