Layer-by-layer assembly of long-afterglow self-supporting thin films with dual-stimuli-responsive phosphorescence and antiforgery applications

The assembly of thin films (TFs) having long-lasting luminescence can be expected to play an important role in the development of new-generation smart sensors,anti-counterfeiting materials,and information-encryption systems.However,such films are limited compared with their powder and solution counterparts.In this study,by exploiting the self-organization of phosphors in the two-dimensional (2D) galleries between clay nanosheets,we developed a method for the ordered assembly of long-afterglow TFs by utilizing a hydrogen-bonding layer-by-layer (LBL) process.Compared with the pristine powder,the TFs exhibit high polarization and up-conversion room-temperature phosphorescence (RTP),as well as enhanced quantum yields and luminescence lifetimes,allowing them to be used as room-temperature phosphorescent sensors for humidity and oxygen.Moreover,modified day-based hybrids with multicolor RTP can serve as anti-counterfeiting marks and triple-mode 2D barcode displays.We anticipate that the LBL assembly process can be extended to the fabrication of other inorganic-organic room-temperature phosphorescent hybrids with smart luminescent sensor and antiforgery applications.     

桥塔自立状态下抗风性能的比较研究

首先介绍了桥塔的材料及其构造形式,列表说明了目前大跨度悬索桥以及斜拉桥在桥塔的材料、构造形式以及塔高等方面的选取;阐述了桥塔在自立状态下可能发生的风致振动,包括抖振、驰振以及涡激共振;分析了某大桥桥塔在自立状态下风洞模型试验的现象及其结果,并且与其他桥塔在自立状态下风洞模型试验结果相比较,根据它们各自材料与构造形式所决定的不同气动特性作出分析,得出了一些有意义的结论;最后提出有效的减振对策.     

矿用自承式感温光缆设计及应用研究

结合井下火灾监测用感温光缆特殊要求,通过分析自承式感温光缆技术现状,提出矿用自承式感温光缆设计方案,按照煤矿对阻燃护套规范要求,设计了2种自承式结构形式:"8"字吊带形快速感温结构和扁平跑道形高强度抗拉、抗压结构。现场应用过程中,整体结构较轻便,易于安装铺设,运行近180 d状态良好,无光缆损坏现象。     

碳酸盐岩油藏高温超深井高导流自支撑酸化压裂技术

针对超深井酸化压裂改造形成的酸蚀裂缝易闭合、导流能力衰减快的问题,合成了新型酸化压裂屏蔽保护剂,并对其自聚性、油溶性、黏附性等关键指标进行了评价。该技术通过对水力裂缝表面非连续的、暂时性屏蔽,阻断酸岩反应,实现酸蚀裂缝由点支撑向面状支撑转变,裂缝有效支撑高度可提高3倍。采用CFD软件模拟优化了屏蔽保护剂颗粒在裂缝中的分布形态,确定了屏蔽保护剂用量、注入排量、携带液种类等工艺参数。该技术在塔河油田高温超深井进行了应用,压裂后效果表明,屏蔽剂在地层温度下黏附性、油溶性达到设计要求,自支撑裂缝的导流能力和有效期明显延长。该技术对提高超深井酸化压裂效果具有重要意义。     

全介质自承式架空光缆的研制

本文提出了全介质自承式架空光缆结构参数的设计方法，并对光缆材料的选取，工艺技术的关键点进行了分析，最后给出了我们研制的全介质自承式架空光缆的测试数据。     

Edge-rich MoS2 nanosheets for high performance self-supporting Li-S batteries

提高硫的电化学活性和抑制多硫离子的溶解是提高锂硫电池性能的关键问题。层状二维金属硫化物的边缘位点相对于平面位点具有更强的吸附多硫离子的能力。然而利用液相法控制合成具有丰富边缘位点的层状二维过渡金属硫化物材料仍是一个挑战。本文以碳布作为导电基体,设计生长了由小尺寸单层S-Mo-S单元通过层层自组装而成的MoS₂多晶纳米片（V-MoS₂/CC）。探究了该复合材料作为活性物质S载体时对锂硫电池倍率性能和循环稳定性的影响。垂直生长的MoS₂纳米片暴露较多的S-Mo-S层边缘活性位点,不仅可以使得随后负载的硫单质的尺寸保持在纳米级（5～10 nm）,而且对多硫化锂的催化转化及抑制溶解具有一定程度的促进作用。同时,基底材料碳布的存在使得电极材料无需添加导电剂和黏结剂且提高了整体导电性。使用V-MoS₂/CC@S复合材料组装而成的半电池,在1 C和2 C下循环400和800圈后比容量维持在857 mA·h/g和579 mA·h/g。     

Highly active and stable electrocatalytic transition metal phosphides (Ni2P and FeP) nanoparticles on porous carbon cloth for overall water splitting at high current density

Highly active and stable hydrogen production at high current densities is required for practical application of electrocatalytic water splitting. In this study, highly active self-supporting electrodes with excellent durability were designed and developed for high-performance overall water splitting at a high current density. First, a colloid-based dip-coating method using porous carbon cloth (PCC) was introduced to obtain uniformly coated Ni and Fe nanoparticles on a conductive substrate. Then, the desired phase transitions of Ni and Fe to Ni₂P and FeP, respectively, proceeded by thermal phosphidation at optimum temperature. The uniformly interconnected Ni₂P layers on the PCC substrate (Ni₂P@PCC) and FeP layers on the PCC substrate (FeP@PCC) exhibited outstanding oxygen and hydrogen evolution reactions, respectively. When each electrode was adopted as an anode and a cathode for the overall water splitting cell, excellent performance was achieved, with a low operational voltage of 1.76 V and high durability for 100 hours at a high current density of 50 mA cm⁻².     

折叠网架基本结构单元的构成和几何分析

主要论述了折叠网架结构的构成和基本结构单元中杆件间的几何关系,提出了保证结构折叠、展开的几何限制条件,给出了几种常见的结构构形及结点构造.     

硅/石墨烯基自支撑薄膜的制备及电化学性能

采用简单的超声、抽滤和水合肼化学还原相结合的方法制备硅/石墨烯基自支撑薄膜,系统研究了硅含量对硅/石墨烯复合材料电化学性能的影响。结果表明：通过在石墨烯水凝胶的片层之间插入纳米硅颗粒,可以有效地控制硅体积变化,增加该复合膜的机械强度并提高其导电性。提高硅/石墨烯复合材料中硅含量的比例可以提升其可逆比容量和首次库仑效率,当硅质量分数为53%时,复合膜在0.1C倍率下的可逆比容量及首次库仑效率分别达到945.6mA·h/g和64.8%（纯硅的229倍和9倍）;继续提高硅含量的比例,可以提升其循环寿命（循环50次容量保持率60.9%、质量分数为67%的Si）,但材料比容量有所下降,说明石墨烯在稳定硅基复合材料电化学性能方面发挥着非常重要作用。     

自承式外挂石材轻钢复合外墙板的研发与应用

钢结构是工业化住宅体系中的一种主要结构体系,自承式外挂石材轻钢复合外墙板是应低(多)层钢结构工业化住宅高端市场需求,在原工业化集成围护结构体系基础上开发的升级产品。从构造设计、研究试验、工程应用等方面对该产品的特点、性能和适用范围进行介绍,探索该产品在低(多)层钢结构工业化住宅市场中推广应用的优势,并提出措施和建议。