串联式连续混炼设备转子转速对白炭黑补强效果的影响

采用自主设计的串联式连续混炼设备,在保证下游连续混炼机各段机筒控制温度一定的条件下,研究下游连续混炼机转子转速对胶料内部硅烷偶联反应程度的影响。结果表明,在下游连续混炼机喂料段、混炼段、挤出段机筒控制温度分别为145,135,125℃的条件下,当转子转速为30 r·min~(-1)时,胶料停留时间为2.75 min,排胶温度为154℃,胶料内部硅烷偶联反应程度最高,白炭黑补强效果最好。     

混炼工艺对白炭黑硅烷偶联反应程度及胶料性能的影响

研究混炼工艺对白炭黑硅烷偶联反应程度及胶料性能的影响。结果表明：随着白炭黑硅烷偶联反应程度的增大，胶料的门尼焦烧时间延长，硫化速度加快，小应变下的模量减小，Payne效应降低，填料与填料之间的相互作用减弱，70℃时的损耗因子明显减小，白炭黑在胶料中的分散均匀性提高；白炭黑硅烷偶联反应程度对混炼温度的敏感度较高，混炼温度对硅烷偶联反应程度的影响大于混炼时间的影响；当混炼温度为140～145℃、混炼时间为100～180 s时，胶料的物理性能最佳。通过计算白炭黑硅烷偶联反应的表观活化能，得到大配合试验胶料混炼工艺的最佳混炼时间。     

XLH-150型连续混炼工业化机台的混炼工艺参数 对胶料性能的影响

研究XLH-150型双转子连续混炼机的混炼工艺参数与胶料性能间的关系,确定XLH-150型连续混炼工业化机台的最佳混炼工艺,并与传统密炼机三段混炼工艺进行对比。结果表明：XLH-150型连续混炼工业化机台的最佳混炼工艺为初炼采用GK-45E型啮合型密炼机,转子转速为50 r·min^-1,温度为40℃,混炼时间为270 s,填充因数为0.6;补充混炼采用XLH-150型双转子连续混炼机,转子转速为40 r·min^-1,过2遍连续混炼机,各段温度分别为70,65,60和55℃。采用连续混炼工艺的胶料性能优于采用传统三段混炼工艺的胶料性能,即胶料的Payne效应降低11%,滚动阻力降低15%,拉伸强度和撕裂强度略有提高;同时生产效率提高44%以上,总单位能耗降低39%。     

橡胶双转子连续混炼机母炼全过程各阶段的实验研究

本研究针对块状橡胶串联式连续混炼装备和方法,采用了自主研发的块状橡胶串联式连续混炼实验平台,主要针对双转子连续混炼机母炼过程,通过设计连续母炼全过程各阶段对比实验,得到未添加硫化体系的各阶段连续母炼胶。通过Payne效应、硅烷化反应指数、门尼黏度来判断胶料的质量水平,实验结果表明:胶料在依次通过连续混炼机各混炼模块后,各组样品的Payne效应依次呈现下降趋势,实现填料的良好分散;各组样品硅烷化反应程度整体呈现上升趋势,说明橡胶连续母炼系统能够实现白炭黑的硅烷化反应。胶料进入双转子连续混炼机后门尼黏度也在持续下降,最终门尼黏度维持在55左右,适宜后续的加工。     

串联式连续混炼设备用于炭黑配方胶料低温混炼的实验研究

本文根据低温混炼原理,将自主研发设计的串联式连续混炼机用于炭黑配方胶料的低温混炼,不仅实现了块状橡胶的连续混炼、保证了基体胶和配合剂配比的准确性,同时保证了混炼温度低于135℃,保留了橡胶大分子链的完整性,经实验验证:与密炼机高温混炼相比,串联式连续混炼设备采用低温法制备的炭黑配方胶料分散度高、综合物理机械性能好。同时,通过实验探究了串联式连续混炼设备中下游连续混炼机转子转速对于混炼胶质量的影响,结果表明:当连续混炼机转子转速为30rpm时,所制备的胶料性能最好。     

基于能量等效的双转子连续混炼机混炼段相似放大研究探讨

根据双转子连续混炼机自身特性和等效平均停留时间、等价转子顶部剪切速率的原则,以能量等效为衡量混合效果的准则,提出双转子连续混炼机混炼段相似放大设计的流程及其理论模型。在该模型确定的转子转速和喂料速率下,利用Polyflow软件模拟了机筒内径分别为30 mm和100 mm的双转子连续混炼机混炼段和卸料段内的流场特征,以能量等效为指导准则,通过对流场特征和混合效果进行分析,对所提出的相似放大设计理论模型进行了验证。     

双转子连续混炼机结构与混炼原理

双转子连续混炼机，是一种新型橡塑连续混炼机械。本文介绍了该机器的主要结构，分析了其工作原理和影响剪切速率、剪应力大小的因素，提出最大剪应力出现在转子混炼段螺校的顶部，其大小与转子的结构、操作条件有关，适当降低转子混炼段螺棱宽度和转子与机筒的间隙，提高转子转速，可以有效地增强转子对物料的剪切作用。     

混炼工艺对丁苯橡胶/顺丁橡胶并用胶性能的影响

研究混炼工艺对丁苯橡胶(SBR)/顺丁橡胶(BR)并用胶性能的影响。结果表明:将预处理白炭黑与橡胶浸润后再加入炭黑,填料的分散性提高,胶料的结合胶含量大,物理性能和耐磨性能好;在相同转子转速下,随着混炼温度提高,胶料的强度和耐磨性能总体提高;在相同混炼温度下,随着转子转速增大,胶料的强度和耐磨性能总体提高,生热降低;混炼温度和转子转速过高的胶料综合性能降低;当混炼温度为90℃、转子转速为70 r·min~(-1)时,胶料的综合性能较好。     

串联式低温连续混炼中转子转速和停留时间对炭黑配方混炼胶质量的影响

基于低温混炼原理,利用自行设计研发的串联式连续混炼设备对炭黑配方胶料进行低温高分散混炼,该方法在保证基体胶和配合剂准确配比的前提下,实现了块状橡胶在135℃以下的低温连续混炼,从而在一定程度上保证了橡胶大分子链的完整性。本文通过实验探究了串联式连续混炼设备中连续混炼系统转子转速和连续混炼停留时间对于混炼胶质量的影响,结果表明:当连续混炼系统转子转速为30 r/min、停留时间为186 s时,所制备的混炼胶综合性能最好;同时将串联式低温连续混炼与密炼机高温混炼法相对比,发现前者制备的炭黑配方胶料分散度高、加工性和综合物理机械性能好,证明了其对炭黑配方胶料混炼具有较好的适用性。     

混炼机类型对新型白炭黑-硅烷混炼加工性能的影响

综述了混炼机类型对白炭黑一硅烷混炼加工性能的影响。通过使用现有硅烷如Si69与新型硅烷VP Si363的胶料对比,证明新型硅烷VP Si363的胶料其加工性能在很大程度上取决于可用的混炼设备;对于啮合型转子捏合机和切线型转子捏合机,其整体加工行为与性能必须保持平衡,从而实现VP Si363胶料的最佳结果。     

The Effect of Melatonin on Periodontitis

Background: Periodontitis is a chronic disease with a complex etiology that includes bacterial colonization, excessive inflammation, and oxidative stress. The hormone melatonin has antioxidant properties and might contribute to alleviating chronic conditions by reducing oxidative stress. The aim of this study was to analyze the effect of exogenous melatonin on periodontitis in an animal model of the disease as well as in patients with periodontitis. Methods: In rats with ligature-induced periodontitis, melatonin was administered in drinking water for two weeks. In the human study, patients with treatment-resistant periodontitis were asked to rinse their mouths with a solution containing melatonin or placebo every evening for two weeks. Periodontal status as well as salivary markers of oxidative stress were assessed at the end of the study. Results: Neither radiography nor μCT revealed any significant effects of melatonin on alveolar bone loss. Gum recession was the only improved macroscopic measure in rats (p < 0.05). Analysis of salivary markers of oxidative stress revealed no effects of treatment in rats or humans despite clearly elevated melatonin concentrations in melatonin treated groups. Conclusion: Our results do not support the use of melatonin for the treatment of periodontitis. However, the negative outcome is limited by the short duration of the study and the chosen route of application as well as the dose of melatonin.     

表面活性剂对高速Zn－SiO_2复合镀层的影响

采用实验室高速复合电镀装置，研究向Ｚｎ－ＳｉＯ_２复合镀液中分别引入表面活性剂ＤＴＡＢ和ＰＯＥＬＡ，对Ｚｎ－ＳｉＯ_２镀层中ＳｉＯ_２复合量和镀层表面形貌的影响，确定了理想的表面活性剂加入范围，由此获得了表面凹凸状态和复合量得到显著改善的复合镀层。     

多效唑在花生上的应用效果

本文研究了多效唑在花生上的应用效果，结果表明，多效唑能促进花生根系发育，控制株高和侧枝伸长、提高单株结果数和饱果率。喷施浓度以３叶期１００ｐｐｍ和盛花期１５０ｐｐｍ为好，其增产率分别达３３．０％和３６．３％。     

微生物对原油的作用

选用兼性厌氧菌,使原油-水体系中烃性质改变、水相酸度增加、表面张力下降、出现乳化现象。以原油为碳源发酵后,油粘度、蜡含量、凝固点均显著降低。在矿场进行了7口井微生物单井吞吐试验,结果表明可有效地清除井筒及近井地带的石蜡,降低原油粘度,改善原油的流动性,提高原油产量。     

The Effect of Pressure on Organic Reactions

The utility of high pressure for the understanding of chemical reactions and its application in organic synthesis is shown for cycloadditions (inter‐ and intramolecular Diels‐Alder reactions, 1,3‐dipolar and [2+2] cycloadditions), cheletropic reactions and pericyclic rearrangements (Cope and Claisen rearrangements and electrocyclizations). The origin of the effect of pressure on chemical reactions is discussed. Especially, the change in the packing coefficient during cyclization of chains and the effect of electrostriction on reactions, in which charged species are generated, contribute substantially to a volume contraction leading to a powerful pressure‐induced acceleration of such reactions. Finally, the effect of pressure on free‐radical reactions (homolytic bond dissociations and quinone oxidations) is described.     

钒化合物对氮化钼电极的影响

在氮化钼的制备中加入了钒化合物,研究了其对氮化钼电极的影响.钒化合物加入后,氮化钼电极的工作电势窗口拓宽约0.34v,电极的电化学性能得到明显改进.     

温度对微生物生长的影响

<正>《中国药典》2010版(二部)微生物限度检查法规定,细菌总数培养温度为30℃～35℃。那么,在实际检验工作中,温度控制在30℃或35℃对微生物生长有何影响?为此,本人进行了如下的试验。     

The Effect of Urea on Wool Fibres

The role of urea in the cold dyeing of wool fabrics by commercially feasible methods which use dye liquors containing high concentrations of urea was examined. Urea was found to penetrate wool fibres readily and promote swelling particularly in the presence of sodium bisulphite.     

The Effect of Moisture on Polyurethane Adhesives

Polyurethane adhesives predominate for bonding shoe soles but the moisture resistance of the adhesive polymer has been questioned. A typical polymer was hydrolytically degraded at 120°C for up to 29 hours and at 20, 30 or 37°C for up to one year and changes in physical and bonding properties monitored. Considerable degradation was necessary before bonding was seriously impaired due to cohesive failure of the adhesive, although heat resistance declined more rapidly. Joints made with undegraded adhesive on exposure to moisture showed rapid loss of strength and cohesive failure at 60 or 70°C, but little loss of strength and failure at or near the interface at 30 or 40°C.