Synergistic flame retardant effects of activated carbon and molybdenum oxide in poly(vinyl chloride)

The synergistic effects of activated carbon (AC) and molybdenum oxide (MoO₃) in improving the flame retardancy of poly(vinyl chloride) (PVC) were investigated. The effects of AC, MoO₃ and their mixture with a mass ratio of 1:1 on the flame retardancy and smoke suppression properties of PVC were studied using the limiting oxygen index and cone calorimeter tests. It was found that the flame retardancy of the relatively cheaper AC was slightly weaker than that of MoO₃. In addition, the incorporation of AC and MoO₃ greatly reduced the total heat release and improved smoke suppressant property of PVC composites. When the total content of AC and MoO₃ was 10 phr, PVC/AC/MoO₃ had the lowest peak heat release rate and peak smoke production rate values of 173.80 kW m^?2 and 0.1472 m² s^?1, which represented reductions of 47.3 and 59.9%, respectively, compared with those of PVC. Furthermore, thermogravimetric analysis and gel content tests were used to analyze the flame retardant mechanism of AC and MoO₃, with results showing that AC could promote early crosslinking in PVC. Char residue left after heating at 500 °C was analyzed using scanning electron microscopy and Raman spectroscopy, and the results showed that MoO₃ produced the most compact char, with the smallest and most organized carbonaceous microstructures. © 2017 Society of Chemical Industry     

天津电网的静态电压稳定分析

本利用最重负荷节点导纳模型的常规牛顿潮流算法求解电力系统的电压静稳极限。在此基础上确定系统的弱节点和弱区域，包括正常运行方式和一些支路停运的运行方式下对系统的电压稳定性进行分析，以防止电压不稳定的出现。天津电网的实例计算结果验证了所采用的方法是简易简易有效的。     

循环管道式油流带电模型的研制及应用

在对国内外油流带电模型进行研究比较的基础上，研制了一种循环管道式油流带电模型用于模拟大型强迫油循环电力变压器油道中的电荷分离情况，并进行了常温及加温条件下的流速特性试验，探讨了表征油流带电大小的泄漏电流同油流速及温度的关系，对变压器油流设计及油流带电问题的解决有一定参考价值。     

冲击式水电机组流量与效率在线监测的探讨

鉴于冲击水轮机结构上的特殊性，其流量，效率的在线监测目前在国内的实际应用方面还是项空白，本文针对冲击式机级珠具体情况，探讨了基于差理论的监测途径，在此基础上的结合一个冲击式电站的实例，设计出了利用单片机来实现的方案。     

新型玻璃清洗剂的研制

开发一种新型玻璃清洗剂,讨论其制备方法,并对其性能进行了测试.这种清洗剂可在玻璃上形成一层易于剥离的薄膜,具有清洁性能好,易剥离,使用方便等优点.     

一种改进的势函数欠定盲源分离算法

针对原有的拉普拉斯混合模型势函数法复杂度高、随机选取部分观测数据点作为初始聚类中心的算法聚类结果不稳定、准确率低的问题,提出了一种改进的势函数欠定盲源分离算法．该算法在基于密度概念的基础上,以簇内距离小、簇间距离大为原则,选取部分高密度点作为势函数的初始聚类中心．理论分析与仿真实验表明,改进算法的复杂度大大降低,而估计准确度降低很少．在信噪比为10dB时,该算法仿真时间降为原始势函数法的5％;相对随机选取算法,在计算复杂度基本一致的前提下,该算法的估计准确度大大提高,源信号个数估计准确率由61％提高到85％,混合矩阵估计误差由0.47下降为0.27．     

液体混合物的表面张力方程

本文从统计热力学模型和表面热力学理论出发,导出了局部组成表达式,结合绝对反应速率理论,建立了一个液体混合物新的表面张力方程。对于二元体系,该方程可表示为: σ=x_1θ_(11)σ_1 x_2θ_(22)σ_2 (σ_(11)·σ_(22))~(1/2)(x_1θ_(21) x_2θ_(12))该方程应用于64个二元体系的关联,结果令人满意,表明该方程是可行的。     

Enhancing the Nucleolytic Resistance and Bioactivity of Functional Nucleic Acids by Diverse Nanostructures through in Situ Polymerization-Induced Self-assembly

Functional nucleic acids (FNAs) are garnering tremendous interest owing to their high modularity and unique bioactivity. Three-dimensional FNAs have been developed to overcome the issues of nuclease degradation and limited cell uptake. We have developed a new facile approach to the synthesis of multiple three-dimensional FNA nanostructures by harnessing photo-polymerization-induced self-assembly. Sgc8 aptamer and CpG oligonucleotide were modified as macro chain-transfer reagents to mediate in situ polymerization and self-assembly. Diverse structures, including micelles, rods, and short worms, afford these two FNAs afford these two FNAs with higher nuclease resistance in serum serum, greater cellular uptake efficiency, and increased bioactivity.     

Thermal analysis and non‐isothermal kinetics of poly(ethylene glycol) with different molecular weight

This study focuses on comprehensively investigating polyethylene glycol (PEG) with different molecular weight. Thermal properties of the PEGs were investigated by differential scanning calorimetry (DSC), as well as gradual melting and freezing tests with thermocouples. Results show that the degree of PEG crystallization increased with the increasing of the molecular weight of polymers. The temperatures of pure PEG 1000 and PEG 1000‐PEG 600 blends ranged from 20 to 50°C. The apparent activation energy of pure PEG1000 was 300 kJ/mol, whereas that of the PEG blend was 239 kJ/mol. During the crystallization process, Avrami index n ranged from 5 to 3 and half‐crystallization time t_1/2 decreased with the acceleration of the crystallization rate R. This difference was due to the increase in polydispersity of the PEG system and decrease in the degree of crystallization. POLYM. ENG. SCI., 54:2872–2876, 2014. © 2014 Society of Plastics Engineers     

制备条件对钯/陶瓷膜催化剂性能的影响

将钯纳米颗粒负载于陶瓷膜表面制备钯/陶瓷膜催化剂,并用于对硝基苯酚催化加氢反应中,考察了陶瓷膜孔径,硅烷偶联剂KH550溶剂及其浓度和改性时间,钯盐浸渍浓度、温度及时间以及还原温度对膜催化剂催化性能的影响.结果表明,采用孔径为200 nm 的氧化铝陶瓷膜,在6g/L的硅烷偶联剂KH550溶液中浸渍48 h,然后在40℃的浓度为0.030 mol/L乙酸钯溶液中浸渍20 h,最后采用水合肼在0℃还原30 min,得到的钯/陶瓷膜催化剂在对硝基苯酚催化加氢反应中显示了较好的催化性能,其加氢速率达15.5 mol/(h·m2).