Effects of nano-SiC particles on the FSSW welded AZ31 magnesium alloy joints

The microstructure of nano-SiC enhancing friction stir spot welding (FSSW) joint with dwell time of 3?s was characterised by an onion ring structure which consisted of alternate SiC-free zones and SiC-rich zones where SiC particles refined the grains. However, onion ring structure disappeared and SiC particles dispersed homogeneously when dwell time was 5?s. The microhardness of stir zone (SZ) and tensile shear load of SiC enhancing FSSW joint were higher than those of conventional FSSW joints. After heat treatment at 200°C for an hour, grains of the SZ grew substantially and coursed reduction in mechanical properties of joints, while grain size of SZ and tensile shear load of SiC enhancing joint was invariant but the microhardness of SZ increased.     

对采煤机摇臂调高抖动问题的研究

分析了采煤机调高系统产生抖动的原因,并提出了可靠的解决方法,实用效果良好。     

钢筋网焊机自动生产线的实时控制

在网焊机自动化生产线的研制中,由于点焊控制器、自动上料机构中焊点总数多、驱动路数多、网格间距小、运行速度快,因而对控制系统的实时性提出了较高要求,用工控机与单片机、PLC组成的网焊机控制系统,在软、硬件实现上采取多种方案有机结合,实现了网焊机生产线的高速实时控制。     

基于双掩模图像差影的工业产品表面缺陷检测

针对利用图像差影法进行缺陷检测时易受配准精度和产品制作过程扰动的影响,以及单掩模算法难以检测不同类型缺陷的问题,结合工业产品表面缺陷,提出基于双掩模的图像差影策略.通过分别提取模板图像和待测图像的边缘并作膨胀处理得到双掩模即模板掩模和待测掩模,双掩模进行融合处理后分别与模板图像和待测图像做卷积,再采用差影法进行缺陷检测.实验证明:该方法能精确检测出多类表面缺陷,且满足实时要求.     

Dried Blood Spots as Matrix for Evaluation of Valproate Levels and the Immediate and Delayed Metabolomic Changes Induced by Single Valproate Dose Treatment

The immediate and delayed metabolic changes in rats treated with valproate (VPA), a drug used for the treatment of epilepsy, were profiled. An established approach using dried blood spots (DBS) as sample matrices for gas chromatography/mass spectrometry-based metabolomics profiling was modified using double solvents in the extraction of analytes. With the modified method, some of the previously undetectable metabolites were recovered and subtle differences in the metabolic changes upon exposure to a single dose of VPA between males and female rats were identified. In male rats, changes in 2-hydroxybutyric acid, pipecolic acid, tetratriacontane and stearic acid were found between the control and treatment groups at various time points from 2.5 h up to 24 h. In contrast, such differences were not observed in female rats, which could be caused by the vast inter-individual variations in metabolite levels within the female group. Based on the measured DBS drug concentrations, clearance and apparent volume of distribution of VPA were estimated and the values were found to be comparable to those estimated previously from full blood drug concentrations. The current study indicated that DBS is a powerful tool to monitor drug levels and metabolic changes in response to drug treatment.     

MLCC装配质量优化研究

针对本所产品中多层陶瓷电容器(MLCC)在经过环境试验后出现的失效问题,通过对失效原因进行分析,结合生产实际情况,进行了技术改进.制作了技术改进前后的试验板,经过环境试验后测试,结果表明,未改进前的试验板中的MLCC出现问题,而改进后的试验板没有发现问题.最后对故障MLCC进行了DPA检查,结果发现MLCC端头出现45°角裂纹.试验结果表明经过技术改进后有效地解决了MLCC装配质量问题,提高了产品装配合格率,达到了预期的效果.     

螺纹锁紧环换热器主螺纹设计与强度校核

介绍螺纹锁紧环换热器管箱密封结构特点,分析其载荷传递方式,总载荷最终通过主螺纹传递到管程筒体.目前螺纹锁紧环换热器主螺纹设计中是假设将总载荷平均分配,再对螺纹进行强度校核,但每扣螺纹实际承受载荷是不均匀的.以某螺纹锁紧环换热器为例,参照GB/T 34019—2017《超高压容器》中关于螺纹载荷分布的计算校核方法,计算主...     

新型光学动态靶标模拟空间目标研究

  光学动态靶标是用于对光电经纬仪进行室内检测的重要设备.为检验新型光学动态靶标模拟空间飞行目标的能力,衡量其检测性能,验证其结构优点,利用Matlab软件模拟靶场常用飞行轨迹,对多种形式空间飞行目标进行仿真计算.得出靶标在模拟空间目标过程中各种参数的变化曲线,包括角度变化曲线、速度变化曲线以及加速度变化曲线;同时利用已有数据,拟合靶标俯仰角度误差曲线.仿真结果显示,新型动态靶标的速度、加速度匹配灵活,模拟目标区域广阔,模拟目标形式多样,且更加接近真实目标,与传统靶标相比,具有明显的创新性和实用性,其性能能够满足光电经纬仪室内检测的需要.利用靶标俯仰角误差曲线进行实时误差补偿的方法,为进一步提高靶标精度提供理论参考.     

基于PIC单片机的多点温控系统的设计与实现

单点温度控制系统不能满足自动化生产过程中对多点温度控制的需求。本文基于PIC单片机提出一种多点温度控制系统,设计了硬件电路、单片机程序以及上位机程序实现的核心部分。该系统具有三个优点：灵活配置、在线增加结点和删除结点。实践证明,该系统能够很好地实现自动化生产过程中的温度控制,达到预期的目的。     

黄瓜褐斑病病原菌鉴定及生物学特性研究

对辽宁省保护地发生的黄瓜褐斑病进行病原菌的分离、鉴定 ,明确该病的病原菌为多主棒孢霉[Corynesporacassiicola(B.&C.)Wei]。生物学特性研究表明 ,该菌孢子萌发的最适温度范围为15～35℃ ,最适pH值为5～8,水滴是孢子萌发的必要条件。病菌营养生长的最适温度为15～35℃ ,最适 pH值为6～8 ,在PSA、PDA等常规培养基上生长良好 ,光照对菌丝生长速度影响不显著。病菌产孢的最适温度为25～30℃,最适pH值为5～8,光照有助于孢子形成,在PSA、PDA等常规培养基上能大量产孢。病菌分生孢子在室外难以安全越冬,在保护地内能够安全越夏。该菌寄主范围广,能寄生黄瓜和番茄等20余种作物