[en] Objective: To investigate the possible causes and the intervention measures of acute in-stent thrombosis after stent angioplasty for intracranial artery stenosis. Methods: A total of 102 patients with symptomatic atherosclerotic intracranial artery stenosis, who received Winspan stent angioplasty, were collected. Among the 102 patients, acute in-stent thrombosis occurred in 5, and their clinical data were retrospectively analyzed. Results: In the 5 patients, the acute in-stent thrombosis occurred within the period from 5 minutes to 6 hours after stent implantation. Vascular re-canalization was successfully achieved in all 5 patients after intra-arterial thrombolysis therapy, and no thrombolysis-related complication occurred. Conclusion: The causes of acute in-stent thrombosis after stent angioplasty for intracranial artery stenosis are various, and active intervention measures can reduce the incidence of adverse outcomes. (authors)

[en] The flexible rolling process (FRP) is a novel three-dimensional (3D) forming process that combines the multipoint and traditional rolling forming. The principle of FRP is based on thickness thinning, so the deformation path significantly impacts the forming effect. In this study, the multistep forming process with different deformation paths was introduced to improve the forming effect of FRP. For instance, with the convex surface part, three finite element models of multistep FRP (MSFRP) were established. The corresponding numerical simulations and forming experiments performed among different deformation paths showed the surface part with a longer effective forming region was obtained and the forming regions with more steps in MSFRP were smoother. Thus, the sheet-metal utilization rate was greatly improved. Moreover, the MSFRP can improve the longitudinal bending effect dramatically and thereby endowing the forming part with a better forming effect. Therefore, MSFRP is a prospective method for broad applications.

[en] In existing schemes of cold neutron sources, two-phase thermo-siphon loop is widely adopted for its high heat exchange performance. However, the void fraction in moderator may affect the stability of moderation. In this paper, the single-phase thermo-siphon loop was studied in its performance of dealing with high heat flux in order to replace the two-phase one. A couple method based on iteration, which combines the one-dimensional theoretical formula and three-dimensional numerical simulation, was presented to analyze the feasibility of single-phase moderator cell scheme in CARR cold neutron source. Both macro-performance of the loop and the detailed information such as flow and temperature field inside moderator cell can be analyzed by this method. The results show that the thermo-siphon loop only takes away about 30% of the total heat release. However, with the addition of helium cooling jacket, the rest of heat can be removed by the direct heat transfer between the metal walls and helium gas. The temperature field shows maximum temperatures of liquid hydrogen and walls are 21.7 K and 23.7 K, respectively. The above results indicate that the moderator cell can be cooled adequately, which proves the single-phase thermo-siphon with helium direct cooling as well as the corresponding moderator cell scheme can meet the requirement of CARR project. (authors)

[en] Motivated by the recent studies of the novel asymptotically global AdS${}_4$ black hole with deformed horizon, we consider the action of Einstein–Maxwell gravity in AdS spacetime and construct the charged deforming AdS black holes with differential boundary. In contrast to deforming black hole without charge, there exists at least one value of horizon for an arbitrary temperature. The extremum of temperature is determined by charge q and divides the range of temperature into several parts. Moreover, we use an isometric embedding in the three-dimensional space to investigate the horizon geometry. The entropy and quasinormal modes of deforming charged AdS black hole are also studied in this paper. Due to the existence of charge q, the phase diagram of entropy is more complicated. We consider two cases of solutions: (1) fixing the chemical potential μ; (2) changing the value of μ according to the values of horizon radius and charge. In the first case, it is interesting to find there exist two families of black hole solutions with different horizon radii for a fixed temperature, but these two black holes have same horizon geometry and entropy. The second case ensures that deforming charged AdS black hole solutions can reduce to standard RN–AdS black holes.

[en] We construct a class of counterexamples to cosmic censorship in four dimensional Einstein-Born-Infeld theory with asymptotically anti-de Sitter boundary conditions, and investigate the effect of the Born-Infeld parameter b in comparison with the counterpart of Einstein-Maxwell theory. When a charged massive scalar field is included into the action, we find that this class of counterexamples to cosmic censorship would be removed if the charge of scalar fields is above the bound of charge q${}_w$. In particular, the bound of charge required to preserve cosmic censorship increases with the increasing of Born-Infeld parameter. Meanwhile, we also show the lower bounds on charge-to-mass ratio with the different values of Born-Infeld parameter.

[en] Quantum emitters are an integral component for a broad range of quantum technologies, including quantum communication, quantum repeaters, and linear optical quantum computation. Solid-state color centers are promising candidates for scalable quantum optics due to their long coherence time and small inhomogeneous broadening. However, once excited, color centers often decay through phonon-assisted processes, limiting the efficiency of single-photon generation and photon-mediated entanglement generation. Herein, we demonstrate strong enhancement of spontaneous emission rate of a single silicon-vacancy center in diamond embedded within a monolithic optical cavity, reaching a regime in which the excited-state lifetime is dominated by spontaneous emission into the cavity mode. We observe 10-fold lifetime reduction and 42-fold enhancement in emission intensity when the cavity is tuned into resonance with the optical transition of a single silicon-vacancy center, corresponding to 90% of the excited-state energy decay occurring through spontaneous emission into the cavity mode. Here, we also demonstrate the largest coupling strength (g/2π = 4.9 ± 0.3 GHz) and cooperativity (C = 1.4) to date for color-center-based cavity quantum electrodynamics systems, bringing the system closer to the strong coupling regime.

[en] A simple method is introduced to obtain recycled Nd-Fe-B powders from waste bonded Nd-Fe-B bulk magnets. The main difficulty of the recovery of waste MQ bonded Nd-Fe-B magnets is how to remove the epoxy resins between the magnetic particles and the oxide impurities on the surfaces of the waste magnetic powders. Mixed solvents of acetone, Dimethyl Formamide and N-butyl alcohol were used to dissolve the epoxy resins. Oxide impurities were removed using 0.5% acetic acid/acetone solutions. After these treatments, the carbon and oxygen contents were reduced from 21,200 ppm to 9700 ppm, and from 11,007 ppm to 8177 ppm, respectively. Under optimum processing conditions, the recycled magnetic powders possess improved magnetic properties with M_s of 151.5 emu/g, M_r of 98.0 emu/g, H_cj of 7.1 kOe, and (BH)_max of 13.7 MGOe. These values, compared to the waste magnetic powders, represent increases of 21.2%, 18%, 0 and 34.3%, respectively.

[en] Rechargeable lithium batteries are one of the most appropriate energy storage systems in our electrified society, as virtually all portable electronic devices and electric vehicles today rely on the chemical energy stored in them. However, sub-zero Celsius operation, especially below -20 °C, remains a huge challenge for lithium batteries and greatly limits their application in extreme environments. Slow Li${}^{+}$ diffusion and charge transfer kinetics have been identified as two main origins of the poor performance of RLBs under low-temperature conditions, both strongly associated with the liquid electrolyte that governs bulk and interfacial ion transport. In this review, we first analyze the low-temperature kinetic behavior and failure mechanism of lithium batteries from an electrolyte standpoint. We next trace the history of low-temperature electrolytes in the past 40 years (1983-2022), followed by a comprehensive summary of the research progress as well as introducing the state-of-the-art characterization and computational methods for revealing their underlying mechanisms. Finally, we provide some perspectives on future research of low-temperature electrolytes with particular emphasis on mechanism analysis and practical application. (© 2023 Wiley‐VCH GmbH)

[en] A comprehensive understanding of the organic semiconductor material pentacene is meaningful for organic field-effect transistors (OFETs). Thin films of pentacene are the most mobile molecular films known to date. This paper reported that the pentacene sample was successfully synthesized. The purity of pentacene is up to 95%. The results of a joint experimental investigation based on a combination of infrared absorption spectra, mass spectra (MS), element analysis, x-ray diffraction (XRD) and atom force microscopy (AFM). The authors fabricated OFET with the synthesized pentacene. Its field effect mobility is about 1.23 cm²/(V·s) and on-off ratio is above 10⁶

[en] We report on the fabrication of metallic, ultra-sharp atomic force microscope tips for localized nanoscale infrared (IR) spectrum measurements by using focused electron-beam-induced deposition of platinum or tungsten. The tip length can be controlled by changing the duration time of the electron beam. Probes of 12.0 ± 5.0 nm radius-of-curvature can be routinely produced with high repeatability and near-100% yield. The near-field-enhancement appears stronger at the extremity of the metallic tip, compared with commercial pristine silicon-nitride probe tip. Finally, the performance of the modified metallic tips is demonstrated by imaging PVDF and PMMA thin films, which shows that spatial resolution is greatly enhanced. In addition, the signal intensity of the localized nanoscale IR spectrum is increased offering greater sensitivity for chemical IR imaging. (paper)