GeS2-Ga2S3-CdS硫系玻璃的非线性光学性能

采用传统的熔融-急冷法制备了GeS2-Ga2s3-CdS硫系玻璃.用飞秒OKE技术、Maker条纹法分别测试了室温下玻璃的超快三阶非线性光学效应和二阶非线性光学效应,分析了玻璃的组成、结构对玻璃的三阶非线性光学效应与二阶非线性光学效应的影响.结果表明:玻璃具有较强的超快三阶非线性光学效应,当玻璃中S-Ge、S-Ga键的数量最多,离子极化程度最大,电子云的变形程度最大时,具有最大的χ(3)值;电场-温度场极化的玻璃表现出明显的二阶非线性光学效应,当玻璃中定向排列的偶极子的数量最多和程度最大时,具有最大的χ(2)值.χ(2)和χ(3)之间不呈线性关系.     

非线性相位共轭腔的光学多稳性

本文提出并分析了非线性相位共轭腔的光学多稳性.结果表明,这种腔容易实现多稳运转,主要的控制参数是相位共轭镜的反射率和腔内非线性介质的三阶极化率.给出了输入输出的解析表达式和稳定性判据.     

1,3-对称取代的克酮酸衍生物光学性能研究

通过实验来研究1,3-对称取代的克酮酸衍生物的三阶非线性光学特性,计算出其分子超极化率,探讨了产生三阶非线性光学性能的原因.确定该衍生物在一定条件下具有较大的三阶非线性光学性质和较快的光学响应.     

Mn2O3超微粒子的制备及其光学非线性

本文合成了表面修饰的Ｍｎ２Ｏ３超微粒子（ＵＦＰ）有机溶胶，并采用简并的四波混频（ＤＦＷＭ）手段研究了Ｍｎ２Ｏ３有机溶胶的三阶非线性光学特性，得到了较大的非线性极化率Ｘ＾３，最后讨论了Ｍｎ２Ｏ３超微粒子的三阶非线性产生机制。     

CuInS2纳米晶的制备及三阶非线性光学性质的研究

以无水醋酸铜(Cu(AC)2)为铜源,氯化铟(InCl3)为铟源,正十二硫醇(DDT)为硫源,1-十八稀(ODE)为溶剂在240℃条件下反应3h,合成了金字塔形的CuInS2纳米晶。用X射线粉末衍射(XRD),X射线光电子能谱(XPS),透射电子显微镜(TEM),能量分散光谱(EDS),Z-Scan技术对粉体的结构、形貌、相组成、三阶非线性光学特性进行表征。结果表明:通过一锅法可以合成单分散颗粒尺寸为5-7nm的金字塔形CuInS2纳米晶;分散在正己烷中的CuInS2纳米晶的三阶光学非线性折射率γ,三阶光学非线性吸收系数β以及三阶光学非线性极化率χ(3)分别为3.444×10-17m2/W,4.526×10-7m/W和1.390×10-8esu。     

聚乙烯醇改性聚丙烯微孔膜的性能

为了得到亲水性和抗污染性能好的聚丙烯微孔膜,采用表面涂覆法将聚乙烯醇固定在聚丙烯膜的表面.通过红外光谱对聚丙烯微孔膜改性前后的基团进行了表征;研究了反应时间、聚乙烯醇浓度等反应条件对聚乙烯醇固定率的影响.结果表明,聚乙烯醇的固定率随着反应时间和聚乙烯醇浓度的增加而增加.最佳反应条件为50 ℃下反应2 h,聚乙烯醇质量分数为1%,戊二醛质量分数为2%,得到的改性膜的水接触角从110°下降至62°,两个月内水通量的变化不明显,膜的亲水性和抗污染性较好.     

位相共轭的力学研究

本文利用机械振子来研究位相共轭。文中计算了一个非谐和振子在同时受到一个强的力偶矩及一个弱的检测力偶矩的激励下其响应的位相共轭部分。此外,还介绍了它与非线性光学中的三阶极化率张量之间的关系。     

相干反斯托克斯光计算谱与X(3)

相干反斯托克斯光是四波混频过程，即是由三阶非线性极化率引起的三阶非线性光学过程。相干反斯托克斯光测温技术已取得了很大进展，具有很大的实用价值。由相干反斯托克斯光谱理论计算公式及χ^(3)的理论计算公式，通过改变χ^(3)中的各因子算出的计算谱，讨论了χ^(3)中各因子对相干反斯托克斯光谱的影响。并给出了激光线宽对相干反斯托克斯光谱的影响。     

四叔丁基萘酞菁氧钒非线性及光限幅特性

为提高酞菁化合物的非线性光学性能,以1,8-二氮杂双环[5.4.0]十一碳烯-7(DBU)为催化剂,采用液相法合成了四叔丁基萘酞菁氧钒((t-Bu)4NcVO)化合物.利用元素分析、红外光谱、核磁共振氢谱方法,验证了化合物的分子结构.应用调Q倍频ns/ps Nd∶YAG脉冲激光系统,在波长为532nm下,研究了化合物的非线性和光限幅特性.测得化合物的非线性折射率n2和三阶非线性极化率χ(3)分别为2.51×10-11esu和8.54×10-12esu,通过计算得到分子极化率γ’为3.7×10-29esu.在透过率69%时限幅阈值为1608mJ/cm2,箝位值为585mJ/cm2,有效激发态与基态吸收截面比为3.66.     

热处理对掺杂ZnS硼硅酸盐玻璃的非线性光学性能的影响

用二阶段熔化方法制备了掺杂ＺｎＳ的ＳｉＯ２－Ｂ２Ｏ３－Ａｌ２Ｏ３－Ｋ２Ｏ玻璃,测定了热处理样品的发光光谱和吸收光谱。利用Ｚ－扫描法测定和计算了非线性折射率ｎ２和三阶非线性极化率ｘ。发现热处理后激子峰和吸收线的位置向低能量方向移动,而且非线性折射率和三阶极化率随样品热处理温度的增加而降低。此现象可用玻璃中ＺｎＳ半导体微晶的量子尺寸效应来解释。     

Compatibility and Properties of Biodegradable Blend Films with Gelatin and Poly（vinyl alcohol）

The blend films with gelatin and poly（vinyl alcohol） （PVA） were prepared by a solution casting method. The compatibility between gelatin and PVA in the blend films was investigated. The transmittance, Fourier-transform infrared spectroscopy （FTIR）, x-ray diffraction （XRD）, thermogravimetry analysis （TG）, and differential scanning calorimetry （DSC） were employed to characterize the resultant blend films. According to optic result, the opacity of the blend film at the ratio of 20/80 （w/w, Gel to PVA） was the lowest, indicating the best compatibility between Gel and PVA at the ratio. The results oflR, XRD, DSC, and TG revealed an intensive interaction and good compatibility between them in the blend film at the ratio. The mechanical properties and solubility showed that PVA content in the blend films obviously affected the elongation at break and solubility. The mechanical properties and water resistance of gelatin film may be improved by the introduetion of PVA.     

Effect of Microfibrillated Cellulose Loading on Physical Properties of Starch/Polyvinyl Alcohol Composite Films

The starch/polyvinyl alcohol (PVA)/ microfibrillated cellulose (MFC) composite films were prepared using solution casting method after adding MFC into starch/PVA blend matrix.The effects of MFC content on the mechanical properties of starch/PVA composite films were investigated.As MFC content increases,the elongation at break and tensile strength increase firstly and then decrease.When the content of MFC is 2wt%,the tensile strength is 26.6 MPa and reaches the maximum.Through Fourier transform infrared (FTIR),scanning electron microscopy (SEM),X-ray diffraction (XRD) and thermogravimetric analysis (TGA),good dispersion of MFC in starch/PVA matrix at the loading of 2wt%,lower crystallinity of the starch/PVA/MFC films in comparison with starch/PVA blend and the effect of glass transition temperature increasing with MFC content from 0.5wt% to 4wt% can be found observed.And,incorporating MFC does not change the composition and crystal structure of the starch/PVA composite films.Thus,the reinforcing mechanism for the improvement of mechanical properties is attributed to the homogeneous dispersion of MFC with large aspect ratio,good compatibility and interfacial interactions between starch/PVA blend matrix and MFC.     

PVA与超高摩尔质量PEO复合膜的制备及表征

将聚乙烯醇（PVA）与超高摩尔质量的聚氧化乙烯（PEO）进行共混,制备了PVA-PEO复合膜,并对混合溶液的流变行为、力学性能及其结晶行为进行了考察.研究发现：PVA水溶液及PVA-PEO混合溶液的稳态流变行为均呈现明显的第一牛顿区、非牛顿区和第二牛顿区.少量PEO的加入使混合溶液的黏度增大,但增加幅度不大|PEO加入后得到的PVA-PEO复合膜的弹性模量、断裂强度及断裂伸长率等力学性能及玻璃化温度均有所提高,且随着PEO质量分数的提高,各项力学性能均得到增强,这与在成膜过程中PEO的加入使PVA的晶区尺寸变小而分布均匀,以及体系中物理交联点增加有关.     

Biocompatibility of implantable electrodes coated with PVA films in the brain of rats: a histological evaluation

The biocompatibility of silicone rubber (SR) based electrodes coating with poly (vinyl alcohol) (PVA) films after implanted in the brain of rats was investigated. Twenty-two Wistar rats were used and implanted with SR electrodes and PVA/PAA films coated electrodes in left and right cerebral cortex respectively. After 4 and 8 weeks, the expression of glial fibrillary acidic protein (GFAP, a specific marker of astrocytes) and cluster of differentiation 68 (CD68, a specific marker of macrophages) were evaluated by immunohistochemistry. After 8 weeks, GFAP and CD68 expressions around PVA electrodes were significantly lower than those around SR electrodes in every stratified area (0–50 μm, 50–100 μm, 100 μm from further up to the electrode-tissue interface). The results show that PVA coating can reduce the expressions of GFAP and CD68, suggesting the PVA coating can improve the biocompatibility of the SR while it is implanted in brain. Funded by the “863” Program of China (No.2006AA02Z4E6) and the National Nature Science Foundation of China (No.30570516)     

淀粉基生物降解性塑料薄膜的研究

本文以淀粉和聚乙烯醇（ＰＶＡ）为主要原料，制备了淀粉基生物降解性塑料薄膜。讨论了共混和降解机理，并研究了制备过程中诸因素对薄膜性能及其混体系相容性的影响。     

离子液体中丝素/聚乙烯醇共混膜的制备及表征

采用离子液体氯化1-丁基-3-甲基咪唑（BMIMCl）溶解丝素（SF）,获得BMIMCl/SF溶液,再与聚乙烯醇（PVA）水溶液共混,制备得到PVA/SF共混膜。共混膜经红外光谱、紫外可见光谱、对水接触角、拉力试验等表征。结果表明,溶液共混使共混膜中SF与PVA发生了化学键键合,乙醇处理使共混膜中SF主要以β-折叠结构存在。随着SF含量的增加,共混膜的透光率逐渐变小,亲水性则逐渐增大。     

高品质立方氮化硼薄膜的制备及应用基础研究

采用射频（RF）磁控溅射的方法，成功地在（100）单晶硅片上沉积制备出了高品质的c-BN薄膜，并通过对基片的高能离子束的预处理，有效地改善了c－BN薄膜中因内应力导致的差的附着性能．进一步研究了衬底负偏压、温度与薄膜质量的关系，讨论了薄膜中内应力的状态．在此基础上，深入开展了硬质合金上沉积c-BN薄膜的工作，为c-BN薄膜的实际应用奠定了基础．     

Fabrication of Poly-Si Thin Film on Glass Substrate by Aluminum-induced Crystallization

Amorphous silicon （ a-Si ） thin films were deposited on glass substrate by PECVD, and polycrystalline silicon （ poly- Si ） thin films were prepared by aluminum- induced crystallization （ AlC ）. The effects of annealing temperature on the microstructure and morphology were investigated. The AlC poly-Si thin films were characterized by XRD, Raman and SEM. It is found that a-Si thin film has a amorphous structure after annealing at 400℃ for 20 min, a-Si films begin to crystallize after annealing at 450 ℃ for 20 min, and the crystallinity of a-Si thin films is enhanced obviously with the increment of annealing termperature.     

脉冲多弧离子镀制备类金刚石薄膜的结构分析

利用脉冲多弧离子镀技术在硅基底上沉积类金刚石薄膜．喇曼光谱和Ｘ 射线衍射分析表明：类金刚石薄膜是无定形结构;利用扫描电镜发现：类金刚石薄膜表面不光滑,石墨颗粒的大小和密度随厚度增加而增加,但薄膜致密．     

溶胶凝胶法制备透明氧化铝薄膜及光学性能

以异丙醇铝为先驱体,采用溶胶凝胶方法制备了透明氧化铝薄膜;并采用DTA-TG,XRD, UV-vis分光光度计和PL光谱等测试手段对氧化铝薄膜进行表征.研究结果表明, 氧化铝薄膜(膜厚为100 nm) 在紫外到近红外范围内具有高的透射性,750 ℃热处理后氧化铝薄膜的光透射性最好;氧化铝薄膜在360-600 nm波长范围具有一个宽的蓝色发光带,且氧化铝膜的光致发光强度和峰位与热处理温度和激发光波长有关, 在345 nm 波长激发下,500 ℃热处理后氧化铝薄膜的发光强度最强;氧化铝薄膜的蓝色发光由氧空位缺陷(F+色心)引起.