共查询到20条相似文献，搜索用时 62 毫秒
1.
对一种基质沥青和3种硅藻土沥青进行了差示热扫描分析,并结合相应的混合料约束试件的温度应力试验分析了硅藻土沥青的低温抗裂机理.结果表明:硅藻土沥青有优于基质沥青的低温性能;玻璃态转化温度可以较好地反映硅藻土沥青的低温性能;玻璃态转化温度与破断温度有较高的相关性.另外还进行了相应的4种沥青混合料的低温弯曲试验、低温压缩试验和收缩系数试验.结果表明:硅藻土沥青混合料的低温性能优于基质沥青混合料;硅藻土沥青混合料临界弯曲应变能密度及压缩应变能密度均大于基质沥青混合料;沥青混合料加入硅藻土后收缩系数降低.在此基础上,从混合料收缩性能和破坏能量2个角度分析了硅藻土沥青混合料的低温抗裂机理. 相似文献
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钢铁生产过程中固体废弃物钢渣掺入沥青混合料中,本文通过分别对掺钢渣沥青混合料和掺碎石沥青混合料两种类型的路面材料进行一系列力学性能的比对试验,检验掺钢渣沥青混合料路用性能的高温状态下的稳定性、水稳定性和劈裂强度进行检验,根据试验分析结果,以评价掺钢渣沥青混合料路用性能。 相似文献
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沥青混合料的抗裂性能在很大程度上决定了沥青路面的使用寿命,其粗集料骨架及细观介质成分（FAM）等内部结构组成的差异又会影响沥青混合料的抗裂性能。纤维因其优异的物理力学特性被广泛应用于提升沥青混合料的抗裂性能,为了有效表征纤维沥青混合料的瞬时损伤演化并评估其断裂特性,开发了一种新型测试方法,通过原位动态拉伸（ISDT）试验对沥青混合料细观损伤断裂性能进行表征。为了研究纤维沥青混合料细观损伤与宏观断裂性能之间的关系,设计添加和不添加纤维的沥青混合料,进行宏观半圆弯拉（SCB）及细观ISDT试验,定义荷载-位移曲线的特征参数表征其抗裂性能,并实时观测细观裂纹密度扩展情况。结果表明,随着纤维用量的增加,沥青混合料和FAM的断裂能和断裂韧性有相当的增加趋势,且沥青混合料及FAM的裂纹萌生及扩展存在滞后效应。因此,ISDT试验是评价纤维沥青混合料细观损伤断裂性能的一种有效手段。 相似文献
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浇注式沥青混合料高温性能研究 总被引：5，自引：0，他引：5
车辙是正交异性钢桥面沥青混凝土铺装主要病害之一 .采用汉堡轮辙试验机 ,提出了适宜于德国、考察浇注式沥青混合料高温性能的试验条件 ,测试和比较了不同浇注式沥青混合料的高温性能 .聚合物改性沥青混合料具有较高的抗车辙能力 .滞留时间和拌和频率对浇注式沥青混合料的性能有明显的影响 相似文献
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钢桥面铺装用热固性环氧沥青混合料动态模量试验研究（英文） 总被引：1，自引：0，他引：1
为了研究热固性环氧沥青混合料的动态性能,对环氧沥青混合料的动态模量进行了试验研究.首先,通过简单性能试验（SPT）测试了不同温度与加载频率下的环氧沥青混合料动态模量,并分析了温度与加载频率对动态模量的影响.然后,分别对环氧沥青混合料的静态模量及其他常用沥青混合料的动态模量进行了试验测试,并将其与环氧沥青混合料的动态模量做了对比.最后,利用时温等效原理建立了环氧沥青混合料动态模量主曲线.研究结果表明：环氧沥青混合料的动态模量随加载频率的增加而增加,随加载温度的升高而降低;更符合实际车辆作用的环氧沥青混合料的动态模量较静态模量大得多;环氧沥青混合料的动态模量较SBS改性沥青混合料与普通沥青混合料大.研究成果可为钢桥面铺装的设计及力学分析提供理论依据. 相似文献
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在基层或面层使用沥青混合料时经常发生冻融问题.本文重点介绍了空隙率对沥青混合料抗冻融性能的影响以及沥青混合料低温抗裂性的评价方法. 相似文献
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为了研究胶浆对沥青混合料粘弹性力学响应的影响,采用沥青混合料性能试验（AMPT）对不同粉胶比、纤维掺量、水泥替代矿粉量的沥青混合料进行力学性能试验研究,分析了粉胶比、纤维、水泥替换量对沥青混合料动态模量和相位角等粘弹性力学参数的影响。结果表明,随着粉胶比和纤维掺量的增加,动态模量均先增大后减小,而且加载频率越高,动态模量差异越显著;低粉胶比的混合料相位角最大,较高粉胶比的沥青混合料的相位角差异较小;掺加纤维沥青混合料相位角的变化与加载频率密切相关,掺加纤维可以显著增强沥青混合料的抗永久变形能力;水泥替代矿粉对沥青混合料的粘弹性影响相对较小,可在一定程度上改善沥青混合料的高温抗变形性能。 相似文献
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研究了4种粗集料针片状颗粒含量(0%,原状,30%,40%)对多孔沥青混合料骨架结构和性能的影响.分别采用二维数字图像处理、飞散试验、混合料破碎试验以及渗透试验,评价针片状对多孔沥青混合料的体积指标、骨架接触特性、耐久性、骨架稳定性和渗透性能的影响.试验结果表明:针片状含量对多孔沥青混合料的空隙率、骨架接触线长度、骨架接触点个数、集料破碎率和渗透系数具有显著的影响.由于粗集料针片状的破碎,多孔沥青混合料的有效空隙率、高温性能、长期耐久性以及骨架稳定性随着针片状含量的增大而衰减.与传统密级配沥青混合料相比,由于多孔沥青混合料具有开级配骨架,从而对针片状含量更加敏感,多孔沥青混合料应采用更严格的针片状含量要求. 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
13.
Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
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陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
19.
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
20.
Anton Franks 《English in Education》1999,33(2):39-49
This paper looks at the way drama works to bring a model of an arts curriculum into reality. He also shows how drama is valuable when discussed as a separate, autonomous subject in the school curriculum as opposed to one subsumed within English. He argues for a view of the arts and gives an example of a sequence of work in an English GCSE class based around Arthur Miller's play View from the Bridge. From this he draws out several strands about the relationship of the drama curriculum to the individual students and teachers, the school, and to culture. He also emphasises the primacy of performance in drama education. 相似文献