矿物掺合料对水泥砂浆干缩性能影响的研究

在保持砂浆中单位体积用水量和骨料用量相同的情况下，分别研究粉煤灰（细度为720m^2／kg）、矿渣粉（细度368m^2／kg）、硅粉（细度为16200m^2／kg）等体积取代水泥对砂浆干缩性能影响的规律．结果表明：用粉煤灰取代水泥使砂浆干缩率下降，且取代量变化对干缩的影响不大；用矿渣取代水泥使砂浆干缩率略有增加，且取代量变化对干缩影响不大；用硅灰取代水泥使得砂浆干缩率增加，而且随着取代量增加，干缩率增加。     

高速公路水泥稳定碎石基层干缩特性浅析

分析了路面基层中对水泥稳定碎石干缩特性的影响因素,对用干缩抗裂系数指标评价水泥稳定碎石混合料抗干缩能力进行了探讨。     

水泥粉煤灰稳定炉渣-煤矸石混合料的收缩试验

利用炉渣、粉煤灰和煤矸石配制路面基层混合料可以有效利用工业固废，基层混合料收缩性能的优劣直接决定了其路用性能。文中选用0~4.75 mm粒径炉渣按照不同比例（0、25%、50%、75%、100%）替代同粒径的煤矸石，采用掺入3%、4%、5%和6%的水泥，设计了8组水泥粉煤灰稳定炉渣-煤矸石混合料试验，通过温缩和干缩试验，分析了炉渣替代率和水泥掺量的变化对混合料收缩性能的影响规律。结果表明：温缩应变随炉渣替代率的增大而增大，随水泥掺量的增大而减小，-10~-20℃时温缩系数较大；干缩应变随炉渣替代率的增大而减小，随水泥掺量的增大而增大；干缩应变在7 d龄期内增长速率较快，30 d龄期内的干燥收缩率占整个龄期的86.5%，30 d龄期后干缩应变逐渐趋于稳定；当水泥掺量为5%，炉渣替代率为50%~75%时，混合料的干缩系数和温缩系数均较小。     

基于干缩变形特性的水泥稳定碎石级配组成

根据目前国内高速公路水泥稳定碎石基层的使用情况，针对苏南地区高温多雨，水泥稳定碎石基层在湿度变化时易产生干缩裂缝这一缺陷，提出了改善收缩性能、减少干缩量的水泥稳定碎石混合料的级配组成范围及级配组成设计方案，分析了不同级配组成对干缩变形特性的影响．     

水泥乳化沥青稳定碎石基层收缩特性

由于水泥稳定碎石基层干缩、温缩较大,容易引起路面反射裂缝,提出用水泥乳化沥青复合胶浆来稳定碎石作为一种抗收缩能力较强的新型基层材料.在分析半刚性基层的收缩机理和水泥乳化沥青稳定碎石的微观结构后,进行了干缩试验和温缩试验,并利用室内试验结果计算了水泥稳定碎石和水泥乳化沥青稳定碎石两种混合料作为基层应用时的干缩应力和温缩应力.通过分析比较,水泥乳化沥青稳定碎石的干缩应力和温缩应力更小,表明其抗收缩性能更好,能较好地延缓基层开裂.     

外加剂在硫铝酸盐水泥系统中的作用

研究外加剂对硫酸铝盐水泥凝结时间，强度，抗渗性，抗化学侵蚀性及抗干缩性的影响，并采用XRD，SEM和DTA等测试方法分析了探讨了其作用机理。结果表明，有机外加剂可以明显延长硫铝酸盐水泥的凝结时间；烧石膏取代二水石膏后不仅可以提高水泥各龄期的强度，而且可以抑制基后期强度的倒缩；这种水泥的抗渗性，抗化学侵蚀性及抗干缩性能都比较好。外加剂的加入改善了硫铝酸盐水泥的性能。     

水泥粉煤灰稳定碎石配合比设计

通过强度、干缩和冲刷试验，研究了水泥粉煤灰稳定碎石混合料的组成结构对混合料强度的影响，水泥质量分数与粉煤灰质量分数的最优比例，水泥质量分数及结合料总质量分数对混合料干缩和冲刷性能的影响。提出了混合料配合比设计方法：首先测试低质量分数水泥7d龄期抗压强度，以确定混合料的最优集料质量分数；接着以后期抗压强度增幅指标（180d／28d）确定水泥质量分数与粉煤灰质量分数的最优比例；最后从抗冲刷和抗干缩性能考虑，前两步选定的配合比水泥质量分数应控制在3％-5％之间，结合料总质量分数不应超过25％。     

水热条件对硅酸盐水泥的水化及其干缩性能的影响

通过强度试验、干缩测定、MIP、TG-DSC、NMR分析,研究了不同水热条件下硅酸盐水泥的早期（3 d）水化及其干缩性能。结果表明：约2 d时间的水养护温度由20℃提高到60℃,水泥的早期（3 d）水化程度显著提高,C-S-H凝胶数量显著增多,同时C-S-H凝胶的硅酸盐聚合度提高,C-S-H的表面积减小,致密度提高;水泥的3 d强度显著提高,但28 d强度明显下降;水泥的干缩显著减小。养护温度提高减小干缩的原因是由于干燥前C-S-H凝胶的化学结构等发生变化而使水泥的不可逆干缩显著减小。     

土凝岩新型固化剂稳定路基粉质黏土的干缩性能

为探究土凝岩新型固化剂稳定路基粉质黏土的干缩性能,对粉质粘土添加土凝岩新型固化剂和传统固化剂水泥后的干缩进行对比试验探究,并利用IBM SPSS Statistics与MATLAB数据处理软件对两种固化土进行无重复双因素回归曲线估计分析,结果表明:水泥掺量6%与土凝岩固化剂掺量8%固化土的干缩应变较小,两种固化土在失水率达到最优含水率左右出现干缩应变最大值,同时前15天所产生的干缩应变在整个稳定应变的80%之上,固化剂的干缩应变与失水量(相应的含水量)关系较密切且掺量对干缩应变的影响大于时间因素,土凝岩新型固化剂的前期保水性较优可延缓与减小收缩,利用时间与干缩应变倒数回归曲线方程式反映实际固化土干缩应变。整体这种新型固化剂不仅充分利用了工业废料并在干缩性能上还略优于水泥,说明这种经济环保土凝岩新型固化剂在稳定粉质黏土的干缩性能上可代替水泥使用。     

不同类型半刚性基层材料性能的试验与分析

采用石灰粉煤灰稳定碎石、水泥稳定碎石及水泥粉煤灰稳定碎石进行干缩试验,对比研究3种半刚性材料的累积干缩量、失水率、累积失水率和干缩系数4个性能指标;对3种半刚性材料进行温缩试验,通过温缩系数对比,分析其温缩特性;通过抗压回弹模量试验和抗弯拉回弹模量试验,对比研究了其力学特性;对3种半刚性材料进行疲劳试验和冲刷试验,对比分析其耐久性。研究结果表明：3种半刚性材料干缩性能的优劣顺序为：石灰粉煤灰稳定碎石、水泥粉煤灰稳定碎石、水泥稳定碎石;温缩性能的优劣顺序为：水泥粉煤灰稳定碎石、石灰粉煤灰稳定碎石、水泥稳定碎石;抗冲刷性能的优劣顺序为：石灰粉煤灰碎石、水泥粉煤灰稳定碎石、水泥稳定碎石;水泥粉煤灰稳定碎石的抗疲劳性能优于水泥稳定碎石。     

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.     

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.     

A computer generator for randomly layered structures

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

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.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the