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Abstract The air gap magnetic field of a magnetic coupling plays a crucial role in the examination of its static torque and eddy current losses. Precise characterization of the air gap magnetic field is essential for ensuring the accuracy of performance assessments of the magnetic coupling. This study focuses on the cylindrical magnetic coupling as the subject of investigation, employing mathematical analysis and finite element methods to evaluate and quantify the magnetic field properties. The study establishes a mathematical model of the magnetic field of a magnetic coupling based on electromagnetic field principles and the superposition theorem. An analytical formula for the magnetic flux density distribution of the air-gap magnetic field is derived. Subsequently, a three-dimensional magnetic field finite element model is created using the finite element method to numerically calculate the air gap magnetic field and validate the analytical formula. The research also explores the periodic distribution characteristics of the magnetic field in the air gap, analyzing axial differences in magnetic flux density value and direction distribution influenced by end effects.

Objective: This paper puts forward one cylinder driving five-row longan core-removing mechanism for the low production efficiency of the pneumatic longan core-removing mechanism. Methods: The mechanism adopts one cylinder driving five rows handspikes in the direction, which transport longan to core-removing hole, after the longan is cut under the triangular blade, and another cylinder drives five handspikes in the vertical direction in order to remove longan core. Five longan cores is removed one working process, so that the production efficiency is improved. Results: The result of experiments showed that the order of influencing on longan core-removing loss rate is blade thickness, flow rate, mandril diameter, pneumatic pressure and the interaction of flow rate and pneumatic pressure. Conclusion: When blade thickness is fixed at 2.5 mm, mandril diameter at 6.0 mm, pneumatic pressure at 0.6 MPa, flow rate at 6 m3/h, the core-removing loss rate achieves the lowest value, which is 7.04%.

Abstract With the higher requirements of various tactical and technical indicators of the weapon systems, the current research on the ignition and combustion characteristics of different types of solid propellants is not comprehensive. In more complex and harsh environmental conditions, the pressure affects the ignition and combustion characteristics. Therefore, the paper studies the ignition and combustion characteristics of the modified double-base propellants (MDB propellants) and fuel-rich propellants (FR propellants) under low-pressure environment. Combining experiment and theory, the ignition delay time and burning rate of two kinds of solid propellants are compared and analyzed at low pressure by the laser ignition experimental device. The results displayed that the burning flames of the FR and MDB propellant presented evident V-shape and cylindrical, respectively. The flame brightness decreased with the decrease in pressure. With the increase of pressure and heat flux, the ignition delay time of the MDB propellant and the FR propellant decreased. By comparison, Model 2 of the ignition delay time was more effective for the estimation of the ignition delay time of the FR propellant. The experimental results are compared with the three burning rate models, which are the Vielle formula (Model 1), Summerfield formula (Model 2), and B-number burning rate formula (Model 3). The results showed the burning rate was more in accord with Model 3.

In order to solve the failure of support structure of tunnel in high stress soft rock, based on the principle of reasonably releasing the stress in surrounding rocks and reducing the stress of support structure, a hydraulic tunnel graded yielding support structure is proposed. Considering the spatial effect of the excavation surface and the strain softening condition of the surrounding rocks, by analyzing the attenuation law of the virtual supporting force, the static balance equation of stress in the surrounding rocks, the virtual support force and the support reaction force is established. The synergy between the supporting structure and the surrounding rocks at each stage is studied to generate the relationship between the displacement and stress of the surrounding rocks in the whole deformation process of the support structure. The supporting effect of the proposed graded yielding support structure is revealed. The results show that the stress of surrounding rocks is significantly released at the two yielding stages and the deformation characteristics of surrounding rocks are consistent with the yielding characteristics of structure. The simulation results show the consistent variation trend with that of the theoretical values, which verifies the rationality of the theoretical analysis. The proposed yielding support structure can effectively release the stress in the surrounding rocks and reduce the stress of the supporting structure. It can avoid the yield failure of the support structure, solving the support problem of the tunnel in the soft rock with high stress, which can provide theoretical support for the application and development of the support structure.

Background: Rheumatoid arthritis (RA) joint inflammation severely affects joint function and quality of life in patients and leads to joint deformities and limb disability. The non-steroidal anti-inflammatory drugs used in the treatment of RA do not fully control the progression of joint inflammation and bone destruction and have notable adverse reactions. Traditional Chinese medicine formula JuanBiQiangGu Granules (JBQG) are commonly used for the treatment of RA inflammation and delay of bone destruction, but has not been evaluated through high-quality clinical studies. There is a pressing need for well-designed, randomized, parallel, controlled clinical studies to evaluate the exact effect of JBQG on RA joint inflammation and improvement of patient quality of life.Methods: This is a randomized, parallel, controlled clinical study in which 144 patients with rheumatoid arthritis who met the inclusion criteria were randomly assigned to 2 groups in a 1:1 ratio. The JBQG group received methotrexate 7.5 mg qw and JBQG granules 8 mg tid, while the MTX group received methotrexate 7.5 mg qw. The endpoint was 12 weeks after treatment. Relevant indices at baseline, 4 weeks, 8 weeks, and 12 weeks after treatment were observed and recorded, and DAS28-ESR, HAQ-DI, and Sharp scores were recorded for each patient. Blood samples were collected to test for CRP, ESR, TNF-α, IL-1β, IL-6, IL-17, and INF-γ, and adverse reactions and liver and kidney function (AST, ALT, Cr, BUN) were recorded for safety assessment. After 12 weeks of treatment, the effect of JBQG granules on disease activity, improvement in bone damage, and patient quality of life scores and safety in RA patients were evaluated.Results: A total of 144 subjects completed treatment (71 in the JBQG group and 73 in the MTX group) and were included in the analysis. At baseline, there were no significant differences between the groups in terms of the observed indicators (p > 0.05). After treatment, 76.06% of patients in the JBQG group had DAS28-ESR levels below or equal to Low, including 45.07% in Remission and 5.63% in High, compared to 53.1% in the MTX group below or equal to Low, 12.33% in Remission, and 17.81% in High. CRP was significantly reduced (8.54 ± 5.87 vs. 11.86 ± 7.92, p < 0.05, p = 0.005), ESR was significantly reduced (15.1 ± 6.11 vs. 21.96 ± 9.19, p < 0.0001), TNF-α was significantly reduced (1.44 ± 0.83 vs. 1.85 ± 1.07, p < 0.05, p = 0.011), IL-17 was significantly reduced (0.53 ± 0.33 vs. 0.71 ± 0.38, p < 0.05, p = 0.004), and INF-γ was significantly reduced (3.2 ± 1.51 vs. 3.89 ± 1.77, p < 0.05, p = 0.014). The median (IQR) OPG in the JBQG group was 2.54 (2.21–3.01), significantly higher than in the MTX group 2.06 (1.81–2.32), p < 0.0001), and the median (IQR) β-CTX in the JBQG group was 0.4 (0.32–0.43), significantly lower than in the MTX group 0.55 (0.47–0.67), p < 0.0001). The median (IQR) VSA scores were 2 (1–3), a decrease from 3 (2–4) in the MTX group (p < 0.0001). The median (IQR) Sharp scores were 1 (1–2), a decrease from 2 (1–2) in the MTX group, but the difference was not statistically significant (p > 0.05, p = 0.28). The median (IQR) HAQ-DI scores were 11 (8–16), significantly lower than in the MTX group 26 (16–30) (p < 0.0001). The median (IQR) AST in the JBQG group was 16 (12–20), with a significant difference compared to the MTX group 19 (13–25) (p < 0.01, p = 0.004); the median (IQR) ALT in the JBQG group was 14 (10–18), with a significant difference compared to the MTX group 16 (11–22.5) (p < 0.05, p = 0.015). There were no statistically significant differences in Cr or BUN (p > 0.05).Conclusion: JuanBiQiangGu Granules can be used to treat patients with rheumatoid arthritis, alleviate joint inflammation, reduce the incidence of adverse reactions to methotrexate, and has good safety.Clinical Trial Registration:http://www.chinadrugtrials.org.cn/index.html; identifier: ChiCTR2100046373.

In this paper, we extend the self-consistent quasi-particle model proposed by Zong et al. [Phys. Lett. B 711, 65 (2012)] to the case of finite magnetic field. The vacuum infinity zero-point energy is successfully eliminated by introducing a classical thermo-magnetic background field B (T , e B) in the effective Lagrangian based on Zong's method. By considering relativistic Landau energy levels, we have applied the improved quasi-particle model to the case of a two-flavor quark gluon plasma. We obtain a finite partition function and calculate the energy density, pressure and entropy density at zero chemical potential. These results are qualitatively consistent with the results of previous literature works. [ABSTRACT FROM AUTHOR]

Carbon paper is one of the most commonly used materials for the gas diffusion layer of proton exchange membrane fuel cell, and its performance is the premise to ensure the stable operation of the cell. In order to improve the structure and properties of carbon paper and make it better meet the performance requirements of fuel cell, this study was conducted to press different amounts of graphite plates in the carbonization process to control the applied pressure and analyze the microstructure evolution and mechanism of carbon paper under different pressure. In addition, the effects of applied pressure on the in-plane resistivity, pore size distribution, surface roughness and mechanical properties of carbon paper were also studied. The results show that applying pressure helps to restrain the cracking of resin carbon, reduce the generation of cracks and improve graphitization degree of carbon paper to a certain extent. Furthermore, with the increase of applied pressure, the surface roughness of carbon paper is reduced gradually, while the average and maximum apertures also decrease. When the applied pressure reaches 3600 Pa, compared with the samples without pressure, the in-plane resistivity of carbon paper decreases from 17.15 mΩ·cm to 12.79 mΩ·cm, the tensile strength and flexural strength are improved by 150% and 82.9% respectively.

Abstract Background We aimed to determine the efficacy and safety of multiple doses of intravenous tranexamic acid (IV-TXA) on perioperative blood loss in patients with rheumatoid arthritis (RA) who had undergone primary unilateral total knee arthroplasty (TKA). Methods For this single-center, single-blind randomized controlled clinical trial, 10 male and 87 female participants with RA, aged 50–75 years, who underwent unilateral primary TKA were recruited. The patients received one dose of 1 g IV-TXA 10 min before skin incision, followed by articular injection of 1.5 g tranexamic acid after cavity suture during the surgery. The patients were randomly assigned (1:1) into two groups and received an additional single dose of IV-TXA (1 g) for 3 h (group A) or three doses of IV-TXA (1 g) for 3, 6, and 12 h (group B) postoperatively. Primary outcomes were total blood loss (TBL), hidden blood loss (HBL), and maximum hemoglobin (Hb) level decrease. Secondary outcomes were transfusion rate and D-dimer levels. All parameters were measured postoperatively during inpatient hospital stay. Results The mean TBL, HBL, and maximum Hb level decrease in group B (506.1 ± 227.0 mL, 471.6 ± 224.0 mL, and 17.5 ± 7.7 g/L, respectively) were significantly lower than those in group A (608.8 ± 244.8 mL, P = 0.035; 574.0 ± 242.3 mL, P = 0.033; and 23.42 ± 9.2 g/L, P = 0.001, respectively). No episode of transfusion occurred. The D-dimer level was lower in group B than in group A on postoperative day 1 (P 0.05). Conclusion In patients with RA, three doses of postoperative IV-TXA further facilitated HBL and Hb level decrease without increasing the incidence of adverse events in a short period after TKA. Trial registration The trial was registered in the Chinese Clinical Trial Registry ( ChiCTR1900025013 ).

Background: The chronic pain arising from knee osteoarthritis (KOA) is a prevalent clinical manifestation. As a traditional Chinese approach, electroacupuncture (EA) has a positive influence in relieving chronic pain from KOA. The study aims to explore functional connectivity (FC) and effective connectivity (EC) alterations induced by EA in anterior cruciate ligament transection (ACLT) rat model of KOA using resting-state functional magnetic resonance imaging (fMRI). Methods: After the establishment of ACLT, rats were randomly divided into the EA group and the sham-EA group. The EA group received EA intervention while the sham-EA group received sham-intervention for 3 weeks. Mechanical pain threshold (MPT) assessment was performed before and after intervention, and fMRI was conducted after intervention. Results: EA intervention effectively relieved pain in post-ACLT rats. Results of rest-state functional connectivity (rs-FC) analysis revealed that compared with the sham-EA group, the EA group had higher FC between the right raphe and the left auditory cortex, the left caudate_ putamen and the left internal capsule (IC), as well as the right zona incerta (ZI) and the left piriform cortex, but lower FC between the right raphe and the left hippocampus ventral, as well as the right septum and the left septum. Furthermore, Granger causality analysis (GCA) found the altered EC between the right septum and the left septum, as well as the left IC and the right septum. Conclusion: The results confirmed the effect of EA on analgesia in post- ACLT rats. The alterations of FC and EC, mainly involving basal ganglia and limbic system neural connections, might be one of the neural mechanisms underlying the effect of EA, providing novel information about connectomics plasticity of EA following ACLT. [ABSTRACT FROM AUTHOR]

Objective To identify the efficacy and safety of multiple doses of intravenous tranexamic acid (IV‐TXA) following primary total knee arthroplasty (TKA) with a tourniquet. Methods This is a single‐blind randomized controlled study that recruited osteoarthritis patients who had undergone primary unilateral TKA from May 2019 to May 2020 at our medical center. A total of 300 patients were randomly divided into three groups to receive: one dose (1 g) of IV‐TXA before skin incision combined with one dose (1.5 g) of intra‐articular tranexamic acid（IA‐TXA) followed by a single dose of IV‐TXA (1 g) for 3 h (group A); two doses of IV‐TXA (1 g) for 3 and 6 h (group B); or three doses of IV‐TXA (1 g) for 3, 6, and 12 h (group C) postoperatively. TKA with a tourniquet was performed by the same surgical team. The primary outcomes were total blood cell loss (TBL), hidden blood loss (HBL), maximum hemoglobin (Hb) drop, and transfusion rate. Secondary outcomes were levels of C‐reactive protein (CRP) and D‐dimer, and the incidence of postoperative complications. One‐way analysis of variance, subgroup analysis, and multivariate correlation analysis were used to calculate the differences among the three groups. Results The study included 56 male and 244 female patients aged 60–80 years. The mean TBL, the mean HBL, and the maximum Hb drop in group C (471.2 ± 190.6 mL, 428.4 ± 190.3 mL, and 21.2 ± 3.8 g/L, respectively) were significantly lower than those in groups B (563.4 ± 224.6 mL, P = 0.030; 519.9 ± 226.4 mL, P = 0.033; and 23.2 ± 4.1 g/L, P = 0.001, respectively), and A (651.6 ± 254.1 mL, P 0.05). In addition, there were positive correlations between the HBL and the tourniquet inflation time (r = 0.844, P