Using visual reinforcement to establish stimulus control of responding of Siamese fighting fish (Betta splendens).

Stimulus control of ring swimming was studied with male Siamese fighting fish (Betta splendens) using 2-component multiple schedules in which the components were correlated with the presence or absence of air bubbles in the water. In Experiment 1, either response-independent mirror presentations or extinction was juxtaposed with immediate response-dependent mirror presentations. Rates of ring swimming generally were higher with immediate reinforcement than with either response-independent mirror presentations or extinction. In Experiment 2, different durations of response-dependent mirror presentations were juxtaposed. Generally, higher rates of ring swimming occurred with 15-s than with 0-, 1-, or 3-s durations. Results demonstrate that stimulus control of responding can be established with these fish under several conditions of differential reinforcement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

配置抗冲切钢筋的混凝土异形柱-板柱连接试验研究

在9个柱截面为三种典型异形柱(十字形、T形和L形) -板柱连接未配置抗冲切钢筋时的冲切特性试验基础上,以十字形柱-板柱连接为代表,通过三个配置抗冲切钢筋试件与三个未配抗冲切钢筋试件的对比试验,研究了异形柱-板柱连接配置抗冲切钢筋后的冲切特性,同时将锚栓和箍筋的抗冲切性能进行了对比。试验结果表明,抗冲切钢筋可以有效地提高板的受冲切承载力和延性,在改善延性方面,锚栓比箍筋更有效。另外,将国外几个主要规范ACI3 18、BS8110及MC90 ,关于对非矩形荷载面冲切临界截面周长的规定进行了比较,从试验结果看,ACI3 18规范的取法更合理。     

混凝土框架节点有限元分析

以文献[4]中所做的碳纤维布加固节点的试验为依据,应用ANSYS程序对其中的试件2进行单调加载情况下的全过程数值模拟计算,最后通过数值计算结果与试验结果在承载能力、裂缝开展及破坏形态等方面的比较,来验证应用ANSYS程序模拟碳纤维布加固钢筋混凝土框架节点抗震性能试验的有效性和可行性。     

The response of mountain pine beetle (Dendroctonus ponderosae) to lodgepole pine trees baited with verbenone and exo-brevicomin

exo-brevicomin, a multifunctional pheromone of the mountain pine beetle,Dendroctonus ponderosae, was tested at release rates of 0.5 and 2.5 mg/day alone and in combination with the antiaggregation pheromone verbenone against unbaited controls. Significantly more lodgepole pinePinus contorta var.latifolia trees were attacked, and at higher densities, with both release rates ofexo-brevicomin than with all other treatments. Verbenone significantly reduced the response of mountain pine beetles toexo-brevicomin. Verbenone alone did not reduce the number of trees attacked by mountain pine beetle or the attack density when compared to the unbaited controls.     

上向分层尾砂充填法在仓上金矿的新应用

本文介绍了垂直矿体走向布置的上向分层尾砂充填采矿法新方案的特点及其在仓上金矿中厚矿体的具体应用。     

机械合金化Al－Al_3Ti复合材料的研究进展

本文综述了机械合金化Ａｌ－Ａｌ_３Ｔｉ材料的发展现状，论述了增强体Ａｌ_３Ｔｉ的性质和机械合金化制备的Ａｌ－Ａｌ_３Ｔｉ的组织与性能。采用机械合金化制备的Ａｌ－Ａｌ_３Ｔｉ具有理想的组织。相当高的强度与塑性，良好的热强性。目前对机械合金化制备的Ａｌ－Ａｌ_３Ｔｉ的研究不够深入，还需进行大量的工作。     

SiCf/O′-SiAlON composite: properties and oxidation retained properties

A composite of O′SiAlON (Si_2-xAl_xN_2-xO_1+x, with x 0.14) reinforced with 20 vol.% SiC monofilaments was fabricated by hot-pressing, at 1600°C, for 2 h under 34 MPa pressure. The mechanical and interfacial properties of the composites, as-fabricated as well as post-oxidized, were, investigated. The composite exhibited a significant improvement in ultimate flexure strength (640 MPa) and work of fracture (42 kJ m⁻²) compared with that (350 MPa and 1.8 kJ m⁻², respectively) of the monolithic material. These mechanical properties were slightly increased after the composite was heat treated for 24 h in air at 1200 and 1300°C. However, the composite exhibited a significant degradation in ultimate strength, while the work of fracture (WOF) remained unchanged after exposure in air at temperatures beyond 1400°C. The as-fabricated composite revealed a low interfacial shear strength (6.2 MPa) and a frictional sliding stress (3.2 MPa). After the composite was oxidized at elevated temperatures, the interfacial bonding and sliding stresses were reduced to noticeable extents, resulting from the degradation of the carbon coating layer of the SiC monofilaments.     

纤维表面处理对植物纤维增强水泥的物理力学性能影响

植物纤维增强水泥的力学性能具有湿敏感性，随湿度增加弯曲强度下降幅度较大。本文工作采用的几种浸渍处理纤维表面的方法，有效地改善了这种状况，其中一种经处理的纤维增强水泥较没有处理的对比试样在饱水状态下的弯曲强度提高了67％，气干状态提高了18％，缩小了二者间的差距。     

房屋基础因地道塌陷的加固处理

本文通过对房屋基础因地道塌陷事故的处理，提出一种结构受力合理、施工便利、经济性好的基础加固新方法，供今后实际工程事故处理时参考。     

桥梁病害桩基的加固处理

通过对铁路桥梁钻孔灌注桩病害事故的分析 ,探讨在保证列车安全运营条件下的临时加固措施 ,并提出了对此问题的一些看法