449 results about "Single test" patented technology

The invention discloses a crane slewing bearing test tool which comprises a base and a frame plate arranged on the base, a supporting plate is horizontally arranged on the frame plate, tool bases are arranged at the two ends of the supporting plate, a mandrel is movably arranged between the two tool bases, a tool sleeve is arranged on the mandrel in a sleeving mode, and a mounting cavity is formed between the tool sleeve and the mandrel. The base is provided with a first loading piece used for applying radial loading acting force to the tool sleeve and a regulation and control piece used for being in linkage fit with the first loading piece to enable the loading direction of the first loading piece to be changed, and the frame plate is provided with a second loading piece used for applying radial loading acting force to the tool sleeve. The supporting plate is provided with a driving part used for driving the mandrel to operate so as to simulate the actual operation condition of the bearing. The problems that a traditional crane slewing bearing test tool is single in test loading direction, the actual operation working condition of the bearing is difficult to simulate, and the loading working conditions of loads in different directions during actual operation of the bearing cannot be simulated are solved.

The invention discloses an electrical safety test data analysis method and system for an electrical cabinet, and relates to the technical field of electrical measurement and test. The method is used for solving the problems of single test dimension, poor anti-interference capability and inaccurate fault positioning in the safety test of the electrical cabinet. Firstly, multi-channel electrical parameter synchronous acquisition is triggered based on a working condition event, real discharge and interference signals are distinguished through time-frequency analysis, and a time sequence incidence matrix of discharge pulses and load currents is established; then, analyzing phase distribution characteristics of partial discharge, calculating a correlation coefficient between a discharge repetition rate and a load current, and dynamically adjusting a weight to generate an insulation state comprehensive test index; further, insulation degradation characteristics are extracted through signal decomposition, and an insulation degradation trend and a fault probability are predicted in combination with energy entropy analysis and discharge mode recognition; and finally, the position of a fault component is analyzed and positioned based on the impedance network, and a maintenance priority sequence is generated according to the fault probability and the degradation rate.

The invention relates to the technical field of testing devices, and discloses a tension testing device for composite rope production, which comprises a workbench, the top of the workbench is fixedly connected with a fixed rope clamp, the top of the workbench is fixedly provided with a telescopic hydraulic cylinder, and the output end of the telescopic hydraulic cylinder is fixedly connected to a moving plate. The movable plate is fixedly provided with a tension sensor, the other end of the tension sensor is connected with the movable rope clamps, the top of the workbench is fixedly connected with the frame bodies, the number of the fixed rope clamps is three, the number of the movable rope clamps is three, and the three frame bodies are arranged on the top of the workbench in a front-and-back mode. By arranging the three fixed rope clamps and the movable rope clamp, tension detection can be carried out on the three composite ropes at the same time, by comparing tension data of the three composite ropes in different environments, errors of a single test can be effectively reduced, the test result is more representative and reliable, and therefore the accuracy of the tension test is improved.

The invention discloses an automatic test method, system and device applied to a WSDL sending interface and a medium, and the method comprises the steps: associating a single test case into various scenes through a scene page preset parameter rule, and verifying the coupling between interface response and scene logic in real time during automatic execution; a WSDL interface definition and parameterization rule engine is dynamically analyzed, and automatic execution of multiple test cases is achieved; encrypted feedback data flow returned by an interface is captured in real time, key indexes are dynamically analyzed and extracted, automatic comparison and root cause tracing are carried out based on a multi-dimensional verification rule, and a test report is generated. According to the method, the problems that interface testing depends on manual coding, the process is split and the maintenance cost is high in aerospace engineering can be solved, zero-code rapid verification, forward and reverse closed-loop testing and interface change self-adaptive maintenance are achieved, and the aerospace software testing efficiency and reliability are remarkably improved.

The invention discloses a multi-dimensional power consumption test method and device for a solid state disk and a storage medium, and the method comprises the steps: controlling a test environment parameter and the solid state disk to enter a preset initial state in response to a test start instruction; based on a test matrix which predefines a plurality of temperature and capacity occupation combinations, controlling a test device to apply a multi-dimensional dynamic working load to the solid state disk, and synchronously acquiring power consumption data, internal state data and performance data; performing time synchronization and data fusion on the collected multi-source data to form an associated data set; and performing intelligent analysis on the data set, extracting power consumption characteristics of the solid state disk, and generating a power consumption evaluation report based on the power consumption characteristics. According to the method, the problems of single test dimension, incomplete test condition coverage, failure in effective fusion of multi-source data and lack of intelligent analysis in the prior art are solved, and comprehensive, accurate and automatic evaluation of the power consumption of the solid state disk is realized.

The invention belongs to the field of mechanical performance testing, and relates to an intelligent testing method for the fatigue performance of a wet brake, which comprises the following steps of: acquiring real-time operation data of the wet brake under the condition that a load is applied by a loading device in a testing process by deploying a multi-source monitoring array; generating a fatigue stress distribution diagram representing the stress state of a preset test area of the wet brake based on working condition fusion analysis, correspondingly identifying a failure early warning signal representing the current fatigue damage stage so as to dynamically adjust the parameters of a loading device, and adjusting the stress state of the wet brake in the loading intermittent period of a single test cycle period. The fatigue performance response effect of the wet brake under the action of the current loading strategy is analyzed, the correction direction of the loading strategy of a secondary test cycle is determined, test convergence is achieved through iterative optimization, the consistency of a test result and a real fatigue damage rule is improved, meanwhile, the test efficiency and evaluation precision are improved through closed-loop regulation and control and a self-adaptive iterative framework, and the test accuracy is improved. And a reliable basis is provided for fatigue performance evaluation of the wet brake.

The present invention discloses an active control wind tunnel for separately simulating mean wind and pulsating wind, belonging to the technical field of wind tunnel experimental research. This wind tunnel is a single test section direct current unsteady wind tunnel. A power section A is arranged at the front section of the wind tunnel. The power section A includes an array of fans for generating pulsating wind located at the very front end of the wind tunnel and a fan A for generating mean wind located in the flow direction of the pulsating wind air flow. The air flows generated by the array of fans and the fan A pass through the test section and are finally discharged from the air outlet at the end of the wind tunnel. A rainfall device is arranged in the test section. The wind tunnel is controlled by two independent active control modules, namely the fan A control system and the array of fans control system. The array of fans and the fan A can be used separately or in combination to achieve the simulation of complex wind field changes. A steady wind tunnel can also be arranged under the unsteady wind tunnel. The two layers of wind tunnels can be used separately or in combination to achieve specific functions such as simulating natural phenomena.

The invention provides a sleeve testing device and a strength checking and correcting method, and relates to the technical field of offshore high temperature and high pressure, and the device comprises a temperature control system which is used for providing a steady-state high-temperature simulation environment and a transient high-temperature simulation environment for a sleeve sample; the loading system is used for applying axial, radial and internal loads to the casing sample; the monitoring system is used for monitoring a surface temperature field, inner wall strain and leakage of the casing sample; and the data processing and control unit is respectively connected with the temperature control system, the loading system and the monitoring system. The method adopts the device and comprises the following steps: selecting a casing sample, fixing a sensor and completing initial calibration; heating the whole casing pipe and keeping the temperature constant, and applying instantaneous thermal shock to a specific area; synchronously applying axial, radial and internal loads; cooperatively monitoring the temperature field, the strain and the leakage rate to form an associated database; and correcting the safety coefficient. The invention solves the problems of single test temperature and insufficient load coupling of the traditional casing, and is suitable for casing performance evaluation.

The invention relates to an ultrasonic radar aging test method, system and device and a medium. The method comprises the following steps: acquiring a batch configuration file and a corresponding test scheduling table, and performing initial calibration on each to-be-tested AK1 sensor based on the scheduling table to obtain a baseline parameter set of the sensor; configuring an excitation-observation sequence according to the batch configuration file and the baseline parameter set to obtain a test plan, and executing a single test cycle according to the test plan to obtain original sampling data; preprocessing the original sampling data to obtain an observation vector and an event mark, and performing state estimation on the observation vector and the driving excitation corresponding to the observation vector to obtain a state estimation and residual error sequence; based on a preset validity criterion, performing validity judgment on each observation vector according to the event mark and the residual sequence to obtain a valid sample set; and performing health degree evaluation based on the effective sample set and state estimation to obtain an aging test report. By adopting the method, the accuracy of the radar aging test can be improved.

The utility model discloses a dustproof test device, which relates to the technical field of dustproof test of equipment and comprises a box body, a sliding cavity is arranged in the box body, an air outlet is arranged on the inner wall of the box body, an air inlet is arranged on the outer side wall of the box body, and a fan and a dust box for guiding air into the box body are fixedly arranged at the air inlet of the outer side wall of the box body. The dust boxes are installed in the sliding cavity of the box body in a sliding mode, the multiple dust boxes are vertically aligned, the control mechanism controls the dust boxes to slide up and down in the sliding cavity, various kinds of test dust can be loaded into the test device through the multiple dust boxes, and when the test environment needs to be replaced, the dust boxes are moved and replaced through the control mechanism, so that the test environment can be replaced. And the fan is started to blow required dust into the box body, so that the problems that only single test dust is injected into most existing dustproof test devices before the test, and when the simulation environment needs to be replaced, the dust replacement process is complicated and tedious, and the test efficiency is low are solved.

The invention discloses a testing device for an arm sleeve of a semiconductor chip transfer robot, and relates to the technical field of robots, the testing device comprises a testing platform, a controller and a grabbing module, the grabbing module is connected with the controller through a signal line, the controller is installed on the left side of the outer wall of the testing platform, and the grabbing module is installed on the upper side of the outer wall of the testing platform. The grabbing module comprises a storage box, a lifting rod, a rotating shaft, a first moving assembly and a grabbing motor, the lifting rod, the rotating shaft and the first moving assembly are connected with the grabbing motor through a connecting shaft, and the grabbing motor is connected with the controller through a signal line. By installing the grabbing module, the multi-scene grabbing simulation function is achieved, the problems that the environment interferes with the test result, the adjustment time is long and the test scene is single are solved, different test scenes can be set, the coverage range of grabbing test is widened, manual intervention is reduced, and the test efficiency and the test precision are improved.

The application provides a kind of automobile fastener wire material tension testing device, it is related to tension testing device field, comprising: indicating component, the indicating component is by conversion mechanism and displacement sensor composition, test component can realize the tension testing of automobile fastener wire material, material is in the tension testing simultaneously, indicating component can real-time monitoring the deformation degree of material, test data is comprehensive and efficient, and indicating component can automatically control the opening and closing of deformation monitoring function according to test state, solve the single test effect of the tension testing device of existing automobile fastener wire material, since automobile fastener wire material has ductility, existing tension testing device can not record monitoring the deformation of material when testing, test data is not comprehensive enough.

The invention discloses an automatic test and evaluation method of a load identification algorithm, and discloses a system with the automatic test and evaluation method of the load identification algorithm. According to the automatic test and evaluation method of the load identification algorithm, system construction is carried out from three aspects of test scene construction, scene complexity grading and intelligent evaluation, and self-adaptive construction and complexity calculation of a load identification test scene and multi-dimensional evaluation of the load identification algorithm are realized. The training and verification of the load identification model can complete standardized test evaluation without depending on a large amount of home-entry actual measurement data, the problems that a traditional method is single in test scene, scene complexity cannot be evaluated, and evaluation standards are not uniform are solved, and the quantifiable evaluation level and engineering application reliability of the load identification technology are effectively improved.

The invention discloses a power semiconductor board-level test system and method, and belongs to the technical field of power semiconductor device test. According to the system, a reactive aging test and a dynamic characteristic test are creatively integrated on a single test platform, and the problems of low efficiency and high cost of a traditional substation test are solved through modular design. The system comprises a multifunctional test head arranged at a test station and capable of being connected with a power terminal and a signal terminal of a power module at the same time; the reactive load loop is formed by a three-phase adjustable reactor; the high-precision signal acquisition module comprises a flexible current probe and a differential voltage probe; the oscilloscope realizes multi-channel synchronous acquisition; and accurate control is realized based on the main control board card of the FPGA. According to the testing method, Vge, Vce, Ic and other parameters are collected in real time in the reactive aging process, online monitoring of dynamic characteristics is achieved through a current triggering mechanism, and a fault recording function is achieved.

The invention discloses an in-situ test device and method for simulating boiling scale deposition on the surface of a pipe body of a reactor core runner. The device comprises a test section pipeline, a plurality of tubular samples arranged in an array are inserted in the pipeline, inner heating rods are arranged in the tubular samples, the tubular samples penetrate through sealing pieces at the two ends of the pipeline, and one end of each tubular sample is connected with a pressure regulating device; a plurality of connecting holes are formed in one side of the test section pipeline in the axial direction, the connecting holes are connected with a medium inlet pipeline, a medium outlet pipeline and a plurality of sealing plugs respectively, the sealing plugs comprise at least one visible sealing plug, a laser signal transceiver is arranged outside the visible sealing plug, and the visible sealing plug is connected with a data processing system. And laser emitted by the laser signal transceiver can pass through the window on the visible sealing plug, is reflected by the tubular sample and then returns. The device and the method have obvious advantages in the aspects of authenticity, flexibility and connection reliability of simulated working conditions, and can be fixed for a long time for single test or quick adjustment to adapt to different test purposes.

The invention discloses an intelligent commanding and testing integrated system for hydropower station debugging, and relates to the technical field of hydropower station equipment debugging and operation testing. Based on the physical connection relation and debugging parameters of the water turbine and the speed regulator, a three-dimensional function sub-region model is constructed, a multi-test-mode working condition database is established, through the effect recognition module, the system can construct and judge key indexes in each test mode, and the test efficiency is improved. Whether the problems of resonance effect, guide vane hysteresis, water attack abnormity and disturbance deviation exist or not is automatically recognized, a corresponding early warning instruction is sent out, and a closed-loop link from'phenomenon recognition 'to'reason tracing' is achieved. According to the method, whether a single test is qualified or not can be judged, the collaborative imbalance risk coefficient in the ith test mode can be further calculated, the risk level between collaborative effects is evaluated according to the collaborative imbalance risk coefficient, and intelligent adjustment of a test strategy is supported.

The invention relates to the technical field of elevator assembly performance testing, and particularly provides an elevator component safety automatic detection device. Comprising a detection table, a linkage rack horizontally installed on the detection table in a sliding mode, a vertical test piece assembled on the linkage rack and a horizontal test piece assembled on the linkage rack. The vertical test piece comprises two test assemblies which are vertically and oppositely arranged and a transposition assembly which is assembled between the two test assemblies; the device provided by the invention can be used for detecting the safety strength of the elevator landing door, the elevator landing door to be detected can be fixedly mounted through the arranged detection table, comprehensive detection including a plurality of single tests in two force application directions of vertical force application and horizontal force application can be performed on the elevator landing door, the test comprehensiveness and convenience in operability are improved, and the detection efficiency is improved. And the standardization and uniformity of the test are improved, and the accuracy and reliability of the test result are ensured.

A corrosion protection monitoring system having multiple test point monitors (2200) for monitoring the corrosion protection of a structure (5000) at synchronous timing of instant off or low power of corrosion protection units by coordination of internal clocks to an external clock (5100), (5200), wherein simultaneous interruption for say one second, allows simultaneous measurement at every single test point at an instant off or low electrical potential. Use of such multiple synchronous testing to provide cloud-based feedback control of optimising setpoints.

The invention discloses a test incentive generation method and device, equipment, a storage medium and a product, and belongs to the technical field of artificial intelligence chips, the method comprises the steps that a test case is acquired, the test case comprises multiple pairs of equipment identifiers, and each pair of equipment identifiers comprises an equipment identifier of one piece of master equipment and an equipment identifier of one piece of slave equipment; selecting a first excitation constraint set matched with the master device from the master device constraint set according to the device identifier of the master device in each pair of device identifiers, and selecting a second excitation constraint set matched with the slave device from the slave device constraint set according to the device identifier of the slave device in each pair of device identifiers; and according to the first excitation constraint set and the second excitation constraint set corresponding to each pair of device identifiers, generating a test excitation, the test excitation being used for testing a communication path from one master device to one slave device. According to the invention, a single test case can test a plurality of communication paths, and the number of the test cases is obviously reduced.

The utility model relates to the field of sand control screen detection, and discloses a pulling-twisting-bending composite clamp for detecting the general mechanical performance of a sand control screen, which comprises a driving end clamp, a linear guide rail is slidably connected to the bottom end of the driving end clamp, and a bending clamp is slidably connected to the top end of a sliding block of the linear guide rail. A driven end clamp is slidably connected to the top end of a sliding block of the linear guide rail, a sand control screen pipe is fixedly connected into the bending clamp, one end of the sand control screen pipe is fixedly connected to the right side of the driving end clamp, the other end of the sand control screen pipe is fixedly connected to the left side of the driven end clamp, and a hydrostatic bearing is fixedly connected to the right side of the driven end clamp. According to the utility model, through the arrangement of the driving end clamp, the bending clamp and the driven end clamp, various combined tests or single tests in different forms can be carried out, so that the actual working condition load of the sand control screen pipe and the well completion tool in a well can be simulated, and the test is relatively accurate.

The utility model relates to the technical field of building material test piece manufacturing equipment, in particular to a test piece batching tool for a proportioning test of construction waste roadbed filling soil, which comprises a frame body, a front cover, a partition plate, an unloading drawing plate, a drawing plate film and a film roller, wherein the front cover is mounted at one end of the frame body, the unloading drawing plate is mounted at the lower part of the frame body, the frame body, the front cover and the unloading drawing plate form a batching box with an upper opening, and the partition plate is mounted in the frame body and used for partitioning the space in the batching box; the material supply proportion is controlled through the partition plate, weighing operation is converted into measurement operation, the operation process is simplified, meanwhile, the installation angle and position of the partition plate are changed, continuous change of the proportion of a single test piece can be achieved, the function of testing indexes of test pieces with different proportions at different positions of the same test piece is achieved, the manufacturing amount of the test pieces is reduced, and the cost is reduced. And the efficiency of related work is improved.

The invention provides a battery thermal runaway test system, which comprises a battery, a gas outlet pipe, a first thermocouple, a second thermocouple, a first gas detection device, a gas mass flow meter, a voltage detection device, a pressure detection device and the like, the second end of the gas outlet pipe is communicated with an inlet of a gas mass flowmeter, a second thermocouple is arranged at an outlet of the gas mass flowmeter, and a first gas detection device is arranged at the outlet of the gas mass flowmeter. According to the invention, a plurality of parameter measuring devices are arranged on an air flow spraying path of the battery pressure release valve, so that synchronous acquisition of key parameters such as voltage, expansive force, spraying speed, gas concentration and temperature in the thermal runaway process of the battery is realized, and the problems of single traditional test parameter and asynchronous data are solved; and the multi-physical field coupling data of the whole thermal runaway process can be completely obtained.

The invention discloses a relay protection plug-in automatic simulation test method and system based on a universal backboard. The method comprises the steps that a relay protection plug-in to be tested is connected to the universal backboard; semantic information in the relay protection configuration file of the plug-in is analyzed and extracted, a corresponding test data model is dynamically constructed, and a matched operation scheme is generated; on the basis of the operation scheme, real-time simulation parameters are set, and a multi-dimensional excitation signal is applied to the plug-in through the universal backboard so as to simulate various operation conditions of the power system; and acquiring response data of the plug-in under the excitation signal through the universal backboard, and comparing the response data with an expected response to obtain a test result. According to the invention, plug-in level universal testing is realized, special debugging instruments of various models can be replaced by a single testing system, and the operation and maintenance efficiency and the spare part management level of the relay protection device are remarkably improved.

The invention discloses master-slave integrated MVB (Multifunction Vehicle Bus) simulation test equipment based on an FPGA (Field Programmable Gate Array) and an MCU (Microprogrammed Control Unit). An FPGA chip, an MCU chip and an MVB communication physical layer circuit are arranged in an equipment body; an MVB master logic unit and an MVB slave logic unit are integrated in the FPGA chip; the MCU chip is in communication connection with the main logic unit and the MVB slave logic unit; and the MVB communication physical layer circuit is used for realizing conversion between a logic level signal output by the FPGA chip and an EMD signal of an MVB bus. The MVB main logic control unit sends an MVB main frame according to the port traversal table stored in the port table unit; and after the MVB slave logic data and state control unit obtains the sending control right of the MVB sending control unit, the MVB slave logic unit sends or receives data with the MVB bus. The device number and cable connection are reduced, the deployment time of the test system is shortened, and the single test duration is shortened.

The invention discloses a distributed system-oriented test station model generation method, relates to the technical field of automatic testing, and aims to solve the problem that a single test station cannot meet the test requirement along with the increase of the size of a test object and the increase of complexity in the conventional test station model generation method. Therefore, a distributed test system needs to be applied to test a large-scale and complex system, a test station modeling method of the distributed system needs to be designed, and research on the aspect in the industry is few. According to the test station model generation method oriented to the distributed system, an automatic generation algorithm is achieved, the generation efficiency and accuracy of the test station can be greatly improved, and the development efficiency of an automatic test system is improved.

The present invention relates to a method and device for rapidly and comprehensively evaluating the performance of tunnel muck used for manufactured sand, comprising the following steps: 1) Specimen preparation: Using a vibration device (1), a temperature control device (3), and a weighing device (10) to rapidly obtain dried and saturated surface-dry specimens. 2) Apparent density and water absorption test: Measuring the mass of water discharged by a known mass of saturated surface-dry specimens and heating to obtain the mass of the dried specimens. 3) Crushing index and softening coefficient test: Pressurizing, automatically screening, and weighing the dried and saturated surface-dry specimens respectively. 4) Soundness test: Realizing the rapid test of soundness based on temperature control, automatic screening, and weighing. 5) Automatic data acquisition and processing: Automatically acquiring and processing the above data. The evaluation method and device proposed by the present invention can simultaneously and rapidly test the physical and mechanical properties and durability of muck, solve the problems such as long test cycle and single test result of muck performance, and are applicable to the rapid evaluation of manufactured sand parent rocks such as muck, pebbles / gravels.

The invention provides a nuclear power generator compactness test method. The nuclear power generator compactness test method comprises the following steps: S1, cleaning; and the to-be-detected product is comprehensively cleaned. S2, preparation before measurement; and the end socket and the cover plate are assembled to ensure that the product forms a sealed cavity. And S3, carrying out an airtight test. And S4, preliminary inspection. And S5, carrying out a hydrostatic test. And S6, performing secondary inspection. And S7, reducing the pressure. And S8, dismounting the end socket and the cover plate, and completing the detection. By combining the airtight test and the hydrostatic test, the compactness of the nuclear power generator can be comprehensively detected, a detection blind area possibly existing in a single test method is effectively avoided, a special pressure boosting and reducing mode is adopted for hydraulic pressure detection, the accuracy and reliability of a test result are guaranteed, welding residual stress can be effectively eliminated, and the reliability of the nuclear power generator is improved. And the sealing performance and the structural stability of a nuclear power generator product are obviously improved.

This invention discloses a glass non-destructive testing system based on data analysis. The invention relates to the field of glass testing technology. It obtains a set of test images of a glass product by repeatedly capturing images of the bottle body during a step-rotating process using an image acquisition module. A test data interaction module crops several images within the test image set, reducing its size. This accelerates the defect detection speed and efficiency of a single glass product. A defect analysis unit analyzes stored defect analysis data to determine redundant image numbers that can be quickly identified. This ensures that the overlapping areas retained in the test image set are the overlapping areas with the optimal recognition rate, reducing the transmission rate of the test image set and saving resources for the glass defect detection model in recognizing image data from a single test image set.

The application relates to the technical field of vehicles, in particular to a test method and device of an electric drive system, electronic equipment and a storage medium, wherein the method comprises the following steps: obtaining an electric drive test requirement of a to-be-tested electric drive system; controlling a load simulator, an environment simulator, a simulated charging pile and a battery simulator to provide at least one test state for the to-be-tested electric drive system according to the electric drive test requirement; obtaining test information output by the to-be-tested electric drive system in the corresponding test state, so as to generate a test result according to the test information. Thus, the problem of single test dimension and insufficient dynamic performance evaluation in the electric drive boost charging test method is solved, the real complex working condition is reproduced by synchronously applying electrical, thermal and control multi-dimensional stress, the dynamic response capability and control robustness of the system are quantitatively evaluated through step disturbance and transient mode switching, and the fault detection rate and the research and development efficiency are improved.

The present disclosure relates to a system for a test. More particularly, the present disclosure relates to a continuous loadable module-typed system for a test, a computer readable storage medium containing instructions to configure a processor to enable a continuous loadable module-typed system for a test, and a method for testing a sample. The exemplary embodiment of the presently disclosed system may be configured to support (i) single tests, (ii) batch tests, (iii) syndromic tests and / or (iv) combination tests. In addition, the exemplary embodiment of the presently disclosed system automatically processes and tests samples based on identification information, without requiring the user to classify and load the samples according to test type.