奥氏体不锈钢激光焊接过程中残留液体金属的在线观察

激光焊接时较快的冷却速度,有可能促进凝固热裂纹的生成,而凝固热裂纹的生成与凝固温度区间内的残留液体金属行为直接相关.采用由高速摄像机和光学显微镜头组成的摄像装置,针对SUS304,SUS316,SUS310S等3种奥氏体不锈钢激光焊接熔池后端残留液体金属的凝固行为进行高速高倍在线观察,对不同焊接速度下的熔池凝固行为进行了分析,并对3种材料凝固前沿残留液体金属的存在范围进行了量化比较.结果表明,在线观察法可辨别的残留液体金属是固液相共存区间的一部分,在线观察得到的残留液体金属的存在范围与热裂纹试验获得的热裂纹敏感性有较好的对应关系.     

低聚噻吩的p型掺杂行为和CF3COOH浓度的影响

分别在空气、氮气和氧气气氛下，用CF3COOH作掺杂剂对三种低聚噻吩的p型掺杂行为进行了系统研究。结果发现三聚噻吩（a-Th3）在本试验条件下没有发生任何掺杂，而四聚噻吩（a-Th4）和五聚噻吩（a-Th5）不同程度地发生了掺杂。CF3COOH浓度对于低聚噻吩的p型掺杂的影响比较明显。     

TEMPERATURE MEASUREMENT ERROR BY RADIAL INSERTION OF THERMOCOUPLE IN THERMAL CONDUCTIVITY MEASURING DEVICE

To measure the temperature of the inner part of a material, an axially inserted thermocouple is often used. But, when the measurement by an axially inserted thermocouple is difficult, we must insert the thermocouple radially. In the case of radial insertion, a measuring error usually exists. To know the true temperature by the method of radial insertion of a thermocouple, we must conduct numerical calculations.

In this report, numerical calculations have been conducted for the temperature measuring error by radial insertion of thermocouple in a gas thermal conductivity measuring device.^2-5     

一种基于互相关的三维PIV图像处理方法

本文建立了一种基于互相关技术的三维PIV图像处理方法，在该方法中，建立了粒子图像坐标与空间坐标的关系式；利用互相关技术构成连续两时刻三维空间粒子的对应方法；通过图像粒子的标定，照相机系统的标定，粒子空间坐标的确定，连续两时刻空间粒子的对应，误对应速度向量的判断和消除步骤，形成了一个完整的三维PIV图像处理系统。将本方法运用于日本可视化协会（VSJ）提供的三维标准图像的处理，结果表明，无论是低粒子浓度图像还是高粒子浓度图都具有精度高，可靠性强的特点。     

TEXTURE-STRUCTURE RELATIONSHIPS IN HEAT-INDUCED SOY PROTEIN GELS

Structural factors responsible for textural properties of heat-induced soy protein gels were investigated using microscopic and mechanical testing techniques. The gels were prepared by heating 20% soy protein pastes for 30 min at temperatures ranging from 25 to 130°C . Gel hardness increased linearly with the heating temperature up to 80°C , and decreased when the gels were heated at over 90°C , especially over 120°C . The equilibrium modulus estimated by tensile stress relaxation experiments was of the order of 10⁴ - 10⁵ dyne/cm², suggesting the presence of crosslinks, and there was a good correlation between the equilibrium modulus and the hardness of the gels. Solubility in phosphate buffer containing 2 -mercaptoethanol and/or urea suggested that the gel network was formed through crosslinking of the disulfide-, hydrogen- and hydrophobic-bonding types, and that the textural properties were governed by the degree of the network formation controlled by the heating temperature. SEM images of the 80°C -induced hard gels revealed a porous structure having membranous walls of thin compact film. With the 40°C -induced soft gels, the formation of the porous structure was not yet adequate, while a partial collapse of this structure was observed in the 120°C -induced fragile gels.     

充入气体含水量对超高真空系统排气特性的影响

在未烘烤的超高真空系统中，真空室表面所吸附的水蒸汽是影响排气时间及极限真空度的关键因素。通过实验，对充气气体中水蒸汽含量及操作方式与真空系统排气特性的关系进行了测试，为超高真空系统操作工艺的确定提供了依据。     

EFFECT OF SLAUGHTER METHOD ON DEGRADATION OF INTRAMUSCULAR TYPE V COLLAGEN DURING SHORT-TERM CHILLED STORAGE OF CHUB MACKEREL SCOMBER JAPONICUS

The present paper demonstrates that a nonstntggling slaughter method can delay degradation of type V collagen in meat of chub mackerel Scomber japonicus and softening of the meat during postharvest chilled storage. The fish were slaughtered by piercing a knife into nape (nonstruggling method) or by leaving on ground (struggling method) and then stored in an ice box. Sensory study revealed that the postharvest softening of the meat was moderated at 4 and 8 h by the non‐struggling slaughter method in comparison with the struggling method. On the basis of the specific solubilization of type V collagen and reduced tyrosine content in it, a cleavage of the nonhelical regions (telopeptides) of the type V collagen occurred during the chilled storage in the fish slaughtered by the struggling method. The degradation of type V collagen was also slower in the meat of the fish slaughtered by the nonstruggling method, which can be directly linked to the moderation of the postharvest softening.