轮胎压路机在沥青混合料摊铺层碾压中的作用探讨

应用力学原理,研究了轮胎压路机在碾压热拌沥青混合料时充气轮胎与沥青混合料的相互作用,进一步分析了充气轮胎在压实过程中的揉压机理和作用,并对轮胎压路机与光轮压路机及振动压路机,在压实沥青混合料摊铺层时的性能进行了对比研究。结果表明,轮胎压路机压实沥青混合料摊铺层能得到更高的压实质量,应选用轮胎压路机作为沥青混合料复压的主要机械。     

轮胎压路机压实热拌沥青混合料的机理和作用

本文利用了应用力学原理研究了轮胎压路机在碾压热拌沥青混合料时充气轮胎与沥青混合料的相互作用进一步分析了充气轮胎在压实过程中的揉压机理和作用,并对轮胎压路机与光轮压路机及振动压路机在压实沥青混合料摊铺层时的性能进行了对比研究。结果表明．轮怡压路机压实沥青混合料摊铺层能得到更高的压实质量,应选用轮胎压路机作为沥青混合料复压的主要机械。     

乳化沥青厂拌冷再生混合料的加热碾压方法

在常温下拌合和摊铺乳化沥青厂拌冷再生沥青混合料;然后,采用红外线或微波辐射加热摊铺后的再生沥青混合料,使底层混合料的加热温度为140℃～160℃,表层混合料的加热温度为150℃～170℃;最后,采用双钢轮压路机和轮胎压路机碾压加热后的沥青混合料至95%～100%的压实度。加热碾压工艺使得冷再生混合料中旧沥青和新添加的沥青加热融化后,在碾压过程中共同渗透、扩散到矿料表面,在矿料颗粒之间起黏结作用,提高了再生混合料的黏结强度,回收混合料中的旧沥青得以充分利用。具有广泛的应用前景。     

沥青混合料面层平行四边形推进碾压数理分析

为了有效提高沥青混合料面层的压实度和平整度,在有效碾压作用时间的基础上,通过建立数学模型,从理论上分析了平行四边形推进法压路机前进距离L1与倒退距离L2确定的方法。研究结果表明：采用平行四边形推进法,可有效提高沥青混合料面层的均匀度;前进距离L1和后退距离L2要根据压路机运行的速度、摊铺速度、始终点温度和外界环境温度等因素综合考虑;适当选择L1和L2就可实现四的倍数的多遍压实,便于自动控制;并且在摊铺机连续摊铺的过程中,压路机不得随意停顿。压路机不得在未碾压成型并冷却的路段上转向、调头或停车等。     

沥青混合料压实特性及沥青路面碾压遍数确定

在研究沥青混合料压实特性的基础上,从能量等效角度确定沥青路面达到密实所需要的碾压遍数.首先对典型沥青混合料进行室内击实试验,得出不同类型沥青混合料达到要求密实度所需要的能量;然后依据理论计算与现场实测,得到了施工过程中摊铺机振捣提供给路面的能量及振动压路机和轮胎压路机一次碾压提供给沥青路面的可吸收能量.室内击实试验表明...     

桥面铺装施工中振荡压实技术的应用

结合邵怀高速公路第37,41合同段桥面沥青混合料铺装施工振荡压路机的实际应用,对采集的沥青路面的压实度增长率、横向压实度的均匀度和平整度等技术参数进行了分析,阐述了振荡压路机压实的工作原理.振荡压路机实际应用效果表明,振荡压实技术在桥梁结构免受振动冲击影响的前提下,能够快速提高沥青混合料压实度的增长率,充分保证沥青混合料的压实度,有效地提高了桥面的平整度.     

连续摊铺的下层沥青混合料最佳预压实度的确定

为了研究连续摊铺是否存在下层最佳预压实度,预先设计按照6种不同的击实次数换算成0、7%、20%、33%、67%、100%的下层压实度。制作由两种不同级配组合的双层马歇尔试件,先检测其密度和孔隙率大小,再采用两种层间抗剪试验,分别检测其在常温、低温和冻融条件下的层间抗剪切性能。结果表明,双层连续摊铺沥青混合料的下层最佳压实度为33%,此时的沥青混合料层间抗剪切强度最大,且混合料密度最大。     

沥青混合料温度离析特性

借助红外摄像仪观察了不同条件下沥青混合料摊铺面的温度分布,分析了其温度离析的不同表现性状和温度差异的形成原因,利用无核密度仪(PQI)研究了温度离析对沥青面层压实质量的影响。研究结果表明:温度离析对沥青面层压实质量的影响与离析区域的形状、面积和温度有关;当较低温度区域面积较大、温度低于不可接受的初压(表面)温度时,温度离析对沥青面层压实质量的影响必须予以足够重视;当温度离析区域面积较小,较低温度区域摊铺面温度高于不可接受的初压(表面)温度时,即使相邻摊铺面温度差异较大,但从压实度的角度看,沥青面层的质量仍符合《公路沥青路面施工技术规范》(JTG F40—2004)的要求。     

水泥乳化沥青混合料施工和易性评价方法及影响因素

为了研究水泥乳化沥青混合料的施工和易性及其对压实性能的影响,基于沥青表面自由能理论,采用拌和扭矩表征该混合料的施工和易性。通过拌和和易性测试设备和旋转压实仪分别测定混合料的拌和扭矩和压实性能。通过抗压强度极差分析法确定常温下混合料的最优配合比方案,提出该混合料的拌和和易性评价方法及影响因素;根据拌和状态和拌和扭矩值确定10℃、25℃、40℃时混合料的最佳含水率与拌和时间的推荐值,并分析3种温度下不同摊铺模拟初压次数时的摊铺和易性对压实性能的影响。研究结果表明:含水率对混合料的拌和和易性有显著影响,10℃、25℃、40℃时的最佳含水率(质量分数)分别为5.25%、6%、6.5%,3种温度下混合料的推荐拌和时间均为12s;整体上随着温度的增加,试件空隙率随扭矩的增加逐渐下降,抗压强度随扭矩的增加而逐渐增大,最佳施工温度为40℃;10℃、25℃时的最佳初压次数为20,相应的试件密实度分别为84.3%和85%;40℃时最佳初压次数为30,相应的试件密实度为85.7%。采用给出的水泥乳化沥青混合料拌和和易性评价方法可为路面拌和施工工艺提供参考,最佳初压次数对应的密实度可对摊铺机振捣梁和熨平板频率参数的选择与优化组合提供参考。     

热沥青混合料碾压过程的离析现象

针对混合料不均匀导致路面早期损坏的问题，采用综合分析的方法，从碾压施工角度重点分析了热沥青混合料碾压过程的不均匀现象，通过分析可能造成沥青混合料碾压过程离析的多种原因，提出了碾压离析的概念。认为除热沥青混合料生产、摊铺和碾压可能造成碾压离析外，路面结构设计、施工工艺和压路机的设计与制造不合理也是造成碾压离析的3个重要原因。研究结果表明：造成混合料不均匀的原因很多，应该综合考虑混合料生产、摊铺和碾压，路面结构和施工工艺，以及压路机的设计等因素，才能进一步提高路面的质量。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

正~~     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with