Environmental pollution and energy consumption problems today are seriously affecting people’s lives. In this paper, a new magnesium AZ31B matrix syntactic foam (MMSF) prepared by gravity penetration with hollow alumina microspheres as reinforcement was simulated using ANSYS Workbench for the lightweight design of vehicles. The mechanical properties and heat conductivity of MMSFs prepared by hollow microspheres with different diameters and volume fractions before and after heat treatment were investigated using finite element analysis. The simulation results showed that the MMSF prepared by hollow microspheres with a diameter of 3.6 mm and a volume fraction of 40% had the best mechanical properties and heat conductivity after heat treatment strengthening. Due to low density, high strength, excellent thermal insulation and other advantages, this high-performance MMSF is suitable for making vehicle bodies, which can effectively reduce the overall weight, thus reducing the fuel consumption and pollutant emission caused by driving.

In order to solve the problems that the feature data type are not rich enough in the data collection process about the vehicle-following task in marine scene which results in a long model convergence time and high training difficulty,a two-stage vehicle-following system was proposed.Firstly,semantic segmentation model predicts the number of pixels of the followed target,then the number of pixels of the followed target is mapped to the position feature.Secondly,deep reinforcement learning algorithm enables the control equipment to make decision action,to ensure that two moving objects remain within the safe distance.The experimental results show that the two-stage vehicle-following system has a 40％faster convergence rate than the model without position feature,and the following stability is significantly improved by adding the position feature.

Lead halide perovskites are promising semiconductors for various optoelectronic devices working in a wide photo-excitation density regime. However, photo-induced instability, attributed to illumination-activated mobile ions, has been an obstacle to their application. Herein, we use the time evolution of photoluminescence (PL) to investigate the light illumination effects of CH3NH3PbBr3 perovskite films under relatively high excitation (up to 4.5 W cm-2). We demonstrate that continuous illumination can lead to both PL enhancement and PL quenching simultaneously, with their weight ratios depending on the excitation density. The experimental data can be well described and interpreted by considering the coexistence of and competition between the photo-induced annihilation and the formation of long-living filled trap states. Our study may provide in-depth insight into the photo-induced instability of perovskite films and help to improve the performance of perovskite-based optoelectronic devices.

Lead halide perovskites, which can be grown by solution process, are very suitable for various optoelectronic applications, such as in solar cells, light-emitting diodes, lasers and photo-detectors, due to their outstanding electrical and optical properties. However, lead halide perovskites are unstable under continuous light illumination, which severely degrades the performance and lifetime of optoelectronic devices based on them. Therefore, the photo-stability of perovskites and the mechanisms have received more and more attention. In this article we review the main phenomena in perovskites, induced by continuous light illumination, namely photo curing, photo dissociation, photo-induced phase separation, and photo-induced phase transition. The proposed mechanisms for the instability from the perspectives of defect states, ion migration, thermodynamics and chemical bonds, respectively, are also introduced. Finally, the complexity presented in the studying of photo-stability, and the issues should be addressed in the future are also briefly discussed.

Colloidal all-inorganic perovskite CsPbBr3 nanocrystals present versatile outstanding optoelectronic properties as well as greatly improved stability when compared with their hybrid analogues. However, the performance of blue-emitting CsPbBr3 nanocrystals is still inferior to their green counterpart. Moreover, their synthesis generally demands a high temperature and inert gas environment. Synthesis of perovskite nanocrystals with high efficiency blue emission in air ambience is highly desired. In this work we demonstrate a top-down strategy for the facile synthesis of blue-emitting CsPbBr3 quantum dots (QDs) in ambient air through cutting CsPbBr3 nanoplatelets (NPLs) into spherical QDs with the assistance of ultrasonication and hydrobromic acid (HBr) treatment. The CsPbBr3 QDs show excellent monodispersion with an average size of about 5 nm and a blue emission at 460 nm with high photoluminescence quantum yield (PL QY) of 53.2%. The key role of HBr is suggested to solubilize the inorganic cores of the NPLs and repair the surface. The CsPbBr3 QDs are used to prepare mixed phosphors emitting high quality white light.

Solution-processed all-inorganic CsPbX3(X = Br, I, and Cl) perovskites are proven to be promising materials for various optoelectronic applications. However, CsPbX3 films as optical gain media were confronted with unsatisfactory surface coverage and inferior photoluminescence performance when compared with their colloidal nanocrystal counterparts. Herein, we demonstrate a strategy for improving the optical properties via modification of both top and bottom surfaces of CsPbBr3 films. The treated perovskite films show ultra-smooth morphology and a carrier lifetime of 44 ns, more than one order of magnitude longer than the untreated one. Meanwhile, a mixed polymer layer on the top of the perovskite film could combine surface passivation with symmetric waveguide effects, leading to an outstanding net gain coefficient of 694 cm-1. These merits predict the great potential of all-inorganic perovskite films to support high efficiency charge transport or stimulated emission.

Objective To investigate the expression of interleukin (IL)-10 in the ulcer skin of the lower limbs in patients with post-thrombotic syndrome (PTS) and discuss the role of IL-10 in the formation of ulceration.Methods 41 patients cured with vascular surgery in our hospital were included in this study.IL-10 was analyzed by immunohistochemistry among ulceration group、ulceration group by sugery a week later and normal skin group.Results The positive expression rate of IL-10 in the three groups were 82.9％,36.5％,7.3％,and the difference was significant (P ＜ 0.05).Conclusion The corelation between high expression of IL-10 and the pathogenesis of limb ulcer is significant and IL-10 could inhibite the pro-inflammatory cytokines.

目的:探讨深静脉置管(PICC)致上肢深静脉血栓形成(DVT)的危险因素、诊断及治疗.方法:2011年6月-2012年6月间29例PICC相关性上肢DVT患者的临床资料,探讨其临床特点、诊治措施及疗效.结果:全组29例经患肢抬高并制动、抗凝、溶栓、促进静脉回流等治疗后,患者临床症状缓解、血栓吸收,期间未发现明显肺动脉栓塞(PE)症状,随访1年后未见复发及明显深静脉血栓后遗症(PTS).结论:PICC相关性上肢DVT一经确诊,应及早予抗凝、溶栓治疗,后期给予抗凝等治疗,疗效满意.

目的:探讨急性腹主动脉栓塞的外科诊断及治疗方法。方法:回顾4年间笔者参与完成的5例腹主动脉栓塞患者的临床资料,观察其手术方式、术中注意事项及术后处理。结果:5例患者中3例经手术治疗后效果良好,2例经非手术治疗后效果亦满意,未出现死亡及致残病例。结论:腹主动脉栓塞虽然存在较高的致残及致死率,但经合理诊治仍可获得满意的效果。