PP-g-(St-co-MMA)/PP/PVC共混物相容性研究

利用扫描电子显微镜(SEM)和X射线能谱仪(EDS)对聚丙烯／聚氯乙烯(PP80／PVC20)二元体系,以及聚丙烯多单体接枝物[PP-g-(St-co-MMA)]／PP／PVC三元体系的相容性进行了研究。由X射线能谱微区分析得到了共混物中氯元素面分布图。对氯元素面分布进行了粒径分布统计和面积计算。实验结果表明：在PP80／PVC20共混物100份中加入6份PP-g-(St-co-MMA)增容剂时,增容效果最好;进一步增加PP-g-(St-co-MMA)含量时,PP／PVC的相容性反而降低。差示扫描量热仪(DSC)的实验结果也佐证了SEM和EDS的实验结果。     

颜料体积浓度对水在醇酸涂层中传输行为的影响

水、离子和氧气是导致涂层下金属发生腐蚀的三个重要因素,它们在涂层中的传输过程对其下面金属的腐蚀会产生较大的影响,研究它们在涂层中的传输过程对于弄清涂层下金属发生腐蚀的机制至关重要 .研究表明 [1－ 8], 水在涂层中的传输是一个扩散过程,分起始和饱和两个阶段;在起始阶段,随研究体系和实验条件的不同,水在涂层中的扩散过程遵循不同的规律,可能满足菲克第二扩散定律,也可能会发生较大的偏差 .　　颜料与基料界面间的孔隙是水在涂层中传输的主要通道,调整颜料体积浓度（ PVC）可以改变涂层中这种孔隙的数量和分布,从而…     

一种基于PVC膜电极的电位式葡萄糖传感器的研制

以三庚基十二烷基碘代季铵盐为电活性物质的PVC膜电极, 对过氧化氢和六价钼的络合物具有良好的电位响应. 将葡萄糖氧化酶固定到PVC膜电极表面, 制备成电位式葡萄糖传感器. 在优化的实验条件下, 该传感器在葡萄糖浓度为2×10^－4～5×10^－3 mol/L范围内有线性响应, 检测下限为5×10^－5 mol/L. 另外该传感器具有较高的稳定性和良好的选择性, 抗坏血酸、尿酸和一些氨基酸未对测定产生干扰.     

Quantitative Analysis of Holmium Ion by a Ho3+ Ion‐Selective Sensor Based on a Symmetric Thio‐Schiff's Base

A poly(vinyl chloride) (PVC) membrane sensor for holmium ions was fabricated based on N‐[(Z)‐1‐(2‐thienyl)‐ methylidene]‐N‐[4‐(4‐{[(Z)‐1‐(2‐thienyl)methylidene]amino} phenoxy)phenyl] amine (TPA) as a new ion carrier, acetophenon (AP) as plasticizing solvent mediator and sodium tetraphenyl borate (NaTPB) as an anion excluder. The electrode shows a good selectivity towards Ho³⁺ ions respect to other inorganic cations, including alkali, alkaline earth, transition and heavy metal ions. The constructed sensor displays a Nernstian behavior (19.5±0.3 mV/decade) over the concentration range of 1.0×10⁻⁶ to 1.0×10⁻² mol·L⁻¹ with the detection limit of the electrode being 4.6×10⁻⁷ mol·L⁻¹ and very short response time (ca. 5 s). It has a useful working pH range of 3.2–9.8 for at least 8 weeks. The electrode was successfully applied as an indicator electrode for the potentiometric titration of a Ho³⁺ solution with EDTA and holmium determination in some alloys. The proposed sensor accuracy was studied by the determination of Ho³⁺ in mixtures of three different ions.     

Erbium(Ⅲ) PVC membrane sensor based on N-(benzyloxycarbonyloxy)succinimide as a new neutral ionophore

In this study,a new Er³⁺ sensor based on N-（benzyloxycarbonyloxy）succinimide（BCS） as a neutral carrier has been constructed. The sensor exhibits potential linear response with a Nernstian slope of 20.5±0.4 mV/decade in the concentration range of 1.0×10^-6to 1.0×10^-2mol/L of Er³⁺.It has a very short response time（<10 s）,detection limit of 6.3×10^-7 mol/L and a good selectivity relative to a wide variety of other metal ions including common alkali,alkaline earth,heavy,and transition metal ions.It can be used in the pH range of 2.5-10.6 without any considerable divergence in potentials.The proposed sensor was successfully applied for the recovery of Er³⁺ ions spiked in tap and river water samples.     

溶剂对聚氯乙烯-聚乙二醇-KOH体系脱氯行为的影响

废旧塑料的回收利用是当今研究的热点之一.据报道,2007年中国聚氯乙烯(PVC)产量高达960万吨[1],如何合理利用相应产生的废旧PVC是一个十分重要的课题.     

厚壁管道周向导波检测技术实验研究

厚壁管道是火电机组四大管道系统的核心部件,将超声导波技术应用于厚壁管道的无损检测显得十分重要.首先确定厚壁管道检测的激励方式,优化选取适合厚壁管道检测的0.5MHz探头和楔形块角度为60°的斜探头组合.通过改变斜探头与外壁轴向缺陷之间周向距离,在一定范围内仍可检测到缺陷回波,且接收到的周向回波幅值变化不大,表明周向导波...     

高饱和黏土中爆炸波作用下直埋聚乙烯管的动力响应

为了解决爆破作业对近距离埋地管道的安全评估问题,对高饱和粘土中爆炸波作用下聚乙烯(polyethylene, PE)管道进行了一系列管道动态响应的原型实验,得到了不同药量下管道动应变、动压力的实验数据和管体及地面的振速数据。实验结果表明:PE管动应变峰值同比例距离具有良好的幂函数衰减关系,在6～11 m/kg^1/3比例距离范围内,PE管的环向峰值应变衰减指数(绝对值)比轴向峰值应变衰减指数大;管道动态响应的主振频率略高于土体的主振频率,两者在同一量级,管道合成速度衰减指数大体和管道轴向应变衰减指数相当;压电陶瓷片所测得的电压信号和同测点的应变变化率信号具有较强的相关性。高饱和黏性土由于含水量较高,近距离柔性PE管因受到局部冲击会产生较大的环向应变,管道安全计算时应充分考虑这一因素;随着比例距离的增大,环向应变水平降低,轴向应变水平相对增强;压电陶瓷片因为具有良好可靠的动态性能,作为埋地管道现场监测的技术手段值得采用和推广。     

Dynamic and Isothermal Thermogravimetric Degradation of Poly(vinyl Chloride)/Chlorinated Poly(ethylene) Blends

The thermal degradation of poly(vinyl chloride)/chlorinated poly(ethylene) (PVC/CPE) blends of different compositions was investigated by means of dynamic and isothermal thermogravimetric analysis in flowing atmosphere of nitrogen. Kinetic parameters (the apparent activation energy E, and pre-exponential factor Z) were calculated after Flynn-Wall-Ozawa method for the first stage of dynamic degradation of PVC/CPE blends, and after Flynn method for the isothermal degradation. In both cases, there is the compensation dependence between the values E and logZ. The values of compensation ratios as well as the characteristics of TG and DTG curves, confirm the stabilizing effect of CPE on PVC dehydrochlorination. This revised version was published online in July 2006 with corrections to the Cover Date.     

椭圆截面曲线管道内二次流动的Galerkin解

推导了任意空间曲线直角坐标系内的张量流体力学方程．采用Galerkin方法和计算机符号运算技术求解了椭圆截面螺旋管道（电括弯管、扭管）内的二次流动．计算结果表明了Galerkin方法的适用和有效性，克服了振动法的小参数局限．对所得结果的分析揭示了椭圆截面螺旋管道内流动的特性，给出了k,r和Re较大情况的研究结论．