Hole transport materials with high glass transition temperatures for highly stable organic light-emitting diodes

Two hole transport materials with high glass transition temperatures (T_g ~ 200 °C) have been synthesized by replacing the phenyl groups of 4,4′-bis[N-(1-naphthyl-1)-N′-phenyl-amino]-biphenyl (α-NPD) with the bulkier phenanthrene (N,N′-di(naphthalene-1-yl)-N,N′-di(phenanthrene-9-yl)biphenyl-4,4′-diamine, NPhenD) or anthracene (N,N′-di(anthracene-9-yl)-N,N′-di(naphthalene-1-yl)biphenyl-4,4′-diamine, NAD). The organic light-emitting diodes (OLEDs) using these hole transport materials exhibited stable operation at high temperatures up to 420 K, improved device lifetimes, and reduced operating voltage changes compared to the conventional hole transport materials owing to their high T_g. Although NAD has quite small bandgap as a hole transport material, superior thermal properties of NPhenD and NAD suggest that they can be promising materials for highly stable and high temperature-durable OLEDs and other organic optoelectronic devices.     

基于人机工程学的公交车拉手设计

应用人机工程学原理和人体测量尺寸数据展开对公交车拉手的深入设计。 在分析现有产品和设计存在问题的基础上,提出拉手改良设计原理,缓解车辆运行中的惯性 带来的眩晕和安全隐患,并充分考虑不同身高人群的使用和广告效益,从手柄、连接结构、 广告放置、限位卡及各个部件的材质、色彩等方面,结合手的解剖学特征和立姿静动态尺寸, 对拉手进行了改进和完善,为提高该类产品的使用舒适度和改善乘车环境提供新的思路。     

Effects of steam dilution on laminar flame speeds of H2/air/H2O mixtures at atmospheric and elevated pressures

The laminar flame speeds of H₂/air with steam dilution (up to 33 vol%) were measured over a wide range of equivalence ratio (0.9–3.0) at atmospheric and elevated pressures (up to 5 atm) by an improved Bunsen burner method. Burke, Sun, HP (High Pressure H₂/O₂ mechanism), and Davis mechanisms were employed to calculate the laminar flame speeds and analyze different effects of steam addition. Four studied mechanisms all underestimated the laminar flame speeds of H₂/air/H₂O mixtures at medium equivalence ratios while the Burke mechanism provided the best estimates. When the steam concentration was lower than 12%, increasing pressure first increased and then decreased the laminar flame speed, the inflection point appeared at 2.5 atm. When the steam concentration was greater than 12%, increasing the pressure monotonously decrease the laminar flame speed. The chemical effect was amplified by elevated pressure and it played an important role for the inhibiting effect of the pressure on laminar flame speed. The fluctuations of the chemical effect at 1 atm were mainly caused by three-body reactions, while the turn at 5 atm was mainly caused by the direct reaction effect. Elevated pressure and steam addition amplified the influences of uncertainties in the rate constants for elementary reactions, which might leaded to the disagreement between experimental and simulation results.     

溅射方法和基体材料对氧化钛薄膜微观结构的影响

目的研究不同溅射方法和基体材料对沉积氧化钛薄膜的晶体结构、化学价态、表面形貌的影响。方法采用高功率脉冲磁控溅射(HPPMS)和直流磁控溅射(DCMS)在316L不锈钢和硅片表面制备了氧化钛薄膜。采用等离子光发射谱检测了沉积薄膜时的等离子体特征。采用X射线衍射仪(XRD)、X射线光电子能谱(XPS)、原子力显微镜(AFM)和扫描电子显微镜(SEM),分别评价氧化钛薄膜的晶体结构、化学价态、晶粒尺寸和表面粗糙度。结果等离子体特征显示,沉积氧化钛薄膜时,HPPMS比DCMS具有更高的离化率和等离子体密度。XRD结果显示,在相同的平均溅射功率下,采用HPPMS和DCMS方法,均在不锈钢表面制备出纯金红石结构的氧化钛薄膜,而在硅片表面得到的氧化钛薄膜为金红石、锐钛矿混合结构,且采用HPPMS比DCMS技术制备的氧化钛薄膜含有更高的金红石含量。XPS结果显示,两种方法在所有基体表面均制备出了含有氧缺位的氧化钛薄膜。采用HPPMS和DCMS制备氧化钛薄膜时,不锈钢基体沉积的薄膜中,Ti3+/Ti4+比值均高于Si基体上的薄膜。SEM和硬度测试结果显示,HPPMS制备的氧化钛薄膜为等轴晶,晶粒较小,硬度较高。DCMS制备的氧化钛薄膜具有柱状晶的结构,晶粒较大。AFM的结果显示,采用不同溅射方法制备的氧化钛薄膜表面粗糙度没有明显差别。结论不同溅射方法和基体材料导致了薄膜沉积时样品表面离子轰击能量的差异,因此影响了氧化钛薄膜的晶体结构、化学价态和晶粒尺寸。     

DC04钢板胀形-渐进复合成形锥形件成形能力的实验研究

为了提高渐进成形过程中板料的成形极限和加工效率,提出了胀形-渐进成形的复合成形方法,通过胀形-渐进成形复合成形锥形件实验,研究了DC04钢板胀形-渐进成形复合成形锥形件和纯渐进成形锥形件的成形极限角和应变变化以及壁厚分布规律。结果表明:预成形高度为h=15 mm和h=25 mm时,复合成形零件的成形极限角分别为α极=66°和α极=69°;采用胀形-渐进成形复合成形锥形件,当胀形的最大减薄量发生在局部渐进成形区内,并且胀形和渐进成形的最大减薄量位置方向相反时,锥形件壁厚趋于均匀,提高了胀形-渐进成形的复合成形能力。     

齿形件精冲成形时的齿顶塌角分析及措施

针对精冲成形齿形件时的齿顶塌角问题,首先分析了齿形零件的几何特征及精冲成形特点,并分析了这些特征与齿形零件精冲时齿顶塌角的关系;将精冲变形区分为2个核心变形区和2个变形影响区,对核心变形区Ⅰ精冲塌角的形成过程进行了分析。然后,通过有限元模拟软件Deform-3D,找出齿顶塌角处材料在成形过程中的流动规律。结果表明:齿顶处A面轮廓附近的材料沿齿顶径向运动,一部分材料流向齿顶外侧;齿廓B、C侧附近的材料沿其轮廓线所指向的齿顶方向流动。再次,全面分析了影响精冲齿顶塌角大小的各种因素,找出压边力和反顶力对塌角大小的影响规律,得出反顶力比压边力对控制塌角的效果更显著。最后,提出了在齿形零件精冲成形过程中减小或消除齿顶塌角的具体措施对策。     

叶片模具型面逆向设计方法

针对我国叶片精锻模具逆向设计精度低、设计过程复杂等问题,运用VS自定义算法,实现了对模具型面点云数据的分块化处理,提高了数据点处理精度;运用UG二次开发,实现了曲线曲面的参数化建模和模具模型的检测与自动化修正,并运用Menu Script菜单脚本,实现点云数据处理、模具逆向建模以及检测与修正在UG中的集成,提高了模具逆向设计效率;最后运用Deform-3D软件对叶片模具设计的某些参数进行了验证,并通过工程实例对逆向设计的叶片模具进行了检测分析。     

超高效液相色谱-串联质谱法测定竹笋中百草枯的残留

目的运用超高效液相色谱-串联质谱联用技术,建立竹笋中百草枯残留的检测方法。方法样品用甲醇-0.1 mol/L盐酸溶液(1∶1,V/V)提取后,经Oasis WCX固相萃取柱(60 mg/3 ml)净化,采用UPLC BEH HILIC色谱柱(100 mm×2.1 mm,1.7μm)分离,正离子多反应监测模式监测,外标法定量。结果百草枯在10~500μg/L范围内具有良好线性关系,相关系数为0.998 2,检出限为2μg/kg,定量限为5μg/kg。进行5、50和200μg/kg三个浓度的样品加标试验,回收率为82.2%~104.8%,相对标准偏差为8.3%~10.9%。结论该方法简便、灵敏、准确,适合于竹笋中百草枯的检测。     

钻井用耐剪切堵漏剂DLJ-5的性能

针对裂缝性地层钻井过程中,常规的桥塞堵漏材料堵漏效果不佳或者堵漏后发生重复性漏失的难题,通过引入锂皂石,研制出了一种耐剪切的钻井液堵漏剂DLJ-5,借助激光粒度分析仪和衍射仪研究了其微观形貌,并对其吸水膨胀性能、耐剪切性能以及与钻井液的配伍性进行了评价,最后研究了DLJ-5的堵漏性能。结果表明,研制出的堵漏剂DLJ-5的平均初始粒径为204.5μm,内部的有机和无机双网络结构提高了堵漏剂的强度。堵漏剂DLJ-5在50℃模拟地层水条件下的膨胀倍数为35.52,具有很好的耐剪切性能,与长庆油田钻井液的配伍性好,在高矿化度地层具有一定的堵漏承压性能。该耐剪切堵漏剂在裂缝性地层的钻井过程中具有广泛的应用前景。