300M超高强钢在中性盐雾环境中的腐蚀行为及机制

摘要：为了研究300M超高强钢在中性盐雾环境中的腐蚀行为及腐蚀机制，采用失重法，宏观、微观腐蚀形貌分析，三维表面轮廓分析及电化学分析的研究方法，来表征腐蚀实验现象并进行分析。结果表明：300M超高强钢在中性盐雾环境中的腐蚀产物为FeOOH、Fe2O3、Fe(OH)3和Fe3O4；腐蚀速率随着腐蚀时间逐渐降低，腐蚀后期（72h）腐蚀速率降低50%；腐蚀初期以点蚀为主，点蚀坑通过横向扩展，逐渐发展为后期的均匀腐蚀，腐蚀表面形貌呈沟壑状；外腐蚀层对基体的保护能力很弱，Cr元素在锈层靠近基体的一侧偏聚使内腐蚀层具有一定的抗腐蚀性。     

镍基高温合金锥筒形件拉深旋压成形机理研究

针对镍基高温合金因加工硬化严重成形时极易产生破裂和起皱等典型缺陷的问题,以锥筒形壳体类零件为对象,提出了一种由锥形预制坯经过真空固溶处理后拉深旋压成形锥筒形件的方法,并对其成形机理进行了研究。基于Abaqus/Explicit平台,建立了锥筒形件拉深旋压有限元模型,分析了成形过程中的瞬态等效应力、等效塑性应变、切向应力、壁厚及三向应变分布规律。结果表明:在旋压成形过程中,最大瞬态等效应力位于旋轮接触区及附近区域、最大瞬态等效塑性应变位于坯料口部;瞬态切向压应力最大值位于旋轮接触区,而瞬态切向拉应力最大值位于旋轮接触区附近的两侧区域。筒形段中部壁厚减薄,而坯料口部壁厚增厚。旋压成形试验表明,锥形预制坯经拉深旋压后可获得壁厚均匀的锥筒形件。     

阿片受体影响雄性睾酮分泌的外周机制研究

目的:研究阿片μ受体对雄性睾酮的影响和外周机制。方法:通过在体动物模型的睾丸内吗啡注射和离体培养睾丸组织的特异性μ受体拮抗剂和激动剂处理，检测血浆、培养基和睾丸匀浆睾酮水平、睾丸匀浆睾酮合成酶mRNA水平、睾丸匀浆胰岛素样生长因子1（IGF1）蛋白和mRNA表达水平。结果:睾丸内注射吗啡后血清睾酮水平下降［（722.11±121.02）vs. (346.91±75.31) pg/mL；t=7.898，P=0.001］，睾丸匀浆中的睾酮水平下降［（133.61±16.82）vs. (66.56±14.96) pg/mg总蛋白；t=8.941，P=0.001］，同时下调睾酮合成酶的表达；吗啡睾丸内注射显著降低睾丸内IGF1蛋白［（7.93±2.13）vs. (2.54±0.74) ng/mg总蛋白，t=7.155，P=0.001］和mRNA［（3.22±1.12） vs. (1.66±0.55)，t=3.751，P=0.001］的表达。睾丸体外培养模型中阿片μ受体特异性的激动剂（DAMGO）下调培养基的睾酮水平及睾丸匀浆合成酶、IGF1的表达；阿片μ受体抑制剂（CTOP）则上调睾酮水平及合成酶、IGF1的表达。结论:阿片类药物作用于睾丸Sertoli细胞（支持细胞）表面的阿片μ受体，抑制IGF1的合成，进而减少睾丸Leydig细胞（间质细胞）睾酮合成酶Scarb1（清道夫受体B1）、Star（类固醇合成快速调节蛋白）、3βHsd（3-羟基-5类固醇脱氢酶）、Cyp17α1（17α-羟化酶）和17βHsd（17β羟基固醇脱氢酶）的表达，最终导致睾酮合成减少。     

5%碳酸氢钠严格控制代谢性酸中毒对活体肾移植患者术后早期肾功能的影响

目的：观察使用5%碳酸氢钠严格控制代谢性酸中毒是否可改善活体肾移植患者术后早期肾功能。方法：选择2019年3月至2020年3月于中国科学技术大学附属第一医院择期行活体肾移植手术的120例尿毒症患者为研究对象，随机分为观察组和对照组。观察组术中根据碱剩余（BE）测量值补充5%碳酸氢钠，维持－3 mmol/L≤BE≤+3 mmol/L。对照组仅在明显代谢性酸中毒（BE≤－10 mmol/L或pH≤7.25）时才补充5%碳酸氢钠。调整分钟通气量，使PaCO2在正常范围内。记录患者麻醉前（T0）、麻醉诱导后10 min（T1）、肾动脉血流开放前（T2）、肾动脉血流开放后5 min（T3）、手术结束时（T4）的血流动力学指标及术中出血量、输液量、手术时间。记录术后1、2、3、7、30 d的肌酐、尿素氮及尿量。结果：与对照组相比，观察组术中5%碳酸氢钠输注量明显增加，去氧肾上腺素使用量明显减少（P<0.05），对照组无输注5%碳酸氢钠指征；观察组术毕时pH、BE明显大于对照组（P<0.05）。与T0时比较，T3时两组MAP、CVP均明显降低（P<0.05）。观察组术后1、2、3、7 d血肌酐、尿素氮含量明显低于对照组（P<0.05）。观察组术后1、2、3 d尿量明显多于对照组（P<0.05）。结论：活体肾移植术中应用5%碳酸氢钠严格控制代谢性酸中毒可改善术后早期肾功能。     

Microstructural characteristic,outward-inward growth behavior and formation mechanism of MAO ceramic coating on the surface of ADC12 Al alloy with micro-groove

The ceramic coatings on the surface of aluminum alloy substrates with micro-grooves have been successfully fabricated in the silicate solution via micro-arc oxidation (MAO) approach. Microstructure characterization showed that the larger main discharge channels were located in the center of micro-groove, the smaller secondary discharge channels were located on both sides of main discharge channel; and a few irregular micro-pores existed in the vicinity of all discharge channels, which were mainly cause by the rapid cooling and solidification of discharge channels hindering the removal of gases produced via reaction. Moreover, the growing direction of coating in the initial stage was mainly outward-growth and resulted in the formation of inverted triangle coating structure, which was due to the sharp-angled effect. But in the final growing stage, the inward-growth behavior played a key role owing to the spark transfer. According to above results and discussion, the formation of smooth, uniform and homogeneous ceramic coating on the surface of whole trapezoidal micro-groove substrate contained four stages: anodic oxidation growth, sharp corner rapid growth, coating homogenization and groove self-filling.     

Loadbearing capacity of infill masonry walls considering the deformation‐based membrane effect

According to currently valid codes, it is not possible to determine the loadbearing capacity of unreinforced infill walls considering the deformation‐based membrane effect by incorporating the exact support conditions. One reason for this is the lack of a validated calculation procedure, which in addition to the equilibrium conditions also realistically represents the compatibility conditions of these systems. In the present paper, therefore, a new non‐linear analytical calculation procedure is presented. The main focus of the analysis of walls subject to area loading is the incorporation of the support conditions and thus the consideration of the deformation‐based membrane compressive force. Through generalised formulation and a standardised notation of the determination equations, different material behaviours and various support conditions can be taken into account with few parameters. On the action side, both lighter loading like wind loads and heavier loading like explosion loads can be considered. Through the implementation of the partial factor concept, it is possible to comply with the requirements of European codes and thus ensure the applicability of the analysis model.     

Economy supervision mode of electricity market and its incentive mechanism

The analysis of a supervision environment is the first step for a company to enter the new electricity market. Transmission and distribution assets are the main investment targets of a company. The overseas power market belongs to the regulated industry; whether it is a stock M&A project or a green land bidding project, the regulatory environment determines the assets. The level of return and investment risk that guides the operation strategy of existing overseas assets, has a significant impact on the investment and operations of international companies. A comprehensive and rapid assessment of the regulatory environment can help the project teams of international companies understand the macroenvironment of the target electricity market within a short period, quickly identify investment risks, qualitatively analyze the return level of the underlying assets, shorten the decision time, capture investment opportunities, and enhance the team. Efficiency and quality of work are factors of great importance.     

漆包机烘炉加热失效原因探究及处理

针对漆包机烘炉加热失效形式及产生原因,进行了深入的研究和分析。结果表明,影响烘炉加热失效的主要原因是加热管损坏及装配异常、催化剂表面粘有金属化合物等颗粒杂质、排废风机转速设定不合理,并对加热管、催化剂、排废风机提出了合理实用的技术措施,为降低烘炉加热失效提高加热效果提供帮助。     

长江武惠堤堤防渗透破坏风险计算模型及应用

针对渗透水压力引起堤防渗透破坏问题,以堤防渗透破坏风险为目标,考虑堤防计算水位条件和土层渗透系数的不确定性,建立了堤防渗透破坏风险计算模型。以长江武惠堤17+750断面为例,对汉口水文站水位监测资料进行分析并拟合水位概率密度函数,对该断面渗流规律进行有限元分析,从而拟合渗透破坏概率密度函数,以此建立该断面堤防渗透破坏风险定量表达式。研究结果表明,武惠堤17+750断面堤防在警戒水位与防洪设计水位下,渗透破坏概率分别为0.442 9、0.764 0,渗透破坏风险分别为0.001 421、0.002 52;堤防渗透破坏风险随着堤外水位的升高而增加,但在防洪设计水位内运行时,堤防渗透破坏风险低,堤防渗流安全可得到有效控制。