基于阵列扩展解模糊方法研究

指出了长短基线法、参差基线法、无模糊长基线三种解模糊方法的各自缺点,介绍了四阶累积量MUSIC算法原理和阵列扩展原理,并根据阵列扩展原理提出了在较小空间内放置三阵元均匀线阵扩展的解模糊方法,并进行了Matlab仿真,验证了方法的可行性。为解模糊方法提出了一个崭新的思路。     

Flocculation behavior of cationic pea starch prepared by the graft copolymerization of acrylamide for wastewater treatment

To improve the flocculation efficiency of coal mine wastewater treatment, we synthesized a cationic flocculant by grafting acrylamide (AM) onto pea starch, and we performed the characterization with elemental analysis, Fourier transform infrared spectrometry, scanning electron microscopy, thermogravimetric analysis, and NMR. The effects of the synthesis conditions were also investigated, and the optimal synthesis parameters of the cationic flocculant were obtained. The mass ratio between pea starch and AM was 0.5 with a reaction temperature of 65 °C. The dosages of ceric ammonium nitrate and 3‐chloro‐2‐hydroxypropyl‐trimethylammonium chloride were 0.02 and 0.11 mol/L, respectively. Application experiments for wastewater treatment were carried out consequently, and the optimal dosage of cationic pea starch was 40 mg/L within the pH range 6–8. Compared with other traditional flocculation products, the cationic pea starch showed the best flocculation behavior for coal mine wastewater. Therefore, the cationic pea‐starch‐grafted AM may be applicable as a novel flocculant in wastewater treatment and has already demonstrated outstanding features. It is bound to replace other traditional flocculants in the future. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43922.     

钢-混凝土组合框架梁变形计算的有效翼缘宽度

由于剪滞效应的存在,组合框架梁的混凝土翼板不能完全参与共同工作,按照完全组合的换算截面法计算组合梁的变形将得到不安全的计算结果。首先根据弹性理论推导传统的完全组合梁以及剪滞组合梁理论模型的基本方程,并采用有限元软件Msc.Marc对理论模型进行验证,理论结果与有限元计算结果吻合良好,说明理论模型的准确性及合理性。然后基于两个理论模型,提出一种物理意义更为明确的有效翼缘宽度系数的定义,直接用于组合梁的变形计算。研究楼板的宽跨比、楼板宽厚比、板梁高度比以及组合梁高宽比这4个无量纲参数对有效翼缘宽度系数的影响。研究发现,影响有效翼缘宽度系数的关键参数为楼板的宽跨比。在此基础上,提出有效翼缘宽度的计算公式,为组合梁的研究及设计人员提供参考。     

加固用丁苯混凝土长期黏结性能及机理研究

研究了加固用丁苯乳液水泥基混凝土/砂浆/浆体与既有混凝土的长期黏结性能,对此类聚合物水泥基材料长期黏结性能作用机理进行试验研究。结果表明,丁苯浆体斜剪、直剪、受折、轴向拉伸及丁苯混凝土劈裂强度性能优越,丁苯砂浆的长期水泥水化程度较高和其特有的有益的水泥水化变化规律相关,丁苯砂浆受热和干缩变形规律不损害其长期黏结性能,有些变形甚至对其长期黏结性能有益,电镜照片显示其界面黏结效果良好,与其宏观良好的长期黏结性能相一致,诠释和推证了其长期黏结机理。研究成果有助于理解此类聚合物水泥基材料的中长期黏结性能,并对实际工程应用中正确选用界面黏结材料及评价黏结效果提供参考。     

多水平井巷施工对竖井稳定性影响的数值分析

针对金川三矿区主、副井系统的井巷工程进行了动态施工及相互影响的数值分析,并得到了一些有价值的成果。首先根据工程地质和围岩自身的特点,建立了主、副井控制性工程的三维数值模型。然后,根据主、副井及其各水平中段巷道的开挖特点,设计了6种不同的开挖施工方案,并采用FLAC3D对这些方案进行了计算和分析,得到了较为合理的开挖方案。计算结果表明：同时进行多个工程的开挖,势必会引起其他工程特别是1 165 m水平附近的围岩,产生较大的位移,应及时进行支护和加固。     

软岩巷道桁架锚索支护参数优化

为了合理确定软岩巷道桁架锚索支护参数设计,通过理论分析,FLAC3D数值模拟和SPSS差分析正交试验等方法,结合木孔煤矿实际地质环境,对软岩巷道的预应力桁架锚索支护参数进行优化分析,使桁架锚索组合支护能力充分发挥,避免支护材料浪费和支护成本偏高,现场观测结果显示:两帮水平位移最大值为260 mm,顶板最大下沉量为163 mm,巷道围岩的收敛率在有效控制范围内,预应力桁架锚索支护对提高巷道围岩的整体稳定性有良好效果.     

高固含、高透明水性木器底漆的配方设计

阐述了高固含、高透明水性木器底漆的配方体系中水性树脂及各种助剂的选择构思,以配制出打磨性好、透明度佳及丰满度好的水性木器底漆。     

The Friction and Wear of Aramid Fiber-Reinforced Polyamide 6 Composites Filled with Nano-MoS2

The friction and wear behaviors of aramid-filled PA 6 composites filled with and without nano-MoS₂ were investigated on an end-face tribometer through rubbing against ASTM 1045 steel under dry friction. The experimental results indicated that the wear rate and the friction coefficient of PA 6 decreased with the addition of nano-MoS₂. The friction coefficients of PA 6 composites filled with aramid fiber are lower than those without nano-MoS₂. The main wear mechanisms under dry sliding condition are the plastic deformation and mechanical microploughing. For best combination of friction coefficient and wear rate, the optimal volume content of MoS₂ in the composites appears to be 10 vol %.     

Ca对高Zn镁合金高温抗蠕变性能的影响

系统研究了微量Ca的加入对Mg-12Zn-4Al-0.3Mn合金显微组织和高温抗蠕度性能的影响。结果表明,Mg-12Zn-4Al-0.3Mn铸造镁合金的显微组织主要由α-Mg基体和块状准晶晶界相组成,在成分上准晶相与三元平衡相图中τ相(Mg32(Al,Zn)49)接近。少量Ca加入母合金后,块状准晶相部分转变为τ相和层片状φ相(Al2Mg5Zn2)。随Ca加入量增加,φ相的体积分数增多。Ca的加入显著提高了合金高温抗蠕变性能,175 ℃, 70 MPa蠕变条件下,Ca加入量为0.6%时,合金呈现最好的蠕变抗力,其稳态蠕变速率比母合金下降了近一个数量级