一种新型的基于LP01模的双模色散补偿光纤

通过计算机模拟发现在可传输双模的三包层色散补偿光纤中如果抑制ＬＰ０２模，而仅传输ＬＰ０１模时能在一个较窄的带宽内产生大于数千ｐｓ／ｎｍ·ｋｍ的负色散，并且具有较大的模场直径、较小的弯曲损耗和偏振模色散，另外还具有较小的温度波长漂移以及同其它色散补偿光纤一样大小的损耗，是一种非常有前途的新型色散补偿光纤     

高能超声作用下数种金属基复合材料的制备及机制

利用高能超声振动制备了A l/陶瓷, ZA 22/陶瓷(粒子平均直径2L) ,A l/P b (Pb 粒子直径< 25L) 和A l/F eA l₃等金属基复合材料, 弥散相在基体中有良好的分布均匀性。依据超声波对熔体作用时的空化和声流效应, 讨论了上述数种复合材料的制备机制。试验结果显示, 该项技术在制备数类金属基复合材料方面具有广泛的适用性。     

In situ FTIR spectroscopy on rhodium-exchanged NaX zeolite with different metal dispersion during syngas reaction

In situ FTIR spectroscopy has been applied to study the reason of the different selectivity behaviour of rhodium in the CO hydrogenation reaction in dependence on the different particle size. Several forms of molecularly adsorbed CO are observed, such as linearly- and bridgedbonded CO on metallic rhodium as well as dicarbonyl species with Rh(I) centres formed by oxidation of Rh(0) with protons in presence of CO. Furthermore, non-reactive formate, acetate, and carbonate species are produced as side products of the reaction. The higher selectivity to oxygenates, particularly to methanol, is explained by the existence of multiple-bonded CO present only on small rhodium crystallites. The multiple-bonded CO formed at low temperatures is converted at higher temperatures to the highly reactive formyl species, which is hydrogenated to methanol.     

Colour extension properties of individual pigments and effects on shades of foundations in cake form

The mechanism of colour change during the pigment dispersion process and during powder application to the skin surface was studied by examining the colour extension properties of Yellow. Red , and Black iron oxides in white powder bases. A new measure for the evaluation of the degree of colour extension was devised. This measure corresponded well with human visual sensation, and was found to be useful for comparing the rates of colour extension of pigments. The rate of colour extension of pigments was found to vary in the order: Yellow acicular Red granular Red Black. This result explains colour darkening and the change towards reddish tones during the pigment dispersion process, because Yellow extends fully in the early stage of the process but Red , especially in granular form, and Black continue to extend even in the later stage. Acicular Red iron oxide is more favourably employed than the granular form to attain sufficient colour extension of foundations with lower energy expenditure, and to decrease the discrepancy between the cake colour and the colour of applied powder.
Le développement des oxydes de fer et effet sur les nuances des fonds de teint compacts     

长途传输波分复用系统的设计

随着波分复用（WDM）技术的广泛应用，在工程调测和系统的运行过程中出现了由于系统的适应能力较差和灵活性不够而引起系统优化时间过长的问题，给运营商带来了许多不便，同时，WDM已经由一般的长途应用向超长距离传输和城域网方面发展，适应性和灵活性成为WDM系统网络应用的主要要求，本文将介绍WDM系统的关键技术，重点论述WDM网络设计的一些原则，最后提出WDM系统设计的注意事项。     

高稳定度CPM飞秒激光特性的研究

利用最优化动力学参数的方法,获得了高稳定度的CPM飞秒激光器运转特性。激光器输出平均脉宽43fs,中心波长624nm,平均功率20mW,脉宽不稳定度±3.3％,频率不稳定度小于10~(-6)。     

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下部钻具组合力学性能分析中,稳定器与井壁的间隙是影响其性能的重要因素。对于多稳定器组合,事先设定稳定器与井壁接触情况既困难也不准确。本文从有限单元的基本总势能表达式出发,采用最优化理论中的罚函数法,分析了稳定器间隙对下部钻具力学性能的影响,为解决稳定器与井壁的接触问题找到了一个新方向。     

一种可用于可调谐环行Ti：Al_2O_3激光器的宽带单向器

本文介绍一种宽带单向器的原理及设计。选用ＴＧＧ作磁旋光介质，旋光石英晶片作补偿片，所设计的色散补偿型宽带单向器预计可在７００～１０００ｎｍ波长范围内实现环行激光腔中的单向行波运行；将其应用在可调谐环行Ｔｉ：Ａｌ２Ｏ３激光器中，获得了良好的实验结果。     

共晶强制性熔化的界面形态

对透明共晶系ＣＢｒ４－８．４ｗｔ－％Ｃ２Ｃ１６生长的典型层片共晶组织强制熔化进行实时实地观测．表明相对于强制生长时的“界面滞后”现象，熔化界面温度高于静止时界面温度，熔化界面比静止界面更靠近热端，称为“界面超前”．随熔化速度增大，“界面超前量”增大；共晶组织分层熔化，出现两个熔化界面，α和β相熔化秩序不同，α，β相分别单独熔化，两熔化界面的相对位置由α，β相成分，熔化速度和共晶相间距等因素决定．     

基于类间分散度和类内集中度的文本特征选择。

特征选择是文本分类的关键步骤之一,所选特征子集的优劣直接影响文本分类的结果。论文首先定义了两种特征分类能力：一种是特征对类间文档的分散程度,该分散度越大越好;另一种是特征对类内文档的聚集程度,该集中度越大越好。然后把这两种特征影响度有机地结合起来设计了一个新的特征选择方法,该方法能够对所选特征进行综合考虑,从而使获得的特征集具有较好的代表性。仿真实验表明所提特征选择方法在一定程度上能够提高文本分类性能。