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By adjusting the inter-wire arc (IWA) posture, the skew-coupling arc (SCA) is proposed to address the polar effect in the cross arc, enabling decoupling control of heat, force, and mass transfer. Despite the advancement, the arc stabilization mechanism in the SCA remains poorly understood, hindering its application as a heat source in welding or additive manufacturing. To elucidate this mechanism, various influencing factors such as power supply characteristics, shielding gas composition, IWA posture, and plasma main arc (PMA) were analyzed. An electrical signal and high-speed camera synchronous acquisition system was utilized to analyze current-voltage waveforms and arc shapes. The results indicate that the arc stability of the SCA can be enhanced by ensuring specific external conditions. Constant voltage power supply enhances the self-regulating effect of the IWA, maintaining the IWA and the PMA in a hybrid state at all times. Introducing an oxidizing gas to the shielding gas can effectively suppress cathode spot climbing and stabilize the IWA. The vertical spacing between wires directly impacts the PMA deflection, while the wire horizontal angle has a lesser effect. The heat-regulating effect of the PMA column boosts the arc length regulation by the IWA. The current and the ion gas flow rate in the PMA minimally influence the SCA stability. These findings can provide a solid foundation for further applications of the SCA as heat source.

This paper describes the droplet transfer behavior and weld formation of laser-arc hybrid welding with cable-type welding wire (CWW). The droplet transfer behavior was photographed in real time by using a high-speed camera. The effects of energy parameters on arc morphology, droplet transfer behavior and weld formation were studied through experimental and theoretical analyses. The results show that the arc is deflected toward the laser direction, and the deflection degree increases with increasing laser power. The interaction between the laser and arc is enhanced by rotating the arc. The rotating arc enhances the interaction between plasma, the arc is more compressed and the arc volume is smaller as the welding current increases. The droplet transfer frequency increased with increasing laser power and decreased after reaching the critical value. The reaction force of metal vapor and electromagnetic force affect the droplet transfer frequency, and the maximum frequency of droplet transfer is 180.8 Hz under a laser power of 2.5 kW. The rotational force promotes molten droplet transfer and maintains the axial transition, and the welding current has a strong effect on increasing the droplet transfer frequency. The influence of laser power on weld penetration is greater than that of welding current, the weld penetration increases significantly with increasing laser power, and the cross section of the weld seam exhibits laser-arc hybrid welding characteristics.

Background: Jingshu Keli (or Jingshu granules), a traditional Chinese medicine, are widely used for treating cervical spondylotic radiculopathy in China; however, no randomized, double-blind, controlled study has verified their effectiveness. Purpose: To evaluate the efficacy and safety of Jingshu Keli for the treatment of cervical spondylotic radiculopathy in a randomized controlled trial. Design: From August 2015 to July 2017, a multicenter, randomized, double-blind, placebo-controlled trial was conducted at 13 large- and medium-sized hospitals in China. Patient sample: A total of 360 and 120 patients were initially enrolled in the Jingshu and control groups, respectively; 386 patients completed the study, with 299 in the Jingshu group and 87 in the control group. Outcome measures: The main index for evaluating the curative effect was the pain score on a visual analogue scale (VAS; 0–100 points). Methods: All patients were administered a bag of Jingshu Keli or placebo 3 times a day for 4 weeks, and were interviewed at the second and fourth weeks. The decrease in pain scores and rate of change in pain scores after treatment were calculated, related laboratory indices were reviewed, and adverse reactions were recorded. Results: In the Per Protocol Set (PPS) analysis, the baseline pain VAS scores in the control and Jingshu groups were 49.31 ​± ​6.97 and 50.06 ​± ​7.33, respectively, with no significant difference between the groups (P ​> ​0.05). While there were no differences at 2 weeks between groups, at four weeks the pain VAS scores in the control and Jingshu groups decreased by 12.86 ​± ​13.45 and 22.72 ​± ​15.08, respectively relative to the values at baseline, with significant group differences (P ​

The air-core reactor has the advantage of good linearity and low noise, however the problem of large space occupation. Power filter with the air-core reactor is indispensable with the widespread use of the power electronic devices in electrified transportation system and urban distribution system. It is hoped that the air-core reactor can be integrated in the transformer to reduce the space while the good performance of the power filter is kept. In this paper, a non-orthogonal decoupling (NOD) method is proposed, as well as a new design to integrate the linear reactor based on it. Further research including the structure of the integrated linear reactor (ILR) windings, the mechanism of the power decoupling among windings and the calculation of the inductance values are introduced. A 3-D finite-element simulation model is established which demonstrate the correctness of the analysis and provided an assistant approach of engineering design. Finally, the prototype system of the box-type distribution substation with integrated filter reactor and its experimental date are shown, the distribution transformer with integrated air-core reactors are confirmed to have excellent performance.

The purity of circulating hydrogen after desulfurization is mainly affected by the content of inert component methane. Based on this, the prediction method of methane content in circulating hydrogen after desulfurization is studied. From the process of hydrogen facing system, it can be seen that the methane content in circulating hydrogen after desulfurization is mainly affected by methane solubility, feed oil density, new hydrogen components, reaction temperature, hydrogen consumption per ton of oil and catalyst components. In the process of predicting the change of methane content in circulating hydrogen after desulfurization, the methane content in circulating hydrogen after desulfurization was detected under different working conditions (different influencing factors) by means of spectral absorption method and methane content detection device. According to the real-time test results, the influence of different working conditions on methane content in circulating hydrogen after desulfurization was obtained. Based on this, the change of methane content in circulating hydrogen after desulfurization was predicted under the fluctuating conditions of various influencing factors. The results show that the methane content in recycled hydrogen after desulfurization increases with the increase of methane content, reaction temperature and the addition of higher active catalyst in the reactor. When the density of feed oil is 892–909 kg/m3, the change of composition is small, which has little effect on the circulating hydrogen methane content after desulfurization. Keywords: Desulfurization, Circulating hydrogen, Methane content, Prediction, Hydrogen system, Spectral absorption method

Background: Forkhead box protein f1 (Foxf1) is associated with cell differentiation, and may be a key player in bone homoeostasis. However, the effect of Foxf1 on osteogenesis of bone marrow-derived mesenchymal stem cells (BMSCs) and ovariectomy-induced bone loss, as well as its clinical implications, is unknown. Methods: By quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and western blotting, we assayed Foxf1 expression in bone tissue, BMSCs, and bone marrow-derived macrophages (BMMs), derived from ovariectomised (OVX) mice, and during osteogenic differentiation and osteoclast differentiation. Using a loss-of-function approach (small interfering RNA [siRNA]-mediated knockdown) in vitro, we examined whether Foxf1 regulates osteoblast differentiation of BMSCs via the Wnt/β-catenin signalling pathway. Furthermore, we assessed the anabolic effect of Foxf1 knockdown (siFoxf1) in OVX mice in vivo. We also assayed the expression of Foxf1 in bone tissue derived from postmenopausal osteoporosis (PMOP) patients and its link with bone mineral density (BMD). Finally, we examined the effect of Foxf1 knockdown on the osteoblastic differentiation of human BMSCs. Findings: Foxf1 expression was significantly increased in bone extract and BMSCs from OVX mice and gradually decreased during osteoblastic differentiation of BMSCs but did not differ significantly in OVX mouse-derived BMMs or during osteoclast differentiation. In vitro, Foxf1 knockdown markedly increased the expression of osteoblast specific genes, alkaline phosphatase (ALP) activity, and mineralisation. Moreover, siFoxf1 activated the Wnt/β-catenin signalling pathway. The siFoxf1-induced increase in osteogenic differentiation was partly rescued by inhibitor of Wnt signalling (DKK1). In OVX mice, Foxf1 siRNA significantly reduced bone loss by enhancing bone formation. Foxf1 expression levels negatively correlated with reduced bone mass and bone formation in bone tissue from PMOP patients. Finally, Foxf1 knockdown significantly promoted osteogenesis by human BMSCs. Interpretation: Our findings indicate that Foxf1 knockdown promotes BMSC osteogenesis and prevents OVX-induced bone loss. Therefore, Foxf1 has potential as a biomarker of osteogenesis and may be a therapeutic target for PMOP. Keywords: Foxf1, Osteogenic differentiation, Mesenchymal stem cells, Postmenopausal osteoporosis, Bone metabolism