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Objective The millisecond-level precision of NTP (network time protocol) in train communication networks has increasingly failed to meet the requirements of high traffic and deterministic transmission. Meanwhile, existing research is limited to applying the PTP (precision time protocol) to train communication scenarios, lacking research on time synchronization in time-sensitive networks within train communication networks. Therefore, it is necessary to conduct relevant analysis. Method Firstly, based on the current research status of time synchronization in train communication networks, the deviation and delay in train communication networks are analyzed according to time-sensitive network synchronization protocols. Secondly, redundancy mechanis for clock service source failures and jumps are proposed. Finally, the effectiveness of the redundancy mechanism is verified through simulation of the time synchronization process. Result & Conclusion Time-sensitive networks are well suited for time synchronization of clock service sources in train communication networks, and their redundancy mechanisms effectively mitigate synchronization errors caused by clock service source failures and jumps.

Objective TCN (train communication networks) has complex topologies and requires high real-time transmission capabilities. Currently, train data transmission mainly relies on TRDP (train real-time data protocol) for carriage, while there are issues of network latency uncertainty. TSN is thus adopted to ensure bounded latency for data transmission, addressing the aforementioned issues faced by TCN. Method A method called TTAM (TRDP and TSN adaptive method) is proposed to achieve protocol conversion between TRDP and TSN, ensuring data transmission in the network. Result & Conclusion Through the establishment of a TSN testbed, the functionality and performance of TSN networks (IEEE 802.1 AS and IEEE 802.1 Qbv) are tested, validating the effectiveness of TTAM in TSN technology application.

Using Fe-modified biochar (Fe-B) to capture phosphorus in eutrophic water and then reusing it as a phosphorus fertilizer for agricultural production is a sustainable way to remediate surface water eutrophication and develop agriculture. However, the adsorption efficiency of Fe-modified biochar is influenced by a variety of factors including methods to produce biochar and surface water environment. In this review, we analyze different methods to manufacture Fe-B and their efficacy for phosphate adsorption. Other factors we analyzed include pH value, coexisting ions, biochar application rate, temperature which have shown to affect the capacity of Fe-B to adsorb phosphorus. We also discuss the potential of Fe-B and the phosphorus it adsorbed to be reused as a slow-release phosphorus fertilizer for agricultural production, as well as the perspective of Fe -modified biochar (Fe-B) and its applications.

The nuclear heating rate is a critical parameter for reactor core design and irradiation tests, it is typically determined via experimental measurements in a reactor experimental channel. In-pile calibration of calorimeter is an important method for measuring the nuclear heating rate in a fission reactor. This paper summarizes the working principle of the common in-pile calorimeter and reviews the current situation and research progress with regard to in-pile calorimetry employed worldwide. The structural design and performance characteristics of single-cell and multi-cell (differential) calorimeters are compared, and the design method of multimodal integrated measurement device, which represents one of development directions of calorimeters, is introduced. Moreover, the in- and out-pile calibration principles and application methods are described. The advantages and disadvantages of the calibration methods are analyzed, and the developing trend and direction for next-generation in-pile calorimeters are prospected.

To ensure the safety and precision of surgery, the robotic system applied in magnetic resonance (MR) image-guided robot-assisted surgery should be MR-compatible. In terms of this issue, a MR compatibility analysis method for surgical robotic system based on image quality evaluation is proposed in this paper, and the image sets are extended. The image quality evaluation model is constructed by combining evaluation parameters such as signal-to-noise ratio of MR images, image change factor and MR image distortion. The model can analyze the effect of the robot component and robot motion on image quality, forming a basis for image quality evaluation. The experimental results show that the image quality evaluation method can fully analyze the MR compatibility of the robotic system component, and provide an evaluative method and theoretical basis for the MR compatibility analysis of other kinds of medical robotic systems.

BackgroundSampling filter membrane is an important part of the continuous monitoring system for radioactive aerosols. The performance of the sampling filter membrane directly affects detection efficiency of the system. In addition, tailing effect in α spectra increases the difficulty of identifying nuclides, reduces the accuracy of aerosol measurement, and elevates the minimum detectable activity.PurposeThis study aims to find a sampling filter membrane with high detection efficiency, small α spectrum tailing and the pore size suitable for actual environmental measurement.MethodsThe detection efficiency and spectrum tailing performance of the three most commonly used filter membranes at present, i.e., mixed cellulose ester membrane (MCEM), hydrophobic polytetrafluoroethylene (PTFE) and polypropylene (PP) filter membranes, were tested under different radon concentrations and various pore sizes. Then, based on obtained data of the tests, the comprehensive evaluation was performed on their adsorption performances to determine the optimal sampling filter membrane.ResultsThe results show that the MCEM filter membrane has the highest detection efficiency and the hydrophobic PTFE filter membrane has the least tailing effect in the three kinds of filter membranes. In comparison of other pore sizes under different radon concentrations, the MCEM filter membrane or hydrophobic PTFE filter membrane has the highest detection efficiency when its pore size is 0.45 µm, which is close to the maximum particle size of natural radioactive aerosols. No obvious effect of the pore size of the filter membrane is observed on the α spectrum tailing. In addition, for one filter membrane with the same pore size, the detection efficiency decreases with the increase of aerosol concentration and vice versa.ConclusionsThis study provides a useful reference for the optimal selection of filter membranes for natural radioactive aerosols under various conditions.

Objective To investigate the methylation status of ZIC1 gene in peripheral blood and lung cancer tissues of NSCLC patients and its prognostic significance. Methods We took the peripheral blood, cancer tissues and adjacent tissues of 95 NSCLC patients. The peripheral blood of 95 healthy people was taken as control group. MSP was used to compare the detection rate of ZIC1 methylation between peripheral blood and cancer tissues. And we analyzed the correlation of ZIC1 methylation in peripheral blood and cancer tissues with the clinicopathological factors of NSCLC patients. Results The methylation detection rates of ZIC1 in peripheral blood and lung cancer tissues in NSCLC patients were significantly higher than those in peripheral blood of healthy people and adjacent tissues of NSCLC patients (P < 0.05), and the sensitivity and specificity of ZIC1 methylation in the diagnosis of tumor tissues were higher. The positive rate of ZIC1 gene methylation in peripheral blood and tumor tissues of NSCLC patients was significantly correlated with tumor diameter, metastasis, stage and pleural effusion (P < 0.05). Conclusion The methylation of ZIC1 gene is related to the occurrence, development, metastasis and stage of NSCLC. It may be used as a diagnostic and prognostic indicator of NSCLC.

Automated rubber tapping not only frees the workers from heavy physical labor and harsh working conditions, but also reduces the dependence on the workers' skills and greatly increases tapping efficiency. The key technologies for tapping robots are the independent acquisition of operational information and servo control of the tapping position in unstructured environments. In this study, taking rubber tree in rubber plantations as object, incorporating robot kinematics, machine vision technology and multi-sensor feedback control technology, a modular prototype of a rubber tapping robot was developed. The rubber tapping robot was mainly composed of an orbital mobile platform, a multi-joint robotic arm, a binocular stereo vision system and an end-effector. The binocular stereo vision and structured light system were used to obtain the structural parameters of the rubber trunk and secant. A six-joint tandem robotic arm was used for the planning and realization of complex rubber tapping trajectories. An multi-sensor fusion end-effector was developed to complete the identification of the starting point, the measurement of cut compensation and the tapping operation. To address the technical difficulties in rubber tapping operations, such as complex and variable environment, superimposed interaction of operational information, similar target background features and sub-millimeter operational accuracy requirements, the spatial mathematical model of the rubber tapping trajectory was established to plan the robot's movement path for fast approaching and moving away from the operation space. The results of the field tests conducted at a natural rubber plantation in Hainan province showed that the accuracy in bark consumption was about 0.28 mm and the accuracy in cutting depth was about 0.49 mm when the rubber tapping robot cut 1 mm thick bark. Compared to manual operations, the continuity of the chips and the flatness of the rubber output surface were improved significantly. This research could provide a positive reference and development direction for exploring automated rubber tapping operations.

Objective To explore the relation between WNT7A methylation and clinical factors of NSCLC patients. Methods We selected 120 NSCLC patients as NSCLC group and 120 healthy people as control group. The detection rate of WNT7A methylation in two groups was compared by methylation specific polymerase chain reaction, and the relation between WNT7A methylation and clinical factors of NSCLC patients was compared. Results The methylation rate of WNT7A in peripheral blood of NSCLC group was significantly higher than that in control group (P < 0.05). In peripheral blood of NSCLC group, there was no significant correlation between WNT7A gene methylation and gender, pathological type, age, smoking history(P > 0.05). The methylation rate of WNT7A gene was significantly correlated with tumor size, distant metastasis, TNM stage and pleural effusion(P < 0.05). The detection rate of WNT7A gene methylation in peripheral blood of NSCLC patients with pleural effusion, tumor size > 5cm and TNM stage Ⅲ-Ⅳ was significantly higher than that of patients without pleural effusion, tumor size ≤5cm and stage Ⅰ-Ⅱ (P < 0.05). Conclusion The detection rate of WNT7A gene methylation is high in NSCLC patients, which can be used as an effective diagnostic basis for NSCLC.

In the industrial field，the rigid mechanism design of the pick-and-place robot tends to be mature，but it has the defects of has a lot of mass and high risk factor when human and machine work together. At the same time，as a new design material，the elastic rod has been applied in the fields of medical treatment and exploration due to its own material advantages. Based on this，a parallel elastic rod robot mechanism that can be applied to pick-and-place tasks is proposed. By using the simplified Cosserat elastic rod model，the deformation of the elastic rod is described from the perspective of rigid body motion，and the dynamics model of the elastic rod is derived. The equation and virtual prototype model of the parallel elastic rod are established in Matlab. Through the analysis of key materials and workspace，the corresponding mechanism parameters are obtained. The relationship between the input angle，the torque and the displacement of the end-effector is studied. The feasibility of the theory and the rationality of the design are verified by setting up the prototype，which also provides a reference for the industrial application of the elastic rod.

BackgroundDetermination of the elements in lunar soil samples returned by Chang'E 5- mission is of great significance for exploring the origin of lunar soil and the physical and chemical conditions for its formation, and for studying the evolutionary history of the moon. Neutron activation analysis (NAA) has the inherent advantages of non-destructiveness, high sensitivity, and the ability to analyze multiple elements. The NAA Laboratory of China Institute of Atomic Energy (CIAE) is responsible for the quantitative analysis of elements in the lunar soil samples returned by Chang'E-5 mission.PurposeThis study aims at the quality assurance and the control of NAA for the determination of element content of lunar soil samples to ensure the accuracy and reliability of the analysis results.MethodsBased on the principle of neutron activation analysis and sources of error, the quality assurance measures taken by NAA laboratory in sample preparation, selection of analysis protocols, γ-ray spectrometer performance control, measurement, spectrum analysis, calibration were discussed. The results of NAA were evaluated and verified by internal quality control samples with known property values (and uncertainties) and the consistent in different characteristics γ rays of the same radionuclide. The analysis results of each element to be measured were compared with relative method and single comparator k0 method to achieve the purpose of internal quality control.ResultsThe analysis results of internal quality control samples meet the laboratory's acceptance criteria. Internal quality control methods such as repeated tests, etc., verify the consistency of the element measurement results.ConclusionsBy analyzing the measurement data, the reliability of the test results is verified, and the quality assurance process and quality control method are proved to be effective.

A seepage-stress coupling model of coal containing gas was established considering effect of coal permeability changing on gas flow based on coal seam gas flow theory and elastic mechanic. The second development of COMSOL Multiphysics numerical simulation software was taken according to the model. A model of gas drainage model of drilling hole in coal seam was established taking a gas outburst mine as an example and resolved with numerical solution. The results show that coal seam gas pressure and coal permeability decrease gradurally with time extending, meanwhile effective radius of drilling hole increases gradually, and both have certain timeliness. The field test is taken by use of a pressure testing method with a result in accordance with the simulated one basically, which verifies correctness of the seepage-stress coupling model of coal containing gas and feasibility of calculating effective drainage radius of drilling hole by numerical simulation method.