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2025 Vol. 46, No. 3
Published: 2025-03-28
 
309 Discuss Problems on the Lunar Calendar
LIU Min, PING Jingsong, WANG Qianjuan
DOI: 10.3969/j.issn.1000-1158.2025.03.01
The periods of movement of celestial bodies seen by observers on the moon and their transfer relationships are called the "lunar calendar". Calendar belongs to the category of time metrology， and the time metrology outside the earth is a scientific problem of space metrology. To study the lunar calendar need first analyzes the spatial coordinate structure of the moon， put the moon in a layered， nested multilevel coordinate system， lunar observers choosing different references from different levels of coordinates will measure different rotation periods and revolution periods.Secondly， to analyze the periodicity and locality of the lunar calendar， these observers into different locations： such as the front， the back， the halo， and the lunar equator， observe the period of celestial phenomena from different positions respectively， and the conclusion can be drawn due to the different references： for example， the earth is the best reference， the moon has no rotation relative to the earth， but swings； refer to the sun and stars， although the lunar observer sees the similar periodic movement of the sun and stars， but is not uniform. Therefore， unlike the characteristics of the moon and the earth， the existing calendar rules on the earth cannot be copied to the moon.
2025 Vol. 46 (3): 309-315 [Abstract] ( 10 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
316 Rapid scanning measurement of inhomogeneity in calorimetric optical power detectors
The inhomogeneity of response is a key parameter for a calorimetric optical detector. Due to the thermal equilibrium process, calorimetric detectors have relative long response time. In order to improve the measurement efficiency of the inhomogeneity of the detectors, a two-dimensional scanning measurement system is constructed, and the scanning experiments are carried out with different scanning interval time, and the inhomogeneity characteristics obtained under different scanning interval times are statistically evaluated. Methods based on comparison of the image similarity of the inhomogeneity and the calculation of the variance of the two-dimensional raw data are applied. The results show that when the scanning interval time is no less than 45% of the full response time, the deviation of the rapid scanning is no more than 0.2% compare to the full scanning. With further reduction of the scanning interval time, the difference between the rapid measurement and the full response measurement is gradually increased, results in 20% inequality while the scanning interval time reduced to 20% of the full response time. The feasibility of rapid scanning measurement to measure inhomogeneity under incomplete detector response is experimentally demonstrated, which significantly improved the speed of inhomogeneity measurement on the basis of a reliable measurement results.
2025 Vol. 46 (3): 316-322 [Abstract] ( 4 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
323 An Improved Image Registration Algorithm Based on SURF-ORB
Aiming at the problems of existing algorithms combining ORB with scale space, an improved algorithm is proposed. Establish SURF image pyramid, detect ORB feature points on it and use 256 bit binary characters as feature vectors to describe feature points. The nearest neighbor method matches feature points. Filter matching points by utilizing the similar properties of neighborhood average gray difference, Euclidean distance, matching point line and x-axis angle among the correct matching points. The K-means algorithm is improved, using points with a density greater than the threshold as the center point of the class, clustering, deleting classes with a sum of squared errors greater than the threshold and reclassifying the remaining feature points into the reserved classes. The RANSAC algorithm is improved, merging all transformation matrixes’ interior points into a set and classifying the matching points in the set that meet the error distance threshold with the candidate optimal transformation model into its inner points. Use the least squares method to recalculate the transformation matrix with all its interior points to obtain a more accurate solution. The experimental results show that the number of feature points extracted by this algorithm is about 26% less than that of SURF and ORB algorithm, the matching accuracy is improved by about 16%,and the operation time is reduced by about 26%.The algorithm proposed in this paper has better overall performance and stronger real-time performance.
2025 Vol. 46 (3): 323-328 [Abstract] ( 7 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
329 Defect detection method for strip alloy functional materials based on improved YOLOv8
In order to solve the problems of missed detection, false detection, and slow detection speed in the defect detection of strip alloy functional materials, a defect detection algorithm for strip alloy functional materials based on improved YOLOv8 is proposed. In order to fully integrate the multi-scale features extracted by the model backbone network, a multi-scale feature encoder (MFE) module is first designed, and a multiscal feature affregation-diffusion (MFAD) structure is constructed at the neck. The unique diffusion mechanism is used to diffuse features with rich contextual information to all scales. Then, a shared parameter task dynamic alignment detection head (TDADH) is designed at the head of the model. Through convolution parameter sharing and task alignment mechanisms, the model complexity is reduced while the detection accuracy is improved. Finally, a perceptual attention spatial pyramid pooling (PASPP) module is designed to enhance the feature expression ability of the model using the explicit dynamic selection mechanism of attention mechanism. Experimental results indicate that the method proposed attains a mean average precision (PmAP50) of 90.1% on the alloy functional material dataset. It boasts a parameter count of 2.543×106 and a detection speed of 232FPS, outperforming leading deep detection algorithms. Moreover, it achieves top performance on the GC10-DET and PASCAL VOC2012 datasets, demonstrating strong generalizability ability.
2025 Vol. 46 (3): 329-339 [Abstract] ( 6 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
340 Research on the calibration method of non-standard short uncompensated wire iridium-rhodium thermocouple
Non - standardized short thermocouples (with a length of 80 - 150 mm) without compensating wires usually have significant deviations in measurement or calibration because of their short length and the incapability of extending the cold junction. In this research, a short iridium-rhodium thermocouple is used as an example. The calibration was carried out by using a dry - block furnace and a thermal equalization block device. Three different cold - junction treatments methods were adopted: air cooling, using a circulating water - cooled plate, and immersion water cooling. All of these were corrected with K - type thermocouples. The thermoelectric potential-temperature relationship of a long iridium - rhodium thermocouple from the same source was taken as a reference for the short thermocouple. It was found that the deviation of the reference values from the national standard was over 1%, and the differences in the calibration results at the In, Sn, and Zn fixed points were 0.23°C, 0.32°C, and 0.48°C, respectively. The experimental results indicate that within the temperature range of 0 - 500°C, by using the circulating water - cooled plate to control the cold junction and applying temperature correction during calibration, the error of the short iridium - rhodium thermocouple was less than 1%, with uncertainties ranging from 0.9°C to 3.2 °C.
2025 Vol. 46 (3): 340-346 [Abstract] ( 5 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
347 Study on Effect of Interference Filter Characteristics and Using Mode on Effective Wavelength of Photoelectric Pyrometers
Interference filter is a monochromator element in the photoelectric pyrometer, its characteristics and use method will directly affect the result of effective wavelength indexing, which affects the accuracy of pyrometer temperature measurement. Based on the spectral responsivity test system and filter transmittance test system of the supercontinuum laser, the effects of filter characteristics and use methods on the effective wavelength of the pyrometer at the center wavelength of 660 nm were analyzed from four aspects, including filter selection and angle of incidence, internal reflection and measurement repeatability. The test finds that poor cut-off characteristics of filters and their use methods will directly affect the results of effective wavelength of pyrometer. It is found that filters with poor cutoff characteristics may lead to a temperature measurement error of 0.5℃, non-parallel light-incidence mounted filters will have the risk of light leakage in the cut-off wavelength of 950nm ~ 1100nm, which may affect the temperature measurement by more than 1 ℃, and the reflected light inside the pyrometer is not effectively shielded, which also leads to the generation of spectral response that should not be present in the cut-off wavelength of 700nm ~ 1100nm, which may even affect the temperature measurement by more than 10 ℃. The experimental results in this paper show that the measurement repeatability of the new responsivity test system is good, and the uncertainty of the evaluated effective wavelength division is 0.066nm(k=2), the uncertainty affecting the photoelectric pyrometer temperature measurement of 2700°C does not exceed 0.3°C..
2025 Vol. 46 (3): 347-353 [Abstract] ( 4 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
354 Fabrication and study on the Response Characteristics of Micro-thermocouples Using Electrolytic Corrosion Method
Reducing the diameter of the thermocouple’s temperature-sensitive junction is an important method to improve the dynamic response characteristics of the thermocouple, but it is difficult to find finer thermos wires in actual fabrication. In order to further reduce the diameter of the thermos wire, the more stable E-type thermocouple wire(?0.025mm) was selected, and the diameter of the two metal wires was further reduced to about ?0.01 mm by electrolytic corrosion, and a micro-thermocouple with a temperature-sensitive junction size of about 0.02 mm was welded under a digital microscope. The time constants of micro-thermocouples and thermocouple made of 25 um original thermos wires were measured by the temperature step method, and the reliability of the results was analyzed, the time constant of the thermocouple made of 25 um original thermos wires is （30.06?1.16） ms, while the time constant of the micro-thermocouple is （11.62?1.02） ms, so the dynamic response characteristics of this by the method is significantly improved. The experiment also show that, the positive step response time of the micro-thermocouple is smaller than the negative step response time after the thermocouple temperature sensing junction is further reduced, And the uneven composition of the material after wire electrolysis can lead to changes in the thermoelectric potential of the micro-thermocouple.
2025 Vol. 46 (3): 354-360 [Abstract] ( 5 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
361 Emissivity Correction and Uncertainty Analysis of Alloy Infrared Temperature Measurement
The low emissivity of metals and poor consistency between samples are the main sources of error in infrared temperature measurement. It is necessary to accurately measure the emissivity and experimentally evaluate its consistency for specific applications to ensure that the uncertainty of temperature measurement after emissivity correction meets the application requirements. For the infrared temperature measurement of GH3128 alloy pipelines in the research of endothermic properties of hydrocarbon fuels, a wide temperature range emissivity test method based on conical cavity samples was designed. Propose to improve the consistency of emissivity between metal samples through pre-oxidation and explore relevant process parameters. Four samples were used, and 6 measurement areas and 10 oxidation times were experimented. The emissivity in the temperature range of 200~900°C at two different wavelengths was evaluated. The results showed that after natural oxidation for 18 hours at 900°C isothermal environment, the relative standard deviation of emissivity could be less than 0.01. Key sources of uncertainty such as sample emissivity consistency, reference cavity emissivity, and sample temperature uniformity were evaluated. The final synthesized standard uncertainty was 0.016, resulting in a temperature measurement uncertainty of less than 0.8%, which could meet application requirements. The pre-oxidation treatment, emissivity test method, and uncertainty evaluation framework proposed in this paper can provide reference for other applications that require accurate infrared temperature measurement of metals.
2025 Vol. 46 (3): 361-367 [Abstract] ( 5 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
368 Temperature field measurement and analysis of high-pressure critical flow Venturi nozzle gas flow standard device
Based on the high-pressure gas source, a high-pressure critical flow Venturi nozzle gas flow standard device was established. In the calibration experiment of small flow rate, the temperature field distribution upstream of the standard critical flow Venturi nozzle array has an important influence on the measurement uncertainty. Aiming at the temperature field upstream of the standard critical flow Venturi nozzle array, in the calibration experiment of the critical flow Venturi nozzle with throat diameter of 8.251 mm, the temperature field distribution characteristics of three different standard critical flow Venturi nozzle array combinations and different flow rates were analyzed and compared. The experimental results show that the maximum temperature difference upstream of the standard critical flow Venturi nozzle array is 1.97 K at a small flow rate, with the increase of the flow rate in the tube, the unevenness of the temperature field distribution decreases; the maximum temperature difference in the upstream of the array varies from 1.10 K to 1.97 K under three different combinations of standard critical flow venturi nozzle arrays. Therefore, in order to improve the measurement accuracy of stagnation temperature, it is necessary to optimize the temperature measurement method under small flow rate.
2025 Vol. 46 (3): 368-375 [Abstract] ( 4 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
376 Influence of Upstream Turbulence Intensity on the Discharge Coefficient of Sonic Nozzle
The discharge coefficient serves as a crucial parameter for the sonic nozzle, typically be determined through experimental flow calibration. Usually the turbulence intensity in the upstream of critical nozzle that works as meter under test or reference meter could be different. However, the influence of turbulence intensity on the discharge coefficient has not been investigated. Numerical simulation was performed on sonic nozzles with throat diameters of 46.62 mm, 43.09 mm, 30.46 mm, 21.54 mm and 15.26 mm. By examining the critical flow in the nozzle throat under different upstream turbulence intensity, the investigation was conducted into the effects of turbulence intensity on the discharge coefficient of sonic nozzles. The result indicates that upstream turbulence intensity affects the velocity and density distribution at the throat of the sonic nozzle. When the upstream turbulence intensity increases from 1% to 30%, both the average velocity and density at the throat of the sonic nozzle decrease, resulting in a maximum decrease of 0.013% in the discharge coefficient. Furthermore, there is difference in the influence of upstream turbulence intensity on sonic nozzles with different throat diameters. For larger throat diameters of sonic nozzles, as upstream turbulence intensity increases, the velocity and density near the boundary layer region in the nozzle throat decrease more rapidly, resulting in a more significant influence of upstream turbulence intensity on the discharge coefficient.
2025 Vol. 46 (3): 376-382 [Abstract] ( 4 ) HTML (1 KB)  PDF  (0 KB)  ( 4 )
383 Research on Gas-Solid Two-Phase Flow Detection Method Based on Audio Signal
By utilizing the characteristic that the audio signal generated by gas-solid two-phase flow in pipeline flow contains a large amount of fluid information, the audio signal is introduced into gas-solid two-phase flow detection. A detection method for gas-solid two-phase flow classification based on audio signals is proposed, and the feasibility of audio signals in gas-solid two-phase flow detection is demonstrated. Wavelet packet analysis is used for multi-scale analysis of audio signals, and its denoising effect is better than the ensemble empirical mode decomposition reconstruction method. Select Mel frequency cepstral coefficients (MFCCs) as features from the reconstructed audio signal and input them into a Long Short Term Memory (LSTM) recurrent neural network. The experimental results indicate that the amplitude of the audio signal collected in the rising section of the bend in gas-solid two-phase flow is larger, making it suitable for installing sampling equipment. The detection method has a good classification effect on the gas-solid two-phase flow of six flow states in the experiment, with an accuracy rate of 96.11%.
2025 Vol. 46 (3): 383-390 [Abstract] ( 5 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
391 Research on Quality Factor of Resonant Tube Sensor
The quality factor of the resonant sensor is an important parameter that affects the performance of the sensor.In order to improve the performance of the resonant tube liquid density sensor and analyze the quality factor of the resonant tube sensor, this paper starts from the mathematical model of the resonant tube sensor, solves the kinematic equation during the vibration process of the resonant tube, and obtains an analytical formula for the quality factor of the resonant tube. On this basis, a method for improving the quality factor of sensors is proposed, which is to design a sensor with a double tube symmetrical structure or to maintain stable resonant tube boundaries when increasing the base mass. The effectiveness of these two methods was further verified through different comparative experiments. The calibration of the sensor using a new symmetrical structure showed that the absolute error of the sensor measurement was within 1.0kg/m3.
2025 Vol. 46 (3): 391-397 [Abstract] ( 3 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
398 Development of Double U Type Vibrating Tube Densimeter
In order to realize high-precision measurement of liquid density, a double U type vibrating tube densimeter based on electromagnetically driven principle was developed. The instrument constant of the device was calibrated in the temperature range from 278 K to 345 K. The performance of the device was verified by measuring the densities of ethanol and isopropanol, and the experimental data were compared with the results from REFPROP and literatures. The results showed that the experimental results agreed well with the literature data, which confirmed the reliability and accuracy of the experimental system. Finally, the measurement uncertainty of the experimental device was evaluated, and the expanded uncertainty of density was 0.42 kg/m3 (k=2).
2025 Vol. 46 (3): 398-404 [Abstract] ( 4 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
405 Sensitivity compensation analysis of coupled cavity reciprocity method under variable voltage conditions
Abstract：To address the low-frequency reciprocity calibration in coupled cavities under variable pressure conditions, the influence of changing pressure on the low-frequency calibration in cavities is explored through a combination of theoretical calculations, Comsol acoustic field simulations, and experiments. We analyze the reciprocity principle of low-frequency calibration of the coupled cavity and the characteristics of the acoustic field in the cavity by theory, derive the calibration formula for the reciprocity constant, and show the influence of the distribution structure of the transducer in the cavity on the acoustic field under the state of the original liquid-cavity by Comsol simulation, and calculate the correction factor by the acoustic field distribution, and compensate for the low-frequency reciprocity calibration formula of the coupled cavity, and the results show that the change of the transducer's position in the cavity affects the calibration theoretical system, and the increase of frequency affects the low-frequency calibration of the cavity. The results show that the change of the position of the transducer in the cavity will affect the calibration theoretical system, and the frequency increase will affect the sound field distribution in the cavity even more, and the correction factor of 1-1100Hz band is added to the measured reciprocity constant, and the optimization scheme of the correction factor of the coupling cavity is explored by the variable pressure experiment of the cavity from atmospheric pressure to 4MPa, combined with the simulation, and the experimental results show that the maximum difference in the sensitivity of calibration using the correction factor (bit-shape coefficient) is 1.1dB, and the average standard deviation is 0.29 dB.
2025 Vol. 46 (3): 405-411 [Abstract] ( 3 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
412 Comparison of Programmable Josephson Junction Array voltage output algorithms
Introduces the principles of a balanced ternary algorithm and a non-integer multiple algorithm for the voltage output of programmable Josephson junction arrays. Through a comprehensive comparative analysis of these algorithms, including the algorithm's execution process, time complexity, structure number offset, and segment bias, based on a practical programmable Josephson junction array case, it was found that the non-integer multiple algorithm has a more concise execution process, higher computational speed, and the ability to choose fewer subarrays to output the same voltage. In terms of structure number offset, the results of the two algorithms are almost identical. In addition, the non-integer multiple algorithm can be used to expressing integer using binary sequence, ternary sequence or non-integer multiple sequence. It demonstrates that non-integer multiple algorithm has a strong advantage.
2025 Vol. 46 (3): 412-418 [Abstract] ( 5 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
419 Measurement and Evaluation of Dose Characteristics of DomesticFarmer Type Ionization Chamber
In the photon beam dose calibration of medical accelerators, the ionization chamber is excessively dependent on imports, and the domestic detector lacks systematic experiments in radiotherapy applications. Through the quantitative measurement of dosimetric parameters such as angular response, composite polarization correction, leakage current, dose linearity and energy response of domestic QF 60 series farmer ionization chamber in high-energy photon beams, and referring to the performance requirements of JJG912-2010 therapeutic horizontal ionization chamber dosimeter, the use suggestions of QF 60 detector are given. The results show that the maximum impact of the angular response of the detector is 0.88%, and the repeatability of the same model is 0.21%. The polarization correction factor is 1.001. The ion composite correction values in the dose rate range of conventional radiotherapy were less than 1.0049. The leakage current and dose linearity basically meet the requirements of JJG912-2010. The energy response of 6 MV, 10 MV, 25 MV photons relative to Co-60γ-rays is 0.9883, 0.9820, 0.9597, and the maximum relative deviation of energy and noise of the same model is 0.17%. However, due to the lack of influence on the angular response in the use of position cutting lines, timely and sufficient pre-irradiation should be conducted in the measurement, and the Co-60γ-ray water absorption dose and energy response calibration should be conducted regularly.
2025 Vol. 46 (3): 419-425 [Abstract] ( 5 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
426 Investigation on X-ray flux spectrum measurement
The flux spectrum produced by X-ray tube is indirectly measured based on the absorption method. Based on this, the principle of unfolding is clarified, and combined with the response function and presetting spectrum, the unfolding of 100kV X-ray toughness radiation spectrum is completed by the unfolding program, and its mean energy is calculated to verify the accuracy of the unfolding results. Compared with the mean energy result calculated by numerical analysis software, the error between the two is 14%. And the reason for the error between the pulse amplitude spectrum and the X-ray flux spectrum has been analyzed.
2025 Vol. 46 (3): 426-432 [Abstract] ( 2 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
433 Development and application of Saccharomyces cerevisiae reference material for the metrological evaluation of biological sampling efficiency of planktonic bacteria sampler
Biological sampling efficiency is an important performance indicator of planktonic bacteria sampler, in response to the lack of fungal model microorganism reference material and evaluation method, central composite design method was used to optimise the formulation of the protective agents of reference material, the effects of two different pre-freezing methods (liquid nitrogen quick-freezing method and -80℃ slow-freezing method) on the survival rate of Saccharomyces cerevisiae were compared. The homogeneity, stability and value of the reference material were also evaluated. The test conditions of the biological sampling efficiency evaluation were researched. The concentration of Saccharomyces cerevisiae suspension for aerosol generation, humidity and sampling time were optimized by comparing different reference samplers. With the selected Andersen six-stage as the reference sampler, the biological sampling efficiency of planktonic bacteria sampler BAS C230 was evaluated. The results showed that the optimal concentration (W/V) of the freeze-dried protectants for Saccharomyces cerevisiae were: skimmed milk powder 8.05%, trehalose 9%, protectant a 1.41%, protectant b 1.5%, and protectant c 0.011%, where protectant a could increase the survival rate of Saccharomyces cerevisiae by about 9.0%. -80°C slow freezing for 2 h followed by freeze-drying, the survival rate of yeast was higher than that of liquid nitrogen quick-freezing. Finally, freeze-dried Saccharomyces cerevisiae reference material of the value of 8.65×106CFU/bottle with relative expanded uncertainty of 4.32%（k=2）was obtained, with a survival rate of 81.2%±1.4% and good homogeneity and stability. It has good solubility and the concentration of its suspension liquid is easy to adjust. The Saccharomyces cerevisiae in bioaerosol can be captured by the reference sampler and the tested sampler and grow well on the medium plate, which indicated that the Saccharomyces cerevisiae reference material and the method can be applied in the metrological evaluation of the biological sampling efficiency of planktonic bacteria sampler successfully.
2025 Vol. 46 (3): 433-441 [Abstract] ( 3 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
442 Development and experimental study of DPHP-FBG sensor for loess moisture content
The spatial and temporal dynamics of soil water content affects the migration of soil moisture and energy, and accurate monitoring of soil water content is of great significance to agricultural production, geological disaster prevention and engineering geological evaluation. Double Probe Peat Pulse (DPHP-FBG) method based on fiber Bragg grating is proposed, and a DPHP-FBG sensor is developed for the determination of water content of loess in Yan'an and the effects of different heating times and different heating powers on the results of the water content measurements are analysed. The study shows that the DPHP-FBG method can realize the accurate measurement of water content in unsaturated loess, especially suitable for monitoring low water content soils. When the heating time is controlled within 16 s at constant heating power, the measurement error decreases with the increase of heating time. The effect of heating power is small under sufficient heating time, so there is no need to use too high heating power. 30.15 W/m? heating power can achieve high accuracy of moisture content measurement when the heating time is 20 s. The DPHP-FBG method can realise remote, real-time, and fine monitoring of soil moisture content, which provides a new monitoring method for the study of in situ soil moisture field, soil moisture evaporation, and freezing and thawing. The DPHP-FBG method can achieve remote, real-time and fine monitoring of soil moisture content, providing a new monitoring method for the study of in situ soil moisture field, soil moisture evaporation and freeze-thaw.
2025 Vol. 46 (3): 442-449 [Abstract] ( 3 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
450 Research Advances of Reference Materials in Absolute Quantification of Microbiome
Microbiome research based on amplicon and metagenomic sequencing can help to analysis microbial community composition and function, and is an important tool for the study of microbial structure ecology and interaction mechanism. In order to represent the host-microbiome interactions, microbiome sequencing is gradually changing from relative abundance to absolute quantitative analysis of community composition. Reference material can be used as a standardized factor to accurately quantify the total load of each microorganism in the community. The reference materials for absolute quantification of microbiome, including microbial consortia, microbial genome, internal standard strains and spike-in sequences, and their applications were reviewed in this paper, the development trend of reference materials in quality control and standardization of microbiome is also proposed, so as to call for further expanding the application range of reference materials for absolute quantification for microbiome in microbial ecology.
2025 Vol. 46 (3): 450-458 [Abstract] ( 5 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
459 Techniques on accurate qualitative characterization of therapeutic oligonucleotides
Therapeutic oligonucleotide with chemical groups modification has been used for the treatment of specific diseases with significant superiorities. The sequence of therapeutic oligonucleotide is designable, for different loci of interest can be targeted by hybridization. However, the sequence of the oligonucleotides can cause risk when being delivered into target regions because of off-target effects or unknown side-effect. And the length of the synthesized products can also be another problem. The modification of therapeutic oligonucleotides is able to prevent its degradation and prolongates the effective drug duration. The solid phase process of the therapeutic oligonucleotides could produce structural analogues of the parent oligonucleotides, thus introducing product impurities. The accurate sequencing and structure characterization of therapeutic oligonucleotides will provide key information for their synthesized product and clinical research. The sequencing techniques and separation techniques of therapeutic oligonucleotides are aim to offer chemical information of the detailed structure, including length, sequence, and impurities, thus the quality control of producing and drug safety assessment can be benefited from the introductions of these techniques.
2025 Vol. 46 (3): 459-466 [Abstract] ( 4 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
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