仿水晶工艺品制作工艺

本文介绍了采用不饱和聚酯树脂制作的仿水晶工艺品固化原理和制作工艺,而制作工艺主要由模具制作、浇铸成型、制品后加工三部分组成,因此,文章详细地介绍了这三部分制作过程应用的原料、制作了步骤、配方的控制及应注意的问题。     

Microstructure development during constant-force drawing of poly(ethylene terephthalate) film

Structure development in PET film during high strain-rate, constant-force (CF) deformation in the temperature range 80–96°C is compared with structure development during lower strain rate, constant-extension-rate (CER) deformation in a similar temperature range. The higher (maximum) strain rates involved in CF drawing mean that much of the deformation takes place in a regime where the time available for orientational relaxation and crystallization is short. This results in high levels of ‘non-crystalline orientation' and low levels of crystallinity compared to structures obtained from CER drawing. In CER drawing, due to the lower strain rates, the degree of crystallinity always has time to reach pseudo-equilibrium values corresponding to a given level of non-crystalline orientation, and the amount of orientational relaxation occurring during drawing has the dominant influence on structure development. In CF drawing, pseudo-equilibrium crystallinity values are not reached, except when the deformation approaches the tail-end of the strain-rate spectrum. The results also provide confirmation that microstructure data obtained from rapidly quenched samples are consistent with microstructure data obtained from real-time experiments.     

光纤磁场传感器的磁场探头设计

光纤磁场传感器的探头是光纤磁场传感器中最关键的部分，它直接影响到传感器的测量精度。根据光纤传感器的测量要求和磁敏元件(磁光晶体：BiGd：YIG-Y3-x-yBixGdyFe3O12)的工作原理及特点，必须在光纤磁场传感器探头中产生线偏振光，同时为了在磁敏元件加入传感器探头后不至于增加固有损耗，故在探头两端使用了两个光纤准直器。介绍了在探头设计中，各部分的工作原理和结构特点。     

差动石英谐振式力传感器的温度特性及其温度自测

推导出了差动石英谐振式力传感器的一种输出表达式，考虑温度的影响进一步得到了温度影响下的传感器输出特性。并找到了一种新的温度自测方法——差动式温度自测法。结果表明：选择较高的泛音次数、合适的作用力方位，能够提高传感器的测力灵敏度，可使其达到单敏感型传感器的4．1倍；温度是影响传感器输出特性的一个主要因素，温度越高，影响越大，必须对输出特性进行补偿。选择合适的泛音次数、作用力方位能提高温度自测的灵敏度，可使其达到双频温度自测的2，7倍。     

光纤电压传感器传感头的设计

基于逆压电效应原理，介绍了光纤电压传感器的工作原理，提出了一种全新的传感头设计方案，为光纤电压传感器测量高电压提出了理论依据。     

Hydrogen redistribution in the solid solutions ZrV2Dx, 2.2≤x≤2.7: I. Interconnection between hydrogen-ordered phases: intermediate phase instead of phase separation

We have studied, by means of neutron powder diffraction, the temperature evolution of the hydrogen solid solutions ZrV₂D_x in the intermediate range, 2.18≤x≤2.73, separating two hydrogen-ordered phases, ZrV₂D_≤2 with k=(1/2, 1/2, 1/2) and ZrV₂D_≥2.8 with k=(0, 0, 1−δ). Instead of ordinary phase separation, we have found an uncommon phase. This phase is a kind of a disordered one and, simultaneously, it keeps a modulation of hydrogen density with the same k as for the ordered phase, one or another. Under favourable conditions this modulation transforms into the regular ordered phase.     

Hydrogen redistribution in the solid solutions ZrV2Dx, 2.2≤x≤2.7.: II. Structure of the intermediate phase: ‘Lattice liquid crystal’. A neutron-diffraction study

We have studied the crystal structure of the uncommon phase with k=0 in ZrV₂D_x, 2.2<x<2.5, which is an intermediate between the hydrogen-disordered phase and two hydrogen superstructures, ZrV₂D_<2 with k=(1/2 1/2 1/2) and ZrV₂D_>2.7 with k=(001). This phase is a primary superstructure combining the features of the disordered phase and, depending on the hydrogen concentration, one or another superstructure with k≠0. Its lattice (translational symmetry) is the same as in the disordered phase, which is k=0. Simultaneously, the lattice sites (the hydrogen arrangement in them) are prototypes of the sites of the subsequent superstructure with k≠0. Specifically, each site of the primary superstructure with k=0 is a mix of the sites with different spatial orientation of the superstructure with k≠0. In this sense the primary superstructure can be considered as a ‘lattice liquid crystal’ whereas usual superstructure with k≠0 is a ‘lattice crystal’. In addition, we have determined the crystal structure of the ‘ordered’ phase with k=(001) in ZrV₂D_2.73. It is a transitional state between the primary superstructure and the regular superstructure with the same k.     

Investigation of the titanium–indium system

The phase diagram of the Ti–In system was determined using DTA, XRD and EDX analyses. The existence of the phases Ti₂In₅ [Mn₂Hg₅ type structure, space group P4/mbm, a=0.99995(3), c=0.29960(2) nm] and Ti₃In [Ni₃Sn type structure, space group P6₃/mmc, a=0.5978(1), c=0.4812(1) nm] was confirmed. The phase previously labeled Ti₃In₂ was found to exist in a narrow homogeneity region near Ti₅₆In₄₄. Rietveld refinement of the XRD powder pattern yielded solutions compatible with a Cu₃Au-type or a BiIn-type crystal structure, but not with a CuAu-type crystal structure. Furthermore, at 38.5 at.% In, a new phase was observed having a γ-brass related crystal structure [Ti₈In₅, space group , a=0.99578(6) nm]. The intermetallic phases were formed by a cascade of peritectic reactions ending in a eutectic at >99 at.% indium between Ti₂In₅ and (In) at 0.4 K below the melting temperature of pure indium.     

A 12R long-period stacking-ordered structure in a Mg-Ni-Y alloy

A hitherto unreported long-period stacking-ordered (LPSO) phase, designated 12R, was observed in a Mg₈₀Ni₅Y₁₅ (at.%) alloy. Microstructure was investigated by electron diffraction and high-angle annular dark-field scanning transmission electron microscopy. Results show that the 12R has a trigonal lattice (a = b = 1.112 nm, c = 3.126 nm, α = β = 90°, and γ = 120°). Unit cell of the 12R is consisted of three ABCA-type building blocks and each building block contains dominant Ni₆Y₈-type building clusters. A sound structural model is proposed based on relative positions of Ni₆Y₈ clusters in neighboring building blocks.     

316不锈钢应力腐蚀断裂扫描电镜研究

应用扫描电镜和Ｘ射线能量色散谱仪对３１６不锈钢应力腐蚀断口形貌、腐蚀产物及裂纹扩展的晶体学特征进行研究。结果表明,断裂为穿晶断裂,断口形貌为台阶条纹和河流花样,并有腐蚀产物和腐蚀坑等。通过对腐蚀坑形貌的研究,提出了腐蚀坑形态与晶面之间的关系,证明了３１６不锈钢在氯离子环境下的应力腐蚀开裂主要沿｛１００｝、｛１１１｝、｛１１０｝晶面扩展的机制。