量子点与人源抗谷胱甘肽单链抗体的连接与表征

用已构建的表达载体pPELB-B3, 在大肠杆菌Rosetta中可溶性表达人源抗谷胱甘肽(GSH)单链抗体B3(scFv-B3), 经Ni2+螯合亲和层析纯化后, 用点印迹法验证了其与GSH结合的特异性. 将水相合成的半导体纳米粒子(半导体量子点, QDs)在N-羟基琥珀酰亚胺(NHS)和1-乙基-3-(3-二甲基氨基丙基)碳酰二亚胺盐酸盐(EDC)的作用下, 与scFvs连接. 光谱分析和膜印迹结果表明, scFvs成功地共价连接到QDs表面, 所得的QD-scFvs复合物能够较好地识别GSH. 荧光显微镜观察QD-scFvs与人乳腺癌细胞MCF-7的作用结果, 初步判断QD-scFvs能够跨膜进入细胞.     

Generation of Red Light Femtosecond Pulses from an Intra-Cavity Frequency-Doubled Cr^4＋： Forsterite Laser

We demonstrate the generation of red light femtosecond laser pulses from an intra-cavity frequency-doubled Cr^4＋ ：forsterite laser. An average output power of 75 mW is obtained at the central wavelength of 647nm with a pulse width of 55 fs by inserting a 500μm-thick BBO crystal in the laser cavity. The bandwidth of the spectrum of second harmonic pulses is 9 nm, corresponding to a time-bandwidth product of 0.355.     

高应变率压缩下纳米孔洞对金属铝塑性变形的影响研究

本文利用分子动力学模拟方法研究了含纳米孔洞金属铝在[110]晶向高应变率单轴压缩下弹塑性变形的微观过程. 对比单孔洞和完整单晶的模型, 讨论了多孔金属的应力应变关系及其位错发展规律. 研究结果表明, 对于多孔模型的位错积累过程, 位错密度随应变的增加可大致分为两个线性阶段. 由同一个孔洞生成的位错在相互靠近过程中, 其滑移速度越来越小; 随着位错继续滑移, 源自不同孔洞的位错之间开始交叉相互作用导致应变硬化. 达到流变峰应力之后又由于位错密度增殖速率升高发生软化. 当应变增加到11.8%时, 所有孔洞几乎完全坍缩, 并观察到在此过程中有棱位错生成.     

单斜与锐钛矿双晶相TiO2/MWNTs复合材料的制备及其可见光光催化活性

以超强耐酸碱的表面活性剂-丁基封端脂肪醇聚氧乙烯醚作为晶型调节剂,利用钛酸丁酯和氢氧化钠的水热反应制备了单斜相与锐钛矿相双晶相TiO2/多壁碳纳米管(简称MWNTs)复合材料,并考察了复合材料的可见光光催化活性。结果显示:MWNTs的加入可调控TiO2的晶相组成,增强TiO2的光催化活性,其中含5%MWNTs的样品具有较高的催化降解效率;随煅烧温度的升高,样品的光催化活性大幅提升。其机理归因于(1)促进单斜相和锐钛矿相双晶相结构的形成;(2)碳纳米管优良的导电作用及碳纳米管/TiO2间的异质结效应;(3)高温下碳纳米管分解产生的碳元素掺杂作用。     

Long-Term Stabilization of Carrier-Envelope Phase for Few Cycles Ti：Sapphire Laser Amplifier

We realize a long-term carrier-envelope phase （CEP） stabilization for a chirped pulse amplified Ti：sapphire laser by locking the oscillator and amplifier independently. Based on the measurement of CEP by employing f-to-2f interference technique between the octave-spanning spectrum which is generated from a rare gas filled hollow fiber, continuous locking time up to 7.2 h with 85 mrad fluctuation is demonstrated. Finely compensating the dispersion by a set of chirped mirrors, quasi-mono cycle pulses as shorter as 3.8 fs are obtained. Further experimental research on high harmonic generation dependence on CEP shown the waveform of laser pulses has been successfully controlled.     

Covalent Organic Framework for Improving Near-Infrared Light Induced Fluorescence Imaging through Two-Photon Induction

Fluorescent materials exhibiting two-photon induction (TPI) are used for nonlinear optics, bioimaging, and phototherapy. Polymerizations of molecular chromophores to form π-conjugated structures were hindered by the lack of long-range ordering in the structure and strong π–π stacking between the chromophores. Reported here is the rational design of a benzothiadiazole-based covalent organic framework (COF) for promoting TPI and obtaining efficient two-photon induced fluorescence emissions. Characterization and spectroscopic data revealed that the enhancement in TPI performance is attributed to the donor-π-acceptor-π-donor configuration and regular intervals of the chromophores, the large π-conjugation domain, and the long-range order of COF crystals. The crystalline structure of TPI-COF attenuates the π–π stacking interactions between the layers, and overcomes aggregation-caused emission quenching of the chromophores for improving near-infrared two-photon induced fluorescence imaging.     

Gires-Tournois干涉镜补偿色散的自启动飞秒Cr4+:YAG激光器实验研究

利用一片GTI镜补偿腔内色散,并使用宽带半导体可饱和吸收片,实现了锁模自启动的飞秒Cr4 :YAG激光输出.在9 W平均功率的1030 nm激光抽运下,获得输出脉冲功率为95 mW,光谱半高全宽45 nm,中心波长1508 nm,实测脉冲宽度为65 fs.     

适宜氧空位诱导α-MnO2高效催化消除碳烟研究

柴油机排放的碳烟颗粒对人类和自然产生了严重的威胁,开发高活性低成本的碳烟燃烧催化剂是解决这一问题的关键。本文采用不同煅烧气氛（空气、真空和氮气）成功制备了含有不同浓度氧空位的α-MnO2催化剂（记为M-Air-500,M-Va-500,M-N-500,M-N-450）。M-Va-500和M-N-500催化剂在500 ℃煅烧会失去过多晶格氧,导致晶相结构发生改变,出现Mn3O4相,这与XRD和HRTEM结果一致。XPS和Soot-TPR的结果说明,适量的表面氧空位能够吸附并活化氧气分子,催化剂表面的化学吸附氧提高了催化剂的催化性能。H2-TPR结果说明适量的氧空位能够加快晶格氧的迁移,提高可移动氧物种丰度,增强催化剂的氧化能力。结合催化活性测试结果可以得出：在保持α-MnO2晶相结构的前提下,氧空位越多,催化剂表面的化学吸附氧越多,催化活性越好。     

CdHgTe纳米晶/聚乙烯醇近红外纳米纤维的制备

采用一步法制备了性质稳定的CdHgTe纳米晶, 将其与聚乙烯醇水溶液共混, 通过静电纺丝方法获得了CdHgTe纳米晶/聚乙烯醇纳米纤维. 改变聚乙烯醇水溶液的浓度可以使纤维的直径在200~400 nm范围内可调. 所制备的纳米纤维在近红外区域具有很强的荧光, 而且发光峰位与原水相纳米晶的峰位基本一致, 这是采用其它方法制备纳米晶与聚合物的复合材料难以实现的. 通过与聚乙烯醇的复合, 纳米晶的热稳定性得到进一步增强, 在120 ℃下将纳米纤维加热2 h, 其形貌和发光性质都未发生明显的变化.