国产环氧沥青混合料施T控制与强度增长特性

通过室内试验研究了国产环氧沥青混合料在低温环境条件下的施工和易性、容留时间范围,以及强度增长规律等施工控制特性.选取芯样空隙率和试件马歇尔稳定度作为评价施工质量的性能指标;通过轮碾试验模拟实际施工过程中的碾压成型过程;选择马歇尔试验和布氏粘度试验研究强度增长特性.试验结果表明:国产环氧沥青混合料可以在10℃的低温环境条件下进行施工;混合料在120℃的容留温度条件下最长容留时间达到70min;在国产环氧沥青混合料完全固化以前,混合料强度随着时间和温度的增长而不断增长.最后,用有机化学理论分析了国产环氧沥青混合料强度增长规律的理论依据.     

废胶粉改性沥青微表处性能试验研究

分析了影响废胶粉改性沥青性能主要因素包括混合温度、混合时间、胶粉加入量及SBS添加剂,通过试验确定最佳油石比并进行废胶粉改性沥青混合料车辙试验、劈裂试验、浸水马歇尔试验。试验数据表明在各影响因素的最佳条件下进行废胶粉改性沥青性能试验,确定最佳油石比为4.73时废胶粉改性沥青混合料的车辙试验、劈裂试验、浸水马歇尔试验满足规范要求且优于基质沥青混合料路用性能。     

SMA混合料路面性能影响因素研究

本文通过对SMA混合料的关键粒级、沥青用量和纤维稳定剂用量进行调整,进行了一系列的室内对比试验,试验结果表明,各影响因素的变动对SMA混合料的高温稳定性能有重要的影响。     

基于细观结构有限元模型的环氧沥青混合料间接拉伸试验研究

运用有限元方法建立环氧沥青混合料细观结构模型,对其间接拉伸试验(IDT)进行数值模拟.首先借助图像处理技术得到由集料和沥青砂浆组成的环氧沥青混合料二相细观结构,并通过蠕变试验获取沥青砂浆常温下的黏弹性材料参数,最后结合有限元手段建立包含集料、砂浆等在内的混合料细观结构有限元模型.数值模拟结果表明,有限元计算的混合料劲度模量与实际IDT试验结果吻合较好,通过改变加载方向、加载速率等参数,发现对混合料细观结构的劲度模量以及局部点位应力均造成一定影响,分析主要原因可能是由沥青混合料的内部结构分布不均匀性以及沥青砂浆的黏弹性特点所造成.研究成果可为微观有限元方法进一步推广应用于不同条件下沥青混合料微观力学响应仿真提供理论依据.     

基于弯曲试验模式的环氧沥青混合料动态模量

为研究环氧沥青混合料的动态特性,采用弯曲试验模式,测试并分析-15,5,25,45,60℃以及0.1,0.5,1.0,5.0,10.0,20.0 Hz条件下环氧沥青混合料的动态弯曲模量及其应力依赖性,依据时-温等效原理和WLF模型建立了动态弯曲模量主曲线,并与改性沥青SMA进行对比.研究结果表明:环氧沥青混合料动态弯曲模量主要受温度影响,随温度升高而显著减少,-15℃与60℃时相差2个数量级,动态弯曲模量还随频率的增大而增加;动态弯曲模量具有一定的应力依赖性,随应力水平的增大而减小;非线性S形主曲线连续而光滑,可以很好地预测任意温度和频率组合的动态弯曲模量;环氧沥青混合料动态弯曲模量在宽频范围内均大于改性沥青SMA.     

武钢钢渣用作沥青混凝土集料研究

通过对武钢钢渣以及钢渣沥青混凝土的路用性能进行的一系列试验，全面分析钢渣的集料性质以及钢渣沥青混合料的高温变形特性、水稳定性、低温抗裂性、抗疲劳性以及抗滑特性。试验结果表明：钢渣具有良好的物理特性，作为道路用集料，性能优于石灰岩；钢渣沥青混合料同样具有优良的路用性能，也优于石灰岩沥青混合料。     

轻烧白云石灰在沥青填料中的应用研究

轻烧白云石是一种重要的炼钢辅料,轻烧白云石生产和转运过程中收尘产生轻烧白云石灰,其含有大量CaO与MgO,属碱性物料.轻烧白云石灰亲水系数与加热安定性均符合沥青填料标准,结合沥青胶浆试验和填料表观相对密度等技术指标,在沥青填料中的合理掺量为20％～40％.沥青混合料试验表明,轻烧白云石灰按20％～40％掺入沥青填料,能有效改善AC-13高温稳定性和水稳定性;轻烧白云石灰按40％掺入沥青填料,也能有效改善SMA-13高温稳定性和水稳定性.轻烧白云石灰在防潮储存以及风选加工前提下,可以部分应用于沥青填料.     

温拌沥青在隧道路面工程中的应用

以京包高速公路德胜口隧道摊铺温拌沥青混合料路面施工为基础,根据隧道中热量散失少温度上升快的特点,按施工时达到的温度高低不同,划分为2种区域施工.对温拌沥青混合料在这2种区域内的施工工艺及如何改善隧道施工环境做了研究.     

沥青老化及RAP料的评价

沥青混合料再生利用技术,是将需要翻修或者废弃的旧沥青混合料,经过翻挖、回收、破碎、筛分,再和新集料、新沥青材料适当配合,重新拌合,形成具有一定路用性能的再生沥青混合料,用于路面坑槽修补、铺筑路面面层或基层的整套工艺技术.在这个变化中,沥青老化是一个重要的方面,其次是对RAP料的性能评价,本文通过对沥青老化和RAP料的分析评价,以数据说明这一变化中的相关指标的变化.     

钒钛钢渣配制AC-13型沥青混合料的研究

钒钛钢渣具有较好的力学和表面特性,研究了其作为AC-13型沥青混合料集料的可行性。结果认为,钒钛钢渣可以作为AC-13型沥青混合料的集料,该沥青混合料的配合比设计为:钒钛钢渣(4.75~13.2 mm)、钒钛钢渣粉(0.075~4.75 mm)、矿粉三者之比为58∶40∶2,外配油石比最佳比例为4.9%。     

论从实践理解世界的物质性和自然世界的先在性

马克思主义唯物论是一种物本主义形态的唯物论,还是一种超越物本主义形态、从实践理解世界的本质相关问题的实践的唯物主义的唯物论?这是一个我们必须搞清楚的有关马克思主义唯物论的本质规定性和精神实质的重大问题.在考察物本主义的唯物论及其思维方式的局限性的基础上,揭示了马克思主义唯物论是现代的、实践的唯物主义,并重点研讨了马克思主义唯物论关于从实践理解世界的物质性和自然世界的先在性的原理,以期为马克思主义唯物论进一步阐明人类世界的实践性原理奠定基础.     

Effect of cyproheptadine on the ultrastructure of the neurons of the arcuate nucleus in the hypothalamus of the rat

The data are presented on changes in the rat arcuate nuclear neuron ultrastructure after using cyproheptadine (peritol, Egyt Pharmaceutical Works, Hungary) in a water suspension at a dose of 20 mg/kg once daily during 7 successive days and twice a day within 10 days. It was shown that cyproheptadine decreases the functional activity of the arcuate nuclear neurons, depending on the total amount of the drug used. Cyproheptadine-induced inhibition of the forming neurohormone release from neurons is likely to be one of the mechanisms of its therapeutic effect in Itsenko-Cushing's disease.     

Characteristics of the sympathetic innervation of the nictitating membrane and of the vasculature of the nose and tongue of the cat

Vasomotor responses from the nasal mucosa and tongue, and contractions of the nictitating membrane, were recorded on stimulation of the cervical sympathetic or internal carotid nerves. Preganglionic sympathetic nerve fibres which elicited a membrane response possessed a lower threshold than those which evoked nasal vasoconstriction, while the latter displayed a lower threshold than fibres which evoked tongue vasoconstriction. The sympathetic vasodilator fibres to the tongue whose activity was revealed after alpha-receptor blockade, had a similar threshold to the vasoconstrictor fibres. Membrane contraction, nasal vasoconstriction and occasionally tongue vasoconstriction could be evoked by stimulating the internal carotid nerve. The postganglionic fibres innervating the nasal mucosa had a similar threshold to those of the nictitating membrane, which may indicate that there are small myelinated fibres innervating the mucosa. The preganglionic compound nerve action potential had four major components, S1-S4. S1, S2 and usually S3 fibres were associated with membrane contraction; S2, S3 and sometimes S1 fibres were associated with nasal vasoconstriction; and S3, usually S2 and occasionally S1 fibres were associated with vasoconstriction in the tongue. It is concluded that each of these three groups of nerve fibres, but not S4 fibres, may include fibres associated functionally with the three effectors. There was a considerable difference between the relative amplitude of the responses of the three effectors elicited by stimulation of the cervical sympathetic nerve at frequencies between 0.2 and 2 Hz. Vasoconstrictor responses were relatively larger than membrane contractions suggesting differences in the mechanisms of neurotransmission at the neuroeffector junctions.     

Structure of the attachment of the vocal ligament to the perichondrium of the thyroid cartilage

The ventral attachement of the ligamentum vocale of eleven larynges (new-born and adults has been studied in sagittal, frontal and horizontal sections. 1. Supplementary to the known structure of the ventral attachement of the ligamentum vocale we have noticed collagen fibers which ascend in the inner angle of the thyroid cartilage and which partly cross to the other side. Sometimes a few fibers which are running downward have been observed. This structure of the attachement must be more firm than the known structure. 2. Moreover it has been observed that a lot of the angles of the crossing collagen fibers in the cartilage of the lamina mediana (near the attachement of the ligamentum vocale) are right-angled, whereas the angles of the fibers which lie in the laminae laterales in their majority are acute-angled. This phenomenon also is interpreted as a structure which makes the lamina mediana firmer. The fact, that this structure is not so evident in the specimens of the new-born as in those of the adults indicates that there are postnatal changes in the structure of the lamina mediana.