Abstract: The brain is a high-level organ with the most delicate structure and complex function in the human body, with a large variety of chemicals, diverse functions, and complex mechanisms of action. Studies have shown that changes in some molecules are involved in cerebral neuropathy tissues in the study of central nervous system diseases. However, due to the analysis and detection methods, sample preparation, imaging technology, and other reasons, it has always been difficult to conduct research on the component analysis, functional identification, and spatial distribution of brain nerve tissue. With the development of mass spectrometry technology and the development of imaging software, a new analysis and detection method, Mass Spectrometry Imaging (MSI), has emerged. This technique combines highly sensitive mass spectrometry with imaging software that provides spatial information of detectors, and is an imaging technique with high sensitivity, no specific labeling, and can monitor the spatial distribution and content changes of multiple target molecules simultaneously, providing a new option for mapping the spatial distribution and content changes of molecules in brain neural tissue. Among them, Matrix-Assisted Laser Desorption/Ionization-Mass Spectrometry Imaging (MALDI-MSI) has significant advantages in the detection of proteins, lipids, drugs, and small molecules, and is widely used in biological It has been widely used in imaging studies of biological tissues, especially brain neural tissue. At present, with the emergence of some MSI quantitative analysis methods and correction strategies, quantitative mass spectrometry imaging technology (q-MSI) is becoming more and more mature. It can not only be used to visualize the content and in-situ distribution information of various molecules in biological tissues, but also provide absolute analysis of concentration. This paper aims to briefly introduce the basic principle, operation process, sample processing, matrix selection, and spraying, data acquisition and analysis, qualitative and quantitative analysis methods of mass spectrometry imaging, and summarize the application progress of MALDI-MSI in common brain diseases such as Parkinson's disease, Alzheimer's disease, multiple sclerosis, brain injury and ischemic stroke, which is helpful to understand the function of brain central nervous system The mechanism of disease formation and the metabolism of neuro drugs are conducive to the discovery of new drug targets and biomarkers, provide a reference for the study of the potential mechanism of its treatment strategy, and look forward to the future development direction.
Abstract: To evaluate the uncertainty of determination of Salidroside in proficiency testing samples of traditional Chinese medicine by high-performance liquid chromatography (HPLC), the content of salidroside was determined by the content determination method of Rhodiola in the first part of Pharmacopoeia of the People's Republic of China (2015 Edition). According to JJF 1059.1-2012 "Evaluation and Expression of Uncertainty in Measurement", the sources of uncertainty in the determination of Salidroside in two samples of Rhodiola powder No. 153 and No. 275 were analyzed. The mathematical model is established to quantify the uncertainty components, and the combined uncertainty and expanded uncertainty are calculated and compared with the results of capability verification. The result of No.153 Rhodiola powder sample was (1.41±0.05) % with k=2, the result of No.275 Rhodiola powder sample was (2.58±0.08)% with k=2, and the result of the proficiency test was satisfactory. The uncertainty of salidroside content in the two samples mainly came from repeatability tests, standard curve fitting, and dilution of reference series solution. This study can provide a reference for evaluating the quality of salidroside content determination results and controlling the internal quality of the laboratory. At the same time, uncertainty evaluation and proficiency testing results showed that the laboratory was capable of conducting the determination of salidroside in Chinese medicinal materials at the concentration level from 102.8 μg/mL to 1028 μg/mL and ensure the reliability of data.
Abstract: Malvern Laser Particle Size Analyzer is a commonly used instrument to measure the particle size distribution of Arizona test dust. The sample size distribution was characterized by both dry and wet methods using Malvern Mastersizer (MS2000). The results show that for different particle sizes, the dry method results have good repeatability, but the sample was used in a large amount. Although the wet test uses a small amount of sample, when there are large particle sizes in the sample, the large particle sizes tend to settle in the solution and are not easily mixed, making it difficult to be absorbed into the detector, resulting in poor repeatability of the measurement results, and the particle size (D50) corresponding to the cumulative percent size distribution up to 50% of the test obtained was significantly different from that of the dry method. By grinding A2 dust to reduce the particle size distribution from 1～100 μm to 1～50 μm, the repeatability of the wet test was greatly improved and was comparable to that of the dry method, which is close to that of the dry method, including the D50.
Abstract: It is of great practical significance to measure solar radiation in agricultural production, meteorology, and the environment. This paper mainly introduces a signal processing method of solar radiation measuring instrument suitable for the field environment. The radiation measuring instrument uses solar power to solve the problem of no mains electricity in the field environment and uses wireless communication to solve the problem of long communication distance between the upper and lower computers. Signal processing mainly includes signal modulation, signal amplification, bandpass filtering, and signal demodulation. Finally, the radiation measuring instrument is used to test the signal processing method, and the rationality of the signal processing method is proved by the measured data.
Abstract: To solve the problem of on-site calibration of mechanical accuracy of some non-standard equipment with geometric parameters, a set of follow-up calibration device integrating displacement and angle was designed, and the grating signal acquisition and measurement system design and software development were carried out. Through a large number of field comparative tests under different conditions, technical problems such as rotational eccentricity were solved, and the reliability of the system and the effectiveness of the device were verified. Through the research of geometric parameter follow-up calibration device, the application of follow-up calibration technology in geometric parameter equipment calibration is realized.
Abstract: This paper introduces a design scheme for wireless measuring instrument data acquisition and analysis instrument based on the ARM processor. The whole instrument is developed with FPGA as the data processing unit, together with the wireless module, AD conversion module, human-machine interaction, and other functional module circuits. In terms of function, the developed instrument prototype can establish communication with multiple wireless measuring tools of different types and distances, and the performance is stable, which basically meets the design expectation.
Abstract: This paper introduces the measurement principle, detection methods, and precautions of using the laser interferometer straightness mirror set and angular mirror set to detect straightness, and focuses on the comparative analysis of the two detection methods. Relying on the detection data, this paper analyzed the differences in the accuracy, advantages, and application environments of the two detection methods.
Abstract: In this paper, a measuring device for measuring the thickness deviation of feeler gauge is designed to address the problems of the cumbersome and inefficient measurement process, and the structure and working principle of the measuring device are described in detail. Through the uncertainty assessment of the thickness deviation measurement results of the feeler gauge and the comparison with the length measuring instrument, it is verified that the measurement results of the measuring device are accurate and reliable and can meet the requirements of traceability.
Abstract: To improve the verification efficiency of DN15～DN25 water meters, considering the piston water meter verification device has good flow stability, precise adjustment, and high accuracy. due to the difficulty of processing and manufacturing and the high economic cost, its effective volume is small, and it is only suitable for the test of small and medium flow. As a water meter verification device of standard meter, the electromagnetic flowmeter has good stability and high accuracy in large flow, but it is not suitable for detecting medium and small flow. A set of improved verification device of the piston water meter with 0.2 level flow range of (0.01～10) m3/h and electromagnetic flowmeter as standard meter is designed. Through three DN15 rotor wet cold water meters, the flow point errors of Q3, Q2, and Q1 are tested by this device and the static mass method device respectively. The results show that the maximum difference of Q3 point is 0.15%, and the difference of all flow points is less than MPE/5. The test accuracy of the device is verified and showed that the efficiency is improved by 8 times, which meets the verification requirements of DN15～DN25 civil water meters. The piston can regularly check the standard meter online to ensure its measurement accuracy, providing a practical solution to the current widespread problem of inefficient water meter verification.
Abstract: Due to the upgrading of energy-saving technology and the improvement of the manufacturing process, air conditioners have become a common appliance used in home life and public places. In recent years, inverter technology has been applied, and the compressor, heat exchanger, and electronic control components in air conditioners have reached the most accurate and reasonable configuration and operation, and the product performance has been greatly improved.
Abstract: Combined with the manufacturing characteristics of smart meters, an appropriate big data analysis model was established based on the factory verification data, primary verification data, random sampling re-verification data, and re-verification data after eight years of continuous operation, and the distribution of the corresponding data was shown in the form of a diagram. Based on the above big data, the identification procedures of high-risk meters and medium-risk meters were established, and on-site calibration and screening of meters were carried out according to the identification results and corresponding technical specifications. The results of continuous tracking and risk control measures supported the implementation of the policy of extending the replacement cycle from 8 years to 12 or even 16 years, which supported the deepening of energy-saving and carbon-reduction work and boosted the construction of a conservation-oriented society.