1.3微米高密度量子点结构及其制备方法

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半导体激光器无源对准耦合与高频封装用硅基版

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双异质结构氮化镓基高电子迁移率晶体管结构及制作方法

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能引出低熔点金属离子的冷阴极潘宁离子源

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一种光瞬态自动测试系统

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使多个V形光伏器件组件连接的方法

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一种高阶ΣΔ噪声整形直接数字频率合成器

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提高氮化镓基高电子迁移率晶体管性能的结构及制作方法

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Dual-wavelength photochromic fulgides for parallel recording memory

Two photochromic fulgides, 2-{2-[4-(N,N-dimethylnilino)-5-methyl-4-oxazoly]}ethylidene-4-(1-methylethylidene) tetrahydrofuran-2,5-dione (A) and 3-(1,2-dimethyl-5-phenyl-3-pyrolloethylidene)-4-(1-methylethylidene)tetrahydrofuran-2,5-dione (B), doped in PMMA as candidates of dual-wavelength optical memory for parallel recording has been investigated. With 488 nm-laser and 650 nm-laser, both "cross" and "star" images are recorded on the fulgides-PMMA film and read out clearly, respectively. Crosstalk between two fulgides in PMMA matrix and nondestructive readout has also been explored. The results show that no significant cross-talk is detected between them, and nondestructive readout is up to 201 times. (C) 2005 Elsevier B.V. All rights reserved.

Structuring by multi-beam interference using symmetric pyramids

A method for producing optical structures using rotationally symmetric pyramids is proposed. Two-dimensional structures can be achieved using acute prisms. They form by multi-beam interference of plane waves that impinge from directions distributed symmetrically around the axis of rotational symmetry. Flat-topped pyramids provide an additional beam along the axis thus generating three-dimensional structures. Experimental results are consistent with the results of numerical simulations. The advantages of the method are simplicity of operation, low cost, ease of integration, good stability, and high transmittance. Possible applications are the fabrication of photonic micro-structures such as photonic crystals or array waveguides as well as multi-beam optical tweezers. (c) 2006 Optical Society of America.

Franz-Keldysh effect and dynamical Franz-Keldysh effect of cylindrical quantum wires

We investigate the interband optical absorption spectra near the band edge of a cylindrical semiconductor quantum wire in the presence of a static electric field and a terahertz electric field polarized along the axis. Optical absorption spectra are nonperturbatively calculated by solving the low-density semiconductor Bloch equations in real space and real time. The influence of the Franz-Keldysh (FK) effect and dynamical FK effect on the absorption spectrum is investigated. To highlight the physics behind the FK effect and dynamical FK effect, the spatiotemporal dynamics of the polarization wave packet are also presented. Under a reasonable static electric field, substantial and tunable absorption oscillations appear above the band gap. A terahertz field, however, will cause the Autler-Townes splitting of the main exciton peak and the emergence of multiphoton replicas. The presented results suggest that semiconductor quantum wires have potential applications in electro-optical devices.

Casting preforms for microstructured polymer optical fibre fabrication

A monolithic structured polymer preform was formed by in-situ chemical polymerization of high-purity MMA monomer in a home-made mould. The conditions for fabrication of the preforms were optimized and the preform was drawn to microstructured polymer optical fibre. The optical properties of the resultant elliptical-core fibre were measured. This technique provides advantages over alternative preform fabrication methods such as drilling and capillary stacking, which are less suitable for mass production. (c) 2006 Optical Society of America.

新的白光LED灯用不同光色发射荧光体的研究

凡是与某种发光二极管（LED）匹配能够产生白光发射的荧光体均可称作白光LED荧光体，通过这种匹配构筑起来的白光发射体系（或器件），简称作白光LED。白光LED是一种新的固态光源，具有环保、节能等诸多优点。目前已实用化的白光LED只有蓝光LED＋YAG:Ce荧光粉，但其显色性差，不能满足通常的照明要求。因此，寻找并研究可以与UVLED、蓝光LED匹配的、能产生高效的各种光色发射的新的荧光体具有重要的理论和现实意义。 本工作利用高温固相法合成了四个白光LED灯用多光色发射荧光新体系。研究成果如下： 1. 合成出一种新的白光LED灯用荧光体－黄橙光发射的Eu2+掺杂的高温相氯硅酸钙荧光体，HTP-Ca3SiO4Cl2:Eu2+。该荧光体与近紫外LED匹配产生暖白光发射。晶体结构解析表明，HTP-Ca3SiO4Cl2属单斜晶系。 2. 研究发现Eu2+离子掺杂的低温相氯硅酸钙荧光体可用作白光LED灯用绿色荧光体，LTP-Ca3SiO4Cl2:Eu2+。实验结果证明与已报道的硫化物、氮化物LED灯用绿色荧光体相比，该荧光体具有合成条件相对温和、简便、无污染等优点。 3. 合成出一种新的白光LED灯用蓝绿光发射荧光体－Eu2+掺杂的硅酸锂钙，Li2CaSiO4:Eu2+。该荧光体的激发光谱从紫外延伸到可见区，和已报道的氯磷酸盐、铝酸盐LED灯用蓝光发射荧光体相比，具有更广泛的应用性。 4. 找到了一种可明显改善CaMoO4:Eu3+发光特性途径，通过碱金属离子和空穴进行电荷补偿可以使CaMoO4:Eu3+的红光发射强度提高3倍左右，使其有可能应用作白光LED红光发射组分。

中孔分子筛的合成及其在乙烯聚合和聚乙烯降解中的应用

本论文对中孔分子筛的合成及其在茂金属催化剂载体、聚乙烯催化降解方面的应用进行了研究，重点研究了有机中孔分子筛的合成、载体表面官能团和骨架结构与组成对乙烯聚合行为、聚乙烯分子链结构参数、聚乙烯催化降解的影响，以及原位聚合中载体的自破碎原理的应用。本论文的主要工作和研究成果总结如下： 1. 制备了胺基中孔分子筛，并在合成过程中发现了添加尿素的效应。通过与相应的没有尿素添加剂合成的胺基中孔分子筛对比发现，合成过程中加入尿素后，胺基中孔分子筛的孔壁厚度增加，孔之间排列的有序度提高，而且随着中孔分子筛中胺基含量的增加，有序度提高程度更明显。论文中给出了尿素对分子筛有序度影响的几个可能因素，即尿素的pH值缓冲作用及其尿素对非离子表面活性剂胶束分散作用。 2. 制备了胺基中孔分子筛、无机中孔分子筛和胺基实心球形二氧化硅，并用于茂金属催化剂的负载化和乙烯聚合实验中，研究了载体表面官能团和结构对聚合物分子量的影响。结果表明，负载在无机中孔分子筛和胺基实心球形二氧化硅上的茂金属催化剂只能得到分子量呈单峰分布的聚乙烯；而负载在胺基中孔分子筛上的茂金属催化剂在铝/锆比小于等于500时能得到分子量呈双峰分布的聚乙烯，当铝锆比大于等于800时只能得到分子量呈单峰分布的聚乙烯。说明在低的铝锆比时，由于载体上胺基和中孔结构的影响，所负载的茂金属催化剂具有两种不同的活性中心，XPS结果与上述推论相符。 3. 提出了聚乙烯回收利用的新途径，即利用原位聚合过程中载体催化剂破碎原理，将中孔分子筛固体酸均匀分布在聚乙烯基体中，从而使得所制备的聚乙烯催化降解产生的气体物质比相同含量下的固体酸/聚乙烯物理混合物的多了许多，固体酸催化降解效率明显提高。所用的固体酸包括HMCM-41、AlMCM-41、中孔SAPO1和SAPO2。 4．通过在纳米二氧化硅水溶胶中进行丙烯酰胺自由基聚合得到二氧化硅/聚丙烯酰胺杂化粉末，其中聚丙烯酰胺覆盖在纳米二氧化硅上得到次级纳米粒子，该纳米粒子疏松地团聚在一起得到大的二氧化硅/聚丙烯酰胺杂化粒子。以此种二氧化硅/聚丙烯酰胺杂化颗粒作为载体负载茂金属催化剂进行乙烯聚合。由于二氧化硅/聚丙烯酰胺是疏松的团聚在一起的，它们很容易通过聚合过程中载体的破碎分散在聚合物中，所以得到的聚合产物为二氧化硅/聚乙烯纳米复合材料。

全固态电流型氧传感器及Pt-Fe复合催化剂的研究

控制电位电解型即电流型气体传感器由于具有检测气体种类多、浓度范围宽、体积小、价格低、测量精度高、可用于现场直接检测等优点，在环境监测与安全生产等领域中得到了广泛应用。本文论述了纳米级铂、碳纳米管负载铂及铂铁催化剂的合成方法，并对其进行了物理化学表征和电化学研究，主要结果如下： 采用柠檬酸钠还原的方法，合成了纳米级铂催化剂。TEM和XRD测试表明，该球形多晶铂的粒径为2－5nm。用此种铂催化剂制备了离子交换膜电极复合体，并组装了全固态电流型氧传感器；在对低浓度氧气进行测试时，具有高的灵敏度、较短的响应时间、较低的底电流和噪声，且响应信号与氧气的浓度呈良好的线性关系。 1．利用空气氧化和硝酸相结合对多壁碳纳米管进行了纯化，并利用1:1的H2SO4-HNO3混酸使其表面羧基化，TEM和CV测试表明多壁碳纳米管达到了纯化和表面官能团化的目的。 2．利用喷雾冷却法制备了多壁碳纳米管负载的铂及铂铁合金纳米级催化剂复合体，并利用TEM、EDS、XRD、ICP等进行了表征；在循环伏安扫描中，铂铁合金催化剂呈现较高的比表面积。将多壁碳纳米管负载的铂及铂铁合金纳米级催化剂应用于C1有机小分子的电化学氧化研究中发现，铂铁合金催化剂具有较高的催化活性.