利用设计经验保证开发和设计的质量

在开发和设计开始前尽可能充分地澄清任务要求，并且最佳地准备好具有企业特征的设计经验，是改善设计质量的重要措施。作者介绍了一种收集任务要求和准备经验数据的ＤＶ工具。该信息系统的核心是在一个具有企业特征的面向功能的产品单元基础上对任务要求进行系统描述的广阔     

反应注射成型工艺进展

本文介绍了反应注射成型新工艺和演变过程，论述反应注射成型工艺所需新材料及其发展．     

直接法制取高纯锑白

直接法制取高纯锑白该工艺流程包括：添加白云石、无烟煤粉和锑矿粉，用腐植酸盐作粘合剂制成锑矿团，将锑矿团置于韦氏炉中在１０００～１１００℃煅烧，挥发出含锑化合物，烟气经氧化和分离机械杂质后，直接回收粗锑氧。然后将粗锑氧置于装有超声波搅拌装置的桶中，用热...     

Optimization of signal detection in SPECT

Parallel-hole collimators of varying design are discussed, using the display signal-to-noise ratio of R.F. Wagner et al. (Med. Phys., vol.6, p.83-94, 1979) to obtain contrast-detail diagrams and analytical expressions for the signal-to-noise ratio in SPECT (single-photon-emission computed tomography). It is concluded: (1) that the detectability of deeply embedded small objects (more than ~10 cm deep) may be improved only slightly by improvements in the resolution and geometric efficiency of parallel-hole collimators; (2) that a long-bore collimator outperforms a low-energy general-purpose collimator for objects smaller than ~2 cm, but only to a minor degree; and (3) that for improvement of small object detectability by SPECT, the most fruitful technological pursuit would probably involve development of focused collimators.     

Fourier classification images in cardiac nuclear medicine

At present, the diagnosis of cardiac left ventricular regional wall motion abnormalities (RWMA) in nuclear medicine is aided mainly by phase images and amplitude images, which picture the spatial distribution of the phase and of the amplitude of the first harmonics of pixel time activity curves, respectively. However, they do not utilize other information contained in the original radionuclide images, and they do not offer a direct diagnostic interpretation of the data. The proposed Fourier classification images (FCI) overcome these deficiencies. Their pixel intensities express directly the diagnostic class of RWMA. The FCI pixel intensities are functions of pixel coordinates, Fourier features of pixel time activity curves, and their distribution parameters, and they are not limited by the first harmonics model. The derivation of the pixel classifier includes normalization transformation of coordinates and activities. Fourier analysis of raw image data, and teaching the computer by examples of already diagnosed cases with the help of discriminant analysis. FCI offer direct and robust diagnosis of RWMA, superior to that derived from phase and amplitude images, especially in the detection of mild RWMA.     

盐浴硫氮碳共渗45钢的接触疲劳性能

对４５钢经盐浴硫氮碳共渗处理的大批试样，进行了滚子接触疲劳性能试验，绘出了Ｐ－Ｓ－Ｎ曲线，分析了接触疲劳断口形貌及破坏机理。     

PP/纳米级CaCO_3复合材料的研究

研究了纳米级CaCO3填充粒状、粉状PP复合材料的力学性能,并用SEM观察纳米级碳酸钙在PP中的分散状态及用SALS分析了其结晶行为。结果表明,粉状PP更有利于纳米级碳酸钙在PP中的分散,并具有更好的加工性能、力学性能。同时纳米级碳酸钙改性PP的SALS图像变得弥散、模糊,PP球晶变得不完善,晶粒更小。     

铝和铝合金的晶粒细化

1 晶粒细化剂(中间合金)的生产和试验工业用晶粒细化剂通常是含有不同量的其他元素(主要是硼)的Al-Ti基合金。因此,研究二元Al-Ti平衡相图是很必要的,示于图1。Momdolfo评述了该合金系的相平衡,这里仅概述一些要点。相图中存在四方晶结构     

Degradation of organic dye using zero-valent iron prepared from by-product of pickling line

In this study, zero-valent iron (ZVI) was produced using iron oxide that is a by-product of a pickling line at a steel works. The reaction activity of the produced ZVI was evaluated through a series of decomposition experiments of Orange II aqueous solution. The size of ZVI particles increased with reduction temperature due to coalescence. Correspondingly, the specific surface area of ZVI decreased with increasing reduction temperature. The decomposition efficiency of synthesized ZVI particles was higher at a lower pH. In particular, no significant decomposition reaction was observed at pH of 4 and higher. The rate of the ZVI-assisted decomposition of Orange II was increased by addition of H2O2 at pH of 3, whereas it was reduced by addition of H2O2 at a higher pH of 6. Nevertheless, simultaneous use of ZVI, UV and H2O2 led to a considerable increase in the decomposition rate even at a high pH condition (pH = 6).