气相色谱法分析氯乙酸

采用带有TDC检测器和OV-101色谱柱的气相色谱仪,用酯化法对氯乙酸样品处理,分析结果用修正面积归一化法进行计算;与化学容量法相比,精确度较高,适用于氯乙酸生产的中控分析和成品质量检验.     

我国烧碱市场分析与展望

回顾了2005年我国烧碱的生产与市场消费情况,分析了2006年国内烧碱市场形势,对“十一五”期间我国烧碱市场总体趋势进行了展望。     

智能混合控制器在转炉干法除尘中的应用

转炉干法除尘蒸发冷却器出口烟气温度大多数采用常规串级控制方式,但转炉冶炼前期控制效果并不理想.对转炉冶炼过程及蒸发冷却器出口烟气温度的控制难点进行研究,找出常规串级控制方式的缺点,并设计出一种智能混合控制器.采用智能模糊控制器和常规控制器并联的控制方式,对蒸发冷却器出口烟气温度进行控制,控制效果理想.实际应用表明,同常规串级控制器相比,智能混合控制器具有响应快、被控对象稳定等优点.     

Seeded Crystallization of Leucite

The leucite crystallization kinetics from a hydrothermally derived precursor seeded with nano-crystalline leucite was investigated by X-ray diffraction and non-isothermal differential thermal analysis. The nano-crystalline leucite was prepared by high-energy milling of high-purity leucite powder and the leucite precursor was prepared by the hydrothermal method of silica sol, aluminum nitrate, and potassium nitrate. After the seeds were introduced, the crystallization temperature of the precursor was lowered by 100°C and the transition phase kalsilite did not appear during the crystallization process. When the seeded precursor was heat treated at 700°C, a small amount of cubic leucite was stabilized to room temperature. The seeded precursor showed an exothermic peak between 800° and 920°C under different heating rates. The activation energy for the growth of leucite from the seeded precursor was 256(SD9) kJ/mol.     

Synthesis and characterization of copolythiophene

Copolythiophenes (Co‐PTs), poly(3‐hexylthiophene‐co‐3‐thiophene carboxylic acid) (P3HT‐TCa), poly(3‐hexyloxylthiophene‐co‐3‐thiophene carboxylic acid) (P3HOT‐TCa), and poly(3‐phenylthiophene‐co‐3‐thiophene carboxylic acid) (P3PhT‐TCa), were synthesized by chemical oxidized polymerization to investigate the effect of copolymerization on the properties of polythiophenes (PTs). Gel permeation chromatography showed that the molecular weight (MW) of Co‐PT was lower than that of homopolythiophene. Fourier transform infrared (FTIR) spectra indicated that the copolymerization was successful between the monomers. The λ_max of Co‐PTs gave a “blue shift” in ultraviolet‐visible (UV‐VIS) spectra. Photoluminescence (PL) spectra showed that the PL intensity of Co‐PT became weaker than that of homopolythiophene and the disappearance of PL had been observed in P3HOT‐TCa. The thermal stability of Co‐PT was influenced by the carboxyl for its low decomposition temperature. Furthermore, the copolymerization between multi‐wall carbon nanotube containing thiophene ring (MWNT‐Th) and 3‐hexyloxylthiphene could also take place successfully. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

2-硝基-4''''-氨基二苯胺-4-磺酸的工艺改进

将3-硝基-4-氯苯磺酸与对苯二胺进行缩合反应制得2-硝基-4’-氨基二苯胺-4-磺酸。传统的合成工艺：缩合反应的收率只有83％，主含量86.4％，必须精制后才能使用。本实验对缩合工艺的反应条件如温度，缚酸剂，抑制剂以及加料方式等进行了较为详细的探讨，通过正交实验，选择了最佳缩合反应条件，m（硝化物）：m（对苯二胺）=1.10：1，分次加料，分段保温，获得纯度94.7％的产品。收率提高了8％-10％，减少了废物的排放量，并省去精制步骤。     

CaO-SiO2系玻璃的析晶动力学研究

利用溶胶-凝胶法制得CaO-SiO2系基础玻璃,通过差热分析曲线分析质量比为CaO-SiO2玻璃的析晶能力。经分析,其析晶活化能E=457.1kJ·mol-1,而晶化生长指数是随升温速率的不同而不同,速率越大,晶化生长指数越小。     

民法法典化视野下的社员权

社员权问题学界少有论及,在目前民法法典化这个大背景之下研究社员权有着其独特的价值。社员权产生于日耳曼法,正式确立于近代。所谓社员权,系指社员基于其社员身份而对社团和其他社员所享有的权利。作为基本私权利的一个种类,社员权在未来民法典中应当占有一席之地。未来民法典中的社员权法应当包括社员权法通则、建筑物区分所有人的社员权、集体经济组织成员的社员权以及合作社成员的社员权共四部分。     

Analysis of junction temperatures in high-power GaN-based LEDs

We presented the analysis of the incomplete conduction in bonding medium in high power GaN-based light-emitting diode (LED) packages. A numerical study was carried out with parametric model to understand the junction temperature variation due to bonding medium defects. Transient thermal measurement was performed to evaluate LED’s junction temperature. Thermal resistance from chip to lead frame was 20 K/W in our sample LED. It was suggested that only 60% of the surface area of the bonding medium was involved...     

Dynamic equivalent method of interconnected power systems with consideration of motor loads

The existing equivalent methods usually only deal with static load models and neglect the dynamic characteristics of loads such as induction motors.This paper presents a dynamic equivalent method which considers motor dynamics.At first,the clustering criterion of motor loads is given.The motors with similar dynamic characteristics are classified into one group.Then,reduction of motors in the same group is carried out.Finally,parameters of the equivalent motor are calculated and the equivalent system is thus...