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Objective To assess the engineering safety and reliability of undersea large-diameter shield tunnel structures, it is essential to analyze the stress on lining segments. Method Taking the lining segments of Dalian Railway Station-Suoyuwan South Station Interval undersea shield tunnel on Dalian Metro Line 5 as research object, MIDAS GTS finite element analysis software is used to model the shield tunnel structure and the surrounding rock mass. The stress on lining segments after a period of construction is obtained and comparatively analyzed with field monitoring and theoretical calculation data. Result & Conclusion The earth pressure on lining segments remains relatively stable as construction progresses. There are certain differences in earth pressure at different points on the same monitoring section, with the arch vault and bottom experiencing higher stress. Therefore, during both the construction and future operation periods of the tunnel, the arch vault and bottom should be areas of key focus and be reinforced through physical measures. The onsite monitoring and numerical simulation data indicate that the internal forces on lining segments are quite similar. Under certain simplified conditions, the numerical model can quite realistically reflect the actual stress conditions of lining segments.

Objective To explore the influencing factors affecting somatosensory evoked potential (SEP) during decompression laminectomy and to establish a prediction model. b>Methods The SEP monitoring data from 120 patients with spinal stenosis who underwent decompression laminectomy at the Spinal Orthopedics Department of Ma'anshan People's Hospital from January 2021 to January 2023 were analyzed retrospectively. Patients were divided into SEP-altered group (n=21) and control group (n=99) based on the presence or absence of SEP signal alteration. Predictors were determined using Lasso regression, cross-validation, logistic regression analysis. A column-line plot predicting change in SEP based on independent predictors was drawn. Receiver operating characteristic (ROC) curves, calibration curves, and clinical decision curves were used to evaluate the model. Results Logistic regression analysis indicated that overweight, hemorrhage, body temperature, and use of electrosurgical equipment were independent risk factors affecting SEP, with statistically significant differences (P＜0.05). In the validation of the model, the AUC of the column-line plot was 0.914, indicating that the model had good discrimination. The optimal calibration curve showed good agreement between predicted and actual values. The clinical decision curve attested to the practical efficacy of the model. Conclusion Factors affecting changes in SEP include overweight, hemorrhage, body temperature, and the use of electrosurgical equipment. The construction of a column chart to forecast SEP changes empowers spinal physicians to implement proactive therapeutic interventions effectively, concurrently enhancing the precision of electrophysiological monitoring.

In the process of aircraft structure X-ray images evaluation，there are some problems such as inaccurate crack segmentation and difficult crack detection under complex background. An intelligent evaluation model （ELAN-Seg） for X-ray crack images of aircraft structures is proposed based on efficient layer aggregation network. The ELAN-Seg model is compared with the DeepLabv3+ model in the crack segmentation ability of the Xray images. Combined with image processing technology，the crack length of model segmentation is evaluated，and the model is verified by X-ray images acquired during aircraft strength test and field maintenance. The results show that the segmented minimum crack length is about 3 mm，the ELAN-Seg model is more accurate in crack segmentation of complex background X-ray images，and the crack detection rate is less than 3.8%. The proposed model has engineering applicability.

Metallic magnetic calorimetry holds significant promise in critical defense applications such as nuclear proliferation prevention, radionuclide classification, nuclear safety and anti-terrorism. Metallic magnetic calorimetry realizes energy resolution in the order of a few electron Volts by utilizing the significant contribution of heat capacity of a magnetic origin at milli-Kelvin temperatures in rare-earth doped Au films. For detecting gamma-ray photons with an energy of around 100 keV, the energy resolution is better than 0.1%, 10 times better than the high-purity germanium (HPGe) gamma spectrometer with the highest energy resolution. The metallic magnetic calorimeter can detect other radiation types than gamma rays such as alpha and beta emissions. Metallic magnetic calorimetry can also be used for precise measurement of astrophysical phenomena, cosmic rays and other high-energy physics phenomena. As an critical part of the metallic magnetic calorimeter, the pick-up coil plays a dual role in the sensor unit. It is not only responsible for converting magnetic flux changes into electrical signals, which is subsequently picked up by the SQUID chip, but also responsible for generating persistent excitation magnetic field and magnetizing the rare-earth doped sensor thin-film. The design configuration and electromagnetic parameters of pick-up coil can directly influence the energy resolution of the sensor. In the paper the influences of various parameters (e.g., number of turns of soil, duty ratio) on the electromagnetic characteristics using the finite element method was calculated. The actual pick-up coil size is in the order of micrometers. As direct measurement of such tiny devices is extremely difficult with conventional means and such measurements suffer high errors, in this paper scaled-up samples were measured, and the validity of the simulation model and parameters through comparison with measurement results was verified to provide a reliable foundation for design work of pick-up coils. The calculation results show that the influence of turn number of pick-up meander coil on inductance is more significant than other parameters such as duty ratio and loop pitch. With the increase of the duty ratio, the inductance shows a monotonic decrease trend. When the duty ratio increases from 30% to 70%, the inductance decreases by about 76.4%. On the other hand, with the increase of the turn number, the inductance shows an obvious increasing trend. When the turn number increases from 15 to 75, the inductance increases by about 253%. The simulation result also reveals the magnetic field distribution inside the metal magnetic calorimeter sensor pick-up coil, which provides critical information for the design of the sensor thin film.

The neutron texture diffractometer has unique advantage in the texture research for the key materials in the fields of aerospace, transportation, nuclear industry and so on. In order to improve the detection efficiency, the detection system of the neutron texture diffractometer at China Advanced Research Reactor (CARR) has been upgraded from a single 3He counter tube to a large-area two-dimensional position sensitive detector during 2020-2021. However, due to the difference of configuration and hardware design of the neutron texture diffractometer at the major neutron scattering laboratories in the world, the formats of obtained experimental data are also different, which results in the significant difference of the data analysis and processing. Therefore, the new method and software should be proposed to analyze the experimental data collected from two-dimensional position sensitive detector of neutron texture diffractometer at CARR.The results of texture measurement using neutron texture diffractometer generally were represented by pole figure. The pole figure window resolution of the texture diffractometer is an important factor affecting the results of texture measurement. Due to the diffraction signal of larger range angles along the longitudinal direction (α direction) can be detected by the two-dimensional position-sensitive detector, therefore, in order to meet the demand of texture measurement for resolution, the diffraction data should be firstly divided into several pieces in longitudinal direction to adjust the α direction resolution of the pole figure window. Then, during data preprocessing, it is key to accurately obtain the integral intensity of the diffraction peak for getting an accurate pole figure. However, the position of diffraction peaks may shift slightly due to the possible eccentricity during sample installation and uneven background of diffraction spectrum caused by noise, which result in the inaccurate fitting results. Moreover, generally the massive experimental data were collected by the two-dimensional sensitive detector during texture measurement. Thus, the parameters of background and peaks position should be strictly constricted for data corresponding to each-phi angle before fitting diffraction spectrum. The constrained parameters obtained through optimization of polynomial background function and peak shape function by fitting sum-phi data (the sum of intensity for all phi angle according to each chi angle) were used to fit each-phi data. Finally, the fitting integral intensity were converted and normalized for all each-phi data to get pole figure. Based on these design ideals, the data processing and analysis software was developed using Python language for neutron texture measurement with two-dimensional position sensitive detector. The experimental data of magnesium alloy was analyzed and processed with this software system, and the results verified the reliability of software.In a word, according to the experimental requirements of neutron texture diffractometer equipped with two-dimensional position sensitive detector at CARR, the experimental data analysis method has been established, and the data analysis and processing software has been developed. Especially, the resolution adjustment method of pole figure window along α direction has been achieved based on two-dimensional position sensitive detector. The batch processing of conversion from neutron counting to the integrated intensity of diffraction peaks is realized. In addition, the pole density normalization and the drawing of pole figures can be achieved smoothly. All of these meet the functional requirements of the upgraded neutron texture diffractometer and provide the guidance for the similar data analysis and processing.