偏氯乙烯—丙烯酸酯悬浮共聚树脂的研究进展

本文对偏氯乙烯—丙烯酸酯悬浮共聚树脂的研究进展进行了综述。讨论了丙烯酸酯的引入对聚偏氯乙烯树脂加工性、热稳定性等性能的改进,并对国际上就该树脂合成工艺以及分子量及分布的研究进行了分析。     

Magnetic field integral equation at very low frequencies

It is known that there is a low-frequency breakdown problem when the method of moments (MOM) with Rao-Wilton-Glisson (RWG) basis is used in the electric field integral equation (EFIE); it can be solved through the loop and tree basis decomposition. The behavior of the magnetic field integral equation (MFIE) at very low frequencies is investigated using MOM, where two approaches are presented based on the RWG basis and loop and tree bases. The study shows that MFIE can be solved by the conventional MOM with the RWG basis at arbitrarily low frequencies, but there exists an accuracy problem in the real part of the electric current. Although the error in the current distribution is small, it results in a large error in the far-field computation. This is because a big cancellation occurs during the far field computation. The source of error in the current distribution is easily detected through the MOM analysis using the loop and tree basis decomposition. To eliminate the error, a perturbation method is proposed, from which a very accurate real part of the tree current has been obtained. Using the perturbation method, the error in the far-field computation is also removed. Numerical examples show that both the current distribution and the far field can be accurately computed at extremely low frequencies by the proposed method.     

SF－2催化裂化油浆防垢剂的研制与应用

通过对催化裂化装置分馏塔底和换热器的积垢组成的分析，探明了积垢的机理。根据机理研制了ＳＦ－２防垢剂，实验室的评价和工业装置上的初步试验表明：ＳＦ－２防垢剂能有效地抑制催化裂化装置分馏塔底油浆系统的积垢。     

Inactivation of brainstem motor nuclei blocks expression but not acquisition of the rabbit's classically conditioned eyeblink response.

Rabbits were eyeblink conditioned while their accessory abducens nucleus (ACC), facial nucleus ( FN), and surrounding reticular formation (RF) were temporarily inactivated with microinjections of muscimol to determine whether these structures are critically involved in acquisition of the conditioned eyeblink response (CR). Rabbits performed no CRs or unconditioned responses (URs) during inactivation training. Training was continued without inactivation and rabbits performed the CR at asymptotic levels from the start of training without inactivation. They had fully learned the CR while their ACC, FN, and RF were inactivated, despite performing no CRs or URs at all during inactivation. These results rule out any critical role for neurons within the ACC, FN, or surrounding RF in acquisition of the classically conditioned eyeblink response. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

硝基杂环化合物N-6、N-8对5’-鸟苷酸的辐射敏化作用及其机理的研究

本工作用磷钼蓝比色法研究发现,在缺氧的中性水溶液中,硝基杂环化合物N-6、N-8对5’鸟苷酸(5’-GMP)的γ射线辐解过程中无机磷的释放均有敏化效应,其中以N-8较佳,但它们的敏化效果都与敏化剂的浓度和辐照剂量有关,其化学增强比C.E.R’=G(P_1)有敏化剂/G(P_1)无敏化剂,对于同一浓度的敏化剂,随剂量的增大而减小;而在同一剂量条件下,则随敏化剂浓度的增大而增大。敏化机制则是由于电子从5’-鸟苷酸的C’_5自由基向硝基杂环化合物(一种亲电子敏化剂S)转移形成阳碳离子继而水解的结果,从而增加了γ射线辐射诱发无机磷释放的产额G(R_1)。     

Matching two perspective views

A computational approach to image matching is described. It uses multiple attributes associated with each image point to yield a generally overdetermined system of constraints, taking into account possible structural discontinuities and occlusions. In the algorithm implemented, intensity, edgeness, and cornerness attributes are used in conjunction with the constraints arising from intraregional smoothness, field continuity and discontinuity, and occlusions to compute dense displacement fields and occlusion maps along the pixel grids. The intensity, edgeness, and cornerness are invariant under rigid motion in the image plane. In order to cope with large disparities, a multiresolution multigrid structure is employed. Coarser level edgeness and cornerness measures are obtained by blurring the finer level measures. The algorithm has been tested on real-world scenes with depth discontinuities and occlusions. A special case of two-view matching is stereo matching, where the motion between two images is known. The algorithm can be easily specialized to perform stereo matching using the epipolar constraint     

Effect of Matrix Constitution on Microstructure and Mechanical Properties of Rheocast Metal Matrix Composites

In this study, aluminum-based metallic matrices with varying amounts of copper (I wt.% Cu, 3 wt.% Cu and 4.5 wt.% Cu) were reinforced with SiC particulates using a partial liquid phase casting technique. Microstructural characterization studies conducted on the composite samples revealed an increase in uniformity of distribution of SiC particulates and SiC/Al interfacial integrity and a decrease: in porosity in the metallic matrix with decreasing weight percent of copper. The results of the ageing studies revealed an accelerated ageing kinetics for the Al-1% Cu/SiC composite when compared to Al-3% Cu/SiC and Al-4.5% Cu/SiC samples. Results of ambient temperature mechanical tests demonstrate an increase in 0.2% yield strength and ultimate tensile strength of the composites and a decrease in ductility and strain hardening rate with an increasing weight percent of copper in the metallic matrix. Fracture studies revealed the presence of interfacial debonding, particulate breakage and cracks in the matrix of tensile specimens. The results of microstructural characterization, mechanical testing and fractography were finally rationalized in terms of the effect of variation in weight percent of copper in the metallic matrix.     

通过VB6.0数据报表对象创建多记录集报表

在VB6．0中通过一种变通的方法．实现在数据报表对象的细节区输出多个记录集中的记录。