U71Mn75 kg/m重型钢轨的性能研究

研究了U71Mn75kg/m重型钢轨钢的等温转变曲线及连续冷却曲线，发现将冷却速度控制在8－2℃/s之间，可获得强度高，耐磨性好的珠光体，通过与U7460kg/m钢轨的对比试验可知，在二者实物疲劳强度相近的情况下，U71Mn75kg/m重型钢轨的承载能力是U7460kg/m钢轨的1．3倍，在同样的冲击能量下，前者所承受的冲击次数高于后者。     

基于聚邻苯二胺/石墨烯修饰电极的肠道病毒71型（EV71）电化学免疫传感器

采用改性的Hummers法制备石墨烯氧化物（GO）,并将其滴涂在玻碳电极（GCE）表面。通过电化学还原将GO还原为石墨烯,并进一步采用电化学聚合法在石墨烯表面形成聚邻苯二胺（PoPD）膜,从而制备了PoPD/石墨烯修饰GCE。将EV71抗体固定在修饰电极表面,制备新型的电化学免疫传感器。当发生免疫反应时,由于EV71抗原与抗体生成的免疫复合物阻碍了电子的传递,PoPD的氧化峰电流下降。当抗原的浓度在0.1-80ng/mL范围内,PoPD氧化峰电流的降低值与抗原的浓度成正比。该免疫传感器对EV71的检测限为0.08ng/mL（信噪比为3）。     

攀钢重轨钢初轧坯堆冷的除氢效果

用石腊油法测定了U71Mn重轨钢初轧坯中的可扩散氢和氢在钢中的扩散系数,并通过解剖经过堆垛缓冷的初轧坯,测定氢在断面上的分布结果表明,重轨钢坯中的氢绝大部分均为可扩散氢,室温下氢在U71Mn钢坯中扩散系数为(0.85—1.02)×10~(-6)cm~2/s初轧坯经堆冷后,含氢量大幅度下降,它有助于形成攀钢重轨无白点现象.     

ATV71变频器在氧化铝生产线中的应用

本文结合氧化铝的生产流程和它对变频器的使用要求,介绍了ATV71系列变频器在氧化铝生产线中的应用.同时,重点阐述了ATV71变频器与PLC在生产线自动控制中的通讯设置.     

Introduction of gallium in HZSM5 and HY zeolites by post-synthesis treatment with trimethylgallium

Framework gallium was introduced in dealuminated HZSM5 and HY zeolites by treatment with trimethylgallium (TMG). The experiments were successful for both zeolites, particularly when performed in a hydrogen atmosphere. Side reactions of TMG with isolated silanol groups or Brxnsted acid sites resulted in the formation of extra-framework gallium. The Ga/HZSM5 zeolite showed an enhanced selectivity to aromatics in the propane conversion.     

Mesh modelling and analysis of cracked uni-planar tubular K-joints

In this paper, a new modeling method is proposed for a uni-planar tubular K-joint containing an arbitrary surface crack located along the chord weld toe. The crack is defined first in a 2-D plane and then mapped onto a 3-D curved crack surface. Subsequently, an automatic mesh generation is developed for producing the complete finite element mesh model. This technique can be realized by sub-dividing the entire structure into distinct zones. In each zone, the mesh is generated separately. After the mesh of all the zones have been completed, the complete model is obtained by merging the mesh of every zone. It has been proved to be efficient and effective in producing different quality mesh at different zones. In order to locate the likely crack initiation position, the hot spot stresses and hence the stress concentration factors (SCFs) need to be determined precisely. The hot spot stress correlated to the number of cycles, i.e. the S-N curve, has been used to predict the life of uncracked tubular K-joints. For a cracked tubular K-joint, its remaining service life depends on the fracture parameter called the stress intensity factors (SIFs). Two different methods, namely the displacement extrapolation and J-integral methods, are used to evaluate the SIFs along the crack front for different crack shapes in this study. Convergence tests for numerical analysis have been carried thoroughly to check the accuracy of the computed SIFs. The two sets of numerical results are in complete agreement. To evaluate the accuracy of numerical modeling, a full-scale fatigue test on tubular K-joint subjected to combined axial load and in-plane bending load was conducted. Comparison between the numerical and experimental results again shows a good agreement. Therefore, the proposed modelling and mesh generation methods demonstrate that the estimated stress intensity factors for any tubular K-joints are both accurate and reliable.     

基亏精加工的数控车削技术探究

探讨了数控切削中的精加工工艺与编程技术，提出通过刃磨刀具、预留Z向对刀偏、修改刀具补偿参数和修改G71指令U参数等方法，来提高零件精加工精度和效率。研究结果表明，该方法行之有效，能广泛应用于生产实践当中。     

络筒车间的温湿度测量与纱线材料值修正

针对络筒车间的温湿度变化导致纱线含水量不稳定,使同一种纱线在不同温湿度下具有不同材料值这一现象,介绍了一种在清纱器上配接的温湿度测量装置,采用低成本数字化传感器SHT71芯片对络筒车间温湿度进行实时测量,简要说明其电路方案,并指出纱线材料值的修正方法;得出此技术的应用提高了电容式清纱器的环境适应性,为清纱器在络筒车间的准确运行提供了保障的结论。     

From Carnival to Satire: Photomontage as a Commentary on Photography

This article discusses two eras of manipulated photography –that of trick photography before 1914 and that of photomontage of the 1930s. The former had a carnivalesque character, while the latter highlighted political satire. Although profusely discussed in its days, trick photography was largely anonymous. By contrast, the 1930s brought about distinct personalities such as John Heartfield or the Soviet cartoonist Boris Klinch as well as prominent theorists, including Karel Teige or Günther Anders. Despite formal differences the article argues for a continuity of approaches: both periods represent steps that question photography as a medium that claims stable signification.     

薄层色谱原位富集显微拉曼检测荧光增白剂

利用薄层色谱(TLC)原位富集与显微拉曼光谱(micro-Raman)联用的方法对食品包装材料中荧光增白剂71(C.I.71)和113(C.I.113)进行检测。采用硅胶60F₂₅₄铝板为固定相,甲醇-乙酸乙酯-冰醋酸-水(0.6︰3.4︰0.5︰0.5)混合溶液为展开剂,在UV₂₅₄nm和UV₃₆₅nm下检测定位,用乙醇对薄层板上的目标斑点进行原位富集,在波长532nm条件下进行显微拉曼光谱micro-Raman检测,并对专属性、灵敏度进行考察。结果显示,C.I.71和C.I.113检测限分别为1.25 mg/kg和3.75 mg/kg,该法检测的7批食品包装材料一次性纸杯中,有2批含有C.I.113。所建立的方法专属性强、灵敏度高,可为食品包装材料中荧光增白剂的检测提供备选方法。