增粘树脂对湿固化聚氨酯热熔胶性能的影响

针对湿固化聚氨酯热熔胶,考察增粘树脂中松香树脂、萜烯树脂和萜烯酚醛树脂的加入对湿固化聚氨酯热熔胶初粘强度、终粘强度、熔融粘度、开放时间等性能的影响。结果表明,萜烯酚醛树脂作为增粘树脂所得的湿固化聚氨酯热熔胶熔融粘度低,粘结强度大,热稳定性高,增粘效果显著。     

聚对苯二甲酸戊二酯的性能研究

采用酯化法合成聚对苯二甲酸戊二酯 (PPT) ,利用IR与1H NMR对其结构进行表征 ,对其特性粘数的测定方法进行了研究 ,得到k +k′约为 0 5,即PET切片特性粘数的测试方法同样适用于PPT .用差热扫描量热法 (DSC)研究了PPT的结晶能力 ,并进行了等温结晶动力学分析 ,结果表明PPT的结晶速度很慢 ,需要较长的结晶时间 .热失重法 (TG)比较了PPT与聚对苯二甲酸丙二酯 (PTT)的热降解过程 ,结果表明尽管二者熔点相差很大 ,但热分解温度相近 .     

测试条件对聚酰胺粘数测试结果的影响

分析了测试条件对聚酰胺粘数测试结果产生影响的原因。结果表明,样品实验前的烘干处理对聚酰胺粘数结果影响不大,但是对于长期敞口放置的聚酰胺样品以及做异常调查测试等,建议还是有必要对样品进行烘干处理的;浓硫酸的浓度对结果有明显影响,98%浓硫酸的粘数结果比96%浓硫酸的粘数结果至少偏高10 mL/g,对原料的影响更加显著;样品浓度对粘数的结果有显著的影响,样品浓度太低或太高都会导致粘数结果发生明显地偏差。     

导电聚苯胺的热分析及粘弹性能研究

本文用热分忻的方法和粘弹谱仪对聚苯胺（ＰＡＮ）的热性能和粘弹性进行了研究．结果表明ＰＡＮ的耐热性较好，本征态（非掺杂）ＰＡＮ的玻璃化转变温度为 １３４℃，转变活化能为 ２７３ＫＪ／ｍｏｌ．     

高聚物各种平均相对分子质量的绝对测定——GPC和特性粘数法

从ＧＰＣ数据和特性粘数能较准确迅速求出高聚物的数均、粘均、重均、Ｚ查对分子后进琢相对分子质量与特性粘数关联参数。该方法经聚甲基丙烯酸甲酯验证后，用其表征了聚碳酸亚乙酯（ＰＥＣ）和聚碳酸亚丙酯（ＰＰＣ）。     

树状高分子的特性粘数与代数的关系

从爱因斯坦的粘度理论出发 ,联系树状高分子的分子结构参数 ,计算了树状高分子的特性粘数 ,得到了树状高分子的特性粘数与代数的内在关系 ,分析了树状高分子特性粘数特异行为的内在原因 ,使得对树状高分子特性粘数的理论预测成为可能     

基团贡献法研究环型聚苯乙烯稀溶液流体力学参数

首次采用基团贡献法,根据内聚能、摩尔体积、摩尔吸引常数和临界特性粘数等分别计算并通过实验数据验证了环型和线型聚苯乙烯的溶度参数,特性粘数、摩尔极限粘数函数、临界分子量和Mark-Houwink参数,详细地讨论了计算大环高分子的K_(θ,r)值所取用的临界分子量应具有的理论意义。     

丹皮酚与钙粘素相互作用的分析研究

丹皮酚对多种肿瘤细胞具有抑制作用,而钙粘素是与肿瘤产生和恶化密切相关的一类糖蛋白.本研究运用荧光光谱法和原子力显微技术探索了丹皮酚与钙粘素的相互作用.荧光光谱法研究结果表明,丹皮酚对钙粘素的荧光具有显著的猝灭作用,通过猝灭常数随温度变化趋势推断为静态猝灭过程.丹皮酚与钙粘素形成复合物的热力学参数分别为ΔH=-4.3×10.5 J/mol和ΔS=-1.3×10.3 J/(mol·K), 表明此结合过程以氢键和范德华力为主.原子力显微观察结果表明,钙粘素分子间可形成有序长链结构,丹皮酚加入后能显著破坏这种组装结构而形成短链结构,这是由于丹皮酚与钙粘素末端色氨酸残基的作用而影响相邻钙粘素分子结构域间的交错作用所致.本研究结果表明,钙粘素可能是丹皮酚体现其活性的一个重要作用靶点.     

浓缩型精制蝮蛇抗栓酶治疗高粘血症20例疗效观察

收集了２０例高粘血症病例，观察了浓缩型精制蝮蛇抗栓酶对其治疗的疗效。结果显示，治疗后高粘血症患者的血液粘度、等血液流变学指标均有明显的下降，表明浓缩型精制蝮蛇抗栓酶能有效改善高粘血症患者的血液流变状态。     

从GPC和特性粘数计算高聚物各种平均相对分子质量的新方法

聚合物相对分子质量表征问题可以从ＧＰＣ数据和特性粘数较可靠地迅速解决，同时求出其烽均、粘均、重均，动力学平均相对分子质量及相对分子质量－特性粘数关联参数。为些须对以往方法作较大的改进，其关键是用迭代法进行特性粘数与相对分子质量的关联。方法经用聚甲基丙烯酸甲酯验证后用于聚碳酸亚乙酯（ＰＥＣ）和聚碳酸亚丙酯（ＰＰＣ）分别得到关系式。     

碳柱热电极的制备及应用

用铅笔芯制作了不同直径的碳柱热电极,表征了碳柱热电极的电化学和温敏等各种性质。结果表明,碳柱热电极在多次加热过程中均表现出对温度变化的快速响应以及良好的热稳定性。将其应用于痕量铅的方波阳极溶出伏安法测定,65℃时灵敏度比常温高,Pb2＋浓度在1~22μg/L呈线性关系,线性回归系数r=0.995 5,检测限0.5μg/L。     

热压/热变形纳米复合永磁体的制备和磁性能的研究

研究了热压热变形纳米复合永磁体制备的新工艺,探讨了制备高性能高各向异性块状纳米复合永磁体的新方法。以晶态纳米复合永磁粉末为原料,研究了热压热变形工艺参数与磁体密度和磁性能的关系。实验中制备出的热压热变形磁体的密度高达7.508g·cm-3,磁体的磁能积为61kJ·m-3。实验表明,温度是影响热压热变形磁体性能的重要因素。磁体在平行于压力方向的磁性能稍高于垂直于压力方向的磁性能,体现出微弱的各向异性。     

稀土对镁-铝合金抗热裂性能的影响及其机制

研究了稀土（0.1%～1.2%,质量分数）对Mg-Al合金抗热裂性能的影响及其机制.结果表明： 往Mg-Al合金中添加稀土后,合金的抗热裂性能显著下降,其原因可归为： 稀土引起了Mg-Al合金晶粒粗化,使得热裂纹萌生所需的断裂应变降低;稀土减少了Mg-Al合金中的共晶组织,缩短了枝晶通道保持开通的时间,不利于合金进行补缩;而且稀土还提高了共晶反应的温度,使得凝固后期枝晶间液膜的强度有所下降;当α-Mg枝晶连成骨架时,分布在枝晶间的Al11RE3相容易堵塞枝晶通道,增加了合金补缩的难度;Al11RE3相与α-Mg基体的凝固收缩率不同,容易产生凝固收缩应力,促进热裂纹的萌生.     

SANS from hot-stretched polystyrene revisited

Small-angle neutron scattering (SANS) has been used to investigate macromolecular orientation of uniaxially hot-stretched partially deuterated polystyrene. Principle radii of gyration and degree of eccentricity were measured over a range of hot-stretch temperatures, strain rates, and external draw ratios (EDR). Results show affine deformation for EDR <4 and an increase in the degree of local molecular orientation with increasing rate of strain and decreasing stretching temperature. It also is found that although the macromolecules follow the external stretching affinely on average, they do not deform uniformly.     

Bioethanol Production from Glucose by Thermophilic Microbes from Ciater Hot Springs

Bioethanol has been considered as one of the alternative energy resources for fossil fuel substitute. Second generation of bioethanol production usually uses lignocellulosic material as its raw material which conducted at high temperature range (70-80^oC). In this case the thermophilic microbe is needed for fermentation process in order to minimize the use of energy. This paper will discuss the results of the study on bioethanol production from glucose by using thermophilic microbes isolated from local source namely from Ciater hot springs in Subang District, Indonesia. In this study six thermophilic isolates (C1, C2, C3, C4, C5 and C6) were tested their capability in producing ethanol in the fermentation medium containing 5% glucose substrate for 5 days incubation. To determine the activity of isolates in ferment substrate is done by measuring the concentration of glucose and ethanol produced using a spectrophotometer. Isolates tested (C1,C2,C3,C4 and C5) could reduce glucose concentration from 1.1up to 1.7% in the fermentation medium. The ethanol produced was tested qualitatively by reacting the samples with K₂Cr₂O₇inacidic conditions by observing its color change from yellow-orange to green-blue. The presence of ethanol indicatedby the decrease of OD's sample. This study showed that all isolates have the ability to produce ethanol. However, there are 2 isolates potentially produce ethanol that isolates C3 and C5 are characterized by low absorbance after adding potassium dichromate (K₂Cr₂O₇).     

对辣椒色素某些性能的测试

对辣椒色素某些性能的测试陈连文（河北经贸大学轻工系石家庄０５００６１）刘敬兰（河北师范大学实验中心石家庄０５００１６）关键词分离辣椒色素测定红辣椒属茄科，辣椒属（ＣａｐｓｉｃｕｍｆｒｕｔｅｓｃｅｎｓＬ．），我国各地均有栽培，品种多，资源丰富。内服有开...     

汤湖热矿泥抑制化疗药物心脏毒性的实验研究

探讨了汤湖热矿泥抑制阿霉素（Dox)心脏毒性的作用机制。通过建立SD大鼠心脏阿霉素损伤的模型，表明汤湖热矿泥能够通过明显降低心肌细胞内游离Ca^2 和活性氧分子（ROS）水平，对线粒体正常结构起保护作用，达到抑制Dox所致的心脏毒性损伤作用。     

Effect of aluminium content on the coating structure and dross formation in the hot‐dip galvanizing process

Hot dipping of steel in aluminium–zinc baths of varying composition (5–90% Al) has been undertaken with the aim of elucidating the mechanism of coating formation. On the basis of these experiments, it has been possible to define a range of aluminium content over which there is a change from a normal galvanizing process to a typical aluminizing process. Alternatively, the coating structure and properties were markedly affected by the aluminium content of the dipping bath. The kinetics of such coatings acquires the character of the activation energy E_a. The effect of various silicon levels as an inhibitor to iron dissolution during hot dipping at different aluminium percentages was studied. The structure of dross formation in 55 wt.% Al–Zn was identified. The adverse effect of heavy accumulation of dross in the dipping pot on the coating structure also was shown. Copyright © 2003 John Wiley & Sons, Ltd.