基于多线结构光的弱纹理物体形貌测量方法

大多数现有的主流结构光测量装置在被测物体的表面上投射单条激光,通过移动装置实现物体表面的扫描重建。为了实现物体表面的在线快速重建,将多线结构光和双目立体视觉理论相结合,设计了一种新的三维测量方法。提出了一种结合形态滤波和Zhang-Suen细化算法的光条骨架提取方法和基于光条序列关系的光条匹配算法,并通过极线约束实现光条上特征点的精确匹配。通过实验验证了方法的有效性,相对误差在3%以内。     

Preparation and characterization of novel addition cured polydimethylsiloxane nanocomposites using nano‐silica sol as reinforcing filler

A series of novel addition cured polydimethylsiloxane (PDMS) nanocomposites with various amounts of nano‐silica sol were prepared via hydrosilylation for the first time. The influence of various amounts of nano‐silica sol on the morphology, thermal behavior, mechanical and optical properties of these PDMS nanocomposites was studied in detail. It was found that with an increment in the amount of nano‐silica sol the reinforcing effect of the nano‐silica sol on the thermal and mechanical properties of the PDMS nanocomposites was very noticeable compared with the reference material. The prominent improvements in resistance to thermal degradation and mechanical properties can probably be attributed to the strong interaction of PDMS chains and uniformly dispersed particles resulting from the nano‐silica sol. However, the transparency of the PDMS nanocomposites slightly decreased with an increment in weight fraction of nano‐silica, compared with that of PDMS composite without nano‐silica (Sol‐0), which can probably be ascribed to an increasing size of the aggregated particles in the PDMS nanocomposites. The optimum amount of nano‐silica sol for preparing novel addition curing PDMS nanocomposites was about 15 wt%. © 2015 Society of Chemical Industry     

Fabrication and photocatalytic performance of one-dimensional Ag3PO4 sensitized SrTiO3 nanowire

The 1D Ag₃PO₄ sensitized SrTiO₃ nanowires are prepared by simple route of electrospinning-in situ deposition technique. The results of the thermogravimetry (TG), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive Spectrometer (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV–Visible diffuse reflectance spectroscopy (UV–Vis) indicate that the Ag₃PO₄ nanoparticles has been deposited on the surface of the SrTiO₃ nanowires successfully. Experimental results showed that compared with pure SrTiO₃, the as-prepared 1D Ag₃PO₄ sensitized SrTiO₃ nanowires exhibit obvious enhancement of photocatalytic performance and stability. Especially, the Ag₃PO₄/SrTiO₃ (3AS sample) had a satisfactory photocatalytic activity for degrading methylene blue (MB) more than 98% under visible light irradiation. As to pure SrTiO₃ and Ag₃PO₄, only 9.8% and 49% of MB was decomposed after 35?min irradiation respectively. Furthermore, the mechanism of the enhancing photocatalytic activity could be ascribed to the nano-heterojunction of the Ag₃PO₄/SrTiO₃, the visible light response of the Ag₃PO₄, and the 1D structure of the nanowires.     

TiO2 nano-flakes with high activity obtained from phosphorus doped TiO2 nanoparticles by hydrothermal method

TiO₂ nano-wires (Ti-NWs) and nano-flakes (Ti-NFs) were obtained from phosphorus doped TiO₂ nanoparticles (Ti-P) by hydrothermal method and by subsequent heat treatment respectively. FE-SEM micrograph of the as prepared sample depicts well formed, entangled and randomly oriented nano-wires morphology, which changes to nano-flakes morphology after heat treatment. Structural characterization of the samples by X-ray diffraction shows anatase phase for both the samples. Absorption edge of the Ti-NWs sample shows blueshift where as the Ti-NFs sample exhibit redshift compared to precursor sample as evidenced by UV–Visible absorption spectra, which is due to change in morphology and crystallinity of the samples. XPS studies indicate the presence of titanium and oxygen species only. From the EPR measurements with in-situ visible light irradiation, the number of photogenerated charge carriers is found to be very high for nano-flakes sample. Methyleneblue degradation profiles depict very high activity of Ti-NFs sample compared to Ti-NWs and the precursor samples, which is due to the observed redshift in the absorption edge, change in morphology and high crystallinity of the sample which in turn increases the optical response and separation of photogenerated charge carriers as evidenced by the optical and EPR measurements respectively.     

White light emission based on both upconversion and thermal processes from Nd3+ doped yttrium silicate

In the present study, white light emission based on both upconversion and thermal processes from single-phase yttrium silicate nanopowder doped with Neodymium (III) (Nd³⁺) was investigated at both room pressure and vacuum (0.01 mbar) with a diode laser excitation of 808 nm. 1% Nd³⁺ doped (per mole) yttrium silicate (Y₂O₃:SiO₂) nanopowder was synthesized by using the sol-gel method and annealed at 1250 °C for 12 h to obtain the powder form. Emission for upconverted white light mainly due to the transitions of Nd³⁺ ions was obtained below ~ 5.79 W of the laser beam power at atmospheric pressure. For powers exceeding ~ 5.79 W, the powder emitted a thermal white light (WL) due to the photon avalanche mechanism together with thermal processes. The threshold power to obtain thermal white light with the transitions of Nd³⁺ ions was decreased to ~ 3.51 W at the vacuum condition. These processes were investigated in detail by studying the spectral differences of the rise and decay patterns at atmospheric pressure and vacuum conditions.     

3＋9×0.175NT钢丝帘线在轻型载重子午线轮胎胎体中的应用

研究3+9×0.175NT钢丝帘线在轻型载重子午线轮胎胎体中的应用。结果表明,采用1层压延密度为83根·dm-1的3+9×0.175NT钢丝帘布替代3层压延密度为110根·dm^-1的1670dtex/2-28EPI聚酯帘布用于6.50R1610PR轻型载重子午线轮胎胎体,压延工艺良好,成型和硫化过程正常。成品轮胎质量减小,成本降低,充气外缘尺寸、强度性能、耐久性能和高速性能均符合国家标准或企业标准要求。     

CVD金刚石表面增透膜的研究进展

CVD金刚石膜因特有的物理化学性质，具有发展成为新一代光学材料的前景。但由于CVD金刚石膜自身局限性导致其理论透过率不到71%，在金刚石膜表面镀制增透膜，通过改变增透膜组成成分、显微组织和晶体结构，可有效地改善CVD金刚石膜自身理论透过率的问题。首先，介绍了CVD金刚石表面镀制单层增透膜增透原理，并总结了物理和化学气相沉积技术制备增透膜的优缺点。然后，重点综述了近年来CVD金刚石表面氮化物、金属氧化物和稀土金属氧化物等增透膜材料的研究进展，详细分析了增透膜制备参数、热处理工艺、衬底表面改性和掺杂工艺对增透膜整体组织和性能影响的规律。其中优化增透膜沉积温度、氧分压和热处理等工艺参数，是通过改变增透膜微观组织形貌以及晶体结构来提高其光学透过性能，而改变衬底表面结构能够通过改变增透膜与基体之间的成键方式来提升界面结合能力，而稀土元素掺杂方式是通过改变增透膜化学组成成分来改善增透膜的光学透过性能，并指出掺杂元素成型机理和影响机制。最后，展望了未来CVD金刚石表面增透膜的发展方向。     

超亲水防雾表面研究进展

透明玻璃和树脂材料应用广泛，是未来世界重要的构成元素。但这些材料表面常易发生水蒸气凝结起雾现象，不但降低了材料本身的透明度，影响相关产品的使用，还会给设备的运行安全带来隐患。因此，如何防雾逐渐引起研究人员和产业届的关注。常见的防雾技术有自动擦拭、热力防雾、表面涂层等。其中，具有主动防雾性能的超亲水表面涂层技术在施工简便性、持续防护性及运行维护成本的经济性等方面具有独特优势，是最有发展潜力的防雾技术。详细介绍了超亲水防雾表面的设计和制造技术的最新进展，从起雾现象的机制出发，介绍了水滴的形核和生长，并由此引出超亲水表面的防雾机理。分类介绍了由不同制备方法所得到的超亲水防雾表面，重点综述了近年来超亲水防雾涂层技术的研究进展，包括有机超亲水涂层、无机超亲水涂层与有机无机杂化超亲水涂层。针对各种形式的超亲水涂层技术，分别从涂层的亲水性、防雾性、耐久性及制备膜层的结构与性能之间的关系等方面进行了归纳。最后，根据超亲水防雾表面在不同领域的实际应用，对其未来的发展进行了展望。     

铱磷光配合物Ir(dfppy)2(phbudio)的合成及表征

以氯桥二聚体[Ir(dfppy)2(μ-Cl2)]2、1-苯基-1,3-丁二酮为原料合成了一种铱磷光配合物Ir(dfppy)2(phbudio)，产率86.0%，并通过元素分析、核磁共振谱、质谱和红外光谱表征确认了目标产物的化学结构。通过紫外-可见吸收以及荧光光谱对其光物理性质进行测试，其常温最大发射位于522 nm处，显示发射强烈的绿光，初步推测该铱磷光配合物发射可能来自金属铱到环金属配体和辅助配体的电荷转移(MLCT)跃迁。     

Efficient photothermal conversion of Fe2O3–RGO guided from ultrafast quenching effect of photoexcited state

In solar thermal utilization, effective photo capture and photothermal conversion are crucial. Improving the nonradiative transition rate of photoexcited electrons is important to enhance the photothermal conversion efficiency and develop efficient solar thermal utilization. Herein, we designed a new kind of light absorption-enhanced and efficient photothermal conversion material, namely, Fe₂O₃-functionalized reduced graphene oxide (Fe₂O₃–RGO). On the basis of the selective absorption (350–560 nm) of Fe₂O₃ and the synergistic effect of RGO on the quenching energy transfer of the excited state of Fe₂O₃ and ultrafast nonradiative thermal decay of RGO, the optical absorption capacity, and photothermal conversion efficiency of the composites were effectively improved. Fe₂O₃–RGO can be successfully applied to photothermal conversion phase change materials and seawater solar desalination, showing excellent photothermal conversion ability and application prospect.