Influence of expandable graphite on fire resistance and water resistance of flame-retardant coatings

Expandable graphite (EG) coating and ammonium polyphosphate-pentaerythritol-melamine (APP-PER-MEL) coating were prepared. Thermal degradation and char formation of the coatings were investigated by differential thermal analysis (DTA), thermogravimetry (TG), X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results have shown that the anti-oxidation and fire-resistant properties of expandable graphite coating containing EG with size of 74 μm are better than those of APP-PER-MEL coating. The static immersion test was applied to study water resistance of the coatings, and the fire protection test and mechanical test were used to analyse heat insulation and mechanical properties of coatings before and after water immersion. The fire-resistant and mechanical properties of APP-PER-MEL coating were severely damaged by water immersion, whereas EG coating containing 8.5% EG with size of 74 μm could retain the good fire resistance even after 500 h water immersion.     

链霉亲和素-蛋白A融合蛋白基因在大肠杆菌中的表达

将合链霉亲和亲-蛋白A（Streptavidin－proteinA）融合蛋白基因的表达质粒pTSAPA导入大肠杆菌BL21（DE3），成功地表达了该融合蛋白，经SIJS－PAGE及免疫印迹等方法证实该蛋白既具有IgG的结合活性，又具生物素结合活性。     

Effect of preparation conditions on the properties of a coal-derived activated carbon honeycomb monolith

Activated carbon honeycomb (ACH) monoliths were prepared by extruding of a mixture of bituminous coal and organic additives and subsequent carbonization and steam activation. Preparation parameters that were varied were carbonization temperature and activation time. The carbonization conditions were 500, 650 and 800 °C for 1 h and the steam activation conditions were 850 °C for 2, 4 and 6 h. The monoliths at various states were characterized by SEM, XRD, nitrogen adsorption and compression test. It was found that carbonization temperature has significant effects on pore size distribution and mechanical strength of ACH monoliths. The ACH monoliths prepared from high carbonization temperatures exhibited lower values of the BET surface area and total pore volume and higher value of the mechanical strength than those of the ACH monoliths prepared from low carbonization temperatures. This was attributed to the effect of high temperature carbonization that results in the formation of relatively less defective structures.     

复合材料纤维缠绕成型CAD/CAM相关技术研究

纤维缠绕成型是制造高强度复合材料制品的一种重要的工艺方法，将CAD／CAM方法应用其中可以大大提高生产效率，降低设计成本。本文提出了纤维缠绕CAD／CAM系统的总体方案，并对其中缠绕数学模型、线型优化、丝嘴轨迹生成等量要组成部分进行了分析与研究，为CAD／CAM系统的开发奠定了理论基础。     

Automatic optical phase identification of micro-drill bits based on improved ASM and bag of shape segment in PCB production

This paper addresses the problem of automatic optical phase identification of micro-drill bits for micro-drilling tool inspection in printed circuit board production. To overcome the limitations of conventional active shape model (ASM) on shape modeling of micro-drill bits, six key landmarks are defined for the initialization and optimization of ASM, and a novel method based on projection profiles is also proposed for these key landmarks detection. In addition, to involve the local shape feature, a bag of shape segment (BoSS) model is developed. Based on the improved ASM and BoSS, a new shape representation of micro-drill bits is proposed for phase identification. Experimental results show that the proposed method outperforms the conventional ASM and can improve the phase identification accuracy of micro-drill bits.     

平面线弹性问题的等几何形状优化方法

介绍具有等几何分析功能的GeoPDEs平台的数据结构和分析流程,针对二维平面形状优化问题,以控制顶点为设计变量,在推导出等几何分析的灵敏度计算公式后,提出基于GeoPDEs平台的灵敏度分析的高效实现方法,并采用移动渐近线法(Method of Moving Asymptotes,MMA)算法进行等几何形状优化.形状优化实例表明该方法收敛速度快,优化结果较理想.     

水煤浆在燃油热水锅炉内的燃烧试验

主要介绍了７ＭＷ燃油热水锅炉改烧水煤浆的改造设计，水煤浆炉前系统的调试，锅炉改造后的调试和水煤浆燃烧试验的结果。     

Carbon-encapsulated Fe nanoparticles from detonation-induced pyrolysis of ferrocene

Carbon-encapsulated Fe nanoparticles with size between 5 and 20 nm were synthesized via a picric acid-detonation-induced pyrolysis of ferrocene, which is characterized by a self-heating and extremely fast process. The nanoparticles exhibit well-constructed core-shell structures, with bcc-Fe cores and graphitic shells. The graphitic shells can protect effectively the cores against the attack of HNO₃ solution. The formation of the core-shell nanoparticles can be selectively controlled by adjusting the composition of the picric acid-ferrocene mixture, which determines C/Fe atomic ratio of the reaction system. The core-shell nanoparticles are preferably formed at low C/Fe atomic ratios, while tubular structures are formed at high C/Fe ratio. The possible pathway for the carbon-encapsulated Fe nanoparticles formation is discussed briefly.     

Effects of the electrospray ionization parameters on the formation and morphology of colloidal microspheres of polyacrylonitrile

Polyacrylonitrile colloidal microspheres have been successfully prepared with different concentrations of electrospraying polyacrylonitrile solutions. The morphology of the colloidal spheres has two kinds of structures and is strongly affected by electrospray‐ionization parameters, such as the polymer concentration, applied voltage, and distance between the electrodes. The solvent can also affect the morphology of polyacrylonitrile. The optimum conditions for preparing colloidal spheres have been found, and differential scanning calorimetry results indicate that polyacrylonitrile colloid spheres are amorphous. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2889–2893, 2006     

再生混凝土力学性能提升技术与应用

针对大量混凝土废弃物造成生态环境日益恶化及天然骨料资源日益缺乏的问题,通过配制不同强度等级和不同再生骨料掺量的再生混凝土,并结合锡澄运河三级航道整治工程对再生混凝土力学性能及其提升技术进行试验研究。结果表明:再生骨料的掺量对C35及以下中低强度混凝土力学性能影响较小,而对C40及以上中高强度混凝土有较大影响,随再生骨料掺量的增加,再生混凝土力学性能降低;通过合理选用再生骨料级配、与天然骨料复掺、对再生骨料进行强化以及优化配合比参数等措施能提升混凝土力学性能;锡澄运河三级航道整治工程实际应用取得了很好的技术经济效益。