S型焊接金属波纹管波片波形优化设计

S型焊接金属波纹管的波片波形结构对波纹管性能影响较大,目前尚无准确表达波形结构对波纹管性能影响的具体设计公式及理论。利用ANSYS Workbench软件建立了直边波形及斜边45°波形这2种S型焊接金属波纹管波片的二维模型,以提高波片压力刚度为优化设计目标,对模型进行静力学分析,确定了需要优化的波形结构参数及其取值范围。调用ANSYS Workbench响应面优化模块,设置优化参数与目标函数,求解得到优化设计后的波片波形结构参数数值。优化设计前后波纹管波片的应力分布和压力刚度对比表明,优化设计后的波片具有更高的压力刚度及更小的应力,优化后的斜边45°波形波片的力学性能更优。     

金属掺杂中孔分子筛的合成及其研究

以十二烷二胺(DADD)为模板剂,TEOS为硅源,通过水热合成法制备出了具有高金属含量的中孔分子筛Zr-MSU-V和Nd-MSU-V,采用XRD、TG-DTA和TEM等对合成的分子筛进行了表征.XRD结果表明,即使当Si/Zr或Si/Nd的摩尔比达到5或20时,获得的两种分子筛Zr-MSU-V和Nd-MSU-V均能保持良好的结晶度,TEM图清楚地展示了Zr-MSU-V具有有序的层状结构;TG-DTA的结果显示,903 K焙烧脱除模板剂不会破坏金属嵌入分子筛的结构,说明其具有良好的热稳定性;通过48 h水热处理后的分子筛仍保持其结构有序性,说明其具有优良的水热稳定性.     

g-C3N4/Ti-MOF复合材料的合成及其光催化性能

采用快速微波合成法合成了Ti-MOF(MOF,金属有机骨架材料),并在其基础上合成新型可见光响应光催化剂g-C3N4/Ti-MOF。通过X射线衍射、扫描电镜、EDS能谱仪、傅里叶变换红外光谱、N2吸附-脱附和紫外-可见漫反射光谱等手段对其进行表征,同时光催化还原Cr(Ⅵ)研究g-C3N4/Ti-MOF的光催化性能。结果表明,g-C3N4/Ti-MOF复合光催化剂在150 min内能还原92%的Cr(Ⅵ),远远高于g-C3N4和Ti-MOF;同时g-C3N4/Ti-MOF复合光催化剂经过4次循环实验后仍能保持较稳定的光催化活性。最后提出了g-C3N4/Ti-MOF复合材料光催化还原Cr(Ⅵ)的可能机理。     

水中苯酚和邻苯二酚在磁性氧化石墨烯表面的吸附

使用制备的磁性氧化石墨烯纳米复合材料研究其对水中苯酚和邻苯二酚的吸附行为。系统考察接触时间、溶液酸碱条件、离子强度等因素对磁性氧化石墨烯吸附苯酚和邻苯二酚的影响。利用吸附等温线和吸附动力学探讨吸附机理和可能的吸附控速步骤。结果表明,磁性氧化石墨烯对苯酚和邻苯二酚的吸附量随时间变化不断增加,60 min为适宜的吸附时间。过大的无机盐离子强度会降低磁性氧化石墨烯对苯酚和邻苯二酚的吸附。磁性氧化石墨烯适合在弱酸性条件下对苯酚和邻苯二酚进行吸附。吸附等温线的结果表明,苯酚和邻苯二酚在磁性氧化石墨烯上的吸附行为可用Langmuir型等温方程描述。磁性氧化石墨烯吸附苯酚符合准一级动力学模型,而磁性氧化石墨烯吸附邻苯二酚符合准二级动力学模型。     

葛洲坝水利枢纽泄洪、冲砂闸金属结构防腐技术研究

葛洲坝泄水闸金属结构部分长期处于水下及潮湿的环境中,表面锈蚀严重,尤其是弧形工作门及侧轨处于水下,启闭频繁,受高速挟沙水流的冲磨、气蚀、摩擦作用,以及工作门侧止水的挤压、出现局部厚度减薄、表面冲槽及蚀坑等缺陷,为了确保枢纽工程的安全运行,延长其金属结构的使用寿命,须采取有效的防腐措施.葛洲坝泄水闸金属结构部分在解决防腐问题中不断进行新技术、新材料和新工艺的探索和研究,取得了一定成效.本文就其防腐技术的研究成果加以概括总结,希望能对同类工程提供有益的借鉴和帮助.     

金属目标后向散射特性与表面温度场关系的研究

本文研究金属目标的后向散射特性与入射角、表面温度场之间的关系。根据现有条件设计了实验装置,并用该装置测量了部分实验数据。相关结论对激光探测等领域的研究具有一定的参考价值。     

Boosting the Charge Transport Property of Indeno[1,2‐b]fluorene‐6,12‐dione though Incorporation of Sulfur‐ or Nitrogen‐Linked Side Chains

Alkyl chains are basic units in the design of organic semiconductors for purposes of enhancing solubility, tuning electronic energy levels, and tailoring molecular packing. This work demonstrates that the carrier mobilities of indeno[1,2‐b ]fluorene‐6,12‐dione ( IFD )‐based semiconductors can be dramatically enhanced by the incorporation of sulfur‐ or nitrogen‐linked side chains. Three IFD derivatives possessing butyl, butylthio, and dibutylamino substituents are synthesized, and their organic field‐effect transistors (OFET) are fabricated and characterized. The IFD possessing butyl substituents exhibits a very poor charge transport property with mobility lower than 10^?7 cm² V^?1 s^?1. In contrast, the hole mobility is dramatically increased to 1.03 cm² V^?1 s^?1 by replacing the butyl units with dibutylamino groups ( DBA‐IFD ), while the butylthio‐modified IFD ( BT‐IFD ) derivative exhibits a high and balanced ambipolar charge transport property with the maximum hole and electron mobilities up to 0.71 and 0.65 cm² V^?1 s^?1, respectively. Moreover, the complementary metal–oxide–semiconductor‐like inverters incorporated with the ambipolar OFETs shows sharp inversions with a maximum gain value up to 173. This work reveals that modification of the aromatic core with heteroatom‐linked side chains, such as alkylthio or dialkylamino, can be an efficient strategy for the design of high‐performance organic semiconductors.     

UV–Vis–Infrared Light Driven Thermocatalytic Activity of Octahedral Layered Birnessite Nanoflowers Enhanced by a Novel Photoactivation

Nanoflowers of octahedral layered birnessite (OL‐NF) were synthesized and characterized with a variety of techniques. Remarkably, OL‐NF exhibits a catalytic activity with a high efficiency for CO oxidation under irradiation of the full solar spectrum, visible‐infrared, or infrared light. This highly efficient catalytic activity under solar‐light irradiation originates from solar‐light‐driven thermocatalysis related to the efficient photothermal conversion and thermocatalytic activity of OL‐NF. A conceptually novel photoactivation effect is found to significantly improve the activity of the lattice oxygen of OL‐NF, thus considerably increasing the thermocatalytic activity of OL‐NF.     

Recent advances in optoelectronic properties and applications of two-dimensional metal chalcogenides

Since two-dimensional (2D) graphene was fabricated successfully, many kinds of graphene-like 2D materials have attracted extensive attention. Among them, the studies of 2D metal chalcogenides have become the focus of intense research due to their unique physical properties and promising applications. Here, we review significant recent advances in optoelectronic properties and applications of 2D metal chalcogenides. This review highlights the recent progress of synthesis, characterization and isolation of single and few layer metal chalcogenides nanosheets. Moreover, we also focus on the recent important progress of electronic, optical properties and optoelectronic devices of 2D metal chalcogenides. Additionally, the theoretical model and understanding on the band structures, optical properties and related physical mechanism are also reviewed. Finally, we give some personal perspectives on potential research problems in the optoelectronic characteristics of 2D metal chalcogenides and related device applications.     

太赫兹波导器件研究进展

近年来,太赫兹科学技术的发展极为迅速。与此同时,以波导为基础的、用于太赫兹传输的器件应运而生,其中主要包括：太赫兹金属波导、太赫兹光子晶体波导、太赫兹光子晶体光纤、太赫兹聚合物波导、太赫兹塑料带状波导、太赫兹蓝宝石光纤等。为此,就国际上太赫兹波导器件方面的研究进展和最新动态进行了较详细的分析和归纳总结。