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.     

大型变压器的特殊温升试验

介绍了大型变压器在急救负载或冷却器停运两种特殊情况下绕组热点温度的变化情况 ,验证了GB/T15 16 4— 1994《油浸式电力变压器负载导则》的有关内容     

一种伪随机码引信对TBM目标的电磁散射特性分析

分析了 TBM目标特点 ,针对一种伪随机码引信 ,计算了该目标的镜面反射点的位置和强度 ,建立了目标近区电磁散射的数学模型 ,给出了针对该引信的目标回波信号的表达式     

钨化学气相淀积工艺方块电阻均匀性的研究

钨化学气相淀积因为其在接触孔/通孔填充中出色的台阶覆盖能力而在半导体工业中被广泛应用,在量产中经常会出现监控片的方块电阻均匀性超规格。本文主要研究了加热器、气体输送、氟化铝、机械传片定位、真空微漏等因素对方块电阻均匀性的影响,特别周期性等离子清洗产生的氟化铝对晶圆边缘的抑制反应是影响腔体维护频率的主要原因,并提出改善均匀性的有效办法。     

电流卡钳传输阻抗的线性补偿

为了扩展电流卡钳的频率测试范围,根据其等效电路模型,分析并测试了传输阻抗特性,发现了传输阻抗在频率范围内的非线性现象,进而提出了基于放大器的线性补偿方法.通过测试结果表明,在1-50kHz的被测信号情况下,匹配了放大器的电流探头的传输阻抗的波动范围≤±1dB.因而,利用这一补偿方法,可以给单片机信号采集转换成被测电流值带来方便.     

钢筋接驳器与柱翼缘板的焊接

阐述了钢筋接驳器与柱翼缘板的可焊性、焊脚尺寸的确定和焊接过程应注意的问题,并做了详细介绍。     

矿物绝缘电缆铜带纵包氩弧焊焊接连续轧制生产工艺

简述了矿物绝缘电缆铜带纵包氩弧焊焊接连续轧制的生产工艺,并对该生产工艺中可加硅油氧化镁粉运用、定芯管的设计、氩弧焊焊接、轧辊轧制以及中频感应退火作了描述,同时对连续生产过程中相关工艺作了说明。     

汽车车轮锁圈槽开裂原因及对策

分析钢制汽车车轮在CO2气体自动保护焊接过程中开裂的原因及防止措施,通过金属材料成份和焊接工艺规范的分析及汽车车轮弯曲疲劳试验,分析引起汽车车轮锁圈槽开裂的各种因素。为防止汽车车轮锁圈槽开裂,降低不良率提供参考。     

巨型球体钢结构工程焊接技术

根据安装顺序,严格执行焊接程序,消化创新了“鸟巢”钢结构合龙技术,实现了分层错45°合龙线的均匀布置,使合龙进展顺利;特别是根据主结构“统一对称、分区进行;自内而外、隔层焊接;分层合龙”的思想,焊接程序应当是:第一步,以柱为点,自内而外,分区进行,对称焊接;第二步,以梁为主,自内而外,先环后径,分区对称,逐步合龙;注意...     

Material flow and core/multi-shell structures in a friction stir welded aluminum alloy with embedded copper markers

The objective of this study was to reveal the material flow and temperature distribution in a thick aluminum plate during friction stir welding and examine the subsequent microstructural change with particular attention to the reaction between copper marker and aluminum matrix. It is shown that the material adjacent to the threaded pin was transported from the top to bottom non-symmetrically, and then was forced to move upwards at a small distance from the pin due to the constraint of an extrusion-die-like configuration. The interaction between the copper marker and aluminum matrix led to the formation of (i) a unique core/multi-shell microstructure consisting of copper core, inner shell of AlCu and outer shell of Al₂Cu, and (ii) a composite band containing uniformly-distributed Al₂Cu particles with refined grains due to the lower stacking fault energy of copper and the pinning role of Al₂Cu particles.