悬浮聚合法制备聚合物(甲基丙烯酸甲酯-共聚-丙烯酸丁酯)/蒙脱土纳米复合微球与性能研究

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)及蒙脱土(MMT)为主要原料,使用悬浮聚合法制备聚合物(甲基丙烯酸甲酯-共聚-丙烯酸丁酯)/蒙脱土纳米复合微球。采用红外光谱(FTIR)、X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电镜(TEM)对所制备的复合材料微观结构进行了表征;通过热重分析(TGA)对复合材料的热稳定性进行了研究。探讨了蒙脱土含量对复合材料热稳定性及膨胀性能的影响。结果表明,聚合物/MMT纳米复合微球(蒙脱土含量为3%(质量分数))表面光滑且颗粒间团聚现象对比于纯聚合物微球明显改善,平均粒径在60~120μm;XRD分析得出钠基蒙脱土的层间距为1.21 nm,十六烷基三甲基溴化铵(CTAB)离子交换改性后的有机蒙脱土层间距为1.88nm,聚合物/MMT复合材料的层间距约为3.53 nm,这与TEM分析相符;纯共聚物最大质量损失温度为482℃,当蒙脱土含量为3%时,聚合物/MMT复合材料最大质量损失温度提高到505℃;在本实验条件下,纯聚合物微球在水中最后膨胀率约为250%,聚合物/MMT纳米复合微球(MMT 3%)在水中最后膨胀率约为125%。岩心封堵率效果测试表明,纳米聚合物复合微球具有良好的运移能力和深部封堵性能。     

改性凹凸棒滤料对苯酚废水动态吸附研究

以十六烷基三甲墓澳化按(CATB)改性凹凸棒土对微污染废水中苯酚及其再生后吸附效果进行动态试验,研究了去除笨酚的动力学特征结果表明,凹凸棒滤料经CATB改性后在动态试验过程中对微污染水中笨酚具有较强的吸附能力,苯酚的去除率随着废水流速的减少而增大,在pH为6～8,废水中苯酚浓度为17.74 mg/L,流速为2 m/s,吸附时间25 min条件下,吸附去除率达93.07%;改性后的凹凸棒滤料可用碱进行再生,再生后对苯酚的吸附能力没有明显下降;苯酚的动态吸附过程遵循一级反应动力学模型.     

凹凸棒土处理含酚废水及生物再生的研究

[目的]研究凹凸棒土对苯酚的吸附效果及生物再生条件.[方法]用苯酚溶液模拟含酚废水,研究吸附剂投加量、pH、温度等因素对凹凸棒土吸附苯酚的影响及最佳条件.[结果]凹凸棒土吸附苯酚的最佳条件为吸附剂投加量4 g/100 ml、吸附温度40℃、pH10.0、吸附时间40 min,对苯酚的去除率可达27.1%.在pH为4.0、酵母力液浓度2.040 g/L、30℃条件下对吸附饱和的凹凸棒土再生3h,再生后的凹凸棒土达到最佳吸附效果,对苯酚的去除率达到39.07%.[结论]该研究可为含酚废水的处理及凹凸棒土的再生提供指导.     

基于Langmuir理论的平衡吸附量预测模型

为了实现对吸附反应的平衡吸附量的预测,建立了平衡吸附量预测模型.以高岭土、蒙脱土这两种黏土矿物吸附Ca2+为例,验证其等温吸附曲线符合Langmuir吸附方程.在Langmuir吸附等温式的基础上,建立了平衡吸附量预测模型,该模型应用于单组分吸附反应的平衡吸附量的预测.通过实验对该模型进行了验证,模型的计算结果与实验结果可以较好地吻合,证明该模型的可靠性较高.     

有机改性膨润土吸附Cr（Ⅵ）性能

研究了有机改性膨润土对Cr（Ⅵ）的吸附性能。结果表明：有机改性膨润土对水中Cr（Ⅵ）的吸附在60min达到平衡;在50mL、10mg／L的Cr（Ⅵ）溶液中,当其用量为1．0g时,有机改性膨润土对水中Cr（Ⅵ）的吸附去除率达到91．5％;温度对水溶液中Cr（Ⅵ）的去除有一定的影响,有机改性膨润土吸附水中Cr（Ⅵ）的过程为放热反应。平衡吸附量与平衡质量浓度之间的关系符合Freundlich和Langmuir等温吸附方程所描述的规律。     

碱浸和污泥强化对钢渣陶粒除磷效果的影响

为提高钢渣除磷效果,采用碱浸预处理,并添加污泥强化制备碱浸钢渣-蒙脱土-污泥复合钢渣陶粒,与钢渣-蒙脱土-可溶性淀粉复合陶粒进行对比研究,探讨强化后钢渣陶粒的除磷性能和除磷机理,考察含磷溶液中磷的去除。结果表明,两种钢渣陶粒的最大除磷率均可达到93%,磷酸盐浓度为1 mg/L时,碱浸-污泥强化钢渣陶粒的最佳投加量为0.5 g,显著低于未强化钢渣陶粒（1 g）。扫描电镜显示碱浸-污泥强化钢渣陶粒孔隙更为密集。X射线衍射表明两种陶粒内含多种金属盐,可与水样中磷酸根离子发生反应将其去除。两种陶粒对Langmuir吸附等温方程拟合度最高,碱浸-污泥强化钢渣陶粒吸附饱和时,最大吸附量（39.18 mg/g）高于未强化钢渣陶粒(19.18 mg/g)。两种陶粒对准二级动力学模型的拟合度高于准一级动力学模型,表明两种陶粒对磷吸附属于单分子层吸附,以化学吸附为主。     

PAM基复合水凝胶电解质的制备及其在Zn–MnO2电池中的应用

水系锌离子电池具有低成本、安全、环保等优点，在规模化储能和智能可穿戴方面极具应用前景.提高其循环稳定性以及循环寿命是实现水系锌离子电池进一步应用的关键问题之一.本工作采用二维层状蒙脱土(MMT)和丙烯酰胺单体，通过两步法合成了具有三维网状结构的蒙脱土–聚丙烯酰胺水凝胶电解质(Montmorillonite–polyacrylamide hydrogel,MMT–PAM).蒙脱土的加入为丙烯酰胺单体的原位聚合提供了吸附位点，并通过MMT和PAM高分子链之间的氢键作用显著提高了水凝胶的机械性能，抑制了锌枝晶生长(在0.5 mA·cm^-1电流密度下稳定循环250 h).此外，蒙脱土表面丰富的负电荷为Zn²⁺的快速传输提供更多离子传输通道，提高其离子电导率(室温下为34 mS·cm^-1)，赋予MMT–PAM水凝胶电解质更好的倍率性能和循环稳定性.基于上述优点，组装的水系Zn–MnO₂电池在0.2 A·g^-1的电流密度下提供了289 mA·h·g^-1的比容量，且可稳...     

插层法制备PVC/蒙脱土纳米复合材料的研究进展

本文的目的是总结分析了插层法制备PVC/蒙脱土纳米复合材料的研究进展,并对其应用加以综述,对进一步研究开发该纳米复合材料将具有一定的参考价值。采用熔融插层、单体熔融聚合插层及溶液插层等方法可以制备PVC/蒙脱土纳米复合材料,并被应用到工程材料、阻隔性材料、功能性材料等领域。通过大量实验证明,插层法是制备PVC/蒙脱土纳米复合材料的成功方法。     

双硫腙修饰有机皂土吸附富集-原子吸收光谱法测定水中痕量镉

采用静态浸渍法,将双硫腙修饰于用十六烷基三甲基溴化铵(CTMAB)改性的皂土表面,制备了双硫腙修饰有机皂土,对其结构及其对水中镉离子的吸附性能进行了研究,确立了双硫腙修饰有机皂土对镉离子的吸附和洗脱条件,建立了双硫腙修饰有机皂土吸附富集-火焰原子吸收光谱法测定水中镉的新方法。结果表明,经CTMAB改性后,双硫腙可牢固地负载于皂土上,当介质的pH值为4~8时,双硫腙修饰有机皂土对水中镉离子具有很强的吸附能力,其吸附容量可达1.428 mg/g。经富集10倍后,该法检出限为0.16μg/L。应用于管网水和河水     

石墨烯改性有机膨润土吸附性能及其动力学

为提高有机膨润土的吸附性能,采用微波合成法,以石墨烯对有机膨润土进行改性,制备一种吸附效果好且回收效率高的新型石墨烯改性有机膨润土复合材料,研究其结构和吸附性能,探讨新吸附材料的作用机理。通过扫描电镜、红外光谱和X射线衍射对有机膨润土及石墨烯改性有机膨润土进行表征,并将其用于水中腐殖酸的吸附。结果表明:石墨烯与有机膨润土均匀复合,有机膨润土的层间距由1.37 nm增大至2.68 nm;当温度为25℃、p H值为6、吸附剂的用量为5 g·L-1及吸附时间为1 h时,溶液中腐殖酸的去除率达到95.52%;石墨烯改性有机膨润土对腐殖酸的吸附等温线符合Langmuir模型和准二级动力学模型,最大理论吸附量为52.08 mg·g-1,且为放热反应。利用0.1 mol·L-1Na OH溶液对石墨烯改性有机膨润土进行解吸再生,5次再生后其对腐殖酸的去除率为86.3%。      

重庆高校推进产学研合作的案例分析

以重庆大学、重庆邮电大学和重庆理工大学为例,剖析重庆高校推进产学研合作的基本模式,已经取得的突出成绩,分析总结其基本经验.从完善政策法规体系、强化经济调控、建立组织机构、加强中介建设及开展国际产学研合作等方面,提出了深入推进重庆高校产学研合作的对策建议.     

Benzimidazole resistance in cyathostomes in horses in the Ukraine

The efficacy of treatment with cambendazole was tested in 1-year-old horses on a farm in Dubrovka, Ukraine. Thirty-five horses were treated. Their egg output was compared on the day of treatment and 14 days later with that of 33 untreated horses. Before treatment the mean number of eggs g-1 faeces was 614 in the controls and 766 in horses that had been treated. After 14 days the mean egg output in the controls was 580 and in the treated horses 369. This means a reduction of 54.5%. Only cyathostome larvae could be cultured from faeces collected after treatment. It can be concluded that benzimidazole resistance in cyathostomes is present in the Ukraine.     

Fractures in childhood in Khartoum

A prospective study of fractures in 231 children received at Khartoum North Teaching Hospital(KNTH) was carried out for a period of six months. The incidence of child fracture rated as one per day, then it increased from the age of 5 years onwards in boys and between 6 and 8 years in girls. Most injuries were sustained during the day time, especially between late afternoon and sunset. 82% of injured children presented to a medical facility, while 18% were taken to native healers first. Non-road traffic accidents accounted for 84% of the fractures mainly due to sports, domestic injuries and falls; whereas road traffic accidents were 16% and occurred mainly in pedestrians. Forty three percent of the fractures needed only first aid and splintage while 42% needed closed reduction. Thirty one percent of all patients were treated as inpatients. The long bones were affected in 91% of all fractures, the commonest site being the distal end of the forearm (26%), followed by supracondylar fracture of the humerus (15.6%). In the upper limb, left-sided fractures predominated. The epiphyseal injuries were 3.5% of all fractures, mainly at the distal radial epiphysis. Boys were commonly affected between 13-15 years of age. Open fractures constituted 9.8% of the series and were mainly due to traffic accidents in town dwellers, the most vulnerable bones were those of the leg and foot. Pathological fractures accounted for 2.2% and were due to bone cysts and osteogenesis imperfecta. The problem of child safety and the preventive measures need to be more stressed.     

Apoptosis in experimental myocardial infarction in situ and in the perfused heart in vitro

We report the appearance of apoptotic cells in experimental myocardial infarction (rabbit heart) in in situ and in vitro preparations. Apoptosis was recognized by intravital staining with Hoechst 33342 (Ho342), by nick-end labeling (TUNEL) and by DNA laddering. A steady rise in the relative number of apoptotic cardiomyocytes (apoptotic index) was noted in in situ preparations. Apoptosis was first noted 6 h after the onset of ischemia with its highest value occurring after 72 h. Apoptotic nuclei were absent in remote areas of the left and right ventricles. Apoptotic nuclei within the infarcted area showed diminished intensity of Ho342 fluorescence. Three days after ischemia, a border zone adjacent to the infarcted area consisting of apoptotic macrophages was recognized. A novel finding was the appearance of apoptotic cardiomyocytes in the isolated perfused ischemic heart. Occurring as early as 50 min after the onset of ischemia, a high apoptotic index was present adjacent to the ligature placed around the coronary artery. This observation provides the opportunity to selectively examine factors leading to apoptosis in the ischemic heart under controlled experimental conditions.     

Botulism in Poland in 1996

A model is presented in which ion translocation through the F0 part of the ATP synthase drives the rotation of the ring of c subunits (rotor) versus the a subunit (stator). The coupling ion binding sites on the rotor are accessible from the cytoplasm of a bacterial cell except for the c subunit at the interface to the stator. Here, the binding site is accessible from the periplasm through a channel formed by subunit a. In the ATP synthesis mode, a coupling ion is anticipated to pass through the stator channel into the binding site of the adjacent rotor subunit, following the electrical potential. Occupation of this site triggers, probably by electrostatic forces, the rotation of the ring. This makes the binding site accessible to the cytoplasm, where the coupling ion dissociates. Simultaneously, this rotation moves again an empty rotor subunit into the contact site with the stator, where its binding site becomes loaded and rotation continues.     

Problems in falling in love

Certain patients enter psychoanalysis because of their inability to love another person. Often they report a repetitive erotic pursuit of desired partners, without being able to experience or maintain loving feelings. Kernberg has understood such difficulties as representing effects of early narcissistic disappointments and/or of difficulties in resolving oedipal conflicts. In this paper, Lacanian concepts of the mirror phase and symbolic love are employed to develop these issues. Sexualization of problems in mirroring may be fused with oedipal conflicts in some cases. An extended vignette is presented to illustrate the technical and theoretical issues.