核壳橡胶粒子改性沥青的高温贮存稳定性

主要采用乳液接枝聚合技术,合成核壳结构的聚丁二烯橡胶粒子接枝苯乙烯及少量沥青壳层结构的聚合物,共混改性基质沥青.通过考察核壳橡胶粒子改性沥青高温离析上下层的软化点及差值,DSC分析,以及内部分散形态结构,得到了高温贮存稳定的改性沥青.此时,改性沥青的软化点明显提高,离析差不超过1℃;沥青与核壳橡胶粒子发生作用使能产生吸热峰的组分向低温发生偏移,且峰值减小;橡胶相以区域网络结构均匀分散.     

全透式沥青路面专用高黏度改性沥青性能对比

为了制备一种全透式沥青路面专用高黏度改性沥青,采用自制改性粒子(SR)与SBS粒子为复配改性剂,对基质沥青进行复合改性。通过荧光显微照相、针入度试验、延度试验、软化点试验、薄膜老化试验、动力黏度试验及布氏黏度试验等,对自制高黏度改性沥青性能进行表征,并与SK90#基质沥青、橡胶沥青、SBS改性沥青进行性能对比。结果表明:各改性材料在基质沥青中分散良好,自制高黏度改性沥青中的SR粒子作为高弹嵌挤单元提高了沥青交联网状结构的稳定性;与基质沥青相比,改性沥青具有较高的软化点和延度,以及较低的针入度(25℃);自制高黏度改性沥青的动力黏度高达230kPa·s,明显高于橡胶沥青和SBS改性沥青;动态剪切流变试验(DSR))中自制高黏度改性沥青高温分级达到PG82℃,较SBS改性沥青和橡胶沥青提高1个等级,较基质沥青提高4个等级,高温变形可恢复性能最强;4种沥青的原样和薄膜老化后沥青中以自制高黏度改性沥青的车辙因子随温度变化最为缓慢,高温敏感性最弱,耐老化性能优异;弯曲梁流变试验(BBR)中,SBS改性沥青和自制高黏度改性沥青的低温分级均达到PG-18℃,较基质沥青和橡胶沥青高1个等级,但自制高黏度改性沥青的蠕变劲度较小,蠕变速率较大,具有更强的低温柔性。     

国产天然沥青对基质沥青路用性能的影响

为更好地将天然沥青应用于路面,通过在基质沥青中掺加不同剂量的四川天然沥青,对天然沥青改性沥青的高温性能、粘附性、低温性能和水稳定性等路用性能进行了分析。试验结果表明,将四川天然沥青掺加基质沥青能够大大提高和改善基质沥青的高温性、粘附性以及水稳定性,并且随着天然沥青剂量的逐渐增加,沥青由溶胶型沥青向溶—凝胶型沥青转化,其高温稳定性、粘附性及水稳定性逐渐增强。天然沥青对基质沥青的低温流变性则表现为双重性,低温延度有所下降,但当量脆点指标却得以改善,且其玻璃化温度相对于基质沥青有所升高。掺入天然沥青后改性沥青混合料在低温时的最大拉应变、抗弯拉强度和劲度模量均增加,表明低温抗裂性能总体上得以改善,但柔韧性有所下降。     

纳米CaCO_3-SBR复合改性沥青路用性能研究

纳米改性技术虽能较好地提升沥青高温性能,但其低温性能不甚理想。针对这一问题,采用纳米材料-聚合物复合改性技术,制备了一种新型沥青及其混合料。通过5℃延度、当量脆点和BBR等试验研究了其低温改善效果,并通过DSR、软化点、当量软化点、针入度指数、RTFOT等试验对其高温性能、温度敏感性和抗老化性能等进行了研究。采用低温弯曲试验对基质沥青、5%SBS改性沥青和纳米材料-聚合物复合改性沥青混合料的低温抗裂性进行比较分析,并通过车辙试验、浸水马歇尔试验和冻融劈裂试验对其混合料高温抗车辙性能和水稳定性进行评价。试验结果表明:纳米CaCO_3-SBR复合改性沥青及其混合料明显改善了基质沥青的低温性能,且具有令人满意的高温抗车辙性能。纳米材料-聚合物复合改性沥青具有良好的低温抗裂性,可作为寒冷地区路面铺装材料。     

3种添加剂对改性沥青性能影响的测试与评价

对TPS、路孚8000和Sasob it三种新型沥青添加剂的改性效果进行了系统测试和分析,考虑到常规试验和评价指标在评价改性沥青性能时存在的不足,本文利用沥青稠度测试仪和测力延度仪,并引入能表征沥青结合料高温性能的稠度指标、反映沥青低温性能的测力延度以及评判温度敏感性能的稠度—温度指数等新的评价指标,评价了添加剂对沥青的改性效果。结果表明:新指标能很好的评价改性沥青的高温、低温和温度敏感性能,路孚8000对沥青各项性能改善明显。     

复合工艺橡胶沥青混合料的性能

为了对复合工艺的橡胶沥青技术指标及其混合料路用性能进行研究,在制备橡胶改性沥青时掺入适量裂解剂,确定合理的制备温度和时间;对4种复合工艺橡胶沥青混合料的水稳定性能、低温弯曲性能及疲劳性能进行耐久性试验.结果表明:裂解剂质量分数为0.4%的橡胶沥青,以制备温度190℃,制备时间2 h为宜;掺加裂解剂的橡胶沥青混合料具有优异的高温、低温以及抗水损害性能,其动稳定度甚至是基质沥青混合料的3倍左右;复合工艺的橡胶沥青混合料具有优异的抗水损害、抗疲劳破坏性能以及抗低温弯曲性能,其弯拉破坏应变甚至高于橡胶颗粒SBS改性沥青混合料.     

纳米改性沥青混合料路用性能

通过室内试验研究了纳米SiO2改性沥青混合料、膨润土改性沥青混合料、纳米SiO2/膨润土复合改性沥青混合料、纳米SiO2/膨润土/SBS复合改性沥青混合料的高温稳定性、低温抗裂性和水稳定性,并与基质沥青混合料和SBS改性沥青混合料进行对比.结果表明,纳米SiO2改性沥青混合料、膨润土改性沥青混合料、纳米SiO2/膨润土复合改性沥青混合料的高温稳定性较基质沥青提高了56%～77%,水稳定性提高了3%～7%,与SBS改性沥青相比则相差不大.其中,纳米SiO2/膨润土/SBS复合改性沥青混合料的高温稳定性和水稳定性最优,较SBS改性沥青分别提高86%和3%.纳米SiO2改性沥青混合料、膨润土改性沥青混合料和纳米SiO2/膨润土复合改性沥青混合料的低温抗裂性较基质沥青略有降低,但仍能满足沥青路面对低温抗裂性能的要求.因此,纳米改性沥青混合料具有优良的路用性能,可适用于沥青改性技术中.     

采用测力延度评价复合改性沥青的低温性能

将煤沥青与石油沥青共混,经SBS和橡胶粉改性制得复合改性沥青.针对不同改性剂以及不同的改性剂掺量,对复合改性沥青的测力延度进行分析,评价相关的指标屈服应变能E、拉断功W、韧性比R和柔量D5℃/F2对复合改性沥青低温性能的影响.结果表明,SBS复合改性沥青中,随着SBS含量的增大,其低温抗变形能力增强;在4％的SBS改性沥青中加入一定量的胶粉,其低温延度减小.     

基于化学改性的废胶粉复合 改性沥青性能与机理研究

为探究废胶粉复合改性沥青性能与改性机理,采用软化点、5℃延度、弹性恢复、动态剪切流变试验指标等来评价其性能,通过微观形貌观测、红外光谱图、差示扫描量热法进行微观分析,将其与普通胶粉改性沥青、基质沥青进行对比,分析废胶粉复合改性沥青的改性机理.结果表明,废胶粉复合改性沥青具有更高的PG高温等级,表现出更好的高温性能;储存48 h废胶粉复合改性沥青仅有少量的废胶粉大颗粒开始被沥青胶团吸附并下沉,至储存72 h后才出现明显的离析现象,储存稳定性能得到明显改善;微观形貌下废胶粉复合改性沥青大部分胶粉颗粒均匀分散在沥青中,排列致密,形成亚均相结构;废胶粉复合改性沥青表现为物理共混改性的同时存在化学反应;相较于单一的物理改性,在复合改性的作用下,整个体系呈致密交联型网络状结构,使得分子间结合牢固,低温性能方面表现更好.     

沥青胶结料的测力延度试验研究

改性沥青的流变特性较为复杂，简单的常规试验方法不能很好地测出其特性．文中通过对基质沥青、SBS改性沥青、APAO和SBR改性沥青胶结料进行大量测力延度试验，分析了基质沥青、改性沥青的拉伸特性，证明了测力延度试验是评价改性沥青胶结料性能的一种有效方法，它可以作为一种简单、快捷判定沥青胶结料种类的方法，并有助于选择出性能优良的沥青胶结料．     

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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。     

A computer generator for randomly layered structures

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

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

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.