Excited-state absorption of meso-tetrasulfonatophenyl porphyrin: Effects of pH and micelles

The influence of the environment on the excited state transitions of meso-tetrakis(p-sulfonatophenyl) porphyrin (TPPS) is reported. TPPS was investigated in protonated and non-protonated forms, and in the presence of the cationic cetyltrimethylammonium bromide (CTAB) micelles. The singlet excited-state absorption spectra were measured by using the white-light continuum Z-scan technique and the triplet–triplet absorption spectra were acquired employing an association of laser flash photolysis and Z-scan techniques. Our results show that the perseveration of the molecular symmetry, upon excitation, depends on the state of multiplicity of the molecules, as well as on the environment and structural characteristics of the porphyrin. Additionally, it was observed that for excited molecules, the ring distortion caused by the protonation of porphyrin ring has great influence on the changes observed for the symmetry and vibronic structure. The results clearly show that the porphyrin investigated is a promising candidate for optical limiting applications for all investigated environments.     

红外光谱法用于快速测定车用柴油酸度等性质的研究

针对车用柴油酸度等性质测定过程繁琐，采用衰减全反射样品池测定车用柴油的红外光谱，用偏最小二乘法（PLS）建立红外光谱测定车用柴油酸度、密度、闪点和凝点的4个校正模型，验证标准误差分别为0.46 mg/(100 mL),0.77kg/m3,2.60 ℃,2.77 ℃，该方法符合标准方法再现性要求。与标准方法相比，该方法具有无需预处理、操作简单、测量快速、重复性好等优点。     

嵌人式与独立存储器设计上的差异分析和研究

进入21世纪,随着集成电路的发展,SoC(System on Chip)片上系统应运而生。而作为SoC重要组成部分的嵌入式存储器,在SoC中所占的比重正逐步增加,并起着越来越重要的作用,那么嵌入式存储器与独立的存储器芯片在设计上存在着哪些差异?对此本文将以NOR型闪存为例在制造工艺的选取、衍生产品的设计、功耗与噪声、后端功能仿真、测试与修复等方面进行分析和研究。     

VRDS装置常压分馏塔系统的问题分析

胜利炼油厂重油加氢 (VRDS)装置的常压分馏塔为填料塔 ,2 0 0 1年检修开工后该系统出现异常 ,经过查找分析 ,确定轻烃 /产品减压渣油换热器和柴油汽提塔重沸器内漏是装置异常的主要原因     

调节阀的闪蒸和气蚀

针对调节阀的闪蒸和气蚀问题，介绍了调节阀在选型和使用中的要点。     

国产50%离子膜法烧碱蒸发装置及运行情况

介绍了升降膜法双效逆流蒸发生产50%离子膜法烧碱的工艺流程、主要设备、装置特点及运行情况.     

冲天炉熔炼过程模拟

冲天炉是熔炼铸铁的最主要设备,熔炼时炉内的反应复杂,而又因温度高等原因很难直接对炉内状况进行观察测试,这为进一步了解它的工作情况及熔炼原理制造了麻烦。而我国冲天炉熔炼的规模小、质量和效益比较低,浪费、污染问题严重,更需要进行冲天炉的改造及熔化工艺优化。计算机模拟为冲天炉研究提供了一个新途径。本文提出以flash或采用虚拟现实技术来模拟冲天炉熔炼过程。并简单介绍了冲天炉熔炼的flash模拟。     

Study on the flash butt welding of 400 MPa ultra-fine grain steel

A 400 MPa ultra-fine grain steel possesses high strength and toughness. Due to its fine grain size, the heat affect zone (HAZ) of the weld joint will soften during welding. The weldability of 400 MPa ultra-fine reinforced steel bar of flash butt welding is investigated by using the micro metallographical examination and macro-mechanical-property tests. The joint of flash butt welding has a superior mechanical property. The HAZ in the weld joint does not show apparent softening. There is only a localized softening spot inside the weld seam, which does not affect the property of the whole joint. Therefore, flash butt welding is appropriate for joining the 400 MPa ultra-fine grain reinforced steel bars. The resulting weld joint has excellent mechanical properties.     

提高发酵过程乙醇分离效率的新型反应器

设计了一种新型的带侧臂循环的气升式反应器,该反应器可以有效地把真空闪蒸发酵和汽提发酵2项技术结合起来。实验结果表明,与单独的汽提和闪蒸过程相比,利用此反应器进行同步汽提闪蒸操作,大大提高了乙醇的移出效率,从而进一步提高了发酵强度。