谈淤泥质复杂基坑地基处理及支护技术

淤泥质地形在施工过程中可能因地基强度不够而发生事故,施工难度高,对此类地基处理及支护技术的研究较为重要。     

建筑产业转型升级新时代下高职建筑工程技术特色专业建设问题的新思考

随着建筑业技术进步和转型升级,高职建筑工程技术专业建设应顺应新时代要求,产教融合,办出特色。本文提出了“四个对接一个融合”的特色专业建设新思考。     

融合前沿研究的液体电介质击穿教学研究

针对《高电压与绝缘技术》课程中液体电介质的教学难点，提出了融合前沿研究的液体电介质击穿教学方法。基于前沿的液体放电应用背景与先进的液体放电研究平台，形象地展示液体电介质的动态击穿过程，在教学内容、教学方法、考核方式等方面进行科教融合改进，实施“以学生为中心”理念的课程教学设计。该教学方式取得了较好的教学效果，能够为其它知识点的教学质量提升提供参考。     

高强度大桥缆索用盘条生产现状分析

最近5年，大桥缆索用镀锌钢丝抗拉强度有了大幅提高，从1 770 MPa级、1 860 MPa级、1 960 MPa级到目前的2 000 MPa及以上级别，扭转指标有了颠覆性的改变，从之前的几转到目前的十几转、二十几转。论述了国内外钢铁企业生产大桥缆索镀锌钢丝用盘条的不同现状。从成分设计、生产工艺流程、盘条韧化处理方式和组织特点等方面进行阐述，讨论了国内外不同生产工艺特点及发展趋势，为中国大桥缆索镀锌钢丝用盘条的生产提供理论支持。     

Microstructured Fischer‐Tropsch Reactor Scale‐up and Opportunities for Decentralized Application

Current projects focusing on the energy transition in traffic will rely on a high‐level technology mix for their commissioning. One of those technologies is the Fischer‐Tropsch synthesis (FTS) that converts synthesis gas into hydrocarbons of different chain lengths. A microstructured packed‐bed reactor for low‐temperature FTS is tested towards its versatility for biomass‐based syngas with a high inert gas dilution. Investigations include overall productivity, conversion, and product selectivity. A 60‐times larger pilot‐scale reactor is further tested. Evaporation cooling is introduced which allows to increase the available energy extraction from the system. From that scale on, an autothermal operation at elevated conversion levels is applicable.     

Synthesis of the Antibiotic Precursor Thiazolyl‐7‐Aminocephalosporanic Acid in a Microstructured Flow System

The synthesis of thiazolyl‐7‐aminocephalosporanic acid, a pharmaceutical precursor of the β‐lactam antibiotic drug cefodizime, could be successfully realized in a continuous microstructured flow system. This was accomplished by changing the process window from batch, having a reaction temperature of 60 °C with a reaction time of 1 h, to a flow system at temperatures > 100 °C and reaction times of several minutes. The space‐time yield could be increased by a factor of 130.     

Distributed allocation and dynamic reassignment of channels in UAV networks for wireless coverage

Providing wireless coverage to users using Unmanned Aerial Vehicles (UAVs) encounters two major challenges: deployment and channel allocation. To this end, solutions to both issues are proposed in this paper. An overloaded UAV attempts to acquire more channels by performing channel bonding/aggregation followed by requesting its chosen peers to move closer for load sharing. The proposed channel reallocation schemes minimize interference caused by channel reassignments, or change in network topology. The simulation results show that when employing these schemes, more data is served with reduced discontinuous service time and efficient usage of limited battery power.     

Reaction synthesis of spark plasma sintered MoSi2-B4C coatings for oxidation protection of Nb alloy

MoSi₂-B₄C coatings with different B₄C contents were prepared on Nb alloy by spark plasma sintering (SPS) process. Powder mixtures of Mo, Si and B₄C were used as the coating starting materials. Besides MoSi₂ and B₄C phases, small amounts of SiC and MoB are also found in the coatings because of the reactions of Mo, Si and B₄C powders during sintering. Compared with single MoSi₂ coating, the MoSi₂-B₄C coatings show better oxidation resistance at 1450?℃, and dense B₂O₃-SiO₂ oxide scales form after 100?h oxidation. The B₄C or MoB in the MoSi₂-B₄C coatings can serve as the B donor for the formation of B₂O₃. A slight degradation in the microstructure of the MoSi₂-B₄C coatings after oxidation is observed, which can be attributed to the presence of an NbB layer in the inter-diffusion zone of the coatings that retards the inward diffusion of Si from the coating into the substrate alloy. The microstructure development and oxidation behavior of the MoSi₂-B₄C coatings have been discussed.     

Frequency dependence of plasma characteristics at different pressures in cylindrical inductively coupled plasma source

The effects of driving frequency on plasma parameters and electron heating efficiency are studied in cylindrical inductively coupled plasma (ICP) source. Measurements are made in an Ar discharge for driving frequency at 13.56/2 MHz, and pressures of 0.4–1.2 Pa. In 13.56 MHz discharge, higher electron density (n_e) and higher electron temperature (T_e) are observed in comparison with 2 MHz discharge at 0.6–1.2 Pa. However, slightly highern_e andT_e are observed in 2 MHz discharge at 0.4 Pa. This observation is explained by enhanced electron heating efficiency due to the resonance between the oscillation of 2 MHz electromagnetic field and electron-neutral collision process at 0.4 Pa. It is also found that the variation ofT_e distribution is different in 13.56 and 2 MHz discharge. For ICP at 13.56 MHz, T_e shows an edge-high profile at 0.4–1.2 Pa. For 2 MHz discharge,T_e remains an edge-high distribution at 0.4–0.8 Pa. However, the distribution pattern involves into a center-high profile at 0.9–1.2 Pa. The spatial profiles ofn_e remain a center-high shape in both 13.56 and 2 MHz discharges, which indicates the nonlocal kinetics at low pressures. Better uniformity could be achieved by using 2 MHz discharge. The effects of gas pressure on plasma parameters are also examined. An increase in gas pressure necessitates the rise ofn_e in both 13.56 and 2 MHz discharges. Meanwhile, T_e drops when gas pressure increases and shows a flatter distribution at higher pressure.