一种高精度的偏移速度分析方法——广义屏偏移加Born反演

在波动方程叠前深度偏移中，速度是最关键的成像参数。首先分别对各种求取速度的方法进行了回顾和分析，然后按照判断速度正确性的不同标准将求取速度的方法分为3类：第1类是以正演结果与实际数据的拟合最优作为判断标准；第2类是以成像质量最优作为判断标准；第3类是解析类型的方法。在此基础上提出，基于逆散射理论反演慢度扰动的方法和双域偏移成像方法在理论基础上有相当的一致性，所以在利用波形信息的高精度速度分析中可以将二者有机地结合起来。进而提出了一种将广义屏偏移与Born反演结合在一起实现速度分析的新思路。该方法保证了速度分析和偏移在理论基础上的一致性，能够充分发挥波动方程偏移在振幅保真方面的优势，是一种稳定的、高精度的速度分析方法。     

An Inverse Problem for the ac Magnetic Force Microscopy of Superconductors

A basic inversion problem for the magnetic force microscopy (MFM) of a semiinfinite superconductor in the Meissner state is formulated, ac Detection is assumed, with the MFM tip oscillating at angular frequency Ω. The coupling of all electrodynamic fields is treated, including a normal-current density in the superconductor. Under certain assumptions on the tip and superconductor geometry, a unique penetration depth λ(z) can be recovered from onedimensional force gradient measurements. This development opens new possibilities for the nondestructive evaluation of superconducting crystals and films.     

Improvement of inverse heat conduction solution using Laplace transformation: Method of partial division of time

Any solution for an inverse heat conduction problem makes the estimation of surface temperature and surface heat flux worsen in the case where these values behave like a triangular shape change with time. In order to compensate for this defect, Monde and colleagues, who succeeded in obtaining analytical inverse solutions using the Laplace transform technique, introduce a new idea where these changes over the entire measurement time can be split into several parts depending on the behavior. Therefore, an approximate equation to trace the measured temperature change can be derived, resulting in good estimation of surface temperature and surface heat flux even in the case of the triangular shape change and sharp change. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(7): 630–638, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10117     

螺杆钻具逆向检测方法的研究

为了确保螺杆钻具的效率和使用寿命 ,研究了采用液马达驱动的螺杆钻具逆向检测试验法。此法只是类比试验 ,因此报表中的压力、转速、扭矩、功率和效率或特性曲线并不准确反映钻具的特性 ,但经过一定的经验积累 ,用户根据这些参数 ,可以方便而准确地判断出螺杆钻具性能的好坏 ,甚至可以判断低性能钻具的问题所在。鉴于螺杆钻具在出厂前的检测试验目的并不在于得到钻具准确的性能指标 ,而是评价钻具是否合格 ,故此法完全满足检测要求 ,所得结果可以用于产品检验 ,生成的报表直观、实用、易被现场人员接受     

Solubility of Ruthenium Dioxide in Lead Borosilicate Glasses

The solubility of RuO₂ in a lead borosilicate glass was measured in the range of 700° to 1000°C. The effect of dissolved alumina in the glass was studied in the same range using 2%, 4%, 6%, and 10% dissolved alumina. The solubility showed an exponential dependence on temperature, and the dissolved alumina decreased the solubility at any given temperature; however, the solubility was essentially the same in all of the alumina-containing glasses. The Kelvin equation was used to deduce the concentration of RuO₂ in glass as a function of the curvature of the RuO₂ particles, and the dependence was found to be quite small. The implications of the results in processing thick-film resistors using RuO₂ as the conductive phase and these glasses as insulating phases on an alumina substrate are discussed.     

活性染料印花用合成增稠剂的研制

用反相乳液聚合方法,以“C_(?)—r射线引发而得到一种新型活性染料印花增稠剂。并研究了辐照剂量,辅助单体、交联剂用量及水相的PH值对乳液的增稠性和耐电解质性的影响,运用正交设计总结出了最佳反应条件,结果证明合成增稠剂代替天然品是可行的。     

Inverse resolution of the heat-transfer equation with internal heat source: Application to the quenching of steels with phase transformations

A method is described for calculating the time dependence of the temperature and heat flux (on heating and cooling) at the surface of a solid body. For a given ambient temperature and a known time-temperature function of an interior point, the surface heat flux is computed through an inverse conduction algorithm taking into account the nonlinear nature of the problem. Moreover, this algorithm includes the enthalpy of phase transformations. The influence of space and time steps on inverse calculations (precision, stability) is investigated. The method is then applied to thermal cases involving different transformations in steels.     

高压下甲烷在环己烷-乙醇及苯-乙醇中的溶解度测定与研究

利用自己建立的高压下测定气体在液体中溶解度的测定装置,在15-45℃、2.0-12.0 MPa的条件下,首次测定了甲烷在环已烷-乙醇、苯-乙醇混合体系中的溶解度。用PRSV状态方程及3种不同的混合规则对实验测定的气液平衡数据进行了计算。计算结果表明,使用同一种状态方程的不同混合规则计算极性体系的气液平衡数据所得的结果不同,改变传统的混合规则可提高计算精度。同时还使用Aalto-Keskinen模型及本研究提出的Yen-Woods-Aalto-Keskinen模型对实验得到的高压液相摩尔体积进行了估算,均得到满意的结果。     

抛物型方程的一个反问题

本文讨论了抛物型方程u_t-u_m+a(x)■=0在区域 x>0,t>0上确定系数 a(x)的■,给出了反问题局部解的存在性和唯一性.     

A Model for the Diffusion of Moisture in Adhesive Joints. Part I: Equations Governing Diffusion

A methodology is proposed to relate the diffusion coefficient of small penetrant molecules in polymers to temperature, strain, and penetrant concentration. The approach used is based on well-known free volume theories. It is assumed that the transport kinetics is governed by the constant redistribution of the free volume, caused by the segmental motions of the polymeric chains. An expression for the diffusion coefficient is inferred from the temperature, strain, and penetrant concentration dependence of the free volume. The stress dependence of solubility is predicted from the Hildebrand theory. It is shown that the resulting constitutive equations exhibit many features desirable for joint durability studies. Finally, a non-Fickian driving force arising from differential swelling is included in the governing equations.