For the cylinder of the axial piston pump suffers complicated forces including hydraulic pressure force, mechanical forces and mutual coupling, which causes the cylinder fatigue damage with all forces whose fluctuation is caused by fluid striking on the cylinder of the pump cyclically, it is necessary to develop the fatigue analysis research. And the sensitive fatigue areas of the cylinder in the axial piston pump is presented through the nephogram of the fatigue life, the fatigue safety factor over the whole model and the curve of fatigue sensitivity, which can verify the theory of micro crack propagation and the transient dynamics analysis of the axial piston pump cylinder is simulated. All the results are produced by software, Solidworks is used to build the three-dimension assembling model containing seven pistons and ANSYS Workbench is used to manage the model through setting the parameters of different materials and constrains of the cylinder. It's promising to provide a theoretical basis when optimizing the design of the axial piston pump and to offer new ideas and methods for the study of reliability and fatigue durability on the axial piston pump.
Abstract Background The preoperative platelet count and serum tumor markers have been shown to correlate with the lymph node metastasis (LNM) of gastric cancer (GC).The aim of this study was to establish a risk assessment model that incorporated the platelet-to-albumin ratio (PAR) for LNM of GC and to evaluate its clinical significance. Methods The clinical data of 314 patients with GC diagnosed by postoperative pathology were collected in our hospital. According to whether there was LNM in the pathological specimens of the operation, the patients were divided into the group without LNM and the group with LNM. Univariate analysis and multivariate logistic regression were used to analyze the relevant factors affecting LNM of GC and to identify independent risk factors for LNM of GC. The random forest algorithm was used to extract the important risk factors of LNM in GC. A nomogram model of the risk assessment of LNM of GC was constructed by the “rms” package of R software. The receiver operating characteristic (ROC) curve was used to evaluate the accuracy, sensitivity and specificity of the model for predicting LNM of GC. Results Univariate analysis showed that the factors associated with LNM of GC were sex (P=0.015), smoking (P=0.027), lesion size (P=0.000), pathological type (P=0.001), differentiation degree (P=0.000), infiltration depth (P=0.000), PAR (P=0.005), carbohydrate antigen (CA) 19-9 (P=0.017), CA125 (P=0.000) and CA72-4 (P=0.005). Multivariate logistic regression showed that lesion size [odds ratio (OR): 1.322; P = 0.000], differentiation degree (OR: 0.582; P = 0.001), and depth of invasion (OR: 1.734; P = 0.000) were independent risk factors for LNM in GC. The risk assessment model of LNM in GC was established according to the ranking of variables shown by the random forest algorithm. The C statistic of the model evaluation was 0.827, the sensitivity was77.2%, and the specificity was 74.8%. Conclusion Lesion diameter larger than 2.65 cm, poor differentiation and deep infiltration were high-risk factors for LNM in GC. The nomogram model constructed by PAR, lesion size, infiltration depth, CA125, CA19-9, CA72-4, and differentiation degree, can well predict the risk of LNM in GC.
Integrated sensing and communication (ISAC) has been regarded as a key technology for 6G wireless communications, in which large-scale multiple input and multiple output (MIMO) array with higher and wider frequency bands will be adopted. However, recent studies show that the beam squint phenomenon can not be ignored in wideband MIMO system, which generally deteriorates the communications performance. In this paper, we find that with the aid of true-time-delay lines (TTDs), the range and trajectory of the beam squint in near-field communications systems can be freely controlled, and hence it is possible to reversely utilize the beam squint for user localization. We derive the trajectory equation for near-field beam squint points and design a way to control such trajectory. With the proposed design, beamforming from different subcarriers would purposely point to different angles and different distances, such that users from different positions would receive the maximum power at different subcarriers. Hence, one can simply localize multiple users from the beam squint effect in frequency domain, and thus reduce the beam sweeping overhead as compared to the conventional time domain beam search based approach. Furthermore, we utilize the phase difference of the maximum power subcarriers received by the user at different frequencies in several times beam sweeping to obtain a more accurate distance estimation result, ultimately realizing high accuracy and low beam sweeping overhead user localization. Simulation results demonstrate the effectiveness of the proposed schemes.
In this paper, we propose a practical integrated sensing and communications (ISAC) framework to sense dynamic targets from clutter environment while ensuring users communications quality. To implement communications function and sensing function simultaneously, we design multiple communications beams that can communicate with the users as well as one sensing beam that can rotate and scan the entire space. To minimize the interference of sensing beam on existing communications systems, we divide the service area into sensing beam for sensing (S4S) sector and communications beam for sensing (C4S) sector, and provide beamforming design and power allocation optimization strategies for each type sector. Unlike most existing ISAC studies that ignore the interference of static environmental clutter on target sensing, we construct a mixed sensing channel model that includes both static environment and dynamic targets. When base station receives the echo signals, the mean phasor cancellation (MPC) method is employed to filter out the interference from static environmental clutter and to extract the effective dynamic target echoes. Then a complete and practical dynamic target sensing scheme is designed to detect the presence of dynamic targets and to estimate their angles, distances, and velocities. In particular, dynamic target detection and angle estimation are realized through angle-Doppler spectrum estimation (ADSE) and joint detection over multiple subcarriers (MSJD), while distance and velocity estimation are realized through the extended subspace algorithm. Simulation results demonstrate the effectiveness of the proposed scheme and its superiority over the existing methods that ignore environmental clutter.
The system of gas-liquid two-phase bubbly flows is widely found in many industrial fields, such as nuclear energy, chemical, petroleum, and refrigeration. Bubbly two-phase flows measuring including detection and tracking affects the specific engineering problem solving to a great extent. The particle tracking velocity (PTV) algorithm is generally used for the tracking of the particles in the flow field. However, it does not take the shape change of particles into account in the process of flow. In this paper, a kind of bubble feature matching method based on ORB algorithm is proposed, and the edge detection method of findContours in OpenCV is used to extract the bubble contour in the image. The proposed algorithm implements the trajectory tracking of the bubbles with shape change when moving up in liquid. The feasibility of bubble trajectory tracking is shown by displaying of different bubble tracks in the plan, 3D plots and contour changing plots.
SRY-box transcription factor 21 antisense divergent transcript 1 (SOX21-AS1) is a multifaceted long non-coding RNA (lncRNA) that plays diverse roles in both neoplastic conditions and Alzheimer's disease.Its aberrant expression intricately regulates a wide spectrum of cellular processes, spanning from epithelial-mesenchymal transition (EMT), apoptosis, migration, metastasis, and stemness to drug resistance.SOX21-AS1 achieves these effects through its involvement in the competitive endogenous RNA (ceRNA) network, modulation of downstream genes, and regulation of critical pathways, including PI3K/AKT, Hippo, Wnt/β-catenin, and ERK signaling.Of significant clinical relevance, SOX21-AS1 expression has shown robust correlations with various clinical-pathological features.Moreover, it has demonstrated promising prognostic and diagnostic potential across a spectrum of tumors, as evidenced by existing literature and TCGA pan-cancer analyses.In Alzheimer's disease, SOX21-AS1 assumes a distinctive role.It influences neuronal viability, apoptosis, and oxidative stress by interacting with miR-107 and miR-132, and affecting the PI3K/AKT and Wnt signaling pathways.This comprehensive review sheds light on the functions of SOX21-AS1 and the regulated mechanisms underpinning its impact on neoplastic conditions and Alzheimer's disease.It underscores the clinical significance of SOX21-AS1 and positions it as a promising therapeutic target in both the oncological and neurodegenerative domains.
Integrated sensing and communication (ISAC) has been regarded as a key technology of 6G wireless communications, in which large-scale multiple input and multiple output (MIMO) with higher and wider frequency bands will be adopted. However, recent studies show that the beam squint phenomenon can not be ignored in the wideband MIMO system, which generally deteriorates the communications performance. In this paper, we find that with the aid of the true-time-delay lines (TTDs), the range and trajectory of the beam squint in the near-field communications systems can be freely controlled, and hence it is possible to reversely utilize the beam squint for user localization. We derive the trajectory equation for near-field beam squint points and design a way to control such trajectory. With the proposed design, beamforming from different subcarriers would purposely point to different angles and different distances, such that users from different positions would receive the maximum power at different subcarriers. Hence, one can simply localize multiple users from the beam squint effect in frequency domain, and thus reduce the timing overhead as compared to the conventional beam sweeping approach. Simulation results demonstrate the effectiveness of the proposed scheme.
In view of valve problems occurred in water supply network and based on research and field investigation,buried resilient seated gate valve system was developed,and its application in water supply network was analyzed.The related standards of buried resilient seated gate valves are described,the valve problems occurred in water supply network are discussed,and relevant suggestions are made.
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