对苯二甲酸加氢精制催化剂研究进展及应用

介绍了Pd/C催化剂的工艺制备、失活原因及再生技术的研究现状,叙述了Pd/TiO2加氢精制催化剂的研究进展,认为用于加氢精制的Pd/TiO2催化剂具有很大的发展前景,但目前研究进展较慢,应加大研发力度.对某氧化装置Pd/C催化剂使用情况进行了分析,总结了催化剂失活原因,再生过程中水洗、碱洗和分批更换催化剂可取得较好的效...     

六硝基茋的合成研究进展

2,2’,4,4',6,6’-六硝基縣(HNS)是一种性能优越的高能耐热炸药,在航空航天、深井石油开采等方面有着及其重要的作用,但由于得率很低因而产品价格昂贵,所以对其合成的研究有着重要的意义.本文论述了国内外六硝基縣的多种合成方法及其中间体的合成论述.     

Preparation and electrochemical behavior of water-soluble inclusion complex of ferrocene with β-cyclodextrin polymer

A new water-soluble inclusion complex of ferrocene (Fc) with β-cyclodextrin polymer (β-CDP) was prepared by a facile strategy and characterized by ¹H NMR spectroscopy, elemental analysis, powder X-ray diffractometry, thermogravimetry, UV–vis spectroscopy and cyclic voltammetry. Compared with Fc and the inclusion complex of Fc with β-cyclodextrin (Fc-β-CD), the solubility of ferrocene-β-cyclodextrin polymer (Fc-β-CDP) was greatly enhanced due to the water-soluble β-CDP host. The ratio of β-cyclodextrin (β-CD) unit in β-CDP to Fc was determined as 1:1. At 25 °C, the dissociated constant of Fc-β-CDP was measured as 3.65 mM by UV–vis spectroscopy and cyclic voltammetry. The electrochemical properties of Fc-β-CDP in water were studied. The diffusion coefficients of oxidation state and reduction state were calculated as 3.52 × 10⁻⁷ cm² s⁻¹ and 3.93 × 10⁻⁷ cm² s⁻¹. The resulting value of standard rate constant was measured as 1.95 × 10⁻³ cm s⁻¹. The diffusion activation energy was calculated as 21.8 kJ mol⁻¹.     

Exceptional ion-exchange selectivity for perchlorate based on polyaniline films

Polyaniline (PANI) films were electrochemically synthesized on graphite electrode and their ion-exchange selectivities for ClO₄⁻ were investigated. Cyclic voltammetry (CV) results showed that PANI-H₂SO₄ film represented higher selectivity for ClO₄⁻ than PANI–HCl and PANI–HClO₄. Furthermore, the CV records of PANI–H₂SO₄ film in different acidic solutions demonstrated that ClO₄⁻ exchange was performed in a lower potential range (from −0.025 V to 0.097 V), which is distinguished from SO₄²⁻ and Cl⁻. Additionally, chronoamperomertry (CA) studies of PANI–H₂SO₄ film in 0.1 M various acidic solutions (H₂SO₄, HCl and HClO₄) confirmed that the diffusion coefficient values in HClO₄ (13.319/18.184 × 10⁻⁶ cm² s⁻¹) were the biggest during doping/de-doping process. The exceptional ion-exchange selectivity for ClO₄⁻ was explained by the process of dominant accumulation, quick insertion of anions, and the sluggish mobility of ClO₄⁻ inside the membrane. Results of present work demonstrated that PANI may serve as a promising membrane for ClO₄⁻ removal by ion-exchange process.     

聚酰亚胺/多壁碳纳米管杂化薄膜的力学性能研究

通过对多壁碳纳米管进行纯化和酸化处理,以4,4-二氨基二苯醚(ODA)和均苯四甲酸二酐(PDMA)为单体,用原位聚合和超声振荡法制备了聚酰胺酸杂化胶液(PAA),经热亚胺化法制得聚酰亚胺杂化薄膜.通过电镜扫描(SEM)观察了杂化薄膜的微观结构;对薄膜的拉伸强度、弹性模量和断裂伸长率进行测试,研究杂化薄膜的微结构与力学性...     

香辛料提取物清除亚硝酸盐及阻断亚硝胺合成的比较研究

通过微波法和超声波法提取大蒜、丁香、花椒和桂皮的活性成分,在模拟人体胃液的条件下,采用分光光度法测定提取物对亚硝胺的阻断能力及其对亚硝酸盐的清除能力,并与VC进行了对比。结果表明,花椒、丁香和桂皮提取物清除亚硝酸盐的能力较强;对亚硝胺阻断能力方面,丁香强于其它三种香辛料。     

远程荧光LED器件影响因素研究

远程荧光技术是传统LED封装散热不良问题的解决方法之一。本文用红色和黄色荧光粉以及光固化树脂,通过光同化方式制备了荧光转换膜,并制备了简单的远程白光LED器件,研究了荧光粉组成、芯片与荧光转换膜的距离及输入电流对远程自光LED器件光学特性的影响,实验结果表明,荧光粉的组成比例对显色指数,色温等都有影响,而荧光转换膜与芯片的距离以及输入电流对器件的光学特性影响不大。本实验还通过添加光扩散剂解决了白光LED芯片发光刺眼问题。研究结果可为新型白光LED的结构设计提供参考。     

南极磷虾肉冻融循环过程水分的迁移及微观结构变化

以冷冻南极磷虾肉为研究对象,基于低场核磁共振(LF-NMR)及磁共振成像(MRI)技术,结合解冻汁液损失率、离心损失率,分析南极磷虾肉在反复冷冻-解冻循环过程中水分的迁移规律。借助电子、光学显微成像和SDS-PAGE观察反复冻融后南极磷虾肉肌原纤维结构及蛋白质的变化,并通过硫代巴比妥酸值(TBA)判断其脂质氧化情况。结果表明:随着反复冻融次数的增加,南极磷虾肉的解冻汁液损失率和离心损失率均显著增加(P＜0.05),同时MRI氢质子加权伪彩图亮度逐渐下降,表明南极磷虾肉内水分含量逐渐降低。LF-NMR结果显示:强结合水和结合水含量无显著性变化(P＞0.05),不易流动水含量显著减少(P＜0.05),自由水含量显著增加(P＜0.05),表明冻融循环中南极磷虾肉的不易流动水向自由水迁移。由相关性分析结果可知,不易流动水和自由水的NMR参数与解冻汁液损失率极显著相关性(P＜0.01)。反复冻融后冰晶生长使南极磷虾肉的肌原纤维排列由整齐紧密变为杂乱,甚至发生断裂,SDS-PAGE分析表明南极磷虾肉经反复冻融后其肌球蛋白重链完全降解,肌动蛋白、肌钙蛋白T和肌球蛋白轻链均有不同程度的降解,而TBA值无显著变化(P＞0.05)。结论:反复冻融使南极磷虾肉水分迁移、蛋白降解,而对脂质氧化影响不显著。     

栾川县百炉沟废弃露天矿山地质环境特征及生态环境修复治理研究

矿区经过多年的露天粗放式开采,形成了12处边坡及相对应的采矿平台,对原有地质环境条件造成了极大的破坏,共计损毁土地面积11.860 9 hm2。为了实现资源可持续发展,保护自然生态环境,通过对栾川县历史遗留露天矿山地质环境问题调查,讨论了治理区生态恢复治理方法,采取坡修整工程、场地平整工程、挡土保水岸墙工程、排水沟工程、垫渣和覆土工程、生物工程及后期养护等最优的生态恢复工程,达到改善治理区生态环境和消除地质灾害隐患目的,缓解矿业开发与环境保护之间的矛盾。同时,可取得较好的环境、经济和社会效益,有利于人民群众安居乐业和社会稳定。     

化学工程与工艺专业综合应用实验的改革与实践——以重庆科技学院为例

针对化学工程与工艺传统专业综合实验教学的不足,本文介绍了重庆科技学院化学工程与工艺专业综合应用实验的教学改革措施.我们进行的教学改革实践,强化了学生在实验中的主观能动性和实践能力,取得了良好的教学效果.