N,N′-二(2-硫代-5,5-二甲基-1,3,2-二氧磷杂环己基)乙二胺的合成及阻燃性能

以新戊二醇与PSCl3合成2-硫代-2-氯-5,5-二甲基-1,3,2-二氧磷杂环己烷(DDSP),再与乙二胺反应,合成了一种新型含有磷、氮、硫的阻燃剂:N,N′-二(2-硫代-5,5-二甲基-1,3,2-二氧磷杂环己基)乙二胺(DDPSN),用元素分析、FTIR、1HNMR、MS测试技术对其结构进行了表征。采用热重(TG)分析,研究了反应物摩尔比、缚酸剂及催化剂、反应温度对DDPSN产率的影响。结果表明,所合成的标题化合物结构与预期一致,其初始热分解温度大于290℃,在1000℃时仍有24.5%的残炭率。新戊二醇与PSCl3摩尔比为1.75∶1时,DDSP产率高达85%,而DDSP与乙二胺摩尔比为1∶1.25时,DDPSN产率为89%;采用4-二甲氨基吡啶(DMAP)作为缚酸剂的效果优于吡啶和三乙胺,其加入量为新戊二醇质量分数的1%时,可使DDPSN产率提高到92%,反应温度以0~5℃为宜。其阻燃粘胶膜实验结果表明,DDPSN在粘胶中质量分数为18%时,极限氧指数(LOI)值可达28%,是一种效果很好的阻燃剂。由阻燃粘胶膜燃烧后生成的炭残渣的扫描电子显微镜(SEM)可知,炭残渣表面有很多隆起的泡状物,且试样的断面为蜂窝状结构,表明该阻燃剂为膨胀型阻燃剂。     

新型Li4Ti5O12@石墨烯的微波辅助合成及电化学性能研究

将钛酸四丁酯和氧化石墨超声分散于叔丁醇,微波辐射下加入醋酸锂溶液制备尖晶石Li₄Ti₅O₁₂（LTO）前驱体/氧化石墨烯。一方面,微波作用促进了钛酸四丁酯水解,前驱体的形成能在15min内完成。另一方面,叔丁醇的“软模板”限域作用导致形成粒子极小且形貌单一的LTO前驱体。同时,细小的LTO前驱体粒子通过二次团聚将氧化石墨烯纳米片完全包埋。最后,LTO前驱体/氧化石墨烯在800℃下煅烧8h得到尖晶石LTO@石墨烯（LTO@G）。研究表明,LTO@G晶体尺寸在0.2~1.5μm之间,其振实密度达到1.7g·cm^-3。石墨烯位于晶体内部,并显著提高了材料的电子传导性。LTO@G的电导率为1.84×10^-3S·m^-1,远高于纯相LTO（1.1×10^-7S·m^-1）。1C和4C下,LTO@G首次充放电容量分别是170.1和97.5mAh·g^-1。可见,LTO@G具有高倍率性能和振实密度,可广泛应用于各种商品锂离子电池。     

Robustness of Cyber-Physical Supply Networks in Cascading Failures

A cyber-physical supply network is composed of an undirected cyber supply network and a directed physical supply network. Such interdependence among firms increases efficiency but creates more vulnerabilities. The adverse effects of any failure can be amplified and propagated throughout the network. This paper aimed at investigating the robustness of the cyber-physical supply network against cascading failures. Considering that the cascading failure is triggered by overloading in the cyber supply network and is provoked by underload in the physical supply network, a realistic cascading model for cyber-physical supply networks is proposed. We conducted a numerical simulation under cyber node and physical node failure with varying parameters. The simulation results demonstrated that there are critical thresholds for both firm’s capacities, which can determine whether capacity expansion is helpful; there is also a cascade window for network load distribution, which can determine the cascading failures occurrence and scale. Our work may be beneficial for developing cascade control and defense strategies in cyber-physical supply networks.     

组合评价模型在港口物流综合服务能力评价中的应用

为了对港口物流综合服务能力进行科学评价,提出了基于组合评价方法的港口物流服务能力评价模型,并对我国15个港口的物流综合服务能力进行实证分析说明模型的有效性.首先分别采用5种评价方法进行评价,然后使用KendallW系数检验各方法评价结果的一致性,再运用4种组合评价模型进行组合评价,采用Spearman等级系数进行事后检验并得到最终结果.方法可克服单一评价方法的不足,为港口物流服务能力评价提供新的思路.     

Capacitance performances of supramolecular hydrogels based on conducting polymers

The capacitance performances of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT-PSS) supramolecular hydrogels have been investigated systematically. The materials show a specific capacitance of 67 F/g and display excellent rate capability at the scan rate as high as 5000 m V/s in the cyclic voltammogram measurements, accompanied by good cycle stability. On the basis of the measurements of the microscale morphologies, specific areas and electrical conductivities, the mechanisms for the improvement of the electrochemical properties are discussed and ascribed to the novel porous microstructures of the hydrogels and the synergetic effect of the rigid PEDOT and soft PSS components. Furthermore, polyaniline(PAn) is compounded with the PEDOT-PSS hydrogels through an interfacial polymerization process, endowing the hydrogel materials with a higher specific capacitance of 160 F/g at the scan rate of 5000 m V/s. The significance of this work lies in the demonstration of a novel method to solve the problems of conducting polymers in electrochemical applications.     

工序能力评估经济分析

工序能力不一定是越高越好．提高工序能力有时意味着增加成本，故应作经济分析。本文提出了一种经济分析的方法．     

过程能力指数与不合格品率的关系模型

传统的质量管理观认为,过高或过低的过程能力指数都不利于企业经济效益的提高。本文基于传统的质量管理观,研究过程能力指数与产品不合格品率之间的关系,建立了过程有无漂移时的过程能力指数与产品不合格品率之间的关系模型。     

可配位液晶分子的合成及表征

以焦性没食子酸和异烟酸为原料合成了带吡啶官能团的液晶配体。将液晶和配体相结合，成功合成了具有配位能力的液晶分子，采用红外光谱（FT-IR）对其结构进行了表征，通过示差扫描量热法（DSC），热失重（TGA）和偏光显微镜（POM）等方法研究了它的液晶性和相变温度。结果表明，合成产物液晶性良好。     

Ad Hoc网络中的区域划分和资源分配问题

建立了Ad Hoc网络中的区域划分和资源分配的模型,重点对网络的最少小区数覆盖、抗毁性、节点分簇等问题进行了研究,并对节能性、通信质量评估进行了初步探讨.