木素减水剂对水泥生料浆的分散作用

以磺化改性木素为例 ,从磺化改性木素水溶液的表面张力、水泥料浆颗粒表面吸附量及其沉降性能等三个方面研究了木素减水剂对水泥生料浆的分散作用。通过实验测定发现 :减水剂能够极大地降低溶液的表面张力 ,并被大量吸附在水泥生料浆颗粒的表面 ,降低了水泥颗粒的表面能 ,从而改变了沉降性质 ,表现出较好的分散作用     

酸析木素的接枝磺化改性及减水增强作用

通过接枝反应在酸析木素上引入活性分子链,提高其磺化活性,得到接枝磺化酸析木素;采用红外光谱研究了接枝磺化酸析木素的分子结构,并对其减水增强性能进行了研究.结果表明:接枝磺化酸析木素分子中含有较多的磺酸基和酚羟基,分子中的甲氧基被活性基团所取代,使产物具有更大的活性;接枝磺化酸析木素以70%和60%的用量(占减水剂总掺量的百分数)与木钙复配,可分别得到减水剂MCL1和MCL2,当水灰比为0.28、掺量为0.6%时,掺复配产品的水泥净浆流动度达230mm以上,掺量为0.8%时,掺复配产品的水泥净浆初凝时间延长50~80min,终凝时间延长6~7 h;掺MCL1的砂浆的减水率为25.5%,7天和28天抗压强度比分别为135%和123%,其对水泥的减水增强作用与萘系高效减水剂FDN相当.     

改性木质素磺酸盐表面活性剂合成及性能研究

以草浆或木浆碱木素为原料,经过与脂肪多胺的曼尼希反应、与油酰氯的酰化反应和磺甲基化反应,合成了一系列含有酰胺结构的改性木质素磺酸盐表面活性剂．对改性木质素磺酸盐界面性能进行了测试,讨论了表面活性剂质量分数及碱质量分数对界面张力的影响．结果表明改性产品具有非常优良的界面活性,单独使用即可在较宽的表面活性剂质量分数和碱质量分数的变化范围内,形成超低油-水界面张力,符合三次采油的基本要求．     

木质素磺酸钙减水剂在碱矿渣水泥系统中的吸附作用研究

本文通过测试木钙表面活性剂的掺量、激发剂品种、掺量等对表面活性剂在矿渣表面的吸附量的影响,结果表明：在碱矿渣水泥系统中,矿渣颗粒对木钙减水剂的吸附量随系统碱浓度（氧化钠当量）升高而降低;水玻璃模数对矿渣颗粒对表面活性剂的吸附量的影响为,当水玻璃模数在1.0到2.0范围内时,水玻璃模数越高,表面活性剂在矿渣颗粒表面的吸附量越小。     

混凝土高效减水剂的性能与作用机理

提出了一系列表征混凝土高效减水剂的方法，通过对表面张力，活性吻含量，附量和ζ电位的测定，从微观上研究了高效水剂的作用机理，分析了造成坍落度损失的原因。     

混凝土高效减水剂

混凝土高效减水剂又称超塑化剂,是一类高分子缩聚物,根据它的化学组成可分为萘磺酸盐甲醛缩聚物、三聚氰胺甲醛缩聚物和改性木质素磺酸盐等三类。它出现在本世纪六十年代。1963年日本花王石碱公司首先研制成了一种以β-萘磺酸盐甲醛缩聚物为主要成分的高效减水剂,其商品名为迈蒂(mighth)。日本用这种     

高氧化铁粉煤灰影响聚羧酸减水剂吸附特性的机理

采用净浆流动度、ζ电位、总有机碳(TOC)、红外光谱等实验,研究粉煤灰中氧化铁含量对不同结构聚羧酸减水剂吸附性能的影响,探讨氧化铁影响聚羧酸减水剂对水泥分散性能的机理,并提出了相应改进方法.结果表明:粉煤灰中氧化铁含量对掺不同结构聚羧酸减水剂的水泥净浆流动度均有很大影响,当氧化铁质量为粉煤灰总质量的18%时相应浆体基本失去流动性;加入硫化钠能使氧化铁与聚羧酸减水剂的吸附性能降低,浆体流动度有所改善.高氧化铁粉煤灰对聚羧酸减水剂的吸附性很强,与普通Ⅱ级粉煤灰相比,外加剂溶液中有机碳的含量要减少1/3.电泳实验表明:氧化铁的含量越多,体系ζ电位绝对值越小,分散稳定性越差.红外光谱表明:硫化钠的加入降低了高氧化铁粉煤灰对聚羧酸减水剂的吸附.     

脂肪族高效减水剂的合成与性能

丙酮，甲醛和亚硫酸钠为主要原料合成了脂肪族羟基磺酸盐类高效减水剂，讨论了合成条件对产物分散性能的影响并研究了这类高效减水剂的应用性能。丙酮，甲醛和亚硫酸钠在一定摩尔比条件下，通过适当的混合和加入，在90～93℃时反应3h。所得的产物脂肪族羟基磺酸盐高效减水剂HAF具有良好的分散性能。合成的高效减水剂HAF对水泥净浆有轻微缓凝作用；在混凝土中掺量为0．5％时，减水率达到19％，且具有明显的早强和增加抗压强度的特性。     

减水剂对新拌混凝土表观粘度的影响机理

分析减水剂对新拌混凝土表观粘度的影响机理,指出减水剂是一种表面活性剂,它吸附在新拌混凝土的颗粒表面,降低颗粒表面自由能,增大ξ电位,从而增大了新拌混凝土颗粒的分散性,降低了表观粘度。另外,减水剂的掺入可使水泥颗粒湿润,可使水泥颗粒之间的滑动能力增强,因此降低了新拌混凝土的表观粘度。     

减水剂对新拌混凝土表观粘度的影响机理

分析减水剂对新拌混凝土表观粘度的影响机理 ,指出减水剂是一种表面活性剂 ,它吸附在新拌混凝土的颗粒表面 ,降低颗粒表面自由能 ,增大ξ电位 ,从而增大了新拌混凝土颗粒的分散性 ,降低了表观粘度。另外 ,减水剂的掺入可使水泥颗粒湿润 ,可使水泥颗粒之间的滑动能力增强 ,因此降低了新拌混凝土的表观粘度。     

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.     

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…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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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。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

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