单源点法的一种改进

在应用能量线性叠加计算港内不规则波绕射系数时^[1,2]，通过假设不同的计算点具有不同的方向谱，从而增加单源点法考虑地形变化的能力。其中各计算点的方向谱由逆波向线追踪方向确定。本文由此观点建立数学模型。并通过实例计算。来验证这个想法。     

X-ray structure analysis and elastic properties of a fabric reinforced carbon/carbon composite

The effect of heat treatment on microstructure of a plain-weave carbon fabric reinforced carbon-carbon composite with phenolformaldehyde-derived carbon matrix was investigated by X-ray diffraction. The diffraction patterns were analysed by the least-square fitting program Carbonxs. After heat treatment from 1000 to 2800 °C the interplanar distance of (002) planes decreased from 3.488 to 3.420 Å and the lattice parameter in basal plane increased from 2.440 to 2.464 Å, respectively. Simultaneously, the coherent block size in the basal plane directions increased from 18 to 54 Å, which was accompanied by an increase of the fraction of organised carbon atoms from 0.50 to 0.85. The 002 diffraction profile of the composite was much narrower than the sum of peaks of the matrix and fabric alone. This can probably be caused by a better crystallographic ordering (or by a partial graphitisation) of the matrix in the composite. On the other hand, the composite Young’s modulus slightly decreased with the treatment temperature increasing from 2200 to 2800 °C in spite of the established strong improvement of fibre crystallinity and, therefore, fibre modulus. The mechanisms diminishing the modulus of composite (e.g. partial matrix graphitisation at the fibre/matrix interface and decreasing fibre/matrix contact area) probably prevailed over the increasing contribution of the fibre modulus.     

Study of the solid-liquid equilibria in the LiPO3-Y(PO3)3 binary system

The LiPO₃-Y(PO₃)₃ system has been studied for the first time. Microdifferential thermal analysis (μ-DTA), infrared spectroscopy (IR) and X-ray diffraction were used to investigate the liquidus and solidus relations. The only new compound observed within this system is LiY(PO₃)₄, melting incongruently at 1104 K. An eutectic appears at 4±1 mol% Y(PO₃)₃ at 933 K. LiY(PO₃)₄ crystallizes in the monoclinic system C_2/c with a unit cell: a=16.201(4) Å, b=7.013(2) Å, c=9.573(2) Å, β=125.589(9)°, Z=4 and V=884.5 Å³, which is isostructural to LiNd(PO₃)₄. The infrared absorption spectrum indicates that this salt is a chain polyphosphate.     

Mössbauer effect studies and X-ray diffraction analysis of cobalt ferrite prepared in powder form by thermal decomposition method

Cobalt ferrite (Co_xFe_3?xO₄) is prepared in powder form by thermal decomposition of iron and cobalt salts and is analysed by X-ray diffraction and Mössbauer spectroscopic techniques. The variation of Mössbauer parameters, lattice parameters and crystallite size of the products formed with variation in the composition of Fe and Co ratios are studied. The studies confirm the formation of nano-size cobalt ferrite particles with defect structure and it is found to be maximum for the Fe : Co = 60 : 40 ratio of the initial precursor oxides.     

Elastic properties of polycrystalline gold thin films: Simulation and X-ray diffraction experiments

The elastic behavior of supported gold thin films has been studied using a framework in which the elastic interaction between grains and the actual structure of the film (i.e. preferential grain orientation and grain shape) are taken into account. Experiments were carried out using synchrotron X-ray diffraction combined with in-situ tensile testing and thereafter, no assumptions on the residual stress state and on the stress-free lattice parameter a₀ have to be made. Modeling of grain elastic interactions is based on the extension of Eshelby-Kröner model, which allows for estimating the elastic behavior of polycrystals considering the texture and the shape of the crystallites. Flat-disc shaped grains arrangement is shown to yield the best representation of the elastic behavior of the fiber-textured gold thin films composed of columnar grains. This non-intuitive representation results from free-surface effect.     

Thermogravimetry and wide angle X-ray diffraction study on the structure of irradiated and thermally treated kodar film

The degradation behaviour of Kodar [poly(1,4-cyclohexylene dimethyl-eneterephthalate)] was investigated in air using thermogravimetry, differential thermal analysis and wide angle X-ray diffraction studies. The rates of crystallization and degradation were influenced by thermal exposure and polychromatic irradiation (Λ > 290 nm) for different time intervals. The crystallinity changes (X_c%) and activation energies (ΔE) for the systems have been determined.     

多相物质粉末衍射的物相检索

讨论了多相物质粉末衍射的物相检索问题，介绍了XRDS的物相检索软件。这是一种智能型的物相检索程序，考虑了测试数据的不确定度，以及粉末样品和块状样品衍射图谱各自的特点，不仅注意到实际样品中微量物相存在的可能，也注意到块状样品结构有序性的可能。XRDS能够帮助材料工作者同时检出样品中所含的多种物相及其含量，操作简单、结果可靠。     

自动实时X射线检测技术在半导体制程控制中的应用

对X光检测的不同技术在半导体制程上的应用作了详细的介绍;着重讨论了全旋倾斜(off-axis)X射线技术的特点和优势。