400 results about "Dual wavelength" patented technology

The invention is suitable for the technical field of intelligent wearable devices, and provides a blood pressure dynamic calibration method and device of an intelligent wearable device and the wearable device. According to the blood pressure dynamic calibration method of the intelligent wearable device, the dual-wavelength pulse wave signal collected by the dual-wavelength PPG sensor is obtained, differential processing is conducted on the dual-wavelength pulse wave signal, the purified pulse wave signal is obtained, the signal-to-noise ratio of the purified pulse wave signal is calculated, and when the signal-to-noise ratio is higher than the threshold value, the blood pressure dynamic calibration of the intelligent wearable device is completed. Extracting a pulse wave characteristic value from the purified pulse wave signal, iterating the vascular elasticity coefficient according to the pulse wave characteristic value to obtain an iterative vascular elasticity coefficient, and outputting a first calibrated blood pressure value according to the pulse wave characteristic value and the iterative vascular elasticity coefficient. According to the embodiment of the invention, motion artifacts are effectively suppressed through differential processing of the dual-wavelength PPG sensor, the signal-to-noise ratio of signals is increased, and the problem that the blood pressure measurement error is large due to noise interference and blood vessel elastic fixation when a traditional intelligent wearable device is in a motion state is solved.

The invention relates to the technical field of gas detection, in particular to a dual-wavelength-based adaptive methane detection method and system, and the method comprises the following steps: collecting environmental interference characteristics of a to-be-detected gas environment in real time; synchronously emitting a first laser beam and a second laser beam to a to-be-detected gas environment according to the tunable laser source; receiving optical signals of the first laser beam and the second laser beam and converting the optical signals into electric signals; calculating a light intensity difference value of the first laser beam and the second laser beam based on the electric signal to generate a differential absorption signal; performing optical differential compensation on the differential absorption signal, outputting a methane concentration value, and performing environmental drift compensation on the methane concentration value based on environmental interference characteristics; and performing real-time threshold value judgment on the methane concentration value, and if the methane concentration value exceeds a preset threshold value, triggering a local early warning signal. According to the invention, the problem that the detection precision is reduced due to the fact that methane absorption signal common-mode noise and absorption coefficient drift cannot be synchronously inhibited due to dust concentration and temperature and humidity interference in a dynamic complex environment under a mine is effectively solved.

The invention discloses an optical adhesive with dynamic bond exchange and gradient curing functions and a preparation method thereof, relates to an optical adhesive, and aims to solve the problems of interface failure and light transmission attenuation which are easy to occur in the existing optical adhesive. The invention starts from the following three points: 1, two-stage dynamic covalent cross-linking: 1, UV (ultraviolet) initiates acrylate polymerization to form a main network; part of unreacted epoxy groups are retained. 2, thermally activating dynamic boric acid ester bond exchange to realize network reconstruction and stress release; 2, a dual-wavelength gradient initiation system: a 365nm UV curing surface and a 405nm LED penetrate through a curing deep layer to avoid an uncured layer caused by oxygen inhibition; 3, a nano composite anti-reflection technology: mesoporous SiO (at) TiO core-shell nanoparticles (refractive index gradient matching) improve the light transmittance to gt; the content is 99.5%.

The invention relates to the technical field of vegetation root system nondestructive testing, in particular to a multispectral vegetation root system identification system and method based on a differentiable physical engine, and the system comprises a multispectral LiDAR module which is used for transmitting near-infrared laser and short-wave infrared laser, scanning a target area, obtaining dual-wavelength reflectivity data, and determining the vegetation root system according to the dual-wavelength reflectivity data; generating a reflectivity ratio matrix by adopting a reflectivity ratio classification model; the differentiable physical engine is used for quantizing the dynamic relationship between the vegetation root growth rate and the soil resistance by adopting a coupling model according to the reflectivity ratio matrix, generating a physical model and updating the physical model at a preset time interval; and the data processing and three-dimensional modeling module is used for generating a three-dimensional root system model and a health assessment result according to the reflectivity ratio matrix and the physical model, and outputting the three-dimensional root system model and the health assessment result. According to the scheme, soil penetration and root system and foreign matter distinguishing can be carried out, the vegetation native environment is not damaged, dynamic monitoring analysis is carried out, and the accuracy of recognition analysis is improved.

The invention discloses a dynamic leaching-spectrophotometric detection method for the release rate of nutrients in a slow-release fertilizer, and relates to the field of agrochemical analys.The detection method comprises the following steps that S1, a slow-release fertilizer sample is placed in a leaching column to be leached, and leachate is collected; s2, sequentially adding a masking agent solution and a chromogenic reagent into the leachate, and carrying out chromogenic reaction; s3, pumping the solution into a double-optical-path flow cell, and measuring absorbance values under a target nutrient characteristic absorption wavelength and a background interference characteristic wavelength; s4, calculating the corrected net absorbance; and S5, calculating the nutrient concentration, and drawing a nutrient release kinetic curve. By adopting a dual-wavelength synchronous detection and real-time dynamic subtraction correction algorithm, the method can eliminate system errors of time-varying background chromaticity, so that accurate and reliable absorbance readings can be obtained at the initial stage of nutrient release even if the nutrient concentration in the leachate is very low, thereby ensuring the authenticity of the initial stage of a release curve and improving the accuracy of nutrient release. And initial release kinetic parameters are accurately captured.

The invention discloses a diffraction neural network optical classification method and system based on dual-wavelength differential modulation, and relates to the technical field of optical calculation and optical information processing, and the method comprises the steps: S1, optimizing the phase distribution of a single diffraction layer through a deep learning back propagation algorithm; s2, loading a code corresponding to the input information through an input layer; s3, introducing two coherent light sources with different wavelengths to irradiate the codes in sequence or in parallel; s4, after the single diffraction layer modulates the input light field, an output light field is detected through a detector; and S5, performing differential normalization operation on the light intensities of different wavelengths to obtain a discrimination signal Sc of each category, and completing optical classification. According to the invention, the adjustment error caused by a multilayer device is eliminated through a single-layer diffraction structure, a dual-wavelength differential detection mechanism is introduced, and the non-negativity limitation of a light intensity signal is broken through, so that the classification precision and robustness are remarkably improved while the structure simplification is ensured, and the method has important engineering value and application prospect.

The embodiment of the invention provides a flip chip offset measurement system and method, the measurement system comprises a first light source and a second light source which are different in emergent light beam wavelength, an imaging assembly and a processing assembly, and the first light source is controlled to emit a first light beam which penetrates through a flip chip and irradiates a first target in a deep layer; obtaining a first image containing the first target from the first detector; controlling a second light source to emit a second light beam to irradiate a second target on the surface of the flip chip, acquiring a second image containing the second target from a second detector, and finally acquiring a first offset and a second offset of the flip chip relative to the substrate based on the first image and the second image by a processing assembly, and obtaining the bonding offset of the flip chip according to the first offset and the second offset. According to the invention, the dual-wavelength light source is adopted to cooperatively irradiate the flip chip in a time-sharing / wave-band-sharing manner, so that the penetrability-reflectivity contradiction of single-wavelength detection is broken through, and the accuracy and reliability of lamination offset detection are improved.

The invention discloses a wavelength and polarization multiplexing super-structure lens construction method based on a double-layer geometric phase, and provides a double-layer geometric phase super-structure surface theoretical model by using a super-structure based on an artificial micro-nano structure, and designs a lens structure of which two working wavelengths and two polarization modes can be regulated and controlled at will by using the model. The working principle of the double-layer geometric phase super-structure lens is elaborated; secondly, optimizing and screening unit structures of the single-layer super-structure lens, establishing a unit structure database, and designing a double-layer super-unit structure on the basis of the unit structures; and finally, a double-layer super-structure lens is constructed by using a super-unit structure, so that the double-layer super-structure lens works at two wavelengths and two polarization states, and the adjustable multifunctional characteristics of dual-wavelength switchability and polarization sensitivity are realized. The method has important application prospects in the fields of dual-wavelength polarization sensitive imaging, optical tomography, sensing, new energy automobile display systems, AR / MR display and the like.

The invention relates to the technical field of bridge load tests, and provides a bridge load test crack increment change observation method and system, and the method comprises the steps: collecting prestressing tendon circumferential strain distribution data and dual-wavelength strain response data; calculating an interface bonding stiffness change parameter; pre-stress modulation effect compensation and polar coordinate system conversion are carried out on the strain response data and the rigidity change parameters, and micro-crack characteristic signals are obtained; load data and beam group arrangement parameters are collected, and a micro-crack propagation prediction model is established in combination with the interface bonding stiffness change parameters; inputting the micro-crack characteristic signal into a micro-crack propagation prediction model, and outputting a micro-crack development trend prediction result; and adjusting sampling parameters of a dual-wavelength time division multiplexing algorithm and characteristic extraction parameters of prestress modulation effect compensation according to a micro-crack development trend prediction result. According to the invention, the precision of observing the increment change of the micro-crack in the bridge load test is improved, and the automatic monitoring and prediction of the micro-crack of the prestressed concrete bridge are realized.

The present invention includes methods for reducing photoexcitation of a photoswitchable photoinitiator in volumetric printing including a volume of a photohardenable composition at locations in the volume at which intersection of two wavelengths does not occur; methods of three-dimensional (3D) printing including dual-wavelength photoexcitation of a photohardenable composition included in a volume, the method including photoexcitation by a modified or controllably-sized light sheet including a first wavelength and an optical projection including a second wavelength; and methods for extending the reuse-printing lifetime of a photohardenable composition including a photoswitchable photoinitiator. Preferably the photohardenable composition includes the dual-wavelength photoinitiator and a photohardenable resin component. The present invention also includes a photohardenable composition including a photoswitchable photoinitiator with an improved reuse-printing lifetime.

The invention discloses an fNIRS adaptive feedback emotion cognition cooperative training device and method, and relates to the technical field of emotion disorder cognition training. The device comprises a data acquisition module used for acquiring an original dual-wavelength light intensity signal from a brain; the data processing module is used for performing multi-stage preprocessing on the original dual-wavelength light intensity signal; the neural feedback module is used for calculating a multi-dimensional evaluation index according to the hemoglobin concentration data and adjusting a difficulty level and a feedback threshold value of a training task by using a dynamic threshold value control algorithm; the training module is used for training participants based on the emotion stimulation task and the cognitive training task; and the evaluation module is used for performing training evaluation according to the comparison result of the comprehensive performance score and the feedback threshold. Brain function equipment is closely combined with cognitive training and emotion stimulation tasks, dynamic evaluation and real-time feedback are added for traditional tasks, and through the brain network analysis technology, accurate evaluation of the user training effect is achieved.

The invention discloses a dual-wavelength mode-locked laser generating device and a dual-wavelength mode-locked laser generating method, and belongs to the technical field of optical communication, and the dual-wavelength mode-locked laser generating device comprises a pumping source, an optical integration module, a gain optical fiber, a saturable absorber and a dual-wavelength pulse independent polarization mode linear coupling regulation and control structure, linear coupling strength of cross-polarization components in two wavelength pulses is independently regulated and controlled by using a structure of a polarization controller and a polarization maintaining optical fiber, and dual-wavelength mode-locked pulse laser of different types of pulse combinations can be obtained. The coherent pulse light source with unique spectral characteristics can provide a low-cost light source for the fields of high repetition frequency optical combs, all-fiber architecture high repetition frequency soliton sequences and microwave photonics.

The invention provides a full-dynamic non-invasive blood glucose detection method based on a full-spectrum peak segment optimization algorithm. The method comprises the following steps: step S1, performing blood glucose testing on a nail bed part of a human little finger by matching an infrared dual-wavelength semiconductor laser with a spectrograph, and recording blood glucose Raman spectrum data obtained in each blood glucose testing; step S2, carrying out pretreatment on the obtained blood glucose Raman spectrum data; s3, dividing the preprocessed blood glucose Raman spectrum data into a training set and a prediction set, analyzing through a principal component analysis method and a partial least square regression analysis method, and establishing a model; s4, inputting the preprocessed blood glucose Raman spectrum data as an independent variable into the model in the step S3, analyzing the blood glucose concentration of the human body, and giving a reference value; according to the full-dynamic non-invasive blood glucose detection method based on the full-spectrum peak segment optimization algorithm, the accuracy of quantitative analysis of a high-fluorescence background sample through a Raman spectrum is achieved, complex treatment on the sample is not needed, and the accuracy of human body non-invasive blood glucose detection is improved.

The invention relates to a microbial electrode online monitoring system and method based on multi-modal fusion and a self-repairing mechanism, and belongs to the technical field of environmental monitoring and bioelectrochemistry. Aiming at the problems of high cost, weak anti-interference capability, poor long-term stability, difficulty in precise decoupling of multi-parameter coupling and the like in the existing microbial electrode monitoring technology, the method comprises the following steps: synchronously acquiring multi-modal signals of a dual-wavelength differential near infrared spectrum and an electrochemical impedance spectrum; a front decoupling mechanism based on equivalent circuit fitting and reinforcement learning is combined to clearly distinguish change sources of charge transfer resistance and diffusion resistance; performing deep fusion on the decoupled features by using a convolutional neural network, and outputting a microbial activity score and a metabolite concentration; and a self-repairing electrode material and a closed-loop feedback control mechanism are introduced, and repairing is automatically triggered when electrode performance degradation is monitored. According to the invention, low-cost, high-precision and strong-anti-interference long-term stable in-situ monitoring of the microbial electrode is realized.

The invention relates to the technical field of optical fiber sensing, in particular to a distributed optical fiber vibration-temperature combined monitoring method and system. Comprising the following steps: carrying out linear frequency modulation on single-frequency light waves output by a light source to enable the single-frequency light waves to serve as probe light for distributed vibration and distributed temperature sensing at the same time; linear sweep frequency light is injected into an optical fiber to be measured, and Rayleigh scattering and Raman scattering light signals in the optical fiber are separated by using a wavelength division multiplexer. And the vibration information of each point along the optical fiber is recovered by combining a Rayleigh scattering light signal with a coherent detection architecture through algorithms such as back-end matched filtering and the like. And the Raman scattering light signal is combined with intensity detection and a dual-wavelength difference algorithm, so that the temperature information of all optical fiber lengths can be recovered. According to the invention, vibration and temperature measurement is realized in the same system, and the problems of temperature and vibration measurement time synchronization, sampling rate alignment and the like in different systems are avoided.

The invention provides a high-power external cavity tunable quantum cascade laser output module. The high-power external cavity tunable quantum cascade laser output module comprises a first lens, a first half-wave plate and a first mid-infrared grid polaroid which are sequentially arranged along a light path of a first laser; a second lens, a second half-wave plate, a second mid-infrared grid polarizer and a third half-wave plate are sequentially arranged along the light path of the second laser; emergent light of the first mid-infrared grid polaroid and the third half-wave plate is converged on different surfaces of the third mid-infrared grid polaroid, the first blazed grating is arranged on a reflection light path of the first mid-infrared grid polaroid, and the second blazed grating is arranged on a reflection light path of the second mid-infrared grid polaroid. According to the invention, the problems of wavelength locking and low polarization beam combination efficiency caused by insufficient polarization state of the quantum cascade laser can be effectively solved, narrow linewidth output and wavelength tuning of the quantum cascade laser can be realized, and even high-power dual-wavelength tunable output can be realized through polarization beam combination structure expansion.

The invention discloses a vein blood oxygen saturation real-time measurement system and method based on an LED light source. The method comprises the steps that 1, a pulse driving circuit outputs pulse voltage to drive LEDs with different wavelengths in a dual-wavelength LED light source to flicker alternately; collecting a photoacoustic signal by an ultrasonic transducer; 2, the ultrasonic signal processing platform receives the collected sound signals and carries out subsequent processing; 3, controlling the ultrasonic transducer to transmit an ultrasonic signal to the same measured part, and receiving an echo signal of the ultrasonic transducer; reconstructing an ultrasonic image of the measured part based on the echo signal; step 4, in the obtained ultrasonic image, positioning a vein to be analyzed and an adjacent artery thereof, and positioning the vein in the ultrasonic image; 5, the arterial oxygen saturation value of the whole body is measured through a finger clamping type pulse oximeter, and quantitative calculation of the venous oxygen saturation is achieved; and step 6, carrying out pixel-level fusion on the oxyhemoglobin saturation information and the ultrasonic image, and realizing visualization on the same frame of ultrasonic image.

A spherical, bone or other shaped pet health device includes a 0.5% to 5% thermoplastic resin casing, equipped with a dual wavelength LED system emitting blue (400-460 nm) and red (600-670 nm) light. The device incorporates a printed circuit board (PCB) with LEDs, a voltage regulator, and a motion sensor which activates the LEDs upon impact, with light emission lasting between 4-6 minutes. Some embodiments include a capacitive touch sensor or pressure sensor to trigger the LED system. The device may be charged via USB cable or completely sealed and charged only via induction or have a removable water resistant inner compartment with removable batteries. The outer can feature texture, scent infusion and indentations for flavor agents and health supplements such as probiotics. Additional embodiments may include a vibration motor and conductive fillers in the casing to enhance signal transmission for various health promoting applications.

The invention discloses a photoacoustic spectrum laser gas detection dual-wavelength interference noise cancellation method and system. The method comprises the following steps: configuring laser wavelengths of a main light source and a compensation light source according to a main absorption spectral line and a non-absorption wave band of target gas; the main light source and the compensation light source are driven by same-frequency and same-phase signals to emit laser with the configured wavelength; lasers emitted by the main light source and the compensation light source respectively enter an excitation cavity and a compensation cavity which have the sound wave phase difference of 180 degrees, are equal in sound pressure amplitude and are coupled through a sound wave guide pipe; and detecting the mixed sound wave signal in the excitation cavity and the mixed sound wave signal in the compensation cavity, and offsetting the dual-wavelength interference noise through differential operation. According to the invention, coherent noise can be adaptively offset, a fixed wavelength light source is compatible, complex phase regulation is not needed, the coherent noise suppression rate is improved, and a new solution is provided for the application of the fixed wavelength laser in trace gas detection.

The invention provides a dual-wavelength multi-parameter self-compensation intelligent control system and method based on pollution grading. Comprising a sensing module used for acquiring a dual-wavelength optical measurement signal and a multi-parameter sensing measurement signal of a to-be-treated water body; the self-compensation module is used for generating a compensated pollution characterization characteristic quantity; the uncertainty generation module is used for performing consistency residual calculation on the compensated pollution characterization characteristic quantity and at least one water quality parameter signal and generating an uncertainty parameter; the pollution grading module is used for executing boundary correction on the initial pollution grade under the constraint of the uncertainty parameter and outputting the pollution grade and grading confidence; the decision control module is used for selecting a target control strategy cluster and generating a control set value of the water treatment process based on rolling optimization; and the execution control module is used for issuing the control set value to an execution mechanism of the water treatment process. Pollution grading accuracy can be improved, long-term stability of measurement is enhanced, and control fluctuation and energy consumption are reduced.

The invention discloses a micro-displacement measurement system based on dual-wavelength medium metasurface conjugate vortex light interference, and relates to the technical field of optical displacement measurement, the micro-displacement measurement system comprises an optical coupler, a metasurface, an objective lens and a first beam splitter, the input end of the optical coupler is connected with a first laser and a second laser at the same time; two parts of light output by the first beam splitter are respectively input into a measuring arm and a reference arm, the measuring arm comprises a Dove prism, a second beam splitter, a measuring quarter-wave plate and a measuring reflector, the reference arm comprises a third beam splitter, a reference quarter-wave plate and a reference reflector, light reflected by the measuring reflector and the reference reflector is input into a fourth beam splitter, and light reflected by the fourth beam splitter is input into a fourth beam splitter. The fourth beam splitter combines the two beams of light and inputs the combined light to the CCD camera; and the computer processes the interference image to obtain the displacement of the to-be-measured object. Through the metasurface and dual-wavelength theory, the problems that a displacement measurement system is large in size and small in measuring range are solved at the same time.

The application discloses a kind of dual-wavelength metal 3D printing optical path device and 3D printing system.The device includes first laser, second laser, first collimating unit, second collimating unit, dichroic mirror, galvanometer and field lens;The wavelength of the laser emitted by the first laser is greater than the wavelength of the laser emitted by the second laser;The first collimating unit, the dichroic mirror, the galvanometer and the field lens are arranged in the advancing direction of the laser emitted by the first laser in turn;The laser emitted by the second laser can reach the dichroic mirror through the second collimating unit;The dichroic mirror can make the spot of the laser emitted by the second laser surround the spot of the laser emitted by the first laser;The absorption rate of the metal to the laser emitted by the second laser is greater than the absorption rate to the laser emitted by the first laser.The system includes the device.The application can realize fine printing.

The present disclosure relates to a monolithically integrated dual-wavelength transmitter for a passive optical network (PON), which may be suitable for both a gigabit PON (GPON) and a 10-gigabit-PON (XG-PON). The integrated transmitter includes two distributed feedback (DFB) lasers, a first DFB laser to emit a continuous first laser beam at a first wavelength along an optical path, and a second DFB laser to emit a modulated second laser beam at a second wavelength along the optical path in the same direction as the first DFB laser. The transmitter also includes an electro-absorption modulator (EAM) after the first DFB laser in the optical path, which is configured to modulate the first laser beam, and a distributed Bragg reflector (DBR) between the EAM and the second DFB laser in the optical path, which is configured to transmit light at the first wavelength

The application belongs to the technical field of luminescent materials, and particularly relates to a nickel ion doped fluoride near-infrared two-region long-wave luminescent nano probe and a preparation method thereof, wherein the nano probe comprises a fluoride nanocrystal matrix and transition metal nickel ions as a luminescent center, or a core-shell structure nano probe formed by taking the above-mentioned substances as a shell layer and being externally coated with an inert shell layer or a homogenous epitaxial layer. The probe realizes wide-range regulation of an emission peak in a 1300nm to 2150nm near-infrared two-region long-wave band; through core-shell structure design and inert shell layer coating, surface defects are effectively passivated, luminescent quantum efficiency is significantly improved, and particle size is precisely controlled. Through nickel ion doping and crystal field regulation strategies, the application develops a new type of non-lanthanide near-infrared two-region long-wave luminescent material; the application has unique dual-wavelength excitation characteristics and wideband emission characteristics, and has wide application prospects in multi-channel biological detection and imaging analysis.

The application provides a dual-wavelength coaxial aiming system capable of automatic collimation, which is used for attitude adjustment and target positioning aiming of a picosecond terminal optical path cone target of inertial confinement fusion (ICF). The system comprises automatic collimation optical paths and aiming optical paths of different working wavelengths; the automatic collimation optical paths comprise a light source, a light splitting prism, a secondary mirror, a reflecting mirror and a CCD detector; the aiming optical paths are composed of a primary mirror, a secondary mirror, a lens group, a light splitting prism and a CCD detector group, and each optical element is coaxial; the system multiplexes the secondary mirror, and realizes automatic collimation and positioning aiming through different wavelength transmission and reflection respectively; the system adopts combination of flint and crown glasses to correct chromatic aberration of different wavelengths; the image planes of the dual-wavelength optical paths are located at the same position; and the system adopts a coaxial two-mirror structure, and is compact in structure and small in size.

The utility model provides a light source device and a lamp. A containing groove is formed in a support of the light source device. The first blue light chip is arranged on the groove bottom of the accommodating groove, and the first blue light chip is used for emitting blue light of which the peak wavelength is a; the second blue light chip is arranged on the groove bottom of the containing groove, the second blue light chip and the first blue light chip are arranged in a spaced mode, the second blue light chip is used for emitting blue light with the peak wavelength being b, and b is larger than a; the first fluorescent structure covers the first blue light chip; the second fluorescent structure covers the second blue light chip and the first fluorescent structure, and the second fluorescent structure comprises yellow-green fluorescent powder; according to the invention, a regional excitation structure can be formed, light of different colors can be excited in a targeted manner to complement spectrum deficiency, and the overall color rendering index can be improved; meanwhile, mutual absorption loss between different fluorescent structures is reduced through dual-wavelength hierarchical excitation and physical isolation of the fluorescent structures, and optimization of light extraction efficiency is facilitated.

The invention provides a material water content detection method and system based on dual-wavelength infrared light, and relates to the technical field of material detection.The method comprises the steps that an infrared light source is controlled to emit at least two infrared light of different wavelengths to irradiate the surface of a to-be-detected material; receiving reflected light signals of the surface of the to-be-detected material to the infrared light, and acquiring light intensity information of the reflected light signals corresponding to different wavelengths; the average absorbance value of the water content characteristic of the to-be-detected material is constructed according to the ratio relation between the light intensity information of different wavelengths; and performing environmental disturbance compensation on the average absorbance value to obtain a compensated average absorbance value, and inputting the compensated average absorbance value into a preset calibration model to output the water content of the to-be-detected material. According to the scheme, the stability and the reliability of the water content detection of the material in an actual application environment are improved, and the problem of measurement errors caused by environmental changes is solved.

The application relates to a dual-wavelength silicon-based PIN photoelectric sensor with ultralow dark current and high responsivity, which comprises a silicon substrate, a central P + anode region, high resistance / intrinsic silicon absorption region, bottom N + cathode region, junction termination extension region JTE, guard ring GRL, surface passivation layer and electrode structure. Through accurate regulation of the junction edge electric field, the application effectively suppresses the leakage current and early breakdown phenomenon caused by the high edge electric field in the plane PIN structure, realizes sub-nanoampere dark current output, and simultaneously, through synergistic optimization of the intrinsic region thickness and the doping distribution, the sensor obtains higher light responsivity at two typical wavelengths of 660 nm and 940 nm, and meets the requirements of short-wave shallow absorption and long-wave deep absorption.

A liquid photohardenable composition for volumetric printing including a photohardenable resin component, a dual-wavelength photoinitiator, and a thixotrope,, wherein the liquid photohardenable composition exhibits non-Newtonian rheological behavior and a light transmittance greater than 90% for a 5 centimeter (cm) pathlength. Preferably such transmissivity remains above 90% for at least 10 days after preparation. Preferably the liquid photohardenable composition exhibiting non-Newton rheological behavior has a yield stress greater than or equal to about 5 Pascals at 50 degrees Celsius, Methods of forming an object in a volume of a liquid photohardenable composition of the invention and a method for screening thixotropes for inclusion in a liquid photohardenable composition are also disclosed.

The invention provides a method for detecting fusion of extracellular vesicles by adopting fluorescence resonance energy transfer, and belongs to the technical field of extracellular vesicles. A dynamic fluorescence monitoring system is established, low-power laser excitation is adopted, dual-wavelength fluorescence signals are monitored at the same time, fluorescence signal data are collected, graded gain regulation and control processing is carried out through five threshold values, and a fluorescence signal super-sparse matrix is constructed; establishing a fluorescence signal processing matrix model, converting the super-sparse matrix into a dense matrix, constructing a gain matrix for signal correction, calculating a fluorescence resonance energy transfer efficiency parameter, obtaining a standardized efficiency value through matrix operation, outputting an extracellular vesicle fusion kinetic analysis result, and establishing a quantitative evaluation system. The technical problems of poor signal stability and low detection precision in the process of fluorescence resonance energy transfer detection of extracellular vesicle fusion are solved.