排水性沥青混合料热老化性能

为了研究排水性沥青混合料的热老化性能,首先研究了沥青混合料的热老化机理,然后通过对比分析确定了排水性沥青混合料的短期和长期热老化试验方法,最后对3种不同空隙率的排水性沥青混合料,分别研究了热老化对其高温稳定性、低温抗变形能力和抗水损害性能的影响规律。研究结果表明:热老化使结合料变脆,劲度模量变大,沥青混合料的动稳定度变大;相同热老化时间,随空隙率的增大,动稳定度增大,空隙率高的排水性沥青混合料低温抗弯拉破坏和抗收缩应力的能力越低;在同一空隙率下,排水性沥青混合料的最大弯拉强度和最大弯拉应变在老化后均减小;经过热老化处理后,排水性沥青混合料的抗水损害性能有所提高;在热老化时间相同条件下,空隙率越大,其抗水损害的能力就越差。     

沥青混合料室内加速热氧老化特性与预估研究

为了探明沥青混合料室内加速热氧老化的特性并进行预估,研究采用沥青混合料加速老化系统,利用阿布森法回收沥青进行相关指标测试,建立了与LTOA老化时间与温度的对应关系,对SBSⅠ-C改性沥青AC-13沥青混合料进行加速老化试验,并基于试验结果建立了沥青混合料加速老化性能衰减预估方程。研究结果表明：对沥青混合料在175℃下进行老化后回收的沥青与原样沥青旋转薄膜烘箱加热试验在相同老化时间内的技术指标相仿;随着老化时间的延长,沥青混合料的残留稳定度、TSR逐渐降低;动稳定度逐渐升高;本文所建立的沥青混合料加速老化性能衰减预估方程与试验数据具有较高的相关性。     

沥青混合料室内加速热氧老化特性与预估

为了探明沥青混合料室内加速热氧老化的特性并进行预估,研究采用沥青混合料加速老化系统,利用阿布森法回收沥青进行相关指标测试,建立了与LTOA老化时间与温度的对应关系。对SBSⅠ-C改性沥青AC-13沥青混合料进行加速老化试验;并基于试验结果建立了沥青混合料加速老化性能衰减预估方程。研究结果表明:对沥青混合料在175℃下进行老化后回收的沥青与原样沥青旋转薄膜烘箱加热试验在相同老化时间内的技术指标相仿;随着老化时间的延长,沥青混合料的残留稳定度、TSR逐渐降低;动稳定度逐渐升高。所建立的沥青混合料加速老化性能衰减预估方程与试验数据具有较高的相关性。     

拌合时间对掺Duroflex~抗车辙剂沥青混合料高温稳定性的影响

为了探讨掺加Duroflex的沥青混合料拌合时间对其抗车辙性能的影响,对不同拌合条件下的AC-20C沥青混合料进行了车辙试验。试验结果显示,基质沥青和SBS改性沥青混合料的动稳定度都随着拌合时间的延长而降低;拌合时间从3min延长至11min时,基质沥青混合料动稳定度减低比率为49%,而SBS改性沥青动稳定度降低比率高达74%,SBS改性沥青掺加3%Duro的动稳定度降低比率为29%;不同拌合时间会对沥青混合料动稳定度产生较大影响,在同等试验条件下掺加Duroflex能够提高沥青混合料的动稳定度。     

干法TPCB改性沥青AC-13混合料制备参数

为确定干法TPCB改性沥青AC-13混合料的制备参数,研究TPCB掺量、拌合时间、拌合温度和矿料加热温度对动稳定度和冻融劈裂强度比的影响规律,通过直观分析、方差分析和多因素相互作用分析方法,确定干法TPCB改性沥青混合料制备参数,检验干法TPCB改性沥青混合料室内性能.研究结果表明:TPCB掺量对动稳定度和冻融劈裂强度的影响最大;室内制备程序将加热温度为170~180 ℃的粗细集料和10%TPCB置于拌合机干拌15 s,然后加入160 ℃基质沥青湿拌90 s,最后加入加热的矿粉拌和90 s,拌合温度为170~180 ℃;干法TPCB改性沥青AC-13混合料具有良好的高温性能与水稳定性能.     

基于使用性能的浇注式沥青混凝土设计

针对钢桥面铺装浇注式沥青混凝土使用中容易出现的高温车辙、疲劳开裂问题,提出浇注式沥青混凝土"四阶段设计法"确保高温性能与疲劳性能的平衡;基于黏弹力学原理,提出动稳定度为浇注式沥青混凝土高温性能评价指标,通过大型加速加载试验进行验证其可靠性;基于断裂力学和能量法原理,提出冲击韧性为浇注式沥青混凝土疲劳性能评价指标,通过试验建立起冲击韧性和四点弯曲疲劳寿命的关系。研究结果表明:动稳定度可准确反映浇注式沥青混凝土高温抗变形能力;冲击韧性和疲劳性能之间有良好的线性相关性,采用冲击韧性能有效评价浇注式沥青混凝土疲劳性能。     

紫外光及温度老化对冷拌冷铺乳化沥青混合料的性能影响评价

目的 研究紫外光及温度老化对冷拌冷铺乳化沥青混合料(CMA)高温稳定性、低温抗裂性及水稳定性的影响.方法 基于CMA与热拌沥青混合料(HMA)的对比分析,在紫外光老化方面,通过Verhulst生物模型建立沥青混合料各项性能与紫外光老化时间的关系方程,提出紫外光老化速率评价指标,评价各项性能的紫外光老化速率;在温度老化方...     

泡沫沥青及其温拌混合料高温性能分析

为研究泡沫沥青及其温拌混合料高温性能,采用动态剪切试验(DSR)分析沥青样品发泡前后在原样及短期老化(RTFOT)条件下的高温性能及沥青在经历发泡过程后的性能变化;通过动稳定度和动态模量试验评价泡沫沥青温拌混合料及热拌沥青混合料的高温性能,基于动态模量试验数据拟合得到沥青混合料动态模量主曲线及位移因子,并与热拌沥青混合料的高温性能进行对比。结果表明:采用动态剪切试验(DSR)得到沥青抗车辙因子结果与其混合料高温性能有良好的相关性;基于动态模量主曲线方法可以更全面的评价沥青混合料的高温性能。     

沥青软化点和环境温度对混合料高温稳定性的影响

分别对基质沥青和改性沥青不同温度下的车辙试验结果进行分析,分析结果表明:环境温度对沥青混合料的高温稳定性有显著影响,特别是当路面温度达到沥青软化点附近时,沥青混合料的动稳定度将出现大幅度下降.无论普通重交沥青混合料还是改性沥青混合料,在其动稳定度与温度之间的关系曲线上都存在一个动稳定度相对保持不变的温度区域,这个温度区域可称为高温抗变形的临界温度.当温度超过沥青混合料高温抗变形的临界温度后,其抗变形能力急剧下降.据此,可以根据工程项目的路而最高设计温度选择沥青及混合料,即所采用的沥青与混合料的临界温度必须高于路面最高设计温度.     

TLA改性沥青及其混合料氯盐侵蚀作用下的性能

为研究不同盐雾作用时间和不同盐雾浓度作用对TLA改性沥青老化性能的影响,采用盐雾试验箱模拟沿海地区的盐雾环境,通过对TLA改性沥青老化前后的针入度、软化点和延度的分析,对盐雾侵蚀后的基质沥青和TLA改性沥青混合料的高温稳定性进行探究。结果表明,TLA改性沥青比基质沥青更能抵抗氯盐盐雾侵蚀,具有更好的耐腐蚀性,盐浓度变化对沥青混合料动稳定度的影响比盐蚀作用时间对其影响更大,盐浓度的增加会比盐蚀作用时间的增加更能造成沥青混合料的高温稳定性的破坏,沥青混合料的动稳定度和变形量都与盐蚀浓度和盐蚀作用时间呈线性相关的关系。     

超强超短激光与固体靶相互作用产生准静态磁场的研究

建立了一个超强超短激光脉冲与固体密度等离子体相互作用，产生超热电子和环形磁场的简单模型，通过演算，得到了在相互作用过程中，有质动力，超热电子，自生磁场三者之间的关系。     

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…     

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。     

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     

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     

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

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

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.