Determination and correlation solubility of 4-nitroimidazole in twelve pure solvents from 278.15 K to 323.15 K

In this paper, the solubility of 4-nitroimidazole in twelve pure solvents (toluene, benzene, 1,4-dioxane, acetonitrile, ethyl acetate, acetone, GBL, ethanol, methanol, n-butanol, DMF and NMP) were determined by using the laser monitoring system from 278.15 K to 323.15 K under 101.1 kPa, which are 0.00018–0.00070, 0.00021–0.00073, 0.00034–0.00092, 0.00038–0.00142, 0.00047–0.00120, 0.00126–0.00303, 0.00225–0.00517, 0.00310–0.00724, 0.00467–0.00982, 0.00453–0.01940, 0.01947–0.04652, and 0.04670–0.07452, respectively. At constant temperature, the mole fraction solubility of 4-nitroimidazole were increased as the following order: toluene < benzene < 1,4-dioxane < (ethyl acetate or acetonitrile) < acetone < GBL < ethanol < (methanol or n-butanol) < DMF < NMP, and the solubility of 4-nitroimidazole in (ethyl acetate, acetonitrile) and (methanol, n-butanol) had an intersection point at 297.55 K and 281.85 K, respectively. The solubility of 4-nitroimidazole could be increased with increasing temperature in twelve pure solvents. The ideal model, modified Apelblat equation, polynomial empirical equation, and λh equation were used to correlate the experimental values. The experimental solubility values were employed to calculate the standard dissolution enthalpy, standard dissolution entropy and Gibbs energy. The dissolution of 4-nitroimidazole could be an endothermic process in twelve pure solvents. The determination and fitting solubility of 4-nitroimidazole have important guiding significance for the purification and crystallization of its preparation process.     

In-situ elongated aluminium borate grains toughening WC- 1.87 wt % Al2O3- 4.13 wt % ZrO2 composite via spark plasma sintering

In this work, a novel way was developed to facilitate the sintering of a binderless cemented carbide with Al₂O₃ contain while improving its toughness. WC- 1.87 wt % Al₂O₃- 4.13 wt %ZrO₂ cemented carbides with 1 wt % B₂O₃ as additives were consolidated by high energy ball-milling and spark plasma sintering the as-milled composite powders. The effects of 1 wt % B₂O₃ content on the sintering behaviour, microstructure and mechanical properties of the obtained cemented carbides were investigated. The presence of B₂O₃ significantly lowers the sintering temperature by forming liquid phase and react with Al₂O₃ which contributed to obtaining fully dense specimens at 1350 °C and maintains fine grain sizes of WC until the temperature exceeding 1450 °C. The sintering temperature of the specimens with optimum mechanical properties has been also reduced comparing that of the original WC- 1.87 wt % Al₂O₃- 4.13 wt %ZrO₂ cemented carbides. Furthermore, the addition of B₂O₃ triggered the reaction between B₂O₃ and Al₂O₃ resulting in forming in-situ elongated aluminium borate grains (A₄B₂O₉ and A₁₈B₄O₃₃ whiskers), which promoted the toughness. The specimens sintered at 1450 °C exhibited optimal mechanical properties: the Vickers hardness and fracture toughness were 19.26 GPa and 11.49 MPa m^1/2, respectively.     

PE0一PP0一PE0 嵌段共聚物的表面活性

采用吊环法测量了PEO－PPO－PEO嵌段共聚物溶液的表面张力,观测到嵌段共聚物溶液的表面张力随着时间延长逐渐降低。根据嵌段共聚物在气液界面形成分子刷的结构模型,解释了嵌段共聚物溶液的表面张力随浓度的变化。     

佛山陶瓷二0一0年总目录

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CESARE TOFFOL0

1991年出生在意大利Murano岛，成长于玻璃艺术世家，他的祖父Giacomo在Venini Furnace是一位吹制玻璃大师，他把技术传给他的儿子Florino（CESARE TOFFOLO的父亲），Florino在17岁时也成为一名玻璃吹制大师，随后Florino从事玻璃烧制，并受到了Murano大多数传统人士认可。     

蔡司0-INSPECT

应用于0-INSPECT中的每个组件皆体现了顶级的性能表现，完美的结合确保了最佳的效率。     

0，0－二乙基硫代磷酰氯生产工艺述评

叙述了国内乙基氯化物的各种生产工艺，并分析了各种生产工艺的特点，指出了较理想的生产方法。     

Study 0n properties 0f antistatic，CDPET fiber

An antistatic agent of temary block co-polyester-ether-metalion chip(DC) and cationic dyeable polyester chip(CDPET)were produced by Dalian Institute of Light Indus-try．The melting point of DC was 224℃．The concentration of SIPM was 2％mol in CDPET．The intrinsic viscosity of CD-PET was 0．58dL／g and the melling point was 246℃．     

中国腐植酸工业协会二0一0年工作要点

2010年,我会将结合腐植酸行业发展新特点,以绿色低碳经济为主题,引领重点产业项目建设,大力提升产业水平,全面推动腐植酸绿色低碳经济迈上新台阶。对此,我们必须抓住机遇、开拓进取、团结奋斗,努力做好全年工作。     

变形金刚3．0

以改造“宝马变形金刚”一炮而红的“铁哥们”决心改造出更加令人惊叹的作品,将《变形金刚2》的精彩升级为3.0