地面高速轮胎复合材料生热专家系统的应用

介绍地面高速轮胎复合材料生热计算机专家系统。该系统在对不同规格、不同厂牌的轮胎进行大量测温试验主材料生热性能试验的基础上,利用轮胎材料生热性能和导热性能的研究结果,采用有限元计法计算轮胎各部件在各种使用条件下的温度场分布,并进一步研究了轮胎生热与气压,速度及负荷等使用条件之间的关系。应用该系统有利于各种使用条件的合理匹配,确保轮胎正常使用。     

轮胎材料热生成率的确定

探讨了确定轮胎全部材料热生成率的简化条件。在应变于一个周期内按正弦波形变化、材料的粘弹性按线性处理、橡胶的生热性能按各向同性处理、忽略橡胶－骨架增强材料垂直于帘线方向应变分量的作用等简化条件下，测定了１６５Ｒ１５轿车子午线轮胎所用各种材料在不同使用条件下的热生成率，为轮胎温度场的计算提供了材料生热特性。     

炭黑填充橡胶复合材料动态力学性能和生热预报

基于应变放大因子的概念,对炭黑填充橡胶的动态力学性能和不同外载条件下的生热性能作了分析预报。对非均一橡胶复合部件或混炼不充分导致炭黑分散不均匀胶料和生热性能和动态模量进行了研究,用两种材料并联而成的复合材料模型说明了炭黑分散度对橡胶性能的影响。结果表明,随着炭黑分散度的提高,动态模量和滞后损失都下降,并且趋于炭黑完全分散时的值。还对复合部件在不同外载条件下的生热情况和动态性能作了比较。     

炭黑填充橡胶复合材料动态力学性能和生热预报

基于应变放大因子的概念,对炭黑填充橡胶的动态力学性能和在不同外载条件下的生热性能作了分析预报。对非均一橡胶复合部件或混炼不充分导致炭黑分散不均匀胶料的生热性能和动态模量进行了研究。用两种材料并联而成的复合材料模型说明了炭黑分散度对橡胶性能的影响。结果表明,随着炭黑分散度的提高,动态模量和滞后损失都下降,并且趋于炭黑完全分散时的值。还对复合部件在不同我上的生热情况和动态性能作了比较。     

网络稳定的新力学观点

现今，卡车和越野胎常常需要在高负荷和高速下长时间工作。在这些苛刻的工作条件下，轮胎的生热要比一般工作条件下的生热大的多。结果是，过高的运行温度导至胶料发生硫化返原从而降低轮胎的耐久性，或在极端情况下使轮胎破坏。     

降低负重轮天然橡胶基复合材料生热的研究状况

概述负重轮天然橡胶(NR)基复合材料的生热原理及表征方法,重点介绍交联结构和填料包括炭黑、硅烷偶联剂改性白炭黑、新型碳材料氧化石墨烯和多壁碳纳米管对复合材料生热影响的研究状况。指出将新型碳材料部分取代炭黑,采用胶乳共沉法制备新型碳材料母胶有利于将新型碳材料均匀分散在NR基复合材料中,在有效提高NR基复合材料强度的同时降低其生热。新型碳材料制备成本高,需要进一步探讨其放量制备的简易方法及分散工艺,以开发能够工业化生产的应用于负重轮的高强度和低生热NR基复合材料。     

子午线轮胎有限元分析第9讲子午线轮胎温度场分析

子午线轮胎是由多种材料组成的复杂结构体。轮胎在周期性载荷的作用下,橡胶和骨架材料的滞后损失、橡胶与骨架材料之间的摩擦等因素会导致生热,使轮胎温度升高。轮胎的使用温度很大程度上决定着轮胎的使用寿命。轮胎所用材料的力学性能和耐疲劳性能与温度密切相关,使用时温升越高,性能下降就越大,过高的温升甚至会导致材料性能严重下降,使轮胎迅速损坏。因此,轮胎设计人员在积极寻求一种能够有效降低轮胎滚动生热、延长使用寿命的方法,轮胎滚动内部温度场一直是国内外研究的一个热点。1轮胎应力/应变与温度的关系影响轮胎生热和温升的因素主…     

硬脂酸用量对天然橡胶胎面胶的撕裂性能与生热性的影响

在天然橡胶／聚丁二烯不同的并用比及不同的硫化温度条件下，研究硬脂酸用量对生热性与撕裂性的影响。增加硬脂酸用量能提高抗硫化退原性，同时不会对拉伸性能产生过分的副作用，对室温下撕裂性能的影响程度不明显。尤其在试验条件苛刻及聚丁二烯用量较高的条件下，高温撕裂强度明显降低，生热性得到改进。     

沉淀法白炭黑的性能对载重汽车轮胎胎面特性的影响

我们在实验室和现场对具有不同比表面积和／或分散度的白炭黑进行了比较。一种加有沉淀法白炭黑的天然橡胶胎面可以减少滚动阻力、生热和提高在荷刻条件下的耐磨性。高分散度的沉淀法白炭黑具有较好的性能。只有通过调整配方,即用高比表面积白炭黑部分替代炭黑才能提高在各种严苛条件下的耐磨性,同时降低滚动阻力和保持湿路面牵引力。     

微波辐照下涤纶的热收缩行为

本文探讨高收缩涤纶在常规加热和微波辐照两种条件下的热收缩行为及内部结构变化的差异.温度相同条件下微波辐照时纤维的热收缩行为加快,说明微波除具有热效应外,还对纤维具有促进聚集态结构调整的非热效应.     

水的焦耳-汤姆逊效应对井筒温度的影响

在通过地层和孔隙的流动过程中由于压力的下降而引起注入水的热效应,此热效应将影响流动期间井筒附近地层的温度分布。由于热传导,水的焦耳-汤姆逊热效应也将影响到关井之后的井筒温度分布。因此,本文用数学模型的方法研究了水的焦耳-汤姆逊效应对井筒温度的分布有着重要的影响。     

Application of fractal theory for characterisation of crystalline deposits

The objective of this investigation was to study the mechanisms of mixed salt crystallisation fouling on heat transfer surfaces and to characterise the structure of the deposits formed on the heat transfer surfaces. The effects of various operating parameters such as solution composition and hydrodynamics of the system on crystallisation fouling of mixtures of calcium sulphate and calcium carbonate, which are the most common constituents of scales formed on heat transfer surfaces, were studied experimentally. After clarification of the effects of operating parameters on the deposition process, deposits on the heat transfer surfaces were collected for analysis. The crystalline samples were analysed using Scanning Electron Microscopy, X-Ray Diffraction and Ion Chromatography techniques. It was found that crystallisation fouling on heat transfer surfaces exhibits fractal geometry. Therefore, the concept of fractal theory was used to quantify the structure of the deposits by introducing a new quantity called the fractal dimension.     

进料温度对整个重油催化裂化装置反应的影响

对于无取热设施的重油催化裂化装置,反应进料温度对反—再系统热平衡有一定的调节作用,但是靠降低反应进料温度来维持反—再系统热平衡有一定的局限。由于雾化效果变差和剂油比增加导致焦炭产率增加,烧焦放热将会超过由反应进料温度降低而少带入反应器的热量,因此降低反应进料温度有一极限,超过该值对热平衡的调节作用就会发生逆转。     

井下电潜式往复泵举升系统的井筒温度场分布研究

井筒内温度分布情况对井下电潜式往复泵举升系统的设计和工作有着重要影响。本文根据传热学和能量守恒原理,建立了井下电潜式往复泵系统的井筒温度场模型。模型中考虑了不同井段的传热热阻情况和电机、电缆和泵的热量产生规律,较为准确的体现了井筒温度场的实际情况,为油田中井下电潜式往复泵举升系统的应用提供了依据。     

A Reconsideration of the Link between the Energetics of Water and of ATP Hydrolysis Energy in the Power Strokes of Molecular Motors in Protein Structures

Mechanical energy from oxygen metabolism by mammalian tissues has been studied since 1837. The production of heat by mechanical work was studied by Fick in about 1860. Prior to Fick’s work, energetics were revised by Joule’s experiments which founded the First Law of Thermodynamics. Fenn in 1923/24 found that frog muscle contractions generated extra heat proportional to the amount of work done in shortening the muscle. This was fully consistent with the Joule, Helmholtz concept used for the First Law of Thermodynamics. The link between the energetics of water and ATP hydrolysis in molecular motors is recommended for reconsideration.     

不同脂肪酸钙和脂肪酸锌热稳定作用机制研究

将硬脂酸钙/硬脂酸锌、月桂酸钙/月桂酸锌、癸二酸钙/癸二酸锌、亚磷酸-苯二异辛酯(PDOP)、季戊四醇(PER)作为稳定剂应用于聚氯乙烯(PVC)中,通过热老化法、电导法和紫外光谱分析法对比了上述不同脂肪酸钙和脂肪酸锌稳定剂的热稳定特性,并进一步研究了单独脂肪酸钙和脂肪酸锌的热稳定机理.结果表明:单独硬脂酸钙的热稳定性相对较好;硬脂酸钙/脂肪酸锌的协同效应相对较好;月桂酸钙/月桂酸锌/PDOP的协同效应最为明显;月桂酸钙/月桂酸锌/PER能有效抑制PVC降解形成共轭长链烯烃,硬脂酸钙/硬脂酸锌/PER能有效抑制PVC降解形成共轭短链烯烃;硬脂酸钙能吸收PVC降解所产生氯化氢,硬脂酸锌能置换PVC中的不稳定氯原子.     

新型磷氮阻燃剂对尼龙6的阻燃作用

研究了一种基于烷基次磷酸铝的新型磷氮阻燃剂(OP)对尼龙6(PA6)的阻燃作用。试验结果表明:该阻燃剂对PA6具有良好的阻燃作用,当其添加质量分数为25%时,PA6的氧指数(LOI)大于30%,阻燃级别达到FV-0级,燃烧时材料的热释放速率、质量损失速率和总热释放量明显降低。热重分析结果表明:OP改变了PA6的热降解过程,使之成炭化学反应提前,形成的炭层通过隔热和隔氧而产生阻燃作用。添加OP对材料的机械性能有些影响,如弯曲强度和弯曲模量有所增加,而拉伸强度和冲击功有所下降,但影响不大。     

Synthesis of Silicalite-1 film on a quartz superface using the vapor phase transport method

Aging and compositional effects of silicalite layer synthesis on a quartz surface using the vapor phase transport method were studied. Silicalite layers can be synthesized from a wide compositional range when not-aged mixtures were used. But reproducibility of the film synthesis was low due to the heterogeneity of the starting mixtures. In order to increase the reproducibility, both aging of the starting mixtures and compositional changes were attempted. Silicalite layer can be synthesized successfully on quartz surface within 0.3 of the ratio TPAOH/SiO₂. Higher ratio of TPAOH/SiO₂ smaller crystals are formed. If the TPAOH/SiO₂ ratio is larger than 0.3, the formed silicalite crystal cannot be attached on the quartz surface. When the TPAOH/SiO₂ ratio of the aged starting mixture was 0.28, requirements for both reproducibility and smaller crystal size resulted were satisfied. The crystal size and shape in the silicalite layer are also influenced by the water content in the mixture. The crystal size in the silicalite layer increases with increasing water content in the mixture. This paper was presented at the 8th APCChE (Asia Pacific Confederation of Chemical Engineering) Congress held at Seoul between August 16 and 19, 1999.     

Evaluation of the Catalytic Effect of the Ozone/Carbon Nanotube (O3/CNT) Process Using para-Chlorobenzoic Acid (pCBA)

The catalytic effects and mechanisms of the ozone/carbon nanotube (O₃/CNT) process using para-chlorobenzoic acid (pCBA) were evaluated. To use pCBA as an O₃-resistant OH? probe compound in a pure water system at pH 7, an adequate amount of scavenger was needed. During the O₃/CNT process, a synergetic catalytic effect by OH? generation on the CNT surface could be evaluated in the condition of excess tert-butyl alcohol (TBA) concentration. The OH? radicals were generated and existed on both the bulk phase and CNT surface. The OH-ct values of the CNT surface and bulk phase in the O₃/CNT process for 10 min were 2.1 × 10^?5 and 2.5 × 10^?5μ M·s, respectively. In modifying CNT evaluation, the catalytic effects were the most apparent in the following order: CNT treated with acid then heat (CNT-T), original untreated CNT (CNT-O), and CNT treated with an acid (CNT-A).     

增塑剂对氯化聚乙烯防水卷材增塑效果的研究

分析了几种增塑剂[邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二辛酯(DOP)、邻苯二甲酸二异癸酯(DIDP)、癸二酸二辛酯(DOS)、偏苯三甲酸三辛酯(TOTM)以及氯化石蜡等]对氯化聚乙烯(CPE)防水卷材的增塑机理。在保持其他条件不变的前提下,选取增塑剂的份数为25份,并在此基础上从力学性能、耐温性能、流变性能以及微观结构四个方面比较各种增塑剂与CPE树脂的相容性,从而比较它们的增塑效果。结果表明:DSC以及电镜结果显示邻苯类增塑剂效果明显优于其他类型增塑剂;其中DOP为主增塑剂的体系综合性能最好;DOS作为主增塑剂时具有良好的耐低温析出性;DIDP作为主增塑剂时具有耐高温析出性;氯化石蜡可作为辅助增塑剂;以上增塑剂可根据各自特点复配使用。