水基Fe3O4磁流体的制备工艺研究

用共沉淀法制备Fe3O4磁流体,总结出用十二烷基磺酸钠与聚乙二醇作为表面活性剂制备水基磁流体的合适条件:(1)反应温度为室温或不高于35℃;(2)表面活性剂十二烷基磺酸钠的最佳用量为0.0030～0.0040 g/80 mL;(3)第一次包裹的最佳pH为9～10;(4)聚乙二醇作为第二次包裹的表面活剂时,体系最佳温度为40℃左右;(5)表面活性剂聚乙二醇的最佳用量为0.0050～0.0060 g/80 mL。通过实验制得了能稳定存在180 d的水基磁流体。并用透射电镜、红外光谱、分光光度计、古埃磁天平等进行了初步表征。     

不同拉压特性结构振动分析的双线性近似方法

对拉压特性不同的双模量结构的非线性自由振动进行了研究。给出了恢复力-位移曲线由三段斜率不 同的直线构成的单自由度系统自由振动频率的精确解。应用双线性近似方法讨论了有间隙双模量结构和无间隙双模量 结构非线性自由振动频率的近似求解问题。结果表明,不管恢复力-位移表达式多么复杂,应用双线性近似方法都可以 方便地求得结构的等效线性刚度,进而获得结构固有频率的近似解。通过近似计算结果与精确解之间的比较,验证了双 线性近似方法对于工程中大量存在的一类具有不同拉压特性的结构进行振动分析的实用性。     

基于指纹识别和数字认证的网络商务系统

讨论了一种互联网上实现电子身份认证的系统方案，提出用指纹识别和数字认证相结合的方式来实现具备高安全特性的在线支付，同时介绍了指纹识别算法并给出了整个系统的体系结构及工作流程。     

Effect of sodium benzoate on zinc electrodeposition in chloride solution

The effect of sodium benzoate on the electrodeposition of zinc on carbon steel electrode from acidic chloride solution was studied by cyclic voltammetry (CV), differential capacitance (DC), chronoamperometry (CA), scanning electron microscopy (SEM), and X-ray diffraction (XRD). A dimensionless graph model was used to analyze the nucleation process of zinc. It is found that the sodium benzoate has a blocking effect on the zinc electrodeposition when its concentration is higher than 0.03 M but will accelerate the formation rate of zinc nuclei when its concentration is lower than 0.03 M. Benzoate can be adsorbed on the surface of the electrode, which reduces the interface tension of electrode/solution and favors the formation and growth of zinc nuclei when its concentration is lower than 0.03 M, but forms a separated layer and retards the formation and growth of zinc nuclei when its concentration is higher than 0.03 M.     

深立井围岩稳定性分析

文章目的在于揭示超深立井岩石开挖后，井帮围岩在地应力重新分布情况下的应力变化情况，然后利用围岩的强度准则和变形标准来分析围岩的稳定性，进而为是否采用临时支护提供理论依据。文章的理论分析过程，应用了弹性力学中轴对称理论、应力集中原理和库仑-纳维尔强度准则。本文的研究成果，可作为基岩段井壁结构设计的依据和快速掘进方案制定的基础。     

Optimized TQ-MAP: An Adaptive Mapping Mechanism to Guarantee the Coherence of QoS Support from IP to OBS

Because of its scalability, the idea of coarse packet classification can be utilized to OBS networks. However, due to the limited number of priorities supported by OBS networks, we usually adopt a many-to-one composite class burst (CCB) assembly technique, e.g., N:1-CCB. In this kind of technique, there are two aspects related to scalable QoS support, i.e., mapping relationship and assembly resource allocation. This paper simultaneously takes the two aspects into consideration, and proposes a novel assembly mapping mechanism, called Optimized TQ-MAP, in which the most important feature is adaptivity. Based on nonlinear programming and differential calculus, it allocates the burst assembling capacity between classes fairly, efficiently and differentially, and matches IP QoS requirement with OBS QoS capacity as possible as it can. The simulation results show that Optimized TQ-MAP is more adaptive, and can efficiently guarantee the coherence of QoS support from IP to OBS.     

MAX相Ti3SiC2高导电涂层的研究进展

钛硅碳(Ti3 SiC2,TSC)是一种兼具金属材料和陶瓷材料优异性能的新型三元化合物MAX相.Ti3 SiC2作为高导电功能涂层具有很大的应用潜力,近年来受到越来越多的关注.Ti3 SiC2涂层的制备技术在不断改革优化,主要有五种常见制备工艺,分别是化学气相沉积法(CVD)、物理气相沉积法(PVD)、固相反应合成法(Solid-state reaction)、气溶胶沉积法(ADM)和热喷涂法(Thermal spraying).Ti3 SiC2涂层的性能在很大程度上与其纯度相关,通常制得的Ti3 SiC2涂层均含有一定程度的杂质,这是制约其广泛应用的一个重要因素.Ti3 SiC2涂层中经常出现的杂质主要是TiC、Ti5 Si3、SiC、TiSi2等,不同的制备方法产生的杂质种类也不一样.为了提高Ti3 SiC2涂层的纯度,需要对其制备工艺进行探索和优化.目前,反应化学气相沉积(RCVD)实现了通过消耗碳化硅(SiC)子层在石墨基底上生长纯Ti3 SiC2涂层.近年来利用ADM也实现了在室温下合成纯Ti3SiC2涂层,这一技术降低了常规Ti3SiC2涂层的合成温度.此外,PVD法不仅为低温制备Ti3SiC2涂层提供了可能性,还实现了Ti-Si-C复合涂层的工业化生产.本文综述了Ti3 SiC2涂层的研究现状,分析了Ti3 SiC2涂层独特的晶体结构及优异性能,介绍了近年来几种常见的Ti3 SiC2涂层制备技术,并指出了目前合成纯Ti3 SiC2涂层所面临的巨大挑战.     

WDM+EDFA+DCF光纤传输系统中色散补偿方案的分析

由于在ＷＤＭ＋ＥＤＦＡ光纤传输系统中使用常规单模光纤（ＳＭＦ）在１５５０ｎｍ窗口的大色散限制了传输距离,采用色散补偿光纤（ＤＣＦ）进行色散补偿是上前一种较为理想的方法。本文基于光纤ＷＤＭ＋ＥＤＦＡ＋ＤＣＦ的长距离传输系统,讨论了ＤＣＦ色散补偿对光纤非线性效应交叉相位调制和四波混频（ＦＷＭ）的影响,提出了采用ＤＣＦ集总、后置、非完全补偿的色散补偿方案,这种方案可合系统具有更佳的传输性能。     

层层自组装法制备百里香精油微胶囊条件优化

采用层层自组装的方法,以百里香精油乳化液纳米微粒作为核心,利用壳聚糖和海藻酸钠对百里香精油进行包埋;以司盘80和吐温60复配乳化剂亲水亲油平衡（hydrophilic lipophilic balance,HLB）值、用量及油乳比例3 个因素进行实验,确定乳化液最适制备条件;以壁材溶液质量浓度、组装层数、每层组装时间、搅拌速率、组装温度、壁材溶液pH值和固化剂用量进行单因素试验,以主要因素设计正交试验,确定最佳包埋条件。结果表明,乳化液制备条件为HLB值10、乳化剂用量6%、精油与乳化剂体积比1∶6,此条件下所制备的乳化微粒为模板,组装层数4 层、搅拌速率1 040 r/min、每层组装时间15 min、壁材溶液pH 5.0、组装温度30 ℃,此条件下包埋率最高为80.23%。     

Cresyl diphenyl phosphate as flame retardant additive for lithium-ion batteries

To improve the safety of lithium-ion batteries, cresyl diphenyl phosphate (CDP) was used as a flame retardant additive in a LiPF₆ electrolyte solution. The flammability of the electrolytes containing CDP and the electrochemical performances of the cells, LiCoO₂/Li, graphite/Li and the battery LiCoO₂/graphite with these electrolytes, were studied by measuring the self-extinguishing time of the electrolytes, the variation of surface temperature of the battery and the charge/discharge curve of the cells or battery. It is found that the addition of CDP to the electrolyte provides a significant suppression in the flammability of the electrolyte and an improvement in the thermal stability of battery. On the other hand, the electrochemical performances of the cells become slightly worse due to the application of CDP in the electrolyte. This alleviated trade-off between the flammability and thermal stability and cell performances provides a possibility to formulate a nonflammable electrolyte by using CDP.