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Event sequences that would lead to an early radioactive release or a large radioactive release are required to be practically eliminated in HAF102—2016. But there are lack of specific acceptance criteria and demonstration method of practical elimination in China. Safety requirement of practical elimination was studied, and some insights, acceptance criteria and demonstration method of practical elimination were proposed in this paper. Demonstration of practical elimination for HPR1000 was evaluated. The main conclusions are as follows: 1) Practical elimination is a higher requirement for the safety design of nuclear power plants. It is not a requirement that accident conditions have no release, but the plant states that could lead to an early or a large radioactive release have been practically eliminated. And conditions that have not been practically eliminated should be fully considered in the design to ensure its radiological consequences limited. 2) With reference to international practice and the relevant requirements of emergency plans and preparations in China, it is the first time to propose the deterministic and probability acceptance criteria for practical elimination in China at this stage. The radiological release acceptance criteria at this stage are suggested that there is no evacuate action beyond 3 km from the site boundary, and no sheltering action beyond 5 km. It is recommended that the DEC�B design requirement is less than 100 TBq equivalent 137Cs. This criterion is also the criterion for large radioactive release in the level 2 PSA. 3) Demonstration method of practical elimination was proposed in this paper, and demonstration of practical elimination for HPR1000 was evaluated. In the final analysis, DBA is effectively mitigated by defence�in�depth, and severe accident prevention and mitigation measures are considered sufficiently for HPR1000. Even if severe accident considered in design is happened, the containment could be intact. Practical elimination is realized on HPR1000.

Monitoring the shipyard production state is of great significance to shipbuilding industry development and coastal resource utilization. In this article, it is the first time that satellite remote sensing (RS) data is utilized to monitor the shipyard production state dynamically and efficiently, which can make up for the traditional production state data collection mode. According to the imaging characteristics of optical remote sensing images in shipyards with a different production state, the characteristics are analyzed to establish reliable production state evidence. Firstly, in order to obtain the characteristics of the production state of optical remote sensing data, the high-level semantic information in the shipyard is extracted by transfer learning convolutional neural networks (CNNs). Secondly, in the evidence fusion, for the conflict evidence from the core sites of the shipyard, an improved DS evidence fusion method is proposed, which constructs the correlation metric to measure the degree of conflict in evidence and designs the similarity metric to measure the credibility of evidence. Thirdly, the weight of all the evidence is calculated according to the similarity metric to correct the conflict evidence. The introduction of the iterative idea is motivated by the fact that the fusion result aligns more closely with the desired result, the iterative idea is introduced to correct the fusion result. This method can effectively solve the conflict of evidence and effectively improve the monitoring accuracy of the shipyard production state. In the experiments, the Yangtze River Delta and the Bohai Rim are selected to verify that the proposed method can accurately recognize the shipyard production state, which reveals the potential of satellite RS images in shipyard production state monitoring, and also provides a new research thought perspective for other industrial production state monitoring. [ABSTRACT FROM AUTHOR]

In this work, a model for predicting the leakage rate was developed to investigate the effect of irradiation on the sealing performance of ethylene propylene diene monomer (EPDM) O-rings. The model is based on a mesoscopic interfacial gap flow simulation and accurately predicts the sealing performance of irradiated and non-irradiated materials by utilizing the gap height as an indicator in a mechanical simulation of the O-ring under operating conditions. A comparison with vacuum test results indicates that the model is a good predictor of leak initiation. The positive pressure leakage of the O-rings was investigated numerically. The results show the following. The sealing performance of the non-irradiated O-ring is much better than that of the irradiated one. The sealing performance is the worst at 0. 713 MGy and the best at 1.43 MGy, and the seal is maintained at an absorbed dose of 3.55 MGy. A theoretical analysis of the non-monotonic variation using the proposed model shows that the leakage behavior of the O-rings depends not only on the material properties but also on the roughness and prestressing properties. Finally, a method was proposed to classify the sealing performance, using the maximum allowable leakage rate as an indicator. [ABSTRACT FROM AUTHOR]

With the development of Industry 4.0, hard-cut materials such as titanium alloys have been widely used in the aerospace industry. However, due to the poor rigidity of titanium alloy parts, deformation and vibration easily occur during the cutting process, which affects the accuracy, surface quality and efficiency of part machining. Therefore, in this paper, tool runout and workpiece deformation are introduced into the milling process of flat-end mills. Based on the tool's hypocycloid motion, a geometric parameter model of the milling process is established, and the undeformed cutting thickness model is obtained considering the tool runout and workpiece deformation. Finally, the milling force model for side-milling titanium alloy thin-walled parts was established. The accuracy of the force model is verified through experiments. The error of the proposed model is far less than that of the traditional basic method. The maximum error of the traditional basic method is 87.09%. However, the maximum error of the proposed model is only 66.54%. The results show that the proposed force model considering tool runout and workpiece deformation can provide more accurate milling force prediction. [ABSTRACT FROM AUTHOR]

In metal milling, especially in the machining of low-stiffness workpieces, chatter is a key factor affecting many aspects such as surface quality, machining efficiency, and tool life. In order to avoid chatter, a milling chatter identification method based on dynamic wavelet packet decomposition (WPD) is proposed from the perspective of signal processing. The dynamic characteristics of the system are obtained by a hammer test. Based on the principle that the chatter frequency will reach a peak value near the natural frequency of the system, the original milling force signal is decomposed by WPD, and the sub-signals containing rich chatter information are selected for signal reconstruction. After numerical analysis and spectrum comparison, the reconstruction scheme is proved to be robust. Then, the time–frequency domain image of the reconstructed signal and the Hilbert spectrum feature are compared and analyzed to identify the chatter. Finally, the validity and reliability of the proposed method for chatter recognition are verified by experiments. [ABSTRACT FROM AUTHOR]

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Copyright of Remote Sensing for Natural Resources is the property of Remote Sensing for Natural Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Herein, a better mesophase pitch as precursor for the manufacturing of green needle coke is obtained by a new process, whereas the refined medium‐ and low‐temperature coal tar pitch (RCTP) is obtained by a solvent sedimentation method, and then, it is co‐carbonized with coal‐based hydrogenated diesel oil at 420 °C for 6 h. The mesophase pitch structure is characterized by a polarized light optical microscope, Fourier transform IR (FT‐IR) spectroscopy, and 1 H nuclear magnetic resonance (NMR). The results indicate that the aromatic hydrogen content of mesophase pitch gradually increases, as the carbonization temperature increases. Also, the mesophase pitch with aliphatic side chain substitution (CH3 and CH2) is obtained at 420 °C for 2 h, which is conducive for polyaromatic hydrocarbon to the orderly accumulation. It is also a basis for preparing better green needle coke. The polarized light analysis results propose that the mesophase with a wide‐area streamlined structure is obtained at a constant temperature of 420 °C for 6 h, whose temperature and soaking time are lower than that of the high‐temperature coal tar pitch and petroleum pitch for preparing the mesophase pitch. Also, the better direction and order fiber of green needle coke with 53 % fiber are acquired. [ABSTRACT FROM AUTHOR]

This work addresses the issues of long-term leakage rate prediction, which is crucial for durability study of proton exchange membrane fuel cells (PEMFCs). A theoretical model is presented for the leakage rate of compressive seal structures in PEMFCs, based on the combination of three numerical techniques, namely Lattice-Boltzmann method (LBM) simulations for rough wall interfacial gaps, a numerical 3D rough-surface generation technique, and Finite-Element-Analysis (FEA) for micro-contact mechanics of single asperity. The model clearly reveals the quantitative influence of various factors on the leakage rate without any empirical regression coefficients, and therefore can be easily integrated with structural mechanics and aging mechanism analyses. Long term sealing performance comparisons with three types of rubber material identify liquid silicone rubber to have the optimal durability. When influences of water environment are taken into account, an accelerated degradation of sealing performance can be observed after approximately 3000 h of operation. In addition, the effect of stress loss on leakage rate can be effectively suppressed by reducing surface roughness, reducing gasket thickness and increasing strain level. The proposed theoretical model provides an effective approach for the design of metal-bipolar-plate PEMFCs seal structures. • A theoretical leakage-prediction model is proposed on the basis of interfacial flow calculation. • The model can be easily integrated with material mechanical and aging analyses. • Long-term sealing performance of different sealing designs is further quantitatively evaluated. • The influence of stress loss is proven to be suppressed under guidance of the model. [ABSTRACT FROM AUTHOR]

Centimeter-level localization and precise rotation angle estimation for flatbed trucks pose significant challenges in unmanned forklift automated loading scenarios. To address this issue, the study proposed a method for high-precision positioning and rotation angle estimation of flatbed trucks using the BeiDou Navigation Satellite System (BDS) and vision technology. First, an unmanned forklift equipped with a Time-of-Flight (ToF) camera and a dual-antenna mobile receiver for BDS positioning collected depth images and localization data near the front and rear endpoints of the flatbed. The Deep Dual-Resolution Network-23-slim (DDRNet-23-slim) model was used to segment the flatbed from the depth image and extract the straight lines at the edges of the flatbed using the Hough transform. The algorithm then computed the set of intersection points of the lines. A neighborhood feature vector was designed to identify the endpoint of a flatbed from a set of intersection points using feature screening. Finally, the relative coordinates of the endpoints were converted to a customized forklift navigation coordinate system by BDS positioning. A rotation angle estimation was then performed using the endpoints at the front and rear. Experiments showed that the endpoint positioning error was less than 3 cm, and the rotation angle estimation error was less than 0.3°, which verified the validity and reliability of the method.

Background: With the development of science and technology, high-altitude environments, involving aviation, aerospace, and mountainous regions, have become the main areas for human exploration, while such complex environments can lead to rapid decreases in air and oxygen pressure. Although modern aircrafts have pressurized cabins and support equipment that allow passengers and crew to breathe normally, flight crew still face repeated exposure to hypobaric and hypoxic conditions. The eye is a sensory organ of the visual system that responds to light and oxygen plays a key role in the maintenance of normal visual function. Acute hypoxia changes ocular structure and function, such as the blood flow rate, and can cause retinal ischemia., Methods: We reviewed researches, and summarized them briefly in a review., Results: The acute hypobaric hypoxia affects corneal, anterior chamber angle and depth, pupils, crystal lens, vitreous body, and retina in structure; moreover, the acute hypoxia does obvious effect on visual function; for example, vision, intraocular pressure, oculometric features and dynamic visual performance, visual field, contrast sensitivity, and color perception., Conclusion: We summarized the changes in the physiological structure and function of the eye in hypoxic conditions and to provide a biological basis for the response of the human eye at high-altitude., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Wang, Yu, Liu, Lv, Xia, Wang, Li and Li.)

Background: Ovarian cancer is the most malignant gynecological disease, which seriously threatens female physical and mental health. Paclitaxel is a first-line chemotherapy drug in the clinical treatment of ovarian cancer, but drug resistance has become an important factor affecting the survival of ovarian cancer patients. However, the main mechanism of chemotherapy resistance in ovarian cancer remains unclear. In this study, we analyzed the Integrated Gene Expression Database (GEO) dataset using comprehensive bioinformatics tools to provide new therapeutic strategies and search for prognostic targets for ovarian cancer. Methods: Ovarian cancer related genes were extracted from GSE18520 by bioinformatics method. Differentially expressed genes (DEGs) were obtained by differential analysis, and related genes and functions were elucidated. The key gene CRTC2 was identified by prognostic analysis. Immunohistochemistry was used to detect the expression of CRTC2 in chemotherapy-resistant and chemotherapy-sensitive ovarian cancer tissues. Functional analysis (cell assay) confirmed the role of CRTC2 in paclitaxel resistance. Autophagy related proteins were detected by Western blot. Autophagy flux analysis was performed using the GFP/RFP-LC3 adenovirus reporter. Results: A total of 3,852 DEGs were identified in the GEO microarray dataset. Key genes were screened by prognostic analysis. We found that CRTC2 was highly expressed in chemoresistant tissues of ovarian cancer. In 110 patients with ovarian cancer, high expression of CRTC2 was associated with poorer prognostic factors and shorter survival. At the same time, we found that CRTC2 can promote the proliferation and invasion ability of ovarian cancer cells. In addition, CRTC2 can affect the expression of PI3K, AKT, autophagic flux and sensitivity to paclitaxel chemotherapy in ovarian cancer. Conclusion: CRTC2 can affect autophagy partially through PI3K-AKT signaling pathway, and then affect the sensitivity of ovarian cancer to paclitaxel chemotherapy. CRTC2 may be a potential predictor or target for ovarian cancer therapy., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Objective: With the wide use of transmission displays to improve operation performance, the display information highlights clutter because of the contradiction between the massive amount of information and limited display area. Our study aimed to develop a quantitative measurement for declutter design and appraisal., Methods: Using the ergonomics research system of characters and symbols in a see-through cockpit display, we set the simulated flight task interface at four pixel scale levels by enlarging all the display elements in a certain ratio. Flight task videos of 12 clutter degrees were recorded using each flight interface matched with three flight scene complexity levels. A total of 60 pilots completed the visual search tasks in the flight task video while the eye tracker was used to record the view path in real time. Visual search performance was analyzed to study the effect of various clutter factors and levels on pilots' performance in visual search tasks, and acquire quantitative clutter measure parameters., Results: GLM univariate test revealed that there were significant differences among the fixation time in areas of interest (AOI), total Fixation point number, total fixation time at four pixel scale levels, and three flight scene complexity levels ( P < 0.05). Visual search performance declined after the cutoff point, while the clutter degree increased. According to the visual search performance data, the recommend feature congestion upper pixel number limit in a 600*800 display was 18,576, and the pixel ratio was 3.87%., Conclusion: A quantitative measurement for declutter design and appraisal of cockpit displays was developed, which can be used to support see-through display design., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Liu, Wang, Bai, Yu, Cao, Yu and Ding.)