亚共晶的

The results show: the strongest bond is the Al-Al bond in the segregated cell without containing vacancy, where the Al atomic covalence radius is greater than that of Li atom in the cell; while the strongest bond is the Al-Li bond in the segregated cell containing vacancy, and the Al atomic covalence radius in the cell is less than that of Li atom. Since the difference of electronagativity between the Al and Li atoms is obvious, it is inclined to formed the Al-Li segregated cell of short range order structure in the condition of vacancy present. The short range order structure containing vacancy is probably the embryo or precursor structure of the metastable phase δ′(Al3Li). Because the strongest covalent bond in the Al-Li-vacancy segregated cell in alloy formed in quenching is the main strength reason for supersaturated solid solution of alloy. The bond net of succeeding precipitation of δ′(Al3Li) has the picture of anisotropic Al-Al bonding and the bond intensity enhanced. Since the δ′(Al3Li) is coherence with matrix, the bond net strength is enhanced by the precipitation of δ′(Al3Li) and so strengthen the alloy.

计算结果表明：不包含空位的偏聚晶胞的键络最强键为Al—Al键，其中Al原子的共价半径较Li原子的共价半径要大；而含空位的偏聚晶胞的最强键为Al—Li键， Al原子的共价半径要比Li原子的共价半径要小；在空位存在的情况下，由于Al原子与Li原子的电负性相差明显，促使Al和Li原子结合，倾向形成Al-Li短程序结构偏聚区，这种含空位的短程序结构很可能就是δ′(Al3Li)亚稳相的前兆结构和生长胚胎；由于Al-Li-空位有序偏聚晶胞的Al—Li键络比基体键络要强许多，因此，淬火过程中合金生成的Al-Li-空位偏聚晶胞对合金过饱和固溶体起主要强化作用；后续析出的δ′(Al3Li)亚稳相键络各项异性显著，键络强度明显提高；由于Al3Li与基体共格，其大量均匀弥散析出起到提升基体整体键络强度，同样对合金产生强化作用。

The results show: the strongest bond is the Al-Al bond in the segregated cell without containing vacancy, where the Al atomic covalence radius is greater than that of Li atom in the cell; while the strongest bond is the Al-Li bond in the segregated cell containing vacancy, and the Al atomic covalence radius in the cell is less than that of Li atom. Since the difference of electronagativity between the Al and Li atoms is obvious, it is inclined to formed the Al-Li segregated cell of short range order structure in the condition of vacancy present. The short range order structure containing vacancy is probably the embryo or precursor structure of the metastable phase δ'(Al3Li). Because the strongest covalent bond in the Al-Li-vacancy segregated cell in alloy formed in quenching is the main strength reason for supersaturated solid solution of alloy. The bond net of succeeding precipitation of δ'(Al3Li) has the picture of anisotropic Al-Al bonding and the bond intensity enhanced. Since the δ'(Al3Li) is coherence with matrix, the bond net strength is enhanced by the precipitation of δ'(Al3Li) and so strengthen the alloy.

计算结果表明：不包含空位的偏聚晶胞的键络最强键为Al-Al键，其中Al原子的共价半径较Li原子的共价半径要大；而含空位的偏聚晶胞的最强键为Al-Li键，Al原子的共价半径要比Li原子的共价半径要小；在空位存在的情况下，由於Al原子与Li原子的电负性相差明显，促使Al和Li原子结合，倾向形成Al-Li短程序结构偏聚区，这种含空位的短程序结构很可能就是δ'(Al3Li)亚稳相的前兆结构和生长胚胎；由於Al-Li-空位有序偏聚晶胞的Al-Li键络比基体键络要强许多，因此，淬火过程中合金生成的Al-Li-空位偏聚晶胞对合金过饱和固溶体起主要强化作用；后续析出的δ'(Al3Li)亚稳相键络各项异性显著，键络强度明显提高；由於Al3Li与基体共格，其大量均匀弥散析出起到提升基体整体键络强度，同样对合金产生强化作用。

Block-copolyimide film from pPDA/ODA-PMDA was studied by TEM, SEM, PLM, ultra-deep three-dimensional microscope, TMA, and WAXD, which showed that the extensile strength and modulus of b-PI film were higher than that of irregular copolyimide film. It was also revealed that there was a large amount of crystallite formed in b-PI film, which was mainly attributed to its chain structure: rigid pPDA-PMDA chains were easy to form crystal nucleus because of phase separation, based on which semi-rigid PMDA-ODA molecular chains began to crystallize.

以pPDA／ODA-PMDA型嵌段共聚酰亚胺薄膜为对象，借助TEM、SEM、PLM、超景深三维显微镜、TMA、WAXD等手段，研究结果表明：b-PI薄膜的拉伸强度、弹性模量均高于无规共聚酰亚胺薄膜；b-PI薄膜中形成了大量的微晶，这是由于刚棒状的pPDA-PMDA分子链段因相分离容易形成晶核，然后半刚性的PMDA-ODA分子链段以PMDA-pPDA为晶核进行晶体生长造成的，而且ODA-PMDA分子链的结晶和酰亚胺化反应基本上是同步进行的。

It is for the first time found that the liquid hypoeutectic Al-Fe alloy has a critical temperature of 920℃ in the curve of the cluster size to temperature. Below 920℃ the structural change is predominantly in the medium-range order, while in the short-range order above 920℃.

首次发现，亚共晶Al-Fe合金熔体的原子团簇尺寸等在920℃左右存在明显的变化。920℃以下熔体结构的变化以原子团簇尺寸即中程尺度参数的变化为主，而920℃以上则以配位数等短程序参数的变化为主。

ABSTRACT Using the θ-θ X-ray diffractometer, the structure of liquid Al-Fe system alloys at different composition was investigated at a constant temperature 1550℃. The relationship between parameters of the pre-peak in the structure factor and composition was studied. In addition, the structural change of the liquid hypoeutectic Al-Fe alloy and pure Al etc.

本文利用θ-θX射线衍射仪，在1550℃研究了不同成分Al-Fe合金的熔体结构，探讨了结构因子上的预峰参数随成分变化的规律，以及亚共晶Al-Fe合金和纯。。。

The results show that, there is a white zonal area between the AZ61 and Al-alloyed coating, which indicates that a good metallurgical bonding is obtained. The coating shows typical hypoeutectic structure. Due to lots of Mg17Al12 phases in Al-alloyed coating, the corrosion resistance of AZ61 magnesium alloy is increased obviously.

结果表明，涂层与基体形成了扩散白亮带，实现了较好的冶金结合；涂层具有亚共晶组织的特点；大量的Mg17Al12相存在于涂层表面是耐腐蚀性能提高的主要原因。

The microsturcture characteristics of M2 cast-strip were studied with such experimental methods as metallographic analysis, SEM, XRD and TEM[0]. The effect of sub-rapid solidification on the size, type and distribution of eutectic carbides in M2 cast-strip was analyzed. The effect of heat treatment temperature and its holding time on the eutectic carbides in M2 cast-strip was explored. The eveolution of metastable phase of M2C eutectic carbide during the heat treatment period and the decomposition dynamics concerned were researched. The M2 cast-strips were rolled into thin strips and the effect of deformation ratio on carbides in M2 cast-strip was examined. Then these thin strips were comparied with those that were produced by conventional technology on carbide, hardness, red-hardness and bend strength. At last the rolled M2 cast-strips were made into saw blades and their cutting performance was experimented on in tools factories and then compared with that of similar products produced by conventional technology.

采用常规金相、扫描电镜、X射线衍射及透射电镜等实验研究了M2高速钢铸带的凝固组织特征，分析了亚快速凝固对铸带中的共晶碳化物的析出类型和尺寸以及分布的影响；探索了后续热处理温度和保温时间对铸带碳化物组织的影响规律，分析了铸带中的亚稳相M2C共晶碳化物在热处理过程中的分解情况以及分解动力学；将铸带热轧成薄带，研究了压下率对铸带碳化物组织的影响，并将热轧薄带与常规工艺生产的相同规格的M2高速钢薄带在碳化物组织、硬度与红硬性以及抗弯性能等方面进行了对比；将热轧薄带加工成机用锯条后在工具厂进行了锯切性能试验，并与常规工艺生产的同类产品进行了使用性能对比。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。