88results about How to "Overcoming repetitiveness" patented technology

The invention provides a magnetic mesoporous silica gel material extracting agent used for enriching and / or separating trace organic pollutants in an environment water sample, and a preparation method thereof. A core of the extracting agent provided by the invention is a silicon gel microsphere (i.e. magnetic silicon gel microsphere) wrapped with a plurality of Fe3O4 magnetic nano particles, and a shell of the extracting agent is a mesoporous silicon gel shell layer with inner and outer surfaces modified by C18 silanization. The extracting agent integrates huge special surface area, excellent extracting capacity and ultrahigh extracting volume of a mesoporous material, magnetic separating capacity of a magnetic material, strong extracting capacity of C18 groups and special volume exclusion function of a vertical channel of the mesoporous material. In addition, the extracting agent provided by the invention has the advantages of high extracting efficiency, low preparation cost and simple preparation method, and is very suitable for preprocessing samples of the trace organic pollutants in a bulk-mass water sample.

A semi-supervised polarization SAR terrain classification method based on full convolution GAN is implemented by the following steps: performing refined Lee filtering; inputting polarization SAR data;constructing a generation network G; constructing a discrimination network D; training and testing the networks and calculating classification accuracy rate. Compared with the semi-supervised Co-training classification method in the prior art, the invention improves the classification accuracy of polarization SAR data of the polarized synthetic aperture radar, solves the problem of insufficient utilization of polarization information, enhances the robustness of the model to the input data, and has the effect of end-to-end classification. The invention can be applied to the terrain classification of polarized synthetic aperture radar polarized SAR data.

The invention relates to a multi-system digital optical fiber category 5 cable distribution system which is characterized by being composed of a near-end access unit part, an expansion unit part and a far-end cover unit part. The near-end access unit part, the expansion unit part and the far-end cover unit part form an up link and a down link of the system. The multi-system digital optical fiber category 5 cable distribution system is high in integration level. Low-noise circuits, frequency conversion circuits and amplifying circuits of the near-end access unit part, the expansion unit part, the far-end cover unit part and the like are all in an integration module design thought, and therefore the multi-system digital optical fiber category 5 cable distribution system is smaller in size, stronger in reliability and more beneficial for installation and use of practical projects.

The invention discloses a preparation method of black a phosphene nano sheet. The black phosphene nano sheet is prepared by stripping black phosphorus crystals through liquid phase shear force generated by a high-speed rotation cutter head, wherein the whole preparation process is carried out in an argon environment. The preparation method particularly includes the following steps: placing the black phosphorus crystals and an organic solvent in a stirring barrel; setting the rotation speed of the high-speed rotation cutter head; connecting a power supply to drive the high-speed rotation cutter head to rotate in the stirring barrel; setting stripping time to prepare a dispersion liquid of the black phosphene nano sheet; and finally performing centrifugation, filtration and cleaning to obtain clean black phosphene nano sheets. The preparation method is low in cost and has potential of large-scale production.

The invention provides a cash voucher generation method adopting incremental mining in the retail trade, which mainly comprises a series of processes including using a card, excavating data stream, accessing of knowledge base and printing cash vouchers. Each customer has a membership card which is for free. When the customer uses the card for shopping, a computer automatically checks the shopping mode of the customer, if the shopping mode meets certain conditions, a cash voucher for the customer is automatically printed after a shopping receipt is printed. Concrete steps are as follows: 1. a commodity inventory of retail enterprises, discount commodity database and customer resource database are established; 2. the collection of daily database information and the excavation of long-term data are carried out; 3. commodities bought are scanned and input and each POS machine sends shopping lists of customers to a data excavating tool for generating customer consumption records after data preprocessing; and 4. cash vouchers of conventional consumables or commodities predicted to be bought are printed and discount information is stored in the customer resource database simultaneously.

The invention provides a performance tester of a continuous flat ultrafiltration membrane and a reverse osmosis membrane and a use method thereof. The tester comprises a water supply unit, a drainage unit and a plurality of parallel infiltration ponds, wherein each infiltration pond comprises a substrate, a shell, a water inlet, a water outlet, an exhaust port, a bottom inserting tube, a stirrer and a constant-temperature water bath jacket. Produced water penetrating through a separation membrane to be measured is discharged out of the infiltration ponds via the water outlets. The tester can carry out constant-temperature and stable operation at higher temperature and can realize the functions of testing membrane separation performance and membrane flux attenuation, extracting key pollutants of the membrane, cleaning the membrane on line and testing membrane performance restore after cleaning.

The invention belongs to a microdeformable mirror and the machining and preparing field thereof, concretely relating to a piezoelectric film drive-based microdeformable mirror and the preparing method thereof. And the mcirodeformable mirror comprises micro actuator array composed of actuating units and mirror surface, where the micro actuator array is of a centrosymmetric regular hexagonal structure and the mirror composed of monocrystalline silicon diaphragm is connected with upper electrodes through photosensitive high polymer boss; the preparing course comprises: preparing silicon substrate piezoelectric ceramic base film, using wet-etching process to etch the silicon substrate piezoelectric ceramic base film, using wet-etching process to etch silicon substrate piezoelectric ceramic thick film shape, preparing upper electrode array on the silicon substrate piezoelectric ceramic thick film array, and preparing connection boss on the upper surface of the upper electrode array and using photosensitive high polymer to fix the mirror surface on the actuator array. And the microdeformable mirror can drive the mirror to generate larger displacement so as to meet the requirements of the fields of astro-observation, amotio imaging, etc; and the preparing method has simple process, low cost and good commercial application prospect.

The invention discloses a method for preparing a full-silicon DD3R zeolite molecular sieve with a pure phase and uniform crystal morphology and size. The purpose of the invention is to provide the method for preparing the full-silicon DD3R zeolite molecular sieve with the pure phase and uniform crystal morphology and size. The method is simple in process, low in cost, good in repeatability and excellent in product quality. The method for preparing the full-silicon DD3R zeolite molecular sieve comprises the following steps: (1) adding an organic structure directingagent, a silicon source and a mineralizer into deionized water to mix and agitate; (2) adding a crystal seed to a mixing system obtained from the step (1); after mixing, agitating and aging, transferring the mixture into a hydrothermal reaction kettle to crystallize; (3), filtering and washing a sample obtained from the step (2), and obtaining the pure-phase DD3R zeolite molecular sieve with uniform crystal morphology and size after drying and baking the sample. The method has the characteristics that the crystallization time is short, the synthetic energy consumption is low, and the obtained pure-phase DD3R zeolite molecular sieve has excellent quality.

The invention relates to a CAN / LIN network interference automation test system. The system comprises an upper computer (network interference automation test software), an arbitrary waveform signal generator, a signal interference coupler, a bus monitoring device, a relay matrix, an I / O simulation board card, a load simulation board card, a collecting board card and a power supply device. The system is divided into a management module, a consistency test module and a network interference module. The system is characterized in that the system carries out an automatic and quick interference fault injection test, automatically reads diagnostic information, a bus signal and other information through a consistency test after fault injection, carries out state comparison analysis before and after the test, and rapidly confirms the state of a vehicle control unit. The system monitors the bus state of a controller to confirm the anti-interference ability of the controller. The test tracks and solves the problem of network interference as a sample is upgraded to a genuine sample from initial design and development, so as to protect the network communication stability of the controller in a vehicle.

The invention belongs to the technical field of organic chemical catalytic synthesis, which relates to a device and a method for performing olefin gaseous phase epoxidation by using industrial hydrogen peroxide. A reactor casing of the device is made of metal materials, the inner wall contacted with the hydrogen peroxide is passivated through acid solution, or the inner wall is coated with hydrogen peroxide inert materials. The processed raw material enters a reactor to perform reaction along with feeding materials of the olefin raw material, diluent gas, auxiliaries and the like, and after reacted materials pass through a separation unit, unreacted olefin raw material, the diluent gas and auxiliaries circulate back to the reactor. The device and the method directly use industrial hydrogen peroxide products, overcome bottlenecks of low efficiency, fast catalytic agent inactivation and poor regeneration repeatability of in-situ hydrogen peroxide preparation, are strong in raw material adaptability, safe and high in efficiency, few in gaseous phase epoxidation reactive by-product, simple in separation and high in catalyst stability.

The invention belongs to the technical field of a sewage treating agent and especially relates to a treating agent applied to papermaking sewage. The treating agent applied to the papermaking sewage comprises the following components by weight part: 40-55 parts of flocculating agents, 15-25 parts of chelating agents, 10-15 parts of adsorbents and 5-35 parts of PH(Potential of Hydrogen) regulators. The treating agent can enable the physicochemical indexes of the papermaking sewage to meet the GB18918-2002 standard, the contents of COD (Chemical Oxygen Demand), BOD (Biochemical Oxygen Demand), SS (Suspended Solids) and metal ions are effectively reduced and the PH is approximately neutral and meets a emission standard.

The invention discloses a preparation method of ZnSe / ZnS core-shell quantum dots through illumination assisted room-temperature synthesis. The method comprises the steps of: A. preparing a potassium hydrogen selenide solution by reducing selenium powder with potassium borohydride; B. weighing zinc acetate crystals, which is then dissolved in deionized water to a constant volume, thus obtaining a zinc acetate solution; C. adding quantitative thioglycolic acid into the zinc acetate solution; D. adjusting the solution to a specific pH value with a sodium hydroxide solution; E. after introducing an inert gas for deoxygenation, adding the potassium hydrogen selenide solution; F. placing the stock solution or a diluted solution of the mixed solution under an ultraviolet light for radiation for a certain period of time, and conducting detection with fluorescence spectrum analysis; and G. adding isopropyl alcohol for purification, then carrying out drying by a freeze drier so as to obtain ZnSe / ZnS core-shell quantum dot solid powder, which is dissolved in a PBS solution or deionized water before using, thus obtaining a ZnSe / ZnS core-shell quantum dot solution. The method of the invention has the advantages of simple process, easily controllable technological parameters, as well as cheap raw materials. The synthesized ZnSe / ZnS core-shell quantum dots are free of heavy metal ions, and can be used for biological labeling and imaging.

The invention belongs to the technical field of preparation of metal oxyhydroxides, and specifically relates to a preparation method and an application for iron oxyhydroxide. The preparation method comprises the following steps: under the condition of supergravity, mixing a Fe2+ metal salt solution with an alkaline solution, and allowing oxygen to reversely contact with a reaction solution at thesame time so as to obtain a mixed reaction slurry; subjecting the mixed reaction slurry to gas-liquid separation, and subjecting an obtained liquid to aging under the conditions of stirring and bubbling oxidation so as to prepare a suspension containing the iron oxyhydroxide; and subjecting the suspension to liquid-solid separation, and subjecting an obtained solid phase to washing and drying so as to obtain the iron oxyhydroxide. According to the invention, the precipitation process and the bubbling aging process of a supergravity reaction are performed in different reactors, so the processesof crystal nucleus generation and crystal nucleus growth are separated; through adjustment of parameters of temperature, time and stirring degree in bubbling aging, the environment of crystal nucleusgrowth is controlled; and preferably, nanoscale or submicron iron oxyhydroxide can be prepared, and has the characteristics of small average particle size, large specific surface area and uniform particle size distribution.

The invention provides a cipher character string generation method. The method comprises the following steps: prestoring multiple encryption algorithms; acquiring data to be encrypted in a data set S of cipher character strings to be generated; and by use of the encryption algorithms, performing encryption operation on the data to be encrypted so as to generate the cipher character strings. According to the embodiments of the invention, the cipher character strings are generated through arrangement of the multiple encryption algorithms, and the method and apparatus have the positive effects of reducing the risk of cracking the cipher character strings and improving the security of the cipher character string.

The invention relates to the field of oil-gas field development tests, in particular to a bubble point pressure testing device and method. According to the bubble point pressure testing method, fluid bubble point pressure can be rapidly and accurately obtained by testing the changing relation of fluid pressure and volume in capillary tubes. The defects that bubble point pressure is poor in repeatability and low in accuracy when core testing is adopted are overcome, bubble point pressure under the condition of different parameters can be obtained according to the parallel-connection way of the capillary tubes by changing the parameters such as the inner diameter and length of the capillary tubes, and a numerical simulation model can be built.

The invention discloses molecular markers closely linked to an RBSDV (rice black-streaked dwarf virus) major QTL (quantitative trait locus). The essence of the invention is that according to the linkage and segregation rules, the F2 population of the hybrid generation of Tetep and RBSDV susceptible varieties is taken as the mapping population and the SSR (simple sequence repeat) markers RM5626 and RM7097 on the No.3 chromosome, which are closely linked to the RBSDV resistant major QTL are obtained through analysis of linkage between the results of evaluation of disease resistance and the SSR marker data. Whether a plant has resistance to RBSDV can be judged by detecting the SSR marker banding pattern of the single rice plant of the hybrid combination generation of Tetep and derived varieties (lines) thereof and the RBSDV susceptible varieties. After the SSR markers are applied to assistant selection breeding of the RBSDV resistant varieties of Tetep and derived varieties (lines) thereof / RBSDV susceptible varieties, the defects of poor stability and repeatability of RBSDV resistance evaluation, time and labor waste, high technical threshold and the like in conventional breeding can be overcome and the results can conduce to simplifying the selection method and improving the breeding efficiency and then accelerating the breeding process of RBSDV resistant varieties.

The invention relates to a method for realizing voice called service and calling service, and a system thereof. The called method of the invention includes that when a call request is received, an intelligent called service query is carried out; when a called unity number service code is resolved from a response, a called unity number service is triggered; a unity number is queried; a plurality of called terminals are called. The calling method of the invention includes that a call request is received; an intelligent calling service query is carried out; when a calling unity number service code is resolved from a response, a calling unity number service is triggered; a master number is used for updating and sending a calling number; according to the master number, calling operation is executed. The system of the invention comprises a user data center which is used for storing the calling unity number service code and the called unity number service code, a fixed network unity number service controlling point which is used for storing the master number and the slave number of a unity number user, a fixed network service interchange point which is used for processing the unity number service. By adopting the invention, the unity number service is added into the call service of an intelligent network to fully utilize the advantages of the fixed network and a mobile network, thus improving user experiences.

The invention belongs to the field of molecular biology, and particularly relates to a nasopharyngeal carcinoma microRNA detection kit. A purpose of the present invention is to solve the problems of poor stability, poor reproducibility, low specificity and easy false positive generation of the existing nasopharyngeal carcinoma microRNA detection kit. The invention provides the nasopharyngeal carcinoma microRNA detection kit, which comprises a probe composition, wherein the probe composition comprises a capture probe bound with a target microRNA and a signal amplification composition, and the target microRNA is one or a plurality of microRNA selected from hsa-miR-17-5p, hsa-miR-20a-5p, hsa-miR-29c-3p, hsa-miR-223-3p, hsa-miR-34b-3p, hsa-miR-34c-5p, hsa-miR-212-3p, hsa-miR-216a-5p, hsa-miR-217, hsa-miR-151a-3p, and hsa-miR-192-5p. The nasopharyngeal carcinoma microRNA detection kit of the present invention has advantages of good stability, good repeatability, high specificity, less false positive generation, and high sensitivity.

A polarization maintaining fibre with high birefringence is composed of fibre core and cladding layer in which there are the triangular stress element arranged symmetrically at both sides of fibre core and the optional stress holes. Its preparing process includes combining core rod with stress rods by OVD technology, spraying the cladding layer, and drawing. Its advantages are simple preparing process, and high axial uniforming, strength and performance.

The invention discloses an immunologic diagnosis kit for detecting dengue virus NS1 antigen and application thereof. The kit comprises a capturing antibody and a detecting body combined with a marker, and the kit is characterized in that the capturing antibody consists of a monoclonal antibody 2E8A5, a monoclonal antibody DV2M6 and a monoclonal antibody 4B14A1, the detecting antibody is a monoclonal antibody 3B1A15, and the marker can be biotin, horseradish peroxidase, alkaline phosphatase, colloidal gold or fluorescein. The kit can specifically detect NS1 proteins of four serotype dengue viruses and does not have cross reaction with other viruses of flavivirus system, such as flavivirus and encephalitis B virus, the sensitivity of the kit is at least four times higher than that of detection of foreign commodity kits, and the kit can efficiently reduce the omission factor of the clinical application.

The invention relates to a method for preparing a three-dimensional manometer load-type catalyst, comprising the following steps of: (1) covering solution with nanosphere on a substrate evenly and drying; (2) using the nanosphere as a mask plate and adopting dry etching or wet corrosion based on different etching or corroding rate with the substrate; and (3) depositing a catalyst material. The method has simple process, low cost and is easy to be promoted and used. The scale of the catalyst carrier in the three-dimensional direction is within the nanometer magnitude and the body of the carrier has larger specific surface area so that the catalyst acts on large areas, and the catalyst materials are highly dispersed, easily recycled and can be reused.

The invention relates to a preparation method and application of a CuxO-Fe2O3 nano material, and belongs to the technical field of advanced waste water treatment and environmental catalysis.The CuxO-Fe2O3 nano material is prepared through an impregnation method, the CuxO-Fe2O3 nano material serves as a catalyst and is added into organic waste water which is difficult to degrade to catalyze an ozone reaction, degradation of organic contaminants is promoted, and the mineralization rate of organic matter is greatly increased; the CuxO-Fe2O3 nano material is small in size and good in dispersity in a nano material system, CuxO-Fe2O3 has magnetism, the catalyst subjected to the reaction can be effectively separated from water and recycled by means of an external magnetic field, the catalyst is good in stability, and the high catalytic activity can still be maintained after the catalyst is repeatedly used three times.The added CuxO-Fe2O3 catalyst can obviously improve the the removal efficiency of ozone to the contaminants, a good catalytic effect can be achieved on the condition that the pH ranges from 3 to 11, and the catalyst is small in dosage and stable in repeatedly used performance and has a wide prospect in water treatment.

The invention relates to a wood material adhesive which takes corn starch as main material and the preparation method thereof and belongs to the adhesive technical filed. The adhesive consists of the following components with different weight proportion: cornstarch, mixture of dicarboxyl and acetic anhydride, polyvinyl alcohol, metallic oxide, rubber latex and water. The procedure of the invention is as follows: adding water to cornstarch and stirring; then adding the mixture of dicarboxyl and acetic anhydride and stirring; then adjusting PH value, heating up, adjusting PH value and reducing temperature to obtain cross bonding cornstarch; putting the polyvinyl alcohol into water, heating up, reducing temperature, adding the cross bonding cornstarch; heating up, stirring, reducing temperature, adding rubber latex and metallic oxide and stirring at last to obtain the adhesive. The adhesive and the preparation method have the advantages of high strenghth, good water resistance, long storage life, simple fabrication technology, low cost, no pollution and wide application range. The invention can be used for the cementation of various wood materials including density boards, glued boards, laminated wood boards and decorated boards.

A high frequency high voltage pulse generator is a pulse driving and emission source which is applied to fields of display measurement, display drive, communication technology and the like. The generator comprise a pulse signal amplification circuit, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) driving circuit, and a high voltage pulse output circuit which are in serial connection in order. An input terminal of the pulse signal amplification circuit is an input terminal of the generator, and an output terminal of the high voltage pulse output circuit is an output terminal of the generator. An upper end suspension power supply of the MOSFET driving circuit of the generator is formed by a high voltage pulse attenuator, so a positive / negative high frequency pulse which has a duty ratio of 0.005 % in a frame period and meets a technical index is generated in the display measurement, a maintenance pulse which has a duty ratio of 50% and satisfies more than 8 subfields is provided in the display drive, and an emission source pulse which 100% operating efficiency, large power and low loss is outputted in the communication technology.

The invention provides a concrete-poured sandwich metal plate type composite armor and a manufacture method thereof. The concrete-poured sandwich metal plate type composite armor comprises a metal front faceplate, a metal back faceplate and a metal core body fixed between the metal front faceplate and the metal back faceplate, wherein the metal core body is a metal plate with the angle of theta, the metal front faceplate, the metal back faceplate and the metal core body form into a sandwich metal sandwich plate, and the concrete is poured into a hollow structure of the sandwich metal sandwich plate. The manufacture method of the concrete-poured sandwich metal plate type composite armor comprises the following steps of: 1, firstly, flattening the metal plate material by a flattening machine, blasting sand, carrying out mould pressing by a hydraulic machine or bending by a bending machine to obtain the metal plate with the angle of theta, and welding the metal core body between the metal front faceplate and the metal back faceplate layer by layer, thus forming the sandwich metal sandwich plate; 2, dosing, mixing and stirring raw materials of the concrete; and 3, pouring the concrete into the hollow structure of the sandwich metal sandwich plate, standing, and maintaining, thus obtaining a finished product. The armor provided by the invention is light in weight, low in cost, and good in ballistic performance. The preparation method of the armor is simple, and low in cost.

The invention discloses a bell jar paste pouring device for multi-layer mixed paste pouring and a method for preparing tiles. The bell jar paste pouring device comprises a multi-layer paste storage tank and a paste pouring bell jar. The multi-layer paste storage tank is arranged above the paste pouring bell jar and is formed by sleeving a plurality of tank bodies with different diameters. Each tank body is provided with a paste injecting opening and a columnar paste outlet, wherein the paste injecting opening is formed in the side wall or the top of the tank body, and the columnar paste outlet is formed in the bottom of the tank body. The paste pouring bell jar is located under the columnar paste outlets. Various types of color paste is poured, the space and manufacturing cost of the bell jar paste pouring device are saved, operation is convenient, the structure is simple, paste pouring is more stable and convenient, the mixing effect of different types of paste is more nature, rich patterns and textures can be formed, the texture and line effect of the tiles is more vivid and natural, rich in color, clear and dreamlike, and the richness and naturalness of the textures on the surfaces of the natural-like tiles are improved.

The invention discloses an oil desulfurization method of the silica gel loaded with cesium salt catalyst of heteropoly acid and the method uses hydrogen peroxide as oxidant and the silica gel loaded with cesium salt of heteropoly acid as catalyst. The method comprises the following steps: oi and acetonitrile used as solvent are mixed according to a certain ratio, the mixture of the oxidant and the catalyst are added in the mixed solution at a certain temperature under the atmospheric pressure, the mixture is cooled to the room temperature after the reaction, then the reaction fluid is layered naturally, the upper oil phase is desulfurized oil, the lower layer is acetonitrile phase with the product and the catalyst, and the catalyst performs solid-liquid separation and is cleaned with acetonitrile, thus the catalyst can be recycled and reused. The catalyst used in the method has simple and safe preparation process, is non-toxic and harmless, has no pollution and can be recycled and reused. Compared with the traditional process, the process is simple, the catalyst can be recycled and directly reused, the desulfurization efficiency is high, the dosage of the oxidant is low and the method is suitable for industrial popularization and application.

The invention relates to a simple, quick, specific and sensitive real-time fluorescence PCR (Polymerase Chain Reaction) detection method and a kit thereof for simultaneously detecting one or more soybean virus diseases of tobacco ringspot viruses, southern bean mosaic viruses, tomato ringspot viruses and arabis mosaic viruses. In the real-time PCR detection method, primer sequences of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8 and oligonucleotide probes of SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NO:12 are used. The real-time fluorescence PCR detection method and the kit thereof are suitable for departments of port inspection and quarantine, agricultural production, plant protection, and the like.

The invention relates to an analytical method of iodine-containing hydriodic acid concentration, and belongs to the fields of electrochemistry and analytical chemistry. The analytical method disclosed by the invention comprises the following steps: performing analysis by adopting a density measurement device and a constant current electrolysis-electrodialysis cell, and firstly establishing a mathematical relation formula among material concentration and the material density of an iodine-containing hydriodic acid standard sample, as well as a cell voltage value when material flows through the constant current electrolysis-electrodialysis cell; and determining the density of an iodine-containing hydriodic acid sample to be determined and the cell voltage value thereof when the iodine-containing hydriodic acid sample flows through the constant current electrolysis-electrodialysis cell, and determining the specific concentration of the sample to be determined from the mathematical relation. By adopting the method disclosed by the invention, the accuracy is higher, and the shortcomings of trivial operation, time-consuming process, poor repeatability and the like of a conventional titration analytical method can be overcome.

The invention provides a realizing method for generating random user and the simulation method for communication network. The realizing method is used in the communication system to generate the position information of the users randomly. The said communication simulation system comprises the geomorphologic and geological property of the planned region, comprising the steps of: (1) forming business density grid image layer according to the geomorphologic and geological property of the planned region, the set business density; (2) setting the grids in the said image to different groups according to the business density of the business; (3) selecting its own grids from all the groups, saving the position information of the said grids and getting the position where the random user's in.