关于青田山区农村生活污水处理的调查与思考

当前,我国进一步加大了对农村生活污水处理的重视程度,这是因为全面治理农村生活污水,是改善农村生态环境,深入推进美丽乡村建设的一项重要工作.本文在对青田山区农村生活污水处理的调查中发现,该地区在山区农村生活污水处理工作中还存在着污水排放达标率偏低的情况,因此,需要制定出相应的应对策略和建设规划,以有效改善青田山区农村生活...     

Effect of blending on the multiple melting behavior of polyphenylene sulfide

The effects of melting time (t_melt) and annealing time (t_a) at a temperature closer to the melting point of polyphenylene sulfide (PPS) on the multiple melting behavior of neat PPS, and PPS component in their blends have been investigated by differential scanning calorimetry (DSC). It is found that double endotherm peak of PPS annealed at 275°C for less than three hours is different from that annealed for twelve hours. Double endotherm peak of PPS in PEEK/PPS blends shifts to lower temperature, and the intensity of the upper melting peak decreases significantly by addition of polyether ether ketone (PEEK). An additional third melting peak could be observed. The temperature of third melting peak is above 310°C and increases as the t_a and PEEK content are increased. For PEK-C/PPS blends, the lower and upper melting temperatures of the PPS component are higher than that of neat PPS annealed at 275°C for twenty-three hours. © 1996 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1001–1008, 1997     

Studies of the stability of thermoplastic-modified bismaleimide resin

The stability of bismaleimide—o,o′-diallyl bisphenol A (BMI—DABA) blends modified with high-performance amorphous thermoplastic bisphenol A polysulfone (PSF), polyether ketone (PEK-C), and polyether sulfone (PES-C) bearing a phthalidylidene group has been studied by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The extent of stability of thermoplastic components has been compared with the area of the endothermic peak that appears within the glass transition region for thermoplastic component in cured blends aged at temperature below the glass transition temperature (T_g). The stability of thermoplastic can be improved by the formation of semi-interpenetrating polymer networks (semi-IPNs). The stability of thermoplastic with higher T_g is more easily controlled. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1965–1970, 1997     

Structural properties and mechanical behavior of injection molded composites of polypropylene and sisal fiber

Composites based on isotactic polypropylene (PP) and sisal fiber (SF) were prepared by melt mixing and injection molding. The melt mixing characteristics, thermal properties, morphology, crystalline structure, and mechanical behavior of the PP/SF composites were systematically investigated. The results show that the PP/SF composites can be melt mixed and injection molded under similar conditions as the PP homo‐polymer. For the composites with low sisal fiber content, the fibers act as sites for the nucleation of PP spherulites, and accelerate the crystallization rate and enhance the degree of crystallinity of PP. On the other hand, when the sisal fiber content is high, the fibers hinder the molecular chain motion of PP, and retard the crystallization. The inclusion of sisal fiber induces the formation of β‐form PP crystals in the PP/SF composites and produces little change in the inter‐planar spacing corresponding to the various diffraction peaks of PP. The apparent crystal size as indicated by the several diffraction peaks such as L_(110)α, L_(040)α, L_(130)α and L_(300)β of the α and β‐form crystals tend to increase in the PP/SF composites considerably. These results lead to the increase in the melting temperature of PP. Moreover, the stiffness of the PP/SF composites is improved by the addition of sisal fibers, but their tensile strength decreases because of the poor interfacial bonding. The PP/SF composites are toughened by the sisal fibers due to the formation of β‐form PP crystals and the pull‐out of sisal fibers from the PP matrix, both factors retard crack growth.     

SFCC现场导热系数与温度场实测及预测方法研究

为确定钢纤维页岩陶粒混凝土（SFCC）现场实际的导热系数,与桥面板施工同步制作了不同钢纤维体积分数的SFCC试件,采用热板法进行测定,校核并扩展了导热系数预测公式,并且对高温沥青摊铺时SFCC桥面板的温度场进行了实测和数值模拟.结果表明：环境湿度为67%时,SFCC的实测导热系数为0.915~1.409 W/（m·K）,增加钢纤维体积分数可提高SFCC导热系数;考虑湿度和钢纤维影响后的扩展Maxwell公式预测值与实测值吻合良好;高温沥青摊铺时桥面板SFCC混凝土内的温度梯度可达20.5 ℃,超过规范日温差,采用数值模拟可有效计算桥面板温度场.     

基于水合物分解传热模型的固体自生热解堵剂热量扩散模拟

固体自生热解堵技术是一种适用于解除井筒内水合物堵塞的创新技术。针对自生热解堵剂反应时的放热量扩散及损耗问题,建立了水合物生成相平衡、分解速率及分解传热数学模型。开展了不同含量、不同管径时的热量扩散模拟研究,获得了不同条件下井筒内温度、水体积分数、天然气体积分数、水合物体积分数的分布云图。研究发现:随着自生热解堵剂含量的增加,释放热量的速率加快,向周围传递的热量增加,且热量扩散时呈不规则状;随着井筒内径的增加,解堵时间增加,自生热解堵剂用量也随之增加。本实验开展的模拟计算值与现场实际值的吻合度大于85%,为现场解堵施工提供了理论指导。      

超高效液相色谱-串联质谱法测定动物性食品中8 种抗病毒类药物残留量

建立同时测定鸡肉、猪肉、鸡肝和猪肝中阿比朵尔、金刚烷胺、金刚乙胺、泛昔洛韦、帕拉米韦、咪喹莫特、奥司他韦、拉米夫定8?种抗病毒药物残留的超高效液相色谱-串联质谱的检测方法。样品采用乙腈-0.1%甲酸溶液（9∶1,V/V）经一次性振荡提取,用MCX固相萃取柱净化,内标法定量。结果表明：8?种抗病毒药物的检出限均低于1.0?μg/kg,定量限均低于3.0?μg/kg,空白鸡肉、鸡肝、猪肉、猪肝中分别添加5.0、10.0?μg/kg和20.0?μg/kg,8?种抗病毒药物的回收率均在70%～120%之间。该方法基质干扰小、灵敏度高、回收率好,可用于日常动物性样品中抗病毒类药物的残留检测。     

油气管道环焊缝搅拌摩擦焊机的研制

为了保障油气管道对接环焊缝的焊接质量,提高焊接效率,开发设计了专门用于油气管道对接环焊缝的搅拌摩擦焊机。介绍了搅拌摩擦焊接（friction stir welding,FSW）的焊接机理以及油气管道对接环焊缝搅拌摩擦焊机的主要构成及其工作参数。该焊机的机械系统主要由支撑系统、夹持系统、环形运动驱动系统、搅拌头系统与退出孔消除系统等组成,焊机最大扭矩达186 N·m,可以在较宽的焊接参数范围内完成多种材质、不同直径管道的搅拌摩擦焊接。