53results about How to "Strict requirements" patented technology

This invention relates to the interdisciplinary field of mechanical engineering and optical inspection, and discloses a method and system for quality sorting of automotive stamping parts combined with optical inspection. The method includes: synchronous imaging by a high-speed linear array camera and a structured light projector via an encoder and photoelectric triggering device; fusing 3D point clouds and 2D images, and using a deep convolutional neural network for defect identification and quality grading; calculating the six-degree-of-freedom pose of the workpiece using an iterative nearest-point algorithm and principal component analysis; calculating the spatiotemporal parameters of sorting based on a predictive instruction generation module, and issuing dynamic control commands to multi-degree-of-freedom pneumatic push rods via a hard real-time communication bus to execute sorting. The system includes a synchronous triggering unit, an imaging unit, a defect identification unit, a pose calculation unit, a predictive instruction generation module, and a dynamic sorting execution unit. This invention achieves millisecond-level accurate identification and adaptive sorting, significantly improving detection accuracy, sorting efficiency, and system robustness.

The application discloses a power supply with an on-board rectification correction module, comprising an input filter module, a surge suppression module, a PFC rectification correction module and an output filter module; the input end of the input filter module inputs a 115Vac voltage; the output end of the input filter module is connected with the input end of the surge suppression module; the output end of the surge suppression module is connected with the input end of the PFC rectification correction module; the output end of the PFC rectification correction module is connected with the output filter module; and the output filter module can output a 260Vdc voltage. The 115Vac alternating current is converted into a pure and stable 260Vdc direct current output, the system tolerance to power grid surges and subsequent faults is significantly enhanced, and the strict requirements of the industrial, aviation and server fields on high-performance power supplies are met.

Power electronic equipment comprises a power box body internally provided with a heating device, a heat dissipation box body fixed to one side of the power box body, and a two-phase flow heat dissipation device vertically arranged in the heat dissipation box body. The power box body is provided with a first side plate, the upper portion of the first side plate is provided with an inner concave portion, one side of the heat dissipation box body is provided with an opening, the opening side of the heat dissipation box body is attached to the outer side of the first side plate, the two-phase flow radiator comprises an evaporator, a condenser and a connecting cavity connecting the evaporator and the condenser, and the evaporator is attached to the outer surface of the lower portion of the first side plate. The condenser is located above the evaporator and arranged in the inner concave part, an air inlet is formed in the lower portion of the heat dissipation box body, and an air outlet is formed in the upper portion of the heat dissipation box body. The power electronic equipment is high in heat dissipation efficiency, compact in structure and capable of adapting to various installation angles and installation directions in the range from the vertical direction to the horizontal direction, and the application flexibility and scene adaptability of the power electronic equipment are improved.

A wind tunnel test model structure with a high slenderness ratio belongs to the field of wind tunnel test vehicle design technology. It solves the problems of large vibration amplitude and low data accuracy in existing technologies during testing. Key technical points: The rectifier cap, front cylinder, and front port flange are sequentially bonded together, with the front port flange connected to the front end of the central steel shell; the rear port flange, rear end cylinder, and rear end plate are sequentially bonded together, with the rear port flange connected to the rear end of the central steel shell; a balance sleeve is fitted onto the balance, the central steel shell is fitted onto the balance sleeve, the balance front cone tension plate is connected to the central steel shell, the front end of the balance is connected to the balance front cone tension plate, and the rear end of the balance is connected to the tail end of the balance sleeve. This invention significantly reduces the vibration amplitude of the model structure during testing, avoids damage to the model and equipment caused by resonance, and improves the safety and stability of the entire wind tunnel high angle-of-attack test process; it effectively suppresses the interference of model vibration on measurement results, ensuring accurate and reliable test data acquisition.

This invention discloses a voltage detection and grounding drone and its control method, applied in the field of power system maintenance technology. It includes a drone and a voltage detection and grounding device located beneath the drone. The voltage detection and grounding device consists of an insulating rod, a locking mechanism, and a clamping mechanism. The clamping mechanism is located at one end of the insulating rod, which is fixed to the drone via the locking mechanism. The locking mechanism includes a rear locking mechanism located under the drone's belly, consisting of a vertical slide rail, a rear locking baffle, and a motor mechanism. The motor drives the baffle to move up and down along the slide rail, thereby moving the insulating rod. The clamping mechanism uses a V-shaped fixing plate with a voltage detection and grounding module at the bottom, including a voltage detection sensor, a grounding unit, and a clamping ratchet. The ratchet can rotate laterally to fix the cable within the V-shaped opening, realizing voltage detection and grounding operations. This invention solves the technical problems of low efficiency in existing voltage detection and grounding methods, high safety risks and costs associated with manual operations, and limited applicability of drones for attaching and removing grounding wires.

The invention provides a phthalocyanine sulfonamide derivative dye as well as a preparation method and application thereof, and belongs to the technical field of phthalocyanine series dyes. The structural general formula of the phthalocyanine sulfonamide derivative dye is (PC)-(SO2-N-X) z-(SO3R) y, PC is a phthalocyanine or metal phthalocyanine group, X is hydrogen, C1-C14 alkyl, hydroxyalkyl, aralkyl or aromatic group, R is hydrogen, C1-C4 alkyl or amine salt cation, the value range of z is 1-4, the value range of y is 1-3, and the sum of z and y is less than or equal to 4. According to the invention, the sulfonamide group and the sulfonic acid group are introduced at the same time, so that the prepared derivative dye has excellent organic solvent solubility and water solubility, and the problem of single solubility of the traditional zinc phthalocyanine dye is effectively solved.

This application discloses a method for preparing high-purity electronic-grade titanium dioxide from ilmenite, belonging to the field of titanium dioxide preparation technology. The method includes steps such as raw material processing, concentrated sulfuric acid acidolysis, sedimentation and filtration, FeSO4 crystallization and separation, preparation of hydrated titanium dioxide, washing and bleaching of hydrated titanium dioxide, acidolysis of hydrated titanium dioxide, secondary hydrolysis, washing and filtration, and calcination. This method effectively removes various impurities such as iron, phosphorus, niobium, and zirconium through acidolysis, secondary hydrolysis, and multiple fine washing operations on the hydrated titanium dioxide intermediate. The resulting titanium dioxide product has a purity of over 99.9%, providing a new route for preparing high-purity electronic-grade titanium dioxide from ilmenite.

This application relates to a method, system, computer device, and storage medium for dual-person sleep monitoring. This application converts the acquired mixed multimodal signals from both individuals into a time-frequency graph matrix, extracts the spatial features of body movement amplitude and posture angle changes from the time-frequency graph matrix, captures the time-series features of respiratory signals, and decouples the respiratory signal sequence, body movement signal sequence, and posture signal sequence for each individual. This overcomes the limitations of traditional Fourier transform and other algorithms, achieving accurate separation of dual-person sleep multimodal signals, solving the problem of signal cross-interference, and through multi-algorithm collaborative processing, achieving high-precision extraction of key parameters such as respiratory rate and body movement during dual-person sleep, reducing the monitoring error rate to within 3%. The method of analyzing each individual's sleep quality and generating individual sleep monitoring reports can adapt to different individual body types, sleep habits, and spatial location changes, improving the algorithm's generalization ability and effectively reducing monitoring blind spots and the risk of misjudgment.

This invention discloses a method, system, and computer equipment for electronic data forensics in police vehicles. The method includes: confirming whether the vehicle's onboard data storage device has read permissions; if read permissions exist, the investigating officer performs bidirectional authentication between the vehicle-mounted forensics equipment and the identity authentication module in the public security platform, activating and authorizing the secure, legal, and operable nature of the vehicle-mounted forensics equipment; if read permissions do not exist, data is directly read from the vehicle-mounted data storage device; and different data integrity checks and extractions are performed based on the two communication protocol types of the vehicle-mounted data storage device. This invention, in police enforcement scenarios, overcomes permission barriers and equipment damage constraints, enabling rapid acquisition and analysis of onboard data.

The application discloses an anti-white-spot optical coating and a preparation method thereof, and relates to the technical field of coating, which comprises a resin matrix and functional particles dispersed in the resin matrix, the particle size of the functional particles is 5-10 microns, the reflectivity of the optical coating is greater than or equal to 95% at a wavelength of 550 nm, the coating adhesion reaches 5B level according to the hundred-grid method, the coating pencil hardness is greater than or equal to B level, and the optical coating is free of white spots after being tested and lightened. The anti-white-spot optical coating and the preparation method thereof adopt a high-toughness and high-adhesion glue resin system as the resin matrix, and select the functional particles with a particle size of 5-10 microns, the interface bonding force between the functional particles and the resin matrix is optimized, the functional particles are uniformly dispersed in the resin matrix and form stable interface bonding, stress concentration and interface debonding are effectively avoided, and the generation of white spots is inhibited from the root. After testing, the coating is free of white spots when being lightened, and the anti-white-spot reliability of the coating is remarkably improved.

This invention discloses a method for preparing titanium alloy ingots with coordinated control of melting rate and cooling rate, specifically implemented according to the following steps: S1, establishing a finite element model of vacuum self-consuming arc melting of titanium alloy ingots, completing mesh generation, and setting core process and physical property parameters; S2, determining parameter gradient values ​​and calculating deviation; S3, dividing the melting process into three stages: arc initiation period, normal melting period, and feeding period, ensuring that the average elemental composition deviation throughout the process is within the range of 0.02~0.06; S4, evaluating and analyzing the composition at the head, middle, and tail points and the longitudinal section composition of the ingot after melting. This method solves the ingot quality problem caused by mismatched process parameters in existing VAR melting processes, improves ingot quality and performance, and reduces production costs.

The utility model discloses a two -axis body -turning cutting mechanism relates to the technical field of automotive parts, including fixed floor, rotary air cylinder, rotating support and fixed axle, the fixed axle is rigidly connected with fixed floor, the rotary air cylinder is fixed on fixed floor, and its rotary end drives rotating support, the rotating support both sides symmetry sets up support pivot no.

The invention discloses a movable flue lifting device and converter equipment. The technical problem that in the prior art, the lifting distance is not stable is solved. The movable flue lifting device comprises a rack, a winch, a transmission structure and a lifting pin shaft. The winch is installed on the rack. The transmission structure comprises a steel wire rope and a pulley block, one end of the steel wire rope is connected to the winch, and the other end of the steel wire rope is wound around the pulley block installed on the rack. The first section of the lifting pin shaft is connected with the movable flue, and the second end of the lifting pin shaft is connected with the end, away from the winch, of the steel wire rope. When the winch shrinks the steel wire rope, the lifting pin shaft drives the movable flue to ascend. According to the movable flue lifting device, the lifting pin shaft has the characteristics of high strength and deformation resistance, the movable flue can be accurately driven to ascend and descend to the designated position under the driving of the winch, it is ensured that smoke dust is effectively collected in the converter smelting process, and the strict requirement of the technology for the flue position is met.

The application provides a multifunctional climbing protection tool test device, and relates to the technical field of physical testing.The real-time collection of electromagnetic radiation data and ultrasonic data is introduced, advanced data processing technologies such as multivariate nonlinear regression analysis and Gaussian mixture model are combined, comprehensive and accurate evaluation of the pressure resistance and static load bearing capacity of the tool is realized, and the scientificity and reliability of the evaluation of the climbing protection tool are significantly improved.

The application relates to the field of radio transmission technology, in particular to a signal transmission method and system of a transmitter and a storage medium. The method comprises the following steps: obtaining an original transmission signal to be transmitted and performing filtering processing on the original transmission signal to obtain a transmission signal to be input into a power amplifier; and performing block processing on the transmission signal according to a preset signal length. The application can locate signal peak points in the time domain, identify peak value regions to be compressed, and perform nonlinear amplitude-phase joint mapping compression on the peak value regions by using a polarization constraint matrix. The nonlinear amplitude-phase joint correction path enables the signal energy to be redistributed without damaging the sideband spectrum characteristics, thereby avoiding the problem of the dynamic range expansion of the input signal of the power amplifier caused by excessive compression. The application enables the power amplifier in the transmitter to work in a lower backoff zone, and improves the conversion efficiency of the power amplifier.

This invention discloses a verification sample and verification method for halftone mask HTM repair process, relating to the field of flat panel display mask manufacturing technology. The verification sample includes a substrate, on which are integrated dimensional accuracy testing structures, edge straightness testing structures, seam straightness testing structures, and ZAP repair straightness testing structures. The ZAP repair straightness testing structure comprises two opposing HTM patterns, forming an overlapping area. After being removed by ZAP laser scanning, a third seam is formed for evaluating the repair effect. The halftone layer of the verification sample has a light transmittance of 35%-45%. The verification method includes five steps: dimensional accuracy verification, edge straightness verification, seam straightness verification, ZAP repair effect verification, and transmittance consistency verification. This invention, through the integrated design of four types of testing structures, achieves systematic quantitative verification of the dimensional accuracy, multi-directional straightness, ZAP repair straightness, and optical transmittance of the HTM repair process.

The utility model discloses an elbow nozzle for dispensing, which comprises a steering adjusting mechanism, an angle adjusting mechanism for adjusting the inclination angle is arranged below the steering adjusting mechanism, and a connecting mechanism is arranged below the angle adjusting mechanism. On one hand, through the unique bent structural design of the head of the nozzle, the limitation of a common nozzle with a straight pipe structure on space and angle is broken through, a part which is narrow in position or forms a certain angle with the dispensing head can be glued, the application range of dispensing operation is widened, and the problem of gluing on a special part is solved; on the other hand, an angle adjusting mechanism is arranged, an operator can accurately control the rotating angle of a worm gear by controlling the rotating direction and the number of turns of a worm, a lower structure is driven to change the inclination angle, the angle of the nozzle head and the gluing part can be freely adjusted according to needs, precise gluing is achieved, and the dispensing quality and precision are improved; and the strict requirements of different workpieces and the dispensing process on the inclination angle are met.

The application discloses a control method and device for a push-the-bit rotary steerable system, and the method comprises the following steps: inputting formation parameter data into a multi-dimensional data matching model to obtain predicted rib plate adjustment parameters; searching in a constructed formation database to obtain rib plate adjustment parameters matched with the formation characteristics corresponding to the formation parameter data; when the similarity between the predicted rib plate adjustment parameters and the searched rib plate adjustment parameters is greater than a similarity threshold, generating control instructions for each rib plate of the push-the-bit rotary steerable system according to the predicted rib plate adjustment parameters, a design trajectory and an actual trajectory of a well hole in which drilling operation is performed; and sending the control instructions for each rib plate to a driving device of the push-the-bit rotary steerable system to drive the driving device to drive the movement of each rib plate. The application can deeply integrate formation characteristics, realize self-adaptive adjustment of rib plates and keep the resultant force stable, thereby improving the efficiency and quality of drilling operation and reducing operation cost and risk.

The production device comprises a primary impurity removal module, a phosphoric acid solution generation module, an arsenic removal module and a blending module which are connected in sequence, the primary impurity removal module comprises a yellow phosphorus tank, a primary filter and an impurity removal tank which are connected in sequence; the phosphoric acid solution generation module comprises a combustion tower; the arsenic removal module comprises an arsenic removal tank and an ultrafiltration system; the blending module comprises a phosphoric acid dilution tank; a secondary filter is arranged between the primary impurity removal module and the phosphoric acid solution generation module; a three-stage filter is arranged between the phosphoric acid solution generation module and the arsenic removal module; and the electronic-grade phosphoric acid is discharged through the four-stage filter. The device can effectively remove impurities of front-end raw materials, middle-end reaction liquid and rear-end products, and the yield of phosphoric acid reaches 95% or above.

The application belongs to the field of high polymer materials, and provides a water-permeable and air-permeable sponge and a preparation method thereof. The application adopts a synergistic design of a crosslinked polydimethylsiloxane continuous phase and a directional through-hole network, forms a through-hole network with an open hole rate of 85-92% and an orientation index not less than 0.60 through directional soluble particle template dissolution, and introduces cellulose nanocrystals with a mass fraction of 0.50-2.00% modified by silane coupling to enhance the network, and covalently fixes 0.10-1.00 wt% of hydrophilic functional silane to realize surface hydrophilic modification, realizes air permeability not less than 400 L·m⁻²·s⁻¹, a pore size gradient of 150-250 μm on the near-skin side to 400-600 μm on the far-skin side, and double-medium high-flux water-permeable and air-permeable performance, solves the coupling contradiction problem between high open hole rate and mechanical bearing rebound attenuation, directional through-hole network cycle stability, and double-medium high-flux and low VOC, and has wide application value in the fields of nursing and sports underwear, masks, briefs, eye masks, shoes and mattresses.

The utility model discloses a kind of desalted water cooling adjusting devices, including desalted water cooling device, desalted water regulating water tank, water inlet pipe and water outlet pipe, the shell side import of high-efficiency cooler is communicated by second pipeline with the pipe side import of desalted water cooling device, the shell side export of high-efficiency cooler is communicated by first pipeline with the lower end of desalted water regulating water tank, the pipe side export of desalted water regulating water tank is communicated with the lower end of desalted water cooling device by pipeline assembly, water inlet pipe and the shell side import of desalted water cooling device are communicated, water outlet pipe and the shell side export of desalted water cooling device are communicated, the utility model is cooled to sample water by desalted water circulation, industrial water is as desalted water in and out and realizes circulation, ensure that sample water is cooled to 20-30 ℃, satisfy the strict requirement of on-line monitoring equipment to sample water temperature.

The invention discloses a cross-platform omics data integration and standardization method and system based on a depth auto-encoder, and belongs to the field of bioinformatics and computational biology, and the method comprises the steps: receiving cross-platform omics data and quality evaluation; correcting the batch effect by using platform information as a condition and introducing a condition variation self-encoder for resisting loss; fusing multiple omics data into a shared hidden space through a multi-head encoder and an attention mechanism; carrying out missing value filling and enhancement on the fused data based on the generative adversarial network; and outputting the standardized data and evaluating the quality. According to the method, the problems of nonlinear batch effect correction, multi-modal deep fusion and missing value intelligent processing in cross-platform omics data integration are effectively solved, and high-quality automatic data integration and standardization are realized.

This invention relates to the field of computer-aided engineering technology and discloses a method for generating unstructured meshes based on graph convolutional networks (GCNs) and high-order size fields. It aims to solve the problems of striping artifacts easily generated when generating size fields from STL background meshes, and the excessive computational burden caused by global encryption. The method first generates an initial size field based on an STL mesh; then, it constructs a GCN model to extract features and classifies edges to identify striped edges; next, it employs a "detection-selective order-upgrading" strategy, inserting high-order nodes only on striped mesh edges to construct a high-order background mesh; finally, it uses a hybrid interpolation strategy, employing linear interpolation for non-striped mesh edges and cubic spline interpolation for high-order edges to calculate size values. This invention efficiently eliminates artifacts without changing the global topology, enabling the generation of high-quality unstructured meshes.

The invention relates to the technical field of image processing, and discloses an intelligent image compression system and method based on multi-modal fusion, and the system comprises an intelligent pre-analysis layer which is used for predicting and outputting an optimal compression scheme for balancing image quality and storage efficiency through a pre-trained adaptive decision tree model based on a multi-dimensional feature analysis result; the core processing layer is used for calling the format conversion module and the color quantization module to carry out standardized conversion and color gamut optimization processing on the image, and then respectively executing visual lossless image intelligent compression and rate distortion optimization-based image limit compression; and the fusion optimization layer is used for automatically combining the intelligent pre-analysis module, the color quantization module, the intelligent compression module and the limit compression module and forming an optimal image compression path. According to the method, the high compression rate can be achieved through the multi-modal fusion technology, the compression level is greatly superior to that of a single technology, and the visual lossless image quality effect is guaranteed through the perception optimization algorithm and the self-adaptive selection strategy.

The invention discloses an injection for preventing and treating delirium of ICU (intensive care unit) critical and cancer postoperative patients as well as a preparation method and application of the injection, and belongs to the technical field of pharmaceutical preparations. The injection is prepared from the following components in percentage by weight: 0.001 to 0.5 percent of melatonin receptor stimulant, 530 percent of oil for injection, 0.55 percent of phospholipid, 00.5 percent of co-emulsion, 0.55 percent of isoosmotic adjusting agent, 0.011.0 percent of pH (Potential of Hydrogen) adjusting agent and the balance of water for injection, and the pH is 5.010.0. The preparation process comprises the steps of oil phase preparation, water phase preparation, emulsification, high-pressure homogenization, sterilization and the like. The average particle size (D50) of the injection is 100350nm, the content of large emulsion particles with the particle size of 5 microns is 0-0.05%, the release rate within one hour is not lower than 80%, and the main drug content within 24 months of validity is not lower than 90%. According to the invention, the drug treatment accessibility of existing ICU severe illness and cancer postoperative delirium is realized. The product takes effect quickly after administration, can realize smooth transition from short-term injection administration to oral administration in a recovery phase after ICU / severe illness operation, and has a remarkable clinical compliance advantage.

This invention relates to the field of radio transmission technology, specifically to a signal transmission method, system, and storage medium for a transmitter. It includes: acquiring the original transmission signal to be transmitted and filtering the original transmission signal to obtain the transmission signal to be input to a power amplifier; and dividing the transmission signal into blocks according to a preset signal length. This invention, through local sparsity analysis and oversampling rate detection of the signal sub-blocks, can locate signal peaks in the time domain, identify peak regions to be compressed, and perform nonlinear amplitude-phase joint mapping compression on the peak regions using a polarization constraint matrix. This nonlinear amplitude-phase joint correction path allows the signal energy to be redistributed without damaging the sideband spectral characteristics, avoiding the problem of increased dynamic range of the power amplifier input signal due to over-compression. This application enables the power amplifier in the transmitter to operate in a lower back-off region, improving the conversion efficiency of the power amplifier.

The utility model provides an automatic flanging machine, which relates to the technical field of flanging equipment, and comprises milling equipment, a conveying roller way and a flanging device, the conveying roller way is fixedly connected with the milling equipment; the edge folding device is fixedly connected with the milling equipment, is arranged on one side of the conveying roller way, and comprises a first edge folding mechanism, a second edge folding mechanism and a third edge folding mechanism; the first edge folding mechanism, the second edge folding mechanism and the third edge folding mechanism are sequentially arranged in the conveying direction of the conveying roller way. According to the automatic flanging machine, high-quality flanging of plates can be achieved, the strict requirements of different products for the flanging angle and shape are met, and the overall production efficiency is effectively improved.

The utility model provides a spherical oxide powder dynamic wet demagnetizing device which comprises a device body, the device body is vertically arranged, a spiral flow deflector is arranged in the device body, an inlet is formed in the lower end of the side wall of the device body, and an outlet is formed in the upper end of the side wall of the device body. The spiral flow deflector spirals from the inlet to the outlet along the inner wall of the device body; a discharge hole of the slurry blending barrel is communicated with the inlet through a water pump, and a stirring device is arranged in the slurry blending barrel; the slurry collecting barrel is communicated with the outlet; the strong magnetic rod assembly is detachably connected with the device body, and the rotating center axis of the strong magnetic rod assembly coincides with the rotating center axis of the device body. The demagnetizing device disclosed by the utility model can be used for effectively removing magnetic impurities in powder particles.

The present application relates to a kind of data-driven mode under the method and system for predicting net pressure in fractured well fracture, comprising: collecting oilfield field data, and calculating fracture net pressure;Correlation between well logging parameters and fracture net pressure is calculated and screened, and the well logging parameters after screening are pretreated;Fracture net pressure prediction model is constructed, part of data set is input into fracture net pressure prediction model for training, and the hyperparameters of fracture net pressure prediction model are optimized;Optimized fracture net pressure prediction model is trained using all data sets;When obtaining incremental data, the trained fracture net pressure prediction model is used as submodel, the structure and parameters of submodel are replicated to generate new submodel, and submodel is trained to form submodel for different well sections;The comprehensive prediction value of all submodels is calculated.The present application effectively overcomes the limitation of traditional prediction method, significantly improves the prediction accuracy and model adaptability, and has important significance for oil and gas exploitation engineering.

The utility model discloses a uniform drying device for vitamin D production, which comprises a bottom plate, a sterilization cylinder is arranged on the bottom plate, a circular bearing plate and a vortex-shaped drying wall with a vortex-shaped cross section are arranged in the sterilization cylinder, a vortex-shaped drying channel and a vortex-shaped exhaust channel are formed, and the vortex-shaped drying channel and the vortex-shaped exhaust channel are communicated with a sterilization cavity through drying holes and exhaust holes. A sterilization assembly and a drying assembly are arranged on the two sides of the bottom plate respectively, the sterilization assembly comprises a first barrel cover capable of being opened and closed and an ultraviolet disinfection lamp, and the drying assembly is provided with a second barrel cover capable of being movably opened and closed and a dry hot air spraying structure. The device realizes uniform drying by spraying dry hot air up and down in two directions, has a sterilization function, is reasonable in structural design and convenient to operate, and improves the drying efficiency and the product quality of vitamin D production.