纳米团聚生长的多重分形谱

采用小角x射线散射（SAXS）方法，对两类具有代表性的纳米团聚的生长分形进行了表征.一 类为用化学方法 (水合肼溶液还原法) 制备的纳米金属Ni粉；另一类通过物理方法(纳米晶 化处理)，由非晶基体相中生长纳米晶相、形成非晶/纳米晶双相结构的Finemet (Fe_{73 .5} Cu₁Nb₃Si_13.5B₉) 合金.上述两 类材料的纳米团聚在生长过程中都存在 明显元素扩散迁移，形成在1—100 nm范围内的元素分布非均匀区域.这些元素分布的非均匀 区域具有多重质量生长分形特征，其尺度大小和分布方式对最终的材料的物理性能至关重要 .SAXS方法是表征这类具有分形生长特征的纳米团聚微观结构信息的强有力手段.从方法论的 角度详述了从SAXS测量到获得多重分形谱的处理过程，这一实验研究分析手段对于定量考察 纳米微结构形貌的生长机理和性能的其他研究课题有一定的帮助作用. 关键词： 纳米材料 分形生长 小角x射线散射 磁性材料     

基于多个无标度区的多重分形分析方法

用计算机模拟生成了多重分形结构,通过对比分析结构的解析多重分形谱和配分函数法计算得到的多重分形谱,总结出多重分形谱可以描述结构在某一无标度区内生长规律的特性,发现结构的各个无标度区都具有研究价值,针对传统方法不能充分利用数据的缺陷,提出了基于多个无标度区的多重分形谱计算方法.     

对以并五苯和酞菁铜为不同有源层的有机薄膜晶体管特性研究

通过扫描电镜和X射线衍射对SiO₂衬底上生长并五苯和酞菁铜薄膜的表面形貌进行表征,并得到在SiO₂衬底上生长的并五苯薄膜是以岛状结构生长,其大小约为100nm,且薄膜有较好的结晶取向,呈多晶态存在. 酞菁铜薄膜则没有表现出明显的生长机理,其呈非晶态存在. 还对通过掩膜的方法制作得以酞菁铜和并五苯为有源层的顶栅极有机薄膜晶体管的特性进行了研究. 有源层的厚度为40nm,绝缘层SiO₂的厚度为250nm,器件的沟道宽长比(W/关键词： 有机薄膜晶体管 并五苯薄膜 酞菁铜薄膜 μ_EF)')" href="#">场效应迁移率(μ_EF)     

酞菁铜薄膜的光记录特性

研究了有机染料酞菁铜（ＣｕＰｃ）真空蒸镀薄膜在可见及近红外区域的吸收光谱和光学常数，发现酞菁铜薄膜在５５０－７５０ｎｍ波长范围内具有较强的吸收，在静态测试仪上测试了酞菁铜薄膜的光存储记录特性，发现用低功率氦氖激光照样品时薄膜反射率变化较大，在酞菁记录层上覆盖金属反射层将提高写入激光的阈值能量并且增大反射率的对比度。     

炉内碳黑团聚物形态影响辐射特性分析

碳黑团聚物光谱辐射特性是炉内辐射换热、火焰温度诊断以及光学检测碳黑性质的必要参数。基于分形理论,利用CCA模型研究碳黑团聚物随分形维数和前向因子变化的形态特征,利用T矩阵计算了不同形态参数的多组粒子数碳黑团聚物的辐射特性,分析了不同形态碳黑团聚物辐射特性。结果表明:随分形维数和前向因子分别增加,团聚物粒子密实程度增强,无因次消光和吸收截面变化幅度较小,无因次散射截面缓慢增大,无因次非对称因子有减小的趋势。说明随着碳黑团聚物密实程度增强,碳黑团聚物粒子间相互作用增强,从而增大了团聚物辐射特性。     

Ag(110)表面吸附酞菁铜分子的紫外光电子谱研究

用紫外光电子能谱(UPS)研究了酞菁铜分子在Ag(110)单晶表面上的吸附,随着酞菁铜分子覆盖度增加,衬底Ag的3d电子信号逐渐减弱,在此能带区域出现两个新的谱峰,这两个与吸附有机分子轨道有关的谱峰的束缚能分别为4.45 和6.36 eV.随着覆盖度的增加,在结合能为1.51和9.20 eV处又出现了两个谱峰,它们同样来自吸附有机分子的轨道.随着覆盖度的继续增加,上述四个谱峰的强度逐渐增加,其能量位置均发生了明显的偏移.根据角分辨光电子能谱的实验结果,酞菁铜分子的分子平面基本与衬底表面平行.密度泛函理论计 关键词： 酞菁铜 紫外光电子谱 吸附电子态 密度泛函理论     

PMP/Cu泡沫材料中Cu颗粒的三维分布

为观测和分析铜掺杂聚-4-甲基-1-戊烯(PMP/Cu)低密度泡沫材料中铜颗粒的三维空间分布,采用高分辨X射线断层扫描技术,扫描PMP/Cu泡沫材料样品,对铜颗粒在聚合物泡沫中的分布进行了成像分析。经过图像处理和三维重构,获得铜颗粒在PMP聚合物泡沫中的三维立体分布图。结果分析显示:铜纳米粒子在PMP泡沫中存在团聚现象;不同尺寸的团聚物形态呈现出明显的多样化特征,小颗粒团聚物趋于球形,大颗粒团聚物趋于不规则的短木棒状,与在电子显微镜下直接观测到的结果一致。研究表明,该技术可以在不破坏样品的前提下,实现对有机聚合物泡沫材料中掺杂金属颗粒空间分布情况的直接观测。     

脂肪醇甲酸酯类酞菁铜配合物的合成、表征及荧光性能

报道了四甲酰氯酞菁铜的合成及其与反应得到正丁醇、正戊醇、正己醇、正辛醇、正十二醇5个含脂肪链取代基的酞菁铜衍生物.分别用红外光谱、紫外-可见光谱、元素分析、核磁共振氢谱等方法对这些衍生物进行了结构和取代度的表征,并研究了该系列酞菁铜衍生物在有机溶剂中的溶解性及荧光性能与浓度、取代基的关系.研究结果表明在一般有机溶剂中这些酞菁铜衍生物的溶解性显著提高,荧光强度不随浓度的变化而线性变化、长链要高于短链取代酞菁铜衍生物的荧光强度.     

海杂波背景下小目标检测的分形方法

针对海杂波背景下小目标检测对海情依赖性强的问题, 本文采用分数布朗运动模型对实测海杂波建模, 结合多重分形去势波动分析法确定分形参数, 分析了海杂波的单尺度、多重分形特性. 在单尺度分形的基础上, 利用表征海杂波分形特征的分数维和Hurst指数构建了分形差量, 提出了基于分形差量的小目标检测方法;在多重分形基础上, 比较了两种海杂波的高尺度多重分形特性. 结果表明, 当尺度q > 10时, 纯海杂波的多重分形参数H(q) < 0, 而存在小目标的H(q) > 0, 此差异性为高尺度分形参数的海杂波背景小目标检测提供了判定依据. 所研究的两种方法均能实现不同海情下的小目标检测.     

一系列酞菁红外谱图的性质

因为酞菁在信息、医疗、化工等众多领域有很广泛的应用,所以近百年来一直是科学家研究的热点课题.本文首次对一系列氮杂金属酞菁谱图性质研究,这些酞菁是氮杂酞菁铜、氮杂酞菁锌、氮杂酞菁钴、氮杂酞菁镍和氮杂酞菁汞,这5种氮杂金属酞菁的红外光谱图性质进行研究与比较.这些原因主要和中心配位为金属原子不同引起的.     

Laser-driven metal exchange and preparation of metal phthalocyanine

Two types of laser-driven dry processes for the preparation of metal phthalocyanine are reported. In the first one, laser-driven metal exchange, the excimer laser beam was focused on a copper target, and ablated copper atoms were injected onto a thin film of dilithium phthalocyanine (Li₂Pc). The central metal atoms of Li₂Pc were partially exchanged by copper atoms, and the blue thin film of copper phthalocyanine (CuPc) was obtained after removal of the residual Li₂Pc by the hydrochloric acid treatment. In the second one, direct synthesis using the component organic molecule, CuPc was prepared by the implantation of laser-ablated copper atoms onto a thin film of 1,3-diiminoisoindoline (D I I I).     

酞菁铜衍生物在酞菁酮—氧化铁纳米粒子交替LB膜中的分子取向

通过Langmuir-Blodett技术制备了酞菁酮－氧化铁纳米粒子交替LB膜,利用偏振紫外－可见光谱对酞菁铜衍生物在不同制膜条件下所制得的交替膜中的分子取向进行了研究。结果表明,在同一氧化铁溶胶亚相中,随着表面压的增大,或在相同的表面压下,随着亚相中氧化铁浓度的减小,酞菁铜分子在其复合LB膜中倾斜程度变大。     

酞菁铜薄膜的折射率及吸收特性

通过真空镀膜法在单晶硅制备了酞菁铜薄膜，在波长扫描和入射角可变全自动椭圆偏振光谱仪上研究了ＣｕＰｃ薄膜的椭偏光谱并分析了其电子结构。     

Nitrogen Dioxide Sensing Properties and Mechanism of Copper Phthalocyanine Film

Copper phthalocyanine film, a p-type organic semiconductor, is synthesized by vacuum sublimation and its surface morphology is characterized by SEM. A silicon-based copper phthalocyanine film gas sensor for NO2 detection is fabricated by MEMS technology. The results show that the resistance and sensitivity of copper phthalocyanine film decrease obviously as the NO2 concentration increases from Oppm to lOOppm. However, the sensitivity nearly keeps a constant of O. 158 between 30 ppm and 70 ppm. The best working temperature of the gas sensor is 90℃ for NO2 gas concentrations of lOppm, 20ppm and 30ppm, which is much lower than that of general metal oxide gas sensor.     

Copper phthalocyanine film studied with spectroscopic ellipsometry

The ellipsometric spectra of vacuum sublimed copper phthalocyanine (CuPc) thin film on single-crystal silicon were studied on a new type of scanning ellipsometer with the analyser and polarizer rotate synchronously. The electronic structure of the spectra is discussed.     

双异质结结构的双极型有机薄膜晶体管的研制

制备了基于F₁₆CuPc和CuPc的双异质结结构的双极型有机薄膜晶体管。该器件的载流子迁移率是相同工艺制备的F₁₆CuPc和CuPc双层单异质结有机薄膜晶体管器件的4~5倍。同时,该双异质结结构还能调整载流子的阈值电压,减少双层结构对薄膜厚度等工艺条件的苛刻要求。这种双异质结结构为提升双极型有机薄膜晶体管器件的性能提供了一种有效方法。     

Morphological control of copper phthalocyanine films by protonation-electrophoretic deposition

Films composed of various nanostructured copper phthalocyanine are controllably prepared by the method of protonation-electrophoretic deposition. The ultralong nanowires of copper phthalocyanine are grown at the deposition temperature of 70 °C. And the results of films UV-vis absorption spectra and X-ray diffraction indicate that copper phthalocyanine possesses the transformation tendency from α-phase to thermostable β-phase under the higher deposition temperature. The formation process of the ultralong nanowires illustrates that the nanowires grow in longitudinal orientation much faster than in lateral direction. And the time dependence of the films morphology, from another point of view, proves that copper phthalocyanine is dissolved in the precursor solutions, and the formation of the nanostructured copper phthalocyanine contains the process of crystal growth, which is different from the traditional electrophoretic deposition. So the films morphology is flexible to be controlled by varying the deposition conditions. These diverse nanostructured films have potential applications in the electrochemical and optoelectrical equipments.     

薄膜生长的多重分形谱的计算

规则分形具有理想的标度不变性,而随机分形(如薄膜生长)概率分布曲线及标度不变性的范围与计算方法有关:以偏离平均高度的方差值求概率,标度不变性不好,多重分形谱也不光滑;而以薄膜平均底面为基准面求概率得到的标度不变性可延伸到3个数量级,多重分形谱光滑.采用外延的方法修正灰度设置的偏移可以对多重分形谱有所改善.另外,讨论了权重因子q取值范围的影响,确定了q的取值范围.     

Surface-enhanced Raman effect in ultra-thin CuPc films employing periodic silver nanostructures

In order to investigate the interaction of organic molecules with metals by means of Raman spectroscopy, special substrates were designed which combine interference and surface-enhancement mechanisms. Triangular shaped silver nanostructures with an angle bisector and a height of about 80 nm were prepared by nanosphere lithography on silicon substrates with a 100-nm oxide layer. Utilizing these substrates the dependence of the Raman signal intensity on the thickness of copper phthalocyanine (CuPc) was studied in the range from few percentages of a monolayer coverage up to 80 nm using an in situ setup. At an excitation in resonance with the plasmons of the nanostructures (2.6 eV) an increase of the signal was observed during film growth. Contrary to that, excitation at 1.92 eV in resonance with the CuPc absorption band leads to a strongly enhanced Raman signal for submonolayer coverage which hardly changes with the CuPc film thickness in the ultra-low coverage regime.     

Plasma irradiation effects in phthalocyanine films

Plasma irradiation effects in copper phthalocyanine films were examined. The film surface and chemical composition were characterized by means of atomic force microscopy (AFM) and secondary ion mass spectrometry (SIMS), including SIMS profiling.