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Magnetic field assisted welding could suppress defects and improve weld bead properties obviously. In this paper, a full factorial experiment with coaxial magnetic field assisted welding was conducted to study the mechanism of the magnetic field on the dissimilar laser wire feed welding brazing profile of aluminum and copper. Furthermore, a three dimensional numerical simulation model was developed to reveal the influence of the magnetic field on the weld bead. It was found that with the magnetic flux density increase from 10 mT to 50 mT, the properties of the weld bead were improved significantly, and the wetting angle decreased from 53°to 26°, the main fluid flow direction of the weld bead changed in to horizontal direction. Meanwhile, EDS and XRD results showed that the main intermetallic compounds (IMC) of Al2Cu and CuZn composition changed to Al4.2Cu3.2Zn0.7 in welding beads. Computed and measured distortions illustrated good agreement in the fusion zone.

Yu Chen, 1–3,* Wei Zhu, 4,* Fan Shu, 5 Yan Fan, 1, 2 Ning Yang, 1, 2 Tao Wu, 1, 2 Le Ji, 1, 2 Wei Xie, 1, 2 Rengui Bade, 1, 2 Shuyuan Jiang, 1, 2 Xiaolei Liu, 1, 2 Guo Shao, 1–3 Gang Wu, 1, 2 Xiaoe Jia 1–3 1Biomedicine Research Center, Neuroscience Institute, Baotou Medical College, Baotou 014040, People’s Republic of China; 2Inner Mongolia Key Laboratory of Hypoxic Translational Medicine, Baotou Medical College, Baotou 014040, People’s Republic of China; 3Beijing Key Laboratory of Hypoxic Conditioning Translational Medicine, Xuanwu Hospital, Capital Medical University, Beijing, People’s Republic of China; 4School of Pharmacy, Baotou Medical College, Baotou 014040, People’s Republic of China; 5Third Hospital of Baotou, Baotou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xiaoe Jia Email evangeline2004@163.comGang Wu Tel/Fax +86-472-7167830Email wugang0525@163.comIntroduction: Rare-earth nanoparticles in the environment and human body pose a potential threat to human health. Although toxic effects of rare-earth nanoparticles have been extensively studied, the effects on the early development are not well understood. In this study, we attempted to explain the toxic effects of neodymium oxide (Nd 2O 3) nanoparticles on early development.Methods: We added the Nd 2O 3 nanoparticles at different concentrations and recorded the mortality and malformation rate per 24 hrs under a microscope. The live embryos treated with Nd 2O 3 nanoparticles were imaged as movies and Z step lapses with a confocal microscope, and heart rates were counted for 30 s to measure the cardiac function. The live Tg (Flk1:EGFP) transgenic embryos exposed to Nd 2O 3 nanoparticles were observed under confocal microscope to measure the cerebrovascular development. Subsequently, we extracted the total protein for Western blot at 5 days post-fertilisation (dpf). Embryos were collected to undergo TUNEL staining for apoptosis detection.Results: Nd 2O 3 nanoparticles disturbed embryo development at high concentrations (> 200 μg/mL). The mortality and malformation rate gradually increased in a dose-dependent manner by morphological observation, while the Nd 2O 3 median lethal concentration (LD50) was 203.4 μg/mL at 120 hrs post-fertilisation (hpf). Furthermore, the Nd 2O 3-treated embryos showed severe arrhythmia and reduced heart rate. We also observed the markedly cerebrovascular disappearance at middle concentration (100 and 200 μg/mL). The downregulated autophagy flux in brain blood vessels and increased apoptosis level in neurons might affect vessels sprouting and contribute to the vanished cerebrovascular.Conclusion: The results suggested that the embryos exposed to Nd 2O 3 activated the apoptosis pathway and induced toxicity and abnormal cardiac/cerebrovascular development.Keywords: Nd 2O 3, zebrafish, toxicity, arrhythmias, cerebrovascular

To meet the ever-increasing air traffic flow demand for flight track prediction accuracy in Air Traffic Control, according to the standard flight profile and the real flight plan, the Total-Energy Model and related performance parameters in the BADA database were used to perform numerical simulations on the takeoff phase of the aircraft. We compared the predicted altitude, speed, and voyage results with the actual radar track data simultaneously acquired by regional Air Traffic Control systems in Shenyang, etc., and analyzed the sources of errors. And this would further dig the aircraft intention information and extract the empirical parameters to optimize the aircraft climb profile. The optimized model was used to simulate and predict real flights of different aircraft and different landing airports. The results show that the climbing profile optimization strategy is feasible and effective, and the optimized track prediction accuracy is obviously improved.

NiCoCrAlYTa/TaC metal matrix composite coatings were prepared on single crystal superalloy (SX) using electrospark deposition (ESD) to improve its high temperature performance. The effect of TaC addition on the coating microstructure, oxidation behavior, wear resistance and physical properties of electrode were investigated. The results showed that, with the addition of TaC particles, the density of electrode increased, while the thermal conductivity and thermal diffusivity decreased. In the electrode, TaC particles were distributed around or embedded into the NiCoCrAlYTa powders, while in ESD coatings, they were distributed homogeneously in both dendrite cores and interdendritic regions. The generation of β-NiAl phase in ESD coating was prevented by adding TaC particles. During 1000 °C/100 h oxidation, the mass gain of coating with TaC addition was lower than that without TaC addition during the first 40 h, and then became higher. The oxidative products were similar, except that θ-Al2O3 was relatively more in coating without TaC, while Y3Al5O12 was more in coating with TaC addition. The microhardness and wear resistance in both coatings decreased after oxidation, however, it was on the same level for NiCoCrAlYTa coating before oxidation and NiCoCrAlYTa/TaC coating after oxidation. Thus, the overall high temperature performance of the coatings was improved due to the addition of TaC particles.