双变量线性逼近法处理液晶共聚酯的热分解动力学

本文首次利用双变量线性逼近法处理液晶共聚酯的热分解动力学,并获得令人满意的效果。     

酸化水解-UBF-混凝沉淀处理工艺在造纸黑液中的应用

利用厌氧酸化水解一上流式污泥床过滤复合反应器-混疑沉淀处理工艺对苇浆、草浆等黑液进行厌氧分解过滤、加药混凝处理,从黑液中回收木质素,去除造纸黑液中的有机物,出水水质可以达到(GWPB-1999)《造纸工业水污染物排放标准》,从而为苇浆、草浆造纸黑液的综合处理开拓了重要途径。     

苯并噻唑偶氮-5-二甲氨基苯甲酸及其衍生物作为分析试剂的研究Ⅱ.——2-[2-(6-溴-苯并噻唑偶氮)]-5-二甲氨基苯甲酸和2-(2-苯并噻唑偶氮)-5-二甲氨基苯甲酸与镍反应的研究

研究了2-〔2-(6-溴-苯并噻唑偶氮)〕-5-二甲氨基苯甲酸(Br-BTAMB)和2-(2-苯并噻唑偶氮)-5-二甲氨基苯甲酸(BTAMB)作为显色剂与镍的反应。在Triton X-100存在时,Br-BTAMB与镍反应生成1:3的蓝色络合物。在654nm时其表观摩尔吸光系数高达1.6×10~5。镍含量在从0到10μg/25ml范围中符合比尔定律。对反应动力学进行了研究。     

环氧树脂聚酰胺固化物的热裂解反应研究

热失重法研究填的环氧树聚酰胺固化物的热裂解过程，结果表明，该固化物在１５０℃以前失去吸附的小分子化合物，１５０－２７７℃时主要为活性稀释剂５０１挥发及其在固化物中所形成的端基的消去，２７７－６７０℃时为环氧树脂固化物主体结构的裂解；６７０－７１０℃为填料碳酸钙的分解。     

氟醚橡胶热分解规律及动力学研究

用热失重分析方法(TGA),研究了氟醚橡胶在氮气中的热分解规律,并探讨了不同升温条件和不同失重阶段氟醚橡胶的热分解动力学.研究结果表明：在氮气中,氟醚橡胶的热分解过程可分为两个阶段;不同升温速率下其热分解反应机理相同;升温速率越大,氟醚橡胶的分解温度越高.应用等转化率法(Friedman 微分法),在不假设反应机理函数的情况下,分析了氟醚橡胶热分解在不同转化率时的活化能,其平均值为241.4 kJ/mol;同时用Coats-Redfern法分析得出氟醚橡胶在不同升温速率时的热分解动力学参数基本相同.结合两种分析方法提出：氟醚橡胶在氮气中的热分解活化能E为244.3 kJ/mol,最理想的热分解反应机理函数为幂函数法则,其积分形式为g(α)=α3/2.     

化学混凝沉淀——吸附法处理含氟废水研究

研究了化学混凝沉淀--吸附法处理含氟废水的效果与影响因素.实验结果表明,单投CaCl2沉淀除氟其出水残氟浓度大于15 mg/L,而CaCl2分别与混凝剂聚合氯化铝(PAC)、FeSO4、Al2(SO4)3联用时,CaCl2+PAC除氟效果比单投CaCl2有显著提高,出水残氟浓度为5.1 mg/L,去除率达95.75%.当CaCl2沉淀剂分别与上述三种混凝剂联用,然后再分别加入助凝剂PAM 2～3 mg/L,其处理效果比不加聚丙烯酸胺(PAM)时都分别有明显提高,出水残氟浓度都小于10 mg/L,但效果最好的为CaCl2+PAC+PAM组合,其出水残氟浓度仅为3.9 mg/L.另外,羟基磷灰石(HAP)的吸附容量、吸附速率、除氟效果都优于活性氧化铝,其除氟效率高达92.75%.     

投药自动化在净水厂的应用

混凝投药是影响深度处理水厂治水成本和出水水质的主要因素之一,影响投药量的因素很多,寻找一种当水质发生变化能够及时调整投药量的方法,是给排水工作者多年研究的方向.本文总结南岔铁路净水厂混凝投药自动化系统多年运行的经验,从给水投药自动化方面谈了自己的看法,为同行借鉴.     

干式变压器浇注用环氧树脂体系固化动力学研究

基于非等温DSC方法对干式变压器浇注用环氧树脂体系动态升温过程中的固化动力学进行了研究，采用无模型法得到了体系的活化能和指前因子与固化度之间的关系，分析发现该体系固化反应不是简单的一步反应，而是复杂的多步反应。用唯象模型拟合法对DSC测试结果进行了非线性拟合，两者吻合很好，表明该体系符合通用n级三步分支反应模型。最后用唯象模型对该体系的等温反应进行了预测，得到了等温下体系的固化度随时间的变化规律。研究结果为改进真空浇注干式变压器工艺提供了有力的指导。     

Microstructure and electrical conductivity of 10% Yb-doped SrCeO3 ceramics

As a candidate material for hydrogen separation, Yb-doped SrCeO₃ has attracted increasing attention in recent decades. In the present study, Yb-doped SrCe_0.9Yb_0.1O_3-α ceramics were prepared by the dry pressing and sintering approach, with the microstructure evolution and the micro morphology investigated. It was indicated that the ceramics sintered in air were of a pure perovskite structure, and that the sintering temperature had a significant effect on the growth of ceramic grains. The average grain size increased from 1 ​μm to 10 ​μm with an increase in sintering temperature from 1300 to 1500 ​°C. Further investigation of the thermodynamics and kinetics of grain growth revealed that the grain boundary diffusion was the main driving force of grain growth during solid phase sintering, with a grain growth index of 4 and an activation energy of approximately 61.23 ​kJ ​mol⁻¹. These results illustrate an obvious tendency of grain size growth. By electrochemical workstation with different atmospheres the effects of sintering temperature on the conductivity were characterized in the temperature range of 700–900 ​°C. The electrical conductivities σ of SrCe_0.9Yb_0.1O_3-α ceramics in different atmospheres were as follows: σ(wet hydrogen) ​> ​σ(dry hydrogen) ​> ​σ(dry air) ​> ​σ(wet air). In the test atmosphere containing water and hydrogen the conductivity of protons increased with increasing temperature because of the protons jump between lattices in the form of interstitial hydrogen ions or bare protons.     

Effect of Ce addition on hot corrosion behaviours of a cast γ′-strengthened Co–Al–W–Mo–Ta–B alloy at 800 ​°C

Hot corrosion behaviours of a novel Co–9Al-4.5W-4.5Mo–2Ta-0.02B alloy doped with 0.01, 0.05, 0.1 and 0.2 ?at% Ce exposed at 800 ?°C in a solution of 75%Na₂SO₄/25%NaCl were investigated. The alloys comprised a coherent γ-Co_SS/γ′-Co₃(Al, W) microstructure (0.01Ce and 0.05Ce alloys) and κ-Co₃(W, Mo) precipitates (0.1Ce and 0.2Ce alloys) at grain boundaries. Hot corrosion kinetics curves demonstrated the parabolic time dependency profile with two stages: the first parabolic stage is within the beginning ～50 ?h corrosion and follows by the second parabolic stage. With an increasing nominal Ce content the weight gain of the alloy significantly decreased from approximately 70.1 ?mg ?cm^?2 (0.01Ce) to 40.8 ?mg ?cm^?2 (0.2Ce) when exposed for 100 ?h. A two-layer corrosion scale formed, and the scale was composed of an outer layer of Co₃O₄ oxide with spinel compounds of CoAl₂O₄, CoWO₄and CoSO₄, and an inner γ/needle-like Co₃W/sulphide layer adhered to the substrate. Heavy spallation of the corrosion scale occurred in the 0.01Ce～0.1Ce alloys, however, spallation was slight in the 0.2Ce alloy. The excellent corrosion resistance of the 0.2Ce alloy could be attributed mainly to the formation of continuous Al₂O₃ lines in the corrosion scale, as well as the prolongation of the incubation period of the corrosion product spallation.