醋酸乙烯酯与丙烯酸甲酯的种子乳液聚合

以过硫酸铵（ＡＰＳ）为引发剂,对丙烯酸甲酯（ＭＡ）的乳液聚合进行了研究,得出在ＭＡ／Ｈ２Ｏ重量比为０．５时,６０℃下合成粒径分布均匀的聚合烯酸甲酯（ＰＭＡ）种子乳液的最佳配方为：十二烷基硫酸钠（ＳＤＳ）、（ＡＰＳ）和（ＮａＨＣＯ３）的浓度分别为１１．６、１．７２和４．６９ｍｍｏｌ／Ｌ。然后以ＰＭＡ乳液为种子,以油溶性偶氮二异丁腈（ＡＩＢＡ）为引发剂,分别进行不溶胀与溶胀条件下醋酸乙烯酯（ＶＡ）的种     

乳聚天然橡胶IPN型热塑性弹性体的合成

以天然胶乳为种子乳液，苯乙烯（Ｓｔ），甲基丙烯酸甲酯（ＭＭＡ），丙烯腈（ＡＮ），丙烯酸异冰片酯（ＩＢＡ）等单体或它们的共混物为互穿单体，油酸为稳定剂，二乙烯苯为交联剂，叔丁基过氧化氢／四乙烯五胺为氧化还原引发体系，采用种子乳液聚合法制备出乳胶粒外壳呈硬聚合物梯度分布的复合乳液，经絮凝干燥得固体聚合物。考察了互穿单体的种类和用量，交联剂用量及溶胀时间等对材料力学的影响。结果表明，溶胀时间对聚合物力学     

共混复合胶乳及其胶膜性能的研究

用批量法合成了聚苯乙烯（ＰＳｔ）、聚甲基丙烯酸甲酯（ＰＭＭＡ）、聚丙烯酸丁酯（ＰＢＡ）均聚乳液,以及Ｐ（ＢＡ－Ｓｔ）和Ｐ（ＢＡ－ＭＭＡ）共聚乳液．实验发现极性相近的ＰＢＡ和ＰＭＭＡ乳液可以很好地混合,而极性相差较大的ＰＢＡ和ＰＳｔ乳液则必须在ＰＳｔ乳液中补加乳化剂后方能混合均匀．对乳液最低成膜温度（ＭＦＴ）、胶膜硬度及耐水性的研究表明：质量比为１１的ＰＢＡ／ＰＭＭＡ共混胶膜和Ｐ（ＢＡ－ＭＭＡ）共聚胶膜的连续相组成相近;而对于同样组成的ＰＢＡ／ＰＳｔ共混胶膜,分散在连续相中的ＰＳｔ所占比例明显高于Ｐ（ＢＡ－Ｓｔ）共聚胶膜;ＰＢＡ／ＰＳｔ共混胶乳的使用性能不仅取决于其组成,还取决于成膜温度和使用温度     

PSt／P（BA－BOA）复合乳液性能的研究

以丁氧基甲基丙烯酰胺（ＢＯＡ）为活性单体，采用种子乳液聚合方法制备了ＰＳｔ／Ｐ（ＢＡ－ＢＯＡ）〔聚苯乙烯／聚（丙烯酸丁酯－丁氧基甲基丙烯酰胺）〕核壳型复合乳液．用透射电子显微镜观察了乳液粒子的微观状态，采用粒度分析仪测定了乳液粒子的粒径及其分布，对乳液的流变性能进行了测试．考察了聚合方式、乳化剂用量对乳液性能的影响     

PSt／P（BA—BOA）复合乳液性能的研究

以丁氧基甲基丙烯酰胺为活性单体，采用种子乳液聚合方向制备了ＰＳｔ／Ｐ（ＢＡ－ＢＯＡ）「聚苯乙烯／取（丙烯酸丁酯－丁氧基甲基丙烯酰胺）」核索型复合乳液。用透射电子显微镜观察了乳液粒子的微观状态，采用粒度分析仪测定了乳液粒子的粒径及其分布，对乳液的流变性能进行了测试。     

乳化剂在制备核—壳结构PBA／P（α—MS—AN）反应中 …

研究了以丙烯酸丁酯（ＢＡ）、α－甲基苯乙烯（α－ＭＳ）和丙烯腈（ＡＮ）为单体,在合成ＰＢＡ／Ｐ（α－ＭＳ－ＡＮ）核－壳结构乳液聚合过程中,乳化剂的性质,用量对聚合反应及乳液稳定性的影响。结果表明,两性乳化剂ＭＳ－１具有较高聚合速度,同时具有较好的乳液稳定性,在聚合后的乳液中加入Ｏｐ－１０,可提高乳胶的化学机械稳定性。此外,通过ＤＳＣ测定Ｔｇ,进一步验证了该结构不同于Ｐ（ＢＡ－α－ＭＳ－ＡＮ）的三无     

MgAPO—44舂子筛的合成与性能研究

以Ａｌ（ＯＨ）３．Ｈ３ＰＯ４，ＭｇＣｌ２．６Ｈ２Ｏ为原料，以环己胺为模板剂，用水热晶化法合成了ＭａＡＰＯ－４４分子筛纯相，研究了反应物配比、酸碱度及铝源等水热晶化条件对产物物相的影响，骼ＸＲＤ．ＩＲ，ＳＥＭ／ＥＰＭＡ，ＴＧ－ＤＴＡ等对产物进行了表征。研究表明，所合成的ＭｇＡＰＯ－４４分子筛具有小孔结构和较高的热稳定必一。     

共混复合胶乳及其胶膜性能的研究

用批量法合成了聚苯乙烯，聚甲基丙烯酸甲酯（ＰＭＭＡ）、聚丙烯酸丁酯（ＰＢＡ）均聚乳液，以及Ｐ（ＢＡ－Ｓｔ）和Ｐ（ＢＡ－ＭＭＡ）共聚乳液。实验发现极性相近的ＰＢＡ和ＰＭＭＡ乳液可以很好地混合，而极性相差较大的ＰＢＡ和ＰＳｔ乳液则必须在ＰＳｔ具液中补加乳化剂后方能混合均匀。     

PSt/PMMA核-壳型复合乳液的摩擦学性能

利用分步乳液聚合的方法,经过制种、合成核、合成壳等步骤,制备了一系列不同粒径的以聚苯乙烯（ＰＳｔ） 为内核,以聚甲基丙烯酸甲酯（ＰＭＭＡ） 为壳的复合乳液．采用透射电镜考察了乳液的形貌和粒径,四球摩擦试验表明该结构的复合乳液具有一定的极压减磨效果,其润滑性能与粒径有紧密的关系．     

两亲接枝共聚物作乳化剂时丙烯酰胺分配系数的确定

以两亲接枝共聚物－－聚苯乙烯接枝聚氧乙烯（ＰＳ－ｇ－ＰＥＯ）和聚人酸甲酯接枝聚乙烯（ＰＭＭＡ－ｇ－ＰＥＯ）作为乳化剂,选用合适的方法测试了丙烯酰胺（ＡＭ）在胶束和液滴中的分配系数－考察了两亲支共聚物的浓度对分配系数的影响,结果表明：分配系数与两亲接枝共聚物的浓度成正比关系,ＰＳ－ｇ－ＰＥＯ作乳化剂时,ηＰＳ－ｇ－ＰＥＯ＋０．１７６ｃＥ＾０．９８５,而ＰＭＭＡ－ｇ－ＰＥＯ作乳化剂时,ηＰＭＭＡ－ｇ－     

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