Fracture morphology and mechanical properties of thermocatalytically polymerized MMA-impregnated mortar

Mortar mixes with different water-cement ratios and consistency were impregnated with methyl-methacrylate monomer and polymerized thermally under water using the free radical initiator, -azobis (isobutyronitrile). Results on drying, impregnation and polymerization are presented. It is shown that a considerable amount of polymer remained strongly adhered or chemically inserted in the inorganic matrix. The molecular weight of the inserted polymer is higher than that obtained in the solvent extracted polymer and this is also higher than the polymer molecular weight obtained by bulk polymerization under the same conditions. The compressive and flexural strength of the impregnated mortar were found to be a function of the amount of polymer in the composites. Fracture behaviour under load, and polymer distribution inside the composites were examined by scanning electron microscopic techniques (SEM). It was observed that the polymer acts in two ways, first as a filler of porous and microcrack voids, secondly forming an anisotropic irregular network improving the bond characteristic of the interface between aggregate and matrix. Furthermore, due to the the adhesion of the polymer to both phases, it acts as a reinforcement and improves the mechanical properties, in particular the flexural strength.     

对油水乳浊液分离的研究

本文主要研究了操作条件的改变对分离效果的影响，在研究中还考察了NaCl和絮凝剂加入乳浊液后对分离过程产生的增效作用。得到了一个与实验数据相关联的数学方程，为估算油的去除率提供了一个有用的工具。在电浮选装置中采用不溶电极，为今后的分离技术提供了一个新思路。     

Iterative ultrasonic signal and image deconvolution for estimation of the complex medium response

The ill‐conditioned inverse problem of estimating ultrasonic medium responses by deconvolution of RF signals is investigated. The primary difference between the proposed method and others is that the medium response function is assumed to be complex‐valued rather than restricted to being real‐valued. Derived from the complex medium model, complex Wiener filtering is presented, and a Hilbert transform related limitation to inverse filtering type methods is discussed. We introduce a nonparametric iterative algorithm, the least squares method with point count regularization (LSPC). The algorithm is successfully applied to simulated and experimental data and demonstrates the capability of recovering both the real and imaginary parts of the medium response. The simulation results indicate that the LSPC method can outperform Wiener filters and improve the resolution of the ultrasound system by factors as high as 3.7. Experimental results using a single element transducer and a conventional medical ultrasound system with a linear array transducer show that despite the errors in pulse estimation and the noise in the RF signals, excellent results can be obtained, demonstrating the stability and robustness of the algorithm. © 2006 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 266–277, 2005     

科技项目统计信息系统的设计与实现

根据科技项目情况统计涉及的统计表类型繁多 ,要求统计数字准确、图表精美的特点 ,设计了一个由2 2个关联的表构成的科技项目统计关系数据库 ,对全省每年的科技项目进行各种统计、绘制统计图表 ,并介绍了VFP与 EXCEL间的通信 ,VFP生成图表等几个实现重点     

数字化自动控制系统性能指标的测量方法

针对传统的自动控制系统性能指标的测量方法中存在的测量过程复杂,手工操作带来的测量结果误差大等不足,本文提出一种新的基于数字化测量的控制系统性能指标测量方法,实验证明,该方法可有效降低测量过程的复杂度和主观因素,提高测量数据的精确度.     

BFe30-1-1白铜管早期腐蚀失效原因分析

某电厂凝汽器BFe30-1-1白铜管投运后几年内出现较为严重的局部腐蚀和点腐蚀,为此,对材质、水质等诸多因素进行了分析研究,通过宏观、微观检查和电化学试验,认为是微生物及生物粘泥的附着引起了铜管的早期腐蚀失效.     

电子冷冻加工的特点与应用研究

针对采用热电制冷的冷冻加工方式的特点与应用进行了研究,对于特殊工件的加工提出了一种全新的加工方式,它改革了传统的工件夹持方法,为超小、超薄、异形、低强度脆性材料的工件的加工提供了一种可能,同时电子冷冻加工使低温加工成为现实,可解决一般常用材料及某些特殊材料的加工问题,特别适宜于薄片件,韧、粘性材料的加工,结构简单,温度可调,成本低,无粉尘和气味,可应用于各行各业的机械加工中.     

BFe30-1-1白铜管早期腐蚀失效原因分析

某电厂凝汽器BFe30-1-1白铜管投运后几年内出现较为严重的局部腐蚀和点腐蚀，为此，对材质、水质等诸多因素进行了分析研究，通过宏观、微观检查和电化学试验，认为是微生物及生物粘泥的附着引起了铜管的早期腐蚀失效。     

新产品开发中的计算机辅助应用技术

分析计算机辅助技术在新产品设计领域的应用状况 ,介绍当前CAD软件开发与应用所存在的问题 ,详细论述产品设计过程中对CAD软件开发的需求     

石油化工用泵的行业现状及技术发展趋势

一、前言以原油、炼厂馏份、废气和天然气等为原料制造各种产品的工业称为石油化工行业,应用于该行业的泵类产品,称之为石油化工用泵。石油化工工业属于能源工业,在我国国民经济建设中起着非常重要的作用。石油化工用泵是石油化工生产装置中用量最大的转动设备,在生产装置中它就像心脏输送血液一样,将各种液体介质,例如石油、成品油、化工原料、中间产品和成品,输送到各个地方。在众多的泵类产品中,石油化工用泵占有非常重要的地位。在化工和石油部门生产中,原料半成品和成品大多是液体,而将原料制成半成品和成品,需要经过复杂的工艺过程。泵在这些过程中起到了输送液体和提供化学反应的压力、流量的作用。在这些泵产品中,离心泵占的比例较大,例如:一个中型炼油厂需要1 000余台泵,其中离心泵占83％,往复泵占6％,