150m钢筋混凝土烟囱爆破拆除

在150m高钢筋混凝土烟囱的定向爆破拆除中,选择合理的切口形状和参数,对定向窗口进行精确施工、覆盖和挂网,开挖减振沟,地面软化处理等措施最终安全实施并达到了预计爆破效果。重点介绍了爆破切口的形状和尺寸、预处理措施、爆破参数、起爆网络、爆破切口的近体防护和倒地塌落振动防护措施,可为类似工程提供参考。     

膜蒸馏技术在溶液蓄能中的应用

本文以太阳能热利用和蓄能技术为研究背景,提出了一种基于膜蒸馏的太阳能溶液蓄能模式。采用疏水性聚偏氟乙烯中空纤维膜为膜蒸馏材料,基于膜蒸馏常温操作、小温差大传热面积的特点,利用膜材料微观上的高比表面积和单位体积的高接触面积为载体,选取50%溴化锂溶液为工质,以减压膜蒸馏的方式进行溶液浓缩和潜能存储,浓缩后的溶液可作为吸收式热力系统的工质。为此,针对50%的溴化锂溶液进行了减压膜蒸馏实验,对不同溶液温度、溶液流量在不同真空度下进行减压膜蒸馏实验,得到了3组实验数据。根据实验结果,对膜蒸馏式溶液蓄能系统进行分析,结果表明:蓄能密度可以达到245 kJ/kg,单位面积的膜组件可以产生0.27~0.40 kW的蓄能量,膜蒸馏式溶液蓄能为太阳能利用、吸收式热力系统和蓄能技术提供了一种新的应用方法和途径。     

稀土氧化物薄膜激光感生电压信号采集研究

采用德国Lambda公司LPX300I型KrF激光器,脉冲激光输出波长为248 nm,重复频率为5 Hz,能量为400mJ,在倾斜5°的LaAIO3单晶衬底表面制备了La0.5(CaSr)0.5MnO3(LCSMO)和La0.9Ca0.1MnO3(LCMO)两种稀土氧化物薄膜.使用波长为248 nm的LPX300I型KrF准分子激光进行照射,重复频率为1 Hz,能量为300 mJ,对LCSMO和LCMO薄膜表面产生的激光感生电压(LIV)信号进行采集.对信号响应的波形特征进行分析和讨论,实验得出LIV信号半峰全宽与数据采集卡临界采样率成反比例关系.临界采样率的选择为新型快响应、宽光谱激光功率/能量器件设计和制作提供依据.     

ICP-OES法测定硅碳负极材料中的硅和17种杂质元素

采用HF+HNO_3分解锂离子电池硅碳负极材料,在60℃温度下分解30 min,样品分解完全且几乎不损失。使用带氢氟酸进样系统的ICP-OES测试硅碳负极材料中的硅和铝、锂、钴、钙、镉、铬、铜、铁、钾、镁、锰、钠、镍、铅、钛、钒、锌,3次测试硅的加标回收率为99.17%,精密度为0.07%。其他元素的加标回收率为91.11%～115.66%,精密度在0.24%～5.66%。该方法操作简便快捷,基体干扰小。     

Achieving high-performance phosphorescent organic light-emitting diodes using thermally activated delayed fluorescence with low concentration

We fabricated phosphorescent organic light-emitting diodes (PhOLEDs) using thermally activated delayed fluorescence (TADF) material 10,10''-(4,4''-sulfonylbis(4,1-phenylene)) bis(9,9-dimethyl-9,10-dihydroacridine) (DMAC-DPS) with low concentration, which showed better performance compared with 1,3-bis(carbazole-9-yl) benzene (mCP) based devices. When the concentration of DMAC-DPS was 1wt%, the driving voltage of the device was only 3.3 V at 1 000 cd/m2, and the efficiency and lifetime of the device were effectively improved compared with those of mCP based devices. The result indicated that DMAC-DPS could effectively improve the performance of phosphorescent devices. We believe that the better device performance can be attributed to the optimization of the energy transfer process in the emitter layer and lifetime of triplet excitons by DMAC-DPS. The study may provide a simple and effective strategy to achieve high-performance OLEDs.     

Transparent conductive PVP/AgNWs films for flexible organic light emitting diodes by spraying method

In this study, a simple spraying method is used to prepare the transparent conductive films (TCFs) based on Ag nanowires (AgNWs). Polyvinylpyrrolidone (PVP) is introduced to modify the interface of substrate. The transmittance and bending performance are improved by optimizing the number of spraying times and the solution concentration and controlling the annealing time. The spraying times of 20, the concentration of 2 mg/mL and the annealing time of 10 min are chosen to fabricate the PVP/AgNWs films. The transmittance of PVP/AgNWs films is 53.4%—67.9% at 380—780 nm, and the sheet resistance is 30 Ω/□ which is equivalent to that of commercial indium tin oxide (ITO). During cyclic bending tests to 500 cycles with bending radius of 5 mm, the changes of resistivity are negligible. The performance of PVP/AgNW transparent electrodes has little change after being exposed to the normal environment for 1 000 h. The adhesion to polymeric substrate and the ability to endure bending stress in AgNWs network films are both significantly improved by introducing PVP. Spraying method makes AgNWs form a stratified structure on large-area polymer substrates, and the vacuum annealing method is used to weld the AgNWs together at junctions and substrates, which can improve the electrical conductivity. The experimental results indicate that PVP/AgNW transparent electrodes can be used as transparent conductive electrodes in flexible organic light emitting diodes (OLEDs).     

溶液法制备SimCP:FIrpic掺杂的蓝色磷光器件

文章以小分子材料SimCP作为发光主体,通过溶液法制备了掺杂铱配合物FIrpic的蓝色磷光有机发光二极管,并分别从发光层的溶剂和FIrpic掺杂浓度两方面研究了其对器件发光效率和光谱特性的影响。实验结果表明,选用高沸点、低挥发性的氯苯作为溶剂制作的器件,相比以二氯甲烷作溶剂的器件,开启电压降低到只有6V,且发光光谱的主峰位置由492nm处转移到468nm处,更偏蓝色;客体FIrpic掺杂浓度越小,492nm处的发光强度越弱,而468nm处的主峰相对增强;但浓度过小会使能量转移不充分,在400nm处出现新的发光峰,过大则造成浓度淬灭。当SimCP∶FIrpic比例为12∶1时,器件性能最佳,开启电压4.2V,最大亮度3060cd/m2。     

La1-xCaxMnO3稀土氧化物多晶材料的制备与性能

采用碳酸铵化学共沉淀法在1200℃保温24小时的条件下,制备了x组分为0.2、0.33和0.9的La1-xCaMnO3多晶靶材,通过R-T和XRD测试分析,结果表明化学共沉淀法获得了阻温特性良好(Tm-1为253K、TCR为3.2%)、物相较纯的各组分LCMO多晶材料.随着x组分的增加,Ca掺杂量越大,TCR越大、对应Tp温度越低,LCMO的晶格常数abc线性减小、晶粒尺寸增大.     

Synthesis of ZnO∶Dy Nanopowder and Photoluminescence of Dy~ (3+) in ZnO

Thedevelopmentofadvanceddisplayandlight ing technologysuchasfield emissiondisplays(FEDs)andplasmadisplaypanels(PDPs)requiresphosphor whichhasahighefficiencyandcoloredluminescence films.Zincoxide(ZnO)infilmandpowderformsis oneofthemostefficientoxide basedwideband gap phosphormaterials.ZnOischemicallystableandhas moderateconductivitycomparedwithconventionalsul fidephosphormaterials.RE dopedsemiconductorhas applicationsinactivelayers,forexample,thinfilm electro luminescencedevices[1],optoelec…     

废弃玻璃替代河砂对地聚合物砂浆性能的影响

采用废弃玻璃替代天然河砂细骨料,研究了其对粉煤灰-矿渣基地聚合物砂浆力学性能和耐酸性的影响;利用X射线衍射仪（XRD）、傅里叶变换红外光谱（FTIR）和场发射扫描电镜-元素能谱（FESEM-EDS）,探究了地聚合物砂浆在养护1~56 d时的结晶相组成和反应进程,重点分析了骨料界面过渡区（ITZ）的发展及受硫酸侵蚀后的破坏情况.结果表明：玻璃和河砂细骨料在养护早期均延缓了地聚合反应速率,全砂组砂浆试块养护28 d时在凝胶体系内的反应逐渐停止;而全玻璃组砂浆试块中的玻璃边缘在碱性环境下溶解出硅相,增大了体系内的n（SiO₂）/n（Al₂O₃）,提高了基体的后期密实度.地聚合物砂浆在硫酸溶液中的侵蚀机理主要为硅铝酸盐骨架脱铝破坏、碱金属浸出,以及石膏晶体生长所引起的微裂缝和骨料剥落;在经受硫酸浸泡后,玻璃与ITZ处的凝胶基体间仍具有较好的黏结效果,因而具有更低的抗压强度损失及质量损失.