大气式燃烧黄焰工况的探讨

结合实验对大气式燃烧中黄焰的生成机理,数学描述及其影响因素进行讨论。     

异形柱空间框架结构的受力性能研究

为了研究异形柱对框架结构受力性能的影响,观测空间框架结构的开裂及破坏过程,做了两榀异形柱空间框架结构、一榀矩形柱空间框架结构的大型试验,对试验结果进行了分析比较,得出了有益的结论。     

小浪底地下厂房顶拱的开挖与支护

小浪底工程地下厂房顶拱分两期支护,一期为钢筋网喷混凝土加岩石张拉锚杆,二期为顶拱系统预应力锚索。施工中我们从开挖与支护方案审查、质量控制到进度控制,整个施工过程严格把关,关键工序重点控制,保证了工程质量和进度。     

Radio frequency plasma processing to produce chromium sputter targets

Production of thick chromium layers on copper substrates used for sputter targets provides a number of technological challenges. These challenges were addressed using radio frequency (RF) plasma spray technology. The efforts were focused on several objectives. The coatings should be as dense as possible with residual stresses low enough to avoid strong substrate bending and to prevent adhesive and/or cohesive failure of the coating. In addition, the deposition efficiency should be maximized. Different parameters were varied to find the optimum spraying conditions. Two different powder grain sizes, −90+45 μm and −63+20 μm, were used. First, a spheroidization study was performed to select the most suitable chamber pressure, the optimum plasma power, and a reasonable range of the powder feed rate. During deposition of the coatings, the powder feed rate, the spray distance, the substrate roughness, and the substrate cooling mode were optimized. The substrates were noncooled, gas cooled, or directly water cooled, respectively. The water-cooled samples showed no substrate bending; however, the thermal stresses occurring were strong enough to cause coating failure in adhesion or cohesion. Noncooled samples showed the best adhesion properties, while substrate bending could be kept within acceptable limits.     

Interface reaction between nickel-base self-fluxing alloy coating and steel substrate

The interface reaction between a nickel-base, self-fluxing alloy coating and a steel substrate has been investigated to examine the formation of “pores,” which are observed along the interface of used boiler tubes. It was found that lumpy precipitates form along the interface instead of pores after heating at high temperatures and that the precipitates are of Fe₂B boride. The adhesion strength of the coating is not decreased by the formation of Fe₂B precipitates along the interface because of the increase of the adhesion due to interdiffusion.     

Effect of microstructure and chemical composition of hardfacing alloy on abrasive wear behavior

Hardfacing, a surface modification technique, is used to rebuild the surface of a workpiece. The economic success of the process depends on selective application of hardfacing material and its chemical composition for a particular application. In this context, three hardfacing electrodes having different chemical compositions have been selected and their abrasive wear responses was compared with that of mild steel. The emphasis has been made to realize the effect of microstructure and chemical composition on the wear response of the hardfacing material with respect to mild steel. It has been observed that the wear rate of hardfacing alloys is lower than that of mild steel. The hardfacing alloy having the highest chromium content exhibits the lowest wear rate.     

PT—400型电弧喷涂电源的研制

介绍PT— 4 0 0型电弧喷涂电源的结构、原理、参数、特点及该电源的应用。     

外喷雾水电联锁湿式煤电钻的研制及应用

叙述了外喷雾水电联锁煤电钻湿式打眼法 ,通过现场实践取得良好防尘效果     

九江长江干流江岸赤心堤段高压喷射灌浆施工

介绍了江西省九江长江干流江岸赤心堤段高压喷射灌浆设计与施工,并对高喷灌浆效果进行了评价,分析资料表明高喷灌浆达到了预期的良好效果,所采用的施工工艺合适可行。     

Microbial and Quality Characteristics of Pork Cuts from Carcasses Treated with Sanitizing Sprays

Pork carcasses were sprayed with 1.5% acetic, citric, or lactic acid. Loins were vacuum packed and stored at 0–2°, chops were cut periodically from loins and stored at 2–4°. Acetic and citric acids decreased (P<0.05) aerobic plate counts (APC) and total coliforms in loins for 14 days. Species of Salmonella, Yersinia, and Campylobacter were found on 0, 6, and 5% of samples. Lisreria spp were detected on 69% of loins and on 33% of chops. The sanitizing treatments were of relatively limited effectiveness for long term storage. No pH, TBA or sensory quality differences were observed.