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[en] Structural inhomogeneity is found to be a promising way to overcome intrinsic brittleness and to improve the plasticity of metallic glasses (MGs), although such inhomogeneity has not been well-understood. In this study, quantitative observations and theoretical explanations on the structural inhomogeneity were presented for Al_8_8Ce_8Co_4 MG. Applying a technique called energy filtered electron diffraction (EFED), different medium-range orders (MROs) reflected from conspicuous and inconspicuous prepeaks, were observed, which, following reduced pair distribution functions obtained from the EFED measurement, correspond to different short-range orders (SROs). Then using reverse Monte Carlo (RMC) simulation, the structural inhomogeneity is attributed to diversity of Al−Co clusters, which lead to loosely and densely packed local atomic structures and contribute to soft and hard regions, as evidenced by synchrotron radiation X-ray diffraction, dynamic mechanical analysis and nano-indentation. The obtained structural essence of intrinsic inhomogeneity in MGs lays the foundation for further understanding and designing MGs with high plasticity, by adjusting properly inhomogeneous structure.
[en] Objective: To study retrospectively the curative effect of emergent transcatheter arterial embolization (TAE)on raptured liver cancer with hemorrhage. Methods: Twenty-three patients with rupture of liver cancer were emergent treated with TAE for massive hemorrhage. Results: Twenty-two patients were treated by TAE effectively with good hemostasis and without recurrence of bleeding as well as liver failure, except one referred for surgery, clue to anomalous vascular route leading to failure of catheterization. Nine of 22 patients accepted more than one time of TAE according to the curative effect and progress of the disease, but reduction of tumor size or necrosis could be achieved in all these patients. Conclusions: Emergent TAE is an effective treatment for ruptured liver cancer with hemorrhage, having good effect of hemostasis and providing the possibility for subsequent treatment. (authors)
[en] Objective: To study the diagnostic method and bleeding mechanism of the hemorrhagic moyamoya disease. Methods: Head CT, cerebral arteriography for all and partial lumbar CSF (cerebral spinal fluid) centesis was undertaken in 67 cases of intracranial hemorrhage. Results: 67 cases of hemorrhagic moyamoya disease always involved unilateral or bilateral internal carotid and/or vertebral arterial branches with abnormal hyperplasia of small vessels at the same area. CT scan showed intracranial hemorrhagic foci in different parts clearly. Vasculitis caused by immunologic effect led to cerebral arterial stenosis or occlusion with compensatory small vascular hyperplasia. The mechanism of thinning of these vascular walls enlargement of vascular lumen, rupture of miliary or cystic aneurysms and infraependymal infarctions were due to bleeding and rebleeding. Conclusion: Percutaneous pancerebral arteriography is the main diagnostic method for Moyamoyas disease
[en] We propose a bidirectional quantum secure direct communication (QSDC) network protocol with the hyperentanglment in both the spatial-mode ad the polarization degrees of freedom of photon pairs which can in principle be produced with a beta barium borate crystal. The secret message can be encoded on the photon pairs with unitary operations in these two degrees of freedom independently. Compared with other QSDC network protocols, our QSDC network protocol has a higher capacity as each photon pair can carry 4 bits of information. Also, we discuss the security of our QSDC network protocol and its feasibility with current techniques. (general)
[en] We propose a two-step quantum secure direct communication (QSDC) protocol with hyperentanglement in both the spatial-mode and the polarization degrees of freedom of photon pairs which can in principle be produced with a beta barium borate crystal. The secret message can be encoded on the photon pairs with unitary operations in these two degrees of freedom independently. This QSDC protocol has a higher capacity than the original two-step QSDC protocol as each photon pair can carry 4 bits of information. Compared with the QSDC protocol based on hyperdense coding, this QSDC protocol has the immunity to Trojan horse attack strategies with the process for determining the number of the photons in each quantum signal as it is a one-way quantum communication protocol. (general)
[en] Defect evolution in a single crystal silicon which is implanted with hydrogen atoms and then annealed is investigated in the present paper by means of molecular dynamics simulation. By introducing defect density based on statistical average, this work aims to quantitatively examine defect nucleation and growth at nanoscale during annealing in Smart-Cut"® technology. Research focus is put on the effects of the implantation energy, hydrogen implantation dose and annealing temperature on defect density in the statistical region. It is found that most defects nucleate and grow at the annealing stage, and that defect density increases with the increase of the annealing temperature and the decrease of the hydrogen implantation dose. In addition, the enhancement and the impediment effects of stress field on defect density in the annealing process are discussed. (paper)
[en] The quenching and partitioning (QP) steels have received much attention due to its high strength and good ductility, which results from deformation induced martensitic transformation (DIMT). However, due to the stress state, temperature and strain rate dependent DIMT behavior, the DIMT related flow behavior of QP steels might be more complex than other advanced high strength steels (AHSS) without martensitic transformation. During forming process of such materials (non-linear loading process), effects of DIMT behavior and DIMT related flow behavior on springback prediction are still unknown. In this paper, we focused on the martensitic transformation behavior of QP steels under complex loading (linear loading and cyclic loading). The X-ray diffraction and digital image correlation techniques were performed to monitor the retained austenite evolution and strain history of the specimen, respectively. Then, flow behaviors of QP sheets steels subjected to complex loading are analyzed and compared with DP980 sheets steels (without DIMT). Finally, modified Yoshida and Uemori model calibrated by two different cyclic loading tests, i.e., tension-compression test and cyclic shear test, are adopted in this study to investigate the stress state dependent DIMT effect on springback prediction. The results show, for QP steels, the DIMT is stress state dependent. Accordingly, compared with DP steels, its flow behavior exhibits remarkable stress state sensitivity. Due to these special DIMT behavior and flow behavior of QP steels, its springback prediction should be treated differently compared with DP steels.
[en] The structural, magnetic and electronic properties of Co2MnGe0.75Ga0.25 have been studied by first-principles calculations. Co2MnGe0.75Ga0.25 is found to be nearly half-metallic. The calculated lattice constant and magnetic moments are found to be in good agreement with experiments. Furthermore, we investigate the effect of pressure on the electronic structure and magnetic properties of Co2MnGe0.75Ga0.25. The calculated results show a nearly half-metallic to half-metallic (HM) transition at 12 GPa. Then the half-metal to metal transition is observed at 97 GPa. The calculations show that pressure mainly affects the minority spin states, leading to a slight reconstruction of the minority spin bands with a shift in the Fermi level driving the above-mentioned transition. - Highlights: • A nearly half-metallic to half-metallic transition is observed at 12 GPa. • The half-metal to metal transition is observed at 97 GPa. • The total magnetic moment decreases with the increasing pressure. • The pressure mainly affects the minority spin states
[en] A new polyurethane foam with superhydrophobicity and excellent lipophilicity is presented and demonstrated experimentally in this work. The superhydrophobic foam is synthesized by dip coating the polyurethane foam with a mixture solution of silicone resine and silicon dioxide nanoparticles. Its superhydrophobic and oleophilic capacity is characterized and verified via the SEM images, the water contact angle measurement, the adsorption tests and recyclability tests for water and some typical oils. Combining with the vacuum assisted oil-water separation technology (VAST), continuous recovery of oil spill at the lab scale is realized on the new superhydrophobic foam. Moreover, the break through pressure for water penetrating through the superhydrophobic foam is determined experimentally and referred as the maximum operation pressure in the VAST. (paper)
[en] To evaluate the clinical value of unenhanced magnetic resonance angiography (MRA) at 3.0 T for the diagnosis and therapeutic planning of patients with subarachnoid haemorrhage (SAH). A total of 165 patients with SAH were referred for three-dimensional time-of-flight MRA (3D-TOF-MRA) before digital subtraction angiography (DSA). For each aneurysm, 3D-TOF-MRA was used to determine whether the aneurysm was suitable for coil placement with or without balloon/stent-assisted coiling, surgical clipping or conservative treatment. Treatment planning with 3D-TOF-MRA was compared with actual treatment decisions or treatment that had been carried out in each aneurysm decided using DSA. The aneurysm-based evaluation yielded accuracy of 96.9%, sensitivity of 97.6%, specificity of 93.1%, positive predictive value (PPV) of 98.8% and negative predictive value (NPV) of 87.1%, in the detection of intracranial aneurysms. Treatment planning could be correctly made on the basis of aneurysm anatomy and working view by volume rendering (VR) 3D-TOF-MRA with accuracy, sensitivity, specificity, PPV and NPV of 94.9%, 94.0%, 100%, 100% and 74.4%, respectively, on a per aneurysm-based evaluation. VR 3D-TOF-MRA offers high diagnostic accuracy in the detection of ruptured intracranial aneurysms, and appears to be an effective treatment planning tool for most patients with SAH. (orig.)